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In this article, we present a previously unreported morphology of bacterially precipitated calcite (determined using XRD, FTIR, and SAED) occurring subaqueously in Weebubbie Cave. Observations using FESEM and TEM revealed spindle-shaped crystals with curved {hk.O} faces lying parallel to the c-axis. Calcite precipitated under conditions designed to mimic the inorganic solution chemistry of the cave revealed a different morphology. These differences between the crystals suggest that the formation of the cave crystals is a consequence of biologically activity.

It is theoretically possible to calculate electrical losses in conductors at high frequencies using standard microstrip equations. To do this it is necessary to know the length, width and surface roughness of sample tracks. The sheet resistance at d.c. is replaced with a new term, surface resistance which is the bulk resistivity divided by the skin depth at the frequency under consideration. The paper looks at the relationship between these predictions and measured results. A wide range of commercial thick film conductors has had its physical properties measured and a comparison made with the figures for idealized structures. The paper contains a discussion on the differences between real and ideal materials. It was seen that the predictions were close to the measured results at lower frequencies, but that there was divergence as the frequency approached 15–20 GHz. For low-cost applications it is generally considered that economically viable conductors will be unsuitable for microwave applications. However, the paper discusses whether some of the lesser used conductors, such as fritted silver, could have an application in low-cost microwave devices, for example alarm systems. © 2001 Kluwer Academic Publishers

This paper describes the fabrication and test of a new low cost thick film system using base metals. The resistor pastes were developed using non-precious metal oxides and contain molybdenum trioxide and other additives. The conductors are either silver or nickel. The dielectrics contain barium oxide, but, unlike ruthenium based resistors, on related dielectrics, there is very little difference in resistor behavior on alumina from that on the dielectrics investigated. Long term stability tests show that the new resistor family, while less stable than those based on ruthenium, is suitable for many low cost applications. Results suggest that high temperature ageing tends to minimize contact effects and that they are compatible with both silver and nickel terminations.

This paper examines the influence of the materials on the electrical properties of conductors for both high speed MCM structures and microstrip applications. Calculated figures for attenuation in microstrip lines are compared with published results. It is seen that the nature and physical structure as well as the geometrical shape of a conductor track all strongly influence the microwave performance. However, it is also clear that real materials have been developed for these applications which closely approach the behavior predicted for ideal conductors. It is proposed that microwave performance can be predicted by modelling the d.c. conductor materials and extrapolating to high frequencies.

In this paper we obtain a closed form expression for the convergence rate of the Gibbs sampler applied to the unobserved states of a first-order autoregression plus noise model. The rate is expressed in terms of the parameters of the model, which are regarded as fixed. For the case where the unconditional mean of the states is a parameter of interest we provide evidence that a 'centred' parameterization of a state space model is preferable for the performance of the Gibbs sampler. These two results provide guidance when the Gaussianity or linearity of the state space form is lost. We illustrate this by examining the performance of a Markov chain Monte Carlo sampler for the stochastic volatility model.

This paper assesses the impact of changes in union density on the male structure in the United Kingdom over the 1980s. Using four separate data sets, the authors estimate the kernel density of hourly wages for men. Counterfactual densities are then generated to predict how the distribution of wages has changed over time because of the decline in union membership. They find that approximately 20 percent of the increase in the variance of log wages over the period can be attributed to changes in unionization. The effect is particularly strong in the latter part of the period. The authors also present disaggregated estimates of the impact of declining unionization. Their results are robust across all the data sets the authors examine and similar results are obtained if union coverage is used rather than union membership. Copyright 1998 by Blackwell Publishing Ltd

SUMMARY In this paper we provide methods for estimating non-Gaussian time series models. These techniques rely on Markov chain Monte Carlo to carry out simulation smoothing and Bayesian posterior analysis of parameters, and on importance sampling to estimate the likelihood function for classical inference. The time series structure of the models is used to ensure that our simulation algorithms are efficient.

