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Sample records for lenke type 3c

  1. The Surgical Overcorrection of Lenke Type 1 Deformities with Selective Fusion Segments: What Happens to the Coronal Balance?

    PubMed Central

    Erdogan, Sinan; Akman, Yunus Emre; Mert, Murat; Carkci, Engin; Tuzuner, Tolga

    2016-01-01

    Purpose The aim of our study is to determine the alterations on coronal balance after overcorrection of Lenke type 1 curve, retrospectively. Methods Datas of 34 patients (29 female, 5 male patients; mean age, 16.3±3.3 years; range, 13-24 years) surgically treated for scoliosis between 2004 and 2010 were reviewed, retrospectively. The adolescent idiopathic scoliosis patients with Lenke type 1 curve treated with only posterior pedicle screw and postoperative thoracic curves less than 10° by Cobb method on frontal plane were enrolled in this study. Mean follow-up period was 52.5±29.7 months. Results The mean amount of the preoperative thoracic curves was measured as 41.2°±6.1° (range, 30°-56°). The mean amount of the early postoperative thoracic curves was measured as 6.5°±1.8° (range, 3°-9°). The mean amount of the thoracic curves was measured as 8.5°±4.6° (range, 3°-22°) during the last follow-up (p=0.01). The mean preoperative coronal balance was measured as 8.5mm(range, 1-30mm). The mean early postoperative coronal balance was measured as 3.5mm(range, 0-36 mm). The mean coronal balance was measured as 5.5mm(range, 0-38mm) during the last follow-up (p>0.05). Conclusion We suggest that Lenke type 1B and 1C should be carefully evaluated and the fusion levels should be accurately selected in order to maintain the correction of coronal balance. We suggest that selective fusion with overcorrection in Lenke type 1A are applied to curves that can be corrected lumbar curve at the preoperative bending radiograph and curves that not have coronal decompensation and >10° distal junctional kyphosis, preoperatively. PMID:27799996

  2. Minimally invasive scoliosis surgery assisted by O-arm navigation for Lenke Type 5C adolescent idiopathic scoliosis: a comparison with standard open approach spinal instrumentation.

    PubMed

    Zhu, Weiguo; Sun, Weixiang; Xu, Leilei; Sun, Xu; Liu, Zhen; Qiu, Yong; Zhu, Zezhang

    2017-02-10

    OBJECTIVE Recently, minimally invasive scoliosis surgery (MISS) was introduced for the correction of adult scoliosis. Multiple benefits including a good deformity correction rate and fewer complications have been demonstrated. However, few studies have reported on the use of MISS for the management of adolescent idiopathic scoliosis (AIS). The purpose of this study was to investigate the outcome of posterior MISS assisted by O-arm navigation for the correction of Lenke Type 5C AIS. METHODS The authors searched a database for all patients with AIS who had been treated with either MISS or PSF between November 2012 and January 2014. Levels of fusion, density of implants, operation time, and estimated blood loss (EBL) were recorded. Coronal and sagittal parameters were evaluated before surgery, immediately after surgery, and at the last follow-up. The accuracy of pedicle screw placement was assessed according to postoperative axial CT images in both groups. The 22-item Scoliosis Research Society questionnaire (SRS-22) results and complications were collected during follow-up. RESULTS The authors retrospectively reviewed the records of 45 patients with Lenke Type 5C AIS, 15 who underwent posterior MISS under O-arm navigation and 30 who underwent posterior spinal fusion (PSF). The 2 treatment groups were matched in terms of baseline characteristics. Comparison of radiographic parameters revealed no obvious difference between the 2 groups immediately after surgery or at the final follow-up; however, the MISS patients had significantly less EBL (p < 0.001) and longer operation times (p = 0.002). The evaluation of pain and self-image using the SRS-22 showed significantly higher scores in the MISS group (p = 0.013 and 0.046, respectively) than in the PSF group. Postoperative CT showed high accuracy in pedicle placement in both groups. No deep wound infection, pseudarthrosis, additional surgery, implant failure, or neurological complications were recorded in either group

  3. Bilateral apical vertebral derotation technique by vertebral column manipulation compared with vertebral coplanar alignment technique in the correction of lenke type 1 idiopathic scoliosis

    PubMed Central

    2013-01-01

    Background Widely used rod rotation and translation techniques for idiopathic scoliosis (IS) are effective in correcting spinal coronal deformity. Bilateral apical vertebral derotation technique by vertebral column manipulation (VCM) and vertebral coplanar alignment (VCA) technique are two strategies for three-dimensional (3D) correction for IS. The purpose of this study is to compare the post-surgical results and technical features of the bilateral apical vertebral derotation technique by VCM against the VCA technique in patients with Lenke type 1 IS. Methods Forty-eight patients with Lenke type 1 IS were enrolled in the present prospective clinical assay. They were divided into groups A (bilateral apical vertebral derotation technique by VCM, n=24) and B (VCA technique, n=24). Radiographic parameters measured before and after surgery included the Cobb angle, thoracic kyphosis, and apical vertebral rotation. Scoliosis Research Society (SRS)-22 scores were evaluated during the final follow-up. The differences in the demographics, surgical details, and radiographic measurements between the two groups were determined using a T test. The Mann–Whitney U test was used to evaluate the differences in the SRS-22 scores. A value of P<0.05 was considered statistically significant. Results In the coronal plane, a significant difference was found in the correction rate of the major curve (group A: 84.8%, group B: 78.4%; P=0.045) and in the Cincinnati Correction Index between two groups (group A: 2.21, group B: 1.98; P=0.047). In the sagittal plane, no difference was found in the postoperative thoracic kyphosis between the two groups (P=0.328). In the transverse plane, no difference was found between the two groups in the correction rates of the rotation angle sagittal (P=0.298), rib hump (P=0.934), apical vertebral body-to-rib ratio (P=0.988), or apical rib spread difference (P=0.184). Patients underwent follow up for an average of 21.9 and 22.2 months in groups A and B

  4. Comparative Analysis of Interval, Skipped, and Key-vertebral Pedicle Screw Strategies for Correction in Patients With Lenke Type 1 Adolescent Idiopathic Scoliosis

    PubMed Central

    Wang, Fei; Xu, Xi-Ming; Lu, Yanghu; Wei, Xian-Zhao; Zhu, Xiao-Dong; Li, Ming

    2016-01-01

    Abstract Pedicle screw constructs have become the mainstay for surgical correction in patients with spinal deformities. To reduce or avoid the risk of pedicle screw-based complications and to decrease the costs associated with pedicle screw instrumentation, some authors have introduced interval, skipped, and key-vertebral pedicle screw strategies for correction. However, there have been no comparisons of outcomes among these 3 pedicle screw-placement strategies. The aim of this study was to compare the correlative clinical outcomes of posterior correction and fusion with pedicle screw fixation using these 3 surgical strategies. Fifty-six consecutive patients with Lenke type 1 adolescent idiopathic scoliosis were included in this study. Twenty patients were treated with the interval pedicle screw strategy (IPSS), 20 with the skipped pedicle screw strategy (SPSS), and 16 with the key-vertebral pedicle screw strategy (KVPSS). Coronal and sagittal radiographs were analyzed before surgery, at 1 week after surgery, and at the last follow-up after surgery. There were no significant differences among the 3 groups regarding preoperative radiographic parameters. No significant difference was found between the IPSS and SPSS groups in correction of the main thoracic curve (70.8% vs 70.0%; P = 0.524). However, there were statistically significant differences between the IPSS and KVPSS groups (70.8% vs 64.9%) and between the SPSS and KVPSS groups (70.0% vs 64.9%) in correction of the main thoracic curve (P < 0.001 for both). Additionally, there were no significant differences among the 3 strategies for sagittal parameters at the immediate postoperative and last postoperative follow-up periods, though there were significant differences in the Cobb angle between the preoperative and immediate postoperative periods among the 3 groups, but not between the immediate postoperative and last follow-up periods. The amount of hospital charges in the SPSS group was significantly

  5. Ignoring taboos: Maria Lenk, Latin American inspirationalist.

    PubMed

    Votre, S; Mourão, L

    2001-01-01

    Maria Lenk is widely recognized as an exceptional athlete who participated in women's sport from around 1930 until 1950. In 1932, at the age of seventeen, she was the first woman to be included in a Latin American delegation to the Olympic Games. As a swimmer, she still sets world records at the age of eighty-six. This super-champion's sporting achievements and her persistent dedication to the advancement of sport still impress and surprise todays professional swimmers and researchers. Contextualised in the male-dominated society of Brazil during the first half of the twentieth century, this chapter traces the achievement, and rise to international fame, of Maria Lenk. It examines the factors that enabled her to emerge not only as an important figure in sport but also as an icon of female emancipation in Brazilian and Latin American society. The focus is on Lenk's influence on the issues which affected the development of women's sport in Latin America. It also highlights the significance of Lenk's contribution to the changing place of women in Brazilian and South American society.

  6. Evidence-Based Nursing of the 3C Therapeutic Regimen for Type 1 Diabetes.

    PubMed

    Wu, Jianya; Zou, Ling

    2015-05-01

    The aim of this study is to explore the efficacy of the 3C therapeutic regimen for type 1 diabetes. Thirty-nine patients with type 1 diabetes, who were hospitalized from January 2013 to April 2014, were included to receive 3C therapeutic regimen. Evidence-based nursing was performed in the treatment period and the efficacy was observed 6 days after therapy. Six days after the administration of the 3C therapeutic regimen, the fasting glucose levels in all 39 patients were controlled to be 4.4-6.0 mmol/L and 2h-postprandial glucose levels to be 4.4-7.8 mmol/L. Three patients had a glucose level <3.9 mmol/L, which was corrected after adjusting the dose of insulin infusion. Evidence-based nursing was provided in the treatment period and no nursing-associated complication occurred. All patients were satisfied with the nursing service. The efficacy of the 3C therapeutic regimen for type 1 diabetes is satisfactory. The evidence-based nursing can help to ensure the efficacy and improve the quality of nursing service.

  7. Nanowire-density-dependent field emission of n-type 3C-SiC nanoarrays

    SciTech Connect

    Wang, Lin; Gao, Fengmei; Chen, Shanliang; Yang, Weiyou; Li, Chengming

    2015-09-21

    The density of the nanowires is one of the key issues for their field emission (FE) properties of the nanoarrays, since it plays an important role on the electron emission sites and field screening effect. Here, we reported the nanowire-density-dependent FE properties of the n-type 3C-SiC nanoarrays. The highly oriented and large-scale SiC nanoarrays were grown on the 6H-SiC wafer via pyrolysis of polyureasilazane by adjusting the thicknesses of Au films used as the catalysts. The densities of the nanoarrays were tunable to be ∼2.9 × 10{sup 7}, ∼4.0 × 10{sup 7}, and ∼5.7 × 10{sup 7} nanowires/cm{sup 2} by controlling the Au film thicknesses of 50, 70, and 90 nm, respectively. The measured FE characteristics disclosed that the turn-on fields of the samples could be tailored to be of ∼1.79, 1.57, and 1.95 V/μm with the increase of the densities, suggesting that a suitable nanowire density could favor the enhanced electron emission from the SiC nanoarrays with improved emission sites and limited field screening effects.

  8. Assessment of spontaneous correction of lumbar curve after fusion of the main thoracic in Lenke 1 adolescent idiopathic scoliosis☆

    PubMed Central

    Mizusaki, Danilo; Gotfryd, Alberto Ofenhejm

    2016-01-01

    Objective To evaluate the clinical and radiographic response of the lumbar curve after fusion of the main thoracic, in patients with adolescent idiopathic scoliosis of Lenke type 1. Methods Forty-two patients with Lenke 1 adolescent idiopathic scoliosis who underwent operations via the posterior route with pedicle screws were prospectively evaluated. Clinical measurements (size of the hump and translation of the trunk in the coronal plane, by means of a plumb line) and radiographic measurements (Cobb angle, distal level of arthrodesis, translation of the lumbar apical vertebral and Risser) were made. The evaluations were performed preoperatively, immediately postoperatively and two years after surgery. Results The mean Cobb angle of the main thoracic curve was found to have been corrected by 68.9% and the lumbar curve by 57.1%. Eighty percent of the patients presented improved coronal trunk balance two years after surgery. In four patients, worsening of the plumb line measurements was observed, but there was no need for surgical intervention. Less satisfactory results were observed in patients with lumbar modifier B. Conclusions In Lenke 1 patients, fusion of the thoracic curve alone provided spontaneous correction of the lumbar curve and led to trunk balance. Less satisfactory results were observed in curves with lumbar modifier B, and this may be related to overcorrection of the main thoracic curve. PMID:26962505

  9. GRID3C: Computer program for generation of C type multilevel, three dimensional and boundary conforming periodic grids

    NASA Technical Reports Server (NTRS)

    Dulikravich, D. S.

    1982-01-01

    A fast computer program, GRID3C, was developed for accurately generating periodic, boundary conforming, three dimensional, consecutively refined computational grids applicable to realistic axial turbomachinery geometries. The method is based on using two functions to generate two dimensional grids on a number of coaxial axisymmetric surfaces positioned between the centerbody and the outer radial boundary. These boundary fitted grids are of the C type and are characterized by quasi-orthogonality and geometric periodicity. The built in nonorthogonal coordinate stretchings and shearings cause the grid clustering in the regions of interest. The stretching parameters are part of the input to GRID3C. In its present version GRID3C can generate and store a maximum of four consecutively refined three dimensional grids. The output grid coordinates can be calculated either in the Cartesian or in the cylindrical coordinate system.

  10. Fundamental piezo-Hall coefficients of single crystal p-type 3C-SiC for arbitrary crystallographic orientation

    NASA Astrophysics Data System (ADS)

    Qamar, Afzaal; Dao, Dzung Viet; Phan, Hoang-Phuong; Dinh, Toan; Dimitrijev, Sima

    2016-08-01

    Piezo-Hall effect in a single crystal p-type 3C-SiC, grown by LPCVD process, has been characterized for various crystallographic orientations. The quantified values of the piezo-Hall effect in heavily doped p-type 3C-SiC(100) and 3C-SiC(111) for different crystallographic orientations were used to obtain the fundamental piezo-Hall coefficients, P 12 = ( 5.3 ± 0.4 ) × 10 - 11 Pa - 1 , P 11 = ( - 2.6 ± 0.6 ) × 10 - 11 Pa - 1 , and P 44 = ( 11.42 ± 0.6 ) × 10 - 11 Pa - 1 . Unlike the piezoresistive effect, the piezo-Hall effect for (100) and (111) planes is found to be independent of the angle of rotation of the device within the crystal plane. The values of fundamental piezo-Hall coefficients obtained in this study can be used to predict the piezo-Hall coefficients in any crystal orientation which is very important for designing of 3C-SiC Hall sensors to minimize the piezo-Hall effect for stable magnetic field sensitivity.

  11. Piezoresistive effect in p-type 3C-SiC at high temperatures characterized using Joule heating

    NASA Astrophysics Data System (ADS)

    Phan, Hoang-Phuong; Dinh, Toan; Kozeki, Takahiro; Qamar, Afzaal; Namazu, Takahiro; Dimitrijev, Sima; Nguyen, Nam-Trung; Dao, Dzung Viet

    2016-06-01

    Cubic silicon carbide is a promising material for Micro Electro Mechanical Systems (MEMS) applications in harsh environ-ments and bioapplications thanks to its large band gap, chemical inertness, excellent corrosion tolerance and capability of growth on a Si substrate. This paper reports the piezoresistive effect of p-type single crystalline 3C-SiC characterized at high temperatures, using an in situ measurement method. The experimental results show that the highly doped p-type 3C-SiC possesses a relatively stable gauge factor of approximately 25 to 28 at temperatures varying from 300 K to 573 K. The in situ method proposed in this study also demonstrated that, the combination of the piezoresistive and thermoresistive effects can increase the gauge factor of p-type 3C-SiC to approximately 20% at 573 K. The increase in gauge factor based on the combination of these phenomena could enhance the sensitivity of SiC based MEMS mechanical sensors.

  12. Piezoresistive effect in p-type 3C-SiC at high temperatures characterized using Joule heating

    PubMed Central

    Phan, Hoang-Phuong; Dinh, Toan; Kozeki, Takahiro; Qamar, Afzaal; Namazu, Takahiro; Dimitrijev, Sima; Nguyen, Nam-Trung; Dao, Dzung Viet

    2016-01-01

    Cubic silicon carbide is a promising material for Micro Electro Mechanical Systems (MEMS) applications in harsh environ-ments and bioapplications thanks to its large band gap, chemical inertness, excellent corrosion tolerance and capability of growth on a Si substrate. This paper reports the piezoresistive effect of p-type single crystalline 3C-SiC characterized at high temperatures, using an in situ measurement method. The experimental results show that the highly doped p-type 3C-SiC possesses a relatively stable gauge factor of approximately 25 to 28 at temperatures varying from 300 K to 573 K. The in situ method proposed in this study also demonstrated that, the combination of the piezoresistive and thermoresistive effects can increase the gauge factor of p-type 3C-SiC to approximately 20% at 573 K. The increase in gauge factor based on the combination of these phenomena could enhance the sensitivity of SiC based MEMS mechanical sensors. PMID:27349378

  13. Piezoresistive effect in p-type 3C-SiC at high temperatures characterized using Joule heating.

    PubMed

    Phan, Hoang-Phuong; Dinh, Toan; Kozeki, Takahiro; Qamar, Afzaal; Namazu, Takahiro; Dimitrijev, Sima; Nguyen, Nam-Trung; Dao, Dzung Viet

    2016-06-28

    Cubic silicon carbide is a promising material for Micro Electro Mechanical Systems (MEMS) applications in harsh environ-ments and bioapplications thanks to its large band gap, chemical inertness, excellent corrosion tolerance and capability of growth on a Si substrate. This paper reports the piezoresistive effect of p-type single crystalline 3C-SiC characterized at high temperatures, using an in situ measurement method. The experimental results show that the highly doped p-type 3C-SiC possesses a relatively stable gauge factor of approximately 25 to 28 at temperatures varying from 300 K to 573 K. The in situ method proposed in this study also demonstrated that, the combination of the piezoresistive and thermoresistive effects can increase the gauge factor of p-type 3C-SiC to approximately 20% at 573 K. The increase in gauge factor based on the combination of these phenomena could enhance the sensitivity of SiC based MEMS mechanical sensors.

  14. G -type antiferromagnetic order in the metallic oxide LaC u3C r4O12

    NASA Astrophysics Data System (ADS)

    Saito, Takashi; Zhang, Shoubao; Khalyavin, Dmitry; Manuel, Pascal; Attfield, J. Paul; Shimakawa, Yuichi

    2017-01-01

    The A -site-ordered cubic perovskite LaC u3C r4O12 , where a partial Cu-Cr intersite charge transfer transition occurs at TCT=220 K , was found to be an unconventional metallic and G -type antiferromagnetic oxide. Neutron powder diffraction revealed a G -type antiferromagnetic ordering at the Cr sites and no ordered moments at the Cu sites. Ab initio electronic structure calculations revealed that the narrowing of the Cr-O-Cr bands due to heavy tilting of the Cr O6 octahedra and the strong hybridization of the Cu -3 d ,Cr -3 d , and O - 2 p orbitals near the Fermi level give an unusual electronic structure in the vicinity of a localized-electron regime. The G -type magnetic structure is primarily stabilized by nearest-neighbor antiferromagnetic superexchange interactions of the near-localized Cr spins. The ferromagnetic {1 1 1 } layers of the G -type antiferromagnetic Cr-spin sublattice allow the spin-polarized electron transfer through the strongly hybridized Cu orbitals.

  15. 3c/4e σ-type long-bonding: a novel transitional motif toward the metallic delocalization limit.

    PubMed

    Landis, C R; Weinhold, F

    2013-05-06

    We describe a novel "long-bonding" motif that appears in the framework of natural bond orbital (NBO) analysis as a surprising form of 3-center, 4-electron (3c/4e) L···A···L' bonding with "inverted" electronegativity pattern Ξ(A) > Ξ(L), Ξ(L'). Such long-bonding (denoted L(^)L') underlies the predicted (meta)stability of exotic rare gas species with highly electronegative ligands (e.g., HeF2, NeF2) as well as the absolute stability of low-electronegativity metallic triads (e.g., BeLi2, ZnCu2, and related species) that are experimentally unknown but can be anticipated from simple valency and electronegativity trends. We focus particularly on the BeLi2 triad, whose Lewis-type Li(^)Li' long bond is of paradoxical antibonding phase pattern, denoted σ*(LiLi') to suggest its essential 2(-1/2)(s(Li) - s(Li')) orbital composition. We demonstrate how the long-bonded triad serves as a fundamental building-block for numerous 1-, 2-, and 3-d structures that are predicted to exhibit extraordinary calorimetric, vibrational, and electric polarizability properties, commonly associated with the delocalized metallic limit. Both thermodynamic and kinetic results support the NBO inference that σ/σ*-type long-bonding signals the transition to a fundamentally new regime of chemical association, separated by significant activation barriers from the covalent molecular domain and characterized by reversed perturbative precedence of Lewis-type vs resonance-type donor-acceptor contributions. Long-bond resonance therefore appears to be of central importance to a broadened conceptual picture of molecular and metallic interaction phenomena.

  16. Spontaneous Thoracic Curve Correction After Selective Posterior Fusion of Thoracolumbar/Lumbar Curves in Lenke 5C Adolescent Idiopathic Scoliosis

    PubMed Central

    Wang, Fei; Xu, Xi-ming; Wei, Xian-zhao; Zhu, Xiao-dong; Li, Ming

    2015-01-01

    Abstract Selective fusion of the thoracolumbar/lumbar (TL/L) curve is an effective method for the treatment of Lenke type 5C curves. Several studies have demonstrated that spontaneous correction of the thoracic curve does indeed occur. However, how this correction occurs after isolated posterior segmental instrumentation of the structural lumbar curve has not been well described. The aim of this study was to evaluate the response of the thoracic curve to selective TL/L curve fusion in patients with Lenke type 5C adolescent idiopathic scoliosis (AIS) and assess the correlative clinical outcomes. Thirty-four consecutive patients with Lenke type 5C AIS were included in this study. All patients underwent selective TL/L curve instrumentation and fusion via the posterior approach. Coronal and sagittal radiographs were analyzed before surgery, at 1 week after surgery and at least 2 years after surgery. The preoperative coronal Cobb angle of the major TL/L curve was 45.4° ± 7.0°, and that of the minor thoracic curve was 25.4° ± 8.8°. The major TL/L and minor thoracic curves were corrected to postoperative angles of 9.5° ± 5.0° and 11.2° ± 5.2°, respectively, and measured 10.5° ± 6.0° and 13.4° ± 7.5° at the follow-up, respectively. The supine side-bending average Cobb angle of the thoracic curve was 9.9°. These results demonstrate satisfactory improvements because of coronal and sagittal restoration. Significant correlations were found between the preoperative and early postoperative conditions and the Cobb angle changes of the minor thoracic curve and the major TL/L curves (r = 0.42, P = 0.01). Significant correlations were also observed between the early and final follow-up postoperative conditions and the Cobb angle changes of the minor thoracic curve and the major TL/L curves (r = 0.57, P < 0.001). Significant correlations were observed between increased thoracic kyphosis (TK) and increased lumbar lordosis (LL

  17. Outbreak of bullous impetigo caused by Staphylococcus aureus strains of phage type 3C/71 in a maternity ward linked to nasal carriage of a healthcare worker.

    PubMed

    Piechowicz, Lidia; Garbacz, Katarzyna; Budzyńska, Anna; Dąbrowska-Szponar, Maria

    2012-01-01

    We describe an outbreak of bullous impetigo (BI) that occurred in a maternity unit and show phenotypic and genotypic properties and relatedness of isolated Staphylococcus aureus strains. Clinical material was obtained from 11 affected neonates. Additionally, nasal swabs from 67 healthy care workers (HCWs) as well as 107 environmental swabs were investigated. All isolates were screened for exfoliative toxin genes (eta, etb), antibiotic susceptibility and phage typed. Chromosomal DNA was genotyped by MLVF method and PCR/RFLP of coagulase gene were tested. Affected neonates were infected by two clusters of eta-positive S. aureus of phage type 3C/71: (1) MLVF type A isolates resistant only to penicillin, and (2) MLVF type B isolates resistant to penicillin and erythromycin/clindamycin. All isolates were susceptible to methicillin. We found 19 of 67 HCWs to be S. aureus nasal carriers. Two nasal isolates from HCWs were related to the outbreak on the basis of phage typing, PCR detection of eta/etb genes, antibiotyping and genotyping. Additionally, environmental swabs from the maternity unit revealed a 3C/71 S. aureus in the mattress of a baby bed. This is the first documented case of an outbreak of BI caused by phage type 3C/71 eta-positive strain of S. aureus.

  18. A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese

    DOE PAGES

    Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; ...

    2015-03-12

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only bemore » achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Altogether with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.« less

  19. A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese

    SciTech Connect

    Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; Bravo, Eduardo; Williams, Brian J.; Maeda, Keiichi; Nobukawa, Masayoshi; Eriksen, Kristoffer A.; Brickhouse, Nancy S.; Petre, Robert; Koyama, Katsuji

    2015-03-12

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only be achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Altogether with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.

  20. A CHANDRASEKHAR MASS PROGENITOR FOR THE TYPE Ia SUPERNOVA REMNANT 3C 397 FROM THE ENHANCED ABUNDANCES OF NICKEL AND MANGANESE

    SciTech Connect

    Yamaguchi, Hiroya; Williams, Brian J.; Petre, Robert; Badenes, Carles; Foster, Adam R.; Brickhouse, Nancy S.; Bravo, Eduardo; Maeda, Keiichi; Nobukawa, Masayoshi; Koyama, Katsuji; Eriksen, Kristoffer A.

    2015-03-10

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only be achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Together with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.

  1. A Chandrasekhar Mass Progenitor for the Type Ia Supernova Remnant 3C 397 from the Enhanced Abundances of Nickel and Manganese

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; Bravo, Eduardo; Williams, Brian J.; Maeda, Keiichi; Nobukawa, Masayoshi; Eriksen, Kristoffer A.; Brickhouse, Nancy S.; Petre, Robert; Koyama, Katsuji

    2015-03-01

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11-0.24 and 0.018-0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only be achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Together with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.

  2. Postoperative trunk shift in Lenke 1 and 2 curves: how common is it? and analysis of risk factors.

    PubMed

    Trobisch, Per D; Samdani, Amer F; Pahys, Joshua M; Cahill, Patrick J

    2011-07-01

    The goal of surgical treatment for adolescent idiopathic scoliosis (AIS) is to achieve a solid fusion in a balanced spine. While many previous studies analyzed coronal balance, there is a paucity of studies that comment on postoperative trunk shift, which has shown to have impact on clinical outcome. The purpose of this retrospective, multicenter data analysis was to analyze the incidence of postoperative trunk shift in patients with surgical treatment for AIS. We conducted a retrospective, multicenter data analysis of 1,555 patients with AIS. Patients with a Lenke type 1 or 2 curve pattern and a minimum follow-up of 24 months after surgery were included. A >2 cm deviation of the trunk in relation to the pelvis was considered positive trunk shift. A subanalysis was performed to identify potential risk factors for trunk shift. 273 patients meeting the inclusion criteria were analyzed. While the preoperative prevalence of trunk shift was surgically reduced from 29.3 to 13.6%, 24 patients (8.8%) with postoperative trunk shift had not had preoperative trunk shift, and the trunk shift was considered iatrogenic. Undercorrection of the lumbar curve was identified as potential risk factor, whereas thoracic correction, coronal balance, angulation and translation of the lowest instrumented vertebra did not seem to influence postoperative trunk shift. Iatrogenic postoperative trunk shift has an incidence of 8.8% in the surgical treatment of AIS.

  3. Preliminary crystallographic analysis of mouse Elf3 C-terminal DNA-binding domain in complex with type II TGF-[beta] receptor promoter DNA

    SciTech Connect

    Agarkar, Vinod B.; Babayeva, Nigar D.; Rizzino, Angie; Tahirov, Tahir H.

    2010-10-08

    Ets proteins are transcription factors that activate or repress the expression of genes that are involved in various biological processes, including cellular proliferation, differentiation, development, transformation and apoptosis. Like other Ets-family members, Elf3 functions as a sequence-specific DNA-binding transcriptional factor. A mouse Elf3 C-terminal fragment (amino-acid residues 269-371) containing the DNA-binding domain has been crystallized in complex with mouse type II TGF-{beta} receptor promoter (TR-II) DNA. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 42.66, b = 52, c = 99.78 {angstrom}, and diffracted to a resolution of 2.2 {angstrom}.

  4. Surgical treatment of Lenke 5 adolescent idiopathic scoliosis: Comparison of anterior vs posterior approach

    PubMed Central

    Abel, Mark F; Singla, Anuj; Feger, Mark A; Sauer, Lindsay D; Novicoff, Wendy

    2016-01-01

    AIM To compare the posterior vs anterior approaches for fusion of Lenke 5 adolescent idiopathic scoliosis curves, matched for curve magnitude and for the distal level of fixation (dLOF) standardized to the third lumbar vertebrae (L3). METHODS A prospectively collected multicenter database was used for this retrospective comparative study. Our dependent variables included sagittal and coronal radiographic measurements, number of fused vertebrae, estimated blood loss, length of hospitalization and SRS total and individual domain scores at the two-year follow-up. Subject demographics were similar for all group comparisons. Independent t-test was used to compare groups for all analyses at P < 0.01. RESULTS For all matched cases of Lenke 5 curves, a selective approach was used only 50% of the time in cases undergoing a posterior fusion. When comparing a posterior selective approach to an anterior selective approach, surgeons utilizing a posterior approach fused significantly more levels than surgeons using an anterior approach with no other significant differences in radiographic or SRS outcomes (Ant = 4.8 ± 1.0 levels vs post = 6.1 ± 1.0 levels, P < 0.0001). When the dLOF was standardized to L3, the anterior approached provided significantly greater lumbar Cobb percent correction than the posterior approach (Ant = 69.1% ± 12.6% vs post = 54.6% ± 16.4%, P = 0.004), with no other significant radiographic or SRS score differences between approaches. CONCLUSION Surgeons treating Lenke 5c curves with a posterior instrumentation and fusion vs an anterior approach include more motion segments, even with a selective fusion. When controlled for the distal level of fixation, the anterior approach provides greater correction of the thoracolumbar curve. PMID:27672568

  5. Higher Flexibility and Better Immediate Spontaneous Correction May Not Gain Better Results for Nonstructural Thoracic Curve in Lenke 5C AIS Patients

    PubMed Central

    Zhang, Yanbin; Lin, Guanfeng; Wang, Shengru; Zhang, Jianguo; Shen, Jianxiong; Wang, Yipeng; Guo, Jianwei; Yang, Xinyu; Zhao, Lijuan

    2016-01-01

    Study Design. Retrospective study. Objective. To study the behavior of the unfused thoracic curve in Lenke type 5C during the follow-up and to identify risk factors for its correction loss. Summary of Background Data. Few studies have focused on the spontaneous behaviors of the unfused thoracic curve after selective thoracolumbar or lumbar fusion during the follow-up and the risk factors for spontaneous correction loss. Methods. We retrospectively reviewed 45 patients (41 females and 4 males) with AIS who underwent selective TL/L fusion from 2006 to 2012 in a single institution. The follow-up averaged 36 months (range, 24–105 months). Patients were divided into two groups. Thoracic curves in group A improved or maintained their curve magnitude after spontaneous correction, with a negative or no correction loss during the follow-up. Thoracic curves in group B deteriorated after spontaneous correction with a positive correction loss. Univariate analysis and multivariate analysis were built to identify the risk factors for correction loss of the unfused thoracic curves. Results. The minor thoracic curve was 26° preoperatively. It was corrected to 13° immediately with a spontaneous correction of 48.5%. At final follow-up it was 14° with a correction loss of 1°. Thoracic curves did not deteriorate after spontaneous correction in 23 cases in group A, while 22 cases were identified with thoracic curve progressing in group B. In multivariate analysis, two risk factors were independently associated with thoracic correction loss: higher flexibility and better immediate spontaneous correction rate of thoracic curve. Conclusion. Posterior selective TL/L fusion with pedicle screw constructs is an effective treatment for Lenke 5C AIS patients. Nonstructural thoracic curves with higher flexibility or better immediate correction are more likely to progress during the follow-up and close attentions must be paid to these patients in case of decompensation. Level of Evidence: 4

  6. Crystal Structure of Mouse Elf3 C-terminal DNA-binding Domain in Complex with Type II TGF-[beta] Receptor Promoter DNA

    SciTech Connect

    Agarkar, Vinod B.; Babayeva, Nigar D.; Wilder, Phillip J.; Rizzino, Angie; Tahirov, Tahir H.

    2010-08-18

    The Ets family of transcription factors is composed of more than 30 members. One of its members, Elf3, is expressed in virtually all epithelial cells as well as in many tumors, including breast tumors. Several studies observed that the promoter of the type II TGF-{beta} receptor gene (T{beta}R-II) is strongly stimulated by Elf3 via two adjacent Elf3 binding sites, the A-site and the B-site. Here, we report the 2.2 {angstrom} resolution crystal structure of a mouse Elf3 C-terminal fragment, containing the DNA-binding Ets domain, in complex with the B-site of mouse type II TGF-{beta} receptor promoter DNA (mT{beta}R-II{sub DNA}). Elf3 contacts the core GGAA motif of the B-site from a major groove similar to that of known Ets proteins. However, unlike other Ets proteins, Elf3 also contacts sequences of the A-site from the minor groove of the DNA. DNA binding experiments and cell-based transcription studies indicate that minor groove interaction by Arg349 located in the Ets domain is important for Elf3 function. Equally interesting, previous studies have shown that the C-terminal region of Elf3, which flanks the Ets domain, is required for Elf3 binding to DNA. In this study, we determined that Elf3 amino acid residues within this flanking region, including Trp361, are important for the structural integrity of the protein as well as for the Efl3 DNA binding and transactivation activity.

  7. Splitting of type-I (N-B, P-Al) and type-II (N-Al, N-Ga) donor-acceptor pair spectra in 3C-SiC

    NASA Astrophysics Data System (ADS)

    Sun, J. W.; Ivanov, I. G.; Juillaguet, S.; Camassel, J.

    2011-05-01

    Discrete series of lines have been observed for many years in donor-acceptor pair (DAP) spectra in 3C-SiC. In this work, the splitting of both type-I (N-B, P-Al) and type-II (N-Al, N-Ga) DAP spectra in 3C-SiC has been systematically investigated by considering the multipole terms. For type-I spectra, in which either N or B substitutes on C sites or P and Al replace Si, the splitting energy of the substructure for a given shell is almost the same for both pairs. For type-II spectra, in which N is on the C site while Al and Ga acceptors replace Si, we find that, when compared with literature data, the splitting energy for a given shell is almost independent of the identity of the acceptor. For both type-I and type-II spectra, this splitting energy can be successfully explained by the octupole term V3 alone with k3 = -2 × 105 Å4 meV. Comparing the experimental donor and acceptor binding energies with the values calculated by the effective-mass model, this suggests that the shallow donor (N,P) ions can be treated as point charges while the charge distribution of the acceptor ions (Al,Ga,B) is distorted in accord with the Td point group symmetry, resulting in a considerable value for k3. This gives a reasonable explanation for the observed splitting energies for both type-I and type-II DAP spectra.

  8. Dr. Lenke Horvath (1917-1991): Creator of Pediatric Neurosurgery in Romania.

    PubMed

    Mohan, Dumitru; Moisa, Horatiu Alexandru; Nica, Dan Aurel; Ciurea, Alexandru Vlad

    2016-04-01

    The development of neurosurgery as an independent specialty took place with great difficulty in Romania. In this respect, the most revered personalities are those of Professor Alexandru Moruzzi (1900-1957) (in Iasi) and Professor Dimitrie Bagdasar (1893-1946) (in Bucharest), who are the fathers of modern neurosurgery in Romania. Professor Bagdasar was schooled in Professor Harvey Cushing's clinic in Boston and is credited with creating the first completely independent neurosurgical unit in Romania. His legacy was carried on with honor by Professor Constantin Arseni (1912-1994), who, in 1975, tasked Dr. Lenke Horvath (1917-1991) with creating the first autonomous pediatric neurosurgery unit in Bucharest. This article is a small tribute to the founder of pediatric neurosurgery in Romania and one of the female pioneer neurosurgeons, who, by personal example of dedication and hard work, radically changed medical thinking and neurosurgery in Romania.

  9. A density-functional study of the phase diagram of cementite-type (Fe,Mn)3C at absolute zero temperature.

    PubMed

    Von Appen, Jörg; Eck, Bernhard; Dronskowski, Richard

    2010-11-15

    The phase diagram of (Fe(1-x) Mn(x))(3)C has been investigated by means of density-functional theory (DFT) calculations at absolute zero temperature. The atomic distributions of the metal atoms are not random-like as previously proposed but we find three different, ordered regions within the phase range. The key role is played by the 8d metal site which forms, as a function of the composition, differing magnetic layers, and these dominate the physical properties. We calculated the magnetic moments, the volumes, the enthalpies of mixing and formation of 13 different compositions and explain the changes of the macroscopic properties with changes in the electronic and magnetic structures by means of bonding analyses using the Crystal Orbital Hamilton Population (COHP) technique.

  10. INTEGRATED POLARIZATION PROPERTIES OF 3C48, 3C138, 3C147, AND 3C286

    SciTech Connect

    Perley, R. A.; Butler, B. J. E-mail: BButler@nrao.edu

    2013-06-01

    We present the integrated polarization properties of the four compact radio sources 3C48, 3C138, 3C147, and 3C286, from 1 to 50 GHz, over a 30 yr time frame spanning 1982-2012. Using the polarized emission of Mars, we have determined that the position angle of the linearly polarized emission of 3C286 rises from 33 Degree-Sign at 8 GHz to 36 Degree-Sign at 45 GHz. There is no evidence for a change in the position angle over time. Using these values, the position angles of the integrated polarized emission from the other three sources are determined as a function of frequency and time. The fractional polarization of 3C286 is found to be slowly rising, at all frequencies, at a rate of {approx}0.015% yr{sup -1}. The fractional polarizations of 3C48, 3C138, and 3C147 are all slowly variable, with the variations correlated with changes in the total flux densities of these sources.

  11. Multifrequency observations of extended radio galaxies V - 3C 31, 3C 33.1, 3C 35, 3C 66B, 3C 129, 3C 130, 3C 223, 3C 310, 3C 390.3 and 4C 48.29

    NASA Astrophysics Data System (ADS)

    van Breugel, W.; Jagers, W.

    1982-08-01

    A sample of 3C radio sources of large angular size has been observed in total and polarized intensity at several wavelengths with the Westerbork Synthesis Radio Telescope. The sources were selected such that their largest angular size was greater than about 200 arcsec and their declination greater than about 25 degrees. Some additional sources with radio jets or peculiar morphology were also included. The name of each source, its structural type classification, wavelength of observation, and data references are given.

  12. The Fate of Exploding Carbon-Oxygen Chandrasekhar-Mass White Dwarfs: The Production of Stable Iron-Peak Elements in the Type Ia Supernova Remnant 3C 397

    NASA Astrophysics Data System (ADS)

    Fisher, Robert; Dave, Pranav; Kashyap, Rahul; Timmes, Francis; Townsley, Dean

    2017-01-01

    Type Ia supernovae are important across many astrophysical domains, serving as standardizable candles for cosmology, sources of cosmic rays, turbulence, and enriched isotopes for the interstellar medium, and endpoints of binary evolution. Yet, the nature of their stellar progenitors remains elusive. For decades, the leading model to explain the relative uniformity of Type Ia supernovae properties consisted of carbon-oxygen white dwarfs accreting material to near-Chandrasekhar mass from a stellar companion, in the single-degenerate channel. It has slowly become apparent that there are likely several diverse ways in which carbon-oxygen white dwarfs may explode and produce a range of outcomes, including both normal and peculiar Type Ia supernovae. Indeed, it is only very recently that strong observational evidence supporting the single-degenerate channel has emerged, and that numerous questions surrounding it have begun to be unraveled.In this talk, I will focus upon the use of multidimensional numerical simulations in modeling the stable iron-group elemental abundances inferred from the hard X-ray spectrum of the galactic supernova remnant 3C 397. Because the electron capture rates involved in the production of these stable iron-group abundances are very sensitive functions of density, we now have an exquisite probe into the internal structure and composition of the progenitor near-Chandrasekhar mass white dwarf, as well as of the physics of the ignition and detonation, which gave rise to the observed remnant. I will conclude with an outlook on some of the many exciting prospects for future observational and theoretical investigation, which will have the potential of helping crack the mystery of the Type Ia supernovae progenitors.

  13. A Massive Molecular Gas Reservoir in the Z = 2.221 Type-2 Quasar Host Galaxy SMM J0939+8315 Lensed by the Radio Galaxy 3C220.3

    NASA Astrophysics Data System (ADS)

    Leung, T. K. Daisy; Riechers, Dominik A.

    2016-02-01

    We report the detection of CO(J = 3 \\to 2) line emission in the strongly lensed submillimeter galaxy (SMG) SMM J0939+8315 at z = 2.221, using the Combined Array for Research in Millimeter-wave Astronomy. SMM J0939+8315 hosts a type-2 quasar, and is gravitationally lensed by the radio galaxy 3C220.3 and its companion galaxy at z = 0.685. The 104 GHz continuum emission underlying the CO line is detected toward 3C220.3 with an integrated flux density of Scont = 7.4 ± 1.4 mJy. Using the CO(J = 3 \\to 2) line intensity of ICO(3-2) = (12.6 ± 2.0) Jy km s-1, we derive a lensing- and excitation-corrected CO line luminosity of {L}{{CO(1-0)}}\\prime = (3.4 ± 0.7) × 1010 (10.1/μL) K km s-1 pc2 for the SMG, where μL is the lensing magnification factor inferred from our lens modeling. This translates to a molecular gas mass of Mgas = (2.7 ± 0.6) × 1010 (10.1/μL) M⊙. Fitting spectral energy distribution models to the (sub)-millimeter data of this SMG yields a dust temperature of T = 63.1{}-1.3+1.1 K, a dust mass of Mdust = (5.2 ± 2.1) × 108 (10.1/μL) M⊙, and a total infrared luminosity of LIR = (9.1 ± 1.2) ×1012 (10.1/μL) L⊙. We find that the properties of the interstellar medium of SMM J0939+8315 overlap with both SMGs and type-2 quasars. Hence, SMM J0939+8315 may be transitioning from a starbursting phase to an unobscured quasar phase as described by the “evolutionary link” model, according to which this system may represent an intermediate stage in the evolution of present-day galaxies at an earlier epoch.

  14. Molecular evolution of VP3, VP1, 3C(pro) and 3D(pol) coding regions in coxsackievirus group A type 24 variant isolates from acute hemorrhagic conjunctivitis in 2011 in Okinawa, Japan.

    PubMed

    Nidaira, Minoru; Kuba, Yumani; Saitoh, Mika; Taira, Katsuya; Maeshiro, Noriyuki; Mahoe, Yoko; Kyan, Hisako; Takara, Taketoshi; Okano, Sho; Kudaka, Jun; Yoshida, Hiromu; Oishi, Kazunori; Kimura, Hirokazu

    2014-04-01

    A large acute hemorrhagic conjunctivitis (AHC) outbreak occurred in 2011 in Okinawa Prefecture in Japan. Ten strains of coxsackievirus group A type 24 variant (CA24v) were isolated from patients with AHC and full sequence analysis of the VP3, VP1, 3C(pro) and 3D(pol) coding regions performed. To assess time-scale evolution, phylogenetic analysis was performed using the Bayesian Markov chain Monte Carlo method. In addition, similarity plots were constructed and pairwise distance (p-distance) and positive pressure analyses performed. A phylogenetic tree based on the VP1 coding region showed that the present strains belong to genotype 4 (G4). In addition, the present strains could have divided in about 2010 from the same lineages detected in other countries such as China, India and Australia. The mean rates of molecular evolution of four coding regions were estimated at about 6.15 to 7.86 × 10(-3) substitutions/site/year. Similarity plot analyses suggested that nucleotide similarities between the present strains and a prototype strain (EH24/70 strain) were 0.77-0.94. The p-distance of the present strains was relatively short (<0.01). Only one positive selected site (L25H) was identified in the VP1 protein. These findings suggest that the present CA24v strains causing AHC are genetically related to other AHC strains with rapid evolution and emerged in around 2010.

  15. An optical study of 3C 31, 3C 66B, 3C 120, and their jets

    SciTech Connect

    Fraix-burnet, D.; Golombek, D.; Macchetto, F.D. Space Telescope Science Institute, Baltimore, MD )

    1991-08-01

    The paper presents the results of BVRI CCD photometry of the radio galaxies 3C 31, 3C 66B, and 3C 120, and V polarimetry of 3C 120. The photometry of the jet of 3C 66B definitively establishes the synchrotron nature of the optical emission. No optical counterpart of the radio counterjet in 3C 66B and of the radio jets in 3C 31 and 3C 120 is found. A rotating ring and an ionized region are present, respectively, in 3C 31 (NGC 383) and its companion galaxy NGC 382, but no isophotal distortions are found which could have revealed a gravitational interaction between the two galaxies as is the case in 3C 66B. The elliptical isophotes of 3C 120 show a slight off-centering, roughly in the direction of the radio jet, very much like 3C 66B. An upper limit of 20 percent is found for the polarization level of the condensations in 3C 120. 50 refs.

  16. Curtiss XSO3C-1 Seagull

    NASA Technical Reports Server (NTRS)

    1940-01-01

    Curtiss XSO3C-1 Seagull: Although drag reduction was very important to radial engined aircraft, it was no less important to aircraft such as this inline Ranger powered Curtiss XSO3C-1 Seagull. Here the Seagull is shown in the 30 x 60 Full Scale Tunnel in October of 1940. The XSO3C-1 was also undergoing study to improve engine cooling. Published in Aircraft; FST; Curtiss XSO3C-1 Seagull; Full Scale Tunnel; Nicklas

  17. 18 CFR 3c.2 - Nonpublic information.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Nonpublic information. 3c.2 Section 3c.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES STANDARDS OF CONDUCT § 3c.2 Nonpublic information. (a) Section 1264(d)...

  18. 18 CFR 3c.2 - Nonpublic information.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Nonpublic information. 3c.2 Section 3c.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES STANDARDS OF CONDUCT § 3c.2 Nonpublic information. (a) Section 1264(d)...

  19. 18 CFR 3c.2 - Nonpublic information.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Nonpublic information. 3c.2 Section 3c.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES STANDARDS OF CONDUCT § 3c.2 Nonpublic information. (a) Section 1264(d)...

  20. 18 CFR 3c.2 - Nonpublic information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Nonpublic information. 3c.2 Section 3c.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES STANDARDS OF CONDUCT § 3c.2 Nonpublic information. (a) Section 1264(d)...

  1. 18 CFR 3c.2 - Nonpublic information.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Nonpublic information. 3c.2 Section 3c.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES STANDARDS OF CONDUCT § 3c.2 Nonpublic information. (a) Section 1264(d)...

  2. Potential impact of viral load and genetic makeup of HIV type 1 on mother-to-child transmission: characterization of env-C2V3C3 and nef sequences.

    PubMed

    Pádua, Elizabeth; Parreira, Ricardo; Tendeiro, Rita; Nunes, Baltazar; Castela, João; Soares, Isabel; Mouzinho, Ana; Reis, Eduarda; Paixão, Maria Teresa

    2009-11-01

    HIV-1 mother-to-child transmission (MTCT) was evaluated in terms of the molecular characterization of the env and nef genomic regions and quantification of maternal RNA viral loads. Assignment of viral subtype was achieved by direct sequencing of PCR 1172 products amplified from proviral DNA in 45 HIV-1-nontransmitting mothers (NTM), along with 13 pairs of HIV-1-transmitting mothers (TM) and their infected children (C). Analysis of the env C2V3C3 and nef sequences revealed that subtypes G and B, and their genetic combinations (AG, BG), accounted for over 84.5% of all viruses identified. The genetic structure form envA-nefG was the most commonly observed, with a lower frequency in the NTM (13.3%) compared to the TM (23.1%) group. A greater number of genetic forms was observed among NTM, namely the presence of sequences assigned to subtypes D and F, as well as the intergenetic A/J, and C/U, recombinant forms, along with a mosaic provirus with a complex putative envA-nefEGE genetic structure. No significant differences were found when RNA viral loads were evaluated as a function of the viral subtypes. Nevertheless, a relatively high quantification of HIV-1 RNA was obtained in the NTM group, emphasizing the importance of the compliance and effectiveness of therapeutic schemes to control viral replication and reduce the risk of HIV vertical transmission. V3 sequences displaying features associated with the R5 phenotype dominated in both groups. Both C2V3C3 and Nef's functional domains were conserved during HIV-1 vertical transmission.

  3. The high energy source 3C 273

    NASA Technical Reports Server (NTRS)

    Vonmontigny, Corinna

    1990-01-01

    The properties of 3C 273 are reviewed and an attempt is made to find an answer to the question why 3C 273 is the only extragalactic source so far, which was detected at energies greater than or equal to 50 MeV.

  4. Hydrothermal synthesis of a new organic-inorganic hybrid with Dawson type polyanions as building blocks: Na3(C7NH8O2)3[P2W18O62]·16H2O

    NASA Astrophysics Data System (ADS)

    Hmida, Fatma; Ayed, Brahim; Haddad, Amor

    2016-07-01

    A new organic-inorganic hybrid compound based on dawson polyoxotungstate, Na3(C7NH8O2)3 [P2W18O62].16H2O have been isolated under autogenous pressure method and characterized by single-crystal X-ray diffraction, infrared, ultraviolet spectroscopy, cyclic voltammetry and Thermogravimetric analysis (TGA). This compound crystallized in the triclinic system, space group P-1, with a = 14.063 (1) Å; b = 17.009 (1) Å; c = 17.868 (1) Å; α = 79.88 (1)°; β = 77.14 (1)°; γ = 79.25 (1)° and Z = 2. The crystal structures of the compounds exhibit three-dimensional supramolecular assembly based on the extensive hydrogen bonding interactions between organic cations, sodium cations, water molecules and Dawson polyoxoanions. The infrared spectrum fully confirms the X-ray crystal structure and the UV spectrum of the title compound exhibits an absorption peak at 295 nm.

  5. NATO-3C/Delta launch

    NASA Technical Reports Server (NTRS)

    1978-01-01

    NATO-3C, the third in a series of NATO defense-related communication satellites, is scheduled to be launched on a delta vehicle from the Eastern Test Range no earlier than November 15, 1978. NATO-3A and -3B were successfully launched by Delta vehicles in April 1976 and January 1977, respectively. The NATO-3C spacecraft will be capable of transmitting voice, data, facsimile, and telex messages among military ground stations. The launch vehicle for the NATO-3C mission will be the Delta 2914 configuration. The launch vehicle is to place the spacecraft in a synchronous transfer orbit. The spacecraft Apogee Kick motor is to be fired at fifth transfer orbit apogee to circularize its orbit at geosynchronous altitude of 35,900 km(22,260 miles) above the equator over the Atlantic Ocean somewhere between 45 and 50 degrees W longitude.

  6. EGRET observations of 3C 273

    NASA Technical Reports Server (NTRS)

    Von Montigny, C.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.

    1993-01-01

    The quasar 3C 273 was detected by COS-B in the 1970's. EGRET observations of this sky region in June and October 1991 revealed a flux from 3C 273 lower than that measured by COS-B. The flux observed by EGRET in the June period is approximately 3 x 10 exp -7/sq cm s for energies greater than 100 MeV. During the October observation it appears to be even lower. For the first observation a preliminary spectrum which has a photon index of 2.4 has been derived.

  7. EGRET observations of 3 C 273

    NASA Technical Reports Server (NTRS)

    Vonmontigny, C.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.

    1992-01-01

    The quasar 3C 273 was detected by the Compton Observatory Satellite (COS-B) in the 1970's. Energetic Gamma Ray Experiment Telescope (EGRET) observations of this sky region in Jun. and Oct. 1991 revealed a flux from 3C 273 lower than that measured by COS-B. The flux observed by EGRET in the June period is approximately 0.0000003/sq cm(exp -2) sec(exp -1) for energies greater than 100 MeV. During the Oct. observation it appears to be even lower. For the first observation a preliminary spectrum was derived which was a photon index of 2.4.

  8. Photovoltaic performance of dye-sensitized solar cells based on donor-acceptor pi-conjugated benzofuro[2,3-c]oxazolo[4,5-a]carbazole-type fluorescent dyes with a carboxyl group at different positions of the chromophore skeleton.

    PubMed

    Ooyama, Yousuke; Shimada, Yoshihito; Kagawa, Yusuke; Imae, Ichiro; Harima, Yutaka

    2007-07-07

    Donor-acceptor pi-conjugated benzofuro[2,3-c]oxazolo[4,5-a]carbazole-type fluorescent dyes 3a, 3b, 8a, and 8b with a carboxyl group at different positions of the chromophore skeleton have been designed and synthesized. The absorption and fluorescence spectra and cyclic voltammograms of the fluorescent dyes agree very well, showing that the position of the carboxyl group has a negligible influence on the photophysical and electrochemical properties of these dyes. When these dyes are used in dye-sensitized solar cells, however, their photovolatic performances are considerably different. The short-circuit photocurrents and energy conversion efficiencies under a simulated solar light increase in the order: 3a (2.12 mA cm(-2), 1.00%) approximately 3b (2.10 mA cm(-2), 1.06%) > 8b (1.50 mA cm(-2), 0.67%) > 8a (0.84 mA cm(-2), 0.34%). Based on semi-empirical molecular orbital calculations (AM1 and INDO/S) together with spectral analyses and their photovolatic performance, the relationships between the observed photovolatic properties and the chemical structures of the benzofuro[2,3-c]oxazolo[4,5-a]carbazole-type fluorescent dyes are discussed. It is found that strong interaction between a TiO(2) surface and the electron accepting moiety of the dye leads to a high photovoltaic performance.

  9. ALMA Polarization Science Verification: 3C 286

    NASA Astrophysics Data System (ADS)

    Nagai, H.; Nakanishi, K.; Paladino, R.; Moellenbrock, G.; Fomalont, E.; Amigano, A.; Vlahakis, C.; Remijan, A.; ALMA Polarization Team

    2015-12-01

    The ALMA polarization science verification results on 3C 286 are presented. The measured polarization percentage and polarization position angle of the continuum emission at 1.3 mm are about 16% and 39 degrees, respectively. They are quite similar to those at longer wavelength, but seem to increase slightly. Similar trends were also found in the previous measurement using the IRAM 30-m telescope (Agudo et al. 2012). The final image rms on the polarization image is better than 0.1% of the total intensity, demonstrating the very high polarization sensitivity of ALMA.

  10. Structure of the radio sources 3C 196 and 3C 280

    SciTech Connect

    Bovkun, V.; Zhuk, I.; Men', A.

    1981-05-01

    The structure of the quasar 3C 196 and the radio galaxy 3C 280 at 20- and 25-MHz frequency has been surveyed by the scintillation technique with the URAN-1 interferometer. Angular sizes are estimated for the scintillating components and the extended portions of each source. In 3C 196 these components have effective angular sizes of 2'' +- 1''.5 and 18'' x 25'', with the compact feature contributing 0.46 +- 0.20 of the total flux. Spectra of the various structural components of the source are compiled for the range 20--5000 MHz. In 3C 280 the effective angular size of the scintillating component is 1''.5 +- 1''.2; the extended region measures >10'' across. The compact feature contributes 0.35 +- 0.20 of the total flux.

  11. CHANDRA Observations OF The Shock Heated Gas Around 3c 288 And 3c 449

    NASA Astrophysics Data System (ADS)

    Lal, Dharam V.; Kraft, R. P.; Evans, D. A.; Hardcastle, M. J.; Nulsen, P. E. J.; Croston, J. H.; Forman, W. R.; Jones, C.; Lee, J. C.

    2010-03-01

    The inflation of radio bubbles in the hot gas atmospheres of clusters of galaxies plays an important role in the overall energy budget of the ICM. Regular gentle (i.e. subsonic) nuclear outbursts may be able to provide sufficient energy to the gas in the cool cores of clusters to offset radiative losses and regulate large cooling flows; and one method to supplement the total energy input into the gas is for the lobes to initially drive strong shocks into the gas. We present results from Chandra/ACIS-S observations of the hot gas atmospheres of two powerful, nearby radio galaxies in poor clusters: 3C 288 and 3C 449. We measure the total energy of the current outburst to be a few times 10^{59} ergs for 3C 288 (T = 2.8 keV, L_X = 1.4 × 10^{44} ergs) and ˜10^{58} ergs for 3C 449 (T = 1.5 keV, L_X = 2.0 × 10^{42} ergs). We find multiple surface brightness discontinuities in the gas, which are probably shocks and are indicative of supersonic heating by the inflation of the radio lobe. We do not find X-ray cavity in 3C 288, whereas cavities are associated with both the radio lobes in 3C 449.

  12. Etudes structurales de composés de type cémentite: Effet de l'hydroge`ne sur Fe 3C suivi par diffraction neutronique. Spectrométrie Mössbauer sur FeCo 2B et Co 3B dopés au 57Fe

    NASA Astrophysics Data System (ADS)

    Fruchart, D.; Chaudouet, P.; Fruchart, R.; Rouault, A.; Senateur, J. P.

    1984-02-01

    Accurate neutron diffractograms obtained using Fe 3C powdered samples have been recorded using position sensitive detectors. The structure parameters have been determined in the 20-650°C range both in vacuo and in hydrogen atmosphere. No significant location of hydrogen atoms in the cell could be detected before the complete decomposition of Fe 3C, which is considerably enhanced by H 2 gas and is accompanied by an initial loss of carbon (<5%). The magnetic diffraction peaks correspond to ferromagnetic moments directed along the yaxis: M(4 c) ⋍ M(8f) = 1.8 ± 0.1 μ B(extrapolated). Such a value agrees reasonably well with those obtained from Mössbauer data. Comparison with the isomorphous borides or Fe-substitutedCo 3X compounds indicates that a rigid band model is inadequate to describe the electronic scheme of Fe in cementite and related compounds. Analysis of the stability of M3Xcementite-type structured materials reveals the major role of M(d)-X(p) hybridization.

  13. Epstein–Barr virus nuclear antigen 3C regulated genes in lymphoblastoid cell lines

    PubMed Central

    Zhao, Bo; Mar, Jessica C.; Maruo, Seiji; Lee, Sungwook; Gewurz, Benjamin E.; Johannsen, Eric; Holton, Kristina; Rubio, Renee; Takada, Kenzo; Quackenbush, John; Kieff, Elliott

    2011-01-01

    EBV nuclear antigen 3C (EBNA3C) is an essential transcription factor for EBV transformed lymphoblast cell line (LCL) growth. To identify EBNA3C-regulated genes in LCLs, microarrays were used to measure RNA abundances in each of three different LCLs that conditionally express EBNA3C fused to a 4-OH-Tamoxifen–dependent estrogen receptor hormone binding domain (EBNA3CHT). At least three RNAs were assayed for each EBNA3CHT LCL under nonpermissive conditions, permissive conditions, and nonpermissive conditions with wild-type EBNA3C transcomplementation. Using a two-way ANOVA model of EBNA3C levels, we identified 550 regulated genes that were at least 1.5-fold up- or down-regulated with false discovery rates < 0.01. EBNA3C-regulated genes overlapped significantly with genes regulated by EBNA2 and EBNA3A consistent with coordinated effects on cell gene transcription. Of the 550 EBNA3C-regulated genes, 106 could be placed in protein networks. A seeded Bayesian network analysis of the 80 most significant EBNA3C-regulated genes suggests that RAC1, LYN, and TNF are upstream of other EBNA3C-regulated genes. Gene set enrichment analysis found enrichment for MAP kinase signaling, cytokine–cytokine receptor interactions, JAK-STAT signaling, and cell adhesion molecules, implicating these pathways in EBNA3C effects on LCL growth or survival. EBNA3C significantly up-regulated the CXCL12 ligand and its CXCR4 receptor and increased LCL migration. CXCL12 up-regulation depended on EBNA3C's interaction with the cell transcription factor, RBPJ, which is essential for LCL growth. EBNA3C also up-regulated MYC 1.3-fold and down-regulated CDKN2A exons 2 and 3, shared by p16 and p14, 1.4-fold, with false discovery rates < 5 × 10−4. PMID:21173222

  14. Double Faraday rotation toward 3C 27

    NASA Astrophysics Data System (ADS)

    Goldstein, S. J., Jr.; Reed, J. A.

    1984-08-01

    From observations of the integrated flux of 3C 27 with the NRAO 140 foot (43 m) telescope at 40 frequencies between 1250 and 1445 MHz, the authors deduce rotation measures of 165±15 and -104±4 rad m-2. Since the source (assumed to be a radio galaxy) has components 45arcsec apart, it is concluded that the net magnetic field reverses between these directions. One explanation is that a large magnetic field surrounding the central galaxy of the distant source covers one component but not the other. Another explanation is that our Galaxy contains a dipole field with a scale of order 1 pc. One component of the distant source is seen inside the current loop associated with the dipole field, while the other is seen outside the loop.

  15. Optimal High-TC Superconductivity in Cs3C60

    NASA Astrophysics Data System (ADS)

    Harshman, Dale; Fiory, Anthony

    The highest superconducting transition temperatures in the (A1-xBx)3C60 superconducting family are seen in the A15 and FCC structural phases of Cs3C60 (optimized under hydrostatic pressure), exhibiting measured values for near-stoichiometric samples of TC0 meas . = 37.8 K and 35.7 K, respectively. It is argued these two Cs-intercalated C60 compounds represent the optimal materials of their respective structures, with superconductivity originating from Coulombic e- h interactions between the C60 molecules, which host the n-type superconductivity, and mediating holes associated with the Cs cations. A variation of the interlayer Coulombic pairing model [Harshman and Fiory, J. Supercond. Nov. Magn. 28 ̲, 2967 (2015), and references therein] is introduced in which TC0 calc . ~ 1 / lζ , where l relates to the mean spacing between interacting charges on surfaces of the C60 molecules, and ζ is the average radial distance between the surface of the C60 molecules and the neighboring Cs cations. For stoichiometric Cs3C60, TC0 calc . = 38.08 K and 35.67 K for the A15 and FCC macrostructures, respectively; the dichotomy is attributable to differences in ζ.

  16. Photometric reverberation mapping of 3C 120

    NASA Astrophysics Data System (ADS)

    Pozo Nuñez, F.; Ramolla, M.; Westhues, C.; Bruckmann, C.; Haas, M.; Chini, R.; Steenbrugge, K.; Murphy, M.

    2012-09-01

    We present the results of a five month monitoring campaign of the local active galactic nuclei (AGN) 3C 120. Observations with a median sampling of two days were conducted with the robotic 15 cm telescope VYSOS-6 located near Cerro Armazones in Chile. Broad band (B, V) and narrow band (NB) filters were used in order to measure fluxes of the AGN and the Hβ broad line region (BLR) emission line. The NB flux is constituted by about 50% continuum and 50% Hβ emission line. To disentangle line and continuum flux, a synthetic Hβ light curve was created by subtracting a scaled V-band light curve from the NB light curve. Here we show that the Hβ emission line responds to continuum variations with a rest frame lag of 23.6 ± 1.69 days. We estimate a virial mass of the central black hole MBH = 57 ± 27 × 106 M⊙, by combining the obtained lag with the velocity dispersion of a single contemporaneous spectrum. Using the flux variation gradient method, we determined the host galaxy subtracted rest frame 5100 Å luminosity at the time of our monitoring campaign with an uncertainty of 10% (LAGN = (6.94 ± 0.71) × 1043 erg s-1). Compared with recent spectroscopic reverberation results, 3C 120 shifts in the RBLR - LAGN diagram remarkably close to the theoretically expected relation of R ∝ L0.5. Our results demonstrate the performance of photometric AGN reverberation mapping, in particular for efficiently determining the BLR size and the AGN luminosity. Table 5 is available in electronic form at http://www.aanda.org

  17. FULL POLARIZATION SPECTRA OF 3C 279

    SciTech Connect

    Homan, D. C.; Lister, M. L.; Aller, H. D.; Aller, M. F.; Wardle, J. F. C. E-mail: mlister@physics.purdue.edu E-mail: mfa@umich.edu

    2009-05-01

    We report the results of parsec-scale, multifrequency Very Long Baseline Array observations of the core region of 3C 279 in Stokes I, linear polarization, and circular polarization. These full polarization spectra are modeled by radiative transfer simulations to constrain the magnetic field and particle properties of the parsec-scale jet in 3C 279. We find that the polarization properties of the core region, including the amount of linear polarization, the amount and sign of Faraday rotation, and the amount and sign of circular polarization can be explained by a consistent physical picture. The base of the jet, component D, is modeled as an inhomogeneous Blandford-Koenigl style conical jet dominated by a vector-ordered poloidal magnetic field along the jet axis, and we estimate its net magnetic flux. This poloidal field is responsible for the linear and circular polarization from this inhomogeneous component. Farther down the jet, the magnetic field in two homogeneous features is dominated by local shocks and a smaller fraction of vector-ordered poloidal field remains along the jet axis. This remaining poloidal field provides internal Faraday rotation which drives Faraday conversion of linear polarization into circular polarization from these components. In this picture, we find the jet to be kinetically dominated by protons with the radiating particles being dominated by electrons at an approximate fraction of {approx}>75%, still allowing the potential for a significant admixture of positrons. Based on the amounts of Faraday conversion deduced for the homogeneous components, we find a plausible range for the lower cutoff in the relativistic particle energy spectrum to be 5 {approx}< {gamma} {sub l} {approx}< 35. The physical picture described here is not unique if the observed Faraday rotation and depolarization occur in screens external to the jet; however, we find the joint explanation of linear and circular polarization observations from a single set of

  18. Multiwavelength observations of giant radio galaxy 3C 35 and 3C 284

    NASA Astrophysics Data System (ADS)

    Pal, Sabyasachi; Chakrabarti, Sandip Kumar; Patra, Dusmanta; Konar, Chiranjib

    2016-07-01

    We report multi wavelength observations of large radio galaxy 3C35 and 3C284. The low frequency observations were done with the Giant Metrewave Radio Telescope (GMRT) starting from 150 MHz. The high frequency observations were done with Jansky Very Large Array (JVLA). Our main motivation for these observations is to estimate the spectral ages of these galaxies and to examine any proof of extended emission at low radio frequencies due to an earlier cycle of activity. The spectral age is measured by fitting the spectra with different spectral ageing models e.g. Kardashev-Pacholczyk (KP), Jaffe-Perola (JP) and Continuous Injection (CI).

  19. THE SUZAKU VIEW OF 3C 382

    SciTech Connect

    Sambruna, R. M.; Gliozzi, M.; Tombesi, F.; Braito, V.; Ballo, L.; Reynolds, C. S.

    2011-06-20

    We present a long (116 ks) Suzaku observation of the broad-line radio galaxy (BLRG) 3C 382 acquired in 2007 April. A Swift BAT spectrum in 15-200 keV from the 58 month survey is also analyzed, together with an archival XMM-Newton EPIC exposure of 20 ks obtained one year after Suzaku. Our main result is the finding with Suzaku of a broad Fe K line with a relativistic profile consistent with emission from an accretion disk at tens of gravitational radii from the central black hole. The XIS data indicate emission from highly ionized iron and allow us to set tight, albeit model-dependent, constraints on the inner and outer radii of the disk reflecting region, r{sub in} {approx_equal} 10 r{sub g} and r{sub out} {approx_equal} 20 r{sub g} , respectively, and on the disk inclination, i {approx_equal} 30{sup 0}. Two ionized reflection components are possibly observed, with similar contributions of {approx}10% to the total continuum-a highly ionized one, with log{xi} {approx_equal} 3 erg s{sup -1} cm, which successfully models the relativistic line, and a mildly ionized one, with log{xi} {approx_equal} 1.5 erg s{sup -1} cm, which models the narrow Fe K{alpha} and high energy hump. When both these components are included, there is no further requirement for an additional blackbody soft excess below 2 keV. The Suzaku data confirm the presence of a warm absorber previously known from grating studies. After accounting for all the spectral features, the intrinsic photon index of the X-ray continuum is {Gamma}{sub x} {approx_equal} 1.8 with a cutoff energy at {approx}200 keV, consistent with Comptonization models and excluding jet-related emission up to these energies. Comparison of the X-ray properties of 3C 382 and other BLRGs to Seyferts recently observed with Suzaku and BAT confirms the idea that the distinction between radio-loud and radio-quiet active galactic nucleus at X-rays is blurred. The two classes form a continuum distribution in terms of X-ray photon index

  20. The resolved outflow from 3C 48

    SciTech Connect

    Shih, Hsin-Yi; Stockton, Alan E-mail: stockton@ifa.hawaii.edu

    2014-10-20

    We investigate the properties of the high-velocity outflow driven by the young radio jet of 3C 48, a compact-steep-spectrum source. We use the Space Telescope Imaging Spectrograph on board the Hubble Space Telecope to obtain (1) low-resolution UV and optical spectra and (2) multi-slit medium-resolution spectra of the ionized outflow. With supporting data from ground-based spectrographs, we are able to accurately measure the ratios of diagnostic emission lines such as [O III] λ5007, [O III] λ3727, [N II] λ6548, Hα, Hβ, [Ne V] λ3425, and [Ne III] λ3869. We fit the observed emission-line ratios using a range of ionization models, powered by active galactic nucleus (AGN) radiation and shocks, produced by the MAPPINGS code. We have determined that AGN radiation is likely the dominant ionization source. The outflow's density is estimated to be in the range n = 10{sup 3}-10{sup 4} cm{sup –3}, the mass is ∼6 × 10{sup 6} M {sub ☉}, and the metallicity is likely equal to or higher than solar. Compared with the typical outflows associated with more evolved radio jets, this young outflow is denser, less massive, and more metal rich. Multi-slit observations allow us to construct a two-dimensional velocity map of the outflow that shows a wide range of velocities with distinct velocity components, suggesting a wide-angle clumpy outflow.

  1. 3C 236: Radio Source, Interrupted?

    NASA Astrophysics Data System (ADS)

    O'Dea, Christopher P.; Koekemoer, Anton M.; Baum, Stefi A.; Sparks, William B.; Martel, André R.; Allen, Mark G.; Macchetto, Ferdinando D.; Miley, George K.

    2001-04-01

    We present new Hubble Space Telescope Space Telescope Imaging Spectrograph MAMA near-UV images and archival Wide Field Planetary Camera 2 (WFPC2) V- and R-band images that reveal the presence of four star-forming regions in an arc along the edge of the dust lane in the giant (4 Mpc) radio galaxy 3C 236. Two of the star-forming regions are relatively young, with ages of order ~107 yr, while the other two are older, with ages of order ~108-109 yr, which is comparable to the estimated age of the giant radio source. Based on dynamical and spectral aging arguments, we suggest that the fuel supply to the active galactic nucleus (AGN) was interrupted for ~107 yr and has now been restored, resulting in the formation of the inner 2 kpc-scale radio source. This timescale is similar to that of the age of the youngest of the star-forming regions. We suggest that the transport of gas in the disk is nonsteady and that this produces the multiple episodes of star formation in the disk, as well as the multiple epochs of radio source activity. If the inner radio source and the youngest star-forming region are related by the same event of gas transport, the gas must be transported from the hundreds of parsec scale to the subparsec scale on a timescale of ~107 yr, which is similar to the dynamical timescale of the gas on the hundreds of parsec scale.

  2. 3C236: Radio Source, Interrupted?

    NASA Astrophysics Data System (ADS)

    O'Dea, C. P.; Koekemoer, A. M.; Baum, S. A.; Sparks, W. B.

    We present highlights of the results of new HST STIS/MAMA near-UV images and archival WFPC2 V- and R-band images which reveal the presence of four apparently star forming regions in an arc along the edge of the dust lane in the giant (4 Mpc) radio galaxy 3C236. Two of the star forming regions are relatively young with ages of order ~107 yr, while the other two are older with ages of order ~108 -- 109 yr, which is comparable to the estimated age of the giant radio source. Based on dynamical and spectral aging arguments, we suggest that the fuel supply to the AGN was interrupted for ~107 yr and has now been restored, resulting in the formation of the inner 2 kpc scale radio source. This time scale is similar to that of the age of the youngest of the star forming regions. We suggest that the transport of gas in the disk is non-steady and that this produces both the multiple episodes of star formation in the disk as well as the multiple epochs of radio source activity. If the inner radio source and the youngest star forming region are related by the same event of gas transport, the gas must be transported from the hundreds of pc scale to the sub-parsec scale on a time scale of ~107 yr, which is similar to the dynamical timescale of the gas on the hundreds of pc scales.

  3. OSSE observations of 3C 273

    NASA Technical Reports Server (NTRS)

    Johnson, W. N.; Dermer, C. D.; Kinzer, R. L.; Kurfess, J. D.; Strickman, M. S.; Mcnaron-Brown, K.; Jourdain, E.; Jung, G. V.; Grabelsky, D. A.; Purcell, W. R.

    1995-01-01

    We report results of multiple observations of the quasar 3C 273 with the Oriented Scintillation Spectrometer Experiment (OSSE) instrument on the Compton Gamma Ray Observatory. These observations span the period from 1991 June through 1993 January and represent the most sensitive observations to date in low-energy gamma rays. The source was detected at historically weak 100 keV fluxes compared with previous measurements. Variability by factors of approximately 3 on timescales of approximately equal 2 months was observed in the energy band 50-150 keV. The data are well described by a single power law with a proton number index Gamma = 1.7 +/- 0.1. No significant change of Gamma was observed during changes in intensity. Thermal models do not provide acceptable fits to the data. When the OSSE data are combined with contemporaneous measurements by COMPTEL and EGRET, the spectrum is seen to break at an energy of 1.0(+0.9, -0.4) MeV to a softer power law with Delta Gamma = 0.7(+0.06, -0.11), forming a power law with Gamma = 2.4 between approximately 1 MeV and several GeV.

  4. HST And VLA Polarimetry Of 3C 264 And 3C 66B

    NASA Astrophysics Data System (ADS)

    Padgett, C. Alexander; Perlman, E. S.; Georganopoulos, M.; O'Dea, C. P.; Baum, S. A.; Sparks, W. B.; Biretta, J. A.

    2006-09-01

    We present new VLA A- and B-array radio polarimetry at 22.5 GHz, and images at 8.4GHz of 3C 264, a low luminosity FR I in Abell 1367. We also present high resolution VLA A-array polarimetry of the jet of 3C 66B, both at 22.5 GHz and 43 GHz. This is the latest addition to an ongoing study of these objects, which includes optical polarimetry in several bands and multiband imaging with HST, and X-ray observations with Chandra. We find further evidence for the hypothesis that 3C 264 falls into the category of low luminosity BL Lac objects (Rector, Stocke & Perlman, 1999) in significant variability of the polarization position angle in the core of this object in only 4 years (Lara et al, 2003). This variability, together with our measured value of its optical spectral index of alpha = 0.77, and a previously derived viewing angle of < 50 degrees (Baum et al, 1997; Lara et al, 2003), puts a fairly strong constraint on the classification of 3C 264 as a low luminosity BL Lac. We also present matched resolution HST and VLA data for both of these objects, allowing for direct morphological comparisons to be made, as well as full resolution radio to optical spectral index maps.

  5. Low-frequency study of two giant radio galaxies: 3C 35 and 3C 223

    NASA Astrophysics Data System (ADS)

    Orrù, E.; Murgia, M.; Feretti, L.; Govoni, F.; Giovannini, G.; Lane, W.; Kassim, N.; Paladino, R.

