bluuebunny/crossref_metadata_2025_split huggingface dataset:
Explaining Counter‐Intuitive Clinical Outcomes Predicted by Kt/V
Authors: Owen William F. , Coladonato Joe , Szczech Lynda , Reddan Donal 
Published: March 2003

ABSTRACTPopulation‐based studies of maintenance hemodialysis patients have demonstrated a reproducible relationship between the dose of hemodialysis and mortality and morbidity outcomes. In these analyses, which have aggregated hemodialysis patient subgroups, improved outcomes are associated with greater doses of hemodialysis. However, remarkable counterintuitive findings are observed if patients are analyzed by subgroups based on their race, gender, and anthropometric and blood‐based biomarkers of nutritional state. For example, blacks generally receive lower doses of hemodialysis than whites, but enjoy relatively improved survival; patients who receive the highest doses of hemodialysis have an increased death risk; and the dose response curve between hemodialysis and survival is altered based on the patients' body mass index. These seemingly paradoxical relationships between hemodialysis dose and patient survival can be explained because of the use of mathematical urea kinetic constructs as clinical outcome predictors; they integrate a measure of solute removal (K×t) with an anthropometric surrogate of nutrition, the urea distribution volume (V). Both these measures have an independent influence on patient survival and in some clinical circumstances are of unequal power as clinical outcome predictors. These complex interactions must be kept in perspective as clinical care is delivered in the context of hemodialysis dose.
The Effect of Chronic Renal Failure on Hepatic Drug Metabolism and Drug Disposition
Authors: Dreisbach Albert W. , Lertora Juan J. L. 
Published: March 2003

AbstractThere is abundant evidence that chronic renal failure (CRF) and end‐stage renal disease (ESRD) alter drug disposition by affecting protein and tissue binding and reducing systemic clearance of renally cleared drugs. What is not fully appreciated is that CRF can significantly reduce nonrenal clearance and alter the bioavailability of drugs predominantly metabolized by the liver. Animal studies in CRF have shown a major down‐regulation (40–85%) of hepatic cytochrome P‐450 metabolism involving specific isozymes. Phase II reactions such as acetylation and glucuronidation are also involved, with some isozymes showing induction and others inhibition. Hepatic enzymes exhibiting genetic polymorphisms such as N‐acetyl‐transferase‐2 (NAT‐2), which is responsible for the rapid and slow acetylator phenotypes, have been shown to be inhibited by ESRD and reversed by transplantation. There is some evidence pointing to the possibility of inhibitory factors circulating in the serum in ESRD patients which may be dialyzable. This review includes all significant animal and clinical studies using the search terms “chronic renal failure,”“cytochrome P‐450,” and “liver metabolism” over the past 10 years obtained from the National Library of Medicine MEDLINE database, including relevant articles back to 1969.
HEPARIN‐INDUCED THROMBOCYTOPENIA IN DIALYSIS: The Pathophysiology of Immune‐mediated Heparin‐induced Thrombocytopenia
Authors: Reilly Robert F. 
Published: March 2003

AbstractHeparin‐induced thrombocytopenia (HIT) is an important side effect of heparin therapy associated with significant morbidity and mortality if unrecognized. The platelet count typically falls below 150,000/µl 5–14 days after heparin is started. Thrombosis is the major clinical complication. The diagnosis is confirmed with a variety of functional and antigenic assays. Heparin binds to PF4, resulting in a conformational change in the molecule that exposes neo‐epitopes that act as immunogens. Antibodies form against the heparin‐PF4 complex, the major target antigen. The IgG‐heparin‐PF4 immune complex binds either via its Fab domain to the platelet surface or via its Fc domain to the FcγIIA receptor on the surface of the platelet, resulting in further platelet activation. Continued release of PF4 from activated platelets leads to increasing PF4‐heparin complex formation, and a self‐propagating cycle of platelet consumption and generation of procoagulant platelet‐derived microparticles. Other procoagulant effects of the HIT antibody include endothelial cell damage, stimulation of platelet‐leukocyte aggregates, and release of tissue factor from monocytes.
Cultural and Noncultural Predictors of Health Outcomes in Korean Daughter and Daughter‐in‐Law Caregivers
Authors: Kim Jin‐Sun , Lee Eun‐Hyun 
Published: March 2003

