bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environmental Heterogeneity, Animal Disturbances, Microsite Characteristics, and Seedling Establishment in a Quercus havardii Community
Authors: Dhillion Shivcharn S. 
Published: March 2003

AbstractIn restoration experiments it is imperative to consider the study of mechanisms of how species are maintained and preserved in a system. This paper reports on the results of a field experiment examining the growth and survival of seedlings of Schizachyrium scoparium, a dominant perennial bunchgrass member of the Quercus havardii (sand shinnery oak) communities of semiarid western Texas, on mounds of displaced soil produced by Sylvilagus auduboni (rabbit). The central question posed is: does environmental heterogeneity created by small mammals influence seedling survival and growth? The specific questions addressed are: (1) Does seedling survival, growth, and nutrient uptake vary when grown on mounds, off‐mound soils, and artificially created mounds?; (2) What is the influence of the microbial and litter components of mound soils on seedling survival?; and (3) In communities where animal disturbances create environmental heterogeneity and may impact seedling establishment, is it possible to artificially create mounds that could serve a similar function? Results show that characteristics of mound soils increase seedling survival, shoot and root biomass, root length, number of tillers, mycorrhizal infection, and nutrient uptake more in plants grown on mounds than off mounds. Both the microbial and litter components of mound soils are essential components of this effect. Artificial mounds generated from soils associated with the herbaceous community were more similar to intact rabbit mounds than artificial mounds generated from soils associated with the oaks. The results indicate that rabbits produce rich patches (both nutrient and microbial) favorable to the growth of seedlings of the dominant bunchgrass, and point to the potential importance of rabbit disturbances in shaping the dynamics of this plant community. Thus, rabbit‐generated disturbances produce environmental heterogeneity in the sand shinnery oak community, similar to that produced by harvester ants in this community as shown by an earlier study. Small animal activity that results in soil displacement, and influences soil characteristics, may indirectly contribute to the persistence of certain plant species within a community. Thus, disturbances may well operate in semiarid communities to produce nutrient and microbe rich microsites which may function to maintain diversity.
Correlates to Colonizations of New Patches by Translocated Populations of Bighorn Sheep
Authors: Singer Francis J. , Moses Michael E. , Bellew Susan , Sloan William 
Published: March 2003

AbstractBy 1950, bighorn sheep were extirpated from large areas of their range. Most extant populations of bighorn sheep (Ovis canadensis) in the Intermountain West consist of <100 individuals occurring in a fragmented distribution across the landscape. Dispersal and successful colonizations of unoccupied habitat patches has been rarely reported, and, in particular, translocated populations have been characterized by limited population growth and limited dispersal rates. Restoration of the species is greatly assisted by dispersal and successful colonization of new patches within a metapopulation structure versus the existing scenario of negligible dispersal and fragmented, small populations. We investigated the correlates for the rate of colonizations of 79 suitable, but unoccupied, patches by 31 translocated populations of bighorn sheep released into nearby patches of habitat. Population growth rates of bighorn sheep in the release patches were correlated to Ne of the founder group, and early contact with a second released population in a nearby release patch (logistic regression, p = 0.08). Largest population size of all extant released populations in 1994 was correlated to potential Ne of the founder group, the number of different source populations represented in the founder, and early contact with a second released population (p = 0.016). Dispersal rates were 100% higher in rams than ewes (p = 0.001). Successful colonizations of unoccupied patches (n = 24 of 79 were colonized) were associated with rapid growth rates in the released population, years since release, larger area of suitable habitat in the release patch, larger population sizes, and a seasonal migratory tendency in the released population (p = 0.05). Fewer water barriers, more open vegetation and more rugged, broken terrain in the intervening habitat were also associated with colonizations (p = <0.05). We concluded that high dispersal rates and rapid reoccupation of large areas could occur if bighorn sheep are placed in large patches of habitat with few barriers to movements to other patches and with no domestic sheep present. Many restorations in the past that did not meet these criteria may have contributed to an insular population structure of bighorn sheep with limited observations of dispersal.
Using Functional Trajectories to Track Constructed Salt Marsh Development in the Great Bay Estuary, Maine/New Hampshire, U.S.A.
Authors: Morgan Pamela A. , Short Frederick T. 
Published: March 2003