    2010-06-01

    Aims: Radio galaxies with a projected linear size ⪆1 Mpc are classified as giant radio sources. According to the current interpretation these are old sources which have evolved in a low-density ambient medium. Because radiative losses are negligible at low frequency, extending spectral aging studies in this frequency range will allow us to determine the zero-age electron spectrum injected and then to improve the estimate of the synchrotron age of the source. Methods: We present Very Large Array images at 74 MHz and 327 MHz of two giant radio sources: 3C 35 and 3C 223. We performed a spectral study using 74, 327, 608 and 1400 GHz images. The spectral shape is estimated in different positions along the source. Results: The radio spectrum follows a power-law in the hotspots, while in the inner region of the lobe the shape of the spectrum shows a curvature at high frequencies. This steepening agrees with synchrotron aging of the emitting relativistic electrons. In order to estimate the synchrotron age of the sources, the spectra were fitted with a synchrotron model of emission. They show that 3C 35 is an old source of 143 ± 20 Myr, while 3C 223 is a younger source of 72 ± 4 Myr.

  6. The Accelerating Jet of 3C 279

    NASA Astrophysics Data System (ADS)

    Bloom, S. D.; Fromm, C. M.; Ros, E.

    2013-01-01

    Analysis of the proper motions of the subparsec scale jet of the quasar 3C 279 at 15 GHz with the Very Long Baseline Array shows significant accelerations in four of nine superluminal features. Analysis of these motions is combined with the analysis of flux density light curves to constrain values of Lorentz factor and viewing angle (and their derivatives) for each component. The data for each of these components are consistent with significant changes to the Lorentz factor, viewing angle, and azimuthal angle, suggesting jet bending with changes in speed. We see that for these observed components Lorentz factors are in the range Γ = 10-41, viewing angles are in the range thetav = 0.°1-5.°0, and intrinsic (source frame) flux density is in the range, F ν, int = 1.5 × 10-9-1.5 × 10-5 Jy. Considering individual components, the Lorentz factors vary from Γ = 11-16 for C1, Γ = 31-41 for C5, Γ = 29-41 for C6, and Γ = 9-12 for C8, indicating that there is no single underlying flow speed to the jet and likely we are seeing pattern speeds from shocks in the jet. The viewing angles vary in time from 0.°6 to 1.°5 in the case of C1 (the least extreme example), from 0.°5 to 5.°0 in the case of C8, and from 0.°1 to 0.°9 for C5 (the last two being the most extreme examples). The intrinsic flux density varies by factors from 1.4 for C8 and 430 for C5. Theoretical analysis of the accelerations also indicates potential jet bending. In addition, for one component, C5, polarization measurements also set limits to the trajectory of the jet.

  7. Jet precession and its observational evidence: The cases of 3C 345 and 3C 120

    NASA Astrophysics Data System (ADS)

    Caproni, Anderson; Abraham, Zulema

    2004-11-01

    Several radio-loud objects exhibit a complex structure when observed at radio wavelengths: a stationary core, which is thought to harbour the central engine that powers the AGN phenomena, and a relativistic jet, formed by several superluminal components. In some cases, jet components are ejected with different apparent proper motions and directions on the plane of the sky. Moreover, these sources can also show signatures of long-term periodic variability in their historical optical light curve. In this work, we selected the objects 3C 120 and 3C 345, which exhibit both characteristics mentioned above, and interpret them in the framework of jet inlet precession. A brief discussion about what kind of mechanism could be responsible for jet precession is also presented.

  8. THE ACCELERATING JET OF 3C 279

    SciTech Connect

    Bloom, S. D.; Fromm, C. M.; Ros, E.

    2013-01-01

    Analysis of the proper motions of the subparsec scale jet of the quasar 3C 279 at 15 GHz with the Very Long Baseline Array shows significant accelerations in four of nine superluminal features. Analysis of these motions is combined with the analysis of flux density light curves to constrain values of Lorentz factor and viewing angle (and their derivatives) for each component. The data for each of these components are consistent with significant changes to the Lorentz factor, viewing angle, and azimuthal angle, suggesting jet bending with changes in speed. We see that for these observed components Lorentz factors are in the range {Gamma} = 10-41, viewing angles are in the range thetav = 0. Degree-Sign 1-5. Degree-Sign 0, and intrinsic (source frame) flux density is in the range, F{sub {nu},int} 1.5 Multiplication-Sign 10{sup -9}-1.5 Multiplication-Sign 10{sup -5} Jy. Considering individual components, the Lorentz factors vary from {Gamma} = 11-16 for C1, {Gamma} = 31-41 for C5, {Gamma} = 29-41 for C6, and {Gamma} = 9-12 for C8, indicating that there is no single underlying flow speed to the jet and likely we are seeing pattern speeds from shocks in the jet. The viewing angles vary in time from 0. Degree-Sign 6 to 1. Degree-Sign 5 in the case of C1 (the least extreme example), from 0. Degree-Sign 5 to 5. Degree-Sign 0 in the case of C8, and from 0. Degree-Sign 1 to 0. Degree-Sign 9 for C5 (the last two being the most extreme examples). The intrinsic flux density varies by factors from 1.4 for C8 and 430 for C5. Theoretical analysis of the accelerations also indicates potential jet bending. In addition, for one component, C5, polarization measurements also set limits to the trajectory of the jet.

  9. The Resolved Outflow from 3C 48

    NASA Astrophysics Data System (ADS)

    Shih, Hsin-Yi; Stockton, Alan

    2014-10-01

    We investigate the properties of the high-velocity outflow driven by the young radio jet of 3C 48, a compact-steep-spectrum source. We use the Space Telescope Imaging Spectrograph on board the Hubble Space Telecope to obtain (1) low-resolution UV and optical spectra and (2) multi-slit medium-resolution spectra of the ionized outflow. With supporting data from ground-based spectrographs, we are able to accurately measure the ratios of diagnostic emission lines such as [O III] λ5007, [O III] λ3727, [N II] λ6548, Hα, Hβ, [Ne V] λ3425, and [Ne III] λ3869. We fit the observed emission-line ratios using a range of ionization models, powered by active galactic nucleus (AGN) radiation and shocks, produced by the MAPPINGS code. We have determined that AGN radiation is likely the dominant ionization source. The outflow's density is estimated to be in the range n = 103-104 cm-3, the mass is ~6 × 106 M ⊙, and the metallicity is likely equal to or higher than solar. Compared with the typical outflows associated with more evolved radio jets, this young outflow is denser, less massive, and more metal rich. Multi-slit observations allow us to construct a two-dimensional velocity map of the outflow that shows a wide range of velocities with distinct velocity components, suggesting a wide-angle clumpy outflow. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-11574. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Some of the

  10. VLBA Monitoring of 3C 273 and 3C 279 During INTEGRAL Campaigns

    NASA Astrophysics Data System (ADS)

    Savolainen, T.; Wiik, K.; Valtaoja, E.

    2004-10-01

    The gamma-ray blazars 3C 273 and 3C 279 were ob- served with the Very Long Baseline Array (VLBA) over seven epochs during the year 2003 as a part of support- ing observations for two INTEGRAL campaigns targeted on these sources. The VLBA observations were carried out in a full multi-wavelength polarimetric mode yield- ing total and polarized intensity maps at six frequencies ranging from 5 to 86 GHz. The VLBA maps probe the emission of the parsec scale jets in the angular scales of 0.1 - 50 mas, providing information about the dynam- ical state of the jets close to the central engine. As the gamma-ray emission above 100 keV is likely to be jet related, the co-ordinated VLBA observations give a pos- sibility to correlate the gamma-ray flux variations with the structural changes in the jet and, furthermore, with the flux and spectral variations of the individual syn- chrotron emitting components. Possible correlations can help to pinpoint the region where the gamma-ray emis- sion originates, and also establish the source of seed pho- tons for the inverse Compton process. We describe here the VLBA observations and present the first fully cali- brated maps together with a preliminary analysis.

  11. Poliovirus protease 3C(pro) kills cells by apoptosis.

    PubMed

    Barco, A; Feduchi, E; Carrasco, L

    2000-01-20

    The tetracycline-based Tet-Off expression system has been used to analyze the effects of poliovirus protease 3C(pro) on human cells. Stable HeLa cell clones that express this poliovirus protease under the control of an inducible, tightly regulated promoter were obtained. Tetracycline removal induces synthesis of 3C protease, followed by drastic morphological alterations and cellular death. Degradation of cellular DNA in nucleosomes and generation of apoptotic bodies are observed from the second day after 3C(pro) induction. The cleavage of poly(ADP-ribose) polymerase, an enzyme involved in DNA repair, occurs after induction of 3C(pro), indicating caspase activation by this poliovirus protease. The 3C(pro)-induced apoptosis is blocked by the caspase inhibitor z-VAD-fmk. Our findings suggest that the protease 3C is responsible for triggering apoptosis in poliovirus-infected cells by a mechanism that involves caspase activation.

  12. New redshift determinations for three 3C radio sources.

    NASA Astrophysics Data System (ADS)

    Reynaldi, V.

    2017-01-01

    I report the new redshift determinations of three radio sources 3C 196.1, 3C 268.2 and 3C 303.1 by using GMOS/Gemini North long-slit optical spectroscopy. The details of the observations are summarized in the following table (the B600 grating was used for the three observations): Object | RA(J2000) | DEC(J2000) | Date of obs. | width-slit(arcsec) | PA(deg) | Exp.Time(sec) 3C 196.1 | 8:15:27.8 | -03:08:27 | Mar 2012 | 0.5 | 50 | 2560 3C 268.2| |12:00:59.1 | 31:33:28 | Feb 2011 | 0.5 | 165 | 2576 3C 303.1 | 14:43:14.5 | 77:07:28 | Feb 2012 | 1 | 145 | 2560 The three of the sources have extended regions of ionized gas that do not obey a spherical distribution.

  13. Extended Optical Flaring of the Blazar 3C 279

    NASA Astrophysics Data System (ADS)

    Turner, C. S.; Miller, H. R.

    2017-03-01

    The blazar, 3C 279, was previously reported to be undergoing a major optical outburst (ATEL#10121 and ATEL#10161). We report optical observations of 3C 279 on March 19 when it was observed with the 24-inch telescope at Georgia State University's Hard Labor Creek Observatory with R=13.46+/-0.01 mag. These observations indicate that 3C 279 continues to be in an extremely bright state.

  14. Cleavage of Interferon Regulatory Factor 7 by Enterovirus 71 3C Suppresses Cellular Responses

    PubMed Central

    Lei, Xiaobo; Xiao, Xia; Xue, Qinghua; Jin, Qi

    2013-01-01

    Enterovirus 71 (EV71) is a positive-stranded RNA virus which is capable of inhibiting innate immunity. Among virus-encoded proteins, the 3C protein compromises the type I interferon (IFN-I) response mediated by retinoid acid-inducible gene-I (RIG-I) or Toll-like receptor 3 that activates interferon regulatory 3 (IRF3) and IRF7. In the present study, we report that enterovirus 71 downregulates IRF7 through the 3C protein, which inhibits the function of IRF7. When expressed in mammalian cells, the 3C protein mediates cleavage of IRF7 rather than that of IRF3. This process is insensitive to inhibitors of caspase, proteasome, lysosome, and autophagy. H40D substitution in the 3C active site abolishes its activity, whereas R84Q or V154S substitution in the RNA binding motif has no effect. Furthermore, 3C-mediated cleavage occurs at the Q189-S190 junction within the constitutive activation domain of IRF7, resulting in two cleaved IRF7 fragments that are incapable of activating IFN expression. Ectopic expression of wild-type IRF7 limits EV71 replication. On the other hand, expression of the amino-terminal domain of IRF7 enhances EV71 infection, which correlates with its ability to interact with and inhibit IRF3. These results suggest that control of IRF7 by the 3C protein may represent a viral mechanism to escape cellular responses. PMID:23175366

  15. The changes of relative position of the thoracic aorta after anterior or posterior instrumentation of type I Lenke curve in adolescent idiopathic thoracic scoliosis.

    PubMed

    Wang, Weijun; Zhu, Zezhang; Zhu, Feng; Wang, Bin; Chu, Winnie C W; Cheng, Jack C Y; Qiu, Yong

    2008-08-01

    The risk of impingement of the aorta associated with thoracic vertebral screw or pedicle screw instrumentation in the treatment of thoracic scoliosis has been an important concern. To understand this phenomenon more systematically, the relative position of the aorta with reference to the thoracic vertebrae in right thoracic adolescent idiopathic scoliosis (AIS) following anterior and posterior spinal instrumentation was analyzed in detail quantitatively; 34 patients underwent anterior (n = 14) or posterior (n = 20) spinal instrumentation were recruited in the present study. The relative position of the thoracic aorta, vertebral rotation, apical vertebral translation and thoracic kyphosis were measured from pre- and post-operative CT images from T5 to T12. The aorta was found to shift antero-medially in the anterior instrumentation group but not in the posterior spinal instrumentation group. It is likely that the disc removal, soft tissue release and spontaneous vertebral derotation of the scoliosis could account for the antero-medial shifting of the aorta. By the shifting, the space for contralateral screw penetration was reduced.

  16. Epstein-Barr Virus Essential Antigen EBNA3C Attenuates H2AX Expression

    PubMed Central

    Jha, Hem C.; AJ, Mahadesh Prasad; Saha, Abhik; Banerjee, Shuvomoy; Lu, Jie

    2014-01-01

    Epstein-Barr virus (EBV) latent antigen EBNA3C is implicated in B-cell immortalization and linked to several B-cell malignancies. Deregulation of H2AX can induce genomic instability with increased chromosomal aberrations, which ultimately leads to tumorigenesis. Here we demonstrated that EBNA3C can attenuate H2AX expression at the transcript and protein levels. A reduction of total H2AX levels was clearly observed upon infection of primary B cells with wild-type EBV but not with EBNA3C knockout recombinant EBV. H2AX also interacted with EBNA3C through its N-terminal domain (residues 1 to 100). Furthermore, H2AX mutated at Ser139 failed to interact with EBNA3C. Luciferase-based reporter assays also revealed that the binding domain of EBNA3C is sufficient for transcriptional inhibition of the H2AX promoter. EBNA3C also facilitated H2AX degradation through recruitment of components of the ubiquitin proteasome pathway. We further demonstrated that knockdown of H2AX in lymphoblastoid cell lines (LCLs) led to the upregulation of the Bub1 oncoprotein and downregulated expression of p53. Overall, our study provides additional insights into EBV-associated B-cell lymphomas, which are linked to the regulation of the DNA damage response system in infected cells. The importance of these insights are as follows: (i) EBNA3C downregulates H2AX expression at the protein and transcript levels in epithelial cells, B cells, and EBV-transformed LCLs, (ii) EBNA3C binds with wild-type H2AX but not with the Ser139 mutant of H2AX, (iii) the N terminus (residues 1 to 100) of EBNA3C is critical for binding to H2AX, (iv) localization of H2AX is predominantly nuclear in the presence of EBNA3C, and (v) H2AX knocked down in LCLs led to enhanced expression of Bub1 and downregulation of the tumor suppressor p53, which are both important for driving the oncogenic process. PMID:24429368

  17. Despite phylogenetic effects, C3-C4 lineages bridge the ecological gap to C4 photosynthesis.

    PubMed

    Lundgren, Marjorie R; Christin, Pascal-Antoine

    2017-01-01

    C4 photosynthesis is a physiological innovation involving several anatomical and biochemical components that emerged recurrently in flowering plants. This complex trait evolved via a series of physiological intermediates, broadly termed 'C3-C4', which have been widely studied to understand C4 origins. While this research program has focused on biochemistry, physiology, and anatomy, the ecology of these intermediates remains largely unexplored. Here, we use global occurrence data and local habitat descriptions to characterize the niches of multiple C3-C4 lineages, as well as their close C3 and C4 relatives. While C3-C4 taxa tend to occur in warm climates, their abiotic niches are spread along other dimensions, making it impossible to define a universal C3-C4 niche. Phylogeny-based comparisons suggest that, despite shifts associated with photosynthetic types, the precipitation component of the C3-C4 niche is particularly lineage specific, being highly correlated with that of closely related C3 and C4 taxa. Our large-scale analyses suggest that C3-C4 lineages converged toward warm habitats, which may have facilitated the transition to C4 photosynthesis, effectively bridging the ecological gap between C3 and C4 plants. The intermediates retained some precipitation aspects of their C3 ancestors' habitat, and likely transmitted them to their C4 descendants, contributing to the diversity among C4 lineages seen today.

  18. 17 CFR 270.3c-6 - Certain transfers of interests in section 3(c)(1) and section 3(c)(7) funds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF... gift or bequest or pursuant to an agreement relating to a legal separation or divorce. (2) The term Section 3(c)(1) Company means a company that would be an investment company but for the exclusion...

  19. A Novel Enterovirus 71 (EV71) Virulence Determinant: The 69th Residue of 3C Protease Modulates Pathogenicity.

    PubMed

    Li, Bingqing; Yue, Yingying; Zhang, Yajie; Yuan, Zenglin; Li, Peng; Song, Nannan; Lin, Wei; Liu, Yan; Gu, Lichuan; Meng, Hong

    2017-01-01

    Human enterovirus type 71 (EV71), the major causative agent of hand-foot-and-mouth disease, has been known to cause fatal neurological complications. Unfortunately, the reason for neurological complications that have been seen in fatal cases of the disease and the relationship between EV71 virulence and viral genetic sequences remains largely undefined. The 3C protease (3C(pro)) of EV71 plays an irreplaceable role in segmenting the precursor polyprotein during viral replication, and intervening with host life activity during viral infection. In this study, for the first time, the 69th residue of 3C protease has been identified as a novel virulence determinant of EV71. The recombinant virus with single point variation, in the 69th of 3C(pro), exhibited obvious decline in replication, and virulence. We further determined the crystal structure of 3C N69D at 1.39 Ǻ resolution and found that conformation of 3C N69D demonstrated significant changes compared with a normal 3C protein, in the substrate-binding site and catalytic active site. Strikingly, one of the switch loops, essential in fixing substrates, adopts an open conformation in the 3C N69D-rupintrivir complex. Consistent with this apparent structural disruption, the catalytic activity of 3C N69D decreased sharply for host derived and viral derived substrates, detected for both in vitro and in vivo. Interestingly, in addition to EV71, Asp69 was also found in 3C proteases of other virus strains, such as CAV16, and was conserved in nearly all C type human rhinovirus. Overall, we identified a natural virulence determinant of 3C protease and revealed the mechanism of attenuated virulence is mediated by N69D substitution. Our data provides new insight into the enzymatic mechanism of a subdued 3C protease and suggests a theoretical basis for virulence determinantion of picornaviridae.

  20. Spatially Resolved Spectra of 3C Galaxy Nuclei

    NASA Technical Reports Server (NTRS)

    Hutchings, J. B.; Baum, S. A.; Weistrop, D.; Nelson, C.; Kaiser, M. E.; Gelderman, R. F.

    1998-01-01

    We present and discuss visible-wavelength long-slit spectra of four low-redshift 3C galaxies obtained with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope (HST). The slit was aligned with near-nuclear jet-like structure seen in HST images of the galaxies, to give unprecedented spatial resolution of their inner regions. In 3C 135 and 3C 171, the spectra reveal clumpy emission-line structures that indicate outward motions of a few hundred kilometers per second within a centrally illuminated and ionized biconical region. There may also be some low-ionization, high-velocity material associated with 3C 135. In 3C 264 and 3C 78, the jets have blue featureless spectra consistent with their proposed synchrotron origin. There is weak associated line emission in the innermost part of the jets with mild outflow velocity. These jets are bright and highly collimated only within a circumnuclear region of lower galaxy luminosity, which is not dusty. We discuss the origins of these central regions and their connection with relativistic jets.

  1. Self-diffusion of molecular hydrogen in clathrasils compared: dodecasil 3C versus sodalite.

    PubMed

    van den Berg, A W C; Flikkema, E; Jansen, J C; Bromley, S T

    2005-05-22

    The self-diffusion coefficient of molecular hydrogen through the all-silica microporous dodecasil 3C structure is calculated by means of molecular-dynamics (MD) calculations, allowing for full framework flexibility, in order to assess the material's feasibility as a hydrogen storage medium. The hydrogen uptake rate into dodecasil 3C is compared to that previously calculated for sodalite and it is found that the latter performs significantly better. The reason for this variation in performance is found to lie in intrinsic topological differences between each framework type. This is explicitly demonstrated by means of a simplified version of transition state theory helping to succinctly rationalize the MD data.

  2. Fine Structure in 3C 120 and 3C 84. Ph.D. Thesis - Maryland Univ., 24 Aug. 1976

    NASA Technical Reports Server (NTRS)

    Hutton, L. K.

    1976-01-01

    Seven epochs of very long baseline radio interferometric observations of the Seyfert galaxies 3C 120 and 3C 84, at 3.8-cm wave length using stations at Westford, Massachusetts, Goldstone, California, Green Bank, West Virginia, and Onsala, Sweden, have been analyzed for source structure. An algorithm for reconstructing the brightness distribution of a spatially confined source from fringe amplitude and so called closure phase data has been developed and successfully applied to artificially generated test data and to data on the above mentioned sources. Over the two year time period of observation, 3C 120 was observed to consist of a double source showing apparent super relativistic expansion and separation velocities. The total flux changes comprising one outburst can be attributed to one of these components. 3C 84 showed much slower changes, evidently involving flux density changes in individual stationary components rather than relative motion.

  3. Characterization of chirally-coupled-core (3C) fibers fabricated with direct nanoparticle deposition (DND)

    NASA Astrophysics Data System (ADS)

    Ye, Changgeng; Koponen, Joona; Kimmelma, Ossi; Aallos, Ville; McComb, Timothy S.; Lowder, Tyson L.

    2016-03-01

    We report detailed characterization results of Yb-doped Chirally-Coupled-Core (3C) fibers fabricated with Direct Nanoparticle Deposition (DND) technique. Two types of 3C fibers with core/clad geometries of 34/250μm and 55/400μm and another 25/250μm conventional large-mode-area (LMA) fiber are measured and the results are compared in terms of modal content, transmission spectrum, etc. A picosecond fiber amplifier is built based on 55/400μm 3C fiber, showing robust single-mode operation with peak power >1MW with no sign of stimulated Raman scattering (SRS).

  4. Spitzer and near-infrared observations of the young supernova remnant 3C397

    NASA Astrophysics Data System (ADS)

    Rho, Jeonghee; Jarrett, Tom

    2016-06-01

    We present Spitzer IRS, IRAC and MIPS observations and near-infrared imaging and spectroscopy of the young supernova remnant 3C397 (G41.1-0.2). Near-infrared observations were made using the Palomar 200 inch telescope. Both mid- and near-infrared spectra are dominated by Fe lines and near-infrared imaging shows bright Fe emission with a shell-like morphology. There is no molecular hydrogen line belong to the SNR and some are in background. The Ni, Ar, S and Si lines are detected using IRS and hydrogen recombination lines are detected in near-infrared. Two nickel lines at 18.24 and 10.69 micron are detected. 3C397 is ejecta-dominated, and our observations support 3C397 to be a Type Ia supernova.

  5. Atomic probe microscopy of 3C SiC films grown on 6H SiC substrates

    NASA Technical Reports Server (NTRS)

    Steckl, A. J.; Roth, M. D.; Powell, J. A.; Larkin, D. J.

    1993-01-01

    The surface of 3C SiC films grown on 6H SiC substrates has been studied by atomic probe microscopy in air. Atomic-scale images of the 3C SiC surface have been obtained by STM which confirm the 111 line type orientation of the cubic 3C layer grown on the 0001 plane type surface of the hexagonal 6H substrate. The nearest-neighbor atomic spacing for the 3C layer has been measured to be 3.29 +/- 0.2 A, which is within 7 percent of the bulk value. Shallow terraces in the 3C layer have been observed by STM to separate regions of very smooth growth in the vicinity of the 3C nucleation point from considerably rougher 3C surface regions. These terraces are oriented at right angles to the growth direction. Atomic force microscopy has been used to study etch pits present on the 6H substrate due to high temperature HCl cleaning prior to CVD growth of the 3C layer. The etch pits have hexagonal symmetry and vary in depth from 50 nm to 1 micron.

  6. EBNA3C regulates p53 through induction of Aurora kinase B.

    PubMed

    Jha, Hem C; Yang, Karren; El-Naccache, Darine W; Sun, Zhiguo; Robertson, Erle S

    2015-03-20

    In multicellular organisms p53 maintains genomic integrity through activation of DNA repair, and apoptosis. EBNA3C can down regulate p53 transcriptional activity. Aurora kinase (AK) B phosphorylates p53, which leads to degradation of p53. Aberrant expression of AK-B is a hallmark of numerous human cancers. Therefore changes in the activities of p53 due to AK-B and EBNA3C expression is important for understanding EBV-mediated cell transformation. Here we show that the activities of p53 and its homolog p73 are dysregulated in EBV infected primary cells which can contribute to increased cell transformation. Further, we showed that the ETS-1 binding site is crucial for EBNA3C-mediated up-regulation of AK-B transcription. Further, we determined the Ser 215 residue of p53 is critical for functional regulation by AK-B and EBNA3C and that the kinase domain of AK-B which includes amino acid residues 106, 111 and 205 was important for p53 regulation. AK-B with a mutation at residue 207 was functionally similar to wild type AK-B in terms of its kinase activities and knockdown of AK-B led to enhanced p73 expression independent of p53. This study explores an additional mechanism by which p53 is regulated by AK-B and EBNA3C contributing to EBV-induced B-cell transformation.

  7. Peptide aldehyde inhibitors of hepatitis A virus 3C proteinase.

    PubMed

    Malcolm, B A; Lowe, C; Shechosky, S; McKay, R T; Yang, C C; Shah, V J; Simon, R J; Vederas, J C; Santi, D V

    1995-06-27

    Picornaviral 3C proteinases are a group of closely related thiol proteinases responsible for processing of the viral polyprotein into its component proteins. These proteinases adopt a chymotrypsin-like fold [Allaire et al. (1994) Nature 369, 72-77; Matthews et al. (1994) Cell 77, 761-771] and a display an active-site configuration like those of the serine proteinases. Peptide-aldehydes based on the preferred peptide substrates for hepatitis A virus (HAV) 3C proteinase were synthesized by reduction of a thioester precursor. Acetyl-Leu-Ala-Ala-(N,N'-dimethylglutaminal) was found to be a reversible, slow-binding inhibitor for HAV 3C with a Ki* of (4.2 +/- 0.8) x 10(-8) M. This inhibitor showed 50-fold less activity against the highly homologous human rhinovirus (strain 14) 3C proteinase, whose peptide substrate specificity is slightly different, suggesting a high degree of selectivity. NMR spectrometry of the adduct of the 13C-labeled inhibitor with the HAV-3C proteinase indicate that a thiohemiacetal is formed between the enzyme and the aldehyde carbon as previously noted for peptide-aldehyde inhibitors of papain [Lewis & Wolfenden (1977) Biochemistry 16,4890-4894; Gamcsik et al. (1983) J. Am. Chem. Soc. 105, 6324-6325]. The adduct can also be observed by electrospray mass spectrometry.

  8. A Sema3C Mutant Resistant to Cleavage by Furin (FR-Sema3C) Inhibits Choroidal Neovascularization

    PubMed Central

    Toledano, Shira; Lu, Huayi; Palacio, Agustina; Ziv, Keren; Kessler, Ofra; Schaal, Shlomit; Neufeld, Gera; Barak, Yoreh

    2016-01-01

    In age-related macular degeneration (AMD), abnormal sub retinal choroidal neovascularization (CNV) is a major cause of blindness. FR-sema3C is a point mutated form of semaphorin-3C that is resistant to cleavage by furin like pro-protein convertases (FPPC). We have found in previous work that FR-sema3C functions as an anti-angiogenic factor. In this study we investigated the possible use of FR-sema3C as an inhibitor of CNV. FR-sema3C inhibits VEGF as well as PDGF-BB signal transduction in endothelial cells and to less extent bFGF induced signal transduction using a mechanism that does not depend upon the binding of VEGF like the drugs that are currently the mainstay treatment for AMD. CNV was induced in eyes of C57 black mice by laser photocoagulation. Intravitreal injection of FR-Sema3C or aflibercept (VEGF-trap) was then used to inhibit CNV formation. Invading choroidal vessels were visualized a week later by injection of FITC-dextran into the circulation, followed by the measurement of the area of the invading blood vessels. Injection of 0.1 μg FR-Sema3C inhibited CNV by 55% (P<0.01) and was as effective as 5 μg aflibercept. FR-sema3C did not display any adverse effects on retinal function following its injection into eyes of healthy mice as assessed by optokinetic reflex (OKR) and Electro-retinogram (ERG) criteria. Furthermore, FR-sema3C did not induce apoptosis in the retina as determined by TUNEL nor was there any discernable structural damage to the retina as assessed by several immuno-histochemical criteria. Our results suggest that FR-sema3C could perhaps be used for the treatment of AMD, and that it may perhaps be of benefit to patients that do not respond well to current treatments relying on VEGF sequestering agents. PMID:28036336

  9. Viability of Stored Rabbit Erythrocytes Carrying Number C3c.

    DTIC Science & Technology

    1984-05-31

    A-A165 440 VIABILITY OF STORED RABBIT ERYTHROCYTES CARRYING NUBR V no C3C(U) MASSACHUSETTS UNIV MEDICAL SCHOOL MORCESTER UNCLRSSIFI 0 SZYMANSKI 31...Carrying No C3c 0 Annual and Final Report Irma 0. Szymanski, M.D. Ln CD May 31, 1984 I Supported by U.S. ARMY MEDICAL RESEARCH AND DEVELOPMENT COMMAND...Fort Detrick, Frederick, Maryland 21701-5012 Contract No. DAMD17-82-C-2150 .TICD ET University of Massachusetts Medical Center .EC, Worcester

  10. The Radio Spectral Index and Expansion of 3C 58

    DTIC Science & Technology

    2001-10-20

    it has often been described as morphologically similar to the Crab Nebula , the Crab being the prototype for this class. 3C 58 is at a similar distance...the Ðla- ments. This last situation does seem to obtain in the Crab Nebula , where strong circumstantial evidence points to the existence of such a...the surrounding material. We are then brought to a crucial di†erence between 3C 58 and the Crab Nebula : in the case of the Crab, the synchro- tron

  11. A Novel Enterovirus 71 (EV71) Virulence Determinant: The 69th Residue of 3C Protease Modulates Pathogenicity

    PubMed Central

    Li, Bingqing; Yue, Yingying; Zhang, Yajie; Yuan, Zenglin; Li, Peng; Song, Nannan; Lin, Wei; Liu, Yan; Gu, Lichuan; Meng, Hong

    2017-01-01

    Human enterovirus type 71 (EV71), the major causative agent of hand-foot-and-mouth disease, has been known to cause fatal neurological complications. Unfortunately, the reason for neurological complications that have been seen in fatal cases of the disease and the relationship between EV71 virulence and viral genetic sequences remains largely undefined. The 3C protease (3Cpro) of EV71 plays an irreplaceable role in segmenting the precursor polyprotein during viral replication, and intervening with host life activity during viral infection. In this study, for the first time, the 69th residue of 3C protease has been identified as a novel virulence determinant of EV71. The recombinant virus with single point variation, in the 69th of 3Cpro, exhibited obvious decline in replication, and virulence. We further determined the crystal structure of 3C N69D at 1.39 Ǻ resolution and found that conformation of 3C N69D demonstrated significant changes compared with a normal 3C protein, in the substrate-binding site and catalytic active site. Strikingly, one of the switch loops, essential in fixing substrates, adopts an open conformation in the 3C N69D-rupintrivir complex. Consistent with this apparent structural disruption, the catalytic activity of 3C N69D decreased sharply for host derived and viral derived substrates, detected for both in vitro and in vivo. Interestingly, in addition to EV71, Asp69 was also found in 3C proteases of other virus strains, such as CAV16, and was conserved in nearly all C type human rhinovirus. Overall, we identified a natural virulence determinant of 3C protease and revealed the mechanism of attenuated virulence is mediated by N69D substitution. Our data provides new insight into the enzymatic mechanism of a subdued 3C protease and suggests a theoretical basis for virulence determinantion of picornaviridae. PMID:28217559

  12. VLBI Observations of the Radio Jet in 3C273

    NASA Astrophysics Data System (ADS)

    Unwin, S. C.; Davis, R. J.

    The authors present a new high dynamic range map of the quasar 3C 273, made from observations with a VLBI network of 12 telescopes. This new map at 18 cm wavelength has one of the highest dynamic ranges yet achieved with VLBI, and it shows the 'jet' extending to at least 180 milliarcsec, or 330 pc from the nucleus of the quasar.

  13. Microwave Radiometer – 3 Channel (MWR3C) Handbook

    SciTech Connect

    Cadeddu, MP

    2012-05-04

    The microwave radiometer 3-channel (MWR3C) provides time-series measurements of brightness temperatures from three channels centered at 23.834, 30, and 89 GHz. These three channels are sensitive to the presence of liquid water and precipitable water vapor.

  14. 223 GHz VLBI observations of 3C 273

    NASA Astrophysics Data System (ADS)

    Padin, S.; Woody, D. P.; Hodges, M. W.; Rogers, A. E. E.; Emerson, D. T.; Jewell, P. R.; Lamb, J.; Perfetto, A.; Wright, M. C. H.

    1990-09-01

    In the first 1.4 mm wavelength VLBI test observations, fringes have been detected on the active nucleus of 3C 273 on a baseline from Owens Valley Radio Observatory to Kitt Peak. The observations are consistent with a source whose angular size is smaller than 0.5 mas.

  15. Connection Between X-Ray Emission and Relativistic Jets in the Radio Galaxies 3C 111 and 3C 120

    NASA Technical Reports Server (NTRS)

    Aller, Margo F.

    2005-01-01

    This work represents a part of a longterm study of the X-ray flux variability in radio galaxies and its relation to flux and structural changes in the associated radio jet. The work described here included: 1) continued study of the emission properties of the FR I radio galaxy 3C 120 known to exhibit a jet/disk connection from our past work; and 2) the commencement of monitoring of a second radio galaxy, the FR I1 object 3C 111 which was selected because of similar radio and X-ray properties to 3C 120, including the presence of Fe K a emission. The association between X-ray dips and new superluminal components, suggesting a picture in which the radio jet is fed by accretion events near the black hole, was identified in 3C 120 using combined RXTE and radio flux monitoring data and bi-monthly to monthly imaging data from the VLBA at 43 GHz. Such data were also obtained for both targets during the period described here. Specific goals were to more broadly investigate the X-ray dip/superluminal connection in 3C 120, thereby determining the epochs of X-ray minima and superluminal ejections more accurately (and hence more precisely determining the distance between the accretion disk and the core of the radio jet), and to determine whether a similar pattern is present in the data for a second radio galaxy. In 3C 111 a different time scale (longer time delays between X-ray dips and superluminal ejections) was expected due to the higher black hole mass implied by its higher radio luminosity: no black hole mass is published for this object but one can be determined from a PDS analysis of the RXTE data. The addition of the second source to the study would identify whether a similar connection was present in other sources and, if found, would provide important information on how time scale (and hence size scale) of accretion disk/jet systems depends on black hole mass. The grant included funding for the reduction and analysis of data obtained during the time period of Rossi

  16. 3C-SiC nanocrystals/TiO{sub 2} nanotube heterostructures with enhanced photocatalytic performance

    SciTech Connect

    Zhang, J.; Liu, L. Z.; Yang, L.; Gan, Z. X.; Wu, X. L. E-mail: paul.chu@cityu.edu.hk; Chu, Paul K. E-mail: paul.chu@cityu.edu.hk

    2014-06-09

    p-type ultrathin 3C-SiC nanocrystals are coated on heat-treated n-type TiO{sub 2} nanotube arrays formed by electrochemical etching of Ti sheets to produce heterostructured photocatalysts. Depending on the amounts of 3C-SiC nanocrystals on the TiO{sub 2} nanotubes, photocatalytic degradation of organic species can be enhanced. The intrinsic electric field induced by the heterojunction promotes separation of the photoexcited electrons-holes in both the TiO{sub 2} nanotubes and 3C-SiC nanocrystals. Hence, holes can more effectively travel to the surface of 3C-SiC nanocrystals and there are more electrons on the surface of TiO{sub 2} nanotubes consequently forming more {sup •}O{sub 2}{sup −} and {sup •}OH species to degrade organic molecules.

  17. HST Polarimetry of the 3C 273 Jet

    NASA Astrophysics Data System (ADS)

    Clautice, Devon; Perlman, Eric S.; Sparks, William B.; Biretta, John A.; O'Dea, Christopher P.; Baum, Stefi Alison; Cheung, Chi C.; Birkinshaw, Mark; Worrall, Diana M.; Martel, Andre; Urry, C. Megan; Stawarz, Lukasz; Coppi, Paolo S.; Uchiyama, Yasunobu; Cara, Mihai; Meisenheimer, Klaus; Begelman, Mitchell C.

    2017-01-01

    We present preliminary results using HST polarimetry of the jet of 3C 273. Polarization is a critical parameter for understanding jet flows, and has proven essential in characterizing the physics of FR I jets; high-quality HST polarimetry has been done for just two other FR II jets previously. Our recent work on two quasar jets, where we measured high optical polarization in the brightest X-ray knots, has favored the synchrotron emission model over the alternative IC/CMB model for their optical to X-ray emission. These new observations of 3C 273 allow for the determination of the magnetic field structure and confirmation of which emission mechanisms are operating to create its optical to X-ray emission, and will allow us to greatly advance modeling efforts for this jet and nail down its kinetic power, a key unknown parameter for understanding quasars and their cosmological effects.

  18. A decade of 3C technologies: insights into nuclear organization

    PubMed Central

    de Wit, Elzo; de Laat, Wouter

    2012-01-01

    Over the past 10 years, the development of chromosome conformation capture (3C) technology and the subsequent genomic variants thereof have enabled the analysis of nuclear organization at an unprecedented resolution and throughput. The technology relies on the original and, in hindsight, remarkably simple idea that digestion and religation of fixed chromatin in cells, followed by the quantification of ligation junctions, allows for the determination of DNA contact frequencies and insight into chromosome topology. Here we evaluate and compare the current 3C-based methods (including 4C [chromosome conformation capture-on-chip], 5C [chromosome conformation capture carbon copy], HiC, and ChIA-PET), summarize their contribution to our current understanding of genome structure, and discuss how shape influences genome function. PMID:22215806

  19. Enhancing superconductivity in A3C60 fullerides

    NASA Astrophysics Data System (ADS)

    Kim, Minjae; Nomura, Yusuke; Ferrero, Michel; Seth, Priyanka; Parcollet, Olivier; Georges, Antoine

    2016-10-01

    Motivated by the recent experimental report of a possible light-induced superconductivity in K3C60 at high temperature [Mitrano et al., Nature 530, 451 (2016), 10.1038/nature16522], we investigate theoretical mechanisms for enhanced superconductivity in A3C60 fullerenes. We find that an "interaction imbalance" corresponding to a smaller value of the Coulomb matrix element for two of the molecular orbitals in comparison to the third one, efficiently enhances superconductivity. Furthermore, we perform first-principle calculations of the changes in the electronic structure and in the screened Coulomb matrix elements of K3C60 , brought in by the deformation associated with the pumped T1 u intramolecular mode. We find that an interaction imbalance is indeed induced, with a favorable sign and magnitude for superconductivity enhancement. The physical mechanism responsible for this enhancement consists of a stabilization of the intramolecular states containing a singlet pair, while preserving the orbital fluctuations allowing for a coherent interorbital delocalization of the pair. Other perturbations have also been considered and found to be detrimental to superconductivity. The light-induced deformation and ensuing interaction imbalance is shown to bring superconductivity further into the strong-coupling regime.

  20. The Trails of Superluminal Jet Components in 3C 111

    NASA Technical Reports Server (NTRS)

    Kadler, M.; Ros, E.; Perucho, M.; Kovalev, Y. Y.; Homan, D. C.; Agudo, I.; Kellermann, K. I.; Aller, M. F.; Aller, H. D.; Lister, M. L.; Zensus, J. A.

    2007-01-01

    The parsec-scale radio jet of the broad-line radio galaxy 3C 111 has been monitored since 1995 as part of the 2cm Survey and MOJAVE monitoring observations conducted with the VLBA. Here, we present results from 18 epochs of VLBA observations of 3C 111 and from 18 years of radio flux density monitoring observations conducted at the University of Michigan. A major radio flux-density outburst of 3C 111 occurred in 1996 and was followed by a particularly bright plasma ejection associated with a superluminal jet component. This major event allows us to study a variety of processes associated with outbursts of radio-loud AGN in much greater detail than possible in other cases: the primary perturbation gives rise to the formation of a forward and a backward-shock, which both evolve in characteristically different ways and allow us to draw conclusions about the workflow of jet-production events; the expansion, acceleration and recollimation of the ejected jet plasma in an environment with steep pressure and density gradients are revealed; trailing components are formed in the wake of the primary perturbation as a result of Kelvin- Helmholtz instabilities from the interaction of the jet with the external medium. The jet-medium interaction is further scrutinized by the linear-polarization signature of jet components traveling along the jet and passing a region of steep pressure/density gradients.

  1. Variability studies of 3C 371. [extragalactic radio source

    NASA Technical Reports Server (NTRS)

    Worrall, D. M.

    1986-01-01

    The compact extragalactic radio source, 3C 371, was observed with the X-ray detectors of the EXOSAT satellite for 19.5 hours in 2 observing periods separated by 18 days. This resulted in the discovery of X-ray variability of the source on time scales between 8 hours and about 25 minutes and the confirmation of earlier reports of variability on longer time scales. The short time scale variability agrees remarkably well with earlier predictions based on fitting multifrequency data from the source to a relativistically beamed inhomogeneous synchrotron self-Compton (SSC) jet model. This SSC model is frequently applied to BL Lac objects and related sources, such as 3C 371. However, the number of free parameters in model fits tends to be large, and so independent support such as from this work is important. The X-ray spectral results for 3C 371 also may provide qualitative support for the SSC model in that the spectrum probably consists of two components, with the steeper one at low photon energies. In terms of the model, the low-energy spectrum would be dominated by synchrotron emission extending down to radio energies, whereas the higher energy X-rays would be dominated by Compton radiation.

  2. Hydrodynamical Simulations of Colliding Jets: Modeling 3C 75

    NASA Astrophysics Data System (ADS)

    Molnar, S. M.; Schive, H.-Y.; Birkinshaw, M.; Chiueh, T.; Musoke, G.; Young, A. J.

    2017-01-01

    Radio observations suggest that 3C 75, located in the dumbbell shaped galaxy NGC 1128 at the center of Abell 400, hosts two colliding jets. Motivated by this source, we perform three-dimensional hydrodynamical simulations using a modified version of the GPU-accelerated Adaptive-MEsh-Refinement hydrodynamical parallel code (GAMER) to study colliding extragalactic jets. We find that colliding jets can be cast into two categories: (1) bouncing jets, in which case the jets bounce off each other keeping their identities, and (2) merging jets, when only one jet emerges from the collision. Under some conditions the interaction causes the jets to break up into oscillating filaments of opposite helicity, with consequences for their downstream stability. When one jet is significantly faster than the other and the impact parameter is small, the jets merge; the faster jet takes over the slower one. In the case of merging jets, the oscillations of the filaments, in projection, may show a feature that resembles a double helix, similar to the radio image of 3C 75. Thus we interpret the morphology of 3C 75 as a consequence of the collision of two jets with distinctly different speeds at a small impact parameter, with the faster jet breaking up into two oscillating filaments.

  3. How 3-D, 3-C seismic characterized a carbonate reservoir

    SciTech Connect

    Arestad, J.F.; Mattocks, B.W.; Davis, T.L.; Benson, R.D.

    1995-04-01

    The Reservoir Characterization Project (RCP) at the Colorado School of Mines has pioneered research into 3-D, 3-C (multicomponent) reflection seismology for nearly a decade utilizing both P-wave and S-wave sources. Multicomponent-seismic surveys provide significantly more information about petroleum reservoirs than compressional-wave surveys. Initial 3-D, 3-C surveys acquired by RCP were targeted at characterizing naturally fractured reservoirs. The current phase of the project is oriented towards utilizing shear waves to discriminate lithologic and diagenetic changes within stratigraphic reservoirs where compressional-seismic data has not be effective. The Joffre field, Nisku reservoir, is the site of RCP`s ongoing multidisciplinary research effort in Western Canada. The research team is directed by Colorado School of Mines faculty with graduate team members from geology, geophysics and petroleum engineering departments. While this study is still in progress, some key findings and directions of this research are reported here. The following topics will be discussed: Joffre field 3-D, 3-C survey; compressional wave 3-D technique; shear-wave 3-D technique; converted-wave 3-D technique; reservoir characterization, and future directions.

  4. Infrared spectrophotometry of three Seyfert galaxies and 3C 273

    NASA Technical Reports Server (NTRS)

    Cutri, R. M.; Puetter, R. C.; Rudy, R. J.; Willner, S. P.; Aitken, D. K.; Jones, B.; Merrill, K. M.; Roche, P. F.; Russell, R. W.; Soifer, B. T.

    1981-01-01

    Spectrophotometry in the range 2.1-4.0 microns is presented for the Seyfert galaxies NGC 1068, NGC 4151 and Mrk 231 and the quasar 3C 273, together with broadband and narrowband observations of the Seyfert galaxies in the range 8-13 microns. The spectra of NGC 1068 and NGC 4151 are found to contain a significant component due to starlight, especially at shorter wavelengths. The nonstellar component in NGC 1068 is observed to fall off rapidly at wavelengths shorter than 4 microns, consistent with the interpretation of the excess beyond 5 microns as thermal reradiation by dust. Observations confirm the variability of NGC 4151, and indicate the presence of two components of the flux other than starlight: a nonthermal variable component predominant at shorter wavelengths and a constant, probably thermal component at wavelengths greater than 3 microns. Mrk 231 and 3C 273 exhibit no discernable stellar component and were not observed to vary by more than 10%. Evidence is obtained for a broad minimum in the 8 to 13 micron spectrum of Mrk 231, as well as possible structure between rest wavelengths of 2.8 and 2.9 microns, and the spectrum is not a power law. The spectrum of 3C 273 is consistent with a power law from 1.2 to 10 microns, with small but significant deviations.

  5. The milliarcsecond structure of 3C 273 at 22 GHz

    SciTech Connect

    Zensus, J.A.; Biretta, J.A.; Unwin, S.C.; Cohen, M.H. Owens Valley Radio Observatory, Pasadena, CA )

    1990-12-01

    The first VLBI images at 22 GHz of the jet in the quasar 3C 273 are presented. In addition to the compact core region, two emission regions can be identified with features seen at lower frequencies; they separate from the core with constant speeds of 0.65 + or - 0.09 and 0.92 + or - 0.11 mas/yr, corresponding to apparent superluminal motion of 4.3 + or - 0.3c and 6.1 + or - 0.3c (for Ho = 100 km/s Mpc, qo = 0.5). The core region brightened at about the estimated epoch of zero separation for the latest superluminal component, suggesting a causal relationship. The curved ridge line of the jet smoothly extends inward towards the core, although no pronounced bends in the range of core distance 0.5-2.5 mas are seen. No significant evidence is found against a common path of subsequent superluminal features. An apparent frequency dependence in the position of one superluminal feature tentatively suggests that opacity effects across the jet direction are present. The results are consistent with an interpretation of the superluminal features as shocks in an underlying relativistic flow, although alternative explanations cannot be ruled out. 43 refs.

  6. An Overview of the 3C-STAR project

    NASA Astrophysics Data System (ADS)

    Zhang, Y.

    2009-04-01

    Over the past three decades, city clusters have played a leading role in the economic growth of China, owing to their collective economic capacity and interdependency. However, pollution prevention lags behind the economic boom, led to a general decline in air quality in city clusters. As a result, industrial emissions and traffic exhausts together contribute to high levels of ozone (O3) and fine particulate matter (PM2.5) pollution problems ranging from urban to regional scale. Such high levels of both primary and secondary airborne pollutants lead to the development of a (perhaps typically Chinese) "air pollution complex" concept. Air pollution complex is particularly true and significant in Beijing-Tianjin area, Pearl River Delta (PRD) and Yangtze River Delta. The concurrent high concentrations of O3 and PM2.5 in PRD as well as in other China city clusters have led to rather unique pollution characteristics due to interactions between primary emissions and photochemical processes, between gaseous compounds and aerosol phase species, and between local and regional scale processes. The knowledge and experience needed to find solutions to the unique pollution complex in China are still lacking. Starting from 2007, we launch a major project "Synthesized Prevention Techniques for Air Pollution Complex and Integrated Demonstration in Key City-Cluster Region" (3C-STAR) to address those problems scientifically and technically. The purpose of the project is to build up the capacity of regional air pollution control and to establish regional coordination mechanism for joint implementation of pollution control. The project includes a number of key components technically: regional air quality monitoring network and super-sites, regional dynamic emission inventory of multi-pollutants, regional ensemble air quality forecasting model system, and regional management system supported by decision making platform. The 3C-STAR project selected PRD as a core area to have technical

  7. Glucocorticoid receptor gene (NR3C1) methylation following stressful events between birth and adolescence. The TRAILS study.

    PubMed

    van der Knaap, L J; Riese, H; Hudziak, J J; Verbiest, M M P J; Verhulst, F C; Oldehinkel, A J; van Oort, F V A

    2014-04-08

    Stress early in life is a known risk factor for the development of affective disorders later in life. Epigenetic mechanisms, such as DNA methylation, may have an important role in mediating that risk. Recent epigenetic research reported on the long-term relationship between traumatic stress in childhood and DNA methylation in adulthood. In this study, we examined the impact of various types of stress (perinatal stress, stressful life events (SLEs) and traumatic youth experiences) on methylation of the glucocorticoid receptor gene (NR3C1) in the blood of a population sample of 468 adolescents (50.4% female, mean age 16.1 years). Second, we determined whether stress at different ages was associated with higher NR3C1 methylation. NR3C1 methylation rates were higher after exposure to SLEs and after exposure to traumatic youth experiences. NR3C1 methylation in adolescence was not higher after exposure to perinatal stress. Experience of SLEs in adolescence was associated with a higher NR3C1 methylation, independently of childhood SLEs. We demonstrate that not only traumatic youth experiences but also (more common) SLEs are associated with higher NR3C1 methylation. In addition, our findings underline the relevance of adolescent stress for epigenetic changes in the NR3C1 gene.

  8. Multiwavelength and polarimetric analysis of the flat spectrum radio quasars 3C 273 and 3C 279

    NASA Astrophysics Data System (ADS)

    Fernandes, Sunil Anthony

    This dissertation presents results of multiwavelength analyses of 3C 273 and 3C 279. The main goals were to identify the gamma-ray emission region and dominant high-energy emission processes. Our methodology consisted of analyzing light curves from radio to gamma-rays over 6 - 8 years and polarimetric, spectral and line emission behavior. In 3C 279, we found that the emission from millimeter to ultraviolet was simultaneous and therefore co-spatial. We identified two active states where different high-energy emission processes were dominant. We found multiwavelength flaring events consistent with component ejections and shocks. We proposed that the gamma-ray emission region changed over time based on observations of both simultaneous and delayed gamma-rays emission with respect to low-energy emission during different time-frames. In 3C 273, we identified a non-thermal flare related to a component ejection and a thermal flare related to accretion. From reverberation mapping we found that the broad line region dynamical behavior over time possibly affects the derived supermassive black hole mass. In both objects we found that the gamma-ray spectral index was variable, and a trend of harder spectral index with higher gamma-ray luminosity. From the identification of different dominant high-energy emission processes, we concluded that the dominant high-energy emission mechanism changes with time. Overall, we concluded that similar results from both objects points to behavior that is potentially common to flat spectrum radio quasars. Increasing the sample size of objects analyzed with similar methodologies will provide more results to confirm or refine our conclusions.

  9. Multiwavelength and Polarimetric Analysis of the Flat Spectrum Radio Quasars 3C 273 and 3C 279

    NASA Astrophysics Data System (ADS)

    Fernandes, Sunil; Patiño-Álvarez, Victor; Chavushyan, Vahram; Schlegel, Eric M.; Lopez-Rodriguez, Enrique; León-Tavares, Jonathan; Carrasco, Luis; Valdés, José; Carramiñana, Alberto

    2017-01-01

    This poster presents results of multiwavelength analyses of 3C 273 and 3C 279. The main goals were to identify the gamma-ray emission region and dominant high-energy emission processes. Our methodology consisted of analyzing light curves from radio to gamma-rays over 6 - 8 years and polarimetric, spectral and line emission behavior.In 3C 279, we found that the emission from millimeter to ultraviolet was simultaneous and therefore co-spatial. We identified two active states where different high-energy emission processes were dominant. We found multiwavelength flaring events consistent with component ejections and shocks. We proposed that the gamma-ray emission region changed over time based on observations of both simultaneous and delayed gamma-rays emission with respect to low-energy emission during different time-frames.In 3C 273, we identified a non-thermal flare related to a component ejection and a thermal flare related to accretion. From reverberation mapping we found that the broad line region dynamical behavior over time possibly affects the derived supermassive black hole mass.In both objects we found that the gamma-ray spectral index was variable, and a trend of harder spectral index with higher gamma-ray luminosity. From the identification of different dominant high-energy emission processes, we concluded that the dominant high-energy emission mechanism changes with time. Overall, we concluded that similar results from both objects points to behavior that is potentially common to flat spectrum radio quasars. Increasing the sample size of objects analyzed with similar methodologies will provide more results to confirm or refine our conclusions.

  10. Multiwavelength Observations of 3C 66A in 2003 -- 2004

    NASA Astrophysics Data System (ADS)

    Böttcher, M.

    2006-07-01

    The BL Lac object 3C 66A was the target of an extensive multiwavelength campaign from July 2003 through April 2004. Radio, infrared, and optical observations were carried out by the WEBT-ENIGMA collaboration. At higher energies, 3C 66A was observed in X-rays (RXTE), and at very-high-energy (VHE) γ-rays (STACEE, VERITAS). In addition, the source has been observed with the VLBA at 9 epochs throughout the period September 2003 -- December 2004, including 3 epochs contemporaneous with the core campaign. The source was in an optically bright state, with several bright flares on time scales of several days and microvariability with flux changes of ˜ 5 % on time scales as short as ˜ 2 hr. Spectral variability indicating a softening throughout both the rising and decaying phases of flares, has been found. The spectral energy distribution (SED) indicates a ν Fν peak in the optical regime. The 3 -- 10 keV X-ray flux of 3C 66A during the core campaign was historically high and its spectrum very soft, indicating that the low-frequency component of the broadband SED extends beyond ˜ 10 keV. No significant X-ray flux and/or spectral variability was detected. STACEE and Whipple observations provided upper flux limits at > 150 GeV and > 390 GeV, respectively. The 22 and 43 GHz VLBA data indicate a rather smooth jet with only moderate internal structure. Evidence for superluminal motion (8.5 ± 5.6 h-1 c) was found in only one out of 6 components, while all other components are consistent with 0 proper motion. The radial brightness profile suggests a magnetic field decay ∝ r-1 and, thus, a predominantly perpendicular magnetic field orientation.

  11. Optical flare of the Quasar 3C279

    NASA Astrophysics Data System (ADS)

    Jorstad, Svetlana; Savchenko, Sergey

    2017-02-01

    The quasar 3C279 shows significant activity at optical wavelengths. According to our observations at the Perkins telescope of Lowell Obs. (Flagstaff, AZ) on February 23 R band magnitude of the quasar reached 14.088+-0.004 with the degree of polarization P=8.82+-0.11%, while observations at the AZT-8 telescope of Crimean Astrophysical Obs. show that the source was more than 1 mag fainter on February 20, R=15.237+-0.005, with P=6.45+0.88%.

  12. Discovery of an optical synchrotron jet in 3C 264

    NASA Technical Reports Server (NTRS)

    Crane, P.; Peletier, R.; Baxter, D.; Sparks, W. B.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.; Deharveng, J. M.; Disney, M. J.

    1993-01-01

    Observations with the Faint Object Camera on board the Hubble Space Telescope have revealed a new optical jet in the core of the elliptical galaxy NGC 3862 (3C 264). Morphologically, this jet is similar to the synchrotron jets seen in other galaxies, as it shows knots and bifurcations. The optical spectral index is also similar to that found in other jets. Thus, the nucleus of NGC 3862 appears to contain the fifth known example of an optical synchrotron jet. Since NGC 3862 is a typical radio-loud elliptical galaxy, it seems likely that many nonthermal jets found in the radio continuum may also have optical counterparts.

  13. Bcl11a (Ctip1) Controls Migration of Cortical Projection Neurons through Regulation of Sema3c.

    PubMed

    Wiegreffe, Christoph; Simon, Ruth; Peschkes, Katharina; Kling, Carolin; Strehle, Michael; Cheng, Jin; Srivatsa, Swathi; Liu, Pentao; Jenkins, Nancy A; Copeland, Neal G; Tarabykin, Victor; Britsch, Stefan

    2015-07-15

    During neocortical development, neurons undergo polarization, oriented migration, and layer-type-specific differentiation. The transcriptional programs underlying these processes are not completely understood. Here, we show that the transcription factor Bcl11a regulates polarity and migration of upper layer neurons. Bcl11a-deficient late-born neurons fail to correctly switch from multipolar to bipolar morphology, resulting in impaired radial migration. We show that the expression of Sema3c is increased in migrating Bcl11a-deficient neurons and that Bcl11a is a direct negative regulator of Sema3c transcription. In vivo gain-of-function and rescue experiments demonstrate that Sema3c is a major downstream effector of Bcl11a required for the cell polarity switch and for the migration of upper layer neurons. Our data uncover a novel Bcl11a/Sema3c-dependent regulatory pathway used by migrating cortical neurons.

  14. A high state of activity of the quasar 3C454.3

    NASA Astrophysics Data System (ADS)

    Jorstad, S.; Larionov, V.; Mokrushina, A.; Troitsky, I.; Morozova, D.

    2015-08-01

    The quasar 3c454.3 shows a new state of high activity. According to the Fermi LAT Collaboration it is brighter than 1.0e-05 ph/cm2/sec at gamma-rays: TITLE: GCN/FERMI NOTICE NOTICE_DATE: Fri 21 Aug 15 14:47:48 UT NOTICE_TYPE: Fermi-LAT Monitor SOURCE_OBJ: 3C454.3 CURR_FLUX: 1.40e-05 +- 6.09e-07 [ph/cm2/sec] BASE_FLUX: 2.60e-06 +- 4.59e-07 [ph/cm2/sec] The BU group monitors the source with the VLBA at 43 GHz.

  15. Multiwavelength variability analysis of the FSRQ 3C 279

    NASA Astrophysics Data System (ADS)

    Patiño-Álvarez, V.; Chavushyan, V.; León-Tavares, J.; Carramiñana, A.; Carrasco, L.; Fernandes, S.; Schlegel, E. M.; López-Rodríguez, E.

    2015-03-01

    We present a multifrequency analysis of the variability in the flat-spectrum radio quasar 3C 279 from 2008 to 2014. Our multiwavelength dataset includes gamma-ray data from Fermi/LAT (Abdo et al. 2009), observations in 1mm from SMA (Gurwell et al. 2007), Near Infrared from OAGH (Carramiñana & Carrasco 2009) and SMARTS (Bonning et al. 2012); optical V band from the Steward Observatory (Smith et al. 2009) and SMARTS; optical spectra from OAGH (Patiño-Álvarez et al. 2013) and the Steward Observatory; and polarization spectra from the Steward Observatory. The light curves are shown in Fig. 1. Six out of seven optical activity periods identified within our dataset show clear counterparts in mm, NIR and gamma-rays, however, the late 2011 - early 2012 optical flare does not have a counterpart in the GeV regime. In this contribution, we discuss the flaring evolution of 3C 279 and speculate about the production of the anomalous activity period.

  16. A Radio-Jet-Galaxy Interaction in 3C441

    NASA Technical Reports Server (NTRS)

    Lacy, Mark; Rawlings, Steve; Blundell, Katherine M.; Ridgway, Susan E.

    1998-01-01

    Multi-wavelength imaging and spectroscopy of the zeta = 0.708 radio galaxy 3C441 and a red aligned optical/infrared component are used to show that the most striking aspect of the radio-optical "alignment effect" in this object is due to the interaction of the radio jet with a companion galaxy in the same group or cluster. The stellar population of the red aligned continuum component is predominately old, but with a small post-starburst population superposed, and it is surrounded by a low surface- brightness halo, possibly a face-on spiral disc. The [OIII]500.7/[OII]372.7 emission line ratio changes dramatically from one side of the component to the other, with the low-ionisation material apparently having passed through the bow shock of the radio source and been compressed. A simple model for the interaction is used to explain the velocity shifts in the emission line gas, and to predict that the ISM of the interacting galaxy is likely to escape once the radio source bow shock has passed though. We also discuss another, much fainter, aligned component, and the sub-arcsecond scale alignment of the radio source host galaxy. Finally we comment on the implications of our explanation of 3C441 for theories of the alignment effect.

  17. The Warped Nuclear Disk of Radio Galaxy 3C 449

    NASA Astrophysics Data System (ADS)

    Tremblay, G. R.; Quillen, A. C.; Floyd, D. J. E.; Noel-Storr, J.; Baum, S. A.; Axon, D. J.; O'Dea, C. P.; Chiaberge, M.; Macchetto, F. D.; Sparks, W. B.; Miley, G. K.; Capetti, A.; Madrid, J. P.; Perlman, E.

    2005-12-01

    Among radio galaxies containing nuclear dust disks, the bipolar jet axis is generally expected to be perpendicular to the disk major axis. However, the FR I radio source 3C 449, possessing a nearly parallel jet/disk orientation on the sky, is an extreme example of a system that does not conform to this expectation. We examine the 600 pc dusty disk in this galaxy with images from the Hubble Space Telescope. We find that a colormap of the disk exhibits a twist in its isocolor contours (isochromes). We model the colormap by integrating galactic starlight through an absorptive disk, and find that the anomalous twist in the isochromes can be reproduced in the model with a vertically thin, warped disk. The model predicts that the disk is nearly perpendicular to the jet axis within 100 pc of the nucleus. We discuss physical mechanisms capable of causing such a warp. We show that a torque on the disk arising from a possible binary black hole in the AGN or radiation pressure from the AGN causes precession on a timescale that is too long to generate such a warp. However, we estimate that the pressure in the X-ray emitting interstellar medium is large enough to perturb the disk. The warped disk in 3C 449 may be a new manifestation of feedback from an active galactic nucleus.

  18. 17 CFR 270.3c-4 - Definition of “common trust fund” as used in section 3(c)(3) of the Act.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 1940 § 270.3c-4 Definition of “common trust fund” as used in section 3(c)(3) of the Act. The term common trust fund as used in section 3(c)(3) of the Act (15 U.S.C. 80a-3(c)(3)) shall include a common...; Provided, That: (a) The common trust fund is operated in compliance with the same State and...

  19. Porcine Epidemic Diarrhea Virus 3C-Like Protease Regulates Its Interferon Antagonism by Cleaving NEMO

    PubMed Central

    Wang, Dang; Fang, Liurong; Shi, Yanling; Zhang, Huan; Gao, Li; Peng, Guiqing; Chen, Huanchun; Li, Kui

    2015-01-01

    ABSTRACT Porcine epidemic diarrhea virus (PEDV) is an enteropathogenic coronavirus causing lethal watery diarrhea in piglets. Since 2010, a PEDV variant has spread rapidly in China, and it emerged in the United States in 2013, posing significant economic and public health concerns. The ability to circumvent the interferon (IFN) antiviral response, as suggested for PEDV, promotes viral survival and regulates pathogenesis of PEDV infections, but the underlying mechanisms remain obscure. Here, we show that PEDV-encoded 3C-like protease, nsp5, is an IFN antagonist that proteolytically cleaves the nuclear transcription factor kappa B (NF-κB) essential modulator (NEMO), an essential adaptor bridging interferon-regulatory factor and NF-κB activation. NEMO is cleaved at glutamine 231 (Q231) by PEDV, and this cleavage impaired the ability of NEMO to activate downstream IFN production and to act as a signaling adaptor of the RIG-I/MDA5 pathway. Mutations specifically disrupting the cysteine protease activity of PEDV nsp5 abrogated NEMO cleavage and the inhibition of IFN induction. Structural analysis suggests that several key residues outside the catalytic sites of PEDV nsp5 probably impact NEMO cleavage by modulating potential interactions of nsp5 with their substrates. These data show that PEDV nsp5 disrupts type I IFN signaling by cleaving NEMO. Previously, we and others demonstrated that NEMO is also cleaved by 3C or 3C-like proteinases of picornavirus and artertivirus. Thus, NEMO probably represents a prime target for 3C or 3C-like proteinases of different viruses. IMPORTANCE The continued emergence and reemergence of porcine epidemic diarrhea virus (PEDV) underscore the importance of studying how this virus manipulates the immune responses of its hosts. During coevolution with its hosts, PEDV has acquired mechanisms to subvert host innate immune responses for its survival advantage. At least two proteins encoded by PEDV have been identified as interferon (IFN

  20. Angular Structure of FrII Radio Sources 3C169.1 and 3C263 at Decameter Wavelengths

    NASA Astrophysics Data System (ADS)

    Vashchishin, R. V.; Shepelev, V. A.; Lozinskyy, A. B.; Lytvynenko, O. A.

    The radio galaxy 3C169.1 and the quasar 3C263, located at nearly the same distance with red shift z>0.6, have similar morphological and spectral characteristics. The maps of the sources obtained at decimeter and centimeter wavelengths have shown they are FRII radio sources with steep spectra and approximately equal angular sizes. The very first investigation of the sources structure at decameter wavelengths is presented in the report. Observations were made using a network of the URAN decameter interferometers with baselines 42 to 950 km and with maximum angular resolution of arcsec order of magnitude. The models of the image of these sources based on visibility functions measured have been obtained at frequencies of 20 and 25 MHz. They were composed of elliptical components with Gaussian brightness distribution. To facilitate the comparison of these lowfrequency models with high-frequency radio images, the latter were converted to the similar models by fitting the Gaussian components to lobes and hot spots selected at the maps. Comparison of the models revealed changes in a structure of the sources caused by the frequency decrease.

  1. The Galactic Magnetic Field in the Quasar 3C 216

    NASA Astrophysics Data System (ADS)

    Venturi, T.; Taylor, G. B.

    1999-11-01

    Multifrequency polarimetric observations made with the Very Long Baseline Array of the quasar 3C 216 reveal the presence of Faraday rotation measures (RMs) in excess of 2000 rad m-2 in the source rest frame in the arc of emission located at ~140 mas from the core. Rotation measures in the range -300 to +300 rad m-2 are detected in the inner 5 mas (~30 pc). While the rotation measure near the core can be explained as being caused by a magnetic field in the narrow-line region, we favor the interpretation for the high RM in the arc that it is caused by a ``local'' Faraday screen produced in a shock where the jet is deflected by the interstellar medium of the host galaxy. Our results indicate that a galactic magnetic field of the order of ~50 μG on a scale greater than 100 pc must be present in the ambient medium.

  2. 3C 279 - The case for 'superluminal' expansion

    NASA Technical Reports Server (NTRS)

    Cotton, W. D.; Counselman, C. C., III; Geller, R. B.; Shapiro, I. I.; Wittels, J. J.; Hinteregger, H. F.; Knight, C. A.; Rogers, A. E. E.; Whitney, A. R.; Clark, T. A.

    1979-01-01

    The compact extragalactic radio source 3C 279 was observed with the Haystack-Goldstone interferometer (wavelength approximately 3.8 cm) during six separate sessions spread between October 1970 and April 1972. The fringe amplitudes from each of these observation sessions were consistent with a two-component model of the brightness distribution of the source. The position angle of the line joining the components remained at 38 + or - 2 deg, while the angular separation between the components increased nearly linearly at the rate of 0.5 + or 0.1 milliarcsec/yr during this period. The corresponding apparent expansion speed is (21 + or - 4)c, for H = 50 km/s per Mpc and q = 0.05

  3. Multifrequency observations of the superluminal quasar 3C 345

    NASA Technical Reports Server (NTRS)

    Bregman, J. N.; Glassgold, A. E.; Huggins, P. J.; Neugebauer, G.; Soifer, B. T.; Matthews, K.; Roellig, T. P. L.; Bregman, J. D.; Witteborn, F. C.; Lester, D. F.

    1986-01-01

    Attention is given to the continuum properties of the superluminal quasar 3C 345, on the basis of radio, optical, IR, and X-ray frequency monitorings, as well as by means of simultaneous multifrequency spectra extending from the radio through the X-ray bands. Radio outbursts, which appear to follow IR-optical outbursts by about one year, first occur at the highest frequencies, as expected from optical depth effects; the peak flux is nevertheless often reached at several frequencies at once. The beginning of outbursts, as defined by mm-measurements, corresponds to the appearance of the three known 'superluminal' components. An increase in the X-ray flux during 1979-1980 corresponds to increased radio flux, while the IR flux changes in the opposite sense.

  4. Extended Ly-alpha emission associated with 3C 294

    NASA Technical Reports Server (NTRS)

    Mccarthy, Patrick J.; Spinrad, Hyron; Dickinson, Mark; Van Breugel, Wil; Liebert, James; Djorgovski, S.; Eisenhardt, Peter

    1990-01-01

    Optical, IR, and radio observations of the powerful radio source 3C 294, which is surrounded by a large cloud of ionized gas, are presented. The galaxy is faint in the rest-frame UV, yet has a near-IR luminosity that is typical of radio galaxies at redshifts of order two. In contrast to the large extent of the ionized gas, the K-band image is quite compact. The emission-line cloud is closely aligned with the radio source axis and has an ionization state indicative of ionization by a nonstellar source. The velocity field of the gas has both large ordered motions and large turbulent components. The total mass required to keep the gas bound to the system is comparable to present-day massive galaxies and their halos. The velocity fields of the high-ionization lines are systematically different from Ly-alpha in a manner that is not easily understood.

  5. Trisodium citrate, Na3(C6H5O7)

    PubMed Central

    Rammohan, Alagappa; Kaduk, James A.

    2016-01-01

    The crystal structure of anhydrous tris­odium citrate, Na3(C6H5O7), has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory (DFT). There are two independent five-coordinate Na+ and one six-coordinate Na+ cations in the asymmetric unit. The [NaO5] and [NaO6] polyhedra share edges and corners to form a three-dimensional framework. There are channels parallel to the a and b axes in which the remainder of the citrate anions reside. The only hydrogen bonds are an intra­molecular one between the hy­droxy group and one of the terminal carboxyl­ate O atoms and an intermolecular one between a methylene group and the hydroxyl O atom. PMID:27308044

  6. NIR Flaring of the Quasar 3C454.3

    NASA Astrophysics Data System (ADS)

    Carrasco, L.; Carramiñana, A.; Recillas, E.; Escobedo, G.; Porras, A.; Mayya, Y. D.; Valdes, J. R.

    2010-10-01

    We report the ongoing NIR flare of the quasar 3C454.3, also known as [HB89]2251+158. It is likely associated with a gamma ray source CGRaBSJ2253+1608 and the radio source WMAP055. It is an intermediate redshift FRSQSO Z=0.859 (RA=22:53:57.75, Dec=+16:08:53.6(J2000). On October 31th,2010 (JD 2455500.781451), we determined the NIR flux from this object to correspond to H = 11.190 +/- 0.03, 0.63mag brighter than it was two days earlier(JD 2455498.821166) when we determined it to have H = 11.820 +/- 0.03.

  7. Extended component in the quasar 3C 380

    NASA Astrophysics Data System (ADS)

    Megn, A. V.; Rashkovskiĭ, S. L.; Shepelev, V. A.; Inyutin, G. A.; Brazhenko, A. I.; Bulatsen, V. G.; Vashchishin, R. V.; Koshevoĭ, V. V.; Lozinskiĭ, A. B.; Kassim, N. E.

    2006-09-01

    Results of radio interferometric observations of the quasar 3C 380 carried out on the URAN interferometers at decameter wavelengths and on the aperture synthesis radio telescope VLA at meter wavelengths are reported. The spectral index of an extended lobe about 10″ in size is considerably lower than at decimeter wavelengths. Below ˜ 100 MHz, the ratio of the emission from the compact components associated with hot spots in the radio lobe to the total flux of the source decreases due to synchrotron self-absorption at hot spots, whose flux density at 20 MHz does not exceed 65 Jy. A halo with a full width at a half-maximum of about 40″ was detected, whose angular extent considerably exceeds the total source size measured at shorter wavelengths.

  8. Structural Variability of 3C 111 on Parsec Scales

    NASA Technical Reports Server (NTRS)

    Grossberger, C.; Kadler, M.; Wilms, J.; Muller, C.; Beuchert, T.; Ros, E.; Ojha, R.; Aller, M.; Aller, H.; Angelakis, E.; Fuhrmann, L.; Nestoras, I.; Schmidt, R.; Zensus, J. A.; Krichbaum, T. P.; Ungerechts, H.; Sievers, A.; Riquelme, D.

    2011-01-01

    We discuss the parsec-scale structural variability of the extragalactic jet 3C 111 related to a major radio flux density outburst in 2007, The data analyzed were taken within the scope of the MOJAVE, UMRAO, and F-GAMMA programs, which monitor a large sample of the radio brightest compact extragalactic jets with the VLBA, the University of Michigan 26 m, the Effelsberg 100 m, and the IRAM 30 m radio telescopes. The analysis of the VLBA data is performed by fitting Gaussian model components in the visibility domain, We associate the ejection of bright features in the radio jet with a major flux-density outburst in 2007, The evolution of these features suggests the formation of a leading component and multiple trailing components

  9. Diffuse radio emission around FR II sources as exemplified by 3C452

    NASA Astrophysics Data System (ADS)

    Wiita, Paul J.; Sirothia, S. K.; Gopal-Krishna, ..

    2014-01-01

    We have discovered a pair of megaparsec size radio lobes of extremely steep spectrum straddling the well-known classical double radio source 3C452. For the past several decades 3C452 has been regarded as a textbook example of an edge-brightened double radio source of Fanaroff-Riley type II (FR II) but we show it to be a bonafide "double-double" radio galaxy (DDRG). The inner double fed by the jets has evolved into a perfectly normal FR II radio source. Thus, 3C452 presents a uniquely robust example of recurrent nuclear activity in which the restarted jets are expanding non-relativistically within the relic synchrotron plasma from an earlier active phase. This situation contrasts markedly with the strikingly narrow inner doubles observed in a few other DDRGs that have been interpreted in terms of compression of the synchrotron plasma of the relic outer lobes at the relativistic bow-shocks driven by the near ballistic propagation of the two inner jets through the relic plasma. We also present additional examples of the occurrence of faded outer lobes around well defined FRII sources, using our deep GMRT images at meter wavelengths processed with AIPS++ software. We also examine the statistics of the occurrence of such sources using a flux density limited sample. A key ramification of our findings are that they caution against the use of FR II classical double radio sources for testing cosmological models and unification schemes for active galactic nuclei.

  10. A short-time fading study of Al2O3:C

    NASA Astrophysics Data System (ADS)

    Nascimento, L. F.; Vanhavere, F.; Silva, E. H.; Deene, Y. De

    2015-01-01

    This paper studies the short-time fading from Al2O3:C by measuring optically stimulated luminescence (OSL) signals (Total OSL: TOSL, and Peak OSL: POSL) from droplets and Luxel™ pellets. The influence of various bleaching regimes (blue, green and white) and light power is compared. The fading effect is the decay of the OSL signal in the dark at room temperature. Al2O3:C detectors were submitted to various bleaching regimes, irradiated with a reference dose and read out after different time spans. Investigations were carried out using 2 mm size droplet detectors, made of thin Al2O3:C powder mixed with a photocured polymer. Tests were compared to Luxel™-type detectors (Landauer Inc.). Short-time post-irradiation fading is present in OSL results (TOSL and POSL) droplets for time spans up to 200 s. The effect of short-time fading can be lowered/removed when treating the detectors with high-power and/or long time bleaching regimes; this result was observed in both TOSL and POSL from droplets and Luxel™.

