Auditory memory and the irrelevant sound effect: further evidence for changing state disruption

Four experiments investigate the hypothesis that irrelevant sound interferes with serial recall of auditory items in the same fashion as with visually presented items. In Experiment 1 an acoustically changing sequence of 30 irrelevant utterances was more disruptive than 30 repetitions of the same utterance (the changing-state effect; Jones, Madden, & Miles, 1992) whether the to-be-remembered items were visually or auditorily presented. Experiment 2 showed that two different utterances spoken once (a heterogeneous compound suffix; LeCompte & Watkins, 1995) produced less disruption to serial recall than 15 repetitions of the same sequence. Disruption thus depends on the number of sounds in the irrelevant sequence. In Experiments 3a and 3b the number of different sounds, the "token-set" size (Tremblay & Jones, 1998), in an irrelevant sequence also influenced the magnitude of disruption in both irrelevant sound and compound suffix conditions. The results support the view that the disruption of memory for auditory items, like memory for visually presented items, is dependent on the number of different irrelevant sounds presented and the size of the set from which these sounds are taken. Theoretical implications are discussed.

Remote sensing of tidal networks and their relation to vegetation

The study of the morphology of tidal networks and their relation to salt marsh vegetation is currently an active area of research, and a number of theories have been developed which require validation using extensive observations. Conventional methods of measuring networks and associated vegetation can be cumbersome and subjective. Recent advances in remote sensing techniques mean that these can now often reduce measurement effort whilst at the same time increasing measurement scale. The status of remote sensing of tidal networks and their relation to vegetation is reviewed. The measurement of network planforms and their associated variables is possible to sufficient resolution using digital aerial photography and airborne scanning laser altimetry (LiDAR), with LiDAR also being able to measure channel depths. A multi-level knowledge-based technique is described to extract networks from LiDAR in a semi-automated fashion. This allows objective and detailed geomorphological information on networks to be obtained over large areas of the inter-tidal zone. It is illustrated using LIDAR data of the River Ems, Germany, the Venice lagoon, and Carnforth Marsh, Morecambe Bay, UK. Examples of geomorphological variables of networks extracted from LiDAR data are given. Associated marsh vegetation can be classified into its component species using airborne hyperspectral and satellite multispectral data. Other potential applications of remote sensing for network studies include determining spatial relationships between networks and vegetation, measuring marsh platform vegetation roughness, in-channel velocities and sediment processes, studying salt pans, and for marsh restoration schemes.

On defining base units in terms of fundamental constants

The definitions of the base units of the international system of units have been revised many times since the idea of such an international system was first conceived at the time of the French revolution. The objective today is to define all our units in terms of 'invariants of nature', i.e. by referencing our units to the fundamental constants of physics, or the properties of atoms, rather than the characteristics of our planet or of artefacts. This situation is reviewed, particularly in regard to finding a new definition of the kilogram to replace its present definition in terms of a prototype material artefact.

Effects of stabiliser addition and in-container sterilisation on selected properties of milk related to casein micelle stability

Different stabilising salts and calcium chloride were added to raw milk to evaluate changes in pH, ionic calcium, ethanol stability, casein micelle size and zeta potential. These milk samples were then sterilised at 121 °C for 15 min and stored for 6 months to determine how these properties changed. Addition of tri-sodium citrate (TSC) and di-sodium hydrogen phosphate (DSHP) to milk reduced ionic calcium, increased pH and increased ethanol stability in a concentration-dependent fashion. There was relatively little change in casein micelle size and a slight decrease in zeta potential. Sodium hexametaphosphate (SHMP) also reduced ionic calcium considerably, but its effect on pH was less noticeable. In contrast, sodium dihydrogen phosphate (SDHP) reduced pH but had little effect on ionic calcium. In-container sterilisation of these samples reduced pH, increased ethanol stability and increased casein micelle size, but had variable effects on ionic calcium; for DSHP and SDHP, ionic calcium decreased after sterilisation but, for SHMP, it remained little changed or increased. Milk containing 3.2 mM SHMP and more than 4.5 mM CaCl2 coagulated upon sterilisation. All other samples were stable but there were differences in browning, which increased in intensity as milk pH increased. Heat-induced sediment was not directly related to ionic calcium concentration, so reducing ionic calcium was not the only consideration in terms of improving heat stability. After 6 months of storage, the most acceptable product, in appearance, was that containing SDHP, as this minimised browning during sterilisation and further development of browning during storage.

