bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional assessment of myoblast transplantation for cardiac repair with magnetic resonance imaging
Authors: van den Bos Ewout J. , Thompson Richard B. , Wagner Anja , Mahrholdt Heiko , Morimoto Yoshihisa , Thomson Louise E.J. , Wang Lynn H. , Duncker Dirk J. , Judd Robert M. , Taylor Doris A. 
Published: April 2005

Background:Contraction of transplanted myoblasts and their effects on function and remodeling after myocardial infarction remain controversial.Aim:We used magnetic resonance imaging (MRI) to study wall thickening and left ventricular (LV) function and geometry after myoblast transplantation.Methods and results:Three weeks after cryo‐infarction rabbits were randomized to receive an injection of ∼2×108 myoblasts (n=8) or medium (n=9) into the scar. Cine MRI and contrast enhanced (ce) MRI images were acquired before injection (baseline) and 4 weeks later (endpoint). Regional wall thickening was measured at the site of transmural hyperenhancement. In the control group, regional wall thickening decreased to −15.3±8.6% at baseline, which further decreased to −18.3±5.7% at endpoint. Further, end‐diastolic volume increased from 3.96±0.27 to 5.00±0.46 ml and end‐systolic volume from 2.23±0.19 to 2.96±0.30 ml (both P<0.05 vs. baseline), which was accompanied by increased LV wall volumes (P<0.05 vs. baseline). In contrast, myoblast transplantation increased regional wall thickening from −11.9±15.9% at baseline to 26.9±17.0% (P<0.05 vs. control), which resulted in significantly improved two‐dimensional ejection fractions at the infarct level and prevented the increase in end‐diastolic and end‐systolic volumes and wall volume.Conclusion:Intracardiac myoblast transplantation after myocardial infarction improves regional wall thickening and prevents progressive left ventricular remodeling.
The B‐Lynch and other uterine compression suture techniques
Authors: Allam M.S. , B‐Lynch C. 
Published: April 2005

AbstractBackgroundPostpartum hemorrhage (PPH) remains among the 5 main causes of maternal death in developing and developed countries, and uterine atony is the most common cause (75–90%) of primary PPH. Uterine compression sutures running through the full thickness of both uterine walls (posterior as well as anterior) have recently been described for surgical management of atonic PPH. Christopher B‐Lynch was the first to highlight this revolutionary principle, and other uterine compression suture techniques have since been described by Hayman and Cho.ObjectivesStep‐by‐step description of the B‐Lynch brace suture and discussion of the current compression suture techniques.ConclusionsThe different uterine suture techniques have proved to be valuable and safe alternatives to hysterectomy in the control of massive PPH, and the present review can make the surgeon better aware of their effective use and the risks they may entail.
Histomorphology and microradiography of quadriceps tendon–patellar bone grafts in press‐fit anterior cruciate ligament reconstruction
Authors: Dargel Jens , Schmidt‐Wiethoff Rüdiger , Schmidt Joachim , Koebke Jürgen 
Published: April 2005

AbstractThe press‐fit fixation technique has become an alternative fixation method in anterior cruciate ligament (ACL) reconstruction. While the stability of press‐fit fixated grafts reported in the literature predominantly had been analysed by biomechanical testing, this study investigated the specific histomorphologic and microradiographic features important for graft stability, using human quadriceps tendon–patellar bone (QTPB) grafts. Six QTPB grafts with cylindrical bone plugs were obtained from frozen fresh human cadaver knees and fixed to porcine, bovine, or human femora in a press‐fit technique. The specimens were plastinated, dissected into 1.5 mm slices, studied microradiographically and stained for histologic evaluation. The specimens showed an osseous inclusion of the graft within the femoral tunnel, which was most evident on the cancellous side. Histologic analysis revealed a trabecular interdigitation with a penetration of patellar and femoral trabecular structures, contributing to primary stability of the press‐fit fixation. Graft inclusion was most obvious in bovine and least in human femora, assumably because of varying bone quality. The circular bone‐to‐bone contact in press‐fit fixation technique should contribute to both rapid and stable graft healing. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
A single systemic dose of pamidronate improves bone mineral content and accelerates restoration of strength in a rat model of fracture repair
Authors: Amanat Negin , Brown Richard , Bilston Lynne E. , Little David G. 
Published: April 2005

