Kerr metric in Bondi-Sachs form
Bishop, Nigel T.; Venter, Liebrecht R.
2006-04-15
A metric representing the Kerr geometry has been obtained by Pretorius and Israel. We make coordinate transformations on this metric, to bring it into Bondi-Sachs form. We investigate the behavior of the metric near the axis of symmetry and confirm elementary flatness, and we also confirm that it is asymptotic to the Bondi-Sachs form of the Schwarzschild geometry. The results obtained here are needed so that numerical relativity codes based on the characteristic formalism can be applied to a situation that contains a rotating black hole.
Substrate reduction therapy in the infantile form of Tay-Sachs disease.
Bembi, B; Marchetti, F; Guerci, V I; Ciana, G; Addobbati, R; Grasso, D; Barone, R; Cariati, R; Fernandez-Guillen, L; Butters, T; Pittis, M G
2006-01-24
Substrate reduction therapy (SRT) with miglustat has been proposed for treatment of some lysosomal storage disorders. Based on the positive experience in Gaucher disease and experimental data in Tay-Sachs (TSD) and Sandhoff animal models, the authors investigated the clinical efficacy of SRT in two patients with infantile TSD. SRT could not arrest the patients' neurologic deterioration. However, a significant drug concentration in CSF as well as macrocephaly prevention were observed.
Diagnosis and molecular characterization of non-classic forms of Tay-Sachs disease in Brazil.
Rozenberg, R; Kok, F; Burin, M G; Sá Miranda, M C; Vasques, C; Henriques-Souza, A M M; Giugliani, R; Vainzof, Mariz; Pereira, L V
2006-06-01
Molecular analysis of five Brazilian families, including eight patients presenting with nonclassic Tay-Sachs disease, was performed to identify frequent causative mutations and their correlation with clinical course. Three patients were affected by the B1 subacute variant and were shown to carry the R178H mutation (the DN allele), which is also common among Portuguese patients. Two of them were compound heterozygotes, whereas the third presented with the mutation in both alleles. Since Brazil was a Portuguese colony for over two centuries, common ancestry might be the probable explanation. The fourth patient presented with a juvenile phenotype and carries the R499H mutation, which has been reported only once worldwide and is associated with residual enzyme activity, responsible for a slower clinical course. The fifth family, of an Ashkenazi Jewish background, showed an extensive intrafamilial clinical variability among three affected sibs presenting with muscle atrophy, ataxia, and psychiatric symptoms. They were first diagnosed as having atypical spinal muscular atrophy and, subsequently, spinocerebellar ataxia, but, recently, the diagnosis of late-onset Tay-Sachs disease was confirmed based on reduced plasma hexosaminidase A activity and the G269S/InsTATC1278 genotype. It is therefore highly recommended to test patients with a similar clinical history for Tay-Sachs disease. In the same family, one first cousin committed suicide at the age of 24 years, presenting with a clinical phenotype that suggested an undiagnosed case and highlighting the effect of the intrafamilial clinical variability in delaying a prompt diagnosis. It is now recognized that his parents are, in fact, a carrier couple. Additionally, another relative had been previously identified as a heterozygote in a Tay-Sachs disease screening program, but the information was not shared among the family. Since this information might anticipate diagnosis and genetic counseling, it is advisable that
Resources - Tay-Sachs ... The following organizations provide information on Tay-Sachs disease : March of Dimes -- www.marchofdimes.com/pnhec/4439_1227.asp National Tay-Sachs and Allied Diseases Association -- www.ntsad.org
Tay-Sachs disease is a rare, inherited disease. It is a type of lipid metabolism disorder. It causes too ... cells, causing mental and physical problems. . Infants with Tay-Sachs disease appear to develop normally for the first few ...
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Electromagnetic nucleon form factors
Bender, A.; Roberts, C.D.; Frank, M.R.
1995-08-01
The Dyson-Schwinger equation framework is employed to obtain expressions for the electromagnetic nucleon form factor. In generalized impulse approximation the form factor depends on the dressed quark propagator, the dressed quark-photon vertex, which is crucial to ensuring current conservation, and the nucleon Faddeev amplitude. The approach manifestly incorporates the large space-like-q{sup 2} renormalization group properties of QCD and allows a realistic extrapolation to small space-like-q{sup 2}. This extrapolation allows one to relate experimental data to the form of the quark-quark interaction at small space-like-q{sup 2}, which is presently unknown. The approach provides a means of unifying, within a single framework, the treatment of the perturbative and nonperturbative regimes of QCD. The wealth of experimental nucleon form factor data, over a large range of q{sup 2}, ensures that this application will provide an excellent environment to test, improve and extend our approach.
Nucleon electromagnetic form factors
Kees de Jager
2000-01-01
A review of data on the nucleon electromagnetic form factors in the space-like region is presented. Recent results from experiments using polarized beams and polarized targets or nucleon recoil polarimeters have yielded a significant improvement on the precision of the data obtained with the traditional Rosenbluth separation. Future plans for extended measurements are outlined.
Kees de Jager
2001-12-01
A review of data on the nucleon electromagnetic form factors in the space-like region is presented. Recent results from experiments using polarized beams and polarized targets or nucleon recoil polarimeters have yielded a significant improvement on the precision of the data obtained with the traditional Rosenbluth separation. Future plans for extended measurements are outlined.
Kees de Jager
2002-10-01
A review of data on the nucleon electro-weak form factors in the space-like region is presented. Recent results from experiments using polarized beams and either polarized targets or nucleon recoil polarimeters have yielded a significant improvement on the precision of the electromagnetic data obtained with the traditional Rosenbluth separation. An outlook is presented of planned experiments.
NASA Astrophysics Data System (ADS)
Lomon, Earle L.; Pacetti, Simone
2016-09-01
The pion electromagnetic form factor and two-pion production in electron-positron collisions are simultaneously fitted by a vector dominance model evolving to perturbative QCD at large momentum transfer. This model was previously successful in simultaneously fitting the nucleon electromagnetic form factors (spacelike region) and the electromagnetic production of nucleon-antinucleon pairs (timelike region). For this pion case dispersion relations are used to produce the analytic connection of the spacelike and timelike regions. The fit to all the data is good, especially for the newer sets of timelike data. The description of high-q2 data, in the timelike region, requires one more meson with ρ quantum numbers than listed in the 2014 Particle Data Group review.
Nucleon Electromagnetic Form Factors
Kees de Jager
2004-08-01
Although nucleons account for nearly all the visible mass in the universe, they have a complicated structure that is still incompletely understood. The first indication that nucleons have an internal structure, was the measurement of the proton magnetic moment by Frisch and Stern (1933) which revealed a large deviation from the value expected for a point-like Dirac particle. The investigation of the spatial structure of the nucleon, resulting in the first quantitative measurement of the proton charge radius, was initiated by the HEPL (Stanford) experiments in the 1950s, for which Hofstadter was awarded the 1961 Nobel prize. The first indication of a non-zero neutron charge distribution was obtained by scattering thermal neutrons off atomic electrons. The recent revival of its experimental study through the operational implementation of novel instrumentation has instigated a strong theoretical interest. Nucleon electro-magnetic form factors (EMFFs) are optimally studied through the exchange of a virtual photon, in elastic electron-nucleon scattering. The momentum transferred to the nucleon by the virtual photon can be selected to probe different scales of the nucleon, from integral properties such as the charge radius to scaling properties of its internal constituents. Polarization instrumentation, polarized beams and targets, and the measurement of the polarization of the recoiling nucleon have been essential in the accurate separation of the charge and magnetic form factors and in studies of the elusive neutron charge form factor.
Electromagnetic pion form factor
Roberts, C.D.
1995-08-01
A phenomenological Dyson-Schwinger/Bethe-Salpeter equation approach to QCD, formalized in terms of a QCD-based model field theory, the Global Color-symmetry Model (GCM), was used to calculate the generalized impulse approximation contribution to the electromagnetic pion form factor at space-like q{sup 2} on the domain [0,10] GeV{sup 2}. In effective field theories this form factor is sometimes understood as simply being due to Vector Meson Dominance (VMD) but this does not allow for a simple connection with QCD where the VMD contribution is of higher order than that of the quark core. In the GCM the pion is treated as a composite bound state of a confined quark and antiquark interacting via the exchange of colored vector-bosons. A direct study of the quark core contribution is made, using a quark propagator that manifests the large space-like-q{sup 2} properties of QCD, parameterizes the infrared behavior and incorporates confinement. It is shown that the few parameters which characterize the infrared form of the quark propagator may be chosen so as to yield excellent agreement with the available data. In doing this one directly relates experimental observables to properties of QCD at small space-like-q{sup 2}. The incorporation of confinement eliminates endpoint and pinch singularities in the calculation of F{sub {pi}}(q{sup 2}). With asymptotic freedom manifest in the dressed quark propagator the calculation yields q{sup 4}F{sub {pi}}(q{sup 2}) = constant, up to [q{sup 2}]- corrections, for space-like-q{sup 2} {approx_gt} 35 GeV{sup 2}, which indicates that soft, nonperturbative contributions dominate the form factor at presently accessible q{sup 2}. This means that the often-used factorization Ansatz fails in this exclusive process. A paper describing this work was submitted for publication. In addition, these results formed the basis for an invited presentation at a workshop on chiral dynamics and will be published in the proceedings.
Kees de Jager; B. Pire
1999-06-01
The authors review recent progress in the experimental knowledge of and theoretical speculations about nucleon form factors, with special emphasis on the large Q{sup 2} region. There is now a long history of continuous progress in the understanding of electromagnetic form factors at large momentum transfer. After the pioneering works leading to the celebrated quark counting rules, the understanding of hard scattering exclusive processes has been solidly founded. A perturbative QCD subprocess is factorized from a wave function-like distribution amplitude {var_phi}(x{sub i},Q{sup 2}) (x{sub i} being the light cone fractions of momentum carried by valence quarks), the Q{sup 2} dependence of which is analyzed in the renormalization group approach. Although an asymptotic expression emerges from this analysis for the x dependence of the distribution, it was quickly understood that the evolution to the asymptotic Q{sub 2} is very slow and that indeed some non perturbative input is required to get reliable estimates of this distribution amplitude at measurable Q{sup 2}.
Venus - Sag Caldera 'Sachs Patera
NASA Technical Reports Server (NTRS)
1991-01-01
This image of Sachs Patera on Venus is centered at 49 degrees north, 334 degrees east. Defined as a sag-caldera, Sachs is an elliptical depression 130 meters (81 feet) in depth, spanning 40 kilometers (25 miles) in width along its longest axis. The morphology implies that a chamber of molten material drained and collapsed, forming a depression surrounded by concentric scarps spaced 2-to-5 kilometers (1.2- to-3 miles) apart. The arc-shaped set of scarps, extending out to the north from the prominent ellipse, is evidence for a separate episode of withdrawal; the small lobe-shaped extension to the southwest may represent an additional event. Solidified lava flows 10-to-25 kilometers (6-to-16 miles) long, give the caldera its flower-like appearance. The flows are a lighter tone of gray in the radar data because the lava is blockier in texture and consequently returns more radar waves. Much of the lava, which was evacuated from the chamber, probably traveled to other locations underground, while some of it may have surfaced further south. This is unlike calderas on Earth, where a rim of lava builds up in the immediate vicinity of the caldera.
Ryong Ji, C.; Pang, A.; Szczepaniak, A.
1994-04-01
It is pointed out that the correct criterion to define the legal PQCD contribution to the exclusive processes in the lightcone perturbative expansion should be based on the large off-shellness of the lightcone energy in the intermediate states. In the lightcone perturbative QCD calculation of the pion form factor, the authors find that the legal PQCD contribution defined by the lightcone energy cut saturates in the smaller Q{sup 2} region compared to that defined by the gluon four-momentum square cut. This is due to the contribution by the highly off-energy-shell gluons in the end point regions of the phase space, indicating that the gluon four-momentum-square cut may have cut too much to define the legal PQCD.
Nucleon Electromagnetic Form Factors
Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi
2007-10-01
There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has greatly improved by performing double polarization experiments, in comparison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at JLab, MAMI, and MIT-Bates. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed, including the recent progress in the determination of the valence quark generalized parton distributions of the nucleon, as well as the steady rate of improvements made in the lattice QCD calculations.
Hou, Y.; Vavougios, G.; Hinek, A.
1996-07-01
Substitution mutations adversely affecting the {alpha}-subunit of {beta}-hexosaminidase A ({alpha}{beta}) (EC 3.2.1.52) result in Tay-Sachs disease. The majority affect the initial folding of the pro-{alpha} chain in the endoplasmic reticulum, resulting in its retention and degradation. A much less common occurrence is a mutation that specifically affects an {open_quotes}active-site{close_quotes} residue necessary for substrate binding and/or catalysis. In this case, hexosaminidase A is present in the lysosome, but it lacks all {alpha}-specific activity. This biochemical phenotype is referred to as the {open_quotes}B1-variant form{close_quotes} of Tay-Sachs disease. Kinetic analysis of suspected B1-variant mutations is complex because hexosaminidase A is heterodimeric and both subunits possess similar active sites. In this report, we examine a previously identified B1-variant mutation, {alpha}-Val{sup 192}Leu. Chinese hamster ovary cells were permanently cotransfected with an {alpha}-cDNA-construct encoding the substitution and a mutant {beta}-cDNA ({beta}-Arg{sup 211}Lys), encoding a {beta}-subunit that is inactive but normal in all other respects. We were surprised to find that the Val{sup 192}Leu substitution produced a pro-{alpha} chain that did not form {alpha}-{beta} dimers and was not transported to the lysosome. Finally, we reexamined the hexosaminidase activity and protein levels in the fibroblasts from the original patient. These data were also not consistent with the biochemical phenotype of the B1 variant of Tay-Sachs disease previously reported to be present. Thus, we conclude that the Val{sup 192}Leu substitution does not specifically affect the {alpha}-active site. 23 refs., 4 figs., 2 tabs.
Exact solution of the Einstein-Skyrme model in a Kantowski-Sachs spacetime
NASA Astrophysics Data System (ADS)
Paliathanasis, Andronikos; Tsamparlis, Michael
2017-04-01
We consider a Skyrme fluid with a constant radial profile in locally rotational Kantowski-Sachs spacetime. The Skyrme fluid is an anisotropic fluid with zero heat flux and with an equation of state parameter wS that |ws | ≤ 1/3. From the Einstein field equations we define the Wheeler-DeWitt equation. For the last equation we perform a Lie symmetry classification and we determine the invariant solutions for the wavefunction of the model. Moreover from the Lie symmetries of the Wheeler-DeWitt equation we construct Noetherian conservation laws for the field equations which we use in order to write the solution in closed form. We show that all of the cosmological parameters are expressed in terms of the scale factor of the two dimensional sphere of the Kantowski-Sachs spacetime. Finally from the application of Noether's theorem for the Wheeler-DeWitt equation we derive conservation laws for the wavefunction of the universe.
Learning about Tay-Sachs Disease
... Sachs carriers to give birth to healthy babies. Embryos created in-vitro are tested for Tay-Sachs ... being implanted into the mother, allowing only healthy embryos to be selected. Top of page NHGRI Clinical ...
Schubert, Mathias
2016-11-18
A coordinate-invariant generalization of the Lyddane-Sachs-Teller relation is presented for polar vibrations in materials with monoclinic and triclinic crystal systems. The generalization is derived from an eigendielectric displacement vector summation approach, which is equivalent to the microscopic Born-Huang description of polar lattice vibrations in the harmonic approximation. An expression for a general oscillator strength is also described for materials with monoclinic and triclinic crystal systems. A generalized factorized form of the dielectric response characteristic for monoclinic and triclinic materials is proposed. The generalized Lyddane-Sachs-Teller relation is found valid for monoclinic β-Ga_{2}O_{3}, where accurate experimental data became available recently from a comprehensive generalized ellipsometry investigation [Phys. Rev. B 93, 125209 (2016)]. Data for triclinic crystal systems can be measured by generalized ellipsometry as well, and are anticipated to become available soon and results can be compared with the generalized relations presented here.
Well-posed ADM equivalent of the Bondi-Sachs problem
Frittelli, Simonetta
2006-06-15
Every well-posed hyperbolic problem has an associated characteristic representation. In the case of the Einstein equations, traditionally, characteristic problems have been stated in the Bondi-Sachs form, whereas initial-value problems have been represented in the ADM form, both being looked upon as independent versions of the Einstein equations. Under the restriction of spherical symmetry, we provide an ADM version of the Einstein equations that functions as the initial-value representation of the Bondi-Sachs equations. The ADM version allows us to interpret the Bondi-Sachs variables precisely in terms of characteristic fields of the Cauchy problem. The Bondi-Sachs version thus leads us to a version of the Cauchy problem that is first order in time (with no need for reduction) and automatically well posed.
Dru Renner
2012-04-01
Precision computation of hadronic physics with lattice QCD is becoming feasible. The last decade has seen precent-level calculations of many simple properties of mesons, and the last few years have seen calculations of baryon masses, including the nucleon mass, accurate to a few percent. As computational power increases and algorithms advance, the precise calculation of a variety of more demanding hadronic properties will become realistic. With this in mind, I discuss the current lattice QCD calculations of generalized parton distributions with an emphasis on the prospects for well-controlled calculations for these observables as well. I will do this by way of several examples: the pion and nucleon form factors and moments of the nucleon parton and generalized-parton distributions.
The neutron electric form factor to Q² = 1.45 (GeV/c)²
Plaster, Bradley
2004-02-01
The nucleon elastic electromagnetic form factors are fundamental quantities needed for an understanding of nucleon and nuclear electromagnetic structure. The evolution of the Sachs electric and magnetic form factors with Q^{2}, the square of the four-momentum transfer, is related to the distribution of charge and magnetization within the nucleon. High precision measurements of the nucleon form factors are essential for stringent tests of our current theoretical understanding of confinement within the nucleon. Measurements of the neutron form factors, in particular, those of the neutron electric form factor, have been notoriously difficult due to the lack of a free neutron target and the vanishing integral charge of the neutron. Indeed, a precise measurement of the neutron electric form factor has eluded experimentalists for decades; however, with the advent of high duty-factor polarized electron beam facilities, experiments employing polarization degrees of freedom have finally yielded the first precise measurements of this fundamental quantity. Following a general overview of the experimental and theoretical status of the nucleon form factors, a detailed description of an experiment designed to extract the neutron electric form factor from measurements of the neutron's recoil polarization in quasielastic 2H(e, e')1H scattering is presented. The experiment described here employed the Thomas Jefferson National Accelerator Facility's longitudinally polarized electron beam, a magnetic spectrometer for detection of the scattered electron, and a neutron polarimeter designed specifically for this experiment. Measurements were conducted at three Q^{2} values of 0.45, 1.13, and 1.45 (GeV/c)^{2}, and the final results extracted from an analysis of the data acquired in this experiment are reported and compared with recent theoretical predictions for the nucleon form factors.
Tay-Sachs and Sandhoff Diseases
... from the same country, who share language or culture. Tay-Sachs is more common in these ethnic ... blood tests to diagnose the diseases. Are there different types of each disease? Yes. They’re named ...
Testing Gravity Against Early Time Integrated Sachs-Wolfe Effect
Zhang, Pengjie; /Shanghai, Astron. Observ. /Fermilab
2005-11-01
A generic prediction of general relativity is that the cosmological linear density growth factor D is scale independent. But in general, modified gravities do not preserve this signature. A scale dependent D can cause time variation in gravitational potential at high redshifts and provides a new cosmological test of gravity, through early time integrated Sachs-Wolfe (ISW) effect-large scale structure (LSS) cross correlation. We demonstrate the power of this test for a class of f(R) gravity, with the form f(R) = {lambda}{sub 1}H{sub 0}{sup 2} exp(-R/{lambda}{sub 2}H{sub 0}{sup 2}). Such f(R) gravity, even with degenerate expansion history to {Lambda}CDM, can produce detectable ISW effect at z {approx}> 3 and l {approx}> 20. Null-detection of such effect would constrain {lambda}{sub 2} to be {lambda}{sub 2} > 1000 at > 95% confidence level. On the other hand, robust detection of ISW-LSS cross correlation at high z will severely challenge general relativity.
[Tay-Sachs disease in non-Jewish infant in Israel].
Nadim, Nasser
2012-01-01
Tay-Sachs disease, also known as GM2 gangliosidosis or Hexosaminidase A deficiency is an autosomal recessive genetic fatal disorder. The disease is known to appear in East European Ashkenazi Jews, North African Jews, and Quebec French Canadians exclusively, but, with different frequency and type of mutation. Its most common variant is the infantile type Tay-Sachs disease. Juvenile and late-onset forms of the disease are infrequent and slowly progressive. At nearly 3 to 6 months old, a baby with Tay-Sachs progressively loses his motor skills and attentiveness. Startle responses and hyperreflexia become prominent, especially on eliciting deep patellar and Achilles reflexes, as a consequence of neurodegeneration of the upper motor neuron. Other systemic damage ensues gradually; seizures, blindness, spasticity of limbs, inability to swallow and breathe, and eventually the baby dies at 1-4 years of age. All Tay-Sachs patients have a "cherry red spot", easily seen in the macula area of the retina, using an ophthalmoscope. The "cherry red spot" is the only normal part of the retina in these sick babies. The case presented here emphasizes that Tay-Sachs disease is sometimes misdiagnosed at first visits even by an experienced clinician, because of his lack of awareness that this disease is not exclusively a Jewish disease.
Form factors in the radiative pion decay
NASA Astrophysics Data System (ADS)
Mateu, V.; Portolés, J.
2007-10-01
We perform an analysis of the form factors that rule the structure-dependent amplitude in radiative pion decay. The resonance contributions to π→eνeγ decays are computed through the proper construction of the vector and axial-vector form factors by setting the QCD driven asymptotic properties of the three-point Green functions
Kantowski-Sachs cosmological solutions in the generalized teleparallel gravity via Noether symmetry
NASA Astrophysics Data System (ADS)
Motavalli, H.; Akbarieh, A. Rezaei; Nasiry, M.
2016-04-01
We study the f(T) theory as an extension of teleparallel gravity and consider the Noether symmetry of Kantowski-Sachs (KS) anisotropic model for this theory. We specify the explicit teleparallel form of f(T) and find the corresponding exact cosmological solutions under the assumption that the Lagrangian admits the Noether symmetry. It is found that the universe experiences a power law expansion for the scale factors in the context of f(T) theory. By deriving equation of state (EOS) parameter, we show that the universe passes through the phantom and ΛCDM theoretical scenarios. In this way, we estimate a lower limit age for the universe in excellent agreement with the value reported from recent observations. When KS model reduces to the flat Friedmann-Robertson-Walker (FRW) metric, our results are properly transformed into the corresponding values.
Burg-Metzner-Sachs symmetry, string theory, and soft theorems
NASA Astrophysics Data System (ADS)
Avery, Steven G.; Schwab, Burkhard U. W.
2016-01-01
We study the action of the Burg-Metzner-Sachs (BMS) group in critical, bosonic string theory living on a target space of the form Md×C . Here Md is d -dimensional (asymptotically) flat spacetime and C is an arbitrary compactification. We provide a treatment of generalized Ward-Takahashi identities and derive consistent boundary conditions for any d from string theory considerations. Finally, we derive BMS transformations in higher-dimensional spacetimes and show that the generalized Ward-Takahashi identity of BMS produces Weinberg's soft theorem in string theory.
Brown, C.A.; Mahuran, D.J. )
1993-08-01
In vitro mutagenesis and transient expression in COS cells has been used to associate a missense mutation with a clinical or biochemical phenotype. Mutations affecting the [alpha]-subunit of [beta]-hexosaminidase A ([alpha][beta]) (E.C.3.2.1.52) result in Tay-Sachs disease. Because hexosaminidase A is heterodimeric, analysis of [alpha]-chain mutations is not straightforward. The authors examine three approaches utilizing previously identified mutations affecting [alpha]-chain folding. These involve transfection of (1) the [alpha] cDNA alone; (2) a [beta] cDNA construct encoding a [beta]-subunit substituted at a position homologous to that of the [alpha]-subunit, and (3) both [alpha] and [beta] cDNAs. The latter two procedures amplified residual activity levels over that of patient samples, an effect not previously found with mutations affecting an [open quotes]active[close quotes] [alpha]Arg residue. This effect may help to discriminate between protein-folding and active-site mutations. The authors conclude that, with proper controls, the latter method of cotransfection can be used to evaluate the effects and perhaps to predict the clinical course of some [alpha]-chain mutations. Using this technique, they demonstrate that the adult-onset Tay-Sachs mutation, [alpha]Gly[yields]Ser[sup 269], does not directly affect [alpha][beta] dimerization but exerts an indirect effect on the dimer through destabilizing the folded [alpha]-subunit at physiological temperatures. Two other [alpha] mutations linked to more severe phenotypes appear to inhibit the initial folding of the subunit. 36 refs., 2 figs., 5 tabs.
Measurements of baryon form factors at BESIII
NASA Astrophysics Data System (ADS)
Li, Cui
2016-08-01
The momentum transfer dependence of the electromagnetic form factors is an important probe of the structure of hadrons at different scales. Using data samples collected with the BESIII detector at the BEPCII collider, we study the process of e+e- → pp¯ at 12 c.m. energies from 2232.4 to 3671.0 MeV. The Born cross section at these energy points are measured as well as the corresponding effective electromagnetic form factors. Furthermore, the ratio of electric to magnetic form factors, |GE/GM | and |GM | are measured at the c.m. energies where the data samples are the largest. We also report preliminary results of e+e- → ˄˄̅, which is analysed with the same method. Moreover, future prospects of the measurement of baryon electromagnetic form factors from a unique high luminosity data scan by BESIII, are given.
Strangeness contributions to nucleon form factors
Ross Young
2006-09-11
We review a recent theoretical determination of the strange quark content of the electromagnetic form factors of the nucleon. These are compared with a global analysis of current experimental measurements in parity-violating electron scattering.
Burns, David; Chahal, Jaskarndip; Shahrokhi, Shahram; Henry, Patrick; Wasserstein, David; Whyne, Cari; Theodoropoulos, John S.; Ogilvie-Harris, Darrell; Dwyer, Tim
2016-01-01
Objectives: Anatomic studies have demonstrated that bipolar glenoid and humeral bone loss have a cumulative impact on shoulder instability, and that these defects may engage in functional positions depending on their size, location, and orientation, potentially resulting in failure of stabilization procedures. Determining which lesions pose a risk for engagement remains a challenge, with arthroscopic assessment and Itoi’s 3DCT based glenoid track method being the accepted approaches at this time. The purpose of this study was to investigate the interaction of humeral and glenoid bone defects on shoulder engagement in a cadaveric model. Two alternative approaches to predicting engagement were evaluated; 1) CT scanning the shoulder in abduction and external rotation 2) measurement of Bankart lesion width and a novel parameter, the intact anterior articular angle (IAAA), on conventional 2D multi-plane reformats. The results of these two approaches were compared to the results obtained using Itoi’s glenoid track method for predicting engagement. Methods: Hill-Sachs and Bony Bankart defects of varying size were created in 12 cadaveric upper limbs, producing 45 bipolar defect combinations. The shoulders were assessed for engagement using cone beam CT in various positions of function, from 30 to 90 degrees of both abduction and external rotation. The humeral and glenoid defects were characterized by measurement of their size, location, and orientation. Diagnostic performance measures for predicting engagement were calculated for both the abduction external rotation scan and 2D IAAA approaches using the glenoid track method as reference standard. Results: Engagement was predicted by Itoi’s glenoid track method in 24 of 45 specimens (53%). The abduction external rotation CT scan performed at 60 degrees of glenohumeral abduction (corresponding to 90 degrees of abduction relative to the trunk) and 90 degrees of external rotation predicted engagement accurately in 43 of
Electromagnetic nucleon form factors in instant and point form
Melde, T.; Berger, K.; Plessas, W.; Wagenbrunn, R. F.; Canton, L.
2007-10-01
We present a study of the electromagnetic structure of the nucleons with constituent quark models in the framework of relativistic quantum mechanics. In particular, we address the construction of spectator-model currents in the instant and point forms. Corresponding results for the elastic nucleon electromagnetic form factors as well as charge radii and magnetic moments are presented. We also compare results obtained by different realistic nucleon wave functions stemming from alternative constituent quark models. Finally, we discuss the theoretical uncertainties that reside in the construction of spectator-model transition operators.
George Wilbur: Otto Rank and Hanns Sachs.
Roazen, Paul
2006-01-01
George Wilbur, a pioneering Cape Cod psychoanalytic psychiatrist, was a long-standing editor of the journal "American Imago," and an excellent source of information about the Viennese analysts Otto Rank and Hanns Sachs. Wilbur was also knowledgeable about the early reception of psychoanalysis in the Boston community.
Rapid identification of HEXA mutations in Tay-Sachs patients.
Giraud, Carole; Dussau, Jeanne; Azouguene, Emilie; Feillet, François; Puech, Jean-Philippe; Caillaud, Catherine
2010-02-19
Tay-Sachs disease (TSD) is a recessively inherited neurodegenerative disorder due to mutations in the HEXA gene resulting in a beta-hexosaminidase A (Hex A) deficiency. The purpose of this study was to characterize the molecular abnormalities in patients with infantile or later-onset forms of the disease. The complete sequencing of the 14 exons and flanking regions of the HEXA gene was performed with a unique technical condition in 10 unrelated TSD patients. Eleven mutations were identified, including five splice mutations, one insertion, two deletions and three single-base substitutions. Four mutations were novel: two splice mutations (IVS8+5G>A, IVS2+4delAGTA), one missense mutation in exon 6 (c.621T>G (p.D207E)) and one small deletion (c.1211-1212delTG) in exon 11 resulting in a premature stop codon at residue 429. The c.621T>G missense mutation was found in a patient presenting an infantile form. Its putative role in the pathogenesis of TSD is suspected as residue 207 is highly conserved in human, mouse and rat. Moreover, structural modelling predicted changes likely to affect substrate binding and catalytic activity of the enzyme. The time-saving procedure reported here could be useful for the characterization of Tay-Sachs-causing mutations, in particular in non-Ashkenazi patients mainly exhibiting rare mutations.
Nucleon Form Factors - A Jefferson Lab Perspective
John Arrington, Kees de Jager, Charles F. Perdrisat
2011-06-01
The charge and magnetization distributions of the proton and neutron are encoded in their elastic electromagnetic form factors, which can be measured in elastic electron--nucleon scattering. By measuring the form factors, we probe the spatial distribution of the proton charge and magnetization, providing the most direct connection to the spatial distribution of quarks inside the proton. For decades, the form factors were probed through measurements of unpolarized elastic electron scattering, but by the 1980s, progress slowed dramatically due to the intrinsic limitations of the unpolarized measurements. Early measurements at several laboratories demonstrated the feasibility and power of measurements using polarization degrees of freedom to probe the spatial structure of the nucleon. A program of polarization measurements at Jefferson Lab led to a renaissance in the field of study, and significant new insight into the structure of matter.
Study of Baryon Form Factor at BESIII
NASA Astrophysics Data System (ADS)
Zhang, Bingxin
Using data samples collected with BESIII detector at BEPCII collider, we measure Born cross section of e+e- → pbar{p} at center of mass energies √{s} from 2232.4 to 3671.0 MeV. The effective electromagnetic form factor of the proton is deduced with assumption that electric and magnetic form factors are equal GE = GM . For e+e- → Λ bar{Λ }, the Born cross sections and effective form factors are measured at √{s} = 2.2324, 2.40, 2.80, and 3.08 GeV. It is the first time that e+e- → Λ bar{Λ } process is studied closed to Λ bar{Λ } production threshold, and measured cross section is much larger than phase space expectations, which suggests that something more is at play beyond expected phase space behavior.
The form factors of the nucleons
Petratos, G.G.
1993-12-01
The study of the electromagnetic form factors of the nucleons are of fundamental importance in understanding nucleon structure. The form factors contain all the information about the deviation from pointlike structure of the charge and magnetization current distributions of the nucleons. The hope is that measurements at sufficiently large momentum transfers can provide a microscopic understanding of the nucleon wave functions in terms of their constituent quark amplitudes. Recent measurements of the electric G{sub E}(Q{sup 2}) and magnetic G{sub M}(Q{sup 2}) form factors of the nucleons are reviewed and compared to theoretical calculations based on non-perturbative QCD sum rules, diquark, relativistic constituent quark, and vector meson dominance (VMD) models. A short summary of ongoing and future measurements is also presented.
The form factors of the nucleons
NASA Astrophysics Data System (ADS)
Perdrisat, C. F.
2013-11-01
There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has been greatly improved by performing double-polarization experiments, in comparison with with previous unpolarized cross section data. Here we will review the experimental data base in view of the new results for the proton and the neutron, obtained at MIT-Bates, JLab and MAMI. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed. In particular, the possibility that the proton is non-spherical in its ground state, and that the transverse charge density are model independently defined in the infinite momentum frame. Likewise, flavor decomposition of the nucleon form factors into dressed u and d quark form factors, may give information about the quark-diquark structure of the nucleon. The current proton radius "crisis" will also be discussed.
The Form Factors of the Nucleons
Perdrisat, Charles F.
2013-11-01
There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has been greatly improved by performing double-polarization experiments, in comparison with with pre-vious unpolarized cross section data. Here we will review the experimental data base in view of the new results for the proton and the neutron, obtained at MIT-Bates, JLab and MAMI. The rapid evolution of phenomenological models triggered by these high- precision experiments will be discussed. In particular, the possibility that the proton is non-spherical in its ground state, and that the transverse charge density are model in- dependently defined in the infinite momentum frame. Likewise, flavor decomposition of the nucleon form factors into dressed u and d quark form factors, may give information about the quark-diquark structure of the nucleon. The current proton radius "crisis" will also be discussed.
Charm form factors in hadronic interactions
Bracco, M. E.; Navarra, F. S.; Nielsen, M.; Chiapparini, M.
2010-12-28
We calculate the form factors and the coupling constants in vertices with charm mesons, such as {rho}D*D*, in the framework of QCD sum rules. We first discuss the applications of these form factors in heavy ion collisions and in B decays. We then present an introduction to the method of QCD sum rules and describe how to work with the three-point function. We give special attention to the procedure employed to extrapolate results obtained in the deep euclidean region to the poles of the particles, located in the time-like region. Finally we present a table of ready-to-use parametrizations of all the form factors, which are relevant for the processes mentioned in the introduction. We also give the coupling constants.
Hadronic form factors in kaon photoproduction
Syukurilla, L. Mart, T.
2014-09-25
We have revisited the effect of hadronic form factors in kaon photoproduction process by utilizing an isobaric model developed for kaon photoproduction off the proton. The model is able to reproduce the available experimental data nicely as well as to reveal the origin of the second peak in the total cross section, which was the main source of confusion for decades. Different from our previous study, in the present work we explore the possibility of using different hadronic form factors in each of the KΛN vertices. The use of different hadronic form factors, e.g. dipole, Gaussian, and generalized dipole, has been found to produce a more flexible isobar model, which can provide a significant improvement in the model.
Form Factors and Radii of Light Nuclei
Sick, Ingo
2015-09-15
We discuss the determination of electromagnetic form factors from the world data on electron–nucleus scattering for nuclei Z ≤ 3, with particular emphasis on the derivation of the moments required for comparison with measurements from electronic/muonic atoms and isotope shifts.
Meson-photon transition form factors
Balakireva, Irina; Lucha, Wolfgang; Melikhov, Dmitri
2012-10-23
We present the results of our recent analysis of the meson-photon transition form factors F{sub P{gamma}}(Q{sup 2}) for the pseudoscalar mesons P {pi}{sup 0},{eta},{eta} Prime ,{eta}{sub c}, using the local-duality version of QCD sum rules.
Electromagnetic charged and neutral kaon form factors
Roberts, C.D.; Burden, C.J.; Thomson, M.J.
1995-08-01
The electromagnetic form factor of the charged and neutral kaon is calculated using the approach applied in the successful study of the pion form factor, described above. The charged kaon form factor will be measured in forthcoming experiments at CEBAF. Our calculation involves the dressed strange quark propagator, to which F{sub {pi}}(q{sup 2}) is not sensitive, and hence it provides us with constraints on the strange-quark sector of QCD. Our preliminary results are encouraging. We find that the strange and up/down quark propagators are not too different, once the change in the current-quark-mass is accounted for. However, the difference that remains is important since it allows {l_angle}{bar s}s{r_angle}<{l_angle}{bar u}u{r_angle}. This calculation is the first to yield a value of f{sub K}/f{sub {pi}} that is in good agreement with experiment and also yields r{sub K+}/r{sub {pi}} in good agreement with experiment. Our calculated charged kaon form factor provides a prediction that will be tested in the forthcoming CEBAF experiments. Our studies also show that K{sup 0} has a negative charge radius, as is to be expected. Our calculated value will be compared with that measured in K{sub s}{sup 0} regeneration from electrons.
[Tay-Sachs disease: a case report].
Koch, S; Widhalm, K
1991-01-01
After an infection of the respiratory tract at the age of one a male infant showed progressive mental and physical retardation. Outstanding signs (e.g. baby doll face, startle reaction and frog position) as well as results of special investigations (cherry red spots of the maculae, short tubular bones) were suspicious for the presence of a lipidstorage disease, that could be identified as Tay-Sachs disease because of absent hexosaminidase A-activity in the patient's serum. Inspite the very low incidence of Tay-Sachs disease in our population, compared with a frequency of 1: 1200 in Ashkenzi Jews, the importance of establishing a diagnosis, based on typical clinical features and biochemical results, has to be emphasized. Genetic consultation is the only point of influence in positive family history, for attempts of causal therapy are not successful at present.
Nucleon and Deuteron Form Factors from BLAST
Hasell, D. K.
2009-12-17
The BLAST experiment was designed to study in a systematic manner the spin-dependent, electromagnetic interaction on hydrogen and deuterium. Measuring only asymmetries in electron scattering with respect to the beam helicity, target spin, or both; the BLAST experiment was able to extract information on nucleon and deuteron form factors independent of beam intensity or target density. By further forming 'super-ratios' of asymmetries, measurements were possible independent of beam and target polarization thus reducing uncertainties due to these quantities as well. Some of the form factor results from BLAST will be briefly presented here. Also, in response to observed discrepancies between polarization measurements and those obtained using traditional Rosenbluth separation techniques a proposed experiment, OLYMPUS, which will use the BLAST detector to measure the two photon contribution to elastic electron scattering will also be presented.
Tay Sachs disease: an autopsy case report.
Jadhav, Meenal Vitthal; Landge, Meenal P; Sawaimoon, Satyakam K; Harke, Arun B; Deshmukh, Sanjay D
2005-10-01
This report describes a case report of a postmortem performed on a 5-year old patient of Tay-Sachs disease, presenting with failure to thrive, muscular flaccidity, and cherry-red spots on macula on fundoscopy. There was no history of similarly affected sibling or any other family member. The diagnosis was confirmed by enzyme studies. At postmortem, there was no organomegaly. The brain, on microscopy, showed vacuolated swollen neurons.
Baryon transition form factors at the pole
NASA Astrophysics Data System (ADS)
Tiator, L.; Döring, M.; Workman, R. L.; Hadžimehmedović, M.; Osmanović, H.; Omerović, R.; Stahov, J.; Švarc, A.
2016-12-01
Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the GM, GE, and GC form factors for the Δ (1232 ) resonance excitation at the Breit-Wigner resonance and pole positions up to Q2=5 GeV2 . We also explore the E /M and S /M ratios as functions of Q2. For pole and residue extraction, we apply the Laurent + Pietarinen method.
Baryon transition form factors at the pole
Tiator, L.; Döring, M.; Workman, R. L.; Hadžimehmedović, M.; Osmanović, H.; Omerović, R.; Stahov, J.; Švarc, A.
2016-12-01
Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the $G_M$, $G_E$, and $G_C$ form factors for the $\\Delta(1232)$ resonance excitation at the Breit-Wigner resonance and pole positions up to $Q^2=5$ GeV$^2$. We also explore the $E/M$ and $S/M$ ratios as functions of $Q^2$. For pole and residue extraction, we apply the Laurent + Pietarinen method.
Form factors for Russian doll droplet models
NASA Astrophysics Data System (ADS)
Wilemski, G.; Obeidat, A.; Hrahsheh, F.
2013-05-01
Molecular dynamics (MD) simulations of nanodroplets containing water and nonane show them to be nonspherical and strongly phase separated. A simple, but realistic model for these "Russian doll" structures is a spherical nonane lens that partially wets a spherical water droplet. This document contains an analytical calculation of the particle form factor P(q) needed to analyze experimental measurements of small angle neutron and x-ray scattering from aerosols of particles with this type of structure. In addition, an exact formulation of the particle form factor is developed for cylindrically symmetric droplets with otherwise arbitrary scattering length density functions. This result will be useful to calculate P(q) directly from MD simulation results. We compare results using both formulations and find excellent agreement between them.
Elastic form factors at higher CEBAF energies
Petratos, G.G.
1994-04-01
The prospects for elastic scattering from few body systems with higher beam energies at CEBAF is presented. The deuteron and{sup 3}He elastic structure functions A(Q{sup 2}) can be measured at sufficiently high momentum transfers to study the transition between the conventional meson-nucleon and the constituent quark-gluon descriptions. Possible improvements in the proton magnetic form factor data are also presented.
A new approach for Delta form factors
C. Aubin, K. Orginos
2011-10-01
We discuss a new approach to reducing excited state contributions from two- and three-point correlation functions in lattice simulations. For the purposes of this talk, we focus on the Delta(1232) resonance and discuss how this new method reduces excited state contamination from two-point functions and mention how this will be applied to three-point functions to extract hadronic form factors.
Heavy to light baryon transition form factors
Guo, X. |; Huang, T. |; Li, Z.
1996-05-01
Recently, Stech found form factor relations for heavy to light transitions based on two simple dynamical assumptions for a spectator particle. In this paper we generalize his approach to the case of baryons and find that for {Lambda}{sub {ital Q}}{r_arrow}{Lambda} ({ital Q}={ital b} or {ital c}) only one independent form factor remains in the limit {ital m}{sub {ital Q}}{r_arrow}{infinity}. Furthermore, combining with the model of Guo and Kroll we determine both of the two form factors for {Lambda}{sub {ital Q}}{r_arrow}{Lambda} in the heavy quark limit. The results are applied to {Lambda}{sub {ital b}}{r_arrow}{Lambda}+{ital J}/{psi} which is not clarified both theoretically and experimentally. It is found that the branching ratio of {Lambda}{sub {ital b}}{r_arrow}{Lambda}+{ital J}/{psi} is of order 10{sup {minus}5}. {copyright} {ital 1996 The American Physical Society.}
Camci, Ugur; Kucukakca, Yusuf
2007-10-15
We consider some scalar-coupled theories of gravity, including induced gravity, and study the Noether symmetries of Bianchi I, Bianchi III, and Kantowski-Sachs cosmological models for this theory. For various forms of coupling of the scalar field with gravity, some potentials are found in these cosmological models under the assumption that the Lagrangian admits Noether symmetry. The solutions of the field equations for the considered models are presented by using the results obtained from the Noether symmetry. We also find the explicit form of the scalar field in terms of the conformal time for Bianchi I, III, and Kantowski-Sachs models.
The National Tay Sachs and Allied Diseases Association.
ERIC Educational Resources Information Center
Zeitlin, Paula
1986-01-01
The National Tay-Sachs and Allied Diseases Association is involved in education, research, and prevention of Tay-Sachs, an inherited metabolic disorder which destroys the central nervous system, and over 30 related disorders. The group features a parent peer group network and a support group for carrier couples. (CL)
National Tay-Sachs and Allied Diseases Association, Inc.
ERIC Educational Resources Information Center
Exceptional Parent, 1977
1977-01-01
Reviewed are the history and organization, purpose and programs, and public services of the National Tay-Sachs and Allied Diseases Association, an organization geared toward eradicating Tay-Sachs disease (a hereditary disorder affecting primarily Jewish infants which generally leads to deterioration and death by the child's fifth year). (SBH)
Axillary shoulder with exaggerated rotation: the Hill-Sachs defect.
Rafert, J A; Long, B W; Hernandez, E M; Kreipke, D L
1990-01-01
One of the most common fractures of the humeral head resulting from an anterior dislocation is the Hill-Sachs defect. Other special radiographic positions to demonstrate this injury may prove difficult for the patient to assume and maintain. An axillary shoulder projection with exaggerated external rotation is easy to position and clearly demonstrates the Hill-Sachs defect.
Recent Studies of Nucleon Electromagnetic Form Factors
NASA Astrophysics Data System (ADS)
Gilad, Shalev
2010-08-01
The electromagnetic form factors of nucleons are fundamental quantities in nucleon structure. As such, they have been studied extensively both theoretically and experimentally. Significant progress has been made with new measurements at Jlab, MAMI and MIT-Bates, with emphases on expanding the momentum-transfer range and on higher precision. In this paper, we describe the status of this field and present new results from measurements at both low and high momentum transfers. We also compare the experimental data to model predictions, and mention possible implications of the new results to other fields.
Lattice Calculations of Nucleon Form Factors
Syritsyn, S. N.
2011-10-24
We present recent results of calculation of the isovector electromagnetic and axial form factors of the nucleon using lattice QCD with three different lattice actions and pion masses down to m{sub {pi}} > or approx. 300 MeV. Because of the precision of our high-statistics calculations, we can test predictions of baryon chiral perturbation theory for the charge and axial radii of the nucleon. We find that currently available baryon ChPT calculations disagree with our data, indicating that the corresponding effective theory approximations are not valid above m{sub {pi}{approx_equal}3}00 MeV.
Survey of nucleon electromagnetic form factors
Perdrisat, Charles F.; Punjabi, Vina A.
2011-09-20
There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has been greatly improved by performing double polarization experiments, in compar- ison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at MIT-Bates, MAMI, and JLab. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed.
Neutron electric form factor via recoil polarimetry
Madey, Richard; Semenov, Andrei; Taylor, Simon; Aghalaryan, Aram; Crouse, Erick; MacLachlan, Glen; Plaster, Bradley; Tajima, Shigeyuki; Tireman, William; Yan, Chenyu; Ahmidouch, Abdellah; Anderson, Brian; Asaturyan, Razmik; Baker, O; Baldwin, Alan; Breuer, Herbert; Carlini, Roger; Christy, Michael; Churchwell, Steve; Cole, Leon; Danagoulian, Samuel; Day, Donal; Elaasar, Mostafa; Ent, Rolf; Farkhondeh, Manouchehr; Fenker, Howard; Finn, John; Gan, Liping; Garrow, Kenneth; Gueye, Paul; Howell, Calvin; Hu, Bitao; Jones, Mark; Kelly, James; Keppel, Cynthia; Khandaker, Mahbubul; Kim, Wooyoung; Kowalski, Stanley; Lung, Allison; Mack, David; Manley, D; Markowitz, Pete; Mitchell, Joseph; Mkrtchyan, Hamlet; Opper, Allena; Perdrisat, Charles; Punjabi, Vina; Raue, Brian; Reichelt, Tilmann; Reinhold, Joerg; Roche, Julie; Sato, Yoshinori; Seo, Wonick; Simicevic, Neven; Smith, Gregory; Stepanyan, Samuel; Tadevosyan, Vardan; Tang, Liguang; Ulmer, Paul; Vulcan, William; Watson, John; Wells, Steven; Wesselmann, Frank; Wood, Stephen; Yan, Chen; Yang, Seunghoon; Yuan, Lulin; Zhang, Wei-Ming; Zhu, Hong Guo; Zhu, Xiaofeng
2003-05-01
The ratio of the electric to the magnetic form factor of the neutron, G_En/G_Mn, was measured via recoil polarimetry from the quasielastic d({pol-e},e'{pol-n)p reaction at three values of Q^2 [viz., 0.45, 1.15 and 1.47 (GeV/c)^2] in Hall C of the Thomas Jefferson National Accelerator Facility. Preliminary data indicate that G_En follows the Galster parameterization up to Q^2 = 1.15 (GeV/c)^2 and appears to rise above the Galster parameterization at Q^2 = 1.47 (GeV/c)^2.
Pion form factor from a contact interaction
Gutierrez-Guerrero, L. X.; Bashir, A.; Cloeet, I. C.; Roberts, C. D.
2010-06-15
In a Poincare-covariant vector-boson-exchange theory, the pion possesses components of pseudovector origin, which materially influence its observable properties. For a range of such quantities, we explore the consequences of a momentum-independent interaction, regularized in a symmetry-preserving manner. The contact interaction, while capable of describing pion static properties, produces a form factor whose evolution for Q{sup 2}>0.17 GeV{sup 2} disagrees markedly with experiment and whose asymptotic power-law behavior conflicts strongly with perturbative QCD.
Integrated Sachs-Wolfe effect in massive bigravity
NASA Astrophysics Data System (ADS)
Enander, Jonas; Akrami, Yashar; Mörtsell, Edvard; Renneby, Malin; Solomon, Adam R.
2015-04-01
We study the integrated Sachs-Wolfe (ISW) effect in ghost-free, massive bigravity. We focus on the infinite-branch bigravity (IBB) model which exhibits viable cosmic expansion histories and stable linear perturbations, while the cosmological constant is set to zero and the late-time accelerated expansion of the Universe is due solely to the gravitational interaction terms. The ISW contribution to the CMB auto-correlation power spectrum is predicted, as well as the cross-correlation between the CMB temperature anisotropies and large-scale structure. We use ISW amplitudes as inferred from the WMAP 9-year temperature data together with galaxy and AGN data provided by the WISE mission in order to compare the theoretical predictions to the observations. The ISW amplitudes in IBB are found to be larger than the corresponding ones in the standard Λ CDM model by roughly a factor of 1.5, but are still consistent with the observations.
TCP transcription factors: architectures of plant form.
Manassero, Nora G Uberti; Viola, Ivana L; Welchen, Elina; Gonzalez, Daniel H
2013-04-01
After its initial definition in 1999, the TCP family of transcription factors has become the focus of a multiplicity of studies related with plant development at the cellular, organ, and tissue levels. Evidence has accumulated indicating that TCP transcription factors are the main regulators of plant form and architecture and constitute a tool through which evolution shapes plant diversity. The TCP transcription factors act in a multiplicity of pathways related with cell proliferation and hormone responses. In recent years, the molecular pathways of TCP protein action and biochemical studies on their mode of interaction with DNA have begun to shed light on their mechanism of action. However, the available information is fragmented and a unifying view of TCP protein action is lacking, as well as detailed structural studies of the TCP-DNA complex. Also important, the possible role of TCP proteins as integrators of plant developmental responses to the environment has deserved little attention. In this review, we summarize the current knowledge about the structure and functions of TCP transcription factors and analyze future perspectives for the study of the role of these proteins and their use to modify plant development.
Helium Compton Form Factor Measurements at CLAS
Voutier, Eric J.-M.
2013-07-01
The distribution of the parton content of nuclei, as encoded via the generalized parton distributions (GPDs), can be accessed via the deeply virtual Compton scattering (DVCS) process contributing to the cross section for leptoproduction of real photons. Similarly to the scattering of light by a material, DVCS provides information about the dynamics and the spatial structure of hadrons. The sensitivity of this process to the lepton beam polarization allows to single-out the DVCS amplitude in terms of Compton form factors that contain GPDs information. The beam spin asymmetry of the $^4$He($\\vec {\\mathrm e}$,e$' \\gamma ^4$He) process was measured in the experimental Hall B of the Jefferson Laboratory to extract the real and imaginary parts of the twist-2 Compton form factor of the $^4$He nucleus. The experimental results reported here demonstrate the relevance of this method for such a goal, and suggest the dominance of the Bethe-Heitler amplitude to the unpolarized process in the kinematic range explored by the experiment.
Measurements of hadron form factors at BESIII
NASA Astrophysics Data System (ADS)
Morales, Cristina Morales
2016-05-01
BEPCII is a symmetric e+e--collider located in Beijing running at center-of-mass energies between 2.0 and 4.6 GeV. This energy range allows the BESIII-experiment to measure hadron form factors both from direct e+e--annihilation and from initial state radiation processes. In this paper, results on e+e- → p p ¯ based on data collected by BESIII in 2011 and 2012 are presented. We also present preliminary results on e+e- → Λ Λ ¯ based on the same data samples at 4 center-of-mass energies. BESIII results obtained from e+e- → π+π- using the initial state radiation technique at the center-of-mass energy of 3.773 GeV are also summarized. Finally, expectations on the measurement of baryon electromagnetic form factors from the BESIII high luminosity energy scan in 2015 and from initial state radiation processes at different center-of-mass energies are also explained.
Electromagnetic Transition Form Factors of Nucleon Resonances
Burkert, Volker D.
2008-10-13
Recent measurements of nucleon resonance transition form factors with CLAS at Jefferson Lab are discussed. The new data resolve a long-standing puzzle of the nature of the Roper resonance, and confirm the assertion of the symmetric constituent quark model of the Roper as the first radial excitation of the nucleon. The data on high Q{sup 2} n{pi}{sup +} production confirm the slow fall off of the S{sub 11}(1535) transition form factor with Q{sup 2}, and better constrain the branching ratios {beta}{sub N{pi}} = 0.50 and {beta}{sub N{eta}} = 0.45. For the first time, the longitudinal transition amplitude to the S{sub 11}(1535) was extracted from the n{pi}{sup +} data. Also, new results on the transition amplitudes for the D{sub 13}(1520) resonance are presented showing a rapid transition from helicity 3/2 dominance seen at the real photon point to helicty 1/2 dominance at higher Q{sup 2}.
OLYMPUS and the proton form factor puzzle
NASA Astrophysics Data System (ADS)
Ice, Lauren; Alarcon, Ricardo; Olympus Collaboration
2012-02-01
Recent measurements of the proton electric to magnetic form factor ratio using polarization techniques reveal a large discrepancy with measurements found using the Rosenbluth separation technique. It has been proposed that this discrepancy is due to a non-negligible multiple photon exchange contribution in the electron-proton elastic scattering cross section. The OLYMPUS experiment will measure the multiple photon exchange contribution by finding the cross section ratio of positron-proton to electron-proton scattering within 1%. The experiment will be carried out at the DESY laboratory in Hamburg Germany using the electron and positron storage ring DORIS and an internal unpolarized hydrogen gas target. The scattered particles will be detected using the Bates Large Acceptance Spectrometer Toroid (BLAST).
Physical Nucleon Form Factors from Lattice QCD
Hrayr Matevosyan; Anthony W. Thomas; Gerald A. Miller
2005-10-25
We explore the possibility of extrapolating state of the art lattice QCD calculations of nucleon form factors to the physical regime. We find that the lattice results can be reproduced using the Light Front Cloudy Bag Model and the Extended Gari-Krmpelmann Model by letting their parameters be analytic functions of the quark mass. We then use the models to extend the lattice calculations to large values of Q{sup 2} of interest to current and planned experiments. These functions for the first model are also used to define extrapolations to the physical value of the pion mass, thereby allowing us to study how the predicted zero in G{sub E}(Q{sup 2})/G{sub M}(Q{sup 2}) varies as a function of quark mass.
Julius Sachs (1832-1897) and the Unity of Life.
Kutschera, Ulrich; Baluška, František
2015-01-01
In 1865, the German botanist Julius Sachs published a seminal monograph entitled Experimental-Physiologie der Pflanzen (Experimental Physiology of Plants) and hence became the founder of a new scientific discipline that originated 150 y ago. Here, we outline the significance of the achievements of Sachs. In addition, we document, with reference to his Vorlesungen über Pflanzen-Physiologie (Lectures on the Physiology of Plants, 1882), that Sachs was one of the first experimentalists who proposed the functional unity of all organisms alive today (humans, animals, plants and other "vegetable" organisms, such as algae, cyanophyceae, fungi, myxomycetes, and bacteria).
Julius Sachs (1832–1897) and the Unity of Life
Kutschera, Ulrich; Baluška, František
2015-01-01
In 1865, the German botanist Julius Sachs published a seminal monograph entitled Experimental-Physiologie der Pflanzen (Experimental Physiology of Plants) and hence became the founder of a new scientific discipline that originated 150 y ago. Here, we outline the significance of the achievements of Sachs. In addition, we document, with reference to his Vorlesungen über Pflanzen-Physiologie (Lectures on the Physiology of Plants, 1882), that Sachs was one of the first experimentalists who proposed the functional unity of all organisms alive today (humans, animals, plants and other “vegetable” organisms, such as algae, cyanophyceae, fungi, myxomycetes, and bacteria). PMID:26359706
Constant mean curvature slicings of Kantowski-Sachs spacetimes
Heinzle, J. Mark
2011-04-15
We investigate existence, uniqueness, and the asymptotic properties of constant mean curvature (CMC) slicings in vacuum Kantowski-Sachs spacetimes with positive cosmological constant. Since these spacetimes violate the strong energy condition, most of the general theorems on CMC slicings do not apply. Although there are in fact Kantowski-Sachs spacetimes with a unique CMC foliation or CMC time function, we prove that there also exist Kantowski-Sachs spacetimes with an arbitrary number of (families of) CMC slicings. The properties of these slicings are analyzed in some detail.
Bondi-Sachs energy-momentum for the constant mean extrinsic curvature initial value problem
NASA Astrophysics Data System (ADS)
Bardeen, James M.; Buchman, Luisa T.
2012-03-01
The constraints on the asymptotic behavior of the conformal factor and conformal extrinsic curvature imposed by the initial value equations of general relativity on constant mean extrinsic curvature (CMC) hypersurfaces are analyzed in detail. We derive explicit formulas for the Bondi-Sachs energy and momentum in terms of coefficients of asymptotic expansions on CMC hypersurfaces near future null infinity. Precise numerical results for the Bondi-Sachs energy, momentum, and angular momentum are used to interpret physically Bowen-York initial data on conformally flat CMC hypersurfaces similar to that calculated earlier by Buchman et al. [L. T. Buchman, H. P. Pfeiffer, and J. M. Bardeen, Phys. Rev. DPRVDAQ1550-7998 80, 084024-1 (2009).10.1103/PhysRevD.80.084024].
The {Delta}(1232) resonance transition form factor
Staurt, L.M. |; Bosted, P.E.; Lung, A.
1993-08-01
Old and new measurements of inclusive e--p cross sections in the {Delta}(1232) resonance region have been combined, and a global data fit has been made. Using this fit to parameterize the nonresonant background, the transition form factors have been extracted out to a four-momentum transfer, Q{sup 2}, of 9.8 (GeV/c){sup 2}. The results are systematically higher than those from a previous analysis, but agree within errors. A similar analysis has been done with e--d cross sections, and {sigma}{sub n}/{sigma}{sub p} in the {Delta}(1232) resonance region has been extracted out to a Q{sup 2} of 7.9 (GeV/c){sup 2}. {sigma}{sub n}/{sigma}{sub p} for {Delta}(1232) production is consistent with unity, while {sigma}{sub n}/{sigma}{sub p} for the nonresonant background is constant with Q{sup 2} at approximately 0.4.
Vector and Axial Vector Pion Form Factors
NASA Astrophysics Data System (ADS)
Vitz, Michael; PEN Collaboration
2015-04-01
Radiative pion decay π+ -->e+ νγ (RPD) provides critical input to chiral perturbation theory (χPT). Aside from the uninteresting ``inner bremsstrahlung'' contribution from QED, the RPD rate contains ``structure dependent'' terms given by FV and FA, the vector and axial-vector pion form factors, respectively. The two appear in the decay rate in combinations FV -FA and FV +FA , i.e., in the so-called SD- and SD+ terms, respectively. The latter has been measured to high precision by the PIBETA collaboration. We report on the analysis of new data, measured by the PEN collaboration in runs between 2008 and 2010 at the Paul Scherrer Institute, Switzerland. We particularly focus on the possibility of improvement in the determination of the SD- term. Precise determinations of FV and FA test the validity of the CVC hypothesis, provide numerical input for the l9 +l10 terms in the χPT lagrangian, and constrain potential non-(V - A) terms, such as a possible tensor term FT. NSF grants PHY-0970013, 1307328, and others.
Tay Sachs and Related Storage Diseases: Family Planning
ERIC Educational Resources Information Center
Schneiderman, Gerald; And Others
1978-01-01
Based on interviews with 24 families, the article discusses family planning and the choices available to those families in which a child has previously died from Tay-Sachs or related lipid storage diseases. (IM)
75 FR 44031 - Goldman, Sachs & Co., et al.; Notice of Application and Temporary Order
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-27
... Management International (``GSAMI''), Goldman Sachs Hedge Fund Strategies LLC (``GSHFS''), Commonwealth... global investment banking and securities firm. Goldman Sachs is registered as an investment adviser with... marketing materials used in connection with residential mortgage-related securities offerings by...
Plant sulfur nutrition: From Sachs to Big Data
Kopriva, Stanislav
2015-01-01
Together with water and carbon dioxide plants require 14 essential mineral nutrients to finish their life cycle. The research in plant nutrition can be traced back to Julius Sachs, who was the first to experimentally prove the essentiality of mineral nutrients for plants. Among those elements Sachs showed to be essential is sulfur. Plant sulfur nutrition has been not as extensively studied as the nutrition of nitrogen and phosphate, probably because sulfur was not limiting for agriculture. However, with the reduction of atmospheric sulfur dioxide emissions sulfur deficiency has become common. The research in sulfur nutrition has changed over the years from using yeast and algae as experimental material to adopting Arabidopsis as the plant model as well as from simple biochemical measurements of individual parameters to system biology. Here the evolution of sulfur research from the times of Sachs to the current Big Data is outlined. PMID:26305261
A critique of Jeffrey D. Sachs's The end of poverty.
Henwood, Doug
2006-01-01
Jeffrey Sachs's The End of Poverty is a manifesto and how-to guide on ending extreme poverty around the world; it promotes the U.N. Millennium Development Goals. Sachs achieved fame with his policy package for the "stabilization" of Bolivia (which did nothing to relieve Bolivia's poverty), and became advisor to the Yeltsin government in Russia and to Poland, Slovenia, and Estonia as they began their transitions to capitalism (the last three mixed successes; Russia a thorough disaster). Sachs later became more prominent as a critic of development orthodoxy, and was economic advisor to the Jubilee 2000 movement. The End of Poverty is full of sharp critiques of Western imperialism, but his views on the rest of the development business are more conventional.
Progress in the Calculation of Nucleon Transition form Factors
NASA Astrophysics Data System (ADS)
Eichmann, Gernot
2016-10-01
We give a brief account of the Dyson-Schwinger and Faddeev-equation approach and its application to nucleon resonances and their transition form factors. We compare the three-body with the quark-diquark approach and present a quark-diquark calculation for the low-lying nucleon resonances including scalar, axialvector, pseudoscalar and vector diquarks. We also discuss the timelike structure of transition form factors and highlight the advantages of form factors over helicity amplitudes.
The form factor of H-comb polymers
NASA Astrophysics Data System (ADS)
Zweier, Steven; Bishop, Marvin
2009-12-01
A Monte Carlo pivot algorithm is employed to investigate the form factor of continuum, tangent hard sphere H-comb polymers in both the ideal and excluded volume regimes. The simulated form factors for 241 and 931 "bead" ideal H-combs are essentially the same. The results for these polymers are in excellent agreement with the theoretical prediction. There is only a slight difference in the form factor between the ideal and excluded volume regimes at larger values of distance.
Tay-Sachs disease in Jacob sheep.
