bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Test of a Habitat Evaluation Procedure for Rocky Mountain Bighorn Sheep
Authors: Johnson Therese L. , Swift David M. 
Published: March 2003

AbstractHabitat analysis is an important component of animal population restoration. We tested a habitat evaluation procedure for Rocky Mountain bighorn sheep (Ovis canadensis canadensis) using a geographic information system (GIS). We applied the model to eight bighorn sheep translocation sites in Colorado and compared the model's habitat suitability assessments with translocation results. The model considered the habitat unsuitable for four failed translocations, and did not recognize suitable habitat for four successful translocations. We performed a sensitivity analysis to determine how individual parameters affected model suitability assessments. To improve the model's ability to distinguish between suitable and unsuitable habitat, we relaxed the suitability criteria for four parameters: barriers created by dense vegetation, barriers created by fences, buffer zones on human use areas, and horizontal visibility. The refined model can be useful to bighorn sheep restoration efforts by facilitating evaluation of large areas of potential habitat, but numerical thresholds for required amounts of suitable habitat must consider the scale of data used for analysis.
Restoration Ecology of an Endangered Plant Species: Establishment of New Populations of Cirsium pitcheri
Authors: Rowland Jennifer , Maun M. A. 
Published: March 2003

AbstractWe determined the effects of shade, burial by sand, simulated herbivory, and fertilizers on the survival and growth of artificially planted population of Cirsium pitcheri—an endangered plant species of the sand dunes along Lake Huron. Sand burial experiments showed that greenhouse grown plants should optimally be transplanted into areas receiving 5 cm of sand deposition: burial at this depth maximized emergence, survivorship, and below‐ground biomass. Under field conditions, simulated herbivory of up to 50% of the plant height produced a slight increase in biomass after one year of growth. Field observations showed that when white‐tailed deer removed more than 50% of the transplant's leaf tissue, the plant died. The application of a 20:20:20 (N:P:K) water‐soluble fertilizer produced a significant increase in the dry leaf biomass, total leaf area, and total dry biomass relative to control plants. We also tested for the presence or absence of a persistent seed bank. Few seeds were recovered from soil samples collected from Pinery Provincial Park and Providence Bay. However, C. pitcheri has the ability to form a persistent seed bank under field conditions but only at soil depths of 15 cm. Cirsium pitcheri seeds are able to germinate and seedlings can emerge from a burial depth of up to 6 cm. Thus, seeds planted in open, sunny areas will probably maximize emergence, growth, and survivorship of seedlings. Populations of C. pitcheri can be restored by planting seeds at shallow depths, transplanting greenhouse‐grown plants, applying water soluble fertilizers, and protecting plants from herbivores.
Ecological and Landscape Rehabilitation of a Quarry Site in Hong Kong
Authors: Jim C. Y. 
Published: March 2003

AbstractQuarrying for granite in Hong Kong, mainly for construction aggregates, has left huge and unsightly scars on the landscape. Recent government policy demands rehabilitation of the disturbed lands and restoration of the landscape adopting the ecological approach. At an active quarry, a method was tested for controlled restoration: blasting of the vertical rocky production faces to pile up the debris and to form artificial slopes that mimic those of the environs in a landform replication approach. On the scree blast piles, a soil cap of fine‐earth materials with organic amendments was installed to grow mainly tropical leguminous trees. The restoration trial largely failed, with extensive death or poor performance of most plants. The inability of the soil and the site to support vegetation was investigated. The main physical problems are shallow solum, large cavities in the bouldery substrate, high stone content, excessively coarse texture, compaction, and limited available‐moisture storage. The main chemical problems are the lack of nitrogen and phosphorus related to the meager organic‐matter content, low cation exchange capacity, and base saturation. Suggestions are made to ameliorate habitat conditions for plant growth in a comprehensive ecosystem‐reconstitution package that encompasses the landform, hydrology, microclimate, soil, and plant assemblage. Recommendations are given on the application of organic amendments to establish and maintain soil structure, restore decomposition regime, and raise nutrient and moisture storage capacities for a modified approach that could overcome the site difficulties.
Colonization of Colliery Spoil Heaps by Millipedes (Diplopoda) and Terrestrial Isopods (Oniscidea) in the Sokolov Region, Czech Republic
Authors: Tajovský Karel 
Published: March 2003