Abstract  In Western cultures, adverse health effects resulting from providing care for impaired elders is well documented for family caregivers, but little is known about the health of Korean caregivers. This study examined the level of depression and physical health of 120 daughter and daughter‐in‐law caregivers who cared for cognitively or functionally impaired elderly in Korea. It was hypothesized that cultural factors would have a greater effect on caregivers' health outcomes than noncultural factors, but, contrary to this expectation, the effects of noncultural factors were found to outweigh those of cultural factors. Moreover, the caregivers in this study reported a relatively high level of depression, and more caregivers rated their own health as “poor” than did Western caregivers in previous studies.Family caregiving for the impaired elderly is stressful and negatively affects Korean caregivers' health outcomes regardless of societal values such as filial piety and familism regarding parent care in Korea. Culturally acceptable and sensible support programs may be useful in sustaining long‐term care at home by Korean daughter and daughter‐in‐law caregivers. Further family caregiving studies in the Korean sociocultural context are recommended.
Tracking Wetland Restoration: Do Mitigation Sites Follow Desired Trajectories?
Authors: Zedler Joy B. , Callaway John C. 
Published: March 2003

AbstractHypothetical models in the scientific literature suggest that ecosystem restoration and creation sites follow a smooth path of development (called a trajectory), rapidly matching natural reference sites (the target). Multi‐million‐dollar mitigation agreements have been based on the expectation that damages to habitat will be compensated within 5–10 years, and monitoring periods have been set accordingly. Our San Diego Bay study site, the Sweetwater Marsh National Wildlife Refuge, has one of the longest and most detailed records of habitat development at a mitigation site: data on soil organic matter, soil nitrogen, plant growth, and plant canopies for up to 10 years from a 12‐year‐old site. High interannual variation and lack of directional changes indicate little chance that targets will be reached in the near future. Other papers perpetuate the trajectory model, despite data that corroborate our findings. After reviewing “trajectory models” and presenting our comprehensive data for the first time, we suggest alternative management and mitigation policies.
Factors Affecting Revegetation of Carex lacustris and Carex stricta from Rhizomes
Authors: Yetka Leslie A. , Galatowitsch Susan M. 
Published: March 2003

AbstractThe revegetation of sedge meadows has been problematic because natural recolonization does not occur under many circumstances and because planted propagules often fail to reestablish successfully. In this study, detached rhizomes of Carex lacustris Willd. and Carex stricta Lam. were transplanted in both fall (September) and spring (May) into three experimental wetlands to determine the effects of both planting season and hydrology on survival and establishment. Each experimental wetland had the same mean water depth across 5% slopes, but one had a constant water depth (0.5 m) throughout the growing season, another fell from a mean depth of 0.75 m to 0.25 m, and a third rose from a mean depth of 0.25 m to 0.75 m. Initial rhizome survival, shoot growth, and soil characteristics were recorded over 2 years. Neither planting proved successful (6.9% versus 0.5%) for C. stricta, a tussock‐forming sedge. For C. lacustris, a sedge with spreading rhizomes, spring planting had greater rhizome survival (53.2% survival) than fall planting (0.7%). Since both species initiate new shoots in the fall, they are susceptible to transplant failure during this season. The highest survival rates (71–100%) and plant production (736.0 and 494.5 g/m2) for C. lacustris occurred near the water’s edge in both the constant and falling basins. In the rising basin, establishment and growth of this species was high at all water depths (71–96%; 399 g/m2). C. lacustris grew optimally at the same elevations where rhizome survival was greatest, suggesting that shoots are more sensitive to early‐season than late‐season water levels.
Nurse Plants, Mycorrhizae, and Plant Establishment in a Disturbed Area of the Sonoran Desert
Authors: Carrillo‐Garcia Á. , De La Luz J.‐L. León , Bashan Y. , Bethlenfalvay G. J. 
Published: March 2003