Torres, Paola A; Zeng, Bai Jin; Porter, Brian F; Alroy, Joseph; Horak, Fred; Horak, Joan; Kolodny, Edwin H
2010-12-01
Autopsy studies of four Jacob sheep dying within their first 6-8 months of a progressive neurodegenerative disorder suggested the presence of a neuronal storage disease. Lysosomal enzyme studies of brain and liver from an affected animal revealed diminished activity of hexosaminidase A (Hex A) measured with an artificial substrate specific for this component of β-hexosaminidase. Absence of Hex A activity was confirmed by cellulose acetate electrophoresis. Brain lipid analyses demonstrated the presence of increased concentrations of G(M2)-ganglioside and asialo-G(M2)-ganglioside. The hexa cDNA of Jacob sheep was cloned and sequenced revealing an identical number of nucleotides and exons as in human HexA and 86% homology in nucleotide sequence. A missense mutation was found in the hexa cDNA of the affected sheep caused by a single nucleotide change at the end of exon 11 resulting in skipping of exon 11. Transfection of normal sheep hexa cDNA into COS1 cells and human Hex A-deficient cells led to expression of Hex S but no increase in Hex A indicating absence of cross-species dimerization of sheep Hex α-subunit with human Hex β-subunits. Using restriction site analysis, the heterozygote frequency of this mutation in Jacob sheep was determined in three geographically separate flocks to average 14%. This large naturally occurring animal model of Tay-Sachs disease is the first to offer promise as a means for trials of gene therapy applicable to human infants.
Analytical evaluation of atomic form factors: Application to Rayleigh scattering
Safari, L.; Santos, J. P.; Amaro, P.; Jänkälä, K.; Fratini, F.
2015-05-15
Atomic form factors are widely used for the characterization of targets and specimens, from crystallography to biology. By using recent mathematical results, here we derive an analytical expression for the atomic form factor within the independent particle model constructed from nonrelativistic screened hydrogenic wave functions. The range of validity of this analytical expression is checked by comparing the analytically obtained form factors with the ones obtained within the Hartee-Fock method. As an example, we apply our analytical expression for the atomic form factor to evaluate the differential cross section for Rayleigh scattering off neutral atoms.
Analytical evaluation of atomic form factors: Application to Rayleigh scattering
NASA Astrophysics Data System (ADS)
Safari, L.; Santos, J. P.; Amaro, P.; Jänkälä, K.; Fratini, F.
2015-05-01
Atomic form factors are widely used for the characterization of targets and specimens, from crystallography to biology. By using recent mathematical results, here we derive an analytical expression for the atomic form factor within the independent particle model constructed from nonrelativistic screened hydrogenic wave functions. The range of validity of this analytical expression is checked by comparing the analytically obtained form factors with the ones obtained within the Hartee-Fock method. As an example, we apply our analytical expression for the atomic form factor to evaluate the differential cross section for Rayleigh scattering off neutral atoms.
Tay-Sachs disease screening and prevention in South Africa.
Jenkins, T; Lane, A B; Kromberg, J G
1977-01-22
Tay-Sachs disease is potentially preventable in Ashkenazi Jewish communities. About 1 out of 25 individuals is a carrier of the gene and can be accurately identified by means of a simple, inexpensive blood test. 'At risk' couples, i.e. couples of whom both partners are carriers, can be enabled, by means of prenatal diagnosis and selective abortion, to have only unaffected children. Mass screening programmes have been successfully carried out in the USA, Canada and Israel. A discussion of South African Jewish deomgraphy, attitudes to health, and priorities for public health projects, provide the background to a consideration of Tay-Sachs disease prevention in South Africa.
X-Ray Form Factor, Attenuation and Scattering Tables
National Institute of Standards and Technology Data Gateway
SRD 66 X-Ray Form Factor, Attenuation and Scattering Tables (Web, free access) This database collects tables and graphs of the form factors, the photoabsorption cross section, and the total attenuation coefficient for any element (Z <= 92).
Nucleon Form Factors experiments with 12 GeV CEBAF
Wojtsekhowski, B.
2008-10-13
A number of precision form factor experiments at high momentum transfer will be performed with the 11 GeV electron beam of CEBAF. We review the approved proposals and the conceptual schemes of several new suggestions. Form factor data will serve as a major input for the construction of a tomographic image of the nucleon.
Electromagnetic Form Factors of the Nucleon in Chiral Soliton Models
NASA Astrophysics Data System (ADS)
Holzwarth, Gottfried
The ratio of electric to magnetic proton form factors {G_E^P}/{G_M^P} as measured in polarization transfer experiments shows a characteristic linear decrease with increasing momentum transfer Q2(< 10 (GeV/c)2). We present a simple argument how such a decrease arises naturally in chiral soliton models. For a detailed comparison of model results with experimentally determined form factors it is necessary to employ a boost from the soliton rest frame to the Breit frame. To enforce asymptotic counting rules for form factors, the model must be supplemented by suitably chosen interpolating powers n in the boost prescription. Within the minimal π-ϱ-ω soliton model, with the same n for both, electric and magnetic form factors, it is possible to obtain a very satisfactory fit to all available proton data for the magnetic form factor and to the recent polarization results for the ratio {G_E^P}/{G_M^P}. At the same time the small and very sensitive neutron electric form factor is reasonably well reproduced. The results show a systematic discrepancy with presently available data for the neutron magnetic form factor {G_M^n } for Q2 > 1 (GeV/c)2 for Q2 > 1 (GeV/c)2. We additionally comment on the possibility to extract information about the form factors in the time-like region and on two-photon exchange contributions to unpolarized elastic scattering which specifically arise in soliton models.
Orthopositronium decay form factors and two-photon correlations
Adkins, Gregory S.; Droz, Daniel R.; Rastawicki, Dominik; Fell, Richard N.
2010-04-15
We give results for the orthopositronium decay form factors through one-loop order. We use the form factors to calculate momentum correlations of the final-state photons
Measuring the integrated Sachs-Wolfe effect
NASA Astrophysics Data System (ADS)
Dupé, F.-X.; Rassat, A.; Starck, J.-L.; Fadili, M. J.
2011-10-01
Context. One of the main challenges of modern cosmology is to understand the nature of the mysterious dark energy that causes the cosmic acceleration. The integrated Sachs-Wolfe (ISW) effect is sensitive to dark energy, and if detected in a universe where modified gravity and curvature are excluded, presents an independent signature of dark energy. The ISW effect occurs on large scales where cosmic variance is high and where owing to the Galactic confusion we lack large amounts of data in the CMB as well as large-scale structure maps. Moreover, existing methods in the literature often make strong assumptions about the statistics of the underlying fields or estimators. Together these effects can severely limit signal extraction. Aims: We aim to define an optimal statistical method for detecting the ISW effect that can handle large areas of missing data and minimise the number of underlying assumptions made about the data and estimators. Methods: We first review current detections (and non-detections) of the ISW effect, comparing statistical subtleties between existing methods, and identifying several limitations. We propose a novel method to detect and measure the ISW signal. This method assumes only that the primordial CMB field is Gaussian. It is based on a sparse inpainting method to reconstruct missing data and uses a bootstrap technique to avoid assumptions about the statistics of the estimator. It is a complete method, which uses three complementary statistical methods. Results: We apply our method to Euclid-like simulations and show we can expect a ~7σ model-independent detection of the ISW signal with WMAP7-like data, even when considering missing data. Other tests return ~5σ detection levels for a Euclid-like survey. We find that detection levels are independent from whether the galaxy field is normally or lognormally distributed. We apply our method to the 2 Micron All Sky Survey (2MASS) and WMAP7 CMB data and find detections in the 1.0-1.2σ range, as
Characterization of two Turkish beta-hexosaminidase mutations causing Tay-Sachs disease.
Ozkara, Hatice Asuman; Sandhoff, Konrad
2003-04-01
Two homoallelic mutations have recently been identified in the alpha-subunit of hexosaminidase A (EC 3.2.1.52) causing the infantile form of Tay-Sachs disease in Turkish patients. Both of these mutations, a 12 bp deletion (1096-1107 or 1098-1108 or 1099-1109) in exon 10 and a point mutation (G1362 to A, Gly454 to Asp) in exon 12, are located in the catalytic domain of the hexosaminidase alpha-chain. In order to determine whether these mutations affect the function of the catalytic domain or result in an instable protein, both mutant cDNAs were overexpressed in COS-1 cells. As judged by Western blotting, transfections of wild-type cDNA produced pro-alpha-chain and mature alpha-chain in parallel with a fivefold increase in cellular hexosaminidase activity using the synthetic substrate 4-methylumbelliferyl beta-N-acetylglucosamine 6-sulfate (MUGS). However, both mutants produced only pro-alpha-chains, although no mature form or detectable hexosaminidase activity towards two different synthetic substrates was observed. These data are consistent with the biochemical phenotype of infantile Tay-Sachs disease. We conclude that the overexpressed mutant pro-alpha-chains were misfolded and could not undergo further proteolytic processing to the active form of the enzyme in the lysosome.
Rapid detection of fetal Mendelian disorders: Tay-Sachs disease.
Guetta, Esther; Peleg, Leah
2008-01-01
Tay-Sachs disease is an autosomal recessive storage disease caused by the impaired activity of the lysosomal enzyme hexosaminidase A. In this fatal disease, the sphingolipid GM2 ganglioside accumulates in the neurons. Due to high carrier rates and the severity of the disease, population screening and prenatal diagnosis of Tay-Sachs disease are routinely carried out in Israel. Laboratory diagnosis of Tay-Sachs is carried out with biochemical and DNA-based methods in peripheral and umbilical cord blood, amniotic fluid, and chorionic villi samples. The assay of hexosaminidase A (Hex A) activity is carried out with synthetic substrates, 4-methylumbelliferyl-6-sulfo-N-acetyl-beta-glucosaminide (4-MUGS) and 4-methylumbelliferil-N-acetyl-beta-glucosamine (4-MUG), and the DNA-based analysis involves testing for the presence of specific known mutations in the alpha-subunit gene of Hex A. Prenatal diagnosis of Tay-Sachs disease is accomplished within 24-48 h from sampling. The preferred strategy is to simultaneously carry out enzymatic analysis in the amniotic fluid supernatant or in chorionic villi and molecular DNA-based testing in an amniotic fluid cell-pellet or in chorionic villi.
ERIC Educational Resources Information Center
bin Pet, Mokhtar; Sihes, Ahmad Johari Hj
2015-01-01
This study aims to examine the external factors of form six teachers who can influence thinking domain form six teachers in their teaching. This study was conducted using a quantitative approach using questionnaires. A total of 300 form six teacher schools in Johor were chosen as respondents. The findings were obtained as student background…
Axial transition form factors and pion decay of baryon resonances
Julia-Diaz, B.; Riska, D.O.; Coester, F.
2004-10-01
The pion decay constants of the lowest orbitally excited states of the nucleon and the {delta}(1232) along with the corresponding axial transition form factors are calculated with Poincare covariant constituent-quark models with instant, point, and front forms of relativistic kinematics. The model wave functions are chosen such that the calculated electromagnetic and axial form factors of the nucleon represent the empirical values in all three forms of kinematics, when calculated with single-constituent currents. The pion decay widths calculated with the three forms of kinematics are smaller than the empirical values. Front and instant form kinematics provide a similar description, with a slight preference for front form, while the point form values are significantly smaller in the case of the lowest positive parity resonances.
Light-Cone Sum Rule Approach for Baryon Form Factors
NASA Astrophysics Data System (ADS)
Offen, Nils
2016-10-01
We present the state-of-the-art of the light-cone sum rule approach to Baryon form factors. The essence of this approach is that soft Feynman contributions are calculated in terms of small transverse distance quantities using dispersion relations and duality. The form factors are thus expressed in terms of nucleon wave functions at small transverse separations, called distribution amplitudes, without any additional parameters. The distribution amplitudes, therefore, can be extracted from the comparison with the experimental data on form factors and compared to the results of lattice QCD simulations.
The structure of the nucleon: Elastic electromagnetic form factors
Punjabi, V.; Perdrisat, C. F.; Jones, M. K.; Brash, E. J.; Carlson, C. E.
2015-07-10
Precise proton and neutron form factor measurements at Jefferson Lab, using spin observables, have recently made a significant contribution to the unraveling of the internal structure of the nucleon. Accurate experimental measurements of the nucleon form factors are a test-bed for understanding how the nucleon's static properties and dynamical behavior emerge from QCD, the theory of the strong interactions between quarks. There has been enormous theoretical progress, since the publication of the Jefferson Lab proton form factor ratio data, aiming at reevaluating the picture of the nucleon. We will review the experimental and theoretical developments in this field and discuss the outlook for the future.
Extracting nucleon strange and anapole form factors from data
R.D. Young; J. Roche; R.D. Carlini; A.W. Thomas
2006-04-14
Using the complete world set of parity violating electron scattering data up to Q{sup 2} {approx} 0.3 GeV{sup 2}, we extract the current best determination of the strange electric and magnetic form factors of the proton, as well as the weak axial form factors of the proton and neutron at Q{sup 2} = 0.1 GeV{sup 2}. The results are consistent with state of the art calculations of all four form factors, with the latter including the anapole contribution.
Tropak, Michael B; Reid, Stephen P; Guiral, Marianne; Withers, Stephen G; Mahuran, Don
2004-04-02
Tay-Sachs and Sandhoff diseases are lysosomal storage disorders that result from an inherited deficiency of beta-hexosaminidase A (alphabeta). Whereas the acute forms are associated with a total absence of hexosaminidase A and early death, the chronic adult forms exist with activity and protein levels of approximately 5%, and unaffected individuals have been found with only 10% of normal levels. Surprisingly, almost all disease-associated missense mutations do not affect the active site of the enzyme but, rather, inhibit its ability to obtain and/or retain its native fold in the endoplasmic reticulum, resulting in its retention and accelerated degradation. By growing adult Tay-Sachs fibroblasts in culture medium containing known inhibitors of hexosaminidase we have raised the residual protein and activity levels of intralysosomal hexosaminidase A well above the critical 10% of normal levels. A similar effect was observed in fibroblasts from an adult Sandhoff patient. We propose that these hexosaminidase inhibitors function as pharmacological chaperones, enhancing the stability of the native conformation of the enzyme, increasing the amount of hexosaminidase A capable of exiting the endoplasmic reticulum for transport to the lysosome. Therefore, pharmacological chaperones could provide a novel approach to the treatment of adult Tay-Sachs and possibly Sandhoff diseases.
Tropak, Michael B.; Reid, Stephen P.; Guiral, Marianne; Withers, Stephen G.; Mahuran, Don
2010-01-01
Tay-Sachs and Sandhoff diseases are lysosomal storage disorders that result from an inherited deficiency of β-hexosaminidase A (αβ). Whereas the acute forms are associated with a total absence of hexosaminidase A and early death, the chronic adult forms exist with activity and protein levels of ~5%, and unaffected individuals have been found with only 10% of normal levels. Surprisingly, almost all disease-associated missense mutations do not affect the active site of the enzyme but, rather, inhibit its ability to obtain and/or retain its native fold in the endoplasmic reticulum, resulting in its retention and accelerated degradation. By growing adult Tay-Sachs fibroblasts in culture medium containing known inhibitors of hexosaminidase we have raised the residual protein and activity levels of intralysosomal hexosaminidase A well above the critical 10% of normal levels. A similar effect was observed in fibroblasts from an adult Sandhoff patient. We propose that these hexosaminidase inhibitors function as pharmacological chaperones, enhancing the stability of the native conformation of the enzyme, increasing the amount of hexosaminidase A capable of exiting the endoplasmic reticulum for transport to the lysosome. Therefore, pharmacological chaperones could provide a novel approach to the treatment of adult Tay-Sachs and possibly Sandhoff diseases. PMID:14724290
Atomic form factor for twisted vortex photons interacting with atoms
NASA Astrophysics Data System (ADS)
Guthrey, Pierson; Kaplan, Lev; McGuire, J. H.
2014-04-01
The relatively new atomic form factor for twisted (vortex) beams, which carry orbital angular momentum (OAM), is considered and compared to the conventional atomic form factor for plane-wave beams that carry only spin angular momentum. Since the vortex symmetry of a twisted photon is more complex that that of a plane wave, evaluation of the atomic form factor is also more complex for twisted photons. On the other hand, the twisted photon has additional parameters, including the OAM quantum number, ℓ, the nodal radial number, p, and the Rayleigh range, zR, which determine the cone angle of the vortex. This Rayleigh range may be used as a variable parameter to control the interaction of twisted photons with matter. Here we address (i) normalization of the vortex atomic form factor, (ii) displacement of target atoms away from the center of the beam vortex, and (iii) formulation of transition probabilities for a variety of photon-atom processes. We attend to features related to experiments that can test the range of validity and accuracy of calculations of these variations of the atomic form factor. Using the absolute square of the form factor for vortex beams, we introduce a vortex factor that can be directly measured.
Classical limit of diagonal form factors and HHL correlators
NASA Astrophysics Data System (ADS)
Bajnok, Zoltan; Janik, Romuald A.
2017-01-01
We propose an expression for the classical limit of diagonal form factors in which we integrate the corresponding observable over the moduli space of classical solutions. In infinite volume the integral has to be regularized by proper subtractions and we present the one, which corresponds to the classical limit of the connected diagonal form factors. In finite volume the integral is finite and can be expressed in terms of the classical infinite volume diagonal form factors and subvolumes of the moduli space. We analyze carefully the periodicity properties of the finite volume moduli space and found a classical analogue of the Bethe-Yang equations. By applying the results to the heavy-heavy-light three point functions we can express their strong coupling limit in terms of the classical limit of the sine-Gordon diagonal form factors.
Proton Form Factors Measurements in the Time-Like Region
Anulli, F.; /Frascati
2007-10-22
I present an overview of the measurement of the proton form factors in the time-like region. BABAR has recently measured with great accuracy the e{sup +}e{sup -} {yields} p{bar p} reaction from production threshold up to an energy of {approx} 4.5 GeV, finding evidence for a ratio of the electric to magnetic form factor greater than unity, contrary to expectation. In agreement with previous measurements, BABAR confirmed the steep rise of the magnetic form factor close to the p{bar p} mass threshold, suggesting the possible presence of an under-threshold N{bar N} vector state. These and other open questions related to the nucleon form factors both in the time-like and space-like region, wait for more data with different experimental techniques to be possibly solved.
Pion form factor in the NLC QCD SR approach
Bakulev, A. P. Pimikov, A. V.; Stefanis, N. G.
2010-06-15
We present results of a calculation of the electromagnetic pion form factor within the framework of QCD sum rules with nonlocal condensates and using a perturbative spectral density which includes O({alpha}{sub s}) contributions.
Hadronic Form Factors in Asymptotically Free Field Theories
DOE R&D Accomplishments Database
Gross, D. J.; Treiman, S. B.
1974-01-01
The breakdown of Bjorken scaling in asymptotically free gauge theories of the strong interactions is explored for its implications on the large q{sup 2} behavior of nucleon form factors. Duality arguments of Bloom and Gilman suggest a connection between the form factors and the threshold properties of the deep inelastic structure functions. The latter are addressed directly in an analysis of asymptotically free theories; and through the duality connection we are then led to statements about the form factors. For very large q{sup 2} the form factors are predicted to fall faster than any inverse power of q{sup 2}. For the more modest range of q{sup 2} reached in existing experiments the agreement with data is fairly good, though this may well be fortuitous. Extrapolations beyond this range are presented.
Flavor decomposition of the elastic nucleon electromagnetic form factors
C.D. Cates, C.W. Jager, S. Riordan, B. Wojtsekhowski
2011-06-01
The u- and d-quark contributions to the elastic nucleon electromagnetic form factors have been determined using experimental data on GEn , GMn , GpE , and GpM . Such a flavor separation of the form factors became possible up to 3.4 GeV2 with recent data on GEn from Hall A at JLab. At a negative four-momentum transfer squared Q2 above 1 GeV2, for both the u- and d-quark components, the ratio of the Pauli form factor to the Dirac form factor, F2/F1, was found to be almost constant, and for each of F2 and F1 individually, the d-quark component drops continuously with increasing Q2.
Vector Meson Form Factors and Wave Functions from Holographic QCD
Hovhannes Grigoryan; Anatoly Radyushkin
2007-10-10
Based on the holographic dual model of QCD, we study 2- and 3-point functions of vector currents and derive form factors as well as wave functions for the vector mesons. As a result, generalized vector-meson dominance representation for form factors is obtained with a very specific VMD pattern. The calculated electric radius of the rho-meson is shown to be in a good agreement with predictions from lattice QCD.
Future Perspectives on Baryon Form Factor Measurements with BES III
NASA Astrophysics Data System (ADS)
Schönning, Karin; Li, Cui
2017-03-01
The electromagnetic structure of hadrons, parameterised in terms of electromagnetic form factors, EMFF's, provide a key to the strong interaction. Nucleon EMFF's have been studied rigorously for more than 60 years but the new techniques and larger data samples available at modern facilities have given rise to a renewed interest for the field. Recently, the access to hyperon structure by hyperon time-like EMFF provides an additional dimension. The BEijing Spectrometer (BES III) at the Beijing Electron Positron Collider (BEPC-II) in China is the only running experiment where time-like baryon EMFF's can be studied in the e+e- → BB̅ reaction. The BES III detector is an excellent tool for baryon form factor measurements thanks to its near 4π coverage, precise tracking, PID and calorimetry. All hyperons in the SU(3) spin 1/2 octet and spin 3/2 decuplet are energetically accessible within the BEPC-II energy range. Recent data on proton and Λ hyperon form factors will be presented. Furthermore, a world-leading data sample was collected in 2014-2015 for precision measurements of baryon form factors. In particular, the data will enable a measurement of the relative phase between the electric and the magnetic form factors for Λ and Λc+ and hyperons. The modulus of the phase can be extracted from the hyperon polarisation, which in turn is experimentally accessible via the weak, parity violating decay. Furthermore, from the spin correlation between the outgoing hyperon and antihyperon, the sign of the phase can be extracted. This means that the time-like form factors can be completely determined for the first time. The methods will be outlined and the prospects of the BES III form factor measurements will be given. We will also present a planned upgrade of the BES III detector which is expected to improve future form factor measurements.
Charm and bottom hadronic form factors with QCD sum rules
Bracco, M. E.; Rodrigues, B. O.; Cerqueira, A. Jr.
2013-03-25
We present a brief review of some calculations of form factors and coupling constants in vertices with charm and bottom mesons in the framework of QCD sum rules. We first discuss the motivation for this work, describing possible applications of these form factors to charm and bottom decays processes. We first make a summarize of the QCD sum rules method. We give special attention to the uncertainties of the method introducing by the intrinsic variation of the parameters. Finally we conclude.
Strange form factors of octet and decuplet baryons
Hong, Soon-Tae
1999-11-22
The strange form factors of baryon octet are evaluated, in the chiral models with the general chiral SU(3) group structure, to yield the theoretical predictions comparable to the recent experimental data of SAMPLE Collaboration and to study the spin symmetries. Other model predictions are also briefly reviewed to compare with our results and then the strange form factors of baryon octet and decuplet are predicted.
Online Soil Science Lesson 3: Soil Forming Factors
Technology Transfer Automated Retrieval System (TEKTRAN)
This lesson explores the five major factors of soil formation, namely: 1) climate; 2) organisms; 3) time; 4) topography; and 5) parent material and their influence in forming soil. The distinction between active and passive factors, moisture and temperature regimes, organism and topographic influen...
Analytic results for massless three-loop form factors
NASA Astrophysics Data System (ADS)
Lee, R. N.; Smirnov, A. V.; Smirnov, V. A.
2010-04-01
We evaluate, exactly in d, the master integrals contributing to massless threeloop QCD form factors. The calculation is based on a combination of a method recently suggested by one of the authors (R.L.) with other techniques: sector decomposition implemented in
Sidashenko, O I; Voronkova, O S; Sirokvasha, O A; Vinnikov, A I
2015-01-01
A comparative study of the manifestation of pathogenicity factors: hemolytic, lipase, letsytinase activity and ability to adhere in 20 film-forming and 17 non-film-forming strains of S. epidermidis. Studying pathogenicity factors of the film-forming strains it was found that complete hemolysis and lipase activity shown was by all the film-forming strains of S. epidermidis, letsytinase activity was observed in 80%. Among the non-film-forming strains complete hemolysis and lipase activity were observed in 89% and letsytinase - 71%. Researched non-film-forming and film-forming strains of S. epidermidis showed the ability to adhere to buccal epithelial cells of humans. Found that all the film-forming strains of S. epidermidis were hight level adgesion, the highest IAM was equal to 11,84. It was found that among non-film-forming strains of S. epidermidis were low-, medium- and hight level adgesion. IAM of non-film-forming strains of S. epidermidis is 3 times lower compared to the IAM of the film-forming strains of human epithelial cells and was 3.2.
INTEGRATED SACHS-WOLFE EFFECT FOR GRAVITATIONAL RADIATION
Laguna, Pablo; Larson, Shane L.; Spergel, David; Yunes, Nicolas
2010-05-20
Gravitational waves (GWs) are messengers carrying valuable information about their sources. For sources at cosmological distances, the waves will also contain the imprint left by the intervening matter. The situation is in close analogy with cosmic microwave photons, for which the large-scale structures the photons traverse contribute to the observed temperature anisotropies, in a process known as the integrated Sachs-Wolfe effect. We derive the GW counterpart of this effect for waves propagating on a Friedman-Robertson-Walker background with scalar perturbations. We find that the phase, frequency, and amplitude of the GWs experience Sachs-Wolfe-type integrated effects, in addition to the magnification effects on the amplitude from gravitational lensing. We show that for supermassive black hole binaries, the integrated effects could account for measurable changes on the frequency, chirp mass, and luminosity distance of the binary, thus unveiling the presence of inhomogeneities, and potentially dark energy, in the universe.
Choroidal coloboma in a case of tay-sachs disease.
Ahmed, Nasreen Raees; Tripathy, Koushik; Kumar, Vivek; Gogia, Varun
2014-01-01
Coloboma as an ocular finding has been documented in various syndromes. Here we have a case of infantile Tay-Sachs disease associated with unilateral choroidal coloboma. To the best of our knowledge, such an association has not been documented in the literature. Whether such an association is a matter of chance or signifies the involvement of ganglioside metabolism in ocular embryogenesis remains to be elucidated.
Distribution of a pseudodeficiency allele among Tay-Sachs carriers
Tomczak, J.; Grebner, E.E. ); Boogen, C. )
1993-08-01
Recently Triggs-Raine et al. (1992) identified a new mutation in the gene coding for the [alpha]-subunit of [beta]-hexosaminidase A (hex A), the enzyme whose deficiency causes Tay-Sachs disease. This mutation, a C[sub 739]-to-T transition in exon 7, results in an altered enzyme that is active (albeit at reduced levels) in cells but that has essentially no activity in serum. This so-called pseudodeficient allele was first detected in compound heterozygotes who also carried a Tay-Sachs disease allele and therefore had no detectable hex A in their serum but who were in good health. Carriers of this apparently benign mutation are generally indistinguishable from carriers of a lethal mutation by means of routine enzyme-based screening tests, because the product of the pseudodeficient allele is not detectable in serum and has decreased activity in cells. This suggests that some individuals who have been classified as Tay-Sachs carriers are actually carriers of the pseudodeficient allele and are not at risk to have a child affected with Tay-Sachs disease. The pseudodeficient allele may also be responsible for some inconclusive diagnoses, where leukocyte values fall below the normal range but are still above the carrier range. The fact that there are now two mutant alleles (the psuedodeficient and the adult) that are indistinguishable from the lethal infantile mutations by means of enzyme assay yet that are phenotypically very different and that together may account for as much as 12% of enzyme-defined carriers on the basis of the data here suggests that DNA analysis should be part of a comprehensive screening program. It will be particularly useful to identify the mutations in couples at risk, before they undergo prenatal diagnosis. DNA analysis will also resolve some inconclusive diagnoses.
Kantowski-Sachs universes sourced by a Skyrme fluid
NASA Astrophysics Data System (ADS)
Parisi, Luca; Radicella, Ninfa; Vilasi, Gaetano
2015-03-01
The Kantowski-Sachs cosmological model sourced by a Skyrme field and a cosmological constant is considered in the framework of general relativity. Assuming a constant radial profile function α =π /2 for the hedgehog ansatz, the Skyrme contribution to Einstein equations is shown to be equivalent to an anisotropic fluid. Using dynamical system techniques, a qualitative analysis of the cosmological equations is presented. Physically interesting features of the model such as isotropization, bounce and recollapse are discussed.
Measurements of the Helium Form Factors at JLab
Khrosinkova, Elena
2007-10-26
An experiment to measure elastic electron scattering off {sup 3}He and {sup 4}He at large momentum transfers is presented. The experiment was carried out in the Hall A Facility of Jefferson Lab. Elastic electron scattering off {sup 3}He was measured at forward and backward electron scattering angles to extract the isotope's charge and magnetic form factors. The charge form factor of {sup 4}He will be extracted from forward-angle electron scattering angle measurements. The data are expected to significantly extend and improve the existing measurements of the three- and four-body form factors. The results will be crucial for the establishment of a canonical standard model for the few-body nuclear systems and for testing predictions of quark dimensional scaling and hybrid nucleon-quark models.
The structure of the nucleon: Elastic electromagnetic form factors
Punjabi, V.; Perdrisat, C. F.; Jones, M. K.; ...
2015-07-10
Precise proton and neutron form factor measurements at Jefferson Lab, using spin observables, have recently made a significant contribution to the unraveling of the internal structure of the nucleon. Accurate experimental measurements of the nucleon form factors are a test-bed for understanding how the nucleon's static properties and dynamical behavior emerge from QCD, the theory of the strong interactions between quarks. There has been enormous theoretical progress, since the publication of the Jefferson Lab proton form factor ratio data, aiming at reevaluating the picture of the nucleon. We will review the experimental and theoretical developments in this field and discussmore » the outlook for the future.« less
Two-loop SL(2) form factors and maximal transcendentality
NASA Astrophysics Data System (ADS)
Loebbert, Florian; Sieg, Christoph; Wilhelm, Matthias; Yang, Gang
2016-12-01
Form factors of composite operators in the SL(2) sector of N = 4 SYM theory are studied up to two loops via the on-shell unitarity method. The non-compactness of this subsector implies the novel feature and technical challenge of an unlimited number of loop momenta in the integrand's numerator. At one loop, we derive the full minimal form factor to all orders in the dimensional regularisation parameter. At two loops, we construct the complete integrand for composite operators with an arbitrary number of covariant derivatives, and we obtain the remainder functions as well as the dilatation operator for composite operators with up to three covariant derivatives. The remainder functions reveal curious patterns suggesting a hidden maximal uniform transcendentality for the full form factor. Finally, we speculate about an extension of these patterns to QCD.
Measuring Form Factors and Structure Functions with CLAS
G.P. Gilfoyle
2007-09-10
The physics program at the Thomas Jefferson National Accelerator Facility includes a strong effort to measure form factors and structure functions to probe the structure of hadronic matter, reveal the nature of confinement, and develop an understanding of atomic nuclei using quark-gluon degrees of freedom. The CLAS detector is a large acceptance device occupying one of the end stations. We discuss here two programs that use CLAS; measuring the magnetic form factor of the neutron and the virtual photon asymmetry of the proton. The form factor has been measured with unprecedented kinematic coverage and precision up to Q2=4.7 GeV2 and is consistent within 5%-10% of the dipole parameterization. The proton virtual photon asymmetry has been measured across a wide range in Bjorken x. The data exceed the SU(6)-symmetric quark prediction and show evidence of a smooth approach to the scaling limit prescribed by perturbative QCD.
The Proton Form Factor Ratio Measurements at Jefferson Lab
Punjabi, Vina A.; Perdrisat, Charles F.
2014-03-01
The ratio of the proton form factors, G{sub Ep}/G{sub Mp}, has been measured from Q{sup 2} of 0.5 GeV{sup 2} to 8.5 GeV{sup 2}, at the Jefferson Laboratory, using the polarization transfer method. This ratio is extracted directly from the measured ratio of the transverse and longitudinal polarization components of the recoiling proton in elastic electron-proton scattering. The discovery that the proton form factor ratio measured in these experiments decreases approximately linearly with four-momentum transfer, Q{sup 2}, for values above ~1 GeV{sup 2}, is one of the most significant results to come out of JLab. These results have had a large impact on progress in hadronic physics; and have required a significant rethinking of nucleon structure. The increasingly common use of the double-polarization technique to measure the nucleon form factors, in the last 15 years, has resulted in a dramatic improvement of the quality of all four nucleon electromagnetic form factors, G{sub Ep}, G{sub Mp}, G{sub En} and G{sub Mn}. There is an approved experiment at JLab, GEP(V), to continue the ratio measurements to 12 GeV{sup 2}. A dedicated experimental setup, the Super Bigbite Spectrometer (SBS), will be built for this purpose. It will be equipped with a focal plane polarimeter to measure the polarization of the recoil protons. The scattered electrons will be detected in an electromagnetic calorimeter. In this presentation, I will review the status of the proton elastic electromagnetic form factors and discuss a number of theoretical approaches to describe nucleon form factors.
Master integrals for the four-loop Sudakov form factor
NASA Astrophysics Data System (ADS)
Boels, Rutger H.; Kniehl, Bernd A.; Yang, Gang
2016-01-01
The light-like cusp anomalous dimension is a universal function in the analysis of infrared divergences. In maximally (N = 4) supersymmetric Yang-Mills theory (SYM) in the planar limit, it is known, in principle, to all loop orders. The non-planar corrections are not known in any theory, with the first appearing at the four-loop order. The simplest quantity which contains this correction is the four-loop two-point form factor of the stress tensor multiplet. This form factor was largely obtained in integrand form in a previous work for N = 4 SYM, up to a free parameter. In this work, a reduction of the appearing integrals obtained by solving integration-by-parts (IBP) identities using a modified version of Reduze is reported. The form factor is shown to be independent of the remaining parameter at integrand level due to an intricate pattern of cancellations after IBP reduction. Moreover, two of the integral topologies vanish after reduction. The appearing master integrals are cross-checked using independent algebraic-geometry techniques explored in the Mint package. The latter results provide the basis of master integrals applicable to generic form factors, including those in Quantum Chromodynamics. Discrepancies between explicitly solving the IBP relations and the MINT approach are highlighted. Remaining bottlenecks to completing the computation of the four-loop non-planar cusp anomalous dimension in N = 4 SYM and beyond are identified.
Pion transition form factor through Dyson-Schwinger equations
NASA Astrophysics Data System (ADS)
Raya, Khépani
2016-10-01
In the framework of Dyson-Schwinger equations (DSE), we compute the γ*γ→π0 transition form factor, G(Q2). For the first time, in a continuum approach to quantun chromodynamics (QCD), it was possible to compute G(Q2) on the whole domain of space-like momenta. Our result agrees with CELLO, CLEO and Belle collaborations and, with the well- known asymptotic QCD limit, 2ƒπ. Our analysis unifies this prediction with that of the pion's valence-quark parton distribution amplitude (PDA) and elastic electromagnetic form factor.
Measurement of the Charged Pion Electromagnetic Form Factor
J. Volmer; David Abbott; H. Anklin; Chris Armstrong; John Arrington; K. Assamagan; Steven Avery; Oliver K. Baker; Henk Blok; C. Bochna; Ed Brash; Herbert Breuer; Nicholas Chant; Jim Dunne; Tom Eden; Rolf Ent; David Gaskell; Ron Gilman; Kenneth Gustafsson; Wendy Hinton; Garth Huber; Hal Jackson; Mark K. Jones; Cynthia Keppel; P.H. Kim; Wooyoung Kim; Andi Klein; Doug Koltenuk; Meme Liang; George Lolos; Allison Lung; David Mack; D. McKee; David Meekins; Joseph Mitchell; H. Mkrtchian; B. Mueller; Gabriel Niculescu; Ioana Niculescu; D. Pitz; D. Potterveld; Liming Qin; Juerg Reinhold; I.K. Shin; Stepan Stepanyan; V. Tadevosian; L.G. Tang; R.L.J. van der Meer; K. Vansyoc; D. Van Westrum; Bill Vulcan; Stephen Wood; Chen Yan; W.X. Zhao; Beni Zihlmann
2001-02-26
Separated longitudinal and transverse structure functions for the reaction 1H(e,eprime pi+)n were measured in the momentum transfer region Q2=0.6-1.6 (GeV/c)**2 at a value of the invariant mass W=1.95 GeV. New values for the pion charge form factor were extracted from the longitudinal cross section by using a recently developed Regge model. The results indicate that the pion form factor in this region is larger than previously assumed and is consistent with a monopole parameterization fitted to very low Q2 elastic data.
Reanalysis of Rosenbluth measurements of the proton form factors
NASA Astrophysics Data System (ADS)
Gramolin, Alexander; Nikolenko, Dmitry
2017-01-01
We have reanalyzed the elastic electron-proton scattering data from SLAC experiments E140 and NE11. This work was motivated by recent progress in calculating the corresponding radiative corrections and by the apparent discrepancy between the Rosenbluth and polarization transfer measurements of the proton electromagnetic form factors. New, corrected values for the scattering cross sections are presented, as well as a new form factor fit in the Q2 range from 1 to 8 . 83GeV2 . Our reanalysis brings the combined results of the SLAC experiments into better agreement with the polarization transfer data, but a significant discrepancy remains for Q2 > 3GeV2 .
Pion Electromagnetic Form Factor in Virtuality Distribution Formalism
Radyushkin, Anatoly V.
2016-01-01
We discuss two applications of the {\\it Virtuality Distribution Amplitudes} (VDA) formalism developed in our recent papers. We start with an overview of the main properties of the pion distribution amplitude emphasizing the quantitative measures of its width, and possibility to access them through the pion transition form factor studies. We formulate the basic concepts of the VDA approach and introduce the pion {\\it transverse momentum distribution amplitude} (TMDA) which plays, in a covariant Lagrangian formulation, a role similar to that of the pion wave function in the 3-dimensional Hamiltonian light-front approach. We propose simple factorized models for soft TMDAs, and use them to describe existing data on the pion transition form factor, thus fixing the scale determining the size of the transverse-momentum effects. Finally, we apply the VDA approach to the one-gluon exchange contribution for the pion electromagnetic form factor. We observe a very late $Q^2 \\gtrsim 20$ GeV$^2$ onset of transition to the asymptotic pQCD predictions and show that in the $Q^2 \\lesssim 10$ GeV$^2$ region there is essentially no sensitivity to the shape of the pion distribution amplitude. Furthermore, the magnitude of the one-gluon exchange contribution in this region is estimated to be an order of magnitude below the Jefferson Lab data, thus leaving the Feynman mechanism as the only one relevant to the pion electromagnetic form factor behavior for accessible $Q^2$.
Electromagnetic Form Factors of Hadrons in Quantum Field Theories
Dominguez, C. A.
2008-10-13
In this talk, recent results are presented of calculations of electromagnetic form factors of hadrons in the framework of two quantum field theories (QFT), (a) Dual-Large N{sub c} QCD (Dual-QCD{sub {infinity}}) for the pion, proton, and {delta}(1236), and (b) the Kroll-Lee-Zumino (KLZ) fully renormalizable Abelian QFT for the pion form factor. Both theories provide a QFT platform to improve on naive (tree-level) Vector Meson Dominance (VMD). Dual-QCD{sub {infinity}} provides a tree-level improvement by incorporating an infinite number of zero-width resonances, which can be subsequently shifted from the real axis to account for the time-like behaviour of the form factors. The renormalizable KLZ model provides a QFT improvement of VMD in the framework of perturbation theory. Due to the relative mildness of the {rho}{pi}{pi} coupling, and the size of loop suppression factors, the perturbative expansion is well defined in spite of this being a strong coupling theory. Both approaches lead to considerable improvements of VMD predictions for electromagnetic form factors, in excellent agreement with data.
Myerowitz, R. )
1988-06-01
Tay-Sachs disease is an inherited disorder in which the {alpha} chain of the lysosomal enzyme {beta}-N-acetylhexosaminidase A bears the mutation. Ashkenazi Jews are found to be carriers for a severe type of Tay-Sachs disease, the classic form, 10 times more frequently than the general population. Ashkenazi Jewish patients with classic Tay-Sachs disease have appeared to be clinically and biochemically identical, and the usual assumption has been that they harbor the same {alpha}-chain mutation. The author has isolated the {alpha}-chain gene from an Ashkenazi Jewish patient, GM2968, with classic Tay-Sachs disease and compared its nucleotide sequences with that of the normal {alpha}-chain gene in the promoter region, exon and splice junction regions, and polyadenylylation signal area. Only one difference was observed between these sequences. The alteration is presumed to be functionally significant and to result in aberrant mRNA splicing. Utilizing the polymerase chain reaction to amplify the region encompassing the mutation, the author developed an assay to screen patients and heterozygote carriers for this mutation. Surprisingly, in each of two Ashkenazi patients, only one {alpha}-chain allele harbored the splice junction mutation. Only one parent of each of these patients was positive for the defect. Another Ashkenazi patient did not bear this mutation at all nor did either of the subject's parents. The data are consistent with the presence of more than one mutation underlying the classic form of Tay-Sachs disease in the Ashkenazi Jewish population.
Miklyaeva, Elena I; Dong, Weijia; Bureau, Alexandre; Fattahie, Roya; Xu, Yongqin; Su, Meng; Fick, Gordon H; Huang, Jing-Qi; Igdoura, Suleiman; Hanai, Nobuo; Gravel, Roy A
2004-03-19
Tay-Sachs disease is an autosomal recessive neurodegenerative disease resulting from a block in the hydrolysis of GM2 ganglioside, an intermediate in ganglioside catabolism. The mouse model of Tay-Sachs disease (Hexa -/-) has been described as behaviorally indistinguishable from wild type until at least 1 year of age due to a sialidase-mediated bypass of the metabolic defect that reduces the rate of GM2 ganglioside accumulation. In this study, we have followed our mouse model to over 2 years of age and have documented a significant disease phenotype that is reminiscent of the late onset, chronic form of human Tay-Sachs disease. Onset occurs at 11-12 months of age and progresses slowly, in parallel with increasing storage of GM2 ganglioside. The disease is characterized by hind limb spasticity, weight loss, tremors, abnormal posture with lordosis, possible visual impairment, and, late in the disease, muscle weakness, clasping of the limbs, and myoclonic twitches of the head. Immunodetection of GM2 ganglioside showed that storage varies widely in different regions, but is most intense in pyriform cortex, hippocampus (CA3 field, subiculum), amygdala, hypothalamus (paraventricular supraoptic, ventromedial and arcuate nuclei, and mammilary body), and the somatosensory cortex (layer V) in 1- to 2-year-old mutant mice. We suggest that the Tay-Sachs mouse model is a phenotypically valid model of disease and may provide for a reliable indicator of the impact of therapeutic strategies, in particular geared to the late onset, chronic form of human Tay-Sachs disease.
Spin-2 form factors at three loop in QCD
NASA Astrophysics Data System (ADS)
Ahmed, Taushif; Das, Goutam; Mathews, Prakash; Rana, Narayan; Ravindran, V.
2015-12-01
Spin-2 fields are often candidates in physics beyond the Standard Model namely the models with extra-dimensions where spin-2 Kaluza-Klein gravitons couple to the fields of the Standard Model. Also, in the context of Higgs searches, spin-2 fields have been studied as an alternative to the scalar Higgs boson. In this article, we present the complete three loop QCD radiative corrections to the spin-2 quark-antiquark and spin-2 gluon-gluon form factors in SU(N) gauge theory with n f light flavors. These form factors contribute to both quark-antiquark and gluon-gluon initiated processes involving spin-2 particle in the hadronic reactions at the LHC. We have studied the structure of infrared singularities in these form factors up to three loop level using Sudakov integro-differential equation and found that the anomalous dimensions originating from soft and collinear regions of the loop integrals coincide with those of the electroweak vector boson and Higgs form factors confirming the universality of the infrared singularities in QCD amplitudes.
Measurement of the pion form factor at higher energies
Mack, D.J.
1994-04-01
One of the strongest arguments for increasing the nominal CEBAF beam energy to equal or exceed 6 GeV is that one would be able to make quality high Q{sup 2} measurements of the charged pion form factor.
Nucleon form factors program with SBS at JLAB
Wojtsekhowski, Bogdan B.
2014-12-01
The physics of the nucleon form factors is the basic part of the Jefferson Laboratory program. We review the achievements of the 6-GeV era and the program with the 12- GeV beam with the SBS spectrometer in Hall A, with a focus on the nucleon ground state properties.
The Super Bigbite Project: A Study of Nucleon Form Factors
Jager, Kees de
2010-06-01
A proposed set of instrumentation, collectively referred to as the Super Bigbite project, is presented. Used in three different con figurations it will allow measurements of three nucleon electromagnetic form factors GEn, GEp, and GMn with unprecedented precision to Q2-values up to three times higher than existing data.
Determination of Transverse Charge Density from Kaon Form Factor Data
NASA Astrophysics Data System (ADS)
Mejia-Ott, Johann; Horn, Tanja; Pegg, Ian; Mecholski, Nicholas; Carmignotto, Marco; Ali, Salina
2016-09-01
At the level of nucleons making up atomic nuclei, among subatomic particles made up of quarks, K-mesons or kaons represent the most simple hadronic system including the heavier strange quark, having a relatively elementary bound state of a quark and an anti-quark as its valence structure. Its electromagnetic structure is then parametrized by a single, dimensionless quantity known as the form factor, the two-dimensional Fourier transform of which yields the quantity of transverse charge density. Transverse charge density, in turn, provides a needed framework for the interpretation of form factors in terms of physical charge and magnetization, both with respect to the propagation of a fast-moving nucleon. To this is added the value of strange quarks in ultimately presenting a universal, process-independent description of nucleons, further augmenting the importance of studying the kaon's internal structure. The pressing character of such research questions directs the present paper, describing the first extraction of transverse charge density from electromagnetic kaon form factor data. The extraction is notably extended to form factor data at recently acquired higher energy levels, whose evaluation could permit more complete phenomenological models for kaon behavior to be proposed. This work was supported in part by NSF Grant PHY-1306227.
Measurements of Form Factors with the BaBar Experiment
Li, Selina Z.; /SLAC
2011-08-25
Selected recent results on measurements of form factors by the BaBar Collaboration are reviewed, including e{sup +}e{sup -} {yields} {eta}{prime}{gamma}, leptonic and semileptonic charm decays from data collected at or near the {Upsilon}(4S) resonance.
Electromagnetic form factors of heavy flavored vector mesons
NASA Astrophysics Data System (ADS)
Priyadarsini, M.; Dash, P. C.; Kar, Susmita; Patra, Sweta P.; Barik, N.
2016-12-01
We study the electromagnetic form factors of heavy flavored vector mesons such as (D*,Ds*,J /Ψ ) , (B*,Bs*,ϒ ) via one photon radiative decays (V →P γ ) in the relativistic independent quark (RIQ) model based on a flavor independent average interaction potential in the scalar vector harmonic form. The momentum dependent spacelike (q2<0 ) form factors calculated in this model are analytically continued to the physical timelike region 0 ≤q2≤(MV-MP)2 . The predicted coupling constant gV P γ=FV P(q2=0 ) for real photon case in the limit q2→0 and decay widths Γ (V →P γ ) are found in reasonable agreement with experimental data and other model predictions.
Genetics Home Reference: Tay-Sachs disease
... rare inherited disorder that progressively destroys nerve cells ( neurons ) in the brain and spinal cord . The most common form of ... this substance accumulates to toxic levels, particularly in neurons in the brain and spinal cord. Progressive damage caused by the ...
78 FR 26407 - Goldman Sachs Trust II, et al.; Notice of Application
Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-06
... the applicable Subadvised Fund (if required by applicable law), to delegate portfolio management... Trust II (the ``Trust''), Goldman Sachs Asset Management L.P. (``GSAM'') and Goldman Sachs Asset Management International (``GSAMI'', each of GSAM and GSAMI an ``Adviser'' and collectively,...
The white matter of the human cerebrum: Part I The occipital lobe by Heinrich Sachs
Forkel, Stephanie J.; Mahmood, Sajedha; Vergani, Francesco; Catani, Marco
2015-01-01
This is the first complete translation of Heinrich Sachs' outstanding white matter atlas dedicated to the occipital lobe. This work is accompanied by a prologue by Prof Carl Wernicke who for many years was Sachs' mentor in Breslau and enthusiastically supported his work. PMID:25527430
Precision Measurements of the Proton Elastic Form Factor Ratio
Douglas Higinbotham
2010-08-01
New high precision polarization measurements of the proton elastic form factor ratio in the Q^2 from 0.3 to 0.7 [GeV/c]^2 have been made. These elastic H(e,e'p) measurementswere done in Jefferson Lab's Hall A using 80% longitudinally polarized electrons and recoil polarimetry. For Q^2 greater than 1 [GeV/c]^2, previous polarization data indicated a strong deviation of the form factor ratio from unity which sparked renewed theoretical and experimental interest in how two-photon diagrams have been taken into account. The new high precision data indicate that the deviation from unity, while small, persists even at Q^2 less than 1 [GeV/c]^2.
Two-photon transition form factor of c ¯ quarkonia
NASA Astrophysics Data System (ADS)
Chen, Jing; Ding, Minghui; Chang, Lei; Liu, Yu-xin
2017-01-01
The two-photon transition of c ¯c quarkonia are studied within a covariant approach based on the consistent truncation scheme of the quantum chromodynamics Dyson-Schwinger equation for the quark propagator and the Bethe-Salpeter equation for the mesons. We find the decay widths of ηc→γ γ and χc 0 ,2→γ γ in good agreement with experimental data. The obtained transition form factor of ηc→γ γ* for a wide range of spacelike photon-momentum-transfer squared is also in agreement with the experimental findings of the BABAR experiment. As a by-product, the decay widths of ηb,χb 0 ,2→γ γ and the transition form factor of ηb,χc 0 ,b 0→γ γ* are predicted, which await experimental testing.
Octet Baryon Electromagnetic Form Factors in a Relativistic Quark Model
Gilberto Ramalho, Kazuo Tsushima
2011-09-01
We study the octet baryon electromagnetic properties by applying the covariant spectator quark model, and provide covariant parametrization that can be used to study baryon electromagnetic reactions. While we use the lattice QCD data in the large pion mass regime (small pion cloud effects) to determine the parameters of the model in the valence quark sector, we use the nucleon physical and octet baryon magnetic moment data to parameterize the pion cloud contributions. The valence quark contributions for the octet baryon electromagnetic form factors are estimated by extrapolating the lattice parametrization in the large pion mass regime to the physical regime. As for the pion cloud contributions, we parameterize them in a covariant, phenomenological manner, combined with SU(3) symmetry. We also discuss the impact of the pion cloud effects on the octet baryon electromagnetic form factors and their radii.
Flavor Analysis of Nucleon, Δ , and Hyperon Electromagnetic Form Factors
NASA Astrophysics Data System (ADS)
Rohrmoser, Martin; Choi, Ki-Seok; Plessas, Willibald
2017-03-01
By the analysis of the world data base of elastic electron scattering on the proton and the neutron (for the latter, in fact, on ^2H and ^3He) important experimental insights have recently been gained into the flavor compositions of nucleon electromagnetic form factors. We report on testing the Graz Goldstone-boson-exchange relativistic constituent-quark model in comparison to the flavor contents in low-energy nucleons, as revealed from electron-scattering phenomenology. It is found that a satisfactory agreement is achieved between theory and experiment for momentum transfers up to Q^2˜ 4 GeV^2, relying on three-quark configurations only. Analogous studies have been extended to the Δ and the hyperon electromagnetic form factors. For them we here show only some sample results in comparison to data from lattice quantum chromodynamics.
Reanalysis of Rosenbluth measurements of the proton form factors
NASA Astrophysics Data System (ADS)
Gramolin, A. V.; Nikolenko, D. M.
2016-05-01
We present a reanalysis of the data from Stanford Linear Accelerator Center (SLAC) experiments E140 [R. C. Walker et al., Phys. Rev. D 49, 5671 (1994), 10.1103/PhysRevD.49.5671] and NE11 [L. Andivahis et al., Phys. Rev. D 50, 5491 (1994), 10.1103/PhysRevD.50.5491] on elastic electron-proton scattering. This work is motivated by recent progress in calculating the corresponding radiative corrections and by the apparent discrepancy between the Rosenbluth and polarization transfer measurements of the proton electromagnetic form factors. New, corrected values for the scattering cross sections are presented, as well as a new form factor fit in the Q2 range from 1 to 8.83 GeV2. We also provide a complete set of revised formulas to account for radiative corrections in single-arm measurements of unpolarized elastic electron-proton scattering.
Precision Rosenbluth measurement of the proton elastic form factors
I. A. Qattan; J. Arrington; R. E. Segel; X. Zheng; K. Aniol; O. K. Baker; R. Beams; E. J. Brash; J. Calarco; A. Camsonne; J.-P. Chen; M. E. Christy; D. Dutta; R. Ent; S. Frullani; D. Gaskell; O. Gayou; R. Gilman; C. Glashausser; K. Hafidi; J.-O. Hansen; D. W. Higinbotham; W. Hinton; R. J. Holt; G. M. Huber; H. Ibrahim; L. Jisonna; M. K. Jones; C. E. Keppel; E. Kinney; G. J. Kumbartzki; A. Lung; D. J. Margaziotis; K. McCormick; D. Meekins; R. Michaels; P. Monaghan; P. Moussiegt; L. Pentchev; C. Perdrisat; V. Punjabi; R. Ransome; J. Reinhold; B. Reitz; A. Saha; A. Sarty; E. C. Schulte; K. Slifer; P. Solvignon; V. Sulkosky; K. Wijesooriya; B. Zeidman
2004-10-01
We report the results of a new Rosenbluth measurement of the proton form factors at Q{sup 2} values of 2.64, 3.20 and 4.10 GeV{sup 2}. Cross sections were determined by detecting the recoiling proton in contrast to previous measurements in which the scattered electron was detected. At each Q{sup 2}, relative cross sections were determined to better than 1%. The measurement focused on the extraction of G{sub E}/G{sub M} which was determined to 4-8% and found to approximate form factor scaling, i.e. {mu}{sub p}G{sub E} {approx} G{sub M}. These results are consistent with and much more precise than previous Rosenbluth extractions. However, they are inconsistent with recent polarization transfer measurements of comparable precision, implying a systematic difference between the two techniques.
η' transition form factor from space- and timelike experimental data
NASA Astrophysics Data System (ADS)
Escribano, R.; Gonzàlez-Solís, S.; Masjuan, P.; Sanchez-Puertas, P.
2016-09-01
The η' transition form factor is reanalyzed in view of the recent first observation by BESIII of the Dalitz decay η'→γ e+e- in both space- and timelike regions at low and intermediate energies using the Padé approximants method. The present analysis provides a suitable parametrization for reproducing the measured form factor in the whole energy region and allows one to extract the corresponding low-energy parameters together with a prediction of their values at the origin, related to Γη'→γ γ , and the asymptotic limit. The η - η' mixing is reassessed within a mixing scheme compatible with the large-Nc chiral perturbation theory at next-to-leading order, with particular attention to the Okubo-Zweig-Iizuka-rule-violating parameters. The J /ψ , Z →η(')γ decays are also considered and predictions are reported.
Phenomenological dynamics of loop quantum cosmology in Kantowski-Sachs spacetime
Chiou, D.-W.
2008-08-15
The fundamental theory and the semiclassical description of loop quantum cosmology (LQC) have been studied in the Friedmann-Robertson-Walker and Bianchi I models. As an extension to include both anisotropy and intrinsic curvature, this paper investigates the cosmological model of Kantowski-Sachs spacetime with a free massless scalar field at the level of phenomenological dynamics with the LQC discreteness corrections. The LQC corrections are implemented in two different improved quantization schemes. In both schemes, the big bang and big crunch singularities of the classical solution are resolved and replaced by the big bounces when the area or volume scale factor approaches the critical values in the Planck regime measured by the reference of the scalar field momentum. Symmetries of scaling are also noted and suggest that the fundamental spatial scale (area gap) may give rise to a temporal scale. The bouncing scenarios are in an analogous fashion of the Bianchi I model, naturally extending the observations obtained previously.
Two-photon exchange corrections to the pion form factor
Peter G. Blunden; Melnitchouk, Wally; Tjon, John A.
2010-01-06
Here, we compute two-photon exchange corrections to the electromagnetic form factor of the pion, taking into account the finite size of the pion. Compared to the soft-photon approximation for the infrared divergent contribution which neglects hadron structure effects, the corrections are found to be ≲ 1% for small Q2 (Q2 < 0.1 GeV2), but increase to several percent for Q2 ≳ 1 GeV2 at extreme backward angles.
Stackable Form-Factor Peripheral Component Interconnect Device and Assembly
NASA Technical Reports Server (NTRS)
Somervill, Kevin M. (Inventor); Ng, Tak-kwong (Inventor); Torres-Pomales, Wilfredo (Inventor); Malekpour, Mahyar R. (Inventor)
2013-01-01
A stackable form-factor Peripheral Component Interconnect (PCI) device can be configured as a host controller or a master/target for use on a PCI assembly. PCI device may comprise a multiple-input switch coupled to a PCI bus, a multiplexor coupled to the switch, and a reconfigurable device coupled to one of the switch and multiplexor. The PCI device is configured to support functionality from power-up, and either control function or add-in card function.
Helicity non-conserving form factor of the proton
Voutier, E.; Furget, C.; Knox, S.
1994-04-01
The study of the hadron structure in the high Q{sup 2} range contributes to the understanding of the mechanisms responsible for the confinement of quarks and gluons. Among the numerous experimental candidates sensitive to these mechanisms, the helicity non-conserving form factor of the proton is a privileged observable since it is controlled by non-perturbative effects. The authors investigate here the feasibility of high Q{sup 2} measurements of this form factor by means of the recoil polarization method in the context of the CEBAF 8 GeV facility. For that purpose, they discuss the development of a high energy proton polarimeter, based on the H({rvec p},pp) elastic scattering, to be placed at the focal plane of a new hadron spectrometer. It is shown that this experimental method significantly improves the knowledge of the helicity non-conserving form factor of the proton up to 10 GeV{sup 2}/c{sup 2}.
Strange vector form factors from parity-violating electron scattering
Kent Paschke, Anthony Thomas, Robert Michaels, David Armstrong
2011-06-01
The simplest models might describe the nucleon as 3 light quarks, but this description would be incomplete without inclusion of the sea of glue and qbar q pairs which binds it. Early indications of a particularly large contribution from strange quarks in this sea to the spin and mass of the nucleon motivated an experimental program examining the role of these strange quarks in the nucleon vector form factors. The strangeness form factors can be extracted from the well-studied electromagnetic structure of the nucleon using parity-violation in electron-nuclear scattering to isolate the effect of the weak interaction. With high luminosity and polarization, and a very stable beam due to its superconducting RF cavities, CEBAF at Jefferson Lab is a precision instrument uniquely well suited to the challenge of measurements of the small parity-violating asymmetries. The techniques and results of the two major Jefferson Lab experimental efforts in parity-violation studies, HAPPEX and G0, as well as efforts to describe the strange form factors in QCD, will be reviewed.
Meson Transition Form Factors in Light-Front Holographic QCD
Brodsky, Stanley J.; Cao, Fu-Guang; de Teramond, Guy F.; /Costa Rica U.
2011-06-22
We study the photon-to-meson transition form factors (TFFs) F{sub M{gamma}}(Q{sup 2}) for {gamma}{gamma}* {yields} M using light-front holographic methods. The Chern-Simons action, which is a natural form in 5-dimensional anti-de Sitter (AdS) space, leads directly to an expression for the photon-to-pion TFF for a class of confining models. Remarkably, the predicted pion TFF is identical to the leading order QCD result where the distribution amplitude has asymptotic form. The Chern-Simons form is local in AdS space and is thus somewhat limited in its predictability. It only retains the q{bar q} component of the pion wavefunction, and further, it projects out only the asymptotic form of the meson distribution amplitude. It is found that in order to describe simultaneously the decay process {pi}{sup 0} {yields} {gamma}{gamma} and the pion TFF at the asymptotic limit, a probability for the q{bar q} component of the pion wavefunction P{sub q{bar q}} = 0.5 is required; thus giving indication that the contributions from higher Fock states in the pion light-front wavefunction need to be included in the analysis. The probability for the Fock state containing four quarks (anti-quarks) which follows from analyzing the hadron matrix elements, P{sub q{bar q}q{bar q}} {approx} 10%, agrees with the analysis of the pion elastic form factor using light-front holography including higher Fock components in the pion wavefunction. The results for the TFFs for the {eta} and {eta}{prime} mesons are also presented. The rapid growth of the pion TFF exhibited by the BABAR data at high Q{sup 2} is not compatible with the models discussed in this article, whereas the theoretical calculations are in agreement with the experimental data for the {eta} and {eta}{prime} TFFs.
Unitary evolution for a quantum Kantowski-Sachs cosmology
NASA Astrophysics Data System (ADS)
Pal, Sridip; Banerjee, Narayan
2015-10-01
It is shown that like the Bianchi I, V and IX models, a Kantowski-Sachs cosmological model also allows unitary evolution on quantization. It has also been shown that this unitarity is not at the expense of anisotropy. Non-unitarity, if there is any, cannot escape notice here, as the evolution is studied against a properly oriented time parameter fixed by the evolution of the fluid. Furthermore, we have constructed a wave packet by superposing different energy eigenstates, thereby establishing unitarity in a non-trivial way, which is a stronger result than an energy eigenstate trivially giving a time independent probability density. For α \
Neutron charge radius and the neutron electric form factor
Gentile, T. R.; Crawford, C. B.
2011-05-15
For nearly forty years, the Galster parametrization has been employed to fit existing data for the neutron electric form factor, G{sub E}{sup n}, vs the square of the four-momentum transfer, Q{sup 2}. Typically this parametrization is constrained to be consistent with experimental data for the neutron charge radius. However, we find that the Galster form does not have sufficient freedom to accommodate reasonable values of the radius without constraining or compromising the fit. In addition, the G{sub E}{sup n} data are now at sufficient precision to motivate a two-parameter fit (or three parameters if we include thermal neutron data). Here we present a modified form of a two-dipole parametrization that allows this freedom and fits both G{sub E}{sup n} (including recent data at both low and high four-momentum transfer) and the charge radius well with simple, well-defined parameters. Analysis reveals that the Galster form is essentially a two-parameter approximation to the two-dipole form but becomes degenerate if we try to extend it naturally to three parameters.
Gravitational, shear and matter waves in Kantowski-Sachs cosmologies
Keresztes, Zoltán; Gergely, László Á.; Forsberg, Mats; Bradley, Michael; Dunsby, Peter K.S. E-mail: forsberg.mats.a.b@gmail.com E-mail: peter.dunsby@uct.ac.za
2015-11-01
A general treatment of vorticity-free, perfect fluid perturbations of Kantowski-Sachs models with a positive cosmological constant are considered within the framework of the 1+1+2 covariant decomposition of spacetime. The dynamics is encompassed in six evolution equations for six harmonic coefficients, describing gravito-magnetic, kinematic and matter perturbations, while a set of algebraic expressions determine the rest of the variables. The six equations further decouple into a set of four equations sourced by the perfect fluid, representing forced oscillations and two uncoupled damped oscillator equations. The two gravitational degrees of freedom are represented by pairs of gravito-magnetic perturbations. In contrast with the Friedmann case one of them is coupled to the matter density perturbations, becoming decoupled only in the geometrical optics limit. In this approximation, the even and odd tensorial perturbations of the Weyl tensor evolve as gravitational waves on the anisotropic Kantowski-Sachs background, while the modes describing the shear and the matter density gradient are out of phase dephased by π /2 and share the same speed of sound.
Gravitational, shear and matter waves in Kantowski-Sachs cosmologies
NASA Astrophysics Data System (ADS)
Keresztes, Zoltán; Forsberg, Mats; Bradley, Michael; Dunsby, Peter K. S.; Gergely, László Á.