AbstractComplications in fracture repair that lead to a delay in union remain clinically problematic. We believe that unwanted pre‐mature catabolism of the healing callus, for example, in stress shielded situations, diminishes the rate at which strength is restored in bone repair and possibly leads to delayed union. We hypothesized that a single systemic dose of a nitrogen‐containing bisphosphonate (N‐BP) would increase bone mineral content (BMC), volume, and mechanical strength of union in fracture repair. We also set out to investigate local delivery to assess whether systemic exposure could be eliminated, due to concerns of bisphosphonate dosing of non‐target organs. After an open osteotomy fixed with a K wire, 40 12‐week old Wistar male rats were divided into four groups of 10: saline control, bolus systemic subcutaneous injection of pamidronate (3 mg/kg), local low dose of pamidronate (0.1 mg), and a local high dose of pamidronate (1.0 mg). Rats were sacrificed 6 weeks post‐operatively. Operated and non‐operated femora underwent radiographic evaluation, quantitative computer tomography, and biomechanical testing in torsion. The growth plates and metaphyses of the tibia of the non‐operated side were assessed for evidence of systemic exposure in the local groups. Significant increases in callus BMC and volume of the bolus systemic dose group were found compared to the saline control (p ⩽ 0.05). Further, the strength of the systemic dose callus was increased by 60% from 0.35 Nm (±0.11) for the saline control callus to 0.56 Nm (±0.25) for the systemic group (p = 0.05). Local treatment did not result in increased strength. The contralateral tibial growth plates of the local groups showed evidence of systemic exposure by the presence of retained primary spongiosa. This study confirms that a single perioperative systemic dose of pamidronate leads to significant increases in the BMC, volume, and strength of healing fractures in rats, making single dose N‐BP therapy an appealing candidate for further examination in fracture repair. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Callose synthase (CalS5) is required for exine formation during microgametogenesis and for pollen viability in Arabidopsis
Authors: Dong Xiaoyun , Hong Zonglie , Sivaramakrishnan Muthuswamy , Mahfouz Magdy , Verma Desh Pal S. 
Published: April 2005

SummaryCallose (β‐1,3‐glucan) is produced at different locations in response to biotic and abiotic cues. Arabidopsis contains 12 genes encoding callose synthase (CalS). We demonstrate that one of these genes, CalS5, encodes a callose synthase which is responsible for the synthesis of callose deposited at the primary cell wall of meiocytes, tetrads and microspores, and the expression of this gene is essential for exine formation in pollen wall. CalS5 encodes a transmembrane protein of 1923 amino acid residues with a molecular mass of 220 kDa. Knockout mutations of the CalS5 gene by T‐DNA insertion resulted in a severe reduction in fertility. The reduced fertility in the cals5 mutants is attributed to the degeneration of microspores. However, megagametogenesis is not affected and the female gametes are completely fertile in cals5 mutants. The CalS5 gene is also expressed in other organs with the highest expression in meiocytes, tetrads, microspores and mature pollen. Callose deposition in the cals5 mutant was nearly completely lacking, suggesting that this gene is essential for the synthesis of callose in these tissues. As a result, the pollen exine wall was not formed properly, affecting the baculae and tectum structure and tryphine was deposited randomly as globular structures. These data suggest that callose synthesis has a vital function in building a properly sculpted exine, the integrity of which is essential for pollen viability.
An essential function of phosphatidylinositol phosphates in activation of plant shaker‐type K+ channels
Authors: Liu Kun , Li Legong , Luan Sheng 
Published: April 2005

SummaryA prominent regulatory property of plant shaker‐type K+ channels is the ‘rundown’ that causes channel closure upon membrane excision from the cell, implicating intracellular factor(s) in maintaining channel activity. One such factor has been identified as hydrolysable ATP‐Mg although the mechanism for ATP function remains unknown. Here we report identification of phosphatidylinositol (PI) phosphates (PIPs) as essential regulators for the voltage‐dependent and ‐independent activation of plant shaker‐type channels such as SKOR, an outward rectifying K+ channel. Inhibition of PI kinase activity abolished the function of ATP‐Mg in restoration of rundown channel activity, demonstrating that PIPs production by PI kinases and ATP‐Mg underlies ATP‐induced activation of the rundown channel. We also identified aluminum block as a common feature of the plant shaker‐type channels and provided evidence that aluminum block of these channels may result from Al interaction with PIPs.
New Perspectives on the Pelagic Stage of Sea Turtle Development
Authors: CARR ARCHIE 
Published: April 2005

