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The reaction p(e,e'p)pi^0 has been studied at Q^2=0.2 (GeV/c)^2 in the region of W=1232 MeV. From measurements left and right of q, cross section asymmetries \rho_LT have been obtained in forward kinematics \rho_LT(\theta_\pi^0=20deg) = (-11.68 +/- 2.36_stat +/- 2.36_sys)$ and backward kinematics \rho_LT(\theta_\pi^0=160deg) =(12.18 +/- 0.27_stat +/- 0.82_sys). Multipole ratios \Re(S_1+^* M_1+)/|M_1+|^2 and \Re(S_0+^* M_1+)/|M_1+|^2 were determined in the framework of the MAID2003 model. The results are in agreement with older data. The unusally strong negative \Re(S_0+^* M_1+)/|M_1+|^2 required to bring also the result of Kalleicher et al. in accordance with the rest of the data is almost excluded.

This work describes methodical studies of thermally assisted hydrolysis and methylation (THM) of fatty acids (FA) and triglycerides comparing different derivatization reagents, such as tetramethylammonium hydroxide (TMAH), tetramethylammonium acetate (TMAAc), trimethylsulfonium hydroxide (TMSH), trimethylphenylamine hydroxide (TMPAH), and (m-trifluoromethylphenyl) trimethylammonium hydroxide (MethPrep 2). The performance of these reagents using different injection techniques, such as pyrolysis, hot split injection, and programmed temperature vaporization (PTV) has been investigated.

AGC method has been developed for the analysis of tricholoroacetic acid (TCA) in water samples. It entails large-volume injection (LVI) and programmed-temperature vaporization (PTV) of water samples, thermal decarboxylation of TCA to chloroform in the injector, and GC-ECD analysis of the decarboxylation product. Conditions such as final injector temperature, splitless time, and injection volume were optimized. The limit of detection is approximately 0.1 μg L−1 Several real samples were analyzed. The method presented is an easy means of determination of TCA and eliminates sample-preparation steps such as extraction and derivatization.

The reaction p(e,e'pi+)n was measured at the Mainz Microtron MAMI at an invariant mass of W=1125 MeV and four-momentum transfers of Q^2=0.117, 0.195 and 0.273 (GeV/c)^2. For each value of Q^2, a Rosenbluth separation of the transverse and longitudinal cross sections was performed. An effective Lagrangian model was used to extract the `axial mass' from experimental data. We find a value of M_A=(1.077+-0.039) GeV which is (0.051+-0.044) GeV larger than the axial mass known from neutrino scattering experiments. This is consistent with recent calculations in chiral perturbation theory.

We present a new approach to the calculation of solvent-accessible surface areas of molecules with potential application to surface area based methods for determination of solvation free energies. As in traditional analytical and statistical approaches, this new algorithm, called TRIFORCE, reports both component areas and derivatives as a function of the atomic coordinates and radii. Unique to TRIFORCE are the rapid and scalable approaches for the determination of sphere intersection points and numerical estimation of the surface areas, derivatives, and other properties that can be associated with the surface area facets. The algorithm performs a special tessellation and semianalytical integration that uses a precomputed look-up table. This provides a simple way to balance numerical accuracy and memory usage. TRIFORCE calculates derivatives in the same manner, enabling application in force-dependent activities such as molecular geometry minimization. TRIFORCE is available free of charge for academic purposes as both a C++ library, which can be directly interfaced to existing molecular simulation packages, and a web-accessible application.

IκB proteins are the primary inhibitors of NF-κB. Here, we demonstrate that sumoylated and phosphorylated IκBα accumulates in the nucleus of keratinocytes and interacts with histones H2A and H4 at the regulatory region of HOX and IRX genes. Chromatin-bound IκBα modulates Polycomb recruitment and imparts their competence to be activated by TNFα. Mutations in the Drosophila IκBα gene cactus enhance the homeotic phenotype of Polycomb mutants, which is not counteracted by mutations in dorsal/NF-κB. Oncogenic transformation of keratinocytes results in cytoplasmic IκBα translocation associated with a massive activation of Hox. Accumulation of cytoplasmic IκBα was found in squamous cell carcinoma (SCC) associated with IKK activation and HOX upregulation., M.M. is an investigator of the Sara Borrell program (CD09/00421). E.L.A. is a recipient of a predoctoral fellowship from the Department of Education, Universities and Research of the Basque Government (BFI-2011), and V.R. was a recipient of FIMIM predoctoral fellowship. L.E. is an investigator at the Carlos III program. This work was supported by a grant from the Instituto de Salud Carlos III (PI041890), Fundación Mutua Madrileña, AGAUR (SGR23), and RTICCS/FEDER (RD06/0020/0098 and RD12/0036/0054). M.D. was funded by the Ministerio de Ciencia e Innovación (BFU2009-09074 and MEC-CONSOLIDER CSD2007-00023), Generalitat Valenciana (PROMETEO 2008/134), and a grant from European Union Research (UE-HEALH-F2-2008-201666). J.V-F. was funded by a MICINN grant (CTQ2008-00755) and the EC VPH (no. FP7-2007-IST-223920).

