Psi Gamma Research Articles

Fermion localization mechanism with derivative geometrical coupling on branes

In order to localize fermions on branes with codimension one, one usually introduces the Yukawa coupling between fermions and background scalar fields or the recently proposed derivative fermion-scalar coupling in [Phys. Rev. D 89 (2014) 086001]. In this paper, we explore the coupling between a spinor field $\Psi$ and the scalar curvature of spacetime $R$, $\eta\Psi\Gamma^M\partial_M F(R)\gamma^5\bar{\Psi}$ with $F(R)$ a function of $R$, to investigate localization of the fermion. Because of $Z_2$ symmetry of the extra dimension, the new coupling mechanism proposed here can easily deal with the problem encountered in the Yukawa coupling with even background scalar fields. More importantly, the new mechanism will also work for the branes without background scalar fields. By investigating three examples, we find that fermions can be localized on the branes with the new mechanism.

Rototranslational sum rules for electromagnetic hypershielding at the nuclei and related atomic Cartesian derivatives of the optical rotatory power

Two molecular properties, the nuclear electromagnetic hypershielding (psi(gamma,alphabeta) ('I)) and the gradient of the electric dipole-magnetic dipole polarizability (nabla(Igamma)G(alphabeta) (')), have been calculated using the time-dependent Hartree-Fock method. Provided the Hellmann-Feynman theorem is satisfied, these quantities are equivalent and are related through the nabla(Igamma)G(alphabeta) (')=eZ(I)psi(gamma,alphabeta) ('I) relation, where Z(I) is the atomic number of atom I and e the magnitude of the electron charge. In such a case, the determination of the nuclear electromagnetic hypershielding presents the computational advantage over the evaluation of the gradient of G(alphabeta) (') of requiring only the knowledge of nine mixed second-order derivatives of the density matrix with respect to both electric and magnetic fields (D(alpha,beta)(-omega,omega)) instead of the 3N (N is the number of atoms) derivatives of the density matrix with respect to the Cartesian coordinates (D(Igamma)). It is shown here for the H(2)O(2) molecule that very large basis sets such as the aug-cc-pVQZ or the R12 basis are required to satisfy the Hellmann-Feynman theorem. These basis set requirements have been substantiated by considering the corresponding rototranslational sum rules. The origin dependence of the rototranslational sum rules for the gradient of G(alphabeta) (') has then been theoretically described and verified for the H(2)O(2) molecule.

Noncoplanarity effects in proton-proton bremsstrahlung

Noncoplanarity in proton-proton bremsstrahlung is investigated. Significant effects are observed for certain photon polar angles, psi(gamma). Such noncoplanarity effects, not of dynamical origin, are possibly responsible for past disagreements between theory and experiment. The Harvard noncoplanar coordinate system, which avoids kinematic singularities in the cross section, is used in our calculations and is recommended for use in the analysis of experimental data. Alternative methods of presenting cross sections are discussed. [S0556-2813(98)50110-0].

Activation of the gamma E-crystallin pseudogene in the human hereditary Coppock-like cataract.

The locus for the hereditary human Coppock-like cataract (CCL) is closely linked to a particular combination of polymorphic TaqI sites within the human gamma-crystallin gene cluster. Mapping of these sites shows that they define a 15 kb region encompassing the gamma D and psi gamma E gene. The gamma D and the psi gamma E gene were cloned from the CCL chromosome and characterized. The gamma D gene was functionally equivalent to its allele cloned from a wild-type chromosome. The CCL psi gamma E gene contains a cluster of sequence changes within and around its TATA box. Together these cause a ten-fold increase in the activity of the psi gamma E promoter, raising the level of expression of this gene to 30% of that of the gamma D gene. The predicted protein product of the psi gamma E gene is a 6 kD N-terminal gamma-crystallin fragment. Reactivation of the psi gamma E gene and concomitant overexpression of the gamma-crystallin fragment could be the cause of the Coppock-like cataract.

Complete physical map of the human immunoglobulin heavy chain constant region gene complex.

