The foraging ecology and feeding behaviour of the grey heron (Ardea Cinerea) in the Camargue, S. France

Foraging patterns of breeding Grey Herons were studied in the Camargue. Most individual birds used several different and widely dispersed feeding sites during the season. Some birds abandoned certain foraging sites but no seasonal trends were detected. There was evidence of both flock and territorial feeding at different sites. Birds were observed feeding in a number of different food patches (discrete feeding sites). There was evidence that the biomass intake rate influenced how long a bird would remain in a patch. When this was high, birds remained in patches, conversely when the rate was low birds left to feed elsewhere. Departures from a breeding colony to the feeding grounds were clumped. Birds leaving the colony together were likely to go to the same feeding site more often than birds leaving successively, but not together. I t is argued that the colony may have been used as an information centre. The diet of chicks in different colonies was compared. The proportions of the important prey types from different colonies and from different broods were different. There was evidence that adults sometimes pre-digest large prey so that their small chicks can consume prey that would normally be too large for them to eat. An experiment on prey selection provided evidence that chicks could select between two prey types which differed only in the irrelative profitability. The chicks consumed the most profitable prey type first. When the relative profit ability of the prey types was reversed, the chicks reversed their selection. This may be an adaption to maximise prey intake rate in the face of sibling competition. The results are discussed in relation to the success of the birds at different stages of their life cycle. The implications for the conservation of the species are considered

PARTISAN WEBS: INFORMATION EXCHANGE AND PARTY NETWORKS

What is a party? We argue that the formal party apparatus is only one part of an extended network of interest groups, media, 527s, and candidates. We systematically measure a portion of this network by tracking transfers of names between political organizations. Our analysis reveals two distinct and polarized networks corresponding to a more liberal Democratic group and a more conservative Republican group. Formal party organizations, like the Democratic National Committee and the Republican National Committee, tend to receive information within their respective networks, which suggests that other groups serve to funnel information toward the formal party

Technology use in everyday life: Implications for designing for older users

This study examines the experience and attitudes of older adults towards technology and how they compare with younger age groups. Two hundred and thirty seven participants completed an extensive questionnaire exploring their daily lifestyle, use of technology, attitudes towards technology, and perceived difficulty of household devices. The main findings from the study were; (1) there was a strong motivation to learn or to continue learning to use computers by the older group; (2) social connectedness influenced how the older group used or would like to use technology and also why some preferred not to use it; and finally (3) there was an age-related increase in perceived difficulty for many household devices, however some devices maintained intergenerational usability. These finding can be used to inform the design of future intergenerational household technologies

Engineering ambient visual sensors

Visual sensors are an indispensable prerequisite for those AmI environments that require a surveillance component. One practical issue concerns maximizing the operational longevity of such sensors as the operational lifetime of an AmI environment itself is dependent on that of its constituent components. In this paper, the intelligent agent paradigm is considered as a basis for managing a camera collective such that the conflicting demands of power usage optimization and system performance are reconciled

Backbone-free duplex-stacked monomer nucleic acids exhibiting Watson-Crick selectivity.

We demonstrate that nucleic acid (NA) mononucleotide triphosphates (dNTPs and rNTPs), at sufficiently high concentration and low temperature in aqueous solution, can exhibit a phase transition in which chromonic columnar liquid crystal ordering spontaneously appears. Remarkably, this polymer-free state exhibits, in a self-assembly of NA monomers, the key structural elements of biological nucleic acids, including: long-ranged duplex stacking of base pairs, complementarity-dependent partitioning of molecules, and Watson-Crick selectivity, such that, among all solutions of adenosine, cytosine, guanine, and thymine NTPs and their binary mixtures, duplex columnar ordering is most stable in the A-T and C-G combinations

Preliminary soil and groundwater assessment of the Mantinea Development area, East Kimberley, Western Australia

In 2008, the Ord Stage 2 or ‘Ord East Kimberley Expansion Project’ was initiated by the Western Australian Government. The goal of the project was to advance development in the East Kimberley and to bring to market the Weaber Plain (Goomig Farmlands) and Knox Plain. In addition to the existing Ord River Irrigation Area (ORIA) Stage 1 (14 000ha), current Goomig and proposed Knox Plain areas (14 300ha), an estimated 50 000ha of land has potential for irrigation in the region. One of the areas proposed for future development is the Mantinea Development area. It is located on the south bank of the Ord River, 30km from Kununurra. It is north-west of the existing ORIA, which is located on the Ivanhoe and Packsaddle plains, and south-west of the most recent Stage 2 Goomig Farmlands, released in 2012. For the Mantinea Development, the state government is seeking a proponent from the private sector to manage the development process and operate the new farmlands created. The potential development area covers about 9500ha, 430ha of which has been set aside in the Mantinea conservation excision. To support the development process, DAFWA has reviewed relevant soil and water data and undertaken a preliminary assessment of that information. The Mantinea Flat – Carlton Plain area was identified as potentially suitable for irrigated agriculture by the Department of Agriculture and CSIRO as early as 1944, following soil surveys of about 12 000ha in the area. Preliminary soil survey results show that the soils of the proposed development area comprise a mixture of modern alluvial sediments, from fine cracking clays (1500ha, 17%) to sands and loams (6600ha, 73%), and stony soils (800ha, 10%). From this limited data, 4796ha (53%) of the proposed development area has a potentially high capability for irrigated agriculture, 2876ha (32%) is potentially capable but requires further investigation, and 1395ha (15%) of the area has a low capability. Areas assessed as having low capability for irrigated agriculture predominantly have salinity risk, poor drainage, shallow basement or unsuitable soil types

