In order for a network to provide end-to-end guarantees on quality of service (QoS), it must allocate its resources according to the traffic characteristics and performance requirements of its clients. However, the burstiness of typical variable bit rate traffic streams makes it difficult to provide the QoS guarantees that the network’s clients require and simultaneously make efficient use of n...

As the new requirements for wireless sensor networks are emerging, real-time communications is becoming a major research challenge because resource-constrained sensor nodes are not powerful enough to accommodate the complexity of the protocol. In addition, an efficient energy management scheme has naturally been a concern in wireless sensor networks for a long time. However, the existing scheme...

We present an admission control framework and loss management techniques in support of a guaranteed statistical service. The service is characterized by (i) the loss rate of application data units (ADUs) bounded below a specified value, and (ii) ADU losses distributed evenly among flows subscribing to the service and uniformly over the duration of each flow. Specifically, a flow is modeled as a...

Sociality can be associated with significant costs due to the increased risk of disease transmission. However, in some organisms the costs may be offset by benefits due to improvements in defences against parasites. To examine this possible trade-off between infection risk and disease resistance, we used Acromyrmex leaf-cutting ants and the entomopathogenic fungus Metarhizium anisopliae as the ...

BACKGROUND AND AIMS Changes in number of trichomes and in composition and concentrations of their exudates throughout leaf development may have important consequences for plant adaptation to abiotic and biotic factors. In the present study, seasonal changes in leaf trichomes and epicuticular flavonoid aglycones in three Finnish birch taxa (Betula pendula, B. pubescens ssp. pubescens, and B. pub...