Copulas are popular as models for multivariate dependence because they allow the marginal densities and the joint dependence to be modeled separately. However, they usually require that the transformation from uniform marginals to the marginals of the joint dependence structure is known. This can only be done for a restricted set of copulas, e.g. a normal copula. Our article introduces copula-type estimators for flexible multivariate density estimation which also allow the marginal densities to be modeled separately from the joint dependence, as in copula modeling, but overcomes the lack of flexibility of most popular copula estimators. An iterative scheme is proposed for estimating copula-type estimators and its usefulness is demonstrated through simulation and real examples. The joint dependence is is modeled by mixture of normals and mixture of normals factor analyzers models, and mixture of t and mixture of t factor analyzers models. We develop efficient Variational Bayes algorithms for fitting these in which model selection is performed automatically. Based on these mixture models, we construct four classes of copula-type densities which are far more flexible than current popular copula densities, and outperform them in simulation and several real data sets., 27 pages, 3 figures

This article develops a general-purpose adaptive sampler that approximates the target density by a mixture of multivariate t densities. The adaptive sampler is based on reversible proposal distributions each of which has the mixture of multivariate t densities as its invariant density. The reversible proposals consist of a combination of independent and correlated steps that allow the sampler to traverse the parameter space efficiently as well as allowing the sampler to keep moving and locally exploring the parameter space. We employ a two-chain approach, in which a trial chain is used to adapt the proposal densities used in the main chain. Convergence of the main chain and a strong law of large numbers are proved under reasonable conditions, and without imposing a Diminishing Adaptation condition. The mixtures of multivariate t densities are fitted by an efficient Variational Approximation algorithm in which the number of components is determined automatically. The performance of the sampler is evaluated using simulated and real examples. Our autocorrelated framework is quite general and can handle mixtures other than multivariate t., 39 pages, 5 figures, 5 tables

In 1901 excavations by the German Archaeological Institute in the Lower Agora of pergamon uncovered an inscribed Hellenistic law laying out the duties and powers of the city astynomoi, a board of magistrates whose responsibilities included care for both city and suburban streets, city blocks and their party walls, water channels, fountains, and cisterns. The inscription provides a wealth of information about Hellenistic city planning and maintenance, as well as offering insights into the legal and procedural framework in which a variety of polis officials, citizens, and slaves operated. Keywords: city; legal history; urban history

This article discusses a partially adapted particle filter for estimating the likelihood of a nonlinear structural econometric state space models whose state transition density cannot be expressed in closed form. The filter generates the disturbances in the state transition equation and allows for multiple modes in the conditional disturbance distribution. The particle filter produces an unbiased estimate of the likelihood and so can be used to carry out Bayesian inference in a particle Markov chain Monte Carlo framework. We show empirically that when the signal to noise ratio is high, the new filter can be much more efficient than the standard particle filter, in the sense that it requires far fewer particles to give the same accuracy. The new filter is applied to several simulated and real examples and in particular to a dynamic stochastic general equilibrium model., Typo correction

Particle learning provides a simulation-based approach to sequential Bayesian computation. To sample from a posterior distribution of interest we use an essential state vector together with a predictive and propagation rule to build a resampling-sampling framework. Predictive inference and sequential Bayes factors are a direct by-product. Our approach provides a simple yet powerful framework for the construction of sequential posterior sampling strategies for a variety of commonly used models.

This article provides a description of time series methods that emphasize modern macroeconomics and finance. It discusses a variety of posterior simulation algorithms and illustrates their use in a range of models. This article introduces the state space framework and explains the main ideas behind filtering, smoothing, and likelihood computation. It also mentions the particle filter as a general approach for estimating state space models and gives a brief discussion of its methods. The particle filter is a very useful tool in the Bayesian analysis of the kinds of complicated nonlinear state space models that are increasingly being used in macroeconomics. It also deals with conditionally Gaussian state space models and non-Gaussian state space models. A discussion of the advantages and disadvantages of each algorithm is provided in this article. This aims to help with the use of these methods in empirical work.

The University of Southampton Thick‐Film Unit (TFU) was originally established in the Department of Electronics in 1985 to service the requirements of a transducer research group. This group originally pioneered the concept of the intelligent transducer and the thick‐film unit was initially used to explore the opportunities for fabricating low‐cost miniature and robust electronic interface circuits suitable for incorporation within transducers. The benefits to be derived from these thick‐film fabrication techniques soon become evident and the unit rapidly grew in stature with the commencement of several research programmes in the area of thick‐film sensors. The 1989 review of advanced sensor technologies undertaken by the DTI reported that the Southampton group was emerging as a centre of expertise in a technology offering significant short to medium‐term scope for commercial exploitation. This prediction is rapidly being fulfilled with an ever increasing number of thick‐film sensors being made commercially available.