AbstractSuccessive development of millipede and terrestrial isopod assemblages in colliery spoil heaps in the Sokolov region (northwest Bohemia, Czech Republic) was studied during the years 1993–1998. Younger colliery spoil heaps were characterized by a lower number and low density of millipede species. The millipedes Polydesmus inconstans, Polydesmus testaceus, and Craspedosoma rawlinsii represented the main pioneer species. Alder afforestation proved to be more suitable for the recolonization of millipede populations, especially for the predominant Julus scandinavius. Terrestrial isopods colonized all parts of the heaps, including the youngest open plots. The most frequent isopod, Trachelipus rathkii, is a colonizing species with an apparently high adaptability to different environmental conditions. The isolated character of the extensive heap areas, together with existing extreme soil conditions, resulted in slow recolonization and a successional development of stable populations of these animals. However, the relatively high densities of millipede and isopod assemblages in suitable alder afforestation can represent further potential sources for colonization of other open‐heap areas.
Floristic Development Patterns in a Restored Elk River Estuarine Marsh, Grays Harbor, Washington
Authors: Thom Ronald M. , Zeigler Robert , Borde Amy B. 
Published: March 2003

AbstractWe describe the changes in the floral assemblage in a salt marsh after reconnection to estuarine tidal inundation. The Elk River marsh in Grays Harbor, Washington was opened to tidal flushing in 1987 after being diked for approximately 70 years. The freshwater pasture assemblage dominated by Phalarais arundinacea (reed canary grass) converted to low salt marsh vegetation within 5 years, with the major flux in species occurring between years 1 and 4. The system continued to develop through the 11‐year post‐breach monitoring period, although change after year 6 was slower than in previous years. The assemblage resembles a low salt marsh community dominated by Distichlis spicata (salt grass) and Salicornia virginica (pickleweed). Because of subsidence of the system during the period of breaching, the restored system remains substantially different from the Deschamsia cespitosa (tufted hairgrass)‐dominated reference marsh. Use of a similarity index to compare between years and also between reference and restored marshes in the same year revealed that similarity in floral composition between year 0 and subsequent years decreased with time. However, there was a period of dramatic dissimilarity during years 1 to 3 when the system was rapidly changing from a freshwater to estuarine condition. Similarity values between the reference and restored system generally increased with time. Somewhat surprisingly the reference marsh showed considerable between‐year variation in similarity, which indicated substantial year‐to‐year variability in species composition. Based on accretion rate data from previous studies we predict that full recovery of the system would take between 75 and 150 years.
Winter Burning and the Reduction of Cornus sericea in Sedge Meadows in Southern Wisconsin
Authors: Middleton Beth 
Published: March 2003

AbstractTo control shrubs, which are increasing in dominance in wetlands worldwide, winter burning may be an important tool, especially from the perspective of minimizing urban hazards. The goal of this project was to determine if winter burning was successful in reducing the dominance (mean percentage cover and maximum height) of Cornus sericea in sedge meadows in southern Wisconsin, where shrubs proliferated after cattle were excluded. Experimental burn and control plots were set up within sedge meadows, including an ungrazed “reference” site that had been little, if ever, grazed and a “historically grazed” site, a recovery site that had not been grazed by cattle since 1973. None of the dominant species including C. sericea was significantly affected by burning for either mean percentage cover or maximum height (analysis of variance: no burning × species interaction). Both mean percentage cover and maximum height were only weakly related to burning (28.1 and 14.3% of the variability contributed to the cumulative percentage of the coefficient of determination, respectively) at both sites based on non‐metric multidimensional scaling analysis. Although species richness increased in burned plots in 1999 and 2000, no differences were apparent between pre‐burned and unburned plots in 1997 and unburned plots in 1999 and 2000 (analysis of variance: year × burning interaction). After burning in the ungrazed site, herbaceous species appeared that had not been detected for decades, including Chelone glabra and Lathyrus palustris. Exotic species were present in both the ungrazed reference and recovery site. Although winter burning treatments did not reduce the dominance of woody shrub species in the site recovering from cattle grazing, burning was useful in stimulating the maintenance of species richness in the ungrazed sedge meadow.
DNA DAMAGE AND PHOTOSYNTHETIC PERFORMANCE IN THE ANTARCTIC TERRESTRIAL ALGA PRASIOLA CRISPA SSP. ANTARCTICA (CHLOROPHYTA) UNDER MANIPULATED UV‐B RADIATION
Authors: Lud Daniela , Buma Anita G.J. , Van De Poll Willem , Moerdijk Tanja C.W. , Huiskes Ad H.L. 
Published: March 2003

