Design of an integrated shallow water wave experiment

The experimental design and instrumentation for an integrated shallow-water surface gravity wave experiment is discussed. The experiment required the measurement of the water surface elevation, meteorological parameters, and directional spectra at a number of locations on a shallow lake. In addition, to acquire data under a wide range of conditions, an experimental period of three years was required. A system of telephone and radio modem links were installed to enable real-time monitoring of instrument performance at eight separate measurement locations on the lake. This system also enabled logging sessions to be optimized to ensure the maximum possible data return from this extended experimentIEEE Oceanic Engineering Societ

Electric and magnetic dipole coupling in near-infrared split ring metamaterial arrays

We present experimental observations of strong electric and magnetic interactions between split ring resonators (SRRs) in metamaterials. We fabricated near-infrared (1.4 $\mu$m) planar metamaterials with different inter-SRR spacings along different directions. Our transmission measurements show blueshifts and redshifts of the magnetic resonance, depending on SRR orientation relative to the lattice. The shifts agree well with a simple model with simultaneous magnetic and electric near-field dipole coupling. We also find large broadening of the resonance, accompanied by a decrease in effective cross section per SRR with increasing density. These effects result from superradiant scattering. Our data shed new light on Lorentz-Lorenz approaches to metamaterials.Comment: 4 pages, 4 color figure

Exploring the dynamics of transport in the Dutch limes

Very little is known about local scale transport in the Roman period in the Netherlands, and therefore this paper aims to reconstruct and examine local transport networks through an integrative approach, using data and research from palaeogeography, physiology, archaeology and computational archaeological approaches. This study particularly focusses on the role of different modes of transport and the role of the natural environment. Firstly, a palaeogeographic reconstruction is presented encompassing both the natural and the cultural landscape. Transport networks for several modes are then reconstructed by calculating least cost paths that incorporate functions from physiological research. These networks are analysed using standard network analytical procedures. Interesting interpretations can be inferred from the results of these procedures, including some relating to the different characteristics of the transport modes but notably also the relative important role of stone- built settlements in the networks and the relative lack of control that the Roman forts have over the transport network

THE USE OF RAINFALL PATTERNS IN PREDICTING POPULATION DENSITIES OF MULTIMAMMATE RATS, \u3ci\u3eMastomys natalensis\u3c/i\u3e

During 3 years we studied a population of multimammate rats, Mastomys natalensis (Smith 1834), in Morogoro, Tanzania. Data were collected in both removal and capture-recapture schemes. We present evidence that patterns of growth and reproduction were related to onset and abundance of rains. This partially explains differences in densities. Additionally, we investigated available literature data and related them with climatological data. A scenario is presented which enables us to predict how densities of multimammate rats may evolve in the following year and whether there will be a risk of outbreaks. The use and implications of this scenario in planning control actions are discussed

Loneliness Across the Life Span

Most people have experienced loneliness and have been able to overcome it to reconnect with other people. In the current review, we provide a life-span perspective on one component of the evolutionary theory of loneliness—a component we refer to as the reaffiliation motive (RAM). The RAM represents the motivation to reconnect with others that is triggered by perceived social isolation. Loneliness is often a transient experience because the RAM leads to reconnection, but sometimes this motivation can fail, leading to prolonged loneliness. We review evidence of how aspects of the RAM change across development and how these aspects can fail for different reasons across the life span. We conclude with a discussion of age-appropriate interventions that may help to alleviate prolonged lonelines

Spatio-temporal genetic structure and gene flow between two distinct shell morphs of the planktonic developing periwinkle <i>Littorina striata</i> (Mollusca : Prosobranchia)

The planktonic developing periwinkle Littorina striata produces both nodulose and smooth shells, which were originally regarded as 2 separate species. Although both morphs occur microsympatrically, their distribution is not random. Nodulose shells predominate at wave-sheltered sites, whereas smooth shells are more common at wave-exposed sites. The degree of genetic similarity between the 2 shell types and their microgeographic spatio-temporal genetic structuring were investigated using allozyme electrophoresis. This indicated that: (1) both morphs share a common gene pool, (2) gene flow between populations is high and of comparable magnitude to gene flow between both morphs, (3) the population genetic structure of L. striata remains stable over a sampling period of 3 yr, and (4) genetic and morphological distances between populations are not correlated. These results thus confirm the conspecific status of the 2 shell types and suggest that shell variability and spatial patterning in L. striata persist in the presence of intense gene flow

Towards the architecture of an instructional multimedia database

The applicability of multimedia databases in education may be extended if they can serve multiple target groups, leading to affordable costs per unit for the user. In this contribution, an approach is described to build generic multimedia databases to serve that purpose. This approach is elaborated within the ODB Project ('Instructional Design of an Optical DataBase'); the term optical refers to the use of optical storage media to hold the audiovisual components. The project aims at developing a database in which a hypermedia encyclopedia is combined with instructional multimedia applications for different target groups at different educational levels. The architecture of the Optical Database will allow for switching between application types while working (for instance from tutorial instruction via the encyclopedia to a simulation and back). For instruction, the content of the database is thereby organized around so-called standard instruction routes: one route per target group. In the project, the teacher is regarded as the manager of instruction.\ud \ud From that perspective, the database is primarily organized as a teaching facility. Central to the research is the condition that the architecture of the Optical Database has to enable teachers to select and tailor instruction routes to their needs in a way that is perceived as logical and easy to use

Ankles back in randomized controlled trial (ABrCt): braces versus neuromuscular exercises for the secondary prevention of ankle sprains. Design of a randomised controlled trial

<p>Abstract</p> <p>Background</p> <p>Ankle sprains are the most common sports and physical activity related injury. There is extensive evidence that there is a twofold increased risk for injury recurrence for at least one year post injury. In up to 50% of all cases recurrences result in disability and lead to chronic pain or instability, requiring prolonged medical care. Therefore ankle sprain recurrence prevention in athletes is essential. This RCT evaluates the effect of the combined use of braces and neuromuscular training (e.g. proprioceptive training/sensorimotor training/balance training) against the individual use of either braces or neuromuscular training alone on ankle sprain recurrences, when applied to individual athletes after usual care.</p> <p>Methods/Design</p> <p>This study was designed as three way randomized controlled trial with one year follow-up. Healthy individuals between 12 and 70 years of age, who were actively participating in sports and who had sustained a lateral ankle sprain in the two months prior to inclusion, were eligible for inclusion. After subjects had finished ankle sprain treatment by means of usual care, they were randomised to any of the three study groups. Subjects in group 1 received an eight week neuromuscular training program, subjects in group 2 received a sports brace to be worn during all sports activities for the duration of one year, and group 3 received a combination of the neuromuscular training program and a sports brace to be worn during all sports activities for the duration of eight weeks. Outcomes were assessed at baseline and every month for 12 months therafter. The primary outcome measure was incidence of ankle sprain recurrences. Secondary outcome measures included the direct and indirect costs of recurrent injury, the severity of recurrent injury, and the residual complaints during and after the intervention.</p> <p>Discussion</p> <p>The ABrCt is the first randomized controlled trial to directly compare the secondary preventive effect of the combined use of braces and neuromuscular training, against the use of either braces or neuromuscular training as separate secondary preventive measures. This study expects to identify the most effective and cost-efficient secondary preventive measure for ankle sprains. The study results could lead to changes in the clinical guidelines on the prevention of ankle sprains, and they will become available in 2012.</p> <p>Trial registration</p> <p>Netherlands Trial Register (NTR): <a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2157">NTR2157</a></p