437 research outputs found
Trophic modes of large Antarctic Foraminifera: roles of carnivory, omnivory, and detritivory
Astrammina rara, Crithionina delacai, and Notodendrodes hyalinosphaira are 3 of the largest and most abundant members of the foraminiferal assemblage at a shallow-water (28 to 32 m) site in Explorers Cove, Antarctica. This study summarizes observations from 2 decades of research, during which we employed laboratory-based feeding experiments and fatty acid biomarker analysis to characterize trophic dynamics and ecological roles of the 3 species, In feeding experiments, A. rara consumed a variety of co-occurring metazoans (several Crustacea, Mollusca, Echinodermata, and a Nephtys species). C. delacai, N. hyalinosphaira, and a number of other foraminiferal species from Explorers Cove successfully trapped Artemia sp. nauplius prey in a setup designed to examine the efficiency of prey capture. Fatty acid analyses on samples from early (November 7, 2001) and late (January 31, 2002) austral summer revealed that the 3 species contained substantial amounts (33 to 45.5%) of polyunsaturated fatty acids (PUFAs), which are produced by microalgae, indicating the downwards transfer of carbon from sea-ice associated primary production. In the case of A. rara, this may be due to the ingestion of herbivorous metazoa, rather than direct uptake of microalgal material. A. rara contained significantly (p < 0.05) higher amounts of the zooplankton biomarkers 20:1(n-9) and 22:1(n-11), and C. delacai contained more PUFAs early, compared to late, in the season. Two morphotypes of N. hyalinosphaira had different fatty acid Profiles, indicating distinct trophotypes. Our results illustrate specific adaptations to different trophic resources in these protists, and they demonstrate the potential impact that large carnivorous species of Foraminifera may have on the structure of benthic communities where they are abundant
Nonstandard order parameters and the origin of CP violation
The consideration of chirality-preserving 2-fermion order parameters may shed
new light on the strong CP problem and the breakdown of flavor symmetries. We
describe two situations, one having the standard KM picture for weak CP
violation and another having new sources of weak CP violation.Comment: 12 pages, no figure
Medicines adherence: Involving patients in decisions about prescribed medicines and supporting adherence
It is thought that between a third and a half of all medicines1
There are many causes of non-adherence but they fall into two overlapping categories: intentional and unintentional. Unintentional non-adherence occurs when the patient wants to follow the agreed treatment but is prevented from doing so by barriers that are beyond their control. Examples include poor recall or difficulties in understanding the instructions, problems with using the treatment, inability to pay for the treatment, or simply forgetting to take it. prescribed for long-term conditions are not taken as recommended. If the prescription is appropriate, then this may represent a loss to patients, the healthcare system and society. The costs are both personal and economic. Adherence presumes an agreement between prescriber and patient about the prescriber’s recommendations. Adherence to medicines is defined as the extent to which the patient’s action matches the agreed recommendations. Non-adherence may limit the benefits of medicines, resulting in lack of improvement, or deterioration, in health. The economic costs are not limited to wasted medicines but also include the knock-on costs arising from increased demands for healthcare if health deteriorates. Non-adherence should not be seen as the patient’s problem. It represents a fundamental limitation in the delivery of healthcare, often because of a failure to fully agree the prescription in the first place or to identify and provide the support that patients need later on. Addressing non-adherence is not about getting patients to take more medicines per se. Rather, it starts with an exploration of patients’ perspectives of medicines and the reasons why they may not want or are unable to use them. Healthcare professionals have a duty to help patients make informed decisions about treatment and use appropriately prescribed medicines to best effec
Detection of the heavy Higgs boson at colliders
We consider the possibility of detecting a heavy Higgs boson () in
proposed colliders through the semi-leptonic mode . We show that
due to the non-monochromatic nature of the photon beams produced by the
laser-backscattering method, the resultant cross section for Higgs production
is much smaller than the on-resonance cross section and generally {\it
decreases} with increasing collider energy. Although continuum production
is expected to be negligible, we demonstrate the presence of and calculate
sizeable backgrounds from ,
with , respectively, and
.
This channel may be used to detect a Higgs of mass up to around 350~GeV
at a 0.5~TeV collider, assuming a nominal yearly luminosity of
10--20~fb.Comment: 18 pages (in RevTeX) plus Postscript figures (available by email or
FAX), NUHEP-TH-92-29 and DOE-309-CPP-47. (Revised version: NO CHANGES to the
manuscript, simply removed corrupted figure files
The Neutron Electric Dipole Moment and CP-violating Couplings in the Supersymmetric Standard Model without R-parity
We analyze the neutron electric dipole moment (EDM) in the Minimal
Supersymmetric Model with explicit R-parity violating terms. The leading
contribution to the EDM occurs at the 2-loop level and is dominated by the
chromoelectric dipole moments of quarks, assuming there is no tree-level
mixings between sleptons and Higgs bosons or between leptons and gauginos.