The effect of reduced, natural ambient, and enhanced UV‐B radiation (UVBR) on photosynthesis and DNA damage in the Antarctic terrestrial alga Prasiola crispa ssp. antarctica (Kützing) Knebel was investigated in two field experiments. Samples of P. crispa were collected underneath snow cover and exposed outside to reduced and natural UVBR in the austral spring. In a second experiment at the end of the austral summer, samples were exposed to ambient and enhanced UVBR. PSII efficiency, net photosynthetic rate (NP), dark respiration rate (DR), UV‐absorbing pigments, and cyclobutyl pyrimidine dimer (CPD) formation were measured during the experiments.In October 1998, a spring midday maximum of 2.0 W·m−2 of UVBR did not significantly affect effective quantum yield (ΔF/Fm′), and a reduction in the ratio of variable to maximal fluorescence (Fv/Fm) in the late afternoon was transient. Exposure to natural ambient UVBR in October increased CPD values significantly. Midday maxima of UVBR during the experiments in October and January were comparable, but Setlow‐DNA‐weighted UVBR was more than 50% lower in January than in October. In January, 0.5 W·m−2 additional UVBR during 10 h did not have a negative effect on ΔF/Fm′. The reduction in Fv/Fm was not significant. NP and DR were not affected by supplementation of UVBR. Although photosynthetic activity remained largely unaffected by UVBR treatment, DNA damage was shown to be a sensitive parameter to monitor UVBR effects. Supplementation of additional UVBR did significantly enhance the amounts of CPD in exposed samples and repair took place overnight. It is concluded that PSII and whole‐chain photosynthesis of P. crispa is well adapted to ambient and enhanced levels of UVBR but that CPD formation is more sensitive to UVBR than to photosynthesis.
New Insights in the Systematics of the Phyllophoraceae (Gigartinales, Rhodophyta)
Authors: Fredericq S. , Lopez‐Bautista J. M. , Moe R. L. 
Published: March 2003

AbstractThe Phyllophoraceae, consisting of about 100 species worldwide, stands out in exhibiting a wide spectrum of unique life history types that makes it unusually interesting for assessing the phylogenetic importance of reproductive traits relative to classification criteria. Type of life history and position of the reproductive structures on the thallus have traditionally formed the basis for separating 11 genera in the Phyllophoraceae; however, phylogenetic analyses inferred from three sets of DNA sequences [chloroplast‐encoded rbcL, nuclear large‐subunit ribosomal RNA gene (LSU rDNA), and internal transcribed spacer regions (ITS) of nuclear ribosomal DNA], instead indicate a lack of correlation between type of life history and phylogenetic relationships among the established taxa. This lack of correlation dramatically challenges all of the traditional taxonomy, and we will present a revised classification for the family that downplays life‐history features. The study will answer the question which morphological features can be used as meaningful indicators of phylogenetic relationships in the Phyllophoraceae. The results will also be addressed in light of global biogeographic hypotheses for the family.
Calcification and Decalcification During Epithallial Cell Turnover in Coralline Red Algae
Authors: Pueschel C. , Wegeberg S. 
Published: March 2003