AbstractArbuscular‐mycorrhizal (AM) fungi stabilize the soil and enhance plant growth by alleviating nutrient and drought stress. Their contributions to agriculture are well known, but their role in desert ecosystems has received less attention. The AM status of perennial plants in disturbed and undisturbed plots were investigated in the Sonoran Desert near La Paz, Baja California Sur, Mexico to determine if AM fungi contribute to resource‐island stability and plant establishment. All perennial plants (46 species) in the study plots were AM, but root colonization varied widely (<10 to> 70%). Roots of plants that established in greatest numbers in plant‐free zones (colonizers) of disturbed areas were highly AM. Plants with trace (<10%) root colonization (cacti of the tribe Pachycereae: Pachycereus pringlei,Machaerocereus gummosus, andLemaireocereus thurberi;andAgave datilyo) established preferentially in association with nurse trees. The pachycereid cacti grew underProsopis articulataandA. datilyounderOlneya tesotacanopies. Of the nine species of trees and arborescent shrubs in the area, the mature (>20 yr) nurse‐legumesP. articulataandO. tesotasupported the largest number of under‐story plants. Younger plants had only occasional associates. AM propagule densities in plant‐free areas were lower than under plant canopies (40 vs. 280 propagules/kg soil). Occurrence of soil mounds (islands) under plants owing to soil deposition was related to the nature of the canopies and to the AM status of the roots. Island soils were enmeshed with AM‐fungal hyphae, especially in the upper layer (approximately 10 cm). Seedlings ofP. pringlei, growing in a screenhouse for six months in soil collected underP. articulata, had a biomass ten times greater than plants growing in bare‐area soil. The results are consistent with the proposition that AM fungi contributed to the plant‐soil system of our study area by: (1) helping to stabilize windborne soil that settles under dense plant canopies; (2) enhancing the establishment of colonizer plants in bare soils of disturbed areas; and (3) influencing plant associations through differences in the mycotrophic status of the associates.
Translocation of Herb‐Rich Grassland from a Site in Wales Prior to Opencast Coal Extraction
Authors: Good J. E. G. , Wallace H. L. , Stevens P. A. , Radford G. L. 
Published: March 2003

AbstractReinstatement of vegetation to a similar condition to that prior to disturbance is often required in industrial restoration schemes. Seeding with specially prepared seed mixes containing species suited to local soils is often the preferred option on grounds of practicality and cost. Turf translocation is more difficult and costly but, if successful, meets the reinstatement requirement more precisely. In a pilot study at a proposed opencast coal site in Wales, we compared the effectiveness of whole‐turf translocation of herb‐rich mesic grassland communities, with a less technically demanding and more cost‐effective technique involving spreading turf over twice the area at the receiver site and rotovating it into the underlying soil. The translocated whole turf and rotovated turf plots were cut annually and the vegetation removed to simulate grazing that had occurred prior to translocation. Both the whole‐turf and rotovated turf transplant techniques gave successful re‐establishment of 50% or more of the species originally present. After three years, the cover and species composition were similar in “whole‐turf” and “spread and rotovated” plots. This suggests that the “spread and rotovate” technique provides a satisfactory ecological alternative to whole‐turf translocation. However, plant communities changed, in some cases substantially, after translocation using either technique. Altered soil hydrology and nutrition combined with the substitution of cutting for grazing are probably the main causes of these changes.
Recovery of Bird Species in Minimally Restored Indonesian Tin Strip Mines
Authors: Passell Howard D. 
Published: March 2003

