Water management in Minoan Crete, Greece: the two cisterns of one Middle Bronze Age settlement

The two earliest structures of Minoan Crete that may be considered as large cisterns were both built in the first half of the second millennium BC (the time of the first Minoan palaces) at Myrtos-Pyrgos (lerapetra). A considerable feat of engineering and social management, they remain a most unusual attribute of a Minoan settlement, all the more so since the Myrtos river is/was available to supply water at the foot of the hill of Pyrgos. This paper presents these cisterns, briefly, in terms of geology and technology, the history of their use and re-use, and their relevance to understanding the culture and society (at local and regional levels) of Crete in the time of the Old Palaces, as well as their possible contribution to the political and military history of the period. I then review possible precursors of, and architectural parallels to, the Pyrgos cisterns at Knossos, Malia and Phaistos (none of which has been proved to be a cistern), and the later history of cisterns in Bronze Age Crete. Since only three others are known (at Archanes, Zakro and Tylissos, of Late Bronze Age date), the two cisterns of Myrtos-Pyrgos are an important addition to our still rudimentary knowledge of how the Bronze Age Cretans managed their water supplies.

Spectral functions of half-filled one-dimensional Hubbard rings with varying boundary conditions

We study the effect of varying the boundary condition on: the spectral function of a finite one-dimensional Hubbard chain, which we compute using direct (Lanczos) diagonalization of the Hamiltonian. By direct comparison with the two-body response functions and with the exact solution of the Bethe ansatz equations, we can identify both spinon and holon features in the spectra. At half-filling the spectra have the well-known structure of a low-energy holon band and its shadow-which spans the whole Brillouin zone-and a spinon band present for momenta less than the Fermi momentum. Features related to the twisted boundary condition are cusps in the spinon band. We show that the spectral building principle, adapted to account for both the finite system size and the twisted boundary condition, describes the spectra well in terms of single spinon and holon excitations. We argue that these finite-size effects are a signature of spin-charge separation and that their study should help establish the existence and nature of spin-charge separation in finite-size systems.

Analytical potentials for triatomic molecules from spectroscopic data VI. On choosing internal coordinates to describe triatomic potential energy surfaces with more than one minimum

Orthogonal internal coordinates are defined which have useful properties for constructing the potential energy functions of triatomic molecules with two or three minima on the surface. The coordinates are used to obtain ground state potentials of ClOO and HOF, both of which have three minima.

Simple and surprisingly effective one-step extraction-cleanup by Soxflo for DDT and its metabolites from environmental samples

A pilot study found that DDT breakdown at the GC inlet was extensive in extracts from some-but not all-samples with high organic carbon contents. However, DDT losses could be prevented with a one-step extraction-cleanup in the Soxflo instrument with dichloromethane and charcoal. This dry-column procedure took 1 h at room temperature. It was tested on spiked soil and peat samples and validated with certified soil and sediment reference materials. Spike recoveries from freshly spiked samples ranged from 79 to 111% at 20-4000 mug/kg concentrations. Recoveries from the real-world CRMs were 99.7-100.2% of DDT, 89.7-90.4% of DDD and 89.6-107.9% of DDE. It was concluded that charcoal cleanups should be used routinely during surveys for environmental DDX pollution in order to mitigate against unpredictable matrix-enhanced breakdown in the GC. (C) 2004 Elsevier B.V. All rights reserved.

From a discrete to a continuum model of cell dynamics in one dimension

Multiscale modeling is emerging as one of the key challenges in mathematical biology. However, the recent rapid increase in the number of modeling methodologies being used to describe cell populations has raised a number of interesting questions. For example, at the cellular scale, how can the appropriate discrete cell-level model be identified in a given context? Additionally, how can the many phenomenological assumptions used in the derivation of models at the continuum scale be related to individual cell behavior? In order to begin to address such questions, we consider a discrete one-dimensional cell-based model in which cells are assumed to interact via linear springs. From the discrete equations of motion, the continuous Rouse [P. E. Rouse, J. Chem. Phys. 21, 1272 (1953)] model is obtained. This formalism readily allows the definition of a cell number density for which a nonlinear "fast" diffusion equation is derived. Excellent agreement is demonstrated between the continuum and discrete models. Subsequently, via the incorporation of cell division, we demonstrate that the derived nonlinear diffusion model is robust to the inclusion of more realistic biological detail. In the limit of stiff springs, where cells can be considered to be incompressible, we show that cell velocity can be directly related to cell production. This assumption is frequently made in the literature but our derivation places limits on its validity. Finally, the model is compared with a model of a similar form recently derived for a different discrete cell-based model and it is shown how the different diffusion coefficients can be understood in terms of the underlying assumptions about cell behavior in the respective discrete models.

Application of one-list capture-recapture models to scrapie surveillance data in Great Britain

In this paper, we apply one-list capture-recapture models to estimate the number of scrapie-affected holdings in Great Britain. We applied this technique to the Compulsory Scrapie Flocks Scheme dataset where cases from all the surveillance sources monitoring the presence of scrapie in Great Britain, the abattoir survey, the fallen stock survey and the statutory reporting of clinical cases, are gathered. Consequently, the estimates of prevalence obtained from this scheme should be comprehensive and cover all the different presentations of the disease captured individually by the surveillance sources. Two estimators were applied under the one-list approach: the Zelterman estimator and Chao's lower bound estimator. Our results could only inform with confidence the scrapie-affected holding population with clinical disease; this moved around the figure of 350 holdings in Great Britain for the period under study, April 2005-April 2006. Our models allowed the stratification by surveillance source and the input of covariate information, holding size and country of origin. None of the covariates appear to inform the model significantly. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.

The first metamagnetic thiocyanato-bridged one-dimensional nickel(II) complex

A novel single thiocyanato- bridged one- dimensional polymer, [NiL(NCS)(mu-NCS)](n) (L = N-1-(1-pyridin-2-yl-ethylidine)propane-1,3-diamine) has been synthesized and characterized by X-ray crystallography and a variable temperature magnetic study; the compound is a metamagnet with a Neel temperature (T-N) of 3.5 K.