Private Sector Involvement in Public Procurement Opportunities: An Assessment of the Extent and Effect in Tanzanian Public Entities

The main purpose of this study was to assess the current status of private sector participation in public procurement opportunities and their effect on performance of the procurement function in the Tanzanian public entities. In particular the study intended to establish the extent to which the private sector organizations participate in the public procurement opportunities focusing on accessibility to the opportunities, the existing PPPs arrangements, proportion of contracts awarded to the private firms and the existing buyer – supplier relationships. The target population consisted of all 470 public entities in Tanzania out of which 100 entities purposively constituted the sample size. A mixed - qualitative and quantitative- research design was used as a technique for data collection, presentation and analysis. The study used a multistage stratified random sampling technique in identifying potential respondents. The study was guided by a null hypothesis that there is no considerable effect of private sector participation on performance of the procurement function in the Tanzanian public entities. Data were mainly collected through structured and self administered questionnaires supported with face to face oral interviews. Results of the regression analysis indicated that the coefficient for private sector participation is 0.428 and the t-test value is 3.621. Statistically, this coefficient is significant (p – value =0.000 < 0.05). These findings imply that 43% of the variation in performance of the procurement functions in the public entities was explained by the extent to which private sector organizations participate in the procurement opportunities as offered by the respective public entities. The study recommends that public entities must treat the private sector as a key partner to the well functioning of their procurement departments so that the latter can participate effectively. More specifically, the public entities must put in place commercial disciplines that will create confidence and attract the private sector organizations. Keywords: Private Sector, Procurement Performance. Procurement Function, Public Entity

Role of atmosphere-ocean interactions in supermodeling the tropical Pacific climate

The supermodel strategy interactively combines several models to outperform the individual models comprising it. A key advantage of the approach is that nonlinear improvements can be achieved, in contrast to the linear weighted combination of individual unconnected models. This property is found in a climate supermodel constructed by coupling two versions of an atmospheric model differing only in their convection scheme to a single ocean model. The ocean model receives a weighted combination of the momentum and heat fluxes. Optimal weights can produce a supermodel with a basic state similar to observations: a single Intertropical Convergence zone (ITCZ), with a western Pacific warm pool and an equatorial cold tongue. This is in stark contrast to the erroneous double ITCZ pattern simulated by both of the two stand-alone coupled models. By varying weights, we develop a conceptual scheme to explain how combining the momentum fluxes of the two different atmospheric models affects equatorial upwelling and surface wind feedback so as to give a realistic basic state in the tropical Pacific. In particular, we propose a mechanism based on the competing influences of equatorial zonal wind and off-equatorial wind stress curl in driving equatorial upwelling in the coupled models. Our results show how nonlinear ocean-atmosphere interaction is essential in combining these two effects to build different sea surface temperature structures, some of which are realistic. They also provide some insight into observed and modelled tropical Pacific climate.publishedVersio

Comparative study of Irish and Scottish logboats

This thesis examines Irish logboats and compares them in detail to Scottish logboats. It catalogues extant and recorded Irish Logboats, and includes drawings and photographic records. All aspects of both countries' boats, such as their dimensions, form, and evidence for propulsion are examined and interpreted. Those logboats that have dating evidence are also examined and compared to literary and other sources. The distributions of the boats are compared to their geographical and archaeological contexts and emerging patterns explored in detail. The results of this study are investigated on a national and regional basis. The native tree species of Ireland and Scotland are considered with particular reference to those used to make the logboats as well as their availability during the demise of logboat use. In keeping with this, evidence for construction techniques is studied, as are their applications in logboat reconstructions. The logboat reconstructions are used with aspects of naval architecture to determine and compare the operational capabilities of logboats under differing load and propulsive conditions. Where applicable, the data which is discerned from the logboats' contexts, forms, dimensions and functional features are combined with aspects of the wood science and naval architecture to determine their original operational uses. Finally, this data is incorporated into an ongoing computer programme which enables the performance capabilities of other logboats, as yet undiscovered, to be determined