Relativistic corrections have been calculated for the Drell-Hearn-Gerasimov sum rule in the framework of the constituent-quark model. These corrections lead to additional absorption strength due to relativistic dipole currents in the case of a hyperfine interaction. The introduction of anomalous magnetic moments requires a subtraction of the dispersion integral at infinity. The additional effects of such anomalous moments, however, are numerically very small within the model.

Rule based interpolating control ( RIP control) is an approach to deal with linguistic expert knowledge in the form of production rules, As an alternative to fuzzy control. RIP control transforms the production rules into support points in a hyperspace and applies multidimensional interpolation methods to obtain the input/output mapping of the controller. The paper introduces RIP control and its application in knowledge-based systems. The potential of hybrid RIP rule bases are demonstrated using flow control as an example.

Arthritis is a rare manifestation of systemic sporotrichosis. A patient who had sporotrichal arthritis of both wrists and elbows is described. Predisposing factors included alcoholism, rose gardening, and antecedent trauma. The onset of the arthritis was insidious, and the diagnosis was made 2 1/2 years after his first symptoms were noted. Treatment with surgical debridement and a 23-week course of ketoconazole was unsuccessful. A review of the literature suggests that some combination of intravenous or intraarticular amphotericin B and potassium iodide, ketoconazole, or surgery is necessary for effective treatment.

The helicity structure function of the nucleon has been calculated for the constituent quark model and compared to the prediction of the Drell-Hearn-Gerasimov sum rule. The multipole decomposition of the sum rule shows large cancellations between different resonances. The small isoscalar-isovector contribution is related to the admixture of aD-state (“bag deformation”) in the nucleon's wave function. The calculations indicate a relatively slow saturation of this part of the sum rule with excitation energy.

The Gerasimov-Drell-Hearn sum rule and related dispersive integrals connect real and virtual Compton scattering to inclusive photo- and electroproduction. Being based on universal principles as causality, unitarity, and gauge invariance, these relations provide a unique testing ground to study the internal degrees of freedom that hold a system together. The present contribution reviews the spin-dependent sum rules and cross sections of the nucleon. At small momentum transfer, the data sample information on the long range phenomena (Goldstone bosons and collective resonances), whereas the primary degrees of freedom (quarks and gluons) become visible at large momentum transfer (short distance). The rich body of new data covers a wide range of phenomena from coherent to incoherent processes, and from the generalized spin polarizabilities on the low-energy side to higher twist effects in deep inelastic scattering., 15 pages, 7 figures, Proc. of Spin structure at long distance, Newport News, Virginia, 2009

It is shown that the anomalous magnetic moment of the electron, kappa e, is irrelevant for the experimental determination of the nucleon form factors ('Rosenbluth plot'). The large corrections claimed by previous authors are due to the neglect of the form factor associated with kappa e.

Pion photoproduction at threshold has been studied in the chiral bag model (CBM) and compared with the predictions of the low energy theorem (LET). Based on a boost for individual quarks bound in a scalar potential, the authors develop a projection technique to eliminate spurious centre-of-mass motion from the excitation spectrum. Recoil corrections are treated with the same boost operator. While the static CBM fails completely to reproduce the isospin amplitudes A(0) and A(+) in leading order of mu =mpi /mN, the proposed projection mechanism yields A(0)=-0.41 mu and A(+)=-0.49 mu in close agreement with the LET prediction A(0)=A(+)=-(1/2) mu .

