311 research outputs found
Pilbarana, a new subterranean amphipod genus (Hadzioidea: Eriopisidae) of environmental assessment importance from the Pilbara, Western Australia
The Pilbara and nearby regions in north-western Western Australia have an exceptionally high diversity of short-range endemic invertebrates inhabiting threatened groundwater-dependent habitats. Amphipod crustaceans, in particular, are dominant in these communities, but are poorly understood taxonomically, with many undescribed species. Recent molecular phylogenetic analyses of Pilbara eriopisid amphipods have, nonetheless, uncovered a previously unknown biodiversity. In this study, we formally establish a new genus, Pilbarana Stringer & King gen. nov., and describe two new species, P. grandis Stringer & King sp. nov. from Cane River Conservation Park and P. lowryi Stringer & King sp. nov. from the Fortescue River Basin near the Hamersley Range, using a combination of molecular and morphological data. The new genus is similar morphologically to the two additional Western Australian eriopisid genera, Nedsia Barnard & Williams, 1995 and Norcapensis Bradbury & Williams, 1997, but represents a genetically divergent, reciprocally monophyletic lineage, which can be differentiated by its vermiform body shape, the presence of an antennal sinus, and by the length and form of the antennae and uropods. This research signifies an important contribution to knowledge of Pilbara subterranean communities and has critical implications for future environmental impact assessments and conservation management.Danielle N. Stringer, Rachael A. King, Andrew D. Austin, Michelle T. Guzi
Constraints on Natural MNS Parameters from |U_e3|
The MNS matrix structure emerging as a result of recent neutrino measurements
strongly suggests two large mixing angles (solar and atmospheric) and one small
angle (|U_e3| << 1). Especially when combined with the neutrino mass hierarchy,
these values turn out to impose rather stringent constraints on possible flavor
models connecting the three active fermion generations. Specifically, we show
that an extremely small value of |U_e3| would require fine tuning of Majorana
mass matrix parameters, particularly in the context of seesaw models.Comment: 21 pages, ReVTeX, 2 .eps figure files, updated references and
acknowledgment
Comments on Hastings' Additivity Counterexamples
Hastings recently provided a proof of the existence of channels which violate
the additivity conjecture for minimal output entropy. In this paper we present
an expanded version of Hastings' proof. In addition to a careful elucidation of
the details of the proof, we also present bounds for the minimal dimensions
needed to obtain a counterexample.Comment: 38 page
Scintillation of liquid neon from electronic and nuclear recoils
We have measured the time dependence of scintillation light from electronic
and nuclear recoils in liquid neon, finding a slow time constant of 15.4+-0.2
us. Pulse shape discrimination is investigated as a means of identifying event
type in liquid neon. Finally, the nuclear recoil scintillation efficiency is
measured to be 0.26+-0.03 for 387 keV nuclear recoils
Anatomy of F_D-Term Hybrid Inflation
We analyze the cosmological implications of F-term hybrid inflation with a
subdominant Fayet--Iliopoulos D-term whose presence explicitly breaks a
D-parity in the inflaton-waterfall sector. This scenario of inflation, which is
called F_D-term hybrid model for brevity, can naturally predict lepton number
violation at the electroweak scale, by tying the mu-parameter of the MSSM to an
SO(3)-symmetric Majorana mass m_N, via the vacuum expectation value of the
inflaton field. We show how a negative Hubble-induced mass term in a
next-to-minimal extension of supergravity helps to accommodate the present CMB
data and considerably weaken the strict constraints on the theoretical
parameters, resulting from cosmic string effects on the power spectrum P_R. The
usual gravitino overabundance constraint may be significantly relaxed in this
model, once the enormous entropy release from the late decays of the ultraheavy
waterfall gauge particles is properly considered. As the Universe enters a
second thermalization phase involving a very low reheat temperature, which
might be as low as about 0.3 TeV, thermal electroweak-scale resonant
leptogenesis provides a viable mechanism for successful baryogenesis, while
thermal right-handed sneutrinos emerge as new possible candidates for solving
the cold dark matter problem. In addition, we discuss grand unified theory
realizations of F_D-term hybrid inflation devoid of cosmic strings and
monopoles, based on the complete breaking of an SU(2) subgroup. The F_D-term