A simple yet rigorous method has been developed to enable the loss tangent of dielectrics, having a known relative permittivity, to be accurately measured using a waveguide resonant cavity. The novel method eliminates the need for any physical measurement, either on the cavity or dielectric sample under test. The only electrical parameters that need to be measured are resonant frequencies and Q-factors of a reference cavity and those of the same cavity loaded with the dielectric sample. One of the advantages of the new technique is that dielectrics, of arbitrary shape, can be characterized at very high microwave frequencies. The new method has been verified through measurement over X-band.

ISHM, acting as a professional body for a very large sector of microelectronics manufacturing and design, naturally takes a strong and active interest in the education and training of people working in its industry. An annual Education Prize is awarded by the Society at either undergraduate or post‐graduate level and sometimes both. The aim of the awards is to encourage the writing up of work completed by students as part of the education route. It may be from an internal project such as a B.Eng. report or a Masters Dissertation. It may also be work done by the student in an industrial placement. These three authors or their institutions have been associated with entries which have been awarded a prize. The winning paper is normally published in Hybrid Circuits.

Cardiac involvement is a recognized complication of systemic lupus erythematosus (SLE), which can involve most cardiac components, including pericardium, conduction system, myocardium, heart valves, and coronaries. Libman-Sacks (verrucous) endocarditis is the characteristic cardiac valvular manifestation. We report a patient with SLE who had severe aortic regurgitation caused by Libman-Sacks endocarditis. The patient underwent successful mechanical aortic valve replacement.

This paper provides methods for carrying out likelihood based inference for diffusion driven models, for example discretely observed multivariate diffusions, continuous time stochastic volatility models and counting process models. The diffusions can potentially be non-stationary. Although our methods are sampling based, making use of Markov chain Monte Carlo methods to sample the posterior distribution of the relevant unknowns, our general strategies and details are different from previous work along these lines. The methods we develop are simple to implement and simulation efficient. Importantly, unlike previous methods, the performance of our technique is not worsened, in fact it improves, as the degree of latent augmentation is increased to reduce the bias of the Euler approximation. In addition, our method is not subject to a degeneracy that afflicts previous techniques when the degree of latent augmentation is increased. We also discuss issues of model choice, model checking and filtering. The techniques and ideas are applied to both simulated and real data.

Heart disease is the major cause of death in Wales. Myocardial infarction accounts for most fatalities either acutely or as a result of late heart failure and unheralded sudden cardiac death. Prompt relief of new coronary occlusions by thrombolytic agents has been shown to reduce significantly both early mortality and subsequent morbidity from acute myocardial infarction. The prehospital delivery of these drugs is feasible, and carries no greater risk than administration in hospital. This study tests the hypothesis that paramedics can identify patients with acute myocardial infarction who are suitable for prehospital thrombolysis, and thus reduce the "call to needle" time.Paramedics from rural Wales were trained in the acquisition and recognition of 12 lead ECGs, and also in the modified indications for thrombolytic therapy as defined by the Joint Royal Colleges Ambulance Liaison Committee (JRCALC). Ninety six consecutive patients, with possible myocardial infarction, were included in the study. The paramedics made an independent decision regarding the eligibility of the patients for thrombolysis before hospital admission, noting the time that they could have administered the drug. These decisions were compared with the treatment subsequently received in hospital.No errors were made by the paramedics in case selection (specificity of 100% (95% CI 95.9% to 100%)). There was a potential reduction in call to needle time of 41.2 minutes (95% CI 25.7 minutes to 56.9 minutes, p=0.001).It was concluded that the paramedic selection of patients for the prehospital administration of a thrombolytic is both feasible and safe.

Heart failure and left ventricular dysfunction are common and are most often caused by myocardial ischemia/infarction secondary to occlusive coronary artery disease. Although recent refinements in medical therapy have resulted in improved survival, morbidity and mortality remain high in patients with advanced heart failure. Heart transplantation remains an option for selected patients, and implantable left ventricular assist devices may soon provide another treatment strategy for such patients. However, patients with established postischemic heart failure, significant myocardial viability, and coronary artery anatomy amenable to surgical revascularization can derive significant functional and survival benefit after coronary artery surgery, albeit with an increased perioperative risk. We discuss the role of coronary artery surgery in ischemic heart failure and review the evidence for such an approach.

