2,284 research outputs found

### Population need and geographical access to general practitioners in rural New Zealand

To use a geographical information system (GIS) approach to demonstrate the extent to which different areas in New Zealand vary in their geographical access to GPs, and to analyse the extent to which spatial access varies in relation to different population groups.
Methods
Three methods; population/GP ratios, least cost path analysis (LCPA), and an allocation method (which considered the capacity constraint of GPs) were used to demonstrate differences in geographic accessibility to GPs. Travel time, and distance to the closest GP, was calculated for every census enumeration district in New Zealand (n=38336)—thus enabling population-based accessibility statistics to be calculated and aggregated to the territorial local authority level. These calculations include the average travel time if everybody visited a GP once and the population more than 30 minutes from a GP. The composition of this population is analysed according to three criteria of need: the level of deprivation (NZDep2001), ethnicity (%Maori), and age (% <5 years, and %65 years and over).
Results
There are significant regional variations in geographical accessibility in New Zealand, and these differences are dependent upon the method to calculate accessibility. Ratio measures give a different picture of GP access than the other two indicators, reflecting the fact that TAs with similar ratios often have wide variations in travel times as well as the size and proportion of the population living more than 30 minutes from the closest GP. TAs with larger numbers and a higher proportion of their populations living in such areas tend to be more deprived and have a higher proportion of Maori, especially in the North Island. There appears to be no significant trend by age.
Conclusion
Given the health and service consequences of poor access, the results suggest that more attention needs to be paid to extending the spatial information base in primary care, in order to achieve more effective planning of services for disadvantaged populations

### Corrigendum to "The holomorphic flow of the Riemann Zeta function"

Theorem 4.5 of [2], describing the topological type of the zeros of the flow s˙ = ζ(s) at reflected points off the critical line, claiming they were the same, contains an error. We gratefully acknowledge Professor Cevat Gokcek for pointing out the error to us

### Linear law for the logarithms of the Riemann periods at simple critical zeta zeros

Each simple zero 1/2 + iγn of the Riemann zeta function on the critical line with γn > 0 is a center for the flow s˙ = ξ(s) of the Riemann xi function with an associated period Tn. It is shown that, as γn →∞, log Tn ≥ π/4 γn + O(log γn).
Numerical evaluation leads to the conjecture that this inequality can be replaced by an equality. Assuming the Riemann Hypothesis and a zeta zero separation conjecture γn+1 − γn≥ γn-θ for some exponent θ > 0, we obtain the upper bound log Tn ≤ γn2 + θ Assuming a weakened form of a conjecture of Gonek, giving a bound for the reciprocal of the derivative of zeta at each zero, we obtain the expected upper bound for the periods so, conditionally, log Tn = π/ 4 γn +O(log γn). Indeed, this linear relationship is equivalent to the given weakened conjecture, which implies the zero separation conjecture, provided the exponent is sufficiently large. The frequencies corresponding to the periods relate to natural eigenvalues for the Hilbert–Polya conjecture. They may provide a goal for those seeking a self-adjoint operator related to the Riemann hypothesis

### The holomorphic flow of the Riemann zeta function

The flow of the Riemann zeta function, ś = ς(s), is considered, and phase portraits are presented. Attention is given to the characterization of the flow lines in the neighborhood of the first 500 zeros on the critical line. All of these zeros are foci. The majority are sources, but in a small proportion of exceptional cases the zero is a sink. To produce these portraits, the zeta function was evaluated numerically to 12 decimal places, in the region of interest, using the Chebyshev method and using Mathematica.
The phase diagrams suggest new analytic properties of zeta, of which some are proved and others are given in the form of conjectures

### The weight for random quark masses

In theories in which the parameters of the low energy theory are not unique,
perhaps having different values in different domains of the universe as is
possible in some inflationary models, the fermion masses would be distributed
with respect to some weight. In such a situation the specifics of the fermion
masses do not have a unique explanation, yet the weight provides the visible
remnant of the structure of the underlying theory. This paper introduces this
concept of a weight for the distribution of masses and provides a quantitative
estimate of it from the observed quarks and leptons. The weight favors light
quark masses and appears roughly scale invariant (rho ~ 1/m). Some relevant
issues, such as the running of the weight with scale and the possible effects
of anthropic constraints, are also discussed.Comment: 35pages, 19 figure