2015-11-01
A general treatment of vorticity-free, perfect fluid perturbations of Kantowski-Sachs models with a positive cosmological constant are considered within the framework of the 1+1+2 covariant decomposition of spacetime. The dynamics is encompassed in six evolution equations for six harmonic coefficients, describing gravito-magnetic, kinematic and matter perturbations, while a set of algebraic expressions determine the rest of the variables. The six equations further decouple into a set of four equations sourced by the perfect fluid, representing forced oscillations and two uncoupled damped oscillator equations. The two gravitational degrees of freedom are represented by pairs of gravito-magnetic perturbations. In contrast with the Friedmann case one of them is coupled to the matter density perturbations, becoming decoupled only in the geometrical optics limit. In this approximation, the even and odd tensorial perturbations of the Weyl tensor evolve as gravitational waves on the anisotropic Kantowski-Sachs background, while the modes describing the shear and the matter density gradient are out of phase dephased by π /2 and share the same speed of sound.
Integrated Sachs-Wolfe effect in interacting dark energy models
Olivares, German; Pavon, Diego; Atrio-Barandela, Fernando
2008-05-15
Models with dark energy decaying into dark matter have been proposed in cosmology to solve the coincidence problem. We study the effect of such coupling on the cosmic microwave background temperature anisotropies. The interaction changes the rate of evolution of the metric potentials and the growth rate of matter density perturbations and modifies the integrated Sachs-Wolfe component of cosmic microwave background temperature anisotropies, enhancing the effect. Cross correlation of galaxy catalogs with cosmic microwave background maps provides a model-independent test to constrain the interaction. We particularize our analysis for a specific interacting model and show that galaxy catalogs with median redshifts z{sub m}=0.1-0.9 can rule out models with an interaction parameter strength of c{sup 2}{approx_equal}0.1 better than 99.95% confidence level. Values of c{sup 2}{<=}0.01 are compatible with the data and may account for the possible discrepancy between the fraction of dark energy derived from Wilkinson microwave anisotropy probe 3 yr data and the fraction obtained from the integrated Sachs-Wolfe effect. Measuring the fraction of dark energy by these two methods could provide evidence of an interaction.
Clostridial pore-forming toxins: powerful virulence factors.
Popoff, Michel R
2014-12-01
Pore formation is a common mechanism of action for many bacterial toxins. More than one third of clostridial toxins are pore-forming toxins (PFTs) belonging to the β-PFT class. They are secreted as soluble monomers rich in β-strands, which recognize a specific receptor on target cells and assemble in oligomers. Then, they undergo a conformational change leading to the formation of a β-barrel, which inserts into the lipid bilayer forming functional pore. According to their structure, clostridial β-PFTs are divided into several families. Clostridial cholesterol-dependent cytolysins form large pores, which disrupt the plasma membrane integrity. They are potent virulence factors mainly involved in myonecrosis. Clostridial heptameric β-PFTs (aerolysin family and staphylococcal α-hemolysin family) induce small pores which trigger signaling cascades leading to different cell responses according to the cell types and toxins. They are mainly responsible for intestinal diseases, like necrotic enteritis, or systemic diseases/toxic shock from intestinal origin. Clostridial intracellularly active toxins exploit pore formation through the endosomal membrane to translocate the enzymatic component or domain into the cytosol. Single chain protein toxins, like botulinum and tetanus neurotoxins, use hydrophobic α-helices to form pores, whereas clostridial binary toxins encompass binding components, which are structurally and functionally related to β-PFTs, but which have acquired the specific activity to internalize their corresponding enzymatic components. Structural analysis suggests that β-PFTs and binding components share a common evolutionary origin.
Dispersive analysis of the scalar form factor of the nucleon
NASA Astrophysics Data System (ADS)
Hoferichter, M.; Ditsche, C.; Kubis, B.; Meißner, U.-G.
2012-06-01
Based on the recently proposed Roy-Steiner equations for pion-nucleon ( πN) scattering [1], we derive a system of coupled integral equations for the π π to overline N N and overline K K to overline N N S-waves. These equations take the form of a two-channel Muskhelishvili-Omnès problem, whose solution in the presence of a finite matching point is discussed. We use these results to update the dispersive analysis of the scalar form factor of the nucleon fully including overline K K intermediate states. In particular, we determine the correction {Δ_{σ }} = σ ( {2M_{π }^2} ) - {σ_{{π N}}} , which is needed for the extraction of the pion-nucleon σ term from πN scattering, as a function of pion-nucleon subthreshold parameters and the πN coupling constant.
Bonner Prize: The Elastic Form Factors of the Nucleon
NASA Astrophysics Data System (ADS)
Perdrisat, Charles F.
2017-01-01
A series of experiments initiated in 1998 at the then new Continuous Electron Beam Accelerator, or CEBAF in Newport News Virginia, resulted in unexpected results, changing significantly our understanding of the structure of the proton. These experiments used a relatively new technique to obtain the ratio of the two form factors of the proton, namely polarization. An intense beam of highly polarized electrons with energy up to 6 GeV was made to interact elastically with un-polarized protons in a hydrogen target. The polarization of the recoiling protons, with energies up to 5 GeV, was measured from a second interaction in a polarimeter consisting of blocs of graphite or CH2 and tracking wire chambers. The scattered electrons were detected in an electromagnetic lead-glass calorimeter, to select elastically scattered events. After a short introduction describing the path which brought me from the University of Geneva to the College of William and Mary in 1966, I will introduce the subject of elastic electron scattering, describe some of the apparatus required for such experiments, and show the results which were unexpected at the time. These results demonstrated unequivocally that the two form factors required to describe elastic ep scattering, electric GE and magnetic GM in the Born approximation, had a drastically different dependence upon the four-momentum squared q2 = q2 -ω2 with q the momentum, and ω the energy transferred in the reaction. The finding, in flagrant disagreement with the data available at the time, which had been obtained dominantly from cross section measurements of the type first used by Nobel Prize R. Hofstadter 60 years ago, have led to a reexamination of the information provided by form factors on the structure of the nucleon, in particular its quark-gluon content. The conclusion will then be a brief outline of several theoretical considerations to put the results in a proper perspective.
Two-photon exchange corrections to the pion form factor
Peter G. Blunden; Melnitchouk, Wally; Tjon, John A.
2010-01-06
Here, we compute two-photon exchange corrections to the electromagnetic form factor of the pion, taking into account the finite size of the pion. Compared to the soft-photon approximation for the infrared divergent contribution which neglects hadron structure effects, the corrections are found to be ≲ 1% for small Q^{2} (Q^{2} < 0.1 GeV^{2}), but increase to several percent for Q^{2} ≳ 1 GeV^{2} at extreme backward angles.
Neutral pion form factor measurement by the NA62 experiment
NASA Astrophysics Data System (ADS)
Pepe, Monica
2017-03-01
The NA62 experiment at CERN collected a large sample of charged kaon decays with a highly efficient trigger for decays into electrons in 2007. A measurement of the electromagnetic transition form factor slope of the neutral pion in the time-like region from about one million fully reconstructed π0 Dalitz decays is presented. The limits on dark photon production from a sample of about 1.7 × 107 π0 Dalitz decays collected in 2003-2004 by the earlier kaon experiment at CERN NA48/2 are also reported.
Proton Elastic Form Factor Ratio: the JLab Polarization Experiments
Charles Perdrisat; Vina Punjabi
2003-07-30
The ratio of the electric and magnetic proton form factors, G{sub Ep}/G{sub Mp}, has been obtained in two Hall A experiments, from measurements of the longitudinal and transverse polarization of the recoil proton, P{sub l} and P{sub t}, respectively, in the elastic scattering of polarized electrons, {rvec e}p {yields} e{rvec p}. Together these experiments cover the Q{sup 2}-range 0.5 to 5.6 GeV{sup 2}. A new experiment is currently being prepared, to extend the Q{sup 2}-range to 9 GeV{sup 2} in Hall C.
Proton Form Factor Measurements Using Polarization Method: Beyond Born Approximation
Pentchev, Lubomir
2008-10-13
Significant theoretical and experimental efforts have been made over the past 7 years aiming to explain the discrepancy between the proton form factor ratio data obtained at JLab using the polarization method and the previous Rosenbluth measurements. Preliminary results from the first high precision polarization experiment dedicated to study effects beyond Born approximation will be presented. The ratio of the transferred polarization components and, separately, the longitudinal polarization in ep elastic scattering have been measured at a fixed Q{sup 2} of 2.5 GeV{sup 2} over a wide kinematic range. The two quantities impose constraints on the real part of the ep elastic amplitudes.
CEBAF at higher energies and the kaon electromagnetic form factor
Baker, O.K.
1994-04-01
The electromagnetic production of strangeness, the physics of exciting systems having strangeness degrees of freedom (production of hadrons with one or more strange constituent quarks) using electromagnetic probes (real or virtual photons), is one of the frontier areas of research which will be investigated at the Continuous Electron Beam Accelerator Facility (CEBAF) when it becomes operational. CEBAF is expected to have an important impact upon this field of research using its specialized set of detection instruments and high quality electron beam. This paper focusses upon one aspect of the associated production of strangeness - the determination of the kaon electromagnetic form factor at high squared momentum transfers.
Structural consequences of amino acid substitutions causing Tay-Sachs disease.
Ohno, Kazuki; Saito, Seiji; Sugawara, Kanako; Sakuraba, Hitoshi
2008-08-01
To determine the structural changes in the alpha-subunit of beta-hexosaminidase due to amino acid substitutions causing Tay-Sachs disease, we built structural models of mutant alpha-subunits resulting from 33 missense mutations (24 infantile and 9 late-onset), and analyzed the influence of each amino acid replacement on the structure by calculating the number of atoms affected and determining the solvent-accessible surface area of the corresponding amino acid residue in the wild-type alpha-subunit. In the infantile Tay-Sachs group, the number of atoms influenced by a mutation was generally larger than that in the late-onset Tay-Sachs group in both the main chain and the side chain, and residues associated with the mutations found in the infantile Tay-Sachs group tended to be less solvent-accessible than those in the late-onset Tay-Sachs group. Furthermore, color imaging determined the distribution and degree of the structural changes caused by representative amino acid substitutions, and that there were also differences between the infantile and late-onset Tay-Sachs disease groups. Structural study is useful for elucidating the basis of Tay-Sachs disease.
Measurement of the Λb0 decay form factor
NASA Astrophysics Data System (ADS)
Abdallah, J.; Abreu, P.; Adam, W.; Adzic, P.; Albrecht, T.; Alderweireld, T.; Alemany-Fernandez, R.; Allmendinger, T.; Allport, P. P.; Amaldi, U.; Amapane, N.; Amato, S.; Anashkin, E.; Andreazza, A.; Andringa, S.; Anjos, N.; Antilogus, P.; Apel, W.-D.; Arnoud, Y.; Ask, S.; Asman, B.; Augustin, J. E.; Augustinus, A.; Baillon, P.; Ballestrero, A.; Bambade, P.; Barbier, R.; Bardin, D.; Barker, G.; Baroncelli, A.; Battaglia, M.; Baubillier, M.; Becks, K.-H.; Begalli, M.; Behrmann, A.; Ben-Haim, E.; Benekos, N.; Benvenuti, A.; Berat, C.; Berggren, M.; Berntzon, L.; Bertrand, D.; Besancon, M.; Besson, N.; Bloch, D.; Blom, M.; Bluj, M.; Bonesini, M.; Boonekamp, M.; Booth, P. S. L.; Borisov, G.; Botner, O.; Bouquet, B.; Bowcock, T. J. V.; Boyko, I.; Bracko, M.; Brenner, R.; Brodet, E.; Bruckman, P.; Brunet, J. M.; Bugge, L.; Buschmann, P.; Calvi, M.; Camporesi, T.; Canale, V.; Carena, F.; Castro, N.; Cavallo, F.; Chapkin, M.; Charpentier, Ph.; Checchia, P.; Chierici, R.; Chliapnikov, P.; Chudoba, J.; Chung, S. U.; Cieslik, K.; Collins, P.; Contri, R.; Cosme, G.; Cossutti, F.; Costa, M. J.; Crawley, B.; Crennell, D.; Cuevas, J.; D'Hondt, J.; Dalmau, J.; da Silva, T.; da Silva, W.; Della Ricca, G.; de Angelis, A.; de Boer, W.; de Clercq, C.; de Lotto, B.; de Maria, N.; de Min, A.; de Paula, L.; di Ciaccio, L.; di Simone, A.; Doroba, K.; Drees, J.; Dris, M.; Eigen, G.; Ekelof, T.; Ellert, M.; Elsing, M.; Espirito Santo, M. C.; Fanourakis, G.; Fassouliotis, D.; Feindt, M.; Fernandez, J.; Ferrer, A.; Ferro, F.; Flagmeyer, U.; Foeth, H.; Fokitis, E.; Fulda-Quenzer, F.; Fuster, J.; Gandelman, M.; Garcia, C.; Gavillet, Ph.; Gazis, E.; Gokieli, R.; Golob, B.; Gomez-Ceballos, G.; Goncalves, P.; Graziani, E.; Grosdidier, G.; Grzelak, K.; Guy, J.; Haag, C.; Hallgren, A.; Hamacher, K.; Hamilton, K.; Haug, S.; Hauler, F.; Hedberg, V.; Hennecke, M.; Herr, H.; Hoffman, J.; Holmgren, S.-O.; Holt, P. J.; Houlden, M. A.; Hultqvist, K.; Jackson, J. N.; Jarlskog, G.; Jarry, P.; Jeans, D.; Johansson, E. K.; Johansson, P. D.; Jonsson, P.; Joram, C.; Jungermann, L.; Kapusta, F.; Katsanevas, S.; Katsoufis, E.; Kernel, G.; Kersevan, B. P.; Kerzel, U.; Kiiskinen, A.; King, B. T.; Kjaer, N. J.; Kluit, P.; Kokkinias, P.; Kourkoumelis, C.; Kouznetsov, O.; Krumstein, Z.; Kucharczyk, M.; Lamsa, J.; Leder, G.; Ledroit, F.; Leinonen, L.; Leitner, R.; Lemonne, J.; Lepeltier, V.; Lesiak, T.; Liebig, W.; Liko, D.; Lipniacka, A.; Lopes, J. H.; Lopez, J. M.; Loukas, D.; Lutz, P.; Lyons, L.; MacNaughton, J.; Malek, A.; Maltezos, S.; Mandl, F.; Marco, J.; Marco, R.; Marechal, B.; Margoni, M.; Marin, J.-C.; Mariotti, C.; Markou, A.; Martinez-Rivero, C.; Masik, J.; Mastroyiannopoulos, N.; Matorras, F.; Matteuzzi, C.; Mazzucato, F.; Mazzucato, M.; McNulty, R.; Meroni, C.; Meyer, W. T.; Miagkov, A.; Migliore, E.; Mitaroff, W.; Mjoernmark, U.; Moa, T.; Moch, M.; Moenig, K.; Monge, R.; Montenegro, J.; Moraes, D.; Moreno, S.; Morettini, P.; Mueller, U.; Muenich, K.; Mulders, M.; Mundim, L.; Murray, W.; Muryn, B.; Myatt, G.; Myklebust, T.; Nassiakou, M.; Navarria, F.; Nawrocki, K.; Nicolaidou, R.; Nikolenko, M.; Oblakowska-Mucha, A.; Obraztsov, V.; Olshevski, A.; Onofre, A.; Orava, R.; Osterberg, K.; Ouraou, A.; Oyanguren, A.; Paganoni, M.; Paiano, S.; Palacios, J. P.; Palka, H.; Papadopoulou, Th. D.; Pape, L.; Parkes, C.; Parodi, F.; Parzefall, U.; Passeri, A.; Passon, O.; Peralta, L.; Perepelitsa, V.; Perrotta, A.; Petrolini, A.; Piedra, J.; Pieri, L.; Pierre, F.; Pimenta, M.; Piotto, E.; Podobnik, T.; Poireau, V.; Pol, M. E.; Polok, G.; Poropat, P.; Pozdniakov, V.; Pukhaeva, N.; Pullia, A.; Rames, J.; Ramler, L.; Read, A.; Rebecchi, P.; Rehn, J.; Reid, D.; Reinhardt, R.; Renton, P.; Richard, F.; Ridky, J.; Rivero, M.; Rodriguez, D.; Romero, A.; Ronchese, P.; Rosenberg, E.; Roudeau, P.; Rovelli, T.; Ruhlmann-Kleider, V.; Ryabtchikov, D.; Sadovsky, A.; Salmi, L.; Salt, J.; Savoy-Navarro, A.; Schwickerath, U.; Segar, A.; Sekulin, R.; Siebel, M.; Sisakian, A.; Smadja, G.; Smirnova, O.; Sokolov, A.; Sopczak, A.; Sosnowski, R.; Spassov, T.; Stanitzki, M.; Stocchi, A.; Strauss, J.; Stugu, B.; Szczekowski, M.; Szeptycka, M.; Szumlak, T.; Tabarelli, T.; Taffard, A. C.; Tegenfeldt, F.; Timmermans, J.; Tkatchev, L.; Tobin, M.; Todorovova, S.; Tome, B.; Tonazzo, A.; Tortosa, P.; Travnicek, P.; Treille, D.; Tristram, G.; Trochimczuk, M.; Troncon, C.; Turluer, M.-L.; Tyapkin, I. A.; Tyapkin, P.; Tzamarias, S.; Uvarov, V.; Valenti, G.; van Dam, P.; van Eldik, J.; van Lysebetten, A.; van Remortel, N.; van Vulpen, I.; Vegni, G.; Veloso, F.; Venus, W.; Verdier, P.; Verzi, V.; Vilanova, D.; Vitale, L.; Vrba, V.; Wahlen, H.; Washbrook, A. J.; Weiser, C.; Wicke, D.; Wickens, J.; Wilkinson, G.; Winter, M.; Witek, M.; Yushchenko, O.; Zalewska, A.; Zalewski, P.; Zavrtanik, D.; Zhuravlov, V.; Zimin, N. I.; Zintchenko, A.; Zupan, M.; Delphi Collaboration
2004-04-01
The form factor of Λb0 baryons is estimated using 3.46×106 hadronic Z decays collected by the DELPHI experiment between 1992 and 1995. Charmed Λc+ baryons fully reconstructed in the pK-π+, pK0S, and Λπ+π+π- modes, are associated to a lepton with opposite charge in order to select Λb0→Λc+l-ν¯l decays. From a combined likelihood and event rate fit to the distribution of the Isgur-Wise variable w, and using the Heavy Quark Effective Theory (HQET), the slope of the b-baryon form factor is measured to be ρ̂2=2.03±0.46(stat)+0.72-1.00(syst). The exclusive semileptonic branching fraction Br(Λb0→Λc+l-ν¯l) can be derived from ρ̂2 and is found to be (5.0+1.1-0.8(stat)+1.6-1.2(syst))%. Limits on other branching fractions are also obtained.
Deuteron electromagnetic form factors with the light-front approach
NASA Astrophysics Data System (ADS)
Sun, Bao-dong; Dong, Yu-bing
2017-01-01
The electromagnetic form factors and low-energy observables of the deuteron are studied with the help of the light-front approach, where the deuteron is regarded as a weakly bound state of a proton and a neutron. Both the S and D wave interacting vertexes among the deuteron, proton, and neutron are taken into account. Moreover, the regularization functions are also introduced. In our calculations, the vertex and the regularization functions are employed to simulate the momentum distribution inside the deuteron. Our numerical results show that the light-front approach can roughly reproduce the deuteron electromagnetic form factors, like charge G 0, magnetic G 1, and quadrupole G 2, in the low Q 2 region. The important effect of the D wave vertex on G 2 is also addressed. Supported by National Natural Science Foundation of China (10975146, 11475192), The fund provided by the Sino-German CRC 110 “Symmetries and the Emergence of Structure in QCD" project is also appreciated, YBD thanks FAPESP grant 2011/11973-4 for funding his visit to ICTP-SAIFR
Measurement of the Neutral Weak Form Factors of the Proton
Deur, Alexandre; Fleck, Andre; Saha, Arunava; Gasparian, Ashot; Frois, Bernard; Wojtsekhowski, Bogdan; Vlahovic, Branislav; Perdrisat, Charles; Cavata, Christian; Jutier, Christophe; De Jager, Cornelis; Neyret, Damien; Dale, Daniel; Armstrong, David; Lhuillier, David; Prout, David; Margaziotis, Demetrius; Kim, Donghee; Burtin, Etienne; Chudakov, Eugene; Hersman, F.; Garibaldi, Franco; Marie, Frederic; Miller, Greg; Rutledge, Gary; Gerstner, George; Petratos, Gerassimos; Quemener, Gilles; Cates, Gordon; Thompson, J.; Martino, Jacques; Gomez, Javier; Jorda, Jean-Paul; Hansen, Jens-Ole; Chen, Jian-Ping; Jardillier, Johann; Calarco, John; LeRose, John; Price, John; Gao, Juncai; McIntyre, Justin; McCormick, Kathy; Fissum, Kevin; Kramer, Kevin; Aniol, Konrad; Kumar, Krishna; Wijesooriya, Krishni; Ewell, Lars; Todor, Luminita; Spradlin, Marcus; Jones, Mark; Leuschner, Mark; Epstein, Martin; Baylac, Maud; Holtrop, Maurik; Finn, Michael; Kuss, Michael; Kim, Min; Falletto, Nicolas; Liyanage, Nilanga; Glamazdin, Oleksandr; Rutt, Paul; Souder, Paul; Ulmer, Paul; Mastromarino, Peter; Djawotho, Pibero; Wilson, Richard; Suleiman, Riad; Holmes, Richard; Madey, Richard; Lourie, Robert; Michaels, Robert; Pomatsalyuk, Roman; Gilman, Ronald; Incerti, Sebastien; Escoffier, Stephanie; Pussieux, Thierry; Humensky, Thomas; Gorbenko, Viktor; Punjabi, Vina; Kahl, William; Meziani, Zein-Eddine
1999-02-01
We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The kinematic point [(Theta_{lab}) = 12.3r and (Q^{2}) = 0.48 (GeV/c)^{2}] is chosen to provide sensitivity, at a level that is of theoretical interest, to the strange electric form factor G^{s}_{E}. The result, A = - 14.5 + or - 2.2 ppm, is consistent with the electroweak standard model and no additional contributions from strange quarks. In particular, the measurement implies G^{s}_{E} + 0.39G^{s}_{M} = 0.023 + or - 0.034(stat) + or - 0.022(syst) + or - 0.026(delta-G^{n}_{E}), where the last uncertainty arises from the estimated uncertainty in the neutron electric form factor.
'Cherry red spot' in a patient with Tay-Sachs disease: case report.
Aragão, Ricardo Evangelista Marrocos de; Ramos, Régia Maria Gondim; Pereira, Felipe Bezerra Alves; Bezerra, Andreya Ferreira Rodrigues; Fernandes, Daniel Nogueira
2009-01-01
Tay-Sachs disease is an autosomal recessive disorder of sphingolipid metabolism, caused by enzyme hexosaminidase A deficiency that leads to an accumulation of GM2 in neurocytes which results in progressive loss of neurological function. The accumulation of lipid in retinal ganglion cells that leads to a chalk-white appearance of the fundus called 'cherry red spot' is the hallmark of Tay-Sachs disease. It is also seen in others neurometabolic diseases as well as in central retinal artery occlusion. This case reports a child with Tay-Sachs disease in a family with four previous similar deaths without diagnostic.
Approaches to the control and prevention of Tay-Sachs disease.
Kaback, M M; Zeiger, R S; Reynolds, L W; Sonneborn, M
1974-01-01
A prototype Tay-Sachs disease prevention program is presented and di scussed. The program strategy, design, and methodology are reviewed and results and analyses of epidemiologic data, testing results, and in-prog ram evaluations of the testing method are given, along with overall program results. Psychosocial, genetic, and socioeconomic consideration s in the counseling of screenees and relatives of carriers are discussed. In the 1st year of the program, 11 couples, none of whom had previously had a Tay-Sachs child, were identified to be at risk for Tay-Sachs disease in their offspring.
Algebraic approach to form factors in the complex sinh-Gordon theory
NASA Astrophysics Data System (ADS)
Lashkevich, Michael; Pugai, Yaroslav
2017-01-01
We study form factors of the quantum complex sinh-Gordon theory in the algebraic approach. In the case of exponential fields the form factors can be obtained from the known form factors of the ZN-symmetric Ising model. The algebraic construction also provides an Ansatz for form factors of descendant operators. We obtain generating functions of such form factors and establish their main properties: the cluster factorization and reflection equations.
Richard, M.; Triggs-Raine, B.; Natowicz, M.
1994-09-01
Tay-Sachs disease is an autosomal recessive lysosomal storage disorder resulting from mutations in the HEXA gene that cause a deficiency in the activity of that enzyme {beta}-hexosaminidase A (Hex A). This deficiency leads to the build-up of G{sub M2} ganglioside, resulting in neurodegeneration and death. Biochemical analysis of a non-Jewish patient with a late-infantile form of Tay-Sachs disease revealed a substantial level of Hex A activity (38.4%) when 4-MUG was used as the substrate. However, when a substrate (4-MUGS) specific for the {alpha}-subunit of Hex A ({alpha}{beta}) was used, almost no activity was detected in the HEXA gene of the patient using SSCP analysis followed by sequencing. The first mutation, a G533A substitution in exon 5, is previously described and associated with the B1 form of Tay-Sachs disease. The second mutation is a novel a-to-g base change at the +3 position of intron 8. This was confirmed using the AIRS method, whereby a MaeIII site was created in the presence of the mutation. Normal and patient mRNA was reverse transcribed and exons 7 to 9 were PCR-amplified from the cDNA. An abnormally sized amplification product detected only in the patient cDNA was sequenced; exon 8 had been deleted and exons 7 and 9 were spliced together. A substantial level of normally-sized PCR product was also detected in the patient`s cDNA. Experiments are in progress to determine if this is produced from the allele harboring the G533A mutation. Given that previous mutations of this type have been associated with 97-100% abnormal splicing, this mutation is likely to be the cause, together with the G533A mutation, of Tay-Sachs disease in this patient.
Lattice calculation of composite dark matter form factors
NASA Astrophysics Data System (ADS)
Appelquist, T.; Brower, R. C.; Buchoff, M. I.; Cheng, M.; Cohen, S. D.; Fleming, G. T.; Kiskis, J.; Lin, M. F.; Neil, E. T.; Osborn, J. C.; Rebbi, C.; Schaich, D.; Schroeder, C.; Syritsyn, S.; Voronov, G.; Vranas, P.; Wasem, J.
2013-07-01
Composite dark matter candidates, which can arise from new strongly-coupled sectors, are well-motivated and phenomenologically interesting, particularly in the context of asymmetric generation of the relic density. In this work, we employ lattice calculations to study the electromagnetic form factors of electroweak-neutral dark-matter baryons for a three-color, QCD-like theory with Nf=2 and 6 degenerate fermions in the fundamental representation. We calculate the (connected) charge radius and anomalous magnetic moment, both of which can play a significant role for direct detection of composite dark matter. We find minimal Nf dependence in these quantities. We generate mass-dependent cross sections for dark matter-nucleon interactions and use them in conjunction with experimental results from XENON100, excluding dark matter candidates of this type with masses below 10 TeV.
The Spectral Form Factor Is Not Self-Averaging
Prange, R.
1997-03-01
The form factor, k(t), is the spectral statistic which best displays nonuniversal quasiclassical deviations from random matrix theory. Recent estimations of k(t) for a single spectrum found interesting new effects of this type. It was supposed that k(t) is {ital self-averaging} and thus did not require an ensemble average. We here argue that this supposition sometimes fails and that for many important systems an ensemble average is essential to see detailed properties of k(t). In other systems, notably the nontrivial zeros of Riemann zeta function, it will be possible to see the nonuniversal properties by an analysis of a single spectrum. {copyright} {ital 1997} {ital The American Physical Society}
Meson Form Factors and Deep Exclusive Meson Production Experiments
NASA Astrophysics Data System (ADS)
Horn, Tanja
2017-03-01
Pion and kaon electroproduction data play a unique role in Nature and our understanding of them is essential for explaining hadron structure. Precision longitudinaltransverse separated pion and kaon cross sections are of particular interest. They allow for the extraction of meson form factors and validation of understanding of hard exclusive and semi-inclusive reactions (π+, K+, π0, γ) towards 3D hadron imaging and potential future flavor decomposition. We review recent data and present prospects for deep exclusive pion and kaon electroproduction at the 12 GeV Jefferson Lab including the prospects to use projected charged- and neutral pion data to further determine the spin, charge-parity and flavor of GPDs, including the helicity-flip GPDs.
PCMCIA-like ultrasmall form-factor optical drive
NASA Astrophysics Data System (ADS)
Kim, Sookyung; Lee, Jungkyu; Park, Jinmoo; Park, Gunsoon; Lee, Jeonguk; Lee, Choongwoo; Son, Do-Hyeon; Kim, Jin-Yong; Kim, Seong-hyok; Yee, Youngjoo
2003-09-01
A prototype of ultra small optical drive was studied and developed in order to see the feasibility of mobile application, which is targeted to be attachable into the PCMCIA II slot in small mobile devices. A new design and fabrication technology of optical flying head (OFH) for first surface MO recording was studied, and an effective OFH precisely equipped with high NA lens and MO coil was developed based on miniaturization technology. Design consideration of small form factor optical drive is discussed. Some technical issues and barriers in designing and manufacturing the OFH are introduced. Head-disk interface for reliability and flying stability on plastic disk media was tested and evaluated. Basic tracking and read-write performances in a test bed system were tested.
Thin and small form factor cells : simulated behavior.
Clews, Peggy Jane; Pluym, Tammy; Grubbs, Robert K.; Cruz-Campa, Jose Luis; Zubia, David; Young, Ralph Watson; Okandan, Murat; Gupta, Vipin P.; Nielson, Gregory N.; Resnick, Paul James
2010-07-01
Thin and small form factor cells have been researched lately by several research groups around the world due to possible lower assembly costs and reduced material consumption with higher efficiencies. Given the popularity of these devices, it is important to have detailed information about the behavior of these devices. Simulation of fabrication processes and device performance reveals some of the advantages and behavior of solar cells that are thin and small. Three main effects were studied: the effect of surface recombination on the optimum thickness, efficiency, and current density, the effect of contact distance on the efficiency for thin cells, and lastly the effect of surface recombination on the grams per Watt-peak. Results show that high efficiency can be obtained in thin devices if they are well-passivated and the distance between contacts is short. Furthermore, the ratio of grams per Watt-peak is greatly reduced as the device is thinned.
Tay-Sachs disease: current perspectives from Australia.
Lew, Raelia M; Burnett, Leslie; Proos, Anné L; Delatycki, Martin B
2015-01-01
Tay-Sachs disease (TSD) is a fatal, recessively inherited neurodegenerative condition of infancy and early childhood. Although rare in most other populations, the carrier frequency is one in 25 in Ashkenazi Jews. Australian high-school-based TSD preconception genetic screening programs aim to screen, educate, and optimize reproductive choice for participants. These programs have demonstrated high uptake, low psychological morbidity, and have been shown to result in fewer than expected Jewish TSD-affected births over 18 years of operation. The majority of Jewish individuals of reproductive age outside of the high school screening program setting in Australia have not accessed screening. Recent recommendations advocate supplementing the community high school screening programs with general practitioner- and obstetrician-led genetic screening of Ashkenazi Jewish individuals for TSD and other severe recessive diseases for which this group is at risk. Massively parallel DNA sequencing is expected to become the testing modality of choice over the coming years.
Numerical Relativity and the Bondi-Metzner-Sachs Group
NASA Astrophysics Data System (ADS)
Winicour, Jeffrey
2017-01-01
There are interesting phenomena associated with the Bondi-Metzner-Sachs (BMS) group that deserve numerical exploration. The BMS group, which is the asymptotic symmetry group of an isolated gravitational system, extends the Poincare group by the addition of an infinite set of supertranslations parameterized by a function on the sphere α(θ , ϕ) . The l = 0 and l = 1 spherical harmonics invariantly pick out the time and space translations, which leads to an unambiguous definition of energy and momentum. However, a Poincare subgroup cannot be invariantly defined, which leads to a supertranslation ambiguity in the definition of angular momentum. This opens the possibility of a purely general relativistic mechanism for angular momentum loss. The supertranslations are also associated with the gravitational memory effect. I will discuss these problems which are ripe for the numerical simulation of high spin black hole binaries. Supported by NSF grant PHY-1505965 to the University of Pittsburgh.
INTEGRATED SACHS-WOLFE IMPRINT OF SUPERSTRUCTURES ON LINEAR SCALES
Papai, Peter; Szapudi, Istvan; Granett, Benjamin R.
2011-05-01
We build a model for the density and integrated Sachs-Wolfe (ISW) profile of supervoid and supercluster structures. Our model assumes that fluctuations evolve linearly from an initial Gaussian random field. We find these assumptions capable of describing N-body simulations and simulated ISW maps remarkably well on large scales. We construct an ISW map based on locations of superstructures identified previously in the Sloan Digital Sky Survey Luminous Red Galaxy sample. A matched filter analysis of the cosmic microwave background confirms a signal at the 3.2{sigma} confidence level and estimates the radius of the underlying structures to be 55 {+-} 28 h{sup -1} Mpc. The amplitude of the signal, however, is 2{sigma} higher than {Lambda}CDM predictions.
Tay-Sachs disease: current perspectives from Australia
Lew, Raelia M; Burnett, Leslie; Proos, Anné L; Delatycki, Martin B
2015-01-01
Tay-Sachs disease (TSD) is a fatal, recessively inherited neurodegenerative condition of infancy and early childhood. Although rare in most other populations, the carrier frequency is one in 25 in Ashkenazi Jews. Australian high-school-based TSD preconception genetic screening programs aim to screen, educate, and optimize reproductive choice for participants. These programs have demonstrated high uptake, low psychological morbidity, and have been shown to result in fewer than expected Jewish TSD-affected births over 18 years of operation. The majority of Jewish individuals of reproductive age outside of the high school screening program setting in Australia have not accessed screening. Recent recommendations advocate supplementing the community high school screening programs with general practitioner- and obstetrician-led genetic screening of Ashkenazi Jewish individuals for TSD and other severe recessive diseases for which this group is at risk. Massively parallel DNA sequencing is expected to become the testing modality of choice over the coming years. PMID:25653550
Tay-Sach disease with "cherry-red spot"--first reported case in Malaysia.
Chan, L Y; Balasubramaniam, S; Sunder, R; Jamalia, R; Karunakar, T V N; Alagaratnam, J
2011-12-01
We present a rare case of Tay-Sachs disease with retinal 'cherry-red spots' in a 19-month-old Malay child. Molecular genetic studies confirmed the diagnosis. The case highlights that 'cherry-red spot' is a useful clinical clue in Tay-Sachs disease and several other lysosomal storage disorders. It serves as an ideal illustration of the eye as a window to inborn error of metabolism.
Tomita, Kenji
2010-03-15
On the basis of the Gerlach-Sengupta theory of gauge-invariant perturbations, a formula of the integrated Sachs-Wolfe effect for a central observer is derived on general spherically symmetric spacetimes. It will be useful for comparative studies of theoretical and observational aspects of the integrated Sachs-Wolfe effect in the Lemaitre-Tolman-Bondi cosmological models which have been noticed by explaining the apparent acceleration without cosmological constant.
Mark, Brian L.; Mahuran, Don J.; Cherney, Maia M.; Zhao, Dalian; Knapp, Spencer; James, Michael N.G.
2010-12-01
In humans, two major {beta}-hexosaminidase isoenzymes exist: Hex A and Hex B. Hex A is a heterodimer of subunits {alpha} and {beta} (60% identity), whereas Hex B is a homodimer of {beta}-subunits. Interest in human {beta}-hexosaminidase stems from its association with Tay-Sachs and Sandhoff disease; these are prototypical lysosomal storage disorders resulting from the abnormal accumulation of G{sub M2}-ganglioside (G{sub M2}). Hex A degrades G{sub M2} by removing a terminal N-acetyl-D-galactosamine ({beta}-GalNAc) residue, and this activity requires the G{sub M2}-activator, a protein which solubilizes the ganglioside for presentation to Hex A. We present here the crystal structure of human Hex B, alone (2.4 {angstrom}) and in complex with the mechanistic inhibitors GalNAc-isofagomine (2.2 {angstrom}) or NAG-thiazoline (2.5 {angstrom}). From these, and the known X-ray structure of the G{sub M2}-activator, we have modeled Hex A in complex with the activator and ganglioside. Together, our crystallographic and modeling data demonstrate how {alpha} and {beta}-subunits dimerize to form either Hex A or Hex B, how these isoenzymes hydrolyze diverse substrates, and how many documented point mutations cause Sandhoff disease ({beta}-subunit mutations) and Tay-Sachs disease ({alpha}-subunit mutations).
Mark, Brian L; Mahuran, Don J; Cherney, Maia M; Zhao, Dalian; Knapp, Spencer; James, Michael N G
2003-04-11
In humans, two major beta-hexosaminidase isoenzymes exist: Hex A and Hex B. Hex A is a heterodimer of subunits alpha and beta (60% identity), whereas Hex B is a homodimer of beta-subunits. Interest in human beta-hexosaminidase stems from its association with Tay-Sachs and Sandhoff disease; these are prototypical lysosomal storage disorders resulting from the abnormal accumulation of G(M2)-ganglioside (G(M2)). Hex A degrades G(M2) by removing a terminal N-acetyl-D-galactosamine (beta-GalNAc) residue, and this activity requires the G(M2)-activator, a protein which solubilizes the ganglioside for presentation to Hex A. We present here the crystal structure of human Hex B, alone (2.4A) and in complex with the mechanistic inhibitors GalNAc-isofagomine (2.2A) or NAG-thiazoline (2.5A). From these, and the known X-ray structure of the G(M2)-activator, we have modeled Hex A in complex with the activator and ganglioside. Together, our crystallographic and modeling data demonstrate how alpha and beta-subunits dimerize to form either Hex A or Hex B, how these isoenzymes hydrolyze diverse substrates, and how many documented point mutations cause Sandhoff disease (beta-subunit mutations) and Tay-Sachs disease (alpha-subunit mutations).
Mark, Brian L.; Mahuran, Don J.; Cherney, Maia M.; Zhao, Dalian; Knapp, Spencer; James, Michael N. G.
2010-01-01
In humans, two major β-hexosaminidase isoenzymes exist: Hex A and Hex B. Hex A is a heterodimer of subunits α and β (60% identity), whereas Hex B is a homodimer of β-subunits. Interest in human β-hexosaminidase stems from its association with Tay–Sachs and Sandhoff disease; these are prototypical lysosomal storage disorders resulting from the abnormal accumulation of GM2-ganglioside (GM2). Hex A degrades GM2 by removing a terminal N-acetyl-D-galactosamine (β-GalNAc) residue, and this activity requires the GM2–activator, a protein which solubilizes the ganglioside for presentation to Hex A. We present here the crystal structure of human Hex B, alone (2.4 Å) and in complex with the mechanistic inhibitors GalNAc-isofagomine (2.2 Å) or NAG-thiazoline (2.5 Å). From these, and the known X-ray structure of the GM2–activator, we have modeled Hex A in complex with the activator and ganglioside. Together, our crystallographic and modeling data demonstrate how α and β-subunits dimerize to form either Hex A or Hex B, how these isoenzymes hydrolyze diverse substrates, and how many documented point mutations cause Sandhoff disease (β-subunit mutations) and Tay–Sachs disease (α-subunit mutations). PMID:12662933
The Magnetic Form Factor of the Neutron, G
NASA Astrophysics Data System (ADS)
Markowitz, Pete Edward Christopher
We measured the d(e,e^' n)p cross-section at three values of Q^2 : 0.255, 0.176 and 0.109 (GeV/c)^2 . The electrons were detected with the OHIPS magnetic spectrometer, and the neutrons were detected in a liquid mineral oil scintillator array. The measurement were made at a fixed neutron angle of theta_ {n} = 57^circ; the Q^2 values were obtained by varying the incident electron energy and the scattering angle. These cross sections are sensitive primarily to the neutron magnetic form factor at these quasifree kinematics. The efficiency of the neutron detector was determined by the associated particle technique with the d(gamma ,pn) reaction for each of the three neutron kinetic energies. The value of G_sp{M} {n} extracted from the cross sections are consistent with the dipole parametrization at the two higher momentum transfers; at the lowest momentum transfer the value of G_sp{M}{n} is 10% higher than the dipole model. This enhancement at low momentum transfer is consistent with previous measurements.
Nucleon form factors and hidden symmetry in holographic QCD
Hong, Deog Ki; Rho, Mannque; Yee, Ho-Ung; Yi, Piljin
2008-01-01
The vector dominance of the electromagnetic form factors both for mesons and baryons arises naturally in holographic QCD, where both the number of colors and the 't Hooft coupling are taken to be very large, offering a bona-fide derivation of the notion of vector dominance. The crucial ingredient for this is the infinite tower of vector mesons in the approximations made which share features that are characteristic of the quenched approximation in lattice QCD. We approximate the infinite sum by contributions from the lowest four vector mesons of the tower which turn out to saturate the charge and magnetic moment sum rules within a few percent and compute them totally free of unknown parameters for momentum transfers Q{sup 2} < or approx. 1 GeV{sup 2}. We identify certain observables that can be reliably computed within the approximations and others that are not, and discuss how the improvement of the latter can enable one to bring holographic QCD closer to QCD proper.
Nucleon Structure and Hyperon Form Factors from Lattice QCD.
Lin,H.W.
2007-06-11
In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions, for valence quarks. I begin with the latest lattice results on the nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral fermion actions. We find the chiral-extrapolated axial coupling constant at physical pion mass point. to be 1.23(5), consistent with experimental value. The renormalization constants for the structure functions are obtained from RI/MOM-scheme non-perturbative renormalization. We find first moments of the polarized and unpolarized nucleon structure functions at zero transfer momentum to be 0.133(13) and 0.203(23) respectively, using continuum chiral extrapolation. These are consistent with the experimental values, unlike previous calculations which have been 50% larger. We also have a prediction for the transversity, which we find to be 0.56(4). The twist-3 matrix element is consistent with zero which agrees with the prediction of the Wandzura-Wilczek relation. In the second half of this work, I report an indirect dynamical estimation of the strangeness proton magnetic moments using mixed actions. With the analysis of hyperon form factors and using charge symmetry, the strangeness of proton is found to be -0.066(2G), consistent with the Adelaide-JLab Collaboration's result. The hyperon {Sigma} and {Xi} axial coupling constants are also performed for the first time in a lattice calculation, g{sub {Sigma}{Sigma}} = 0.441(14) and g{sub {Xi}{Xi}} = -0.277(11).
Nucleon Structure and hyperon form factors from lattice QCD
Lin, Huey-Wen
2007-06-11
In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions, for valence quarks. I begin with the latest lattice results on the nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral fermion actions. We find the chiral-extrapolated axial coupling constant at physical pion mass point to be 1.23(5), consistant with experimental value. The renormalization constants for the structure functions are obtained from RI/MOM-scheme non-perturbative renormalization. We find first moments of the polarized and unpolarized nucleon structure functions at zero transfer momentum to be 0.133(13) and 0.203(23) respectively, using continuum chiral extrapolation. These are consistent with the experimental values, unlike previous calculations which have been 50% larger. We also have a prediction for the transversity, which we find to be 0.56(4). The twist-3 matrix element is consistent with zero which agrees with the prediction of the Wandzura-Wilczek relation. In the second half of this work, I report an indirect dynamical estimation of the strangeness proton magnetic moments using mixed actions. With the analysis of hyperon form factors and using charge symmetry, the strangeness of proton is found to be -0.066(26), consistent with the Adelaide-JLab Collaboration's result. The hyperon Sigma and Xi axial coupling constants are also performed for the first time in a lattice calculation, g_SigmaSigma = 0.441(14) and g_XiXi = -0.277(11).
Kantowski-Sachs Einstein-æther perfect fluid models
NASA Astrophysics Data System (ADS)
Latta, Joey; Leon, Genly; Paliathanasis, Andronikos
2016-11-01
We investigate Kantowski-Sachs models in Einstein-æ ther theory with a perfect fluid source using the singularity analysis to prove the integrability of the field equations and dynamical system tools to study the evolution. We find an inflationary source at early times, and an inflationary sink at late times, for a wide region in the parameter space. The results by A.A. Coley, G. Leon, P. Sandin and J. Latta (JCAP 12 (2015) 010), are then re-obtained as particular cases. Additionally, we select other values for the non-GR parameters which are consistent with current constraints, getting a very rich phenomenology. In particular, we find solutions with infinite shear, zero curvature, and infinite matter energy density in comparison with the Hubble scalar. We also have stiff-like future attractors, anisotropic late-time attractors, or both, in some special cases. Such results are developed analytically, and then verified by numerics. Finally, the physical interpretation of the new critical points is discussed.
Reconstructing the integrated Sachs-Wolfe map with galaxy surveys
NASA Astrophysics Data System (ADS)
Muir, Jessica; Huterer, Dragan
2016-08-01
The integrated Sachs-Wolfe (ISW) effect is a large-angle modulation of the cosmic microwave background (CMB), generated when CMB photons traverse evolving potential wells associated with large scale structure (LSS). Recent efforts have been made to reconstruct maps of the ISW signal using information from surveys of galaxies and other LSS tracers, but investigation into how survey systematics affect their reliability has so far been limited. Using simulated ISW and LSS maps, we study the impact of galaxy survey properties and systematic errors on the accuracy of a reconstructed ISW signal. We find that systematics that affect the observed distribution of galaxies along the line of sight, such as photo-z and bias-evolution related errors, have a relatively minor impact on reconstruction quality. In contrast, however, we find that direction-dependent calibration errors can be very harmful. Specifically, we find that, in order to avoid significant degradation of our reconstruction quality statistics, direction-dependent number density fluctuations due to systematics must be controlled so that their variance is smaller than 10-6 (which corresponds to a 0.1% calibration). Additionally, we explore the implications of our results for attempts to use reconstructed ISW maps to shed light on the origin of large-angle CMB alignments. We find that there is only a weak correlation between the true and reconstructed angular momentum dispersion, which quantifies alignment, even for reconstructed ISW maps which are fairly accurate overall.
Evaluation of a Tay-Sachs disease screening program.
Gason, A A; Sheffield, E; Bankier, A; Aitken, M A; Metcalfe, S; Barlow Stewart, K; Delatycki, M B
2003-05-01
Tay-Sachs Disease (TSD) is an autosomal recessive neurodegenerative disorder. TSD is prevalent in the Ashkenazi Jewish population, and carrier screening programs have been implemented worldwide in these communities. A screening program initiated in 1997 involving the Melbourne Jewish community (Australia) incorporated education, counselling and carrier testing of high-school students aged 15 to 18 years. This study aimed to assess the participation rates, level of knowledge obtained and predicted feelings and attitudes of the students involved. Seven hundred and ten students participated, there was a 67% uptake for testing with a carrier rate of 1 in 28 determined. The level of knowledge of the students following education was high and of relative importance in regard to decision making, as were their feelings and attitudes about genetic testing for carrier status. A significant impediment to test uptake was the need for blood sampling, resulting in a recommendation for the introduction of DNA analysis on cheek brush samples. The evaluation of this program has given a wider scope for further development as well as providing valuable information for the implementation of community screening programs.
The integrated Sachs-Wolfe signal from BOSS superstructures
NASA Astrophysics Data System (ADS)
Granett, B. R.; Kovács, A.; Hawken, A. J.
2015-12-01
Cosmic structures leave an imprint on the microwave background radiation through the integrated Sachs-Wolfe (ISW) effect. We construct a template map of the linear signal using the Sloan Digital Sky Survey-III Baryon Acoustic Oscillation Survey at redshift 0.43 < z < 0.65. We verify the imprint of this map on the Planck cosmic microwave background (CMB) temperature map at the 97 per cent confidence level and show consistency with the density-temperature cross-correlation measurement. Using this ISW reconstruction as a template, we investigate the presence of ISW sources and further examine the properties of the Granett-Neyrinck-Szapudi supervoid and supercluster catalogue. We characterize the three-dimensional density profiles of these structures for the first time and demonstrate that they are significant structures. Model fits demonstrate that the supervoids are elongated along the line of sight and we suggest that this special orientation may be picked out by the void-finding algorithm in photometric redshift space. We measure the mean temperature profiles in Planck maps from public void and cluster catalogues. In an attempt to maximize the stacked ISW signal, we construct a new catalogue of superstructures based upon local peaks and troughs of the gravitational potential. However, we do not find a significant correlation between these structures and the CMB temperature.
Integrated Sachs-Wolfe effect in time varying vacuum model
Wang, Y. T.; Gui, Y. X.; Xu, L. X.; Lu, J. B.
2010-04-15
The integrated Sachs-Wolfe (ISW) effect is an important implication for dark energy. In this paper, we have calculated the power spectrum of the ISW effect in the time varying vacuum cosmological model, where the model parameter {beta}=4.407 is obtained by the observational constraint of the growth rate. It is found that the source of the ISW effect is not only affected by the different evolutions of the Hubble function H(a) and the dimensionless matter density {Omega}{sub m}(a), but also by the different growth function D{sub +}(a), all of which are changed due to the presence of a matter production term in the time varying vacuum model. However, the difference of the ISW effect in the {Lambda}(t)CDM model and the {Lambda}CDM model is lessened to a certain extent because of the integration from the time of last scattering to the present. It is implied that the observations of the galaxies with high redshift are required to distinguish the two models.
Conserved charges of the extended Bondi-Metzner-Sachs algebra
NASA Astrophysics Data System (ADS)
Flanagan, Éanna É.; Nichols, David A.
2017-02-01
Isolated objects in asymptotically flat spacetimes in general relativity are characterized by their conserved charges associated with the Bondi-Metzner-Sachs (BMS) group. These charges include total energy, linear momentum, intrinsic angular momentum and center-of-mass location, and, in addition, an infinite number of supermomentum charges associated with supertranslations. Recently, it has been suggested that the BMS symmetry algebra should be enlarged to include an infinite number of additional symmetries known as super-rotations. We show that the corresponding charges are finite and well defined, and can be divided into electric parity "super center-of-mass" charges and magnetic parity "superspin" charges. The supermomentum charges are associated with ordinary gravitational-wave memory, and the super center-of-mass charges are associated with total (ordinary plus null) gravitational-wave memory, in the terminology of Bieri and Garfinkle. Superspin charges are associated with the ordinary piece of spin memory. Some of these charges can give rise to black hole hair, as described by Strominger and Zhiboedov. We clarify how this hair evades the no-hair theorems.
Iso-vector form factors of the delta and nucleon in QCD sum rules
Ozpineci, A.
2012-10-23
Form factors are important non-perturbative properties of hadrons. They give information about the internal structure of the hadrons. In this work, iso-vector axial-vector and iso-vector tensor form factors of the nucleon and the iso-vector axial-vector {Delta}{yields}N transition form factor calculations in QCD Sum Rules are presented.
An inducible mouse model of late onset Tay-Sachs disease.
Jeyakumar, Mylvaganam; Smith, David; Eliott-Smith, Elena; Cortina-Borja, Mario; Reinkensmeier, Gabriele; Butters, Terry D; Lemm, Thorsten; Sandhoff, Konrad; Perry, V Hugh; Dwek, Raymond A; Platt, Frances M
2002-08-01
Mouse models of the G(M2) gangliosidoses, Tay-Sachs and Sandhoff disease, are null for the hexosaminidase alpha and beta subunits respectively. The Sandhoff (Hexb-/-) mouse has severe neurological disease and mimics the human infantile onset variant. However, the Tay-Sachs (Hexa-/-) mouse model lacks an overt phenotype as mice can partially bypass the blocked catabolic pathway and escape disease. We have investigated whether a subset of Tay-Sachs mice develop late onset disease. We have found that approximately 65% of the mice develop one or more clinical signs of the disease within their natural life span (n = 52, P < 0.0001). However, 100% of female mice with repeat breeding histories developed late onset disease at an earlier age (n = 21, P < 0.0001) and displayed all clinical features. Repeat breeding of a large cohort of female Tay-Sachs mice confirmed that pregnancy induces late onset Tay-Sachs disease. Onset of symptoms correlated with reduced up-regulation of hexosaminidase B, a component of the bypass pathway.
Effective gene therapy in an authentic model of Tay-Sachs-related diseases.
Cachón-González, M Begoña; Wang, Susan Z; Lynch, Andrew; Ziegler, Robin; Cheng, Seng H; Cox, Timothy M
2006-07-05
Tay-Sachs disease is a prototypic neurodegenerative disease. Lysosomal storage of GM2 ganglioside in Tay-Sachs and the related disorder, Sandhoff disease, is caused by deficiency of beta-hexosaminidase A, a heterodimeric protein. Tay-Sachs-related diseases (GM2 gangliosidoses) are incurable, but gene therapy has the potential for widespread correction of the underlying lysosomal defect by means of the secretion-recapture cellular pathway for enzymatic complementation. Sandhoff mice, lacking the beta-subunit of hexosaminidase, manifest many signs of classical human Tay-Sachs disease and, with an acute course, die before 20 weeks of age. We treated Sandhoff mice by stereotaxic intracranial inoculation of recombinant adeno-associated viral vectors encoding the complementing human beta-hexosaminidase alpha and beta subunit genes and elements, including an HIV tat sequence, to enhance protein expression and distribution. Animals survived for >1 year with sustained, widespread, and abundant enzyme delivery in the nervous system. Onset of the disease was delayed with preservation of motor function; inflammation and GM2 ganglioside storage in the brain and spinal cord was reduced. Gene delivery of beta-hexosaminidase A by using adeno-associated viral vectors has realistic potential for treating the human Tay-Sachs-related diseases.
Basic versus applied research: Julius Sachs (1832–1897) and the experimental physiology of plants
Kutschera, Ulrich
2015-01-01
The German biologist Julius Sachs was the first to introduce controlled, accurate, quantitative experimentation into the botanical sciences, and is regarded as the founder of modern plant physiology. His seminal monograph Experimental-Physiologie der Pflanzen (Experimental Physiology of Plants) was published 150 y ago (1865), when Sachs was employed as a lecturer at the Agricultural Academy in Poppelsdorf/Bonn (now part of the University). This book marks the beginning of a new era of basic and applied plant science. In this contribution, I summarize the achievements of Sachs and outline his lasting legacy. In addition, I show that Sachs was one of the first biologists who integrated bacteria, which he considered to be descendants of fungi, into the botanical sciences and discussed their interaction with land plants (degradation of wood etc.). This “plant-microbe-view” of green organisms was extended and elaborated by the laboratory botanist Wilhelm Pfeffer (1845–1920), so that the term “Sachs-Pfeffer-Principle of Experimental Plant Research” appears to be appropriate to characterize this novel way of performing scientific studies on green, photoautotrophic organisms (embryophytes, algae, cyanobacteria). PMID:26146794
Basic versus applied research: Julius Sachs (1832-1897) and the experimental physiology of plants.
Kutschera, Ulrich
2015-01-01
The German biologist Julius Sachs was the first to introduce controlled, accurate, quantitative experimentation into the botanical sciences, and is regarded as the founder of modern plant physiology. His seminal monograph Experimental-Physiologie der Pflanzen (Experimental Physiology of Plants) was published 150 y ago (1865), when Sachs was employed as a lecturer at the Agricultural Academy in Poppelsdorf/Bonn (now part of the University). This book marks the beginning of a new era of basic and applied plant science. In this contribution, I summarize the achievements of Sachs and outline his lasting legacy. In addition, I show that Sachs was one of the first biologists who integrated bacteria, which he considered to be descendants of fungi, into the botanical sciences and discussed their interaction with land plants (degradation of wood etc.). This "plant-microbe-view" of green organisms was extended and elaborated by the laboratory botanist Wilhelm Pfeffer (1845-1920), so that the term "Sachs-Pfeffer-Principle of Experimental Plant Research" appears to be appropriate to characterize this novel way of performing scientific studies on green, photoautotrophic organisms (embryophytes, algae, cyanobacteria).
Effective gene therapy in an authentic model of Tay-Sachs-related diseases
Cachón-González, M. Begoña; Wang, Susan Z.; Lynch, Andrew; Ziegler, Robin; Cheng, Seng H.; Cox, Timothy M.
2006-01-01
Tay-Sachs disease is a prototypic neurodegenerative disease. Lysosomal storage of GM2 ganglioside in Tay-Sachs and the related disorder, Sandhoff disease, is caused by deficiency of β-hexosaminidase A, a heterodimeric protein. Tay-Sachs-related diseases (GM2 gangliosidoses) are incurable, but gene therapy has the potential for widespread correction of the underlying lysosomal defect by means of the secretion-recapture cellular pathway for enzymatic complementation. Sandhoff mice, lacking the β-subunit of hexosaminidase, manifest many signs of classical human Tay-Sachs disease and, with an acute course, die before 20 weeks of age. We treated Sandhoff mice by stereotaxic intracranial inoculation of recombinant adeno-associated viral vectors encoding the complementing human β-hexosaminidase α and β subunit genes and elements, including an HIV tat sequence, to enhance protein expression and distribution. Animals survived for >1 year with sustained, widespread, and abundant enzyme delivery in the nervous system. Onset of the disease was delayed with preservation of motor function; inflammation and GM2 ganglioside storage in the brain and spinal cord was reduced. Gene delivery of β-hexosaminidase A by using adeno-associated viral vectors has realistic potential for treating the human Tay-Sachs-related diseases. PMID:16801539
8 CFR 204.309 - Factors requiring denial of a Form I-800A or Form I-800.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Factors requiring denial of a Form I-800A or Form I-800. 204.309 Section 204.309 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS IMMIGRANT PETITIONS Intercountry Adoption of a Convention Adoptee § 204.309...
8 CFR 204.309 - Factors requiring denial of a Form I-800A or Form I-800.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Factors requiring denial of a Form I-800A or Form I-800. 204.309 Section 204.309 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS IMMIGRANT PETITIONS Intercountry Adoption of a Convention Adoptee § 204.309...
8 CFR 204.309 - Factors requiring denial of a Form I-800A or Form I-800.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Factors requiring denial of a Form I-800A or Form I-800. 204.309 Section 204.309 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS IMMIGRANT PETITIONS Intercountry Adoption of a Convention Adoptee § 204.309...
Box products in nilpotent normal form theory: The factoring method
NASA Astrophysics Data System (ADS)
Murdock, James
2016-01-01
Let N be a nilpotent matrix and consider vector fields x ˙ = Nx + v (x) in normal form. Then v is equivariant under the flow eN*t for the inner product normal form or eMt for the sl2 normal form. These vector equivariants can be found by finding the scalar invariants for the Jordan blocks in N* or M; taking the box product of these to obtain the invariants for N* or M itself; and then boosting the invariants to equivariants by another box product. These methods, developed by Murdock and Sanders in 2007, are here given a self-contained exposition with new foundations and new algorithms yielding improved (simpler) Stanley decompositions for the invariants and equivariants. Ideas used include transvectants (from classical invariant theory), Stanley decompositions (from commutative algebra), and integer cones (from integer programming). This approach can be extended to covariants of sl2k for k > 1, known as SLOCC in quantum computing.
Lyso-GM2 ganglioside: a possible biomarker of Tay-Sachs disease and Sandhoff disease.
Kodama, Takashi; Togawa, Tadayasu; Tsukimura, Takahiro; Kawashima, Ikuo; Matsuoka, Kazuhiko; Kitakaze, Keisuke; Tsuji, Daisuke; Itoh, Kohji; Ishida, Yo-Ichi; Suzuki, Minoru; Suzuki, Toshihiro; Sakuraba, Hitoshi
2011-01-01
To find a new biomarker of Tay-Sachs disease and Sandhoff disease. The lyso-GM2 ganglioside (lyso-GM2) levels in the brain and plasma in Sandhoff mice were measured by means of high performance liquid chromatography and the effect of a modified hexosaminidase (Hex) B exhibiting Hex A-like activity was examined. Then, the lyso-GM2 concentrations in human plasma samples were determined. The lyso-GM2 levels in the brain and plasma in Sandhoff mice were apparently increased compared with those in wild-type mice, and they decreased on intracerebroventricular administration of the modified Hex B. The lyso-GM2 levels in plasma of patients with Tay-Sachs disease and Sandhoff disease were increased, and the increase in lyso-GM2 was associated with a decrease in Hex A activity. Lyso-GM2 is expected to be a potential biomarker of Tay-Sachs disease and Sandhoff disease.
Camp, Christopher L.; Dahm, Diane L.; Krych, Aaron J.
2015-01-01
Anterior shoulder instability is often accompanied by a Hill-Sachs defect on the humeral head that can contribute to recurrent instability if not addressed at the time of surgery. We describe a method of performing arthroscopic remplissage to treat engaging Hill-Sachs lesions in patients with glenohumeral instability. It has the benefits of being an efficient procedure that can be performed with minimal technical difficulty and can be used to augment other stabilization procedures such as labral repair. The indications for this technique include the presence of an engaging Hill-Sachs defect in patients will little or no glenoid bone loss. In appropriately selected patients, arthroscopic remplissage has shown reduced rates of recurrent instability. PMID:26697311
Tay-Sachs screening: motives for participating and knowledge of genetics and probability.
Childs, B; Gordis, L; Kaback, M M; Kazazian, H H
1976-01-01
A highly-educated, socially aware group of persons presented themselves for Tay-Sachs screening having learned about it mainly from friends, newspapers, radio, and television but not from physicians or rabbis. After learning that screening was possible and deciding that it is in principle a good idea, and after discussing it with relatives and friends but not with physicians and rabbis, they presented themselves for the test. Although the participants knew that Tay-Sachs is a serious disease and that Jews are vulnerable, few of them knew much about the genetics of the disease, its frequency, or the incidence of the carrier state. This experience of screening for Tay-Sachs carriers suggests the need for physicians to learn the relation of genetics to preventive medicine, and for the public to learn more about the biology of man. PMID:1008060
Knowledge and attitudes toward Tay-Sachs disease among a college student population.
Austein, C. F.; Seashore, M. R.; Mick, S. S.
1981-01-01
To assess the feasibility of screening the single Jewish population for Tay-Sachs disease (TSD), a questionnaire examining the knowledge of and attitudes toward TSD and genetic screening was sent to 348 Yale University Jewish undergraduates. Of those students responding (63 percent), 78 percent were able to answer general genetic questions correctly while only 1.9 percent could answer specific Tay-Sachs questions correctly. A majority of the students (93.9 percent) indicated some concern about being a carrier for TSD, believed that carrier status would affect future social and reproductive behavior, and expressed an interest in having TS carrier status determined while still single (77.4 percent). Strong correlations were found between knowledge and attitudes, but no significant differences appeared between male and female respondents. In addition to leading to improvements in Tay-Sachs screening programs, the observations have led to suggestions that may be generalized to other genetic screening programs. PMID:7336765
[Sandhoff's and Tay-Sachs disease--based on our own cases].
Kokot, Witold; Raczyńska, Krystyna; Krajka-Lauer, Jarosława; Iwaszkiewicz-Bilikiewicz, Barbara; Wierzba, Jolanta
2004-01-01
The authors described two infant with Sandhoff's and Tay-Sachs disease. Tay-Sachs disease is well-known inherited disease leading to an accumulation of gangliosides in the brain and retina. Sandhoffs disease (GM2 gangliosidosis type 0) was diagnosed in an infant, in whom a progressive neurological disorder and cherry-red foveal spots were developed. In addition, to the general clinical examination, indirect ophthalnoscopy, blood white cells enzymatic examination are used to make definitive diagnosis. In this cases, the early eye fundus examination allowed us to make the proper diagnosis. The fundus change is characterized by the "cherry-red spot" in the central area.
Resource Form Factor and Installation of GFA Controllers
DeSteese, John G.; Hammerstrom, Donald J.