AbstractA growing number of studies have assessed the functional equivalency of restored and natural salt marshes. Several of these have explored the use of functional trajectories to track the increase in restored marsh function over time; however, these studies have disagreed as to the usefulness of such models in long‐term predictions of restored marsh development. We compared indicators of four marsh functions (primary production, soil organic matter accumulation, sediment trapping, and maintenance of plant communities) in 6 restored and 11 reference (matched to restored marshes using principal components analysis) salt marshes in the Great Bay Estuary. The restored marshes were all constructed and planted on imported substrate and ranged in age from 1 to 14 years. We used marsh age in a space‐for‐time substitution to track constructed salt marsh development and explore the use of trajectories. A high degree of variability was observed among natural salt marsh sites, displaying the importance of carefully chosen reference sites. As expected, mean values for constructed site (n = 6) and reference site (n = 11) functions were significantly different. Using constructed marsh age as the independent variable and functional indicator values as dependent variables, nonlinear regression analyses produced several ecologically meaningful trajectories (r 2> 0.9), demonstrating that the use of different‐aged marshes can be a viable approach to developing functional trajectories. The trajectories illustrated that although indicators of some functions (primary production, sediment deposition, and plant species richness) may reach natural site values relatively quickly (<10 years), others (soil organic matter content) will take longer.
Restoration of Freshwater Intertidal Habitat Functions at Spencer Island, Everett, Washington
Authors: Tanner Curtis D. , Cordell Jeffery R. , Rubey Jane , Tear Lucinda M. 
Published: March 2003

AbstractIn November 1994 dikes were breached around Spencer Island, restoring tidal inundation and connections to the Snohomish River estuary, Washington. Approximately 23.7 ha (58.5 ac) of palustrine wetlands previously dominated by Phalaris arundinacea (reed canarygrass) now experience diurnal tides and are in the process of transition to a freshwater tidal system. It was expected that brackish water would accompany the return of tidal influence to the site, but post‐project monitoring has revealed little evidence of salinity. Pre‐ and post‐project monitoring of changes in habitat function included aerial photography, vegetation and fish sampling, and benthic prey studies. To date site changes include (1) die back of pre‐project vegetation, development of tidal mudflat, and emergent wetland habitats, with recruitment of vegetation typical of freshwater tidal wetlands; (2) presence of juvenile coho, chum, and chinook salmon that feed on invertebrate prey typical of the site; (3) presence of three distinct benthic invertebrate assemblages in the project area; and (4) some invasion by Lythrum salicaria (purple loosestrife). The unexpected freshwater conditions, the lack of published information about tidal oligohaline marshes in the Pacific Northwest, the use of the site by endangered salmonid species, and the invasion by an undesired plant species underscore the importance of long‐term monitoring at the site.
The Chloroplast Genome Sequence of Chlorokybus Atmophyticus: Evidence that Charophycean Green Algae from an Early Diverging Lineage Adapted to Terrestrial Life
Authors: Turmel M. , Otis C. , De Cambiaire J.‐C. , Pombert J.‐F. , Lemieux C. 
Published: March 2003