We have found by pulsed-field gel electrophoresis that the human immunoglobulin heavy chain constant region gene complex maps entirely to a 350-kilobase (kb) Mlu I fragment. The enzyme Eag I was used with pulsed-field gel electrophoresis alone and in double digests with Spe I to map the region. C gamma 3, of the C gamma 3-C gamma 1-C psi epsilon 1-C alpha 1 cluster, maps 60 kb to the 3' side of C delta; C gamma 2 of the C gamma 2-C gamma 4-C epsilon-C alpha 2 cluster maps 80 kb to the 3' side of C alpha 1, where C gamma 3 encodes the constant region of the immunoglobulin gamma 3 chain, C gamma 1 encodes the constant region of the immunoglobulin gamma 1 chain, etc. C psi gamma maps 35 kb to the 3' side of C alpha 1 and is in the same transcriptional orientation as the other genes. Although in the cloned DNA many CpG-containing restriction sites were identified, most of these were methylated in peripheral blood leukocytes. The sites that were not methylated were predominantly found in three clusters, or Hpa I tiny fragment islands. One was found on the 5' side of C mu; the other two lie 30 kb to the 3' side of each of the C alpha genes and could indicate the presence of regulatory sequences or genes. A region showing strong linkage disequilibrium between all C gamma genes spans at least 160 kb. The 70-kb C mu-C gamma 3 region, however, shows no linkage disequilibrium, possibly indicating a recombination hot spot. The immunoglobulin heavy chain constant region has been almost entirely cloned and mapped, and thus most rearrangements occurring in this region should be detectable.

Molecular and serologic analysis of IgG1 deficiency caused by new forms of the constant region of the Ig H chain gene deletions.

Selective IgG1 deficiency is a rare disease. We report a familial form of IgG1 deficiency, in which IgG1 was undetectable in a 5-yr-old girl with a history of asthma and respiratory tract infections. Her father had an IgG1 level that was one-third of the mean amount found in normal healthy controls. The defect in the proband was caused by a homozygous deletion of the structural gene for C gamma 1. A Southern blot analysis demonstrated that the maternal haplotype contained a deletion encompassing C gamma 1, C psi epsilon 1, C alpha 1, C psi gamma, and C gamma 2, whereas the deletion on the paternal haplotype was confined to the C gamma 1 gene. Neither of these deletions has previously been reported. IgG1 normally constitutes the dominant isotype for antibodies directed against protein Ag, including viral proteins. We have analyzed the immune response to a number of different protein and polysaccharide Ag in the patient and her parents. In the proband, antiviral antibodies were restricted to the IgG3 and IgG4 subclasses. However, the total amount of IgG directed against several viruses was below the concentration found in normal seropositive individuals. The father and the paternal grandfather, both with low serum IgG1 levels, also had asthma, thus indicating a possible causal relationship.

Restriction fragment length polymorphisms associated with immunoglobulin heavy chain gamma genes in Tunisians.

DNA polymorphisms in the human immunoglobulin gamma (gamma) region have been studied in random Arabo-Berber Tunisians and in a large Tunisian Berber kindred. Haplotypes have then been designated, based on variation in the BamHI restriction fragments containing the C gamma 1, C gamma 2, C gamma 4, and C psi gamma genes. Two new haplotypes, in addition to the four previously described, have been observed. These new haplotypes, designated H5 and H6, were confirmed by family studies. The H5 haplotype was associated with black African Gm haplotypes (Gm1,17;..;5,6,11 and Gm1,17;..;5,11) (Gma,z;..;blc3bo and Gma,z;..;blbo) and probably represents a common haplotype in the black population. The haplotype H6 may be derived from H5. One of 39 random Tunisians was homozygous for a multigene deletion. DNA polymorphisms of the C gamma genes, in conjunction with Gm markers, provide highly variable genetic markers important for the characterization of human populations.

Multiple gene deletions within the human immunoglobulin heavy-chain cluster.