Objective: Comparison of two flooring types – carpet and vinyl – in the bed areas, and two modes of physiotherapy – conventional therapy and additional leg strengthening exercises – in avoiding falls. Design: Randomized 2 × 2 controlled trial. Setting: Elderly care rehabilitation ward in a community hospital. Subjects: Fifty-four consecutive patients referred for rehabilitation. Outcome measures: The incidence of falls, and the change in strength. Results: There were 10 falls on carpet, and only a single fall on vinyl floor covering (relative risk 8.3, 95% confidence interval 0.95–73, p = 0.05). There were four falls in those receiving additional exercise, and seven falls in those receiving only conventional physiotherapy (relative risk 0.21, 95% confidence interval 0.04–1.2, p = 0.12). Fifty-nine per cent of patients were able to complete strength measurements on admission and discharge. In these, handgrip strength improved more in those given additional exercise than conventional physiotherapy (2.1 kg versus – 0.3 kg, p < 0.05). Conclusion: There is no evidence to support either intervention in preventing falls on a rehabilitation ward, but within this low-powered study, there was a strong trend towards vinyl being superior.

We model a time series {y t , t = 1, ..., n} using a state-space framework with the {y t |α t } being independent and with the state {α t } assumed to be Markovian. The task will be to use simulation to estimate f(α t |F t ), t = 1, ..., n, where F t is contemporaneously available information. We assume a known measurement density f(y t |α t ) and the ability to simulate from the transition density f(α t+1|α t ). Sometimes we will also assume that we can evaluate f(α t+1|α t ).

Cardiac sarcoidosis can be a challenging diagnosis to make. The introduction of newer technologies, such as cardiac magnetic resonance imaging and positron emission tomography, have meant earlier diagnosis is possible. This is crucial as early treatment improves symptoms and prognosis.

The physiological effects of estrogen on the pituitary, including cellular proliferation and regulation of hormone synthesis, are mediated by the nuclear estrogen receptor (ER). The ER acts as a dimer to modulate gene transcription and contains specific functional domains encoded in different exons. Two separate, but related, forms of the receptor (ERalpha and ERbeta) exist, with distinct tissue and cell patterns of expression. Additional ER isoforms, generated by alternative messenger ribonucleic acid (mRNA) exon splicing, have been defined in several tissues and are postulated to play a role in tumorigenesis or in modulating the estrogen response. We examined 71 human pituitary adenomas of varying phenotypes and 6 normal pituitary specimens for ER mRNA forms by RT-PCR and hybridization blotting analysis. All prolactinomas (n = 14) contained ERalpha, and several contained ERbeta (5 of 14) mRNA. In comparison, 6 tumors that expressed PRL and GH expressed ERbeta (4 of 6) more frequently than ERalpha (3 of 6). ERbeta mRNA was also found more frequently in null cell (8 of 24 ERalpha and 14 of 24 ERbeta) and gonadotrope (13 of 21 ERalpha and 18 of 21 ERbeta) tumors. Additionally, ERbeta was found in 4 of 6 tumors that contained only GH, although ERalpha was not observed in this tumor type. Expression of the two ER forms within a tumor type was overlapping, but some tumors contained only 1 isoform. Expression of ERalpha mRNA splice variants also varied with cell type. All normal pituitaries contained ERalpha deletions of exon 4, 5, and 7, whereas only 2 of 6 samples contained the exon 2 deletion variant. Although the same ERalpha mRNA variants were observed among the various tumor types, the proportion of specific splice variants expressed varied. For example, most ER-positive prolactinomas expressed ERalpha variants with deletions of exon 2, 4, or 5, whereas gonadotropin tumors preferentially expressed the ERalpha exon 7 deletion variant. A novel ERbeta mRNA splice variant, missing exon 2, was observed in a majority of all ERbeta-positive tumors. Immunoblotting analysis of ERalpha and ERbeta proteins supported the mRNA results. Because ERalpha and ERbeta have different biological responses to selective ER modulators, and the ER deletion variants have biological effects distinct from those of the full-length ER, expression of these isoforms may influence the biological properties of these tumors and affect their ability to respond to estrogen and antiestrogen therapies.

