102 research outputs found
Gauge Invariant Pauli-Villars Regularization of Chiral Fermions
We extend the idea of the generalized Pauli-Villars regularization of Frolov
and Slavnov and analyze the general structure of the regularization scheme. The
gauge anomaly-free condition emerges in a simple way in the scheme, and, under
the standard prescription for the momentum assignment, the Pauli-Villars
Lagrangian provides a gauge invariant regularization of chiral fermions in
arbitrary anomaly-free representations. The vacuum polarization tensor is
transverse, and the fermion number and the conformal anomalies have gauge
invariant forms. We also point out that the real representation can be treated
in a straightforward manner and the covariant regularization scheme is directly
implemented.Comment: 33 pages, PHYZZX. The final version to appear in Prog. Theor. Phy
Invariant Regularization of Supersymmetric Chiral Gauge Theory
We formulate a manifestly supersymmetric gauge covariant regularization of
supersymmetric chiral gauge theories. In our scheme, the effective action in
the superfield background field method above one-loop is always supersymmetric
and gauge invariant. The gauge anomaly has a covariant form and can emerge only
in one-loop diagrams with all the external lines being the background gauge
superfield. We also present several illustrative applications in the one-loop
approximation: the self-energy part of the chiral multiplet and of the gauge
multiplet; the super-chiral anomaly and the superconformal anomaly; as the
corresponding anomalous commutators, the Konishi anomaly and an anomalous
supersymmetric transformation law of the supercurrent (the ``central
extension'' of N=1 supersymmetry algebra) and of the R-current.Comment: 43 pages, PHYZZX. Final version to appear in Prog. Theor. Phy
Characterization of some enzymatic properties of recombinant α-glucosidase III from the Thai honeybee, Apis cerana indica Fabricus
Recombinant α-glucosidase III (rHBGase III) from Apis cerana indica Fabricus (rAciHBGase III) was expressed in the yeast Pichia pastoris GS115, enriched and characterized. The full length cDNA of AciHbgase III (ƒî1.8 kb) was amplified by RT-PCR, cloned into the pPICZαA expression vector and used to transform P. pastoris GS115. The maximum secreted expression level of rAciHBGase III [as an N terminal (His)6 tagged chimera] was found 144 h after induction by 1% (v/v) methanol. Enrichment of the enzyme using histrap affinity purification revealed a single active glucosidase band with a molecular mass of ~68 kDa. The optimal pH and temperature for glucosidase activity of the enriched rAciHBGase III were pH 5.0 and 37¢XC, respectively, whilst the enzyme showed a good pH stability between pH 5.0 to 7.5, but not below pH 5.0, and a poor thermotolerance with < 10% and 0% residual activity at 40 and >50¢XC, respectively. The rAciHBGase showed a relatively high substrate specificity for maltose (Km of 4.5 mM) and p-nitrophenyl α-D-glucoside (Km of 4.4 mM) compared to other reported HBGase enzymes.Key words: α-Glucosidase, Apis cerana indica, expression, kinetics, recombinant enzyme
Mate-guarding behavior enhances male reproductive success via familiarization with mating partners in medaka fish
[Background] Male-male competition and female mating preference are major mechanisms of sexual selection, which influences individual fitness. How male-male competition affects female preference, however, remains poorly understood. Under laboratory conditions, medaka (Oryzias latipes) males compete to position themselves between a rival male and the female (mate-guarding) in triadic relationships (male, male, and female). In addition, females prefer to mate with visually familiar males. In the present study, to examine whether mate-guarding affects female preference via visual familiarization, we established a novel behavioral test to simultaneously quantify visual familiarization of focal males with females and mate-guarding against rival males. In addition, we investigated the effect of familiarization on male reproductive success in triadic relationships. [Results] Three fish (female, male, male) were placed separately in a transparent three-chamber tank, which allowed the male in the center (near male) to maintain closer proximity to the female than the other male (far male). Placement of the wild-type male in the center blocked visual familiarization of the far male by the female via mate-guarding. In contrast, placement of an arginine-vasotocin receptor mutant male, which exhibits mate-guarding deficits, in the center, allowing for maintaining close proximity to the female, did not block familiarization of the far male by the female. We also demonstrated that the reproductive success of males was significantly decreased by depriving females visual familiarization with the males. [Conclusions] Our findings indicated that, at least in triadic relationships, dominance in mate-guarding, not simply close proximity, allows males to gain familiarity with the female over their rivals, which may enhance female preference for the dominant male. These findings focusing on the triadic relationships of medaka may contribute to our understanding of the adaptive significance of persistent mate-guarding, as well as female preference for familiar mates
Mate-guarding behavior enhances male reproductive success via familiarization with mating partners in medaka fish