2009-11-15
The focus of this task is to optimize the form and placement of a controller comprising the Grid Friendly™ appliance (GFA) controller, power supply and power relay (and/or a solid-state power electronic switch) that would command a domestic water heater to shed its load in response to stress on the electric power grid. The GFA controller would disconnect the water heater from its supply circuit whenever it senses a low voltage signal or other indicators of system stress communicated via the electric power distribution system. Power would be reconnected to the appliance when the GFA controller senses the absence of these signals. This project has also considered more frequent cycling of this controller’s relay switch to perform demand-side frequency regulation. The principal criteria considered in this optimization are reliability, cost and life expectancy of the GFA components. The alternative embodiments of the GFA equipment under consideration are: Option 1- installation inside the insulation space of the water heater between the tank and jacket Option 2 containment in a separate nearby electrical enclosure Option 3 - as a modification or adjunct to the distribution panel housing and/or the breaker that protects the water heater supply circuit.
Highly Efficient Small Form Factor LED Retrofit Lamp
Steven Allen; Fred Palmer; Ming Li
2011-09-11
This report summarizes work to develop a high efficiency LED-based MR16 lamp downlight at OSRAM SYLVANIA under US Department of Energy contract DE-EE0000611. A new multichip LED package, electronic driver, and reflector optic were developed for these lamps. At steady-state, the lamp luminous flux was 409 lumens (lm), luminous efficacy of 87 lumens per watt (LPW), CRI (Ra) of 87, and R9 of 85 at a correlated color temperature (CCT) of 3285K. The LED alone achieved 120 lumens per watt efficacy and 600 lumen flux output at 25 C. The driver had 90% electrical conversion efficiency while maintaining excellent power quality with power factor >0.90 at a power of only 5 watts. Compared to similar existing MR16 lamps using LED sources, these lamps had much higher efficacy and color quality. The objective of this work was to demonstrate a LED-based MR16 retrofit lamp for replacement of 35W halogen MR16 lamps having (1) luminous flux of 500 lumens, (2) luminous efficacy of 100 lumens per watt, (3) beam angle less than 40{sup o} and center beam candlepower of at least 1000 candelas, and (4) excellent color quality.
Planck 2015 results. XXI. The integrated Sachs-Wolfe effect
NASA Astrophysics Data System (ADS)
Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Basak, S.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Casaponsa, B.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, H. C.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Fergusson, J.; Fernandez-Cobos, R.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Génova-Santos, R. T.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Ilić, S.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Langer, M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Ma, Y.-Z.; Macías-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Marcos-Caballero, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Schaefer, B. M.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, F.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; Yvon, D.; Zacchei, A.; Zonca, A.
2016-09-01
This paper presents a study of the integrated Sachs-Wolfe (ISW) effect from the Planck 2015 temperature and polarization data release. This secondary cosmic microwave background (CMB) anisotropy caused by the large-scale time-evolving gravitational potential is probed from different perspectives. The CMB is cross-correlated with different large-scale structure (LSS) tracers: radio sources from the NVSS catalogue; galaxies from the optical SDSS and the infrared WISE surveys; and the Planck 2015 convergence lensing map. The joint cross-correlation of the CMB with the tracers yields a detection at 4σ where most of the signal-to-noise is due to the Planck lensing and the NVSS radio catalogue. In fact, the ISW effect is detected from the Planck data only at ≈3σ (through the ISW-lensing bispectrum), which is similar to the detection level achieved by combining the cross-correlation signal coming from all the galaxy catalogues mentioned above. We study the ability of the ISW effect to place constraints on the dark-energy parameters; in particular, we show that ΩΛ is detected at more than 3σ. This cross-correlation analysis is performed only with the Planck temperature data, since the polarization scales available in the 2015 release do not permit significant improvement of the CMB-LSS cross-correlation detectability. Nevertheless, the Planck polarization data are used to study the anomalously large ISW signal previously reported through the aperture photometry on stacked CMB features at the locations of known superclusters and supervoids, which is in conflict with ΛCDM expectations. We find that the current Planck polarization data do not exclude that this signal could be caused by the ISW effect. In addition, the stacking of the Planck lensing map on the locations of superstructures exhibits a positive cross-correlation with these large-scale structures. Finally, we have improved our previous reconstruction of the ISW temperature fluctuations by combining the
Up- and Down-Quark Contributions to the Nucleon Form Factors
NASA Astrophysics Data System (ADS)
Qattan, I. A.; Arrington, J.
2014-03-01
Recent measurements of the neutron s electric to magnetic form factors ratio, Rn = µnGnE/GnM, up to 3.4 (GeV/c)2 combined with existing Rp = µpGpE/GpM measurements in the same Q2 range allowed, for the first time, a separation of the up- and downquark contributions to the form factors at high Q2, as presented by Cates, et al.. Our analysis expands on the original work by including additional form factor data, applying two-photon exchange (TPE) corrections, and accounting for the uncertainties associated with all of the form factor measurements.
Calculation of the Nucleon Axial Form Factor Using Staggered Lattice QCD
Meyer, Aaron S.; Hill, Richard J.; Kronfeld, Andreas S.; Li, Ruizi; Simone, James N.
2016-10-14
The nucleon axial form factor is a dominant contribution to errors in neutrino oscillation studies. Lattice QCD calculations can help control theory errors by providing first-principles information on nucleon form factors. In these proceedings, we present preliminary results on a blinded calculation of $g_A$ and the axial form factor using HISQ staggered baryons with 2+1+1 flavors of sea quarks. Calculations are done using physical light quark masses and are absolutely normalized. We discuss fitting form factor data with the model-independent $z$ expansion parametrization.
Triggs-Raine, B.L.; Akerman, B.R.; Gravel, R.A. ); Mules, E.H.; Thomas, G.H.; Dowling, C.E. ); Kaback, M.M.; Lim-Steele, J.S.T. ); Natowicz, M.R. ); Grebner, E.E. ); Navon, R.R. ); Welch, J.P. ); Greenberg, C.R. )
1992-10-01
Deficiency of [beta]-hexosaminidase A (Hex A) activity typically results in Tay-Sachs disease. However, healthy subjects found to be deficient in Hex A activity (i.e., pseudodeficient) by means of in vitro biochemical tests have been described. The authors analyzed the HEXA gene of one pseudodeficient subject and identified both a C[sub 739]-to-T substitution that changes Arg[sub 247][yields]Trp on one allele and a previously identified Tay-Sachs disease mutation of the second allele. Six additional pseudodeficient subjects were found to have the C[sub 739]-to-T but for none of 36 Jewish enzyme-defined carries who did not have one of three known mutations common to this group. The C[sub 739]-to-T allele, together with a [open quotes]true[close quotes] Tay-Sachs disease allele, causes Hex A pseudodeficiency. Given both the large proportion of non-Jewish carriers with this allele and that standard biochemical screening cannot differentiate between heterozygotes for the C[sub 739]-to-T mutations and Tay-Sachs disease carriers, DNA testing for this mutation in at-risk couples is essential. This could prevent unnecessary or incorrect prenatal diagnoses. 40 refs., 3 figs., 4 tabs.
Late-onset Tay-Sachs disease: adverse effects of medications and implications for treatment.
Shapiro, B E; Hatters-Friedman, S; Fernandes-Filho, J A; Anthony, K; Natowicz, M R
2006-09-12
The authors conducted a retrospective and brief prospective study of adverse effects of approximately 350 medications in 44 adults with late-onset Tay-Sachs disease (LOTS). Some medications were relatively safe, whereas others, particularly haloperidol, risperidone, and chlorpromazine, were associated with neurologic worsening.
78 FR 24447 - Goldman Sachs Trust, et al.; Notice of Application
Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-25
... companies, Government securities, and short-term paper; (iii) the aggregate sales loads and distribution... investment company in the same group of investment companies, Government securities, and short-term paper: (i... Variable Insurance Trust (each a ``Trust,'' together, the ``Trusts''), Goldman Sachs Asset Management,...
Factor Structure and Construct Validity of the Counselor Skills Personal Development Rating Form.
ERIC Educational Resources Information Center
Torres-Rivera, Edil; Wilbur, Michael P.; Maddux, Cleborne D.; Smaby, Marlowe H.; Phan, Loan T.; Roberts-Wilbur, Janice
2002-01-01
Presents an exploratory factor analysis of the scores of 248 counselors-in-training on the Counselor Skills Personal Development Rating Form (CSPD-RF). Authors of the test hypothesized that the CPSD-RF measured 2 factors, personal development and skills development. Factor analysis revealed 4 factors accounting for 58.4% of the total variance,…
Transient HEXA expression in a transformed human fetal Tay-Sachs disease neuroglial cell line
Fernandes, M.J.; Hechtman, P.; Kaplan, F.
1994-09-01
Tay-Sachs disease (TSD) is a severe neurodegenerative disorder characterized by the accumulation of GM{sub 2} ganglioside in the neurons of the central cortex. The recessively inherited disorder results from deficiency of hexosaminidase A (Hex A), a heterodimer of an {alpha} and {beta} subunit encoded by the HEXA and HEXB genes. Expression of HEXA mutations in COS cells has several disadvantages including high endogenous hexosaminidase activity. We report a new transient expression system with very low endogenous Hex A activity. An SV40-transformed fetal TSD neuroglial cell line was assessed for transient expression of the HEXA gene. pCMV{alpha}, a vector incorporating the cytomegalovirus promoter with the human {alpha}-subunit cDNA insert, proved to be the most efficient expression vector. Transfection of 4x10{sup 6} cells with 5-20 {mu}g of plasmid resulted in 100 to 500-fold Hex A activity (4MUGS hydrolysis) relative to mock-transfected cells. Use of pCMV{beta}-Gal as a control for transfection efficiency indicated that 10-20% of cells were transfected. Hex A specific activity increased for at least 72 h post-transfection. This new transient expression system should greatly improve the characterization of mutations in which low levels of HEXA expression result in milder clinical phenotypes and permit studies on enzymatic properties of mutant forms of Hex A. Since the cells used are of CNS origin and synthesize gangliosides, it should also be possible to study, in culture, the metabolic phenotype associated with TSD.
Flavor decomposition of the nucleon electromagnetic form factors at low Q2
NASA Astrophysics Data System (ADS)
Qattan, I. A.; Arrington, J.; Alsaad, A.
2015-06-01
Background: The spatial distribution of charge and magnetization within the proton is encoded in the elastic form factors. These have been precisely measured in elastic electron scattering, and the combination of proton and neutron form factors allows for the separation of the up- and down-quark contributions. Purpose: In this work, we extract the proton and neutron form factors from worldwide data with an emphasis on precise new data covering the low-momentum region, which is sensitive to the large-scale structure of the nucleon. From these, we separate the up- and down-quark contributions to the proton form factors. Method: We combine cross section and polarization measurements of elastic electron-proton scattering to separate the proton form factors and two-photon exchange (TPE) contributions. We combine the proton form factors with parametrization of the neutron form factor data and uncertainties to separate the up- and down-quark contributions to the proton's charge and magnetic form factors. Results: The extracted TPE corrections are compared to previous phenomenological extractions, TPE calculations, and direct measurements from the comparison of electron and positron scattering. The flavor-separated form factors are extracted and compared to models of the nucleon structure. Conclusions: With the inclusion of the precise new data, the extracted TPE contributions show a clear change of sign at low Q2, which is necessary to explain the high-Q2 form factor discrepancy while being consistent with the known Q2→0 limit. We find that the new Mainz data yield a significantly different result for the proton magnetic form factor and its flavor-separated contributions. We also observe that the rms radius of both the up- and down-quark distributions are smaller than the rms charge radius of the proton.
Nucleon form factors from high statistics mixed-action calculations with 2+1 flavors
Schroers, Wolfram; Edwards, Robert G; Engelhardt, Michael; Fleming, George Taminga; Hagler, Philipp; Lin, Huey-Wen; Lin, Mei-Feng; Meyer, Harvey B; Musch, Bernhard; Negele, John W; Orginos, Kostas; Pochinsky, Andrew V; Procura, Massimiliano; Renner, Dru B; Richards, David G; Syritsyn, Sergey N; Walker-Loud, Andre P
2009-12-01
We present new high-statistics results for nucleon form factors at pion masses of approximately 290, 350, 500, and 600 MeV using a mixed action of domain wall valence quarks on an improved staggered sea. We perform chiral fits to both vector and axial form factors and compare our results to experiment.
Form factors in quantum integrable models with GL(3)-invariant R-matrix
NASA Astrophysics Data System (ADS)
Pakuliak, S.; Ragoucy, E.; Slavnov, N. A.
2014-04-01
We study integrable models solvable by the nested algebraic Bethe ansatz and possessing GL(3)-invariant R-matrix. We obtain determinant representations for form factors of off-diagonal entries of the monodromy matrix. These representations can be used for the calculation of form factors and correlation functions of the XXX SU(3)-invariant Heisenberg chain.
Quark and gluon form factors to four-loop order in QCD: The Nf3 contributions
NASA Astrophysics Data System (ADS)
von Manteuffel, Andreas; Schabinger, Robert M.
2017-02-01
We calculate the four-loop massless QCD corrections with three closed quark lines to quark and gluon form factors. We apply a novel integration by parts algorithm based on modular arithmetic and compute all relevant master integrals for arbitrary values of the space-time dimension. This is the first calculation of a gluon form factor at this perturbative order in QCD.
Sufian, Raza Sabbir; de Teramond, Guy F.; Brodsky, Stanley J.; ...
2017-01-10
We present a comprehensive analysis of the space-like nucleon electromagnetic form factors and their flavor decomposition within the framework of light-front holographic QCD. We show that the inclusion of the higher Fock componentsmore » $$|{qqqq\\bar{q}}$$ has a significant effect on the spin-flip elastic Pauli form factor and almost zero effect on the spin-conserving Dirac form factor. We present light-front holographic QCD results for the proton and neutron form factors at any momentum transfer range, including asymptotic predictions, and show that our results agree with the available experimental data with high accuracy. In order to correctly describe the Pauli form factor we need an admixture of a five quark state of about 30$$\\%$$ in the proton and about 40$$\\%$$ in the neutron. We also extract the nucleon charge and magnetic radii and perform a flavor decomposition of the nucleon electromagnetic form factors. The free parameters needed to describe the experimental nucleon form factors are very few: two parameters for the probabilities of higher Fock states for the spin-flip form factor and a phenomenological parameter $r$, required to account for possible SU(6) spin-flavor symmetry breaking effects in the neutron, whereas the Pauli form factors are normalized to the experimental values of the anomalous magnetic moments. As a result, the covariant spin structure for the Dirac and Pauli nucleon form factors prescribed by AdS$$_5$$ semiclassical gravity incorporates the correct twist scaling behavior from hard scattering and also leads to vector dominance at low energy.« less
NASA Astrophysics Data System (ADS)
Sufian, Raza Sabbir; de Téramond, Guy F.; Brodsky, Stanley J.; Deur, Alexandre; Dosch, Hans Günter
2017-01-01
We present a comprehensive analysis of the spacelike nucleon electromagnetic form factors and their flavor decomposition within the framework of light-front (LF) holographic QCD (LFHQCD) We show that the inclusion of the higher Fock components |q q q q q ¯ ⟩ has a significant effect on the spin-flip elastic Pauli form factor and almost zero effect on the spin-conserving Dirac form factor. We present light-front holographic QCD results for the proton and neutron form factors at any momentum transfer range, including asymptotic predictions, and show that our results agree with the available experimental data with high accuracy. In order to correctly describe the Pauli form factor we need an admixture of a five quark state of about 30% in the proton and about 40% in the neutron. We also extract the nucleon charge and magnetic radii and perform a flavor decomposition of the nucleon electromagnetic form factors. The free parameters needed to describe the experimental nucleon form factors are very few: two parameters for the probabilities of higher Fock states for the spin-flip form factor and a phenomenological parameter r , required to account for possible SU(6) spin-flavor symmetry breaking effects in the neutron, whereas the Pauli form factors are normalized to the experimental values of the anomalous magnetic moments. The covariant spin structure for the Dirac and Pauli nucleon form factors prescribed by AdS5 semiclassical gravity incorporates the correct twist scaling behavior from hard scattering and also leads to vector dominance at low energy.
48 CFR 247.372 - DD Form 1654, Evaluation of Transportation Cost Factors.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false DD Form 1654, Evaluation... Transportation in Supply Contracts 247.372 DD Form 1654, Evaluation of Transportation Cost Factors. Contracting personnel may use the DD Form 1654 to furnish information to the transportation office for development...
48 CFR 247.372 - DD Form 1654, Evaluation of Transportation Cost Factors.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false DD Form 1654, Evaluation... Transportation in Supply Contracts 247.372 DD Form 1654, Evaluation of Transportation Cost Factors. Contracting personnel may use the DD Form 1654 to furnish information to the transportation office for development...
ERIC Educational Resources Information Center
Samuel, Douglas B.; Mullins-Sweatt, Stephanie N.; Widiger, Thomas A.
2013-01-01
The Five-Factor Model Rating Form (FFMRF) is a one-page measure designed to provide an efficient assessment of the higher order domains of the Five Factor Model (FFM) as well as the more specific, lower order facets proposed by McCrae and Costa. Although previous research has suggested that the FFMRF's assessment of the lower order facets converge…
Can Nonrelativistic QCD Explain the γγ^{*}→η_{c} Transition Form Factor Data?
Feng, Feng; Jia, Yu; Sang, Wen-Long
2015-11-27
Unlike the bewildering situation in the γγ^{*}→π form factor, a widespread view is that perturbative QCD can decently account for the recent BABAR measurement of the γγ^{*}→η_{c} transition form factor. The next-to-next-to-leading-order perturbative correction to the γγ^{*}→η_{c,b} form factor, is investigated in the nonrelativistic QCD (NRQCD) factorization framework for the first time. As a byproduct, we obtain, by far, the most precise order-α_{s}^{2} NRQCD matching coefficient for the η_{c,b}→γγ process. After including the substantial negative order-α_{s}^{2} correction, the good agreement between NRQCD prediction and the measured γγ^{*}→η_{c} form factor is completely ruined over a wide range of momentum transfer squared. This eminent discrepancy casts some doubts on the applicability of the NRQCD approach to hard exclusive reactions involving charmonium.
Delta and Omega electromagnetic form factors in a Dyson-Schwinger/Bethe-Salpeter approach
Diana Nicmorus, Gernot Eichmann, Reinhard Alkofer
2010-12-01
We investigate the electromagnetic form factors of the Delta and the Omega baryons within the Poincare-covariant framework of Dyson-Schwinger and Bethe-Salpeter equations. The three-quark core contributions of the form factors are evaluated by employing a quark-diquark approximation. We use a consistent setup for the quark-gluon dressing, the quark-quark bound-state kernel and the quark-photon interaction. Our predictions for the multipole form factors are compatible with available experimental data and quark-model estimates. The current-quark mass evolution of the static electromagnetic properties agrees with results provided by lattice calculations.
Pion Form Factor in Chiral Limit of Hard-Wall AdS/QCD Model
Anatoly Radyushkin; Hovhannes Grigoryan
2007-12-01
We develop a formalism to calculate form factor and charge density distribution of pion in the chiral limit using the holographic dual model of QCD with hard-wall cutoff. We introduce two conjugate pion wave functions and present analytic expressions for these functions and for the pion form factor. They allow to relate such observables as the pion decay constant and the pion charge electric radius to the values of chiral condensate and hard-wall cutoff scale. The evolution of the pion form factor to large values of the momentum transfer is discussed, and results are compared to existing experimental data.
Armstrong, David S.; McKeown, Robert
2012-11-01
Measurement of the neutral weak vector form factors of the nucleon provides unique access to the strange quark content of the nucleon. These form factors can be studied using parity-violating electron scattering. A comprehensive program of experiments has been performed at three accelerator laboratories to determine the role of strange quarks in the electromagnetic form factors of the nucleon. This article reviews the remarkable technical progress associated with this program, describes the various methods used in the different experiments, and summarizes the physics results along with recent theoretical calculations.
Measurements of the elastic electromagnetic form factor ratio {mu}pGEp/GMp via polarization transfer
Olivier Gayou; Oleksandr Glamazdin; Andrei Afanasev; Arunava Saha; Brendan Fox; Bogdan Wojtsekhowski; C. Chang; Cathleen Jones; Charles Glashausser; Charles Perdrisat; D. Crovelli; Daniel Simon; David Meekins; Demetrius Margaziotis; Dipangkar Dutta; Edgar Kooijman; Elaine Schulte; Edward Brash; Edward Kinney; Eugene Chudakov; Feng Xiong; Franco Garibaldi; Garth Huber; Gerfried Kumbartzki; Guido Urciuoli; Haiyan Gao; Jordan Hovdebo; James Kelly; Javier Gomez; Jens-Ole Hansen; Jian-Ping Chen; John Calarco; John LeRose; Joseph Mitchell; Juncai Gao; Konrad Aniol; Kamal Benslama; Kathy McCormick; Cornelis De Jager; Cornelis de Jager; Kevin Fissum; Krishni Wijesooriya; Louis Bimbot; Ludyvine Morand; Luminita Todor; Moskov Amarian; Marat Rvachev; Mark Jones; Martin Epstein; Meihua Liang; Michael Kuss; Nilanga Liyanage; Adam Sarty; Paul Ulmer; Pete Markowitz; Peter Bosted; R. Holt; Riad Suleiman; Richard Lindgren; Rikki Roche; Robert Michaels; Roman Pomatsalyuk; Ronald Gilman; Ronald Ransome; Stephen Becher; Scott Dumalski; Salvatore Frullani; Seonho Choi; Sergey Malov; Sonja Dieterich; Steffen Strauch; Steve Churchwell; Ting Chang; Viktor Gorbenko; Vina Punjabi; Wang Xu; Xiangdong Ji; Zein-Eddine Meziani; Zhengwei Chai
2001-09-01
We present measurements of the ratio of the proton elastic electromagnetic form factors, {mu}pGEp/GMp. The Jefferson Lab Hall A Focal Plane Polarimeter was used to determine the longitudinal and transverse components of the recoil proton polarization in ep elastic scattering; the ratio of these polarization components is proportional to the ratio of the two form factors. These data reproduce the observation of Jones et al. [Phys. Rev. Lett. 84, 1398 (2000)], that the form factor ratio decreases significantly from unity above Q2 = 1 GeV2.
Andrew Puckett
2009-12-01
Electromagnetic form factors are fundamental properties of the nucleon that describe the effect of its internal quark structure on the cross section and spin observables in elastic lepton-nucleon scattering. Double-polarization experiments have become the preferred technique to measure the proton and neutron electric form factors at high momentum transfers. The recently completed GEp-III experiment at the Thomas Jefferson National Accelerator Facility used the recoil polarization method to extend the knowledge of the proton electromagnetic form factor ratio GpE/GpM to Q2 = 8.5 GeV2. In this paper we present the preliminary results of the experiment.
Interaction between droplets in a ternary microemulsion evaluated by the relative form factor method
Nagao, Michihiro; Seto, Hideki; Yamada, Norifumi L.
2007-06-15
This paper describes the concentration dependence of the interaction between water droplets coated by a surfactant monolayer using the contrast variation small-angle neutron scattering technique. In the first part, we explain the idea of how to extract a relatively model free structure factor from the scattering data, which is called the relative form factor method. In the second part, the experimental results for the shape of the droplets (form factor) are described. In the third part the relatively model free structure factor is shown, and finally the concentration dependence of the interaction potential between droplets is discussed. The result indicates the validity of the relative form factor method, and the importance of the estimation of the model free structure factor to discuss the nature of structure formation in microemulsion systems.
Montalvo, Anna Lisa E; Filocamo, Mirella; Vlahovicek, Kristian; Dardis, Andrea; Lualdi, Susanna; Corsolini, Fabio; Bembi, Bruno; Pittis, Maria Gabriela
2005-09-01
Tay-Sachs disease (TSD) is a recessively inherited disorder caused by the hexosaminidase A deficiency. We report the molecular characterization performed on 31 Italian patients, 22 with the infantile, acute form of TSD and nine patients with the subacute juvenile form, biochemically classified as B1 Variant. Of the 29 different alleles identified, fourteen were due to 15 novel mutations, two being in-cis on a new complex allele. The new alleles caused four frameshifts, three premature stop codons, three amino acid changes, two amino acid deletions and two splicing alterations. As previously reported, the c.533G>A (p.R178H) mutation was present either in homozygosity or as compound heterozygote, in all the patients with the late onset TSD form (B1 Variant); the allele frequency in this group is discussed by comparison with that found in infantile TSD.
Prevention of lysosomal storage in Tay-Sachs mice treated with N-butyldeoxynojirimycin.
Platt, F M; Neises, G R; Reinkensmeier, G; Townsend, M J; Perry, V H; Proia, R L; Winchester, B; Dwek, R A; Butters, T D
1997-04-18
The glycosphingolipid (GSL) lysosomal storage diseases result from the inheritance of defects in the genes encoding the enzymes required for catabolism of GSLs within lysosomes. A strategy for the treatment of these diseases, based on an inhibitor of GSL biosynthesis N-butyldeoxynojirimycin, was evaluated in a mouse model of Tay-Sachs disease. When Tay-Sachs mice were treated with N-butyldeoxynojirimycin, the accumulation of GM2 in the brain was prevented, with the number of storage neurons and the quantity of ganglioside stored per cell markedly reduced. Thus, limiting the biosynthesis of the substrate (GM2) for the defective enzyme (beta-hexosaminidase A) prevents GSL accumulation and the neuropathology associated with its lysosomal storage.
Noncanonical phase-space noncommutativity and the Kantowski-Sachs singularity for black holes
NASA Astrophysics Data System (ADS)
Bastos, Catarina; Bertolami, Orfeu; Dias, Nuno Costa; Prata, João Nuno
2011-07-01
We consider a cosmological model based upon a noncanonical noncommutative extension of the Heisenberg-Weyl algebra to address the thermodynamical stability and the singularity problem of black holes whose interior are described by the Kantowski-Sachs metric and modeled by a noncommutative extension of the Wheeler-DeWitt equation. We compute the temperature and entropy of these black holes and compare the results with the Hawking values. We observe that it is actually the noncommutativity in the momentum sector that allows for the existence of a minimum in the potential, which is the key to apply the Feynman-Hibbs procedure. It is shown that this noncommutative model generates a nonunitary dynamics that predicts a vanishing probability in the neighborhood of the singularity. This result effectively regularizes the Kantowski-Sachs singularity and generalizes a similar result, previously obtained for the case of Schwarzschild black holes.
Electromagnetic form factors of Λb in the Bethe-Salpeter equation approach
NASA Astrophysics Data System (ADS)
Liu, Liang-Liang; Wang, Chao; Liu, Ying; Guo, Xin-Heng
2017-03-01
The heavy baryon Λb is regarded as composed of a heavy quark and a scalar diquark which has good spin and isospin quantum numbers. In this picture, we calculate the electromagnetic form factors of Λb in the Bethe-Salpeter equation approach in the spacelike region. We find that the shapes of the electromagnetic form factors of Λb are similar to those of Λ , with a peak at ω =1 (for the magnetic form factor) and ω ≃1.1 (for the electric form factor)(ω =v'.v is the velocity transfer between the initial state (with velocity v ) and the final state (with velocity v') of Λb), but the amplitudes are much smaller than those of Λ .
Nucleon-to-{delta} axial transition form factors in relativistic baryon chiral perturbation theory
Geng, L. S.; Camalich, J. Martin; Alvarez-Ruso, L.; Vacas, M. J. Vicente
2008-07-01
We report a theoretical study of the axial nucleon-to-delta (1232) (N{yields}{delta}) transition form factors up to one-loop order in relativistic baryon chiral perturbation theory. We adopt a formalism in which the {delta} couplings obey the spin-3/2 gauge symmetry and, therefore, decouple the unphysical spin-1/2 fields. We compare the results with phenomenological form factors obtained from neutrino bubble-chamber data and in quark models.
Interpreting the neutron's electric form factor: Rest frame charge distribution or foldy term?
Nathan Isgur
1998-12-01
The neutron's electric form factor contains vital information on nucleon structure, but its interpretation within many models has been obscured by relativistic effects. The author demonstrates that, to leading order in the relativistic expansion of a constituent quark model, the Foldy term cancels exactly against a contribution to the Dirac form factor F{sub 1} to leave intact the naive interpretation of G{sup n}{sub E} as arising from the neutron's rest frame charge distribution.
The spin-dependent neutralino-nucleus form factor for {sup 127}I
Ressell, M.T.; Dean, D.J.
1996-12-01
We present the results of detailed shell model calculations of the spin-dependent elastic form factor for the nucleus {sup 127}I. the calculations were performed in extremely large model spaces which adequately describe the configuration mixing in this nucleus. Good agreement between the calculated and experimental values of the magnetic moment are found. Other nuclear observables are also compared to experiment. The dependence of the form factor upon the model space and effective interaction is discussed.
ACOG committee opinion. Number 318, October 2005. Screening for Tay-Sachs disease.
2005-10-01
Tay-Sachs disease (TSD) is a severe progressive neurologic disease that causes death in early childhood. Carrier screening, should be offered before pregnancy to individuals and couples at high-risk, including those of Ashkenazi Jewish, French-Canadian, or Cajun descent and those with a family history consistent with TSD. If both partners are determined to be carriers of TSD, genetic counseling and prenatal diagnosis should be offered.
Huang, S.S.; O'Grady, P.; Huang, J.S.
1987-05-01
Human platelet-derived transforming growth factor ..beta.. (TGF..beta..) has been shown to be present as a high molecular weight latent form in human serum. Appearance of transforming growth factor activity, along with the change from high molecular weight form to low molecular weight form, was observed following treatment of the latent form of TGF..beta.. with acid or urea, suggesting that the latent form of TGF..beta.. is a complex of TGF..beta.. and a high molecular weight binding protein. Human ..cap alpha../sub 2/-M has been found to be a plasma binding protein for platelet-derived growth factor (PDGF) in serum or plasma. TGF..beta.. and PDGF share similar properties. They, therefore, investigated the interaction between /sup 125/I-TGF..beta.. and ..cap alpha../sub 2/M. /sup 125/I-TGF..beta.. and purified human ..cap alpha../sub 2/M formed a complex as demonstrated by polyacrylamide gel electrophoresis. Most of the /sup 125/I-TGF..beta..-..cap alpha../sub 2/M complex could be dissociated by acid or urea treatment. These results suggest that ..cap alpha../sub 2/M is a binding protein for TGF..beta.. and that TGF..beta..-..cap alpha../sub 2/M complex may be the latent form of TGF..beta.. in serum.
Lin, C.K.
1983-01-01
The collective model H/sub int/ + H/sub coll/ is used to study the magnetic form factors. For the intrinsic Hamiltonian, we use the Nilsson model to generate the intrinsic state. For the collective Hamiltonian, two models are considered, the rigid body model and the liquid soap model. We use the particle-rotor model to derive the collective operators and their reduced matrix elements, and then apply this model to the elastic M1 form factor of /sup 13/C. One sees clearly the interplay of the intrinsic form factor and the collective form factor. Since the form factor is essentially a Fourier transform of the current density operator, one also sees the effects of the collective current density distribution due to all the particles in addition to that of the intrinsic current due to the unpaired nucleons. The effects of core deformation are explored. This includes discussions on the difference between the variation before projection and the variation after projection. Analytic results are obtained in the case of weak deformations. The collective model focuses on the effects of the quadrupole deformation on the M1 form factor of /sup 13/C, whereas the calculation involving core polarization stresses the monopole effects. By introducing a quenching of the isovector g/sub s/, the fits by the collective models are very comparable to the fit by the core polarization, although the justification for this procedure in light nuclei is questionable.
Proton electromagnetic form factors: present status and future perspectives at PANDA
NASA Astrophysics Data System (ADS)
Tomasi-Gustafsson, E.
2015-05-01
Data and models on electromagnetic proton form factors are reviewed, highlighting the contribution foreseen by the PANDA collaboration. Electromagnetic hadron form factors contain essential information on the internal structure of hadrons. Precise and surprising data have been obtained at electron accelerators, applying the polarization method in electron-proton elastic scattering. At electron-positron colliders, using initial state radiation, BABAR measured proton time-like form factors in a wide time-like kinematical region and the BESIII collaboration will measure very precisely proton and neutron form factors in the threshold region. In the next future an antiproton beam with momentum up to 15 GeV/c will be available at FAIR (Darmstadt). Measurements of the reaction p̅ + p → e+ + e- by the PANDA collaboration will contribute to the individual determination of electric and magnetic form factors in the time-like region of momentum transfer squared, as well as to their first determination in the unphysical region (below the kinematical threshold), through the reaction p̅ + p → e+ + e- + π0. From the discussion on feasibility studies at PANDA, we focus on the consequences of such measurements in view of an unified description of form factors in the full kinematical region. We present models which have the necessary analytical requirements and apply to the data in the whole kinematical region.
Mixed-state form factors of U(1) twist fields in the Dirac theory
NASA Astrophysics Data System (ADS)
Chen, Yixiong
2016-08-01
Using the ‘Liouville space’ (the space of operators) of the massive Dirac theory, we define mixed-state form factors of U(1) twist fields. We consider mixed states with density matrices diagonal in the asymptotic particle basis. This includes the thermal Gibbs state as well as all generalized Gibbs ensembles of the Dirac theory. When the mixed state is specialized to a thermal Gibbs state, using a Riemann-Hilbert problem and low-temperature expansion, we obtain finite-temperature form factors of U(1) twist fields. We then propose the expression for form factors of U(1) twist fields in general diagonal mixed states. We verify that these form factors satisfy a system of nonlinear functional differential equations, which is derived from the trace definition of mixed-state form factors. At last, under weak analytic conditions on the eigenvalues of the density matrix, we write down the large distance form factor expansions of two-point correlation functions of these twist fields. Using the relation between the Dirac and Ising models, this provides the large-distance expansion of the Rényi entropy (for integer Rényi parameter) in the Ising model in diagonal mixed states.
$$B\\to Kl^+l^-$$ decay form factors from three-flavor lattice QCD
Bailey, Jon A.
2016-01-27
We compute the form factors for the B → Kl+l- semileptonic decay process in lattice QCD using gauge-field ensembles with 2+1 flavors of sea quark, generated by the MILC Collaboration. The ensembles span lattice spacings from 0.12 to 0.045 fm and have multiple sea-quark masses to help control the chiral extrapolation. The asqtad improved staggered action is used for the light valence and sea quarks, and the clover action with the Fermilab interpretation is used for the heavy b quark. We present results for the form factors f+(q2), f0(q2), and fT(q2), where q2 is the momentum transfer, together with a comprehensivemore » examination of systematic errors. Lattice QCD determines the form factors for a limited range of q2, and we use the model-independent z expansion to cover the whole kinematically allowed range. We present our final form-factor results as coefficients of the z expansion and the correlations between them, where the errors on the coefficients include statistical and all systematic uncertainties. Lastly, we use this complete description of the form factors to test QCD predictions of the form factors at high and low q2.« less
$B\\to Kl^+l^-$ decay form factors from three-flavor lattice QCD
Bailey, Jon A.
2016-01-27
We compute the form factors for the B → Kl^{+}l^{-} semileptonic decay process in lattice QCD using gauge-field ensembles with 2+1 flavors of sea quark, generated by the MILC Collaboration. The ensembles span lattice spacings from 0.12 to 0.045 fm and have multiple sea-quark masses to help control the chiral extrapolation. The asqtad improved staggered action is used for the light valence and sea quarks, and the clover action with the Fermilab interpretation is used for the heavy b quark. We present results for the form factors f+(q^{2}), f_{0}(q^{2}), and f_{T}(q^{2}), where q^{2} is the momentum transfer, together with a comprehensive examination of systematic errors. Lattice QCD determines the form factors for a limited range of q^{2}, and we use the model-independent z expansion to cover the whole kinematically allowed range. We present our final form-factor results as coefficients of the z expansion and the correlations between them, where the errors on the coefficients include statistical and all systematic uncertainties. Lastly, we use this complete description of the form factors to test QCD predictions of the form factors at high and low q^{2}.
Form and structure factors for impedance and reflection from periodic layers.
Pan, Janet L
2007-01-20
In an exact treatment of the Maxwell equations, we derive form and structure factors for reflection from periodic layers, and we show that these factors are significantly different from their analogs in kinematic x-ray diffraction. Quite generally, we show that reflection and impedance can be written precisely as the sum of an additive form factor and the product of a structure factor and a second form factor. This additive form factor does not have an analog in kinematic x-ray diffraction. It is demonstrated that the form factors are found by analytic continuation to an arbitrary wavelength of expressions for the impedance both at long wavelengths and at quarter wavelengths. A correction to the Bragg law relating fringe spacing to the total structure thickness is derived. We go beyond previous numerical work by deriving simple analytic exact expressions for reflection and impedance of periodic layers for all frequencies within the reflection passband, and for an arbitrary number of periods in the structure, an arbitrary index profile within each period, arbitrary layer thicknesses (not just quarter-wave layers), and for arbitrary sizes of the refractive index differences.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-27
... HUMAN SERVICES Food and Drug Administration 21 CFR Part 522 Implantation or Injectable Dosage Form New... gonadotropin releasing factor analog-diphtheria toxoid conjugate injectable solution. DATES: This rule is...: PART 522--IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS 0 1. The authority citation for...
Huber, Garth; Blok, Henk; Horn, Tanja; Beise, Elizabeth; Gaskell, David; Mack, David; Tadevosyan, Vardan; Volmer, Jochen; Abbott, David; Aniol, Konrad; Anklin, Heinz; Armstrong, Christopher; Arrington, John; Assamagan, Ketevi; Avery, Steven; Baker, O.; Barrett, Robert; Bochna, Christopher; Boeglin, Werner; Brash, Edward; Breuer, Herbert; Chang, C.; Chang, C.C.; Chant, Nicholas; Christy, Michael; Dunne, James; Eden, Thomas; Ent, Rolf; Fenker, Benjamin; Gibson, Edward; Gilman, Ronald; Gustafsson, Kenneth; Hinton, Wendy; Holt, Roy; Jackson, Harold; uk Jin, Seong; Jones, Mark; Keppel, Cynthia; Kim, pyunghun; Kim, Wooyoung; King, Paul; Klein, Andreas; Koltenuk, Douglas; Kovaltchouk, Vitali; Liang, Meihua; Liu, Jinghua; Lolos, George; Lung, Allison; Margaziotis, Demetrius; Markowitz, Pete; Matsumura, Akihiko; McKee, David; Meekins, David; Mitchell, Joseph; Miyoshi, Toshinobu; Mkrtchyan, Hamlet; Mueller, Robert; Niculescu, Gabriel; Niculescu, Maria-Ioana; Okayasu, Yuichi; Pentchev, Lubomir; Perdrisat, Charles; Pitz, David; Potterveld, David; Punjabi, Vina; Qin, Liming; Reimer, Paul; Reinhold, Joerg; Roche, Julie; Roos, Philip; Sarty, Adam; Shin, Ilkyoung; Smith, Gregory; Stepanyan, Stepan; Tang, Liguang; Tvaskis, Vladas; van der Meer, Rob; Vansyoc, Kelley; Van Westrum, Derek; Vidakovic, Sandra; Vulcan, William; Warren, Glen; Wood, Stephen; Xu, Chen; Yan, Chen; Zhao, Wenxia; Zheng, Xiaochao; Zihlmann, Benedikt
2008-10-01
DOI: http://dx.doi.org/10.1103/PhysRevC.78.045203
The charged pion form factor, Fpi(Q2), is an important quantity that can be used to advance our knowledge of hadronic structure. However, the extraction of Fpi from data requires a model of the 1H(e,e'pi+)n reaction and thus is inherently model dependent. Therefore, a detailed description of the extraction of the charged pion form factor from electroproduction data obtained recently at Jefferson Lab is presented, with particular focus given to the dominant uncertainties in this procedure. Results for Fpi are presented for Q2=0.60-2.45 GeV2. Above Q2=1.5 GeV2, the Fpi values are systematically below the monopole parametrization that describes the low Q2 data used to determine the pion charge radius. The pion form factor can be calculated in a wide variety of theoretical approaches, and the experimental results are compared to a number of calculations. This comparison is helpful in understanding the role of soft versus hard c
Factor Structure and Validity of the Parenting Stress Index-Short Form
ERIC Educational Resources Information Center
Haskett, Mary E.; Ahern, Lisa S.; Ward, Caryn S.; Allaire, Jason C.
2006-01-01
The psychometric properties of the Parenting Stress Index-Short Form (PSI-SF) were examined in a sample of 185 mothers and fathers. Factor analysis revealed 2 reasonably distinct factors involving parental distress and dysfunctional parent-child interactions. Both scales were internally consistent, and these scales were correlated with measures of…
ERIC Educational Resources Information Center
Mokula, Lebeloane Lazarus Donald; Lovemore, Nyaumwe
2014-01-01
The present study narrated the forms, factors and consequences of cheating in university examinations by UNISA Open and Distance learning students from anecdotal data. The results showed that the perpetrators mostly used crib materials on paper, ruler and calculator cover. The factors that influenced examination cheating were gender, age range and…
ERIC Educational Resources Information Center
Cui, Lixia; Lin, Wenwen; Oei, Tian P. S.
2011-01-01
This study investigated cross-cultural differences in the factor structure and psychometric properties of the Young Schema Questionnaire (short form; YSQ-SF). The participants were 712 Chinese undergraduate students. The total sample was randomly divided into two sub-samples. Exploratory Factor Analysis (EFA) was conducted on questionnaire results…
Multilevel Confirmatory Factor Analysis of the Teacher My Class Inventory-Short Form
ERIC Educational Resources Information Center
Villares, Elizabeth; Mariani, Melissa; Sink, Christopher A.; Colvin, Kimberly
2016-01-01
Researchers analyzed data from elementary teachers (N = 233) to further establish the psychometric soundness of the Teacher My Class Inventory-Short Form. Supporting previous psychometric research, confirmatory factor analyses findings supported the factorial validity of the hypothesized five-factor solution. Internal reliability estimates were…
Density form factors of the 1D Bose gas for finite entropy states
NASA Astrophysics Data System (ADS)
De Nardis, J.; Panfil, M.
2015-02-01
We consider the Lieb-Liniger model for a gas of bosonic δ-interacting particles. Using Algebraic Bethe Ansatz results we compute the thermodynamic limit of the form factors of the density operator between finite entropy eigenstates such as finite temperature states or generic non-equilibrium highly excited states. These form factors are crucial building blocks to obtain the thermodynamic exact dynamic correlation functions of such physically relevant states. As a proof of principle we compute an approximated dynamic structure factor by including only the simplest types of particle-hole excitations and show the agreement with known results.
Form factor effects in the direct detection of isospin-violating dark matter
Zheng, Hao; Zhang, Zhen; Chen, Lie-Wen E-mail: malkuth@sjtu.edu.cn
2014-08-01
Isospin-violating dark matter (IVDM) provides a possible mechanism to ameliorate the tension among recent direct detection experiments. For IVDM, we demonstrate that the results of direct detection experiments based on neutron-rich target nuclei may depend strongly on the density dependence of the symmetry energy which is presently largely unknown and controls the neutron skin thickness that reflects the relative difference of neutron and proton form factors in the neutron-rich nuclei. In particular, using the neutron and proton form factors obtained from Skyrme-Hartree-Fock calculations by varying the symmetry energy within the uncertainty region set by the latest model-independent measurement of the neutron skin thickness of {sup 208}Pb from PREX experiment at JLab, we find that, for IVDM with neutron-to-proton coupling ratio fixed to f{sub n}/f{sub p}=-0.7, the form factor effect may enhance the sensitivity of Xe-based detectors (e.g., XENON100 and LUX) to the DM-proton cross section by a factor of 3 in the DM mass region constrained by CMDS-II(Si) and even by more than an order of magnitude for heavy DM with mass larger than 80 GeV, compared with the results using the empirical Helm form factor. Our results further indicate that the form factor effect can significantly modify the recoil spectrum of Xe-based detectors for heavy IVDM with f{sub n}/f{sub p}=-0.7.
Form factor effects in the direct detection of isospin-violating dark matter
NASA Astrophysics Data System (ADS)
Zheng, Hao; Zhang, Zhen; Chen, Lie-Wen
2014-08-01
Isospin-violating dark matter (IVDM) provides a possible mechanism to ameliorate the tension among recent direct detection experiments. For IVDM, we demonstrate that the results of direct detection experiments based on neutron-rich target nuclei may depend strongly on the density dependence of the symmetry energy which is presently largely unknown and controls the neutron skin thickness that reflects the relative difference of neutron and proton form factors in the neutron-rich nuclei. In particular, using the neutron and proton form factors obtained from Skyrme-Hartree-Fock calculations by varying the symmetry energy within the uncertainty region set by the latest model-independent measurement of the neutron skin thickness of 208Pb from PREX experiment at JLab, we find that, for IVDM with neutron-to-proton coupling ratio fixed to fn/fp=-0.7, the form factor effect may enhance the sensitivity of Xe-based detectors (e.g., XENON100 and LUX) to the DM-proton cross section by a factor of 3 in the DM mass region constrained by CMDS-II(Si) and even by more than an order of magnitude for heavy DM with mass larger than 80 GeV, compared with the results using the empirical Helm form factor. Our results further indicate that the form factor effect can significantly modify the recoil spectrum of Xe-based detectors for heavy IVDM with fn/fp=-0.7.
A study of the γ ^*-f0(980) transition form factors
NASA Astrophysics Data System (ADS)
Kroll, P.
2017-02-01
The γ ^*-f0(980) transition form factors are calculated within the QCD factorization framework. The f_0-meson is assumed to be mainly generated through its sbar{s} Fock component. The corresponding spin wave function of the f0(980) meson is constructed and, combined with a model light-cone wave function for this Fock component, used in the calculation of the form factors. In the real-photon limit the results for the transverse form factor are compared to the large momentum-transfer data measured by the BELLE collaboration recently. It turns out that, for the momentum-transfer range explored by BELLE, the collinear approximation does not suffice, power corrections to it, modeled as quark transverse moment effects, seem to be needed. Mixing of the f_0 with the σ (500) is also briefly discussed.
Factor structure of the BASC-2 Behavioral and Emotional Screening System Student Form.
Dowdy, Erin; Twyford, Jennifer M; Chin, Jenna K; DiStefano, Christine A; Kamphaus, Randy W; Mays, Kristen L
2011-06-01
The BASC-2 Behavioral and Emotional Screening System (BESS) Student Form (Kamphaus & Reynolds, 2007) is a recently developed youth self-report rating scale designed to identify students at risk for behavioral and emotional problems. The BESS Student Form was derived from the Behavior Assessment System for Children-Second Edition Self-Report of Personality (BASC-2 SRP; Reynolds & Kamphaus, 2004) using principal component analytic procedures and theoretical considerations. Using 3 samples, the authors conducted exploratory factor analyses (EFA) and confirmatory factor analyses (CFA) to understand the underlying factor structure of the BESS Student Form. The results of the EFA suggested that the SRP contained a 4-factor (i.e., Personal Adjustment, Inattention/Hyperactivity, Internalizing, School Problems) emergent structure, which was supported by CFA in 2 additional samples. Practical and research implications are discussed.
Regularization of multi-soliton form factors in sine-Gordon model
NASA Astrophysics Data System (ADS)
Pálmai, T.
2012-08-01
A general and systematic regularization is developed for the exact solitonic form factors of exponential operators in the (1+1)-dimensional sine-Gordon model by analytical continuation of their integral representations. The procedure is implemented in Mathematica. Test results are shown for four- and six-soliton form factors. Catalogue identifier: AEMG_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEMG_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1462 No. of bytes in distributed program, including test data, etc.: 15 488 Distribution format: tar.gz Programming language: Mathematica [1] Computer: PC Operating system: Cross-platform Classification: 7.7, 11.1, 23 Nature of problem: The multi-soliton form factors of the sine-Gordon model (relevant in two-dimensional physics) were given only by highly non-trivial integral representation with a limited domain of convergence. Practical applications of the form factors, e.g. calculation of correlation functions in two-dimensional condensed matter systems, were not possible in general. Solution method: Using analytic continuation techniques an efficient algorithm is found and implemented in Mathematica, which provides a general and systematic way to calculate multi-soliton form factors in the sine-Gordon model. The package contains routines to compute the two-, four- and six-soliton form factors. Running time: Strongly dependent on the desired accuracy and the number of solitons. For physical rapidities after an initialization of about 30 s, the calculation of the two-, four- and six-soliton form factors at a single point takes approximately 0.5 s, 2.5 s and 8 s, respectively. Wolfram Research, Inc., Mathematica Edition: Version 7.0, Wolfram Research, Inc., Champaign, Illinois, 2008.
The puzzle of the π → γ γ* transition form factor
NASA Astrophysics Data System (ADS)
Lucha, Wolfgang; Melikhov, Dmitri
2012-04-01
We study the P → γ γ* (P = π0, η, η‧) transition form factors by means of the local-duality (LD) version of QCD sum rules. For the case of η and η‧, the conventional LD model provides a good description of the existing data. However, for the pion form factor we find a disagreement with recent BaBar results for high Q2, even though the accuracy of the LD approximation is expected to increase with Q2. It remains mysterious why both η and η‧ form factors to virtual photons, on the one hand, and the π0 form factor, on the other hand, show a qualitatively different behaviour, corresponding to a violation of LD that rises with Q2 in the pion case. In a quantum-mechanical example, we show that, for a bound-state size of about 1 fm, the LD sum rule provides an accurate prediction for the form factor for Q2 larger than a few GeV2.
Dersh, Devin; Iwamoto, Yuichiro; Argon, Yair
2016-01-01
Loss of function of the enzyme β-hexosaminidase A (HexA) causes the lysosomal storage disorder Tay–Sachs disease (TSD). It has been proposed that mutations in the α chain of HexA can impair folding, enzyme assembly, and/or trafficking, yet there is surprisingly little known about the mechanisms of these potential routes of pathogenesis. We therefore investigated the biosynthesis and trafficking of TSD-associated HexA α mutants, seeking to identify relevant cellular quality control mechanisms. The α mutants E482K and G269S are defective in enzymatic activity, unprocessed by lysosomal proteases, and exhibit altered folding pathways compared with wild-type α. E482K is more severely misfolded than G269S, as observed by its aggregation and inability to associate with the HexA β chain. Importantly, both mutants are retrotranslocated from the endoplasmic reticulum (ER) to the cytosol and are degraded by the proteasome, indicating that they are cleared via ER-associated degradation (ERAD). Leveraging these discoveries, we observed that manipulating the cellular folding environment or ERAD pathways can alter the kinetics of mutant α degradation. Additionally, growth of patient fibroblasts at a permissive temperature or with chemical chaperones increases cellular Hex activity by improving mutant α folding. Therefore modulation of the ER quality control systems may be a potential therapeutic route for improving some forms of TSD. PMID:27682588
Dersh, Devin; Iwamoto, Yuichiro; Argon, Yair
2016-12-01
Loss of function of the enzyme β-hexosaminidase A (HexA) causes the lysosomal storage disorder Tay-Sachs disease (TSD). It has been proposed that mutations in the α chain of HexA can impair folding, enzyme assembly, and/or trafficking, yet there is surprisingly little known about the mechanisms of these potential routes of pathogenesis. We therefore investigated the biosynthesis and trafficking of TSD-associated HexA α mutants, seeking to identify relevant cellular quality control mechanisms. The α mutants E482K and G269S are defective in enzymatic activity, unprocessed by lysosomal proteases, and exhibit altered folding pathways compared with wild-type α. E482K is more severely misfolded than G269S, as observed by its aggregation and inability to associate with the HexA β chain. Importantly, both mutants are retrotranslocated from the endoplasmic reticulum (ER) to the cytosol and are degraded by the proteasome, indicating that they are cleared via ER-associated degradation (ERAD). Leveraging these discoveries, we observed that manipulating the cellular folding environment or ERAD pathways can alter the kinetics of mutant α degradation. Additionally, growth of patient fibroblasts at a permissive temperature or with chemical chaperones increases cellular Hex activity by improving mutant α folding. Therefore modulation of the ER quality control systems may be a potential therapeutic route for improving some forms of TSD.
Presence of an unusual GM2 derivative, taurine-conjugated GM2, in Tay-Sachs brain.
Li, Yu-Teh; Maskos, Karol; Chou, Chau-Wen; Cole, Richard B; Li, Su-Chen
2003-09-12
Tay-Sachs disease (TSD) is a classical glycosphingolipid (GSL) storage disease. Although the genetic and biochemical bases for a massive cerebral accumulation of ganglioside GM2 in TSD have been well established, the mechanism for the neural dysfunction in TSD remains elusive. Upon analysis of GSLs from a variant B TS brain, we have detected a novel GSL that has not been previously revealed. We have isolated this GSL in pure form. Using NMR spectroscopy, mass spectrometry, and chemical synthesis, the structure of this unusual GSL was established to be a taurine-conjugated GM2 (tauro-GM2) in which the carboxyl group of N-acetylneuraminic acid was amidated by taurine. Using a rabbit anti-tauro-GM2 serum, we also detected the presence of tauro-GM2 in three other small brain samples from one variant B and two variant O TSD patients. On the other hand, tauro-GM2 was not found in three normal human brain samples. The presence of tauro-GM2 in TS brains, but not in normal brains, indicates the possible association of this unusual GM2 derivative with the pathogenesis of TSD. Our findings point to taurine conjugation as a heretofore unelucidated mechanism for TS brain to cope with water-insoluble GM2.
$D$ semileptonic form factors and $|V_{cs(d)}|$ from 2+1 flavor lattice QCD
Bailey, Jon A.; Bazavov, A.; El-Khadra, A.X.; Gottlieb, Steven; Jain, R.D.; Kronfeld, A.S.; Van de Water, R.S.; Zhou, R.
2011-11-01
The measured partial widths of the semileptonic decays D {yields} K{ell}{nu} and D {yields} {pi}{ell}{nu} can be combined with the form factors calculated on the lattice to extract the CKM matrix elements |V{sub cs}| and |V{sub cd}|. The lattice calculations can be checked by comparing the form factor shapes from the lattice and experiment. We have generated a sizable data set by using heavy clover quarks with the Fermilab interpretation for charm and asqtad staggered light quarks on 2+1 flavor MILC ensembles with lattice spacings of approximately 0.12, 0.09, 0.06, and 0.045 fm. Preliminary fits to staggered chiral perturbation theory suggest that we can reduce the uncertainties in the form factors at q{sup 2} = 0 to below 5%.
Electromagnetic form factors of the {Omega}{sup -} in lattice QCD
Alexandrou, C.; Korzec, T.; Koutsou, G.; Negele, J. W.; Proestos, Y.
2010-08-01
We present results on the omega baryon ({Omega}{sup -}) electromagnetic form factors using N{sub f}=2+1 domain-wall fermion configurations for three pion masses in the range of about 350 to 300 MeV. We compare results obtained using domain-wall fermions with those of a mixed-action (hybrid) approach, which combines domain-wall valence quarks on staggered sea quarks, for a pion mass of about 350 MeV. We pay particular attention in the evaluation of the subdominant electric quadrupole form factor to sufficient accuracy to exclude a zero value, by constructing a sequential source that isolates it from the dominant form factors. The {Omega}{sup -} magnetic moment, {mu}{sub {Omega}}{sup -}, and the electric charge and magnetic radius,
Feasibility studies of time-like proton electromagnetic form factors at overlinePANDA at FAIR
NASA Astrophysics Data System (ADS)
Singh, B.; Erni, W.; Krusche, B.; Steinacher, M.; Walford, N.; Liu, B.; Liu, H.; Liu, Z.; Shen, X.; Wang, C.; Zhao, J.; Albrecht, M.; Erlen, T.; Fink, M.; Heinsius, F.; Held, T.; Holtmann, T.; Jasper, S.; Keshk, I.; Koch, H.; Kopf, B.; Kuhlmann, M.; Kümmel, M.; Leiber, S.; Mikirtychyants, M.; Musiol, P.; Mustafa, A.; Pelizäus, M.; Pychy, J.; Richter, M.; Schnier, C.; Schröder, T.; Sowa, C.; Steinke, M.; Triffterer, T.; Wiedner, U.; Ball, M.; Beck, R.; Hammann, C.; Ketzer, B.; Kube, M.; Mahlberg, P.; Rossbach, M.; Schmidt, C.; Schmitz, R.; Thoma, U.; Urban, M.; Walther, D.; Wendel, C.; Wilson, A.; Bianconi, A.; Bragadireanu, M.; Caprini, M.; Pantea, D.; Patel, B.; Czyzycki, W.; Domagala, M.; Filo, G.; Jaworowski, J.; Krawczyk, M.; Lisowski, F.; Lisowski, E.; Michałek, M.; Poznański, P.; Płażek, J.; Korcyl, K.; Kozela, A.; Kulessa, P.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Szczurek, A.; Fiutowski, T.; Idzik, M.; Mindur, B.; Przyborowski, D.; Swientek, K.; Biernat, J.; Kamys, B.; Kistryn, S.; Korcyl, G.; Krzemien, W.; Magiera, A.; Moskal, P.; Pyszniak, A.; Rudy, Z.; Salabura, P.; Smyrski, J.; Strzempek, P.; Wronska, A.; Augustin, I.; Böhm, R.; Lehmann, I.; Nicmorus Marinescu, D.; Schmitt, L.; Varentsov, V.; Al-Turany, M.; Belias, A.; Deppe, H.; Dzhygadlo, R.; Ehret, A.; Flemming, H.; Gerhardt, A.; Götzen, K.; Gromliuk, A.; Gruber, L.; Karabowicz, R.; Kliemt, R.; Krebs, M.; Kurilla, U.; Lehmann, D.; Löchner, S.; Lühning, J.; Lynen, U.; Orth, H.; Patsyuk, M.; Peters, K.; Saito, T.; Schepers, G.; Schmidt, C. J.; Schwarz, C.; Schwiening, J.; Täschner, A.; Traxler, M.; Ugur, C.; Voss, B.; Wieczorek, P.; Wilms, A.; Zühlsdorf, M.; Abazov, V.; Alexeev, G.; Arefiev, V. A.; Astakhov, V.; Barabanov, M. Yu.; Batyunya, B. V.; Davydov, Y.; Dodokhov, V. Kh.; Efremov, A.; Fechtchenko, A.; Fedunov, A. G.; Galoyan, A.; Grigoryan, S.; Koshurnikov, E. K.; Lobanov, Y. Yu.; Lobanov, V. I.; Makarov, A. F.; Malinina, L. V.; Malyshev, V.; Olshevskiy, A. G.; Perevalova, E.; Piskun, A. A.; Pocheptsov, T.; Pontecorvo, G.; Rodionov, V.; Rogov, Y.; Salmin, R.; Samartsev, A.; Sapozhnikov, M. G.; Shabratova, G.; Skachkov, N. B.; Skachkova, A. N.; Strokovsky, E. A.; Suleimanov, M.; Teshev, R.; Tokmenin, V.; Uzhinsky, V.; Vodopianov, A.; Zaporozhets, S. A.; Zhuravlev, N. I.; Zorin, A. G.; Branford, D.; Glazier, D.; Watts, D.; Böhm, M.; Britting, A.; Eyrich, W.; Lehmann, A.; Pfaffinger, M.; Uhlig, F.; Dobbs, S.; Seth, K.; Tomaradze, A.; Xiao, T.; Bettoni, D.; Carassiti, V.; Cotta Ramusino, A.; Dalpiaz, P.; Drago, A.; Fioravanti, E.; Garzia, I.; Savrie, M.; Akishina, V.; Kisel, I.; Kozlov, G.; Pugach, M.; Zyzak, M.; Gianotti, P.; Guaraldo, C.; Lucherini, V.; Bersani, A.; Bracco, G.; Macri, M.; Parodi, R. F.; Biguenko, K.; Brinkmann, K.; Di Pietro, V.; Diehl, S.; Dormenev, V.; Drexler, P.; Düren, M.; Etzelmüller, E.; Galuska, M.; Gutz, E.; Hahn, C.; Hayrapetyan, A.; Kesselkaul, M.; Kühn, W.; Kuske, T.; Lange, J. S.; Liang, Y.; Metag, V.; Nanova, M.; Nazarenko, S.; Novotny, R.; Quagli, T.; Reiter, S.; Rieke, J.; Rosenbaum, C.; Schmidt, M.; Schnell, R.; Stenzel, H.; Thöring, U.; Ullrich, M.; Wagner, M. N.; Wasem, T.; Wohlfahrt, B.; Zaunick, H.; Ireland, D.; Rosner, G.; Seitz, B.; Deepak, P. N.; Kulkarni, A.; Apostolou, A.; Babai, M.; Kavatsyuk, M.; Lemmens, P. J.; Lindemulder, M.; Loehner, H.; Messchendorp, J.; Schakel, P.; Smit, H.; Tiemens, M.; van der Weele, J. C.; Veenstra, R.; Vejdani, S.; Dutta, K.; Kalita, K.; Kumar, A.; Roy, A.; Sohlbach, H.; Bai, M.; Bianchi, L.; Büscher, M.; Cao, L.; Cebulla, A.; Dosdall, R.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Herten, A.; Hu, Q.; Kemmerling, G.; Kleines, H.; Lehrach, A.; Nellen, R.; Ohm, H.; Orfanitski, S.; Prasuhn, D.; Prencipe, E.; Pütz, J.; Ritman, J.; Schadmand, S.; Sefzick, T.; Serdyuk, V.; Sterzenbach, G.; Stockmanns, T.; Wintz, P.; Wüstner, P.; Xu, H.; Zambanini, A.; Li, S.; Li, Z.; Sun, Z.; Xu, H.; Rigato, V.; Isaksson, L.; Achenbach, P.; Corell, O.; Denig, A.; Distler, M.; Hoek, M.; Karavdina, A.; Lauth, W.; Liu, Z.; Merkel, H.; Müller, U.; Pochodzalla, J.; Sanchez, S.; Schlimme, S.; Sfienti, C.; Thiel, M.; Ahmadi, H.; Ahmed, S.; Bleser, S.; Capozza, L.; Cardinali, M.; Dbeyssi, A.; Deiseroth, M.; Feldbauer, F.; Fritsch, M.; Fröhlich, B.; Jasinski, P.; Kang, D.; Khaneft, D.; Klasen, R.; Leithoff, H. H.; Lin, D.; Maas, F.; Maldaner, S.; Martínez, M.; Michel, M.; Mora Espí, M. C.; Morales Morales, C.; Motzko, C.; Nerling, F.; Noll, O.; Pflüger, S.; Pitka, A.; Rodríguez Piñeiro, D.; Sanchez-Lorente, A.; Steinen, M.; Valente, R.; Weber, T.; Zambrana, M.; Zimmermann, I.; Fedorov, A.; Korjik, M.; Missevitch, O.; Boukharov, A.; Malyshev, O.; Marishev, I.; Balanutsa, V.; Balanutsa, P.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Goryachev, V.; Chandratre, V.; Datar, V.; Dutta, D.; Jha, V.; Kumawat, H.; Mohanty, A. K.; Parmar, A.; Roy, B.; Sonika, G.; Fritzsch, C.; Grieser, S.; Hergemöller, A.; Hetz, B.; Hüsken, N.; Khoukaz, A.; Wessels, J. P.; Khosonthongkee, K.; Kobdaj, C.; Limphirat, A.; Srisawad, P.; Yan, Y.; Barnyakov, M.; Barnyakov, A. Yu.; Beloborodov, K.; Blinov, A. E.; Blinov, V. E.; Bobrovnikov, V. S.; Kononov, S.; Kravchenko, E. A.; Kuyanov, I. A.; Martin, K.; Onuchin, A. P.; Serednyakov, S.; Sokolov, A.; Tikhonov, Y.; Atomssa, E.; Kunne, R.; Marchand, D.; Ramstein, B.; van de Wiele, J.; Wang, Y.; Boca, G.; Costanza, S.; Genova, P.; Montagna, P.; Rotondi, A.; Abramov, V.; Belikov, N.; Bukreeva, S.; Davidenko, A.; Derevschikov, A.; Goncharenko, Y.; Grishin, V.; Kachanov, V.; Kormilitsin, V.; Levin, A.; Melnik, Y.; Minaev, N.; Mochalov, V.; Morozov, D.; Nogach, L.; Poslavskiy, S.; Ryazantsev, A.; Ryzhikov, S.; Semenov, P.; Shein, I.; Uzunian, A.; Vasiliev, A.; Yakutin, A.; Tomasi-Gustafsson, E.; Roy, U.; Yabsley, B.; Belostotski, S.; Gavrilov, G.; Izotov, A.; Manaenkov, S.; Miklukho, O.; Veretennikov, D.; Zhdanov, A.; Makonyi, K.; Preston, M.; Tegner, P.; Wölbing, D.; Bäck, T.; Cederwall, B.; Rai, A. K.; Godre, S.; Calvo, D.; Coli, S.; De Remigis, P.; Filippi, A.; Giraudo, G.; Lusso, S.; Mazza, G.; Mignone, M.; Rivetti, A.; Wheadon, R.; Balestra, F.; Iazzi, F.; Introzzi, R.; Lavagno, A.; Olave, J.; Amoroso, A.; Bussa, M. P.; Busso, L.; De Mori, F.; Destefanis, M.; Fava, L.; Ferrero, L.; Greco, M.; Hu, J.; Lavezzi, L.; Maggiora, M.; Maniscalco, G.; Marcello, S.; Sosio, S.; Spataro, S.; Birsa, R.; Bradamante, F.; Bressan, A.; Martin, A.; Calen, H.; Ikegami Andersson, W.; Johansson, T.; Kupsc, A.; Marciniewski, P.; Papenbrock, M.; Pettersson, J.; Schönning, K.; Wolke, M.; Galnander, B.; Diaz, J.; Pothodi Chackara, V.; Chlopik, A.; Kesik, G.; Melnychuk, D.; Slowinski, B.; Trzcinski, A.; Wojciechowski, M.; Wronka, S.; Zwieglinski, B.; Bühler, P.; Marton, J.; Steinschaden, D.; Suzuki, K.; Widmann, E.; Zmeskal, J.