Abstract: An original difficulty in accepting the idea of a pelagic diwelopmental period for sea turtles was to explain bow food could be found in reliable supply in the open ocean The uncertainty that this introduced was removed when I belatedly came to appreciate the prevalence and diversity of convergences where downwelling gathers and aligns buoyant material, including the dispersed food mources of the surface waters. Thus, it now seems clear that an essential factor in the survival of young sea turtles–and of other elements of the epipelagic; open‐ocean fauna as well–is the accessibility of a front; where inanimate debris and any floating animal or plant will be gathered to.This new evidence of complexity in the lost‐year ecology of sea turtles has important implications for their conservation and management. It is now obvious that when young cultured sea turtles are released in so‐called bead‐starting projects, the release sites ought to be chosen with the greatest care. Shores located at a distance from any major current or its eddy ought to be avoided. It is also necessary to avoid release localities where the convergence habitat may carry heavy loads of pollutants.Results of the present work reveal an urgent need for further study of sea turtle life cycles, with special attention to their developmental ecology The growing evidence for a more protracted pelagic stage, during which the juvenile turtles are passive migrants in fronts that are increasingly invaded by debris and toxic wastes, emphasizes the need for a better understanding by marine biologists of the organization of the driftline habitat and the behavioral ecology of its occupants Until these studies of the oceanography and biology of driftlines are done, we are bound to remain peculiarly ignorant of the ecologic organization of three‐fifths of the surface of the earth.
Conservation Lessons from Long‐Term Studies of Checkerspot Butterflies
Authors: EHRLICH PAUL R. , MURPHY DENNIS D. 
Published: April 2005

Abstract: Long‐term studies of checkerspot butterflies (Euphydryas spp.) are used to draw conservation lessons with implications for the design and management of reserves for invertebrates We discuss;

The importance of determining the structure of and patterns of mating within demographic units
The lack of congruence between migration and gene flow.
The crucial role of habitat diversity in the protection of species which otherwise require only small areas of habitat
The importance of identaDing and preserving “reservoir” populations within metapopulations
The necessity of identifying subtle habitat requirements
The key role of environmental stochasticity in the extinction of small populations.
The difficulty of protecting metapopulations and of in ‐hoducing populations into “empty” habitat patches

We conclude, among other things, that the size of reserves required to preserve herbivorous insects is often underestimated; that a “minimum viable metapopulation” approach to their conservation may be needed; that long‐term studies of the biology of populations of sample invertebrate groups would greatly aid conservation biologists; and that more effort is needed to inform the public and decision makers about the need to conserve populations as well as species.
Effects of Kenya's Bura Irrigation Settlement Project on Biological Diversity and Other Conservation Concerns
Authors: LEDEC GEORGE 
Published: April 2005

Abstract: The Bura Irrigation Settlement Project was designed to settle landless farmers and grow irrigated cotton for export in a remote, semiarid region of Kenya Over $100 million* has been invested by the Kenya government, World Bank, Britain's Overseas Development Administration, Finland's FINNIDA, The Netherlands, Commonwealth Development Corporation, and European Development Fund. The project has been plagued by a wide range of financial, managerial, and technical problems, and has been economically disappointing. Some of the disappointing economic performance is linked to the almost complete lack of concern for forestry, wildlife, and other environmental issues during most stages of project implementation.The riverine (gallery) forests of the Tana River represent a biologically unique ecosystem in a semiarid region of Kenya The irrigated areas developed under the Bura project have not been situated on riverine forest lands. Nonetheless, the project seriously threatens the long‐term survival of all the nearby riverine forest owing to the acute shortage of fuel‐wood in the region. This shortage has occurred largely because the planned fuelwood plantations have been neglected.
Gradient Analysis in Nature Reserve Design: A New Zealand Example
Authors: DeVELICE ROBERT L. , DeVELICE JEAN WARD , PARK GEOFF N. 
Published: April 2005

Abstract: Direct and indirect gradient analysis methods were tested to assist in nature reserve design in New Zealand Graphic descriptions were made of community‐environment relationships. Environmental factors considered included altitude, solar radiation, geologic substrate, soil drainage, and landformClassification identified 21 lowland forest community types in the northwestern South Island study area. These community types and their composite species appear to be arranged along soil fertility, landform, and temperature gradients. Direct gradient analysis was particularly useful in portraying the relationship of the plant communities to perceived environmental gradients.Comprehensive gradient diagrams for an ecological district may be compared with gradient diagrams depicting the districts current reserves, if any. A representative reserve system may be achieved if “gaps” between the two diagrams are filled in by expanding the reserve system and/or modifying existing reserve boundaries. Based on this technique, a recommendation is made to incorporate a unique coastal forest remnant in a national park proposal for the study area.
Changes in Wildlife Communities Near Edges
Authors: YAHNER RICHARD H. 
Published: April 2005