AbstractLand plants and green algae belonging to the Charophyceae sensu Mattox and Stewart form the Streptophyta, a lineage sister to the Chlorophyta which comprises most or all of the other green algae. A third green plant lineage, at the base of the split of the Chlorophyta and Streptophyta, is possibly represented by the green alga Mesostigma viride; however, this remains controversial because some phylogenetic analyses place Mesostigma within the Streptophyta. Five orders have been recognized in the Charophyceae: the Chlorokybales, Klebsormidiales, Zygnematales, Coleochaetales, and Charales. Based on its sarcinoid thallus, the only species in the Chlorokybales, Chlorokybus atmophyticus, has long been regarded as the earliest‐diverging member of the Charophyceae. This rare species has been collected only in terrestrial habitats. In the present study, we have determined the complete chloroplast DNA (cpDNA) sequence (149 681 bp) of Chlorokybus to gain insight into its phylogenetic position and also to better understand how the chloroplast genome evolved in the Streptophyta. We have found that Chlorokybus cpDNA closely resembles Mesostigma cpDNA in showing a high degree of ancestral features. It displays a quadripartite structure, encodes 138 genes (only two extra genes compared to Mesostigma cpDNA), and contains a single intron (in trnL(UAA)). The gene order in Chlorokybus cpDNA is similar to that of Mesostigma cpDNA; we estimate that 14 inversions would be required to convert the gene order of one alga into that of the other. Phylogenetic analyses of combined chloroplast protein sequences from Mesostigma, Chlorokybus, other streptophytes, and a number of chlorophytes will be presented. Overall, our results support the idea that the Chlorokybales represent an early diverging lineage.
Recent Changes in the Health Status of the Older U.S. Population: Findings from the 1984 and 1994 Supplement on Aging
Authors: Liao Youlian , McGee Daniel L. , Cao Guichan , Cooper Richard S. 
Published: March 2003

OBJECTIVES: To examine the changes in the use of health care services, physical functioning, disability, and other aspects of health status in the older U.S. population between 1984 and 1994.DESIGN AND SETTING: The 1984 and 1994 National Health Interview Survey Supplements on Aging, which were national probability samples of the civilian, noninstitutionalized population age 70 and older.PARTICIPANTS: A total of 7,541 and 9,447 persons, representing the 17.3 million and 21.8 million U.S. population age 70 and older in 1984 and 1994, respectively.MEASUREMENTS: Annual bed‐limitation days, doctor visits, episodes and days of hospital stays, limitation in 10 measures of physical performance, disability in seven activities of daily living (ADLs) and six instrumental activities of daily living (IADLs), and participation in social activities and exercise.RESULTS: The annual bed‐limitation days and hospital stays declined significantly in both men and women between 1984 and 1994. There was a large decrease in the prevalence of limitation in physical performance and a smaller decrease in disability of IADLs. The changes were greater in women than in men. The prevalence of disability in ADLs was not changed in women in general and increased somewhat in men. Significant increases in the proportion of persons participating in certain social activities and regular exercise were found in both men and women. Jointly considering the indicators, including annual bed days and hospital stays, physical performance, ADLs, and IADLs, 4.2% more men and 3.1% more women were physically robust in 1994 than in 1984. Approximately 420,000 more older people would have lived in a severely restricted and disabled state in 1994 if the rate of limitation had not declined.CONCLUSION: This study provides evidence of an overall improvement in the health status of older Americans but inconsistency in the trends existed for different disability measures and for population subgroups.
Dementia Family Caregiver Training: Affecting Beliefs About Caregiving and Caregiver Outcomes
Authors: Hepburn Kenneth W. , Tornatore Jane , Center Bruce , Ostwald Sharon W. 
Published: March 2003