2016-10-01
Simulation results for future measurements of electromagnetic proton form factors at overlinePANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel bar{p}p→ e+e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e. bar{p}p→ π+π-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
Turek, Marko; Spehner, Dominique; Müller, Sebastian; Richter, Klaus
2005-01-01
We present a semiclassical calculation of the generalized form factor Kab(tau) which characterizes the fluctuations of matrix elements of the operators a and b in the eigenbasis of the Hamiltonian of a chaotic system. Our approach is based on some recently developed techniques for the spectral form factor of systems with hyperbolic and ergodic underlying classical dynamics and f = 2 degrees of freedom, that allow us to go beyond the diagonal approximation. First we extend these techniques to systems with f > 2. Then we use these results to calculate Kab(tau). We show that the dependence on the rescaled time tau (time in units of the Heisenberg time) is universal for both the spectral and the generalized form factor. Furthermore, we derive a relation between Kab(tau) and the classical time-correlation function of the Weyl symbols of a and b.
High Precision Measurement of the Proton Elastic Form Factor Ratio at Low Q2
Xiaohui Zhan
2009-12-01
A high precision measurement of the proton elastic form factor ratio µpGEp/GMp in the range Q2 = 0.3–0.7 GeV2/c2 was performed using recoil polarimetry in Jefferson Lab Hall A. In this low Q2 range, previous data from LEDEX [5] along with many fits and calculations [2, 3, 4] indicate substantial deviations of the ratio from unity. In this new measurement, with 80% polarized electron beam for 24 days, we are able to achieve <1% statistical uncertainty. Preliminary results are a few percent lower than expected from previous world data and fits, indicating a smaller GEp at this region. Beyond the intrinsic interest in nucleon structure, the improved form factor measurements also have implications for DVCS, determinations of the proton Zemach radius and strangeness form factors through parity violation experiments.
Gort, Laura; de Olano, Natalia; Macías-Vidal, Judit; Coll, M A Josep
2012-09-10
The GM2 gangliosidoses are autosomal recessive lysosomal storage diseases caused by a deficiency of the β-hexosaminidase A enzyme. This enzyme is composed of two polypeptide chains designated the α- and β- subunits and it interacts with the GM2 activator protein. The HEXA and HEXB genes encode the α-subunit and the β-subunit, respectively. Mutations in these genes are causative of Tay-Sachs disease (HEXA) and Sandhoff disease (HEXB). We analyzed the complete HEXA gene in 34 Spanish patients with Tay-Sachs disease and the HEXB gene in 14 Spanish patients with Sandhoff disease. We identified 27 different mutations, 14 of which were novel, in the HEXA gene and 14 different mutations, 8 of which unreported until now, in the HEXB gene, and we attempted to correlate these mutations with the clinical presentation of the patients. We found a high frequency of c.459+5G>A (IVS4+5G>A) mutation in HEXA affected patients, 22 of 68 alleles, which represent the 32.4%. This is the highest percentage found of this mutation in a population. All patients homozygous for mutation c.459+5G>A presented with the infantile form of the disease and, as previously reported, patients carrying mutation p.R178H in at least one of the alleles presented with a milder form. In HEXB affected patients, the novel deletion c.171delG accounts for 21.4% of the mutant alleles (6/28). All patients with this deletion showed the infantile form of the disease. The Spanish GM2 gangliosidoses affected patients show a great mutational heterogeneity as seen in other inherited lisosomal diseases in this country.
Master Integrals for Fermionic Contributions to Massless Three-Loop Form Factors
Heinrich, G.; Huber, T.; Maitre, D.
2007-11-28
In this letter we continue the calculation of master integrals for massless three-loop form factors by giving analytical results for those diagrams which are relevant for the fermionic contributions proportional to N{sub F}{sup 2}, N{sub F} {center_dot} N, and N{sub F}/N. Working in dimensional regularization, we express one of the diagrams in a closed form which is exact to all orders in {epsilon}, containing {Lambda}-functions and hypergeometric functions of unit argument. In all other cases we derive multiple Mellin-Barnes representations from which the coefficients of the Laurent expansion in {epsilon} are extracted in an analytical form. To obtain the finite part of the three-loop quark and gluon form factors, all coefficients through transcendentality six in the Riemann {zeta}-function have to be included.
Constraints on the ωπ Form Factor from Analyticity and Unitarity
NASA Astrophysics Data System (ADS)
Ananthanarayan, B.; Caprini, Irinel; Kubis, Bastian
Form factors are important low-energy quantities and an accurate knowledge of these sheds light on the strong interactions. A variety of methods based on general principles have been developed to use information known in different energy regimes to constrain them in regions where experimental information needs to be tested precisely. Here we review our recent work on the electromagnetic ωπ form factor in a model-independent framework known as the method of unitarity bounds, partly motivated by the discre-pancies noted recently between the theoretical calculations of the form factor based on dispersion relations and certain experimental data measured from the decay ω → π0γ*. We have applied a modified dispersive formalism, which uses as input the discontinuity of the ωπ form factor calculated by unitarity below the ωπ threshold and an integral constraint on the square of its modulus above this threshold. The latter constraint was obtained by exploiting unitarity and the positivity of the spectral function of a QCD correlator, computed on the spacelike axis by operator product expansion and perturbative QCD. An alternative constraint is obtained by using data available at higher energies for evaluating an integral of the modulus squared with a suitable weight function. From these conditions we derived upper and lower bounds on the modulus of the ωπ form factor in the region below the ωπ threshold. The results confirm the existence of a disagreement between dispersion theory and experimental data on the ωπ form factor around 0:6 GeV, including those from NA60 published in 2016.
NASA Astrophysics Data System (ADS)
Bianconi, Andrea; Tomasi-Gustafsson, Egle
2017-01-01
As is well known, spacelike proton form factors expressed in the Breit frame may be interpreted as the Fourier transform of static space distributions of electric charge and current. In particular, the electric form factor is simply the Fourier transform of the charge distribution F (q ) =∫ei q ⃗.r ⃗ρ (r ) d3r . We do not have an intuitive interpretation of the same level of simplicity for the proton timelike form factor appearing in the reactions e+e-↔p ¯p . However, one may suggest that, in the center-of-mass frame, where qμxμ=q t , a timelike electric form factor is the Fourier transform F (q ) =∫ei q tR (t ) d t of a function R (t ) expressing how the electric properties of the forming (or annihilating) proton-antiproton pair evolve in time. Here we analyze in depth this idea and show that the functions ρ (r ) and R (t ) can be formally written as the time and space integrals of a unique correlation function depending on both time and space coordinates.
On the ππ continuum in the nucleon form factors and the proton radius puzzle
NASA Astrophysics Data System (ADS)
Hoferichter, M.; Kubis, B.; Ruiz de Elvira, J.; Hammer, H.-W.; Meißner, U.-G.
2016-11-01
We present an improved determination of the ππ continuum contribution to the isovector spectral functions of the nucleon electromagnetic form factors. Our analysis includes the most up-to-date results for the ππ→bar{N} N partial waves extracted from Roy-Steiner equations, consistent input for the pion vector form factor, and a thorough discussion of isospin-violating effects and uncertainty estimates. As an application, we consider the ππ contribution to the isovector electric and magnetic radii by means of sum rules, which, in combination with the accurately known neutron electric radius, are found to slightly prefer a small proton charge radius.
Matching lightcone and anomaly-sum-rule predictions for the pion-photon transition form factor
NASA Astrophysics Data System (ADS)
Oganesian, A. G.; Pimikov, A. V.; Stefanis, N. G.; Teryaev, O. V.
2016-03-01
The pion-photon transition form factor is studied by employing two types of sum rules: light cone sum rules (LCSR) and anomaly sum rules (ASR). By comparing the predictions for the pion-photon transition form factor, obtained from these two approaches, the applicability limit of the LCSRs at low momenta is determined. Reciprocally, the ASR threshold dependence on the momentum was extracted using our LCSR-based method in combination with two different types of pion distribution amplitudes and found that at higher Q2 it approaches a constant.
Generalized heavy-to-light form factors in light-cone sum rules
NASA Astrophysics Data System (ADS)
Meißner, Ulf-G.; Wang, Wei
2014-03-01
We study the form factors for a heavy meson into the S-wave Kπ/ππ system with an invariant mass below 1 GeV. The mesonic final state interactions are described in terms of the scalar form factors, which are obtained from unitarized chiral perturbation theory. Employing generalized light-cone distribution amplitudes, we compute the heavy-to-light transition using light-cone sum rules. Our approach simultaneously respects constraints from analyticity and unitarity, and also takes advantage of the power expansion in the 1/mb and the strong coupling constant.
Computation of form factors in massless QCD with finite master integrals
NASA Astrophysics Data System (ADS)
von Manteuffel, Andreas; Panzer, Erik; Schabinger, Robert M.
2016-06-01
We present the bare one-, two-, and three-loop form factors in massless quantum chromodynamics as linear combinations of finite master integrals. Using symbolic integration, we compute their ɛ expansions and thereby reproduce all known results with an independent method. Remarkably, in our finite basis, only integrals with a less-than-maximal number of propagators contribute to the cusp anomalous dimensions. We report on indications of this phenomenon at four loops, including the result for a finite, irreducible, twelve-propagator form factor integral. Together with this article, we provide our automated software setup for the computation of finite master integrals.
JLab measurement of the 4He charge form factor at large momentum transfers.
Camsonne, A; Katramatou, A T; Olson, M; Sparveris, N; Acha, A; Allada, K; Anderson, B D; Arrington, J; Baldwin, A; Chen, J-P; Choi, S; Chudakov, E; Cisbani, E; Craver, B; Decowski, P; Dutta, C; Folts, E; Frullani, S; Garibaldi, F; Gilman, R; Gomez, J; Hahn, B; Hansen, J-O; Higinbotham, D W; Holmstrom, T; Huang, J; Iodice, M; Jiang, X; Kelleher, A; Khrosinkova, E; Kievsky, A; Kuchina, E; Kumbartzki, G; Lee, B; LeRose, J J; Lindgren, R A; Lott, G; Lu, H; Marcucci, L E; Margaziotis, D J; Markowitz, P; Marrone, S; Meekins, D; Meziani, Z-E; Michaels, R; Moffit, B; Norum, B; Petratos, G G; Puckett, A; Qian, X; Rondon, O; Saha, A; Sawatzky, B; Segal, J; Shabestari, M; Shahinyan, A; Solvignon, P; Subedi, R R; Suleiman, R; Sulkosky, V; Urciuoli, G M; Viviani, M; Wang, Y; Wojtsekhowski, B B; Yan, X; Yao, H; Zhang, W-M; Zheng, X; Zhu, L
2014-04-04
The charge form factor of 4He has been extracted in the range 29 fm(-2) ≤ Q2 ≤ 77 fm(-2) from elastic electron scattering, detecting 4He recoil nuclei and electrons in coincidence with the high resolution spectrometers of the Hall A Facility of Jefferson Lab. The measurements have uncovered a second diffraction minimum for the form factor, which was predicted in the Q2 range of this experiment. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the few-body problem.
Light Cone Sum Rules for gamma*N ->Delta Transition Form Factors
V.M. Braun; A. Lenz; G. Peters; A. Radyushkin
2006-02-01
A theoretical framework is suggested for the calculation of {gamma}* N {yields} {Delta} transition form factors using the light-cone sum rule approach. Leading-order sum rules are derived and compared with the existing experimental data. We find that the transition form factors in a several GeV region are dominated by the ''soft'' contributions that can be thought of as overlap integrals of the valence components of the hadron wave functions. The ''minus'' components of the quark fields contribute significantly to the result, which can be reinterpreted as large contributions of the quark orbital angular momentum.
Charge form factors of two-neutron halo nuclei in halo EFT
NASA Astrophysics Data System (ADS)
Hagen, P.; Hammer, H.-W.; Platter, L.
2013-09-01
We set up a formalism to calculate the charge form factors of two-neutron halo nuclei with S -wave neutron-core interactions in the framework of the halo effective field theory. The method is applied to some known and suspected halo nuclei. In particular, we calculate the form factors and charge radii relative to the core to leading order in the halo EFT and compare to experiments where they are available. Moreover, we investigate the general dependence of the charge radius on the core mass and the one- and two-neutron separation energies.
A form-factor method for determining the structure of distorted stars
NASA Technical Reports Server (NTRS)
Wolfe, R. H., Jr.; Kern, J. W.
1979-01-01
The equilibrium equations of a uniformly rotating and tidally distorted star are reduced to the same form as for a spherical star except for the inclusion of two form factors. One factor, expressing the buoyancy effects of centrifugal force, is determined directly from the integrated structure variables. The other factor, expressing the deviation from spherical shape, is shown to be relatively insensitive to errors in the assumed shape, so that accurate solutions are obtained in spite of the use of an a priori shape. The method is employed by adding computations for the factors to an existing spherical model program. Upper Main Sequence models determined by this method compare closely with results from the double approximation method even for critical rotation and tidal distortion.
X-ray coherent scattering form factors of tissues, water and plastics using energy dispersion
NASA Astrophysics Data System (ADS)
King, B. W.; Landheer, K. A.; Johns, P. C.
2011-07-01
A key requirement for the development of the field of medical x-ray scatter imaging is accurate characterization of the differential scattering cross sections of tissues and phantom materials. The coherent x-ray scattering form factors of five tissues (fat, muscle, liver, kidney, and bone) obtained from butcher shops, four plastics (polyethylene, polystyrene, lexan (polycarbonate), nylon), and water have been measured using an energy-dispersive technique. The energy-dispersive technique has several improvements over traditional diffractometer measurements. Most notably, the form factor is measured on an absolute scale with no need for scaling factors. Form factors are reported in terms of the quantity x = λ-1sin (θ/2) over the range 0.363-9.25 nm-1. The coherent form factors of muscle, liver, and kidney resemble those of water, while fat has a narrower peak at lower x, and bone is more structured. The linear attenuation coefficients of the ten materials have also been measured over the range 30-110 keV and parameterized using the dual-material approach with the basis functions being the linear attenuation coefficients of polymethylmethacrylate and aluminum.
Lecavalier, Luc; Aman, Michael G; Hammer, David; Stoica, Wendy; Mathews, Gregory L
2004-12-01
The Nisonger Child Behavior Rating Form (NCBRF) is a behavior rating scale designed for children and adolescents with mental retardation. The purpose of this study was to explore the psychometric properties of the NCBRF in a sample of 330 children and adolescents with autism spectrum disorders (ASDs). Parent and teacher ratings were independently submitted to both exploratory and confirmatory factor analysis. As reported with the original validation study, parent and teacher versions shared similar but somewhat different factor structures. Social competence items showed more similarity with the original solutions than did problem behavior items. Problem behavior items were distributed into a somewhat simpler five-factor solution for both rating forms. Self-injurious and stereotypic items loaded on two distinct subscales for the teacher form, but not on the parent form. Factor loadings and internal consistencies were generally lower than those reported for the original versions but still within the acceptable range. Confirmatory factor analyses indicated good fits for the social competence items and acceptable fits for the problem behavior items. Overall, results supported the construct validity of the NCBRF in children and adolescents with ASDs.
Clean measurements of the nucleon axial-vector and free-neutron magnetic form factors
Deur, A.
2013-11-07
We discuss the feasibility of a weak charged current experiment using a low energy electron beam. A first goal is to measure the Q{sup 2} dependence of the axial-vector form factor g{sub a}(Q{sup 2}). It can be measured model-independently and as robustly as for electromagnetic form factors from typical electron scattering experiments, in contrast to the methods used so far to measure g{sub a}(Q{sup 2}). If g{sub a}(Q{sup 2}) follows a dipole form, the axial mass can be extracted with a better accuracy than the world data altogether. The most important detection equipment would be a segmented neutron detector with good momentum and angular resolution that is symmetric about the beam direction, and covers a moderate angular range. A high intensity beam (100 uA) is necessary. Beam polarization is highly desirable as it provides a clean measurement of the backgrounds. Beam energies between 70 and 110 MeV are ideal. This range would provide a Q{sup 2} mapping of g{sub a} between 0.01 form factor G{sub M}{sup n}. The experiment employs the usual techniques of electron-nucleon scattering and presents no special difficulty. Higher energy extensions are possible. They could yield measurements of g{sub a}(Q{sup 2}) up to Q{sup 2}=3 GeV{sup 2} and the possibility to access other form factors, such as the almost unknown pseudoscalar form factor g{sub P}. However, the experiments become much more challenging as soon as beam energies pass the pion production threshold.
Nucleon form factors with 2+1 flavor dynamical domain-wall fermions
Takeshi Yamazaki; Aoki, Yasumichi; Blum, Tom; Lin, Huey-Wen; Ohta, Shigemi; Sasaki, Shoichi; Tweedie, Robert; Zanotti, James
2009-06-01
We report our numerical lattice QCD calculations of the isovector nucleon form factors for the vector and axialvector currents: the vector, induced tensor, axialvector, and induced pseudoscalar form factors. The calculation is carried out with the gauge configurations generated with N{sub f} = 2+1 dynamical domain wall fermions and Iwasaki gauge actions at {beta} = 2.13, corresponding to a cutoff a{sup -1} = 1.73 GeV, and a spatial volume of (2.7 fm){sup 3}. The up and down quark masses are varied so the pion mass lies between 0.33 and 0.67 GeV while the strange quark mass is about 12% heavier than the physical one. We calculate the form factors in the range of momentum transfers, 0.2 < q{sup 2} < 0.75 GeV{sup 2}. The vector and induced tensor form factors are well described by the conventional dipole forms and result in significant underestimation of the Dirac and Pauli mean-squared radii and the anomalous magnetic moment compared to the respective experimental values. We show that the axial-vector form factor is significantly affected by the finite spatial volume of the lattice. In particular in the axial charge, g{sub A}/g{sub V}, the finite volume effect scales with a single dimensionless quantity, m{sub {pi}}L, the product of the calculated pion mass and the spatial lattice extent. Our results indicate that for this quantity, m{sub {pi}} L > 6 is required to ensure that finite volume effects are below 1%.
Does Repair of a Hill-Sachs Defect Increase Stability at the Glenohumeral Joint?
Bakshi, Neil K.; Jolly, John T.; Debski, Richard E.; Sekiya, Jon K.
2016-01-01
Background: The effect of osteoallograft repair of a Hill-Sachs lesion and the effect of allograft fit on glenohumeral translations in response to applied force are poorly understood. Purpose: To compare the impact of a 25% Hill-Sachs lesion, a perfect osteoallograft repair (PAR) of a 25% Hill-Sachs lesion, and an “imperfect” osteoallograft repair (IAR) of a 25% Hill-Sachs lesion on glenohumeral translations in response to a compressive load and either an anterior or posterior load in 3 clinically relevant arm positions. Study Design: Controlled laboratory study. Methods: A robotic/universal force-moment sensor testing system was used to apply joint compression (22 N) and an anterior or posterior load (44 N) to cadaveric shoulders (n = 9) with the skin and deltoid removed (intact) at 3 glenohumeral joint positions (abduction/external rotation): 0°/0°, 30°/30°, and 60°/60°. The 25% bony defect state, PAR state, and IAR state were created and the loading protocol was performed. Translational motion was measured in each position for each shoulder state. A nonparametric repeated-measures Friedman test with a Wilcoxon signed-rank post hoc test was performed to compare the biomechanical parameters (P < .05). Results: Compared with the defect shoulder, the PAR shoulder had significantly less anterior translation with an anterior load in the 0°/0° (15.3 ± 8.2 vs 16.6 ± 9.0 mm, P = .008) and 30°/30° (13.6 ± 7.1 vs 14.2 ± 7.0 mm, P = .021) positions. Compared with IAR, the PAR shoulder had significantly less anterior translation with an anterior load in the 0°/0° (15.3 ± 8.2 vs 16.6 ± 9.0 mm, P = .008) and 30°/30° (13.6 ± 7.1 vs 14.4 ± 7.1 mm, P = .011) positions, and the defect shoulder had significantly less anterior translation with an anterior load in the 30°/30° (14.2 ± 7.0 vs 14.4 ± 7.0 mm, P = .038) position. Conclusion: PAR resulted in the least translational motion at the glenohumeral joint. The defect shoulder had significantly less
Parnes, Nata; Carey, Paul A.; Schumacher, Christopher; Price, Mark D.
2015-01-01
Hill-Sachs lesions are a common finding in patients with glenohumeral instability. There have been numerous methods described for addressing Hill-Sachs deformity. One popular method includes transferring a portion of the infraspinatus muscle into the posterior-superior defect (remplissage) to prevent the lesion from engaging and the resultant instability. We present a method of arthroscopic remplissage whereby the lesion is addressed through transtendinous insertion of arthroscopic anchors. Once 2 anchors have been inserted, 1 limb of each suture is tied to the other anchor, the so-called pulley repair technique. This can be performed either under direct visualization in the subacromial space or blindly while the surgeon is viewing from the articular side. Once both limbs have been tied, the infraspinatus tendon nicely spans the defect, and there has been minimal morbidity to the tendon itself. We have found this method to be useful for addressing a large Hill-Sachs deformity. PMID:26759767
Sun, Kyung Ho; Kim, Young-Cheol; Kim, Jae Eun
2014-10-15
While environmental vibrations are usually in the range of a few hundred Hertz, small-form-factor piezoelectric vibration energy harvesters will have higher resonant frequencies due to the structural size effect. To address this issue, we propose a resonant frequency-down conversion based on the theory of dynamic vibration absorber for the design of a small-form-factor piezoelectric vibration energy harvester. The proposed energy harvester consists of two frequency-tuned elastic components for lowering the first resonant frequency of an integrated system but is so configured that an energy harvesting beam component is inverted with respect to the other supporting beam component for a small form factor. Furthermore, in order to change the unwanted modal characteristic of small separation of resonant frequencies, as is the case with an inverted configuration, a proof mass on the supporting beam component is slightly shifted toward a second proof mass on the tip of the energy harvesting beam component. The proposed small-form-factor design capability was experimentally verified using a fabricated prototype with an occupation volume of 20 × 39 × 6.9 mm{sup 3}, which was designed for a target frequency of as low as 100 Hz.
The charge form factor of pseudoscalar mesons in a relativistic constituent quark model
Cardarelli, F.; Pace, E.; Grach, I.L.
1994-04-01
The charge form factor of pseudoscalar mesons has been investigated in the light-cone formalism, up to Q{sup 2} relevant to CEBAF energies. The consequences of adopting the meson wave functions generated through the Godfrey-Isgur q{bar q} potential, which reproduces the mass spectra, are discussed.
ERIC Educational Resources Information Center
Eksi, Füsun
2016-01-01
This study intends to examine the psychometric properties of the Turkish version of the short form of the Five-Factor Narcissism Inventory (FFNI-SF). The study group consists of a total of 526 university students (54% were female) whose ages range from 18 to 32. In the translational equivalence study made over a two-week interval, the FFNI-SF…
Rimal, Dipak
2014-05-01
The electromagnetic form factors are the most fundamental observables that encode information about the internal structure of the nucleon. This dissertation explored dependence of R on kinematic variables such as squared four-momentum transfer (Q^{2}) and the virtual photon polarization parameter (ε).
Studies of Nucleon Form Factors with 12 GeV CEBAF and SuperBigBite
Hansen, Jens-Ole
2012-04-01
The elastic electromagnetic form factors are among the most fundamental quantities that describe the ground-state structure of the proton and neutron. Precision data of the form factors over a wide kinematical range provide a powerful test of current theories of hadron structure. A number of experiments aiming to measure the electric and magnetic elastic form factors of the neutron, G{sub E}{sup n} and G{sub M}{sup n}, and proton, G{sub E}{sup p}, at very high momentum transfer, up to the range of Q{sup 2} = 10-14 (GeV/c){sup 2}, are planned to be carried out with the future 11 GeV electron beam of the upgraded CEBAF at Jefferson Lab. These experiments will determine the nucleon form factors with unprecedented precision to Q{sup 2}-values up to three times higher than those of existing data. We review the approved proposals and the conceptual design of a new spectrometer, SuperBigBite, that will be used in these and other future experiments at Jefferson Lab.
NASA Astrophysics Data System (ADS)
Sun, Kyung Ho; Kim, Young-Cheol; Kim, Jae Eun
2014-10-01
While environmental vibrations are usually in the range of a few hundred Hertz, small-form-factor piezoelectric vibration energy harvesters will have higher resonant frequencies due to the structural size effect. To address this issue, we propose a resonant frequency-down conversion based on the theory of dynamic vibration absorber for the design of a small-form-factor piezoelectric vibration energy harvester. The proposed energy harvester consists of two frequency-tuned elastic components for lowering the first resonant frequency of an integrated system but is so configured that an energy harvesting beam component is inverted with respect to the other supporting beam component for a small form factor. Furthermore, in order to change the unwanted modal characteristic of small separation of resonant frequencies, as is the case with an inverted configuration, a proof mass on the supporting beam component is slightly shifted toward a second proof mass on the tip of the energy harvesting beam component. The proposed small-form-factor design capability was experimentally verified using a fabricated prototype with an occupation volume of 20 × 39 × 6.9 mm3, which was designed for a target frequency of as low as 100 Hz.
Measurement of the ratio of the proton's electric to magnetic form factors by recoil polarization
Mark K. Jones; Hall A Collaboration
1999-03-01
The longitudinal and transverse polarizations of the outgoing proton were measured for the reaction {sup 1}H(e,e' p) at four-momentum transfer squared of 0.5 to 3.5 GeV{sup 2}. The ratio of the electric to magnetic form factors of the proton is proportional to the ratio of the transverse to longitudinal polarizations.
Elastic Form Factors of 3,4He up to Large Q2
Kees De Jager
2007-09-10
Elastic electron scattering off $^3$He and $^4$He has recently been studied at forward and backward scattering angles in Hall A at JLab. The results will provide accurate data on the elastic form factors, charge and magnetic for $^3$He and charge only for $^4$He, up to squared momentum transfer $Q^2$-values of 3.2 GeV$^2$.
Measuring the axial form factor of {sup 3}He using weak capture of polarized electrons
Dutta, D.
2013-11-07
A low energy, high intensity polarized electron beam could enable the extraction of the A=3 weak axial form factors F{sub A} using the reaction →e+{sup 3}He→{sup 3}H+ν. These form factors have never been measured before. We discuss the feasibility of such an experiment using a small toroidal magnet and a radial low energy recoil detector to tag the recoil tritons. A moderately high intensity polarized electron beam (>500 μA) with beam energies between 50 - 150 MeV is necessary for the cross section measurement and to provides a free clean measurement of the background. Moreover, in addition to the cross section, by measuring the electron spin and recoil triton correlation coefficient it may be possible to search for second class currents and to extract the ratio of the axial to the vector form factor of the nucleon. Such novel electron scattering based measurements would have a completely different set of systematic uncertainties compared to polarized neutron beta decay, neutrino scattering and muon capture experiments which are typically used to extract the weak form-factors.
New Precision Limit on the Strange Vector Form Factors of the Proton
Ahmed, Z.; Allada, K.; Aniol, K. A.; Armstrong, D. S.; Arrington, J.; Baturin, P.; Bellini, V.; Benesch, J.; Beminiwattha, R.; Benmokhtar, F.; Canan, M.; Camsonne, A.; Cates, G. D.; Chen, J. -P.; Chudakov, E.; Cisbani, E.; Dalton, M. M.; de Jager, C. W.; De Leo, R.; Deconinck, W.; Decowski, P.; Deng, X.; Deur, A.; Dutta, C.; Franklin, G. B.; Friend, M.; Frullani, S.; Garibaldi, F.; Giusa, A.; Glamazdin, A.; Golge, S.; Grimm, K.; Hansen, O.; Higinbotham, D. W.; Holmes, R.; Holmstrom, T.; Huang, J.; Huang, M.; Hyde, C. E.; Jen, C. M.; Jin, G.; Jones, D.; Kang, H.; King, P.; Kowalski, S.; Kumar, K. S.; Lee, J. H.; LeRose, J. J.; Liyanage, N.; Long, E.; McNulty, D.; Margaziotis, D.; Meddi, F.; Meekins, D. G.; Mercado, L.; Meziani, Z. -E.; Michaels, R.; Muñoz-Camacho, C.; Mihovilovic, M.; Muangma, N.; Myers, K. E.; Nanda, S.; Narayan, A.; Nelyubin, V.; Nuruzzaman, None; Oh, Y.; Pan, K.; Parno, D.; Paschke, K. D.; Phillips, S. K.; Qian, X.; Qiang, Y.; Quinn, B.; Rakhman, A.; Reimer, P. E.; Rider, K.; Riordan, S.; Roche, J.; Rubin, J.; Russo, G.; Saenboonruang, K.; Saha, A.; Sawatzky, B.; Silwal, R.; Sirca, S.; Souder, P. A.; Sperduto, M.; Subedi, R.; Suleiman, R.; Sulkosky, V.; Sutera, C. M.; Tobias, W. A.; Urciuoli, G. M.; Waidyawansa, B.; Wang, D.; Wexler, J.; Wilson, R.; Wojtsekhowski, B.; Zhan, X.; Yan, X.; Yao, H.; Ye, L.; Zhao, B.; Zheng, X.
2012-03-01
The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q^{2} = 0.624 GeV^{2} and beam energy E_{b} = 3.48 GeV to be A_{PV} = -23.80 ± 0.78 (stat) ± 0.36 (syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G_{E}^{s} + 0.517 G_{M}^{s} = 0.003 ± 0.010 (stat) ± 0.004 (syst) ± 0.009 (ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.
Strangeness Vector and Axial-Vector Form Factors of the Nucleon
NASA Astrophysics Data System (ADS)
Pate, Stephen; Trujillo, Dennis
2014-03-01
A revised global fit of electroweak ep and vp elastic scattering data has been performed, with the goal of determining the strange quark contribution to the vector and axial-vector form factors of the nucleon in the momentum-transfer range 0 < Q2 < 1 GeV2. The two vector (electric and magnetic) form factors GsE(Q2) and GsM(Q2) are strongly constrained by ep elastic scattering data, while the major source of information on the axial-vector form factor GsA(Q2) is vp scattering data. Combining the two kinds of data into a single global fit makes possible additional precision in the determination of these form factors, and provides a unique way to determine the strange quark contribution to the nucleon spin, ΔS , independently of leptonic deep-inelastic scattering. The fit makes use of data from the BNL-E734, SAMPLE, HAPPEx, G0, and PVA4 experiments; we will also compare the result of the fit with recent data from MiniBooNE, and anticipate how this fit can be improved when new data from MicroBooNE become available.
New Precision Limit on the Strange Vector Form Factors of the Proton
Ahmed, Z.; Allada, K.; Aniol, K. A.; ...
2012-03-01
The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624 GeV2 and beam energy Eb = 3.48 GeV to be APV = -23.80 ± 0.78 (stat) ± 0.36 (syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors GEs + 0.517 GMs = 0.003 ± 0.010 (stat) ± 0.004 (syst) ± 0.009 (ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections.more » With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.« less
Strangeness Vector and Axial-Vector Form Factors of the Nucleon
NASA Astrophysics Data System (ADS)
Trujillo, Dennis; Pate, Stephen
2013-04-01
A revised global fit of electroweak ep and νp elastic scattering data has been performed, with the goal of determining the strange quark contribution to the vector and axial-vector form factors of the nucleon in the momentum-transfer range 0form factors GE^s(Q^2) and GM^s(Q^2) are strongly constrained by ep elastic scattering data, while the major source of information on the axial-vector form factor GA^s(Q^2) is νp scattering data. Combining the two kinds of data into a single global fit makes possible additional precision in the determination of these form factors. The fit makes use of data from the BNL-E734, SAMPLE, HAPPEx, G0, and PVA4 experiments; we will also compare the result of the fit with recent data from MiniBooNE, and anticipate how this fit can be improved when new data from MicroBooNE become available.
Electromagnetic Transition Form Factor of the η meson with WASA-at-COSY
NASA Astrophysics Data System (ADS)
Goswami, A.
2016-11-01
In this work we present a study of the Dalitz decay η → γe+e-. The aim of this work is to measure the transition form factor of the η meson. The transition form factor of the η meson describes the electromagnetic structure of the meson. The study of the Dalitz decay helps to calculate the transition form factor of the η meson. When a particle is point-like it's decay rate can be calculated within QED. However, the complex structure of the meson modifies its decay rate. The transition form factor is determined by comparing the lepton-antilepton invariant mass distribution with QED. For this study data on proton-proton reaction at a beam energy of 1.4 GeV has been collected with WASA-at-COSY detector at Forschungszentrum Juelich, Germany. In the higher invariant mass region recent theoretical calculations slightly deviate from the fit to the data. We expect better results in the higher invariant mass region than previous measurements. The preliminary results of the analysis will be presented.
Bound state structure and electromagnetic form factor beyond the ladder approximation
NASA Astrophysics Data System (ADS)
Gigante, V.; Nogueira, J. H. Alvarenga; Ydrefors, E.; Gutierrez, C.; Karmanov, V. A.; Frederico, T.
2017-03-01
We investigate the response of the bound state structure of a two-boson system, within a Yukawa model with a scalar boson exchange, to the inclusion of the cross-ladder contribution to the ladder kernel of the Bethe-Salpeter equation. The equation is solved by means of the Nakanishi integral representation and light-front projection. The valence light-front wave function and electromagnetic form factor, considering both ladder and ladder plus cross-ladder kernels, are studied in detail. Their asymptotic forms are found to be quite independent of the inclusion of the cross-ladder kernel, for a given binding energy. The asymptotic decrease of form factor agrees with the counting rules. This analysis can be generalized to fermionic systems, with a wide application in the study of the meson structure.
Mechanism of interrupted saccades in patients with late-onset Tay-Sachs disease.
Optican, Lance M; Rucker, Janet C; Keller, Edward L; Leigh, R John
2008-01-01
In late-onset Tay-Sachs disease (LOTS), saccades are interrupted by one or more transient decelerations. Some saccades reaccelerate and continue on before eye velocity reaches zero, even in darkness. Intervals between successive decelerations are not regularly spaced. Peak decelerations of horizontal and vertical components of oblique saccades in LOTS is more synchronous than those in control subjects. We hypothesize that these decelerations are caused by dysregulation of the fastigial nuclei (FN) of the cerebellum, which fire brain stem inhibitory burst neurons (IBNs).
Detectability of a phantom-like braneworld model with the integrated Sachs-Wolfe effect
Giannantonio, Tommaso; Song, Yong-Seon; Koyama, Kazuya
2008-08-15
We study a braneworld model in which a phantom-like behavior occurs with only cold dark matter and a cosmological constant, due to a large distance modification of gravity. With the addition of curvature, the geometrical tests are not strict enough to rule out models in which gravity is modified significantly on large scales. We show that this degeneracy in the parameter space is broken by the structure formation tests, such as the integrated Sachs-Wolfe effect, which can probe general relativity on large scales.
Induced drag ideal efficiency factor of arbitrary lateral-vertical wing forms
NASA Technical Reports Server (NTRS)
Deyoung, J.
1980-01-01
A relatively simple equation is presented for estimating the induced drag ideal efficiency factor e for arbitrary cross sectional wing forms. This equation is based on eight basic but varied wing configurations which have exact solutions. The e function which relates the basic wings is developed statistically and is a continuous function of configuration geometry. The basic wing configurations include boxwings shaped as a rectangle, ellipse, and diamond; the V-wing; end-plate wing; 90 degree cruciform; circle dumbbell; and biplane. Example applications of the e equations are made to many wing forms such as wings with struts which form partial span rectangle dumbbell wings; bowtie, cruciform, winglet, and fan wings; and multiwings. Derivations are presented in the appendices of exact closed form solutions found of e for the V-wing and 90 degree cruciform wing and for an asymptotic solution for multiwings.
Form factors of descendant operators: reduction to perturbed M (2 , 2 s + 1) models
NASA Astrophysics Data System (ADS)
Lashkevich, Michael; Pugai, Yaroslav
2015-04-01
In the framework of the algebraic approach to form factors in two-dimensional integrable models of quantum field theory we consider the reduction of the sine-Gordon model to the Φ13-perturbation of minimal conformal models of the M (2 , 2 s + 1) series. We find in an algebraic form the condition of compatibility of local operators with the reduction. We propose a construction that make it possible to obtain reduction compatible local operators in terms of screening currents. As an application we obtain exact multiparticle form factors for the compatible with the reduction conserved currents T ±2 k , Θ±(2 k-2), which correspond to the spin ±(2 k - 1) integrals of motion, for any positive integer k. Furthermore, we obtain all form factors of the operators T 2 k T -2 l , which generalize the famous operator. The construction is analytic in the s parameter and, therefore, makes sense in the sine-Gordon theory.
Rpf Proteins Are the Factors of Reactivation of the Dormant Forms of Actinobacteria.
Nikitushkin, V D; Demina, G R; Kaprelyants, A S
2016-12-01
As the response to unfavorable growth conditions, nonsporulating mycobacteria transform into the dormant state with the concomitant formation of the specialized dormant forms characterized by low metabolic activity and resistance to antibiotics. Such dormant cells can be reactivated under the influence of several factors including proteins of Rpf (Resuscitation promoting factor) family, which possess peptidoglycan hydrolase activity and were considered to belong to the group of the autocrine growth factors of the bacteria. Remarkable interest toward Rpf family is determined by its participation in resuscitation of the dormant forms of Mycobacterium tuberculosis, what in turn is the key element in resuscitation of the latent tuberculosis - an infectious disease that affects one third of the World's population. Experiments with Rpf mutant forms and with strains deleted in these proteins revealed a relationship between the enzymatic activity of this protein and its ability to resuscitate mycobacteria both in vitro and in vivo. This review discusses possible mechanisms of Rpf action including those related to possible participation of the products of mycobacterial Rpf-mediated cell wall hydrolysis (muropeptides) as signaling molecules. The unique ability of Rpf proteins to resuscitate the dormant forms of mycobacteria and to stimulate their proliferation would allow these proteins to occupy their niche in medicine - in diagnostics and in creation of antituberculosis subunit vaccines.
The structure of light-front wavefunctions and constraints on hadronic form factors
S. J. Brodsky; J. R. Hiller; D. S. Hwang; V. A. Karmanov
2003-11-17
We study the analytic structure of light-front wave functions (LFWFs) and its consequences for hadron form factors using an explicitly Lorentz-invariant formulation of the front form. The normal to the light front is specified by a general null vector {omega}{sup {mu}}. The LFWFs with definite total angular momentum are eigenstates of a kinematic angular momentum operator and satisfy all Lorentz symmetries. They are analytic functions of the invariant mass squared of the constituents M{sub 0}{sup 2} = ({Sigma} k{sup {mu}}){sup 2} and the light-cone momentum fractions x{sub i} = k{sub i} {center_dot} {omega}/p {center_dot} {omega} multiplied by invariants constructed from the spin matrices, polarization vectors, and {omega}{sup {mu}}. These properties are illustrated using known nonperturbative eigensolutions of the Wick-Cutkosky model. We analyze the LFWFs introduced by Chung and Coester to describe static and low momentum properties of the nucleons. They correspond to the spin-locking of a quark with the spin of its parent nucleon, tog ether with a positive-energy projection constraint. These extra constraints lead to anomalous dependence of form factors on Q rather than Q{sup 2}. In contrast, the dependence of LFWFs on M{sub 0}{sup 2} implies that hadron form factors are analytic functions of Q{sup 2} in agreement with dispersion theory and perturbative QCD. We show that a model incorporating the leading-twist perturbative QCD prediction is consistent with recent data for the ratio of proton Pauli and Dirac form factors.
Development of a Short Form of the Five-Factor Narcissism Inventory: the FFNI-SF.
Sherman, Emily D; Miller, Joshua D; Few, Lauren R; Campbell, W Keith; Widiger, Thomas A; Crego, Cristina; Lynam, Donald R
2015-09-01
The Five-Factor Narcissism Inventory (FFNI; Glover, Miller, Lynam, Crego, & Widiger, 2012) is a 148-item self-report inventory of 15 traits designed to assess the basic elements of narcissism from the perspective of a 5-factor model. The FFNI assesses both vulnerable (i.e., cynicism/distrust, need for admiration, reactive anger, and shame) and grandiose (i.e., acclaim seeking, arrogance, authoritativeness, entitlement, exhibitionism, exploitativeness, grandiose fantasies, indifference, lack of empathy, manipulativeness, and thrill seeking) variants of narcissism. The present study reports the development of a short-form version of the FFNI in 4 diverse samples (i.e., 2 undergraduate samples, a sample recruited from MTurk, and a clinical community sample) using item response theory. The validity of the resultant 60-item short form was compared against the validity of the full scale in the 4 samples at both the subscale level and the level of the grandiose and vulnerable composites. Results indicated that the 15 subscales remain relatively reliable, possess a factor structure identical to the structure of the long-form scales, and manifest correlational profiles highly similar to those of the long-form scales in relation to a variety of criterion measures, including basic personality dimensions, other measures of grandiose and vulnerable narcissism, and indicators of externalizing and internalizing psychopathology. Grandiose and vulnerable composites also behave almost identically across the short- and long-form versions. It is concluded that the FFNI-Short Form (FFNI-SF) offers a well-articulated assessment of the basic traits comprising grandiose and vulnerable narcissism, particularly when assessment time is limited.
The Role of Nerve Growth Factor (NGF) and Its Precursor Forms in Oral Wound Healing
Schenck, Karl; Schreurs, Olav; Hayashi, Katsuhiko; Helgeland, Kristen
2017-01-01
Nerve growth factor (NGF) and its different precursor forms are secreted into human saliva by salivary glands and are also produced by an array of cells in the tissues of the oral cavity. The major forms of NGF in human saliva are forms of pro-nerve growth factor (pro-NGF) and not mature NGF. The NGF receptors tropomyosin-related kinase A (TrkA) and p75 neurotrophin receptor (p75NTR) are widely expressed on cells in the soft tissues of the human oral cavity, including keratinocytes, endothelial cells, fibroblasts and leukocytes, and in ductal and acinar cells of all types of salivary glands. In vitro models show that NGF can contribute at most stages in the oral wound healing process: restitution, cell survival, apoptosis, cellular proliferation, inflammation, angiogenesis and tissue remodeling. NGF may therefore take part in the effective wound healing in the oral cavity that occurs with little scarring. As pro-NGF forms appear to be the major form of NGF in human saliva, efforts should be made to study its function, specifically in the process of wound healing. In addition, animal and clinical studies should be initiated to examine if topical application of pro-NGF or NGF can be a therapy for chronic oral ulcerations and wounds. PMID:28208669
Forming factors of gas hydrate chimney in the Ulleung Basin, East Sea
NASA Astrophysics Data System (ADS)
Kang, Dong-Hyo; Chun, Jong-Hwa; Koo, Nam-Hyng; Kim, Won-Sik; Lee, Ho-Young; Lee, Joo-Yong
2016-04-01
Seismic chimneys ranging in width from 200 m to 1,000 m are observed in the seismic sections obtained in the Ulleung Basin, East Sea. In consequence of Ulleung Basin Gas Hydrate Expedition 1 and 2, concentrations of gas hydrates were identified. Especially, 6 chimney sites were drilled and the occurrence of gas hydrate was identified at all wells. Through the interpreting seismic section, three factors affect the formation of gas hydrate chimney; mass transport deposit, fault, igneous intrusion. These three factors result in three case of forming gas hydrate chimney. Firstly, gas hydrate chimney appears predominantly in the fault zone. Deep-rooted fault reach to mass transport deposit and gas hydrate chimney which is mostly rooted in mass transport deposit is formed. Secondly, Gas hydrate chimney appears linked to igneous intrusion. Igneous intrusion result in forming fault in overlying strata. Similar to first case, this fault traverses mass transport deposit and gas hydrate chimney rooted in mass transport deposit is created. Thirdly, gas hydrate chimney is formed at thick mass transport deposit without fault. In this case, chimney is not reach to seabed in contrast with first and second case. The thickness of mass transport deposit is 0.2 second in two-way travel times. Overburden load cause to pressure at the upper part of mass transport deposit. This leads to fracture in overlying sediments and form gas hydrate chimney.
Factor structure and differential item functioning of the BASC-2 BESS Spanish Language Parent Form.
Dever, Bridget V; Raines, Tara C; Dowdy, Erin
2016-06-01
Given the steady increase of students from diverse backgrounds in the U.S. educational system, in particular immigrant and Latino students, it is important to consider how to best support all students within our schools. The present study focuses on the Behavior Assessment System for Children-Second Edition (BASC-2) Behavioral and Emotional Screening System (BESS) Parent Spanish form, which is a promising assessment tool for those who are interested in screening for behavioral and emotional risk among Spanish-speaking populations. The present study included 725 students of Latino descent in Grades K-6 in an urban school district and their parents or legal guardians, who served as the informants. All parents completed the BESS language form (English or Spanish) of their choice. A confirmatory factor analysis (CFA) supported a 4-factor structure (Externalizing, Internalizing, Inattention, and Adaptive Skills) similar to that of the BESS Parent English form: χ2(77) = 248.06, p < .001; CFI = 0.903; TLI = 0.940. However, differential item functioning (DIF) analyses revealed 5 items (16.7%) demonstrated significant levels of DIF, with 4 of the 5 being easier to endorse in English. This study provides preliminary evidence of partial invariance of the BESS Parent across language forms. Although some evidence of invariance across language forms at the structural and item levels exists, more research is necessary to determine whether the DIF found in the present study results in any perceptible test bias. (PsycINFO Database Record
The Role of Nerve Growth Factor (NGF) and Its Precursor Forms in Oral Wound Healing.
Schenck, Karl; Schreurs, Olav; Hayashi, Katsuhiko; Helgeland, Kristen
2017-02-11
Nerve growth factor (NGF) and its different precursor forms are secreted into human saliva by salivary glands and are also produced by an array of cells in the tissues of the oral cavity. The major forms of NGF in human saliva are forms of pro-nerve growth factor (pro-NGF) and not mature NGF. The NGF receptors tropomyosin-related kinase A (TrkA) and p75 neurotrophin receptor (p75(NTR)) are widely expressed on cells in the soft tissues of the human oral cavity, including keratinocytes, endothelial cells, fibroblasts and leukocytes, and in ductal and acinar cells of all types of salivary glands. In vitro models show that NGF can contribute at most stages in the oral wound healing process: restitution, cell survival, apoptosis, cellular proliferation, inflammation, angiogenesis and tissue remodeling. NGF may therefore take part in the effective wound healing in the oral cavity that occurs with little scarring. As pro-NGF forms appear to be the major form of NGF in human saliva, efforts should be made to study its function, specifically in the process of wound healing. In addition, animal and clinical studies should be initiated to examine if topical application of pro-NGF or NGF can be a therapy for chronic oral ulcerations and wounds.
Measurement of the form factor ratios in semileptonic decays of charm mesons
Zaliznyak, Renata
1998-05-01
I have measured the form factor ratios r_{2} = A_{2} (0)/A_{1} (0) and r_{V} = V (0)/A_{1} (0) in the semileptonic charm meson decay D^{+} → $\\bar{K}$^{*0} e^{+}v_{e} from data collected by the Fermilab E791 collaboration. Form factors are introduced in the calculation of the hadronic current in semileptonic decays of strange, charm, or bottom mesons, such as D^{+} → $\\bar{K}$^{*0} e^{+} v_{e} . Semileptonic decays provide insight into quark coupling to the W boson since the leptonic and hadronic amplitudes in the Feynman diagram for the decay are completely separate. There are no strong interactions between the final state leptons and quarks. A number of theoretical models predict the values of the form factors for D^{+} → $\\bar{K}$^{*0} e^{+} v_{e} , though there is a large range of predictions. E791 is a hadroproduction experiment that recorded over 20 billion interactions with a 500 GeV π^{-} beam incident on five thin targets during the 1991-92 Fermilab fixed-target run. Approximately 3000 D^{+} → $\\bar{K}$^{*0} e^{+} v_{e} decays are fully reconstructed. In order to extract the form factor ratios from the data, I implement a multidimensional unbinned maximum likelihood fit with a large sample of simulated (Monte Carlo) D^{+} → $\\bar{K}$^{*0} e^{+}v_{e} events. The large E791 data sample provides the most precise measurement of the form factor ratios to date. The measured values for the form factor ratios are r_{2} = 0.71 ± 0.08 ± 0.09 and r_{V} = 1.84 ± 0.11 ±} 0.08. These results are in good agreement with some Lattice Gauge calculations. However the agreement with quark model predictions is not as good.
Cohen-Tannoudji, M; Marchand, P; Akli, S; Sheardown, S A; Puech, J P; Kress, C; Gressens, P; Nassogne, M C; Beccari, T; Muggleton-Harris, A L
1995-12-01
Tay-Sachs disease is an autosomal recessive lysosomal storage disease caused by beta-hexosaminidase A deficiency and leads to death in early childhood. The disease results from mutations in the HEXA gene, which codes for the alpha chain of beta-hexosaminidase. The castastrophic neurodegenerative progression of the disease is thought to be a consequence of massive neuronal accumulation of GM2 ganglioside and related glycolipids in the brain and nervous system of the patients. Fuller understanding of the pathogenesis and the development of therapeutic procedures have both suffered from the lack of an animal model. We have used gene targeting in embryonic stem (ES) cells to disrupt the mouse Hexa gene. Mice homozygous for the disrupted allele mimic several biochemical and histological features of human Tay-Sachs disease. Hexa-/- mice displayed a total deficiency of beta-hexosaminidase A activity, and membranous cytoplasmic inclusions typical of GM2 gangliosidoses were found in the cytoplasm of their neurons. However, while the number of storage neurons increased with age, it remained low compared with that found in human, and no apparent motor or behavioral disorders could be observed. This suggests that the presence of beta-hexosaminidase A is not an absolute requirement of ganglioside degradation in mice. These mice should help us to understand several aspects of the disease as well as the physiological functions of hexosaminidase in mice. They should also provide a valuable animal model in which to test new forms of therapy, and in particular gene delivery into the central nervous system.
The three loop slope of the Dirac form factor and the S Lamb shift in hydrogen
Melnikov, K.
1999-12-08
The last unknown contribution to hydrogen energy levels at order malpha{sup 7}, due to the slope of the Dirac form factor at three loops, is evaluated in a closed analytical form. The resulting shift of the hydrogen nS energy level is found to be 3.016/n{sup 3} kHz. Using the QED calculations of the 1S Lamb shift, the authors extract a precise value of the proton charge radius r{sub p} = 0.883{+-}0.014 fm.
High-throughput spectrometer designs in a compact form-factor: principles and applications
NASA Astrophysics Data System (ADS)
Norton, S. M.
2013-05-01
Many compact, portable Raman spectrometers have entered the market in the past few years with applications in narcotics and hazardous material identification, as well as verification applications in pharmaceuticals and security screening. Often, the required compact form-factor has forced designers to sacrifice throughput and sensitivity for portability and low-cost. We will show that a volume phase holographic (VPH)-based spectrometer design can achieve superior throughput and thus sensitivity over conventional Czerny-Turner reflective designs. We will look in depth at the factors influencing throughput and sensitivity and illustrate specific VPH-based spectrometer examples that highlight these design principles.
Factor structure and validity of the parenting stress index-short form.
Haskett, Mary E; Ahern, Lisa S; Ward, Caryn S; Allaire, Jason C
2006-06-01
The psychometric properties of the Parenting Stress Index-Short Form (PSI-SF) were examined in a sample of 185 mothers and fathers. Factor analysis revealed 2 reasonably distinct factors involving parental distress and dysfunctional parent-child interactions. Both scales were internally consistent, and these scales were correlated with measures of parent psychopathology, parental perceptions of child adjustment, and observed parent and child behavior. PSI-SF scores were related to parent reports of child behavior 1 year later, and the Childrearing Stress subscale was a significant predictor of a parental history of abuse.
NASA Astrophysics Data System (ADS)
Patton, Kelly; McLaughlin, Gail; Scholberg, Kate; Engel, Jon; Schunck, Nicolas
2017-01-01
Coherent elastic neutrino-nucleus scattering is a potential probe of nuclear neutron form factors. We show that the neutron root-mean-square (RMS) radius can be measured with tonne-scale detectors of argon, germanium, or xenon. In addition, the fourth moment of the neutron distribution can be studied experimentally using this method. The impacts of both detector size and detector shape uncertainty on such a measurement were considered. The important limiting factor was found to be the detector shape uncertainty. In order to measure the neutron RMS radius to 5%, comparable to current experimental uncertainties, the detector shape uncertainty needs to be known to 1% or better.
Wang, Y. T.; Xu, L. X.; Gui, Y. X.
2010-10-15
In this paper, we investigate the integrated Sachs-Wolfe effect in the quintessence cold dark matter model with constant equation of state and constant speed of sound in dark energy rest frame, including dark energy perturbation and its anisotropic stress. Comparing with the {Lambda}CDM model, we find that the integrated Sachs-Wolfe (ISW)-power spectrums are affected by different background evolutions and dark energy perturbation. As we change the speed of sound from 1 to 0 in the quintessence cold dark matter model with given state parameters, it is found that the inclusion of dark energy anisotropic stress makes the variation of magnitude of the ISW source uncertain due to the anticorrelation between the speed of sound and the ratio of dark energy density perturbation contrast to dark matter density perturbation contrast in the ISW-source term. Thus, the magnitude of the ISW-source term is governed by the competition between the alterant multiple of (1+3/2xc-circumflex{sub s}{sup 2}) and that of {delta}{sub de}/{delta}{sub m} with the variation of c-circumflex{sub s}{sup 2}.
NASA Astrophysics Data System (ADS)
Saini, Sahil; Singh, Parampreet
2016-12-01
Resolution of singularities in the Kantowski-Sachs model due to non-perturbative quantum gravity effects is investigated. Using the effective spacetime description for the improved dynamics version of loop quantum Kantowski-Sachs spacetimes, we show that even though expansion and shear scalars are universally bounded, there can exist events where curvature invariants can diverge. However, such events can occur only for very exotic equations of state when pressure or derivatives of energy density with respect to triads become infinite at a finite energy density. In all other cases curvature invariants are proved to remain finite for any evolution in finite proper time. We find the novel result that all strong singularities are resolved for arbitrary matter. Weak singularities pertaining to above potential curvature divergence events can exist. The effective spacetime is found to be geodesically complete for particle and null geodesics in finite time evolution. Our results add to a growing evidence for generic resolution of strong singularities using effective dynamics in loop quantum cosmology by generalizing earlier results on isotropic and Bianchi-I spacetimes.
The electromagnetic form factors of the Λ in the timelike region
NASA Astrophysics Data System (ADS)
Haidenbauer, J.; Meißner, U.-G.
2016-10-01
The reaction e+e- → Λ bar Λ is investigated for energies close to the threshold. Specific emphasis is put on the role played by the interaction in the final Λ bar Λ system which is taken into account rigorously. For that interaction a variety of Λ bar Λ potential models is employed that have been constructed for the analysis of the reaction p bar p → Λ bar Λ in the past. The enhancement of the effective form factor for energies close to the Λ bar Λ threshold, seen in pertinent experiments, is reproduced. Predictions for the Λ electromagnetic form factors GM and GE in the timelike region and for spin-dependent observables such as spin-correlation parameters are presented.
Shock Response of the Clamped Disk in Small Form Factor Hard Disk Drive
NASA Astrophysics Data System (ADS)
Gu, Bin; Shu, Dongwei; Shi, Baojun; Lu, Guoxing
As small form factor (one-inch and smaller) hard disk drives are widely used in portable consumer appliances and gadgets, their mechanical robustness is of greater concern. In the previous work, it is found that when the disk is more tightly clamped, it helps to decrease the shock response of the disk and then avoid the head slap. In this paper, the real boundary condition of the disk for a small form factor hard disk drive from Seagate is investigated numerically. The disk is clamped between the clamp and the hub. The shock response of the disk under a half-sine acceleration pulse is simulated by using the finite element method. In the finite element model, both contact between disk and clamp and contact between disk and hub are considered. According to the simulation results, how to decrease the shock response of the disk is suggested.
B→πll Form Factors for New Physics Searches from Lattice QCD.
Bailey, Jon A; Bazavov, A; Bernard, C; Bouchard, C M; DeTar, C; Du, Daping; El-Khadra, A X; Freeland, E D; Gámiz, E; Gottlieb, Steven; Heller, U M; Kronfeld, A S; Laiho, J; Levkova, L; Liu, Yuzhi; Lunghi, E; Mackenzie, P B; Meurice, Y; Neil, E; Qiu, Si-Wei; Simone, J N; Sugar, R; Toussaint, D; Van de Water, R S; Zhou, Ran
2015-10-09
The rare decay B→πℓ^{+}ℓ^{-} arises from b→d flavor-changing neutral currents and could be sensitive to physics beyond the standard model. Here, we present the first ab initio QCD calculation of the B→π tensor form factor f_{T}. Together with the vector and scalar form factors f_{+} and f_{0} from our companion work [J. A. Bailey et al., Phys. Rev. D 92, 014024 (2015)], these parametrize the hadronic contribution to B→π semileptonic decays in any extension of the standard model. We obtain the total branching ratio BR(B^{+}→π^{+}μ^{+}μ^{-})=20.4(2.1)×10^{-9} in the standard model, which is the most precise theoretical determination to date, and agrees with the recent measurement from the LHCb experiment [R. Aaij et al., J. High Energy Phys. 12 (2012) 125].
CFD-based method of determining form factor k for different ship types and different drafts
NASA Astrophysics Data System (ADS)
Wang, Jinbao; Yu, Hai; Zhang, Yuefeng; Xiong, Xiaoqing
2016-09-01
The value of form factor k at different drafts is important in predicting full-scale total resistance and speed for different types of ships. In the ITTC community, most organizations predict form factor k using a low-speed model test. However, this method is problematic for ships with bulbous bows and transom. In this article, a Computational Fluid Dynamics (CFD)-based method is introduced to obtain k for different type of ships at different drafts, and a comparison is made between the CFD method and the model test. The results show that the CFD method produces reasonable k values. A grid generating method and turbulence model are briefly discussed in the context of obtaining a consistent k using CFD.
The time-like electromagnetic form factors of proton and charged kaon at high energies
NASA Astrophysics Data System (ADS)
Anulli, Fabio
2016-05-01
The Initial State Radiation method in the BABAR experiment has been used to measure the time-like electromagnetic form factors at the momentum transfer from 9 to 42 (GeV/c)2 for proton and from 7 to 56 (GeV/c)2 for charged kaon. The obtained data show the tendency to approach the QCD asymptotic prediction for kaons and space-like form factor values for proton. The BABAR data have been used together with data from other experiments, to perform a model-independent determination of the relative phases between the single-photon and the three-gluon amplitudes in ψ → KK ¯ decays. The values of the branching fractions measured in the reaction e+e- → K+ K- are shifted due to interference of resonant and nonresonant amplitudes. We have determined the absolute values of the shifts to be 5% for J/ψ and 15% for ψ(2S) decays.
Renormalization versus strong form factors for one-boson-exchange potentials
NASA Astrophysics Data System (ADS)
Calle Cordón, A.; Ruiz Arriola, E.
2010-04-01
We analyze the one-boson-exchange potential from the point of view of renormalization theory. We show that the nucleon-meson Lagrangian, while predicting the NN force, does not predict the NN scattering matrix nor the deuteron properties unambiguously due to the appearance of short distance singularities. While the problem has traditionally been circumvented by introducing vertex functions via phenomenological strong form factors, we propose to impose physical renormalization conditions on the scattering amplitude at low energies. Working in the large Nc approximation with π, σ, ρ, and ω mesons we show that, once these conditions are applied, results for low-energy phases of proton-neutron scattering as well as deuteron properties become largely insensitive to the form factors and to the vector mesons yielding reasonable agreement with the data and for realistic values of the coupling constants.
η -γ and η'-γ transition form factors in a nonlocal NJL model
NASA Astrophysics Data System (ADS)
Gómez Dumm, D.; Noguera, S.; Scoccola, N. N.
2017-03-01
We study the η and η' distribution amplitudes (DAs) in the context of a nonlocal SU(3 ) L⊗SU(3 ) R chiral quark model. The corresponding Lagrangian allows us to reproduce the phenomenological values of pseudoscalar meson masses and decay constants, as well as the momentum dependence of the quark propagator arising from lattice calculations. It is found that the obtained DAs have two symmetric maxima, which arise from new contributions generated by the nonlocal character of the interactions. These DAs are then applied to the calculation of the η -γ and η'-γ transition form factors. Implications of our results regarding higher twist corrections and/or contributions to the transition form factors originated by gluon-gluon components in the η and η' mesons are discussed.
The [Formula: see text] transition form factor from space- and time-like experimental data.
Escribano, R; Masjuan, P; Sanchez-Puertas, P
The [Formula: see text] transition form factor is analyzed for the first time in both space- and time-like regions at low and intermediate energies in a model-independent approach through the use of rational approximants. The [Formula: see text] experimental data provided by the A2 Collaboration in the very low-energy region of the dielectron invariant mass distribution allows for the extraction of the most precise up-to-date slope and curvature parameters of the form factors as well as their values at zero and infinity. The impact of these new results on the mixing parameters of the [Formula: see text]-[Formula: see text] system, together with the role played by renormalization dependent effects, and on the determination of the [Formula: see text] couplings from [Formula: see text] and [Formula: see text] radiative decays is also discussed.
$$B\\to\\pi\\ell\\ell$$ Form Factors for New-Physics Searches from Lattice QCD
Bailey, Jon A.