We read with interest the recent review by Okrainec et al. entitled, “Cardiac Medical Therapy in Patients After Undergoing Coronary Artery Bypass Graft Surgery” ([1][1]). We congratulate the investigators on a comprehensive review of this important subject. We would, however, like to make a few

Meigs' syndrome consists of benign ovarian tumour with ascites and pleural effusion that resolve after resection of the tumour.1 A variant with pericardial effusion has not to our knowledge been reported.

This paper re-examines the data produced in a study of the behaviour of thick film resistors on dielectrics. It uses the published data to investigate the physicochemical nature of the conduction in six combinations of resistors on dielectrics and alumina. The results appear to confirm earlier observations that the presence of barium oxide in thick film resistor glass matrices has a major impact on the conduction mechanism. It is suggested that the cause is the totally different nature of two ions of similar size, possibly giving rise to localized regions of barium-lead compounds.

This paper describes the behaviour of thick film ruthenium resistors when printed and fired onto standard 96% alumina substrates and onto alumina substrates covered with a dielectric film during long-term thermal ageing. It was observed that the behaviour of the resistors on alumina and dielectric depends upon the firing process of the resistors and the kind of terminations. An analysis of the effects of thermal ageing was made as well as some SEM observations of diffusion processes between the resistor and its terminations.

A 52 year old man with hypertension was admitted with a history of sudden onset palpitations, light headedness, and breathlessness. On examination he was apyrexial with a blood pressure of 113/52 mm Hg and pulse rate 110 beats per minute. He had soft systolic and early diastolic murmurs with normal chest auscultation; there was no haemodynamic discrepancy between left and right sides or stigmata of …

Drop size measurements were made in the break-up zone at the tip of three 6 bladed disc turbines of different geometries in a 0·30 m dia. vessl. Three systems kerosene, methyl iso-butyl ketone (MIBK) and n-butanol at a volumetric fractional hold-up of 0·05 in water were examined. Power input and circulation time characteristics were determined and a new dimensionless group (ϵ−13tc/T23) is proposed to account for the effect of geometric parameters in the correlation of the drop size.

Length and age distribution, together with evidence indicating the annual formation of an opaque and translucent hyaline zone on the otoliths of Greenland halibut (Reinhardtius hippoglossoides), point to the validity of using otoliths in age determination. The high incidence of opaque zones during July–October suggests that these fish grew fastest during this period. Young fish appeared to have a longer annual growth period than the older specimens.

Commercial exploitation of American plaice on the Grand Bank increased from the early 1950s reaching a peak of about 90,000 tons in the mid-1960s. Catches have subsequently declined to about 45,000–50,000 tons annually. The increased exploitation of plaice was reflected in declines in catch per hour and stock abundance of fully vulnerable age-groups and an increase in the rate of instantaneous fishing mortality (F). The documentation of these was particularly strong in ICNAF Division 3L, but appeared to be somewhat erratic in 3N, probably because of incomplete sampling of the stock prior to the mid-1960s.Average size at age increased gradually from the early 1950s to the 1970s apparently because of increased growth rate in the initial 2 or 3 yr of life. Coupled with the increased size at age were significant declines in the age at sexual maturity.Significant correlations were found between stock abundance and asymptotic length (L∞), and size at age 5 and 10 in Division 3L and while positive trends could be demonstrated between some of these and mean bottom temperature, the correlations were not significant.

The peak spawning period of American plaice was the first part of April for Flemish Cap and ranged from the end of April for the Grand Bank and surrounding areas to the first part of June for Labrador–Northeast Newfoundland Shelf. Average bottom temperatures during spawning ranged from about 3.5 C for Flemish Cap and the deep spawning areas to the north, to about −1.3 C for St. Mary's Bay and the northern half of the Grand Bank. For the Southeast Grand Bank, Southwest Grand Bank, and St. Pierre Bank average spawning temperatures were 1.1, 2.8, and 2.7 C, respectively.There was evidence that some older, larger fish spawned first and also that plaice in deep water spawned later than those from shallower depths. At the latter depths light was a possible factor.According to samples from St. Mary's Bay the development of the sex products for spring spawning was apparently controlled by water temperatures during the previous fall and late summer.Fifty per cent of the females from Flemish Cap were mature at 7.8 years, the bottom temperature being almost constant at 3.5 C. For other areas the number of years ranged from 12.2 for the Southwest Grand Bank, with prevalent temperatures 0–3, to 15.2 C for St. Mary's Bay where temperatures were −1 to 1.0 C. For males the range was from 5.3 years for the Southeast Grand Bank to 7.5 years for St. Pierre Bank, no data being available for Flemish Cap.