Later Pleistocene evolution of the Exe valley: a chronostratigraphic model of terrace formation and its implications for Palaeolithic archaeology

This paper presents the first systematic chronostratigraphic study of the river terraces of the Exe catchment in South West England and a new conceptual model for terrace formation in unglaciated basins with applicability to terrace staircase sequences elsewhere. The Exe catchment lay beyond the maximum extent of Pleistocene ice sheets and the drainage pattern evolved from the Tertiary to the Middle Pleistocene, by which time the major valley systems were in place and downcutting began to create a staircase of strath terraces. The higher terraces (8-6) typically exhibit altitudinal overlap or appear to be draped over the landscape, whilst the middle terraces show greater altitudinal separation and the lowest terraces are of a cut and fill form. The terrace deposits investigated in this study were deposited in cold phases of the glacial-interglacial Milankovitch climatic cycles with the lowest four being deposited in the Devensian Marine Isotope Stages (MIS) 4-2. A new cascade process-response model is proposed of basin terrace evolution in the Exe valley, which emphasises the role of lateral erosion in the creation of strath terraces and the reworking of inherited resistant lithological components down through the staircase. The resultant emergent valley topography and the reworking of artefacts along with gravel clasts, have important implications for the dating of hominin presence and the local landscapes they inhabited. Whilst the terrace chronology suggested here is still not as detailed as that for the Thames or the Solent System it does indicate a Middle Palaeolithic hominin presence in the region, probably prior to the late Wolstonian Complex or MIS 6. This supports existing data from cave sites in South West England.

Controlling a mobile robot with a biological brain

The intelligent controlling mechanism of a typical mobile robot is usually a computer system. Some recent research is ongoing in which biological neurons are being cultured and trained to act as the brain of an interactive real world robot�thereby either completely replacing, or operating in a cooperative fashion with, a computer system. Studying such hybrid systems can provide distinct insights into the operation of biological neural structures, and therefore, such research has immediate medical implications as well as enormous potential in robotics. The main aim of the research is to assess the computational and learning capacity of dissociated cultured neuronal networks. A hybrid system incorporating closed-loop control of a mobile robot by a dissociated culture of neurons has been created. The system is flexible and allows for closed-loop operation, either with hardware robot or its software simulation. The paper provides an overview of the problem area, gives an idea of the breadth of present ongoing research, establises a new system architecture and, as an example, reports on the results of conducted experiments with real-life robots.

On the question of proportionality of the count of observed Scrapie cases and the size of holding

Background: The present paper investigates the question of a suitable basic model for the number of scrapie cases in a holding and applications of this knowledge to the estimation of scrapie-ffected holding population sizes and adequacy of control measures within holding. Is the number of scrapie cases proportional to the size of the holding in which case it should be incorporated into the parameter of the error distribution for the scrapie counts? Or, is there a different - potentially more complex - relationship between case count and holding size in which case the information about the size of the holding should be better incorporated as a covariate in the modeling? Methods: We show that this question can be appropriately addressed via a simple zero-truncated Poisson model in which the hypothesis of proportionality enters as a special offset-model. Model comparisons can be achieved by means of likelihood ratio testing. The procedure is illustrated by means of surveillance data on classical scrapie in Great Britain. Furthermore, the model with the best fit is used to estimate the size of the scrapie-affected holding population in Great Britain by means of two capture-recapture estimators: the Poisson estimator and the generalized Zelterman estimator. Results: No evidence could be found for the hypothesis of proportionality. In fact, there is some evidence that this relationship follows a curved line which increases for small holdings up to a maximum after which it declines again. Furthermore, it is pointed out how crucial the correct model choice is when applied to capture-recapture estimation on the basis of zero-truncated Poisson models as well as on the basis of the generalized Zelterman estimator. Estimators based on the proportionality model return very different and unreasonable estimates for the population sizes. Conclusion: Our results stress the importance of an adequate modelling approach to the association between holding size and the number of cases of classical scrapie within holding. Reporting artefacts and speculative biological effects are hypothesized as the underlying causes of the observed curved relationship. The lack of adjustment for these artefacts might well render ineffective the current strategies for the control of the disease.