2015-10-07
The rare decay B→πℓ+ℓ- arises from b→d flavor-changing neutral currents and could be sensitive to physics beyond the standard model. Here, we present the first ab initio QCD calculation of the B→π tensor form factor fT. Together with the vector and scalar form factors f+ and f0 from our companion work [J. A. Bailey et al., Phys. Rev. D 92, 014024 (2015)], these parametrize the hadronic contribution to B→π semileptonic decays in any extension of the standard model. We obtain the total branching ratio BR(B+→π+μ+μ-)=20.4(2.1)×10-9 in the standard model, which is the most precise theoretical determination to date, and agreesmore » with the recent measurement from the LHCb experiment [R. Aaij et al., J. High Energy Phys. 12 (2012) 125].« less
Pinto, Sergio Alexandre; Stadler, Alfred; Gross, Franz
2009-05-15
We present the first calculations of the electromagnetic form factors of {sup 3}He and {sup 3}H within the framework of the Covariant Spectator Theory (CST). This first exploratory study concentrates on the sensitivity of the form factors to the strength of the scalar meson-nucleon off-shell coupling, known from previous studies to have a strong influence on the three-body binding energy. Results presented here were obtained using the complete impulse approximation (CIA), which includes contributions of relativistic origin that appear as two-body corrections in a nonrelativistic framework, such as 'Z-graphs', but omits other two and three-body currents. We compare our results to nonrelativistic calculations augmented by relativistic corrections of O(v/c){sup 2}.
Pinto, Sérgio Alexandre; Stadler, Alfred; Gross, Franz
2009-05-01
We present the first calculations of the electromagnetic form factors of ^{3}He and ^{3}H within the framework of the Covariant Spectator Theory (CST). This first exploratory study concentrates on the sensitivity of the form factors to the strength of the scalar meson-nucleon off-shell coupling, known from previous studies to have a strong influence on the three-body binding energy. Results presented here were obtained using the complete impulse approximation (CIA), which includes contributions of relativistic origin that appear as two-body corrections in a non-relativistic framework, such as "Z-graphs," but omits other two and three-body currents. Finally, we compare our results to non-relativistic calculations augmented by relativistic corrections of O(v/c)^{2}.
Alexandre Pinto, SÂ ergio; Stadler, Alfred; Gross, Franz
2009-01-01
We present the first calculations of the electromagnetic form factors of 3He and 3H within the framework of the Covariant Spectator Theory (CST). This first exploratory study concentrates on the sensitivity of the form factors to the strength of the scalar meson-nucleon off-shell coupling, known from previous studies to have a strong influence on the three-body binding energy. Results presented here were obtained using the complete impulse approximation (CIA), which includes contributions of relativistic origin that appear as two-body corrections in a non-relativistic framework, such as ?Z-graphs?, but omits other two and three-body currents. We compare our results to non-relativistic calculations augmented by relativistic corrections of O(v/c)2.
High-precision calculation of the strange nucleon electromagnetic form factors
Green, Jeremy; Meinel, Stefan; Engelhardt, Michael G.; Krieg, Stefan; Laeuchli, Jesse; Negele, John W.; Orginos, Kostas; Pochinsky, Andrew; Syritsyn, Sergey
2015-08-26
We report a direct lattice QCD calculation of the strange nucleon electromagnetic form factors G^{s}_{E} and G^{s}_{M} in the kinematic range 0 ≤ Q^{2} ≤ 1.2GeV^{2}. For the first time, both G^{s}_{E} and G^{s}_{M} are shown to be nonzero with high significance. This work uses closer-to-physical lattice parameters than previous calculations, and achieves an unprecented statistical precision by implementing a recently proposed variance reduction technique called hierarchical probing. We perform model-independent fits of the form factor shapes using the z-expansion and determine the strange electric and magnetic radii and magnetic moment. As a result, we compare our results to parity-violating electron-proton scattering data and to other theoretical studies.
A study of the N to Delta transition form factors in full QCD
Constantia Alexandrou; Robert Edwards; Giannis Koutsou; Theodoros Leontiou; Hartmut Neff; John W. Negele; Wolfram Schroers; Antonios Tsapalis
2005-07-01
The N to Delta transition form factors GM1, GE2 and GC2 are evaluated using dynamical MILC configurations and valence domain wall fermions at three values of quark mass corresponding to pion mass 606 MeV, 502 MeV and 364 MeV on lattices of spatial size 20{sup 3} and 28{sup 3}. The unquenched results are compared to those obtained at similar pion mass in the quenched theory.
Measurement of the neutron electric form factor GEn in quasielastic scattering
Donal Day
2003-07-15
We have measured the electric form factor of the neutron, GEn, at two momentum transfers (Q2= 0.5 and Q2= 1.0 GeV/c2) through quasielastic scattering in Jefferson Lab's Hall C. Longitudinally polarized electrons scattered from polarized deuterated ammonia and GEn was extracted from the beam-target asymmetry AVed which, in quasielastic kinematics, is particularly sensitive to GEn and insensitive to MEC and FSI.
Analytic results for planar three-loop integrals for massive form factors
NASA Astrophysics Data System (ADS)
Henn, Johannes M.; Smirnov, Alexander V.; Smirnov, Vladimir A.
2016-12-01
We use the method of differential equations to analytically evaluate all planar three-loop Feynman integrals relevant for form factor calculations involving massive particles. Our results for ninety master integrals at general q 2 are expressed in terms of multiple polylogarithms, and results for fiftyone master integrals at the threshold q 2 = 4 m 2 are expressed in terms of multiple polylogarithms of argument one, with indices equal to zero or to a sixth root of unity.
QCD Nuclear g-factor and the Spin-Statistics Theorem
NASA Astrophysics Data System (ADS)
Ward, Thomas
2015-04-01
Consideration of the composite three-quark nucleon spin structure and its Pauli spin-statistics follows a new QCD g-factor with implications for the magnetic dipole moments of nucleons and their form factors. The reformulation of the nucleon magnetic moments using the new QCD nucleon g-factor is shown to be in striking agreement with global polarized and unpolarized e-p scattering data using the Sachs electric and magnetic form factors, thus reconciling long standing discrepancies between measurements. Additionally, the introduction of QCD isospin symmetry breaking (ISB) strange quarks terms contained within the meson-baryon exchange currents allow the partially conserved EM axial currents to be restored as well as providing a precise measure of the strange quark probabilities of the nucleons. Work performed under the auspices of US Department of Energy.
Λb→pl⁻ν¯l form factors from lattice QCD with static b quarks
Detmold, William; Lin, C.-J. David; Meinel, Stefan; ...
2013-07-23
We present a lattice QCD calculation of form factors for the decay Λb→pμ⁻ν¯μ, which is a promising channel for determining the Cabibbo-Kobayashi-Maskawa matrix element |Vub| at the Large Hadron Collider. In this initial study we work in the limit of static b quarks, where the number of independent form factors reduces to two. We use dynamical domain-wall fermions for the light quarks, and perform the calculation at two different lattice spacings and at multiple values of the light-quark masses in a single large volume. Using our form factor results, we calculate the Λb→pμ⁻ν¯μ differential decay rate in the range 14more » GeV²≤q²≤q²max, and obtain the integral ∫q²max 14 GeV²[dΓ/dq²]dq²/|Vub|²=15.3±4.2 ps⁻¹. Combined with future experimental data, this will give a novel determination of |Vub| with about 15% theoretical uncertainty. The uncertainty is dominated by the use of the static approximation for the b quark, and can be reduced further by performing the lattice calculation with a more sophisticated heavy-quark action.« less
Time-like nucleon form factor measurements at overline{textbf{P}}textbf{ANDA}
NASA Astrophysics Data System (ADS)
Sudoł, Małgorzata
2009-11-01
The electromagnetic probe is an excellent tool to investigate the structure of the nucleon. The nearly 4 π detector PANDA, to be installed on the FAIR accelerator complex at Darmstadt, will allow to make a precise determination of the electromagnetic form factors of the proton in the time-like (TL) region with unprecedented precision. In the framework of the one-photon exchange, the center of mass unpolarized differential cross section of the reaction overline{p} p rightarrow e^+ e^- is a linear combination of the squared moduli of the electric Gp_E and magnetic Gp_M proton form factors. The precise measurement of the angular distribution over almost full angular range then directly gives these quantities. Only two experiments have provided the ratio R = {|Gp_E|/|Gp_M|} but with very large statistical uncertainties. Within PANDA, there is a unique opportunity to measure separately the moduli of these two proton form factors Gp_E and Gp_M in good conditions, up to around q 2 = 14 GeV2.
Accessing the Elastic Form-Factors of the $Delta(1232)$ Using the Beam-Normal Asymmetry
Dalton, Mark M.
2016-08-01
The beam-normal single-spin asymmetry, $B_n$, exists in the scattering of high energy electrons, polarized transverse to their direction of motion, from nuclear targets. To first order, this asymmetry is caused by the interference of the one-photon exchange amplitude with the imaginary part of the two-photon exchange amplitude. Measurements of $B_n$, for the production of a $\\Delta(1232)$ resonance from a proton target, will soon become available from the Qweak experiment at Jefferson Lab and the A4 experiment at Mainz. The imaginary part of two-photon exchange allows only intermediate states that are on-shell, including the $\\Delta$ itself. Therefore such data is sensitive to $\\gamma\\Delta\\Delta$, the elastic form-factors of the $\\Delta$. This article will introduce the form-factors of the $\\Delta$, discuss what might be learned about the elastic form-factors from these new data, describe ongoing efforts in calculation and measurement, and outline the possibility of future measurements.
γ*N →N*(1520 ) form factors in the timelike regime
NASA Astrophysics Data System (ADS)
Ramalho, G.; Peña, M. T.
2017-01-01
The covariant spectator quark model, tested before in a variety of electromagnetic baryon excitations, is applied here to the γ*N →N*(1520 ) reaction in the timelike regime. The transition form factors are first parametrized in the spacelike region in terms of a valence quark core model together with a parametrization of the meson cloud contribution. The form factor behavior in the timelike region is then predicted, as well as the N*(1520 )→γ N decay width and the N*(1520 ) Dalitz decay, N*(1520 )→e+e-N . Our results may help in the interpretation of dielectron production from elementary p p collisions and from the new generation of HADES results using a pion beam. In the q2=0 - 1 GeV2 range, we conclude that the QED approximation (a q2 independent form factor model) underestimates the electromagnetic coupling of the N*(1520 ) from 1 up to 2 orders of magnitude. We conclude also that the N*(1520 ) and Δ (1232 ) Dalitz decay widths are comparable.
Measurement of the Hadronic Form Factors in Ds to phi e nu Decays
Serrano, J
2006-09-26
Based on the measured four-dimensional rate for D{sub s}{sup +} {yields} {phi}e{sup +}{nu}{sub e} decays, they have determined the ratios of the three hadronic form factors, {tau}{sub V} = V(0)/A{sub 1}(0) = 1.636 {+-} 0.067 {+-} 0.038 and {tau}{sub 2} = A{sub 2}(0)/A{sub 1}(0) = 0.705 {+-} 0.056 {+-} 0.029, using a simple pole ansatz for the q{sup 2} dependence, with fixed values of the pole masses for both the vector and axial form factors. By a separate fit to the same data, they have also extracted the pole mass for the axial form factors, m{sub A}: {tau}{sub V} = V(0)/A{sub 1}(0) = 1.633 {+-} 0.081 {+-} 0.068, {tau}{sub 2} = A{sub 2}(0)/A{sub 1}(0) = 0.711 {+-} 0.111 {+-} 0.096 and m{sub A} = (2.53{sub -0.35}{sup +0.54} {+-} 0.54)GeV/c{sup 2}.
Nonperturbative relativistic approach to pion form factors: Predictions for future JLab experiments
Krutov, A. F.; Troitsky, V. E.; Tsirova, N. A.
2009-11-15
Some predictions concerning possible results of the future experiments at the Thomas Jefferson National Accelerator Facility (JLab) on the pion form factor F{sub {pi}}(Q{sup 2}) are made. The calculations exploit the method proposed previously by the authors and based on the instant-form Poincare invariant approach to pions, considered as quark-antiquark systems. This model has predicted with surprising accuracy the values of F{sub {pi}}(Q{sup 2}), which were measured later in JLab experiments. The results are almost independent from the form of wave function. The pion mean square radius
The proton form factor measurements at Jefferson Lab, past and future
Punjabi, Vina A.
2014-01-01
Use of the double-polarization technique to obtain the elastic nucleon form factors has resulted in a dramatic improvement of the quality of two of the four nucleon electromagnetic form factors, G{sub Ep} and G{sub En}. It has also changed our understanding of the proton structure, having resulted in a distinctly different Q 2-dependence for both G{sub Ep} and G{sub Mp}, contradicting the prevailing wisdom of the 1990’s based on cross section measurements, namely that G{sub Ep} and G{sub Mp} obey a “scaling” relation {mu}G{sub Ep} ~ G{sub Mp}. A related consequence of the faster decrease of G{sub Ep} revealed by the Jefferson Lab (Jlab) polarization results was the disappearance of the early scaling F{sub 2}/F{sub 1} ~ 1/Q{sup 2} predicted by perturbative QCD. In three experiments, Gep(1), Gep(2) and Gep(3), in Halls A and C at Jlab, the ratio of the proton’s electromagnetic elastic form factors, G{sub Ep} /G{sub Mp} , was measured up to four momentum transfer Q{sup 2} of 8.5 GeV{sup 2} with high precision, using the recoil polarization technique. The initial discovery that the proton form factor ratio measured in these three experiments decreases approximately linearly with four-momentum transfer, Q{sup 2}, for values above ~ 1 GeV{sup 2}, was modified by the Gep(3) results, which suggests a slowing down of this decrease. There is an approved experiment, Gep(5), to continue these measurements to 15 GeV{sup 2}. A dedicated experimental setup, the super bigbite spectrometer (SBS), will be built for this purpose. It will be equipped with a new focal plane polarimeter to measure the polarization of the recoil protons. In this presentation, I will review the status of the proton elastic electromagnetic form factors, mention succinctly a number of theoretical approaches to describe results and show some features required for the future Gep(5) experiment.
{gamma}*{gamma}*{yields}{pi}{sup 0} form factor from anti-de Sitter-space/QCD correspondence
Stoffers, Alexander; Zahed, Ismail
2011-08-15
The recently measured {gamma}*{gamma}*{yields}{pi}{sup 0} anomalous form factor is analyzed using the D4/D8D8 holographic approach to QCD. The half-on-shell transition form factor is vector meson dominated and is shown to exactly tie to the charged-pion form factor. The holographic result compares well with the data for the lowest vector resonance.
NASA Astrophysics Data System (ADS)
McEwen, J. D.; Vielva, P.; Hobson, M. P.; Martínez-González, E.; Lasenby, A. N.
2007-04-01
Using a directional spherical wavelet analysis we detect the integrated Sachs-Wolfe (ISW) effect, indicated by a positive correlation between the first-year Wilkinson Microwave Anisotropy Probe (WMAP) and NRAO VLA Sky Survey (NVSS) data. Detections are made using both a directional extension of the spherical Mexican hat wavelet and the spherical butterfly wavelet. We examine the possibility of foreground contamination and systematics in the WMAP data and conclude that these factors are not responsible for the signal that we detect. The wavelet analysis inherently enables us to localize on the sky those regions that contribute most strongly to the correlation. On removing these localized regions the correlation that we detect is reduced in significance, as expected, but it is not eliminated, suggesting that these regions are not the sole source of correlation between the data. This finding is consistent with predictions made using the ISW effect, where one would expect weak correlations over the entire sky. In a flat universe the detection of the ISW effect provides direct and independent evidence for dark energy. We use our detection to constrain dark energy parameters by deriving a theoretical prediction for the directional wavelet covariance statistic for a given cosmological model. Comparing these predictions with the data we place constraints on the equation-of-state parameter w and the vacuum energy density ΩΛ. We also consider the case of a pure cosmological constant, that is, w = -1. For this case we rule out a zero cosmological constant at greater than the 99.9 per cent significance level. All parameter estimates that we obtain are consistent with the standard cosmological concordance model values. Although wavelets perform very well when attempting to detect the ISW effect since one may probe only the regions where the signal is present, once all information is incorporated when computing parameter estimates, the performance of the wavelet analysis is
Clean measurements of the nucleon axial-vector and free-neutron magnetic form factors
Deur, Alexandre P.
2013-11-01
We discuss the feasibility of a weak charged current experiment using a low energy electron beam. A first goal is to measure the Q^2 dependence of the axial-vector form factor g_a(Q^2). It can be measured model-independently and as robustly as for electromagnetic form factors from typical electron scattering experiments, in contrast to the methods used so far to measure g_a(Q^2). If g_a(Q^2) follows a dipole form, the axial mass can be extracted with a better accuracy than the world data altogether. The most important detection equipment would be a segmented neutron detector with good momentum and angular resolution that is symmetric about the beam direction, and covers a moderate angular range. A high intensity beam (100 uA) is necessary. Beam polarization is highly desirable as it provides a clean measurement of the backgrounds. Beam energies between 70 and 110 MeV are ideal. This range would provide a Q^2 mapping of g_a between 0.01
An uncleavable form of pro–scatter factor suppresses tumor growth and dissemination in mice
Mazzone, Massimiliano; Basilico, Cristina; Cavassa, Silvia; Pennacchietti, Selma; Risio, Mauro; Naldini, Luigi; Comoglio, Paolo M.; Michieli, Paolo
2004-01-01
Scatter factor (SF), also known as hepatocyte growth factor, is ubiquitously present in the extracellular matrix of tissues in the form of an inactive precursor (pro-SF). In order to acquire biological activity, pro-SF must be cleaved by specific proteases present on the cell surface. The mature form of SF controls invasive cues in both physiological and pathological processes through activation of its receptor, the Met tyrosine kinase. By substituting a single amino acid in the proteolytic site, we engineered an unprocessable form of pro-SF (uncleavable SF). Using lentivirus vector technology, we achieved local or systemic delivery of uncleavable SF in mice. We provide evidence that (a) uncleavable SF inhibits both protease-mediated pro-SF conversion and active SF–induced Met activation; (b) local expression of uncleavable SF in tumors suppresses tumor growth, impairs tumor angiogenesis, and prevents metastatic dissemination; and (c) systemic expression of uncleavable SF dramatically inhibits the growth of transplanted tumors and abolishes the formation of spontaneous metastases without perturbing vital physiological functions. These data show that proteolytic activation of pro-SF is a limiting step in tumor progression, thus suggesting a new strategy for the treatment or prevention of the malignant conversion of neoplastic lesions. PMID:15545993
An uncleavable form of pro-scatter factor suppresses tumor growth and dissemination in mice.
Mazzone, Massimiliano; Basilico, Cristina; Cavassa, Silvia; Pennacchietti, Selma; Risio, Mauro; Naldini, Luigi; Comoglio, Paolo M; Michieli, Paolo
2004-11-01
Scatter factor (SF), also known as hepatocyte growth factor, is ubiquitously present in the extracellular matrix of tissues in the form of an inactive precursor (pro-SF). In order to acquire biological activity, pro-SF must be cleaved by specific proteases present on the cell surface. The mature form of SF controls invasive cues in both physiological and pathological processes through activation of its receptor, the Met tyrosine kinase. By substituting a single amino acid in the proteolytic site, we engineered an unprocessable form of pro-SF (uncleavable SF). Using lentivirus vector technology, we achieved local or systemic delivery of uncleavable SF in mice. We provide evidence that (a) uncleavable SF inhibits both protease-mediated pro-SF conversion and active SF-induced Met activation; (b) local expression of uncleavable SF in tumors suppresses tumor growth, impairs tumor angiogenesis, and prevents metastatic dissemination; and (c) systemic expression of uncleavable SF dramatically inhibits the growth of transplanted tumors and abolishes the formation of spontaneous metastases without perturbing vital physiological functions. These data show that proteolytic activation of pro-SF is a limiting step in tumor progression, thus suggesting a new strategy for the treatment or prevention of the malignant conversion of neoplastic lesions.
Phenomenological analysis of near-threshold periodic modulations of the proton timelike form factor
NASA Astrophysics Data System (ADS)
Bianconi, A.; Tomasi-Gustafsson, E.
2016-03-01
We have recently highlighted the presence of a periodically oscillating 10% modulation in the BABAR Collaboration data on the proton timelike form factors, expressing the deviations from the pointlike behavior of the proton-antiproton electromagnetic current in the reaction e++e-→p ¯+p . Here we deepen our previous data analysis and confirm that in the case of several standard parametrizations it is possible to write the form factor in the form F0+Fosc , where F0 is a parametrization expressing the long-range trend of the form factor (for q2 ranging from the p ¯p threshold to 36 GeV2), and Fosc is a function of the form exp(-B p )cos(C p ) , where p is the relative momentum of the final p ¯p pair. Error bars allow for a clean identification of the main features of this modulation for q2<10 GeV2 . Assuming this oscillatory modulation to be an effect of final-state interactions between the forming proton and the antiproton, we propose a phenomenological model based on a double-layer imaginary optical potential. This potential is flux absorbing when the distance between the proton and antiproton centers of mass is ≳1.7 - 1.8 fm and flux generating when it is ≲1.7 - 1.8 fm. The main features of the oscillations may be reproduced with some freedom in the potential parameters, but the transition between the two layers must be sudden (0-0.2 fm) to get the correct oscillation period. The flux-absorbing part of the p ¯p interaction is well known in the phenomenology of small-energy antiproton interactions and is due to the annihilation of p ¯p pairs into multimeson states. We interpret the flux-creating part of the potential as due to the creation of a 1 /q -ranged state when the virtual photon decays into a set of current quarks and antiquarks. This short-lived compact state may be expressed as a sum of several hadronic states including the ones with large mass Qn≫q , that may exist for a time t ˜1 /(Qn-q ) . The decay of these large-mass states leads to an
Nematicidal spore-forming Bacilli share similar virulence factors and mechanisms
Zheng, Ziqiang; Zheng, Jinshui; Zhang, Zhengming; Peng, Donghai; Sun, Ming
2016-01-01
In the soil environment, Bacilli can affect nematode development, fecundity and survival. However, although many Bacillus species can kill nematodes, the virulence mechanisms Bacilli utilize remain unknown. In this study, we collected 120 strains comprising 30 species across the Bacillaceae and Paenibacillaceae families of the Bacillales order and measured their nematicidal activities in vitro. Comparison of these strains’ nematicidal capacities revealed that nine species, including Bacillus thuringiensis, B. cereus, B. subtilis, B. pumilus, B. firmus, B. toyonensis, Lysinibacillus sphaericus, Brevibacillus laterosporus and B. brevis, were highly nematicidal, the first of which showed the highest activity. Genome sequencing and analysis identified many potential virulence factors, which grouped into five types. At least four possible mechanisms were deduced on the basis of the combination of these factors and the bacterial nematicidal activity, including a pore-forming mechanism of crystal proteins, an inhibition-like mechanism of thuringiensin and a degradation mechanism of proteases and/or chitinases. Our results demonstrate that 120 spore-forming Bacilli across different families share virulence factors that may contribute to their nematicidal capacity. PMID:27539267
Nematicidal spore-forming Bacilli share similar virulence factors and mechanisms.
Zheng, Ziqiang; Zheng, Jinshui; Zhang, Zhengming; Peng, Donghai; Sun, Ming
2016-08-19
In the soil environment, Bacilli can affect nematode development, fecundity and survival. However, although many Bacillus species can kill nematodes, the virulence mechanisms Bacilli utilize remain unknown. In this study, we collected 120 strains comprising 30 species across the Bacillaceae and Paenibacillaceae families of the Bacillales order and measured their nematicidal activities in vitro. Comparison of these strains' nematicidal capacities revealed that nine species, including Bacillus thuringiensis, B. cereus, B. subtilis, B. pumilus, B. firmus, B. toyonensis, Lysinibacillus sphaericus, Brevibacillus laterosporus and B. brevis, were highly nematicidal, the first of which showed the highest activity. Genome sequencing and analysis identified many potential virulence factors, which grouped into five types. At least four possible mechanisms were deduced on the basis of the combination of these factors and the bacterial nematicidal activity, including a pore-forming mechanism of crystal proteins, an inhibition-like mechanism of thuringiensin and a degradation mechanism of proteases and/or chitinases. Our results demonstrate that 120 spore-forming Bacilli across different families share virulence factors that may contribute to their nematicidal capacity.
Expanding the spectrum of HEXA mutations in Indian patients with Tay-Sachs disease.
Sheth, Jayesh; Mistri, Mehul; Datar, Chaitanya; Kalane, Umesh; Patil, Shekhar; Kamate, Mahesh; Shah, Harshuti; Nampoothiri, Sheela; Gupta, Sarita; Sheth, Frenny
2014-01-01
Tay-Sachs disease is an autosomal recessive neurodegenerative disorder occurring due to impaired activity of β-hexosaminidase-A (EC 3.2.1.52), resulting from the mutation in HEXA gene. Very little is known about the molecular pathology of TSD in Indian children except for a few mutations identified by us. The present study is aimed to determine additional mutations leading to Tay-Sachs disease in nine patients confirmed by the deficiency of β-hexosaminidase-A (< 2% of total hexosaminidase activity for infantile patients) in leucocytes. The enzyme activity was assessed by using substrates 4-methylumbelliferyl-N-acetyl-β-d-glucosamine and 4-methylumbelliferyl-N-acetyl-β-d-glucosamine-6-sulfate for total-hexosaminidase and hexosaminidase-A respectively, and heat inactivation method for carrier detection. The exons and exon-intron boundaries of the HEXA gene were bi-directionally sequenced on an automated sequencer. 'In silico' analyses for novel mutations were carried out using SIFT, Polyphen2 and MutationT@ster software programs. The structural study was carried out by UCSF Chimera software using the crystallographic structure of β-hexosaminidase-A (PDB-ID: 2GJX) as the template. Our study identified four novel mutations in three cases. These include a compound heterozygous missense mutation c.524A>C (D175A) and c.805G>C (p.G269R) in one case; and one small 1 bp deletion c.426delT (p.F142LfsX57) and one splice site mutation c.459+4A>C in the other two cases respectively. None of these mutations were detected in 100 chromosomes from healthy individuals of the same ethnic group. Three previously reported missense mutations, (i) c.532C>T (p.R178C), (ii) c.964G>T (p.D322Y), and (iii) c.1385A>T (p.E462V); two nonsense mutations (i) c.709C>T (p.Q237X) and (ii) c.1528C>T (p.R510X), one 4 bp insertion c.1277_1278insTATC (p.Y427IfsX5) and one splice site mutation c.459+5G>A were also identified in six cases. We observe from this study that novel mutations are more
NASA Astrophysics Data System (ADS)
Rimal, Dipak
The electromagnetic form factors are the most fundamental observables that encode information about the internal structure of the nucleon. The electric (GE) and the magnetic ( GM) form factors contain information about the spatial distribution of the charge and magnetization inside the nucleon. A significant discrepancy exists between the Rosenbluth and the polarization transfer measurements of the electromagnetic form factors of the proton. One possible explanation for the discrepancy is the contributions of two-photon exchange (TPE) effects. Theoretical calculations estimating the magnitude of the TPE effect are highly model dependent, and limited experimental evidence for such effects exists. Experimentally, the TPE effect can be measured by comparing the ratio of positron-proton elastic scattering cross section to that of the electron-proton [R = sigma(e +p)/sigma(e+p)]. The ratio R was measured over a wide range of kinematics, utilizing a 5.6 GeV primary electron beam produced by the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. This dissertation explored dependence of R on kinematic variables such as squared four-momentum transfer (Q2) and the virtual photon polarization parameter (epsilon). A mixed electron-positron beam was produced from the primary electron beam in experimental Hall B. The mixed beam was scattered from a liquid hydrogen (LH2) target. Both the scattered lepton and the recoil proton were detected by the CEBAF Large Acceptance Spectrometer (CLAS). The elastic events were then identified by using elastic scattering kinematics. This work extracted the Q2 dependence of R at high epsilon(epsilon > 0.8) and the $epsilon dependence of R at approx 0.85 GeV2. In these kinematics, our data confirm the validity of the hadronic calculations of the TPE effect by Blunden, Melnitchouk, and Tjon. This hadronic TPE effect, with additional corrections contributed by higher excitations of the intermediate state nucleon, largely
Global analysis of proton elastic form factor data with two-photon exchange corrections
J. Arrington; W. Melnitchouk; J. A. Tjon
2007-09-01
We use the world's data on elastic electron-proton scattering and calculations of two-photon exchange effects to extract corrected values of the proton's electric and magnetic form factors over the full Q^2 range of the existing data. Our analysis combines the corrected Rosenbluth cross section and polarization transfer data, and is the first extraction of G_Ep and G_Mp including explicit two-photon exchange corrections and their associated uncertainties. In addition, we examine the angular dependence of the corrected cross sections, and discuss the possible nonlinearities of the cross section as a function of epsilon.
K(13) FORM FACTOR WITH TWO FLAVORS OF DYNAMICAL DOMAIN WALL QUARKS.
SONI, A.; DAWSON, T.; IZUBUCHI, T.; KANEKO, T.; SASAKI, S.
2005-07-25
We report on our calculation of K {yields} {pi} vector form factor by numerical simulations of two-flavor QCD on a 16{sup 3} x 32 x 12 lattice at a {approx_equal} 0.12 fm using domain-wall quarks and DBW2 glue. Our preliminary result at a single sea quark mass corresponding to m{sub PS}/m{sub V} {approx_equal} 0.53 shows a good agreement with previous estimate in quenched QCD and that from a phenomenological model.
Measurement of the gamma gamma* --> eta and gamma gamma* --> eta' transition form factors
del Amo Sanchez et al, P.
2011-02-07
We study the reactions e{sup +}e{sup -} {yields} e{sup +}e{sup -} {eta}{sup (/)} in the single-tag mode and measure the {gamma}{gamma}* {yields} {eta}{sup (/)} transition form factors in the momentum transfer range from 4 to 40 GeV{sup 2}. The analysis is based on 469 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.
Form Factors for $B$ to $Kll$ Semileptonic Decay from Three-Flavor Lattice QCD
Zhou, Ran; Bailey, Jon A.; Bazavov, Alexei; El-Khadra, Aida X.; Gottlieb, Steven; Jain, Rajendra D.; Kronfeld, Andreas S.; Van de Water, Ruth S.; /Brookhaven
2011-11-01
We study the B {yields} Kl{sup +}l{sup -} semileptonic decay process in three-flavor lattice QCD. We analyze several ensembles generated by theMILC collaboration at different lattice spacings and sea-quark masses. We use the asqtad improved staggered action for the light quarks and the clover action with the Fermilab interpretation for the heavy b quark. We present preliminary results for the vector current induced form factors for a range of kaon energies. Our analysis includes chiral and continuum extrapolations based on SU(2) staggered {chi}PT.
Trinucleon Electromagnetic Form Factors and the Light-Front Hamiltonian Dynamics
Baroncini, F.; Kievsky, A.; Pace, E.; Salme, G.
2008-10-13
This contribution briefly illustrates preliminary calculations of the electromagnetic form factors of {sup 3}He and {sup 3}H, obtained within the Light-front Relativistic Hamiltonian Dynamics, adopting i) a Poincare covariant current operator, without dynamical two-body currents, and ii) realistic nuclear bound states with S, P and D waves. The kinematical region of few (GeV/c){sup 2}, relevant for forthcoming TJLAB experiments, has been investigated, obtaining possible signatures of relativistic effects for Q{sup 2}>2.5(GeV/c){sup 2}.
Electromagnetic proton form factors in dual large-Nc QCD: An update
NASA Astrophysics Data System (ADS)
Bisschoff, B.; Dominguez, C. A.; Hernandez, L. A.
2017-02-01
An updated determination is presented of the electric and magnetic form factors of the proton, in the framework of a dual-model realization of quantum chromodynamics (QCD) in the limit of an infinite number of colors. Very good agreement with data is obtained in the space-like region up to q2 ≃‑30GeV2. In particular, the ratio μPGE(q2)/G M(q2) is predicted in very good agreement with recoil polarization measurements from Jefferson Lab, up to q2 ≃‑8.5GeV2.
Extraction of the Compton Form Factor H from DVCS Measurements in the Quark Sector
H. Moutarde
2011-10-01
Working at twist 2 accuracy and assuming the dominance of the Generalized Parton Distribution H we study the helicity-dependent and independent cross sections measured in Hall A, the beam spin asymmetries measured in Hall B at Jefferson Laboratory and beam charge, beam spin and target spin asymmetries measured by Hermes. We extract the real and imaginary parts of the Compton Form Factor H, the latter being obtained with a 20-50% uncertainty. We pay extra attention to the estimation of systematic errors on the extraction of H. We discuss our results and compare to other extractions as well as to the popular VGG model.
Precise Determination of the Neutron Magnetic Form Factor to Higher Q{sup 2}
William K. Brooks; Jeffery D. Lachniet
2004-10-01
The neutron elastic magnetic form factor G{sub M}{sup n} has been extracted from quasielastic scattering from deuterium in the CEBAF Large Acceptance Spectrometer, CLAS. The kinematic coverage of the measurement is continuous over a broad range, extending from below 1 GeV{sup 2} to nearly 5 GeV{sup 2} in four-momentum transfer squared. High precision is achieved by employing a ratio technique in which most uncertainties cancel, and by a simultaneous in-situ calibration of the neutron detection efficiency, the largest correction to the data. Preliminary results are shown with statistical errors only.
Parity-Violating Electron Deuteron Scattering and the Proton's Neutral Weak Axial Vector Form Factor
Ito, Takeyasu; Averett, Todd; Barkhuff, David; Batigne, Guillaume; Beck, Douglas; Beise, Elizabeth; Blake, A.; Breuer, Herbert; Carr, Robert; Clasie, Benjamin; Covrig, Silviu; Danagoulian, Areg; Dodson, George; Dow, Karen; Dutta, Dipangkar; Farkhondeh, Manouchehr; Filippone, Bradley; FRANKLIN, W.; Furget, Christophe; Gao, Haiyan; Gao, Juncai; Gustafsson, Kenneth; Hannelius, Lars; Hasty, R.; Allen, Alice; Herda, M.C.; Jones, CE; King, Paul; Korsch, Wolfgang; Kowalski, Stanley; Kox, Serge; Kramer, Kevin; Lee, P.; Liu, Jinghua; Martin, Jeffery; McKeown, Robert; Mueller, B.; Pitt, Mark; Plaster, Bradley; Quemener, Gilles; Real, Jean-Sebastien; Ritter, J.; Roche, Julie; Savu, V.; Schiavilla, Rocco; Seely, Charles; Spayde, Damon; Suleiman, Riad; Taylor, S.; Tieulent, Raphael; Tipton, Bryan; Tsentalovich, E.; Wells, Steven; Yang, Bin; Yuan, Jing; Yun, Junho; Zwart, Townsend
2004-03-01
We report on a new measurement of the parity-violating asymmetry in quasielastic electron scattering from the deuteron at backward angles at Q2 = 0.038 (GeV/c)2. This quantity provides a determination of the neutral weak axial vector form factor of the nucleon, which can potentially receive large electroweak corrections. The measured asymmetry A = z3.51Â±0.57 (stat)Â±0.58 (syst) ppm is consistent with theoretical predictions. We also report on updated results of the previous experiment at Q2 = 0.091 (GeV/c)2, which are also consistent with theoretical predictions.
Falkenström, Fredrik; Hatcher, Robert L; Holmqvist, Rolf
2015-10-01
The working alliance concerns the quality of collaboration between patient and therapist in psychotherapy. One of the most widely used scales for measuring the working alliance is the Working Alliance Inventory (WAI). For the patient-rated version, the short form developed by Hatcher and Gillaspy (WAI-SR) has shown the best psychometric properties. In two confirmatory factor analyses of the WAI-SR, approximate fit indices were within commonly accepted norms, but the likelihood ratio chi-square test showed significant ill-fit. The present study used Bayesian structural equations modeling with zero mean and small variance priors to test the factor structure of the WAI-SR in three different samples (one American and two Swedish; N = 235, 634, and 234). Results indicated that maximum likelihood confirmatory factor analysis showed poor model fit because of the assumption of exactly zero residual correlations. When residual correlations were estimated using small variance priors, model fit was excellent. A two-factor model had the best psychometric properties. Strong measurement invariance was shown between the two Swedish samples and weak factorial invariance between the Swedish and American samples. The most important limitation concerns the limited knowledge on when the assumption of residual correlations being small enough to be considered trivial is violated.
Lim, K H; Sumarni, M G; Kee, C C; Christopher, V M; Noruiza Hana, M; Lim, K K; Amal, N M
2010-12-01
A cross-sectional study was conducted among form four students of secondary schools in the District of Petaling, Selangor, Malaysia from February 2008 to June 2008 with the aim of quantifying the prevalence of smoking and identifying the psychosocial factors related to smoking among adolescents in this district. A two-stage stratified sampling strategy was used to obtain a sample of 1300 students based on an estimated prevalence of 10%. The response rate was 80.5% (1045 out of 1298 students). Results showed that prevalence of smoking was higher among male students (22.3%) compared to females (5.5%) and the median age at smoking initiation was lower among males compared to female smokers (14 years old vs 15 years old). Modifiable risk factors associated with smoking were "percentage of friends who smoke" (OR 2.94, 95% CI [1.71- 5.06]) and "having a brother who smokes" (OR 1.97, 95% CI [1.20-3.31]). There was also a correlation between smoking prevalence and the number of risk factors present. Intensification of health education and anti-smoking programmes and modification of external factors in early adolescence are recommended to prevent smoking initiation.
Late-onset Tay-Sachs disease: the spectrum of peripheral neuropathy in 30 affected patients.
Shapiro, Barbara E; Logigian, Eric L; Kolodny, Edwin H; Pastores, Gregory M
2008-08-01
Late-onset Tay-Sachs (LOTS) disease is a chronic, progressive, lysosomal storage disorder caused by a partial deficiency of beta-hexosaminidase A (HEXA) activity. Deficient levels of HEXA result in the intracellular accumulation of GM2-ganglioside, resulting in toxicity to nerve cells. Clinical manifestations primarily involve the central nervous system (CNS) and lower motor neurons, and include ataxia, weakness, spasticity, dysarthria, dysphagia, dystonia, seizures, psychosis, mania, depression, and cognitive decline. The prevalence of peripheral nervous system (PNS) involvement in LOTS has not been well documented, but it has traditionally been thought to be very low. We examined a cohort of 30 patients with LOTS who underwent clinical and electrophysiologic examination, and found evidence of a predominantly axon loss polyneuropathy affecting distal nerve segments in the lower and upper extremities in eight patients (27%).
Two-oscillator Kantowski-Sachs model of the Schwarzschild black hole interior
NASA Astrophysics Data System (ADS)
Djordjevic, Goran S.; Nesic, Ljubisa; Radovancevic, Darko
2016-08-01
In this paper the interior of the Schwarzschild black hole, which is presented as a vacuum, homogeneous and anisotropic Kantowski-Sachs minisuperspace cosmological model, is considered. Lagrangian of the model is reduced by a suitable coordinate transformation to Lagrangian of two decoupled oscillators with the same frequencies and with zero energy in total (an oscillator-ghost-oscillator system). The model is presented in a classical, a p-adic and a noncommutative case. Then, within the standard quantum approach Wheeler-DeWitt equation and its general solutions, i.e. a wave function of the model is written, and then an adelic wave function is constructed. Finally, thermodynamics of the model is studied by using the Feynman-Hibbs procedure.
Tay-Sachs disease carrier screening: a model for prevention of genetic disease.
Kaplan, F
1998-01-01
Tay-Sachs disease (TSD) is an autosomal-recessive, progressive, and ultimately fatal neurodegenerative disorder. Within the last 30 years, the discovery of the enzymatic basis of the disease, namely deficiency of the enzyme hexosaminidase A, made possible both enzymatic diagnosis of TSD and heterozygote identification. In the last decade, the cloning of the HEXA gene and the identification of more than 80 associated TSD-causing mutations has permitted molecular diagnosis in many instances. TSD was the first genetic condition for which community-based screening for carrier detection was implemented. As such, the TSD experience can be viewed as a prototypic effort for public education, carrier testing, and reproductive counseling for avoiding fatal childhood disease. More importantly, the outcome of TSD screening over the last 28 years offers convincing evidence that such an effort can dramatically reduce incidence of the disease.
A MAP OF THE INTEGRATED SACHS-WOLFE SIGNAL FROM LUMINOUS RED GALAXIES
Granett, Benjamin R.; Neyrinck, Mark C.; Szapudi, Istvan
2009-08-10
We construct a map of the time derivative of the gravitational potential traced by Sloan Digital Sky Survey luminous red galaxies (LRGs). The potential decays on large scales due to cosmic acceleration, leaving an imprint on cosmic microwave background (CMB) radiation through the integrated Sachs-Wolfe (ISW) effect. With a template fit, we directly measure this signature on the CMB at a 2{sigma} confidence level. The measurement is consistent with the cross-correlation statistic, strengthening the claim that dark energy is indeed the cause of the correlation. This new approach potentially simplifies the cosmological interpretation. Our constructed linear ISW map shows no evidence for degree-scale cold and hot spots associated with supervoid and supercluster structures. This suggests that the linear ISW effect in a concordance {lambda}CDM cosmology is insufficient to explain the strong CMB imprints from these structures that we previously reported.
Anisotropic Kantowski-Sachs universe from gravitational tunneling and its observational signatures
Adamek, Julian; Campo, David; Niemeyer, Jens C.
2010-10-15
In a landscape of compactifications with different numbers of macroscopic dimensions, it is possible that our Universe has nucleated from a vacuum where some of our four large dimensions were compact while other, now compact, directions were macroscopic. From our perspective, this shapeshifting can be perceived as an anisotropic background spacetime. As an example, we present a model where our Universe emerged from a tunneling event which involves the decompactification of two dimensions compactified on the two-sphere. In this case, our Universe is of the Kantowski-Sachs type and therefore homogeneous and anisotropic. We study the deviations from statistical isotropy of the cosmic microwave background induced by the anisotropic curvature, with particular attention to the anomalies. The model predicts a quadrupolar power asymmetry with the same sign and acoustic oscillations as found by the Wilkinson Microwave Anisotropy Probe. The amplitude of the effect is however too small given the current estimated bound on anisotropic curvature derived from the quadrupole.
The integrated Sachs-Wolfe imprint of cosmic superstructures: a problem for ΛCDM
Nadathur, Seshadri; Sarkar, Subir; Hotchkiss, Shaun E-mail: shaun.hotchkiss@helsinki.fi
2012-06-01
A crucial diagnostic of the ΛCDM cosmological model is the integrated Sachs-Wolfe (ISW) effect of large-scale structure on the cosmic microwave background (CMB). The ISW imprint of superstructures of size ∼ 100 h{sup −1}Mpc at redshift z ∼ 0.5 has been detected with > 4σ significance, however it has been noted that the signal is much larger than expected. We revisit the calculation using linear theory predictions in ΛCDM cosmology for the number density of superstructures and their radial density profile, and take possible selection effects into account. While our expected signal is larger than previous estimates, it is still inconsistent by > 3σ with the observation. If the observed signal is indeed due to the ISW effect then huge, extremely underdense voids are far more common in the observed universe than predicted by ΛCDM.
Accurate measurement of the x-ray coherent scattering form factors of tissues
NASA Astrophysics Data System (ADS)
King, Brian W.
The material dependent x-ray scattering properties of tissues are determined by their scattering form factors, measured as a function of the momentum transfer argument, x. Incoherent scattering form factors, Finc, are calculable for all values of x while coherent scattering form factors, Fcoh, cannot be calculated except at large C because of their dependence on long range order. As a result, measuring Fcoh is very important to the developing field of x-ray scatter imaging. Previous measurements of Fcoh, based on crystallographic techniques, have shown significant variability, as these methods are not optimal for amorphous materials. Two methods of measuring F coh, designed with amorphous materials in mind, are developed in this thesis. An angle-dispersive technique is developed that uses a polychromatic x-ray beam and a large area, energy-insensitive detector. It is shown that Fcoh can be measured in this system if the incident x-ray spectrum is known. The problem is ill-conditioned for typical x-ray spectra and two numerical methods of dealing with the poor conditioning are explored. It is shown that these techniques work best with K-edge filters to limit the spectral width and that the accuracy degrades for strongly ordered materials. Measurements of width Fcoh for water samples are made using 50, 70 and 92 kVp spectra. The average absolute relative difference in Fcoh between our results and the literature for water is approximately 10-15%. Similar measurements for fat samples were made and found to be qualitatively similar to results in the literature, although there is very large variation between the literature values in this case. The angle-dispersive measurement is limited to low resolution measurements of the coherent scattering form factor although it is more accessible than traditional measurements because of the relatively commonplace equipment requirements. An energy-dispersive technique is also developed that uses a polychromatic x-ray beam and an
The effects of rocker sole and SACH heel on kinematics in gait.
Wu, Wen-Lan; Rosenbaum, Dieter; Su, Fong-Chin
2004-10-01
The rocker sole and solid-ankle cushion-heel (SACH) heels are the most commonly prescribed external shoe modification. Only a limited number of scientific evidence exists to support these interventions in clinical practice. The objective of this study was to determine the effects of rocker soles and SACH heels on kinematics during gait. In this study, we investigated the gait parameters during level walking, stair climbing and stair descending in healthy volunteers and assessed the effects of the modified shoes on the motion of the forefoot and hindfoot compared with the traditional shoes. Eleven normal subjects participated in this study. A six-camera motion analysis system was used to capture motion trajectories. The three-dimensional (3D) coordinates of the markers were used to calculate the angles of flexion-extension, valgus-varus, and internal-external rotation at the hindfoot and forefoot joints in a gait cycle by the custom software for foot kinematic analysis. The results showed that the rocker soles offer several advantages from the viewpoint of gait kinematics. The forefoot joint excursion in sagittal plane while wearing rocker shoes was significantly less than that while wearing traditional shoes during level walking, stair climbing and stair descending. It means that they could mimic the action of the forefoot joint, aid in roll off, and simulate forefoot dorsiflexion. Since the bony structures mechanically link the forefoot joint and hindfoot joint to a triplanar axis of motion, they could be used whenever there is minimal or no motion at the forefoot joint or hindfoot joint, because of, for example, fusion, fracture, cast immobilization, orthosis design, pain, or arthritis.
Martino, S; Cavalieri, C; Emiliani, C; Dolcetta, D; Cusella De Angelis, M G; Chigorno, V; Severini, G M; Sandhoff, K; Bordignon, C; Sonnino, S; Orlacchio, A
2002-08-01
The therapeutic potential of bone marrow-derived stromal cells for the therapy of Tay-Sachs disease is primarily related to the restoration of their own GM2 ganglioside storage. With this aim, we produced bone marrow-derived stromal cells from the adult Tay-Sachs animal model and transduced them with a retroviral vector encoding for the alpha-subunit of the lysosomal enzyme beta-hexosaminidase A (E.C. 3.2.1.52). Our results demonstrate that transduced Tay-Sachs bone marrow-derived stromal cells have beta-hexosaminidase A comparable to that of bone marrow-derived stromal cells from wild-type mice. Moreover, beta-hexosaminidase A in transduced Tay-Sachs bone marrow-derived stromal cells was able to hydrolyze the GM2 ganglioside in a feeding experiment, thus demonstrating the correction of the altered phenotype.
Power of two: Assessing the impact of a second measurement of the weak-charge form factor of 208Pb
NASA Astrophysics Data System (ADS)
Piekarewicz, J.; Linero, A. R.; Giuliani, P.; Chicken, E.
2016-09-01
Background: Besides its intrinsic value as a fundamental nuclear-structure observable, the weak-charge density of 208Pb—a quantity that is closely related to its neutron distribution—is of fundamental importance in constraining the equation of state of neutron-rich matter. Purpose: To assess the impact that a second electroweak measurement of the weak-charge form factor of 208Pb may have on the determination of its overall weak-charge density. Methods: Using the two putative experimental values of the form factor, together with a simple implementation of Bayes' theorem, we calibrate a theoretically sound—yet surprisingly little known—symmetrized Fermi function, that is characterized by a density and form factor that are both known exactly in closed form. Results: Using the charge form factor of 208Pb as a proxy for its weak-charge form factor, we demonstrate that using only two experimental points to calibrate the symmetrized Fermi function is sufficient to accurately reproduce the experimental charge form factor over a significant range of momentum transfers. Conclusions: It is demonstrated that a second measurement of the weak-charge form factor of 208Pb supplemented by a robust theoretical input in the form of the symmetrized Fermi function would place significant constraints on the neutron distribution of 208Pb. In turn, such constraints will become vital in the interpretation of hadronic experiments that will probe the neutron-rich skin of exotic nuclei at future radioactive beam facilities.
Proton Magnetic Form Factor from Existing Elastic e-p Cross Section Data
NASA Astrophysics Data System (ADS)
Ou, Longwu; Christy, Eric; Gilad, Shalev; Keppel, Cynthia; Schmookler, Barak; Wojtsekhowski, Bogdan
2015-04-01
The proton magnetic form factor GMp, in addition to being an important benchmark for all cross section measurements in hadron physics, provides critical information on proton structure. Extraction of GMp from e-p cross section data is complicated by two-photon exchange (TPE) effects, where available calculations still have large theoretical uncertainties. Studies of TPE contributions to e-p scattering have observed no nonlinear effects in Rosenbluth separations. Recent theoretical investigations show that the TPE correction goes to 0 when ɛ approaches 1, where ɛ is the virtual photon polarization parameter. In this talk, existing e-p elastic cross section data are reanalyzed by extrapolating the reduced cross section for ɛ approaching 1. Existing polarization transfer data, which is supposed to be relatively immune to TPE effects, are used to produce a ratio of electric and magnetic form factors. The extrapolated reduced cross section and polarization transfer ratio are then used to calculate GEp and GMp at different Q2 values.
Towards a Resolution of the Proton Form Factor Problem: New Electron and Positron Scattering Data
Adikaram, D.; Rimal, D.; Weinstein, L. B.; Raue, B.; Khetarpal, P.; Bennett, R.; Arrington, J.; Brooks, W.; Adhikari, K.; Afanasev, A.; Amaryan, M.; Anderson, M.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A.; Bono, J.; Boiarinov, S.; Briscoe, W.; Burkert, V.; Carman, D.; Careccia, S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dodge, G.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J.; Fradi, A.; Garillon, B.; Gilfoyle, G.; Giovanetti, K.; Girod, F.; Goetz, J.; Gohn, W.; Golovatch, E.; Gothe, R.; Griffioen, K.; Guegan, B.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S.; Hyde, C. E.; Ilieva, Y.; Ireland, D.; Ishkhanov, B.; Jenkins, D.; Jiang, H.; Jo, H.; Joo, K.; Joosten, S.; Kalantarians, N.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F.; Koirala, S.; Kubarovsky, V.; Kuhn, S.; Livingston, K.; Lu, H.; MacGregor, I.; Markov, N.; Mattione, P.; Mayer, M.; McKinnon, B.; Mestayer, M.; Meyer, C.; Mirazita, M.; Mokeev, V.; Montgomery, R.; Moody, C.; Moutarde, H.; Movsisyan, A.; Camacho, C. Munoz; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Osipenko, M.; Ostrovidov, A.; Park, K.; Pasyuk, E.; Pisano, S.; Pogorelko, O.; Price, J.; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabati, F.; Salgado, C.; Schott, D.; Schumacher, R.; Seder, E.; Sharabian, Y.; Simonyan, A.; Skorodumina, I.; Smith, E.; Smith, G.; Sober, D.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tian, Ye; Trivedi, A.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N.; Watts, D.; Wei, X.; Wood, M.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z.; Zonta, I.
2015-02-10
There is a significant discrepancy between the values of the proton electric form factor, GpE, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of GpE from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (epsilon) and momentum transfer (Q2) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ε at Q2=1.45 GeV2. This measurement is consistent with the size of the form factor discrepancy at Q2≈1.75 GeV2 and with hadronic calculations including nucleon and Delta intermediate states, which have been shown to resolve the discrepancy up to 2-3 GeV2.
Towards a Resolution of the Proton Form Factor Problem: New Electron and Positron Scattering Data
NASA Astrophysics Data System (ADS)
Adikaram, D.; Rimal, D.; Weinstein, L. B.; Raue, B.; Khetarpal, P.; Bennett, R. P.; Arrington, J.; Brooks, W. K.; Adhikari, K. P.; Afanasev, A. V.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A. S.; Bono, J.; Boiarinov, S.; Briscoe, W. J.; Burkert, V. D.; Carman, D. S.; Careccia, S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dodge, G. E.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J. A.; Fradi, A.; Garillon, B.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guegan, B.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Jenkins, D.; Jiang, H.; Jo, H. S.; Joo, K.; Joosten, S.; Kalantarians, N.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Koirala, S.; Kubarovsky, V.; Kuhn, S. E.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Mattione, P.; Mayer, M.; McKinnon, B.; Mestayer, M. D.; Meyer, C. A.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Moody, C. I.; Moutarde, H.; Movsisyan, A.; Camacho, C. Munoz; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Peña, C.; Pisano, S.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A. J. R.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Sharabian, Y. G.; Simonyan, A.; Skorodumina, I.; Smith, E. S.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tian, Ye; Trivedi, A.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.; CLAS Collaboration
2015-02-01
There is a significant discrepancy between the values of the proton electric form factor, GEp, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of GEp from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (ɛ ) and momentum transfer (Q2) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ɛ at Q2=1.45 GeV2 . This measurement is consistent with the size of the form factor discrepancy at Q2≈1.75 GeV2 and with hadronic calculations including nucleon and Δ intermediate states, which have been shown to resolve the discrepancy up to 2 - 3 GeV2 .
Towards a Resolution of the Proton Form Factor Problem: New Electron and Positron Scattering Data
Adikaram, D.; Rimal, D.; Weinstein, L. B.; ...
2015-02-10
There is a significant discrepancy between the values of the proton electric form factor, GpE, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of GpE from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (epsilon) and momentummore » transfer (Q2) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ε at Q2=1.45 GeV2. This measurement is consistent with the size of the form factor discrepancy at Q2≈1.75 GeV2 and with hadronic calculations including nucleon and Delta intermediate states, which have been shown to resolve the discrepancy up to 2-3 GeV2.« less
The Proton Coulomb Form Factor from Polarized Inclusive e-p Scattering
Harris, Christopher Matthew
2001-05-01
The proton form factors provide information on the fundamental properties of the proton and provide a test for models based on QCD. In 1998 at Jefferson Lab (JLAB) in Newport News, VA, experiment E93026 measured the inclusive e-p scattering cross section from a polarized ammonia (^{15}NH_{3}) target at a four momentum transfer squared of Q^{2} = 0.5 (GeV/c)^{2}. Longitudinally polarized electrons were scattered from the polarized target and the scattered electron was detected. Data has been analyzed to obtain the asymmetry from elastically scattered electrons from hydrogen in ^{15}NH_{3}. The asymmetry, A_{p}, has been used to determine the proton elastic form factor G_{Ep}. The result is consistent with the dipole model and data from previous experiments. However, due to the choice of kinematics, the uncertainty in the measurement is large.
Determination of the Axial Nucleon Form Factor from the MiniBooNE Data
Butkevich, A. V.; Perevalov, D.
2014-03-26
Both neutrino and antineutrino charged-current quasi-elastic scattering on a carbon target are studied to investigate the nuclear effect on the determination of the axial form factor F_A(Q^2). A method for extraction of F_A(Q^2) from the flux-integrated $d\\sigma/dQ^2$ cross section of (anti)neutrino scattering on nuclei is presented. Data from the MiniBooNE experiment are analyzed in the relativistic distorted-wave impulse approximation, Fermi gas model, and in the Fermi gas model with enhancements in the transverse cross section. We found that the values of the axial form factor, extracted in the impulse approximation and predicted by the dipole approximation with the axial mass M_A~1.37 GeV are in good agreement. On the other hand, the Q^2-dependence of F_A extracted in the approach with the transverse enhancement is found to differ significantly from the dipole approximation.
Towards a resolution of the proton form factor problem: new electron and positron scattering data.
Adikaram, D; Rimal, D; Weinstein, L B; Raue, B; Khetarpal, P; Bennett, R P; Arrington, J; Brooks, W K; Adhikari, K P; Afanasev, A V; Amaryan, M J; Anderson, M D; Anefalos Pereira, S; Avakian, H; Ball, J; Battaglieri, M; Bedlinskiy, I; Biselli, A S; Bono, J; Boiarinov, S; Briscoe, W J; Burkert, V D; Carman, D S; Careccia, S; Celentano, A; Chandavar, S; Charles, G; Colaneri, L; Cole, P L; Contalbrigo, M; Crede, V; D'Angelo, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Dodge, G E; Dupre, R; Egiyan, H; El Alaoui, A; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fegan, S; Filippi, A; Fleming, J A; Fradi, A; Garillon, B; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Gohn, W; Golovatch, E; Gothe, R W; Griffioen, K A; Guegan, B; Guidal, M; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Harrison, N; Hattawy, M; Hicks, K; Holtrop, M; Hughes, S M; Hyde, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Jenkins, D; Jiang, H; Jo, H S; Joo, K; Joosten, S; Kalantarians, N; Keller, D; Khandaker, M; Kim, A; Kim, W; Klein, A; Klein, F J; Koirala, S; Kubarovsky, V; Kuhn, S E; Livingston, K; Lu, H Y; MacGregor, I J D; Markov, N; Mattione, P; Mayer, M; McKinnon, B; Mestayer, M D; Meyer, C A; Mirazita, M; Mokeev, V; Montgomery, R A; Moody, C I; Moutarde, H; Movsisyan, A; Camacho, C Munoz; Nadel-Turonski, P; Niccolai, S; Niculescu, G; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Peña, C; Pisano, S; Pogorelko, O; Price, J W; Procureur, S; Prok, Y; Protopopescu, D; Puckett, A J R; Ripani, M; Rizzo, A; Rosner, G; Rossi, P; Roy, P; Sabatié, F; Salgado, C; Schott, D; Schumacher, R A; Seder, E; Sharabian, Y G; Simonyan, A; Skorodumina, I; Smith, E S; Smith, G D; Sober, D I; Sokhan, D; Sparveris, N; Stepanyan, S; Stoler, P; Strauch, S; Sytnik, V; Taiuti, M; Tian, Ye; Trivedi, A; Ungaro, M; Voskanyan, H; Voutier, E; Walford, N K; Watts, D P; Wei, X; Wood, M H; Zachariou, N; Zana, L; Zhang, J; Zhao, Z W; Zonta, I
2015-02-13
There is a significant discrepancy between the values of the proton electric form factor, G(E)(p), extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of G(E)(p) from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (ϵ) and momentum transfer (Q(2)) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ϵ at Q(2)=1.45 GeV(2). This measurement is consistent with the size of the form factor discrepancy at Q(2)≈1.75 GeV(2) and with hadronic calculations including nucleon and Δ intermediate states, which have been shown to resolve the discrepancy up to 2-3 GeV(2).
$B\\to\\pi\\ell\\ell$ Form Factors for New-Physics Searches from Lattice QCD
Bailey, Jon A.
2015-10-07
The rare decay B→πℓ^{+}ℓ^{-} arises from b→d flavor-changing neutral currents and could be sensitive to physics beyond the standard model. Here, we present the first ab initio QCD calculation of the B→π tensor form factor f_{T}. Together with the vector and scalar form factors f_{+} and f_{0} from our companion work [J. A. Bailey et al., Phys. Rev. D 92, 014024 (2015)], these parametrize the hadronic contribution to B→π semileptonic decays in any extension of the standard model. We obtain the total branching ratio BR(B^{+}→π^{+}μ^{+}μ^{-})=20.4(2.1)×10^{-9} in the standard model, which is the most precise theoretical determination to date, and agrees with the recent measurement from the LHCb experiment [R. Aaij et al., J. High Energy Phys. 12 (2012) 125].
N. Suzuki, T. Sato, T.-S. H. Lee
2010-10-01
We explain the application of a recently developed analytic continuation method to extract the electromagnetic transition form factors for the nucleon resonances ($N^*$) within a dynamical coupled-channel model of meson-baryon reactions.Illustrative results of the obtained $N^*\\rightarrow \\gamma N$ transition form factors, defined at the resonance pole positions on the complex energy plane, for the well isolated $P_{33}$ and $D_{13}$, and the complicated $P_{11}$ resonances are presented. A formula has been developed to give an unified representation of the effects due to the first two $P_{11}$ poles, which are near the $\\pi\\Delta$ threshold, but are on different Riemann sheets. We also find that a simple formula, with its parameters determined in the Laurent expansions of $\\pi N \\rightarrow \\pi N$ and $\\gamma N \\rightarrow\\pi N$ amplitudes, can reproduce to a very large extent the exact solutions of the considered model at energies near the real parts of the extracted resonance positions. We indicate the differences between our results and those extracted from the approaches using the Breit-Wigner parametrization of resonant amplitudes to fit the data.
Measurement of the Hadronic Form factor in D0 to K- e+ nu_e Decays
Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prudent, X.; Tisserand, V.; Zghiche, A.; Garra Tico, J.; Grauges, E.; Lopez, L.; Palano, A.; Eigen, G.; Stugu, B.; Sun, L.; Abrams, G.S.; Battaglia, M.; Brown, D.N.; Button-Shafer, J.; Cahn, R.N.; /Energy Sci. Network /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Leipzig, Tech. Hochsch. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /Frascati /Genoa U. /Harvard U. /Heidelberg U. /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Karlsruhe U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /Milan U. /Mississippi U. /Concordia U., Montreal /Mt. Holyoke Coll. /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /Paris U., VI-VII /Pennsylvania U. /Perugia U. /Pisa U. /Prairie View A-M /Princeton U. /INFN, Rome /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison /Yale U.
2007-04-09
The shape of the hadronic form factor f{sub +} (q{sup 2}) in the decay D{sup 0} {yields} K{sup -} e{sup +}{nu}{sub e} has been measured in a model independent analysis and compared with theoretical calculations. They use 75 fb{sup -1} of data recorded by the BABAR detector at the PEPII electron-positron collider. The corresponding decay branching fraction, relative to the decay D{sup 0} {yields} K{sup -} {pi}{sup +}, has also been measured to be R{sub D} = BR(D{sup 0} {yields} K{sup -}e{sup +}{nu}{sub e})/BR(D{sup 0} {yields} K{sup -}{pi}{sup +}) = 0.927 {+-} 0.007 {+-} 0.012. From these results, and using the present world average value for BR(D{sup 0} {yields} K{sup -}{pi}{sup +}), the normalization of the form factor at q{sup 2} = 0 is determined to be f{sub +}(0) = 0.727 {+-} 0.007 {+-} 0.005 {+-} 0.007 where the uncertainties are statistical, systematic, and from external inputs, respectively.
Measuring the neutral weak form factors in e-N scattering: the G^0 Expriment
NASA Astrophysics Data System (ADS)
King, Paul
2001-10-01
The G^0 experiment(JLab experiment E00-006, D.H. Beck, spokesperson.) will measure the parity-violating asymmetries in elastic electron-nucleon scattering. The experiment will be performed in Hall C at Jefferson Lab using a dedicated apparatus, with the first running period planned to begin in the summer of 2002. Using measurements of the electron-proton asymmetries at forward and backward angles and the electron-deuteron asymmetries at backward angles over the momentum transfer range of 0.1 - 1.0 GeV^2/c^2, the vector neutral weak form factors, G_E^Z and G_M^Z, and the effective axial current of the nucleon, G_A^e, will be extracted. Combining the neutral weak and the known electromagnetic form factors allows one to experimentally extract the contributions of u, d, and s quarks to the proton's charge and magnetization distributions. An overview of the physics of the G^0 experiment will be presented.
The impact of s-bar{s} asymmetry on the strange electromagnetic form factor
NASA Astrophysics Data System (ADS)
Ghasempour Nesheli, Ali
2016-09-01
The existence of the strange quark asymmetry in the nucleon sea has been indicated by both the experimental and theoretical analyses. Although it is well known that the s-bar{{s}} asymmetry is important for some processes in high-energy hadron collisions, it has also been indicated that it can be related to the strange Dirac form factor F 1 s. In this work, we have studied the impact of s- bar{{s}} asymmetry and its uncertainty from various modern parton distribution functions (PDFs) on F 1 s and compared the obtained results with the available experimental information. As a result, we found that the uncertainty in F 1 s( t) due to the s( x) - bar{s}( x) distribution is rather large so that it dominates the model uncertainty at all values of the squared momentum transfer t. However, taking into account the uncertainties, the theoretical predictions of F 1 s( t) are fully compatible with the estimate extracted from experiment. We concluded that the future accurate experimental data of the strange Dirac form factor might be used to put direct constraints on the strange content of the proton and reduce its uncertainty that has always been a challenge.