### Opposing actions of c-ets/PU.1 and c-myb protooncogene products in regulating the macrophage-specific promoters of the human and mouse colony-stimulating factor-1 receptor (c-fms) genes

The receptor for macrophage colony stimulating factor (CSF-1), the c- fms gene product, is a key determinant in the differentiation of monocytic phagocytes. Dissection of the human and mouse c-fms proximal promoters revealed opposing roles for nuclear protooncogenes in the transcriptional regulation of this gene. On the one hand, c-ets-1, c- ets-2, and the macrophage-specific factor PU.1, but not the ets-factor PEA3, trans-activated the c-fms proximal promoter. On the other hand c- myb repressed proximal promoter activity in macrophages and blocked the action of c-ets-1 and c-ets-2. Basal c-fms promoter activity was almost undetectable in the M1 leukaemia line, which expressed high levels of c- myb, but was activated as cells differentiated in response to leukemia inhibitory factor and expressed c-fms mRNA. The repressor function of c- myb depended on the COOH-terminal domain of the protein. We propose that ets-factors are necessary for the tissue-restricted expression of c-fms and that c-myb acts to ensure correct temporal expression of c- fms during myeloid differentiation

### Divergent evolutionary processes associated with colonization of offshore islands

Peer reviewedPublisher PD

### Radiative Corrections to W^+W^- \to W^+W^- in the Electroweak Standard Model

The cross-section for W^+W^- \to W^+W^- with arbitrarily polarized W bosons
is calculated within the Electroweak Standard Model including the complete
virtual and soft-photonic O(alpha) corrections. We show the numerical
importance of the radiative corrections for the dominating polarized
cross-sections and for the unpolarized cross-section. The numerical accuracy of
the equivalence theorem is investigated in O(alpha) by comparing the
cross-section for purely longitudinal W bosons obtained from the equivalence
theorem and from the direct calculation. We point out that the instability of
the W boson, which is inherent in the one-loop corrections, prevents a
consistent calculation of radiative corrections to the scattering of
on-real-mass-shell longitudinal W bosons beyond O(alpha).Comment: 24 pages, LaTeX, uses axodraw, epsfig. Statement clarifie

### Some Implications of a Supersymmetric Model with R-Parity Breaking Bilinear Interactions

We investigate a supersymmetric scenario where R-parity is explicitly broken
through a term bilinear in the lepton and Higgs superfields in the
superpotential. We show that keeping such a term alone can lead to trilinear
interactions, similar to those that are parametrized by $\lambda$-and
${\lambda}'$ in the literature, involving the physical fields. The upper limits
of such interactions are predictable from the constraints on the parameter
space imposed by the lepton masses and the neutrino mass limits. It is observed
that thus the resulting trilinear interactions are restricted to values that
are smaller than the existing bounds on most of the $\lambda$-and
${\lambda}'$-parameters. Some phenomenological consequences of such a scenario
are discussed.Comment: 26 Pages, 6 Postscript figures, Latex. An additional set of
references has been included. Typographic corrections have been made. Figures
remain all unchanged. An additional typographic correction has been mad

### b-tau Unification and neutrino masses in SU(5) extensions of the MSSM with radiative electroweak symmetry breaking

We make a complete analysis of the Yukawa coupling unification in SU(5)
extensions of the MSSM in the framework of the radiative symmetry breaking
scenario. Both logarithmic and finite threshold corrections of sparticles have
been included in the determination of the gauge and Yukawa couplings at M_Z.
The effect of the heavy masses of each model in the renormalization group
equations is also included. We find that in the minimal SU(5) model b-tau
Yukawa unification can be achieved for too large a value of alpha_s. On the
other hand the Peccei-Quinn version of the Missing Doublet model, with the
effect of the right handed neutrino also included, exhibits b-tau unification
in excellent agreement with all low energy experimental data. Unification of
all Yukawa couplings is also discussed.Comment: 20 pages, LaTeX2e,uses psfig,5 figures,full postscript file available
at http://artemis.cc.uoi.gr/~adedes/new97.ps.g

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