Based on the experimental constraint on the neutron EDM, we set limits on the
imaginary parts of complex couplings and
due to the virtual b-loop or tau-loop.Comment: final manuscript to appear in Phys. Rev. D, 15 pages, latex, 4
figures include
The CP asymmetry for B--> K^* l^+ l^- decay in the general two Higgs doublet model
We study CP asymmetry for the exclusive decay B --> K^* l^+ l^- in the two
Higgs doublet model with three level flavor changing neutral currents (model
III). We analyse the dependency of this quantity to the new phase coming from
the complex Yukawa couplings in the theory and we find that there exist a
considerable CP violation for the relevant process. Further, we see that the
sign of the Wilson coefficient C_7^{eff} can be determined by fixing dilepton
mass. Therefore, the future measurements of CP asymmetry for B --> K^* l^+ l^-
decay will give a powerful information about the sign of Wilson coefficient
C_{7}^{eff} and the new physics beyond the SM.Comment: 22 pages, 8 figure
CP Violation in Tau Slepton Pair Production at Muon Colliders
We discuss in detail signals for CP violation in the Higgs boson and
tau-slepton sectors through the production processes , where label the two
slepton mass eigenstates in the minimal supersymmetric standard model. We
assume that the soft breaking parameters of third generation sfermions contain
CP violating phases, which induce CP violation in the Higgs sector through
quantum corrections. We classify all the observables for probing CP violation
in the Higgs boson and slepton sectors. These observables depend on the
initial muon beam polarization, where we include transverse polarization
states. If the heavy Higgs bosons can decay into tau slepton pairs, a complete
determination of the CP properties of the neutral Higgs boson and
--slepton systems is possible. The interference between the Higgs boson
and gauge boson contributions could also provide a powerful method for probing
CP violation, if transversely polarized muon beams are available. We show in
detail how to directly measure CP violation in the tau slepton system, under
the assumption that the neutral Higgs mixing angles are determined through the
on--shell production of the neutral Higgs bosons.Comment: 38 pages, 9 figures Including 7 eps ones. A figure to show the
dependence on tan(beta) and the mass parameters of the sfermion sectors and a
reference added. To appear in Phys. Rev.
Charm multiplicity and the branching ratios of inclusive charmless b quark decays in the general two-Higgs-doublet models
In the framework of general two-Higgs-doublet models, we calculate the
branching ratios of various inclusive charmless b decays by using the low
energy effective Hamiltonian including next-to-leading order QCD corrections,
and examine the current status and the new physics effects on the determination
of the charm multiplicity and semileptonic branching ratio .
Within the considered parameter space, the enhancement to the ratio due to the charged-Higgs penguins can be as large as a factor of 8 (3) in
the model III (II), while the ratio can be increased from
the standard model prediction of 2.49% to 4.91% (2.99%) in the model III (II).
Consequently, the value of and can be decreased simultaneously
in the model III. The central value of will be lowered slightly by
about 0.003, but the ratio can be reduced significantly from the
theoretical prediction of in the SM to , for GeV, respectively. We find that
the predicted and the measured now agree within roughly one
standard deviation after taking into account the effects of gluonic charged
Higgs penguins in the model III with a relatively light charged Higgs boson.Comment: 25 pages, Latex file, axodraw.sty, 6 figures. Final version to be
published in Phys.Rev.
Recommended from our members
Technical review of entrained design report
Morgantown Energy Technology Center (METC) is planning to expand its in-house coal gasification R&D capabilities by installing a research facility that can address a number of concepts including entrained, fluid bed, and catalytic gasification and flash pyrolysis. This Advanced Gasification Concepts (AGC) facility design, as it currently stands, includes piping and instrumentation diagrams, vessel drawings and specifications, instrumentation lists and specifications, and equipment layout and isometric drawings. Before the design is finalized, a critique is needed to ensure that the intended flexibility and objectives can be met. The design approach was evaluated to determine whether the present design will meet the research objectives, including the need for flexibility. Heat and material balances, critical velocity requirements, vessel arrangements, potential operational problems, and instrumentation were reviewed. The mechanical design review included a critique of the drawings and specifications, adherence to standards and codes, materials of construction, vessels, piping, valves, heaters, and fittings. In addition, utilities requirements, heat transfer and particulate removal calculations, and pumping and heat exchanger requirements were checked. An evaluation of the equipment cost includes a critique of the reliability of the equipment cost breakdown, the areas of cost uncertainty, and the areas for potential cost savings. A safety analysis is also provided
- …