  11. The second decade of 3C technologies: detailed insights into nuclear organization

    PubMed Central

    Denker, Annette; de Laat, Wouter

    2016-01-01

    The relevance of three-dimensional (3D) genome organization for transcriptional regulation and thereby for cellular fate at large is now widely accepted. Our understanding of the fascinating architecture underlying this function is based on microscopy studies as well as the chromosome conformation capture (3C) methods, which entered the stage at the beginning of the millennium. The first decade of 3C methods rendered unprecedented insights into genome topology. Here, we provide an update of developments and discoveries made over the more recent years. As we discuss, established and newly developed experimental and computational methods enabled identification of novel, functionally important chromosome structures. Regulatory and architectural chromatin loops throughout the genome are being cataloged and compared between cell types, revealing tissue invariant and developmentally dynamic loops. Architectural proteins shaping the genome were disclosed, and their mode of action is being uncovered. We explain how more detailed insights into the 3D genome increase our understanding of transcriptional regulation in development and misregulation in disease. Finally, to help researchers in choosing the approach best tailored for their specific research question, we explain the differences and commonalities between the various 3C-derived methods. PMID:27340173

  12. Recombining plasma in the gamma-ray-emitting mixed-morphology supernova remnant 3C 391

    SciTech Connect

    Ergin, T.; Sezer, A.; Saha, L.; Majumdar, P.; Chatterjee, A.; Bayirli, A.; Ercan, E. N.

    2014-07-20

    A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MCs) has been discovered to be strong GeV gamma-ray emitters by the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite have revealed that some of these interacting gamma-ray-emitting SNRs, such as IC443, W49B, W44, and G359.1-0.5, have overionized plasmas. 3C 391 (G31.9+0.0) is another Galactic MM SNR interacting with MCs. It was observed in GeV gamma rays by Fermi-LAT as well as in the 0.3-10.0 keV X-ray band by Suzaku. In this work, 3C 391 was detected in GeV gamma rays with a significance of ∼18σ and we showed that the GeV emission is point-like in nature. The GeV gamma-ray spectrum was shown to be best explained by the decay of neutral pions assuming that the protons follow a broken power-law distribution. We revealed radiative recombination structures of silicon and sulfur from 3C 391 using Suzaku data. In this paper, we discuss the possible origin of this type of radiative plasma and hadronic gamma rays.

  13. Spectroscopy of new Sm(III) orange emitting phosphors of the type Na[Sm(SP)4], Na[Sm(WO)4] (where SP = C6H5S(O)2NP(O)(OCH3)2-; WO = CCl3C(O)NP(O)(OCH3)2-) and the polymeric materials obtained on their base

    NASA Astrophysics Data System (ADS)

    Cybińska, Joanna; Guzik, Małgorzata; Gerasymchuk, Yuriy; Trush, Victor A.; Lisiecki, Radosław; Legendziewicz, Janina

    2017-01-01

    Among a wide variety of solid state materials lanthanide beta-diketonates, their derivatives and polymeric materials based on them have become essential for advance technologies. Thus they are the subject of extensive spectroscopic studies. Using appropriate lanthanide chelates for the emission layer one can achieve electroluminescence covering the spectrum from blue to infrared. Moreover, compounds with proper chromophores can be the best way to excite and enhance the emission although the f-f transitions have forbidden character. Two types of new Sm(III) chelates; phosphoro and sulfono-derivatives of beta-diketones and polymeric materials on their base were obtained and characterized by the high resolution photoluminescence spectroscopy at 293, 77 and 4 K, as well as by luminescence decay times. Those new type of phosphors shows strong orange emission after excitation at 404 nm Sm(III) states and 280 nm ligand bands. Radiative transition probabilities were calculated from absorption spectra and Judd- Ofelt parameters evaluated. Effects of the temperature, rigidity of polymeric lattice and the energy of excitation on intensities of the Sm(III) fluorescence were studied. The paths of energy transfer are analysed and mechanism of this process is proposed.

  14. Crystal and electronic structure of the novel layered rare earth metal boride carbide Gd[sub 2]B[sub 3]C[sub 2

    SciTech Connect

    Wiitkar, F.; Halet, J.F.; Saillard, J.Y. ); Rogl, P. ); Bauer, J. )

    1994-03-30

    The crystal structure of Gd[sub 2]B[sub 3]C[sub 2] has been determined from single-crystal X-ray counter data. Gd[sub 2]B[sub 3]C[sub 2] crystallizes in a unique structure type with the orthorhombic space group Cmmm-D[sub 2h[sup 19

  15. Two-dimensional titanium carbonitrides and their hydroxylated derivatives: Structural, electronic properties and stability of MXenes Ti3C2-xNx(OH)2 from DFTB calculations

    NASA Astrophysics Data System (ADS)

    Enyashin, A. N.; Ivanovskii, A. L.

    2013-11-01

    The structural, electronic properties and stability of the new MXene compounds—two-dimensional pristine carbonitrides Ti3C2-xNx and their hydroxylated derivatives Ti3C2-xNx(OH)2 are studied by means of DFTB calculations. The genesis of the properties is discussed in the sequence: binary MXenes Ti3C2 (Ti3N2)→hydroxylated forms Ti3C2(OH)2 (Ti3N2(OH)2)→pristine MXene Ti3C2-xNx→hydroxylated Ti3C2-xNx(OH)2. All examined materials are metallic-like. The most favorable type of OH-covering is presented by the occupation of the hollow sites between three neighboring carbon (nitrogen) atoms. Two-dimensional MXene carbonitrides with random distribution of C and N atoms are found to be thermodynamically more favorable.

  16. S3C: EBT Steady-State Shooting code description and user's guide

    SciTech Connect

    Downum, W.B.

    1983-09-01

    The Oak Ridge National Laboratory (ORNL) one-dimensional (1-D) Steady-State Shooting code (S3C) for ELMO Bumpy Torus (EBT) plasmas is described. Benchmark calculations finding the steady-state density and electron and ion temperature profiles for a known neutral density profile and known external energy sources are carried out. Good agreement is obtained with results from the ORNL Radially Resolved Time Dependent 1-D Transport code for an EBT-Q type reactor. The program logic is described, along with the physics models in each code block and the variable names used. Sample input and output files are listed, along with the main code.

  17. Organocatalyzed enantioselective synthesis of 6-amino-5-cyanodihydropyrano[2,3-c]pyrazoles

    PubMed Central

    Gogoi, Sanjib; Zhao, Cong-Gui

    2009-01-01

    The first enantioselective synthesis of biologically active 6-amino-5-cyanodihydropyrano[2,3-c]pyrazoles has been achieved through a cinchona alkaloid-catalyzed tandem Michael addition and Thorpe-Ziegler type reaction between 2-pyrazolin-5-ones and benzylidenemalononitriles. The reaction may also be carried out in a three-component or a four-component fashion via the in situ formation of these two components from simple and readily available starting materials. The desired products were obtained in excellent yields with mediocre to excellent enantioselectivities (up to >99% ee). PMID:19915654

  18. Broad-Spectrum Antivirals against 3C or 3C-Like Proteases of Picornaviruses, Noroviruses, and Coronaviruses

    PubMed Central

    Kim, Yunjeong; Lovell, Scott; Tiew, Kok-Chuan; Mandadapu, Sivakoteswara Rao; Alliston, Kevin R.; Battaile, Kevin P.; Groutas, William C.

    2012-01-01

    Phylogenetic analysis has demonstrated that some positive-sense RNA viruses can be classified into the picornavirus-like supercluster, which includes picornaviruses, caliciviruses, and coronaviruses. These viruses possess 3C or 3C-like proteases (3Cpro or 3CLpro, respectively), which contain a typical chymotrypsin-like fold and a catalytic triad (or dyad) with a Cys residue as a nucleophile. The conserved key sites of 3Cpro or 3CLpro may serve as attractive targets for the design of broad-spectrum antivirals for multiple viruses in the supercluster. We previously reported the structure-based design and synthesis of potent protease inhibitors of Norwalk virus (NV), a member of the Caliciviridae family. We report herein the broad-spectrum antiviral activities of three compounds possessing a common dipeptidyl residue with different warheads, i.e., an aldehyde (GC373), a bisulfite adduct (GC376), and an α-ketoamide (GC375), against viruses that belong to the supercluster. All compounds were highly effective against the majority of tested viruses, with half-maximal inhibitory concentrations in the high nanomolar or low micromolar range in enzyme- and/or cell-based assays and with high therapeutic indices. We also report the high-resolution X-ray cocrystal structures of NV 3CLpro-, poliovirus 3Cpro-, and transmissible gastroenteritis virus 3CLpro- GC376 inhibitor complexes, which show the compound covalently bound to a nucleophilic Cys residue in the catalytic site of the corresponding protease. We conclude that these compounds have the potential to be developed as antiviral therapeutics aimed at a single virus or multiple viruses in the picornavirus-like supercluster by targeting 3Cpro or 3CLpro. PMID:22915796

  19. 50 CFR Table 3c to Part 680 - Crab Product Codes for Economic Data Reports

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Crab Product Codes for Economic Data Reports 3c Table 3c to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 680, Table 3c Table 3c to Part 680—Crab Product Codes for...

  20. Effluent sampling of Titan 3 C vehicle exhaust

    NASA Technical Reports Server (NTRS)

    Gregory, G. L.; Storey, R. W., Jr.

    1975-01-01

    Downwind in situ ground-level measurements of the exhaust from a Titan 3 C launch vehicle were made during a normal launch. The measurement activity was conducted as part of an overall program to obtain field data for comparison with the multilayer dispersion model currently being used to predict the behavior of rocket vehicle exhaust clouds. All measurements were confined to land, ranging from the launch pad to approximately 2 kilometers downwind from the pad. Measurement systems included detectors for hydrogen chloride (HCl), carbon dioxide (CO2), and particulates (Al2O3). Airborne and ground-based optical systems were employed to monitor exhaust cloud rise, growth, and movement. These measurement systems, located along the ground track (45 deg azimuth from the launch pad) of the exhaust cloud, showed no effluents attributable to the launch. Some hydrogen chloride and aluminum oxide were detected in the surface wind direction (15 deg azimuth) from the pad. Comparisons with the model were made in three areas: (1) assumption of cloud geometry at stabilization; (2) prediction of cloud stabilization altitude; and (3) prediction of the path of cloud travel. In addition, the importance of elemental analyses of the particulate samples is illustrated.

  1. FLASH_TISA_Terra+Aqua_Version3C

    Atmospheric Science Data Center

    2017-03-21

    ... Cloud Particle Phase Cloud Infrared Emissivity Cloud Base Pressure Surface (Radiative) Flux TOA Flux Surface Types Albedo LW Flux Order Data:  Earthdata Search:  Order Data Guide Documents:  ...

  2. Microvariability in the optical polarization of 3C 279

    NASA Astrophysics Data System (ADS)

    Andruchow, I.; Cellone, S. A.; Romero, G. E.; Dominici, T. P.; Abraham, Z.

    2003-10-01

    We present results of a microvariability polarization study in the violently variable quasar 3C279. We have resolved the polarization curves in the V band for this object down to timescales of minutes. We found two main components in the evolution of the degree of linear polarization, one consisting of a flicker with timescales of several tens of minutes and other component with far more significant variations on timescales of a few days. The linear polarization descended from ~ 17% down to ~ 8% in three nights. The polarization angle underwent a sudden change of more that 10 degrees in a few hours, perhaps indicating the injection of a new shock in the jet. The amplitude of the intranight flickering in the degree of polarization is at the level of ~ 1%. These are probably the best sampled polarization data ever obtained for this object. We also performed IR observations and we provide a follow-up of the evolution of this source at such energies after the main polarization outburst. Based on observations made at the Complejo Astronómico El Leoncito, which is operated under agreement between CONICET and the National Universities of La Plata, Córdoba, and San Juan, as well as at the Laboratório Nacional de Astrofísica, LNA-CNPq, Brazil.}\\fnmsep\\thanks{Table 2 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via \\ http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/409/857

  3. Simultaneous Multiwavelength Monitoring of 3C66A

    NASA Technical Reports Server (NTRS)

    Boettcher, M.

    2004-01-01

    The radio-selected BL Lac object 3C66A was the target of an intensive multiwavelength campaign from Sept. 2003 through Feb. 2004. It was monitored by the Whole Earth Blazar Telescope (WEBT) collaboration, in tandem with 20 X-ray monitoring observations by the Rossi X-Ray Timing Explorer (RXTE), VHE gamma-ray observations by STACEE and VERITAS, and long-term monitoring at radio frequencies. In addition. 9 observations using the VLBA are being carried out during the campaign and throughout the year 2004 to follow possible structural changes of the source. 21 pointings with RXTE during the period Sept. 15 - Dec. 27, 2003. All collected data have been fully analyzed, and first results have already been published at the 8th HEAD Meeting in New Orleans, LA, in Sept. 2004, and will also be presented at the 205th AAS Meeting in San Diego, CA, in Jan. 2005. A first Journal paper, to be submitted to the Astrophysical Journal, is currently in preparation, and we plan to have it ready for submission in January 2005. A gradual brightening of the source over the course of the campaign was observed at all optical frequencies, culminating in a very bright flare at the end of January 2004. Optical light curves indicate intraday microvariability on time scales down to about 1.3 hours. No significant color-magnitude correlation for the entire data set was evident, but there is a slight indication of a gradual spectral softening in the optical over the entire duration of multi-day outbursts (in both the rising and decaying phase). The X-ray spectrum is consistent with a power-law with a photon spectral index of approx. 2.1, indicating that the RXTE energy band might be located right at the intersection of the synchrotron and the high-energy emission components. No significant flux or spectral variability at X-ray energies was detected, though there seems to be a trend of very modest brightening in tandem with the optical flux. The first 4 VLBA epochs indicate a rather smooth jet with

  4. DISCOVERY OF GIANT RELIC RADIO LOBES STRADDLING THE CLASSICAL DOUBLE RADIO GALAXY 3C452

    SciTech Connect

    Sirothia, S. K.; Gopal-Krishna; Wiita, Paul J. E-mail: krishna@ncra.tifr.res.in

    2013-03-01

    We report the discovery of a pair of megaparsec size radio lobes of extremely steep spectrum straddling the well-known classical double radio source 3C452. The existence of such fossil lobes was unexpected since for the past several decades this powerful radio galaxy has been regarded as a textbook example of an edge-brightened double radio source of Fanaroff-Riley type II (FR II), which we now show to be a bona fide ''double-double'' radio galaxy (DDRG). Thus, 3C452 presents a uniquely robust example of recurrent nuclear activity in which the restarted jets are expanding non-relativistically within the relic synchrotron plasma from an earlier active phase and hence the inner double fed by them has evolved into a perfectly normal FR II radio source. This situation contrasts markedly with the strikingly narrow inner doubles observed in a few other DDRGs that have been interpreted in terms of compression of the synchrotron plasma of the relic outer lobes at the relativistic bow-shocks driven by the near ballistic propagation of the two inner jets through the relic plasma. A key ramification of this finding is that it cautions against the currently widespread use of FR II classical double radio sources for testing cosmological models and unification schemes for active galactic nuclei.

  5. Electrical activation of nitrogen heavily implanted 3C-SiC(1 0 0)

    NASA Astrophysics Data System (ADS)

    Li, Fan; Sharma, Yogesh; Shah, Vishal; Jennings, Mike; Pérez-Tomás, Amador; Myronov, Maksym; Fisher, Craig; Leadley, David; Mawby, Phil

    2015-10-01

    A degenerated wide bandgap semiconductor is a rare system. In general, implant levels lie deeper in the band-gap and carrier freeze-out usually takes place at room temperature. Nevertheless, we have observed that heavily doped n-type degenerated 3C-SiC films are achieved by nitrogen implantation level of ∼6 × 1020 cm-3 at 20 K. According to temperature dependent Hall measurements, nitrogen activation rates decrease with the doping level from almost 100% (1.5 × 1019 cm-3, donor level 15 meV) to ∼12% for 6 × 1020 cm-3. Free donors are found to saturate in 3C-SiC at ∼7 × 1019 cm-3. The implanted film electrical performances are characterized as a function of the dopant doses and post implantation annealing (PIA) conditions by fabricating Van der Pauw structures. A deposited SiO2 layer was used as the surface capping layer during the PIA process to study its effect on the resultant film properties. From the device design point of view, the lowest sheet resistivity (∼1.4 mΩ cm) has been observed for medium doped (4 × 1019 cm-3) sample with PIA 1375 °C 2 h without a SiO2 cap.

  6. Quantitative Analysis of Intra-chromosomal Contacts: The 3C-qPCR Method.

    PubMed

    Ea, Vuthy; Court, Franck; Forné, Thierry

    2017-01-01

    The chromosome conformation capture (3C) technique is fundamental to many population-based methods investigating chromatin dynamics and organization in eukaryotes. Here, we provide a modified quantitative 3C (3C-qPCR) protocol for improved quantitative analyses of intra-chromosomal contacts. We also describe an algorithm for data normalization which allows more accurate comparisons between contact profiles.

  7. 18 CFR 3c.3 - Reporting fraud, waste, abuse, and corruption and cooperation with official inquiries.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., abuse, and corruption and cooperation with official inquiries. 3c.3 Section 3c.3 Conservation of Power... OF CONDUCT § 3c.3 Reporting fraud, waste, abuse, and corruption and cooperation with official..., abuse, and corruption in Commission programs, including on the part of Commission employees,...

  8. 18 CFR 3c.3 - Reporting fraud, waste, abuse, and corruption and cooperation with official inquiries.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., abuse, and corruption and cooperation with official inquiries. 3c.3 Section 3c.3 Conservation of Power... OF CONDUCT § 3c.3 Reporting fraud, waste, abuse, and corruption and cooperation with official..., abuse, and corruption in Commission programs, including on the part of Commission employees,...

  9. Molecular Dynamics Simulation of Point Defect Accumulation in 3C-SiC

    SciTech Connect

    Devanathan, Ram; Gao, Fei; Weber, William J.

    2004-04-05

    Defect accumulation in silicon carbide has been simulated by molecular dynamics using a Brenner-type potential connected smoothly to the Ziegler-Biersack-Littmark potential. Displacement damage in 3C-SiC, which is known to consist of point defects, vacancy and interstitial clusters and anti-site defects, was modelled by introducing random displacements in the Si or C sublattice. SiC was amorphized by Si displacements at a damage level corresponding to 0.15 displacements per atom (dpa) and by C displacements at 0.25 dpa. In both cases, the damage consists of Si and C Frenkel pairs as well as anti-site defects. The results provide evidence that SiC can be amorphized by displacing C atoms exclusively and suggest that short-range disorder provides the driving force for amorphization of SiC.

  10. Bound States of (Anti-)Scalar-Quarks in SU(3)c Lattice QCD

    SciTech Connect

    Iida, H.; Takahashi, T. T.; Suganuma, H.

    2007-06-13

    Light scalar-quarks {phi} (colored scalar particles or idealized diquarks) and their color-singlet hadronic states are studied with quenched SU(3)c lattice QCD in terms of mass generation. We investigate 'scalar-quark mesons' {phi}{dagger}{phi} and 'scalar-quark baryons' {phi}{phi}{phi} as the bound states of scalar-quarks {phi}. We also investigate the bound states of scalar-quarks {phi} and quarks {psi}, i.e., {phi}{dagger}{psi}, {psi}{psi}{phi} and {phi}{phi}{psi}, which we name 'chimera hadrons'. All the new-type hadrons including {phi} are found to have a large mass due to large quantum corrections by gluons, even for zero bare scalar-quark mass m{phi} = 0 at a-1 {approx} 1GeV. We conjecture that all colored particles generally acquire a large effective mass due to dressed gluon effects.

  11. Stability and melting of Fe3C at high pressure and temperature: Implication for the carbon in the Earth's core

    NASA Astrophysics Data System (ADS)

    Takahashi, S.; Ohtani, E.; Sakai, T.; Hirao, N.; Ohishi, Y.

    2012-12-01

    The Earth's core is regarded as an Fe-Ni alloy but its density is lower than that of pure Fe at the core conditions. Therefore, the Earth's core is supposed to contain light elements and carbon is one of the candidates of the light elements to explain the density deficit of the Earth's core. Nakajima et al. (2009) reported the melting temperature of Fe3C up to around 30 GPa based on textual observations, the chemical analysis of the quenched run products and in situ X-ray diffraction experiments using a Kawai-type multi anvil apparatus. Lord et al. (2009) reported melting temperatures of Fe3C up to 70 GPa, which was determined by the temperature plateau during increasing laser power using a laser-heated diamond anvil cell. They also suggested Fe+Fe7C3 is a stable subsolidus phase. There are obvious discrepancies between the melting curve and the stable subsolidus phase reported by Nakajima et al. (2009) and those reported by Lord et al. (2009). In this study, the melting temperatures of Fe3C and a subsolidus phase relation were determined based on in situ X-ray diffraction experiments. This study aims to reveal the stability field of Fe3C and the melting temperature of Fe3C and to discuss the behaviors of carbon in the Earth's core. We have performed experiments using a laser-heated diamond anvil cell combined with in situ X-ray diffraction experiment at BL10XU beamline, SPring-8 synchrotron facility. An NaCl powder and a rhenium or tungsten foil were used for the insulator and gasket, respectively. Melting of the sample was determined by disappearance of the X-ray diffraction peaks. We determined the melting relation of Fe3C up to 145 GPa by in situ X-ray diffraction experiments. Present results are close to Nakajima et al. (2009) up to 30 GPa but become close to that reported by Lord et al. (2009) at higher pressure conditions. The solidus temperature extrapolated to the ICB pressure, 330 GPa, is 5400 K. We also confirmed that Fe3C is stable as a subsolidus phase

  12. Investigation of neutron converters for production of optically stimulated luminescence (OSL) neutron dosimeters using Al 2O 3:C

    NASA Astrophysics Data System (ADS)

    Mittani, J. C. R.; da Silva, A. A. R.; Vanhavere, F.; Akselrod, M. S.; Yukihara, E. G.

    2007-07-01

    This paper presents the optically stimulated luminescence (OSL) properties of neutron dosimeters in powder and in the form of pellets prepared with a mixture of Al 2O 3:C and neutron converters. The neutron converters investigated were high density polyethylene (HDPE), lithium fluoride (LiF), lithium fluoride 95% enriched with 6Li ( 6LiF), lithium carbonate 95% enriched with 6Li ( 6Li 2CO 3), boric acid enriched with 99% of 10B (H310BO) and gadolinium oxide (Gd 2O 3). The proportion of Al 2O 3:C and neutron converter in the mixture was varied to optimize the total OSL signal and neutron sensitivity. The neutron sensitivity and dose-response were determined for the OSL dosimeters using a bare 252Cf source and compared to the response of Harshaw TLD-600 and TLD-700 dosimeters ( 6LiF:Mg,Ti and 7LiF:Mg,Ti). The results demonstrate the possibility of developing an OSL dosimeter made of Al 2O 3:C powder and neutron converter with a neutron sensitivity (defined as the ratio between the 60Co equivalent gamma dose and the reference neutron absorbed dose) and neutron-gamma discrimination comparable to the TLD-600/TLD-700 combination. It was shown that the shape of the OSL decay curves varied with the type of the neutron converter, demonstrating the influence of the energy deposition mechanism and ionization density on the OSL process in Al 2O 3:C.

  13. Synthesis of carbon nanofibers by CVD as a catalyst support material using atomically ordered Ni3C nanoparticles

    NASA Astrophysics Data System (ADS)

    Li, Meifeng; Li, Na; Shao, Wei; Zhou, Chungen

    2016-12-01

    Atomically ordered nickel carbide (Ni3C) nanoparticles in polygonal shapes were prepared through the reduction of nickelocene. A novel type of carbon nanofiber (CNF) with twisted conformation was synthesized successfully by catalytic chemical vapor deposition (CCVD) using the obtained Ni3C nanoparticles at a relatively low temperature of 350 °C, which is below the lower limit temperature of 400 °C for the growth of CNFs using metal catalysts. The growth mechanism of the twisted CNFs from Ni3C was freshly derived based on the detailed characterizations. Compared with the growth of CNFs from Ni, graphene layers nucleate at monoatomic step edges and grow in a layer-by-layer manner, while the rotation of the polygonal Ni3C nanoparticles fabricates the twisted conformation during the CNF growth. The electrochemical activity and performance of the twisted CNFs loaded with Pt as electrode catalysts for a polymer electrolyte membrane fuel cell (PEMFC) were measured to be better than those of straight CNFs grown from Ni nanoparticles at 500 °C, since the specific surface conformation helps to make the loaded Pt more homogeneous.

  14. Timing of Events in the Central Engine and Jets of the Radio Galaxies 3c 111 and 3c 120 (core Program)

    NASA Astrophysics Data System (ADS)

    The investigators request continuation of their long-term monitoring of the X-ray flux of the radio galaxies 3C 111 (FR 2) and 3C 120 (FR 1) 2 and 4 times per week, respectively, throughout Cycle 12, as well as a 90 days of daily monitoring of 3C 111. In both objects, dips in X-ray flux precede the appearance of bright superluminal knots in the radio jet. The long-term multiwaveband light curves and sequences of 7 mm VLBA images will record the changing pattern of multiwaveband emission in these two AGN. 3C 111 is a probable EGRET source; if the ID is correct, GLAST will measure its flux daily, allowing relative timing of gamma-ray variations with X-ray and optical events from the central engine plus radio events in the jet.

  15. Roles of the Picornaviral 3C Proteinase in the Viral Life Cycle and Host Cells.

    PubMed

    Sun, Di; Chen, Shun; Cheng, Anchun; Wang, Mingshu

    2016-03-17

    The Picornaviridae family comprises a large group of non-enveloped viruses that have a major impact on human and veterinary health. The viral genome contains one open reading frame encoding a single polyprotein that can be processed by viral proteinases. The crucial 3C proteinases (3C(pro)s) of picornaviruses share similar spatial structures and it is becoming apparent that 3C(pro) plays a significant role in the viral life cycle and virus host interaction. Importantly, the proteinase and RNA-binding activity of 3C(pro) are involved in viral polyprotein processing and the initiation of viral RNA synthesis. In addition, 3C(pro) can induce the cleavage of certain cellular factors required for transcription, translation and nucleocytoplasmic trafficking to modulate cell physiology for viral replication. Due to interactions between 3C(pro) and these essential factors, 3C(pro) is also involved in viral pathogenesis to support efficient infection. Furthermore, based on the structural conservation, the development of irreversible inhibitors and discovery of non-covalent inhibitors for 3C(pro) are ongoing and a better understanding of the roles played by 3C(pro) may provide insights into the development of potential antiviral treatments. In this review, the current knowledge regarding the structural features, multiple functions in the viral life cycle, pathogen host interaction, and development of antiviral compounds for 3C(pro) is summarized.

  16. CFD Growth of 3C-SiC on 4H/6H Mesas

    NASA Technical Reports Server (NTRS)

    Neudeck, Philip G.; Trunek, Andrew J.; Spry, David J.; Powell, J. Anthony; Du, Hui; Skowronski, Marek; Huang, XianRong; Dudley, Michael

    2006-01-01

    This article describes growth and characterization of the highest quality reproducible 3C-SiC heteroepitaxial films ever reported. By properly nucleating 3C-SiC growth on top of perfectly on-axis (0001) 4H-SiC mesa surfaces completely free of atomic scale steps and extended defects, growth of 3C-SiC mesa heterofilms completely free of extended crystal defects can be achieved. In contrast, nucleation and growth of 3C-SiC mesa heterofilms on top of 4H-SiC mesas with atomic-scale steps always results in numerous observable dislocations threading through the 3C-SiC epilayer. High-resolution X-ray diffraction and transmission electron microscopy measurements indicate non-trivial in-plane lattice mismatch between the 3C and 4H layers. This mismatch is somewhat relieved in the step-free mesa case via misfit dislocations confined to the 3C/4H interfacial region without dislocations threading into the overlying 3C-SiC layer. These results indicate that the presence or absence of steps at the 3C/4H heteroepitaxial interface critically impacts the quality, defect structure, and relaxation mechanisms of single-crystal heteroepitaxial 3C-SiC films.

  17. Vibrational and Geometric Structures of La{_3}C{_2}O and La{_3}C{_2}O^+ from Masse-Analyzed Threshold Ionization

    NASA Astrophysics Data System (ADS)

    Mourad, Roudjane; Wu, Lu; Yang, D. S.

    2011-06-01

    La{_3}C{_2}O is produced for the first time by laser vaporization in a pulsed cluster source and identified by photoionization time-of-flight mass spectrometry. Vibrationally-resolved ion spectra are obtained with mass-analyzed threshold ionization (MATI) spectroscopy. The adiabatic ionization energy of La{_3}C{_2}O is measured to be 30891(5) Cm-1. The spectra display several short vibrational progressions, and these progressions are associated mainly with La-La, La-C and La{_3}C{_2}O stretching excitations. The electron-spin multiplicities and molecular symmetries of La{_3}C{_2}O and La{_3}C{_2}O^+ are determined by combining the experimental measurements with ab initio calculations at MP2 level. Preliminary data analysis shows that the ^1A_1 ← ^2A_1 transition is responsible for the observed MATI spectra. The cluster has C2v symmetry with La{_3}C{_2}O in a bi-pyramid structure and oxygen being attached to the La_3 plane.

  18. Probing the Disk-Jet Connection of the Radio Galaxy 3C120 Observed With Suzaku

    SciTech Connect

    Kataoka, Jun; Reeves, James N.; Iwasawa, Kazushi; Markowitz, Alex G.; Mushotzky, Richard F.; Arimoto, Makoto; Takahashi, Tadayuki; Tsubuku, Yoshihiro; Ushio, Masayoshi; Watanabe, Shin; Gallo, Luigi C.; Madejski, Greg M.; Terashima, Yuichi; Isobe, Naoki; Tashiro, Makoto S.; Kohmura, Takayoshi; /Tokyo Inst. Tech. /NASA, Goddard /Garching, Max Planck Inst., MPE /JAXA, Sagamihara /SLAC /Ehime U. /Wako, RIKEN /Saitama U. /Kogakuin U.

    2007-01-03

    Broad line radio galaxies (BLRGs) are a rare type of radio-loud AGN, in which the broad optical permitted emission lines have been detected in addition to the extended jet emission. Here we report on deep (40ksec x 4) observations of the bright BLRG 3C 120 using Suzaku. The observations were spaced a week apart, and sample a range of continuum fluxes. An excellent broadband spectrum was obtained over two decades of frequency (0.6 to 50 keV) within each 40 ksec exposure. We clearly resolved the iron K emission line complex, finding that it consists of a narrow K{sub {alpha}} core ({sigma} {approx_equal} 110 eV or an EW of 60 eV), a 6.9 keV line, and an underlying broad iron line. Our confirmation of the broad line contrasts with the XMM-Newton observation in 2003, where the broad line was not required. The most natural interpretation of the broad line is iron K line emission from a face-on accretion disk which is truncated at {approx} 10 r{sub g}. Above 10 keV, a relatively weak Compton hump was detected (reflection fraction of R {approx_equal} 0.6), superposed on the primary X-ray continuum of {Lambda} {approx_equal} 1.75. Thanks to the good photon statistics and low background of the Suzaku data, we clearly confirm the spectral evolution of 3C 120, whereby the variability amplitude decreases with increasing energy. More strikingly, we discovered that the variability is caused by a steep power-law component of {Lambda} {approx_equal} 2.7, possibly related to the non-thermal jet emission. We discuss our findings in the context of similarities and differences between radio-loud/quiet objects.

  19. THE EXTRAORDINARY GAMMA-RAY FLARE OF THE BLAZAR 3C 454.3

    SciTech Connect

    Striani, E.; Tavani, M.; Vittorini, V.; D'Ammando, F.; Vercellone, S.; Donnarumma, I.; Pacciani, L.; Argan, A.; Costa, E.; De Paris, G.; Monte, E. Del; Bulgarelli, A.; Trifoglio, M.; Gianotti, F.; Barbiellini, G.; Caraveo, P.; Chen, A. W.

    2010-07-20

    We present the gamma-ray data of the extraordinary flaring activity above 100 MeV from the flat spectrum radio quasar 3C 454.3 detected by AGILE during the month of 2009 December. 3C 454.3, which has been among the most active blazars of the FSRQ type since 2007, has been detected in the gamma-ray range with a progressively rising flux since 2009 November 10. The gamma-ray flux reached a value comparable with that of the Vela pulsar on 2009 December 2. Remarkably, between 2009 December 2 and 3, the source more than doubled its gamma-ray emission and became the brightest gamma-ray source in the sky with a peak flux of F {sub {gamma},p} = (2000 {+-} 400) x 10{sup -8} ph cm{sup -2} s{sup -1} for a 1 day integration above 100 MeV. The gamma-ray intensity decreased in the following days with the source flux remaining at large values near F {sub {gamma}} {approx_equal} (1000 {+-} 200) x 10{sup -8} ph cm{sup -2} s{sup -1} for more than a week. This exceptional gamma-ray flare dissipated among the largest ever detected intrinsic radiated power in gamma-rays above 100 MeV (L {sub {gamma},source,peak} {approx_equal} 3 x 10{sup 46} erg s{sup -1}, for a relativistic Doppler factor of {delta} {approx_equal} 30). The total isotropic irradiated energy of the month-long episode in the range 100 MeV-3 GeV is E {sub {gamma},iso} {approx_equal} 10{sup 56} erg. We report the intensity and spectral evolution of the gamma-ray emission across the flaring episode. We briefly discuss the important theoretical implications of our detection.

  20. Theoretical understanding of magnetic and electronic structures of Ti3C2 monolayer and its derivatives

    NASA Astrophysics Data System (ADS)

    Wu, Fang; Luo, Kang; Huang, Chengxi; Wu, Wenjuan; Meng, Peiwen; Liu, Yunfei; Kan, Erjun

    2015-11-01

    First-principles calculations were performed to investigate the electronic and magnetic properties of Ti3C2 monolayer and its derivatives. We found that pristine Ti3C2 monolayer acts as a magnetic metal, and magnetic moments come from Ti2+ ions at two sides. Through doping nitrogen atoms, the spin moments is significantly reduced. On other hand, when two surfaces of Ti3C2 monolayer are saturated by external groups, the magnetism will be spontaneously annihilated. Even for the saturation of one side, we also found that the magnetism of Ti3C2Y (Y is O and OH) monolayer is removed because of the invalidation of stoner instability. More importantly, we explored that both doping and surface modification will reduce the Curie temperature of Ti3C2 monolayer. Therefore, our results shed a light on the way to get high-temperature magnetism in Ti3C2 monolayer.

  1. The peculiar hydrogen cloud in the Virgo Cluster and 3C 273

    NASA Technical Reports Server (NTRS)

    Arp, H. C.; Burbidge, G.

    1990-01-01

    It is shown that the nearest bright extragalactic object to the peculiar hydrogen cloud recently discovered in the Virgo Cluster by Giovanelli and Haynes is the bright QSO 3C 273. Further, it is pointed out that the jet in 3C 273 points in almost the same direction as the major axis of the cloud. Despite the redshift difference, possible physical connections between the cloud and 3C 273 are explored.

  2. The nature of the optical variations of Seyfert galaxy 3C 120

    SciTech Connect

    Webb, J.R. Austin State Univ., TX )

    1990-01-01

    Results are presented from 61 years of optical observations of the Seyfert galaxy 3C 120. A previously published model of the 3C 120 light curve, derived from power spectrum analysis, is found to be valid for historical as well as current data. It is concluded that the optical variations of 3C 120 can be separated into a linear component, a sinusoidal component, and rapid, high-amplitude flares. Possible sources of the regular variations observed in 3C 120 are also suggested in the context of accretion models and other theoretical models. 15 refs.

  3. 18 CFR 3c.3 - Reporting fraud, waste, abuse, and corruption and cooperation with official inquiries.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Reporting fraud, waste, abuse, and corruption and cooperation with official inquiries. 3c.3 Section 3c.3 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES...

  4. 18 CFR 3c.3 - Reporting fraud, waste, abuse, and corruption and cooperation with official inquiries.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Reporting fraud, waste, abuse, and corruption and cooperation with official inquiries. 3c.3 Section 3c.3 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES...

  5. 18 CFR 3c.3 - Reporting fraud, waste, abuse, and corruption and cooperation with official inquiries.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Reporting fraud, waste, abuse, and corruption and cooperation with official inquiries. 3c.3 Section 3c.3 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES...

  6. 50 CFR Table 3c to Part 680 - Crab Product Codes for Economic Data Reports

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Crab Product Codes for Economic Data Reports 3c Table 3c to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) SHELLFISH FISHERIES OF...

  7. 50 CFR Table 3c to Part 680 - Crab Product Codes for Economic Data Reports

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Crab Product Codes for Economic Data Reports 3c Table 3c to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) SHELLFISH FISHERIES OF...

  8. Glomerular C3c localization indicates ongoing immune deposit formation and complement activation in experimental glomerulonephritis.

    PubMed Central

    Schulze, M.; Pruchno, C. J.; Burns, M.; Baker, P. J.; Johnson, R. J.; Couser, W. G.

    1993-01-01

    In antibody-mediated glomerular disease, deposits of C3 (C3b) are common and are degraded by factor I to C3c and C3d. However, the kinetics of C3b degradation in glomerulonephritis have not been defined. To do this, we studied three models of complement-dependent glomerulonephritis with established C3 deposits (passive Heymann nephritis, cationized immunoglobulin G membranous nephropathy, and concanavalin A-anticoncanavalin A glomerulonephritis). C3b deposition was halted by administration of cobra venom factor, and the disappearance of C3c and C3d from glomeruli was measured with specific antibodies and quantitative fluorescence densitometry. Results showed that C3c deposits were reduced by over 85% within 24 hours in all three models. C3c clearance was unaffected by site or mechanism of deposit formation. C3d deposits persisted despite lack of ongoing complement activation. In passive Heymann nephritis when disease activity was monitored by urinary C5b-9 excretion, C3c was cleared in parallel with return of urine C5b-9 excretion to normal values. We conclude that glomerular deposits of C3c are cleared within 24 hours of cessation of complement activation. Positive staining for C3 utilizing antibody specific for the C3c portion documents recent complement activation usually reflecting new immune deposit formation. Images Figure 1 Figure 2 Figure 3 PMID:7678717

  9. CVD growth and properties of boron phosphide on 3C-SiC

    NASA Astrophysics Data System (ADS)

    Padavala, Balabalaji; Frye, C. D.; Wang, Xuejing; Raghothamachar, Balaji; Edgar, J. H.

    2016-09-01

    Improving the crystalline quality of boron phosphide (BP) is essential for realizing its full potential in semiconductor device applications. In this study, 3C-SiC was tested as a substrate for BP epitaxy. BP films were grown on 3C-SiC(100)/Si, 3C-SiC(111)/Si, and 3C-SiC(111)/4H-SiC(0001) substrates in a horizontal chemical vapor deposition (CVD) system. Films were produced with good crystalline orientation and morphological features in the temperature range of 1000-1200 °C using a PH3+B2H6+H2 mixture. Rotational twinning was absent in the BP due to the crystal symmetry-matching with 3C-SiC. Confocal 3D Raman imaging of BP films revealed primarily uniform peak shift and peak widths across the scanned area, except at defects on the surface. Synchrotron white beam X-ray topography showed the epitaxial relationship between BP and 3C-SiC was (100) < 011 > BP||(100) < 011 > 3C-SiC and (111) < 11 2 ̅ > BP||(111) < 11 2 ̅ > 3C-SiC. Scanning electron microscopy, Raman spectroscopy and X-ray diffraction analysis indicated residual tensile strain in the films and improved crystalline quality at temperatures below 1200 °C. These results indicated that BP properties could be further enhanced by employing high quality bulk 3C-SiC or 3C-SiC epilayers on 4H-SiC substrates.

  10. Fueling the central engine of radio galaxies. II. The footprints of AGN feedback on the ISM of 3C 236

    NASA Astrophysics Data System (ADS)

    Labiano, A.; García-Burillo, S.; Combes, F.; Usero, A.; Soria-Ruiz, R.; Tremblay, G.; Neri, R.; Fuente, A.; Morganti, R.; Oosterloo, T.

    2013-01-01

    Context. There is growing observational evidence of active galactic nuclei (AGN) feedback on the interstellar medium (ISM) of radio-quiet and radio-loud galaxies. While AGN feedback is expected to be more common at high-redshift objects, studying local universe galaxies helps to better characterize the different manifestations of AGN feedback. Aims: Molecular line observations can be used to quantify the mass and energy budget of the gas affected by AGN feedback. We study the emission of molecular gas in 3C 236, a Faranoff-Riley type 2 (FR II) radio source at z ~ 0.1, and search for the footprints of AGN feedback. The source 3C 236 shows signs of a reactivation of its AGN triggered by a recent minor merger episode. Observations have also previously identified an extreme H i outflow in this source. Methods: The IRAM Plateau de Bure interferometer (PdBI) was used to study the distribution and kinematics of molecular gas in 3C 236 by imaging with high spatial resolution (0.6″) the emission of the 2-1 line of 12CO in the nucleus of the galaxy. We searched for outflow signatures in the CO map. We also derived the star-formation rate (SFR) in 3C 236 using data available from the literature at UV, optical, and IR wavelengths, to determine the star-formation efficiency (SFE) of molecular gas. Results: The CO emission in 3C 236 comes from a spatially resolved ~1.4″(2.6 kpc-) diameter disk characterized by a regular rotating pattern. Within the limits imposed by the sensitivity and velocity coverage of the CO data, we do not detect any outflow signatures in the cold molecular gas. The disk has a cold gas mass M(H2) ~ 2.1 × 109 M⊙. Based on CO we determine a new value for the redshift of the source zCO = 0.09927 ± 0.0002. The similarity between the CO and H i profiles indicates that the deep H i absorption in 3C 236 can be accounted for by a rotating H i structure. This restricts the evidence of H i outflow to only the most extreme velocities. In the light of the new

  11. Long-lived Aqueous Rechargeable Lithium Batteries Using Mesoporous LiTi2(PO4)3@C Anode

    PubMed Central

    Sun, Dan; Tang, Yougen; He, Kejian; Ren, Yu; Liu, Suqin; Wang, Haiyan

    2015-01-01

    The instability of anode materials during cycling has been greatly limiting the lifetime of aqueous rechargeable lithium batteries (ARLBs). Here, to tackle this issue, mesoporous LiTi2(PO4)3@C composites with a pore size of 4 nm and a large BET surface area of 165 m2 g−1 have been synthesized by a novel two-step approach. The ARLB with this type of LiTi2(PO4)3@C anode, commercial LiMn2O4 cathode and 2 M Li2(SO4) aqueous solution (oxygen was removed) exhibited superior cycling stability (a capacity retention of 88.9% after 1200 cycles at 150 mA g−1 and 82.7% over 5500 cycles at 750 mA g−1) and excellent rate capability (discharge capacities of 121, 110, 90, and 80 mAh g−1 based on the mass of LiTi2(PO4)3 at 30, 150, 1500, and 3000 mA g−1, respectively). As verified, the mesoporous structure, large surface area and high-quality carbon coating layer of the LiTi2(PO4)3@C composite contribute to the breakthrough in achieving excellent electrochemical properties for ARLB. PMID:26648263

  12. Quantum wells on 3C-SiC/NH-SiC heterojunctions. Calculation of spontaneous polarization and electric field strength in experiments

    SciTech Connect

    Sbruev, I. S.; Sbruev, S. B.

    2010-10-15

    The results of experiments with quantum wells on 3C-SiC/4H-SiC and 3C-SiC/6H-SiC heterojunctions obtained by various methods are reconsidered. Spontaneous polarizations, field strengths, and energies of local levels in quantum wells on 3C-SiC/NH-SiC heterojunctions were calculated within a unified model. The values obtained are in agreement with the results of all considered experiments. Heterojunction types are determined. Approximations for valence band offsets on heterojunctions between silicon carbide polytypes and the expression for calculating local levels in quantum wells on the 3C-SiC/NH-SiC heterojunction are presented. The spontaneous polarizations and field strengths induced by spontaneous polarization on 3C-SiC/4H-SiC and 3C-SiC/6H-SiC heterojunctions were calculated as 0.71 and 0.47 C/m{sup 2} and 0.825 and 0.55 MV/cm, respectively.

  13. Vibrational properties of Ti3C2 and Ti3C2T2 (T = O, F, OH) monosheets by first-principles calculations: a comparative study.

    PubMed

    Hu, Tao; Wang, Jiemin; Zhang, Hui; Li, Zhaojin; Hu, Minmin; Wang, Xiaohui

    2015-04-21

    We present a comparative study on the static and dynamical properties of bare Ti3C2 and T-terminated Ti3C2T2 (T = O, F, OH) monosheets using density functional theory calculations. First, the crystal structures are optimized to be of trigonal configurations (P3[combining macron]m1), which are thermodynamically and dynamically stable. It is demonstrated that the terminations modulate the crystal structures through valence electron density redistribution of the atoms, particularly surface Ti (Ti2) in the monosheets. Second, lattice dynamical properties including phonon dispersion and partial density of states (PDOS) are investigated. Phonon PDOS analysis shows a clear collaborative feature in the vibrations, reflecting the covalent nature of corresponding bonds in the monosheets. In the bare Ti3C2 monosheet, there is a phonon band gap between 400 and 500 cm(-1), while it disappears in Ti3C2O2 and Ti3C2(OH)2 as the vibrations associated with the terminal atoms (O and OH) bridge the gap. Third, both Raman (Eg and A1g) and infrared-active (Eu and A2u) vibrational modes are predicted and conclusively assigned. A comparative study indicates that the terminal atoms remarkably influence the vibrational frequencies. Generally, the terminal atoms weaken the vibrations in which surface Ti atoms are involved while strengthening the out-of-plane vibration of C atoms. Temperature-dependent micro Raman measurements agree with the theoretical prediction if the complexity in the experimentally obtained lamellae for the Raman study is taken into account.

  14. The WEBT Campaign on the Blazar 3C 279 in 2006

    NASA Astrophysics Data System (ADS)

    Böttcher, M.; Basu, S.; Joshi, M.; Villata, M.; Arai, A.; Aryan, N.; Asfandiyarov, I. M.; Bach, U.; Bachev, R.; Berduygin, A.; Blaek, M.; Buemi, C.; Castro-Tirado, A. J.; De Ugarte Postigo, A.; Frasca, A.; Fuhrmann, L.; Hagen-Thorn, V. A.; Henson, G.; Hovatta, T.; Hudec, R.; Ibrahimov, M.; Ishii, Y.; Ivanidze, R.; Jelínek, M.; Kamada, M.; Kapanadze, B.; Katsuura, M.; Kotaka, D.; Kovalev, Y. Y.; Kovalev, Yu. A.; Kubánek, P.; Kurosaki, M.; Kurtanidze, O.; Lähteenmäki, A.; Lanteri, L.; Larionov, V. M.; Larionova, L.; Lee, C.-U.; Leto, P.; Lindfors, E.; Marilli, E.; Marshall, K.; Miller, H. R.; Mingaliev, M. G.; Mirabal, N.; Mizoguchi, S.; Nakamura, K.; Nieppola, E.; Nikolashvili, M.; Nilsson, K.; Nishiyama, S.; Ohlert, J.; Osterman, M. A.; Pak, S.; Pasanen, M.; Peters, C. S.; Pursimo, T.; Raiteri, C. M.; Robertson, J.; Robertson, T.; Ryle, W. T.; Sadakane, K.; Sadun, A.; Sigua, L.; Sohn, B.-W.; Strigachev, A.; Sumitomo, N.; Takalo, L. O.; Tamesue, Y.; Tanaka, K.; Thorstensen, J. R.; Tosti, G.; Trigilio, C.; Umana, G.; Vennes, S.; Vitek, S.; Volvach, A.; Webb, J.; Yamanaka, M.; Yim, H.-S.

    2007-12-01

    The quasar 3C 279 was the target of an extensive multiwavelength monitoring campaign from 2006 January through April. An optical-IR-radio monitoring campaign by the Whole Earth Blazar Telescope (WEBT) collaboration was organized around target-of-opportunity X-ray and soft γ-ray observations with Chandra and INTEGRAL in 2006 mid-January, with additional X-ray coverage by RXTE and Swift XRT. In this paper we focus on the results of the WEBT campaign. The source exhibited substantial variability of optical flux and spectral shape, with a characteristic timescale of a few days. The variability patterns throughout the optical BVRI bands were very closely correlated with each other, while there was no obvious correlation between the optical and radio variability. After the ToO trigger, the optical flux underwent a remarkably clean quasi-exponential decay by about 1 mag, with a decay timescale of τd~12.8 days. In intriguing contrast to other (in particular, BL Lac type) blazars, we find a lag of shorter wavelength behind longer wavelength variability throughout the RVB wavelength ranges, with a time delay increasing with increasing frequency. Spectral hardening during flares appears delayed with respect to a rising optical flux. This, in combination with the very steep IR-optical continuum spectral index of α0~1.5-2.0, may indicate a highly oblique magnetic field configuration near the base of the jet, leading to inefficient particle acceleration and a very steep electron injection spectrum. An alternative explanation through a slow (timescale of several days) acceleration mechanism would require an unusually low magnetic field of B<~0.2 G, about an order of magnitude lower than inferred from previous analyses of simultaneous SEDs of 3C 279 and other flat-spectrum radio quasars with similar properties. For questions regarding the availability of the data from the WEBT campaign presented in this paper, please contact the WEBT President Massimo Villata at villata@oato.inaf.it.

  15. The encephalomyocarditis virus 3C protease is a substrate for the ubiquitin-mediated proteolytic system.

    PubMed

    Lawson, T G; Gronros, D L; Werner, J A; Wey, A C; DiGeorge, A M; Lockhart, J L; Wilson, J W; Wintrode, P L

    1994-11-11

    The encephalomyocarditis virus 3C protease has been shown to be rapidly degraded in infected cells and in vitro in rabbit reticulocyte lysate. The in vitro degradation, at least, is accomplished by a virus-independent, ATP-dependent proteolytic system. Here we identify this proteolytic system as the ubiquitin-mediated system. Incubation of the 3C protease in rabbit reticulocyte or cultured mouse cell lysate preparations, alone or in the presence of added ubiquitin or methylated ubiquitin, resulted in the generation of new higher molecular weight species. These new products were shown to be 3C protease-ubiquitin conjugates by their ability to bind antibodies against both the 3C protease and ubiquitin. Supplemental ubiquitin also stimulated the degradation of the 3C protease in these preparations. Large 3C protease-polyubiquitin conjugates were observed to accumulate in reticulocyte lysate in the presence of adenosine 5'-O-(3-thiotriphosphate), an inhibitor of the 26 S multicatalytic protease. This, combined with the fact that the proteolytic activity could be removed from the lysate by sedimentation, implicates the multicatalytic protease in the degradation of the 3C protease-ubiquitin conjugates. It was also found that the slow rate of degradation of a model polyprotein, which resembles the stable viral 3CD diprotein produced in vivo, is likely due to the fact that the polyprotein is a poor substrate for the ubiquitin-conjugating system.

  16. The Class II Phosphatidylinositol 3-Phosphate Kinase PIK3C2A Promotes Shigella flexneri Dissemination through Formation of Vacuole-Like Protrusions

    PubMed Central

    Dragoi, Ana-Maria

    2015-01-01

    Intracellular pathogens such as Shigella flexneri and Listeria monocytogenes achieve dissemination in the intestinal epithelium by displaying actin-based motility in the cytosol of infected cells. As they reach the cell periphery, motile bacteria form plasma membrane protrusions that resolve into vacuoles in adjacent cells, through a poorly understood mechanism. Here, we report on the role of the class II phosphatidylinositol 3-phosphate kinase PIK3C2A in S. flexneri dissemination. Time-lapse microscopy revealed that PIK3C2A was required for the resolution of protrusions into vacuoles through the formation of an intermediate membrane-bound compartment that we refer to as a vacuole-like protrusion (VLP). Genetic rescue of PIK3C2A depletion with RNA interference (RNAi)-resistant cDNA constructs demonstrated that VLP formation required the activity of PIK3C2A in primary infected cells. PIK3C2A expression was required for production of phosphatidylinositol 3-phosphate [PtdIns(3)P] at the plasma membrane surrounding protrusions. PtdIns(3)P production was not observed in the protrusions formed by L. monocytogenes, whose dissemination did not rely on PIK3C2A. PIK3C2A-mediated PtdIns(3)P production in S. flexneri protrusions was regulated by host cell tyrosine kinase signaling and relied on the integrity of the S. flexneri type 3 secretion system (T3SS). We suggest a model of S. flexneri dissemination in which the formation of VLPs is mediated by the PIK3C2A-dependent production of the signaling lipid PtdIns(3)P in the protrusion membrane, which relies on the T3SS-dependent activation of tyrosine kinase signaling in protrusions. PMID:25667265

  17. Far Ultraviolet Spectroscopy of the Intergalactic and Interstellar Absorption Toward 3C 273

    NASA Technical Reports Server (NTRS)

    Sembach, Kenneth R.; Howk, J. Christopher; Savage, Blair D.; Shull, J. Michael; Oegerle, William R.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    density toward 3C273, logN O(VI) = 14.73 +/- 0.04, implies n(sub e) < 0.02/cubic cm and P/k < 11,500/cubic cm for an assumed temperature of 3 x 10(exp 5) K. The elemental abundances in the neutral and weakly-ionized interstellar clouds are similar to those found for other halo clouds. The warm neutral and warm ionized clouds along the sight line have similar dust-phase abundances, implying that the properties of the dust grains in the two types of clouds are similar. Interstellar H2 absorption is present at positive velocities at a level of logN(H2) = 15.71, but is very weak at the velocities of the main column density concentration along the sight line observed in H(I) 21 cm emission.

  18. Antiferromagnetic resonance in the Mott insulator fcc-Cs3C60.

    PubMed

    Suzuki, Yuta; Shibasaki, Seiji; Kubozono, Yoshihiro; Kambe, Takashi

    2013-09-11

    The magnetic ground state of the fcc phase of the Mott insulator Cs3C60 was studied using a low-temperature electron spin resonance technique, and antiferromagnetic resonance (AFMR) below 1.57 K was directly observed at ambient pressure. The AFMR modes for the fcc phase of Cs3C60 were investigated using a conventional two-sublattice model with uniaxial anisotropy, and the spin-flop field was determined to be 4.7 kOe at 1.57 K. The static magnetic exchange interactions and anisotropy field for fcc-Cs3C60 were also estimated.

  19. Internal Stress in Freestanding 3C-SiC Grown on Si and Relation to Carrier Lifetime

    NASA Astrophysics Data System (ADS)

    Grivickas, V.; Gulbinas, K.; Manolis, G.; Kato, M.; Linnros, J.

    2010-11-01

    Residual stress and carrier lifetime variation have been measured in free-standing n-type 3C-SiC wafer grown on undulated Si substrate. We identify extended regions of residual stress that lie parallel to epilayer surfaces. The opposite polarity of stress is identified toward the interface and toward the top surface. Integrated carrier lifetime has been determined by random defect density distribution which is enhanced in the areas of double-positioning boundary defects. It is shown that carrier lifetimes are severely reduced by the presence of residual stress towards epilayer surfaces. In this way lifetime depth-distribution can be mistakenly attributed to enhanced surface recombination.

  20. Optically stimulated luminescence and thermoluminescence efficiencies for high-energy heavy charged particle irradiation in Al2O3:C

    NASA Technical Reports Server (NTRS)

    Yukihara, E. G.; Gaza, R.; McKeever, S. W. S.; Soares, C. G.

    2004-01-01

    The thermally and optically stimulated luminescence (TL and OSL) response to high energy heavy-charged particles (HCPs) was investigated for two types of Al2O3:C luminescence dosimeters. The OSL signal was measured in both continuous-wave (CW) and pulsed mode. The efficiencies of the HCPs at producing TL or OSL, relative to gamma radiation, were obtained using four different HCPs beams (150 MeV/u 4He, 400 MeV/u 12C, 490 MeV/u 28Si, and 500 MeV/u 56Fe). The efficiencies were determined as a function of the HCP linear energy transfer (LET). It was observed that the efficiency depends on the type of detector, measurement technique, and the choice of signal. Additionally, it is shown that the shape of the CW-OSL decay curve from Al2O3:C depends on the type of radiation, and, in principle, this can be used to extract information concerning the LET of an unknown radiation field. The response of the dosimeters to low-LET radiation was also investigated for doses in the range from about 1-1000 Gy. These data were used to explain the different efficiency values obtained for the different materials and techniques, as well as the LET dependence of the CW-OSL decay curve shape. c2003 Elsevier Ltd. All rights reserved.

  1. Are 3C 120 and Other Active Galactic Nuclei Overweight Microquasars?

    NASA Astrophysics Data System (ADS)

    Marscher, Alan P.

    2005-11-01

    The appearance of superluminal radio knots follows drops in the X-ray flux in the FR1 radio galaxy 3C 120 and possibly the FR2 source 3C 111. This corresponds in a very general way to the behavior of the X-ray binary GRS 1915 + 105, but the light curves of the microquasar are much richer in detail. Starting in 2003.7, the character of the radio and X-ray light curves of 3C 120 changed, perhaps signaling a new stage of activity. I discuss here what one might expect when a microquasar is scaled up to AGN dimensions, and compare this with what we see in 3C 120. There is a mismatch between expectations and observations.

  2. Thermodynamic properties of solid face centered cubic Rb3C60 at high temperature and pressure

    NASA Astrophysics Data System (ADS)

    Yang, W.; Sun, J. X.; Liu, H.; Yan, G. F.

    2014-03-01

    Analytic equation of state and thermodynamic quantities of solid fcc Rb3C60 are derived by using an analytic mean field potential method. For intermolecular forces, the double-exponential potential is utilized. Four potential parameters are determined by fitting experimental compression data of Rb3C60 up to 14 GPa at 296 K. Various physical quantities including isothermals, thermal expansion, isochoric heat capacity, Helmholtz free energy and internal energy are calculated and analyzed. Calculated results are consistent with available experimental data in literature. Furthermore, spinodal temperature for Rb3C60 is found to be 2,860 K. Results verify that analytic mean field potential method is a useful approach to consider the anharmonic effect at high temperatures. Numerous reasonable predictions and the change trend of the properties for Rb3C60 at high temperature and pressure have been given.

  3. Structural Basis for Molecular Discrimination by a 3',3'-cGAMP Sensing Riboswitch

    SciTech Connect

    Ren, Aiming; Wang, Xin  C.; Kellenberger, Colleen  A.; Rajashankar, Kanagalaghatta  R.; Jones, Roger  A.; Hammond, Ming  C.; Patel, Dinshaw  J.

    2015-04-07

    Cyclic dinucleotides are second messengers that target the adaptor STING and stimulate the innate immune response in mammals. Besides protein receptors, there are bacterial riboswitches that selectively recognize cyclic dinucleotides. We recently discovered a natural riboswitch that targets 3',3'-cGAMP, which is distinguished from the endogenous mammalian signal 2',3'-cGAMP by its backbone connectivity. Here, we report on structures of the aptamer domain of the 3',3'-cGAMP riboswitch from Geobacter in the 3',3'-cGAMP and c-di-GMP bound states. The riboswitch adopts a tuning forklike architecture with a junctional ligand-binding pocket and different orientations of the arms are correlated with the identity of the bound cyclic dinucleotide. Subsequent biochemical experiments revealed that specificity of ligand recognition can be affected by point mutations outside of the binding pocket, which has implications for both the assignment and reengineering of riboswitches in this structural class.

  4. Two new 3-C-carboxylated flavones from the rhizomes of Caragana conferta.

    PubMed

    Khan, Rehan; Malika, Abdul; Yasmeen, Shazia; Afza, Nighat

    2010-12-01

    Confertins A (1) and B (2), new 3-C-carboxylated flavones, have been isolated from the ethyl acetate soluble fraction of the rhizomes of Caragana conferta. Their structures have been assigned on the basis of spectroscopic studies.

  5. Bright optical outburst with rapid optical variability of the blazar 3C 279

    NASA Astrophysics Data System (ADS)

    Jankowsky, F.; Glawion, D.; Schwemmer, S.; Wagner, S.

    2017-03-01

    Optical observations of the gamma-ray bright, flat-spectrum radio quasar 3C 279 (z=0.536) with the Automatic Telescope for Optical Monitoring (ATOM) confirm a very bright optical state and rapid flares.

  6. Growing 3C-SiC heteroepitaxial layers on α-SiC substrate by vapour-liquid-solid mechanism from the Al-Ge-Si ternary system

    NASA Astrophysics Data System (ADS)

    Lorenzzi, Jean; Ferro, Gabriel; Cauwet, François; Souliere, Véronique; Carole, Davy

    2011-03-01

    In this work, we present and compare the results obtained from different Si-based melts (Ge-Si, Al-Si and Al-Ge-Si) for growing SiC layers on α-SiC substrate by vapour-liquid-solid (VLS) mechanism. It was found that, depending on melt composition, the deposit could be either a complete 3C or α-SiC layer or even a mixture of these polytypes. The binary Al-Si melt leads systematically to a highly p-type homoepitaxial α-SiC deposit while Ge-Si melt gives a non-intentional n-type doped layers of either 3C or 6H polytypes depending on growth conditions. However, highly p-type doped 3C heteroepitaxial deposit can be obtained if a small amount of Al is added to the Ge-Si binary liquid phase. This means that the VLS mechanism is very flexible and allows growing either n- or p-type SiC layers of 3C or 6H polytypes.

  7. Magnetic and Electronic Properties of Nanocrystalline Fe2B and Fe3C Compounds

    NASA Astrophysics Data System (ADS)

    Dorolti, E.; Vlaic, P.; Burzo, E.; Djéga-Mariadassou, C.

    2007-04-01

    The nanocrystalline Fe3C and Fe2B samples were prepared by high energy ball milling and subsequent annealing. The saturation magnetization at 4.2 K is 1.94 μB/ f.u. for Fe3C and 1.75 μB/ f.u. for Fe2B. Band structure calculations show a negative polarization at B and C sites. The computed iron moments are close to experimentally determined values.

  8. Efficient femtosecond laser micromachining of bulk 3C-SiC

    NASA Astrophysics Data System (ADS)

    Farsari, M.; Filippidis, G.; Zoppel, S.; Reider, G. A.; Fotakis, C.

    2005-09-01

    We demonstrate surface micromachining of bulk 3C silicon carbide (3C-SiC) wafers by employing tightly focused infrared femtosecond laser pulses of energy less than 10 nJ directly from a femtosecond laser oscillator, thus eliminating the need for an amplified system and increasing the micromachining speed by more than four orders of magnitude. In addition, we show that high aspect ratio through-tapered vias can be drilled in 400 µm thick wafers using an amplified femtosecond laser.

  9. 40 CFR Appendix A-2 to Part 60 - Test Methods 2G through 3C

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 8 2012-07-01 2012-07-01 false Test Methods 2G through 3C A Appendix A-2 to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES (CONTINUED) Pt. 60, App. A-2 Appendix A-2 to Part 60—Test Methods 2G through 3C Method...

  10. 40 CFR Appendix A-2 to Part 60 - Test Methods 2G through 3C

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 7 2011-07-01 2011-07-01 false Test Methods 2G through 3C A Appendix A-2 to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES (CONTINUED) Pt. 60, App. A-2 Appendix A-2 to Part 60—Test Methods 2G through 3C Method...

  11. 40 CFR Appendix A-2 to Part 60 - Test Methods 2G through 3C

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 7 2010-07-01 2010-07-01 true Test Methods 2G through 3C A Appendix A-2 to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES (CONTINUED) Pt. 60, App. A-2 Appendix A-2 to Part 60—Test Methods 2G through 3C...

  12. 40 CFR Appendix A-2 to Part 60 - Test Methods 2G through 3C

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 8 2013-07-01 2013-07-01 false Test Methods 2G through 3C A Appendix A-2 to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES (CONTINUED) Pt. 60, App. A-2 Appendix A-2 to Part 60—Test Methods 2G through 3C Method...

  13. AN ASYMMETRICAL SYNCHROTRON MODEL FOR KNOTS IN THE 3C 273 JET

    SciTech Connect

    Liu, Wen-Po; Chen, Y. J.; Wang, Chun-Cheng

    2015-06-20

    To interpret the emission of knots in the 3C 273 jet from radio to X-rays, we propose a synchrotron model in which, owing to the shock compression effect, the injection spectra from a shock into the upstream and downstream emission regions are asymmetric. Our model could well explain the spectral energy distributions of knots in the 3C 273 jet, and predictions regarding the knots’ spectra could be tested by future observations.

  14. Focusing of 3C144 Source Radiation by the Solar Corona

    NASA Astrophysics Data System (ADS)

    Galanin, V. V.; Derevjagin, V. G.; Kravetz, R. O.

    The research of solar corona by the compact cosmic source radiation was made on URAN-4 radio telescope. In the period from June 6 to June 20 2012 the flow of Crab nebula was measured on the 20 MHz and 25 MHz frequencies. During the eclipse we observe the great increase of 3C144 flow, which is compare with the flow of 3C461 source. Data and results of measurement analysis is presented.

  15. Picornaviral 3C cysteine proteinases have a fold similar to the chymotrypsin-like serine proteinases

    SciTech Connect

    Allaire,M.; Chernaia, M.; Malcolm, B.; James, M.

    1994-01-01

    The picornavirus family includes several pathogens such as poliovirus, rhinovirus (the major cause of the common cold), hepatitis A virus and the foot-and-mouth disease virus. Picornaviral proteins are expressed by direct translation of the genomic RNA into a single, large polyprotein precursor. Proteolysis of the viral polyprotein into the mature proteins is assured by the viral 3C enzymes, which are cysteine proteinases. Here we report the X-ray crystal structure at 2.3 {angstrom} resolution of the 3C proteinase from hepatitis A virus (HAV-3C). The overall architecture of HAV-3C reveals a fold resembling that of the chymotrypsin family of serine proteinases, which is consistent with earlier predictions. Catalytic residues include Cys 172 as nucleophile and His 44 as general base. The 3C cleavage specificity for glutamine residues is defined primarily by His 191. The overall structure suggests that an inter-molecular (trans) cleavage releases 3C and that there is an active proteinase in the polyprotein.

  16. Atomic-scale recognition of surface structure and intercalation mechanism of Ti3C2X.

    PubMed

    Wang, Xuefeng; Shen, Xi; Gao, Yurui; Wang, Zhaoxiang; Yu, Richeng; Chen, Liquan

    2015-02-25

    MXenes represent a large family of functionalized two-dimensional (2D) transition-metal carbides and carbonitrides. However, most of the understanding on their unique structures and applications stops at the theoretical suggestion and lack of experimental support. Herein, the surface structure and intercalation chemistry of Ti3C2X are clarified at the atomic scale by aberration-corrected scanning transmission electron microscope (STEM) and density functional theory (DFT) calculations. The STEM studies show that the functional groups (e.g., OH(-), F(-), O(-)) and the intercalated sodium (Na) ions prefer to stay on the top sites of the centro-Ti atoms and the C atoms of the Ti3C2 monolayer, respectively. Double Na-atomic layers are found within the Ti3C2X interlayer upon extensive Na intercalation via two-phase transition and solid-solution reactions. In addition, aluminum (Al)-ion intercalation leads to horizontal sliding of the Ti3C2X monolayer. On the basis of these observations, the previous monolayer surface model of Ti3C2X is modified. DFT calculations using the new modeling help to understand more about their physical and chemical properties. These findings enrich the understanding of the MXenes and shed light on future material design and applications. Moreover, the Ti3C2X exhibits prominent rate performance and long-term cycling stability as an anode material for Na-ion batteries.

  17. 43 and 86 GHz VLBI Polarimetry of 3C454.3

    NASA Astrophysics Data System (ADS)

    Hunacek, A.; Attridge, J. M.

    2004-12-01

    Very Long Baseline Array (VLBA) observations of the quasar 3C454.3 were made at epoch 2003.75, at 43 and 86 GHz in full polarization mode. Very Long Baseline Polarimetry (VLBP) is used to determine magnetic field structures in the jets of extragalactic radio sources at very high angular resolution - on the order of 0.3 milliarcseconds at 86 GHz. As Faraday rotation decreases with decreasing wavelength, high-frequency, high-resolution VLBP observations allow us to probe the polarization properties of Active Galactic Nuclei (AGNs) close to the super-massive black holes thought to be the central engines of these objects. New total intensity and linear polarization images of 3C454.3 at both 43 and 86 GHz are presented here, along with historical images for comparison. The new images include the first 86 GHz linear polarization images ever made of the source 3C454.3, and these results bring the number of sources for which successful 86 GHz polarimetry has been accomplished to three. As 3C454.3 is fainter at 86 GHz than its counterparts 3C273 and 3C279, the new observations are quite promising for the success of 86 GHz VLBP on weaker sources. This research was carried out as part of MIT Haystack Observatory's Research Experiences for Undergraduates program funded by the National Science Foundation.

  18. Synthesis and electrochemical performance of Ti3C2Tx with hydrothermal process

    NASA Astrophysics Data System (ADS)

    Wang, Libo; Zhang, Heng; Wang, Bo; Shen, Changjie; Zhang, Chuanxiang; Hu, Qianku; Zhou, Aiguo; Liu, Baozhong

    2016-09-01

    In this study, a simple hydrothermal method has been developed to prepare Ti3C2Tx from Ti3AlC2 as a high-performance electrode material for supercapacitors. This method is environmentally friendly and has a low level of danger. The morphology and structure of the Ti3C2Tx can be controlled by hydrothermal reaction time, temperature and NH4F amounts. The prepared Ti3C2Tx was characterized by X-ray diffraction, field emission scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and Brunauer-Emmet-Teller. The results show that the prepared Ti3C2Tx is terminated by O, OH, and F groups. The electrochemical properties of the Ti3C2Tx sample exhibit specific capacitance up to 141 Fcm-3 in 3 M KOH aqueous electrolyte, and even after 1000 cycles, no significant degradation of the volumetric capacitance was observed. These results indicate that the Ti3C2Tx material prepared by this hydrothermal method can be used in high performance supercapacitors.

  19. VLBI observations of a complete sample of radio galaxies. 4: The radio galaxies NGC 2484, 3C 109, and 3C 382

    NASA Technical Reports Server (NTRS)

    Giovannini, G.; Feretti, L.; Venturi, T.; Lara, L.; Marcaide, J.; Rioja, M.; Spangler, S. R.; Wehrle, A. E.

    1994-01-01

    We present here new Very Long Base Interferometry (VLBI) observations of one Fanaroff and Riley (F-R) I radio galaxy (NGC 2484) and two broad-line F-R II radio galaxies (3C 109 and 3C 382). For 3C 109 new Very Large Array (VLA) maps are also shown. These sources belong to a complete sample of radio galaxies under study for a better knowledge of their structures at parsec resolution. The parsec structure of these three objects is very similar: asymmetric emission, which we interpret as the core plus a one-side jet. The parsec-scale jet is always on the same side of the main kiloparsec-scale jet. The limit on the jet to counterjet brightness ratio, the ratio of the core radio power to the total radio power and the synchrotron-self Compton model allow us to derive some constraints on the jet velocity and orientation with respect to the line of sight. From these data and from those published on two other sources of our sample, we suggest that parsec-scale jets are relativistic in both F-R I and F-R II radio galaxies and that parsec scale properties in F-R I and F-R II radio galaxies are very similar despite the large difference between these two classes of radio galaxies on the kiloparsec scale.

  20. Image reconstruction algorithm for optically stimulated luminescence 2D dosimetry using laser-scanned Al2O3:C and Al2O3:C,Mg films

    NASA Astrophysics Data System (ADS)

    Ahmed, M. F.; Schnell, E.; Ahmad, S.; Yukihara, E. G.

    2016-10-01

    The objective of this work was to develop an image reconstruction algorithm for 2D dosimetry using Al2O3:C and Al2O3:C,Mg optically stimulated luminescence (OSL) films imaged using a laser scanning system. The algorithm takes into account parameters associated with detector properties and the readout system. Pieces of Al2O3:C films (~8 mm  ×  8 mm  ×  125 µm) were irradiated and used to simulate dose distributions with extreme dose gradients (zero and non-zero dose regions). The OSLD film pieces were scanned using a custom-built laser-scanning OSL reader and the data obtained were used to develop and demonstrate a dose reconstruction algorithm. The algorithm includes corrections for: (a) galvo hysteresis, (b) photomultiplier tube (PMT) linearity, (c) phosphorescence, (d) ‘pixel bleeding’ caused by the 35 ms luminescence lifetime of F-centers in Al2O3, (e) geometrical distortion inherent to Galvo scanning system, and (f) position dependence of the light collection efficiency. The algorithm was also applied to 6.0 cm  ×  6.0 cm  ×  125 μm or 10.0 cm  ×  10.0 cm  ×  125 µm Al2O3:C and Al2O3:C,Mg films exposed to megavoltage x-rays (6 MV) and 12C beams (430 MeV u-1). The results obtained using pieces of irradiated films show the ability of the image reconstruction algorithm to correct for pixel bleeding even in the presence of extremely sharp dose gradients. Corrections for geometric distortion and position dependence of light collection efficiency were shown to minimize characteristic limitations of this system design. We also exemplify the application of the algorithm to more clinically relevant 6 MV x-ray beam and a 12C pencil beam, demonstrating the potential for small field dosimetry. The image reconstruction algorithm described here provides the foundation for laser-scanned OSL applied to 2D dosimetry.

  1. Image reconstruction algorithm for optically stimulated luminescence 2D dosimetry using laser-scanned Al2O3:C and Al2O3:C,Mg films.

    PubMed

    Ahmed, M F; Schnell, E; Ahmad, S; Yukihara, E G

    2016-10-21

    The objective of this work was to develop an image reconstruction algorithm for 2D dosimetry using Al2O3:C and Al2O3:C,Mg optically stimulated luminescence (OSL) films imaged using a laser scanning system. The algorithm takes into account parameters associated with detector properties and the readout system. Pieces of Al2O3:C films (~8 mm  ×  8 mm  ×  125 µm) were irradiated and used to simulate dose distributions with extreme dose gradients (zero and non-zero dose regions). The OSLD film pieces were scanned using a custom-built laser-scanning OSL reader and the data obtained were used to develop and demonstrate a dose reconstruction algorithm. The algorithm includes corrections for: (a) galvo hysteresis, (b) photomultiplier tube (PMT) linearity, (c) phosphorescence, (d) 'pixel bleeding' caused by the 35 ms luminescence lifetime of F-centers in Al2O3, (e) geometrical distortion inherent to Galvo scanning system, and (f) position dependence of the light collection efficiency. The algorithm was also applied to 6.0 cm  ×  6.0 cm  ×  125 μm or 10.0 cm  ×  10.0 cm  ×  125 µm Al2O3:C and Al2O3:C,Mg films exposed to megavoltage x-rays (6 MV) and (12)C beams (430 MeV u(-1)). The results obtained using pieces of irradiated films show the ability of the image reconstruction algorithm to correct for pixel bleeding even in the presence of extremely sharp dose gradients. Corrections for geometric distortion and position dependence of light collection efficiency were shown to minimize characteristic limitations of this system design. We also exemplify the application of the algorithm to more clinically relevant 6 MV x-ray beam and a (12)C pencil beam, demonstrating the potential for small field dosimetry. The image reconstruction algorithm described here provides the foundation for laser-scanned OSL applied to 2D dosimetry.

  2. Mutations of 3c and spike protein genes correlate with the occurrence of feline infectious peritonitis.

    PubMed

    Bank-Wolf, Barbara Regina; Stallkamp, Iris; Wiese, Svenja; Moritz, Andreas; Tekes, Gergely; Thiel, Heinz-Jürgen

    2014-10-10

    The genes encoding accessory proteins 3a, 3b, 3c, 7a and 7b, the S2 domain of the spike (S) protein gene and the membrane (M) protein gene of feline infectious peritonitis virus (FIPV) and feline enteric coronavirus (FECV) samples were amplified, cloned and sequenced. For this faeces and/or ascites samples from 19 cats suffering from feline infectious peritonitis (FIP) as well as from 20 FECV-infected healthy cats were used. Sequence comparisons revealed that 3c genes of animals with FIP were heavily affected by nucleotide deletions and point mutations compared to animals infected with FECV; these alterations resulted either in early termination or destruction of the translation initiation codon. Two ascites-derived samples of cats with FIP which displayed no alterations of ORF3c harboured mutations in the S2 domain of the S protein gene which resulted in amino acid exchanges or deletions. Moreover, changes in 3c were often accompanied by mutations in S2. In contrast, in samples obtained from faeces of healthy cats, the ORF3c was never affected by such mutations. Similarly ORF3c from faecal samples of the cats with FIP was mostly intact and showed only in a few cases the same mutations found in the respective ascites samples. The genes encoding 3a, 3b, 7a and 7b displayed no mutations linked to the feline coronavirus (FCoV) biotype. The M protein gene was found to be conserved between FECV and FIPV samples. Our findings suggest that mutations of 3c and spike protein genes correlate with the occurrence of FIP.