Novel high-resolution characterization of ancient DNA reveals C > U-type base modification events as the sole cause of post mortem miscoding lesions

Ancient DNA (aDNA) research has long depended on the power of PCR to amplify trace amounts of surviving genetic material from preserved specimens. While PCR permits specific loci to be targeted and amplified, in many ways it can be intrinsically unsuited to damaged and degraded aDNA templates. PCR amplification of aDNA can produce highly-skewed distributions with significant contributions from miscoding lesion damage and non-authentic sequence artefacts. As traditional PCR-based approaches have been unable to fully resolve the molecular nature of aDNA damage over many years, we have developed a novel single primer extension (SPEX)-based approach to generate more accurate sequence information. SPEX targets selected template strands at defined loci and can generate a quantifiable redundancy of coverage; providing new insights into the molecular nature of aDNA damage and fragmentation. SPEX sequence data reveals inherent limitations in both traditional and metagenomic PCR-based approaches to aDNA, which can make current damage analyses and correct genotyping of ancient specimens problematic. In contrast to previous aDNA studies, SPEX provides strong quantitative evidence that C U-type base modifications are the sole cause of authentic endogenous damage-derived miscoding lesions. This new approach could allow ancient specimens to be genotyped with unprecedented accuracy.

Attitudes of landscape professionals towards naturalistic versus formal urban landscapes in the UK

The last 30 years have seen a tide of interest sweeping across Europe in the development of nature in cities, and an increasing amount of landscape development in urban areas has involved the use of 'naturalistic' styles. This is an increasing attempt to find ways for urbanism and nature to co-exist. However, there have been considerable discussions among professionals regarding the advantages and disadvantages of 'naturalistic' styles in urban areas. This research examines professional attitudes to 'naturalistic' landscape styles in Britain, in contrast to more traditional, formal landscape styles, and aims to find out whether the interest in natural landscapes is really a fashion among landscape professionals. A self-administered postal survey was carried out using both quantitative and qualitative data collection techniques and analysis. The survey included 500 professionals from parks and recreation departments of local authorities, private landscape practices and conservation trusts, and resulted in a satisfactory response rate of 53 %. The results of this study suggested that professionals recognise most of the values attached to naturalistic landscapes in urban areas. However, possible benefits that natural areas may have for urban people are not attached to naturalistic landscapes alone. The study also revealed that the naturalistic style is highly popular among conservation trusts but is less so among professionals from local authorities and private landscape practices who seem to appreciate both styles and believe that these styles are not separable from each other and should co-exist in an urban environment. (C) 2006 Elsevier B.V. All rights reserved.

Effect of hyaluronidase on ocular motility and eyelid function in sub-Tenon's anaesthesia: randomised controlled trial

Purpose: To assess the effect of hyaluronidase on eye and eyelid movements when used as an adjunct in sub-Tenon's anaesthesia. Methods: A total of 60 patients who had sub-Tenon's anaesthesia prior to phacoemulsification surgery were divided into two equal groups in a double-masked randomised controlled fashion. Of these, Group A had 4 ml lignocaine 2%, while Group B had 4ml lignocaine 2% with the addition of sodium hyaluronidase 75 IU/ml. Ocular motility, levator, and orbicularis oculi function were measured in all patients at 5 and 8 min. Levator function was scored from 0 (no function) to 3 (complete function) while orbicularis function was scored from 0 to 2. The score for ocular motility was the sum in four positions of gaze, each position scoring from 0 to 2. Results were compared using a nonparametric test. Results Group B achieved significantly better ocular and lid akinesia than Group A both at 5 and 8 min with P < 0.01. The median scores for levator function at 5 and 8 min were 2 for Group A and 0 for Group B. For orbicularis function, the median scores at both time intervals were 2 for Group A and 1 for Group B. For ocular motility, the median score for Group A at 5 min was 3 and at 8 min was 2.5; for Group B at 5 min was 0.5 and at 8 min was 0. Conclusions: The addition of hyaluronidase in sub-Tenon's anaesthesia has a significant effect in improving ocular and lid (levator and orbicularis) akinesia.

Cell cycle perturbations induced by infection with the coronavirus infectious bronchitis virus and their effect on virus replication

In eukaryotic cells, cell growth and division occur in a stepwise, orderly fashion described by a process known as the cell cycle. The relationship between positive-strand RNA viruses and the cell cycle and the concomitant effects on virus replication are not clearly understood. We have shown that infection of asynchronously replicating and synchronized replicating cells with the avian coronavirus infectious bronchitis virus (IBV), a positive-strand RNA virus, resulted in the accumulation of infected cells in the G(2)/M phase of the cell cycle. Analysis of various cell cycle-regulatory proteins and cellular morphology indicated that there was a down-regulation of cyclins D1 and D2 (G(2) regulatory cyclins) and that a proportion of virus-infected cells underwent aberrant cytokinesis, in which the cells underwent nuclear, but not cytoplasmic, division. We assessed the impact of the perturbations on the cell cycle for virus-infected cells and found that IBV-infected G(2)/M-phase-synchronized cells exhibited increased viral protein production when released from the block when compared to cells synchronized in the Go phase or asynchronously replicating cells. Our data suggested that IBV induces a G(2)/M phase arrest in infected cells to promote favorable conditions for viral replication.