Invertebrates, principally benthic forms, occurred most frequently in plaice stomachs from the Grand Bank. Fish, almost entirely capelin and sand lance, however, contributed the greatest proportion of total weight: 85% on the southeast part of the bank (ICNAF Division 3N) and 55% in the northeast section (ICNAF Division 3L).A seasonal feeding cycle was difficult to document because of the lack of winter samples, however, a greater proportion of empty stomachs occurred in February and March. The greater average weight of contents in spring samples (April–June) in Division 3L and in fall samples (October–November) for Division 3N was probably related to the availability of capelin and lance. The greater annual consumption of capelin and lance in Division 3N apparently accounted for the estimated higher caloric values of the average contents in this division than in Division 3L.

Growth curves of American plaice (Hippoglossoides platessoides Fabricius) from the Grand and St. Pierre banks and the areas east of Newfoundland are presented. Ages were determined using otoliths from random samples collected by research vessels in the spring and summer during 1957–63.For the localities sampled, American plaice on the southern half of the Grand Bank are the largest and the St. Mary's Bay population the smallest at comparable ages. A positive association was found between the sizes at ages 5 and 15 for the various localities and the probable bottom temperatures.Samples of otoliths from St. Mary's Bay indicated that the greatest growth occurs during the May–November period.Year-class dominance was noted for St. Mary's Bay, but not for other areas.

Fecundity estimates were made on a total of 140 mature American plaice from the southern and northern slopes of the Grand Bank and from St. Mary's Bay. Log–log relationships were established between fecundity and fish length, gutted and gilled weight, age, and ovary weight. No differences were found to exist between the fecundity–length relationship of plaice from the three areas, but there is a suggestion that within areas there may be annual differences in egg production. At comparable ages plaice from the southern slope of the Grand Bank are larger in size and produce more eggs than those from the northern slope and St. Mary's Bay.

Vertebral numbers of American plaice in the Northwest Atlantic are compared. Counts ranged from 42 to 48 vertebrae excluding the urostylar half-vertebra.No significant difference was found between vertebral averages of males and females.Averages for an area extending from the Northeast Newfoundland Shelf southward over the whole of the Grand Bank and inshore to include St. Mary's Bay are statistically similar. The average for this area is significantly higher than averages for the Gulf of St. Lawrence, the Labrador Shelf, Flemish Cap and Fortune Bay. However, over the whole area differences are not very great, the range of averages being (for a sample of 30 or more) 45.273–45.806 vertebrae.The possible effects of differences in the time of spawning, larval drift and the inclusion of a large number of year-classes in the various samples are discussed as possible explanations for the low degree of variability in the whole area.The vertebral averages of the year-classes 1942–1953 from St. Mary's Bay are not statistically different.

It was definitely established in July, 1950, that capelin were spawning on the Grand Bank. Samples of spawn taken in 1950 on the Southeast Shoal of the Grand Bank indicate that capelin were spawning in temperatures as low as 2.8 °C. In 1951 spawning temperatures were some two degrees higher. These temperatures are 2 to 4 °C. lower than those reported for beach spawning. Capelin, apparently, also spawn on other areas of the bank. The effects of low temperature in 1950 resulted in spawning taking place in the middle of July and the subsequent slow incubation of the eggs would result in larvae being liberated late in September. In 1951 capelin spawning, in the same area of the Grand Bank, took place around the latter part of June or the first of July and larval liberation around the first of August.Meristic studies using vertebral counts indicate that except for the 1950 year-class there is no real difference between any group from Grand Bank areas. The over-all averages for all years from the Grand Bank do not differ significantly from those found inshore by Templeman (1948).Up to the time of spawning the male capelin were found to be the more numerous.