AbstractEpithallial cells of the coralline red algae are characterized by unusual structural specialization, which include deep invaginations of the distal cell surface, and by unique development, which culminates in senescence, shedding, and replacement of the cells. Electron microscopic study of epithelial cell differentiation in morphologically and taxonomically disparate species suggests that the unusual features of epithelial cell structure and development stem from the fact that these dynamics occur within a calcified matrix. Distal wall ingrowths begin to form on the initial cells, cells whose cleavage eventually gives rise distally to new epithelial cells. After the distal wall ingrowths form, the overlying crosswall becomes rich in organic material. For this organic wall material to be deposited into the existing crosswall, the wall must first be decalcified; therefore, the presence of abundant organic material in the crosswall provides a marker of localized decalcification. We propose that the location and time of origin of distal wall ingrowths indicate a connection between the ingrowths and two coordinated processes: localized secretion of wall material, and decalcification of the overlying cell wall in preparation for the movement of the young epithelial cell into a new location relative to the surrounding calcified matrix. The large plasmalemmal surface area associated with the distal wall ingrowths allows for a greater abundance of membrane‐associated components, such as proton pumps, that could drive localized cell wall decalcification.
Low Relative Skeletal Muscle Mass (Sarcopenia) in Older Persons Is Associated with Functional Impairment and Physical Disability
Authors: Janssen Ian , Heymsfield Steven B. , Ross Robert 
Published: March 2003

OBJECTIVES: To establish the prevalence of sarcopenia in older Americans and to test the hypothesis that sarcopenia is related to functional impairment and physical disability in older persons.DESIGN: Cross‐sectional survey.SETTING: Nationally representative cross‐sectional survey using data from the Third National Health and Nutrition Examination Survey (NHANES III).PARTICIPANTS: Fourteen thousand eight hundred eighteen adult NHANES III participants aged 18 and older.MEASUREMENTS: The presence of sarcopenia and the relationship between sarcopenia and functional impairment and disability were examined in 4,504 adults aged 60 and older. Skeletal muscle mass was estimated from bioimpedance analysis measurements and expressed as skeletal muscle mass index (SMI = skeletal muscle mass/body mass × 100). Subjects were considered to have a normal SMI if their SMI was greater than ‐one standard deviation above the sex‐specific mean for young adults (aged 18–39). Class I sarcopenia was considered present in subjects whose SMI was within ‐one to ‐two standard deviations of young adult values, and class II sarcopenia was present in subjects whose SMI was below ‐two standard deviations of young adult values.RESULTS: The prevalence of class I and class II sarcopenia increased from the third to sixth decades but remained relatively constant thereafter. The prevalence of class I (59% vs 45%) and class II (10% vs 7%) sarcopenia was greater in the older (≥ 60 years) women than in the older men (P < .001). The likelihood of functional impairment and disability was approximately two times greater in the older men and three times greater in the older women with class II sarcopenia than in the older men and women with a normal SMI, respectively. Some of the associations between class II sarcopenia and functional impairment remained significant after adjustment for age, race, body mass index, health behaviors, and comorbidity.CONCLUSIONS: Reduced relative skeletal muscle mass in older Americans is a common occurrence that is significantly and independently associated with functional impairment and disability, particularly in older women. These observations provide strong support for the prevailing view that sarcopenia may be an important and potentially reversible cause of morbidity and mortality in older persons.
Development and Testing of a Measure of Health‐Related Quality of Life for Men with Urinary Incontinence
Authors: Robinson Joanne P. , Shea Judy A. 
Published: March 2003

OBJECTIVES: To describe the development and psychometric testing of male versions of the Urogenital Distress Inventory (UDI) and Incontinence Impact Questionnaire (IIQ).DESIGN: Instrument development.SETTING: Urology clinic at a large urban Veterans Affairs Medical Center.PARTICIPANTS: Convenience sample of English‐speaking community‐dwelling male urology clinic patients who acknowledged concerns about urine leakage.MEASUREMENTS: Content experts and male clinic patients evaluated items for clarity and fit. Revised instruments were administered to 153 participants. Data were analyzed to examine issues of feasibility of administration, internal consistency reliability, and validity.RESULTS: Modal completion time for the Male Urogenital Distress Inventory (MUDI) (27 items) and Male Urinary Symptom Impact Questionnaire (MUSIQ) (32 items) was 20 minutes. Cronbach's coefficients were .89 for the MUDI and .95 for the MUSIQ. Total MUDI and MUSIQ scores were moderately correlated (r = .59, P < .001). Mean MUDI and MUSIQ scores varied significantly with self‐reported desire for socialization, urine leakage, and depression. Principal components analyses suggested the presence of seven factors accounting for 65.4% of the variance in the MUDI and six factors accounting for 72.9% of the variance in the MUSIQ.CONCLUSIONS: It is feasible to use the MUDI and MUSIQ to measure health‐related quality of life in men with continence problems. The scores appeared to be reliable and valid in this racially and educationally diverse sample. Use of the MUDI and MUSIQ may provide more sensitive measurement of the specific effect of urinary incontinence and related symptoms on health‐related quality of life in men. Future research should determine reproducibility and responsivity and reexamine the construct validity of these instruments.
Identifying Postmenopausal Women at High Risk of Fracture in Populations: A Comparison of Three Strategies
Authors: Buist Diana S.M. , LaCroix Andrea Z. , Manfredonia David , Abbott Thomas 
Published: March 2003