Isolation and partial characterisation of acid phosphatase isozymes from dormant oilseed of Corylus avellana L.

The acid phosphatase (orthophosphoric-monoester phosphohydrolase, EC 3.1.3.2) complement from dormant hazel (Corylus avellana L.) seeds was found to exhibit significant electrophoretic heterogeneity partially attributable to the presence of distinct molecular forms. In axiferous tissue, total acid phosphatase activity increased in a biphasic fashion during chilling, a treatment necessary to alleviate seed dormancy. Three acid phosphatase isozymes were isolated from cotyledons of dormant hazel seeds by successive ammonium sulphate precipitation, size-exclusion, Concanavalin A affinity, cation- and anion-exchange chromatographies resulting in 75-, 389- and 191-fold purification (APase1, APase2, APase3, respectively). The three glycosylated isoforms were isolated to catalytic homogeneity as determined by electrophoretic, kinetic and heat-inactivation studies. The native acid phosphatase complement of hazel seeds had an apparent Mr of 81.5±3.5 kDa as estimated by size-exclusion chromatography, while the determined pI values were 5.1 (APase1), 6.9 (APase2) and 7.3 (APase3). The optimum pH for p-nitrophenyl phosphate hydrolysis was pH 3 (APase1), pH 5.6 (APase2) and pH 6 (APase3). The hazel isozymes hydrolysed a variety of phosphorylated substrates in a non-specific manner, exhibiting low Km and the highest specificity constant (Vmax/Km) for pyrophosphate. They were not primary phytases since they could not initiate phytic acid hydrolysis, while APase2 and APase3 had significant phospho-tyrosine phosphatase activity. Inorganic phosphate was a competitive inhibitor, while activity was significantly impaired in the presence of vanadate and fluoride.

Construction of coordination polymers of cadmium(II) with mixed hexamethylenetetramine and terephthalate or thiocyanate ligands

Three new polymeric complexes [Cd(hmt)(SCN)(2)(H2O)(2)](n) (1), [Cd-3(mu(2)-hmt)(2)(SCN)(6)(H2O)(2)](n) (2), and [Cd-2(hmt)(2)(tP)(2)(H2O)(6)](n) (3) [hmt = hexamethylenetetramine, tp = terephthalate] have been synthesized and characterized by single crystal X-ray diffraction. Both the compounds 1 and 2 are 1-D polymers where Cd units are linked by double end-to-end thiocyanate bridges but in 2 the chain is wider containing three cadmium atoms instead of one as found in 1. In both compounds the coordination environment around cadmium atom is distorted octahedral. Compound 3 is a three-dimensional polymer having water-filled microporous channels. Both tp and brut are mu(2)-bridged. One of the acid groups of tp is coordinated in chelating bidentate and the other in monodentate fashion. Half of its Cd atoms are hexa-coordinated and the rest are hepta-coordinated. Thermogravimetric analysis and X-ray diffraction study of 3 show that its framework remains intact upon removal of water molecules. The flexibility of coordination number around cadmium atoms (six or seven) probably plays an important role in establishing the rigidity of the framework. (C) 2003 Elsevier Ltd. All rights reserved.

Poly[(2,2 '-bipyridine-kappa N-2,N ')-(mu(2)-dihydrogen phosphato-kappa O-2 : O ')-(mu(2)-hydrogen phosphato-kappa O-2 : O ')-aluminium(III)], Al(2,2 '/bipy)-(HPO4)(H2PO4), a layered inorganic - organic hybrid material

The title compound, [Al(HPO4)(H2PO4)(C10H8N2)]n, consists of AlO4N2 octahedra vertex-linked to H2PO4 and HPO4 tetrahedra to form layers based on a (4,12)- net. The layers stack in an AAA fashion, held in place by pi-pi interactions between 2,2 '-bipyridine molecules coordinated to Al atoms in adjacent layers.

Dicaesium pentacyanotricuprate(I), Cs2Cu3(CN)(5)

Cs2Cu3(CN)(5) has a layered structure consisting of [Cu-3(CN)(5)](2-) sheets stacked in an ABAB fashion along the c axis, with Cs+ cations lying between the sheets. The sheets are generated by linking -(CuCN) - chains, in which the C N groups are ordered, via [Cu(CN)(3)](2-) units. The two bridging cyanide groups of each [Cu(CN)(3)](2-) unit show partial 'head-to-tail' disorder of C and N, whilst the third C N group is terminal and ordered with C bonded to Cu.