The energy dependence of the magnetic polarizability β has been evaluated by use of the delta resonance in the s- and u-channel of the Compton scattering amplitude. It was the idea to extract the influence of higher order terms (higher than ω2, ω = |k| being the photon energy) in the analysis of the polarizability. The static paramagnetic polarizability βPara(0) has been substituted by an energy dependent βδPara(k) and the result is compared with experimental data.

We present an overview of dynamic and related models for pion electroproduction on the nucleon due to Δ(1232) excitation. The electromagnetic multipoles and their ratios obtained from these models and from effective field theories are compared, and the existing contradictory results for the pion cloud effects are discussed.

This paper presents an adaptive control system based on several different control algorithms. The basic idea is to detect several events of the current variations of the controller error variable, to adjust the parameters of a conventional controller. The adaptive control system uses a state and event driven adaptation strategy. The second aspect of this paper outlines a systematic approach to develop, implement and describe adaptive control systems taking into consideration the demands of real time systems. In this case, state graphs and Petrinets are used as appropriate tools for graphical representation of the adaptive control strategy and the total system. The state graphs describe a finite state machine which can be performed by means of a special digital control loop. The architecture of this digital control loop is a hierarchical control structure, subdivided into an operating block and a supervisor.

We investigate the rare radiative eta decay modes eta -> pi+ pi- gamma gamma and eta -> pi0 pi0 gamma gamma within the framework of chiral lagrangians at o(p^4) and present photon spectra for both processes.

We describe the application of a dispersion‐relation formalism to the virtual Compton scattering (VCS) reaction with the aim to extract information on generalized polarizabilities from VCS observables over a large energy range.

The helicity dependence of the gamma--p----ppi(0) reaction has been measured for the first time in the photon-energy range from 550 to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4pi-detector system, a circularly polarized, tagged photon beam, and a longitudinally polarized frozen-spin target. These data are predominantly sensitive to the D13(1520) resonance and are used to determine its helicity amplitudes.

We report on our study of η photoproduction and electroproduction on the nucleon using an isobar model. The model contains nucleon Born terms and contributions from t-channel vector meson exchange as nonresonant background. In addition to the dominant S11(1535), we also include resonance contributions from D13(1520), S11(1650), D15(1675), F15(1680), D13(1700), P11(1710), and P13(1720). Within this model we analyze recent η photoproduction data for differential and total cross sections, beam and target asymmetries, as well as JLab electroproduction data. Good agreement has been achieved. With the new cross section data from GRAAL [2], we show that besides the dominant S11(1535), the second S11 resonance, S11(1650), is required in order to extract S11(1535) resonance parameters properly. In addition, the beam asymmetry data allow us to extract very small (

In a p((--)e,e'p)pi(0) out-of-plane coincidence experiment at the three-spectrometer setup of the Mainz Microtron MAMI, the beam-helicity asymmetry has been precisely measured around the energy of the Delta(1232) resonance and Q(2) = 0.2(GeV/c)(2). The results are in disagreement with three up-to-date model calculations. This is interpreted as a lack of understanding of the nonresonant background, which in dynamical models is related to the pion cloud.

The recoil proton polarization has been measured in the p(e--,e'p--)pi(0) reaction in parallel kinematics around W = 1232 MeV, Q2 = 0.121 (GeV/c)2, and epsilon = 0.718 using the polarized cw electron beam of the Mainz Microtron. All three proton polarization components, Px/P(e) = (-11.4+/-1.3+/-1.4)%, P(y) = (-43.1+/-1.3+/-2.2)%, and P(z)/P(e) = (56.2+/-1.5+/-2.6)%, could be measured simultaneously. The Coulomb quadrupole to magnetic dipole ratio, CMR = (-6.4+/-0.7(stat)+/-0.8(syst))%, was determined from Px in the framework of the Mainz Unitary Isobar Model. The consistency among the reduced polarizations and the extraction of the ratio of longitudinal-to-transverse response is discussed.

Pion photoproduction has been analyzed in the framework of dispersion relations at constant t. The results for S-wave pion production at threshold and P-wave production in the Δ (1232) resonance region are presented and compared to the data and theoretical expectations. The predictions for the GDH sum rule are shown to be very sensitive to the threshold S-wave amplitude.