AbstractBird species richness and individual abundances were recorded in old, unrestored tin strip mine plots, in mined plots restored 1, 2, and 3 years before the study, and in adjacent, unmined, natural secondary forest plots on the 11,340‐km2Indonesian island of Bangka (2°S, 106°E). The objective was to assess the ecological recovery of unrestored and minimally restored mine plots compared with surrounding reference forest. Unrestored mines had not been mined or used for any other purpose for 14–30 years; plots in their first, second, and third year since restoration were old mines planted withAcacia mangium(Leguminosae) at a density of 400 trees/ha. Natural secondary forest plots 20 or more years since the last disturbance were immediately adjacent to both unrestored and restored plots. Bird surveys on 4‐ha plots were performed during the 1995 breeding season. A comparison of data from unrestored plots of widely varying ages showed no significant differences among them for species richness, diversity (Shannon–Wiener index, H′), or individual abundance, indicating that little natural bird community recovery had occurred over time in the plots. However, increases did occur in restored sites over only 3 years for both species richness (r 2=0.29, p=0.04) and diversity (r 2=0.45, p=0.009). All values for third‐year restored plots, however, were still significantly lower than corresponding values for adjacent natural secondary forest plots. The quick return of bird activity on the plots after minimal efforts at restoration supports the idea that simple, inexpensive restoration can be effective for “jump starting” degraded systems at large scales. Such a restoration strategy might be of particular value for degraded land in developing nations, where scientific, professional, and financial resources might be in short supply. Using this strategy, a small number of restoration professionals could mobilize the labor of many local people in many areas, serving to both improve ecological systems and to educate and engage local populations in restoration and conservation projects.
Topsoil Handling and Storage Effects on Woodland Restoration in Western Australia
Authors: Rokich Deanna P. , Dixon Kingsley W. , Sivasithamparam K. , Meney Kathy A. 
Published: March 2003

AbstractAn analysis of the effects of topsoil handling and storage methods was undertaken to optimize the potential rehabilitation of southwest Western Australian Banksia woodland species present before site disturbance. An increase in the depth of topsoil stripped from the Banksia woodland, from 10 to 30 cm, correlated to decreasing seedling recruitment from the soil seedbank by a factor of three following in situ respreading in an area to be restored. There was no significant difference in total seedling recruitment in situ at two depths of spread, 10 cm and 30 cm. These results concur with an ex situ trial on the effects of depth of seed burial on seedling recruitment that showed most species failed to emerge from depths greater than 2 cm. In situ stockpiling of the woodland topsoil for 1 or 3 years demonstrated a substantial and significant decline in seedling recruitment to 54% and 34% of the recruitment achieved in fresh topsoil, respectively. Stripping and spreading during winter substantially depressed seedling recruitment, compared with autumn operations, as did in situ stockpiling followed by spreading in the wet season, or stockpiling in winter followed by spreading in spring. No loss in total seedling recruitment occurred when replaced topsoil and subsoil were ripped to 80 cm following spreading of topsoil in sites to be restored. Conclusions from this study are that (1) topsoil provides a useful source of seeds for rehabilitation of Banksia woodland communities in the southwest of Western Australia, (2) correct handling of the topsoil, stripped and replaced fresh and dry (autumn direct return) to the maximum depths of 10 cm, can be used to optimize revegetation of species‐rich plant communities with this type of seedbank, and (3) ripping of topsoil and subsoil to ease compaction of newly restored soils does not diminish the recruitment potential of the soil seedbank in the replaced topsoil.
Design and Implementation of Monitoring Studies to Evaluate the Success of Ecological Restoration on Wildlife
Authors: Block William M. , Franklin Alan B. , Ward James P. , Ganey Joseph L. , White Gary C. 
Published: March 2003