  3. Antifungal effects of synthetic human β-defensin 3-C15 peptide

    PubMed Central

    Ahn, Ki-Bum; Kim, Christine; Kum, Jong-Won; Gu, Yu; Han, Seung Hyun; Shon, Won-Jun; Lee, Woocheol; Zhu, Qiang

    2016-01-01

    Objectives The purpose of this ex vivo study was to compare the antifungal activity of a synthetic peptide consisting of 15 amino acids at the C-terminus of human β-defensin 3 (HBD3-C15) with calcium hydroxide (CH) and Nystatin (Nys) against Candida albicans (C. albicans) biofilm. Materials and Methods C. albicans were grown on cover glass bottom dishes or human dentin disks for 48 hr, and then treated with HBD3-C15 (0, 12.5, 25, 50, 100, 150, 200, and 300 µg/mL), CH (100 µg/mL), and Nys (20 µg/mL) for 7 days at 37℃. On cover glass, live and dead cells in the biomass were measured by the FilmTracer Biofilm viability assay, and observed by confocal laser scanning microscopy (CLSM). On dentin, normal, diminished and ruptured cells were observed by field-emission scanning electron microscopy (FE-SEM). The results were subjected to a two-tailed t-test, a one way analysis variance and a post hoc test at a significance level of p = 0.05. Results C. albicans survival on dentin was inhibited by HBD3-C15 in a dose-dependent manner. There were fewer aggregations of C. albicans in the groups of Nys and HBD3-C15 (≥ 100 µg/mL). CLSM showed C. albicans survival was reduced by HBD3-C15 in a dose dependent manner. Nys and HBD3-C15 (≥ 100 µg/mL) showed significant fungicidal activity compared to CH group (p < 0.05). Conclusions Synthetic HBD3-C15 peptide (≥ 100 µg/mL) and Nys exhibited significantly higher antifungal activity than CH against C. albicans by inhibiting cell survival and biofilm. PMID:27200276

  4. Atomistic Simulations on the Thermal Stability of the Antisite Pair in 3C- and 4H-SiC

    SciTech Connect

    Posselt, Matthias; Gao, Fei; Weber, William J.

    2006-03-31

    The thermal stability of the first-neighbor antisite pair configurations in 3C- and 4H-SiC is investigated by a comprehensive atomistic study. At first the structure and energetics of these defects is determined in order to check the accuracy of the Gao-Weber interatomic potential used. The results are comparable with literature data obtained by the density-functional theory. Then, the lifetime of the antisite pair configurations is calculated for temperatures between 800 and 2500 K. Both in 3C- and 4H-SiC the thermal stability of the antisite pairs is rather low. In contrast to previous theoretical interpretations, the antisite pair can be therefore not correlated with the DI photoluminescence center that is stable to above 2000 K. The atomic mechanisms during the recombination of the antisite pair in 3C-SiC and of three antisite pair configurations in 4H-SiC is a modified concerted exchange. Due to the different sizes of the silicon and the carbon atoms, this process is not identical with the concerted exchange in Si. Two intermediate metastable configurations found during the recombination are similar to the bond defect in Si. Since the SiC lattice contains two types of atoms, there are also two different types of bond defects. The two bond defects can be considered as the result of the incomplete recombination of a carbon vacancy and a neighboring mixed dumbbell interstitial. For selected temperatures the thermal stability of the antisite pair in 3C-SiC is investigated by molecular dynamics simulations that are based on the density-functional theory. Their results are very similar to those of the atomistic study, i.e. the Gao-Weber potential describes the antisite pair and its recombination reasonably well. The antisite pair in 4H-SiC with the two atoms on hexagonal sites has a slightly different formation energy than the other three antisite pair configurations in 4H-SiC. Its lifetime shows another dependence on the temperature, and its recombination is

  5. Capacitance of Ti3C2Tx MXene in ionic liquid electrolyte

    NASA Astrophysics Data System (ADS)

    Lin, Zifeng; Barbara, Daffos; Taberna, Pierre-Louis; Van Aken, Katherine L.; Anasori, Babak; Gogotsi, Yury; Simon, Patrice

    2016-09-01

    Ti3C2Tx MXene, a two-dimensional (2D) early transition metal carbide, has shown an extremely high volumetric capacitance in aqueous electrolytes, but in a narrow voltage window (less than 1.23 V). The utilization of MXene materials in ionic liquid electrolytes with a large voltage window has never been addressed. Here, we report the preparation of the Ti3C2Tx MXene ionogel film by vacuum filtration for use as supercapacitor electrodes operating in 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI-TFSI) neat ionic liquid electrolyte. Due to the disordered structure of the Ti3C2Tx hydrogel film and a stable spacing after vacuum drying, achieved through ionic liquid electrolyte immersion of the Ti3C2Tx hydrogel film, the Ti3C2Tx surface became accessible to EMI+ and TFSI- ions. A capacitance of 70 F g-1 together with a large voltage window of 3 V was obtained at a scan rate of 20 mV s-1 in neat EMI-TFSI electrolyte. The electrochemical signature indicates a capacitive behavior even at a high scan rate (500 mV s-1) and a high power performance. This work opens up the possibilities of using MXene materials with various ionic liquid electrolytes.

  6. A Single Nucleotide Polymorphism in Human APOBEC3C Enhances Restriction of Lentiviruses

    PubMed Central

    Wittkopp, Cristina J.; Adolph, Madison B.; Wu, Lily I.; Chelico, Linda; Emerman, Michael

    2016-01-01

    Humans express seven human APOBEC3 proteins, which can inhibit viruses and endogenous retroelements through cytidine deaminase activity. The seven paralogs differ in the potency of their antiviral effects, as well as in their antiviral targets. One APOBEC3, APOBEC3C, is exceptional as it has been found to only weakly block viruses and endogenous retroelements compared to other APOBEC3s. However, our positive selection analyses suggest that APOBEC3C has played a role in pathogen defense during primate evolution. Here, we describe a single nucleotide polymorphism in human APOBEC3C, a change from serine to isoleucine at position 188 (I188) that confers potent antiviral activity against HIV-1. The gain-of-function APOBEC3C SNP results in increased enzymatic activity and hypermutation of target sequences when tested in vitro, and correlates with increased dimerization of the protein. The I188 is widely distributed in human African populations, and is the ancestral primate allele, but is not found in chimpanzees or gorillas. Thus, while other hominids have lost activity of this antiviral gene, it has been maintained, or re-acquired, as a more active antiviral gene in a subset of humans. Taken together, our results suggest that APOBEC3C is in fact involved in protecting hosts from lentiviruses. PMID:27732658

  7. Capacitance of Ti3C2Tx MXene in Ionic Liquid Electrolyte

    DOE PAGES

    Lin, Zifeng; Barbara, Daffos; Taberna, Pierre-Louis; ...

    2016-04-14

    Ti3C2Tx MXene, a two-dimensional (2D) early transition metal carbide, has shown an extremely high volumetric capacitance in aqueous electrolytes, but in a narrow voltage window (less than 1.23 V). The utilization of MXene materials in ionic liquid electrolytes with a large voltage window has never been addressed. Here, we report the preparation of the Ti3C2Tx MXene ionogel film by vacuum filtration for use as supercapacitor electrodes operating in 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI-TFSI) neat ionic liquid electrolyte. Due to the disordered structure of the Ti3C2Tx hydrogel film and a stable spacing after vacuum drying, achieved through ionic liquid electrolyte immersion of themore » Ti3C2Tx hydrogel film, the Ti3C2Tx surface became accessible to EMI+ and TFSI- ions. A capacitance of 70 F g-1 together with a large voltage window of 3 V was obtained at a scan rate of 20 mV s-1 in neat EMI-TFSI electrolyte. The electrochemical signature indicates a capacitive behavior even at a high scan rate (500 mV s-1) and a high power performance. This work opens up the possibilities of using MXene materials with various ionic liquid electrolytes.« less

  8. Metagenomic chromosome conformation capture (meta3C) unveils the diversity of chromosome organization in microorganisms

    PubMed Central

    Marbouty, Martial; Cournac, Axel; Flot, Jean-François; Marie-Nelly, Hervé; Mozziconacci, Julien; Koszul, Romain

    2014-01-01

    Genomic analyses of microbial populations in their natural environment remain limited by the difficulty to assemble full genomes of individual species. Consequently, the chromosome organization of microorganisms has been investigated in a few model species, but the extent to which the features described can be generalized to other taxa remains unknown. Using controlled mixes of bacterial and yeast species, we developed meta3C, a metagenomic chromosome conformation capture approach that allows characterizing individual genomes and their average organization within a mix of organisms. Not only can meta3C be applied to species already sequenced, but a single meta3C library can be used for assembling, scaffolding and characterizing the tridimensional organization of unknown genomes. By applying meta3C to a semi-complex environmental sample, we confirmed its promising potential. Overall, this first meta3C study highlights the remarkable diversity of microorganisms chromosome organization, while providing an elegant and integrated approach to metagenomic analysis. DOI: http://dx.doi.org/10.7554/eLife.03318.001 PMID:25517076

  9. Path-integral molecular dynamics simulation of 3C-SiC

    NASA Astrophysics Data System (ADS)

    Ramírez, Rafael; Herrero, Carlos P.; Hernández, Eduardo R.; Cardona, Manuel

    2008-01-01

    Molecular dynamics simulations of 3C-SiC have been performed as a function of pressure and temperature. These simulations treat both electrons and atomic nuclei by quantum mechanical methods. While the electronic structure of the solid is described by an efficient tight-binding Hamiltonian, the nuclei dynamics is treated by the path-integral formulation of statistical mechanics. To assess the relevance of nuclear quantum effects, the results of quantum simulations are compared to others where either the Si nuclei, the C nuclei, or both atomic nuclei are treated as classical particles. We find that the experimental thermal expansion of 3C-SiC is realistically reproduced by our simulations. The calculated bulk modulus of 3C-SiC and its pressure derivative at room temperature show also good agreement with the available experimental data. The effect of the electron-phonon interaction on the direct electronic gap of 3C-SiC has been calculated as a function of temperature and related to results obtained for bulk diamond and Si. Comparison to available experimental data shows satisfactory agreement, although we observe that the employed tight-binding model tends to overestimate the magnitude of the electron-phonon interaction. The effect of treating the atomic nuclei as classical particles on the direct gap of 3C-SiC has been assessed. We find that nonlinear quantum effects related to the atomic masses are particularly relevant at temperatures below 250K .

  10. High-energy lithium-ion hybrid supercapacitors composed of hierarchical urchin-like WO3/C anodes and MOF-derived polyhedral hollow carbon cathodes.

    PubMed

    Xu, Juan; Li, Yuanyuan; Wang, Lei; Cai, Qifa; Li, Qingwei; Gao, Biao; Zhang, Xuming; Huo, Kaifu; Chu, Paul K

    2016-09-22

    A lithium-ion hybrid supercapacitor (Li-HSC) comprising a Li-ion battery type anode and an electrochemical double layer capacitance (EDLC) type cathode has attracted much interest because it accomplishes a large energy density without compromising the power density. In this work, hierarchical carbon coated WO3 (WO3/C) with a unique mesoporous structure and metal-organic framework derived nitrogen-doped carbon hollow polyhedra (MOF-NC) are prepared and adopted as the anode and the cathode for Li-HSCs. The hierarchical mesoporous WO3/C microspheres assembled by radially oriented WO3/C nanorods along the (001) plane enable effective Li(+) insertion, thus exhibit high capacity, excellent rate performance and a long cycling life due to their high Li(+) conductivity, electronic conductivity and structural robustness. The WO3/C structure shows a reversible specific capacity of 508 mA h g(-1) at a 0.1 C rate (1 C = 696 mA h g(-1)) after 160 discharging-charging cycles with excellent rate capability. The MOF-NC achieved the specific capacity of 269.9 F g(-1) at a current density of 0.2 A g(-1). At a high current density of 6 A g(-1), 92.4% of the initial capacity could be retained after 2000 discharging-charging cycles, suggesting excellent cycle stability. The Li-HSC comprising a WO3/C anode and a MOF-NC cathode boasts a large energy density of 159.97 W h kg(-1) at a power density of 173.6 W kg(-1) and 88.3% of the capacity is retained at a current density of 5 A g(-1) after 3000 charging-discharging cycles, which are better than those previously reported for Li-HSCs. The high energy and power densities of the Li-HSCs of WO3/C//MOF-NC render large potential in energy storage.

  11. Temperature behavior of the conduction electrons in the nitrogen-doped 3C SiC monocrystals as studied by electron spin resonance

    NASA Astrophysics Data System (ADS)

    Savchenko, D.; Kalabukhova, E.; Prokhorov, A.; Lančok, J.; Shanina, B.

    2017-01-01

    The temperature behavior of the electron spin resonance (ESR) spectra of nitrogen donors in n-type bulk 3C SiC monocrystals with (ND - NA) ≈ 1017 cm-3 was studied at T = 10-50 K. The triplet lines due to the hyperfine (hf) interaction with 14N nuclei (I = 1, 99.6%) along with a single line with similar isotropic g values of 2.0050(3) were observed in the ESR spectrum of n-type 3C SiC monocrystals in the temperature interval from 10 to 35 K. The observed reduction of the hf splitting for the nitrogen donor residing cubic position (Nk) in the temperature interval from 15 to 35 K was attributed to the motion narrowing effect of the hf splitting. With further increase of the temperature up to 35 K, only one single line with a Lorentzian lineshape was observed in the ESR spectrum of n-type 3C SiC, which was previously assigned in the literature to the unknown deeper donor center. Based on the temperature behavior of the ESR linewidth, integral intensity, and g-value, we have attributed this signal to the conduction electrons (CEs). The temperature dependence of the CE ESR linewidth was described by an exponential law (Orbach process) with the value of the activation energy ΔE ≈ 40 meV close to the energy separation between 1 s(E) excited energy level and conduction band for nitrogen donors. The nitrogen donor pairs were found in the ESR spectrum of n-type 3C SiC. The electrical characteristics of 3C SiC sample were studied by using the contact-free microwave conductivity. The energy ionization of nitrogen donor Ei = 51.4 meV was obtained from the fitting of the experimental data with the theory.

  12. Temperature response of photosynthesis in C3, C4, and CAM plants: temperature acclimation and temperature adaptation.

    PubMed

    Yamori, Wataru; Hikosaka, Kouki; Way, Danielle A

    2014-02-01

    Most plants show considerable capacity to adjust their photosynthetic characteristics to their growth temperatures (temperature acclimation). The most typical case is a shift in the optimum temperature for photosynthesis, which can maximize the photosynthetic rate at the growth temperature. These plastic adjustments can allow plants to photosynthesize more efficiently at their new growth temperatures. In this review article, we summarize the basic differences in photosynthetic reactions in C3, C4, and CAM plants. We review the current understanding of the temperature responses of C3, C4, and CAM photosynthesis, and then discuss the underlying physiological and biochemical mechanisms for temperature acclimation of photosynthesis in each photosynthetic type. Finally, we use the published data to evaluate the extent of photosynthetic temperature acclimation in higher plants, and analyze which plant groups (i.e., photosynthetic types and functional types) have a greater inherent ability for photosynthetic acclimation to temperature than others, since there have been reported interspecific variations in this ability. We found that the inherent ability for temperature acclimation of photosynthesis was different: (1) among C3, C4, and CAM species; and (2) among functional types within C3 plants. C3 plants generally had a greater ability for temperature acclimation of photosynthesis across a broad temperature range, CAM plants acclimated day and night photosynthetic process differentially to temperature, and C4 plants was adapted to warm environments. Moreover, within C3 species, evergreen woody plants and perennial herbaceous plants showed greater temperature homeostasis of photosynthesis (i.e., the photosynthetic rate at high-growth temperature divided by that at low-growth temperature was close to 1.0) than deciduous woody plants and annual herbaceous plants, indicating that photosynthetic acclimation would be particularly important in perennial, long-lived species that

  13. 3C 57 as an atypical radio-loud quasar: implications for the radio-loud/radio-quiet dichotomy

    NASA Astrophysics Data System (ADS)

    Sulentic, J. W.; Martínez-Carballo, M. A.; Marziani, P.; del Olmo, A.; Stirpe, G. M.; Zamfir, S.; Plauchu-Frayn, I.

    2015-06-01

    Lobe-dominated radio-loud (LD RL) quasars occupy a restricted domain in the 4D Eigenvector 1 (4DE1) parameter space which implies restricted geometry/physics/kinematics for this subclass compared to the radio-quiet (RQ) majority of quasars. We discuss how this restricted domain for the LD RL parent population supports the notion for a RQ-RL dichotomy among type 1 sources. 3C 57 is an atypical RL quasar that shows both uncertain radio morphology and falls in a region of 4DE1 space where RL quasars are rare. We present new radio flux and optical spectroscopic measures designed to verify its atypical optical/UV spectroscopic behaviour and clarify its radio structure. The former data confirms that 3C 57 falls off the 4DE1 quasar `main sequence' with both extreme optical Fe II emission (R_{Fe II} ˜ 1) and a large C IV λ1549 profile blueshift (˜-1500 km s-1). These parameter values are typical of extreme Population A sources which are almost always RQ. New radio measures show no evidence for flux change over a 50+ year time-scale consistent with compact steep-spectrum (or young LD) over core-dominated morphology. In the 4DE1 context where LD RL are usually low L/LEdd quasars, we suggest that 3C 57 is an evolved RL quasar (i.e. large blackhole mass) undergoing a major accretion event leading to a rejuvenation reflected by strong Fe II emission, perhaps indicating significant heavy metal enrichment, high bolometric luminosity for a low-redshift source and resultant unusually high Eddington ratio giving rise to the atypical C IV λ1549.

  14. Ab initio study of optical and vibrational properties of Ni3C

    NASA Astrophysics Data System (ADS)

    Golivand, Mohammad Bagher; Boochani, Arash; Akhtar, Arsalan; Torkashvand, Maryam; Karimian, Nashmyl

    2017-01-01

    The structural, electronic, optical and vibrational properties of Ni3C have been studied by density functional theory (DFT) framework with first-principles study. The obtained structural parameters are in good agreement with other works. The electronic study demonstrates metallic behavior of Ni3C since it has no energy gap at Fermi level. The optical parameters such as real and imaginary dielectric functions, loss function, conductivity, reflection, refraction indexes and absorption coefficients are studied. The phonon investigations confirm that the Ni3C bulk is dynamically stable and carbon has a major role in optical spectrum of the material at infrared region. Finally, the T3 behavior of Cv at low temperatures is obtained, as expected.

  15. Superconductivity at 28 K in CaB3C3 predicted from first-principles

    NASA Astrophysics Data System (ADS)

    Chen, Wanjin

    2013-11-01

    The structural parameters, electronic properties, and superconducting state in the graphite-like BxC1-x intercalation compound, CaB3C3, have been studied using pseudopotential density functional theory within the generalized gradient approximation. Electronic and electron-phonon coupling calculations reveal that CaB3C3 is hole conducting and superconducting with critical temperature 28.2 K, which is much higher than that of CaC6 (11.5 K). The excellent superconducting state in CaB3C3 stems from the simultaneous presence of highly mobile and extremely confined conduction electrons, which enhances electron pairing and superconductivity. The current calculations might stimulate further theoretical and experimental investigation in search of new superconducting states in graphite-like BxC1-x intercalated compounds.

  16. New Filling Technique and Performance Evaluations of the Cr3C2-C Peritectic Fixed Point

    NASA Astrophysics Data System (ADS)

    Sasajima, N.; Lowe, D.; Bai, C.; Yamada, Y.; Ara, C.

    2011-12-01

    The Cr3C2-C peritectic fixed point was investigated to test its capability to serve as a practical high-temperature fixed point. An improved filling technique where C/C sheet works as a wick and graphite paper as a hopper was applied successfully, and the long-term stability of the peritectic cell was evaluated by means of radiation thermometry. The repeatability of the melting point in one day was 7 mK with a melting range of approximately 100 mK. The cell was aged for 7 days, and the evaluated 56 melting temperatures during this period all fall within 90 mK, with a standard deviation of 19 mK. X-ray transmission photos showed that the ingot was filled uniformly in the crucible. After the evaluation of long-term stability, no clear degradation of the ingot shape and no leakage of molten metal were observed. From these results, it can be concluded that the Cr3C2-C peritectic cell has good stability and robustness, and the new filling technique was established. The impurity effect on the Cr3C2-C peritectic cell was also investigated by adding tungsten powder to another cell as the impurity component. After the observation of melting and freezing plateaux, the cell was cut in half to analyze the microstructure by means of electron probe microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS). The high concentration of impurity was observed in the area of the chromium-rich domain (eutectic mixture of Cr7C3 and Cr3C2), which suggests that impurities were rejected from the Cr3C2 peritectic phase during the peritectic freezing and were accumulated in the Cr7C3-Cr3C2 eutectic phase. This explains why the impurity effect is more severe for the Cr7C3-Cr3C2 eutectic point than for the Cr3C2-C peritectic point.

  17. Structure of Nanocrystalline Ti3C2 MXene Using Atomic Pair Distribution Function

    NASA Astrophysics Data System (ADS)

    Shi, Chenyang; Beidaghi, Majid; Naguib, Michael; Mashtalir, Olha; Gogotsi, Yury; Billinge, Simon J. L.

    2014-03-01

    The structures of nanocrystalline pristine, potassium hydroxide and sodium acetate intercalated new two-dimensional materials Ti3C2 MXenes were studied using the x-ray atomic pair distribution function technique. Pristine MXene has a hexagonal structure with a =b=3.0505(5) Å, c =19.86(2) Å (S.G. P63/mmc No. 194). Both hydroxyl and fluoride terminating species are present. The intercalation of K+ or Na+ ions expands the Ti3C2 layers perpendicular to the planes but shrinks the in-plane a and b lattice parameters.

  18. Structure of nanocrystalline Ti3C2 MXene using atomic pair distribution function.

    PubMed

    Shi, Chenyang; Beidaghi, Majid; Naguib, Michael; Mashtalir, Olha; Gogotsi, Yury; Billinge, Simon J L

    2014-03-28

    The structures of nanocrystalline pristine, potassium hydroxide and sodium acetate intercalated new two-dimensional materials Ti3C2 MXenes were studied using the x-ray atomic pair distribution function technique. Pristine MXene has a hexagonal structure with a=b=3.0505(5)  Å, c=19.86(2)  Å (S.G. P63/mmc No. 194). Both hydroxyl and fluoride terminating species are present. The intercalation of K+ or Na+ ions expands the Ti3C2 layers perpendicular to the planes but shrinks the in-plane a and b lattice parameters.

  19. Polymorphism control of superconductivity and magnetism in Cs(3)C(60) close to the Mott transition.

    PubMed

    Ganin, Alexey Y; Takabayashi, Yasuhiro; Jeglic, Peter; Arcon, Denis; Potocnik, Anton; Baker, Peter J; Ohishi, Yasuo; McDonald, Martin T; Tzirakis, Manolis D; McLennan, Alec; Darling, George R; Takata, Masaki; Rosseinsky, Matthew J; Prassides, Kosmas

    2010-07-08

    The crystal structure of a solid controls the interactions between the electronically active units and thus its electronic properties. In the high-temperature superconducting copper oxides, only one spatial arrangement of the electronically active Cu(2+) units-a two-dimensional square lattice-is available to study the competition between the cooperative electronic states of magnetic order and superconductivity. Crystals of the spherical molecular C(60)(3-) anion support both superconductivity and magnetism but can consist of fundamentally distinct three-dimensional arrangements of the anions. Superconductivity in the A(3)C(60) (A = alkali metal) fullerides has been exclusively associated with face-centred cubic (f.c.c.) packing of C(60)(3-) (refs 2, 3), but recently the most expanded (and thus having the highest superconducting transition temperature, T(c); ref. 4) composition Cs(3)C(60) has been isolated as a body-centred cubic (b.c.c.) packing, which supports both superconductivity and magnetic order. Here we isolate the f.c.c. polymorph of Cs(3)C(60) to show how the spatial arrangement of the electronically active units controls the competing superconducting and magnetic electronic ground states. Unlike all the other f.c.c. A(3)C(60) fullerides, f.c.c. Cs(3)C(60) is not a superconductor but a magnetic insulator at ambient pressure, and becomes superconducting under pressure. The magnetic ordering occurs at an order of magnitude lower temperature in the geometrically frustrated f.c.c. polymorph (Néel temperature T(N) = 2.2 K) than in the b.c.c.-based packing (T(N) = 46 K). The different lattice packings of C(60)(3-) change T(c) from 38 K in b.c.c. Cs(3)C(60) to 35 K in f.c.c. Cs(3)C(60) (the highest found in the f.c.c. A(3)C(60) family). The existence of two superconducting packings of the same electronically active unit reveals that T(c) scales universally in a structure-independent dome-like relationship with proximity to the Mott metal-insulator transition

  20. Synthesis of WC powder through microwave heating of WO3-C mixture

    NASA Astrophysics Data System (ADS)

    Behnami, Amir Karimzadeh; Hoseinpur, Arman; Sakaki, Masoud; Bafghi, Mohammad Sh.; Yanagisawa, Kazumichi

    2017-02-01

    A simple, easy, and low-cost process for the fabrication of tungsten carbide (WC) powder through microwave heating of WO3-C mixtures was developed. Thermodynamic calculations and experimental investigations were carried out for WO3-C and W-C systems, and a formation mechanism was proposed. In the results, for the synthesis of WC, the use of over stoichiometric amount of C together with a specially assembled experimental setup (which effectively retains heat in the system) is necessary. The WC powder is successfully obtained by heating WO3:5C mixture for 900 s in a domestic microwave oven.

  1. Jet-induced star formation in 3C 285 and Minkowski's Object

    NASA Astrophysics Data System (ADS)

    Salomé, Q.; Salomé, P.; Combes, F.

    2015-02-01

    How efficiently star formation proceeds in galaxies is still an open question. Recent studies suggest that active galactic nucleus (AGN) can regulate the gas accretion and thus slow down star formation (negative feedback). However, evidence of AGN positive feedback has also been observed in a few radio galaxies (e.g. Centaurus A, Minkowski's Object, 3C 285, and the higher redshift 4C 41.17). Here we present CO observations of 3C 285 and Minkowski's Object, which are examples of jet-induced star formation. A spot (named 3C 285/09.6 in the present paper) aligned with the 3C 285 radio jet at a projected distance of ~70 kpc from the galaxy centre shows star formation that is detected in optical emission. Minkowski's Object is located along the jet of NGC 541 and also shows star formation. Knowing the distribution of molecular gas along the jets is a way to study the physical processes at play in the AGN interaction with the intergalactic medium. We observed CO lines in 3C 285, NGC 541, 3C 285/09.6, and Minkowski's Object with the IRAM 30 m telescope. In the central galaxies, the spectra present a double-horn profile, typical of a rotation pattern, from which we are able to estimate the molecular gas density profile of the galaxy. The molecular gas appears to be in a compact reservoir, which could be evidence of an early phase of the gas accretion after a recent merger event in 3C 285. No kinematic signature of a molecular outflow is detected by the 30 m telescope. Interestingly, 3C 285/09.6 and Minkowski's Object are not detected in CO. The cold gas mass upper limits are consistent with a star formation induced by the compression of dense ambient material by the jet. The depletion time scales in 3C 285/09.6 and Minkowski's Object are of the order of and even shorter than what is found in 3C 285, NGC 541, and local spiral galaxies (109 yr). The upper limit of the molecular gas surface density in 3C 285/09.6 at least follows a Schmidt-Kennicutt law if the emitting region

  2. (001) 3C SiC/Ni contact interface: In situ XPS observation of annealing induced Ni2Si formation and the resulting barrier height changes

    NASA Astrophysics Data System (ADS)

    Tengeler, Sven; Kaiser, Bernhard; Chaussende, Didier; Jaegermann, Wolfram

    2017-04-01

    The electronic states of the (001) 3C SiC/Ni interface prior and post annealing are investigated via an in situ XPS interface experiment, allowing direct observation of the induced band bending and the transformation from Schottky to ohmic behaviour for the first time. A single domain (001) 3C SiC sample was prepared via wet chemical etching. Nickel was deposited on the sample in multiple in situ deposition steps via RF sputtering, allowing observation of the 3C SiC/Ni interface formation. Over the course of the experiments, an upward band bending of 0.35 eV was observed, along with defect induced Fermi level pinning. This indicates a Schottky type contact behaviour with a barrier height of 0.41 eV. The subsequent annealing at 850 °C for 5 min resulted in the formation of a Ni2Si layer and a reversal of the band bending to 0.06 eV downward. Thus explaining the ohmic contact behaviour frequently reported for annealed n-type 3C SiC/Ni contacts.

  3. The Galactic plane region near ℓ = 93°. III. Multi-wavelength emission from SNR 3C 434.1

    NASA Astrophysics Data System (ADS)

    Foster, T.

    2005-10-01

    New Canadian Galactic Plane Survey radio continuum, ROSAT X-ray, and optical line observations of supernova remnant (SNR) 3C 434.1 (G94.0+1.0) are presented. A radio spectrum of index α=0.4 (where S∝ ν -α ) confirms this SNR's emission signature as predominantly synchrotron, and suggests the SNR is in the Sedov expansion phase. The morphology of the remnant is compared in X-ray, optical, and radio continuum, and the brightest emission in all three wavelength regimes is from the eastern hemisphere of 3C 434.1, which marks where the SNR shock is interacting with the inside wall of its stellar wind bubble (SWB) home. The system is determined to be 4.5 kpc distant, residing in the Perseus Arm Spiral shock. From a deep Hα mosaic of the region, λ 656 nm Hα line emission is observed that correlates well with radio synchrotron emission and anticorrelates with X-ray emission from the SNR. The origin of this optical emission is likely dense (ne=40 cm-3) cooling H II from the wall of the SWB, where the SNR shock has penetrated and become radiative (vs˜ 100 km s-1). The X-ray spectrum of this SNR between 0.5 and 2.4 keV is well modelled by a single-temperature thermal plasma (Te=4.5×106 K, ne=0.2 cm-3). The magnetic field of the bright radio synchrotron emission region is found (under the assumption of near equipartition) to be B˜ 15 μ G, a factor of 3 compression of the ambient ISM field (5 μ G). The westward extension of 3C 434.1 is the result of ongoing free expansion of the shock into the lower density interior of the SWB. I use multiwavelength observations to arrive at a unique solution for an interaction model of 3C 434.1 with the SWB, from which the age (t=25 000 yr) and mass ejected in the explosion (Mej=15.5 M⊙ ) are determined. I also find an initial blast-wave velocity of 1350 km s-1, typical of type 1b SNe.

  4. Fe3C nanoparticle decorated Fe/N doped graphene for efficient oxygen reduction reaction electrocatalysis

    NASA Astrophysics Data System (ADS)

    Niu, Yanli; Huang, Xiaoqin; Hu, Weihua

    2016-11-01

    Oxygen reduction reaction (ORR) electrocatalysts with high activity, low cost and good durability are crucial to promote the large-scale practical application of fuel cells. Particularly, iron carbide (Fe3C) supported on nitrogen-doped carbon has recently demonstrated compelling promise for ORR electrocatalysis. In this paper, we report the facile synthesis of mesoporous Fe/N-doped graphene with encapsulated Fe3C nanoparticles (Fe3C@Fe/N-graphene) and its superior ORR catalytic activity. This hybrid material was synthesized by the spontaneous oxidative polymerization of dopamine on graphene oxide (GO) sheets in the presence of iron ion, followed by thermal annealing in Argon (Ar) atmosphere. As-prepared material shows high ORR catalytic activity with overwhelming four-electron reduction pathway, long-term durability and high methanol tolerance in alkaline media. This work reports a facile method to synthesize promising ORR electrocatalysis with multiple components and hierarchical architecture, and may offer valuable insight into the underlying mechanism of Fe3C-boosted ORR activity of Fe/N doped carbon.

  5. Fermi LAT detection of renewed GeV activity from blazar 3C 279

    NASA Astrophysics Data System (ADS)

    Ciprini, Stefano; Gonzalez, Josefa Becerra

    2014-04-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed high-level gamma-ray activity from a source positionally consistent with the blazar 3C 279 (RA: 194.046527 deg, Dec: -5.789312 deg, J2000; Johnston et al.1995, AJ, 110, 880). ...

  6. Brightening of 3C 279 observed by INTEGRAL at hard X-rays

    NASA Astrophysics Data System (ADS)

    Bottacini, E.; Ferrigno, C.; Fotopoulou, S.; Collmar, W.; Pian, E.

    2015-06-01

    The flat spectrum radio quasar 3C 279 at z=0.536 is flaring in the gamma-ray band, as announced by AGILE and FERMI (ATels #7631 and #7633); a Swift/XRT follow-up showed a significant brightening in the X-ray band as well (ATel #7639).

  7. Optical monitoring of the superluminal quasar 3C 345 in 1984-1991

    NASA Astrophysics Data System (ADS)

    Babadzhanyants, M. K.; Belokon', E. T.; Gamm, N. G.

    1995-08-01

    This article continues a series of publications containing results of a program of optical monitoring of OVV quasars, blazars, and similar objects (the Petersburg Quasar Monitoring Program), which has been conducted at the Byurakan station of the St. Petersburg Astronomical Institute since 1968. Results of long-term monitoring of the quasar 3C 345 in 1984-1991 are presented. The observations were conducted in the B band and consist of 365 brightness estimates obtained on 219 nights. The optical variability of 3C 345 on time scales from tens of years to tens of minutes is discussed. In 1991, the appearance of a new large amplitude slow outburst is noted (the characteristic time for brightness variation is of the order of a year). This outburst is similar to outbursts in 1967-1968, 1970-1972, 1976-1977, and 1982-1983, which were associated with the emergence of superluminal components in the milliarcsecond radio jet of 3C 345. The 1991 outburst suggests the emergence from the core of a new superluminal component. Analysis of the full known optical brightness curve for 3C 345 (1965-1993) shows the possible existence of a (quasi-)period of 700 days, which implies the appearance of a new brightness maximum in the 1994 observing season.

  8. NMR reveals the surface functionalisation of Ti3C2 MXene.

    PubMed

    Hope, Michael A; Forse, Alexander C; Griffith, Kent J; Lukatskaya, Maria R; Ghidiu, Michael; Gogotsi, Yury; Grey, Clare P

    2016-02-21

    (1)H and (19)F NMR experiments have identified and quantified the internal surface terminations of Ti3C2Tx MXene. -F and -OH terminations are shown to be intimately mixed and there are found to be significantly fewer -OH terminations than -F and -O, with the proportions highly dependent on the synthesis method.

  9. Vip3C, a Novel Class of Vegetative Insecticidal Proteins from Bacillus thuringiensis

    PubMed Central

    Palma, Leopoldo; Hernández-Rodríguez, Carmen Sara; Maeztu, Mireya; Hernández-Martínez, Patricia; Ruiz de Escudero, Iñigo; Escriche, Baltasar; Muñoz, Delia; Van Rie, Jeroen; Ferré, Juan

    2012-01-01

    Three vip3 genes were identified in two Bacillus thuringiensis Spanish collections. Sequence analysis revealed a novel Vip3 protein class (Vip3C). Preliminary bioassays of larvae from 10 different lepidopteran species indicated that Vip3Ca3 caused more than 70% mortality in four species after 10 days at 4 μg/cm2. PMID:22865065

  10. Chandra Detection of a Parsec Scale Wind in the Broad Line Radio Galaxy 3C 382

    NASA Technical Reports Server (NTRS)

    Reeves, J. N.; Sambruna, R. M.; Braito, V.; Eracleous, Michael

    2009-01-01

    We present unambiguous evidence for a parsec scale wind in the Broad-Line Radio Galaxy (BLRG) 3C 382, the first radio-loud AGN whereby an outflow has been measured with X-ray grating spectroscopy. A 118 ks Chandra grating (HETG) observation of 3C 382 has revealed the presence of several high ionization absorption lines in the soft X-ray band, from Fe, Ne, Mg and Si. The absorption lines are blue-shifted with respect to the systemic velocity of 3C 382 by -840+/-60 km/s and are resolved by Chandra with a velocity width of sigma = 340+/-70 km/s. The outflow appears to originate from a single zone of gas of column density N(sub H) = 1.3 x 10(exp 21)/sq cm and ionization parameter log(E/erg/cm/s) = 2.45. From the above measurements we calculate that the outflow is observed on parsec scales, within the likely range from 10-1000 pc, i.e., consistent with an origin in the Narrow Line Region. Finally we also discuss the possibility of a much faster (0.1c) outflow component, based on a blue-shifted iron K(alpha) emission line in the Suzaku observation of 3C 382, which could have an origin in an accretion disk wind.

  11. The Multi-component X-ray Emission of 3C 273

    NASA Astrophysics Data System (ADS)

    Soldi, S.; Türler, M.; Paltani, S.; Courvoisier, T. J.-L.

    2009-05-01

    3C 273 is the brightest quasar in the sky and among the most extensively observed and studied AGN, therefore one of the most suitable targets for a long-term, multi-frequency study. The superposition of a thermal Comptonisation component, similar to that observed in Seyfert galaxies, and of a non-thermal component, related to the jet emission, seems to explain some of the spectral and timing properties of the X-ray emission of 3C 273. Yet, during some observations this dichotomy has not been observed and the variability properties could also be consistent with a single-component scenario, characterised by two parameters varying independently. In order to understand the nature of the X-ray emission in 3C 273, a series of observations up to 80-100 keV, possibly catching the source in different flux states, are essential. Simbol-X will be able to study the emission of 3C 273 in the broad 0.5-80 keV band with high sensitivity, allowing us to disentangle the emission from different spectral components, with 20-30 ks long observations. In addition, the shape and the origin of the high-energy emission of this quasar will be further constrained thanks to the AGILE and Fermi satellites, monitoring the γ-ray sky in the MeV-GeV energy domain.

  12. Cleavage of Maize chlorotic dwarf virus R78 protein by the viral 3C protease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize chlorotic dwarf virus (MCDV) is a member of the genus Waikavirus and encodes a 389 kDa polyprotein from its 11784 nt genomic RNA. Like many polyprotein-encoding viruses, MCDV contains a 3C-like virus protease that is presumably responsible for maturation cleavages of the polyprotein. However,...

  13. Single-step non-thermal plasma synthesis of 3C-SiC nanoparticles

    NASA Astrophysics Data System (ADS)

    Chaukulkar, Rohan P.; de Peuter, Koen; Ghodes, Jacob A.; Pylypenko, Svitlana; Cloud, Jacqueline E.; Yang, Yongan; Stradins, Paul; Agarwal, Sumit

    2015-01-01

    We present a scalable, single-step, non-thermal plasma synthesis technique for the growth of sub-5 nm, hydrogenated amorphous carbon (a-C:H) coated 3C-SiC nanoparticles (NPs). In a tubular flow reactor, we first nucleate and grow c-Si NPs upstream in a SiH4/Ar plasma. These c-Si NPs are then transported by gas flow to a downstream C2H2/Ar plasma, and carburized in-flight by carbon-containing radicals and ions to 3C-SiC NPs. X-ray diffraction and transmission electron microscopy indicate an NP size of ˜4 nm. X-ray photoelectron spectroscopy analysis confirms that the c-Si NPs are completely carburized to 3C-SiC. Fourier transform infrared spectroscopy shows that the surface of the 3C-SiC NPs is coated with a-C:H with some alkenyl termination, which can facilitate further solution-based surface functionalization for biomedical applications.

  14. 880 μm SMA Polarization Observations of the Quasar 3C 286

    NASA Astrophysics Data System (ADS)

    Hull, Charles L. H.; Girart, Josep M.; Zhang, Qizhou

    2016-10-01

    For decades, the bright radio quasar 3C 286 has been widely recognized as one of the most reliable polarization calibrators at centimeter wavelengths because of its unchanging polarization position angle and high polarization percentage. However, it has become clear in recent years that the polarization position angle of 3C 286 changes with increasing frequency, increasing from ˜33° at λ ≳ 3 cm to ˜38° at λ ≈ 1 mm. With the advent of high-sensitivity polarization observations by current and future (sub)millimeter telescopes, knowledge of the position angle of 3C 286 at higher frequencies is critical for calibration. We report the first polarization observations of 3C 286 at submillimeter wavelengths, taken at 880 μm (340 GHz) with the Submillimeter Array. We find a polarization position angle and percentage of 37\\buildrel{\\circ}\\over{.} 4+/- 1\\buildrel{\\circ}\\over{.} 5 and 15.7% ± 0.8%, respectively, which is consistent with previous measurements at 1 mm.

  15. Structural Basis for Molecular Discrimination by a 3',3'-cGAMP Sensing Riboswitch

    DOE PAGES

    Ren, Aiming; Wang, Xin  C.; Kellenberger, Colleen  A.; ...

    2015-04-07

    Cyclic dinucleotides are second messengers that target the adaptor STING and stimulate the innate immune response in mammals. Besides protein receptors, there are bacterial riboswitches that selectively recognize cyclic dinucleotides. We recently discovered a natural riboswitch that targets 3',3'-cGAMP, which is distinguished from the endogenous mammalian signal 2',3'-cGAMP by its backbone connectivity. Here, we report on structures of the aptamer domain of the 3',3'-cGAMP riboswitch from Geobacter in the 3',3'-cGAMP and c-di-GMP bound states. The riboswitch adopts a tuning forklike architecture with a junctional ligand-binding pocket and different orientations of the arms are correlated with the identity of the boundmore » cyclic dinucleotide. Subsequent biochemical experiments revealed that specificity of ligand recognition can be affected by point mutations outside of the binding pocket, which has implications for both the assignment and reengineering of riboswitches in this structural class.« less

  16. The extreme ultraviolet spectrum of the kinetically dominated quasar 3C 270.1

    NASA Astrophysics Data System (ADS)

    Punsly, Brian; Marziani, Paola

    2015-10-01

    Only a handful of quasars have been identified as kinetically dominated, their long-term time-averaged jet power, overline{Q}, exceeds the bolometric thermal emission, Lbol, associated with the accretion flow. This Letter presents the first extreme ultraviolet (EUV) spectrum of a kinetically dominated quasar, 3C 270.1. The EUV continuum flux density of 3C 270.1 is very steep, F_{ν } ˜ ν ^{-α _{EUV}}, αEUV = 2.98 ± 0.15. This value is consistent with the correlation of overline{Q}/L_{bol} and αEUV found in previous studies of the EUV continuum of quasars, the EUV deficit of radio loud quasars. Curiously, although ultraviolet broad absorption line (BAL) troughs in quasar spectra are anticorrelated with overline{Q}, 3C 270.1 has been considered a BAL quasar based on an SDSS spectrum. This claim is examined in terms of the EUV spectrum of O VI and the highest resolution C IV spectrum in the archival data and the SDSS spectrum. First, from [O III]4959,5007 (IR) observations and the UV spectral lines, it is concluded that the correct redshift for 3C 270.1 is 1.5266. It is then found that the standard measure of broad absorption, BALnicity = 0, for Mg II 2800, C IV 1549 and O VI 1032 in all epochs.

  17. Pressure Balance between Thermal and Non-Thermal Plasmas in the 3C129 Cluster

    NASA Astrophysics Data System (ADS)

    Harris, D. E.; Krawczynski, H.

    With new Chandra observations of the cluster containing the two radio galaxies 3C129 and 3C129.1, we have made a fit to the X-ray surface brightness to obtain thermal pressures. VLA data at 1.4 GHz have been obtained to complement previous maps at 0.33 GHz (Lane et al. 2002) and at 5 and 8 GHz (Taylor et al. 2001). From these radio data, we are able to derive the minimum non-thermal pressure of various emitting volumes along the tail of 3C129 and in the lobes of 3C129.1. Under the assumption that the non-thermal plasma excludes significant thermal plasma, we may expect pressure balance for most features since ram pressure should be important only close to the cores of the galaxies. Since we find that the minimum non-thermal pressures are generally only a factor of a few below estimates of the ambient thermal pressure, we conclude that it is unlikely that relativistic protons contribute significantly to the total pressure. Reasonable contributions from low energy electrons and filling factors in the range 0.1 to 1 suffice to achieve pressure balance. Although we do not find strong signatures for the exclusion of hot gas from the radio structures, we find soft features near the cores of both galaxies suggestive of cool gas stripping and hard features associated with radio jets and possibly a leading bow shock.

  18. The Angular Structure of Quasar 3C 47 in the Decameter Waveband

    NASA Astrophysics Data System (ADS)

    Lozinskiy, A. B.; Lozinskiy, R. A.; Ivantishin, O. L.; Romanchev, Y. V.; Rashkovskiy, S. L.; Shepelev, V. A.; Brazhenko, A. I.; Vashchishin, R. V.; Litvinenko, O. A.

    The quasar 3C47 was observed with the URAN network at decameter wavelengths. A model of its angular structure consisting of four components was fitted. Lobes of the source are enlarged significantly in the range if compare with their high frequency dimensions. The hot spots emission is detected at low frequencies but a radio core is disappeared completely due to its flat spectrum.

  19. Semipolar (202̅3) nitrides grown on 3C-SiC/(001) Si substrates

    NASA Astrophysics Data System (ADS)

    Dinh, Duc V.; Presa, S.; Akhter, M.; Maaskant, P. P.; Corbett, B.; Parbrook, P. J.

    2015-12-01

    Heteroepitaxial growth of GaN buffer layers on 3C-SiC/(001) Si templates (4°-offcut towards [110]) by metalorganic vapour phase epitaxy has been investigated. High-temperature grown Al0.5Ga0.5N/AlN interlayers were employed to produce a single (202̅3) GaN surface orientation. Specular crack-free GaN layers showed undulations along [11̅0]{}3{{C}-{SiC}/{Si}} with a root mean square roughness of about 13.5 nm (50 × 50 μm2). The orientation relationship determined by x-ray diffraction (XRD) was found to be [1̅21̅0]GaN ∥[11̅0]{}3{{C}-{SiC}/{Si}} and [3̅034]GaN ∥[110]3C - SiC/Si . Low-temperature photoluminescence (PL) and XRD measurements showed the presence of basal-plane stacking faults in the layers. PL measurements of (202̅3) multiple-quantum-well and light-emitting diode structures showed uniform luminescence at about 500 nm emission wavelength. A small peak shift of about 3 nm was observed in the electroluminescence when the current was increased from 5 to 50 mA (25-250 A cm-2).

  20. Vip3C, a novel class of vegetative insecticidal proteins from Bacillus thuringiensis.

    PubMed

    Palma, Leopoldo; Hernández-Rodríguez, Carmen Sara; Maeztu, Mireya; Hernández-Martínez, Patricia; Ruiz de Escudero, Iñigo; Escriche, Baltasar; Muñoz, Delia; Van Rie, Jeroen; Ferré, Juan; Caballero, Primitivo

    2012-10-01

    Three vip3 genes were identified in two Bacillus thuringiensis Spanish collections. Sequence analysis revealed a novel Vip3 protein class (Vip3C). Preliminary bioassays of larvae from 10 different lepidopteran species indicated that Vip3Ca3 caused more than 70% mortality in four species after 10 days at 4 μg/cm(2).

  1. PIK3C2B inhibition improves function and prolongs survival in myotubular myopathy animal models

    PubMed Central

    Sabha, Nesrin; Volpatti, Jonathan R.; Gonorazky, Hernan; Davidson, Ann E.; Li, Xingli; Eltayeb, Nadine M.; Dall’Armi, Claudia; Di Paolo, Gilbert; Brooks, Susan V.; Buj-Bello, Ana; Feldman, Eva L.; Dowling, James J.

    2016-01-01

    Myotubular myopathy (MTM) is a devastating pediatric neuromuscular disorder of phosphoinositide (PIP) metabolism resulting from mutations of the PIP phosphatase MTM1 for which there are no treatments. We have previously shown phosphatidylinositol-3-phosphate (PI3P) accumulation in animal models of MTM. Here, we tested the hypothesis that lowering PI3P levels may prevent or reverse the MTM disease process. To test this, we targeted class II and III PI3 kinases (PI3Ks) in an MTM1-deficient mouse model. Muscle-specific ablation of Pik3c2b, but not Pik3c3, resulted in complete prevention of the MTM phenotype, and postsymptomatic targeting promoted a striking rescue of disease. We confirmed this genetic interaction in zebrafish, and additionally showed that certain PI3K inhibitors prevented development of the zebrafish mtm phenotype. Finally, the PI3K inhibitor wortmannin improved motor function and prolonged lifespan of the Mtm1-deficient mice. In all, we have identified Pik3c2b as a genetic modifier of Mtm1 mutation and demonstrated that PIK3C2B inhibition is a potential treatment strategy for MTM. In addition, we set the groundwork for similar reciprocal inhibition approaches for treating other PIP metabolic disorders and highlight the importance of modifier gene pathways as therapeutic targets. PMID:27548528

  2. 40 CFR 59.1 - Final determinations under Section 183(e)(3)(C) of the CAA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... COMMERCIAL PRODUCTS General § 59.1 Final determinations under Section 183(e)(3)(C) of the CAA. This section identifies the consumer and commercial product categories for which EPA has determined that CTGs will be... paneling coatings; (h) Industrial cleaning solvents; (i) Paper, film, and foil coatings; (j)...

  3. Synthetic ciguatoxin CTX 3C induces a rapid imbalance in neuronal excitability.

    PubMed

    Martín, Victor; Vale, Carmen; Hirama, Masahiro; Yamashita, Shuji; Rubiolo, Juan Andrés; Vieytes, Mercedes R; Botana, Luis M

    2015-06-15

    Ciguatera is a human global disease caused by the consumption of contaminated fish that have accumulated ciguatoxins (CTXs), sodium channel activator toxins. Symptoms of ciguatera include neurological alterations such as paraesthesiae, dysaesthesiae, depression, and heightened nociperception, among others. An important issue to understand these long-term neurological alterations is to establish the role that changes in activity produced by CTX 3C represent to neurons. Here, the effects of synthetic ciguatoxin CTX 3C on membrane potential, spontaneous spiking, and properties of synaptic transmission in cultured cortical neurons of 11-18 days in vitro (DIV) were evaluated using electrophysiological approaches. CTX 3C induced a large depolarization that decreased neuronal firing and caused a rapid inward tonic current that was primarily GABAergic. Moreover, the toxin enhanced the amplitude of miniature postsynaptic inhibitory currents (mIPSCs), whereas it decreased the amplitude of miniature postsynaptic excitatory currents (mEPSCs). The frequency of mIPSCs increased, whereas the frequency of mEPSCs remained unaltered. We describe, for the first time, that a rapid membrane depolarization caused by CTX 3C in cortical neurons activates mechanisms that tend to suppress electrical activity by shifting the balance between excitatory and inhibitory synaptic transmission toward inhibition. Indeed, these results suggest that the acute effects of CTX on synaptic transmission could underlie some of the neurological symptoms caused by ciguatera in humans.

  4. Brightening of FSRQ 3C 454.3 with an intense optical micro-variability.

    NASA Astrophysics Data System (ADS)

    Kaur, Navpreet; Baliyan, KS; Mukesh, CM; Ganesh, S.; Janaka, A.

    2016-11-01

    On the behalf of blazar monitoring group at Mt Abu InfraRed Observatory operated by the Physical Research Laboratory, India, we report detection of micro-variability in FSRQ 3C 454.3 on November 03, 2016 during which it decays by 0.1 mag in R band.

  5. Poliovirus polypeptide precursors: expression in vitro and processing by exogenous 3C and 2A proteinases.

    PubMed Central

    Nicklin, M J; Kräusslich, H G; Toyoda, H; Dunn, J J; Wimmer, E

    1987-01-01

    Plasmids have been constructed to generate substrates for the study of proteinases 2A and 3C of poliovirus. They contain the P1 (capsomer precursor) region of the poliovirus genome or P1 and part of P2 (a nonstructural precursor), which can be transcribed and translated in vitro. A transcript containing the entire 5' nontranslated region and the P1 region of the viral RNA gave poor translation in a reticulocyte translation system. Truncation of the 5' nontranslated region to its 3'-most segment gave acceptably good yields of radiolabeled P1. P1 was specifically processed to yield capsomer proteins by enzymes supplied in a postmitochondrial supernatant from poliovirus-infected cells. Thus, proteinase 3C can be supplied exogenously (in trans) and effect processing. This system may be used to provide P1 for the assay of proteinase 3C. Precursors that lacked either the 1A or 1D regions were poor substrates for proteinase 3C--observations that demonstrated a stringent structural requirement in processing by 3C. The translation product of a transcript encoding P1 and part of P2 was rapidly cleaved at the P1-P2 site in the absence of infected-cell extract. A transcript that contained a mutated 2A region gave a stable P1-P2 precursor that could be processed specifically by exogenous proteinase from infected-cell fractions. Processing of P1 appeared to require cleavage of the P1-P2 bond. These results support our previous data that 2A is the second polioviral proteinase and also provides a means of assaying proteinase 2A in vitro. Images PMID:3035560

  6. Gamma-Ray Emission from the Broad-Line Radio Galaxy 3C 111

    NASA Technical Reports Server (NTRS)

    Hartman, Robert C.; Kadler, M.; Tueller, Jack

    2008-01-01

    The broad-line radio galaxy 3C 111 has been suggested as the counterpart of the y-ray source 3EG J0416+3650. While 3C 111 meets most of the criteria for a high-probability identification, like a bright flat-spectrum radio core and a blazar-like broadband SED, in the Third EGRET Catalog, the large positional offset of about 1.5' put 3C 111 outside the 99% probability region for 3EG J0416+3650, making this association questionable. We present a re-analysis of all available archival data for 3C 111 from the EGRET archives, resulting in detection of variable hard-spectrum high-energy gamma-ray emission above 1000 MeV from a position close to the nominal position of 3C 111, in three separate viewing periods (VPs), at a 3sigma level in each. A second variable hard-spectrum source is present nearby. At >100 MeV, one variable soft-spectrum source seems to account for most of the EGRET-detected emission of 3EG J0416+3650. A follow-up Swift UVOT/XRT observation reveals one moderately bright X-ray source in the error box of 3EG J0416+3650, but because of the large EGRET position uncertainty, it is not certain that the X-ray and gamma-ray sources are associated. Another Swift observation near the second (unidentified) hard gamma-ray source detected no X-ray source nearby.

  7. Gamma-Ray Emision from the Broad-Line Radio Galaxy 3C 111

    NASA Technical Reports Server (NTRS)

    Hartman, Robert C.; Kadler, Matthias; Tueller, Jack

    2008-01-01

    The broad-line radio galaxy 3C 111 has been suggested as the counterpart of the Gamma-ray source 3EGJ0416+3650. While 3C 111 meets most of the criteria for a high-probability identification, like a bright fla t-spectrum radio core and a blazarlike broadband SED, in the Third EG RET Catalog, the large positional offset of about 1.5 degrees put 3C1 11 outside the 99% probability region for 3EG J0416+3650, making this association questionable. We present a re-analysis of all available data for 3C111 from the EGRET archives, resulting in probable detection of high-energy Gamma-ray emission above 1000MeV from a position clo se to the nominal position of 3C 111, in two separate viewing periods (VPs), at a 3sigma level in each. A new source, GROJ0426+3747, appea rs to be present nearby, seen only in the >1000MeV data. For >100MeV, the data are in agreement with only one source (at the original cata log position) accounting for most of the EGRET-detected emission of 3 EGJ0416+3650. A follow-up Swift UVOT/XRT observation reveals one mode rately bright X-ray source in the error box of 3EGJ0416+3650, but bec ause of the large EGRET position uncertainty, it is not certain that the X-ray and Gamma-ray sources are associated. A Swift observation of GROJ0426+3747 detected no X.ray source nearby.

  8. Digital holography particle image velocimetry for the measurement of 3D t-3c flows

    NASA Astrophysics Data System (ADS)

    Shen, Gongxin; Wei, Runjie

    2005-10-01

    In this paper a digital in-line holographic recording and reconstruction system was set up and used in the particle image velocimetry for the 3D t-3c (the three-component (3c), velocity vector field measurements in a three-dimensional (3D), space field with time history ( t)) flow measurements that made up of the new full-flow field experimental technique—digital holographic particle image velocimetry (DHPIV). The traditional holographic film was replaced by a CCD chip that records instantaneously the interference fringes directly without the darkroom processing, and the virtual image slices in different positions were reconstructed by computation using Fresnel-Kirchhoff integral method from the digital holographic image. Also a complex field signal filter (analyzing image calculated by its intensity and phase from real and image parts in fast fourier transform (FFT)) was applied in image reconstruction to achieve the thin focus depth of image field that has a strong effect with the vertical velocity component resolution. Using the frame-straddle CCD device techniques, the 3c velocity vector was computed by 3D cross-correlation through space interrogation block matching through the reconstructed image slices with the digital complex field signal filter. Then the 3D-3c-velocity field (about 20 000 vectors), 3D-streamline and 3D-vorticiry fields, and the time evolution movies (30 field/s) for the 3D t-3c flows were displayed by the experimental measurement using this DHPIV method and techniques.

  9. Light-Driven Au-WO3@C Janus Micromotors for Rapid Photodegradation of Dye Pollutants.

    PubMed

    Zhang, Qilu; Dong, Renfeng; Wu, Yefei; Gao, Wei; He, Zihan; Ren, Biye

    2017-02-08

    A novel light-driven Au-WO3@C Janus micromotor based on colloidal carbon WO3 nanoparticle composite spheres (WO3@C) prepared by one-step hydrothermal treatment is described. The Janus micromotors can move in aqueous media at a speed of 16 μm/s under 40 mW/cm(2) UV light due to diffusiophoretic effects. The propulsion of such Au-WO3@C Janus micromotors (diameter ∼ 1.0 μm) can be generated by UV light in pure water without any external chemical fuels and readily modulated by light intensity. After depositing a paramagnetic Ni layer between the Au layer and WO3, the motion direction of the micromotor can be precisely controlled by an external magnetic field. Such magnetic micromotors not only facilitate recycling of motors but also promise more possibility of practical applications in the future. Moreover, the Au-WO3@C Janus micromotors show high sensitivity toward extremely low concentrations of sodium-2,6-dichloroindophenol (DCIP) and Rhodamine B (RhB). The moving speed of motors can be significantly accelerated to 26 and 29 μm/s in 5 × 10(-4) wt % DCIP and 5 × 10(-7) wt % RhB aqueous solutions, respectively, due to the enhanced diffusiophoretic effect, which results from the rapid photocatalytic degradation of DCIP and RhB by WO3. This photocatalytic acceleration of the Au-WO3@C Janus micromotors confirms the self-diffusiophoretic mechanism and opens an opportunity to tune the motility of the motors. This work also offers the light-driven micromotors a considerable potential for detection and rapid photodegradation of dye pollutants in water.

  10. Medical morbidities and DNA methylation of NR3C1 in preterm infants

    PubMed Central

    Giarraputo, James; DeLoach, Jordan; Padbury, James; Uzun, Alper; Marsit, Carmen; Hawes, Katheleen; Lester, Barry

    2017-01-01

    Background: Although there are no accepted “normal” levels of circulating cortisol in preterm infants, critically ill preterm infants show lower cortisol levels than healthy preterm infants. The regulation of cortisol reactivity by epigenetic changes in glucocorticoid receptor gene (NR3C1) expression has been demonstrated. This study aims to examine the relationship between medical morbidities in preterm infants and DNA methylation of NR3C1. Methods: Pyrosequencing was used to determine DNA methylation in CpG sites 1-4 of promoter region 1F of NR3C1. Cluster analysis placed 67 preterm infants born <1,500 g into groups based on medical morbidities. The DNA methylation pattern was compared across groups. Results: Cluster analysis identified a high medical risk cluster and a low medical risk cluster. A Mann-Whitney U-test showed lower methylation at CpG1 for infants in the high-risk group (M = 0.336, SE = 0.084) than infants in the low-risk group (M = 0.617, SE = 0.109, P = 0.032). The false discovery rate was low (q = 0.025). Cohen's D effect size was moderate (0.525). Conclusion: Decreased DNA methylation of CpG1 of NR3C1 in high-risk infants may allow for increased binding of transcription factors involved in the stress response, repair and regulation of NR3C1. This may ensure healthy growth in high-risk preterm infants over increasing cortisol levels. PMID:27653086

  11. String completion of an SU(3)c ⊗ SU(3)L ⊗ U(1)X electroweak model

    NASA Astrophysics Data System (ADS)

    Addazi, Andrea; Valle, J. W. F.; Vaquera-Araujo, C. A.

    2016-08-01

    The extended electroweak SU(3)c ⊗ SU(3)L ⊗ U(1)X symmetry framework "explaining" the number of fermion families is revisited. While 331-based schemes can not easily be unified within the conventional field theory sense, we show how to do it within an approach based on D-branes and (un)oriented open strings, on Calabi-Yau singularities. We show how the theory can be UV-completed in a quiver setup, free of gauge and string anomalies. Lepton and baryon numbers are perturbatively conserved, so neutrinos are Dirac-type, and their lightness results from a novel TeV scale seesaw mechanism. Dynamical violation of baryon number by exotic instantons could induce neutron-antineutron oscillations, with proton decay and other dangerous R-parity violating processes strictly forbidden.

  12. Semaphorin 3C Released from a Biocompatible Hydrogel Guides and Promotes Axonal Growth of Rodent and Human Dopaminergic Neurons

    PubMed Central

    Carballo-Molina, Oscar A.; Sánchez-Navarro, Andrea; López-Ornelas, Adolfo; Lara-Rodarte, Rolando; Salazar, Patricia; Campos-Romo, Aurelio; Ramos-Mejía, Verónica

    2016-01-01

    Cell therapy in experimental models of Parkinson's disease replaces the lost dopamine neurons (DAN), but we still need improved methods to guide dopaminergic axons (DAx) of grafted neurons to make proper connections. The protein Semaphorin 3C (Sema3C) attracts DAN axons and enhances their growth. In this work, we show that the hydrogel PuraMatrix, a self-assembling peptide-based matrix, incorporates Sema3C and releases it steadily during 4 weeks. We also tested if hydrogel-delivered Sema3C attracts DAx using a system of rat midbrain explants embedded in collagen gels. We show that Sema3C released by this hydrogel attracts DAx, in a similar way to pretectum, which is known to attract growing DAN axons. We assessed the effect of Sema3C on the growth of DAx using microfluidic devices. DAN from rat midbrain or those differentiated from human embryonic stem cells showed enhanced axonal extension when exposed to hydrogel-released Sema3C, similar to soluble Sema3C. Notably, DAN of human origin express the cognate Sema3C receptors, Neuropilin1 and Neuropilin2. These results show that PuraMatrix is able to incorporate and release Sema3C, and such delivery guides and promotes the axonal growth of DAN. This biocompatible hydrogel might be useful as a Sema3C carrier for in vivo studies in parkinsonian animal models. PMID:27174503

  13. Semaphorin 3C Released from a Biocompatible Hydrogel Guides and Promotes Axonal Growth of Rodent and Human Dopaminergic Neurons.

    PubMed

    Carballo-Molina, Oscar A; Sánchez-Navarro, Andrea; López-Ornelas, Adolfo; Lara-Rodarte, Rolando; Salazar, Patricia; Campos-Romo, Aurelio; Ramos-Mejía, Verónica; Velasco, Iván

    2016-06-01

    Cell therapy in experimental models of Parkinson's disease replaces the lost dopamine neurons (DAN), but we still need improved methods to guide dopaminergic axons (DAx) of grafted neurons to make proper connections. The protein Semaphorin 3C (Sema3C) attracts DAN axons and enhances their growth. In this work, we show that the hydrogel PuraMatrix, a self-assembling peptide-based matrix, incorporates Sema3C and releases it steadily during 4 weeks. We also tested if hydrogel-delivered Sema3C attracts DAx using a system of rat midbrain explants embedded in collagen gels. We show that Sema3C released by this hydrogel attracts DAx, in a similar way to pretectum, which is known to attract growing DAN axons. We assessed the effect of Sema3C on the growth of DAx using microfluidic devices. DAN from rat midbrain or those differentiated from human embryonic stem cells showed enhanced axonal extension when exposed to hydrogel-released Sema3C, similar to soluble Sema3C. Notably, DAN of human origin express the cognate Sema3C receptors, Neuropilin1 and Neuropilin2. These results show that PuraMatrix is able to incorporate and release Sema3C, and such delivery guides and promotes the axonal growth of DAN. This biocompatible hydrogel might be useful as a Sema3C carrier for in vivo studies in parkinsonian animal models.

  14. A CHANDRA SNAPSHOT SURVEY FOR 3C RADIO GALAXIES WITH REDSHIFTS BETWEEN 0.3 AND 0.5

    SciTech Connect

    Massaro, F.; Harris, D. E.; Paggi, A.; Tremblay, G. R.; Liuzzo, E.; Bonafede, A.

    2013-05-01

    This paper contains an analysis of short Chandra observations of 19 3C sources with redshifts between 0.3 and 0.5 not previously observed in the X-rays. This sample is part of a project to obtain Chandra data for all of the extragalactic sources in the 3C catalog. Nuclear X-ray intensities as well as any X-ray emission associated with radio jet knots, hotspots, or lobes have been measured in three energy bands: soft, medium, and hard. Standard X-ray spectral analysis for the four brightest nuclei has also been performed. X-ray emission was detected for all the nuclei of the radio sources in the current sample with the exception of 3C 435A. There is one compact steep spectrum source while all the others are FR II radio galaxies. X-ray emission from two galaxy clusters (3C 19 and 3C 320), from six hotspots in four radio galaxies (3C 16, 3C 19, 3C 268.2, 3C 313), and extended X-ray emission on kiloparsec scales in 3C 187 and 3C 313, has been detected.

  15. Spatial Variations of the Synchrotron Spectrum Within Tycho’s Supernova Remnant (3C 10): A Spectral Tomography Analysis of Radio Observations at 20 and 90 Centimeter Wavelengths

    DTIC Science & Technology

    2000-01-20

    individual ( Tycho ) 1. INTRODUCTION A new star observed by Tycho Brahe (1573) is now identi- Ðed as a supernova whose remnant (SNR) is 3C 10 (SN 1572... Tycho SNR, SNR 120.1]1.4 ; Lozinskaya 1992 and references therein). The explosion itself was mostly likely a Type Ia supernova, and the remnant seems...we adopted.3 Again, this procedure tends to reduce any spectral variations. However, as Reynoso et al. (1997) found, Tycho is not expanding

  16. Dipolar-Distribution Cavity γ-Fe2 O3 @C@α-MnO2 Nanospindle with Broadened Microwave Absorption Bandwidth by Chemically Etching.

    PubMed

    You, Wenbin; Bi, Han; She, Wen; Zhang, Yu; Che, Renchao

    2017-02-01

    Developing microwave absorption materials with ultrawide bandwidth and low density still remains a challenge, which restricts their actual application in electromagnetic signal anticontamination and defense stealth technology. Here a series of olive-like γ-Fe2 O3 @C core-shell spindles with different shell thickness and γ-Fe2 O3 @C@α-MnO2 spindles with different volumes of dipolar-distribution cavities were successfully prepared. Both series of absorbers exhibit excellent absorption properties. The γ-Fe2 O3 @C@α-MnO2 spindle with controllable cavity volume exhibits an effective absorption (<-10 dB) bandwidth as wide as 9.2 GHz due to the chemically dipolar etching of the core. Reflection loss of the γ-Fe2 O3 @C spindle reaches as high as -45 dB because of the optimized electromagnetic impedance balance between polymer shell and γ-Fe2 O3 core. Intrinsic ferromagnetism of the anisotropy spindle is confirmed by electron holography. Strong coupling of magnetic flux stray lines between spindles is directly imaged. This unique morphology and facile etching technique might facilitate the study of core-shell type microwave absorbers.

  17. Protection of guinea pigs and swine by a recombinant adenovirus expressing O serotype of foot-and-mouth disease virus whole capsid and 3C protease.

    PubMed

    Lu, Zengjun; Bao, Huifang; Cao, Yimei; Sun, Pu; Guo, Jianhun; Li, Pinghua; Bai, Xingwen; Chen, Yingli; Xie, Baoxia; Li, Dong; Liu, Zaixin; Xie, Qingge

    2008-12-19

    Two recombinant adenoviruses were constructed expressing foot-and-mouth disease virus (FMDV) capsid and 3C/3CD proteins in replicative deficient human adenovirus type 5 vector. Guinea pigs vaccinated with 1-3 x 10(8)TCID(50) Ad-P12x3C recombinant adenovirus were completely protected against 10,000GID(50) homologous virulent FMDV challenge 25 days post vaccination (dpv). Ad-P12x3CD vaccinated guinea pigs were only partially protected. Swine were vaccinated once with 1x10(9)TCID(50) Ad-P12x3C hybrid virus and challenged 28 days later. Three of four vaccinated swine were completely protected against 200 pig 50% infectious doses (ID(50)) of homologous FMDV challenge, and vaccinated pigs developed specific cellular and humoral immune responses. The immune effect of Ad-P12x3C in swine further indicated that the recombinant adenovirus was highly efficient in transferring the foreign gene. This approach may thus be a very hopeful tool for developing FMD live virus vector vaccine.

  18. SAR405, a PIK3C3/Vps34 inhibitor that prevents autophagy and synergizes with MTOR inhibition in tumor cells.

    PubMed

    Pasquier, Benoit

    2015-04-03

    Autophagy plays an important role in cancer and it has been suggested that it functions not only as a tumor suppressor pathway to prevent tumor initiation, but also as a prosurvival pathway that helps tumor cells endure metabolic stress and resist death triggered by chemotherapeutic agents. We recently described the discovery of inhibitors of PIK3C3/Vps34 (phosphatidylinositol 3-kinase, catalytic subunit type 3), the lipid kinase component of the class III phosphatidylinositol 3-kinase (PtdIns3K). This PtdIns3K isoform has attracted significant attention in recent years because of its role in autophagy. Following chemical optimization we identified SAR405, a low molecular mass kinase inhibitor of PIK3C3, highly potent and selective with regard to other lipid and protein kinases. We demonstrated that inhibiting the catalytic activity of PIK3C3 disrupts vesicle trafficking from late endosomes to lysosomes. SAR405 treatment also inhibits autophagy induced either by starvation or by MTOR (mechanistic target of rapamycin) inhibition. Finally our results show that combining SAR405 with everolimus, the FDA-approved MTOR inhibitor, results in a significant synergy on the reduction of cell proliferation using renal tumor cells. This result indicates a potential therapeutic application for PIK3C3 inhibitors in cancer.

  19. Glucocorticoid receptor gene (NR3C1) methylation processes as mediators of early adversity in stress-related disorders causality: A critical review.

    PubMed

    Palma-Gudiel, Helena; Córdova-Palomera, Aldo; Leza, Juan Carlos; Fañanás, Lourdes

    2015-08-01

    Early life stress (ELS) is a known risk factor for suffering psychopathology in adulthood. The hypothalamic-pituitary-adrenal (HPA) axis has been described to be deregulated in both individuals who experienced early psychosocial stress and in patients with a wide range of psychiatric disorders. The NR3C1 gene codes for the glucocorticoid receptor, a key element involved in several steps of HPA axis modulation. In this review, we gather existing evidence linking NR3C1 methylation pattern with either ELS or psychopathology. We summarize that several types of ELS have been frequently associated with NR3C1 hypermethylation whereas hypomethylation has been continuously found to be associated with post-traumatic stress disorder. In light of the reported findings, the main concerns of ongoing research in this field are the lack of methodological consensus and selection of CpG sites. Further studies should target individual CpG site methylation assessment focusing in biologically relevant areas such as transcription factor binding regions whereas widening the examined sequence in order to include all non-coding first exons of the NR3C1 gene in the analysis.

  20. The picornaviral 3C proteinases: cysteine nucleophiles in serine proteinase folds.

    PubMed

    Malcolm, B A

    1995-08-01

    The 3C proteinases are a novel group of cysteine proteinases with a serine proteinase-like fold that are responsible for the bulk of polyprotein processing in the Picornaviridae. Because members of this viral family are to blame for several ongoing global pandemic problems (rhinovirus, hepatitis A virus) as well as sporadic outbreaks of more serious pathologies (poliovirus), there has been continuing interest over the last two decades in the development of antiviral therapies. The recent determination of the structure of two of the 3C proteinases by X-ray crystallography opens the door for the application of the latest advances in computer-assisted identification and design of anti-proteinase therapeutic/chemoprophylactic agents.

  1. Effects of collision cascade density on radiation defect dynamics in 3C-SiC

    PubMed Central

    Bayu Aji, L. B.; Wallace, J. B.; Kucheyev, S. O.

    2017-01-01

    Effects of the collision cascade density on radiation damage in SiC remain poorly understood. Here, we study damage buildup and defect interaction dynamics in 3C-SiC bombarded at 100 °C with either continuous or pulsed beams of 500 keV Ne, Ar, Kr, or Xe ions. We find that bombardment with heavier ions, which create denser collision cascades, results in a decrease in the dynamic annealing efficiency and an increase in both the amorphization cross-section constant and the time constant of dynamic annealing. The cascade density behavior of these parameters is non-linear and appears to be uncorrelated. These results demonstrate clearly (and quantitatively) an important role of the collision cascade density in dynamic radiation defect processes in 3C-SiC. PMID:28304397

  2. Optical and Hubble Space Telescope ultraviolet spectropolarimetry of 3C 273 and PG 1114+445

    NASA Technical Reports Server (NTRS)

    Smith, Paul S.; Schmidt, Gary D.; Allen, Richard G.

    1993-01-01

    New optical spectropolarimetry and broad-band measurements, made during periods when the linear polarization of the quasar 3C 273 was no greater than 1 pct, are combined with ultraviolet polarization measurements made with the Faint Object Spectrograph of the Hubble Space Telescope. Very weak UV polarization during the time of observation is seen in the HST measurements, which is consistent with the completely unpolarized UV continuum and emission lines. Optical spectropolarimetry, however, reveals polarized light, the source of which is consistent with a nonthermal component, diluted by other unpolarized emission sources, such as the 'big blue bump'. Optical spectropolarimetry of the radio-quiet quasar PG 1114+445 is also presented. The polarization of this QSO is thought to result from scattering by dust external to the narrow-line region. 3C 273 and PG 1114+445 are useful in illustrating the range of polarizing mechanisms which can operate in low-polarization QSOs.

  3. Fermi large area telescope observations of blazar 3C 279 occultations by the sun

    SciTech Connect

    Barbiellini, G.; Bastieri, D.; Buson, S.; Bechtol, K.; Blandford, R. D.; Borgland, A. W.; Buehler, R.; Cameron, R. A.; Chiang, J.; Bellazzini, R.; Bregeon, J.; Bruel, P.; Caraveo, P. A.; Cavazzuti, E.; Ciprini, S.; Cecchi, C.; Chaves, R. C. G.; Cheung, C. C. E-mail: phdmitry@stanford.edu; and others

    2014-04-01

    Observations of occultations of bright γ-ray sources by the Sun may reveal predicted pair halos around blazars and/or new physics, such as, e.g., hypothetical light dark matter particles—axions. We use Fermi Gamma-Ray Space Telescope (Fermi) data to analyze four occultations of blazar 3C 279 by the Sun on October 8 each year from 2008 to 2011. A combined analysis of the observations of these occultations allows a point-like source at the position of 3C 279 to be detected with significance of ≈3σ, but does not reveal any significant excess over the flux expected from the quiescent Sun. The likelihood ratio test rules out complete transparency of the Sun to the blazar γ-ray emission at a 3σ confidence level.

