Arundo donax L. is a tall perennial reed classified as an emergent aquatic plant. In California, it has invaded riparian zones, where it acts as a transformer species. Because plant growth and leaf quality influence the effectiveness of management techniques, we sought to determine if these characters varied temporally and spatially in a northern California population of A. donax. Tissue C and ...

It is generally accepted that seedlings from large seeds are more tolerant to defoliation than those from small seeds due to the additional metabolic reserves present in the large seeds. However, information on the effects of amount of seed reserves (cotyledon removal) from seedlings resulting from large vs. small seeds on seedling growth and long-term survival in the field is limited. Five leg...

Throughout the western United States, the invasive annual grass, medusahead (Taeniatherum caputmedusae L. Nevski), is rapidly invading grasslands once dominated by native perennial grasses, such as bluebunch wheatgrass (Pseudoroegneria spicata (Pursh) A). It is also invading grasslands dominated by less undesirable invasive annual grasses, especially cheatgrass (Bromus tectorum L.). Understandi...

1 We examined amongand within-species effects of seed mass for seedling establishment from seed to 5 years of age in a field experiment at Paracou, French Guiana. 2 Six seeds of each of eight species were weighed and planted into each of 120 plots (1 m 2 ) throughout closed-canopy forest along 12 100-m transects in 1998. 3 We described the microhabitat of each planting site using principal comp...

We studied a guild of desert winter annual plants that differ in long-term variation in per capita reproductive success (lb, the product of per capita survival from germination to reproduction, l, times per capita reproduction of survivors, b) to relate individual function to population and community dynamics. We hypothesized that variation in lb should be related to species' positions along a ...

Little is known about the effects of NaCl stress on perennial ryegrass (Lolium perenne L.) photosynthesis and carbohydrate flux. The objective of this study was to understand the carbohydrate metabolism and identify the gene expression affected by salinity stress. Seventy-four days old seedlings of two perennial ryegrass accessions (salt-sensitive 'PI 538976' and salt-tolerant 'Overdrive') were...

Growing travel and trade threatens biodiversity as it increases the rate of biological invasions globally, either by accidental or intentional introduction. Therefore, avoiding these impacts by forecasting invasions and impeding further spread is of utmost importance. In this study, three forecasting approaches were tested and combined to predict the invasive behaviour of the alien macrophyte L...

Background: Retinal G-protein–coupled receptor opsin (RGR) functions as a photoisomerase that convert the all-trans-retinal to 11-cis-retinal in human retinal pigmented epithelium. Our research and others have demonstrated opsin-based UVR phototransduction system existed skin. However, whether RGR is expressed skin has not yet been identified. Objective: To determine expression, distribution su...

The design of a routing protocol for Unmanned Aeronautical Ad-hoc Networks (UAANETs) is quite challenging, especially due to the high mobility of Unmanned Aerial Vehicles (UAVs) and the low network density. Among all routing protocols that have been designed for UAANETs, the Reactive-Greedy-Reactive (RGR) protocol has been proposed as a promising routing protocol in high mobility and density-va...

The effect of different photon flux densities (PFD) and temperatures on the relative growth rate (RGR) and the concentration of three halogenated monoterpenes in samples of Plocamium cartilagineum L.( Dixon), a marine alga (Rhodophyceae), were studied. The highest RGR (22.8 +/- 0.04 d(-1)) was obtained at 15 degreebC and 41 ,mol m(-2) s)(-1) of PFD and the lowest (18.0 +/- 0.12 d(-1)) was obtai...