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Characteristics Used (characteristic + used)
Selected AbstractsAn experimental test of the effect of plant functional group diversity on arthropod diversityOIKOS, Issue 2 2000Amy J. Symstad Characteristics used to categorize plant species into functional groups for their effects on ecosystem functioning may also be relevant to higher trophic levels. In addition, plant and consumer diversity should be positively related because more diverse plant communities offer a greater variety of resources for the consumers. Thus, the functional group composition and richness of a plant community may affect the composition and diversity of the herbivores and even higher trophic levels associated with that community. We tested this hypothesis by sampling arthropods with a vacuum sampler (34,531 individuals of 494 species) from an experiment in which we manipulated plant functional group richness and composition. Plant manipulations included all combinations of three functional groups (forbs, C3 graminoids, and C4 graminoids) removed zero, one, or two at a time from grassland plots at Cedar Creek Natural History Area, MN. Although total arthropod species richness was unrelated to plant functional group richness or composition, the species richness of some arthropod orders was affected by plant functional group composition. Two plant characteristics explained most of the effects of plant functional groups on arthropod species richness. Nutritional quality, a characteristic related to ecosystem functioning, and taxonomic diversity, a characteristic not used to designate plant functional groups, seemed to affect arthropod species richness both directly and indirectly. Thus, plant functional groups designated for their effects on ecosystem processes will only be partially relevant to consumer diversity and abundance. [source] SEXUAL DIMORPHISM AND BODY SCARRING IN THE BOTO (AMAZON RIVER DOLPHIN) INIA GEOFFRENSISMARINE MAMMAL SCIENCE, Issue 1 2006A. R. Martin Abstract Measurements and quantitative descriptions of a large sample of live adult botos (Inia geoffrensis) were obtained from the Mamirauá Reserve in the central Amazon. Males were on average 16% longer and weighed 55% more than females, demonstrating that this species is one of the most sexually dimorphic of all cetaceans for size. Males were also pinker than females, more heavily scarred by intraspecific tooth rakes, and had more life-threatening injuries. Some larger males had areas of modified skin that may simply be scar tissue, but may also be a heritable characteristic used as a shield or weapon. As in sperm whales, sexual size dimorphism and male-male aggression appear to be linked in botos, suggesting fierce competition for a resource,probably mating opportunities. The boto is unique among river dolphins in that males are larger than females. This distinction implies long evolutionary separation and fundamental differences in social behavior. [source] Patients with Hip Fracture: Subgroups and Their OutcomesJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 7 2002Elizabeth A. Eastwood PhD OBJECTIVES: To present several alternative approaches to describing the range and functional outcomes of patients with hip fracture. DESIGN: Prospective study with concurrent medical records data collection and patient and proxy interviews at the time of hospitalization and 6 months later. SETTING: Four hospitals in the New York metropolitan area. PARTICIPANTS: Five hundred seventy-one hospitalized adults aged 50 and older with hip fracture between July 1997 and August 1998. MEASUREMENTS: Rates of return to function in four physical domains, mortality, and nursing home residence at 6 months. Cluster analysis was used to describe the heterogeneity among the sample and identify variations in 6-month mortality, nursing home residence, and level of functioning and to develop a patient classification tree with associated patient outcomes at 6 months postfracture. RESULTS: In locomotion, transfers, and self-care, 33% to 37% of patients returned to their prior level of function by 6 months, including those needing assistance, but only 24% were independent in locomotion at 6 months. Cluster analysis identified eight patient subgroups that had distinct baseline features and variable outcomes at 6 months. The patient classification tree used four variables: atypical functional status (independent in locomotion but dependent in other domains); nursing home residence; independence/dependence in self-care; and age younger than 85 or 85 and older that identified five subgroups with variable 6-month outcomes that clinicians may use to predict likely outcomes for their patients. CONCLUSION: Patients with hip fracture are heterogeneous with respect to baseline and outcome characteristics. Clinicians may be better able to give patients and caregivers information on expected outcomes based on presenting characteristics used in the classification tree. [source] 95 Development of macroalgal (seaweed) taxonomic keys utilizing digital & media technologyJOURNAL OF PHYCOLOGY, Issue 2003R. L. Lehman Digital, user-friendly seaweed identification keys and instructional materials can provide information that allows students and researchers to enhance and improve marine field and ecological studies by including macroalgae. In much of the scientific literature, the seaweeds are only characterized to division (red, green, and brown), sometimes to genus, and very rarely to species; so there is clearly a need for a reference that facilitates the identification of the seaweeds. Many of the problems occur because of the lack of user-friendly identification keys. However, it is not necessary to be an expert to identify seaweeds as many of the key characteristics used in their identification can be ascertained with the naked eye, a hand lens and an inexpensive microscope. What is needed is an identification guide that uses and displays important characters and identification structures visually (both macroscopic and microscopic) so that research scientists, students, teachers and the general public will be able to identify the seaweeds with confidence. We are using Lucid Professional software to construct digital keys for the identification of macroalgae from the Texas Coastal Bend. The advantages include: 1) key characters along with descriptions and images for specific macroalgae may be chosen from a geographic area of choice, 2) the user may evaluate the characters in any order and difficult or uncertain characters may be ignored, 3) descriptive pages of images, definitions, video clips and illustrations may be included for each taxon, and 4) the key can be displayed as a website or packaged as a CD to be used with laptop computers in the field. [source] | ||||||||||