  4. Grade 3C open femur fractures with vascular repair in adults.

    PubMed

    Balci, Halil I; Saglam, Yavuz; Tunali, Onur; Akgul, Turgut; Aksoy, Murat; Dikici, Fatih

    2015-06-01

    Grade 3C open femur fractures are challenging injuries with higher rates of complications. This is a retrospective review of grade 3C open femur fractures with vascular repair between 2002 and 2012. Outcomes included initial MESS score, additional injuries, duration of operation, complications, secondary operations or amputations, and social life implications. Thirty-one of 39 total patients were selected for revascularization and fracture fixation based on soft tissue injury and MESS score. The intra-operative approach included temporary arterial shunt replacement, orthopedic fixation, arterial reconstruction venous and/or nerve repair and routine fasciotomies. An external fixation and reverse saphenous vein graft was used in a majority of the patients (respectively; 93.5%, 90.3%). The mean follow up was 5.4 years (range 2.2-10). The decision to amputate versus salvage should be left up to patients and their care teams after discussing options and future possibilities rather than using a scoring system.

  5. Optical measurements during increased gamma-ray activity in 3C 454.3

    NASA Astrophysics Data System (ADS)

    Smith, Paul S.; Wehrle, Ann E.

    2010-04-01

    Observations obtained with the Steward Observatory 2.3m Bok Telescope show 3C 454.3 to be optically bright and highly linear polarized during a period of increased gamma-ray activity (ATel #2534). Differential spectrophotometry yield a V-band magnitude of 15.02 ± 0.02 and an R-band (Kron-Cousins bandpass) magnitude of 14.53 ± 0.01 on 2010 April 5, 12:10 UT. Spectropolarimetry of 3C 454.3 with the SPOL instrument find an average linear polarization of 9.85 ± 0.17% at a position angle of 23.0 ± 0.5 degrees over a 5000-7000 Angstrom spectral bin.

  6. Precipitation Retrievals in typhoon domain combining of FY3C MWHTS Observations and WRF Predicted Models

    NASA Astrophysics Data System (ADS)

    Jieying, HE; Shengwei, ZHANG; Na, LI

    2017-02-01

    A passive sub-millimeter precipitation retrievals algorithm is provided based on Microwave Humidity and Temperature Sounder (MWHTS) onboard the Chinese Feng Yun 3C (FY-3C) satellite. Using the validated global reference physical model NCEP/WRF/VDISORT), NCEP data per 6 hours are downloaded to run the Weather Research and Forecast model WRF, and derive the typical precipitation data from the whole world. The precipitation retrieval algorithm can operate either on land or on seawater for global. To simply the calculation procedure and save the training time, principle component analysis (PCA) was adapted to filter out the redundancy caused by scanning angle and surface effects, as well as system noise. According to the comparison and validation combing with other precipitation sources, it is demonstrated that the retrievals are reliable for surface precipitation rate higher than 0.1 mm/h at 15km resolution.

  7. Spin frustration and magnetic ordering in the Mott insulating fcc-Cs3C60

    NASA Astrophysics Data System (ADS)

    Kasahara, Yuichi; Takeuchi, Yuki; Itou, Tatsuaki; Iwasa, Yoshihiro; Arcon, Denis; Rosseinsky, Matthew; Prassides, Kosmas

    2014-03-01

    The low-temperature magnetic state at ambient pressure has been investigated by specific heat and nuclear magnetic resonance (NMR) measurements in face-centered-cubic (fcc-) Cs3C60, which is characterized by a Mott insulating state with S = 1 / 2 spins in C603- anions and a geometrical spin frustration inherent in the fcc lattice. Specific heat exhibited no sharp anomaly down to 0.4 K, but both magnetic specific heat and NMR relaxation rate revealed a broad peak around 2.5 K, indicating that the reported antiferromagnetic ordering is accompanied by a gradual freezing of electronic spins with distributed transition temperatures. These results are unexpected in the conventional fcc antiferromagnets. Interplay of geometrical frustration, orientational disorder of C60 molecules, and weak Mottness gives rise to the unique magnetic ground state in fcc-Cs3C60.

  8. Effects of collision cascade density on radiation defect dynamics in 3C-SiC

    NASA Astrophysics Data System (ADS)

    Bayu Aji, L. B.; Wallace, J. B.; Kucheyev, S. O.

    2017-03-01

    Effects of the collision cascade density on radiation damage in SiC remain poorly understood. Here, we study damage buildup and defect interaction dynamics in 3C-SiC bombarded at 100 °C with either continuous or pulsed beams of 500 keV Ne, Ar, Kr, or Xe ions. We find that bombardment with heavier ions, which create denser collision cascades, results in a decrease in the dynamic annealing efficiency and an increase in both the amorphization cross-section constant and the time constant of dynamic annealing. The cascade density behavior of these parameters is non-linear and appears to be uncorrelated. These results demonstrate clearly (and quantitatively) an important role of the collision cascade density in dynamic radiation defect processes in 3C-SiC.

  9. Time constant of defect relaxation in ion-irradiated 3C-SiC

    NASA Astrophysics Data System (ADS)

    Wallace, J. B.; Bayu Aji, L. B.; Shao, L.; Kucheyev, S. O.

    2015-05-01

    Above room temperature, the buildup of radiation damage in SiC is a dynamic process governed by the mobility and interaction of ballistically generated point defects. Here, we study the dynamics of radiation defects in 3C-SiC bombarded at 100 °C with 500 keV Ar ions, with the total ion dose split into a train of equal pulses. Damage-depth profiles are measured by ion channeling for a series of samples irradiated under identical conditions except for different durations of the passive part of the beam cycle. Results reveal an effective defect relaxation time constant of ˜ 3 ms (for second order kinetics) and a dynamic annealing efficiency of ˜ 40 % for defects in both Si and C sublattices. This demonstrates a crucial role of dynamic annealing at elevated temperatures and provides evidence of the strong coupling of defect accumulation processes in the two sublattices of 3C-SiC.

  10. Effects of collision cascade density on radiation defect dynamics in 3C-SiC.

    PubMed

    Bayu Aji, L B; Wallace, J B; Kucheyev, S O

    2017-03-17

    Effects of the collision cascade density on radiation damage in SiC remain poorly understood. Here, we study damage buildup and defect interaction dynamics in 3C-SiC bombarded at 100 °C with either continuous or pulsed beams of 500 keV Ne, Ar, Kr, or Xe ions. We find that bombardment with heavier ions, which create denser collision cascades, results in a decrease in the dynamic annealing efficiency and an increase in both the amorphization cross-section constant and the time constant of dynamic annealing. The cascade density behavior of these parameters is non-linear and appears to be uncorrelated. These results demonstrate clearly (and quantitatively) an important role of the collision cascade density in dynamic radiation defect processes in 3C-SiC.

  11. Fermi LAT detection of renewed and strong GeV activity from blazar 3C 279

    NASA Astrophysics Data System (ADS)

    Cutini, Sara

    2015-06-01

    The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has observed an intense gamma-ray flare from a source positionally consistent with the flat spectrum radio quasar 3C 279, also known as 3FGL J1256.1-0547 (Acero et al. 2015, APJS, 218, 23), with radio coordinates R.A.: 194.0465271 deg, Dec: -5.7893119 deg (J2000.0; Johnston et al. 1995, AJ, 110, 880).

  12. Luteoloside Acts as 3C Protease Inhibitor of Enterovirus 71 In Vitro

    PubMed Central

    Cao, Zeyu; Ding, Yue; Ke, Zhipeng; Cao, Liang; Li, Na; Ding, Gang; Wang, Zhenzhong; Xiao, Wei

    2016-01-01

    Luteoloside is a member of the flavonoids family that exhibits several bioactivities including anti-microbial and anti-cancer activities. However, the antiviral activity of luteoloside against enterovirus 71 (EV71) and the potential mechanism(s) responsible for this effect remain unknown. In this study, the antiviral potency of luteoloside against EV71 and its inhibitory effects on 3C protease activity were evaluated. First, we investigated the cytotoxicity of luteoloside against rhabdomyosarcoma (RD) cells, which was the cell line selected for an in vitro infection model. In a subsequent antiviral assay, the cytopathic effect of EV71 was significantly and dose-dependently relieved by the administration of luteoloside (EC50 = 0.43 mM, selection index = 5.3). Using a plaque reduction assay, we administered luteoloside at various time points and found that the compound reduced EV71 viability in RD cells rather than increasing defensive mobilization or viral absorption. Moreover, biochemical studies focused on VP1 (a key structural protein of EV71) mRNA transcript and protein levels also revealed the inhibitory effects of luteoloside on the EV71 viral yield. Finally, we performed inhibition assays using luteoloside to evaluate its effect on recombinant 3C protease activity. Our results demonstrated that luteoloside blocked 3C protease enzymatic activity in a dose-dependent manner (IC50 = 0.36 mM) that was similar to the effect of rutin, which is a well-known C3 protease inhibitor. Collectively, the results from this study indicate that luteoloside can block 3C protease activity and subsequently inhibit EV71 production in vitro. PMID:26870944

  13. VizieR Online Data Catalog: VRIJHK photometry of 3C 279 (Sandrinelli+, 2016)

    NASA Astrophysics Data System (ADS)

    Sandrinelli, A.; Covino, S.; Dotti, M.; Treves, A.

    2016-07-01

    The starting point of the present investigation is the VRIJHK photometric observations obtained with the robotic Rapid Eye Mounting telescope (REM) at La Silla, which are described in detail in Sandrinelli et al. 2014 (cat. J/A+A/562/A79). We add to the data available in the above mentioned paper the REM photometry of 3C 279 (see Table2), which is unpublished thus far. (2 data files).

  14. An imaging and spectroscopic study of the peculiar SNR 3C397 with XMM-Newton

    NASA Astrophysics Data System (ADS)

    Safi-Harb, Samar; Franzmann, Erica

    The SNR 3C 397 has a peculiar box-like morphology with a central X-ray `hot spot' and a sharp boundary in the west. Earlier X-ray spectroscopy with ASCA and Chandra showed that the central spot is thermal in nature, that the column density increases from east to west, and that the X-ray spectrum is dominated by thermal emission from (at least) two compo-nents: a low-temperature plasma characterized by a high ionization timescale, mixed with a high-temperature, ejecta-dominated plasma (mainly Fe-K), characterized by a low ionization timescale. This, together with millimeter observations of the environs of 3C 397, led to the suggestion that 3C 397 is a ˜5 kyr old SNR expanding in an inhomogeneous medium, en-countering a molecular cloud towards the west, and evolving into a mixed-morphology SNR. Most recently, new CO observations showed that the SNR is well confined in a cavity of molec-ular gas and embedded at the edge of a molecular cloud at VLSR ˜32 km/s. The 12 CO line broadening of the 32 km/s component provided direct evidence of interaction between the SNR and a molecular cloud at the western boundary of the remnant. To date, there is no evidence of a compact object or a pulsar wind nebula associated with this remnant. We here present an XMM-Newton imaging and spectroscopic analysis of 3C 397 targeted to 1) map the ejecta distribution (in particular of Mg, Si, S and Fe) across the SNR, 2) constrain the spectral and physical properties of the supernova and its progenitor star, and 3) address the absence of a neutron star or wind nebula associated with the SNR.

  15. NMR Study of the Superconducting Gap Variation near the Mott Transition in Cs3C60

    NASA Astrophysics Data System (ADS)

    Wzietek, P.; Mito, T.; Alloul, H.; Pontiroli, D.; Aramini, M.; Riccò, M.

    2014-02-01

    Former extensive studies of superconductivity in the A3C60 compounds, where A is an alkali metal, have led one to consider that Bardeen-Cooper-Schrieffer electron-phonon pairing prevails in those compounds, though the incidence of electronic Coulomb repulsion has been highly debated. The discovery of two isomeric fulleride compounds Cs3C60 which exhibit a transition with pressure from a Mott insulator (MI) to a superconducting (SC) state clearly reopens that question. Using pressure (p) as a single control parameter of the C60 balls lattice spacing, one can now study the progressive evolution of the SC properties when the electronic correlations are increased towards the critical pressure pc of the Mott transition. We have used C13 and Cs133 NMR measurements on the cubic phase A15-Cs3C60 just above pc=5.0(3) kbar, where the SC transition temperature Tc displays a dome shape with decreasing cell volume. From the T dependence below Tc of the nuclear spin lattice relaxation rate (T1)-1 we determine the electronic excitations in the SC state, that is 2Δ, the gap value. The latter is found to be largely enhanced with respect to the Bardeen-Cooper-Schrieffer value established in the case of dense A3C60 compounds. It even increases slightly with decreasing p towards pc, where Tc decreases on the SC dome, so that 2Δ /kBTc increases regularly upon approaching the Mott transition. These results bring clear evidence that the increasing correlations near the Mott transition are not significantly detrimental to superconductivity. They rather suggest that repulsive electron interactions might even reinforce elecron-phonon superconductivity, being then partly responsible for the large Tc values, as proposed by theoretical models taking the electronic correlations as a key ingredient.

  16. 3. 'C.P. Reconstruction Rocklin to Colfax, Standard Double Track Tunnel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. 'C.P. Reconstruction Rocklin to Colfax, Standard Double Track Tunnel Portal Stones, Wings Parallel to Center Line, Ring Stones,' Southern Pacific Standard Double-Track Tunnel, ca. 1909. Compare to photos in documentation sets for Tunnel 18 (HAER No. CA-197), Tunnel 34 (HAER No. CA-206), and Tunnel 1 (HAER No. CA-207). - Central Pacific Transcontinental Railroad, Sacramento to Nevada state line, Sacramento, Sacramento County, CA

  17. Photographic photometry of compact extragalactic objects Optical variability of the quasar 3C 345

    NASA Astrophysics Data System (ADS)

    Babadzhanyants, M. K.; Belokon, E. T.; Denisenko, N. S.; Semenova, E. V.

    1985-08-01

    The results of 11-years photographic observations of optical variability of the quasar 3C 345 are presented. A flare with a timescale of the order of one year, similar to those of 1967 and 1971, was observed in 1982. From a comparison of the obtained series of observations with those of the Rosemary Hill Observatory, a conclusion is drawn on the absence of systematic variability at a timescale of 5 - 20 hours exceeding 0m.2 in magnitude.

  18. Photographic photometry of compact extragalactic objects Optical variability of the quasar 3C 345

    SciTech Connect

    Babadzhaniants, M.K.; Belokon, E.T.; Denisenko, N.S.; Semenova, E.V.

    1985-08-01

    An 11-yr (1973-1983) program of photographic observations at the Leningrad Byurakan station is reported, tracing the optical variability of the quasar 3C 345. A roughly 1-yr flare resembling those of 1967 and 1971 occurred in 1982. Comparison with the concurrent observations at Rosemary Hill, Florida, shows no appreciable systematic B-band fluctuations on time scales of 5-20 h. 10 references.

  19. Resolution of the southern radio lobe of 3C 33 at 660 nm

    NASA Technical Reports Server (NTRS)

    Crane, Phillipe; Stiavelli, Massimo

    1992-01-01

    A strand of emission coincident with the peak in the radio emission at 2 and 6 cm was revealed by an HST planetary camera image of the southern radio lobe of 3C 33. The detailed morphological similarity between the optical and radio data conclusively confirms the common origin of the radio and optical emission. The question of whether or not the detailed correlations in emission seen in the jets can also be observed on the larger scales of radio lobes is addressed.

  20. Parsec-scale jet properties of the gamma-ray quasar 3C 286

    NASA Astrophysics Data System (ADS)

    An, T.; Lao, B.-Q.; Zhao, W.; Mohan, P.; Cheng, X.-P.; Cui, Y.-Z.; Zhang, Z.-L.

    2017-04-01

    The quasar 3C 286 is one of two compact steep-spectrum sources detected by the Fermi/Large Area Telescope. Here, we investigate the radio properties of the parsec(pc)-scale jet and its (possible) association with the gamma-ray emission in 3C 286. The Very Long Baseline Interferometry (VLBI) images at various frequencies reveal a one-sided core-jet structure extending to the south-west at a projected distance of ∼1 kpc. The component at the jet base showing an inverted spectrum is identified as the core, with a mean brightness temperature of 2.8 × 109 K. The jet bends at about 600 pc (in projection) away from the core, from a position angle of -135° to -115°. Based on the available VLBI data, we inferred the proper-motion speed of the inner jet as 0.013 ± 0.011 mas yr-1 (βapp = 0.6 ± 0.5), corresponding to a jet speed of about 0.5 c at an inclination angle of 48° between the jet and the line of sight of the observer. The brightness temperature, jet speed and Lorentz factor are much lower than those of gamma-ray-emitting blazars, implying that the pc-scale jet in 3C 286 is mildly relativistic. Unlike blazars in which gamma-ray emission is in general thought to originate from the beamed innermost jet, the location and mechanism of gamma-ray emission in 3C 286 may be different as indicated by the current radio data. Multiband spectrum fitting may offer a complementary diagnostic clue of the gamma-ray production mechanism in this source.

  1. OPTICAL MONITORING OF TWO BRIGHTEST NEARBY QUASARS, PHL 1811 AND 3C 273

    SciTech Connect

    Fan, J. H.; Liu, Y.; Yuan, Y. H.; Kurtanidze, O.; Chanishvili, R.; Richter, G. M.

    2014-08-01

    Variability is one of the most observable characteristics of active galactic nuclei, and it is important when considering the emission mechanism. In this paper, we report optical photometry monitoring of two nearby brightest quasars, PHL 1811 and 3C 273, using the ST-6 camera attached to the Newtonian focus and the Ap6E CCD camera attached to the primary focus of the 70 cm meniscus telescope at the Abastumani Observatory, Georgia. PHL 1811 was monitored during the period from 2002 September to 2012 December, while 3C 273 was monitored during the period from 1998 February to 2008 May. During our monitoring period, the two sources did not show any significant intra-day variability. The largest detected variations are ΔR = 0.112 ± 0.010 mag. for PHL 1811, ΔB = 0.595 ± 0.099 mag, ΔV = 0.369 ± 0.028 mag, ΔR = 0.495 ± 0.076 mag, and ΔI = 0.355 ± 0.009 mag for 3C 273. When the periodicity analysis methods are adopted for the observations of the sources, a period of p = 5.80 ± 1.12 yr is obtained for PHL 1811 in the R light curve in the present work, and periods of p = 21.10 ± 0.14, 10.00 ± 0.14, 7.30 ± 0.09, 13.20 ± 0.09, 2.10 ± 0.06, and 0.68 ± 0.05 yr are obtained for 3C 273 based on the data in the present work combined with historical works.

  2. The radio structure of the quasar 3C154 at decameter wavelengths

    NASA Astrophysics Data System (ADS)

    Meg'n, A. V.; Braude, S. Ya.; Rashkovskii, S. L.; Sharykyn, N. K.; Shepelev, V. A.; Inyutin, G. A.; Khristenko, A. D.; Brazhenko, A. I.; Bulatsen, V. G.

    1998-11-01

    The results of studies of the radio structure of the quasar 3C154 at 25 and 20 MHz using the URAN-1 and URAN-2 radio interferometers are presented. The object probably has a core-halo structure, consisting of a compact component with a size of about 4'' and a more extended component roughly 45'' in size, detected for the first time at these wavelengths. This extended component contributes most of the decameter emission.

  3. Fluoreno[4,3-c]fluorene: a closed-shell, fully conjugated hydrocarbon.

    PubMed

    Rose, Bradley D; Vonnegut, Chris L; Zakharov, Lev N; Haley, Michael M

    2012-05-04

    The synthesis and optoelectronic properties of 24 π-electron, formally antiaromatic 4,11-di-t-butyl-1,8-dimesitylfluoreno[4,3-c]fluorene (FF) are presented. The solid-state structure shows that the outer rings are aromatic, while the central four rings possess a bond-localized 2,6-naphthoquinone dimethide motif (in red). The biradical character of FF is assessed experimentally and computationally; the results of which implicate a closed-shell ground state.

  4. Superconductivity of Rb 3 C 60 : breakdown of the Migdal-Eliashberg theory

    NASA Astrophysics Data System (ADS)

    Cappelluti, E.; Grimaldi, C.; Pietronero, L.; Strässler, S.; Ummarino, G. A.

    2001-06-01

    In this paper, through an exhaustive analysis within the Migdal-Eliashberg theory, we show the incompatibility of experimental data of Rb3C60 with the basic assumptions of the standard theory of superconductivity. For different models of the electron-phonon spectral function α2F(Ω) we solve numerically the Eliashberg equations to find which values of the electron-phonon coupling λ, of the logarithmic phonon frequency and of the Coulomb pseudopotential μ* reproduce the experimental data of Rb3C60. We find that the solutions are essentially independent of the particular shape of α2F(Ω) and that, to explain the experimental data of Rb3C60, one has to resort to extremely large couplings: λ = 3.0+/-0.8. This results differs from the usual partial analyses reported up to now and we claim that this value exceeds the maximum allowed λ compatible with the crystal lattice stability. Moreover, we show quantitatively that the obtained values of λ and strongly violate Migdal's theorem and consequently are incompatible with the Migdal-Eliashberg theory. One has therefore to consider the generalization of the theory of superconductivity in the nonadiabatic regime to account for the experimental properties of fullerides.

  5. Feline Coronavirus 3c Protein: A Candidate for a Virulence Marker?

    PubMed Central

    Hora, A. S.; Tonietti, P. O.; Taniwaki, S. A.; Asano, K. M.; Maiorka, P.; Richtzenhain, L. J.; Brandão, P. E.

    2016-01-01

    Feline infectious peritonitis virus (FIPV) is highly virulent and responsible for the highly fatal disease feline infectious peritonitis (FIP), whereas feline enteric coronavirus (FECV) is widespread among the feline population and typically causes asymptomatic infections. Some candidates for genetic markers capable of differentiating these two pathotypes of a unique virus (feline coronavirus) have been proposed by several studies. In the present survey, in order to search for markers that can differentiate FECV and FIPV, several clones of the 3a–c, E, and M genes were sequenced from samples obtained from cats with or without FIP. All genes showed genetic diversity and suggested the presence of FCoV mutant spectrum capable of producing a virulent pathotype in an individual-specific way. In addition, all the feline coronavirus FIPV strains demonstrated a truncated 3c protein, and the 3c gene was the only observed pathotypic marker for FCoVs, showing that 3c gene is a candidate marker for the distinction between the two pathotypes when the mutant spectrum is taken into account. PMID:27243037

  6. Ni3C-assisted growth of carbon nanofibres 300 °C by thermal CVD

    NASA Astrophysics Data System (ADS)

    Yu, Bowen; Wang, Shiliang; Zhang, Qiankun; He, Yuehui; Huang, Han; Zou, Jin

    2014-08-01

    Ni-assisted thermal chemical vapor deposition (TCVD) is one of the most common techniques for the growth of carbon nanofibres/nanotubes (CNFs/CNTs). However, some fundamental issues related to the catalytic growth of CNFs/CNTs, such as the low-limit growth temperature, the limiting steps and the state of Ni, are still controversial. Here, we report the growth of CNFs at 300 °C that is the lowest temperature for the growth of CNFs by TCVD using Ni as the catalyst so far. The results showed that the Ni existed in rhombohedral Ni3C, not in the normal form of face-centered cubic Ni, and the C atoms for building the CNFs were precipitated from the (001) planes of the faceted Ni3C nanoparticles. The CNFs are believed to be formed by the decomposition-formation cycle of metastable Ni3C that has a low-limit decomposition temperature of about 300 °C. Our results strongly suggest that TCVD is a valuable tool for the synthesis of CNFs/CNTs at temperatures below 400 °C, which is generally considered as the upper-limit temperature for fabricating complementary metal oxide semiconductor devices but is the low-limit temperature for growing CNFs/CNTs by TCVD at present.

  7. Positron annihilation spectroscopy investigation of vacancy defects in neutron-irradiated 3 C -SiC

    NASA Astrophysics Data System (ADS)

    Hu, Xunxiang; Koyanagi, Takaaki; Katoh, Yutai; Wirth, Brian D.

    2017-03-01

    Positron annihilation spectroscopy characterization results for neutron-irradiated 3 C -SiC are described here, with a specific focus on explaining the size and character of vacancy clusters as a complement to the current understanding of the neutron irradiation response of 3 C -SiC. Positron annihilation lifetime spectroscopy was used to capture the irradiation temperature and dose dependence of vacancy defects in 3 C -SiC following neutron irradiation from 0.01 to 31 dpa in the temperature range from 380°C to 790°C . The neutral and negatively charged vacancy clusters were identified and quantified. The results suggest that the vacancy defects that were measured by positron annihilation spectroscopy technique contribute very little to the transient swelling of SiC. In addition, coincidence Doppler broadening measurement was used to investigate the chemical identity surrounding the positron trapping sites. It was found that silicon vacancy-related defects dominate in the studied materials and the production of the antisite defect CSi may result in an increase in the probability of positron annihilation with silicon core electrons.

  8. Mass-Analyzed Threshold Ionization and Structures of M_3C_2(M=Sc, La)

    NASA Astrophysics Data System (ADS)

    Wu, Lu; Mourad, Roudjane; Yang, D. S.

    2011-06-01

    M_3C_2 (M=Sc, La) clusters are produced by laser vaporization in a pulsed metal-cluster source and identified by photoionization mass spectrometry. Vibrationally resolved ion spectra are obtained with mass-analyzed threshold ionization (MATI) spectroscopy. The MATI spectra of M_3C_2 (M=Sc, La) exhibit a weak 0-0 transition, indicating a significant geometry difference between the neutral and ionized clusters. The ionization energies of Sc_2C_2 and La_3C_2 are measured to be 36398 (5) and 30051(5) Cm-1, respectively. In addition, the spectra of the two clusters display a number of vibrational intervals that are associated with M_3 deformations. Preliminary data analysis shows that both clusters have a C2v bi-pyramid structure in the neutral state and a D3h bi-pyramid structure in the ion state, and the spectra may be assigned to the ^1A'_1 (D3h)← ^2B_2 (C2v) transitions.

  9. Possible light-induced superconductivity in K3C60 at high temperature.

    PubMed

    Mitrano, M; Cantaluppi, A; Nicoletti, D; Kaiser, S; Perucchi, A; Lupi, S; Di Pietro, P; Pontiroli, D; Riccò, M; Clark, S R; Jaksch, D; Cavalleri, A

    2016-02-25

    The non-equilibrium control of emergent phenomena in solids is an important research frontier, encompassing effects such as the optical enhancement of superconductivity. Nonlinear excitation of certain phonons in bilayer copper oxides was recently shown to induce superconducting-like optical properties at temperatures far greater than the superconducting transition temperature, Tc (refs 4-6). This effect was accompanied by the disruption of competing charge-density-wave correlations, which explained some but not all of the experimental results. Here we report a similar phenomenon in a very different compound, K3C60. By exciting metallic K3C60 with mid-infrared optical pulses, we induce a large increase in carrier mobility, accompanied by the opening of a gap in the optical conductivity. These same signatures are observed at equilibrium when cooling metallic K3C60 below Tc (20 kelvin). Although optical techniques alone cannot unequivocally identify non-equilibrium high-temperature superconductivity, we propose this as a possible explanation of our results.

  10. An HST Proper-motion Study of the Large-scale Jet of 3C273

    NASA Astrophysics Data System (ADS)

    Meyer, Eileen T.; Sparks, William B.; Georganopoulos, Markos; Anderson, Jay; van der Marel, Roeland; Biretta, John; Sohn, Sangmo Tony; Chiaberge, Marco; Perlman, Eric; Norman, Colin

    2016-02-01

    The radio galaxy 3C 273 hosts one of the nearest and best-studied powerful quasar jets. Having been imaged repeatedly by the Hubble Space Telescope (HST) over the past twenty years, it was chosen for an HST program to measure proper motions in the kiloparsec-scale resolved jets of nearby radio-loud active galaxies. The jet in 3C 273 is highly relativistic on sub-parsec scales, with apparent proper motions up to 15c observed by very long baseline interferometry. In contrast, we find that the kiloparsec-scale knots are compatible with being stationary, with a mean speed of -0.2 ± 0.5c over the whole jet. Assuming the knots are packets of moving plasma, an upper limit of 1c implies a bulk Lorentz factor Γ < 2.9. This suggests that the jet has either decelerated significantly by the time it reaches the kiloparsec scale, or that the knots in the jet are standing shock features. The second scenario is incompatible with the inverse Compton off the Cosmic Microwave Background (IC/CMB) model for the X-ray emission of these knots, which requires the knots to be in motion, but IC/CMB is also disfavored in the first scenario due to energetic considerations, in agreement with the recent finding of Meyer & Georganopoulos which ruled out the IC/CMB model for the X-ray emission of 3C 273 via gamma-ray upper limits.

  11. Feline Coronavirus 3c Protein: A Candidate for a Virulence Marker?

    PubMed

    Hora, A S; Tonietti, P O; Taniwaki, S A; Asano, K M; Maiorka, P; Richtzenhain, L J; Brandão, P E

    2016-01-01

    Feline infectious peritonitis virus (FIPV) is highly virulent and responsible for the highly fatal disease feline infectious peritonitis (FIP), whereas feline enteric coronavirus (FECV) is widespread among the feline population and typically causes asymptomatic infections. Some candidates for genetic markers capable of differentiating these two pathotypes of a unique virus (feline coronavirus) have been proposed by several studies. In the present survey, in order to search for markers that can differentiate FECV and FIPV, several clones of the 3a-c, E, and M genes were sequenced from samples obtained from cats with or without FIP. All genes showed genetic diversity and suggested the presence of FCoV mutant spectrum capable of producing a virulent pathotype in an individual-specific way. In addition, all the feline coronavirus FIPV strains demonstrated a truncated 3c protein, and the 3c gene was the only observed pathotypic marker for FCoVs, showing that 3c gene is a candidate marker for the distinction between the two pathotypes when the mutant spectrum is taken into account.

  12. Contemporaneous IUE, EUVE, and High-Energy Observations of 3C 273

    NASA Technical Reports Server (NTRS)

    Ramos, E.; Kafatos, M.; Fruscione, A.; Bruhweiler, F. C.; McHardy, I. M.; Hartman, R. C.; Titarchuk, L. G.; vonMontigny, C.

    1997-01-01

    We present the results of our 1994 January and 1995 January observations of the quasar 3C 273 obtained with the International Ultraviolet Explorer (IUE) and the Extreme-Ultraviolet Explorer (EUVE). These observations were part of a large multiwavelength campaign to observe 3C 273 from radio through gamma-rays. Our 1995 January photometric observations with the EUVE Lexan/B Deep Survey (DS) instrument indicate strong evidence for variability, at a 99% confidence level, during the 12 day observing period. We have utilized ROSAT PSPC soft X-ray power-law models to correlate with EUVE count rates. Besides variations in the normalization level between both observations, our EUV count rates are consistent with a simple power-law model with spectral index alpha approx. 1.77 (F(sub upsilon) proportional to upsilon(sup -alpha) that can be extrapolated from the soft X-rays to the EUV range. The active galactic nucleus 3C 273 is an important blazar to study because in our picture it reveals the presence of both disk and relativistic beam spectral contributions.

  13. Controllable magnitude and anisotropy of the electrical conductivity of Hf3C2O2 MXene

    NASA Astrophysics Data System (ADS)

    Zha, Xian-Hu; Zhou, Jie; Luo, Kan; Lang, Jiajian; Huang, Qing; Zhou, Xiaobing; Francisco, Joseph S.; He, Jian; Du, Shiyu

    2017-04-01

    Hf3C2O2, a new MXene member synthesized recently, was predicted to be a semi-metal with high mechanical strength. Based on the unique electronic structure, the energy bands and electrical conductivities of the MXene under various strains are comprehensively investigated in this paper. Biaxial and two orthogonal uniaxial strains in both compressive and tensile manners are studied. Results from this study suggest that Hf3C2O2 shows a transition between semi-metal and semi-conductor under both biaxial and uniaxial strains. A compressive strain generally induces a larger energy overlap between the conduction band minimum and the valance band maximum, while a tensile strain reduces the energy band overlap and even opens a band gap. As a consequence, the magnitude of electrical conductivity decreases drastically from compressive to tensile strains applied. Moreover, the uniaxial strains are determined to be efficient in manipulating the anisotropy of the electrical conductivity. These data imply that the Hf3C2O2 MXene is a promising candidate material for devices such as strain sensors.

  14. Multi-Epoch Multiwavelength Spectra and Models for Blazar 3C 279

    NASA Technical Reports Server (NTRS)

    Hartman, R. C.; Boettcher, M.; Aldering, G.; Aller, H.; Aller, M.; Backman, D. E.; Balonek, T. J.; Bertsch, D. L.; Bloom, S. D.; Bock, H.; White, Nicholas E. (Technical Monitor)

    2001-01-01

    Of the blazars detected by EGRET in GeV gamma-rays, 3C 279 is not only the best-observed by EGRET, but also one of the best-monitored at lower frequencies. We have assembled eleven spectra, from GHz radio through GeV gamma-rays, from the time intervals of EGRET observations. Although some of the data have appeared in previous publications, most are new, including data taken during the high states in early 1999 and early 2000. All of the spectra show substantial gamma-ray contribution to the total luminosity of the object; in a high state, the gamma-ray luminosity dominates over that at all other frequencies by a factor of more than 10. There is no clear pattern of time correlation; different bands do not always rise and fall together, even in the optical, X-ray, and gamma-ray bands. The spectra are modeled using a leptonic jet, with combined synchrotron self-Compton + external Compton gamma-ray production. Spectral variability of 3C 279 is consistent with variations of the bulk Lorentz factor of the jet, accompanied by changes in the spectral shape of the electron distribution. Our modeling results are consistent with the UV spectrum of 3C 279 being dominated by accretion disk radiation during times of low gamma-ray intensity.

  15. The compact radio sources in 4C 39.25 and 3C 345. [quasars

    NASA Technical Reports Server (NTRS)

    Shaffer, D. B.; Kellermann, K. I.; Purcell, G. H.; Pauliny-Toth, I. I. K.; Preuss, E.; Witzel, A.; Graham, D.; Schilizzi, R. T.; Cohen, M. H.; Niell, A. E.

    1977-01-01

    Long-baseline interferometry of the quasars 4C 39.25 and 3C 345 at 10.65 and 14.77 GHz shows that the centimeter radio source in each object is double, with component separations of 0.0020 arcsec (4C 39.25) and 0.0013 arcsec (3C 345 at 1974.5). For each source, the separation is the same at both frequencies, as well as similar to the structure observed at 7.85 GHz (and 5.0 GHz for 4C 39.25). The spectra of the individual components are derived and shown to vary with time approximately as expected for expanding self-absorbed synchrotron sources. The magnetic fields in the components are estimated to be as high as 0.1 gauss, but the structure of the sources appears to be unrelated to the magnetic-field orientation derived from low-resolution polarization measurements. The component separation in 4C 39.25 has not changed for several years, whereas 3C 345 shows rapid expansion.

  16. S3C Active Archive Services and Capabilities Relevant to the eGY

    NASA Astrophysics Data System (ADS)

    McGuire, R.; Bilitza, D.; Candey, R.; Chimiak, R.; Cooper, J.; Fung, S.; Han, D.; Harris, B.; Johnson, R.; Kessel, R.; Klipsch, C.; Kovalick, T.; Leckner, H.; Liu, M.; Papitashvili, N.

    2005-05-01

    The next advances in Sun Solar System Connections (S3C) / Solar-Terrestrial science require an increasingly integrated and transparent data environment, where data can be easily accessed and used across the boundaries of both missions and traditional disciplines. The S3C Active Archive center in the Space Physics Data Facility (SPDF), in close coordination with the National Space Science Data Center (NSSDC), supports uniquely important multi-mission data services and archiving activities. This paper discusses the range of services supported, how they are evolving to meet the needs of programs like LWS/ILWS and the eGY initiative, and how we envision their future actively contributing to the success of the thrust towards virtual discipline-centered observatories (VxOs). The Coordinated Data Analysis [Workshop] Web (CDAWeb) and Satellite Situation Center Web (SSCWeb), critically supported by the Common Data Format (CDF) effort and supplemented by more focused services such as data format translations, COHOWeb, ATMOWeb, FTPBrowser, ModelWeb and HelioWeb, are important current examples suggestive of the scope and functionality needed in the future. These systems serve broad communities now and are already capable of significant contributions to eGY. A new Java-based CDAWeb interface integrates unified user access to this combined set, and key services have already been extended with new web services APIs to allow ready invocation from distributed external middleware and clients expected to form the framework of a new VxO infrastructure in S3C.

  17. EBNA3C-mediated regulation of aurora kinase B contributes to Epstein-Barr virus-induced B-cell proliferation through modulation of the activities of the retinoblastoma protein and apoptotic caspases.

    PubMed

    Jha, Hem Chandra; Lu, Jie; Saha, Abhik; Cai, Qiliang; Banerjee, Shuvomoy; Prasad, Mahadesh A J; Robertson, Erle S

    2013-11-01

    Epstein-Barr virus (EBV) is an oncogenic gammaherpesvirus that is implicated in several human malignancies, including Burkitt's lymphoma (BL), posttransplant lymphoproliferative disease (PTLD), nasopharyngeal carcinoma (NPC), and AIDS-associated lymphomas. Epstein-Barr nuclear antigen 3C (EBNA3C), one of the essential EBV latent antigens, can induce mammalian cell cycle progression through its interaction with cell cycle regulators. Aurora kinase B (AK-B) is important for cell division, and deregulation of AK-B is associated with aneuploidy, incomplete mitotic exit, and cell death. Our present study shows that EBNA3C contributes to upregulation of AK-B transcript levels by enhancing the activity of its promoter. Further, EBNA3C also increased the stability of the AK-B protein, and the presence of EBNA3C leads to reduced ubiquitination of AK-B. Importantly, EBNA3C in association with wild-type AK-B but not with its kinase-dead mutant led to enhanced cell proliferation, and AK-B knockdown can induce nuclear blebbing and cell death. This phenomenon was rescued in the presence of EBNA3C. Knockdown of AK-B resulted in activation of caspase 3 and caspase 9, along with poly(ADP-ribose) polymerase 1 (PARP1) cleavage, which is known to be an important contributor to apoptotic signaling. Importantly, EBNA3C failed to stabilize the kinase-dead mutant of AK-B compared to wild-type AK-B, which suggests a role for the kinase domain in AK-B stabilization and downstream phosphorylation of the cell cycle regulator retinoblastoma protein (Rb). This study demonstrates the functional relevance of AK-B kinase activity in EBNA3C-regulated B-cell proliferation and apoptosis.

  18. Targeting prostate carcinoma by G3-C12 peptide conjugated N-(2-hydroxypropyl)methacrylamide copolymers.

    PubMed

    Yang, Yang; Li, Lian; Zhou, Zhou; Yang, Qingqing; Liu, Chong; Huang, Yuan

    2014-10-06

    Prostate carcinoma is the second leading cause of cancer-related deaths. Increased expression of membrane-bound galectin-3 by prostate carcinoma cell has been found to correlate with more poorly differentiated and increased metastatic potential. In the present study, different amount of galectin-3-binding peptide, G3-C12 (the sequence ANTPCGPYTHDCPVKR), was attached to N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers as targeting moiety. The results of qPCR and competitive binding test indicated that the expression level of galectin-3 in two metastatic prostate carcinoma cell lines (PC-3 and DU145 cells) could be significantly suppressed by the addition of G3-C12-modified HPMA copolymers (PG1 and PG2), demonstrating the high affinity of PG1 and PG2 to galectin-3. Due to the multivalent effects of moieties, the uptake of copolymers was remarkably enhanced with the increasing amount of conjugated G3-C12 peptide. A higher internalization of PG1 and PG2 occurred in PC-3 cells via caveolin- and clathrin-mediated endocytosis, whereas a clathrin-mediated uptake process was involved in DU145 cells. The in vivo biodistribution and pharmacokinetics of nonmodified ((131)I-pHPMA) and G3-C12-modified ((131)I-PG1 and (131)I-PG2) copolymers were estimated on a well-established mice model bearing PC-3 xenografts by (131)I-SPECT-imaging. Higher tumor accumulation of (131)I-PG1 (1.60 ± 0.08% ID/g, p < 0.05) and (131)I-PG2 (1.54 ± 0.06% ID/g, p < 0.05) was observed compared with (131)I-pHPMA (1.19 ± 0.04% ID/g) at 2 h post-intravenous injection. Although the amount of conjugated G3-C12 peptide performed a remarkable in vitro effect on the affinity and internalization of HPMA copolymers to the galectin-3 overexpressed prostate carcinoma cells, the molecular weight and ligand modification all play important roles on their in vivo tumor accumulation.

  19. Test results for the Oasis 3C high performance water-pumping windmill

    SciTech Connect

    Eggleston, D.M.

    1997-12-31

    The WINDTech International, L.L.C. Oasis 3C, a 3 m diameter, high-performance water-pumping windmill, was tested at the DME Engineering Wind Test Site just south of Midland, Texas from August through December, 1996. This machine utilizes a 3:1 gearbox with rotating counterweights, similar to a conventional oilfield pumping unit, driven by a multibladed rotor. The rotating counterweight system balances most of the pumping loads and reduces gear loads and starting torque by a factor of at least two and often by a factor of four or more. The torque reduction substantially extends gear and bearing life, and reduces wind speeds required for starting by 30 to 50% or more. The O3C was tested pumping from a quiescent fluid depth of 12.2 m (40 ft) from a 28.3 m (93 ft)-deep well, with additional pumping depth simulated using a pressure regulator valve system. A 9.53 cm (3.75 in.) diameter Harbison-Fischer seal-less single-acting piston pump was used to eliminate pump seal friction as a variable, and standard O3C stroke lengths of 30.5 and 15.2 cm (12 and 6 inches) were used. The regulator spring was set to give a maximum stroke rate of 33 strokes per minute. The water pumped was returned to the well after flowing through a settling tank. The tests were performed in accordance with AWEA WECS testing standards. Instrumentation provided 16 channels of data to accurately measure machine performance, including starting wind speeds, flow rates, O3C azimuth, tail furl angle, wind direction tracking errors, RPM, sucker rod loads, and other variables. The most significant performance data is summarized herein. A mathematical model of machine performance was developed that fairly accurately predicts performance for each of three test conditions. The results verify that the O3C is capable of pumping water at wind speeds from 30% to more than 50% lower than comparable un-counterbalanced units.

  20. Structures and energies of Cu clusters on Fe and Fe3C surfaces from density functional theory computation.

    PubMed

    Tian, Xinxin; Wang, Tao; Yang, Yong; Li, Yong-Wang; Wang, Jianguo; Jiao, Haijun

    2014-12-28

    Spin-polarized density functional theory computations have been carried out to study the stable adsorption configurations of Cun (n = 1-7, 13) on Fe and Fe3C surfaces for understanding the initial stages of copper promotion in catalysis. At low coverage, two-dimensional aggregation is more preferred over dispersion and three-dimensional aggregation on the Fe(110) and Fe(100) surfaces as well as the metallic Fe3C(010) surfaces, while dispersion is more favorable over aggregation on the Fe(111) surface. On the Fe3C(001) and Fe3C(100) surfaces with exposed iron and carbon atoms, the adsorbed Cu atoms prefer dispersion at low coverage, while aggregation along the iron regions at high coverage. On the iron surfaces, the adsorption energies of Cun (n = 2-7) are highest on Fe(111), medium on Fe(100) and lowest on Fe(110). On the Fe3C surfaces, the adsorption energies of Cun (n = 1-3) are highest on Fe3C(100), medium on Fe3C(010) and lowest on Fe3C(001), while, for n = 4-7 and 13, Fe3C(010) has stronger adsorption than Fe3C(100). On the basis of their differences in electronegativity, the adsorbed Cu atoms can oxidize the metallic Fe(110), Fe(100) and Fe3C(010) surfaces and become negatively charged. On the Fe3C(001) and Fe3C(100) surfaces with exposed iron and carbon atoms, the adsorbed Cu atoms interacting with surface carbon atoms are oxidized and positively charged. Unlike the most stable Fe(110) and Fe3C(001) surfaces, where the Fe(110) surface has stronger Cu affinity than the Fe3C(001) surface, which is in agreement with the experimental finding, the less and least stable Fe3C(010) and Fe3C(100) surfaces have stronger Cu affinities than the Fe(110) and Fe(100) surfaces. Since less stable facets are not preferably formed thermodynamically, it is crucial to prepare such surfaces to explore Cu adsorption and promotion, and this provides challenges to surface sciences.

  1. The Galactic Plane region near ℓ = 93°. II. A stellar wind bubble surrounding SNR 3C 434.1

    NASA Astrophysics Data System (ADS)

    Foster, T.; Routledge, D.; Kothes, R.

    2004-04-01

    New Canadian Galactic Plane Survey λ 21 cm H I line observations towards supernova remnant (SNR) 3C 434.1 (G94.0+1.0) are presented. We find a fragmented and thin-walled atomic hydrogen shell inside which the SNR is seen to be contained at v≃ -80 km s-1, which we report to be a highly evolved stellar wind bubble (SWB) associated with the remnant. A dark area in the midst of otherwise bright line emission is also seen near -71 km s-1. An absorption profile to the extragalactic continuum source 4C 51.45 (superimposed on the shell's north face) allows us to probe the shell's optical depth, kinetic temperature and expansion velocity. The material in the dark area has the same properties as material in the fragmented shell, suggesting that the dark area is actually the far-side ``cap'' of the shell seen absorbing emission from warm background gas, the first instance of H I Self Absorption (HISA) seen in such a structure. We show that the kinematic distance of 10 kpc derived from a flat Galactic rotation model is highly improbable, and that this bubble/SNR system is most likely resident in the Perseus Spiral Arm, lying 5.2 kpc distant. We model the SWB shell in three dimensions as a homologously expanding ellipsoid. Physical and dynamical characteristics of the bubble are determined, showing its advanced evolutionary state. Finally, from a photometric search for one or more stars associated with the SWB, we determine that three B0V stars and one O4V star currently inhabit this bubble, and that the progenitor of 3C 434.1 was at latest also an O4 type star.

  2. Insights into cleavage specificity from the crystal structure of foot-and-mouth disease virus 3C protease complexed with a peptide substrate.

    PubMed

    Zunszain, Patricia A; Knox, Stephen R; Sweeney, Trevor R; Yang, Jingjie; Roqué-Rosell, Núria; Belsham, Graham J; Leatherbarrow, Robin J; Curry, Stephen

    2010-01-15

    Picornavirus replication is critically dependent on the correct processing of a polyprotein precursor by 3C protease(s) (3C(pro)) at multiple specific sites with related but non-identical sequences. To investigate the structural basis of its cleavage specificity, we performed the first crystallographic structural analysis of non-covalent complexes of a picornavirus 3C(pro) with peptide substrates. The X-ray crystal structure of the foot-and-mouth disease virus 3C(pro), mutated to replace the catalytic Cys by Ala and bound to a peptide (APAKQ|LLNFD) corresponding to the P5-P5' region of the VP1-2A cleavage junction in the viral polyprotein, was determined up to 2.5 A resolution. Comparison with free enzyme reveals significant conformational changes in 3C(pro) on substrate binding that lead to the formation of an extended interface of contact primarily involving the P4-P2' positions of the peptide. Strikingly, the deep S1' specificity pocket needed to accommodate P1'-Leu only forms when the peptide binds. Substrate specificity was investigated using peptide cleavage assays to show the impact of amino acid substitutions within the P5-P4' region of synthetic substrates. The structure of the enzyme-peptide complex explains the marked substrate preferences for particular P4, P2 and P1 residue types, as well as the relative promiscuity at P3 and on the P' side of the scissile bond. Furthermore, crystallographic analysis of the complex with a modified VP1-2A peptide (APAKE|LLNFD) containing a Gln-to-Glu substitution reveals an identical mode of peptide binding and explains the ability of foot-and-mouth disease virus 3C(pro) to cleave sequences containing either P1-Gln or P1-Glu. Structure-based mutagenesis was used to probe interactions within the S1' specificity pocket and to provide direct evidence of the important contribution made by Asp84 of the Cys-His-Asp catalytic triad to proteolytic activity. Our results provide a new level of detail in our understanding of the

  3. The kinesin-2 family member KIF3C regulates microtubule dynamics and is required for axon growth and regeneration.

    PubMed

    Gumy, Laura F; Chew, Daniel J; Tortosa, Elena; Katrukha, Eugene A; Kapitein, Lukas C; Tolkovsky, Aviva M; Hoogenraad, Casper C; Fawcett, James W

    2013-07-10

    Axon regeneration after injury requires the extensive reconstruction, reorganization, and stabilization of the microtubule cytoskeleton in the growth cones. Here, we identify KIF3C as a key regulator of axonal growth and regeneration by controlling microtubule dynamics and organization in the growth cone. KIF3C is developmentally regulated. Rat embryonic sensory axons and growth cones contain undetectable levels of KIF3C protein that is locally translated immediately after injury. In adult neurons, KIF3C is axonally transported from the cell body and is enriched at the growth cone where it preferentially binds to tyrosinated microtubules. Functionally, the interaction of KIF3C with EB3 is necessary for its localization at the microtubule plus-ends in the growth cone. Depletion of KIF3C in adult neurons leads to an increase in stable, overgrown and looped microtubules because of a strong decrease in the microtubule frequency of catastrophes, suggesting that KIF3C functions as a microtubule-destabilizing factor. Adult axons lacking KIF3C, by RNA interference or KIF3C gene knock-out, display an impaired axonal outgrowth in vitro and a delayed regeneration after injury both in vitro and in vivo. Murine KIF3C knock-out embryonic axons grow normally but do not regenerate after injury because they are unable to locally translate KIF3C. These data show that KIF3C is an injury-specific kinesin that contributes to axon growth and regeneration by regulating and organizing the microtubule cytoskeleton in the growth cone.

  4. Effect of lithium and sodium ion adsorption on the electronic transport properties of Ti3C2 MXene

    NASA Astrophysics Data System (ADS)

    Berdiyorov, G. R.

    2015-12-01

    MXenes are found to be promising electrode materials for energy storage applications. Recent theoretical and experimental studies indicate the possibility of using these novel low dimensional materials for metal-ion batteries. Herein, we use density-functional theory in combination with the nonequilibrium Green's function formalism to study the effect of lithium and sodium ion adsorption on the electronic transport properties of the MXene, Ti3C2. Oxygen, hydroxyl and fluorine terminated species are considered and the obtained results are compared with the ones for the pristine MXene. We found that the ion adsorption results in reduced electronic transport in the pristine MXene: depending on the type of the ions and the bias voltage, the current in the system can be reduced by more than 30%. On the other hand, transport properties of the oxygen terminated sample can be improved by the ion adsorption: for both types of ions the current in the system can be increased by more than a factor of 4. However, the electronic transport is less affected by the ions in fluorinated and hydroxylated samples. These two samples show enhanced electronic transport as compared to the pristine MXene. The obtained results are explained in terms of electron localization in the system.

  5. Model fitting of the kinematics of ten superluminal components in blazar 3C 279

    NASA Astrophysics Data System (ADS)

    Qian, Shan-Jie

    2013-07-01

    The kinematics of ten superluminal components (C11- C16, C18, C20, C21 and C24) of blazar 3C 279 are studied from VLBI observations. It is shown that their initial trajectory, distance from the core and apparent speed can be well fitted by the precession model proposed by Qian. Combined with the results of the model fit for the six superluminal components (C3, C4, C7a, C8, C9 and C10) already published, the kinematics of sixteen superluminal components can now be consistently interpreted in the precession scenario with their ejection times spanning more than 25 yr (or more than one precession period). The results from model fitting show the possible existence of a common precessing trajectory for these knots within a projected core distance of ~0.2-0.4 mas. In the framework of the jet-precession scenario, we can, for the first time, identify three classes of trajectories which are characterized by their collimation parameters. These different trajectories could be related to the helical structure of magnetic fields in the jet. Through fitting the model, the bulk Lorentz factor, Doppler factor and viewing angle of these knots are derived. It is found that there is no evidence for any correlation between the bulk Lorentz factor of the components and their precession phase (or ejection time). In a companion paper, the kinematics of another seven components (C5a, C6, C7, C17, C19, C22 and C23) have been derived from model fitting, and a binary black-hole/jet scenario was envisaged. The precession model proposed by Qian would be useful for understanding the kinematics of superluminal components in blazar 3C 279 derived from VLBI observations, by disentangling different mechanisms and ingredients. More generally, it might also be helpful for studying the mechanism of jet swing (wobbling) in other blazars.

  6. Preliminary validation of the refractivity from the new radio occultation sounder GNOS/FY-3C

    NASA Astrophysics Data System (ADS)

    Liao, Mi; Zhang, Peng; Yang, Guang-Lin; Bi, Yan-Meng; Liu, Yan; Bai, Wei-Hua; Meng, Xiang-Guang; Du, Qi-Fei; Sun, Yue-Qiang

    2016-03-01

    As a new member of the space-based radio occultation sounders, the GNOS (Global Navigation Satellite System Occultation Sounder) mounted on Fengyun-3C (FY-3C) has been carrying out atmospheric sounding since 23 September 2013. GNOS takes approximately 800 daily measurements using GPS (Global Positioning System) and Chinese BDS (BeiDou navigation satellite) signals. In this work, the atmospheric refractivity profiles from GNOS were compared with the ones obtained from the co-located ECMWF (European Centre for Medium-Range Weather Forecasts) reanalysis. The mean bias of the refractivity obtained through GNOS GPS (BDS) was found to be approximately -0.09 % (-0.04 %) from the near surface to up to 46 km. While the average standard deviation was approximately 1.81 % (1.26 %), it was as low as 0.75 % (0.53 %) in the range of 5-25 km, where best sounding results are usually achieved. Further, COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) and MetOp/ GRAS (GNSS Receiver for Atmospheric Sounding) radio occultation data were compared with the ECMWF reanalysis; the results thus obtained could be used as reference data for GNOS. Our results showed that GNOS/FY-3C meets the design requirements in terms of accuracy and precision of the sounder. It possesses a sounding capability similar to COSMIC and MetOp/GRAS in the vertical range of 0-30 km, though it needs further improvement above 30 km. Overall, it provides a new data source for the global numerical weather prediction (NWP) community.

  7. Polarization angle swings in blazars: The case of 3C 279

    NASA Astrophysics Data System (ADS)

    Kiehlmann, S.; Savolainen, T.; Jorstad, S. G.; Sokolovsky, K. V.; Schinzel, F. K.; Marscher, A. P.; Larionov, V. M.; Agudo, I.; Akitaya, H.; Benítez, E.; Berdyugin, A.; Blinov, D. A.; Bochkarev, N. G.; Borman, G. A.; Burenkov, A. N.; Casadio, C.; Doroshenko, V. T.; Efimova, N. V.; Fukazawa, Y.; Gómez, J. L.; Grishina, T. S.; Hagen-Thorn, V. A.; Heidt, J.; Hiriart, D.; Itoh, R.; Joshi, M.; Kawabata, K. S.; Kimeridze, G. N.; Kopatskaya, E. N.; Korobtsev, I. V.; Krajci, T.; Kurtanidze, O. M.; Kurtanidze, S. O.; Larionova, E. G.; Larionova, L. V.; Lindfors, E.; López, J. M.; McHardy, I. M.; Molina, S. N.; Moritani, Y.; Morozova, D. A.; Nazarov, S. V.; Nikolashvili, M. G.; Nilsson, K.; Pulatova, N. G.; Reinthal, R.; Sadun, A.; Sasada, M.; Savchenko, S. S.; Sergeev, S. G.; Sigua, L. A.; Smith, P. S.; Sorcia, M.; Spiridonova, O. I.; Takaki, K.; Takalo, L. O.; Taylor, B.; Troitsky, I. S.; Uemura, M.; Ugolkova, L. S.; Ui, T.; Yoshida, M.; Zensus, J. A.; Zhdanova, V. E.

    2016-05-01

    Context. Over the past few years, on several occasions, large, continuous rotations of the electric vector position angle (EVPA) of linearly polarized optical emission from blazars have been reported. These events are often coincident with high energy γ-ray flares and they have attracted considerable attention, since they could allow us to probe the magnetic field structure in the γ-ray emitting region of the jet. The flat-spectrum radio quasar 3C 279 is one of the most prominent examples showing this behaviour. Aims: Our goal is to study the observed EVPA rotations and to distinguish between a stochastic and a deterministic origin of the polarization variability. Methods: We have combined multiple data sets of R-band photometry and optical polarimetry measurements of 3C 279, yielding exceptionally well-sampled flux density and polarization curves that cover a period of 2008-2012. Several large EVPA rotations are identified in the data. We introduce a quantitative measure for the EVPA curve smoothness, which is then used to test a set of simple random walk polarization variability models against the data. Results: 3C 279 shows different polarization variation characteristics during an optical low-flux state and a flaring state. The polarization variation during the flaring state, especially the smooth ~360° rotation of the EVPA in mid-2011, is not consistent with the tested stochastic processes. Conclusions: We conclude that, during the two different optical flux states, two different processes govern polarization variation, which is possibly a stochastic process during the low-brightness state and a deterministic process during the flaring activity. The measured and processed optical polarization and R-band photometry data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/590/A10

  8. First 230 GHz VLBI fringes on 3C 279 using the APEX Telescope

    NASA Astrophysics Data System (ADS)

    Wagner, J.; Roy, A. L.; Krichbaum, T. P.; Alef, W.; Bansod, A.; Bertarini, A.; Güsten, R.; Graham, D.; Hodgson, J.; Märtens, R.; Menten, K.; Muders, D.; Rottmann, H.; Tuccari, G.; Weiss, A.; Wieching, G.; Wunderlich, M.; Zensus, J. A.; Araneda, J. P.; Arriagada, O.; Cantzler, M.; Duran, C.; Montenegro-Montes, F. M.; Olivares, R.; Caro, P.; Bergman, P.; Conway, J.; Haas, R.; Johansson, J.; Lindqvist, M.; Olofsson, H.; Pantaleev, M.; Buttaccio, S.; Cappallo, R.; Crew, G.; Doeleman, S.; Fish, V.; Lu, R.-S.; Ruszczyk, C.; SooHoo, J.; Titus, M.; Freund, R.; Marrone, D.; Strittmatter, P.; Ziurys, L.; Blundell, R.; Primiani, R.; Weintroub, J.; Young, K.; Bremer, M.; Sánchez, S.; Marscher, A. P.; Chilson, R.; Asada, K.; Inoue, M.

    2015-09-01

    Aims: We report about a 230 GHz very long baseline interferometry (VLBI) fringe finder observation of blazar 3C 279 with the APEX telescope in Chile, the phased submillimeter array (SMA), and the SMT of the Arizona Radio Observatory (ARO). Methods: We installed VLBI equipment and measured the APEX station position to 1 cm accuracy (1σ). We then observed 3C 279 on 2012 May 7 in a 5 h 230 GHz VLBI track with baseline lengths of 2800 Mλ to 7200 Mλ and a finest fringe spacing of 28.6 μas. Results: Fringes were detected on all baselines with signal-to-noise ratios of 12 to 55 in 420 s. The correlated flux density on the longest baseline was ~0.3 Jy beam-1, out of a total flux density of 19.8 Jy. Visibility data suggest an emission region ≲ 38 μas in size, and at least two components, possibly polarized. We find a lower limit of the brightness temperature of the inner jet region of about 1010 K. Lastly, we find an upper limit of 20% on the linear polarization fraction at a fringe spacing of ~ 38 μas. Conclusions: With APEX the angular resolution of 230 GHz VLBI improves to 28.6 μas. This allows one to resolve the last-photon ring around the Galactic Center black hole event horizon, expected to be 40 μas in diameter, and probe radio jet launching at unprecedented resolution, down to a few gravitational radii in galaxies like M 87. To probe the structure in the inner parsecs of 3C 279 in detail, follow-up observations with APEX and five other mm-VLBI stations have been conducted (March 2013) and are being analyzed.

  9. AN HST PROPER-MOTION STUDY OF THE LARGE-SCALE JET OF 3C273

    SciTech Connect

    Meyer, Eileen T.; Georganopoulos, Markos; Sparks, William B.; Anderson, Jay; Marel, Roeland van der; Biretta, John; Chiaberge, Marco; Norman, Colin; Tony Sohn, Sangmo; Perlman, Eric

    2016-02-20

    The radio galaxy 3C 273 hosts one of the nearest and best-studied powerful quasar jets. Having been imaged repeatedly by the Hubble Space Telescope (HST) over the past twenty years, it was chosen for an HST program to measure proper motions in the kiloparsec-scale resolved jets of nearby radio-loud active galaxies. The jet in 3C 273 is highly relativistic on sub-parsec scales, with apparent proper motions up to 15c observed by very long baseline interferometry. In contrast, we find that the kiloparsec-scale knots are compatible with being stationary, with a mean speed of −0.2 ± 0.5c over the whole jet. Assuming the knots are packets of moving plasma, an upper limit of 1c implies a bulk Lorentz factor Γ < 2.9. This suggests that the jet has either decelerated significantly by the time it reaches the kiloparsec scale, or that the knots in the jet are standing shock features. The second scenario is incompatible with the inverse Compton off the Cosmic Microwave Background (IC/CMB) model for the X-ray emission of these knots, which requires the knots to be in motion, but IC/CMB is also disfavored in the first scenario due to energetic considerations, in agreement with the recent finding of Meyer and Georganopoulos which ruled out the IC/CMB model for the X-ray emission of 3C 273 via gamma-ray upper limits.

  10. The Remarkable X-ray Spectrum of the Broad-Line Radio Galaxy 3C 445

    NASA Technical Reports Server (NTRS)

    Sambruna, R. M.; Reeves, J. N.; Braito, V.

    2007-01-01

    The nearby (z=0.057) radio-loud source 3C 445, optically classified as a Broad-Line Radio Galaxy, exhibits an X-ray spectrum strongly reminiscent of an obscured AGN, suggesting we are seeing this source at a relatively large angle from the radio jet. Here we present an archival 15 ks XMM-Newton observation of 3C 445 which confirms the remarkable complexity of its X-ray emission. The X-ray emission is described by a power law continuum with GAMMA approximately equal to 1.4, absorbed by several layers of cold gas, plus strong cold reflection. A narrow, unresolved Fe Kalpha emission line is detected, confirming previous findings, with EW approximately equal to 400 eV. A soft excess is present below 2 keV over the extrapolation of the hard X-ray power law, which we model with a power law with the same photon index and absorbed by a column density N(sub H)5 approximately equal to 10(sup 20) cm(sup -2) in excess to Galactic. Remarkably, a host of emission lines are present below 2 keV, confirming previous indications from ASCA, due to H- and He-like O, Mg, and Si. The detection of two features at 0.74 and 0.87 keV, identified with OVII and OVIII Radiative Recombination Continuum features, suggest an origin of the lines from a photoionized gas, with properties very similar to radio-quiet obscured AGN. Two different ionized media, or a single stratified medium, are required to fit the soft X-ray data satisfactorily. The similarity of the X-ray spectrum of 3C 445 to Seyferts underscores that the central engines of radio-loud and radio-quiet AGN similarly host both cold and warm gas.

  11. The Detection of Diffuse Extended Structure in 3C 273: Implications for Jet Power

    NASA Astrophysics Data System (ADS)

    Punsly, Brian; Kharb, Preeti

    2016-12-01

    We present deep Very Large Array imaging of 3C 273 in order to determine the diffuse, large scale radio structure of this famous radio-loud quasar. Diffuse extended structure (radio lobes) is detected for the first time in these observations as a consequence of high dynamic range in the 327.5 and 1365 MHz images. This emission is used to estimate a time averaged jet power, 7.2 × 1043 erg s-1 < \\overline{Q} < 3.7 × 1044 erg s-1. Brightness temperature arguments indicate consistent values of the time variability Doppler factor and the compactness Doppler factor for the inner jet, δ ≳ 10. Thus, the large apparent broadband bolometric luminosity of the jet, ˜3 × 1046 erg s-1, corresponds to a modest intrinsic luminosity ≳1042 erg s-1, or ˜1% of \\overline{Q}. In summary, we find that 3C 273 is actually a “typical” radio-loud quasar contrary to suggestions in the literature. The modest \\overline{Q} is near the peak of the luminosity distribution for radio-loud quasars and it is consistent with the current rate of dissipation emitted from millimeter wavelengths to gamma rays. The extreme core-jet morphology is an illusion from a near pole-on line of sight to a highly relativistic jet that produces a Doppler enhanced glow that previously swamped the lobe emission. 3C 273 apparently has the intrinsic kpc scale morphology of a classical double radio source, but it is distorted by an extreme Doppler aberration.

  12. Modelling 20 years of synchrotron flaring in the jet of 3C 273

    NASA Astrophysics Data System (ADS)

    Türler, M.; Courvoisier, T. J.-L.; Paltani, S.

    2000-09-01

    We present a phenomenological jet model which is able to reproduce well the observed variations of the submillimetre-to-radio emission of the bright quasar 3C 273 during the last 20 years. It is a generalization of the original shock model of Marscher & Gear (1985), which is now able to describe an accelerating or decelerating shock wave, in a curved, non-conical and non-adiabatic jet. The model defines the properties of a synchrotron outburst which is expected to be emitted by the jet material in a small region just behind the shock front. By a proper parameterization of the average outburst's evolution and of the peculiarities of individual outbursts, we are able to decompose simultaneously thirteen long-term light-curves of 3C 273 in a series of seventeen distinct outbursts. It is the first time that a model is so closely confronted to the long-term multi-wavelength variability properties of a quasar. The ability of the model to reproduce the very different shapes of the submillimetre-to-radio light curves of 3C 273 gives strong support to the shock model of Marscher & Gear (1985). Indirectly, it also reinforces the idea that the outbursts seen in the light-curves are physically linked to the distinct features observed to move along the jet with apparently superluminal velocities. The more than 5000 submillimetre-to-radio observations in the different light-curves are able to constrain the physical properties of the jet. The results suggest, for instance, that the magnetic field behind the shock front is rather turbulent. There is also some evidence that the jet radius does not increase linearly with distance down the jet or, alternatively, that the synchrotron emitting material decelerates with distance and/or bends away from the line-of-sight.

  13. Zooming in on the Central Regions of a Radio-loud AGN -- 3C120

    NASA Astrophysics Data System (ADS)

    Lohfink, Anne M.; Reynolds, C. S.; Miller, E. D.; Mushotzky, R.; Brenneman, L.

    2013-04-01

    We present a detailed study of the central engine structure in the broad-line radio galaxy 3C120 using a multi-epoch analysis of a deep XMM-Newton observation (taken in 2003) and two deep Suzaku pointings (in 2012), providing the closest look at 3C120 to date. In order to place our X-ray spectral data into the context of the known disk-disruption/jet-ejection cycles displayed by this object, we consider monitoring of the source in the UV/X-ray bands by RXTE and Swift using the UV flux as a proxy for the accretion disk emission and the X-ray flux for the coronal emission. We find two acceptable descriptions of the X-ray data. Using a spectral model in which the soft X-ray excess in 3C120 is described by reflection from an ionized accretion disk, we conclude that the accretion disk must truncate at times of low/rising X-ray flux, in agreement with the jet-cycle picture. Alternatively, no accretion disk reflection changes are required if, instead, the soft excess is described by a second power-law component that may be identified as originating from the jet. We also study short-timescale variability, finding two characteristics, a positive X-ray flux/hardness correlation and the lack of a UV/soft-excess correlation, that are markedly different from those found in Seyfert galaxies. This may be taken as further evidence that the jet is contributing to the soft X-ray band. We also show how the two scenarios could be distinguished using Nustar or Astro-H.

  14. Supporting the SSSC Great Observatory: S3C Active Archive Data and Services Today

    NASA Astrophysics Data System (ADS)

    Kovalick, T.; McGuire, R.; Bilitza, D.; Candey, R.; Chimiak, R.; Cooper, J.; Fung, S.; Han, D.; Harris, B.; Johnson, R.; Kessel, R.; Klipsch, C.; Leckner, H.; Liu, M.; Papatishvili, N.

    2005-12-01

    The next advances in Sun Solar System Connections (S3C) / Solar-Terrestrial science require an increasingly integrated and transparent data environment, where data can be easily accessed and used across the boundaries of both missions and traditional disciplines. While the data environment to best support the longterm strategic and science goals of the S3C Great Observatory will grow over time, the S3C Active Archive within the Space Physics Data Facility (SPDF) already operates uniquely important multi-mission data services with current data from most operating space physics missions. This paper reviews the range of services now available for data and how they are now evolving to meet the future science issues of the Great Observatory program and the needs of programs like LWS/ILWS. The Coordinated Data Analysis [Workshop] Web (CDAWeb) and Satellite Situation Center Web (SSCWeb), critically supported by the Common Data Format (CDF) effort and supplemented by more focused services such as data format translations, COHOWeb, ATMOWeb, FTPBrowser, ModelWeb and HelioWeb, are important current examples suggestive of the scope and functionality needed in the future. These systems serve the broad international community now and are already capable of significant contributions to eGY. Our new Java-based "CDAWeb Plus" interface integrates unified user access to this combined set. Key services increasingly support web services APIs to allow their ready invocation from distributed external middleware and clients expected to form the framework of a new Virtual discipline Observatory (VxO) paradigm for the data environment for NASA solar and space physics data.

  15. PROTON SYNCHROTRON RADIATION FROM EXTENDED JETS OF PKS 0637–752 AND 3C 273

    SciTech Connect

    Bhattacharyya, Wrijupan; Gupta, Nayantara

    2016-02-01

    Many powerful radio quasars are associated with large-scale jets, exhibiting bright knots as shown by high-resolution images from the Hubble Space Telescope (HST) and the Chandra X-ray Observatory. The radio-optical flux component from these jets can be attributed to synchrotron radiation by accelerated relativistic electrons while the IC/CMB model, by far, has been the most popular explanation for the observed X-ray emission from these jets. Recently, the IC/CMB X-ray mechanism has been strongly disfavored for 3C 273 and PKS 0637–752 since the anomalously hard and steady gamma-ray emission predicted by such models violates the observational results from Fermi-LAT. Here we propose the proton synchrotron origin of the X-ray–gamma-ray flux from the knots of PKS 0637–752 with a reasonable budget in luminosity, by considering synchrotron radiation from an accelerated proton population. Moreover, for the source 3C 273, the optical data points near 10{sup 15} Hz could not be fitted using electron synchrotron. We propose an updated proton synchrotron model, including the optical data from HST, to explain the common origin of optical-X-ray–gamma-ray emission from the knots of quasar 3C 273 as an extension of the work done by Kundu and Gupta. We also show that TeV emission from large-scale quasar jets, in principle, can arise from proton synchrotron, which we discuss in the context of knot wk8.9 of PKS 0637–752.

  16. Fabrication and characterization of 3C-silicon carbide micro sensor for wireless blood pressure measurements

    NASA Astrophysics Data System (ADS)

    Basak, Nupur

    A potentially implantable single crystal 3C-SiC pressure sensor for blood pressure measurement was designed, simulated, fabricated, characterized and optimized. This research uses a single crystal 3C-SiC, for the first time, to demonstrate its application as a blood pressure measurement sensor. The sensor, which uses the epitaxial grown 3C-SiC membrane to measure changes in pressure, is designed to be wireless, biocompatible and linear. The SiC material was chosen for its superior physical, chemical and mechanical properties; the capacitive sensor uses a 3C-SiC membrane as one of the electrodes; and, the sensor system is wireless for comfort and to allow for convenient reading of real-time pressure data (wireless communication is enabled by connecting the sensor parallel to a planar inductor). Together, the variable capacitive sensor and planar inductor create a pressure sensitive resonant circuit. The sensor system described above allows for implantation into a human patient's body, after which the planar inductor can be coupled with an external inductor to receive data for real-time blood pressure measurement. Electroplating, thick photo-resist characterization, RIE etching, oxidation, CVD, chemical mechanical polishing and wafer bonding were optimized during the process of fabricating the sensor system and, in addition to detailing the sensor system simulation and characterization; the optimized processes are detailed in the dissertation. This absolute pressure sensor is designed to function optimally within the human blood pressure range of 50-350mmHg. The layout and modeling of the sensor uses finite element analysis (FEA) software. The simulations for membrane deflection, stress analysis and electro-mechanical analysis are performed for 100 μm2 and 400μm2sensors. The membrane deflection-pressure, capacitance-pressure and resonant frequency-pressure graphs were obtained, and detailed in the dissertation, along with the planar inductor simulation for

  17. The Physics of AGN, a Deep Understanding of the Quasar 3C 273

    NASA Technical Reports Server (NTRS)

    Courvoisier, T.; Bottcher, Markus

    2004-01-01

    Upon our successful AO-1 proposal no. 120023, the quasar 3C 273 has been observed with INTEGRAL in 3 epochs in January 2003. The first observation, on January 5, 2003, with a total INTEGRAL exposure of 1.2 x 10(exp 5) s, was simultaneous with RXTE and XMM- Newton observations. Two more INTEGRAL observations were carried out on January 11, 2003 (exposure: lo4 s) and January 17, 2003 (exposure: 1.1 x 10(exp 5) s). The source was detected with high significance by all INTEGRAL instruments, the OMC, JEM-X, SPI, and IBIS/ISGRI. Being one of the first INTEGRAL observations simultaneous with XMM and RXTE, our observations were also used to fix the cross calibration with those instruments. The combined spectrum resulting from the XMM-Newton, JEM-X, RXTE, SPI and ISGRI X-ray / soft gamma-ray observations is consistent with a straight power-law of photon index Gamma = (1.73 +/- 0.015) between 3 keV and at least 200 keV. A possible detection in the 200 keV - 500 keV band by SPI can not be confirmed with our observations. The normalization of the X/gamma-ray spectrum is (2.24 +/- 0.05) x 10(exp -2) photons /sq cm keV at 1 keV. The source showed a moderate amount of optical variability as observed with the OMC onboard INTEGRAL. No evidence for variability at X-rays and gamma-rays could be reported, which may have been a result of insufficient photon statistics. The X-/gamma-ray spectrum observed in our 2003 observations is consistent with previously measured and modelled broadband spectral energy distributions of 3C 273. It has been included in the U.S. lead Col's work on spectral and variability modelling of gamma-ray blazars, supporting the trend of flat-spectrum radio quasars such as 3C 273 being 7-ray dominated due to a strong contribution from Compton upscattering of external radiation by ultrarelativistic electrons in a relativistic jet. 3C 273 is a particularly convincing example for such a picture since it provides very direct evidence for a strong external radiation

  18. Fermi LAT detection of a GeV flare from the FSRQ 3C 279

    NASA Astrophysics Data System (ADS)

    Buson, S.

    2013-12-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed an increasing gamma-ray flux from a source positionally consistent with the blazar 3C279 (RA: 194.0465271, Dec: -5.7893119 , Johnston et al.1995, AJ, 110, 880, J2000). This source is classified as a flat spectrum radio quasar (FSRQ) at redshift of 0.536 (Marziani et al. ApJS, 1996, 104, 37) and is one of the three FSRQs known to be VHE gamma-ray emitters.

  19. Behavior of ion-implanted junction diodes in 3C SiC

    NASA Technical Reports Server (NTRS)

    Avila, R. E.; Kopanski, J. J.; Fung, C. D.

    1987-01-01

    p-n junction diodes have been formed by ion implantation of B or Al in 3C SiC and annealing at 1365 C. The current-voltage characteristics of the Al-implanted structures show little rectification. The B-implanted diodes show rectification, with ideality factors of 2.2 and higher, breakdown voltages between 5 and 10 V, and a series resistance of the order of 20 kohm. The current-voltage characteristics were measured between room temperature and 270 C. The extracted ideality factors increase with temperature.

  20. Lepto-Hadronic Origin of gamma-ray Outbursts of 3C 279

    NASA Astrophysics Data System (ADS)

    Paliya, Vaidehi S.; Diltz, Chris; Böttcher, Markus; Stalin, C. S.; Buckley, David

    The blazar 3C 279 exhibited a giant γ-ray outburst in 2013 December and 2014 April. Apart from the very fast γ-ray flux variability, the spectral nature of the flares were also found to vary significantly between these two flaring events. A prominent curvature in the γ-ray spectrum was noticed in 2014 April flare, on the other hand, the 2013 December displayed an extreme hardening of the spectrum. These observations, thus, put strong constraints on our understanding of the underlying particle acceleration mechanisms.

