856 research outputs found
New records of <i>Scolelepis</i> (Polychaeta : Spionidae) from the sandy beaches of Madagascar, with the description of a new species
Three species of the genus Scolelepis (Polychaeta, Spionidae) are reported from intertidal beaches in Madagascar. A new species, Scolelepis (Scolelepis) vazaha n.sp., is described from Cap Eat (type locality) and Fort Dauphin. This species is unique among spionids in possessing at least one large, curved hook in each notopodium of setiger 4. Males may additionally have similar hooks on setiger 5 or on setigers 5 and 6. On median setigers males also possess peculiar notopodial swellings, some of which contain a geniculate, penicillate seta of a type previously unknown for the family. S. (S.) williami (de Silva, 1961), formerly known only from the original description of two specimens from Sri Lanka, was found on five beaches along the southeast coast of Madagascar. This poorly known species is redescribed and compared to the closely related S. (S.) laciniata Eibye-Jacobsen, 1997, described from the west coast of Thailand. S. (S.) lefebvrei (Gravier, 1905), previously reported from the west coast of Madagascar, was also found on six sandy beaches along the northeast and southeast coasts. Earlier descriptions are supplemented by information on variation in numerical characters. Scanning electron photographs and details on palp morphology are provided for all three species
Effect of Supersymmetric phases on the Direct CP Asymmetry of B -> X_d \gamma
We investigate the effect of supersymmetric CP violating phases on the
inclusive decay B\to X_d\gamma. Although such a decay contains a large
background from B\to X_s\gamma, if isolated it may exhibit sizeable CP
violation, both in the Standard Model (SM) and in the context of models beyond
the SM. With unconstrained supersymmetric CP violating phases we show that the
direct CP asymmetry (A_CP) lies in the region -40%
\le A_CP \le 40%, where a positive asymmetry would constitute a clear signal
of physics beyond the SM. Even if a direct measurement of B\to X_d\gamma proves
too dif ficult experimentally, its asymmetry contributes non-negligibly to the
measurements of A_CP for B\to X_s\gamma, and thus should be included in future
analyses. We show t hat there may be both constructive and destructive
interference between A^d\gamma_CP and A^s\gamma_CP.Comment: 12 pages, 6 figures. Full Res. figures (and PostScript of paper)
available at http://www-th.kek.jp/home/stefan/b2dgamma
Nanomaterials for Advancing the Health Immunosensor
Nanotechnology has exerted a significant impact in the development of biosensors allowing more sensible analytical methods. In health applications, the main challenge of the immunoassay is to reach the suitable limit of detection, recognizing different analytes in complex samples like whole blood, serum, urine, and other biological fluids. Different nanomaterials, including metallic, silica and magnetic nanoparticles, quantum dots, carbon nanotubes, and graphene, have been applied, mainly to improve charge electron transfer, catalytic activity, amount of immobilized biomolecules, low-background current, signal-to-noise ratio that consequently increase the sensitivity of immunosensors. Given the great impact of nanotechnology, this chapter intends to discuss new aspects of nanomaterials relating to immunosensor advancement
Stellar Inversion Techniques
Stellar seismic inversions have proved to be a powerful technique for probing
the internal structure of stars, and paving the way for a better understanding
of the underlying physics by revealing some of the shortcomings in current
stellar models. In this lecture, we provide an introduction to this topic by
explaining kernel-based inversion techniques. Specifically, we explain how
various kernels are obtained from the pulsation equations, and describe
inversion techniques such as the Regularised Least-Squares (RLS) and Optimally
Localised Averages (OLA) methods.Comment: 20 pages, 8 figures. Lecture presented at the IVth Azores
International Advanced School in Space Sciences on "Asteroseismology and
Exoplanets: Listening to the Stars and Searching for New Worlds"
(arXiv:1709.00645), which took place in Horta, Azores Islands, Portugal in
July 201
Geometria e evolução do feixe de zonas de cisalhamento Manhuaçu - Santa Margarida, Orógeno Araçuaí, MG
Rare Decays of \Lambda_b->\Lambda + \gamma and \Lambda_b ->\Lambda + l^{+} l^{-} in the Light-cone Sum Rules
Within the Standard Model, we investigate the weak decays of and with the light-cone
sum rules approach. The higher twist distribution amplitudes of
baryon to the leading conformal spin are included in the sum rules for
transition form factors. Our results indicate that the higher twist
distribution amplitudes almost have no influences on the transition form
factors retaining the heavy quark spin symmetry, while such corrections can
result in significant impacts on the form factors breaking the heavy quark spin
symmetry. Two phenomenological models (COZ and FZOZ) for the wave function of
baryon are also employed in the sum rules for a comparison, which can
give rise to the form factors approximately 5 times larger than that in terms
of conformal expansion. Utilizing the form factors calculated in LCSR, we then
perform a careful study on the decay rate, polarization asymmetry and
forward-backward asymmetry, with respect to the decays of , .Comment: 38 pages, 15 figures, some typos are corrected and more references
are adde
Potencial alelopático de extratos aquosos de Melissa officinalis L. e Mentha x villosa L. na germinação e vigor de sementes de Plantago major L.
Direct CP Asymmetry of B -> X_d,s \gamma in a model with Vector quarks
We investigate the effect of vector quarks on the inclusive decays B -> X_d,s
\gamma. We show that the branching ratio of B -> X_d \gamma can differ sizably
from the SM and MSSM predictions, being enhanced to present experimental
observability or suppressed such that present runs of the B factories would not
observe it. Current measurements of the direct CP asymmetry (A_CP) for B -> X_s
\gamma are sensitive to the contribution from B -> X_d \gamma. For a
sufficiently enhanced BR(B -> X_d \gamma) we show that the dominant
contribution to the combined asymmetry may be from B -> X_d \gamma. Thus any
large value for A_CP should not immediately be attributed to B -> X_s \gamma,
which stresses the importance of good K/pi separation.Comment: 12 pages, 6 figures. v2: Minor changes, 3 references added, to be
publ. in PL
Removing Discrete Ambiguities in CP Asymmetry Measurements
We discuss methods to resolve the ambiguities in CP violating phase angles
that are left when a measurement of is made. We show what
knowledge of hadronic quantities will be needed to fully resolve all such
ambiguities.Comment: 23 pages, revtex, no figure
Modeling the Subsurface Structure of Sunspots
While sunspots are easily observed at the solar surface, determining their
subsurface structure is not trivial. There are two main hypotheses for the
subsurface structure of sunspots: the monolithic model and the cluster model.
Local helioseismology is the only means by which we can investigate
subphotospheric structure. However, as current linear inversion techniques do
not yet allow helioseismology to probe the internal structure with sufficient
confidence to distinguish between the monolith and cluster models, the
development of physically realistic sunspot models are a priority for
helioseismologists. This is because they are not only important indicators of
the variety of physical effects that may influence helioseismic inferences in
active regions, but they also enable detailed assessments of the validity of
helioseismic interpretations through numerical forward modeling. In this paper,
we provide a critical review of the existing sunspot models and an overview of
numerical methods employed to model wave propagation through model sunspots. We
then carry out an helioseismic analysis of the sunspot in Active Region 9787
and address the serious inconsistencies uncovered by
\citeauthor{gizonetal2009}~(\citeyear{gizonetal2009,gizonetal2009a}). We find
that this sunspot is most probably associated with a shallow, positive
wave-speed perturbation (unlike the traditional two-layer model) and that
travel-time measurements are consistent with a horizontal outflow in the
surrounding moat.Comment: 73 pages, 19 figures, accepted by Solar Physic
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