Proton form factors and two-photon exchange in elastic electron-proton scattering
Nikolenko, D. M.; Arrington, J.; Barkov, L. M.; Vries, H. de; Gauzshtein, V. V.; Golovin, R. A.; Gramolin, A. V.; Dmitriev, V. F.; Zhilich, V. N.; Zevakov, S. A.; Kaminsky, V. V.; Lazarenko, B. A.; Mishnev, S. I.; Muchnoi, N. Yu.; Neufeld, V. V.; Rachek, I. A.; Sadykov, R. Sh.; Stibunov, V. N.; Toporkov, D. K.; Holt, R. J.; and others
2015-05-15
Proton electromagnetic form factors are among the most important sources of information about the internal structure of the proton. Two different methods for measuring these form factors, the method proposed by Rosenbluth and the polarization-transfer method, yield contradictory results. It is assumed that this contradiction can be removed upon taking into account the hard part of the contribution of two-photon exchange to the cross section for elastic electron-proton scattering. This contribution can measured experimentally via a precision comparison of the cross sections for the elastic scattering of positrons and electrons on protons. Such a measurement, performed at the VEPP-3 storage ring in Novosibirsk at the beam energies of 1.6 and 1.0 GeV for positron (electron) scattering angles in the ranges of θ{sub e} = 15°–25° and 55°–75° in the first case and in the range of θ{sub e} = 65°–105° in the second case is described in the present article. Preliminary results of this experiment and their comparison with theoretical predictions are described.
Direct CP Violation, Branching Ratios and Form Factors B --> pi, B --> K in B decays
O. Leitner; X.-H. Guo; A.W. Thomas
2004-11-01
The B {yields} {pi} and B {yields} K transitions involved in hadronic B decays are investigated in a phenomenological way through the framework of QCD factorization. By comparing our results with experimental branching ratios from the BELLE, BABAR and CLEO collaborations for all the B decays including either a pion or a kaon, we propose boundaries for the transition form factors B {yields} {pi} and B {yields} K depending on the CKM matrix element parameters {rho} and {eta}. From this analysis, the form factors required to reproduce the experimental data for branching ratios are F{sup B {yields} {pi}} = 0.31 {+-} 0.12 and F{sup B {yields} K} = 0.37 {+-} 0.13. We calculate the direct CP violating asymmetry parameter, a{sub CP}, for B {yields} {pi}{sup +}{pi}{sup -}{pi} and B {yields} {pi}{sup +}{pi}{sup -} K decays, in the case where {rho} - {omega} mixing effects are taken into account. Based on these results, we find that the direct CP asymmetry for B{sup -} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup -}, {bar B}{sup 0} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0}, B{sup -} {yields} {pi}{sup +}{pi}{sup -}K{sup -}, and {bar B}{sup 0} {yields} {pi}{sup +}{pi}{sup -} {bar K}{sup 0}, reaches its maximum when the invariant mass {pi}{sup +}{pi}{sup -} is in the vicinity of the {omega} meson mass. The inclusion of {rho} - {omega} mixing provides an opportunity to erase, without ambiguity, the phase uncertainty mod{pi} in the determination of th CKM angles {alpha} in case of b {yields} u and {gamma} in case of b {yields} s.
Niccoli, G.
2013-05-15
The antiperiodic transfer matrices associated to higher spin representations of the rational 6-vertex Yang-Baxter algebra are analyzed by generalizing the approach introduced recently in the framework of Sklyanin's quantum separation of variables (SOV) for cyclic representations, spin-1/2 highest weight representations, and also for spin-1/2 representations of the 6-vertex reflection algebra. Such SOV approach allow us to derive exactly results which represent complicate tasks for more traditional methods based on Bethe ansatz and Baxter Q-operator. In particular, we both prove the completeness of the SOV characterization of the transfer matrix spectrum and its simplicity. Then, the derived characterization of local operators by Sklyanin's quantum separate variables and the expression of the scalar products of separate states by determinant formulae allow us to compute the form factors of the local spin operators by one determinant formulae similar to those of the scalar products.
Construction of the pion scalar form factor from few poles and zero
NASA Astrophysics Data System (ADS)
Kamiński, Robert; Dubnicka, Stanislav; Dubnickova, Zuzana; Liptaj, Andrej
2016-11-01
Construction and analysis of the pion scalar-isoscalar form factor in the elastic region is presented. Precise S-wave ππ scattering phase shifts generated by dispersive analysis of experimental data with imposed crossing symmetry condition are used. Final result for values of the f0(500) meson mass and width, mσ = (487 ± 31) MeV; Γσ = (542 ± 60) MeV is compatible with the results from dispersive analyses of the Bern and Madrid-Kraków groups to be considered now as the most reliable values of the f0(500) scalar meson parameters. Parameters of the f0(980), although lying almost on the KK¯ threshold also agree with values predicted by these two groups.
Pion mass dependence of the K l3 semileptonic scalar form factor within finite volume
NASA Astrophysics Data System (ADS)
Ghorbani, K.; Yazdanpanah, M. M.; Mirjalili, A.
2011-06-01
We calculate the scalar semileptonic kaon decay in finite volume at the momentum transfer t m =( m K - m π )2, using chiral perturbation theory. At first we obtain the hadronic matrix element to be calculated in finite volume. We then evaluate the finite size effects for two volumes with L=1.83 fm and L=2.73 fm and find that the difference between the finite volume corrections of the two volumes are larger than the difference as quoted in Boyle et al. (Phys. Rev. Lett. 100:141601, 2008). It appears then that the pion masses used for the scalar form factor in ChPT are large which result in large finite volume corrections. If appropriate values for pion mass are used, we believe that the finite size effects estimated in this paper can be useful for lattice data to extrapolate at large lattice size.
The ρ-meson time-like form factors in sub-leading pQCD
NASA Astrophysics Data System (ADS)
de Melo, J. P. B. C.; Ji, Chueng-Ryong; Frederico, T.
2016-12-01
The annihilation/production process e+ +e- →ρ+ +ρ- is studied with respect to the universal perturbative QCD (pQCD) predictions. Sub-leading contributions are considered together with the universal leading pQCD amplitudes such that the matrix elements of the ρ-meson electromagnetic current satisfy the constraint from the light-front angular condition. The data from the BaBar collaboration for the time-like ρ-meson form factors at √{ s} = 10.58 GeV puts a stringent test to the onset of asymptotic pQCD behavior. The e+ +e- →ρ+ +ρ- cross-section for s between 60 GeV2 and 160 GeV2 is predicted where the sub-leading contributions are still considerable.
Meson form factors and P→γγ physics at BESIII
NASA Astrophysics Data System (ADS)
Pettersson, J.
2016-08-01
Using data consisting of 2.93 fb-1 integrated luminosity at the centre of mass energy √s = 3773 MeV, recorded with the BESIII detector at BEPCII, the cross section and form factor |Fπ|2 was extracted in the energy range 600-900 MeV, using the method of radiative return. The cross section is used as input to calculate the leading-order vacuum polarisation contribution of the e+e-→π+π- channel to (g - 2)μ as aμ ππ,LO(600 — 900 MeV) = (368.2±2.5stat ±3.3sys) • 10-10. This result is compatible with corresponding values using KLOE data, but disagrees whit BaBar. The ongoing search for e+e-→ηc at BESIII is also discussed.
Structural properties of reciprocal form factor in neutral atoms and singly charged ions.
Romera, E; Angulo, J C
2004-04-22
Structural characteristics of the spherically averaged internally folded density or reciprocal form factor Br are studied within the Hartree-Fock framework for 103 neutral atoms, 54 singly charged cations, and 43 anions in their ground state. The function Br is classified throughout the Periodic Table into three types: (i) monotonic decrease from the origin, (ii) maximum at r=0 and a negative minimum at r>0, and (iii) a local maximum at r=0 and a pair maximum-minimum out of the origin. A detailed study of the corresponding properties for individual subshells as well as their relative weight for the total Br is also carried out. For completeness, the analytical Br for hydrogenlike atoms in both ground and excited states is also analyzed.
JLab Measurement of the ^{4}He Charge Form Factor at Large Momentum Transfers
Camsonne, Alexandre; Katramatou, A. T.; Olson, M.; Sparveris, Nikolaos; Acha, Armando; Allada, Kalyan; Anderson, Bryon; Arrington, John; Baldwin, Alan; Chen, Jian-Ping; Choi, Seonho; Chudakov, Eugene; Cisbani, Evaristo; Craver, Brandon; Decowski, Piotr; Dutta, Chiranjib; Folts, Edward; Frullani, Salvatore; Garibaldi, Franco; Gilman, Ronald; Gomez, Javier; Hahn, Brian; Hansen, Jens-Ole; Higinbotham, Douglas; Holmstrom, Timothy; Huang, Jian; Iodice, Mauro; Kelleher, Aidan; Khrosinkova, Elena; Kievsky, A.; Kuchina, Elena; Kumbartzki, Gerfried; Lee, Byungwuek; LeRose, John; Lindgren, Richard; Lott, Gordon; Lu, H.; Marcucci, Laura; Margaziotis, Demetrius; Markowitz, Pete; Marrone, Stefano; Meekins, David; Meziani, Zein-Eddine; Michaels, Robert; Moffit, Bryan; Norum, Blaine; Petratos, Gerassimos; Puckett, Andrew; Qian, Xin; Rondon-Aramayo, Oscar; Saha, Arunava; Sawatzky, Bradley; Segal, John; Hashemi, Mitra; Shahinyan, Albert; Solvignon-Slifer, Patricia; Subedi, Ramesh; Suleiman, Riad; Sulkosky, Vincent; Urciuoli, Guido; Viviani, Michele; Wang, Y.; Wojtsekhowski, Bogdan; Yan, X.; Yao, H.; Zhang, W. -M.; Zheng, X.; Zhu, L.
2014-04-01
The charge form factor of ^{4}He has been extracted in the range 29 fm^{-2} <= Q^{2} <= 77 fm^{-2} from elastic electron scattering, detecting ^{4}He nuclei and electrons in coincidence with the High Resolution Spectrometers of the Hall A Facility of Jefferson Lab. The results are in qualitative agreement with realistic meson-nucleon theoretical calculations. The data have uncovered a second diffraction minimum, which was predicted in the Q^{2} range of this experiment, and rule out conclusively long-standing predictions of dimensional scaling of high-energy amplitudes using quark counting.
Scattering from phase-separated vesicles. I. An analytical form factor for multiple static domains
Heberle, Frederick A.; Anghel, Vinicius N. P.; Katsaras, John
2015-08-18
This is the first in a series of studies considering elastic scattering from laterally heterogeneous lipid vesicles containing multiple domains. Unique among biophysical tools, small-angle neutron scattering can in principle give detailed information about the size, shape and spatial arrangement of domains. A general theory for scattering from laterally heterogeneous vesicles is presented, and the analytical form factor for static domains with arbitrary spatial configuration is derived, including a simplification for uniformly sized round domains. The validity of the model, including series truncation effects, is assessed by comparison with simulated data obtained from a Monte Carlo method. Several aspects of the analytical solution for scattering intensity are discussed in the context of small-angle neutron scattering data, including the effect of varying domain size and number, as well as solvent contrast. Finally, the analysis indicates that effects of domain formation are most pronounced when the vesicle's average scattering length density matches that of the surrounding solvent.
Scaling study of the pion electroproduction cross sections and the pion form factor
Tanja Horn; Xin Qian; John Arrington; Razmik Asaturyan; Fatiha Benmokthar; Werner Boeglin; Peter Bosted; Antje Bruell; Eric Christy; Eugene Chudakov; Ben Clasie; Mark Dalton; AJI Daniel; Donal Day; Dipangkar Dutta; Lamiaa El Fassi; Rolf Ent; Howard Fenker; J. Ferrer; Nadia Fomin; H. Gao; K Garrow; Dave Gaskell; C Gray; G. Huber; M. Jones; N Kalantarians; C. Keppel; K Kramer; Y Li; Y Liang; A. Lung; S Malace; P. Markowitz; A. Matsumura; D. Meekins; T Mertens; T Miyoshi; H. Mykrtchyan; R. Monson; T. Navasardyan; G. Niculescu; I. Niculescu; Y. Okayasu; A. Opper; C Perdrisat; V. Punjabi; A. Rauf; V. Rodriguez; D. Rohe; J Seely; E Segbefia; G. Smith; M. Sumihama; V. Tadevoyan; L Tang; V. Tvaskis; A. Villano; W. Vulcan; F. Wesselmann; S. Wood; L. Yuan; X. Zheng
2007-07-12
The $^{1}$H($e,e^\\prime \\pi^+$)n cross section was measured for a range of four-momentum transfer up to $Q^2$=3.91 GeV$^2$ at values of the invariant mass, $W$, above the resonance region. The $Q^2$-dependence of the longitudinal component is consistent with the $Q^2$-scaling prediction for hard exclusive processes. This suggests that perturbative QCD concepts are applicable at rather low values of $Q^2$. Pion form factor results, while consistent with the $Q^2$-scaling prediction, are inconsistent in magnitude with perturbative QCD calculations. The extraction of Generalized Parton Distributions from hard exclusive processes assumes the dominance of the longitudinal term. However, transverse contributions to the cross section are still significant at $Q^2$=3.91 GeV$^2$.
Transition Form Factors: A Unique Opportunity to Connect Non-Perturbative Strong Interactions to QCD
Gothe, Ralf W.
2014-01-01
Meson-photoproduction measurements and their reaction-amplitude analyses can establish more sensitively, and in some cases in an almost model-independent way, nucleon excitations and non-resonant reaction amplitudes. However, to investigate the strong interaction from explored — where meson-cloud degrees of freedom contribute substantially to the baryon structure — to still unexplored distance scales — where quark degrees of freedom dominate and the transition from dressed to current quarks occurs — we depend on experiments that allow us to measure observables that are probing this evolving non-perturbative QCD regime over its full range. Elastic and transition form factors are uniquely suited to trace this evolution by measuring elastic electron scattering and exclusive single-meson and double-pion electroproduction cross sections off the nucleon. These exclusive measurements will be extended to higher momentum transfers with the energy-upgraded CEBAF beam at JLab to study the quark degrees of freedom, where their strong interaction is responsible for the ground and excited nucleon state formations. After establishing unprecedented high-precision data, the imminent next challenge is a high-quality analysis to extract these relevant electrocoupling parameters for various resonances that then can be compared to state-of-the-art models and QCD-based calculations. Recent results will demonstrate the status of the analysis and of their theoretical descriptions, and an experimental and theoretical outlook will highlight what shall and may be achieved in the new era of the 12-GeV upgraded transition form factor program.
Weak charge form factor and radius of 208Pb through parity violation in electron scattering
Horowitz, C. J.; Ahmed, Z.; Jen, C. -M.; ...
2012-03-26
We use distorted wave electron scattering calculations to extract the weak charge form factor FW(more » $$\\bar{q}$$), the weak charge radius RW, and the point neutron radius Rn, of 208Pb from the PREX parity violating asymmetry measurement. The form factor is the Fourier transform of the weak charge density at the average momentum transfer $$\\bar{q}$$ = 0.475 fm-1. We find FW($$\\bar{q}$$) = 0.204 ± 0.028(exp) ± 0.001(model). We use the Helm model to infer the weak radius from FW($$\\bar{q}$$). We find RW = 5.826 ± 0.181(exp) ± 0.027(model) fm. Here the exp error includes PREX statistical and systematic errors, while the model error describes the uncertainty in RW from uncertainties in the surface thickness σ of the weak charge density. The weak radius is larger than the charge radius, implying a 'weak charge skin' where the surface region is relatively enriched in weak charges compared to (electromagnetic) charges. We extract the point neutron radius Rn = 5.751 ± 0.175 (exp) ± 0.026(model) ± 0.005(strange) fm, from RW. Here there is only a very small error (strange) from possible strange quark contributions. We find Rn to be slightly smaller than RW because of the nucleon's size. As a result, we find a neutron skin thickness of Rn-Rp = 0.302 ± 0.175 (exp) ± 0.026 (model) ± 0.005 (strange) fm, where Rp is the point proton radius.« less
Universal behavior of the γ⁎γ→(π0,η,η′) transition form factors
Melikhov, Dmitri; Stech, Berthold
2012-01-01
The photon transition form factors of π, η and η′ are discussed in view of recent measurements. It is shown that the exact axial anomaly sum rule allows a precise comparison of all three form factors at high-Q2 independent of the different structures and distribution amplitudes of the participating pseudoscalar mesons. We conclude: (i) The πγ form factor reported by Belle is in excellent agreement with the nonstrange I=0 component of the η and η′ form factors obtained from the BaBar measurements. (ii) Within errors, the πγ form factor from Belle is compatible with the asymptotic pQCD behavior, similar to the η and η′ form factors from BaBar. Still, the best fits to the data sets of πγ, ηγ, and η′γ form factors favor a universal small logarithmic rise Q2FPγ(Q2)∼log(Q2). PMID:23226917
Hayase, Tomomi; Shimizu, Jun; Goto, Tamako; Nozaki, Yasuyuki; Mori, Masato; Takahashi, Naoto; Namba, Eiji; Yamagata, Takanori; Momoi, Mariko Y
2010-03-01
We report the case of a girl with Tay-Sachs disease who had convulsions and deteriorated rapidly after an upper respiratory infection at the age of 11 months. At the age of 16 months, her seizures became intractable and magnetic resonance imaging of the brain showed high signal intensity on T2-weighted images and marked swelling in the white matter and basal nucelei of the right hemisphere. Her seizures and right hemisphere lesion improved with glycerol and dexamethasone treatment. When dexamethasone was discontinued, her symptoms worsened and lesions later appeared in the left hemisphere. Her cerebrospinal fluid showed elevated levels of the cytokines TNF-alpha and IL-5. It is considered that inflammation contributes to disease progression in Tay-Sachs disease.
Tay-Sachs disease in Brazilian patients: prevalence of the IVS7+1g>c mutation.
Rozenberg, R; Martins, A M; Micheletti, C; Mustacchi, Z; Pereira, L V
2004-01-01
Seven Brazilian Tay-Sachs disease cases were screened for the most frequent causative mutations. They all presented at least one copy of the IVS7+1g>c mutation. Three patients were homozygotes, three were compound heterozygotes, and in one case only the mother was tested and shown to carry the IVS7+1g>c mutation. In the second allele the compound heterozygotes presented: R178H (the DN allele), InsTATC1278 and an unidentified mutation. The IVS7+1g>c mutation has already been described in three Portuguese patients. In this study, all families were unaware of any Portuguese ancestry. Since Brazil was a Portuguese colony, the mutation most probably came from ancient common ancestry. The initial molecular analysis of Tay-Sachs disease patients in Brazil indicated a prevalence of the IVS7+1g>c mutation, possibly as a result of genetic drift.
Felten, T.; Schlickeiser, R.
2013-08-15
Closed analytical expressions for the electromagnetic fluctuation spectra in unmagnetized plasmas are derived using fully relativistic dispersion functions and form factors for the important class of isotropic form-invariant Lorentzian plasma particle distribution functions. Such distribution functions occur frequently in cosmic plasmas due to the presence of suprathermal charged particles and energetic cosmic ray particles. The results are illustrated for the important special case of aperiodic fluctuations. The collective, transverse, damped aperiodic mode, discovered before in nonrelativistic Maxwellian particle distributions, also exists in Lorentzian electron-proton particle distributions, now with the damping rate γ∝−k{sup 3} for all wavenumber values, resulting from the presence of relativistic particles in the tail of the Lorentzian distribution. For longitudinal electric field, fluctuations no damped or growing aperiodic collective mode exists in Lorentzian plasmas. The existence of a damped, collective, transverse, aperiodic mode is not in conflict with earlier general instability studies excluding the existence of growing aperiodic collective modes in isotropic plasmas.
Collett, Jason A; Mehrotra, Purvi; Crone, Allison; Shelley, W Christopher; Yoder, Mervin C; Basile, David P
2017-02-22
Damage to endothelial cells contributes to acute kidney injury (AKI) by leading to impaired perfusion. Endothelial colony-forming cells (ECFCs) are endothelial precursor cells with high proliferative capacity, pro-angiogenic activity, and in vivo vessel forming potential. We hypothesized that ECFCs may ameliorate the degree of AKI and/or promote repair of the renal vasculature following ischemia/reperfusion (I/R). Rat pulmonary microvascular ECs (PMVEC) with high proliferative potential were compared with pulmonary artery ECs (PAEC) with low proliferative potential in rats subjected to renal I/R. PMVEC administration reduced renal injury and hastened recovery as indicated by serum creatinine and tubular injury scores, while PAEC did not. Vehicle-treated control animals showed consistent reductions in renal medullary blood flow (MBF) within 2 hours of reperfusion, while PMVEC protected against loss in MBF as measured by laser Doppler. Interestingly, PMVEC mediated protection occurred in the absence of homing to the kidney. Conditioned medium (CM) from human cultured cord blood ECFC also conveyed beneficial effects against I/R injury and loss of MBF. Moreover, ECFC-CM significantly reduced the expression of adhesion molecules such as ICAM-1 and p-selectin, and decreased the number of differentiated lymphocytes typically recruited into the kidney following renal ischemia. Taken together, these data suggest that ECFC secrete factors that preserve renal function post ischemia, in part, by preserving microvascular function.
Form factors of the isovector scalar current and the [Formula: see text] scattering phase shifts.
Albaladejo, M; Moussallam, B
A model for S-wave [Formula: see text] scattering is proposed which could be realistic in an energy range from threshold up to above 1 GeV, where inelasticity is dominated by the [Formula: see text] channel. The T-matrix, satisfying two-channel unitarity, is given in a form which matches the chiral expansion results at order [Formula: see text] exactly for the [Formula: see text], [Formula: see text] amplitudes and approximately for [Formula: see text]. It contains six phenomenological parameters. Asymptotic conditions are imposed which ensure a minimal solution of the Muskhelishvili-Omnès problem, thus allowing one to compute the [Formula: see text] and [Formula: see text] form factor matrix elements of the [Formula: see text] scalar current from the T-matrix. The phenomenological parameters are determined such as to reproduce the experimental properties of the [Formula: see text], [Formula: see text] resonances, as well as the chiral results of the [Formula: see text] and [Formula: see text] scalar radii, which are predicted to be remarkably small at [Formula: see text]. This T-matrix model could be used for a unified treatment of the [Formula: see text] final-state interaction problem in processes such as [Formula: see text], [Formula: see text], or the [Formula: see text] initial-state interaction in [Formula: see text].
Baculovirus per os infectivity factors form a complex on the surface of occlusion-derived virus.
Peng, Ke; van Oers, Monique M; Hu, Zhihong; van Lent, Jan W M; Vlak, Just M
2010-09-01
Five highly conserved per os infectivity factors, PIF1, PIF2, PIF3, PIF4, and P74, have been reported to be essential for oral infectivity of baculovirus occlusion-derived virus (ODV) in insect larvae. Three of these proteins, P74, PIF1, and PIF2, were thought to function in virus binding to insect midgut cells. In this paper evidence is provided that PIF1, PIF2, and PIF3 form a stable complex on the surface of ODV particles of the baculovirus Autographa californica multinucleocapsid nucleopolyhedrovirus (AcMNPV). The complex could withstand 2% SDS-5% beta-mercaptoethanol with heating at 50 degrees C for 5 min. The complex was not formed when any of the genes for PIF1, PIF2, or PIF3 was deleted, while reinsertion of these genes into AcMNPV restored the complex. Coimmunoprecipitation analysis independently confirmed the interactions of the three PIF proteins and revealed in addition that P74 is also associated with this complex. However, deletion of the p74 gene did not affect formation of the PIF1-PIF2-PIF3 complex. Electron microscopy analysis showed that PIF1 and PIF2 are localized on the surface of the ODV with a scattered distribution. This distribution did not change for PIF1 or PIF2 when the gene for PIF2 or PIF1 protein was deleted. We propose that PIF1, PIF2, PIF3, and P74 form an evolutionarily conserved complex on the ODV surface, which has an essential function in the initial stages of baculovirus oral infection.
Factors limiting the establishment of canopy-forming algae on artificial structures
NASA Astrophysics Data System (ADS)
Cacabelos, Eva; Martins, Gustavo M.; Thompson, Richard; Prestes, Afonso C. L.; Azevedo, José Manuel N.; Neto, Ana I.
2016-11-01
Macroalgal canopies are important ecosystem engineers, contributing to coastal productivity and supporting a rich assemblage of associated flora and fauna. However, they are often absent from infrastructures such as coastal defences and there has been a worldwide decline in their distribution in urbanised coastal areas. The macroalga Fucus spiralis is the only high-shore canopy forming species present in the Azores. It is widely distributed in the archipelago but is never found on coastal infrastructures. Here we evaluate factors that may potentially limit its establishment on artificial structures. A number of observational and manipulative experiments were used to test the hypotheses that: (i) limited-dispersal ability limits the colonisation of new plants onto artificial structures, (ii) vertical substratum slope negatively influences the survivorship of recruits, and (iii) vertical substratum slope also negatively influences the survivorship and fitness of adults. Results showed that the limited dispersal from adult plants may be a more important factor than slope in limiting the species ability to colonise coastal infrastructures, since the vertical substratum slope does not affect its fitness or survivorship.
On the key factors of angular correlations in complex-forming elementary reactions
NASA Astrophysics Data System (ADS)
Bonnet, L.; Rayez, J. C.
2006-04-01
In the mid-seventies, Case and Herschbach argued that for complex-forming three-atom reactions governed by long-range forces and performed in supersonic molecular beam experiments, vectorial properties are determined by a single parameter Λ' =
Crystal Structure of a Translation Termination Complex Formed With Release Factor RF2
Korostelev, A.; Asahara, H.; Lancaster, L.; Laurberg, M.; Hirschi, A.; Zhu, J.; Trakhanov, S.; Scott, W.G.; Noller, H.F.
2009-05-20
We report the crystal structure of a translation termination complex formed by the Thermus thermophilus 70S ribosome bound with release factor RF2, in response to a UAA stop codon, solved at 3 {angstrom} resolution. The backbone of helix -5 and the side chain of serine of the conserved SPF motif of RF2 recognize U1 and A2 of the stop codon, respectively. A3 is unstacked from the first 2 bases, contacting Thr-216 and Val-203 of RF2 and stacking on G530 of 16S rRNA. The structure of the RF2 complex supports our previous proposal that conformational changes in the ribosome in response to recognition of the stop codon stabilize rearrangement of the switch loop of the release factor, resulting in docking of the universally conserved GGQ motif in the PTC of the 50S subunit. As seen for the RF1 complex, the main-chain amide nitrogen of glutamine in the GGQ motif is positioned to contribute directly to catalysis of peptidyl-tRNA hydrolysis, consistent with mutational studies, which show that most side-chain substitutions of the conserved glutamine have little effect. We show that when the H-bonding capability of the main-chain N-H of the conserved glutamine is eliminated by substitution with proline, peptidyl-tRNA esterase activity is abolished, consistent with its proposed role in catalysis.
A pre-formed Pyrogenic Factor Released by Lipopolysaccharide Stimulated Macrophages
Zampronio, A. R.; Melo, M. C. C.; Silva, C. A. A.; Pelá, I. R.; Hopkins, S. J.
1994-01-01
The aim of this study was to investigate the pyrogenic activity of factor(s) released by rat peritoneal macrophages following a brief stimulation with LPS. The effect of this factor on the number of circulating leukocytes and serum Fe, Cu and Zn levels, was also evaluated. The possibility that the content of interleukin (IL)-1β, IL-6 and tumour necrosis factor (TNF) in the supernatant could explain the observations was investigated. Supernatant produced over a period of 1 h by peritoneal macrophages, following a 30 min incubation with LPS at 37°C, was ultrafiltered through a 10 000 MW cut-off Amicon membrane, sterilized, and concentrated 2.5, 5, 10 and 20 times. The intravenous (i.v.) injection of this supernatant induced a concentration-dependent fever in rats with a maximal response at 2 h. The pyrogenic activity was produced by macrophages elicited with thioglycollate and by resident cells. The supernatants also induced neutrophilia and reduction in Fe and Zn 6 h after the injection. Absence of activity in boiled supernatants, or supernatants from macrophages incubated at 4°C with LPS, indicates that LPS was not responsible for the activity. In vitro treatment with indomethacin (Indo), dexamethasone (Dex), or cycloheximide (Chx) did not modify the release of pyrogenic activity into the supernatant or its effects on the reduction in serum metal levels. Although Chx abolished the production of mediator(s) inducing neutrophilia, and Dex reduced the induction of IL-1β, TNF and IL-6, injection of the highest concentration of these cytokines detected in the supernatants did not induce fever. In vivo treatment with Dex, but not Indo, abolished the fever induced by the supernatant. These results suggest that macrophages contain pre-formed pyrogenic mediator(s), not related to IL-1β, IL-6 or TNF, that acts indirectly and independently of prostaglandtn. It also seems likely that the pyrogenic activity is related to the factor responsible for the reduction of serum Fe
ω→π0γ* and ϕ→π0γ* transition form factors in dispersion theory
NASA Astrophysics Data System (ADS)
Schneider, Sebastian P.; Kubis, Bastian; Niecknig, Franz
2012-09-01
We calculate the ω→π0γ* and ϕ→π0γ* electromagnetic transition form factors based on dispersion theory, relying solely on a previous dispersive analysis of the corresponding three-pion decays and the pion vector form factor. We compare our findings to recent measurements of the ω→π0μ+μ- decay spectrum by the NA60 collaboration, and strongly encourage experimental investigation of the Okubo-Zweig-Iizuka forbidden ϕ→π0ℓ+ℓ- decays in order to understand the strong deviations from vector-meson dominance found in these transition form factors.
A Non-parametric approach to the D+ ---> anti-K*0 mu+ nu form-factors
Link, J.M.; Yager, P.M.; Anjos, J.C.; Bediaga, I.; Castromonte, C.; Machado, A.A.; Magnin, J.; Massafferri, A.; de Miranda, J.M.; Pepe, I.M.; Polycarpo, E.; dos Reis, A.C.; Carrillo, S.; Casimiro, E.; Cuautle, E.; Sanchez-Hernandez, A.; Uribe, C.; Vazquez, F.; Agostino, L.; Cinquini, L.; Cumalat, J.P.; /Colorado U. /Fermilab /Frascati /Guanajuato U. /Illinois U., Urbana /Indiana U. /Korea U. /Kyungpook Natl. U. /INFN, Milan /Milan U. /North Carolina U. /Pavia U. /INFN, Pavia /Rio de Janeiro, Pont. U. Catol. /Puerto Rico U., Mayaguez /South Carolina U. /Tennessee U. /Vanderbilt U. /Wisconsin U., Madison
2005-09-01
Using a large sample of D{sup +} {yields} K{sup -} {pi}{sup +} {mu}{sup +}{nu} decays collected by the FOCUS photo-production experiment at Fermilab, we present the first measurements of the helicity basis form factors free from the assumption of spectroscopic pole dominance. We also present the first information on the form factor that controls the s-wave interference discussed in a previous paper by the FOCUS collaboration. We find reasonable agreement with the usual assumption of spectroscopic pole dominance and measured form factor ratios.
Strange magnetic form factor of the proton at $Q^2 = 0.23$ GeV$^2$
Wang, Ping; Leinweber, Derek; Thomas, Anthony; Young, Ross
2009-06-01
We determine the $u$ and $d$ quark contributions to the proton magnetic form factor at finite momentum transfer by applying chiral corrections to quenched lattice data. Heavy baryon chiral perturbation theory is applied at next to leading order in the quenched, and full QCD cases for the valence sector using finite range regularization. Under the assumption of charge symmetry these values can be combined with the experimental values of the proton and neutron magnetic form factors to deduce a relatively accurate value for the strange magnetic form factor at $Q^2=0.23$ GeV$^2$, namely $G_M^s=-0.034 \\pm 0.021$ $\\mu_N$.
Proia, R.L.; Yamanaka, S.; Johnson, M.D.
1994-09-01
Tay-Sachs disease, the prototype of the G{sub M2} gangliosidoses, is a catastrophic neurodegenerative disorder of infancy. The disease is caused by mutations in the HEXA gene resulting in an absence of the lysosomal enzyme, {beta}-hexosaminidase A. As consequence of the enzyme deficiency, G{sub M2} ganglioside accumulates progressively, beginning early in fetal life, to excessive amounts in the central nervous system (CNS). Rapid mental and motor deterioration starting in the first year of life leads to death by 2 to 4 years of age. Through the targeted disruption of the Hexa gene in embryonic stem cells, we have produced mice with biochemical and neuropathologic features of Tay-Sachs disease. The mutant mice exhibited less than 1% of normal {beta}-hexosaminidase A activity and accumulated G{sub M2} ganglioside in their CNS in an age-dependent manner. The accumulated ganglioside was stored in neurons as membranous cytoplasmic bodies characteristically found in the neurons of Tay-Sachs disease patients. At three to five months of age the mutant mice showed no apparent defects in motor or memory function. These {beta}-hexosaminidase A deficient mice should be useful for devising strategies to introduce functional enzymes and genes into the CNS. This model may also be valuable for studying the biochemical and pathologic changes occurring during the course of the disease.
Zampieri, Stefania; Montalvo, Annalisa; Blanco, Mariana; Zanin, Irene; Amartino, Hernan; Vlahovicek, Kristian; Szlago, Marina; Schenone, Andrea; Pittis, Gabriela; Bembi, Bruno; Dardis, Andrea
2012-05-15
Tay-Sachs disease (TSD) is a recessively inherited disorder caused by the deficient activity of hexosaminidase A due to mutations in the HEXA gene. Up to date there is no information regarding the molecular genetics of TSD in Argentinean patients. In the present study we have studied 17 Argentinean families affected by TSD, including 20 patients with the acute infantile form and 3 with the sub-acute form. Overall, we identified 14 different mutations accounting for 100% of the studied alleles. Eight mutations were novel: 5 were single base changes leading to drastic residue changes or truncated proteins, 2 were small deletions and one was an intronic mutation that may cause a splicing defect. Although the spectrum of mutations was highly heterogeneous, a high frequency of the c.459+5G>A mutation, previously described in different populations was found among the studied cohort. Haplotype analysis suggested that in these families the c.459+5G>A mutation might have arisen by a single mutational event.
Griffith, M J; Breitkreutz, L; Trapp, H; Briet, E; Noyes, C M; Lundblad, R L; Roberts, H R
1985-01-01
Two structurally different forms of activated human Factor IX (Factor IXa alpha and IXa beta) have been previously reported to have essentially identical clotting activity in vitro. Although it has been shown that activated Factor IX Chapel Hill, an abnormal Factor IX isolated from the plasma of a patient with mild hemophilia B, and normal Factor IXa alpha are structurally very similar, the clotting activity of activated Factor IX Chapel Hill is much lower (approximately fivefold) than that of normal Factor IXa beta. In the present study we have prepared activated Factor IX by incubating human Factor IX with calcium and Russell's viper venom covalently bound to agarose. Fractionation of the activated Factor IX by high-performance liquid chromatography demonstrated the presence of both Factors IXa alpha and IXa beta. On the basis of active site concentration, determined by titration with antithrombin III, the clotting activities of activated Factor IX Chapel Hill and IXa alpha were similar, but both activities were less than 20% of the clotting activity of Factor IXa beta. Activated Factor IX activity was also measured in the absence of calcium, phospholipid, and Factor VIII, by determination of the rate of Factor X activation in the presence of polylysine. In the presence of polylysine, the rates of Factor X activation by activated Factor IX Chapel Hill, Factor IXa alpha, and Factor IXa beta were essentially identical. We conclude that the clotting activity of activated Factor IX Chapel Hill is reduced when compared with that of Factor IXa beta but essentially normal when compared with that of Factor IXa alpha. PMID:3871202
Dirac and Pauli form factors based on consideration of the gluon effect in light-cone wave functions
NASA Astrophysics Data System (ADS)
Shojaei, Mohammad Reza; Nikkhoo, Negin Sattary
2015-11-01
We discuss Dirac and Pauli form factors based on a generalized parton distribution framework in the range of high momentum transfers of t < 30 GeV2 and calculate the electromagnetic form factors, GE and GM, for the proton. In previous work, Gaussian parameterization has been used in wave functions for calculating electromagnetic form factors at intermediate-high momentum transfers of 1 GeV2 < t < 10 GeV2; in this paper, by considering an improved Gaussian ansatz, we not only calculate the electromagnetic form factors at moderately high momentum transfers t but also can calculate these quantities at high momentum transfers, achieving reasonable agreement with experimental data and other previous work.
Mistri, Mehul; Tamhankar, Parag M; Sheth, Frenny; Sanghavi, Daksha; Kondurkar, Pratima; Patil, Swapnil; Idicula-Thomas, Susan; Gupta, Sarita; Sheth, Jayesh
2012-01-01
Tay Sachs disease (TSD) is a neurodegenerative disorder due to β-hexosaminidase A deficiency caused by mutations in the HEXA gene. The mutations leading to Tay Sachs disease in India are yet unknown. We aimed to determine mutations leading to TSD in India by complete sequencing of the HEXA gene. The clinical inclusion criteria included neuroregression, seizures, exaggerated startle reflex, macrocephaly, cherry red spot on fundus examination and spasticity. Neuroimaging criteria included thalamic hyperdensities on CT scan/T1W images of MRI of the brain. Biochemical criteria included deficiency of hexosaminidase A (less than 2% of total hexosaminidase activity for infantile patients). Total leukocyte hexosaminidase activity was assayed by 4-methylumbelliferyl-N-acetyl-β-D-glucosamine lysis and hexosaminidase A activity was assayed by heat inactivation method and 4-methylumbelliferyl-N-acetyl-β-D-glucosamine-6-sulphate lysis method. The exons and exon-intron boundaries of the HEXA gene were bidirectionally sequenced using an automated sequencer. Mutations were confirmed in parents and looked up in public databases. In silico analysis for mutations was carried out using SIFT, Polyphen2, MutationT@ster and Accelrys Discovery Studio softwares. Fifteen families were included in the study. We identified six novel missense mutations, c.340 G>A (p.E114K), c.964 G>A (p.D322N), c.964 G>T (p.D322Y), c.1178C>G (p.R393P) and c.1385A>T (p.E462V), c.1432 G>A (p.G478R) and two previously reported mutations. c.1277_1278insTATC and c.508C>T (p.R170W). The mutation p.E462V was found in six unrelated families from Gujarat indicating a founder effect. A previously known splice site mutation c.805+1 G>C and another intronic mutation c.672+30 T>G of unknown significance were also identified. Mutations could not be identified in one family. We conclude that TSD patients from Gujarat should be screened for the common mutation p.E462V.
Lu, Hang; Catania, Jason; Baranji, Katalin; Feng, Jie; Gu, Mili; Lathey, Janet; Sweeny, Diane; Sanford, Hannah; Sapru, Kavita; Patamawenu, Terry; Chen, June-Home; Ng, Alan; Fesseha, Zenbework; Kluepfel-Stahl, Stefanie; Minang, Jacob
2013-01-01
The cell-based anthrax toxin neutralization assay (TNA) is used to determine functional antibody titers of sera from animals and humans immunized with anthrax vaccines. The anthrax lethal toxin is a critical reagent of the TNA composed of protective antigen (PA) and lethal factor (LF), which are neutralization targets of serum antibodies. Cytotoxic potency of recombinant LF (rLF) lots can vary substantially, causing a challenge in producing a renewable supply of this reagent for validated TNAs. To address this issue, we characterized a more potent rLF variant (rLF-A) with the exact native LF amino acid sequence that lacks the additional N-terminal histidine and methionine residues present on the commonly used form of rLF (rLF-HMA) as a consequence of the expression vector. rLF-A can be used at 4 to 6 ng/ml (in contrast to 40 ng/ml rLF-HMA) with 50 ng/ml recombinant PA (rPA) to achieve 95 to 99% cytotoxicity. In the presence of 50 ng/ml rPA, both rLF-A and rLF-HMA allowed for similar potencies (50% effective dilution) among immune sera in the TNA. rPA, but not rLF, was the dominant factor in determining potency of serum samples containing anti-PA antibodies only or an excess of anti-PA relative to anti-rLF antibodies. Such anti-PA content is reflected in immune sera derived from most anthrax vaccines in development. These results support that 7- to 10-fold less rLF-A can be used in place of rLF-HMA without changing TNA serum dilution curve parameters, thus extending the use of a single rLF lot and a consistent, renewable supply. PMID:23637044
Karpati, Mazal; Gazit, Ephraim; Goldman, Boleslaw; Frisch, Amos; Colombo, Roberto; Peleg, Leah
2004-02-01
The incidence of Tay-Sachs disease (TSD) carriers, as defined by enzyme assay, is 1:29 among Ashkenazi Jews and 1:110 among Moroccan Jews. An elevated carrier frequency of 1:140 was also observed in the Iraqi Jews (IJ), while in other Israeli populations the world's pan-ethnic frequency of approximately 1:280 has been found. Recently a novel mutation, G749T, has been reported in 38.7% of the IJ carriers (24/62). Here we report a second novel HEXA mutation specific to the IJ TDS carriers: a substitution of cytosine 1351 by guanosine (C1351G), resulting in the change of leucine to valine in position 451. This mutation was found in 33.9% (21/62) of the carriers and in none of 100 non-carrier IJ. In addition to the two specific mutations, 14.5% (9/62) of the IJ carriers bear a known "Jewish" mutation (Ashkenazi or Moroccan) and 11.3% (7/62) carry a known "non-Jewish" mutation. In 1 DNA sample no mutation has yet been detected. To investigate the genetic history of the IJ-specific mutations (C1351G and G749T), the allelic distribution of four polymorphic markers (D15S131, D15S1025, D15S981, D15S1050) was analyzed in IJ heterozygotes and ethnically matched controls. Based on linkage disequilibrium, recombination factor (theta) between the markers and mutated loci, and the population growth correction, we deduced that G749T occurred in a founder ancestor 44.8 +/- 14.2 generations (g) ago [95% confidence interval (CI) 17.0-72.6 g] and C1351G arose 80.4 +/- 35.9 g ago (95% CI 44.5-116.3 g). Thus, the estimated dates for introduction of mutations are: 626 +/- 426 A.D. (200-1052 A.D.) for G749T and 442 +/- 1077 B.C. (1519 B.C. to 635 A.D.) for C1351G.
Covariant Spectator Theory of np scattering: Deuteron magnetic moment and form factors
Gross, Franz L.
2014-06-01
The deuteron magnetic moment is calculated using two model wave functions obtained from 2007 high precision fits to $np$ scattering data. Included in the calculation are a new class of isoscalar $np$ interaction currents which are automatically generated by the nuclear force model used in these fits. After normalizing the wave functions, nearly identical predictions are obtained: model WJC-1, with larger relativistic P-state components, gives 0.863(2), while model WJC-2 with very small $P$-state components gives 0.864(2) These are about 1\\% larger than the measured value of the moment, 0.857 n.m., giving a new prediction for the size of the $\\rho\\pi\\gamma$ exchange, and other purely transverse interaction currents that are largely unconstrained by the nuclear dynamics. The physical significance of these results is discussed, and general formulae for the deuteron form factors, expressed in terms of deuteron wave functions and a new class of interaction current wave functions, are given.
Overview of nucleon form factor experiments with 12 GeV at Jefferson Lab
NASA Astrophysics Data System (ADS)
Cisbani, Evaristo
2014-06-01
Since the R. Hofstadter pioneering experiments in the '50s, the measurements of the electromagnetic space-like nucleon form factors (FF's) have been a precious source of information for the understanding of the internal structure of the nucleons. In the last 15 years, the polarization transfer experiments at the Thomas Jefferson National Accelerator Facility (JLab) have undermined our view of the mechanism of the electron scattering and renewed critical interest in the FF measurements. In the coming years, JLab, with its upgraded 12 GeV polarized, high intensity, electron beam combined to new targets and readout equipments, will offer unprecedented opportunities to extend the current proton and neutron FF's measurements to higher momentum transfer Q2 and to improve statistical and uncertainties at lower Q2, where the nucleon size can be accurately investigated. The measurements at high Q2 will provide also new insights on the elusive quark orbital angular momenta, will contribute to constraint two of the nucleon Generalized Parton Distributions that are expected to describe more consistently the nucleon structure, and in general will test the validity of quite a few fundamental nucleon models in a region of transition between perturbative and non perturbative regimes. A selection of the relevant properties of the FF's, and the main results of JLab are shortly reviewed; the new proposed and approved experiments on FF's at JLab are presented addressing some key details, the expected experimental achievements and the new equipment designed for them.
Antiproton-nucleus electromagnetic annihilation as a way to access the proton timelike form factors
NASA Astrophysics Data System (ADS)
Fonvieille, H.; Karmanov, V. A.
2009-11-01
Contrary to the reaction bar{{p}} p rightarrow e + e - with a high-momentum incident antiproton on a free target proton at rest, in which the invariant mass M of the e + e - pair is necessarily much larger than the bar{{p}} p mass 2 m , in the reaction bar{{p}} d rightarrow e + e - n the value of M can take values near or below the bar{{p}} p mass. In the antiproton-deuteron electromagnetic annihilation, this allows to access the proton electromagnetic form factors in the timelike region of q2 near the bar{{p}} p threshold. We estimate the cross-section dσ _{bar pd to e^ + e^ - n} /dmathcal{M} for an antiproton beam momentum of 1.5GeV/ c. We find that near the bar{{p}} p threshold this cross-section is about 1pb/MeV. The case of heavy-nuclei target is also discussed. Elements of experimental feasibility are presented for the process bar{{p}} d rightarrow e + e - n in the context of the overline{{P}} ANDA project.
Scalar K{pi} form factor and light-quark masses
Jamin, Matthias; Oller, Jose Antonio; Pich, Antonio
2006-10-01
Recent experimental improvements on K-decay data allow for a precise extraction of the strangeness-changing scalar K{pi} form factor and the related strange scalar spectral function. On the basis of this scalar as well as the corresponding pseudoscalar spectral function, the strange quark mass is determined to be m{sub s}(2 GeV)=92{+-}9 MeV. Further taking into account chiral perturbation theory mass ratios, the light up and down quark masses turn out to be m{sub u}(2 GeV)=2.7{+-}0.4 MeV as well as m{sub d}(2 GeV)=4.8{+-}0.5 MeV. As a by-product, we also find a value for the Cabibbo angle |V{sub us}|=0.2236(29) and the ratio of meson decay constants F{sub K}/F{sub {pi}}=1.203(16). Performing a global average of the strange mass by including extractions from other channels as well as lattice QCD results yields m{sub s}(2 GeV)=94{+-}6 MeV.
Small Form Factor Information Storage Devices for Mobile Applications in Korea
NASA Astrophysics Data System (ADS)
Park, Young-Pil; Park, No-Cheol; Kim, Chul-Jin
Recently, the ubiquitous environment in which anybody can reach a lot of information data without any limitations on the place and time has become an important social issue. There are two basic requirements in the field of information storage devices which have to be satisfied; the first is the demand for the improvement of memory capacity to manage the increased data capacity in personal and official purposes. The second is the demand for new development of information storage devices small enough to be applied to mobile multimedia digital electronics, including digital camera, PDA and mobile phones. To summarize, for the sake of mobile applications, it is necessary to develop information storage devices which have simultaneously a large capacity and a small size. Korea possesses the necessary infrastructure for developing such small sized information storage devices. It has a good digital market, major digital companies, and various research institutes. Nowadays, many companies and research institutes including university cooperate together in the research on small sized information storage devices. Thus, it is expected that small form factor optical disk drives will be commercialized in the very near future in Korea.
ηc elastic and transition form factors: Contact interaction and algebraic model
NASA Astrophysics Data System (ADS)
Bedolla, Marco A.; Raya, Khépani; Cobos-Martínez, J. J.; Bashir, Adnan
2016-05-01
For the flavor-singlet heavy-quark system of charmonia in the pseudoscalar [ηc(1 S ) ] channel, we calculate the elastic (EFF) and transition form factors (TFFs) [ηc(1 S )→γ γ* ] for a wide range of photon momentum transfer squared (Q2). The framework for this analysis is provided by a symmetry-preserving Schwinger-Dyson equation and Bethe-Salpeter equation treatment of a vector×vector contact interaction. We also employ an algebraic model, developed earlier to describe the light-quark systems. It correctly correlates infrared and ultraviolet dynamics of quantum chromodynamics (QCD). The contact interaction results agree with the lattice data for low Q2. For Q2≥Q02 , the results start deviating from the lattice results by more than 20%. Q02≈2.5 GeV2 for the EFF, and ≈25 GeV2 for the TFF. We also present the results for the EFF, TFF, and ηc(1 S ) parton distribution amplitude for the algebraic model. Wherever the comparison is possible, these results are in excellent agreement with the lattice, perturbative QCD, results obtained through a Schwinger-Dyson equation-Bethe-Salpeter equation study, employing refined truncations, and the experimental findings of the BABAR experiment.
Measurement of the weak magnetism form factor in 6He decay
NASA Astrophysics Data System (ADS)
Naviliat-Cuncic, Oscar; Huyan, Xueying; Bazin, Daniel; Gade, Alexandra; Hughes, Maximilian; Liddick, Sean; Minamisono, Kei; Noji, Shumpei; Paulauskas, Stanley; Simon, Anna; Voytas, Paul; Weisshaar, Dirk
2016-09-01
The Fierz interference terms constitutes a very sensitive probe to searches for exotic scalar and tensor couplings in beta decay. It can directly be determined through measurements of the beta spectrum shape. To this end, the 6He decay happens to have a similar kinematic sensitivity than neutron decay despite its end-point is 4.5 larger; the electromagnetic and radiative corrections can be calculated accurately and, since the 6He ground state is member of an isospin triplet, hadronic contributions to the weak currents can be calculated using CVC. In this contribution we describe an experiment, performed at the National Superconducting Cyclotron Laboratory, which measures the shape of the beta energy spectrum in 6He decay. The technique is based on the implantation of the nuclei of interest in suitable detectors, eliminating thereby the major systematic effect in such measurements related to the back-scattering of beta particles in surrounding matter and detectors. The first goal is to measure the weak magnetism form factor, which has never been measured in 6He decay, and which will provide a sensitivity test of the technique. The status of the data analysis will be presented.
Feasibility studies on time-like proton electromagnetic form factors at PANDA-FAIR
NASA Astrophysics Data System (ADS)
Zimmermann, Iris; Dbeyssi, Alaa; Khaneft, Dmitry
2016-05-01
This contribution reports on the latest status of the feasibility studies for the measurement of time-like proton electromagnetic form factors (FF's) at the PANDA experiment [1] at FAIR (Germany). Electromagnetic FF's are fundamental quantities parameterizing the electric and magnetic structure of hadrons. In the time-like region proton FF's can be accessed experimentally through the annihilation processes p ¯p → l+l- (l = e, μ), assuming that the interaction takes place through the exchange of one virtual photon. Due to the low luminosity available at colliders in the past, an individual determination of the time-like electric and magnetic proton FF's was not feasible. The statistical precision, at which the proton FF's will be determined at PANDA, is estimated for both signal processes p ¯p → l+l- (l = e, μ) using the PandaRoot software, which encompasses full detector simulation and event reconstruction. The signal identification and suppression of the main background process (p ¯p → π+π-) is studied. Different methods have been used to generate and analyze the processes of interest. The results from the different analyses show that time-like electromagnetic FF's can be measured at PANDA with unprecedented statistical accuracy.
Measurement of the gamma gamma* to eta_c transition form factor
Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; Hawkes, C.M.; /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison
2010-04-28
The authors study the reaction e{sup +}e{sup -} {yields} e{sup +}e{sup -} {eta}{sub c}, {eta}{sub c} {yields} K{sub S}K{sup {+-}}{pi}{sup {-+}} and obtain {eta}{sub c} mass and width values 2982.2 {+-} 0.4 {+-} 1.6 MeV/c{sup 2} and 31.7 {+-} 1.2 {+-} 0.8 MeV, respectively. They find {Lambda}({eta}{sub c} {yields} {gamma}{gamma}){Beta}({eta}{sub c} {yields} K{bar K}{pi}) = 0.374 {+-} 0.009 {+-} 0.031 keV, and measure the {gamma}{gamma}* {yields} {eta}{sub c} transition form factor in the momentum transfer range from 2 to 50 GeV{sup 2}. The analysis is based on 469 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.
A versatile small form factor twisted-pair TFC FMC for MTCA AMCs
NASA Astrophysics Data System (ADS)
Meder, L.; Lebedev, J.; Becker, J.
2017-03-01
In continuous readout systems of particle physics experiments, the provision of a common clock and time reference and the distribution of critical low latency messages to the processing and fronted layers of the readout are crucial tasks. In the context of the Compressed Baryonic Matter (CBM) experiment, a versatile small form factor Timing and Fast-Control (TFC) interfacing FPGA Mezzanine Card (FMC) was developed, offering bidirectional twisted-pair (TP) links for the communication between TFC nodes. Also a versatile clocking including voltage controlled oscillators and a connection to the telecommunication clock lines of mTCA crates are available. Being designed for both TFC Master and Slaves, the card allows rapid system developments without additional Slave hardware circuits. Measurements show that it is possible to transmit over cable lengths of 25 m at a rate of 240 Mbit/s for all data channels simultaneously. A TFC Master-Slave system using two of these cards can be synchronized with a precision of ±10 ps to an user-defined phase setpoint.
Radyushkin, Anatoly V.
2014-07-01
We outline basics of a new approach to transverse momentum dependence in hard processes. As an illustration, we consider hard exclusive transition process gamma*gamma -> to pi^0 at the handbag level. Our starting point is coordinate representation for matrix elements of operators (in the simplest case, bilocal O(0,z)) describing a hadron with momentum p. Treated as functions of (pz) and z^2, they are parametrized through a virtuality distribution amplitude (VDA) Phi (x, sigma), with x being Fourier-conjugate to (pz) and sigma Laplace-conjugate to z^2. For intervals with z^+=0, we introduce transverse momentum distribution amplitude (TMDA) Psi (x, k_\\perp), and write it in terms of VDA Phi (x, \\sigma). The results of covariant calculations, written in terms of Phi (x sigma) are converted into expressions involving Psi (x, k_\\perp. Starting with scalar toy models, we extend the analysis onto the case of spin-1/2 quarks and QCD. We propose simple models for soft VDAs/TMDAs, and use them for comparison of handbag results with experimental (BaBar and BELLE) data on the pion transition form factor. We also discuss how one can generate high-k_\\perp tails from primordial soft distributions.
Scattering from phase-separated vesicles. I. An analytical form factor for multiple static domains
Heberle, Frederick A.; Anghel, Vinicius N. P.; Katsaras, John
2015-08-18
This is the first in a series of studies considering elastic scattering from laterally heterogeneous lipid vesicles containing multiple domains. Unique among biophysical tools, small-angle neutron scattering can in principle give detailed information about the size, shape and spatial arrangement of domains. A general theory for scattering from laterally heterogeneous vesicles is presented, and the analytical form factor for static domains with arbitrary spatial configuration is derived, including a simplification for uniformly sized round domains. The validity of the model, including series truncation effects, is assessed by comparison with simulated data obtained from a Monte Carlo method. Several aspects ofmore » the analytical solution for scattering intensity are discussed in the context of small-angle neutron scattering data, including the effect of varying domain size and number, as well as solvent contrast. Finally, the analysis indicates that effects of domain formation are most pronounced when the vesicle's average scattering length density matches that of the surrounding solvent.« less
Lattice calculation of the pion transition form factor π0→γ*γ*
NASA Astrophysics Data System (ADS)
Gérardin, Antoine; Meyer, Harvey B.; Nyffeler, Andreas
2016-10-01
We calculate the π0→γ*γ* transition form factor Fπ0γ*γ*(q12,q22) in lattice QCD with two flavors of quarks. Our main motivation is to provide the input to calculate the π0-pole contribution to hadronic light-by-light scattering in the muon (g -2 ), aμHLbL ;π0 . We therefore focus on the region where both photons are spacelike up to virtualities of about 1.5 GeV2, which has so far not been experimentally accessible. Results are obtained in the continuum at the physical pion mass by a combined extrapolation. We reproduce the prediction of the chiral anomaly for real photons with an accuracy of about 8-9%. We also compare to various recently proposed models and find reasonable agreement for the parameters of some of these models with their phenomenological values. Finally, we use the parametrization of our lattice data by these models to calculate aμHLbL ;π0 .
ES1 is a mitochondrial enlarging factor contributing to form mega-mitochondria in zebrafish cones.
Masuda, Takamasa; Wada, Yasutaka; Kawamura, Satoru
2016-03-01
Total mass of mitochondria increases during cell proliferation and differentiation through mitochondrial biogenesis, which includes mitochondrial proliferation and growth. During the mitochondrial growth, individual mitochondria have been considered to be enlarged independently of mitochondrial fusion. However, molecular basis for this enlarging process has been poorly understood. Cone photoreceptor cells in the retina possess large mitochondria, so-called mega-mitochondria that have been considered to arise via the enlarging process. Here we show that ES1 is a novel mitochondria-enlarging factor contributing to form mega-mitochondria in cones. ES1 is specifically expressed in cones and localized to mitochondria including mega-mitochondria. Knockdown of ES1 markedly reduced the mitochondrial size in cones. In contrast, ectopic expression of ES1 in rods significantly increased both the size of individual mitochondria and the total mass of the mitochondrial cluster without changing the number of them. RNA-seq analysis showed that ERRα and its downstream mitochondrial genes were significantly up-regulated in the ES1-expressing rods, suggesting facilitation of mitochondrial enlargement via ERRα-dependent processes. Furthermore, higher energy state was detected in the ES1-expressing rods, indicating that the enlarged mitochondria by ES1 are capable of producing high energy. ES1 is the mitochondrial protein that is first found to promote enlargement of individual mitochondria.
Measurement of the g_{πNN}(t) Form Factor
Vansyoc, Kelley Gene
2001-08-01
Cross sections were measured for the reaction 1H(e, e' π^{+} )n at the energy W = 1.95 GeV and momentum transfer Q ^{2} = 0.6 (GeV/c) ^{2} . At this W and Q ^{2} , the longitudinal cross section is dominated by t-channel production, giving a unique opportunity to examine the strong coupling form factor g _{πNN}(t). The measured cross sections were separated using a method similar to a Rosenbluth separation. For the extraction of g _{πNN} (t), the Actor and Korner model [42] and a parameterization of the MAID2000 model [3] were employed to fit the longitudinal cross section. Three parameterizations g_{πNN}(π) were used in both models. These fits resulted in a strong coupling constant g_{πNN}(m$2\\atop{2}$) that is consistent with theoretical predictions. However, this coupling constant leads to a cutoff parameter that is less than 1 GeV.
Mirzakouchaki, Behnam; Sharghi, Reza; Shirazi, Samaneh
2016-01-01
Introduction Success of orthodontic retention with removable retainers almost entirely depends on patients’ compliance. Aim This study was carried out to investigate the relationship between adolescent orthodontic patients’ compliance and various clinical and social factors. Materials and Methods The data were collected from 77 orthodontic patients aged 7-11 years old who had finished the full fixed appliance therapy. Hawley’s retainers were used in 34 patients and 43 patients used Vacuum Formed Retainers (VFRs). The subjects completed a questionnaire including several identifiers allowing the respondents to be classified into subgroups. They were also asked to indicate how long they wore their retainers during the day, by writing the number of hours in the report-card for the next three months. Comparison of the results was performed by one-way ANOVA and independent sample-t tests. Results No significant differences were found between males and females. Type of the retainer, patients’ grade of study, mothers’ occupation, clinicians’ and parents’ attitudes and filling the report cards had significant effect on mean wear hours per day. When compliance of the patients was assessed according to treatment location, Living place, parents’ educational degrees and ethnicity, no significant differences could be found. Conclusion The adolescent patients’ compliance was greater with VFRs than with Hawley’s retainers. Parental attitude and doctor-patient relationship had a great impact on adolescent patients’ compliance. PMID:27504404
Hadronic form factor models and spectroscopy within the gauge/gravity correspondence
de Teramond, Guy F.; Brodsky, Stanley J.; /SLAC
2012-03-20
We show that the nonperturbative light-front dynamics of relativistic hadronic bound states has a dual semiclassical gravity description on a higher dimensional warped AdS space in the limit of zero quark masses. This mapping of AdS gravity theory to the boundary quantum field theory, quantized at fixed light-front time, allows one to establish a precise relation between holographic wave functions in AdS space and the light-front wavefunctions describing the internal structure of hadrons. The resulting AdS/QCD model gives a remarkably good accounting of the spectrum, elastic and transition form factors of the light-quark hadrons in terms of one parameter, the QCD gap scale. The light-front holographic approach described here thus provides a frame-independent first approximation to the light-front Hamiltonian problem for QCD. This article is based on lectures at the Niccolo Cabeo International School of Hadronic Physics, Ferrara, Italy, May 2011.
ERIC Educational Resources Information Center
Miller, Matthew J.; Roy, Kerrin Sendrowitz; Brown, Steven D.; Thomas, James; McDaniel, Cyndi
2009-01-01
The present study tested a number of theoretically and empirically derived measurement models of the Career Decision Self-Efficacy Scale-Short Form (CDSES-SF) using confirmatory factor analysis. Betz's five-factor model of the CDSES-SF, along with a number of alternative models, demonstrated adequate model fit in two independent samples. Based on…
ERIC Educational Resources Information Center
Krumm, Gabriela; Aranguren, María; Arán Filippetti, Vanessa; Lemos, Viviana
2016-01-01
The objective of this study was to compare, through a Confirmatory Factor Analysis, two different theoretical models that explain the operationalized creativity construct with the Verbal Torrance Tests of Creative Thinking (TTCT), Form B. Model 1 is represented by six factors which correspond to each activity and its respective indicators while…
Lew, Raelia M; Burnett, Leslie; Proos, Anné L; Barlow-Stewart, Kristine; Delatycki, Martin B; Bankier, Agnes; Aizenberg, Harry; Field, Michael J; Berman, Yemima; Fleischer, Ronald; Fietz, Michael
2015-03-01
Internationally, Tay-Sachs disease (TSD) preconception screening of Ashkenazi Jewish (AJ) individuals and couples has led to effective primary prevention of TSD. In Australia, adolescent preconception genetic screening programs operate mainly in Jewish community high schools. These existing programs offer an effective means of primary prevention of TSD, are cost effective and safe. However, in the broader Australian community TSD screening is not systematically performed and cases still occur in unscreened AJ individuals. In order to improve the effectiveness of Australian screening, there is a need for definitive guidelines for healthcare professionals to facilitate extension of the proven benefits of preconception TSD screening to all AJ individuals at risk. We performed a systematic review of the relevant literature relating to AJ pre-conception and antenatal screening for TSD. The evidence was assessed using an established National Health and Medical Research Council evidence grading system. Evaluations of efficacy of TSD screening programs design and execution, cost-benefit and cost-utility health economic evaluation, and population outcomes were undertaken. The results have been used to propose a model for universal AJ TSD preconception and antenatal screening for the primary care setting.
Simultaneous preimplantation genetic diagnosis for Tay-Sachs and Gaucher disease.