OBJECTIVES: To describe the prevalence of risk factors for women at high risk of fracture in a population‐based sample of postmenopausal women who were not using hormone replacement therapy (HRT), to demonstrate how the estimated prevalence of women at high risk of future fracture is affected by the different criteria used for classification, and to characterize the populations identified and missed by each of the criteria. A key study objective was to compare the proportion of postmenopausal women at high risk of fracture in a managed care population using several different definitions of who is at high risk.DESIGN: The Osteoporosis Population‐based Risk Assessment study, a randomized trial of three screening strategies.SETTING: Conducted at Group Health Cooperative in western Washington state.PARTICIPANTS: Women aged 60 to 79 who had not used HRT for at least 12 months were chosen at random.MEASUREMENTS: In one of the trial arms, 428 women had their bone mineral density (BMD) measured at the hip and spine (L1–L4) using dual energy x‐ray absorptiometry. Minimum t scores and z scores at all sites were used for classification. Risk factors for fractures were assessed at the time of the BMD scan.RESULTS: Guidelines based on the Study of Osteoporotic Fractures classified 25.1% of the women as being at high risk of fracture, compared with 30.0% and 68.0% using World Health Organization (WHO) recommendations and National Osteoporosis Foundation guidelines, respectively. Classification based on low BMD alone (WHO) failed to include more than 50% of women who had already experienced a clinical fracture.CONCLUSIONS: Prevalence of women at high risk of fracture not using HRT varies notably depending on the criteria used for identification. The criteria used to identify women to target for primary and secondary prevention of osteoporotic fractures has major implications for population‐based prevention strategies.
Profiling Nursing Homes Using Bayesian Hierarchical Modeling
Authors: Berlowitz Dan R. , Christiansen Cindy L. , Brandeis Gary H. , Ash Arlene S. , Kader Boris , Morris John N. , Moskowitz Mark A. 
Published: March 2003

OBJECTIVES: New methods developed to improve the statistical basis of provider profiling may be particularly applicable to nursing homes. We examine the use of Bayesian hierarchical modeling in profiling nursing homes on their rate of pressure ulcer development.DESIGN: Observational study using Minimum Data Set data from 1997 and 1998.SETTING: A for‐profit nursing home chain.PARTICIPANTS: Residents of 108 nursing homes who were without a pressure ulcer on an index assessment.MEASUREMENTS: Nursing homes were compared on their performance on risk‐adjusted rates of pressure ulcer development calculated using standard statistical techniques and Bayesian hierarchical modeling.RESULTS: Bayesian estimates of nursing home performance differed considerably from rates calculated using standard statistical techniques. The range of risk‐adjusted rates among nursing homes was 0% to 14.3% using standard methods and 1.0% to 4.8% using Bayesian analysis. Fifteen nursing homes were designated as outliers based on their z scores, and two were outliers using Bayesian modeling. Only one nursing home had greater than a 50% probability of having a true rate of ulcer development exceeding 4%.CONCLUSIONS: Bayesian hierarchical modeling can be successfully applied to the problem of profiling nursing homes. Results obtained from Bayesian modeling are different from those obtained using standard statistical techniques. The continued evaluation and application of this new methodology in nursing homes may ensure that consumers and providers have the most accurate information regarding performance.