hybrid model offers rich particle-physics phenomenology, which could be probed
at high-energy colliders, as well as in low-energy experiments of lepton
flavour or number violation.Comment: 73 pages, LaTeX, minor rewordings, references added, to appear in
JHE
A systematic review of physical activity promotion strategies
This article was first published in:British Journal of Sports Medicine:1996:30:84-89We have reviewed randomised controlled trials of physical activity promotion to provide recent and reliable information on the effectiveness of physical activity promotion. Computerised databases and references of references were searched. Experts were contacted and asked for information about existing work. Studies assessed were randomised controlled trials of healthy, free living, adult subjects, where exercise behaviour was the dependent variable. Eleven trials were identified. No United Kingdom based studies were found. Interventions that encourage walking and do not require attendance at a facility are most likely to lead to sustainable increases in overall physical activity. Brisk walking has the greatest potential for increasing overall activity levels of a sedentary population and meeting current public health recommendations. The small number of trials limits the strength of any conclusions and highlights the need for more research
Reproductive health operations research, 1995–1998
This book presents in-depth reports on promising new interventions that have been developed and important programmatic changes that have been achieved by operations research in Latin America between 1995 and 1998. The INOPAL III project has made advances in five areas including access and quality of services, integration of family planning and other reproductive health services, financial sustainability, post-abortion care, and emergency contraception. Each of these topics are represented by at least three studies conducted in two or more countries. The operations research projects discussed under each topic are not replications of a single study. They use different research designs and address different questions. Nevertheless, when taken together, they provide managers and decision-makers with a body of programmatically relevant information on each broad topic covered
Resonant leptogenesis in a predictive SO(10) grand unified model
An SO(10) grand unified model considered previously by the authors featuring
lopsided down quark and charged lepton mass matrices is successfully predictive
and requires that the lightest two right-handed Majorana neutrinons be nearly
degenerate in order to obtain the LMA solar neutrino solution. Here we use this
model to test its predictions for baryogenesis through resonant-enhanced
leptogenesis. With the conventional type I seesaw mechanism, the best
predictions for baryogenesis appear to fall a factor of three short of the
observed value. However, with a proposed type III seesaw mechanism leading to
three pairs of massive pseudo-Dirac neutrinos, resonant leptogenesis is
decoupled from the neutrino mass and mixing issues with successful baryogenesis
easily obtained.Comment: 22 pages including 1 figure; published version with reference adde
Probing the seesaw mechanism with neutrino data and leptogenesis
In the framework of the seesaw mechanism with three heavy right-handed
Majorana neutrinos and no Higgs triplets we carry out a systematic study of the
structure of the right-handed neutrino sector. Using the current low-energy
neutrino data as an input and assuming hierarchical Dirac-type neutrino masses
, we calculate the masses and the mixing of the heavy neutrinos.
We confront the inferred properties of these neutrinos with the constraints
coming from the requirement of a successful baryogenesis via leptogenesis. In
the generic case the masses of the right-handed neutrinos are highly
hierarchical: ; the lightest mass is GeV and the generated baryon-to-photon ratio is
much smaller than the observed value. We find the special cases which
correspond to the level crossing points, with maximal mixing between two
quasi-degenerate right-handed neutrinos. Two level crossing conditions are
obtained: (1-2 crossing) and (2-3
crossing), where and are respectively the 11-entry and the
12-subdeterminant of the light neutrino mass matrix in the basis where the
neutrino Yukawa couplings are diagonal. We show that sufficient lepton
asymmetry can be produced only in the 1-2 crossing where GeV, GeV and .Comment: 30 pages, 2 eps figures, JHEP3.cls, typos corrected, note (and
references) added on non-thermal leptogenesi
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