Two subjects, of 11,000 healthy individuals screened, were found to be missing three and four immunoglobulin isotypes, respectively (IgA1, IgG2, and IgG4; IgA1, IgG2, IgG4, and IgE), and have been analyzed at the DNA level by means of Southern blotting and Ig heavy-chain-specific probes. A broad deletion within the heavy-chain constant region (C) gene cluster was found on chromosome 14 of both probands. Two different haplotypes are described: the first has lost the C alpha 1, C psi gamma, C gamma 2, C gamma 4, and C epsilon genes; the second lacks the C psi epsilon, C alpha 1, C psi gamma, C gamma 2, and C gamma 4 genes. These findings confirm the reciprocal order of the Ig heavy-chain genes as derived by molecular cloning. The inclusion of the C psi gamma gene within the deleted regions confirms its location between C alpha 1 and C gamma 2. From the observed frequency of the homozygous genotype, 1%-3% of healthy subjects from our population are expected to be heterozygous for multiple heavy-chain gene deletions. Cross-over between mispaired homologous regions seems to be the favored mechanism of multiple Ig gene deletions and duplications, and, generally, in the evolution of the human Ig heavy-chain gene family.

Restriction fragment length polymorphisms associated with immunoglobulin C gamma genes reveal linkage disequilibrium and genomic organization.

We have demonstrated that restriction fragment length polymorphisms (RFLPs) produced by BamHI can be used as markers for constant (C) region heavy chain genes C psi gamma (C gamma pseudogene), C gamma 2, and C gamma 4. These RFLPs were found nonrandomly associated in the population sample studied. Of the eight combinations (haplotypes) of RFLPs theoretically possible, only two accounted for a total of 88% of the 116 chromosomes examined, a value greater than the total of 25% expected from random segregation of alleles. This indicates considerable linkage disequilibrium between C psi gamma, C gamma 2, and C gamma 4. Quantitative assessment of the degree of association between C gamma gene RFLPs, Gm markers, and switch region RFLPs adjacent to C mu and C alpha 1 revealed that C psi gamma is most tightly associated with C gamma 2 (r = 0.81 and 0.95 for the two common haplotypes), suggesting that C psi gamma maps to a position lying between C alpha 1 and C gamma 2. The association analysis used here should have general applicability for studying the genomic organization of other multigene families.

A solution of the neutron transport equation using spherical harmonics

A solution of the neutron transport equation is obtained by expanding the flux Phi (r Omega ) at position r in direction Omega as a series of the form: Phi (r, Omega )= Sigma l=0N(2l+1) Sigma m=0lPlm(cos theta )( psi lm (r)cos(m phi )+ gamma lm(r)sin(m phi )) where Plm(cos theta ) is the associated Legendre polynomial of order l, m with theta and phi the axial and azimuthal angles, respectively, of Omega . psi lm(r) and gamma lm(r) satisfy first-order differential equations and are determined by eliminating terms with odd l and then using finite-difference or finite-element techniques on the resulting second-order system. Complicated algebra is involved in deriving this latter set of relations and FORTRAN subroutines have been written to calculate the necessary coefficients and specify the relevant differentials.

Structure of human immunoglobulin gamma genes: implications for evolution of a gene family.

We have cloned five human immunoglobulin gamma genes from a fetal liver gene library. Four of them encode the known human immunoglobulin gamma chains gamma 1, gamma 2, gamma 3 and gamma 4. A fifth gamma gene seems to be a pseudogene. Nucleotide sequence determination demonstrates that the gamma 3 gene contains four separate hinge exons. Comparison of these hinge exons with those of the other gamma genes indicates that the first hinge exon is homologous to that of the pseudogene, and that the other three hinge exons are homologous to that of the gamma 1 gene, suggesting that the gamma 3 gene ancestor is a hybrid gene created by unequal crossing-over between the ancestral gamma 1 and psi gamma genes. Amplification of the gamma 1-type hinge exon probably followed to complete the gamma 3 gene. This hypothesis inevitably postulates the gene order 5'-gamma 1-gamma 3-psi gamma-3'. Cloning of overlapping chromosomal segments demonstrates that the gamma 2 gene is located 19 kb 5' to the gamma 4 gene. These analyses indicate that the human gamma-gene family has evolved by several types of DNA rearrangemet, including duplication of a complete gene; duplication of a hinge exon; and reassortment of exons by unequal cross-over between two adjacent genes.

Dimensional reduction and axial anomalies

Within the context of dimensional reduction the authors prove that the extraction of the axial anomaly necessitates ( psi mu , Lambda 5) not=0 if the axial current has the bilinear structure i Psi gamma mu Lambda 5 Psi . The desired properties of dimensionally reduced Gamma 5 are given and they then show how to remove the inevitably entrained normal amplitude anomalies.