The long-standing discrepancy between the Gerasimov-Drell-Hearn sum rule and the analysis of pion photoproduction multipoles is greatly diminished by use of s-wave multipoles that are in accord with the predictions of chiral perturbation theory and describe the experimental data in the threshold region. The remaining difference may be due to contributions of channels with more pions and/or heavier mesons whose contributions to the sum rule remain to be investigated by a direct measurement of the photoabsorption cross sections.

The Drell-Hearn-Gerasimov (DHG) sum rule relates the helicity structure of the photoabsorption cross section to the anomalous magnetic moment of the nucleon. It is based on Lorentz and gauge invariance, crossing symmetry, causality and unitarity. A generalized DHG sum rule my be derived for virtual photons. At low momentum transfer this generalized sum rule is saturated by the resonance region, at high momentum transfer it may be expressed by the parton spin distributions measured in deep inelastic scattering. The longitudinal-transverse interference determines the Cottingham sum rule, which is related to the electric and magnetic form factors over the whole range of momentum transfer., 20 pages LATEX plus 12 figures (available by fax from the author)

Photo- and electroproduction of mesons are well suited tools to investigate the structure of hadrons. With the advent of electron accelerators with high current and large duty-factor, new classes of experiments including polarization degrees of freedom have become possible. Such investigations range from threshold production of mesons to detailed studies of nucleon resonances. In addition, there is the large field of meson production and propagation in the nuclear medium.

The microtubule array in neuronal cells undergoes extensive growth, dynamics and rearrangements during neurite outgrowth. While little is known about how these changes are regulated, microtubule-associated proteins (MAPs) including tau protein are likely to perform an important role. Tau is one of the MAPs in mammalian brain. When isolated it is usually a mixture of several isoforms containing between 341 and 441 residues that arise from alternative splicing. Tau can be phosphorylated by several protein kinases. Phosphorylation at certain sites results in major structural and functional changes, as seen by changes in electrophoretic mobility, interaction with microtubules, molecular length and elasticity. Here we show that the sites of phosphorylation by four kinases (PKA, PKC, CK and CaMK) all lie in the C-terminal microtubule-binding half of tau, but only the phosphorylation by CaM kinase shows the pronounced shift in electrophoretic mobility characteristic for tau from Alzheimer neurofibrillary tangles. By using a combination of limited proteolysis, protein sequencing and protein engineering we show that a single phosphorylation site is responsible for this shift, located at Ser 405 in the C-terminal tail of the protein outside the region of internal repeats. Phosphorylation at this site not only reduces the electrophoretic mobility of tau, it also makes the protein long and stiff, as shown earlier. The site is likely to be phosphorylated in tau from Alzheimer neurofibrillary tangles.

A Comment on the Letter by Z-J. Cao and L. S. Kisslinger, Phys. Rev. Lett. 64, 1007 (1990).

The Nucleon pole and 3,3 resonance pole contributions are considered for the reactionspp→ppπ0 andpp→pnπ+ at low and medium incident proton energies. The total and various differential cross sections are calculated, also for polarized nucleons, and compared with experimental data.

The relativistic pair current is re-evaluated in the constituent quark model. Isovector charge and isoscalar current contributions change substantially compared to previous calculations. In particular, the previously predicted large differences in the change form factors of 3 He and 3 H are considerably reduced.

Die „Empfehlungen des Wissenschaftsrates zur Struktur des Studiums” [1, 2] haben eine breite Diskussion uber das Thema Studiendauer und Lange der Diplomarbeit ausgelost. Die DPG und die Konferenz der Fachbereiche Physik (KFP) haben ihrerseits mit einer Erklarung zur Struktur des Physikstudiums reagiert [3]. Im Fruhjahr 1987 beauftragte der Vorstandsrat der DPG den Sprecher der KFP, DPG-Vorstandsmitglied Prof. Drechsel, zu untersuchen, welche Ursachen und Bedingungen innerhalb eines Fachbereichs dazu fuhren, das die mittlere Studienzeit uberdurchschnittlich lang bzw. uberdurchschnittlich kurz ist. Im folgenden Beitrag schildert Prof. Drechsel einige Ergebnisse seiner Situationsanalyse an acht physikalischen Fachbereichen. Ausgewahlt wurden vier Fachbereiche mit kurzer mittlerer Studiendauer (im folgenden als „Typ A” bezeichnet) und vier Fachbereiche mit langer mittlerer Studiendauer (Typ B).