AbstractRestoration projects are often developed with little consideration for understanding their effects on wildlife. We contend, however, that monitoring treatment effects on wildlife should be an integral component of the design and execution of any management activity, including restoration. Thus, we provide a conceptual framework for the design and implementation of monitoring studies to understand the effects of restoration on wildlife. Our underlying premise is that effective monitoring hinges on an appropriate study design for unbiased and precise estimates of the response variables. We advocate using measures of population dynamics for response variables given that they provide the most direct measures of wildlife status and trends. The species to be monitored should be those constituting an assemblage of umbrella species that represent the range of spatial and functional requirements of wildlife in a restored ecological system. Selection of umbrella species should be based on strong empirical evidence that justifies their usage. We also advocate that monitoring be designed as true experiments or quasi‐experiments rather than as observational studies to allow for stronger inferences regarding the effects of restoration on wildlife. Our primary message is that if monitoring is to be done, it must be scientifically based.
Microbial Biomass‐C in Reclaimed Soil of the Rhineland (Germany) and the North Bohemian Lignite Mining Areas (Czech Republic): Measured and Predicted Values
Authors: Růžek L. , Voříšek K. , Sixta J. 
Published: March 2003

AbstractThis article compares reclaimed soils in the Rhineland lignite mining area, Germany (RA) and in the north Bohemian brown coal basin, Czech Republic (NBB). Because of highly significant differences of physical and chemical characteristics (RA was characterized by lower content of sand, clay, soil organic carbon, and total nitrogen) between both analyzed areas, the content of microbial biomass carbon (CMB) differs significantly (p < 0.01): RA: 241.17 ± 96.50 μg C/g dry soil; NBB: 424.42 ± 136.23 μg C/g. Extracellular microbial carbon (CEX) was also significantly higher in RA than NBB. The measured CMB values from both mining areas were verified using two empirical mathematical models. Because our former model (used for evaluation of NBB) did not fit soils with low organic carbon content (0.10–0.80%), a new model was proposed. For evaluation of RA reclaimed sites the measured, model‐predicted, and calculated values were used. The best site in RA was Dürwiss Deponie (site 18 near Eschweiler), reclaimed in 1965 and characterized by good soil physical parameters (sand 4%, silt 77%, and clay 19%). In NBB undisturbed soils were the best, together with the site of Úžín (site 2 near Ústí and Labem), reclaimed in 1964, where high‐quality reclamation management resulted in high biological activity. According to biological criteria, the best management practice in NBB was use of high‐quality loam overlaying montmorillonite clayey subsoil. In RA direct reclamation of high‐quality loess with low content of sand also gave good results.
Does Weeding Promote Regeneration of an Indigenous Tree Community in Felled Pine Plantations in Uganda?
Authors: Chapman Colin A. , Chapman Lauren J. , Zanne Amy , Burgess Matthew A. 
Published: March 2003

AbstractThe use of plantations to manage extensive tracks of deforested lands in the tropics is a conservation strategy that has recently received considerable attention. Plantation trees can promote seed dispersal by attracting dispersers and creating favorable site conditions, leading to increased germination and establishment of indigenous trees. Subsequently, plantation trees can be harvested for profit or left to senesce, leaving a native tree community. We evaluated the effect of vine, grass, and shrub cutting (weeding) over a 3‐year period on regeneration of indigenous trees subsequent to the removal of plantation softwoods in Kibale National Park, Uganda. Counter to what would be expected if weeding released trees from competition, we found no difference in the total number of stems or in the stems greater than 10 cm diameter at breast height between control and weeded plots; there were more stems greater than 1 cm diameter at breast height in the control plots. For species found in both control and weeded plots, the maximum size of individuals did not differ. At the end of the study, 61 species were found in the control plots and 43 species were found in the weeded plots, and in both types of plots the three most abundant species were the same. The number of species and stems classified as early or middle successional species did not differ between weeded and control plots. The fact that weeding did not promote regeneration of indigenous trees after the removal of plantation trees illustrates the importance of evaluating and field‐testing potential management options.