Background: Male-male competition and female mating preference are major mechanisms of sexual selection, which influences individual fitness. How male-male competition affects female preference, however, remains poorly understood. Under laboratory conditions, medaka (Oryzias latipes) males compete to position themselves between a rival male and the female (mate-guarding) in triadic relationships (male, male, and female). In addition, females prefer to mate with visually familiar males. In the present study, to examine whether mate-guarding affects female preference via visual familiarization, we established a novel behavioral test to simultaneously quantify visual familiarization of focal males with females and mate-guarding against rival males. In addition, we investigated the effect of familiarization on male reproductive success in triadic relationships. Results: Three fish (female, male, male) were placed separately in a transparent three-chamber tank, which allowed the male in the center (near male) to maintain closer proximity to the female than the other male (far male). Placement of the wild-type male in the center blocked visual familiarization of the far male by the female via mate-guarding. In contrast, placement of an arginine-vasotocin receptor mutant male, which exhibits mate-guarding deficits, in the center, allowing for maintaining close proximity to the female, did not block familiarization of the far male by the female. We also demonstrated that the reproductive success of males was significantly decreased by depriving females visual familiarization with the males. Conclusions: Our findings indicated that, at least in triadic relationships, dominance in mate-guarding, not simply close proximity, allows males to gain familiarity with the female over their rivals, which may enhance female preference for the dominant male. These findings focusing on the triadic relationships of medaka may contribute to our understanding of the adaptive significance of persistent mate-guarding, as well as female preference for familiar mates
Transient and permanent gene transfer into the brain of the teleost fish medaka (Oryzias latipes) using human adenovirus and the Cre-loxP system
AbstractIn this study, we demonstrated that human type-5 adenovirus infected the brain of the teleost fish, medaka (Oryzias latipes), in vivo. Injection of adenoviral vector into the mesencephalic ventricle of medaka larvae induced the expression of reporter genes in some parts of the telencephalon, the periventricular area of the mesencephalon and diencephalon, and the cerebellum. Additionally, the Cre-loxP system works in medaka brains using transgenic medaka carrying a vector containing DsRed2, flanked by loxP sites under control of the β-actin promoter and downstream promoterless enhanced green fluorescent protein (EGFP). We demonstrated that the presence of green fluorescence depended on injection of adenoviral vector expressing the Cre gene and confirmed that EGFP mRNA was transcribed in the virus-injected larvae
Remark on the Consistent Gauge Anomaly in Supersymmetric Theories
We present a direct field theoretical calculation of the consistent gauge
anomaly in the superfield formalism, on the basis of a definition of the
effective action through the covariant gauge current. The scheme is
conceptually and technically simple and the gauge covariance in intermediate
steps reduces calculational labors considerably. The resultant superfield
anomaly, being proportional to the anomaly d^{abc}=\tr T^a\{T^b,T^c\}, is
minimal without supplementing any counterterms. Our anomaly coincides with the
anomaly obtained by Marinkovi\'c as the solution of the Wess-Zumino consistency
condition.Comment: uses PHYZZX, 17 pages, the result of SUSY anomaly in the Wess-Zumino
gauge adde
Manifestly Gauge Covariant Treatment of Lattice Chiral Fermions. II
We propose a new formulation of chiral fermions on a lattice, on the basis of
a lattice extension of the covariant regularization scheme in continuum field
theory. The species doublers do not emerge. The real part of the effective
action is just one half of that of Dirac-Wilson fermion and is always gauge
invariant even with a finite lattice spacing. The gauge invariance of the
imaginary part, on the other hand, sets a severe constraint which is a lattice
analogue of the gauge anomaly free condition. For real gauge representations,
the imaginary part identically vanishes and the gauge invariance becomes exact.Comment: 15 pages, PHYZZX. The title is changed. The final version to appear
in Phys. Rev.
More about the axial anomaly on the lattice
We study the axial anomaly defined on a finite-size lattice by using a Dirac
operator which obeys the Ginsparg-Wilson relation. When the gauge group is
U(1), we show that the basic structure of axial anomaly on the infinite
lattice, which can be deduced by a cohomological analysis, persists even on
(sufficiently large) finite-size lattices. For non-abelian gauge groups, we
propose a conjecture on a possible form of axial anomaly on the infinite
lattice, which holds to all orders in perturbation theory. With this
conjecture, we show that a structure of the axial anomaly on finite-size
lattices is again basically identical to that on the infinite lattice. Our
analysis with the Ginsparg-Wilson Dirac operator indicates that, in appropriate
frameworks, the basic structure of axial anomaly is quite robust and it
persists even in a system with finite ultraviolet and infrared cutoffs.Comment: 12 pages, uses JHEP.cls and amsfonts.sty, the final version to appear
in Nucl. Phys.
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