OBJECTIVES: Family caregiving is an integral part of the care system for persons with dementing disorders, such as Alzheimer's disease. This study tested role‐training intervention as a way to help family caregivers appreciate and assume a more clinical belief set about caregiving and thereby ameliorate the adverse outcomes associated with caregiving.DESIGN: Training effectiveness was tested in a trial in which family care receiver dyads were randomly assigned to training beginning immediately or were placed in a wait‐list control group and assigned to receive training in 5 to 6 months, following completion of data collection.SETTING: A community‐based 14‐hour training program provided in seven weekly 2‐hour sessions. The training program curriculum was built on a stress and coping theory base. Recruitment and randomization were ongoing. Programs were begun every 2 months over a two and one half‐year period for a total of 16 programs.PARTICIPANTS: Community health and social service agencies referred primary caregivers and at least one other family member of community‐dwelling persons with dementia to participate.MEASUREMENTS: Data reported in this paper were gathered from each participating family at entry to the study and 5 months later. Standard measures of beliefs about caregiving, burden, depression, and reaction to care receiver behavior were administered to caregivers. A standard measure of mental status was administered to the person with dementia and standardized instruments were used to gather information from caregivers concerning care receivers' behavior and abilities to perform activities of daily living (ADLs).RESULTS: Data were analyzed from 94 caregiver/care receiver dyads with complete sets of data. Treatment and control caregivers and care receivers were similar at baseline, and care receivers in both groups declined similarly over the 5‐month period. Significant within‐group improvements occurred with treatment group caregivers on measures of beliefs about caregiving (P = .044) and reaction to behavior (P = .001). When outcomes were compared, treatment group caregivers were significantly different (in the expected direction) from those in the control group on measures of the stress mediator, beliefs (P = .025), and key outcomes, response to behavior (P = .019), depression (P = .040), and burden (P = .051). There was a significant positive association between the strengthened mediator, the caregivers' having less‐emotionally enmeshed beliefs about caregiving roles and responsibilities, and the outcome, namely improvements in burden (P = .019) and depression (P = .007).CONCLUSION: A caregiver training intervention focused on the work of caregiving and targeted at knowledge, skills, and beliefs benefits caregivers in important outcome dimensions. The results suggest the benefits of providing information, linkage, and role coaching to dementia family caregivers.
Cause of Death in Older Patients with Anatomo‐Pathological Evidence of Chronic Bronchitis or Emphysema: A Case‐Control Study Based on Autopsy Findings
Authors: Janssens Jean Paul , Herrmann François , MacGee William , Michel Jean Pierre 
Published: March 2003

OBJECTIVES: To determine the most frequent causes of death of hospitalized older patients based on anatomo‐pathological evidence and to compare the relative frequency of fatal events between patients with and without evidence of either chronic bronchitis (CB) or emphysema (E).DESIGN: Retrospective, case‐control study based on a computerized database including anatomo‐pathological data of patients deceased and autopsied over a 25‐year period.SETTING: Two geriatric hospitals in Geneva.PARTICIPANTS: Not applicable.MEASUREMENTS: Autopsy records for cause(s) of death in patients with CB or E.RESULTS: 3,685 patients deceased in our institution (1,540 men; 2,145 women) were autopsied between 1972 and 1996; mean age at death was 81.5 ± 8.0 years. Anatomo‐pathological evidence of CB or E was found in 983 patients (26.6% of total); 262 (7.2%) had predominantly CB, and 456 (12.3%) predominantly E. Pneumonia was the most frequent cause of death in all patients (21.8%). Myocardial infarction (MI) (17.6% vs 14%), and respiratory failure (5.1% vs 1.5%) occurred more frequently in subjects with CB and/or E than in controls. Fatal pulmonary embolism (PE) was more frequent in patients with E (18.4%) than in patients with CB (10.7%; odds ratio (OR) = 1.89, P = .008), or in controls (12.7%; OR = 1.56, P = .0008).CONCLUSION: Anatomo‐pathological evidence of CB or E is highly prevalent in older patients, suggesting that CB and E are clinically underdiagnosed in this age group. Fatal MI occurred significantly more frequently in older patients with E or CB than in controls. Furthermore, patients with E were at significantly higher risk of fatal PE than patients with CB or controls.
Fragmentation of Care for Frail Older People— an International Problem. Experience from Three Countries: Israel, Canada, and the United States
Authors: Clarfield A. Mark , Bergman Howard , Kane Robert 
Published: March 2003

Cross‐national comparisons of healthcare systems can help us to better understand them and to offer possible solutions for problems identified within these jurisdictions. Because multiple discontinuities present in most healthcare systems interfere with the appropriate clinical care of frail older people, we were interested in comparing the situation in three countries with markedly different healthcare systems. At one end of the spectrum we find Canada, with an almost fully socialized system. At the other stands the United States, where market forces are allowed the freest rein in any developed nation. Israel offers an intermediate model with elements held in common with both the U.S. and Canadian systems.Although the problems outlined in this paper can be addressed at the “micro” level, it is through an improvement in the structuring and organization of national systems of care that the appropriate conditions for the care of frail older people can be truly bettered. This international comparison offers insights for policy makers in these three states in particular and other countries in general.
Is the Use of Benzodiazepines Associated with Incident Disability?
Authors: Gray Shelly L. , LaCroix Andrea Z. , Blough David , Wagner Edward H. , Koepsell Thomas D. , Buchner Dave 
Published: March 2003