  1. SACR ADVance 3-D Cartesian Cloud Cover (SACR-ADV-3D3C) product

    DOE Data Explorer

    Meng Wang, Tami Toto, Eugene Clothiaux, Katia Lamer, Mariko Oue

    2017-03-08

    SACR-ADV-3D3C remaps the outputs of SACRCORR for cross-wind range-height indicator (CW-RHI) scans to a Cartesian grid and reports reflectivity CFAD and best estimate domain averaged cloud fraction. The final output is a single NetCDF file containing all aforementioned corrected radar moments remapped on a 3-D Cartesian grid, the SACR reflectivity CFAD, a profile of best estimate cloud fraction, a profile of maximum observable x-domain size (xmax), a profile time to horizontal distance estimate and a profile of minimum observable reflectivity (dBZmin).

  2. The Blazar 3C 66A in 2003-2004: hadronic versus leptonic model fits

    SciTech Connect

    Reimer, A.

    2008-12-24

    The low-frequency peaked BL Lac object 3C 66A was the subject of an extensive multi-wavelength campaign from July 2003 till April 2004, which included quasi-simultaneous observations at optical, X-rays and very high energy gamma-rays. Here we apply the hadronic Synchrotron-Proton Blazar (SPB) model to the observed spectral energy distribution time-averaged over a flaring state, and compare the resulting model fits to those obtained from the application of the leptonic Synchrotron-Self-Compton (SSC) model. The results are used to identify diagnostic key predictions of the two blazar models for future multi-wavelength observations.

  3. Jet-Intracluster Medium Interactions of the Head Tail Radio Galaxy 3C 129

    NASA Technical Reports Server (NTRS)

    Krawczynski, Henric S. W.

    2005-01-01

    The 50 ksec XMM observations of the galaxy cluster 3C 129 were taken as scheduled, and the data are of good quality. We analyzed the data in the following way. After standard cleaning, we flat-fielded the XMM surface brightness maps. Combining the data from the EPIC MOS and PN Camera CCDs, we performed a cross-correlation analysis of the X-ray surface brightness distribution with the 1.4 GHz VLA radio map. We found evidence for cavities in the X-ray emitting Intra-Cluster Medium (ICM) associated with the radio tail of the head-tail radio galaxy 3C 129. This discovery is very interesting as it excludes the presence of a large fraction of thermal plasma in the radio tail. Together with the observation of an apparent pressure mismatch between the radio plasma and the ICM, and an upper limit on the magnetic field inside the radio tail (from the radio spectral indices map) the observation implies that the tail pressure is dominated either by low-energy electrons/positrons, or, by relativistic protons. Furthermore, we studied the energy spectrum of an X-ray "hot-spot" associated with the head of the radio galaxy 3C 129. It seems likely that the X-ray hot-spot originates from shocked gas in front of the radio galaxy. , The analysis turned out to be much more difficult than anticipated. The main reason is the lack of a comprehensive, publicly available background model that is key for the analysis of extended sources. Small groups like our do not have the man-power to come up with a background model themselves. We used the model from Read & Ponman (A&A 409, 395, 2003). However, the background subtracted X-ray surface brightness maps show a bright ring in the outer 20% of the camera. We tried to get rid of this ring and contacted the XMM helpdesk and Read & Ponman, the authors of the background paper. However, up to this day, we did not entirely succeed to remove the brightness enhancement at the outer parts of the camera. Unfortunately, our results are somewhat sensitive

  4. Another NIR Flare of the quasar 3C454.3

    NASA Astrophysics Data System (ADS)

    Carrasco, L.; Porras, A.; Recillas, E.; Carraminana, A.

    2013-09-01

    We report on another NIR flare of the intermediate redshift quasar 3C454.3 also known as CGRaBSJ2253+1608 (z=0.859), cross identified with the gamma ray source 1FGLJ2353.9_1608. On September 12th,2013, epoch JD2456547.8221 we determined the flux in the H band to be 12.885 +/- 0.05. This value is 0.8 magnitudes brighter than the flux we determined on JD2456432.94229, when we found the object to be H = 13.625 +/- 0.06.

  5. Design and synthesis of irreversible inhibitors of foot-and-mouth disease virus 3C protease.

    PubMed

    Roqué Rosell, Núria R; Mokhlesi, Ladan; Milton, Nicholas E; Sweeney, Trevor R; Zunszain, Patricia A; Curry, Stephen; Leatherbarrow, Robin J

    2014-01-15

    Foot-and-mouth disease virus (FMDV) causes a highly infectious and economically devastating disease of livestock. The FMDV genome is translated as a single polypeptide precursor that is cleaved into functional proteins predominantly by the highly conserved viral 3C protease, making this enzyme an attractive target for antiviral drugs. A peptide corresponding to an optimal substrate has been modified at the C-terminus, by the addition of a warhead, to produce irreversible inhibitors that react as Michael acceptors with the enzyme active site. Further investigation highlighted key structural determinants for inhibition, with a positively charged P2 being particularly important for potency.

  6. Inverse-Compton Emission from the Lobes of 3C 353

    DTIC Science & Technology

    2010-01-01

    v2.2) Inverse- Compton emission from the lobes of 3C 353 J.L. Goodger,1⋆ M.J. Hardcastle,1 J.H. Croston,1 N.E. Kassim2 and R.A. Perley3 1University of...Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801, USA ABSTRACT X-ray emission due to inverse- Compton scattering of microwave background photons...by electrons in the lobes of powerful radio galaxies has now been seen in a large number of objects. Combining an inverse- Compton model for the lobe

  7. Constraining Methane Flux Estimates Using Atmospheric Observations of Methane and 1^3C in Methane

    NASA Astrophysics Data System (ADS)

    Mikaloff Fletcher, S. E.; Tans, P. P.; Miller, J. B.; Bruhwiler, L. M.

    2002-12-01

    Understanding the budget of methane is crucial to predicting climate change and managing earth's carbon reservoirs. Methane is responsible for approximately 15% of the anthropogenic greenhouse forcing and has a large impact on the oxidative capacity of Earth's atmosphere due to its reaction with hydroxyl radical. At present, many of the sources and sinks of methane are poorly understood due in part to the large spatial and temporal variability of the methane flux. Model simulations of methane mixing ratios using most process-based source estimates typically over-predict the latitudinal gradient of atmospheric methane relative to the observations; however, the specific source processes responsible for this discrepancy have not been identified definitively. The aim of this work is to use the isotopic signatures of the sources to attribute these discrepancies to a source process or group of source processes and create global and regional budget estimates that are in agreement with both the atmospheric observations of methane and 1^3C in methane. To this end, observations of isotopic ratios of 1^3C in methane and isotopic signatures of methane source processes are used in conjunction with an inverse model of the methane budget. Inverse modeling is a top-down approach which uses observations of trace gases in the atmosphere, an estimate of the spatial pattern of trace gas fluxes, and a model of atmospheric transport to estimate the sources and sinks. The atmospheric transport was represented by the TM3 three-dimensional transport model. The GLOBALVIEW 2001 methane observations were used along with flask measurements of 1^3C in methane at six of the CMDL-NOAA stations by INSTAAR. Initial results imply interesting differences from previous methane budget estimates. For example, the 1^3C isotope observations in methane call for an increase in southern hemisphere sources with a bacterial isotopic signature such as wetlands, rice paddies, termites, and ruminant animals. The

  8. Investigation of the agglomeration and amorphous transformation effects of neutron irradiation on the nanocrystalline silicon carbide (3C-SiC) using TEM and SEM methods

    NASA Astrophysics Data System (ADS)

    Huseynov, Elchin M.

    2017-04-01

    Nanocrystalline 3C-SiC particles irradiated by neutron flux during 20 h in TRIGA Mark II light water pool type research reactor. Silicon carbide nanoparticles were analyzed by Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM) devices before and after neutron irradiation. The agglomeration of nanoparticles was studied comparatively before and after neutron irradiation. After neutron irradiation the amorphous layer surrounding the nanoparticles was analyzed in TEM device. Neutron irradiation defects in the 3C-SiC nanoparticles and other effects investigated by TEM device. The effect of irradiation on the crystal structure of the nanomaterial was studied by selected area electron diffraction (SAED) and electron diffraction patterns (EDP) analysis.

  9. Are MXenes promising anode materials for Li ion batteries? Computational studies on electronic properties and Li storage capability of Ti3C2 and Ti3C2X2 (X = F, OH) monolayer.

    PubMed

    Tang, Qing; Zhou, Zhen; Shen, Panwen

    2012-10-10

    Density functional theory (DFT) computations were performed to investigate the electronic properties and Li storage capability of Ti(3)C(2), one representative MXene (M represents transition metals, and X is either C or/and N) material, and its fluorinated and hydroxylated derivatives. The Ti(3)C(2) monolayer acts as a magnetic metal, while its derived Ti(3)C(2)F(2) and Ti(3)C(2)(OH)(2) in their stable conformations are semiconductors with small band gaps. Li adsorption forms a strong Coulomb interaction with Ti(3)C(2)-based hosts but well preserves its structural integrity. The bare Ti(3)C(2) monolayer exhibits a low barrier for Li diffusion and high Li storage capacity (up to Ti(3)C(2)Li(2) stoichiometry). The surface functionalization of F and OH blocks Li transport and decreases Li storage capacity, which should be avoided in experiments. The exceptional properties, including good electronic conductivity, fast Li diffusion, low operating voltage, and high theoretical Li storage capacity, make Ti(3)C(2) MXene a promising anode material for Li ion batteries.

  10. Linking anisotropy with Fe3C distribution in AISI 1045 steel

    NASA Astrophysics Data System (ADS)

    Shen, Ke-chang; Li, Gui-hua; Sun, Yi-min; Wang, Yong-gang; Li, Ying-jie; Cao, Guang-hui; Wang, Wei-min

    2015-12-01

    The anisotropy of the microstructure, thermal expansion behavior, corrosion resistance and magnetic properties of AISI 1045 steel was investigated. The distribution of Fe3C lamellae in the investigation plane parallel to the radial directions of molds was observed to differ from that in the investigation plane perpendicular to the radial directions by transmission electron microscopy. The lattice constants a 0 of α-Fe deduced from the XRD patterns of samples prepared using a sand (S)-mold and cut parallel to the radial direction of the mold (S//) and using a metal (M)-mold and cut parallel to the radial direction (M//), the corrosion resistance measured using an electrochemical workstation, and the magnetic permeability obtained by vibrating sample magnetometry also indicated the existence of anisotropy in the tested samples. The anisotropic change of corrosion potential ( E corr), pitting potential ( E pit) and magnetic permeability ( µ) of the samples was observed to depend on the orientation factor F 200 of α-Fe in the measured samples, which is controlled by the distribution of Fe3C lamellae in the eutectoid structure.

  11. Decoupling and ordering of multilayer graphene on C-face 3C-SiC(111)

    NASA Astrophysics Data System (ADS)

    Bouhafs, C.; Stanishev, V.; Zakharov, A. A.; Hofmann, T.; Kühne, P.; Iakimov, T.; Yakimova, R.; Schubert, M.; Darakchieva, V.

    2016-11-01

    We show experimentally that few layer graphene (FLG) grown on the carbon terminated surface (C-face) of 3C-SiC(111) is composed of decoupled graphene sheets. Landau level spectroscopy on FLG graphene is performed using the infrared optical Hall effect. We find that Landau level transitions in the FLG exhibit polarization preserving selection rules and the transition energies obey a square-root dependence on the magnetic field strength. These results show that FLG on C-face 3C-SiC(111) behave effectively as a single layer graphene with linearly dispersing bands (Dirac cones) at the graphene K point. We estimate from the Landau level spectroscopy an upper limit of the Fermi energy of about 60 meV in the FLG, which corresponds to a carrier density below 2.5 × 1011 cm-2. Low-energy electron diffraction μ-LEED) reveals the presence of azimuthally rotated graphene domains with a typical size of ≤200 nm. μ-LEED mapping suggests that the azimuth rotation occurs between adjacent domains within the same sheet rather than vertically in the stack.

  12. Preliminary validation of refractivity from a new radio occultation sounder GNOS/FY-3C

    NASA Astrophysics Data System (ADS)

    Liao, M.; Zhang, P.; Yang, G. L.; Bi, Y. M.; Liu, Y.; Bai, W. H.; Meng, X. G.; Du, Q. F.; Sun, Y. Q.

    2015-09-01

    As a new member of space-based radio occultation sounder, the GNOS (Global Navigation Satellite System Occultation Sounder) mounted on FY-3C has been carrying out the atmospheric sounding since 23 September 2013. GNOS takes a daily measurement up to 800 times with GPS (Global Position System) and Chinese BDS (BeiDou navigation satellite) signals. The refractivity profiles from GNOS are compared with the co-located ECMWF (European Centre for Medium-Range Weather Forecasts) analyses in this paper. Bias and standard deviation have being calculated as the function of altitude. The mean bias is about 0.2 % from the near surface to 35 km. The average standard deviation is within 2 % while it is down to about 1 % in the range 5-30 km where best soundings are usually made. To evaluate the performance of GNOS, COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) and GRAS/METOP-A (GNSS Receiver for Atmospheric Sounding) data are also compared to ECMWF analyses as the reference. The results show that GNOS/FY-3C meets the requirements of the design well. It possesses a sounding capability similar to COSMIC and GRAS in the vertical range of 0-30 km, though it needs improvement in higher altitude. Generally, it provides a new data source for global NWP (numerical weather prediction) community.

  13. Hints of correlation between broad-line and radio variations for 3C 120

    SciTech Connect

    Liu, H. T.; Bai, J. M.; Li, S. K.; Wang, J. M.

    2014-01-01

    In this paper, we investigate the correlation between broad-line and radio variations for the broad-line radio galaxy 3C 120. By the z-transformed discrete correlation function method and the model-independent flux randomization/random subset selection (FR/RSS) Monte Carlo method, we find that broad Hβ line variations lead the 15 GHz variations. The FR/RSS method shows that the Hβ line variations lead the radio variations by a factor of τ{sub ob} = 0.34 ± 0.01 yr. This time lag can be used to locate the position of the emitting region of radio outbursts in the jet, on the order of ∼5 lt-yr from the central engine. This distance is much larger than the size of the broad-line region. The large separation of the radio outburst emitting region from the broad-line region will observably influence the gamma-ray emission in 3C 120.

  14. Confining hot spots in 3C 196 - Implications for QSO-companion galaxies

    NASA Technical Reports Server (NTRS)

    Brown, R. L.; Broderick, J. J.; Mitchell, K. J.

    1986-01-01

    VLBI observations of the extremely compact hot spot in the northern radio lobe of the QSO 3C 196 reveal the angular size of its smallest substructure to be 0.065 arcsec x 0.045 arcsec or about 300 pc at the redshift distance. The morphology of the hot spot and its orientation relative to the more diffuse radio emission suggest that it is formed by an oblique interaction between the nuclear QSO jet and circum-QSO cloud. The inferred density in this cloud, together with its apparent size, imply that the cloud contains a galactic mass, greater than a billion solar masses of gas. The effect of the jet will be to hasten gravitational collapse of the cloud. If many QSOs such as 3C 196 are formed or found in gas-rich environments, the QSO radio phase may commonly stimulate the metamorphosis of circum-QSO gas to QSO-companion galaxies or it may play a significant part in catalyzing star formation in existing companions.

  15. Confining hot spots in 3C 196 - implications for QSO-companion galaxies

    SciTech Connect

    Brown, R.L.; Broderick, J.J.; Mitchell, K.J.

    1986-07-01

    VLBI observations of the extremely compact hot spot in the northern radio lobe of the QSO 3C 196 reveal the angular size of its smallest substructure to be 0.065 arcsec x 0.045 arcsec or about 300 pc at the redshift distance. The morphology of the hot spot and its orientation relative to the more diffuse radio emission suggest that it is formed by an oblique interaction between the nuclear QSO jet and circum-QSO cloud. The inferred density in this cloud, together with its apparent size, imply that the cloud contains a galactic mass, greater than a billion solar masses of gas. The effect of the jet will be to hasten gravitational collapse of the cloud. If many QSOs such as 3C 196 are formed or found in gas-rich environments, the QSO radio phase may commonly stimulate the metamorphosis of circum-QSO gas to QSO-companion galaxies or it may play a significant part in catalyzing star formation in existing companions. 30 references.

  16. High-order ionospheric effects on electron density estimation from Fengyun-3C GPS radio occultation

    NASA Astrophysics Data System (ADS)

    Li, Junhai; Jin, Shuanggen

    2017-03-01

    GPS radio occultation can estimate ionospheric electron density and total electron content (TEC) with high spatial resolution, e.g., China's recent Fengyun-3C GPS radio occultation. However, high-order ionospheric delays are normally ignored. In this paper, the high-order ionospheric effects on electron density estimation from the Fengyun-3C GPS radio occultation data are estimated and investigated using the NeQuick2 ionosphere model and the IGRF12 (International Geomagnetic Reference Field, 12th generation) geomagnetic model. Results show that the high-order ionospheric delays have large effects on electron density estimation with up to 800 el cm-3, which should be corrected in high-precision ionospheric density estimation and applications. The second-order ionospheric effects are more significant, particularly at 250-300 km, while third-order ionospheric effects are much smaller. Furthermore, the high-order ionospheric effects are related to the location, the local time, the radio occultation azimuth and the solar activity. The large high-order ionospheric effects are found in the low-latitude area and in the daytime as well as during strong solar activities. The second-order ionospheric effects have a maximum positive value when the radio occultation azimuth is around 0-20°, and a maximum negative value when the radio occultation azimuth is around -180 to -160°. Moreover, the geomagnetic storm also affects the high-order ionospheric delay, which should be carefully corrected.

  17. STIS Spectroscopy of the Lyman-Alpha Forest Toward 3C 273

    NASA Technical Reports Server (NTRS)

    Heap, Sara R.; Williger, Gerard

    2002-01-01

    We present results on the low-redshift Lyman-alpha forest as based on high-resolution (7 km/s) STIS spectra of 3C 273. A total of 121 intergalactic Lyman-alpha-absorbing systems were detected, of which 60 are above the 3.5sigma completeness limit, logNu(sub HI) approximately equals 12.3. The median line-width parameter, b = 27 km/s, is similar to that seen at high redshift. However the distribution of HI column densities has a steeper slope, beta = 2.02+/-0.21, than is seen at high redshift. Overall, the observed Nu(sub HI)-b distribution is consistent with that derived from a ACDM hydrodynamic simulation. We have used NED to compile a list of 300 galaxies (91 from SDSS, 98 from APM) within 1 Mpc of the line of sight to 3C 273 and are working to find line-of-sight velocity correlations between the galaxies and detected Lyman-alpha absorbers.

  18. Grain growth of nanocrystalline 3C-SiC under Au ion irradiation at elevated temperatures

    SciTech Connect

    Zhang, Limin; Jiang, Weilin; Dissanayake, Amila C.; Varga, Tamas; Zhang, Jiandong; Zhu, Zihua; Hu, Dehong; Wang, Haiyan; Henager, Charles H.; Wang, Tieshan

    2016-01-09

    Nanocrystalline silicon carbide (SiC) represents an excellent model system for a fundamental study of interfacial (grain boundary) processes under nuclear radiation, which are critical to the understanding of the response of nanostructured materials to high-dose irradiation. This study reports on a comparison of irradiation effects in cubic phase SiC (3C-SiC) grains of a few nanometers in size and single-crystal 3C-SiC films under identical Au ion irradiation to a range of doses at 700 K. In contrast to the latter, in which lattice disorder is accumulated to a saturation level without full amorphization, the average grain size of the former increases with dose following a power-law trend. In addition to coalescence, the grain grows through atomic jumps and mass transport, where irradiation induced vacancies at grain boundaries assist the processes. It is found that a higher irradiation temperature leads to slower grain growth and a faster approach to a saturation size of SiC nanograins. The results could potentially have a positive impact on structural components of advanced nuclear energy systems.

  19. The corona of the broad-line radio galaxy 3C 390.3

    SciTech Connect

    Lohfink, A. M.; Ogle, P.; Tombesi, F.; Walton, D.; Baloković, M.; Zoghbi, A.; Ballantyne, D. R.; Boggs, S. E.; Christensen, F. E.; Craig, W. W.; Fabian, A. C.; Hailey, C. J.; Harrison, F. A.; King, A. L.; Madejski, G.; Matt, G.; Reynolds, C. S.; Stern, D.; Ursini, F.; Zhang, W. W.

    2015-11-13

    We present the results from a joint Suzaku/NuSTAR broadband spectral analysis of 3C 390.3. The high quality data enables us to clearly separate the primary continuum from the reprocessed components allowing us to detect a high energy spectral cut-off (${E}_{\\mathrm{cut}}={117}_{-14}^{+18}$ keV), and to place constraints on the Comptonization parameters of the primary continuum for the first time. The hard over soft compactness is ${69}_{-24}^{+124}$ and the optical depth is ${4.1}_{-3.6}^{+0.5},$ this leads to an electron temperature of ${30}_{-8}^{+32}$ keV. Expanding our study of the Comptonization spectrum to the optical/UV by studying the simultaneous Swift-UVOT data, we find indications that the compactness of the corona allows only a small fraction of the total UV/optical flux to be Comptonized. Our analysis of the reprocessed emission show that 3C 390.3 only has a small amount of reflection (R ~ 0.3), and of that the vast majority is from distant neutral matter. However, we also discover a soft-X-ray excess in the source, which can be described by a weak ionized reflection component from the inner parts of the accretion disk. In addition to the backscattered emission, we also detect the highly ionized iron emission lines Fe xxv and Fe xxvi.

  20. Atomic defects in monolayer titanium carbide (Ti3C2Tx) MXene

    DOE PAGES

    Sang, Xiahan; Xie, Yu; Lin, Ming -Wei; ...

    2016-09-06

    Here, the 2D transition metal carbides or nitrides, or MXenes, are emerging as a group of materials showing great promise in lithium ion batteries and supercapacitors. Until now, characterization and properties of single-layer MXenes have been scarcely reported. Here, using scanning transmission electron microscopy, we determined the atomic structure of freestanding monolayer Ti3C2Tx flakes prepared via the minimally intensive layer delamination method and characterized different point defects that are prevalent in the monolayer flakes. We determine that the Ti vacancy concentration can be controlled by the etchant concentration during preparation. Density function theory-based calculations confirm the defect structures and predictmore » that the defects can influence the surface morphology and termination groups, but do not strongly influence the metallic conductivity. Using devices fabricated from single- and few-layer Ti3C2Tx MXene flakes, the effect of the number of layers in the flake on conductivity has been demonstrated.« less

  1. Structure and Properties of Magnetic (Co, Fe, Fe{sub 3}C and Ni) Carbon Beads

    SciTech Connect

    Leonowicz, Marcin; Izydorzak, Marta; Pomogailo, Anatolii D.; Dzhardimalieva, Gulzhian I.

    2010-12-02

    Nanoparticles exhibit unique physical properties due to the surface or quantum-size effects. Particular attention has been focused on magnetic nanoparticles and substantial progress has been done in this field. In this work magnetic composites, consisting of elementary metals or carbides nanocrystallites, stabilized in carbon matrix, were prepared by the procedure comprising formation of appropriate metal acrylamide complexes, followed by frontal polymerization and pyrolysis of the polymer at various temperatures. Application of frontal polymerization and further pyrolysis enables formation of composite beads consisting of Co, Fe, Fe{sub 3}C or Ni nanocrystallites stabilized in carbon matrix. It was found that the lowest pyrolysis temperature, which enables the production of metallic nanocrystallites, was 673 K for Co and Ni, and 773 K for Fe. The magnetic properties of the beads, percentage of the metallic component, their composition and shape depended on the pyrolysis temperature. Extracts on the basis of composites containing Fe{sub 3}C showed no cytotoxicity, whereas those containing Co and Ni exhibited negligible cytotoxicity up to concentrations of 6.25 mg/ml.

  2. Thermal Hysteresis of MEMS Packaged Capacitive Pressure Sensor (CPS) Based 3C-SiC

    NASA Astrophysics Data System (ADS)

    Marsi, N.; Majlis, B. Y.; Mohd-Yasin, F.; Hamzah, A. A.; Mohd Rus, A. Z.

    2016-11-01

    Presented herein are the effects of thermal hysteresis analyses of the MEMS packaged capacitive pressure sensor (CPS). The MEMS CPS was employed on Si-on-3C-SiC wafer that was performed using the hot wall low-pressure chemical vapour deposition (LPCVD) reactors at the Queensland Micro and Nanotechnology Center (QMNC), Griffith University and fabricated using the bulk-micromachining process. The MEMS CPS was operated at an extreme temperature up to 500°C and high external pressure at 5.0 MPa. The thermal hysteresis phenomenon that causes the deflection, strain and stress on the 3C-SiC diaphragm spontaneously influence the MEMS CPS performances. The differences of temperature, hysteresis, and repeatability test were presented to demonstrate the functionality of the MEMS packaged CPS. As expected, the output hysteresis has a low hysteresis (less than 0.05%) which has the hardness greater than the traditional silicon. By utilizing this low hysteresis, it was revealed that the MEMS packaged CPS has high repeatability and stability of the sensor.

  3. Implications of the VHE {gamma}-Ray Detection of 3C279

    SciTech Connect

    Boettcher, M.

    2008-12-24

    We present simultaneous optical (BVRI) and X-ray (RXTE PCA) data on the quasar 3C279 from the day of the recent VHE detection by MAGIC and discuss the implications of the snap-shot spectral energy distribution (SED) for leptonic jet models of blazars. A one-zone synchrotron-self-Compton origin of the SED up to VHE {gamma}-rays can be ruled out. The VHE emission could, in principle, be interpreted as Compton upscattering of external radiation (e.g., from the broad-line regions) in a one-zone leptonic model. However, such an interpretation would require either an unusually low magnetic field of B{approx}0.03 G, or (in order to achieve approximate equipartition between magnetic field at B{approx}0.25 G and relativistic electrons) an unrealistically high Doppler factor of {gamma}{approx}140. In addition, such a model fails to reproduce the observed X-ray flux. We therefore conclude that a simple one-zone, homogeneous leptonic jet model is not able to plausibly reproduce the SED of 3C279 including the recently detected VHE {gamma}-ray emission. This as well as the lag of correlated variability in the optical with the VHE {gamma}-ray emission suggests a multi-zone model in which the optical emission is produced in a different region than the VHE {gamma}-ray emission. Alternatively, also a hadronic origin of the VHE {gamma}-rays seems plausible.

  4. Potent inhibition of feline coronaviruses with peptidyl compounds targeting coronavirus 3C-like protease.

    PubMed

    Kim, Yunjeong; Mandadapu, Sivakoteswara Rao; Groutas, William C; Chang, Kyeong-Ok

    2013-02-01

    Feline coronavirus infection is common among domestic and exotic felid species and usually associated with mild or asymptomatic enteritis; however, feline infectious peritonitis (FIP) is a fatal disease of cats that is caused by systemic infection with a feline infectious peritonitis virus (FIPV), a variant of feline enteric coronavirus (FECV). Currently, there is no specific treatment approved for FIP despite the importance of FIP as the leading infectious cause of death in young cats. During the replication process, coronavirus produces viral polyproteins that are processed into mature proteins by viral proteases, the main protease (3C-like [3CL] protease) and the papain-like protease. Since the cleavages of viral polyproteins are an essential step for virus replication, blockage of viral protease is an attractive target for therapeutic intervention. Previously, we reported the generation of broad-spectrum peptidyl inhibitors against viruses that possess a 3C or 3CL protease. In this study, we further evaluated the antiviral effects of the peptidyl inhibitors against feline coronaviruses, and investigated the interaction between our protease inhibitor and a cathepsin B inhibitor, an entry blocker, against a feline coronavirus in cell culture. Herein we report that our compounds behave as reversible, competitive inhibitors of 3CL protease, potently inhibited the replication of feline coronaviruses (EC(50) in a nanomolar range) and, furthermore, combination of cathepsin B and 3CL protease inhibitors led to a strong synergistic interaction against feline coronaviruses in a cell culture system.

  5. Multi-Wavelength Observations of 3C 273 in 1993-1995

    NASA Technical Reports Server (NTRS)

    vonMontigny, C.; Aller, H.; Aller, M.; Bruhweiler, F.; Collmar, W.; Courvoisier, T. J.-L.; Edwards, P. G.; Fichtel, C. E.; Fruscione, A.; Ghisellini, G.

    1997-01-01

    We present the results of the multi-wavelength campaigns on 3C 273 in 1993-1995. During the observations in late 1993 this quasar showed an increase of its flux for energies >= 100 MeV from about 2.1 x 10(exp -7) photons/sq cm.s to approximately 5.6 x 10(exp -7) photons/sq cm.s during a radio outburst at 14.5, 22 and 37 GHz. However, no one-to-one correlation of the gamma-ray radiation with any frequency could be found. The photon spectral index of the high energy spectrum changed from GAMMA(sub gamma) = (3.20 +/- 0.54) to GAMMA(sub gamma) = (2.20 +/- 0.22) in the sense that the spectrum flattened when the gamma-ray flux increased. Fits of the three most prominent models (synchrotron self-Comptonization, external inverse Comptonization and the proton initiated cascade model) for the explanation of the high gamma-ray emission of active galactic nuclei were performed to the multi-wavelength spectrum of 3C 273 . All three models are able to represent the basic features of the multi-wavelength spectrum. Although there are some differences the data are still not decisive enough to discriminate between the models.

  6. Faraday Rotation Measure Gradients from a Helical Magnetic Field in 3C273

    SciTech Connect

    Zavala, Robert T.; Taylor, G.B.; /NRAO, Socorro /KIPAC, Menlo Park

    2005-06-06

    Using high frequency (12-22 GHz) VLBA observations we confirm the existence of a Faraday rotation measure gradient of {approx}500 rad m{sup -2} mas{sup -1} transverse to the jet axis in the quasar 3C273. The gradient is seen in two epochs spaced roughly six months apart. This stable transverse rotation measure gradient is expected if a helical magnetic field wraps around the jet. The overall order to the magnetic field in the inner projected 40 parsecs is consistent with a helical field. However, we find an unexpected increase in fractional polarization along the edges of the source, contrary to expectations. This high fractional polarization rules out internal Faraday rotation, but is not readily explained by a helical field. After correcting for the rotation measure, the intrinsic magnetic field direction in the jet of 3C273 changes from parallel to nearly perpendicular to the projected jet motion at two locations. If a helical magnetic field causes the observed rotation measure gradient then the synchrotron emitting electrons must be separate from the helical field region. The presence or absence of transverse rotation measure gradients in other sources is also discussed.

  7. Multicolor Optical Monitoring of the Quasar 3C 273 from 2005 to 2016

    NASA Astrophysics Data System (ADS)

    Xiong, Dingrong; Bai, Jinming; Zhang, Haojing; Fan, Junhui; Gu, Minfeng; Yi, Tingfeng; Zhang, Xiong

    2017-04-01

    We have monitored the quasar 3C 273 in the optical V, R, and I bands from 2005 to 2016. Intraday variability (IDV) is detected on seven nights. The variability amplitudes on most of the nights are less than 10%, and on four nights, more than 20%. When considering the nights with time spans >4 hr, the duty cycle (DC) is 14.17%. Over the 12 years, the overall magnitude and color index variabilities are {{Δ }}I=0\\buildrel{{m}}\\over{.} 67, {{Δ }}R=0\\buildrel{{m}}\\over{.} 72, {{Δ }}V=0\\buildrel{{m}}\\over{.} 68, and {{Δ }}(V-R)=0\\buildrel{{m}}\\over{.} 25, respectively. The largest clear IDV has an amplitude of 42% over just 5.8 minutes, and the weakest detected IDV is 5.4% over 175 minutes. The BWB (bluer when brighter) chromatic trend is dominant for 3C 273 and appears at different flux levels on intraday timescales. The BWB trend exists for short-term timescales and intermediate-term timescales but different timescales have different correlations. There is no BWB trend for our whole time-series data sets. A significant anticorrelation between the BWB trend and length of timescales is found. Combining with V-band data from previous works, we find a possible quasi-periodicity of P = 3918 ± 1112 days. The possible explanations for the observed variability, BWB chromatic trend, and periodicity are discussed.

  8. Standard sources at 10.6 GHz and variability in 3C147

    NASA Astrophysics Data System (ADS)

    Andrew, B. H.; MacLeod, J. M.; Feldman, P. A.

    1981-06-01

    It is pointed out that the work of Baars et al. (1977), referred to as BGPW, is among the most recent on the subject of the calibration of radio telescopes. BGPW provides flux densities for a set of secondary calibrators. Observations made at the Algonquin Radio Observatory (ARO) provide very accurate relative flux densities for the BGPW calibrators. Attention is given to questions of data derivation, variability, and absolute flux densities. The ARO relative flux densities are converted to the BGPW scale by means of the 'semi-absolute' 3C274. If the obtained values are adopted at 10.6 GHz, the BGPW scale can be used more efficiently in the 10 GHz range. Flux densities at other frequencies in the 10 GHz range can be obtained by using the spectral indices implied by Table 5 of BGPW. In view of the variability of 3C147, and the hints of variability in the observations of several other sources, observers should also bear in mind that any 'absolute' calibration scale may be ephemeral if it is tied to 'standard' sources that are assumed to be constant.

  9. Giant THz photoconductivity and possible non-equilibrium superconductivity in metallic K3C60

    PubMed Central

    Mitrano, M.; Cantaluppi, A.; Nicoletti, D.; Kaiser, S.; Perucchi, A.; Lupi, S.; Di Pietro, P.; Pontiroli, D.; Riccò, M.; Clark, S. R.; Jaksch, D.; Cavalleri, A.

    2015-01-01

    The non-equilibrium control of emergent phenomena in solids is an important research frontier, encompassing effects like the optical enhancement of superconductivity 1 . Recently, nonlinear excitation 2 , 3 of certain phonons in bilayer cuprates was shown to induce superconducting-like optical properties at temperatures far above Tc 4,5,6. This effect was accompanied by the disruption of competing charge-density-wave correlations7,8, which explained some but not all of the experimental results. Here, we report a similar phenomenon in a very different compound. By exciting metallic K3C60 with mid-infrared optical pulses, we induce a large increase in carrier mobility, accompanied by the opening of a gap in the optical conductivity. Strikingly, these same signatures are observed at equilibrium when cooling metallic K3C60 below the superconducting transition temperature (Tc = 20 K). Although optical techniques alone cannot unequivocally identify non-equilibrium high-temperature superconductivity, we propose this scenario as a possible explanation of our results. PMID:26855424

  10. The impacts of source structure on geodetic parameters demonstrated by the radio source 3C371

    NASA Astrophysics Data System (ADS)

    Xu, Ming H.; Heinkelmann, Robert; Anderson, James M.; Mora-Diaz, Julian; Karbon, Maria; Schuh, Harald; Wang, Guang L.

    2017-01-01

    Closure quantities measured by very-long-baseline interferometry (VLBI) observations are independent of instrumental and propagation instabilities and antenna gain factors, but are sensitive to source structure. A new method is proposed to calculate a structure index based on the median values of closure quantities rather than the brightness distribution of a source. The results are comparable to structure indices based on imaging observations at other epochs and demonstrate the flexibility of deriving structure indices from exactly the same observations as used for geodetic analysis and without imaging analysis. A three-component model for the structure of source 3C371 is developed by model-fitting closure phases. It provides a real case of tracing how the structure effect identified by closure phases in the same observations as the delay observables affects the geodetic analysis, and investigating which geodetic parameters are corrupted to what extent by the structure effect. Using the resulting structure correction based on the three-component model of source 3C371, two solutions, with and without correcting the structure effect, are made. With corrections, the overall rms of this source is reduced by 1 ps, and the impacts of the structure effect introduced by this single source are up to 1.4 mm on station positions and up to 4.4 microarcseconds on Earth orientation parameters. This study is considered as a starting point for handling the source structure effect on geodetic VLBI from geodetic sessions themselves.

  11. Time-dependent radio fine structure of the quasar 3C 345

    NASA Technical Reports Server (NTRS)

    Wittels, J. J.; Shapiro, I. I.; Cotton, W. D.; Counselman, C. C.; Hinteregger, H. F.; Knight, C. A.; Rogers, A. E. E.; Whitney, A. R.; Clark, T. A.; Hutton, L. K.

    1976-01-01

    Results are reported for VLBI observations of 3C 345 at a wavelength of 3.8 cm with left circular polarization. Sixteen sets of correlated flux densities and three sets of closure phases were obtained from observations made over a three-year period with six independent interferometers formed from up to four antennas. The mathematical models employed to represent the radio brightness distribution of the source are described, and the data are analyzed on the basis of a two-component model. The results show that the compact source in 3C 345 consists of two components whose separation increased by about 0.3 milliarcsec over the observational period, that the smaller and weaker component is to the east and south of the larger and stronger one, and that the apparent expansion velocity would be about 2.5c for a redshift of 0.6, a Hubble constant of 60 km/sec per Mpc, and a deceleration parameter of unity. It is concluded that these findings are difficult to reconcile with the 'Christmas tree' model for the apparent change of separation with time over any given series of observations.

  12. Extended radio jets in the high-redshift quasars 3C 9 and 280.1

    NASA Astrophysics Data System (ADS)

    Swarup, G.; Sinha, R. P.; Saikia, D. J.

    1982-10-01

    Total intensity and polarization observations made with the VLA at 5 GHz of two high-redshift quasars 3C 9 and 280.1 are presented. They appear to have extended one-sided radio jets, which are the most luminous yet to be reported. The jet in 3C 280.1 which was observed with rather higher resolution is discussed in greater detail. This jet has no prominent hotspot at its end and shows several wiggles along its path. The magnetic field is nearly aligned with the axis of the jet and appears to bend along with it. Several possible explanations for the morphological features of the jet are considered, and it is suggested that they are likely to be due to hydrodynamic instabilities. In this scenario, the observed wiggles in the jet are attributed to the onset of helical modes of large wavelength. The absence of a prominent hotspot at the end of the jet may be understood if the energy in the beam is gradually dissipated in shocks and small-wavelength perturbations.

  13. Information Literacy in an Inquiry Course for First-Year Science Undergraduates: A Simplified 3C Approach

    ERIC Educational Resources Information Center

    Rangachari, P. K.; Rangachari, Usha

    2007-01-01

    In this article, we describe a simplified approach to teach students to assess information obtained from diverse sources. Three broad categories (credibility, content, and currency; 3C) were used to evaluate information from textbooks, monographs, popular magazines, scholarly journals, and the World Wide Web. This 3C approach used in an inquiry…

  14. 76 FR 3624 - 3C Solar LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission 3C Solar LLC; Supplemental Notice That Initial Market-Based Rate Filing... the above-referenced proceeding 3C Solar LLC's application for market-based rate authority, with...

  15. Surface Characterization of 3C-SiC Mesa Heterofilms: Evidence for Growth by Edge/Corner Nucleation Mechanism

    NASA Technical Reports Server (NTRS)

    Trunek, Andrew J.; Neudeck, Philip G.; Spry, David J.; Powell, J. Anothny

    2003-01-01

    This paper presents the first detailed observations of unique surface morphologies of 3C-Sic films grown on 4W6H-SIC mesas by the step-free surface heteroepitaxy technique. The top surfaces of 3C-Sic films were extensively studied by optical microscopy and atomic force microscopy (AFM) as both film thickness (i.e,, growth time) and growth temperature (i.e., terrace nucleation rate) were varied following complete coverage of each 4W6H mesa by an initial 3C-Sic film. Almost all surface steps observed by AFM were 0.25 nm, the height of a single Si-C bilayer. However, strikingly different step patterns were observed, suggesting that radically different processes dominate the nucleation of new 3C-Sic bilayers on top of existing 3C-Sic film surfaces.

  16. Sardinia Radio Telescope wide-band spectral-polarimetric observations of the galaxy cluster 3C 129

    NASA Astrophysics Data System (ADS)

    Murgia, M.; Govoni, F.; Carretti, E.; Melis, A.; Concu, R.; Trois, A.; Loi, F.; Vacca, V.; Tarchi, A.; Castangia, P.; Possenti, A.; Bocchinu, A.; Burgay, M.; Casu, S.; Pellizzoni, A.; Pisanu, T.; Poddighe, A.; Poppi, S.; D'Amico, N.; Bachetti, M.; Corongiu, A.; Egron, E.; Iacolina, N.; Ladu, A.; Marongiu, P.; Migoni, C.; Perrodin, D.; Pilia, M.; Valente, G.; Vargiu, G.

    2016-10-01

    We present new observations of the galaxy cluster 3C 129 obtained with the Sardinia Radio Telescope in the frequency range 6000-7200 MHz, with the aim to image the large-angular-scale emission at high-frequency of the radio sources located in this cluster of galaxies. The data were acquired using the recently commissioned ROACH2-based backend to produce full-Stokes image cubes of an area of 1°×1° centred on the radio source 3C 129. We modelled and deconvolved the telescope beam pattern from the data. We also measured the instrumental polarization beam patterns to correct the polarization images for off-axis instrumental polarization. Total intensity images at an angular resolution of 2.9 arcmin were obtained for the tailed radio galaxy 3C 129 and for 13 more sources in the field, including 3C 129.1 at the galaxy cluster centre. These data were used, in combination with literature data at lower frequencies, to derive the variation of the synchrotron spectrum of 3C 129 along the tail of the radio source. If the magnetic field is at the equipartition value, we showed that the lifetimes of radiating electrons result in a radiative age for 3C 129 of tsyn ≃ 267 ± 26 Myr. Assuming a linear projected length of 488 kpc for the tail, we deduced that 3C 129 is moving supersonically with a Mach number of M = vgal/cs = 1.47. Linearly polarized emission was clearly detected for both 3C 129 and 3C 129.1. The linear polarization measured for 3C 129 reaches levels as high as 70 per cent in the faintest region of the source where the magnetic field is aligned with the direction of the tail.

  17. Coordinated Multiwavelength Observation of 3C 66A during the WEBT Campaign of 2003-2004

    NASA Astrophysics Data System (ADS)

    Böttcher, M.; Harvey, J.; Joshi, M.; Villata, M.; Raiteri, C. M.; Bramel, D.; Mukherjee, R.; Savolainen, T.; Cui, W.; Fossati, G.; Smith, I. A.; Able, D.; Aller, H. D.; Aller, M. F.; Arkharov, A. A.; Augusteijn, T.; Baliyan, K.; Barnaby, D.; Berdyugin, A.; Benítez, E.; Boltwood, P.; Carini, M.; Carosati, D.; Ciprini, S.; Coloma, J. M.; Crapanzano, S.; de Diego, J. A.; Di Paola, A.; Dolci, M.; Fan, J.; Frasca, A.; Hagen-Thorn, V.; Horan, D.; Ibrahimov, M.; Kimeridze, G. N.; Kovalev, Y. A.; Kovalev, Y. Y.; Kurtanidze, O.; Lähteenmäki, A.; Lanteri, L.; Larionov, V. M.; Larionova, E. G.; Lindfors, E.; Marilli, E.; Mirabal, N.; Nikolashvili, M.; Nilsson, K.; Ohlert, J. M.; Ohnishi, T.; Oksanen, A.; Ostorero, L.; Oyer, G.; Papadakis, I.; Pasanen, M.; Poteet, C.; Pursimo, T.; Sadakane, K.; Sigua, L. A.; Takalo, L.; Tartar, J. B.; Teräsranta, H.; Tosti, G.; Walters, R.; Wiik, K.; Wilking, B. A.; Wills, W.; Xilouris, E.; Fletcher, A. B.; Gu, M.; Lee, C.-U.; Pak, S.; Yim, H.-S.

    2005-09-01

    The BL Lac object 3C 66A was the target of an extensive multiwavelength monitoring campaign from 2003 July through 2004 April (with a core campaign from 2003 September to 2003 December) involving observations throughout the electromagnetic spectrum. Radio, infrared, and optical observations were carried out by the WEBT-ENIGMA collaboration. At higher energies, 3C 66A was observed in X-rays (RXTE), and at very high energy (VHE) in γ-rays (STACEE, VERITAS). In addition, the source has been observed with the VLBA at nine epochs throughout the period 2003 September to 2004 December, including three epochs contemporaneous with the core campaign. A gradual brightening of the source over the course of the campaign was observed at all optical frequencies, culminating in a very bright maximum around 2004 February 18. The WEBT campaign revealed microvariability with flux changes of ~5% on timescales as short as ~2 hr. The source was in a relatively bright state, with several bright flares on timescales of several days. The spectral energy distribution (SED) indicates a νFν peak in the optical regime. A weak trend of optical spectral hysteresis with a trend of spectral softening throughout both the rising and decaying phases has been found. On longer timescales, there appears to be a weak indication of a positive hardness-intensity correlation for low optical fluxes, which does not persist at higher flux levels. The 3-10 keV X-ray flux of 3C 66A during the core campaign was historically high and its spectrum very soft, indicating that the low-frequency component of the broadband SED extends beyond ~10 keV. No significant X-ray flux and/or spectral variability was detected. STACEE and Whipple observations provided upper flux limits at >150 and >390 GeV, respectively. The 22 and 43 GHz data from the three VLBA epochs made between 2003 September and 2004 January indicate a rather smooth jet with only very moderate internal structure. Evidence for superluminal motion (8

  18. The Hyperluminous Infrared Quasar 3C 318 and Its Implications for Interpreting Sub-MM Detections of High-Redshift Radio Galaxies

    NASA Technical Reports Server (NTRS)

    Willott, Chris J.; Rawlings, Steve; Jarvis, Matt J.

    1999-01-01

    We present near-infrared spectroscopy and imaging of the compact steep-spectrum radio source 3C 318 which shows it to be a quasar at redshift z = 1.574 (the z = 0.752 value previously reported is incorrect). 3C 318 is an IRAS, ISO and SCUBA source so its new redshift makes it the most intrinsically luminous far-infrared (FIR) source in the 3C catalogue (there is no evidence of strong gravitational lensing effects). Its bolometric luminosity greatly exceeds the 10(exp 13) solar luminosity level above which an object is said to be hyperluminous. Its spectral energy distribution (SED) requires that the quasar heats the dust responsible for the FIR flux, as is believed to be the case in other hyperluminous galaxies, and contributes (at the greater than 10% level) to the heating of the CIA dust responsible for the sub-mm emission. We cannot determine whether a starburst makes an important contribution to the heating of the coolest dust, so evidence for a high star-formation rate is circumstantial being based on the high dust, and hence gas, C-1 mass required by its sub-mm detection. We show that the current sub-mm and FIR data available for the highest-redshift radio galaxies are consistent with SEDs similar to that of 3C 318. This indicates that at least some of this population may be detected in the sub-mm because of dust heated by the quasar nucleus, and that interpreting sub-mm detection as evidence for very high (approx. less than 1000 solar mass/yr) star-formation rates may not always be valid. We show that the 3C318 quasar is slightly reddened (A(sub v) approx. = 0.5), the most likely cause of which is SMC-type dust in the host galaxy. If very distant radio galaxies are reddened in a similar way then we show that only slightly greater amounts of dust could obscure the quasars in these sources. We speculate that the low fraction of quasars amongst the very high redshift (z approx. greater than 3) objects in low-frequency radio-selected samples is the result of

  19. The compact spiral-like radio structure of the quasar 3 C 119

    NASA Astrophysics Data System (ADS)

    Nan Ren-Dong; Schilizzi, R. T.; van Breugel, W. J. M.; Fanti, C.; Fanti, R.; Muxlow, T. W. B.; Spencer, R. E.

    1991-05-01

    The compact steep spectrum radio source, 3C 119, has been mapped at 18 cm with a resolution of 5 mas using a 10-station global VLBI network combined with MERLIN. The resulting high dynamic range image reveals a complex spiral-like structure in which a number of components are embedded. The overall physical extent of the source is about 300 pc. These new observations demonstrate that the structure is even more complex than had been derived earlier by Fanti et al. (1986). The physical conditions in the source are reevaluated, and the radio structure is briefly discussed in terms of three models: nonrelativistic and relativistic precessing jets, and a jet deflected by the walls of a cavity in the interstellar medium.

  20. Effective defect diffusion lengths in Ar-ion bombarded 3C-SiC

    SciTech Connect

    Bayu Aji, L. B.; Wallace, J. B.; Shao, L.; Kucheyev, S. O.

    2016-04-14

    Above room temperature, SiC exhibits pronounced processes of diffusion and interaction of radiation-generated point defects. Here, we use the recently developed pulsed ion beam method to measure effective defect diffusion lengths in 3C-SiC bombarded in the temperature range of 25–200 °C with 500 keV Ar ions. Results reveal a diffusion length of ~10 nm, which exhibits a weak temperature dependence, changing from 9 to 13 nm with increasing temperature. Lastly, these results have important implications for understanding and predicting radiation damage in SiC and for the development of radiation-resistant materials via interface-mediated defect reactions.

  1. Thermodynamics analysis of diffusion in spark plasma sintering welding Cr3C2 and Ni

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Zhang, Jinyong; Leng, Xiaoxuan; Lei, Liwen; Fu, Zhengyi

    2017-03-01

    Spark plasma sintering (SPS) welding of chromium carbide (Cr3C2) and nickel (Ni) was used to investigate the atomic diffusion caused by bypassing current. It was found that the diffusion coefficient with bypassing current was enhanced by almost 3.57 times over that without bypassing current. Different from the previous researches, the thermodynamics analysis conducted herein showed that the enhancement included a current direction-independent part besides the known current direction-dependent part. A local temperature gradient (LTG) model was proposed to explain the current direction-independent effect. Assuming that the LTG was mainly due to the interfacial electric resistance causing heterogeneous Joule heating, the theoretical results were in good agreement with the experimental results both in the present and previous studies. This new LTG model provides a reasonable physical meaning for the low-temperature advantage of SPS welding and should be useful in a wide range of applications.

  2. Fe3C/Fe nanoparticles with urea: Synthesis, structure and magnetic properties

    NASA Astrophysics Data System (ADS)

    Wang, Xiaobai; Zhang, Daguang; Ren, Xiaozhen; Gao, Jiajia; Han, Yu; Chen, Xiaodong; Shi, Zhan; Yang, Hua

    2016-12-01

    Fe3C/Fe nanocomposites were synthesized by a sol-gel method. Using urea as carbon source and reduce agent in the reaction process. The CTAB works as the surfactant and the bromine contained in CTAB plays a catalytic role. Appropriate choices of the amount of urea and CTAB, reaction temperature and time are very important to obtain high-quality of products. Above 650 °C, the precursor gel turned into the nanocomposites composed of iron carbide and iron. Their structures and magnetic properties are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The possible formation mechanism of as-prepared nanostructures is discussed.

  3. The Fading of the Narrow-Line Region in 3C 390.3: Erratum

    NASA Astrophysics Data System (ADS)

    Clavel, J.; Wamsteker, W.

    1988-07-01

    The Letter "The Fading of the Narrow-Line Region in 3C 390.3" by J. Clavel and W. Wamsteker (Ap. J. [Letters], 320, L9 [1987]) contains an error in the last two sentences of section IIIb: The density we compute for the broad line region (BLR) gas is wrong by a factor of 10 exactly and should read 10^11^ cm^-3^ instead of 10^10^. Such a density is about 30 times larger than the canonical 10^9.5^ cm^-3^ value generally used in model calculations but similar to the density inferred for the BLR in NGC 4151 by J. Clavel et al. (Ap. J., 321, 251 [1987]). The authors are grateful to Paolo Padovani from STScI for bringing this error to their attention.

  4. Computer simulations of 3C-SiC under hydrostatic and non-hydrostatic stresses.

    PubMed

    Guedda, H Z; Ouahrani, T; Morales-García, A; Franco, R; Salvadó, M A; Pertierra, P; Recio, J M

    2016-03-21

    The response of 3C-SiC to hydrostatic pressure and to several uni- and bi-axial stress conditions is thoroughly investigated using first principles calculations. A topological interpretation of the chemical bonding reveals that the so-called non-covalent interactions enhance only at high pressure while the nature of the covalent Si-C bonding network keeps essentially with the same pattern. The calculated low compressibility agrees well with experimental values and is in concordance with the high structural stability of this polymorph under hydrostatic pressure. Under uniaxial [001] stress, the c/a ratio shows a noticeable drop inducing a closure of the band gap and the emergence of a metallic state around 40 GPa. This behavior correlates with a plateau of the electron localization function exhibiting a roughly constant and non-negligible value surrounding CSi4 and SiC4 covalent bonded units.

  5. Associated C IV absorption in radio-loud QSOs - The 3C mini-survey

    SciTech Connect

    Anderson, S.F.; Weymann, R.J.; Foltz, C.B.; Chaffee, F.H. Jr.

    1987-08-01

    A spectroscopic survey at 1 A resolution of twelve 3C and 3CR QSOs reveals a very high incidence of C IV absorption complexes within + or - 5000 km/s of the C IV 1548, 1550-A emission-line redshift. Such associated C IV absorption is found to be strong (rest-frame equivalent width equal to or greater than 1.5 A) in six of these powerful, steep-spectrum radio sources, while four others show weaker associated absorption. Such strong associated C IV complexes with z(abs) approximaely equal to z(em) are comparatively rare in a sample of radio-quiet QSOs investigated previously. The evidence for possible correlations with various radio properties is briefly discussed, although no correlations are thus far confirmed to be statistically significant. 29 references.

  6. RADIOASTRON OBSERVATIONS OF THE QUASAR 3C273: A CHALLENGE TO THE BRIGHTNESS TEMPERATURE LIMIT

    SciTech Connect

    Kovalev, Y. Y.; Kardashev, N. S.; Voitsik, P. A.; Kovalev, Yu. A.; Lisakov, M. M.; Sokolovsky, K. V.; Lobanov, A. P.; Zensus, J. A.; Anderson, J. M.; Bach, U.; Kraus, A.; Johnson, M. D.; Gurvits, L. I.; Jauncey, D. L.; Ghigo, F.; Petrov, L. Yu.; Romney, J. D.

    2016-03-20

    Inverse Compton cooling limits the brightness temperature of the radiating plasma to a maximum of 10{sup 11.5} K. Relativistic boosting can increase its observed value, but apparent brightness temperatures much in excess of 10{sup 13} K are inaccessible using ground-based very long baseline interferometry (VLBI) at any wavelength. We present observations of the quasar 3C 273, made with the space VLBI mission RadioAstron on baselines up to 171,000 km, which directly reveal the presence of angular structure as small as 26 μas (2.7 light months) and brightness temperature in excess of 10{sup 13} K. These measurements challenge our understanding of the non-thermal continuum emission in the vicinity of supermassive black holes and require a much higher Doppler factor than what is determined from jet apparent kinematics.

  7. Optical and near infrared observations of the blazar 3C 279 with the REM telescope.

    NASA Astrophysics Data System (ADS)

    Impiombato, D.; Tosti, G.; Ciprini, C.; REM Collaboration.

    The Rapid Eye Mount (REM) telescope installed at La Silla (Cile) on June 2003, is a robotic telescope able the capability to observe in optical and infrared bands. Since the late commissioning phase a optical and infrared monitoring program of a sample of blazars, most emitting also in the gamma-ray band, was started. Such program is still on going and it make part of an observational activity aimed to the multiwavelength characterization possible blazars candidate to be observed also in gamma-ray by the instruments on board of AGILE satellites(launched on 23 April 2007) and Glast (that will be launched at the end of the 2007). In this poster we present the optical/near-IR data obtained during the January 2007, outburst of 3C279 (the prototype of the gamma-ray loud).

  8. Effect of surface functionalization on the electronic transport properties of Ti3C2 MXene

    NASA Astrophysics Data System (ADS)

    Berdiyorov, G. R.

    2015-09-01

    The effects of surface functionalization on the electronic transport properties of the MXene compound Ti3C2 are studied using density-functional theory in combination with the nonequilibrium Green's function formalism. Fluorinated, oxidized and hydroxylated surfaces are considered and the obtained results are compared with the ones for the pristine MXene. It is found that the surface termination has a considerable impact on the electronic transport in MXene. For example, the fluorinated sample shows the largest transmission, whereas surface oxidation results in a considerable reduction of the electronic transmission. The current in the former sample can be up to 4 times larger for a given bias voltage as compared to the case of bare MXene. The increased transmission originates from the extended electronic states and smaller variations of the electrostatic potential profile. Our findings can be useful in designing MXene-based anode materials for energy storage applications, where enhanced electronic transport will be an asset.

  9. Ionic sieving through Ti3C2(OH)2 MXene: First-principles calculations

    NASA Astrophysics Data System (ADS)

    Berdiyorov, Golibjon R.; Madjet, Mohamed E.; Mahmoud, Khaled A.

    2016-03-01

    Recent experiments revealed a great potential of MXene nanosheets for water desalination applications as ultrathin, high-flux, and size/charge-selective sieving membranes. Here, we conduct first-principles density functional theory calculations to explore possible mechanisms for the charge-selective ionic transport through Ti3C2(OH)2 MXene. We find that the charge selectivity originates from the charged nature of the MXene layers. For example, due to the electrostatic interactions, ions of different charge states have different energy barriers for the intercalation between the MXene layers. In addition, the system shows dynamic response to the intercalating ions, even in their hydrated states, by changing the interlayer spacing. Our findings highlight the importance of membrane surface charges on the ion sieving performance.

  10. Results from monitoring the broad-line radio galaxy 3C 390.3

    NASA Technical Reports Server (NTRS)

    Leighly, K, M.; Dietrich, M.; Waltman, E.; Edelson, R.; George, I.; Malkan, M.; Matsuoka, M.; Mushotzky, R.; Peterson, B. M.

    1996-01-01

    The broad line radio galaxy 3C 390.3 was observed in a multiwavelength monitoring campaign by the Rosat high resolution imager (HRI), the International Ultraviolet Explorer and ground-based optical, infrared and and radio observations. The preliminary results from the campaign are reported, with emphasis on the X-ray observations. A large amplitude variability is observed. The light curve is dominated by a flare near JD 2449800, characterized by a doubling time scale of 9 days and a general increase in flux after the flare. The optical R and I band light curves show a general increase in flux. Spectra from the Advanced Satellite for Cosmology and Astrophysics (ASCA) obtained before and after the flare can be described by an absorbed power law.

  11. A cosmic double helix in the archetypical quasar 3C273.

    PubMed

    Lobanov, A P; Zensus, J A

    2001-10-05

    Finding direct evidence for plasma instability in extragalactic jets is crucial for understanding the nature of relativistic outflows from active galactic nuclei. Our radio interferometric observations of the quasar 3C273 made with the orbiting radio telescope, HALCA, and an array of ground telescopes have yielded an image in which the emission across the jet is resolved, revealing two threadlike patterns that form a double helix inside the jet. This double helical structure is consistent with a Kelvin-Helmholtz instability, and at least five different instability modes can be identified and modeled by a light jet with a Lorentz factor of 2 and Mach number of 3.5. The model reproduces in detail the internal structure of the jet on scales of up to 30 milli-arc seconds ( approximately 300 parsecs) and is consistent with the general morphology of the jet on scales of up to 1 kiloparsec.

  12. Variability of Lyman-alpha and the ultraviolet continuum of 3C 446

    NASA Technical Reports Server (NTRS)

    Bregman, J. N.; Glassgold, A. E.; Huggins, P. J.; Kinney, A. L.

    1986-01-01

    IUE observations have been conducted over the 1230-3175 A range for the violently variable quasar 3C 446, beginning in June 1980, at intervals of 1.2, 2.2, 0.5, and 0.4 yr. Strong absorption of the continuum was found below 1830 A, probably corresponding to a Lyman edge at z of 1.00 + or - 0.01. The absence of Mg II 2798 A absorption implies that the column density is in the lower end of the range, unless the gas is metal-poor. The Lyman-alpha emission line was detected in five spectra; relative to the number of ionizing protons, the line strengths are the same as in normal quasars, and line equivalent widths are small due to the continuum's rise redward of 912 A, which is much steeper than in normal quasars. The Lyman-alpha line and the nearby continuum vary so as to maintain constant equivalent width.

  13. A complete spectral analysis of the flare of the quasar 3C 273

    NASA Technical Reports Server (NTRS)

    Sadun, Alberto C.

    1992-01-01

    The 1983 quasar outburst of the source 3C 273 is investigated by studying several months of radio-frequency and UV data that represent about six decades of frequency. The data are analyzed to account for the differences inherent in various photometric systems, and adjustments are made for reddening and line emission. Individual wavelengths are delineated in light curves which indicate distinct periods of burst activity for specific wavelengths. The spectrum of the flare is characterized by a trend in which the critical wavelength evolves toward longer wavelengths as the outburst progresses. It is suggested that the data are consistent with a model of an expanding gas cloud that emits Doppler-boosted synchrotron radiation. The spectral curves, light curves, and the spectral index are of use in the analysis of similar phenomena when VLBI data of superluminal motion are incorporated.

  14. Probing the connection between the accretion disk, outflows and the jet in 3C111

    NASA Astrophysics Data System (ADS)

    Tombesi, Francesco

    2011-10-01

    Recent XMM-Newton and Suzaku observations of 3C111 demonstrated the presence of ultra-fast outflows (UFOs) with v~0.1c and their relation with the accretion disk. Independent studies found that X-ray dips are followed by ejection of superluminal radio knots, therefore providing a proof of the disk-jet connection. We acquired evidence that UFOs are preferentially present between X-ray dips and new knots, possibly indicating also a link between disk outflows and the jet. The goal of this XMM-Newton proposal is to confirm this evidence. Given the strong correlation with X-rays, we will use an ongoing optical monitoring campaign to trigger a 90ks observation within two days of a dip to detect a UFO and we request a possible additional 60ks >15 days after to compare with the non-dipped state.

  15. Thermal expansion of the cubic (3C) polytype of SiC

    NASA Technical Reports Server (NTRS)

    Li, Z.; Bradt, R. C.

    1986-01-01

    Thermal expansion of the cubic beta or (3C) polytype of SiC was measured from 20 to 1000 C by the X-ray-diffraction technique. Over that temperature range, the coefficient of thermal expansion can be expressed by a second-order polynomial. It increases continuously from about 3.2 x 10 to the -6th/C at room temperature to 5.1 x 10 to the -6th/C at 1000 C, with an average value of 4.45 x 10 to the -6th/C between room temperature and 1000 C. This trend is compared with other published results and is discussed in terms of structural contributions to the thermal expansion.

  16. Determination of aerodynamic stability and drag of the Titan 3 C SRM during entry

    NASA Technical Reports Server (NTRS)

    Ramsey, P. E.

    1974-01-01

    An experimental aerodynamic investigation was conducted in the NASA/MSFC 14-inch Trisonic Wind Tunnel on a 0.00736 scale model of Titan 3 C Solid Rocket Motor (SRM). Static stability and drag data were obtained for Mach numbers of 0.6 to 4.96, angles of attack of minus 10 deg to 190 deg, and roll angles of 0 to 360 deg. The resulting data will be used to predict the dynamic motions of the SRM during entry which will then be compared to flight data. This comparison will improve and lend credibility to methods for predicting the entry dynamics of the space shuttle Solid Rocket Booster (SRB), which is needed for recovery studies and design of the parachute recovery system.

  17. Jet and accretion-disk emission untangled in 3C 273.

    PubMed

    Grandi, Paola; Palumbo, Giorgio G C

    2004-11-05

    A long-term spectral variability study of 3C 273 on data obtained by BeppoSAX allows us to decouple the beamed nonthermal (jet) and unbeamed thermal (accretion flow) radiation produced in the inner region of a radio-loud active galactic nucleus. Jet power, when compared with unbeamed radiation, increases with energy. The thermal component is generally overwhelmed by the nonthermal radiation, by a factor of 1.2 to 3 in the 2- to 10-keV range and up to a factor of 7 above 20 keV. In only one case, the accretion flow overcomes the jet, allowing the K(alpha) iron line to emerge clearly over the continuum.

  18. Synthesis, stereochemical characterization, and antimicrobial evaluation of a potentially nonnephrotoxic 3'-C-acethydrazide puromycin analog.

    PubMed

    Carter, Josh; Weaver, Blair A; Chiacchio, Maria A; Messersmith, Amy R; Lynch, Will E; Feske, Brent D; Gumina, Giuseppe

    2017-03-04

    Puromycin is a peptidyl nucleoside endowed with significant antibiotic and anticancer properties, but also with an unfortunate nephrotoxic character that has hampered its use as a chemotherapeutic agent. Since hydrolysis of puromycin's amide to puromycin aminonucleoside is the first metabolic step leading to nephrotoxicity, we designed a 3'-C-hydrazide analog where the nitrogen and carbon functionality around the amide carbonyl of puromycin are inverted. The title compound, synthesized in 11 steps from D-xylose, cannot be metabolized to the nephrotoxic aminonucleoside. Evaluation of the title compound on Staphylococcus epidermidis and multi-drug resistance Staphylococcus aureus did not show significant antimicrobial activity up to a 400 μM concentration.

  19. Particle accelerators in the hot spots of radio galaxy 3C 445, imaged with the VLT.

    PubMed

    Prieto, M Almudena; Brunetti, Gianfranco; Mack, Karl-Heinz

    2002-10-04

    Hot spots (HSs) are regions of enhanced radio emission produced by supersonic jets at the tip of the radio lobes of powerful radio sources. Obtained with the Very Large Telescope (VLT), images of the HSs in the radio galaxy 3C 445 show bright knots embedded in diffuse optical emission distributed along the post-shock region created by the impact of the jet into the intergalactic medium. The observations reported here confirm that relativistic electrons are accelerated by Fermi-I acceleration processes in HSs. Furthermore, both the diffuse emission tracing the rims of the front shock and the multiple knots demonstrate the presence of additional continuous re-acceleration processes of electrons (Fermi-II).

  20. Interferometer observations of the quasar 3C216 at the decameter wavelengths

    NASA Astrophysics Data System (ADS)

    Megn, A. V.; Braude, S. Ya.; Rashkovskyi, S. L.; Sharykin, N. K.; Shepelev, V. A.; Inyutin, G. A.; Vaschishin, R. V.; Brazhenko, A. I.; Bulatsen, V. G.; Koshovyi, V. V.; Lozinskyi, A. B.

    2001-06-01

    The study of the angular structure of the quasar 3C216 with the URAN interferometers (baselines of 42.3 km, 152.3 km, and 946.2 km) at the decameter wavelengths is presented. The source radio image in this range is shown to be essentially different from that at higher frequencies. The most suitable simple models of radio brightness distribution at frequencies of 20 and 25 MHz were determined. They consist of two practically co-centered components (core-halo model): a compact feature with dimensions from 1.7{''} to 2.4{''} and an extended one with diameter of about 21{'}. Their flux densities at these frequencies are (0.61-0.63)S_0 for the compact component and (0.39-0.37)S_0, for the extended one, S_0 being the total flux density of the quasar.

  1. Observational Studies of the Angular Structure of the Radio Galaxy 3C 234 at Decameter Wavelengths

    NASA Astrophysics Data System (ADS)

    Megn, A. V.; Braude, S. Ya.; Rashkovskiy, S. L.; Sharykin, N. K.; Shepelev, V. A.; Inyutin, G. A.; Vashchishin, R. V.; Brazhenko, A. I.; Bulatsen, V. G.

    2003-12-01

    An analysis of the angular structure of the radio galaxy 3C 234 at decameter wavelengths based on data obtained on the URAN-1 and URAN-2 interferometers is presented. Four of the five model components that describe the radio-brightness distribution at centimeter wavelengths are observed at decameter wavelengths: two compact components and two neighboring extended components. The fifth, undetected, component is the most extended, and encompasses the central region of the radio source, including the nucleus of the galaxy. Self-absorption is detected in the compact components, whose angular sizes are determined to be 0.27±0.03″ (northeast component) and 0.55±0.05″ (southwest component), in agreement with direct measurements at centimeter wavelengths. Most of the decameter emission of the radio galaxy is associated with its extended components.

  2. The Structure of the Radio Galaxy 3C388 at Decameter Wavelengths

    NASA Astrophysics Data System (ADS)

    Megn, A. V.; Braude, S. Ya.; Rashkovskii, S. L.; Sharykin, N. K.; Shepelev, V. A.; Inyutin, G. A.; Vashchishin, R. V.; Brazhenko, A. I.; Bulatsen, V. G.

    2001-02-01

    Observations of the structure of the radio galaxy 3C338 at decameter wavelengths obtained using the URAN-1 and URAN-2 radio interferometers are presented. The structure of this object at these wavelengths differs appreciably from images obtained at higher frequencies. The most probable simple models for the radio brightness distributions at 25 and 20 MHz are determined: two extended components with sizes from 40″ to 50″ whose centers are separated by 90″ 100″ in position angle about 100°, and a single compact component 9″×4″ in size, whose flux density does not exceed 10% of the total flux density of the radio galaxy.

  3. The structure of the radio galaxy 3C 111 at decameter wavelengths

    NASA Astrophysics Data System (ADS)

    Megn, A. V.; Braude, S. Ya.; Rashkovskii, S. L.; Sharykin, N. K.; Shepelev, V. A.; Inyutin, G. A.

    1999-07-01

    Results of the first radio interferometric observations of the radio galaxy 3C 111 at decameter wavelengths are presented. The observations were obtained using the URAN-1 interferometer. A simple model for the radio-brightness distribution of this source at 25 and 20 MHz has been determined. The general properties of the best-fit three-component model at these wavelengths are similar to those observed at centimeter wavelengths; the overall maximum sizes and position angles of the structures are virtually identical. However, there are appreciable differences; in particular, the decameter angular sizes of the outer components are considerably larger, and the relative contribution of the central component (which coincides with the optical galaxy) is much less.

  4. HST observations of 3C 66B - A double-stranded optical jet

    NASA Technical Reports Server (NTRS)

    Macchetto, F.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.

    1991-01-01

    The central region of the synchrotron jet in 3C 66B imaged with ultrahigh spatial resolution by the Faint Object Camera on the HST is discussed. A close correspondence between the general characteristics of the smoothed optical image and the radio map is observed, implying that the young and old relativistic particles occupy similar regions to within about 130 pc. Focus is placed on the double-stranded filamentary nature of the jet, and it is speculated that this could reflect edge-brightening effects due to enhanced radiation from a skinlike structure surrounding the jet. It is noted that the similarity of optical and radio morphologies points to the fact that localized particle acceleration occurs along the jet; however, the filamentary structure and a low filling factor of radiation agree with a model in which the electrons are accelerated within the nucleus and are transported along the jet in a channel having low magnetic field.

  5. Impact of nonintentional Al impurity to carrier lifetime and diffusion in sublimation grown 3C heterostructures

    NASA Astrophysics Data System (ADS)

    Ščajev, P.; Jarašiunas, K.; Kadys, A.; Storasta, J.; Abramov, P. L.; Lebedev, S. P.; Lebedev, A. A.

    2010-11-01

    Using optical techniques, we analyzed an impact of non-intentional Al mpurity and twin boundaries to photoelectrical properties of sublimation-grown 3C heterostructures. Differential transmission techniques revealed Al related contribution to probe beam absorption with cross-section σAl = (1.8±0.5)×10-17 cm2 at 1064 nm, being four times stronger that the free-carrier absorption cross-section at given wavelength. Temperature dependent carrier recombination rates provided trap activation energy of 170 and 210 meV in two samples with different Al concentration. Saturation of probe beam absorption with excitation allowed determination of electrically active Al concentration, not gettered at grain boundaries. Increase of room-temperature mobility with injection in the highly defective layer and the corresponding lifetime decrease pointed out contribution of point and structural defects to carrier scattering.

  6. Probing the parsec-scale accretion flow of 3C 84 with millimeter wavelength polarimetry

    SciTech Connect

    Plambeck, R. L.; Bower, G. C.; Rao, Ramprasad; Marrone, D. P.; Jorstad, S. G.; Marscher, A. P.; Doeleman, S. S.; Fish, V. L.; Johnson, M. D.

    2014-12-10

    We report the discovery of Faraday rotation toward radio source 3C 84, the active galactic nucleus in NGC 1275 at the core of the Perseus Cluster. The rotation measure (RM), determined from polarization observations at wavelengths of 1.3 and 0.9 mm, is (8.7 ± 2.3)× 10{sup 5} rad m{sup –2}, among the largest ever measured. The RM remained relatively constant over a 2 yr period even as the intrinsic polarization position angle wrapped through a span of 300°. The Faraday rotation is likely to originate either in the boundary layer of the radio jet from the nucleus or in the accretion flow onto the central black hole. The accretion flow probably is disk-like rather than spherical on scales of less than a parsec, otherwise the RM would be even larger.

  7. Identification of a Novel Homozygous Mutation, TMPRSS3: c.535G>A, in a Tibetan Family with Autosomal Recessive Non-Syndromic Hearing Loss

    PubMed Central

    Fan, Dongyan; Zhu, Wei; Li, Dejun; Ji, De; Wang, Ping

    2014-01-01

    Different ethnic groups have distinct mutation spectrums associated with inheritable deafness. In order to identify the mutations responsible for congenital hearing loss in the Tibetan population, mutation screening for 98 deafness-related genes by microarray and massively parallel sequencing of captured target exons was conducted in one Tibetan family with familiar hearing loss. A homozygous mutation, TMPRSS3: c.535G>A, was identified in two affected brothers. Both parents are heterozygotes and an unaffected sister carries wild type alleles. The same mutation was not detected in 101 control Tibetan individuals. This missense mutation results in an amino acid change (p.Ala179Thr) at a highly conserved site in the scavenger receptor cysteine rich (SRCR) domain of the TMPRSS3 protein, which is essential for protein-protein interactions. Thus, this mutation likely affects the interactions of this transmembrane protein with extracellular molecules. According to our bioinformatic analyses, the TMPRSS3: c.535G>A mutation might damage protein function and lead to hearing loss. These data suggest that the homozygous mutation TMPRSS3: c.535G>A causes prelingual hearing loss in this Tibetan family. This is the first TMPRSS3 mutation found in the Chinese Tibetan population. PMID:25474651

  8. The N-terminal octapeptide acts as a dimerization inhibitor of SARS coronavirus 3C-like proteinase.

    PubMed

    Wei, Ping; Fan, Keqiang; Chen, Hao; Ma, Liang; Huang, Changkang; Tan, Lei; Xi, Dong; Li, Chunmei; Liu, Ying; Cao, Aoneng; Lai, Luhua

    2006-01-20

    The 3C-like proteinase of severe acute respiratory syndrome (SARS) coronavirus has been proposed to be a key target for structural-based drug design against SARS. Accurate determination of the dimer dissociation constant and the role of the N-finger (residues 1-7) will provide more insights into the enzyme catalytic mechanism of SARS 3CL proteinase. The dimer dissociation constant of the wild-type protein was determined to be 14.0microM by analytical ultracentrifugation method. The N-finger fragment of the enzyme plays an important role in enzyme dimerization as shown in the crystal structure. Key residues in the N-finger have been studied by site-directed mutagenesis, enzyme assay, and analytical ultracentrifugation. A single mutation of M6A was found to be critical to maintain the dimer structure of the enzyme. The N-terminal octapeptide N8 and its mutants were also synthesized and tested for their potency as dimerization inhibitors. Peptide cleavage assay confirms that peptide N8 is a dimerization inhibitor with a K(i) of 2.20mM. The comparison of the inhibitory activities of N8 and its mutants indicates that the hydrophobic interaction of Met-6 and the electrostatic interaction of Arg-4 contribute most for inhibitor binding. This study describes the first example of inhibitors targeting the dimeric interface of SARS 3CL proteinase, providing a novel strategy for drug design against SARS and other coronaviruses.

  9. Porcine Epidemic Diarrhea Virus 3C-Like Protease-Mediated Nucleocapsid Processing: Possible Link to Viral Cell Culture Adaptability.

