Both rewards and signals are important in mutualisms. In myrmecochory, or seed dispersal by ants, the benefits to plants are relatively well studied, but less is known about why ants pick up and move seeds. We examined seed dispersal by the ant Aphaenogaster rudis of four co-occurring species of plants, and tested whether morphology, chemical signaling, or the nutritional quality of fatty seed ...

controlled environment may be adopted for a rapid multiplication of a large number of potato seed tubers. the controlled environment prevents seed tuber degeneration which may occur under field conditions. the objective of this study was to introduce new mini-tuber production system with high multiplication rate and low production cost. to evaluate the performance of culture systems in terms of...

Plant biologists have an enduring interest in assessing components of plant fitness and determining limits to seed set. Consequently, the relative contributions of resource and pollinator availability have been documented for a large number of plant species. We experimentally examined the roles of resource and pollen availability on seed set by the northern pitcher plant Sarracenia purpurea. We...

Land managers of natural areas are under pressure to balance demands for increased recreation access with protection of the natural resource. Unintended dispersal of seeds by visitors to natural areas has high potential for weedy plant invasions, with initial seed attachment an important step in the dispersal process. Although walking and mountain biking are popular nature-based recreation acti...

This paper analyzes some important issues surrounding possible deployment of genetically engineered (GE) insect-resistant potato in Peru, based on a large farmer survey held in Peru in 2003. We found that the formal seed system plays a limited role compared with the informal seed system, especially for smallholder farmers. Although 97% of smallholder farmers would buy seed of an insect-resistan...

We introduce a novel amortization technique for computation of consecutive preimages of hash chains, given knowledge of the seed. While all previously known techniques have a memorytimes-computational complexity of O(n) per chain element, the complexity of our technique can be upper bounded at O(log n), making it a useful primitive for low-cost applications such as authentication, signatures an...

PURPOSE To perform a dosimetric comparison between a pre-planned technique and a pre-plan based intraoperative technique in prostate cancer patients treated with I-125 permanent seed implantation. MATERIAL AND METHODS Thirty patients were treated with I-125 permanent seed implantation using TRUS guidance. The first 15 of these patients (Arm A) were treated with a pre-planned technique using u...

Introduction: A variety of field-map estimation techniques using 3-pt multi-echo acquisitions have been developed for reliable water-fat separation [1-6]. The field-map is mainly estimated by finding a minimum of a cost function, defined as , the difference between measured data and estimated data with field-map values varying, which is periodic with period 1/∆TE . However, there still exists a...