Thorny catfishes produce stridulation (SR) sounds using their pectoral fins and drumming (DR) sounds via a swimbladder mechanism in distress situations when hand held in water and in air. It has been argued that SR and DR sounds are aimed at different receivers (predators) in different media. The aim of this study was to analyse and compare sounds emitted in both air and water in order to test ...

Human hunting is arguably one of the most difficult activities common to foraging peoples now and in the past. Children and teenagers have usually been described as incompetent hunters in ethnographies of hunter-gatherers. This paper explores the extent to which adult-level competence is limited more by the constraints of physical capital, or body size, and brain-based capital, or skills and le...

a knowledge of physical and aerodynamic properties of agricultural crops is important and essentially required for the design and development of a crop's harvesting and post-harvesting equipments. in the present research, experiments were conducted to determine physical and aerodynamic properties of fars province pinto bean namely: kernel size and shape (length, width, thickness, projected...

Size adaptation describes the tendency of the visual system to adjust neural responsiveness of size representations after prolonged exposure to particular stimulations. A larger (or smaller) adaptor stimulus influences the perceived size of a similar test stimulus shown subsequently. Size adaptation may emerge on various processing levels. Functional representations of the adaptor to which the ...

among structured peer-to-peer systems, chord has a general popularity due to its salient features like simplicity, high scalability, small path length with respect to network size, and flexibility on node join and departure. however, chord doesn’t take into account the topology of underlying physical network when a new node is being added to the system, thus resulting in high routing latency an...

OBJECTIVE To examine the impact of state- and school district-level policies on the prevalence of physical education (PE) and recess in a nationally representative sample of US public elementary schools. DESIGN Analyses from annual, nationally representative, cross-sectional surveys of school administrators in the United States. SETTING Data were collected through surveys conducted between ...

BACKGROUND Structured, regular exercise is recommended to improve health outcomes. Exercise takes many forms and varies in type, intensity, duration and frequency. The authors used the example of exercise for chronic health conditions to examine how exercise programmes are described and summarised in systematic reviews. METHODS Two independent reviewers conducted a review of exercise reportin...

Sample size calculation: Can the authors provide means and SDs on which the effect size (of 0.66) is estimated (for the main trial), rather than stating an effect size without any justification? It may be that this effect size is unrealisic, in which case the main trial would be underpowered at 30 per group. A sample size of 12 per group for the pilot study is very small and I am concerned that...