    PubMed

    Jaru-Ampornpan, Peera; Jengarn, Juggragarn; Wanitchang, Asawin; Jongkaewwattana, Anan

    2017-01-15

    Porcine epidemic diarrhea virus (PEDV) causes severe diarrhea and high mortality rates in newborn piglets, leading to massive losses to the swine industry worldwide during recent epidemics. Intense research efforts are now focusing on defining viral characteristics that confer a growth advantage, pathogenicity, or cell adaptability in order to better understand the PEDV life cycle and identify suitable targets for antiviral or vaccine development. Here, we report a unique phenomenon of PEDV nucleocapsid (N) cleavage by the PEDV-encoded 3C-like protease (3Cpro) during infection. The identification of the 3Cpro cleavage site at the C terminus of N supported previous observations that PEDV 3Cpro showed a substrate requirement slightly different from that of severe acute respiratory syndrome coronavirus (SARS-CoV) 3Cpro and revealed a greater flexibility in its substrate recognition site. This cleavage motif is present in the majority of cell culture-adapted PEDV strains but is missing in emerging field isolates. Remarkably, reverse-genetics-derived cell culture-adapted PEDVAVCT12 harboring uncleavable N displayed growth retardation in Vero E6-APN cells compared to the wild-type virus. These observations altogether shed new light on the investigation and characterization of the PEDV nucleocapsid protein and its possible link to cell culture adaptation.

  10. Second hyperpolarizabilities of the lithium salt of pyridazine Li-H3C4N2 and lithium salt electride Li-H3C4N2⋯Na2

    NASA Astrophysics Data System (ADS)

    Silveira, Orlando; Castro, Marcos A.; Leão, Salviano A.; Fonseca, Tertius L.

    2015-07-01

    This Letter reports static and dynamic second hyperpolarizabilities of the lithium salt of pyridazine Li-H3C4N2 and lithium salt electride Li-H3C4N2⋯Na2. The results show strong dependence of the computed values with respect to the electron correlation treatment. The static value obtained at the CCSD level with the aug-cc-pVDZ basis set for the Li-H3C4N2⋯Na2 is 1.1 × 109 au. This extremely large value of the second hyperpolarizability reinforces the potential of this system for application in nonlinear optics.

  11. The direct arylation of allylic sp3 C-H bonds via organic and photoredox catalysis

    NASA Astrophysics Data System (ADS)

    Cuthbertson, James D.; MacMillan, David W. C.

    2015-03-01

    The direct functionalization of unactivated sp3 C-H bonds is still one of the most challenging problems facing synthetic organic chemists. The appeal of such transformations derives from their capacity to facilitate the construction of complex organic molecules via the coupling of simple and otherwise inert building blocks, without introducing extraneous functional groups. Despite notable recent efforts, the establishment of general and mild strategies for the engagement of sp3 C-H bonds in C-C bond forming reactions has proved difficult. Within this context, the discovery of chemical transformations that are able to directly functionalize allylic methyl, methylene and methine carbons in a catalytic manner is a priority. Although protocols for direct oxidation and amination of allylic C-H bonds (that is, C-H bonds where an adjacent carbon is involved in a C = C bond) have become widely established, the engagement of allylic substrates in C-C bond forming reactions has thus far required the use of pre-functionalized coupling partners. In particular, the direct arylation of non-functionalized allylic systems would enable access to a series of known pharmacophores (molecular features responsible for a drug's action), though a general solution to this long-standing challenge remains elusive. Here we report the use of both photoredox and organic catalysis to accomplish a mild, broadly effective direct allylic C-H arylation. This C-C bond forming reaction readily accommodates a broad range of alkene and electron-deficient arene reactants, and has been used in the direct arylation of benzylic C-H bonds.

  12. Feeding and Feedback in the Powerful Radio Galaxy 3C 120

    NASA Astrophysics Data System (ADS)

    Tombesi, F.; Mushotzky, R. F.; Reynolds, C. S.; Kallman, T.; Reeves, J. N.; Braito, V.; Ueda, Y.; Leutenegger, M. A.; Williams, B. J.; Stawarz, Ł.; Cappi, M.

    2017-03-01

    We present a spectral analysis of a 200 ks observation of the broad-line radio galaxy 3C 120, performed with the high-energy transmission grating spectrometer on board the Chandra X-ray Observatory. We find (i) a neutral absorption component intrinsic to the source with a column density of {log}{N}{{H}}=20.67+/- 0.05 cm‑2 (ii) no evidence for a warm absorber (WA) with an upper limit on the column density of just {log}{N}{{H}}< 19.7 cm‑2, assuming the typical ionization parameter logξ ≃ 2.5 erg s‑1 cm the WA may instead be replaced by (iii) a hot emitting gas with a temperature kT ≃ 0.7 keV observed as soft X-ray emission from ionized Fe L-shell lines, which may originate from a kiloparsec-scale shocked bubble inflated by the active galactic nucleus (AGN) wind or jet with a shock velocity of about 1000 km s‑1 determined by the emission line width; (iv) a neutral Fe Kα line and accompanying emission lines indicative of a Compton-thick cold reflector with a low reflection fraction R ≃ 0.2, suggesting a large opening angle of the torus; (v) a highly ionized Fe xxv emission feature indicative of photoionized gas with an ionization parameter logξ ={3.75}-0.38+0.27 erg s‑1 cm and a column density of {log}{N}{{H}}> 22 cm‑2 localized within ∼2 pc from the X-ray source; and (vi) possible signatures of a highly ionized disk wind. Together with previous evidence for intense molecular line emission, these results indicate that 3C 120 is likely a late-state merger undergoing strong AGN feedback.

  13. Jet-driven outflows of ionized gas in the nearby radio galaxy 3C 293

    NASA Astrophysics Data System (ADS)

    Mahony, E. K.; Oonk, J. B. R.; Morganti, R.; Tadhunter, C.; Bessiere, P.; Short, P.; Emonts, B. H. C.; Oosterloo, T. A.

    2016-01-01

    Fast outflows of gas, driven by the interaction between the radio jets and interstellar medium (ISM) of the host galaxy, are being observed in an increasing number of galaxies. One such example is the nearby radio galaxy 3C 293. In this paper we present integral field unit observations taken with OASIS on the William Herschel Telescope, enabling us to map the spatial extent of the ionized gas outflows across the central regions of the galaxy. The jet-driven outflow in 3C 293 is detected along the inner radio lobes with a mass outflow rate ranging from ˜0.05 to 0.17 M⊙ yr-1 (in ionized gas) and corresponding kinetic power of ˜0.5-3.5 × 1040 erg s-1. Investigating the kinematics of the gas surrounding the radio jets (i.e. not directly associated with the outflow), we find linewidths broader than 300 km s-1 up to 5 kpc in the radial direction from the nucleus (corresponding to 3.5 kpc in the direction perpendicular to the radio axis at maximum extent). Along the axis of the radio jet linewidths >400 km s-1 are detected out to 7 kpc from the nucleus and linewidths of >500 km s-1 at a distance of 12 kpc from the nucleus, indicating that the disturbed kinematics clearly extend well beyond the high surface brightness radio structures of the jets. This is suggestive of the cocoon structure seen in simulations of jet-ISM interaction and implies that the radio jets are capable of disturbing the gas throughout the central regions of the host galaxy in all directions.

  14. A Hard Gamma-Ray Flare from 3C 279 in 2013 December

    NASA Astrophysics Data System (ADS)

    Paliya, Vaidehi S.; Diltz, Chris; Böttcher, Markus; Stalin, C. S.; Buckley, David

    2016-01-01

    The blazar 3C 279 exhibited twin γ-ray flares of similar intensity in 2013 December and 2014 April. In this work, we present a detailed multi-wavelength analysis of the 2013 December flaring event. Multi-frequency observations reveal the uncorrelated variability patterns with X-ray and optical-UV fluxes peaking after the γ-ray maximum. The broadband spectral energy distribution (SED) at the peak of the γ-ray activity shows a rising γ-ray spectrum but a declining optical-UV flux. This observation along with the detection of uncorrelated variability behavior rules out the one-zone leptonic emission scenario. We, therefore, adopt two independent methodologies to explain the SED: a time-dependent lepto-hadronic modeling and a two-zone leptonic radiative modeling approach. In the lepto-hadronic modeling, a distribution of electrons and protons subjected to a randomly orientated magnetic field produces synchrotron radiation. Electron synchrotron is used to explain the IR to UV emission while proton synchrotron emission is used to explain the high-energy γ-ray emission. A combination of both electron synchrotron self-Compton emission and proton synchrotron emission is used to explain the X-ray spectral break seen during the later stage of the flare. In the two-zone modeling, we assume a large emission region emitting primarily in IR to X-rays and γ-rays to come primarily from a fast-moving compact emission region. We conclude by noting that within a span of four months, 3C 279 has shown the dominance of a variety of radiative processes over each other and this reflects the complexity involved in understanding the physical properties of blazar jets in general.

  15. Mechanistic Insight into the Chemical Exfoliation and Functionalization of Ti3C2 MXene.

    PubMed

    Srivastava, Pooja; Mishra, Avanish; Mizuseki, Hiroshi; Lee, Kwang-Ryeol; Singh, Abhishek K

    2016-09-14

    MXene, a two-dimensional layer of transition metal carbides/nitrides, showed great promise for energy storage, sensing, and electronic applications. MXene are chemically exfoliated from the bulk MAX phase; however, mechanistic understanding of exfoliation and subsequent functionalization of these technologically important materials is still lacking. Here, using density-functional theory we show that exfoliation of Ti3C2 MXene proceeds via HF insertion through edges of Ti3AlC2 MAX phase. Spontaneous dissociation of HF and subsequent termination of edge Ti atoms by H/F weakens Al-MXene bonds. Consequent opening of the interlayer gap allows further insertion of HF that leads to the formation of AlF3 and H2, which eventually come out of the MAX, leaving fluorinated MXene behind. Density of state and electron localization function shows robust binding between F/OH and Ti, which makes it very difficult to obtain controlled functionalized or pristine MXene. Analysis of the calculated Gibbs free energy (ΔG) shows fully fluorinated MXene to be lowest in energy, whereas the formation of pristine MXene is thermodynamically least favorable. In the presence of water, mixed functionalized Ti3C2Fx(OH)1-x (x ranges from 0 to 1) MXene can be obtained. The ΔG values for the mixed functionalized MXenes are very close in energy, indicating the random and nonuniform functionalization of MXene. The microscopic understanding gained here unveils the challenges in exfoliation and controlling the functionalization of MXene, which is essential for its practical application.

  16. Probing the gamma-ray variability in 3C 279 using broad-band observations

    NASA Astrophysics Data System (ADS)

    Rani, B.; Krichbaum, T. P.; Lee, S.-S.; Sokolovsky, K.; Kang, S.; Byun, D.-Y.; Mosunova, D.; Zensus, J. A.

    2017-01-01

    We present the results of a broad-band radio-to-GeV observing campaign organized to get a better understanding of the radiation processes responsible for the γ-ray flares observed in 3C 279. The total intensity and polarization observations of the source were carried out between 2013 December 28 and 2014 January 03 using the Fermi-Large Area Telescope, Swift-XRT, Swift-UVOT, and Korean VLBI Network telescopes. A prominent flare observed in the optical/near-UV passbands was found to be correlated with a concurrent γ-ray flare at a confidence level >95 per cent, which suggests a co-spatial origin of the two. Moreover, the flaring activity in the two regimes was accompanied by no significant spectral variations. A peak in the X-ray light curve coincides with the peaks of the fractional polarization curves at 43 and 86 GHz radio bands. No prominent variation was noticed for the total intensity and the electric vector position angle observations at radio bands during this period. We noticed a possible hint of steepening of the radio spectrum with an increase in percentage polarization, which suggests that the radio polarization variations could be simply due to a spectral change. In a simple scenario, the correlated optical/γ-ray flares could be caused by the same population of emitting particles. The coincidence of the increase in radio polarization with the X-ray flux supports the picture that X-rays are produced via inverse-Compton scattering of radio photons. The observed fractional variability for the γ-ray flare ˜0.23 does not exceed that in the optical regime, which is inconsistent with what we usually observe for 3C 279; it could be due to different dependencies of the magnetic field and the external radiation field energy density profiles along the jet.

  17. X-ray absorption toward the red quasar 3C 212

    NASA Technical Reports Server (NTRS)

    Elvis, Martin; Fiore, Fabrizio; Mathur, Smita; Wilkes, Belinda J.

    1994-01-01

    A Roentgen Satellite (ROSAT) X-ray spectrum of the z = 1.049 'red quasar' 3C 212 has a strong low-energy cutoff. The spectrum can be fitted with a power law (of energy index 1.4(+0.8, -0.6) with low-energy photoelectric absorption in excess of the Galactic value that, if at the redhsift of the quasar, would have a column density of (0.9(+0.8, -0.6)) x 10(exp 22) atoms/sq cm. Possible sites for the absorption are a nuclear torus, an intervening damped Lyman-alpha system, or intracluster material (e.g., a cooling flow) around the quasar. The implied absorbing column density is sufficient to redden a normal quasar spectrum to the observed steep optical slope. The observed continuum, if dereddened by this amount, can produce the observed emission line fluxes and ratios. The absence of the graphite lambda-2175 feature in 3C 212 however, requires dust different from the local Milky Way composition, or an intervening absorber with z less than 0.4. Alternative acceptable fits to the X-ray spectrum are (1) a blackbody with a temperature of 0.7 keV (in the quasar frame) modified only by Galactic absorption, and (2) an optically thin thermal plasma with excess absorption. Although a blackbody spectrum would be unprecedented, the model is consistent with all the available X-ray and optical data and cannot be ruled out. We discuss possible observations that can discriminate among the above models.

  18. THE 2009 DECEMBER GAMMA-RAY FLARE OF 3C 454.3: THE MULTIFREQUENCY CAMPAIGN

    SciTech Connect

    Pacciani, L.; Vittorini, V.; Tavani, M.; Fiocchi, M. T.; Sakamoto, T.; Krimm, H. A.; Pian, E.; Raiteri, C. M.; Villata, M.; Sasada, M.; Itoh, R.; Yamanaka, M.; Uemura, M.; Striani, E.; Fugazza, D.; Tiengo, A.

    2010-06-20

    During the month of 2009 December, the blazar 3C 454.3 became the brightest gamma-ray source in the sky, reaching a peak flux F {approx} 2000 x 10{sup -8} photons cm{sup -2} s{sup -1} for E > 100 MeV. Starting in 2009 November intensive multifrequency campaigns monitored the 3C 454 gamma-ray outburst. Here, we report on the results of a two-month campaign involving AGILE, INTEGRAL, Swift/XRT, Swift/BAT, and Rossi XTE for the high-energy observations and Swift/UVOT, KANATA, Goddard Robotic Telescope, and REM for the near-IR/optical/UV data. GASP/WEBT provided radio and additional optical data. We detected a long-term active emission phase lasting {approx}1 month at all wavelengths: in the gamma-ray band, peak emission was reached on 2009 December 2-3. Remarkably, this gamma-ray super-flare was not accompanied by correspondingly intense emission in the optical/UV band that reached a level substantially lower than the previous observations in 2007-2008. The lack of strong simultaneous optical brightening during the super-flare and the determination of the broadband spectral evolution severely constrain the theoretical modeling. We find that the pre- and post-flare broadband behavior can be explained by a one-zone model involving synchrotron self-Compton plus external Compton emission from an accretion disk and a broad-line region. However, the spectra of the 2009 December 2-3 super-flare and of the secondary peak emission on 2009 December 9 cannot be satisfactorily modeled by a simple one-zone model. An additional particle component is most likely active during these states.

  19. Ti 3 C 2 T x (MXene)–polyacrylamide nanocomposite films

    DOE PAGES

    Naguib, Michael; Saito, Tomonori; Lai, Sophia; ...

    2016-07-20

    Polymer nanocomposite films are of great interest due to their enhanced properties over base polymers. By incorporating 2D titanium carbide a representative of a new family of 2D materials, MXenes, as nanofillers into a water soluble polyacrylamide (PAM) matrix, the resulting films benefit from the flexibility, robustness, and processability of PAM, as well as the conductivity and mechanical properties of MXene fillers. We report on manufacturing and characterization of MXene-PAM nanocomposite films. Dimethylsulfoxide (DMSO) intercalation in-between the Ti3C2-based MXene layers led to full delamination of the MXene layers and hence a uniform dispersion of hydrophilic MXene nanosheets in aqueous PAMmore » solutions was achieved. Moreover, the polymer composite solutions of up to 75 wt.% MXene loading were sonicated and cast onto large Teflon trays and dried at room temperature to produce shiny black films. The observation of reduced 0002 peaks of Ti3C2Tx phase in X-ray diffraction patterns and TEM images indicate the presence of well dispersed nanoflakes. The as-prepared composite films are flexible and the conductivity was increased significantly to 3 x 10-3 S cm-1 for 6 wt. % MXene-PAM films. With high MXene loading, some non-uniformity between the top and bottom surfaces was observed. This could be due to the segregation of MXene layers in composite films during drying. Finally, the power law dependence of conductivity above the percolation threshold is presented through detailed conductivity measurements.« less

  20. The direct arylation of allylic sp(3) C-H bonds via organic and photoredox catalysis.

    PubMed

    Cuthbertson, James D; MacMillan, David W C

    2015-03-05

    The direct functionalization of unactivated sp(3) C-H bonds is still one of the most challenging problems facing synthetic organic chemists. The appeal of such transformations derives from their capacity to facilitate the construction of complex organic molecules via the coupling of simple and otherwise inert building blocks, without introducing extraneous functional groups. Despite notable recent efforts, the establishment of general and mild strategies for the engagement of sp(3) C-H bonds in C-C bond forming reactions has proved difficult. Within this context, the discovery of chemical transformations that are able to directly functionalize allylic methyl, methylene and methine carbons in a catalytic manner is a priority. Although protocols for direct oxidation and amination of allylic C-H bonds (that is, C-H bonds where an adjacent carbon is involved in a C = C bond) have become widely established, the engagement of allylic substrates in C-C bond forming reactions has thus far required the use of pre-functionalized coupling partners. In particular, the direct arylation of non-functionalized allylic systems would enable access to a series of known pharmacophores (molecular features responsible for a drug's action), though a general solution to this long-standing challenge remains elusive. Here we report the use of both photoredox and organic catalysis to accomplish a mild, broadly effective direct allylic C-H arylation. This C-C bond forming reaction readily accommodates a broad range of alkene and electron-deficient arene reactants, and has been used in the direct arylation of benzylic C-H bonds.

  1. Mesophyll Chloroplast Investment in C3, C4 and C2 Species of the Genus Flaveria.

    PubMed

    Stata, Matt; Sage, Tammy L; Hoffmann, Natalie; Covshoff, Sarah; Ka-Shu Wong, Gane; Sage, Rowan F

    2016-05-01

    The mesophyll (M) cells of C4 plants contain fewer chloroplasts than observed in related C3 plants; however, it is uncertain where along the evolutionary transition from C3 to C4 that the reduction in M chloroplast number occurs. Using 18 species in the genus Flaveria, which contains C3, C4 and a range of C3-C4 intermediate species, we examined changes in chloroplast number and size per M cell, and positioning of chloroplasts relative to the M cell periphery. Chloroplast number and coverage of the M cell periphery declined in proportion to increasing strength of C4 metabolism in Flaveria, while chloroplast size increased with increasing C4 cycle strength. These changes increase cytosolic exposure to the cell periphery which could enhance diffusion of inorganic carbon to phosphenolpyruvate carboxylase (PEPC), a cytosolic enzyme. Analysis of the transcriptome from juvenile leaves of nine Flaveria species showed that the transcript abundance of four genes involved in plastid biogenesis-FtsZ1, FtsZ2, DRP5B and PARC6-was negatively correlated with variation in C4 cycle strength and positively correlated with M chloroplast number per planar cell area. Chloroplast size was negatively correlated with abundance of FtsZ1, FtsZ2 and PARC6 transcripts. These results indicate that natural selection targeted the proteins of the contractile ring assembly to effect the reduction in chloroplast numbers in the M cells of C4 Flaveria species. If so, efforts to engineer the C4 pathway into C3 plants might evaluate whether inducing transcriptome changes similar to those observed in Flaveria could reduce M chloroplast numbers, and thus introduce a trait that appears essential for efficient C4 function.

  2. A HARD GAMMA-RAY FLARE FROM 3C 279 IN 2013 DECEMBER

    SciTech Connect

    Paliya, Vaidehi S.; Stalin, C. S.; Diltz, Chris; Böttcher, Markus; Buckley, David

    2016-01-20

    The blazar 3C 279 exhibited twin γ-ray flares of similar intensity in 2013 December and 2014 April. In this work, we present a detailed multi-wavelength analysis of the 2013 December flaring event. Multi-frequency observations reveal the uncorrelated variability patterns with X-ray and optical–UV fluxes peaking after the γ-ray maximum. The broadband spectral energy distribution (SED) at the peak of the γ-ray activity shows a rising γ-ray spectrum but a declining optical–UV flux. This observation along with the detection of uncorrelated variability behavior rules out the one-zone leptonic emission scenario. We, therefore, adopt two independent methodologies to explain the SED: a time-dependent lepto-hadronic modeling and a two-zone leptonic radiative modeling approach. In the lepto-hadronic modeling, a distribution of electrons and protons subjected to a randomly orientated magnetic field produces synchrotron radiation. Electron synchrotron is used to explain the IR to UV emission while proton synchrotron emission is used to explain the high-energy γ-ray emission. A combination of both electron synchrotron self-Compton emission and proton synchrotron emission is used to explain the X-ray spectral break seen during the later stage of the flare. In the two-zone modeling, we assume a large emission region emitting primarily in IR to X-rays and γ-rays to come primarily from a fast-moving compact emission region. We conclude by noting that within a span of four months, 3C 279 has shown the dominance of a variety of radiative processes over each other and this reflects the complexity involved in understanding the physical properties of blazar jets in general.

  3. Is there any relationship between Toll-like receptor 3 c.1377C/T and -7C/A polymorphisms and susceptibility to Crimean Congo hemorrhagic fever?

    PubMed

    Engin, Aynur; Arslan, Serdal; Özbilüm, Nil; Bakir, Mehmet

    2016-10-01

    Crimean-Congo hemorrhagic fever (CCHF) is an infectious disease that is caused by CCHF virus. A family of transmembrane receptors called as Toll-like receptors (TLRs) selectively acts in recognizing a wide range of microbial components and endogenous molecules released by damaged tissue and have been preserved throughout evolution. TLRs initiate some signaling cascades which activate the innate immune system. Mainly four TLRs act in protection against viral infections; TLR3 is one of them. TLR3 identifies dsRNA. By producing inflammatory cytokines and type I interferons, it generates an antiviral immune response. Proper response to TLR ligands may be impaired by single nucleotide polymorphisms (SNPs) within TLR genes in some indviduals, and this can cause varied susceptibility to infections. In the present work, polymerase chain reaction-based restriction fragment length polymorphism is used to analyze the frequencies of TLR3 (c.1377C/T and -7C/A) polymorphisms in 149 CCHF patients and 171 healthy adults as controls, in Cumhuriyet University, Sivas/Turkey. We also investigated the relation between these polymorphisms and severity or mortality of CCHF disease. This is the first study investigating the TLR3 SNPs in patients with CCHF. In the present study, the frequency of the TLR3 (c.1377C/T and -7A/C) genotypes in fatal and non-fatal cases were comparable, however, the homozygous mutant (TT) genotype frequency of TLR3 c.1377C/T in CCHF patients was significantly higher than that of the healthy controls. In conclusion, presence of TLR3 c.1377 TT genotype may have a role in the susceptibility to CCHF. J. Med. Virol. 88:1690-1696, 2016. © 2016 Wiley Periodicals, Inc.

  4. Constraints on the optical polarization source in the luminous non-blazar quasar 3C 323.1 (PG 1545+210) from the photometric and polarimetric variability

    NASA Astrophysics Data System (ADS)

    Kokubo, Mitsuru

    2017-01-01

    We examine the optical photometric and polarimetric variability of the luminous type 1 non-blazar quasar 3C 323.1 (PG 1545+210). Two optical spectro-polarimetric measurements taken during the periods 1996-98 and 2003 combined with a V-band imaging polarimetric measurement taken in 2002 reveal that (1) as noted in the literature, the polarization of 3C 323.1 is confined only to the continuum emission, that is, the emission from the broad line region is unpolarized; (2) the polarized flux spectra show evidence of a time-variable broad absorption feature in the wavelength range of the Balmer continuum and other recombination lines; (3) weak variability in the polarization position angle (PA) of ˜ 4 deg over a time-scale of 4-6 years is observed; and (4) the V-band total flux and the polarized flux show highly correlated variability over a time-scale of one year. Taking the above-mentioned photometric and polarimetric variability properties and the results from previous studies into consideration, we propose a geometrical model for the polarization source in 3C 323.1, in which an equatorial absorbing region and an axi-asymmetric equatorial electron-scattering region are assumed to be located between the accretion disc and the broad line region. The scattering/absorbing regions can perhaps be attributed to the accretion disc wind or flared disc surface, but further polarimetric monitoring observations for 3C 323.1 and other quasars with continuum-confined polarization are needed to probe the true physical origins of these regions.

  5. DFT studies on the structure and properties of the carbon aluminium Al3C cluster, a pseudohalogen superatom.

    PubMed

    Luo, Qiong

    2012-11-21

    The neutral carbon aluminium cluster Al(3)C and its anion Al(3)C(-) have been investigated at the B3LYP/6-311+G(d) and BP86/6-311+G(d) levels of theory. It is suggested that the C(2v) neutral cluster Al(3)C could be considered as a pseudohalogen superatom with a smaller electron affinity than the iodine atom. The DFT calculation results confirm that, similar to the halogen atoms, the pseudohalogen superatom Al(3)C cluster could form the compounds corresponding to the dimer, salts, interhalogen compounds, oxides, acid radicals, and coordination complexes as well as superatom compounds of halogen, showing that Al(3)C has similar chemical properties to halogens and maintains its integrity in the related reactions. Based on the maintenance of integrity in the chemical assemblies [(Al(3)C)(KCAl(3))(n)](-) (n = 1-5), it could be anticipated that the neutral cluster Al(3)C holds great potential as a building block for the development of future nanostructured materials. Further, corresponding experimental verifications are invited.

  6. Biophysical and Mutational Analysis of the Putative bZIP Domain of Epstein-Barr Virus EBNA 3C

    PubMed Central

    West, Michelle J.; Webb, Helen M.; Sinclair, Alison J.; Woolfson, Derek N.

    2004-01-01

    Epstein-Barr virus nuclear antigen 3C (EBNA 3C) is essential for B-cell immortalization and functions as a regulator of viral and cellular transcription. EBNA 3C contains glutamine-rich and proline-rich domains and a region in the N terminus consisting of a stretch of basic residues followed by a run of leucine residues spaced seven amino acids apart. This N-terminal domain is widely believed to represent a leucine zipper dimerization motif (bZIP). We have performed the first structural and functional analysis of this motif and demonstrated that this domain is not capable of forming stable homodimers. Peptides encompassing the EBNA 3C zipper domain are approximately 54 to 67% α-helical in solution but cannot form dimers at physiologically relevant concentrations. Moreover, the EBNA 3C leucine zipper cannot functionally substitute for another homodimerizing zipper domain in domain-swapping experiments. Our data indicate, however, that the EBNA 3C zipper domain behaves as an atypical bZIP domain and is capable of self-associating to form higher-order α-helical oligomers. Using directed mutagenesis, we also identified a new role for the bZIP domain in maintaining the interaction between EBNA 3C and RBP-Jκ in vivo. Disruption of the helical nature of the zipper domain by the introduction of proline residues reduces the ability of EBNA 3C to inhibit EBNA 2 activation and interact with RBP-Jκ in vivo by 50%, and perturbation of the charge on the basic region completely abolishes this function of EBNA 3C. PMID:15308737

  7. Development of in vitro PIK3C3/VPS34 complex protein assay for autophagy-specific inhibitor screening.

    PubMed

    Kim, Tae-Mi; Baek, Jong-Hyuk; Kim, Jeong Hee; Oh, Myung Sook; Kim, Joungmok

    2015-07-01

    Autophagy is an important catabolic program to respond to a variety of cellular stresses by forming a double membrane vesicle, autophagosome. Autophagy plays key roles in various cellular functions. Accordingly, dysregulation of autophagy is closely associated with diseases such as diabetes, neurodegenerative diseases, cardiomyopathy, and cancer. In this sense, autophagy is emerging as an important therapeutic target for disease control. Among the autophagy machineries, PIK3C3/VPS34 complex functions as an autophagy-triggering kinase to recruit the subsequent autophagy protein machineries on the phagophore membrane. Accumulating evidence showing that inhibition of PIK3C3/VPS34 complex successfully inhibits autophagy makes the complex an attractive target for developing autophagy inhibitors. However, one concern about PIK3C3/VPS34 complex is that many different PIK3C3/VPS34 complexes have distinct cellular functions. In this study, we have developed an in vitro PIK3C3/VPS34 complex monitoring assay for autophagy inhibitor screening in a high-throughput assay format instead of targeting the catalytic activity of the PIK3C3/VPS34 complex, which shuts down all PIK3C3/VPS34 complexes. We performed in vitro reconstitution of an essential autophagy-promoting PIK3C3/VPS34 complex, Vps34-Beclin1-ATG14L complex, in a microwell plate (96-well format) and successfully monitored the complex formation in many different conditions. This PIK3C3/VPS34 complex protein assay would provide a reliable tool for the screening of autophagy-specific inhibitors.

  8. Growth of void-free 3C-SiC films by modified two-step carbonization methods

    NASA Astrophysics Data System (ADS)

    Su, Jianfeng; Niu, Qiang; Tang, Chunjuan; Zhang, Yongsheng; Fu, Zhuxi

    2012-04-01

    Highly preferred orientation 3C-SiC films were deposited on Si (111) substrates by a modified two-step carbonization method. The crystal quality of SiC films were examined by XRD. To evaluate the effect of the introducing of silane during carbonization, cross-sectional SEM was carried out. Results indicated that the introducing of silane during carbonization is effective to prevent the out-diffusion of silicon atoms from silicon substrates. And by adjusting the carbonization conditions, void-free 3C-SiC films were obtained. XPS results demonstrated that the prepared 3C-SiC films were corresponding with the stoichiometric ratio.

  9. From galaxy-scale fueling to nuclear-scale feedback. The merger-state of radio galaxies 3C 293, 3C 305, and 4C 12.50

    NASA Astrophysics Data System (ADS)

    Emonts, B. H. C.; Morganti, R.; Villar-Martín, M.; Hodgson, J.; Brogt, E.; Tadhunter, C. N.; Mahony, E.; Oosterloo, T. A.

    2016-11-01

    Powerful radio galaxies are often associated with gas-rich galaxy mergers. These mergers may provide the fuel to trigger starburst and active galactic nuclear (AGN) activity. In this Research Note, we study the host galaxies of three seemingly young or re-started radio sources that drive fast outflows of cool neutral hydrogen (H i) gas, namely 3C 293, 3C 305 and 4C 12.50 (PKS 1345+12). Our aim is to link the feedback processes in the central kpc-scale region with new information on the distribution of stars and gas at scales of the galaxy. For this, we use deep optical V-band imaging of the host galaxies, complemented with H i emission-line observations to study their gaseous environments. We find prominent optical tidal features in all three radio galaxies, which confirm previous claims that 3C 293, 3C 305, and 4C 12.50 have been involved in a recent galaxy merger or interaction. Our data show the complex morphology of the host galaxies and identify the companion galaxies that are likely involved in the merger or interaction. The radio sources appear to be (re-)triggered at a different stage of the merger; 4C 12.50 is a pre-coalescent and possibly multiple merger, 3C 293 is a post-coalescent merger that is undergoing a minor interaction with a close satellite galaxy, while 3C 305 appears to be shaped by an interaction with a gas-rich companion. For 3C 293 and 3C 305, we do not detect H i beyond the inner 30-45 kpc region, which shows that the bulk of the cold gas is concentrated within the host galaxy, rather than along the widespread tidal features.

  10. STAR-JET INTERACTIONS AND GAMMA-RAY OUTBURSTS FROM 3C454.3

    SciTech Connect

    Khangulyan, D. V.; Bosch-Ramon, V.; Aharonian, F. A.; Dorodnitsyn, A. V.

    2013-09-10

    We propose a model to explain the ultra-bright GeV gamma-ray flares observed from the blazar 3C454.3. The model is based on the concept of a relativistic jet interacting with compact gas condensations produced when a star (a red giant) crosses the jet close to the central black hole. The study includes an analytical treatment of the evolution of the envelope lost by the star within the jet, and calculations of the related high-energy radiation. The model readily explains the day-long that varies on timescales of hours, GeV gamma-ray flare from 3C454.3, observed during 2010 November on top of a plateau lasting weeks. In the proposed scenario, the plateau state is caused by a strong wind generated by the heating of the stellar atmosphere due to nonthermal particles accelerated at the jet-star interaction region. The flare itself could be produced by a few clouds of matter lost by the red giant after the initial impact of the jet. In the framework of the proposed scenario, the observations constrain the key model parameters of the source, including the mass of the central black hole: M{sub BH} {approx_equal} 10{sup 9} M{sub Sun }, the total jet power: L{sub j} {approx_equal} 10{sup 48} erg s{sup -1}, and the Doppler factor of the gamma-ray emitting clouds: {delta} {approx_equal} 20. Whereas we do not specify the particle acceleration mechanisms, the potential gamma-ray production processes are discussed and compared in the context of the proposed model. We argue that synchrotron radiation of protons has certain advantages compared to other radiation channels of directlyaccelerated electrons. An injected proton distribution {proportional_to}E {sup -1} or harder below the relevant energies would be favored to alleviate the tight energetic constraints and to avoid the violation of the observational low-energy constraints.

  11. Star-jet Interactions and Gamma-ray Outbursts from 3C454.3

    NASA Technical Reports Server (NTRS)

    Khangulyan, D. V.; Barkov, M. V.; Bosch-Romon, V.; Aharonian, F. A.; Dorodnitsyn, A. V.

    2013-01-01

    We propose a model to explain the ultra-bright GeV gamma-ray flares observed from the blazar 3C454.3. The model is based on the concept of a relativistic jet interacting with compact gas condensations produced when a star (a red giant) crosses the jet close to the central black hole. The study includes an analytical treatment of the evolution of the envelope lost by the star within the jet, and calculations of the related high-energy radiation. The model readily explains the day-long that varies on timescales of hours, GeV gamma-ray flare from 3C454.3, observed during 2010 November on top of a plateau lasting weeks. In the proposed scenario, the plateau state is caused by a strong wind generated by the heating of the stellar atmosphere due to nonthermal particles accelerated at the jet-star interaction region. The flare itself could be produced by a few clouds of matter lost by the red giant after the initial impact of the jet. In the framework of the proposed scenario, the observations constrain the key model parameters of the source, including the mass of the central black hole: Blackhole Mass is approx. equal to 10(exp 9) Solar Mass, the total jet power: L(j) is approx. equal to 10(exp 48) erg s(exp -1), and the Doppler factor of the gamma-ray emitting clouds: Delta is approx. equal to 20. Whereas we do not specify the particle acceleration mechanisms, the potential gamma-ray production processes are discussed and compared in the context of the proposed model.We argue that synchrotron radiation of protons has certain advantages compared to other radiation channels of directlyaccelerated electrons. An injected proton distribution varies as E(exp -1) or harder below the relevant energies would be favored to alleviate the tight energetic constraints and to avoid the violation of the observational low-energy constraints.

  12. Exploring the nature of the broadband variability in the flat spectrum radio quasar 3C 273

    NASA Astrophysics Data System (ADS)

    Chidiac, C.; Rani, B.; Krichbaum, T. P.; Angelakis, E.; Fuhrmann, L.; Nestoras, I.; Zensus, J. A.; Sievers, A.; Ungerechts, H.; Itoh, R.; Fukazawa, Y.; Uemura, M.; Sasada, M.; Gurwell, M.; Fedorova, E.

    2016-05-01

    The detailed investigation of the broadband flux variability in the blazar 3C 273 allowed us to probe the location and size of emission regions and their physical conditions. We conducted correlation studies of the flaring activity in 3C 273, which was observed for the period between 2008 and 2012. The observed broadband variations were investigated using the structure function and the discrete correlation function methods. Starting from the commonly used power spectral density (PSD) analysis at X-ray frequencies, we extended our investigation to characterise the nature of variability at radio, optical, and γ-ray frequencies. The PSD analysis showed that the optical and infrared light-curve slopes are consistent with the slope of white-noise processes, while the PSD slopes at radio, X-ray, and γ-ray energies are consistent with red-noise processes. We found that the estimated fractional variability amplitudes strongly depend on the observed frequency. The flux variations at γ-ray and mm-radio bands are found to be significantly correlated. Using the estimated time lag of (110 ± 27) days between γ-ray and radio light-curves, where γ-ray variations lead the radio bands, we constrained the location of the γ-ray emission region at a de-projected distance of 1.2 ± 0.9 pc from the jet apex. Flux variations at X-ray bands were found to have a significant correlation with variations at both radio and γ-ray energies. The correlation between X-ray and γ-ray light curves indicates two possible time lags, which suggests that two components are responsible for the X-ray emission. A negative time lag of -(50 ± 20) days, where the X-rays are leading the emission, suggests that X-rays are emitted closer to the jet apex from a compact region (0.02-0.05 pc in size), most likely from the corona at a distance of (0.5 ± 0.4) pc from the jet apex. A positive time lag of (110 ± 20) days (γ-rays are leading the emission) suggests a jet-base origin of the other X

  13. 3C 220.3: A Radio Galaxy Lensing a Submillimeter Galaxy

    NASA Astrophysics Data System (ADS)

    Haas, Martin; Leipski, Christian; Barthel, Peter; Wilkes, Belinda J.; Vegetti, Simona; Bussmann, R. Shane; Willner, S. P.; Westhues, Christian; Ashby, Matthew L. N.; Chini, Rolf; Clements, David L.; Fassnacht, Christopher D.; Horesh, Assaf; Klaas, Ulrich; Koopmans, Léon V. E.; Kuraszkiewicz, Joanna; Lagattuta, David J.; Meisenheimer, Klaus; Stern, Daniel; Wylezalek, Dominika

    2014-07-01

    Herschel Space Observatory photometry and extensive multiwavelength follow-up have revealed that the powerful radio galaxy (PRG) 3C 220.3 at z = 0.685 acts as a gravitational lens for a background submillimeter galaxy (SMG) at z = 2.221. At an observed wavelength of 1 mm, the SMG is lensed into three distinct images. In the observed near infrared, these images are connected by an arc of ~1''.8 radius forming an Einstein half-ring centered near the radio galaxy. In visible light, only the arc is apparent. 3C 220.3 is the only known instance of strong galaxy-scale lensing by a PRG not located in a galaxy cluster and therefore it offers the potential to probe the dark matter content of the radio galaxy host. Lens modeling rejects a single lens, but two lenses centered on the radio galaxy host A and a companion B, separated by 1''.5, provide a fit consistent with all data and reveal faint candidates for the predicted fourth and fifth images. The model does not require an extended common dark matter halo, consistent with the absence of extended bright X-ray emission on our Chandra image. The projected dark matter fractions within the Einstein radii of A (1''.02) and B (0''.61) are about 0.4 ± 0.3 and 0.55 ± 0.3. The mass to i-band light ratios of A and B, M/Li ˜ 8 +/- 4 M⊙ L⊙ -1, appear comparable to those of radio-quiet lensing galaxies at the same redshift in the CfA-Arizona Space Telescope LEns Survey, Lenses Structure and Dynamics, and Strong Lenses in the Legacy Survey samples. The lensed SMG is extremely bright with observed f(250 μm) = 440 mJy owing to a magnification factor μ ~ 10. The SMG spectrum shows luminous, narrow C IV λ1549 Å emission, revealing that the SMG houses a hidden quasar in addition to a violent starburst. Multicolor image reconstruction of the SMG indicates a bipolar morphology of the emitted ultraviolet (UV) light suggestive of cones through which UV light escapes a dust-enshrouded nucleus.

  14. Epigenetic Regulation of Placental NR3C1: Mechanism Underlying Prenatal Programming of Infant Neurobehavior by Maternal Smoking?

    PubMed Central

    Stroud, Laura R.; Papandonatos, George D.; Salisbury, Amy L.; Phipps, Maureen G.; Huestis, Marilyn A.; Niaura, Raymond; Padbury, James F.; Marsit, Carmen; Lester, Barry

    2015-01-01

    Epigenetic regulation of the placental glucocorticoid receptor gene (NR3C1) was investigated as a mechanism underlying links between maternal smoking during pregnancy (MSDP) and infant neurobehavior in 45 mother-infant pairs (49% MSDP-exposed; 52% minorities; ages 18-35). The NICU Network Neurobehavioral Scale was administered 7 times over the first postnatal month; methylation of placental NR3C1 was assessed via bisulfite pyrosequencing. Increased placental NR3C1 methylation was associated with increased infant attention and self-regulation, and decreased lethargy and need for examiner soothing over the first postnatal month. A causal steps approach revealed that NR3C1 methylation and MSDP were independently associated with lethargic behavior. Although preliminary, results highlight the importance of epigenetic mechanisms in elucidating pathways to neurobehavioral alterations from MSDP. PMID:26822442

  15. Effect of Synthesis on Quality, Electronic Properties and Environmental Stability of Individual monolayer Ti3C2 MXene Flakes

    DOE PAGES

    Lipatov, A.; Alhabeb, M.; Lukatskaya, Maria R.; ...

    2016-01-01

    2D transition metal carbide Ti3C2Tx (T stands for surface termination), the most widely studied MXene, has shown outstanding electrochemical properties and promise for a number of bulk applications. However, electronic properties of individual MXene flakes, which are important for understanding the potential of these materials, remain largely unexplored. Herein, a modified synthetic method is reported for producing high-quality monolayer Ti3C2Tx flakes. Field-effect transistors (FETs) based on monolayer Ti3C2Tx flakes are fabricated and their electronic properties are measured. Individual Ti3C2Tx flakes exhibit a high conductivity of 4600 ± 1100 S cm-1 and field-effect electron mobility of 2.6 ± 0.7 cm2 V-1more » s-1. The resistivity of multilayer Ti3C2Tx films is only one order of magnitude higher than the resistivity of individual flakes, which indicates a surprisingly good electron transport through the surface terminations of different flakes, unlike in many other 2D materials. Finally, the fabricated FETs are used to investigate the environmental stability and kinetics of oxidation of Ti3C2Tx flakes in humid air. The high-quality Ti3C2Tx flakes are reasonably stable and remain highly conductive even after their exposure to air for more than 24 h. It is demonstrated that after the initial exponential decay the conductivity of Ti3C2Tx flakes linearly decreases with time, which is consistent with their edge oxidation.« less

  16. Information literacy in an inquiry course for first-year science undergraduates: a simplified 3C approach.

    PubMed

    Rangachari, P K; Rangachari, Usha

    2007-06-01

    In this article, we describe a simplified approach to teach students to assess information obtained from diverse sources. Three broad categories (credibility, content, and currency; 3C) were used to evaluate information from textbooks, monographs, popular magazines, scholarly journals, and the World Wide Web. This 3C approach used in an inquiry course for freshmen in an undergraduate science program can be readily transferred to other settings.

  17. Synthesis of new class of alkyl azarene pyridinium zwitterions via iodine mediated sp3 C-H bond activation.

    PubMed

    Kumar, Atul; Gupta, Garima; Srivastava, Suman

    2011-12-16

    An efficient and conceptually different approach toward C-H bond activation by using iodine mediated sp(3) C-H functionalization for the synthesis of alkyl azaarene pyridinium zwitterions is described. This work has the interesting distinction of being the first synthesis of a new class of alkyl azaarene pyridinium zwitterion via transition-metal-free sp(3) C-H bond activation of an alkyl azaarene.

  18. Epstein-Barr virus nuclear antigen 3C targets p53 and modulates its transcriptional and apoptotic activities

    SciTech Connect

    Yi Fuming; Saha, Abhik; Murakami, Masanao; Kumar, Pankaj; Knight, Jason S.; Cai Qiliang; Choudhuri, Tathagata; Robertson, Erle S.

    2009-06-05

    The p53 tumor suppressor gene is one of the most commonly mutated genes in human cancers and the corresponding encoded protein induces apoptosis or cell-cycle arrest at the G1/S checkpoint in response to DNA damage. To date, previous studies have shown that antigens encoded by human tumor viruses such as SV40 large T antigen, adenovirus E1A and HPV E6 interact with p53 and disrupt its functional activity. In a similar fashion, we now show that EBNA3C, one of the EBV latent antigens essential for the B-cell immortalization in vitro, interacts directly with p53. Additionally, we mapped the interaction of EBNA3C with p53 to the C-terminal DNA-binding and the tetramerization domain of p53, and the region of EBNA3C responsible for binding to p53 was mapped to the N-terminal domain of EBNA3C (residues 130-190), previously shown to interact with a number of important cell-cycle components, specifically SCF{sup Skp2}, cyclin A, and cMyc. Furthermore, we demonstrate that EBNA3C substantially represses the transcriptional activity of p53 in luciferase based reporter assays, and rescues apoptosis induced by ectopic p53 expression in SAOS-2 (p53{sup -/-}) cells. Interestingly, we also show that the DNA-binding ability of p53 is diminished in the presence of EBNA3C. Thus, the interaction between the p53 and EBNA3C provides new insights into the mechanism(s) by which the EBNA3C oncoprotein can alter cellular gene expression in EBV associated human cancers.

  19. Investigation of the transition layer in 3C-SiC/6H-SiC heterostructures

    SciTech Connect

    Lebedev, A. A.; Zamorianskaya, M. V.; Davydov, S. Yu.; Kirilenko, D. A.; Lebedev, S. P. Sorokin, L. M.; Shustov, D. B.; Scheglov, M. P.

    2013-11-15

    Transmission electron microscopy and the cathodoluminescence method are used to study the transition region in 3C-SiC/6H-SiC heterostructures. It is shown that this region is, as a rule, constituted by alternating 3C-SiC and 6H-SiC layers with the possible inclusion of other silicon carbide polytypes. An assumption is made that this structure of the transition region can be explained in terms of the model of spinodal decomposition.

  20. High temperature energy harvesters utilizing ALN/3C-SiC composite diaphragms

    NASA Astrophysics Data System (ADS)

    Lai, Yun-Ju; Li, Wei-Chang; Felmetsger, Valery V.; Senesky, Debbie G.; Pisano, Albert P.

    2014-06-01

    Microelectromechanical systems (MEMS) energy harvesting devices aiming at powering wireless sensor systems for structural health monitoring in harsh environments are presented. For harsh environment wireless sensor systems, sensor modules are required to operate at elevated temperatures (> 250°C) with capabilities to resist harsh chemical conditions, thereby the use of battery-based power sources becomes challenging and not economically efficient if considering the required maintenance efforts. To address this issue, energy harvesting technology is proposed to replace batteries and provide a sustainable power source for the sensor systems towards autonomous harsh environment wireless sensor networks. In particular, this work demonstrates a micromachined aluminum nitride/cubic silicon carbide (AlN/3C-SiC) composite diaphragm energy harvester, which enables high temperature energy harvesting from ambient pulsed pressure sources. The fabricated device yields an output power density of 87 μW/cm2 under 1.48-psi pressure pulses at 1 kHz while connected to a 14.6-kΩ load resistor. The effects of pulse profile on output voltage have been studied, showing that the output voltage can be maximized by optimizing the diaphragm resonance frequency based on specific pulse characteristics. In addition, temperature dependence of the diaphragm resonance frequency over the range of 20°C to 600°C has been investigated and the device operation at temperatures as high as 600°C has been verified.

  1. RADIO GALAXY 3C 230 OBSERVED WITH GEMINI LASER ADAPTIVE-OPTICS INTEGRAL-FIELD SPECTROSCOPY

    SciTech Connect

    Steinbring, Eric

    2011-11-15

    The Altair laser-guide-star adaptive optics facility combined with the near-infrared integral-field spectrometer on Gemini North have been employed to study the morphology and kinematics of 3C 230 at z = 1.5, the first such observations of a high-redshift radio galaxy. These suggest a bi-polar outflow spanning 0.''9 ({approx}16 kpc projected distance for a standard {Lambda} CDM cosmology) reaching a mean relative velocity of 235 km s{sup -1} in redshifted H{alpha} +[N II] and [S II] emission. Structure is resolved to 0.''1 (0.8 kpc), which is well correlated with optical images from the Hubble Space Telescope and Very Large Array radio maps obtained at similar spatial resolution. Line diagnostics suggest that over the 10{sup 7} yr to 10{sup 8} yr duration of its active galactic nucleus activity, gas has been ejected into bright turbulent lobes at rates comparable to star formation, although constituting perhaps only 1% of the baryonic mass in the galaxy.

  2. Active region of the nucleus of the blazar 3C 454.3

    NASA Astrophysics Data System (ADS)

    Matveyenko, L. I.; Sivakon', S. S.

    2016-10-01

    The superfine structure of the object 3C 454.3 has been investigated at λ = 7 mm in polarized emission. The kinematics of the structure is shown to correspond to a vortex. A spiral structure like an Archimedes spiral has been established in the accretion disk. The orbital velocity of the inflow exceeds considerably the radial velocity. The disk is oriented in the plane of the sky. The bipolar outflow ejection axis is directed toward the observer with a slight inclination to the east. The jet sizes exceed considerably the counterjet sizes. The jet is ejected in a direction opposite to the observer; its apparent separation from the nozzle is determined by the disk shadowing. The counterjet is directed toward the observer; the flow brightness temperature at the exit from the nozzle reaches T b ≈ 1015 K. The jet has a spiral shape with an increasing pitch; the counterjet is a mirror reflection of the initial part of the jet. The incoming thermal plasma is accelerated and heated to relativistic temperatures as it is transferred along a spiral to the center. The orientation of the emission polarization plane changes along the flows due to a change in the ratio of the orbital and radial velocities, a change in the magnetic field orientation.

  3. Connection Between X-Ray Dips and Superluminal Ejections in the Radio Galaxy 3C 120

    NASA Technical Reports Server (NTRS)

    Aller, Margo F.

    2005-01-01

    This work represents a part of a long-term study of the X-ray flux variability of 3C 120 and its relation to flux and structural changes in the radio jet of this galaxy. The grant included fiinding for the rediiction and analysis of data obt,ained during the time pwiod of Rossi XTE cycle 8 (March 1, 2003-February 29, 2004). Prior RXTE observations, combined with single dish monitoring at centimeter wavelengths and 43 GHz mapping (monthly until February 1999 and bimonthly thereafter) of the inner jet with the VLBA, had identified the presence of X-ray dips in the light curves and X-ray spectral hardening 4 weeks prior to the ejection of new VLBI components in the radio jet. This suggested a picture in which the radio jet was fed by accretion events near the black hole. The specific goals of the cycle 8 observations were to better define the relation between the X-ray dips and the radio events using higher sampling, to include more events in the correlation and hence improve the statistics, to look for a possible optical X-ray connection, and to search for quasi periodicities on timescales of 1-3 days. In cycle 8 this project was awarded time for 4 pointings weekly with RXTE.

  4. MULTI-EPOCH OBSERVATIONS OF THE RED WING EXCESS IN THE SPECTRUM OF 3C 279

    SciTech Connect

    Punsly, Brian E-mail: brian.punsly@comdev-usa.com

    2013-01-10

    It has been previously determined that there is a highly significant correlation between the spectral index from 10 GHz to 1350 A and the amount of excess luminosity in the red wing of quasar C IV {lambda}1549 broad emission lines (BELs). Ostensibly, the prominence of the red excess is associated with the radio jet emission mechanism and is most pronounced for lines of sight close to the jet axis. Studying the scant significant differences in the UV spectra of radio-loud and radio-quiet quasars might provide vital clues to the origin of the unknown process that creates powerful relativistic jets that appear in only about 10% of quasars. In this study, the phenomenon is explored with multi-epoch observations of the Mg II {lambda}2798 broad line in 3C 279 which has one of the largest known red wing excesses in a quasar spectrum. The amount of excess that is detected appears to be independent of all directly observed optical continuum, radio, or submillimeter properties (fluxes or polarizations). The only trend that occurs in this sparse data is: the stronger the BEL, the larger the fraction of flux that resides in the red wing. It is concluded that more monitoring is needed and spectropolarimetry with a large telescope is essential during low states to understand more.

  5. H i Absorption in the Steep-Spectrum Superluminal Quasar 3C 216.

    PubMed

    Pihlström; Vermeulen; Taylor; Conway

    1999-11-01

    The search for H i absorption in strong compact steep-spectrum sources is a natural way to probe the neutral gas contents in young radio sources. In turn, this may provide information about the evolution of powerful radio sources. The recently improved capabilities of the Westerbork Synthesis Radio Telescope have made it possible to detect a 0.31% (19 mJy) deep neutral atomic hydrogen absorption line associated with the steep-spectrum superluminal quasar 3C 216. The redshift (z=0.67) of the source shifts the frequency of the 21 cm line down to the ultra-high-frequency (UHF) band (850 MHz). The exact location of the H i-absorbing gas remains to be determined by spectral line VLBI observations at 850 MHz. We cannot exclude that the gas might be extended on galactic scales, but we think it is more likely to be located in the central kiloparsec. Constraints from the lack of X-ray absorption probably rule out obscuration of the core region, and we argue that the most plausible site for the H i absorption is in the jet-cloud interaction observed in this source.

  6. Chandra Detection of a Pulsar Wind Nebula Associated With Supernova Remnant 3C 396

    NASA Technical Reports Server (NTRS)

    Olbert, C. M.; Keohane, J. W.; Arnaud, K. A.; Dyer, K. K.; Reynolds, S. P.; Safi-Harb, S.

    2003-01-01

    We present a 100 ks observation of the Galactic supernova remnant 3C396 (G39.2-0.3) with the Chandra X-Ray Observatory that we compare to a 20cm map of the remnant from the Very Large Array. In the Chandra images, a nonthermal nebula containing an embedded pointlike source is apparent near the center of the remnant which we interpret as a synchrotron pulsar wind nebula surrounding a yet undetected pulsar. From the 2-10 keV spectrum for the nebula (N(sub H) = 5.3 plus or minus 0.9 x 10(exp 22) per square centimeter, GAMMA =1.5 plus or minus 0.3) we derive an unabsorbed x-ray flux of S(sub z)=1.62 x 10(exp -12) erg per square centimeter per second, and from this we estimate the spin-down power of the neutron star to be E(sup dot) = 7.2 x 10(exp 36) ergs per second. The central nebula is morphologically complex, showing bent, extended structure. The radio and X-ray shells of the remnant correlate poorly on large scales, particularly on the eastern half of the remnant, which appears very faint in X-ray images. At both radio and X-ray wavelengths the western half of the remnant is substantially brighter than the east.

  7. Atomistic Study of Intrinsic Defect Migration in 3C-SiC

    SciTech Connect

    Gao, Fei; Weber, William J.; Posselt, Matthias; Belko, V

    2004-06-25

    Atomic-scale computer simulations, both molecular dynamics (MD) and the nudged-elastic band method, have been applied to investigate long-range migration of point defects in 3C-SiC over the temperature range from 0.36 to 0.95 Tm (melting temperature). A wide set of diffusion characteristics has been obtained, including the self-diffusion coefficient, activation energy and defect correlation factor. Stable C split interstitials can migrate via the first or second neighbor sites, but the relative probability for the later mechanism is very low. Si interstitials migrate directly from one tetrahedral position to another neighboring equivalent position by a kick-in/kick-out process via a split interstitial configuration. Both C and Si vacancies jump to one of their equivalent sites through a direct migration mechanism. The migration energies obtained for C and Si interstitials are consistent with those obtained experimentally for the recovery processes in irradiated SiC. Also, energy barriers for C interstitial and vacancy diffusion are in reasonable agreement with ab initio data.

  8. Atomic Computer Simulations of Defect Migration in 3C and 4H-SiC

    SciTech Connect

    Gao, Fei; Weber, William J.; Posselt, Matthias; Belko, V

    2004-05-19

    Knowledge of the migration of intrinsic point defects is crucial to understand defect recovery, various annealing stages and microstructural evolution after irradiation or ion implantation. Molecular dynamics (MD) and the nudged-elastic band method have been applied to investigate long-range migration of point defects in SiC over the temperature range from 0.36 to 0.95 Tm , and the defect diffusion coefficient, activation energy and defect correlation factor have been determined. The results show that the activation energies for C and Si interstitials in 3C-SiC are about 0.74 and 1.53 eV, respectively, while it is about 0.77 eV for a C interstitial in 4H-SiC. The minima energy paths reveal that the activation energies for C and Si vacancies are about 4.1 and 2.35 eV, respectively. Finally, the results are discussed and compared with experimental observations and available ab initio data.

  9. ALMA Science Verification Data: Millimeter Continuum Polarimetry of the Bright Radio Quasar 3C 286

    NASA Astrophysics Data System (ADS)

    Nagai, H.; Nakanishi, K.; Paladino, R.; Hull, C. L. H.; Cortes, P.; Moellenbrock, G.; Fomalont, E.; Asada, K.; Hada, K.

    2016-06-01

    We present full-polarization observations of the compact, steep-spectrum radio quasar 3C 286 made with the Atacama Large Millimeter and Submillimeter Array (ALMA) at 1.3 mm. These are the first full-polarization ALMA observations, which were obtained in the framework of Science Verification. A bright core and a south-west component are detected in the total intensity image, similar to previous centimeter images. Polarized emission is also detected toward both components. The fractional polarization of the core is about 17%; this is higher than the fractional polarization at centimeter wavelengths, suggesting that the magnetic field is even more ordered in the millimeter radio core than it is further downstream in the jet. The observed polarization position angle (or electric vector position angle (EVPA)) in the core is ˜39◦, which confirms the trend that the EVPA slowly increases from centimeter to millimeter wavelengths. With the aid of multi-frequency VLBI observations, we argue that this EVPA change is associated with the frequency-dependent core position. We also report a serendipitous detection of a sub-mJy source in the field of view, which is likely to be a submillimeter galaxy.

  10. Roles of the Picornaviral 3C Proteinase in the Viral Life Cycle and Host Cells

    PubMed Central

    Sun, Di; Chen, Shun; Cheng, Anchun; Wang, Mingshu

    2016-01-01

    The Picornaviridae family comprises a large group of non-enveloped viruses that have a major impact on human and veterinary health. The viral genome contains one open reading frame encoding a single polyprotein that can be processed by viral proteinases. The crucial 3C proteinases (3Cpros) of picornaviruses share similar spatial structures and it is becoming apparent that 3Cpro plays a significant role in the viral life cycle and virus host interaction. Importantly, the proteinase and RNA-binding activity of 3Cpro are involved in viral polyprotein processing and the initiation of viral RNA synthesis. In addition, 3Cpro can induce the cleavage of certain cellular factors required for transcription, translation and nucleocytoplasmic trafficking to modulate cell physiology for viral replication. Due to interactions between 3Cpro and these essential factors, 3Cpro is also involved in viral pathogenesis to support efficient infection. Furthermore, based on the structural conservation, the development of irreversible inhibitors and discovery of non-covalent inhibitors for 3Cpro are ongoing and a better understanding of the roles played by 3Cpro may provide insights into the development of potential antiviral treatments. In this review, the current knowledge regarding the structural features, multiple functions in the viral life cycle, pathogen host interaction, and development of antiviral compounds for 3Cpro is summarized. PMID:26999188

  11. Systems Analysis of an Advanced Nuclear Fuel Cycle Based on a Modified UREX+3c Process

    SciTech Connect

    E. R. Johnson; R. E. Best

    2009-12-28

    The research described in this report was performed under a grant from the U.S. Department of Energy (DOE) to describe and compare the merits of two advanced alternative nuclear fuel cycles -- named by this study as the “UREX+3c fuel cycle” and the “Alternative Fuel Cycle” (AFC). Both fuel cycles were assumed to support 100 1,000 MWe light water reactor (LWR) nuclear power plants operating over the period 2020 through 2100, and the fast reactors (FRs) necessary to burn the plutonium and minor actinides generated by the LWRs. Reprocessing in both fuel cycles is assumed to be based on the UREX+3c process reported in earlier work by the DOE. Conceptually, the UREX+3c process provides nearly complete separation of the various components of spent nuclear fuel in order to enable recycle of reusable nuclear materials, and the storage, conversion, transmutation and/or disposal of other recovered components. Output of the process contains substantially all of the plutonium, which is recovered as a 5:1 uranium/plutonium mixture, in order to discourage plutonium diversion. Mixed oxide (MOX) fuel for recycle in LWRs is made using this 5:1 U/Pu mixture plus appropriate makeup uranium. A second process output contains all of the recovered uranium except the uranium in the 5:1 U/Pu mixture. The several other process outputs are various waste streams, including a stream of minor actinides that are stored until they are consumed in future FRs. For this study, the UREX+3c fuel cycle is assumed to recycle only the 5:1 U/Pu mixture to be used in LWR MOX fuel and to use depleted uranium (tails) for the makeup uranium. This fuel cycle is assumed not to use the recovered uranium output stream but to discard it instead. On the other hand, the AFC is assumed to recycle both the 5:1 U/Pu mixture and all of the recovered uranium. In this case, the recovered uranium is reenriched with the level of enrichment being determined by the amount of recovered plutonium and the combined amount

  12. An XMM-Newton view of the radio galaxy 3C 411

    SciTech Connect

    Bostrom, Allison; Reynolds, Christopher S.; Tombesi, Francesco

    2014-08-20

    We present the first high signal-to-noise XMM-Newton observations of the broad-line radio galaxy 3C 411. After fitting various spectral models, an absorbed double power-law (PL) continuum and a blurred relativistic disk reflection model (kdblur) are found to be equally plausible descriptions of the data. While the softer PL component (Γ = 2.11) of the double PL model is entirely consistent with that found in Seyfert galaxies (and hence likely originates from a disk corona), the additional PL component is very hard (Γ = 1.05); amongst the active galactic nucleus zoo, only flat-spectrum radio quasars (FSRQ) have such hard spectra. Together with the flat radio-spectrum displayed by this source, we suggest that it should instead be classified as an FSRQ. This leads to potential discrepancies regarding the jet inclination angle, with the radio morphology suggesting a large jet inclination but the FSRQ classification suggesting small inclinations. The kdblur model predicts an inner disk radius of at most 20 r {sub g} and relativistic reflection.

  13. The X-ray emission of 3C 273 observed with ASCA

    NASA Technical Reports Server (NTRS)

    Yaqoob, Tahir; Serlemitsos, Peter; Mushotzky, Richard; Ricker, George; Woo, Jonathan; Weaver, Kim; Kii, Tsuneo; Mitsuda, Kazuhisa; Kotani, Taro; Hayashida, Kiyoshi

    1994-01-01

    We report preliminary results of an Advanced Satellite for Cosmology and Astrophysics (ASCA) observation of 3C 273. There is no spectral variability within the ASCA observation, in contrast to the longer term behavior found with European X-ray Observatory Satellite (EXOSAT) and Ginga which established significant changes in the spectral index of the power-law continuum on timescales of a week or more, uncorrelated with luminosity. Comparison of the ASCA data with a simultaneous Roentgen Satellite (ROSAT) Ginga observation in 1990 December shows that while the shape of the spectrum above approximately 1 keV is essentially the same, the flux in the soft component, below approximately 1 keV, considerably weaker relative to the hard component in the ASCA observation. The 2-10 keV luminosity is at least a factor of approximately 1.5 greater in the ASCA observation than in the ROSAT/Ginga observation while the ratio of 2-10 keV luminosity to 0.4-1.0 keV luminosity increases by a factor of approximately 1.2. Thus the spectral shape of the hard component appears to be independent of the relative magnitude of the soft component and is an important constraint on emission and reprocessing models. We find no significant Fe K line-emission in this observation. The data also highlight very well some of the outstanding problems in the instrumental responses.

  14. MXene Ti3C2: An Effective 2D Light-to-Heat Conversion Material.

    PubMed

    Li, Renyuan; Zhang, Lianbin; Shi, Le; Wang, Peng

    2017-03-29

    MXene, a new series of 2D material, has been steadily advancing its applications to a variety of fields, such as catalysis, supercapacitor, molecular separation, electromagnetic wave interference shielding. This work reports a carefully designed aqueous droplet light heating system along with a thorough mathematical procedure, which combined leads to a precise determination of internal light-to-heat conversion efficiency of a variety of nanomaterials. The internal light-to-heat conversion efficiency of MXene, more specifically Ti3C2, was measured to be 100%, indicating a perfect energy conversion. Furthermore, a self-floating MXene thin membrane was prepared by simple vacuum filtration and the membrane, in the presence of a rationally chosen heat barrier, produced a light-to-water-evaporation efficiency of 84% under one sun irradiation, which is among the state of art energy efficiency for similar photothermal evaporation system. The outstanding internal light-to-heat conversion efficiency and great light-to-water evaporation efficiency reported in this work suggest that MXene is a very promising light-to-heat conversion material and thus deserves more research attention toward practical applications.

  15. Modelling the multi-wavelength emission of flat-spectrum radio quasar 3C 279

    NASA Astrophysics Data System (ADS)

    Zheng, Y. G.; Yang, C. Y.

    2016-04-01

    We employ a length-dependent conical jet model for the jet structure and emission properties of flat-spectrum radio quasar 3C 279 in the steady state. In the model, ultra-relativistic leptons are injected at the base of the jet and propagate along the jet structure. Non-thermal photons are produced by both synchrotron emission and inverse Compton scattering off synchrotron photons and external soft photons at each segment of the jet. We derive the total energy spectra contribution through integrating every segment. We apply the model to the quasi-simultaneous multi-wavelength observed data of two quiescent epochs. Using the observed radio data of the source, we determine the length of the jet L ˜ 100 pc and the magnetic field B0 ˜ 0.1-1 G at the base of the jet. Assuming a steady geometry of the jet structure and suitable physical parameters, we reproduce the multi-wavelength spectra during two quiescent observed epochs. Our results show that the initial γ-ray emission site is ˜0.5 pc from the black hole.

  16. Structure of the X-Ray Emission from the Jet of 3C 273

    NASA Technical Reports Server (NTRS)

    Marshall, H. L.; Lee, J. C.; Ogle, P. M.; Drake, J. J.; Fruscione, A.; Grimes, J.; Harris, D.; Kraft, R.; Pease, D.; Schwartz, D.; Siemiginowska, A.; Lavoie, Anthony R. (Technical Monitor)

    2000-01-01

    We present images from four Chandra observations of the quasar 3C 273. The zeroth order images from two grating observations using the AXAF CCD Imaging Spectrometer (ACIS-S) detector are used to examine the structure and spectrum of the jet. The jet has at least four distinct features which are not resolved in previous observations. Using jet feature nomenclature based on HST observations, we find that knot Al is very bright in X-rays. We have measured the X-ray spectrum of this X-ray knot for the first time, obtaining a photon index of 1.36 +/- 0.11 and a flux density of 37 +/- 4 nJy at 1 keV. Combining this measurement with lower frequency data shows that a pure synchrotron model can fit the spectrum of knot Al from 4 GHz to 5 keV (over nine decades in energy) without a change of spectral slope. Knot A2 is also detected and is somewhat blended with knot B1 but synchrotron emission is not likely to explain the X-ray emission due to the spectral turnover observed in the optical-UV band. No other knots are clearly detected but there is an indication of weak emission from the eastern portion of knot H3. near the "head," which is radio-bright. There is diffuse flux which extends from 14 arcsec to 20 arcsec which shows curvature that is comparable to the optical flux found by Bahcall, et al.

  17. Detection of Ne VIII in an Intervening Multiphase Absorption System Toward 3C 263

    NASA Astrophysics Data System (ADS)

    Narayanan, Anand; Wakker, Bart P.; Savage, Blair D.

    2009-09-01

    We report the detection of Ne VIII in an intervening multiphase absorption line system at z = 0.32566 in the Far Ultraviolet Spectroscopic Explorer spectrum of the quasar 3C 263 (zem = 0.646). The Ne VIII λ770 Å detection has a 3.9σ significance. At the same velocity, we also find absorption lines from C IV, O III, O IV, and N IV. The line parameter measurements yield log [N(Ne VIII) cm-2] = 13.98+0.10 -0.13 and b = 49.8 ± 5.5 km s-1. We find that the ionization mechanism in the gas phase giving rise to the Ne VIII absorption is inconsistent with photoionization. The absorber has a multiphase structure, with the intermediate ions produced in cool photoionized gas and the Ne VIII most likely in a warm collisionally ionized medium in the temperature range (0.5-1.0) × 106 K. This is the second ever detection of an intervening Ne VIII absorption system. Its properties resemble the previous Ne VIII absorber reported by Savage and colleagues. Direct observations of H I and O VI are needed to better constrain the physical conditions in the collisionally ionized gas phase of this absorber. Based on observations with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer operated by Johns Hopkins University, supported by NASA contract NAS5-32985.

  18. Multifrequency observation of the optically violent variable quasar 3C 446

    NASA Technical Reports Server (NTRS)

    Bregman, Joel N.; Glassgold, A. E.; Huggins, P. J.; Kinney, A. L.; Mchardy, I.

    1988-01-01

    Nearly 20 years of optical and radio monitoring data as well as seven multifrequency spectra of the violently variable quasar 3C 446 are reported. The monitoring data suggest a correlation between the radio and optical outbursts, with the optical flare preceding the radio activity by 400-600 days. Considerable processing occurs in the optical-emitting plasma before it becomes radio-emitting plasma. Within the radio band, outbursts proceed from high to low frequencies. The flat radio spectrum turns over at 3-10 x 10 to the 11th Hz and the continuum steepens with frequency. The X-ray emission lies an order of magnitude above an extrapolation of the optical-UV spectrum and has a harder spectrum. The power is primarily concentrated in the submillimeter and infrared region. The data suggest that the X-rays are produced by the inverse Compton process from an emitting region smaller than but related to the synchrotron-emitting UV-IR region. The characteristic size of the emitting region increases with decreasing frequency.

  19. X-ray and Radio Observations of the Jet--environment Interaction in 3C 123

    NASA Astrophysics Data System (ADS)

    Harrison, Sarah; Evans, D.; Lee, J.

    2007-12-01

    We present a 46.7 ks Chandra observation of the hot intracluster gas associated with the radio galaxy 3C 123, in order to study the energetics of the interaction between the large-scale radio jets emitted from the AGN and the gaseous, X-ray-emitting ICM. We observe large-scale asymmetries in the gas distribution out to 100'' together with smaller scale variations on scales of 20-30''. While gas temperatures on the large scale are well-described by an APEC model with temperature 8 keV, temperatures of the small-scale gaseous regions are described by a similar model with temperature 3 keV. We find that the significant overdensities and underdensities of the intracluster gas on large and small scales are caused by different processes. We calculate the "bubble” enthalpy of a small-scale eastern cavity to be 3 × 1059 ergs per bubble evacuated. We observe a corresponding overdense region which has the same enthalpy in pressure equilibrium with this cavity. We also find that the black hole accretion rate required to evacuate this region is R = 0.05Msunyear-1 per bubble. Our results support the interpretation that there is a large-scale disturbance from equilibrium most likely due to "sloshing” of gas caused by the impact of a subcluster merger, whereas on small scales, the radio outbursts from the AGN have created cavities within the X-ray--emitting gas.

  20. Time variability in the gamma-ray emission of 3C 279

    NASA Technical Reports Server (NTRS)

    Kniffen, D. A.; Bertsch, D. L.; Fichtel, C. E.; Hatman, R. C.; Hunter, S. D.; Kanbach, G.; Kwok, P. W.; Lin, Y. C.; Mattox, J. R.; Mayer-Hasselwander, H. A.

    1993-01-01

    Following the initial detection of 3C 279 as an intense high-energy gamma-ray emitter during a 1991, June 16-28 observation, the EGRET instrument on the Compton Gamma Ray Observatory made a second observation during 1991, October 3-17. Low-sensitivity observations were also made during 1991, October 12-31 and 1992 April. The relatively intense June fluxes allowed the time structure to be determined down to the level of half-days. During this period a flux enhancement of about a factor of 4 is seen, lasting several days. The October exposures show fluxes somewhat below the minimum June flux, with no significant evidence of time variability. The 1992 April fluxes are well off the main instrument axis, and so the statistics are less compelling, but the evidence appears to show additional time variability. The observations are consistent with a model in which the gamma rays result from Compton scattering of low-energy photons by relativistic electrons in a jet.

  1. The solar flare of the 14th of July 2000 (L3+C detector results)

    NASA Astrophysics Data System (ADS)

    Achard, P.; Adrian, O.; Aguilar-Benitez, M.; van den Akker, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M. G.; Anderhub, H.; Andreev, V. P.; Anselmo, F.; Arefiev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Bähr, J.; Baldew, S. V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillère, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J. J.; Blyth, S. C.; Bobbink, G. J.; Böhm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brochu, F.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chiarusi, T.; Chang, Y. H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; de Asmundis, R.; Déglon, P.; Debreczeni, J.; Degré, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Ding, L. K.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M. T.; Duchesneau, D.; Duda, M.; Duran, I.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F. J.; Extermann, P.; Faber, G.; Falagan, M. A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher, W.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Yu.; Ganguli, S. N.; Garcia-Abia, P.; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z. F.; Grabosch, H. J.; Grenier, G.; Grimm, O.; Groenstege, H.; Gruenewald, M. W.; Guida, M.; Guo, Y. N.; Gupta, S. K.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.; Haas, D.; Haller, Ch.; Hatzifotiadou, D.; Hayashi, Y.; He, Z. X.; Hebbeker, T.; Hervé, A.; Hirschfelder, J.; Hofer, H.; Hofer, H.; Hohlmann, M.; Holzner, A.; Hou, S. R.; Huo, A. X.; Ito, N.; Jin, B. N.; Jindal, P.; Jing, C. L.; Jones, L. W.; de Jong, P.; Josa-Mutuberría, I.; Kantserov, V.; Kaur, M.; Kawakami, S.; Kienzle-Focacci, M. N.; Kim, J. K.; Kirkby, J.; Kittel, W.; Klimentov, A.; König, A. C.; Kok, E.; Korn, A.; Kopal, M.; Koutsenko, V.; Kräber, M.; Kuang, H. H.; Kraemer, R. W.; Krüger, A.; Kuijpers, J.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J. M.; Lei, Y.; Leich, H.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Li, L.; Li, Z. C.; Likhoded, S.; Lin, C. H.; Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo, E.; Lu, Y. S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W. G.; Ma, X. H.; Ma, Y. Q.; Malgeri, L.; Malinin, A.; Maña, C.; Mans, J.; Martin, J. P.; Marzano, F.; Mazumdar, K.; McNeil, R. R.; Meng, X. W.; Merola, L.; Meschini, M.; Metzger, W. J.; Mihul, A.; van Mil, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G. B.; Monteleoni, B.; Muanza, G. S.; Muijs, A. J. M.; Musy, M.; Nagy, S.; Nahnhauer, R.; Naumov, V. A.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Nowak, H.; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Parriaud, J.-F.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pieri, M.; Pioppi, M.; Piroué, P. A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D.; Qing, C. R.; Rahal-Callot, G.; Rahaman, M. A.; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P. G.; Ranieri, R.; Raspereza, A.; Ravindran, K. C.; Razis, P.; Rembeczki, S.; Ren, D.; Rescigno, M.; Reucroft, S.; Rewiersma, P.; Riemann, S.; Rojkov, A.; Romero, L.; Rosca, A.; Rosemann, C.; Rosenbleck, C.; Rosier-Lees, S.; Roth, S.; Rubio, J. A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schäfer, C.; Schegelsky, V.; Schoeneich, B.; Schotanus, D. J.; Sciacca, C.; Servoli, L.; Shen, C. Q.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D. P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L. Z.; Sushkov, S.; Suter, H.; Swain, J. D.; Szillasi, Z.; Tang, X. W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, C.; Ting, Samuel C. C.; Ting, S. M.; Tonwar, S. C.; Tóth, J.; Trowitzsch, G.; Tully, C.; Tung, K. L.; Ulbricht, J.; Unger, M.; Valente, E.; Verkooijen, H.; Van de Walle, R. T.; Vasquez, R.; Vesztergombi, G.; Vetlitsky, I.; Viertel, G.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A. A.; Wadhwa, M.; Wang, R. G.; Wang, Q.; Wang, X. L.; Wang, X. W.; Wang, Z. M.; Weber, M.; van Wijk, R.; Wijnen, T. A. M.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Y. P.; Xu, Z. Z.; Yang, B. Z.; Yang, C. G.; Yang, H. J.; Yang, M.; Yang, X. F.; Yao, Z. G.; Yeh, S. C.; Yu, Z. Q.; Zalite, An.; Zalite, Yu.; Zhang, C.; Zhang, F.; Zhang, J.; Zhang, S.; Zhang, Z. P.; Zhao, J.; Zhou, S. J.; Zhu, G. Y.; Zhu, R. Y; Zhu, Q. Q.; Zhuang, H. L.; Zichichi, A.; Zimmermann, B.; Zöller, M.; Zwart, A. N. M.; L3 Collaboration

    2006-09-01

    Aims.Several experiments have reported observations on possible correlations between the flux of high energy muons and intense solar flares. If confirmed, these observations would have significant implications for acceleration processes in the heliosphere able to accelerate protons and other ions to energies of at least tens of GeV. Methods: The solar flare of the 14 of July 2000 offered a unique opportunity for the L3+C experiment to search for a correlated enhancement in the flux of muons using the L3 precision muon spectrometer. Its capabilities for observing a directional excess in the flux of muons above 15 GeV (corresponding to primary proton energies above 40 GeV) are presented along with observations made on the 14th of July 2000. Results: We report an excess which appeared at a time coincident with the peak increase of solar protons observed at lower energies. The probability that the excess is a background fluctuation is estimated to be 1%. No similar excess of the muon flux was observed up to 1.5 h after the solar flare time.

