EPICS for PDAs

With the advent of readily available wireless communications and small hand-held computers, commonly known as personal digital assistants (PDAs), it is interesting to consider using these portable devices to access a control system. We have successfully ported the Experimental Physics and Industrial Control System (EPICS) to Windows CE 3.0 (WCE) for the Pocket PC (PPC), and this paper describes the issues involved. The PPC was chosen because the WCE application programming interface (API) for the PPC is a subset of the Win32 API, which EPICS already supports, and because PPC devices tend to have more memory than other PDAs. PDAs provide several ways to connect to a network, using wired or wireless Compact Flash or PCMCIA Ethernet cards and modems. It is the recent advent of readily available wireless networks that makes using the portable PDA interesting. The status and issues surrounding the various kinds of wireless systems available are presented

Most transcription factor binding sites are in a few mosaic classes of the human genome

Background: Many algorithms for finding transcription factor binding sites have concentrated on the characterisation of the binding site itself: and these algorithms lead to a large number of false positive sites. The DNA sequence which does not bind has been modeled only to the extent necessary to complement this formulation. Results We find that the human genome may be described by 19 pairs of mosaic classes, each defined by its base frequencies, (or more precisely by the frequencies of doublets), so that typically a run of 10 to 100 bases belongs to the same class. Most experimentally verified binding sites are in the same four pairs of classes. In our sample of seventeen transcription factors — taken from different families of transcription factors — the average proportion of sites in this subset of classes was 75%, with values for individual factors ranging from 48% to 98%. By contrast these same classes contain only 26% of the bases of the genome and only 31% of occurrences of the motifs of these factors — that is places where one might expect the factors to bind. These results are not a consequence of the class composition in promoter regions. Conclusions:This method of analysis will help to find transcription factor binding sites and assist with the problem of false positives. These results also imply a profound difference between the mosaic classes

The formation of mixed germanium–cobalt carbonyl clusters: an electrospray mass spectrometric study, and the structure of a high-nuclearity [Ge₂Co₁₀(CO)₂₄]²⁻ anion

The reaction of [µ₄-Ge{Co₂(CO)₇}₂] with [Co(CO)₄]⁻ has been monitored by electrospray mass spectrometry to detect the cluster anions generated. Conditions giving known mixed Ge–Co carbonyl clusters were established, and a new high nuclearity cluster anion, [Ge₂Co₁₀(CO)₂₄]²⁻ was detected. Conditions for its formation were optimised and it was subsequently isolated as its [Et₄N]⁺ salt and characterised by single-crystal X-ray crystallography. The Ge₂Co₁₀ cluster core has a novel geometry with the two germanium atoms in semi-encapsulated positions, forming seven formal Ge–Co bonds. There are also eighteen formal Co–Co bonds. Corresponding reactions of [µ₄-Si{Co₂(CO)₇}₂] with [Co(CO)₄]⁻ were also investigated

Can VAR's describe monetary policy?

Recent research has questioned the usefulness of Vector Autoregression (VAR) models as a description of monetary policy, especially in light of the low correlation between forecast errors from VARs and those derived from Fed funds futures rates. This paper presents three findings on VARs' ability to describe monetary policy. First, the correlation between forecasts errors is a misleading measure of how closely the VAR forecast mimics the futures market's. In particular, the low correlation is partly due to a week positive correlation between the VAR forecasts and the futures market errors. Second, Fed funds rate forecasts from common VAR specifications do tend to be noisy, but this can be remedied by estimating more parsimonious models on post-1982 data. Third, time aggregation problems caused by the structure of the Fed funds futures market can distort the timing and magnitude of shocks derived from futures rates, and complicate comparisons with VAR-based forecasts.Monetary policy ; Vector autoregression ; Federal funds rate

A generalized model of mutation-selection balance with applications to aging

A probability model is presented for the dynamics of mutation-selection balance in a haploid infinite-population infinite-sites setting sufficiently general to cover mutation-driven changes in full age-specific demographic schedules. The model accommodates epistatic as well as additive selective costs. Closed form characterizations are obtained for solutions in finite time, along with proofs of convergence to stationary distributions and a proof of the uniqueness of solutions in a restricted case. Examples are given of applications to the biodemography of aging, including instabilities in current formulations of mutation accumulation.Comment: 20 pages Updated to include more historical comment and references to the literature, as well as to make clear how our non-linear, non-Markovian model differs from previous linear, Markovian particle system and measure-valued diffusion models. Further updated to take into account referee's comment

Tameness on the boundary and Ahlfors' measure conjecture

Let N be a complete hyperbolic 3-manifold that is an algebraic limit of geometrically finite hyperbolic 3-manifolds. We show N is homeomorphic to the interior of a compact 3-manifold, or tame, if one of the following conditions holds: (1) N has non-empty conformal boundary, (2) N is not homotopy equivalent to a compression body, or (3) N is a strong limit of geometrically finite manifolds. The first case proves Ahlfors' measure conjecture for Kleinian groups in the closure of the geometrically finite locus: given any algebraic limit G of geometrically finite Kleinian groups, the limit set of G is either of Lebesgue measure zero or all of the Riemann sphere. Thus, Ahlfors' conjecture is reduced to the density conjecture of Bers, Sullivan, and Thurston.Comment: New revised version, 22 pages. To appear, Publ. I.H.E.S. This version represents a fairly substantial reorganization of the logical structure of the pape

The Age-Specific Force of Natural Selection and Walls of Death

W. D. Hamilton's celebrated formula for the age-specific force of natural selection furnishes predictions for senescent mortality due to mutation accumulation, at the price of reliance on a linear approximation. Applying to Hamilton's setting the full non-linear demographic model for mutation accumulation of Evans et al. (2007), we find surprising differences. Non-linear interactions cause the collapse of Hamilton-style predictions in the most commonly studied case, refine predictions in other cases, and allow Walls of Death at ages before the end of reproduction. Haldane's Principle for genetic load has an exact but unfamiliar generalization.Comment: 27 page

Letter to Mario Goderich regarding Lucile Elliott Scholarship application form, January 30, 1970

A letter from Kenneth Evans to Mario Goderich requesting that Goderich send Evans a copy of the Lucile Elliott Scholarship application form