OBJECTIVES: This study examined the association between benzodiazepine use and incident disability with an emphasis on elucidating whether the underlying health conditions that result in benzodiazepine use (confounding factors) or intrinsic adverse effects of benzodiazepine use were responsible for functional decline.DESIGN: Cohort study with follow‐up of 4 to 5 years.SETTING: A health maintenance organization (HMO) in western Washington.PARTICIPANTS: Individuals aged 65 and older from a random sample of HMO enrollees who participated in a health promotion intervention trial (n = 1,519).MEASUREMENTS: Benzodiazepine use was ascertained from computerized pharmacy records. Self‐reported functional status was assessed using a six‐item physical function scale ranging from vigorous activity to self‐care activities of daily living (ADLs). Two outcomes were examined: decline in overall physical function and limitations in self‐care ADLs. Multivariate models were examined that included demographic characteristics, health status, and health behaviors that were likely to be confounders. Several analyses were conducted to examine whether benzodiazepine use or confounding factors were responsible for functional decline.RESULTS: Benzodiazepine use was significantly associated with incident loss of physical function (hazard ratio (HR) = 1.51, 95% confidence interval (CI) = 1.02–2.24) in the fully adjusted model. Although use of benzodiazepines was associated with limitations in ADLs, it was not significant when adjusting for other factors (HR = 1.71, 95% CI = 0.87–3.34). Several of our findings suggest that the health conditions leading to benzodiazepine use may partly or fully explain these associations: (1) use of anxiolytic benzodiazepines (HR = 1.95, 95% CI = 1.24–3.07), but not hypnotic agents (HR = 1.21, 95% CI = 0.73–2.00), was associated with functional decline; (2) adjustment for health status variables minimized these associations; and (3) there was little evidence of dose response.CONCLUSIONS: A modestly increased risk for decline in physical function was associated with benzodiazepine use, especially of anxiolytic agents. The health conditions that result in benzodiazepine use may be more important in the pathogenesis of disability than benzodiazepine use itself. Although there are many reasons for avoiding benzodiazepines in older adults, it is still unclear whether use contributes independently to functional decline.
Self‐Reported Driving, Cognitive Status, and Physician Awareness of Cognitive Impairment
Authors: Valcour Victor G. , Masaki Kamal H. , Blanchette Patricia L. 
Published: March 2003

OBJECTIVES: To assess self‐reported driving rates in older people and correlate these data with cognitive status and physician recognition of cognitive impairment.DESIGN: Cross‐sectional study.SETTING: A multiphysician private practice clinic in a primarily Asian‐American community of Honolulu, Hawaii.PARTICIPANTS: Two hundred ninety‐seven ambulatory patients aged 65 and older.MEASUREMENTS: Cognitive function was assessed by physician interview using the Cognitive Abilities Screening Instrument (CASI) and proxy informant data. Subjects' self‐reported driving status. Outpatient medical records were reviewed.RESULTS: Sixty percent of the studied population reported that they currently drove. This rate decreased from 73.3% (148/202) for subjects with good CASI performance (CASI ≥82) to 37.5% (21/56) for subjects with intermediate CASI performance (CASI 74–81.9) and further to 23.7% (9/38) for subjects with poor CASI performance (CASI <74). Further analysis of drivers with intermediate and poor CASI performance scores revealed that almost none of their physicians recognized that these drivers had cognitive problems (4.8% (1/21) of drivers with intermediate CASI performance and 11.1% (1/9) of drivers with poor CASI performance).CONCLUSION: In this convenience sample of older drivers, driving rates dropped precipitously with poorer performance on cognitive tests, yet a significant percentage of individuals with intermediate or poor cognitive test performance reported that they currently drove. This poor performance was often unrecognized by their physicians. Low recognition rates could affect physicians' interventions to curb unsafe driving.