  2. Effects of iriflophenone 3-C-β-glucoside on fasting blood glucose level and glucose uptake

    PubMed Central

    Pranakhon, Ratree; Aromdee, Chantana; Pannangpetch, Patchareewan

    2015-01-01

    Background: One of the biological activities of agar wood (Aquilaria sinensis Lour., Thymelaeaceae), is anti-hyperglycemic activity. The methanolic extract (ME) was proven to possess the fasting blood glucose activity in rat and glucose uptake transportation by rat adipocytes. Objective: To determine the decreasing fasting blood glucose level of constituents affordable for in vivo test. If the test was positive, the mechanism which is positive to the ME, glucose transportation, will be performed. Materials and Methods: The ME was separated by column chromatography and identified by spectroscopic methods. Mice was used as an animal model (in vivo), and rat adipocytes were used for the glucose transportation activity (in vitro). Result: Iriflophenone 3-C-β-glucoside (IPG) was the main constituent, 3.17%, and tested for the activities. Insulin and the ME were used as positive controls. The ME, IPG and insulin lowered blood glucose levels by 40.3, 46.4 and 41.5%, respectively, and enhanced glucose uptake by 152, 153, and 183%, respectively. Conclusion: These findings suggest that IPG is active in lowering fasting blood glucose with potency comparable to that of insulin. PMID:25709215

  3. X-Ray Evidence for the Accretion Disc-Outflow Connection in 3C 111

    NASA Technical Reports Server (NTRS)

    Tombesi, Frank; Sambruna, R. M.; Reeves, J. N.; Reynolds, C. S.; Braito, V.

    2011-01-01

    We present the spectral analysis of three Suzaku X-ray Imaging Spectrometer observations of 3C III requested to monitor the predicted variability of its ultrafast outflow on approximately 7 d time-scales. We detect an ionized iron emission line in the first observation and a blueshifted absorption line in the second, when the flux is approximately 30 per cent higher. The location of the material is constrained at less than 0.006 pc from the variability. Detailed modelling supports an identification with ionized reflection off the accretion disc at approximately 20-100rg from the black hole and a highly ionized and massive ultrafast outflow with velocity approximately 0.1c, respectively. The outflow is most probably accelerated by radiation pressure, but additional magnetic thrust cannot be excluded. The measured high outflow rate and mechanical energy support the claims that disc outflows may have a significant feedback role. This work provides the first direct evidence for an accretion disc-outflow connection in a radio-loud active galactic nucleus, possibly linked also to the jet activity.

  4. The large- and small-scale structures of 3C 293

    NASA Technical Reports Server (NTRS)

    Bridle, A. H.; Fomalont, E. B.; Cornwell, T. J.

    1981-01-01

    A Very Large Array (VLA) 1.465-GHz map of the radio galaxy 3C 293 shows that the source, which is unusual in that it is dominated by a steep-spectrum extended core, has a two-sided Z-shaped structure whose physical association with the galaxy VV 5-33-12 is now clear. The core is resolved by the Multi-Element Radio Linked Interferometer Network (MERLIN) at 1.666-GHz, and the VLA at 15.035 GHz, into an inner, two-sided structure within 1 kpc of the center of VV 5-33-12, and curved bridges of emission linking this structure to the large-scale emission. The major axis of the core lies 35 deg from the major axes of the emission bridges that make up the bar of the large-scale Z structure, and 60 deg from the minor axis of VV 5-33-12. Precessional and buoyant-refraction models for these misalignments are discussed.

  5. Gas Sloshing and Radio Galaxy Dynamics in the Core of the 3C 449 Group

    NASA Technical Reports Server (NTRS)

    Lal, Dharam V.; Kraft, Ralph P.; Randall, Scott W.; Forman, William R.; Nulsen, Paul E.; Roediger, Elke; ZuHone, John A.; Hardcastle, Martin J.; Jones, Christine; Croston, Judith H.

    2013-01-01

    We present results from a 140 ks Chandra/ACIS-S observation of the hot gas around the canonical FR I radio galaxy 3C 449. An earlier, shorter 30 ks Chandra observation of the group gas showed an unusual entropy distribution and a surface brightness edge in the gas that could be a strong shock around the inner radio lobes. In our deeper data we find no evidence for a temperature increase inside of the brightness edge, but a temperature decrease across part of the edge. This suggests that the edge is a "sloshing" cold front due to a merger within the last 1.3-1.6 Gyr. Both the northern and southern inner jets are bent slightly to the west in projection as they enter their respective lobes, suggesting that the sloshing core is moving to the east. The straight inner jet flares at approximately the position where it crosses the contact edge, suggesting that the jet is entraining and thermalizing some of the hot gas as it crosses the edge.We also detect filaments of X-ray emission around the southern inner radio jet and lobe which we attribute to low entropy entrained gas. The lobe flaring and gas entrainment were originally predicted in simulations of Loken et al. and are confirmed in our deep observation.

  6. Rotor Wake Vortex Definition Using 3C-PIV Measurements: Corrected for Vortex Orientation

    NASA Technical Reports Server (NTRS)

    Burley, Casey L.; Brooks, Thomas F.; vanderWall, Berend; Richard, Hughues Richard; Raffel, Markus; Beaumier, Philippe; Delrieux, Yves; Lim, Joon W.; Yu, Yung H.; Tung, Chee

    2003-01-01

    Three-component (3-C) particle image velocimetry (PIV) measurements, within the wake across a rotor disk plane, are used to determine wake vortex definitions important for BVI (Blade Vortex Interaction) and broadband noise prediction. This study is part of the HART II test program conducted using a 40 percent scale BO-105 helicopter main rotor in the German-Dutch Wind Tunnel (DNW). In this paper, measurements are presented of the wake vortex field over the advancing side of the rotor operating at a typical descent landing condition. The orientations of the vortex (tube) axes are found to have non-zero tilt angles with respect to the chosen PIV measurement cut planes, often on the order of 45 degrees. Methods for determining the orientation of the vortex axis and reorienting the measured PIV velocity maps (by rotation/projection) are presented. One method utilizes the vortex core axial velocity component, the other utilizes the swirl velocity components. Key vortex parameters such as vortex core size, strength, and core velocity distribution characteristics are determined from the reoriented PIV velocity maps. The results are compared with those determined from velocity maps that are not corrected for orientation. Knowledge of magnitudes and directions of the vortex axial and swirl velocity components as a function of streamwise location provide a basis for insight into the vortex evolution.

  7. Photolysis rates in correlated overlapping cloud fields: Cloud-J 7.3c

    DOE PAGES

    Prather, M. J.

    2015-08-14

    A new approach for modeling photolysis rates (J values) in atmospheres with fractional cloud cover has been developed and is implemented as Cloud-J – a multi-scattering eight-stream radiative transfer model for solar radiation based on Fast-J. Using observations of the vertical correlation of cloud layers, Cloud-J 7.3c provides a practical and accurate method for modeling atmospheric chemistry. The combination of the new maximum-correlated cloud groups with the integration over all cloud combinations by four quadrature atmospheres produces mean J values in an atmospheric column with root mean square (rms) errors of 4 % or less compared with 10–20 % errorsmore » using simpler approximations. Cloud-J is practical for chemistry–climate models, requiring only an average of 2.8 Fast-J calls per atmosphere vs. hundreds of calls with the correlated cloud groups, or 1 call with the simplest cloud approximations. Another improvement in modeling J values, the treatment of volatile organic compounds with pressure-dependent cross sections, is also incorporated into Cloud-J.« less

  8. Ab initio study of point defects near stacking faults in 3C-SiC

    DOE PAGES

    Xi, Jianqi; Liu, Bin; Zhang, Yanwen; ...

    2016-07-02

    Interactions between point defects and stacking faults in 3C-SiC are studied using an ab initio method based on density functional theory. The results show that the discontinuity of the stacking sequence considerably affects the configurations and behavior of intrinsic defects, especially in the case of silicon interstitials. The existence of an intrinsic stacking fault (missing a C-Si bilayer) shortens the distance between the tetrahedral-center site and its second-nearest-neighboring silicon layer, making the tetrahedral silicon interstitial unstable. Instead of a tetrahedral configuration with four C neighbors, a pyramid-like interstitial structure with a defect state within the band gap becomes a stablemore » configuration. In addition, orientation rotation occurs in the split interstitials that has diverse effects on the energy landscape of silicon and carbon split interstitials in the stacking fault region. Moreover, our analyses of ionic relaxation and electronic structure of vacancies show that the built-in strain field, owing to the existence of the stacking fault, makes the local environment around vacancies more complex than that in the bulk.« less

  9. Extremely high polarization in the 2010 outburst of blazar 3C 454.3

    SciTech Connect

    Sasada, Mahito; Kino, Masaru; Uemura, Makoto; Yoshida, Michitoshi; Kawabata, Koji S.; Akitaya, Hiroshi; Fukazawa, Yasushi; Yasuda, Hajimu; Itoh, Ryosuke; Sakimoto, Kiyoshi; Ikejiri, Yuki; Ohsugi, Takashi; Komatsu, Tomoyuki; Miyamoto, Hisashi; Nagae, Osamu; Tanaka, Hiroyuki; Yamanaka, Masayuki; Nakaya, Hidehiko; Sato, Shuji

    2014-04-01

    The gamma-ray-detected blazar 3C 454.3 exhibits dramatic flux and polarization variations in the optical and near-infrared bands. In 2010 December, the object emitted a very bright outburst. We monitored it for approximately four years (including the 2010 outburst) by optical and near-infrared photopolarimetry. During the 2010 outburst, the object emitted two rapid, redder brightenings, at which the polarization degrees (PDs) in both bands increased significantly and the bands exhibited a frequency-dependent polarization. The observed frequency-dependent polarization leads us to propose that the polarization vector is composed of two vectors. Therefore, we separate the observed polarization vectors into short- and long-term components that we attribute to the emissions of the rapid brightenings and the outburst that varied the timescale of days and months, respectively. The estimated PD of the short-term component is greater than the maximum observed PD and is close to the theoretical maximum PD. We constrain the bulk Lorentz factors and inclination angles between the jet axis and the line of sight from the estimated PDs. In this case, the inclination angle of the emitting region of short-term component from the first rapid brightening should be equal to 90°, because the estimated PD of the short-term component was approximately equal to the theoretical maximum PD. Thus, the Doppler factor at the emitting region of the first rapid brightening should be equal to the bulk Lorentz factor.

  10. Mechanism and kinetics of the reaction NO3 + C2H4.

    PubMed

    Nguyen, Thanh Lam; Park, Jaehee; Lee, Kyungjun; Song, Kihyung; Barker, John R

    2011-05-19

    The reaction of NO(3) radical with C(2)H(4) was characterized using the B3LYP, MP2, B97-1, CCSD(T), and CBS-QB3 methods in combination with various basis sets, followed by statistical kinetic analyses and direct dynamics trajectory calculations to predict product distributions and thermal rate constants. The results show that the first step of the reaction is electrophilic addition of an O atom from NO(3) to an olefinic C atom from C(2)H(4) to form an open-chain adduct. A concerted addition reaction mechanism forming a five-membered ring intermediate was investigated, but is not supported by the highly accurate CCSD(T) level of theory. Master-equation calculations for tropospheric conditions predict that the collisionally stabilized NO(3)-C(2)H(4) free-radical adduct constitutes 80-90% of the reaction yield and the remaining products consist mostly of NO(2) and oxirane; the other products are produced in very minor yields. By empirically reducing the barrier height for the initial addition step by 1 kcal mol(-1) from that predicted at the CBS-QB3 level of theory and treating the torsional modes explicitly as one-dimensional hindered internal rotations (instead of harmonic oscillators), the computed thermal rate constants (including quantum tunneling) can be brought into very good agreement with the experimental data for the overall reaction rate constant.

  11. 3C454.3 Revelas the Structure and Physics of its 'Blazar Zone'

    SciTech Connect

    Sikora, M.; Moderski, R.; Madejski, G.M.

    2007-11-28

    Recent multi-wavelength observations of 3C454.3, in particular during its giant outburst in 2005, put severe constraints on the location of the 'blazar zone', its dissipative nature, and high energy radiation mechanisms. As the optical, X-ray, and millimeter light-curves indicate, significant fraction of the jet energy must be released in the vicinity of the millimeter-photosphere, i.e. at distances where, due to the lateral expansion, the jet becomes transparent at millimeter wavelengths. We conclude that this region is located at {approx} 10 parsecs, the distance coinciding with the location of the hot dust region. This location is consistent with the high amplitude variations observed on {approx} 10 day time scale, provided the Lorentz factor of a jet is {Gamma}{sub j} {approx} 20. We argue that dissipation is driven by reconfinement shock and demonstrate that X-rays and {gamma}-rays are likely to be produced via inverse Compton scattering of near/mid IR photons emitted by the hot dust. We also infer that the largest gamma-to-synchrotron luminosity ratio ever recorded in this object - having taken place during its lowest luminosity states - can be simply due to weaker magnetic fields carried by a less powerful jet.

  12. Image of the Quasar 3C 273 Taken by the High Energy Astronomy Observatory (HEAO)-2

    NASA Technical Reports Server (NTRS)

    1979-01-01

    This image is an observation of Quasar 3C 273 by the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory. It reveals the presence of a new source (upper left) with a red shift that indicates that it is about 10 billion light years away. Quasars are mysterious, bright, star-like objects apparently located at the very edge of the visible universe. Although no bigger than our solar system, they radiate as much visible light as a thousand galaxies. Quasars also emit radio signals and were previously recognized as x-ray sources. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2 was designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center.

  13. Thermal oxidation of 3C silicon carbide single-crystal layers on silicon

    NASA Technical Reports Server (NTRS)

    Fung, C. D.; Kopanski, J. J.

    1984-01-01

    Thermal oxidation of thick single-crystal 3C SiC layers on silicon substrates was studied. The oxidations were conducted in a wet O2 atmosphere at temperatures from 1000 to 1250 C for times from 0.1 to 50 h. Ellipsometry was used to determine the thickness and index of refraction of the oxide films. Auger analysis showed them to be homogeneous with near stoichiometric composition. The oxide growth followed a linear parabolic relationship with time. Activation energy of the parabolic rate constant was found to be 50 kcal/mole, while the linear rate constant was 74 kcal/mole. The latter value corresponds approximately to the energy required to break a Si-C bond. Electrical measurements show an effective density of 4-6 x 10 to the 11th per sq cm for fixed oxide charges at the oxide-carbide interface, and the dielectric strength of the oxide film is aproximately 6 x 10 to the 6th V/cm.

  14. Discovery of recombining plasma in the supernova remnant 3C 391

    NASA Astrophysics Data System (ADS)

    Sato, Tamotsu; Koyama, Katsuji; Takahashi, Tadayuki; Odaka, Hirokazu; Nakashima, Shinya

    2014-12-01

    Recent X-ray study of middle-aged supernova remnants (SNRs) reveals strong radiative recombination continua (RRCs) associated with overionized plasmas, which origin still remains uncertain. We report a discovery of an RRC in the middle-aged SNR 3C 391. If the X-ray spectrum is fitted with a two-temperature plasma model in collisional ionization equilibrium (CIE), residuals of a Si XIV Lyα line at 2.006 keV, a S XVI Lyα line at 2.623 keV and the edge of a RRC of Si XIII at 2.666 keV are found. In fact, the X-ray spectrum is well described by the composite model consisting of the CIE plasma and a recombining plasma (RP). The abundance pattern suggests that the RP is due to ejecta from core-collapse supernova of the progenitor mass of about 15 M⊙. There is no significant difference of the recombining parameters between the south-east region and the north-west region surrounded by dense molecular clouds. We also find a hint of a Fe I Kα line at 6.4 keV (2.4 σ detection) from the south-east region of the SNR.

  15. HEAO 1 observations of high-energy X-rays from 3C273. [quasar emissions

    NASA Technical Reports Server (NTRS)

    Primini, F. A.; Cooke, B. A.; Dobson, C. A.; Howe, S. K.; Scheepmaker, A.; Wheaton, W. A.; Lewin, W. H. G.; Baity, W. A.; Gruber, D. E.; Matteson, J. L.

    1979-01-01

    The first detection of high energy (13 to 120 keV) X rays from the quasar 3C273, made by the HEAO 1 satellite, is reported. Observations were made with the 13 to 180 keV slat collimated detectors of the high energy X-ray and low energy gamma-ray (A4) experiment during December 1977-January 1978 and June-July 1978. Results are consistent with the previously observed X-ray flux variability on a scale of months. Photon count rates are presented for each of five energy bands and count rate and photon spectra for the June through July 1978 observations are derived. A comparison of the data obtained with that at lower X-ray energies and higher gamma-ray energies indicates that there is an overall spectral steepening from low to high energies and a possible break near 20 keV, which may be due to the gamma rays originating from a different region than that of the X rays.

  16. The γ-ray brightest days of the blazar 3C 454.3

    NASA Astrophysics Data System (ADS)

    Bonnoli, G.; Ghisellini, G.; Foschini, L.; Tavecchio, F.; Ghirlanda, G.

    2011-01-01

    In the first week of 2009 December, the blazar 3C 454.3 became the brightest high-energy source in the sky. Its photon flux reached and surpassed the level of 10-5 ph cm-2 s-1 above 100 MeV. The Swift satellite observed the source several times during the period of high γ-ray flux, and we can construct really simultaneous spectral energy distributions (SEDs) before, during and after the luminosity peak. Our main findings are (i) the optical, X-ray and γ-ray fluxes correlate; (ii) the γ-ray flux varies quadratically (or even more) with the optical flux; (iii) a simple one-zone synchrotron inverse Compton model can account for all the considered SED; (iv) in this framework the γ-ray versus optical flux correlation can be explained if the magnetic field is slightly fainter when the overall jet luminosity is stronger and (v) the power that the jet spent to produce the peak γ-ray luminosity is of the same order, or larger, than the accretion disc luminosity.

  17. Selective Growth of Nanocrystalline 3C-SiC Thin Films on Si

    NASA Astrophysics Data System (ADS)

    Beke, D.; Pongrácz, A.; Battistig, G.; Josepovits, K.; Pécz, B.

    2010-11-01

    Epitaxial formation of SiC nanocrystals has been investigated on single crystal silicon surfaces. A simple and cheap method using reactive annealing in CO has been developed and patented by our group (BME AFT and MTA MFA). By this technique epitaxial 3C-SiC nanocrystals can be grown at the Si side of a SiO2/Si interface without void formation at the SiC/Si interface. CO diffusion and SiC nanocrystal formation on different silicon based systems (SiO2/Si, Si3N4/3Si and SiO2/LPCVD poly-Si) after CO treatment at 105 Pa at elevated temperatures (T>1000° C) will be presented. By optimizing the annealing time a thin continuous nanocrystalline SiC layer has been formed. Applying a patterned Si3N4 capping layer as a barrier layer against CO diffusion, SiC nanocrystal formation at the Si3N4/Si interface is inhibited. We will present the selective growth of SiC nanocrystals using the before mentioned technique.

  18. Nanoscale elastic changes in 2D Ti3C2Tx (MXene) pseudocapacitive electrodes

    DOE PAGES

    Come, Jeremy; Xie, Yu; Naguib, Michael; ...

    2016-02-01

    Designing sustainable electrodes for next generation energy storage devices relies on the understanding of their fundamental properties at the nanoscale, including the comprehension of ions insertion into the electrode and their interactions with the active material. One consequence of ion storage is the change in the electrode volume resulting in mechanical strain and stress that can strongly affect the cycle life. Therefore, it is important to understand the changes of dimensions and mechanical properties occurring during electrochemical reactions. While the characterization of mechanical properties via macroscopic measurements is well documented, in-situ characterization of their evolution has never been achieved atmore » the nanoscale. Two dimensional (2D) carbides, known as MXenes, are promising materials for supercapacitors and various kinds of batteries, and understating the coupling between their mechanical and electrochemical properties is therefore necessary. Here we report on in-situ imaging, combined with density functional theory of the elastic changes, of a 2D titanium carbide (Ti3C2Tx) electrode in direction normal to the basal plane during cation intercalation. The results show a strong correlation between the Li+ ions content and the elastic modulus, whereas little effects of K+ ions are observed. Moreover, this strategy enables identifying the preferential intercalation pathways within a single particle.« less

  19. Dihydropyrano [2,3-c] pyrazole: Novel in vitro inhibitors of yeast α-glucosidase.

    PubMed

    Kashtoh, Hamdy; Muhammad, Munira Taj; Khan, Jalaluddin J A; Rasheed, Saima; Khan, Ajmal; Perveen, Shahnaz; Javaid, Kulsoom; Atia-Tul-Wahab; Khan, Khalid Mohammed; Choudhary, M Iqbal

    2016-04-01

    Inhibition of α-glucosidase enzyme activity is a reliable approach towards controlling post-prandial hyperglycemia associated risk factors. During the current study, a series of dihydropyrano[2,3-c] pyrazoles (1-35) were synthesized and evaluated for their α-glucosidase inhibitory activity. Compounds 1, 4, 22, 30, and 33 were found to be the potent inhibitors of the yeast α-glucosidase enzyme. Mechanistic studies on most potent compounds reveled that 1, 4, and 30 were non-competitive inhibitors (Ki=9.75±0.07, 46±0.0001, and 69.16±0.01μM, respectively), compound 22 is a competitive inhibitor (Ki=190±0.016μM), while 33 was an uncompetitive inhibitor (Ki=45±0.0014μM) of the enzyme. Finally, the cytotoxicity of potent compounds (i.e. compounds 1, 4, 22, 30, and 33) was also evaluated against mouse fibroblast 3T3 cell line assay, and no toxicity was observed. This study identifies non-cytotoxic novel inhibitors of α-glucosidase enzyme for further investigation as anti-diabetic agents.

  20. The Supernova Remnant 3C 400.2: Kinematics of its Ionized Gas and Theoretical Results

    NASA Astrophysics Data System (ADS)

    Ambrocio-Cruz, P.; de La Fuente, E.; Rosado, M.; Velázquez, P. F.

    2003-01-01

    3C 400.2 is a supernova remnant (SNR) with a complex morphology consisting of two overlapped shells of different diameters: a large shell at the southeast and a small shell at the northwest. High-resolution radio-continuum observations carried out by Dubner et al. (1994) suggested that this complex morphology could be due to the interaction of two SNRs. However, this view has been challenged by recent studies of the H I distribution around this SNR (Giacani et al. 1998) and by the confrontation of theoretical evolutionary models with the morphology at H alpha of this remnant (Velazquez et al. 2001). These recent results suggest that the double shell structure is produced by a single supernova explosion initially expanding into a dense medium encountering a lower density medium and producing a blowout. In this work we present the results of H alpha Fabry-Perot observations obtained with the PUMA equipment at the 2.1 m telescope of the Observatorio Astronómico Nacional at San Pedro Mártir, B. C., México. The kinematic results obtained can allow us to distinguish between those possibilities: two supernova explosions or one supernova explosion undergoing a blowout due to a density gradient.

  1. An 80 day X-ray light curve of 3C 371

    NASA Technical Reports Server (NTRS)

    Snyder, W. A.; Wood, K. S.; Yentis, D. J.; Meekins, J. F.; Smathers, H. W.; Byram, E. T.; Chubb, T. A.; Friedman, H.

    1982-01-01

    The Large Area Sky Survey (LASS) experiment on HEAO 1 that monitored the N galaxy/BL Lacertae object 3C 371 from August 19 to November 7, 1977 is discussed, noting that statistically significant threefold or larger intensity variations were observed in the flux range 0.5-20 keV. It is found that the degree of variability depends on the time of observation, with the source sometimes appearing constant and sometimes changing on time scales of 1 to 2 weeks. Also observed was an X-ray flare that lasted approximately 25 days. The total 80-day X-ray light curve is seen as suggesting either a superposition of X-ray flares or a variable injection rate that changes on weekly time scales. The observed X-ray flux is found to be consistent with that expected by extrapolating the nonthermal optical spectrum, suggesting that the optical to X-ray flux could be synchrotron radiation, provided that it is possible to account for the patterns of variability seen at optical and X-ray wavelengths and to dispose of inverse Compton difficulties.

  2. Erosion behavior of CVD 3C silicon carbide in inductively coupled plasmas

    NASA Astrophysics Data System (ADS)

    Brooks, Mitchell R.

    2010-11-01

    An electrostatic, capacitively coupled Planar Ion Flux (PIF) probe has been developed as a sensor for use in high volume reactive ion etch (RIE) chambers. An important factor in the design is the material used for the probe collection area that is exposed to the plasma. For use in inductively coupled plasma chambers, bulk-deposited, 3C silicon carbide (SiC) was chosen. The primary objective of this work was to characterize the erosion behavior of the probe tip throughout repeated cycling for 100 RF hours (RFH). Surface morphology, roughness, and composition were documented at the beginning and end of cycling. In addition, the mass of the probe tip was documented three times throughout the experiment. This was used to calculate the wear rate which averaged ~100 mug/RFH. Although physical and chemical mechanisms were evident, it appears that preferential sputtering at pre-existing surface defects had the greatest influence on the erosion behavior. Additionally, an investigation into the sudden abnormal electrical behavior of the probe yielded the conclusion that the added capacitance of a deposited film reduces the number of data points in the ion saturation region used to fit the experimental data. This results in excessive values for extracted plasma parameters, most notably the electron temperature. However, this is only a temporary condition if the film can be removed.

  3. Cleavage of eukaryotic initiation factor eIF5B by enterovirus 3C proteases

    PubMed Central

    de Breyne, Sylvain; Bonderoff, Jennifer M.; Chumakov, Konstantin M.; Lloyd, Richard E.; Hellen, Christopher U. T.

    2008-01-01

    The enteroviruses poliovirus (PV), Coxsackie B virus (CVB) and rhinovirus (HRV) are members of Picornaviridae that inhibit host cell translation early in infection. Enterovirus translation soon predominates in infected cells, but eventually also shuts off. This complex pattern of modulation of translation suggests regulation by a multifactorial mechanism. We report here that eIF5B is proteolytically cleaved during PV and CVB infection of cultured cells, beginning at 3 hours post-infection and increasing thereafter. Recombinant PV, CVB and HRV 3Cpro cleaved purified native rabbit eukaryotic initiation factor (eIF) 5B in vitro at a single site (VVEQ↓G, equivalent to VMEQ↓G479in human eIF5B) that is consistent with the cleavage specificity of enterovirus 3C proteases. Cleavage separates the N-terminal domain of eIF5B from its essential conserved central GTPase and C-terminal domains. 3Cpro-mediated cleavage of eIF5B may thus play an accessory role in the shut-off of translation that occurs in enterovirus-infected cells. PMID:18572216

  4. Apparent 'superrelativistic' expansion of the extragalactic radio source 3C 345

    NASA Technical Reports Server (NTRS)

    Wittels, J. J.; Cotton, W. D.; Counselman, C. C., III; Shapiro, I. I.; Hinteregger, H. F.; Knight, C. A.; Rogers, A. E. E.; Whitney, A. R.; Clark, T. A.; Hutton, L. K.

    1976-01-01

    The compact extragalactic radio source 3C 345 was observed by very-long-baseline interferometry (wavelength about 3.8 cm) at 12 epochs distributed over the nearly four-year period from February 1971 to October 1974. For one of these epochs, the multibaseline data were sufficient to allow the brightness distribution to be estimated in a model-independent manner; the resultant distribution was clearly dominated by two components. The remaining sets of data were also represented adequately by two-component models. The angular separation of the two components increased during this period from about 1.00 to 1.30 milliarcsec, corresponding to an apparent average speed of expansion of approximately 2.5 c at a fixed position angle of 105 (plus or minus 5) deg. These results, coupled with the fact that contraction has never been observed, seem difficult to reconcile with the so-called Christmas-tree model of the 'superrelativistic' expansion of extragalactic radio sources.

  5. Feline infectious peritonitis: insights into feline coronavirus pathobiogenesis and epidemiology based on genetic analysis of the viral 3c gene.

    PubMed

    Chang, Hui-Wen; de Groot, Raoul J; Egberink, Herman F; Rottier, Peter J M

    2010-02-01

    Feline infectious peritonitis (FIP) is a lethal systemic disease caused by FIP virus (FIPV), a virulent mutant of apathogenic feline enteric coronavirus (FECV). We analysed the 3c gene--a proposed virulence marker--in 27 FECV- and 28 FIPV-infected cats. Our findings suggest that functional 3c protein expression is crucial for FECV replication in the gut, but dispensable for systemic FIPV replication. Whilst intact in all FECVs, the 3c gene was mutated in the majority (71.4 %) of FIPVs, but not in all, implying that mutation in 3c is not the (single) cause of FIP. Most cats with FIP had no detectable intestinal feline coronaviruses (FCoVs) and had seemingly cleared the primary FECV infection. In those with detectable intestinal FCoV, the virus always had an intact 3c and seemed to have been acquired by FECV superinfection. Apparently, 3c-inactivated viruses replicate not at all--or only poorly--in the gut, explaining the rare incidence of FIP outbreaks.

  6. Crystalline Ni3C as both carbon source and catalyst for graphene nucleation: a QM/MD study

    PubMed Central

    Jiao, Menggai; Li, Kai; Guan, Wei; Wang, Ying; Wu, Zhijian; Page, Alister; Morokuma, Keiji

    2015-01-01

    Graphene nucleation from crystalline Ni3C has been investigated using quantum chemical molecular dynamics (QM/MD) simulations based on the self-consistent-charge density-functional tight-binding (SCC-DFTB) method. It was observed that the lattice of Ni3C was quickly relaxed upon thermal annealing at high temperature, resulting in an amorphous Ni3C catalyst structure. With the aid of the mobile nickel atoms, inner layer carbon atoms precipitated rapidly out of the surface and then formed polyyne chains and Y-junctions. The frequent sinusoidal-like vibration of the branched carbon configurations led to the formation of nascent graphene precursors. In light of the rapid decomposition of the crystalline Ni3C, it is proposed that the crystalline Ni3C is unlikely to be a reaction intermediate in the CVD-growth of graphene at high temperatures. However, results present here indicate that Ni3C films can be employed as precursors in the synthesis of graphene with exciting possibility. PMID:26169042

  7. GA binding protein augments autophagy via transcriptional activation of BECN1-PIK3C3 complex genes.

    PubMed

    Zhu, Wan; Swaminathan, Gayathri; Plowey, Edward D

    2014-09-01

    Macroautophagy is a vesicular catabolic trafficking pathway that is thought to protect cells from diverse stressors and to promote longevity. Recent studies have revealed that transcription factors play important roles in the regulation of autophagy. In this study, we have identified GA binding protein (GABP) as a transcriptional regulator of the combinatorial expression of BECN1-PIK3C3 complex genes involved in autophagosome initiation. We performed bioinformatics analyses that demonstrated highly conserved putative GABP sites in genes that encode BECN1/Beclin 1, several BECN1 interacting proteins, and downstream autophagy proteins including the ATG12-ATG5-ATG16L1 complex. We demonstrate that GABP binds to the promoter regions of BECN1-PIK3C3 complex genes and activates their transcriptional activities. Knockdown of GABP reduced BECN1-PIK3C3 complex transcripts, BECN1-PIK3C3 complex protein levels and autophagy in cultured cells. Conversely, overexpression of GABP increased autophagy. Nutrient starvation increased GABP-dependent transcriptional activity of BECN1-PIK3C3 complex gene promoters and increased the recruitment of GABP to the BECN1 promoter. Our data reveal a novel function of GABP in the regulation of autophagy via transcriptional activation of the BECN1-PIK3C3 complex.

  8. Surface modified MXene Ti3C2 multilayers by aryl diazonium salts leading to large-scale delamination

    NASA Astrophysics Data System (ADS)

    Wang, Hongbing; Zhang, Jianfeng; Wu, Yuping; Huang, Huajie; Li, Gaiye; Zhang, Xin; Wang, Zhuyin

    2016-10-01

    Herein we report a simple and facile method to delaminate MXene Ti3C2 multilayers by the assistance of surface modification using aryl diazonium salts. The basic strategy involved the preparation of layered MAX Ti3AlC2 and the exfoliation of Ti3AlC2 into Ti3C2 multilayers, followed by Na+ intercalation and surface modification using sulfanilic acid diazonium salts. The resulting chemically grafted Ti3C2 flakes were characterized by Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) to confirm the presence of the surface organic species. Ultraviolet-visible spectroscopy revealed that surface-modified MXene Ti3C2 sheets disperse well in water and the solutions obey Lambert-Beer's law. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to demonstrate the morphology and structure of delaminating MXene Ti3C2 flakes. The results indicated that chemical modification for MXene multilayers by aryl diazonium salts induced swelling that conversely weakened the bonds between MX layers, hence leading to large-scale delamination of multilayered MXene Ti3C2via mild sonication. Advantages of the present approach rely not only on the simplicity and efficiency of the delamination procedure but also on the grafting of aryl groups to MXene surfaces, highly suitable for further applications of the newly discovered two-dimensional materials.

  9. Fabrication and applications of 3C-silicon carbide on insulator by the grow-a-substrate method

    NASA Astrophysics Data System (ADS)

    Kuo, Hung-I.

    Due to its outstanding electrical, chemical and mechanical properties, silicon carbide (SiC) is a leading material for MEMS in harsh environment applications. Silicon carbide-on-oxide wafers are attractive substrates for SiC surface micromachined devices since the buried oxide layer provides both electrical isolation and serves as a sacrificial layer. Wafer bonding is commonly used to fabricate these substrates, but unfortunately bonding yields are often very low due to high tensile stresses in the SIC films. This dissertation reports a novel, bonding-free method to fabricate 3C-SiC-on-insulator substrates. The process, called the Grow-A-Substrate (GAS) method, bypasses wafer bonding by using a high deposition rate polysilicon process in conjunction with wet chemical etching to produce wafer-thick polysilicon layers that serve as substrates for the 3C-SiC-on-insulator (SiCOI) structures. Because wafer bonding is not used, insulators of various material and thickness can be easily utilized. Using this method, transfer rates over 99% are readily achievable. Various applications could benefit from this technology, which include high temperature MEMS sensors and actuators, and SiC electronic devices. 3C-SiC on insulator substrates offer an effective means to fabricate 3C-SiC strain gauges. In order to measure the gauge factor from the 3C-SiC strain gauge, a cantilever beam testing specimen was made and evaluated. The maximum gauge factor obtained from the strain gauge was -17.78 in the <100> direction. 3C-SiCOI Schottky diodes and Schottky diode-based hydrogen sensors were also investigated. Using the rectifying behavior of the Pd/3C-SiCOI system, hydrogen sensors were tested in hydrogen ambients of varying concentration. However, due to the large leakage currents of the diodes, detection was only possible at a hydrogen concentration of 100%. Using the 3C-SiC-on-Insulator wafers, single-crystal (100) and (110) 3C-SiC lateral resonators were fabricated and electrically

  10. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N.P. Paulsson

    2005-08-21

    the rock and the fluid types. The data quality and the data volumes from a 400 level 3C array will allow us to develop the data processing technology necessary for high resolution reservoir imaging.

  11. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N. P. Paulsson

    2005-09-30

    the rock and the fluid types. The data quality and the data volumes from a 400 level 3C array will allow us to develop the data processing technology necessary for high resolution reservoir imaging.

  12. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N.P Paulsson

    2006-05-05

    the rock and the fluid types. The data quality and the data volumes from a 400 level 3C array will allow us to develop the data processing technology necessary for high resolution reservoir imaging.

  13. DEVELOPMENT OF A 400 LEVEL 3C CLAMPED DOWNHOLE SEISMIC RECEIVER ARRAY FOR 3D BOREHOLE SEISMIC IMAGING OF GAS RESERVOIRS

    SciTech Connect

    Bjorn N.P. Paulsson

    2004-05-01

    fluid types. The data quality and the data volumes from a 400 level 3C array will allow us to develop the data processing technology necessary for high resolution reservoir imaging.

  14. 3C 273 variability at 7 mm: evidence of shocks and precession in the jet

    NASA Astrophysics Data System (ADS)

    Beaklini, Pedro Paulo B.; Abraham, Zulema

    2014-01-01

    We report on four years of observations of 3C 273 at 7 mm obtained with the Itapetinga radio telescope, in Brazil, between 2009 and 2013. We detected a flare in 2010 March, when the flux density increased by 50 per cent and reached 35 Jy. After the flare, the flux density started to decrease and reached values lower than 10 Jy. We suggest that the 7-mm flare is the radio counterpart of the γ-ray flare observed by the Fermi Large Area Telescope in 2009 September, in which the flux density at high energies reached a factor of 50 of its average value. A delay of 170 d between the radio and γ-ray flares was revealed using the discrete correlation function (DCF) that can be interpreted in the context of a shock model, in which each flare corresponds to the formation of a compact superluminal component that expands and becomes optically thin at radio frequencies at latter epochs. The differences in flare intensity between frequencies and at different times are explained as a consequence of an increase in the Doppler factor δ, as predicted by the 16-yr precession model proposed by Abraham & Romero. This increase has a large effect on boosting at high frequencies while it does not affect the observed optically thick radio emission too much. We discuss other observable effects of the variation in δ, such as the increase in the formation rate of superluminal components, the variations in the time delay between flares and the periodic behaviour of the radio light curve that we have found to be compatible with changes in the Doppler factor.

  15. Comparison of ejection events in the jet and accretion disc outflows in 3C 111

    NASA Astrophysics Data System (ADS)

    Tombesi, F.; Sambruna, R. M.; Marscher, A. P.; Jorstad, S. G.; Reynolds, C. S.; Markowitz, A.

    2012-07-01

    We present a comparison of the parameters of accretion disc outflows and the jet of the broad-line radio galaxy 3C 111 on subparsec (sub-pc) scales. We make use of published X-ray observations of ultra-fast outflows (UFOs) and new 43-GHz Very Long Baseline Array images to track the jet knot ejection. We find that the superluminal jet coexists with the mildly relativistic outflows on sub-pc scales, possibly indicating a transverse stratification of a global flow. The two are roughly in pressure equilibrium, with the UFOs potentially providing additional support for the initial jet collimation. The UFOs are much more massive than the jet, but their kinetic power is probably about an order of magnitude lower, at least for the observations considered here. However, their momentum flux is equivalent and both of them are powerful enough to exert a concurrent feedback impact on the surrounding environment. A link between these components is naturally predicted in the context of magnetohydrodynamic models for jet/outflow formation. However, given the high radiation throughput of active galactic nuclei, radiation pressure should also be taken into account. From the comparison with the long-term 2-10 keV Rossi X-ray Timing Explorer light curve, we find that the UFOs are preferentially detected during periods of increasing flux. We also find the possibility to place the UFOs within the known X-ray dips-jet ejection cycles, which has been shown to be a strong proof of the disc-jet connection, in analogue with stellar mass black holes. However, given the limited number of observations presently available, these relations are only tentative and additional spectral monitoring is needed to test them conclusively.

  16. Multiwavelength temporal variability of the blazar 3C 454.3 during 2014 activity phase

    NASA Astrophysics Data System (ADS)

    Kushwaha, Pankaj; Gupta, Alok C.; Misra, Ranjeev; Singh, K. P.

    2017-01-01

    We present a multiwavelength temporal analysis of the blazar 3C 454.3 during the high γ-ray active period from May to December, 2014. Except for X-rays, the period is well sampled at near-infrared (NIR)-optical by the Small and Moderate Aperture Research Telescope System (SMARTS) facility, and the source is detected continuously on daily time-scale in the Fermi-Large Area Telescope γ-ray band. The source exhibits diverse levels of variability with many flaring/active states in the continuously sampled γ-ray light curve which are also reflected in the NIR-optical light curves and the sparsely sampled X-ray light curve by the Swift-XRT. Multiband correlation analysis of this continuous segment during different activity periods shows a change of state from no lags between IR and γ-ray, optical and γ-ray, and IR and optical to a state where γ-ray lags the IR/optical by ˜3 d. The results are consistent with the previous studies of the same during various γ-ray flaring and active episodes of the source. This consistency, in turn, suggests an extended localized emission region with almost similar conditions during various γ-ray activity states. On the other hand, the delay of γ-ray with respect to IR/optical and a trend similar to IR/optical in X-rays along with strong broad-band correlations favour magnetic field related origin with X-ray and γ-ray being inverse Comptonization of IR/optical photons and external radiation field, respectively.

  17. Comparison of Ejection Events in the Jet and Accretion Disc Outflows in 3C 111

    NASA Technical Reports Server (NTRS)

    Tombesi, F.; Sambruna, R. M.; Marscher, A. P.; Jorstad, S. G.; Reynolds, C. S.; Markowtiz, A.

    2012-01-01

    We present a comparison of the parameters of accretion disc outflows and the jet of the broad-line radio galaxy 3C 111 on sub-pc scales. We make use of published X-ray observations of ultra-fast outflows (UFOs) and new 43 GHz VLBA images to track the jet knots ejection. We find that the superluminal jet coexists with the mildly relativistic outflows on sub-pc scales, possibly indicating a transverse stratification of a global flow. The two are roughly in pressure equilibrium, with the UFOs potentially providing additional support for the initial jet collimation. The UFOs are much more massive than the jet, but their kinetic power is probably about an order of magnitude lower, at least for the observations considered here. However, their momentum flux is equivalent and both of them are powerful enough to exert a concurrent feedback impact on the surrounding environment. A link between these components is naturally predicted in the context of MHD models for jet/outflow formation. However, given the high radiation throughput of AGNs, radiation pressure should also be taken into account. From the comparison with the long-term 2-10 keV RXTE light curve we find that the UFOs are preferentially detected during periods of increasing flux. We also find the possibility to place the UFOs within the known X-ray dips-jet ejection cycles, which has been shown to be a strong proof of the disc-jet connection, in analogue with stellar-mass black holes. However, given the limited number of observations presently available, these relations are only tentative and additional spectral monitoring is needed to test them conclusively.

  18. Dimensional isotropy of 6H and 3C SiC under neutron irradiation

    DOE PAGES

    Snead, Lance L.; Katoh, Yutai; Koyanagi, Takaaki; ...

    2016-01-16

    This investigation experimentally determines the as-irradiated crystal axes dimensional change of the common polytypes of SiC considered for nuclear application. Single crystal α-SiC (6H), β-SiC (3C), CVD β-SiC, and single crystal Si have been neutron irradiated near 60 °C from 2 × 1023 to 2 × 1026 n/m2 (E > 0.1 MeV), or about 0.02–20 dpa, in order to study the effect of irradiation on bulk swelling and strain along independent crystalline axes. Single crystal, powder diffractometry and density measurement have been carried out. For all neutron doses where the samples remained crystalline all SiC materials demonstrated equivalent swelling behavior.more » Moreover the 6H–SiC expanded isotropically. The magnitude of the swelling followed a ~0.77 power law against dose consistent with a microstructure evolution driven by single interstitial (carbon) mobility. Extraordinarily large ~7.8% volume expansion in SiC was observed prior to amorphization. Above ~0.9 × 1025 n/m2 (E > 0.1 MeV) all SiC materials became amorphous with an identical swelling: a 11.7% volume expansion, lowering the density to 2.84 g/cm3. As a result, the as-amorphized density was the same at the 2 × 1025 and 2 × 1026 n/m2 (E > 0.1 MeV) dose levels.« less

  19. Dimensional isotropy of 6H and 3C SiC under neutron irradiation

    SciTech Connect

    Snead, Lance L.; Katoh, Yutai; Koyanagi, Takaaki; Terrani, Kurt A.; Specht, Eliot D.

    2016-01-16

    This investigation experimentally determines the as-irradiated crystal axes dimensional change of the common polytypes of SiC considered for nuclear application. Single crystal α-SiC (6H), β-SiC (3C), CVD β-SiC, and single crystal Si have been neutron irradiated near 60 °C from 2 × 1023 to 2 × 1026 n/m2 (E > 0.1 MeV), or about 0.02–20 dpa, in order to study the effect of irradiation on bulk swelling and strain along independent crystalline axes. Single crystal, powder diffractometry and density measurement have been carried out. For all neutron doses where the samples remained crystalline all SiC materials demonstrated equivalent swelling behavior. Moreover the 6H–SiC expanded isotropically. The magnitude of the swelling followed a ~0.77 power law against dose consistent with a microstructure evolution driven by single interstitial (carbon) mobility. Extraordinarily large ~7.8% volume expansion in SiC was observed prior to amorphization. Above ~0.9 × 1025 n/m2 (E > 0.1 MeV) all SiC materials became amorphous with an identical swelling: a 11.7% volume expansion, lowering the density to 2.84 g/cm3. As a result, the as-amorphized density was the same at the 2 × 1025 and 2 × 1026 n/m2 (E > 0.1 MeV) dose levels.

  20. The nature of the γ-ray flare associated with blazar 3C 454.3

    NASA Astrophysics Data System (ADS)

    Hu, Wen; Fan, Zhong-Hui; Dai, Ben-Zhong

    2015-09-01

    We have studied the simultaneous spectral energy distributions (SEDs) of the 2009 December flare and those of the quiescent state of blazar 3C 454.3 by constructing a multi-component model. We find that all six SEDs can be explained by a one-zone leptonic model involving synchrotron self-Compton (SSC) plus external Compton emission from an accretion disk (ECD) and that from a broad-line region (ECC). X-ray emission is dominated by the SSC mechanism, and the γ-ray spectrum is well represented by a combination of ECD and ECC processes. Our results indicate that the energy density of the magnetic field and electrons decrease with distance from the central engine, and the Doppler factor increases with the blob moving outward in the development of the 2009 December flare. The increase in the observed flux density is possibly due to the increase in the Doppler factor of the blob. The relation between the Doppler factor δb and the distance from the central black hole suggests the magnetically driven jets span a sub-pc scale, and the relation between the magnetic field B' and the dimension of the emission region R'b is in good agreement with what is required by conservation of magnetic flux. The weak “harder-when-brighter” behavior of the γ-ray spectrum could be a result of the increase in Doppler factor during the outward motion of the blob. The parameters during the quiescent state obviously deviate from those during the flare state. We propose that the flare was likely caused by the ejection of a new blob. The gamma-ray emissions in different states are associated with the evolution of the blob.

  1. Early Fermi Gamma-ray Space Telescope Observations of the Quasar 3C454.3

    SciTech Connect

    Abdo, A

    2009-05-07

    This is the first report of Fermi Gamma-ray Space Telescope observations of the quasar 3C 454.3, which has been undergoing pronounced long-term outbursts since 2000. The data from the Large Area Telescope (LAT), covering 2008 July 7-October 6, indicate strong, highly variable {gamma}-ray emission with an average flux of {approx} 3 x 10{sup -6} photons cm{sup -2} s{sup -1}, for energies > 100 MeV. The {gamma}-ray flux is variable, with strong, distinct, symmetrically-shaped flares for which the flux increases by a factor of several on a time scale of about three days. This variability indicates a compact emission region, and the requirement that the source is optically thin to pair-production implies relativistic beaming with Doppler factor {delta} > 8, consistent with the values inferred from VLBI observations of superluminal expansion ({delta} {approx} 25). The observed {gamma}-ray spectrum is not consistent with a simple power-law, but instead steepens strongly above {approx} 2 GeV, and is well described by a broken power-law with photon indices of {approx} 2.3 and {approx} 3.5 below and above the break, respectively. This is the first direct observation of a break in the spectrum of a high luminosity blazar above 100 MeV, and it is likely direct evidence for an intrinsic break in the energy distribution of the radiating particles. Alternatively, the spectral softening above 2GeV could be due to -ray absorption via photonphoton pair production on the soft X-ray photon field of the host AGN, but such an interpretation would require the dissipation region to be located very close ({approx}< 100 gravitational radii) to the black hole, which would be inconsistent with the X-ray spectrum of the source.

  2. Biochemical Characterization of Recombinant Enterovirus 71 3C Protease with Fluorogenic Model Peptide Substrates and Development of a Biochemical Assay

    PubMed Central

    Shang, Luqing; Zhang, Shumei; Yang, Xi; Sun, Jixue; Li, Linfeng; Cui, Zhengjie; He, Qiuhong; Guo, Yu

    2014-01-01

    Enterovirus 71 (EV71), a primary pathogen of hand, foot, and mouth disease (HFMD), affects primarily infants and children. Currently, there are no effective drugs against HFMD. EV71 3C protease performs multiple tasks in the viral replication, which makes it an ideal antiviral target. We synthesized a small set of fluorogenic model peptides derived from cleavage sites of EV71 polyprotein and examined their efficiencies of cleavage by EV71 3C protease. The novel peptide P08 [(2-(N-methylamino)benzoyl) (NMA)-IEALFQGPPK(DNP)FR] was determined to be the most efficiently cleaved by EV71 3C protease, with a kinetic constant kcat/Km of 11.8 ± 0.82 mM−1 min−1. Compared with literature reports, P08 gave significant improvement in the signal/background ratio, which makes it an attractive substrate for assay development. A Molecular dynamics simulation study elaborated the interactions between substrate P08 and EV71 3C protease. Arg39, which is located at the bottom of the S2 pocket of EV71 3C protease, may participate in the proteolysis process of substrates. With an aim to evaluate EV71 3C protease inhibitors, a reliable and robust biochemical assay with a Z′ factor of 0.87 ± 0.05 was developed. A novel compound (compound 3) (50% inhibitory concentration [IC50] = 1.89 ± 0.25 μM) was discovered using this assay, which effectively suppressed the proliferation of EV 71 (strain Fuyang) in rhabdomyosarcoma (RD) cells with a highly selective index (50% effective concentration [EC50] = 4.54 ± 0.51 μM; 50% cytotoxic concentration [CC50] > 100 μM). This fast and efficient assay for lead discovery and optimization provides an ideal platform for anti-EV71 drug development targeting 3C protease. PMID:25421478

  3. Atmospheric chemistry of CF{sub 3}C(O)OCH{sub 2}CF{sub 3}: UV spectra and kinetic data for CF{sub 3}C(O)OCH({sm_bullet})CF{sub 3} and CF{sub 3}C(O)OCH(OO{sm_bullet})CF{sub 3} radicals, and atmospheric fate of CF{sub 3}C(O)OCH(O{sm_bullet})CF{sub 3} radicals

    SciTech Connect

    Stein, T.N.N.; Christensen, L.K.; Platz, J.; Sehested, J.; Nielsen, O.J.; Wallington, T.J.

    1999-07-22

    Recognition of the adverse effect of chlorofluorocarbon (CFC) release into the atmosphere has led to an international effort to replace CFCs with environmentally acceptable alternatives. Hydrofluoroethers (HFEs) are fluids designed to replace CFCs in applications such as the cleaning of electronic equipment, heat transfer agents in refrigeration systems, and carrier fluids for lubricant deposition. HFEs are volatile compounds and will be released into the atmosphere during its use. In the atmosphere, photochemical oxidation of HFEs will lead to the formation of fluorinated esters and fluorinated formates. The atmospheric fate of these products is unknown at the present. To improve their understanding of the atmospheric chemistry of esters the authors have studied the atmospheric chemistry of 2,2,2-trifluoroethyltrifluoroacetate CF{sub 3}C(O)OCH{sub 2}CF{sub 3} (bp = 55.0 C). This compound provides insight into the behavior of alkyl, alkyl peroxy, and alkoxy radicals formed {alpha} to the ester functionality. The atmospheric fate of CF{sub 3}C(O)OCH(O{sup {sm_bullet}})CF{sub 3} radicals was investigated in a FTIR smog chamber. Three loss processes for the CF{sub 3}C(O)OCH(O{sup {sm_bullet}})CF{sub 3} radicals were identified at 296 K and 700 Torr total pressure, reaction with O{sub 2} to form CF{sub 3}C(O)OC(O)CF{sub 3}, {alpha}-rearrangement to form CF{sub 3}C(O){sm_bullet} radicals and CF{sub 3}C(O)OH, and decomposition via a mechanism which is unclear. In 760 Torr of air at 296 K, 65% of the CF{sub 3}C(O)OCH(O{sm_bullet})CF{sub 3} radicals react with oxygen, 18% undergo {alpha}-rearrangement, while the fate of the remaining 17% is unclear.

  4. A Novel MIF Signaling Pathway Drives the Malignant Character of Pancreatic Cancer by Targeting NR3C2.

    PubMed

    Yang, Shouhui; He, Peijun; Wang, Jian; Schetter, Aaron; Tang, Wei; Funamizu, Naotake; Yanaga, Katsuhiko; Uwagawa, Tadashi; Satoskar, Abhay R; Gaedcke, Jochen; Bernhardt, Markus; Ghadimi, B Michael; Gaida, Matthias M; Bergmann, Frank; Werner, Jens; Ried, Thomas; Hanna, Nader; Alexander, H Richard; Hussain, S Perwez

    2016-07-01

    Pancreatic cancers with aberrant expression of macrophage migration inhibitory factor (MIF) are particularly aggressive. To identify key signaling pathways that drive disease aggressiveness in tumors with high MIF expression, we analyzed the expression of coding and noncoding genes in high and low MIF-expressing tumors in multiple cohorts of pancreatic ductal adenocarcinoma (PDAC) patients. The key genes and pathways identified were linked to patient survival and were mechanistically, functionally, and clinically characterized using cell lines, a genetically engineered mouse model, and PDAC patient cohorts. Here, we report evidence of a novel MIF-driven signaling pathway that inhibits the orphan nuclear receptor NR3C2, a previously undescribed tumor suppressor that impacts aggressiveness and survival in PDAC. Mechanistically, MIF upregulated miR-301b that targeted NR3C2 and suppressed its expression. PDAC tumors expressing high levels of MIF displayed elevated levels of miR-301b and reduced levels of NR3C2. In addition, reduced levels of NR3C2 expression correlated with poorer survival in multiple independent cohorts of PDAC patients. Functional analysis showed that NR3C2 inhibited epithelial-to-mesenchymal transition and enhanced sensitivity to the gemcitabine, a chemotherapeutic drug used in PDAC standard of care. Furthermore, genetic deletion of MIF disrupted a MIF-mir-301b-NR3C2 signaling axis, reducing metastasis and prolonging survival in a genetically engineered mouse model of PDAC. Taken together, our results offer a preclinical proof of principle for candidate therapies to target a newly described MIF-miR-301b-NR3C2 signaling axis for PDAC management. Cancer Res; 76(13); 3838-50. ©2016 AACR.

  5. Haploinsufficiency for NR3C1, the gene encoding the glucocorticoid receptor, in blastic plasmacytoid dendritic cell neoplasms.

    PubMed

    Emadali, Anouk; Hoghoughi, Neda; Duley, Samuel; Hajmirza, Azadeh; Verhoeyen, Els; Cosset, Francois-Loic; Bertrand, Philippe; Roumier, Christophe; Roggy, Anne; Suchaud-Martin, Céline; Chauvet, Martine; Bertrand, Sarah; Hamaidia, Sieme; Rousseaux, Sophie; Josserand, Véronique; Charles, Julie; Templier, Isabelle; Maeda, Takahiro; Bruder-Costa, Juliana; Chaperot, Laurence; Plumas, Joel; Jacob, Marie-Christine; Bonnefoix, Thierry; Park, Sophie; Gressin, Remy; Tensen, Cornelis P; Mecucci, Cristina; Macintyre, Elizabeth; Leroux, Dominique; Brambilla, Elisabeth; Nguyen-Khac, Florence; Luquet, Isabelle; Penther, Dominique; Bastard, Christian; Jardin, Fabrice; Lefebvre, Christine; Garnache, Francine; Callanan, Mary B

    2016-06-16

    Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and highly aggressive leukemia for which knowledge on disease mechanisms and effective therapies are currently lacking. Only a handful of recurring genetic mutations have been identified and none is specific to BPDCN. In this study, through molecular cloning in an index case that presented a balanced t(3;5)(q21;q31) and molecular cytogenetic analyses in a further 46 cases, we identify monoallelic deletion of NR3C1 (5q31), encoding the glucocorticoid receptor (GCR), in 13 of 47 (28%) BPDCN patients. Targeted deep sequencing in 36 BPDCN cases, including 10 with NR3C1 deletion, did not reveal NR3C1 point mutations or indels. Haploinsufficiency for NR3C1 defined a subset of BPDCN with lowered GCR expression and extremely poor overall survival (P = .0006). Consistent with a role for GCR in tumor suppression, functional analyses coupled with gene expression profiling identified corticoresistance and loss-of-EZH2 function as major downstream consequences of NR3C1 deletion in BPDCN. Subsequently, more detailed analyses of the t(3;5)(q21;q31) revealed fusion of NR3C1 to a long noncoding RNA (lncRNA) gene (lincRNA-3q) that encodes a novel, nuclear, noncoding RNA involved in the regulation of leukemia stem cell programs and G1/S transition, via E2F. Overexpression of lincRNA-3q was a consistent feature of malignant cells and could be abrogated by bromodomain and extraterminal domain (BET) protein inhibition. Taken together, this work points to NR3C1 as a haploinsufficient tumor suppressor in a subset of BPDCN and identifies BET inhibition, acting at least partially via lncRNA blockade, as a novel treatment option in BPDCN.

  6. Haploinsufficiency for NR3C1, the gene encoding the glucocorticoid receptor, in blastic plasmacytoid dendritic cell neoplasms

    PubMed Central

    Emadali, Anouk; Hoghoughi, Neda; Duley, Samuel; Hajmirza, Azadeh; Verhoeyen, Els; Cosset, Francois-Loic; Bertrand, Philippe; Roumier, Christophe; Roggy, Anne; Suchaud-Martin, Céline; Chauvet, Martine; Bertrand, Sarah; Hamaidia, Sieme; Rousseaux, Sophie; Josserand, Véronique; Charles, Julie; Templier, Isabelle; Maeda, Takahiro; Bruder-Costa, Juliana; Chaperot, Laurence; Plumas, Joel; Jacob, Marie-Christine; Bonnefoix, Thierry; Park, Sophie; Gressin, Remy; Tensen, Cornelis P.; Mecucci, Cristina; Macintyre, Elizabeth; Leroux, Dominique; Brambilla, Elisabeth; Nguyen-Khac, Florence; Luquet, Isabelle; Penther, Dominique; Bastard, Christian; Jardin, Fabrice; Lefebvre, Christine; Garnache, Francine

    2016-01-01

    Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and highly aggressive leukemia for which knowledge on disease mechanisms and effective therapies are currently lacking. Only a handful of recurring genetic mutations have been identified and none is specific to BPDCN. In this study, through molecular cloning in an index case that presented a balanced t(3;5)(q21;q31) and molecular cytogenetic analyses in a further 46 cases, we identify monoallelic deletion of NR3C1 (5q31), encoding the glucocorticoid receptor (GCR), in 13 of 47 (28%) BPDCN patients. Targeted deep sequencing in 36 BPDCN cases, including 10 with NR3C1 deletion, did not reveal NR3C1 point mutations or indels. Haploinsufficiency for NR3C1 defined a subset of BPDCN with lowered GCR expression and extremely poor overall survival (P = .0006). Consistent with a role for GCR in tumor suppression, functional analyses coupled with gene expression profiling identified corticoresistance and loss-of-EZH2 function as major downstream consequences of NR3C1 deletion in BPDCN. Subsequently, more detailed analyses of the t(3;5)(q21;q31) revealed fusion of NR3C1 to a long noncoding RNA (lncRNA) gene (lincRNA-3q) that encodes a novel, nuclear, noncoding RNA involved in the regulation of leukemia stem cell programs and G1/S transition, via E2F. Overexpression of lincRNA-3q was a consistent feature of malignant cells and could be abrogated by bromodomain and extraterminal domain (BET) protein inhibition. Taken together, this work points to NR3C1 as a haploinsufficient tumor suppressor in a subset of BPDCN and identifies BET inhibition, acting at least partially via lncRNA blockade, as a novel treatment option in BPDCN. PMID:27060168

  7. Biochemical characterization of recombinant Enterovirus 71 3C protease with fluorogenic model peptide substrates and development of a biochemical assay.

    PubMed

    Shang, Luqing; Zhang, Shumei; Yang, Xi; Sun, Jixue; Li, Linfeng; Cui, Zhengjie; He, Qiuhong; Guo, Yu; Sun, Yuna; Yin, Zheng

    2015-04-01

    Enterovirus 71 (EV71), a primary pathogen of hand, foot, and mouth disease (HFMD), affects primarily infants and children. Currently, there are no effective drugs against HFMD. EV71 3C protease performs multiple tasks in the viral replication, which makes it an ideal antiviral target. We synthesized a small set of fluorogenic model peptides derived from cleavage sites of EV71 polyprotein and examined their efficiencies of cleavage by EV71 3C protease. The novel peptide P08 [(2-(N-methylamino)benzoyl) (NMA)-IEALFQGPPK(DNP)FR] was determined to be the most efficiently cleaved by EV71 3C protease, with a kinetic constant kcat/Km of 11.8 ± 0.82 mM(-1) min(-1). Compared with literature reports, P08 gave significant improvement in the signal/background ratio, which makes it an attractive substrate for assay development. A Molecular dynamics simulation study elaborated the interactions between substrate P08 and EV71 3C protease. Arg39, which is located at the bottom of the S2 pocket of EV71 3C protease, may participate in the proteolysis process of substrates. With an aim to evaluate EV71 3C protease inhibitors, a reliable and robust biochemical assay with a Z' factor of 0.87 ± 0.05 was developed. A novel compound (compound 3) (50% inhibitory concentration [IC50] = 1.89 ± 0.25 μM) was discovered using this assay, which effectively suppressed the proliferation of EV 71 (strain Fuyang) in rhabdomyosarcoma (RD) cells with a highly selective index (50% effective concentration [EC50] = 4.54 ± 0.51 μM; 50% cytotoxic concentration [CC50] > 100 μM). This fast and efficient assay for lead discovery and optimization provides an ideal platform for anti-EV71 drug development targeting 3C protease.

  8. G3-C12 Peptide Reverses Galectin-3 from Foe to Friend for Active Targeting Cancer Treatment.

    PubMed

    Sun, Wei; Li, Lian; Yang, Qingqing; Shan, Wei; Zhang, Zhirong; Huang, Yuan

    2015-11-02

    Galectin-3 is overexpressed by numerous carcinomas and is a potential target for active tumor treatments. On the other hand, galectin-3 also plays a key role in cancer progression and prevents cells from undergoing apoptosis, thereby offsetting the benefits of active targeting drugs. However, the relative contribution of the protective antiapoptotic effects of galectin-3 and the proapoptotic effects of galectin-3-targeted therapies has remained yet unrevealed. Here, we show that a galectin-3-binding peptide G3-C12 could reverse galectin-3 from foe to friend for active targeting delivery system. Results showed G3-C12 modified N-(2-hydroxypropyl)methacrylamide copolymer doxorubicin conjugates (G3-C12-HPMA-Dox) could internalize into galectin-3 overexpressed PC-3 cells via a highly specific ligand-receptor pathway (2.2 times higher cellular internalization than HPMA-Dox). The internalized Dox stimulated the translocation of galectin-3 to the mitochondria to prevent from apoptosis. In turn, this caused G3-C12-HPMA-Dox to concentrate into the mitochondria after binding to galectin-3 intracellularly. Initially, mitochondrial galectin-3 weakened Dox-induced mitochondrial damage; however, as time progressed, G3-C12 active-mediation allowed increasing amounts of Dox to be delivered to the mitochondria, which eventually induced higher level of apoptosis than nontargeted copolymers. In addition, G3-C12 downregulates galectin-3 expression, 0.43 times lower than control cells, which could possibly be responsible for the suppressed cell migration. Thus, G3-C12 peptide exerts sequential targeting to both cell membrane and mitochondria via regulating galectin-3, and eventually reverses and overcomes the protective effects of galectin-3; therefore, it could be a promising agent for the treatment of galectin-3-overexpressing cancers.

  9. The EBV Latent Antigen 3C Inhibits Apoptosis through Targeted Regulation of Interferon Regulatory Factors 4 and 8

    PubMed Central

    Banerjee, Shuvomoy; Lu, Jie; Cai, Qiliang; Saha, Abhik; Jha, Hem Chandra; Dzeng, Richard Kuo; Robertson, Erle S.

    2013-01-01

    Epstein-Barr virus (EBV) is linked to a broad spectrum of B-cell malignancies. EBV nuclear antigen 3C (EBNA3C) is an encoded latent antigen required for growth transformation of primary human B-lymphocytes. Interferon regulatory factor 4 (IRF4) and 8 (IRF8) are transcription factors of the IRF family that regulate diverse functions in B cell development. IRF4 is an oncoprotein with anti-apoptotic properties and IRF8 functions as a regulator of apoptosis and tumor suppressor in many hematopoietic malignancies. We now demonstrate that EBNA3C can contribute to B-cell transformation by modulating the molecular interplay between cellular IRF4 and IRF8. We show that EBNA3C physically interacts with IRF4 and IRF8 with its N-terminal domain in vitro and forms a molecular complex in cells. We identified the Spi-1/B motif of IRF4 as critical for EBNA3C interaction. We also demonstrated that EBNA3C can stabilize IRF4, which leads to downregulation of IRF8 by enhancing its proteasome-mediated degradation. Further, si-RNA mediated knock-down of endogenous IRF4 results in a substantial reduction in proliferation of EBV-transformed lymphoblastoid cell lines (LCLs), as well as augmentation of DNA damage-induced apoptosis. IRF4 knockdown also showed reduced expression of its targeted downstream signalling proteins which include CDK6, Cyclin B1 and c-Myc all critical for cell proliferation. These studies provide novel insights into the contribution of EBNA3C to EBV-mediated B-cell transformation through regulation of IRF4 and IRF8 and add another molecular link to the mechanisms by which EBV dysregulates cellular activities, increasing the potential for therapeutic intervention against EBV-associated cancers. PMID:23658517

  10. Transient infrared absorption of t-CH3C(O)OO, c-CH3C(O)OO, and α-lactone recorded in gaseous reactions of CH3CO and O2

    NASA Astrophysics Data System (ADS)

    Chen, Sun-Yang; Lee, Yuan-Pern

    2010-03-01

    A step-scan Fourier-transform infrared spectrometer coupled with a multipass absorption cell was utilized to monitor the transient species produced in gaseous reactions of CH3CO and O2; IR absorption spectra of CH3C(O)OO and α-lactone were observed. Absorption bands with origins at 1851±1, 1372±2, 1169±6, and 1102±3 cm-1 are attributed to t-CH3C(O)OO, and those at 1862±3, 1142±4, and 1078±6 cm-1 are assigned to c-CH3C(O)OO. A weak band near 1960 cm-1 is assigned to α-lactone, cyc-CH2C(O)O, a coproduct of OH. These observed rotational contours agree satisfactorily with simulated bands based on predicted rotational parameters and dipole derivatives, and observed vibrational wavenumbers agree with harmonic vibrational wavenumbers predicted with B3LYP/aug-cc-pVDZ density-functional theory. The observed relative intensities indicate that t-CH3C(O)OO is more stable than c-CH3C(O)OO by 3±2 kJ mol-1. Based on these observations, the branching ratio for the OH+α-lactone channel of the CH3CO+O2 reaction is estimated to be 0.04±0.01 under 100 Torr of O2 at 298 K. A simple kinetic model is employed to account for the decay of CH3C(O)OO.

  11. Invasive C4 Perennial Grass Alters Net Ecosystem Exchange in Mixed C3/C4 Savanna Grassland

    NASA Astrophysics Data System (ADS)

    Basham, T. S.; Litvak, M.

    2006-12-01

    The invasion of ecosystems by non-native plants that differ from native plants in physiological characteristics and phenology has the potential to alter ecosystem function. In Texas and other regions of the southern central plains of the United States, the introduced C4 perennial grass, Bothriochloa ischaemum, invades C3/C4 mixed grasslands and savannas, resulting in decreased plant community diversity (Gabbard 2003; Harmoney et al 2004). The objective of this study was to quantify how the conversion of these mixed grass communities to C4 dominated, B. ischaemum monocultures impacts carbon cycling and sequestration. Seasonal measurements of Net Ecosystem Exchange (NEE) of CO2, leaf level gas exchange and soil respiration were compared between savanna grassland plots composed of either naturally occurring B. ischaemum monocultures or native mixed grasses (n=16). NEE was measured using a closed system chamber that attached to permanently installed stainless steel bases. Temperature, soil moisture, aerial percent species cover and leaf area index were also monitored in plots to explain variability in measured responses. Results showed that NEE differed seasonally between invaded and native plots due to 1) greater leaf surface area per unit ground area in invaded plots, 2) differences in phenological patterns of plant activity and 3) differences in responses to water limitation between invaded and native plots. Cold season and summer drought NEE were driven primarily by belowground respiration in both plot types, however spring uptake activity commenced two months later in invaded plots. This later start in invaded plots was compensated for by greater uptake throughout the growing season and in particular during the drier summer months. Differences in NEE between plot types were not due to differences in soil respiration nor were they due to greater leaf level photosynthetic capabilities of B. ischaemum relative to the dominant native grasses. NEE, soil respiration and

  12. Activity of the Human Rhinovirus 3C Protease Studied in Various Buffers, Additives and Detergents Solutions for Recombinant Protein Production

    PubMed Central

    Tufail, Soban; Ismat, Fouzia; Imran, Muhammad; Iqbal, Mazhar; Mirza, Osman; Rhaman, Moazur

    2016-01-01

    Proteases are widely used to remove affinity and solubility tags from recombinant proteins to avoid potential interference of these tags with the structure and function of the fusion partner. In recent years, great interest has been seen in use of the human rhinovirus 3C protease owing to its stringent sequence specificity and enhanced activity. Like other proteases, activity of the human rhinovirus 3C protease can be affected in part by the buffer components and additives that are generally employed for purification and stabilization of proteins, hence, necessitate their removal by tedious and time-consuming procedures before proteolysis can occur. To address this issue, we examined the effect of elution buffers used for common affinity based purifications, salt ions, stability/solubility and reducing agents, and detergents on the activity of the human rhinovirus 3C protease using three different fusion proteins at 4°C, a temperature of choice for purification of many proteins. The results show that the human rhinovirus 3C protease performs better at 4°C than the frequently used tobacco etch virus protease and its activity was insensitive to most of the experimental conditions tested. Though number of fusion proteins tested is limited, we expect that these finding will facilitate the use of the human rhinovirus 3C protease in recombinant protein production for pharmaceutical and biotechnological applications. PMID:27093053

  13. Structures and Energetics of Defects: A Comparative Study of 3C- and 4H-SiC

    SciTech Connect

    Gao, Fei; Posselt, Matthias; Belko, V; Zhang, Yanwen; Weber, William J.

    2004-05-01

    The structures, formation energies and stable configurations of elementary defects (vacancies, antisite defects and self interstitials) in 3C- and 4H-SiC are studied using classical molecular dynamics simulation with a recently developed interatomic potential. The defect structures in 3C-SiC are relatively simple, but those in 4H-SiC are more complicated. The interstitials between hexagonal and trigonal rings are characteristic for 4H-SiC and other hexagonal polytypes, but not for 3C-SiC. The number of non-equivalent defects in 4H-SiC is much higher than that in 3C-SiC, and a considerable difference is found for some complex and anisotropic defects, in particular for the dumbbells D1Si-Si, D1Si-C and D2Si-C. The lattice deformation beyond the first nearest neighbor shell, which depends strongly on the polytype structure, plays an important role on these effects. However, the polytypism does not have a significant influence on the structure and energetics of the more compact and isotropic defects, such as vacancies and antisite defects. Despite the complexity of defect configurations, the tetrahedral interstitials have very similar properties in 3C- and 4H-SiC because their first, second and third nearest neighbor shells are identical.

  14. Deletion of the late cornified envelope LCE3B and LCE3C genes as a susceptibility factor for psoriasis.

    PubMed

    de Cid, Rafael; Riveira-Munoz, Eva; Zeeuwen, Patrick L J M; Robarge, Jason; Liao, Wilson; Dannhauser, Emma N; Giardina, Emiliano; Stuart, Philip E; Nair, Rajan; Helms, Cynthia; Escaramís, Georgia; Ballana, Ester; Martín-Ezquerra, Gemma; den Heijer, Martin; Kamsteeg, Marijke; Joosten, Irma; Eichler, Evan E; Lázaro, Conxi; Pujol, Ramón M; Armengol, Lluís; Abecasis, Gonçalo; Elder, James T; Novelli, Giuseppe; Armour, John A L; Kwok, Pui-Yan; Bowcock, Anne; Schalkwijk, Joost; Estivill, Xavier

    2009-02-01

    Psoriasis is a common inflammatory skin disease with a prevalence of 2-3% in individuals of European ancestry. In a genome-wide search for copy number variants (CNV) using a sample pooling approach, we have identified a deletion comprising LCE3B and LCE3C, members of the late cornified envelope (LCE) gene cluster. The absence of LCE3B and LCE3C (LCE3C_LCE3B-del) is significantly associated (P = 1.38E-08) with risk of psoriasis in 2,831 samples from Spain, The Netherlands, Italy and the United States, and in a family-based study (P = 5.4E-04). LCE3C_LCE3B-del is tagged by rs4112788 (r(2) = 0.93), which is also strongly associated with psoriasis (P < 6.6E-09). LCE3C_LCE3B-del shows epistatic effects with the HLA-Cw6 allele on the development of psoriasis in Dutch samples and multiplicative effects in the other samples. LCE expression can be induced in normal epidermis by skin barrier disruption and is strongly expressed in psoriatic lesions, suggesting that compromised skin barrier function has a role in psoriasis susceptibility.

  15. Activity of the Human Rhinovirus 3C Protease Studied in Various Buffers, Additives and Detergents Solutions for Recombinant Protein Production.

    PubMed

    Ullah, Raheem; Shah, Majid Ali; Tufail, Soban; Ismat, Fouzia; Imran, Muhammad; Iqbal, Mazhar; Mirza, Osman; Rhaman, Moazur

    2016-01-01

    Proteases are widely used to remove affinity and solubility tags from recombinant proteins to avoid potential interference of these tags with the structure and function of the fusion partner. In recent years, great interest has been seen in use of the human rhinovirus 3C protease owing to its stringent sequence specificity and enhanced activity. Like other proteases, activity of the human rhinovirus 3C protease can be affected in part by the buffer components and additives that are generally employed for purification and stabilization of proteins, hence, necessitate their removal by tedious and time-consuming procedures before proteolysis can occur. To address this issue, we examined the effect of elution buffers used for common affinity based purifications, salt ions, stability/solubility and reducing agents, and detergents on the activity of the hum