Altarescu, Gheona; Brooks, Barry; Margalioth, Ehud; Eldar Geva, Talia; Levy-Lahad, Ephrat; Renbaum, Paul
2007-07-01
Preimplantation genetic diagnosis (PGD) for single gene defects is described for a family in which each parent is a carrier of both Tay-Sachs (TS) and Gaucher disease (GD). A multiplex fluorescent polymerase chain reaction protocol was developed that simultaneously amplified all four familial mutations and 10 informative microsatellite markers. In one PGD cycle, seven blastomeres were analysed, reaching a conclusive diagnosis in six out of seven embryos for TS and in five out of seven embryos for GD. Of the six diagnosed embryos, one was wild type for both TS and GD, and three were wild type for GD and carriers of TS. Two remaining embryos were compound heterozygotes for TS. Two transferable embryos developed into blastocysts (wt/wt and wt GD/carrier TS) and both were transferred on day 5. This single cycle of PGD resulted in a healthy live child. Allele drop-out (ADO) was observed in three of 34 reactions, yielding an 8% ADO rate. The occurrence of ADO in single cell analysis and undetected recombination events are primary causes of misdiagnosis in PGD and emphasize the need to use multiple polymorphic markers. So far as is known, this is the first report of concomitant PGD for two frequent Ashkenazi Jewish recessive disorders.
The presence of two different infantile Tay-Sachs disease mutations in a Cajun population
McDowell, G.A.; Blitzer, M.G. ); Mules, E.H. ); Fabacher, P. ); Shapira, E. )
1992-11-01
A study was undertaken to characterize the mutation(s) responsible for Tay-Sachs disease (TSD) in a Cajun population in southwest Louisiana and to identify the origins of these mutations. Eleven of 12 infantile TSD alleles examined in six families had the [beta]-hexosaminidase A (Hex A) [alpha]-subunit exon 11 insertion mutation that is present in approximately 70% of Ashkenazi Jewish TSD heterozygotes. The mutation in the remaining allele was a single-base transition in the donor splice site of the [alpha]-subunit intron 9. To determine the origins of these two mutations in the Cajun population, the TSD carrier status was enzymatically determined for 90 members of four of the six families, and extensive pedigrees were constructed for all carriers. A single ancestral couple from France was found to be common to most of the carriers of the exon 11 insertion. Pedigree data suggest that this mutation has been in the Cajun population since its founding over 2 centuries ago and that it may be widely distributed within the population. In contrast, the intron 9 mutation apparently was introduced within the last century and probably is limited to a few Louisiana families. 29 refs., 4 figs.
Spontaneous appearance of Tay-Sachs disease in an animal model.
Zeng, B J; Torres, P A; Viner, T C; Wang, Z H; Raghavan, S S; Alroy, J; Pastores, G M; Kolodny, E H
2008-01-01
Tay-Sachs disease (TSD) is a progressive neurodegenerative disorder due to an autosomal recessively inherited deficiency of beta-hexosaminidase A (Hex A). Deficiency of Hex A in TSD is caused by a defect of the alpha-subunit resulting from mutations of the HEXA gene. To date, there is no effective treatment for TSD. Animal models of genetic diseases, similar to those known to exist in humans, are valuable and essential research tools for the study of potentially effective therapies. However, there is no ideal animal model of TSD available for use in therapeutic trials. In the present study, we report an animal model (American flamingo; Phoenicopterus ruber) of TSD with Hex A deficiency occurring spontaneously in nature, with accumulation of G(M2)-ganglioside, deficiency of Hex A enzymatic activity, and a homozygous P469L mutation in exon 12 of the hexa gene. In addition, we have isolated the full-length cDNA sequence of the flamingo, which consists of 1581 nucleotides encoding a protein of 527 amino acids. Its coding sequence indicates approximately 71% identity at the nucleotide level and about 72.5% identity at the amino acid level with the encoding region of the human HEXA gene. This animal model, with many of the same features as TSD in humans, could represent a valuable resource for investigating therapy of TSD.
High school Tay-Sachs disease carrier screening: 5 to 11-year follow-up.
Curd, Helen; Lewis, Sharon; Macciocca, Ivan; Sahhar, Margaret; Petrou, Vicki; Bankier, Agnes; Lieberman, Sari; Levy-Lahad, Ephrat; Delatycki, Martin B
2014-04-01
The Melbourne high school Tay-Sachs disease (TSD) carrier screening program began in 1997. The aim of this study was to assess the outcomes of this screening program among those who had testing more than 5 years ago, to evaluate the long-term impact of screening. A questionnaire was used for data collection and consisted of validated scales and purposively designed questions. Questionnaires were sent to all carriers and two non-carriers for each carrier who were screened in the program between 1999 and 2005. Twenty-four out of 69 (34.8 %) carriers and 30/138 (21.7 %) non-carriers completed the questionnaire. Most participants (82 %) retained good knowledge of TSD and there was no evidence of a difference in knowledge between carriers and non-carriers. Most participants (83 %) were happy with the timing and setting of screening and thought that education and screening for TSD should be offered during high school. There was no difference between carriers and non-carriers in mean scores for the State Trait Anxiety Inventory and Decision Regret Scale. This evaluation indicated that 5-11 years post high school screening, those who were screened are supportive of the program and that negative consequences are rare.
Integrated Sachs-Wolfe effect in cross-correlation: The observer's manual
NASA Astrophysics Data System (ADS)
Afshordi, Niayesh
2004-10-01
The Integrated Sachs-Wolfe (ISW) effect is a direct signature of the presence of dark energy in the universe, in the absence of spatial curvature. A powerful method for observing the ISW effect is through cross-correlation of the cosmic microwave background with a tracer of the matter in the low redshift universe. In this paper, we describe the dependence of the obtained cross-correlation signal on the geometry and other properties of a survey of the low redshift universe. We show that an all-sky survey with about 10×106 galaxies, almost uniformly distributed within 0
Measurement of the Integrated Sachs-Wolfe Effect Using the AllWISE Data Release
NASA Astrophysics Data System (ADS)
Shajib, Anowar J.; Wright, Edward L.
2016-08-01
One of the physical features of a dark-energy-dominated universe is the integrated Sachs-Wolfe (ISW) effect on the cosmic microwave background (CMB) radiation, which gives us a direct observational window to detect and study dark energy. The AllWISE data release of the Wide-field Infrared Survey Explorer (WISE) has a large number of point sources which span a wide redshift range, including where the ISW effect is maximized. AllWISE data are thus very well-suited for the ISW effect studies. In this study, we cross-correlate AllWISE galaxy and active galactic nucleus (AGN) overdensities with the Wilkinson Microwave Anisotropy Probe CMB temperature maps to detect the ISW effect signal. We calibrate the biases for galaxies and AGNs by cross-correlating the galaxy and AGN overdensities with the Planck lensing convergence map. We measure the ISW effect signal amplitudes relative to the ΛCDM expectation of A = 1 to be A=1.18+/- 0.36 for galaxies and A=0.64+/- 0.74 for AGNs. The detection significances for the ISW effect signal are 3.3σ and 0.9σ for galaxies and AGNs, respectively, providing a combined significance of 3.4σ . Our result is in agreement with the ΛCDM model.
Detecting the integrated Sachs-Wolfe effect with high-redshift 21-cm surveys
NASA Astrophysics Data System (ADS)
Raccanelli, Alvise; Kovetz, Ely; Dai, Liang; Kamionkowski, Marc
2016-04-01
We investigate the possibility of detecting the integrated Sachs-Wolfe (ISW) effect by cross-correlating 21-cm surveys at high redshifts with galaxies in a way similar to the usual CMB-galaxy cross-correlation. The high-redshift 21-cm signal is dominated by CMB photons that travel freely without interacting with the intervening matter, and hence its late-time ISW signature should correlate extremely well with that of the CMB at its peak frequencies. Using the 21-cm temperature brightness instead of the CMB would thus be a further check of the detection of the ISW effect, measured by different instruments at different frequencies and suffering from different systematics. We also study the ISW effect on the photons that are scattered by HI clouds. We show that a detection of the unscattered photons is achievable with planned radio arrays, while one using scattered photons will require advanced radio interferometers, either an extended version of the planned Square Kilometre Array or futuristic experiments such as a lunar radio array.
Three Novel Mutations in Iranian Patients with Tay-Sachs Disease
Jamali, Solmaz; Eskandari, Nasim; Aryani, Omid; Salehpour, Shadab; Zaman, Talieh; Kamalidehghan, Behnam; Houshmand, Massoud
2014-01-01
Background: Tay-Sachs disease (TSD), or GM2 gangliosidosis, is a lethal autosomal recessive neurodegenerative disorder, which is caused by a deficiency of beta-hexosaminidase A (HEXA), resulting in lysosomal accumulation of GM2 ganglioside. The aim of this study was to identify the TSD-causing mutations in an Iranian population. Methods: In this study, we examined 31 patients for TSD-causing mutations using PCR, followed by restriction enzyme digestion. Results: Molecular genetics analysis of DNA from 23 patients of TSD revealed mutations that has been previously reported, including four-base duplications c.1274_1277dupTATC in exon 11 and IVS2+1G>A, deletion TTAGGCAAGGGC in exon 10 as well as a few novel mutations, including C331G, which altered Gln>Glu in HEXB, A>G, T>C, and p.R510X in exon 14, which predicted a termination codon or nonsense mutation. Conclusion: In conclusion, with the discovery of these novel mutations, the genotypic spectrum of Iranian patients with TSD disease has been extended and could facilitate definition of disease-related mutations. PMID:24518553
The presence of two different infantile Tay-Sachs disease mutations in a Cajun population.
McDowell, G A; Mules, E H; Fabacher, P; Shapira, E; Blitzer, M G
1992-01-01
A study was undertaken to characterize the mutation(s) responsible for Tay-Sachs disease (TSD) in a Cajun population in southwest Louisiana and to identify the origins of these mutations. Eleven of 12 infantile TSD alleles examined in six families had the beta-hexosaminidase A (Hex A) alpha-subunit exon 11 insertion mutation that is present in approximately 70% of Ashkenazi Jewish TSD heterozygotes. The mutation in the remaining allele was a single-base transition in the donor splice site of the alpha-subunit intron 9. To determine the origins of these two mutations in the Cajun population, the TSD carrier status was enzymatically determined for 90 members of four of the six families, and extensive pedigrees were constructed for all carriers. A single ancestral couple from France was found to be common to most of the carriers of the exon 11 insertion. Pedigree data suggest that this mutation has been in the Cajun population since its founding over 2 centuries ago and that it may be widely distributed within the population. In contrast, the intron 9 mutation apparently was introduced within the last century and probably is limited to a few Louisiana families. Images Figure 1 Figure 2 PMID:1307230
The cross-correlation between 3D cosmic shear and the integrated Sachs-Wolfe effect
NASA Astrophysics Data System (ADS)
Zieser, Britta; Merkel, Philipp M.
2016-06-01
We present the first calculation of the cross-correlation between 3D cosmic shear and the integrated Sachs-Wolfe (iSW) effect. Both signals are combined in a single formalism, which permits the computation of the full covariance matrix. In order to avoid the uncertainties presented by the non-linear evolution of the matter power spectrum and intrinsic alignments of galaxies, our analysis is restricted to large scales, i.e. multipoles below ℓ = 1000. We demonstrate in a Fisher analysis that this reduction compared to other studies of 3D weak lensing extending to smaller scales is compensated by the information that is gained if the additional iSW signal and in particular its cross-correlation with lensing data are considered. Given the observational standards of upcoming weak-lensing surveys like Euclid, marginal errors on cosmological parameters decrease by 10 per cent compared to a cosmic shear experiment if both types of information are combined without a cosmic wave background (CMB) prior. Once the constraining power of CMB data is added, the improvement becomes marginal.
Absence of metabolic cross-correction in Tay-Sachs cells: implications for gene therapy.
Martino, Sabata; Emiliani, Carla; Tancini, Brunella; Severini, Giovanni Maria; Chigorno, Vanna; Bordignon, Claudio; Sonnino, Sandro; Orlacchio, Aldo
2002-06-07
We have investigated the ability of a receptor-mediated gene transfer strategy (cross-correction) to restore ganglioside metabolism in fibroblasts from Tay-Sachs (TS) patients in vitro. TS disease is a GM2 gangliosidosis attributed to the deficiency of the lysosomal enzyme beta-hexosaminidase A (HexA) (beta-N-acetylhexosaminidase, EC ). The hypothesis is that transduced cells overexpressing and secreting large amounts of the enzyme would lead to a measurable activity in defective cells via a secretion-recapture mechanism. We transduced NIH3T3 murine fibroblasts with the LalphaHexTN retroviral vector carrying the cDNA encoding for the human Hex alpha-subunit. The Hex activity in the medium from transduced cells was approximately 10-fold higher (up to 75 milliunits) than observed in non-transduced cells. TS cells were cultured for 72 h in the presence of the cell medium derived from the transduced NIH3T3 cells, and they were analyzed for the presence and catalytic activity of the enzyme. Although TS cells were able to efficiently uptake a large amount of the soluble enzyme, the enzyme failed to reach the lysosomes in a sufficient quantity to hydrolyze the GM2 ganglioside to GM3 ganglioside. Thus, our results showed that delivery of the therapeutic HexA was not sufficient to correct the phenotype of TS cells.
Qualitative analysis of Kantowski-Sachs metric in a generic class of f(R) models
Leon, Genly; Roque, Armando A. E-mail: arestrada@ucf.edu.cu
2014-05-01
In this paper we investigate, from the dynamical systems perspective, the evolution of a Kantowski-Sachs metric in a generic class of f(R) models. We present conditions (i.e., differentiability conditions, existence of minima, monotony intervals, etc.) for a free input function related to the f(R), that guarantee the asymptotic stability of well-motivated physical solutions, specially, self-accelerated solutions, allowing to describe both inflationary- and late-time acceleration stages of the cosmic evolution. We discuss which f(R) theories allows for a cosmic evolution with an acceptable matter era, in correspondence to the modern cosmological paradigm. We find a very rich behavior, and amongst others the universe can result in isotropized solutions with observables in agreement with observations, such as de Sitter, quintessence-like, or phantom solutions. Additionally, we find that a cosmological bounce and turnaround are realized in a part of the parameter-space as a consequence of the metric choice.
Sachs-Wolfe at second order: the CMB bispectrum on large angular scales
Boubekeur, Lotfi; Creminelli, Paolo; D'Amico, Guido; Noreña, Jorge; Vernizzi, Filippo E-mail: creminel@ictp.it E-mail: norena@sissa.it
2009-08-01
We calculate the Cosmic Microwave Background anisotropy bispectrum on large angular scales in the absence of primordial non-Gaussianities, assuming exact matter dominance and extending at second order the classic Sachs-Wolfe result δT/T = Φ/3. The calculation is done in Poisson gauge. Besides intrinsic contributions calculated at last scattering, one must consider integrated effects. These are associated to lensing, and to the time dependence of the potentials (Rees-Sciama) and of the vector and tensor components of the metric generated at second order. The bispectrum is explicitly computed in the flat-sky approximation. It scales as l{sup −4} in the scale invariant limit and the shape dependence of its various contributions is represented in 3d plots. Although all the contributions to the bispectrum are parametrically of the same order, the full bispectrum is dominated by lensing. In the squeezed limit it corresponds to f{sub NL}{sup local} = −1/6−cos(2θ), where θ is the angle between the short and the long modes; the angle dependent contribution comes from lensing. In the equilateral limit it corresponds to f{sub NL}{sup equil} ≅ 3.13.
Weinstein, M J; Chute, L E
1984-01-01
We have characterized Factor VIII coagulant protein, present in normal human plasma, that reacts with a specific human 125I-labeled anti-human VIII:C antigen Fab antibody fragment. Two major Factor VIII coagulant antigen populations were present. The first, approximately 85% of the total antigen, was bound to von Willebrand factor and when tested in a standard one-stage assay had Factor VIII coagulant activity. The second antigenic population, eluting near fibrinogen when plasma was gel filtered, was not bound to von Willebrand protein, did not have Factor VIII coagulant activity unless activated, but did block anti-VIII:C Fab neutralization of clotting activity. The two antigenic populations were separable by cryoprecipitation and agarose gel electrophoresis. Although the two antigenic populations differed in their Factor VIII coagulant activity and in their binding to von Willebrand factor, the principal member of both populations is of mol wt 2.4 X 10(5). Both antigens, when proteolyzed by thrombin, were quickly converted to a 1 X 10(5)-mol wt form in association with the appearance of VIII:C activity. The 1 X 10(5)-mol wt antigen was further slowly degraded to an 8 X 10(4)-mol wt form while Factor VIII coagulant activity declined. These results demonstrate the presence of an inactive Factor VIII coagulant protein in plasma, not associated with von Willebrand factor, that can react with thrombin to yield Factor VIII coagulant activity. Images PMID:6421875
Phenomenology of Semileptonic B-Meson Decays with Form Factors from Lattice QCD
Du, Daping; El-Khadra, A. X.; Gottlieb, Steven; Kronfeld, A. S.; Laiho, J.; Lunghi, E.; Van de Water, R. S.; Zhou, Ran
2016-02-03
We study the exclusive semileptonic B-meson decays B→K(π)ℓ^{+}ℓ^{-}, B→K(π)νν¯, and B→πτν, computing observables in the Standard model using the recent lattice-QCD results for the underlying form factors from the Fermilab Lattice and MILC Collaborations. These processes provide theoretically clean windows into physics beyond the Standard Model because the hadronic uncertainties are now under good control. The resulting partially-integrated branching fractions for B→πμ^{+}μ^{-} and B→Kμ^{+}μ^{-} outside the charmonium resonance region are 1-2σ higher than the LHCb Collaboration's recent measurements, where the theoretical and experimental errors are commensurate. The combined tension is 1.7σ. Combining the Standard-Model rates with LHCb's measurements yields values for the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements |V_{td}|=7.45(69)×10^{-3}, |V_{ts}|=35.7(1.5)×10^{-3}, and |V_{td}/V_{ts}|=0.201(20), which are compatible with the values obtained from neutral B_{(s)}-meson oscillations and have competitive uncertainties. Alternatively, taking the CKM matrix elements from unitarity, we constrain new-physics contributions at the electroweak scale. Furthermore, the constraints on the Wilson coefficients Re(C_{9}) and Re(C_{10}) from B→πμ^{+}μ^{-} and B→Kμ^{+}μ^{-} are competitive with those from B→K*μ^{+}μ^{-}, and display a 2.0σ tension with the Standard Model. Our predictions for B→K(π)νν¯ and B→πτν are close to the current experimental limits.
Phenomenology of Semileptonic B-Meson Decays with Form Factors from Lattice QCD
Du, Daping; El-Khadra, A. X.; Gottlieb, Steven; ...
2016-02-03
We study the exclusive semileptonic B-meson decays B→K(π)ℓ+ℓ-, B→K(π)νν¯, and B→πτν, computing observables in the Standard model using the recent lattice-QCD results for the underlying form factors from the Fermilab Lattice and MILC Collaborations. These processes provide theoretically clean windows into physics beyond the Standard Model because the hadronic uncertainties are now under good control. The resulting partially-integrated branching fractions for B→πμ+μ- and B→Kμ+μ- outside the charmonium resonance region are 1-2σ higher than the LHCb Collaboration's recent measurements, where the theoretical and experimental errors are commensurate. The combined tension is 1.7σ. Combining the Standard-Model rates with LHCb's measurements yields valuesmore » for the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements |Vtd|=7.45(69)×10-3, |Vts|=35.7(1.5)×10-3, and |Vtd/Vts|=0.201(20), which are compatible with the values obtained from neutral B(s)-meson oscillations and have competitive uncertainties. Alternatively, taking the CKM matrix elements from unitarity, we constrain new-physics contributions at the electroweak scale. Furthermore, the constraints on the Wilson coefficients Re(C9) and Re(C10) from B→πμ+μ- and B→Kμ+μ- are competitive with those from B→K*μ+μ-, and display a 2.0σ tension with the Standard Model. Our predictions for B→K(π)νν¯ and B→πτν are close to the current experimental limits.« less
Atomic-scale electronic structure of the cuprate d-symmetry form factor density wave state
M. H. Hamidian; Kim, Chung Koo; Edkins, S. D.; Davis, J. C.; Mackenzie, A. P.; Eisaki, H.; Uchida, S.; Lawler, M. J.; Kim, E. -A.; Sachdev, S.; Fujita, K.
2015-10-26
Research on high-temperature superconducting cuprates is at present focused on identifying the relationship between the classic ‘pseudogap’ phenomenon^{1, 2} and the more recently investigated density wave state^{3–13}. This state is generally characterized by a wavevector Q parallel to the planar Cu–O–Cu bonds ^{4–13} along with a predominantly d-symmetry form factor ^{14–17} (dFF-DW). To identify the microscopic mechanism giving rise to this state ^{18–30}, one must identify the momentum-space states contributing to the dFF-DW spectral weight, determine their particle–hole phase relationship about the Fermi energy, establish whether they exhibit a characteristic energy gap, and understand the evolution of all these phenomena throughout the phase diagram. Here we use energy-resolved sublattice visualization^{14} of electronic structure and reveal that the characteristic energy of the dFF-DW modulations is actually the ‘pseudogap’ energy Δ_{1}. Moreover, we demonstrate that the dFF-DW modulations at E = –Δ_{1} (filled states) occur with relative phase π compared to those at E = Δ_{1} (empty states). Lastly, we show that the conventionally defined dFF-DW Q corresponds to scattering between the ‘hot frontier’ regions of momentum-space beyond which Bogoliubov quasiparticles cease to exist^{30–32}. These data indicate that the cuprate dFF-DW state involves particle–hole interactions focused at the pseudogap energy scale and between the four pairs of ‘hot frontier’ regions in momentum space where the pseudogap opens.
Atomic-scale electronic structure of the cuprate d-symmetry form factor density wave state
M. H. Hamidian; Kim, Chung Koo; Edkins, S. D.; ...
2015-10-26
Research on high-temperature superconducting cuprates is at present focused on identifying the relationship between the classic ‘pseudogap’ phenomenon1, 2 and the more recently investigated density wave state3–13. This state is generally characterized by a wavevector Q parallel to the planar Cu–O–Cu bonds 4–13 along with a predominantly d-symmetry form factor 14–17 (dFF-DW). To identify the microscopic mechanism giving rise to this state 18–30, one must identify the momentum-space states contributing to the dFF-DW spectral weight, determine their particle–hole phase relationship about the Fermi energy, establish whether they exhibit a characteristic energy gap, and understand the evolution of all these phenomenamore » throughout the phase diagram. Here we use energy-resolved sublattice visualization14 of electronic structure and reveal that the characteristic energy of the dFF-DW modulations is actually the ‘pseudogap’ energy Δ1. Moreover, we demonstrate that the dFF-DW modulations at E = –Δ1 (filled states) occur with relative phase π compared to those at E = Δ1 (empty states). Lastly, we show that the conventionally defined dFF-DW Q corresponds to scattering between the ‘hot frontier’ regions of momentum-space beyond which Bogoliubov quasiparticles cease to exist30–32. These data indicate that the cuprate dFF-DW state involves particle–hole interactions focused at the pseudogap energy scale and between the four pairs of ‘hot frontier’ regions in momentum space where the pseudogap opens.« less
NASA Astrophysics Data System (ADS)
Cardenas-Valencia, Andres M.; Adornato, Lori; Short, R. Timothy; Langebrake, Larry
The work reported herein demonstrates a novel method to improve the overall performance of thin-form-factor galvanic cells, fabricated via micro-electromechanical systems (MEMS) processes. Use of solid, low cost, cyclic-halogenated, organic catholyte materials permits water activation of cells consisting of metal anode and catalytic platinum positive electrodes. Similar cells, employing aluminum and zinc anodes, have been activated using sodium hypochlorite (NaClO) solutions, i.e. bleach, in the past. The oxidizers chosen for this study (bromo-, chloro- and iodo-succinimides, and sodium dichloroisocyanuric acid) supply the cathode's oxy-halogenated ions when in contact with water. Zinc, magnesium and aluminum anodes are utilized to fabricate galvanic cells. A comparison between these anodes, coupled with various oxidizers, is included herein. Results using aluminum anode cells show that, even though the utilization efficiency of the catholyte reagents is low (faradic efficiencies between 16 and 19%), the performance of the new water-activated cells (6 cm × 6 cm × 0.25 cm) is superior when compared to those activated with bleach. For instance, operational lives of 6 h (activation with 10% NaClO solution) increase to more than 30 h using the new approach, with a 100-ohm-load. It is also shown that specific energies of 90-110 Wh kg -1 (calculated to include both reagent and packaging mass) could be obtained using the described approach with current draws between 10 and 20 mA. The specific energies obtained suggest that novel MEMS-type cells could have much broader application than low-current, bleach-activated cells.
Singh, B.; Erni, W.; Krusche, B.; ...
2016-10-28
Simulation results for future measurements of electromagnetic proton form factors atmore » $$\\overline{\\rm P}$$ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯p → e+e– is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e. p¯p → π+π–, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. Furthermore, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.« less
Singh, B.; Erni, W.; Krusche, B.; Steinacher, M.; Walford, N.; Liu, B.; Liu, H.; Liu, Z.; Shen, X.; Wang, C.; Zhao, J.; Albrecht, M.; Erlen, T.; Fink, M.; Heinsius, F.; Held, T.; Holtmann, T.; Jasper, S.; Keshk, I.; Koch, H.; Kopf, B.; Kuhlmann, M.; Kümmel, M.; Leiber, S.; Mikirtychyants, M.; Musiol, P.; Mustafa, A.; Pelizäus, M.; Pychy, J.; Richter, M.; Schnier, C.; Schröder, T.; Sowa, C.; Steinke, M.; Triffterer, T.; Wiedner, U.; Ball, M.; Beck, R.; Hammann, C.; Ketzer, B.; Kube, M.; Mahlberg, P.; Rossbach, M.; Schmidt, C.; Schmitz, R.; Thoma, U.; Urban, M.; Walther, D.; Wendel, C.; Wilson, A.; Bianconi, A.; Bragadireanu, M.; Caprini, M.; Pantea, D.; Patel, B.; Czyzycki, W.; Domagala, M.; Filo, G.; Jaworowski, J.; Krawczyk, M.; Lisowski, F.; Lisowski, E.; Michałek, M.; Poznański, P.; Płażek, J.; Korcyl, K.; Kozela, A.; Kulessa, P.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Szczurek, A.; Fiutowski, T.; Idzik, M.; Mindur, B.; Przyborowski, D.; Swientek, K.; Biernat, J.; Kamys, B.; Kistryn, S.; Korcyl, G.; Krzemien, W.; Magiera, A.; Moskal, P.; Pyszniak, A.; Rudy, Z.; Salabura, P.; Smyrski, J.; Strzempek, P.; Wronska, A.; Augustin, I.; Böhm, R.; Lehmann, I.; Nicmorus Marinescu, D.; Schmitt, L.; Varentsov, V.; Al-Turany, M.; Belias, A.; Deppe, H.; Dzhygadlo, R.; Ehret, A.; Flemming, H.; Gerhardt, A.; Götzen, K.; Gromliuk, A.; Gruber, L.; Karabowicz, R.; Kliemt, R.; Krebs, M.; Kurilla, U.; Lehmann, D.; Löchner, S.; Lühning, J.; Lynen, U.; Orth, H.; Patsyuk, M.; Peters, K.; Saito, T.; Schepers, G.; Schmidt, C. J.; Schwarz, C.; Schwiening, J.; Täschner, A.; Traxler, M.; Ugur, C.; Voss, B.; Wieczorek, P.; Wilms, A.; Zühlsdorf, M.; Abazov, V.; Alexeev, G.; Arefiev, V. A.; Astakhov, V.; Barabanov, M. Yu.; Batyunya, B. V.; Davydov, Y.; Dodokhov, V. Kh.; Efremov, A.; Fechtchenko, A.; Fedunov, A. G.; Galoyan, A.; Grigoryan, S.; Koshurnikov, E. K.; Lobanov, Y. Yu.; Lobanov, V. I.; Makarov, A. F.; Malinina, L. V.; Malyshev, V.; Olshevskiy, A. G.; Perevalova, E.; Piskun, A. A.; Pocheptsov, T.; Pontecorvo, G.; Rodionov, V.; Rogov, Y.; Salmin, R.; Samartsev, A.; Sapozhnikov, M. G.; Shabratova, G.; Skachkov, N. B.; Skachkova, A. N.; Strokovsky, E. A.; Suleimanov, M.; Teshev, R.; Tokmenin, V.; Uzhinsky, V.; Vodopianov, A.; Zaporozhets, S. A.; Zhuravlev, N. I.; Zorin, A. G.; Branford, D.; Glazier, D.; Watts, D.; Böhm, M.; Britting, A.; Eyrich, W.; Lehmann, A.; Pfaffinger, M.; Uhlig, F.; Dobbs, S.; Seth, K.; Tomaradze, A.; Xiao, T.; Bettoni, D.; Carassiti, V.; Cotta Ramusino, A.; Dalpiaz, P.; Drago, A.; Fioravanti, E.; Garzia, I.; Savrie, M.; Akishina, V.; Kisel, I.; Kozlov, G.; Pugach, M.; Zyzak, M.; Gianotti, P.; Guaraldo, C.; Lucherini, V.; Bersani, A.; Bracco, G.; Macri, M.; Parodi, R. F.; Biguenko, K.; Brinkmann, K.; Di Pietro, V.; Diehl, S.; Dormenev, V.; Drexler, P.; Düren, M.; Etzelmüller, E.; Galuska, M.; Gutz, E.; Hahn, C.; Hayrapetyan, A.; Kesselkaul, M.; Kühn, W.; Kuske, T.; Lange, J. S.; Liang, Y.; Metag, V.; Nanova, M.; Nazarenko, S.; Novotny, R.; Quagli, T.; Reiter, S.; Rieke, J.; Rosenbaum, C.; Schmidt, M.; Schnell, R.; Stenzel, H.; Thöring, U.; Ullrich, M.; Wagner, M. N.; Wasem, T.; Wohlfahrt, B.; Zaunick, H.; Ireland, D.; Rosner, G.; Seitz, B.; Deepak, P. N.; Kulkarni, A.; Apostolou, A.; Babai, M.; Kavatsyuk, M.; Lemmens, P. J.; Lindemulder, M.; Loehner, H.; Messchendorp, J.; Schakel, P.; Smit, H.; Tiemens, M.; van der Weele, J. C.; Veenstra, R.; Vejdani, S.; Dutta, K.; Kalita, K.; Kumar, A.; Roy, A.; Sohlbach, H.; Bai, M.; Bianchi, L.; Büscher, M.; Cao, L.; Cebulla, A.; Dosdall, R.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Herten, A.; Hu, Q.; Kemmerling, G.; Kleines, H.; Lehrach, A.; Nellen, R.; Ohm, H.; Orfanitski, S.; Prasuhn, D.; Prencipe, E.; Pütz, J.; Ritman, J.; Schadmand, S.; Sefzick, T.; Serdyuk, V.; Sterzenbach, G.; Stockmanns, T.; Wintz, P.; Wüstner, P.; Xu, H.; Zambanini, A.; Li, S.; Li, Z.; Sun, Z.; Xu, H.; Rigato, V.; Isaksson, L.; Achenbach, P.; Corell, O.; Denig, A.; Distler, M.; Hoek, M.; Karavdina, A.; Lauth, W.; Liu, Z.; Merkel, H.; Müller, U.; Pochodzalla, J.; Sanchez, S.; Schlimme, S.; Sfienti, C.; Thiel, M.; Ahmadi, H.; Ahmed, S.; Bleser, S.; Capozza, L.; Cardinali, M.; Dbeyssi, A.; Deiseroth, M.; Feldbauer, F.; Fritsch, M.; Fröhlich, B.; Jasinski, P.; Kang, D.; Khaneft, D.; Klasen, R.; Leithoff, H. H.; Lin, D.; Maas, F.; Maldaner, S.; Martínez, M.; Michel, M.; Mora Espí, M. C.; Morales Morales, C.; Motzko, C.; Nerling, F.; Noll, O.; Pflüger, S.; Pitka, A.; Rodríguez Piñeiro, D.; Sanchez-Lorente, A.; Steinen, M.; Valente, R.; Weber, T.; Zambrana, M.; Zimmermann, I.; Fedorov, A.; Korjik, M.; Missevitch, O.; Boukharov, A.; Malyshev, O.; Marishev, I.; Balanutsa, V.; Balanutsa, P.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Goryachev, V.; Chandratre, V.; Datar, V.; Dutta, D.; Jha, V.; Kumawat, H.; Mohanty, A. K.; Parmar, A.; Roy, B.; Sonika, G.; Fritzsch, C.; Grieser, S.; Hergemöller, A.; Hetz, B.; Hüsken, N.; Khoukaz, A.; Wessels, J. P.; Khosonthongkee, K.; Kobdaj, C.; Limphirat, A.; Srisawad, P.; Yan, Y.; Barnyakov, M.; Barnyakov, A. Yu.; Beloborodov, K.; Blinov, A. E.; Blinov, V. E.; Bobrovnikov, V. S.; Kononov, S.; Kravchenko, E. A.; Kuyanov, I. A.; Martin, K.; Onuchin, A. P.; Serednyakov, S.; Sokolov, A.; Tikhonov, Y.; Atomssa, E.; Kunne, R.; Marchand, D.; Ramstein, B.; van de Wiele, J.; Wang, Y.; Boca, G.; Costanza, S.; Genova, P.; Montagna, P.; Rotondi, A.; Abramov, V.; Belikov, N.; Bukreeva, S.; Davidenko, A.; Derevschikov, A.; Goncharenko, Y.; Grishin, V.; Kachanov, V.; Kormilitsin, V.; Levin, A.; Melnik, Y.; Minaev, N.; Mochalov, V.; Morozov, D.; Nogach, L.; Poslavskiy, S.; Ryazantsev, A.; Ryzhikov, S.; Semenov, P.; Shein, I.; Uzunian, A.; Vasiliev, A.; Yakutin, A.; Tomasi-Gustafsson, E.; Roy, U.; Yabsley, B.; Belostotski, S.; Gavrilov, G.; Izotov, A.; Manaenkov, S.; Miklukho, O.; Veretennikov, D.; Zhdanov, A.; Makonyi, K.; Preston, M.; Tegner, P.; Wölbing, D.; Bäck, T.; Cederwall, B.; Rai, A. K.; Godre, S.; Calvo, D.; Coli, S.; De Remigis, P.; Filippi, A.; Giraudo, G.; Lusso, S.; Mazza, G.; Mignone, M.; Rivetti, A.; Wheadon, R.; Balestra, F.; Iazzi, F.; Introzzi, R.; Lavagno, A.; Olave, J.; Amoroso, A.; Bussa, M. P.; Busso, L.; De Mori, F.; Destefanis, M.; Fava, L.; Ferrero, L.; Greco, M.; Hu, J.; Lavezzi, L.; Maggiora, M.; Maniscalco, G.; Marcello, S.; Sosio, S.; Spataro, S.; Birsa, R.; Bradamante, F.; Bressan, A.; Martin, A.; Calen, H.; Ikegami Andersson, W.; Johansson, T.; Kupsc, A.; Marciniewski, P.; Papenbrock, M.; Pettersson, J.; Schönning, K.; Wolke, M.; Galnander, B.; Diaz, J.; Pothodi Chackara, V.; Chlopik, A.; Kesik, G.; Melnychuk, D.; Slowinski, B.; Trzcinski, A.; Wojciechowski, M.; Wronka, S.; Zwieglinski, B.; Bühler, P.; Marton, J.; Steinschaden, D.; Suzuki, K.; Widmann, E.; Zmeskal, J.
2016-10-28
Simulation results for future measurements of electromagnetic proton form factors at $\\overline{\\rm P}$ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯p → e^{+}e^{–} is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e. p¯p → π^{+}π^{–}, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. Furthermore, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
Sergio Alexandre Pinto; Stadler, Alfred; Gross, Franz L.
2010-01-01
The electromagnetic form factors of the three-nucleon bound states were calculated in Complete Impulse Approximation in the framework of the Covariant Spectator Theory for the new high-precision two-nucleon interaction models WJC-1 and WJC-2. The calculations use an approximation for the three-nucleon vertex functions with two nucleons off mass shell. The form factors with WJC-2 are close to the ones obtained with the older model W16 and to nonrelativistic potential calculations with lowest-order relativistic corrections, while the form factors with the most precise two-nucleon model WJC-1 exhibit larger differences. These results can be understood when the effect of the different types of pion-nucleon coupling used in the various models is examined.
Measurement of the deuteron electric and magnetic form factors at Jefferson Lab
Gerassimos G. Petratos
1998-06-01
The results from an experiment to measure the electric, A(Q{sup 2}), and magnetic, B(Q{sup 2}), form factors of the deuteron at large momentum transfers at the Jefferson Laboratory (JLAB) will be reported. The experiment performed elastic electron scattering from deuterium in coincidence; it has improved the quality of the existing data in the range of overlap and has significantly extended the Q{sup 2} range of the previous A(Q{sup 2}) SLAC data. The range in the squared four-momentum transfer, Q{sup 2}, is 0.7 to 6.0 (GeV/c){sup 2} for the A(Q{sup 2}) measurements and 0.7 to 1.4 (GeV/c){sup 2} for the B(Q{sup 2}) measurements. The measurements used the Continuous Electron Beam Accelerator and Hall-A Facilities of JLAB. Incident electron beams of energy 0.5 to 4.4 GeV and current 10 to 120{mu}A were scattered off a high power (500W) cryogenic deuterium/hydrogen target. Scattered electrons and recoiling deuterons were detected in coincidence using the two 4 GeV/c High Resolution Spectrometers (HRS) in Hall-A. Both HRS's used two planes of scintillators for triggering and timing and a drift chamber system for particle tracking. The electron HRS was also equipped with a gas Cherenkov counter and a lead-glass calorimeter for electron identification. Elastic electron-proton scattering in coincidence was used to calibrate the entire double-arm system. The results will be compared to conventional meson-nucleon physics calculations based on the impulse approximation with the inclusion of meson-exchange-currents, and to predictions of dimensional scaling quark models and perturbative quantum chromodynamics. They are expected to provide a crucial test of nuclear chromodynamics ideas and insights into the transition from the meson-nucleon to quark-gluon descriptions of the two-body nuclear structure.
Nerozzi, Andrea; Bruni, Marco; Re, Virginia; Burko, Lior M.
2006-02-15
We present a numerical study of the evolution of a nonlinearly disturbed black hole described by the Bondi-Sachs metric, for which the outgoing gravitational waves can readily be found using the news function. We compare the gravitational-wave output obtained with the use of the news function in the Bondi-Sachs framework, with that obtained from the Weyl scalars, where the latter are evaluated in a quasi-Kinnersley tetrad. The latter method has the advantage of being applicable to any formulation of Einstein's equations--including the ADM formulation and its various descendants--in addition to being robust. Using the nonlinearly disturbed Bondi-Sachs black hole as a test bed, we show that the two approaches give wave-extraction results which are in very good agreement. When wave extraction through the Weyl scalars is done in a non-quasi-Kinnersley tetrad, the results are markedly different from those obtained using the news function.
Factor Structure of the BASC-2 Behavioral and Emotional Screening System Student Form
ERIC Educational Resources Information Center
Dowdy, Erin; Twyford, Jennifer M.; Chin, Jenna K.; DiStefano, Christine A.; Kamphaus, Randy W.; Mays, Kristen L.
2011-01-01
The BASC-2 Behavioral and Emotional Screening System (BESS) Student Form (Kamphaus & Reynolds, 2007) is a recently developed youth self-report rating scale designed to identify students at risk for behavioral and emotional problems. The BESS Student Form was derived from the Behavior Assessment System for Children-Second Edition Self-Report of…
Three-loop slope of the dirac form factor and the 1S lamb shift in hydrogen
Melnikov; van Ritbergen T
2000-02-21
The last unknown contribution to hydrogen energy levels at order malpha(7), due to the slope of the Dirac form factor at three loops, is evaluated in a closed analytical form. The resulting shift of the hydrogen nS energy level is found to be 3.016/n(3) kHz. Using the QED calculations of the 1S Lamb shift, we extract a precise value of the proton charge radius r(p) = 0.883+/-0.014 fm.
On determinant representations of scalar products and form factors in the SoV approach: the XXX case
NASA Astrophysics Data System (ADS)
Kitanine, N.; Maillet, J. M.; Niccoli, G.; Terras, V.
2016-03-01
In the present article we study the form factors of quantum integrable lattice models solvable by the separation of variables (SoVs) method. It was recently shown that these models admit universal determinant representations for the scalar products of the so-called separate states (a class which includes in particular all the eigenstates of the transfer matrix). These results permit to obtain simple expressions for the matrix elements of local operators (form factors). However, these representations have been obtained up to now only for the completely inhomogeneous versions of the lattice models considered. In this article we give a simple algebraic procedure to rewrite the scalar products (and hence the form factors) for the SoV related models as Izergin or Slavnov type determinants. This new form leads to simple expressions for the form factors in the homogeneous and thermodynamic limits. To make the presentation of our method clear, we have chosen to explain it first for the simple case of the XXX Heisenberg chain with anti-periodic boundary conditions. We would nevertheless like to stress that the approach presented in this article applies as well to a wide range of models solved in the SoV framework.
Schaub, John
2010-07-01
We studied the strange contributions to the elastic vector and axial form factors of the nucleon using all available elastic electroweak scattering data. Specifically, we combine elastic nu-p and nubar-p scattering cross-section data from the Brookhaven E734 experiment with elastic ep and quasi-elastic ed and e-^{4}He scattering parity-violating asymmetry data from the SAMPLE, HAPPEx, PVA4 and G0 experiments. We not only determined these form factors at individual values of momentum-transfer (Q^{2}), as other groups have done recently, but also fit the Q^{2}-dependence of these form factors using simple functional forms. I present an overview of the G^{0} backward-angle experiment as well as the results of these fits using existing data, along with some expectations of how we can improve our knowledge of these form factors if the MicroBooNE collaboration completes their experiment.
NASA Astrophysics Data System (ADS)
Mukherjee, G.; Sharma, S. K.
1985-02-01
A microscopic description of the recent data on the Coulomb form factors for the 0g.s.+-->2+2 transitions in the nuclei 48Ti and 50Cr is attempted in terms of the prolate and oblate intrinsic states resulting from realistic effective interactions operating in the 2p-1f shell. The results for the higher momentum-transfer region show significant improvements compared to the form factor estimates obtained in some recent shell model calculations involving the fn7/2+fn-17/2p3/2 configurations.
Recoil Polarization Measurements of the Proton Electromagnetic Form Factor Ratio to Q^2 = 8.5 GeV^2
Puckett, A J.R.; Jones, M K; Luo, W; Meziane, M; Pentchev, L; Perdrisat, C F; Punjabi, V; Wesselmann, F R; Ahmidouch, A; Albayrak, I; Aniol, K A; Arrington, J; Asaturyan, A; Baghdasaryan, H; Benmokhtar, F; Bertozzi, W; Bimbot, L; Bosted, P; Boeglin, W; Butuceanu, C; Carter, P; Chernenko, S; Christy, E; Commisso, M; Cornejo, J C; Covrig, S; Danagoulian, S; Daniel, A; Davidenko, A; Day, D; Dhamija, S; Dutta, D; Ent, R; Frullani, S; Fenker, H; Frlez, E; Garibaldi, F; Gaskell, D; Gilad, S; Gilman, R; Goncharenko, Y; Hafidi, K; Hamilton, D; Higinbotham, D W; Hinton, W; Horn, T; Hu, B; Huang, J; Huber, G M; Jensen, E; Keppel, C; Khandaker, M; King, P; Kirillov, D; Kohl, M; Kravtsov, V; Kumbartzki, G; Li, Y; Mamyan, V; Margaziotis, D J; Marsh, A; Matulenko, Y; Maxwell, J; Mbianda, G; Meekins, D; Melnik, Y; Miller, J; Mkrtchyan, A; Mkrtchyan, H; Moffit, B; Moreno, O; Mulholland, J; Narayan, A; Nedev, S; Nuruzzaman,; Piasetzky, E; Pierce, W; Piskunov, N M; Prok, Y; Ransome, R D; Razin, D S; Reimer, P; Reinhold, J; Rondon, O; Shabestari, M; Shahinyan, A; Shestermanov, K; Sirca, S; Sitnik, I; Smykov, L; Smith, G; Solovyev, L; Solvingnon, P; Subedi, R; Tomasi-Gustafsson, E; Vasiliev, A; Veilleux, M; Wojtsekhowski, B B; Wood, S; Ye, Z; Zanevsky, Y; Zhang, X; Zhang, Y; Zheng, X; Zhu, L
2010-06-01
Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dynamics of the nucleon’s quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this Letter, we report new measurements of the proton electromagnetic form factor ratio using the recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5 GeV2. By extending the range of Q2 for which GEp is accurately determined by more than 50%, these measurements will provide significant constraints on models of nucleon structure in the nonperturbative regime.
Characterization of inducible models of Tay-Sachs and related disease.
Sargeant, Timothy J; Drage, Deborah J; Wang, Susan; Apostolakis, Apostolos A; Cox, Timothy M; Cachón-González, M Begoña
2012-09-01
Tay-Sachs and Sandhoff diseases are lethal inborn errors of acid β-N-acetylhexosaminidase activity, characterized by lysosomal storage of GM2 ganglioside and related glycoconjugates in the nervous system. The molecular events that lead to irreversible neuronal injury accompanied by gliosis are unknown; but gene transfer, when undertaken before neurological signs are manifest, effectively rescues the acute neurodegenerative illness in Hexb-/- (Sandhoff) mice that lack β-hexosaminidases A and B. To define determinants of therapeutic efficacy and establish a dynamic experimental platform to systematically investigate cellular pathogenesis of GM2 gangliosidosis, we generated two inducible experimental models. Reversible transgenic expression of β-hexosaminidase directed by two promoters, mouse Hexb and human Synapsin 1 promoters, permitted progression of GM2 gangliosidosis in Sandhoff mice to be modified at pre-defined ages. A single auto-regulatory tetracycline-sensitive expression cassette controlled expression of transgenic Hexb in the brain of Hexb-/- mice and provided long-term rescue from the acute neuronopathic disorder, as well as the accompanying pathological storage of glycoconjugates and gliosis in most parts of the brain. Ultimately, late-onset brainstem and ventral spinal cord pathology occurred and was associated with increased tone in the limbs. Silencing transgenic Hexb expression in five-week-old mice induced stereotypic signs and progression of Sandhoff disease, including tremor, bradykinesia, and hind-limb paralysis. As in germline Hexb-/- mice, these neurodegenerative manifestations advanced rapidly, indicating that the pathogenesis and progression of GM2 gangliosidosis is not influenced by developmental events in the maturing nervous system.
Molecular characterization of both alleles in an unusual Tay-Sachs disease BI variant
Coulter-Mackie, M.B. Child Health Research Institute, Children's Hospital of Western Ontario, London Child Parent Resource Institute, London, Ontario )
1994-06-01
In a recent report, the authors described an exon 6 mutation in a Tay-Sachs B1 variant patient, first reported by Gordon et al. (1988), who displayed a typical B1 variant biochemical phenotype - i.e., (a) significant levels of hexosaminidase A (Hex A) activity in an assay with a neutral synthetic substrate, 4-methylumbelliferyl-[beta]-N-acetylglucosamide, and (b) <2% of control Hex A in a test on the sulfated substrate, 4-methylumbelliferyl-[beta]-N-acetylglucosamide-6-sulfate. The patient was found to carry a double mutation (G[sub 574][yields]C [val[sub 192][yields]leu] and G[sub 598][yields]A [val[sub 200][yields]met]) inherited from her mother. Only the 574 mutation produced a deleterious effect on Hex A activity in transfected COS0-1 cells, producing a B1 variant biochemical phenotype. The paternal allele apparently caused decreased abundance of mRNA, since no candidate paternal mutations were found in cloned reverse transcription-PCR (RT-PCR) products in the reported study. The biochemical phenotype of the original patient and the properties of the cDNA carrying the G[sub 574] [yields] C mutation in transient expression studies were compatible with a B1 variant mutation. The possibility remained that there might be some contribution from the paternal allele to the patient's phenotype. However, the paternal allele produces relatively low yields of a largely mis-spliced mRNA whose product would not be functional. Therefore, the G[sub 574] [yields] C (val[yields]leu) mutation in the maternal allele is clearly confirmed as a B1 variant mutation with all the ramifications for the substrate binding site and/or catalytic center that this implies.
Probing violation of the Copernican principle via the integrated Sachs-Wolfe effect
Tomita, Kenji; Inoue, Kaiki Taro
2009-05-15
Recent observational data of supernovae point to {lambda}-dominated flat cosmological models. However, an alternative model in which we happen to live in an underdense region requires no dark energy or modification of gravity. This challenges the Copernican principle. We show that the integrated Sachs-Wolfe (ISW) effect is an excellent discriminator between anti-Copernican inhomogeneous models and the standard Copernican models. As a reference model, we consider an anti-Copernican inhomogeneous model that consists of two inner negatively curved underdense regions and an outer flat Einstein-de Sitter region. We assume that these regions are connected by two thin walls at redshifts z=0.067 and z=0.45. In the inner two regions, the first-order ISW effect is dominant and comparable to that in the concordant flat-{lambda} models. In the outer Einstein-de Sitter region, the first-order ISW effect vanishes but the second-order ISW effect plays a dominant role, while the first-order ISW effect is dominant in the flat-{lambda} models at moderate redshifts. This difference can discriminate the anti-Copernican models from the concordant flat-{lambda} model. At high redshifts, the second-order ISW effect is dominant both in our inhomogeneous model and in the concordant model. In the outer region, moreover, the ISW effect due to large-scale density perturbations with a present matter density contrast {epsilon}{sub m0}<<0.37 is negligible, while the effect due to small-scale density perturbations (such as clusters of galaxies, superclusters, and voids) with {epsilon}{sub m0}>>0.37 would generate anisotropies which are larger than those generated by the ISW effect in the concordant model.
More than one mutant allele causes infantile Tay-Sachs disease in French-Canadians
Hechtman, Peter; Kaplan, Feige; Bayleran, Janet; Boulay, Bernard; Andermann, Eva; de Braekeleer, Marc; Melançon, Serge; Lambert, Marie; Potier, Michel; Gagné, Richard; Kolodny, Edwin; Clow, Carol; Capua, Aniceta; Prevost, Claude; Scriver, Charles
1990-01-01
Two Tay-Sachs disease (TSD) patients of French-Canadian origin were shown by Myerowitz and Hogikyan to be homozygous for a 7.6-kb deletion mutation at the 5' end of the hexosaminidase A α-subunit gene. In order to determine whether all French-Canadian TSD patients were homozygotes for the deletion allele and to assess the geographic origins of TSD in this population, we ascertained 12 TSD families of French-Canadian origin and screened for occurrence of mutations associated with infantile TSD. DNA samples were obtained from 12 French-Canadian TSD families. Samples were analyzed using polymerase-chain-reaction (PCR) amplification followed by hybridization to allele-specific oligonucleotides (ASO) or by restriction analysis of PCR products. In some cases Southern analysis of genomic DNA was performed. Eighteen of the 22 independently segregating mutant chromosomes in this sample carried the 7.6-kb deletion mutation at the 5' end of the gene. One chromosome carried the 4-nucleotide insertion in exon 11 (a “Jewish” mutation). In this population no individuals were detected who had the substitution at the splice junction of exon 12 previously identified in Ashkenazi Jews. One chromosome carried an undescribed B1 mutation; this allele came from a parent of non-French-Canadian origin. Patients in three families carried TSD alleles different from any of the above mutations. The 5' deletion mutation clusters in persons originating in southeastern Quebec (Gaspé) and adjacent counties of northern New Brunswick. ImagesFigure 3Figure 4Figure 5Figure 6 PMID:2220821
Haghighi, Alireza; Rezazadeh, Jamileh; Shadmehri, Azam Ahmadi; Haghighi, Amirreza; Kornreich, Ruth; Desnick, Robert J
2011-09-01
The β-hexosaminidase A (HEXA) mutations in the first reported cases of infantile Tay-Sachs disease in the Persian population were identified in two unrelated consanguineous families. The clinical diagnoses of the affected infants were confirmed by their markedly deficient levels of HEXA activity in plasma or peripheral leukocytes. The specific causative mutation in each family was determined by sequencing the HEXA alleles in both sets of related parents. Two mutations were identified: c.1A>G (p.MIV), which obliterated the initiating methionine in codon 1, and c.1177C>T (p.R393X), which predicted a termination codon or nonsense mutation.
Pathological alterations typical of human Tay-Sachs disease, in the retina of a deep-sea fish
NASA Astrophysics Data System (ADS)
Fishelson, L.; Delarea, Yacov; Galil, Bella S.
Micrographs of retinas from the deep-sea fish Cataetyx laticeps revealed visual cells containing membranous whorls in the ellipsoids of the inner segments resulting from stretching and modifications of the mitochondria membranes and their cristae. These pathological structures seem to be homologous to the whorls observed in retinas of human carriers of Tay-Sachs disease. This disease, a genetic disorder, is found in humans and some mammals. Our findings in fish suggest that the gene responsible can be found throughout the vertebrate evolutionary tree, possibly dormant in most taxa.
At least six different mutations in HEXA gene cause Tay-Sachs disease among the Turkish population.
Ozkara, H A; Navon, R
1998-11-01
Twenty-five Turkish infants with Tay-Sachs disease (TSD) have been diagnosed in the past 8 years. All are from consanguineous, nonrelated families. The present study deals with the molecular basis of six Turkish TSD patients from five unrelated families in which the parents were first cousins. The five mutations identified in this study were INS-5 G-->A, R393X, R137X, 12-bp deletion in exon 10, and G454D. The first three were reported in earlier studies, two in Turkish TSD infants and one in a French TSD infant.
Izzo, M. G.; Bencivenga, F.; Di Fonzo, S.; Cunsolo, A.; Verbeni, R.; De Lorenzo, R. Gimenez
2010-09-28
The high frequency dynamics of liquid iodine has been investigated by deep inelastic x-ray scattering at exchanged wave-vectors (q) ranging from 2.5 to 15 A{sup -1}. The experimental data have been analyzed in the frame of the Sachs-Teller theory of the molecular spectrum while accounting for final state corrections to the lineshape. The performed data analysis carries insights on physical quantities as relevant as the mean rototranslational kinetic energy and the mean square Laplacian of the intermolecular potential. In both cases the measured values are consistent with corresponding theoretical expectations.
Qualitative study of Bianchi type-I, III and Kantowski-Sachs cosmological models with scalar field
NASA Astrophysics Data System (ADS)
Chaubey, Raghavendra; Raushan, Rakesh
2016-08-01
A qualitative analysis of Bianchi type-I, III and Kantowski-Sachs (KS) cosmological models with a scalar field and matter fluid is performed. The analysis of the resulting equations is made by the dynamical system method. To analyze the evolution equations, we have introduced suitable transformation of variables. The evolution of the corresponding solutions is represented by curves in the phase-plane diagram. We analyze the evolution of the effective equation of state parameter for Bianchi type-I, III and KS cosmological models. The nature of critical points are analyzed and stable attractors are examined for each cosmological model.
Expansion of X-ray form factor for close shell using uncorrelated wave function
AL-Robayi, Enas M.
2013-12-16
The atomic scattering factor has been studied for Be+ve, and B+2ve ions using the uncorrelated wave function (Hartree-Fock (HF)) for inter particle electronic shells. The physical importance of this factor appears in its relation to several important atomic properties as, the coherent scattering intensity, the total scattering intensity, the incoherent scattering function, the coherent scattering cross section, the total incoherent cross section, the nuclear magnetic shielding constant, the geometrical structure factor. Also there is one atomic properties the one particle radial density distribution function D(r)has been studied using the partitioning technique.
Díaz-Herrero, Angela; Brito de la Nuez, Alfredo G; López Pina, José Antonio; Pérez-López, Julio; Martínez-Fuentes, María Teresa
2010-11-01
The aim of this study was to analyze the psychometric properties of the Spanish version of Parenting Stress Index-Short Form. After translating the instrument from English into Spanish using the forward-backward translation method, it was administered to a sample of 129 mothers of children aged between 10 and 39 months olds. The exploratory factor analysis identified two factors: Childrearing Stress and Personal Distress, which accounted for 48.77% of the variance. The internal consistency of these factors was high (Childrearing Stress: .90 and Personal Distress: .87). Implications of these findings and suggestions for future research are discussed.
Similarity of urinary risk factors among stone-forming patients in five regions of the United States
NASA Technical Reports Server (NTRS)
Harvey, J. A.; Hill, K. D.; Pak, C. Y.
1990-01-01
Study Objective: To compare urinary biochemical risk factors among stone-forming patients in the Southeast (SE) or "stone belt" versus four other regions of the United States. Design: Prospective biochemical survey for regional comparisons. Setting: Referral-based nephrolithiasis clinics, urologists, nephrologists, and family practitioners. Patients: Consecutive sample of 3473 stone-forming patients who submitted 24-hour urine collections for biochemical analyses of stone-forming risk factors. Interventions: None. Subjects taking medication known to interfere with stone-forming risk factors were deleted from the final data compilation. Measurements and Main Results: Overall, the mean values for each urinary parameter spanned a narrow range without significant difference between the five regions. Among "metabolic" factors, 40% in the SE had hypercalciuria (> 6.25 mmol/d), compared to 35%-43% in other regions, and hyperuricosuria (> 4.2 mmol/d) was found in 16% in the SE versus 17%-19% elsewhere. Among "environmental" factors, low urine volume ( < 2 L/d) was found in 77% patients in the SE compared to 69%-78% elsewhere, and high sodium was encountered in 27% in the SE versus 24%-29% elsewhere. No differences were noted in occurrence of other abnormal risk factors: hyperoxaluria, hypocitraturia, low pH, high sulfate, high phosphorus, or low magnesium. Conclusions: Despite expected regional differences in nutritional and environmental influences, the results of this study showed a striking similarity in urinary biochemical risk factor profiles of stone-formers in all five regions of the United States.
Perturbative corrections to Λ b → Λ form factors from QCD light-cone sum rules
NASA Astrophysics Data System (ADS)
Wang, Yu-Ming; Shen, Yue-Long
2016-02-01
We compute radiative corrections to Λ b → Λ from factors, at next-to-leading logarithmic accuracy, from QCD light-cone sum rules with Λ b -baryon distribution amplitudes. Employing the diagrammatic approach factorization of the vacuum-to-Λ b -baryon correlation function is justified at leading power in Λ /m b , with the aid of the method of regions. Hard functions entering the factorization formulae are identical to the corresponding matching coefficients of heavy-to-light currents from QCD onto soft-collinear effective theory. The universal jet function from integrating out the hard-collinear fluctuations exhibits richer structures compared with the one involved in the factorization expressions of the vacuum-to- B-meson correlation function. Based upon the QCD resummation improved sum rules we observe that the perturbative corrections at {O}({α}_s) shift the Λ b → Λ from factors at large recoil significantly and the dominant contribution originates from the next-to-leading order jet function instead of the hard coefficient functions. Having at hand the sum rule predictions for the Λ b → Λ from factors we further investigate several decay observables in the electro-weak penguin Λ b → Λ ℓ + ℓ - transitions in the factorization limit (i.e., ignoring the "non-factorizable" hadronic effects which cannot be expressed in terms of the Λ b → Λ from factors), including the invariant mass distribution of the lepton pair, the forward-backward asymmetry in the dilepton system and the longitudinal polarization fraction of the leptonic sector.
ERIC Educational Resources Information Center
Oades-Sese, Geraldine V.; Kaliski, Pamela K.; Weiss, Karen
2010-01-01
The Devereux Early Childhood Assessment Clinical Form (DECA-C) is the first instrument to measure the social-emotional resilience of young children from ages 2 to 5 years. This study is an important step toward gathering validity evidence for the teacher-rated DECA-C. This is the first study to investigate the DECA-C factor structure and the first…
Overview of high-Q2 nucleon form factor program with Super BigBite Spectrometer in JLab's Hall A
NASA Astrophysics Data System (ADS)
Puckett, Andrew; Jefferson Lab Hall A; Super BigBite Spectrometer Collaboration
2017-01-01
The elastic electromagnetic form factors (EMFFs) of the nucleon describe the impact-parameter-space distributions of electric charge and magnetization in the nucleon in the infinite momentum frame. The form factors are among the simplest and most fundamental measurable dynamical quantities describing the nucleon's structure. Precision measurements of the nucleon form factors provide stringent benchmarks testing the most sophisticated theoretical models of the nucleon, as well as ab initio calculations in lattice QCD and continuum non-perturbative QCD calculations based on the Dyson-Schwinger equations. Measurements at momentum transfers Q in the few-GeV range probe the theoretically challenging region of transition between the non-perturbative and perturbative regimes of QCD. The recent upgrade of the Continuous Electron Beam Accelerator Facility (CEBAF) to a maximum electron beam energy of 11 GeV will facilitate the measurement of the nucleon helicity-conserving (F1) and helicity-flip (F2) form factors of both proton and neutron to Q2 > 10 GeV2, In this talk, I will present an overview of the Super BigBite Spectrometer, currently under construction in CEBAF's experimental Hall A, and its physics program of high-Q2 nucleon EMFF measurements. Supported by US DOE award DE-SC0014230.
Form factors and the s-wave component of the two-pion-exchange three-nucleon potential
Robilotta, M.R.; Isidro Filho, M.P.; Coelho, H.T.; Das, T.K.
1985-02-01
We argue that the straightforward introduction of ..pi..N form factors into the s-wave component of the two-pion-exchange three-nucleon potential based on chiral symmetry is not free of problems. These can be avoided by means of a redefinition of the potential which considers its physical content.
Transition form factors of P wave bottomonium {chi}{sub b0} (1P) into B{sub c} meson
Suengue, J. Y.; Azizi, K.; Sundu, H.
2012-10-23
Taking into account the two-gluon condensate contributions, the transition form factors enrolled to the low energy effective Hamiltonian describing the semileptonic {chi}{sub b0}{yields}B{sub c} Script-Small-L {nu},( Script-Small-L = (e,{mu},{tau})) decay channel are calculated within three-point QCD sum rules.
ERIC Educational Resources Information Center
Thombs, Brett D.; Bernstein, David P.; Lobbestael, Jill; Arntz, Arnoud
2009-01-01
Objective: The 28-item Childhood Trauma Questionnaire-Short Form (CTQ-SF) has been translated into at least 10 different languages. The validity of translated versions of the CTQ-SF, however, has generally not been examined. The objective of this study was to investigate the factor structure, internal consistency reliability, and known-groups…
Ainsworth, P.J. Child Health Research Institute, London, Ontario ); Coulter-Mackie, M.B. Child Health Research Institute, London, Ontario Children's Psychiatric Research Institute, London, Ontario )
1992-10-01
The B1 variant form of Tay-Sachs disease is enzymologically unique in that the causative mutation(s) appear to affect the active site in the [alpha] subunit of [beta]-hexosaminidase A without altering its ability to associate with the [beta] subunit. Most previously reported B1 variant mutations were found in exon 5 within codon 178. The coding sequence of the [alpha] subunit gene of a patient with the B1 variant form was examined with a combination of reverse transcription of mRNA to cDNA, PCR, and dideoxy sequencing. A double mutation in exon 6 has been identified: a G[sub 574][yields]C transversion causing a val[sub 192][yields]leu change and a G[sub 598][yields] A transition resulting in a val[sub 200][yields]met alteration. The amplified cDNAs were otherwise normal throughout their sequence. The 574 and 598 alterations have been confirmed by amplification directly from genomic DNA from the patient and her mother. Transient-expression studies of the two exon 6 mutations (singly or together) in COS-1 cells show that the G[sub 574][yields]C change is sufficient to cause the loss of enzyme activity. The biochemical phenotype of the 574 alteration in transfection studies is consistent with that expected for a B1 variant mutation. As such, this mutation differs from previously reported B1 variant mutations, all of which occur in exon 5. 31 refs., 2 figs., 2 tabs.