Abstract: Wildlife managers and land managers have traditionally considered edges as beneficial to wildlife because species diversity generally increases near habitat edges. Explanations for this edge effect include greater vegetative complexity at edges or the simultaneous availability of more than one landscape element. However, edges can have negative consequences for wildlife by modifying distribution and dispersal and by increasing incidence of nest predation and parasitism Edges also may be detrimental to species requiring large undisturbed areas because increases in edge generally result in concommitant reductions in size and possible isolation of patches and corridots. Thus, both wildlife and land managers should be cautious when describing the benefits of edges to wildlife: particularly when dealing with species that require forest interiors.Changes in wildlife communities associated with habitat edges are not easily assessed because defining edge species and measuring edge dimensions can be difficult in field studies Also, there is no general consensus as to how edge effect is best measured. Well‐designed long‐term studies of edges in various landscapes are needed (1) to better understand the positive and negative impacts of edges on wildlife communities, guilds, or key species, and (2) to effectively quantify edge effect and thereby develop management recommendations to improve the quality of edges for wildlife. Additional studies of edge effect are timely because greater amounts of edge will continue to be created in future landscapes due to extensive agriculture and other land‐use‐practices, and because developing knowledge in conservation biology and landscape ecology will facilitate multidisciplinary approaches to edge and landscape management for the benefit of wildlife.
Forests Too Deer: Edge Effects in Northern Wisconsin
Authors: ALVERSON WILLIAM S. , WALLER DONALD M. , SOLHEIM STEPHEN L. 
Published: April 2005

Abstract: Browsing by white‐tailed deer (Odocoileus virginianus) can profoundly affect the abundance and population structure of several woody and herbaceous plant species. Enclosure studies and population surveys reveal that past and current deer densities as low as 4 deer/km2 may prevent regeneration of the once common woody species, Canada yew (Taxus canadensis), eastern hemlock (Tsuja canadensis), and white cedar Puja occidentalis), as well as several herbaceous species. Prior to European settlement, forests in northern Wisconsin contained relatively sparse deer populations (<4/km2), but extensive timber cutting in the late nineteenth century boosted deer populations. Continued habitat fragmentation resulting from scattered timber harvests and the creation of “wildlife openings” to improve deer forage maintain these high densities throughout much of the Northeast.Because deer wander widely, the effects of high deer densities penetrate deeply into remaining stands of old and mature forest, greatly modifying their composition Thus, abundant early successional and “edge” habitat, and the high deer densities they engender, represent significant external threats to these plant communities. We hypothesize that establishing large (200–400 km2) continuous areas of maturing forest, especially in conjunction with increased hunting, could reduce local deer densities and so provide a simple and inexpensive method for retaining species sensitive to the deleterious effects of browsing.
Tsetse Flies in Africa: Bane or Boon?
Authors: ROGERS DAVID J. , RANDOLPH SARAH E. 
Published: April 2005

Abstract:This paper examines the changing perception of the role of the tsetse fly in the development of tropical Africa. The trypanosomiases transmitted by this group of vector insects historically prevented the establishment of mixed (i.e., arable and livestock) farming and thus the occurrence of an agricultural revolution within the potentially more productive humid zones of the continent. Initially the colonial powers saw the tsetse as the bane of African development, and much of colonial policy was aimed at eradicating the vectors directly or at eliminating the diseases they transmit. The observation of inefficient farming techniques in the fly‐infested areas, coupled with overstocking of cattle in the fly‐free areas, generally led to naive development plans that often exacerbated the very problems they aimed to solve. The presence of the tsetse fly, however, prevented these mistakes from being more widespread and thus now provides a window of opportunity for sensible development that acknowledges the uniqueness of African soils and ecosystems. Ecologists can play a vital role in this process, although the absence of relevant hard data still retards progress.
Estimating the Distribution and Abundance of a Cryptic Species, Dipodomys stephensi(Rodentia: Heteromyidae), and Implications for Management
Authors: PRICE M. V. , ENDO P. R. 
Published: April 2005

Abstract:A common hurdle in developing conservation plans for endangered species threatened by habitat loss is lack of basic information on distribution and factors affecting population densities. Such information is time‐consuming and expensive to obtain for cryptic species, such as nocturnal small mamma whose presence at a site can only be determined through intensive sampling. We illustrate how readily‐available soils maps can be used to estimate the potential distribution of such a species, Stephens' kangaroo rat. In this case, the distribution map accurately predicts presence or absence of this species at 70% of sites. Our maps reveal extensive habitat loss and fragmentation. Data from repeated censuses at several sites indicate that population densities of this species can vary more than 10‐fold in response to rainfall patterns, and that temporal fluctuations in geographically separated populations are correlated. These results suggest that habitat subdivision is unlikely to substantially increase expected time to extinction for the species as a whole; habitat conservation efforts for Stephens’kangaroo rat should therefore be directed at establishing a few large, widely separated reserves, rather than many smaller reserves.
Trends in Landscape Heterogeneity Along the Borders of Great Smoky Mountains National Park
Authors: AMBROSE JONATHAN P. , P.BRATTON SUSAN 
Published: April 2005

Abstract:Border areas of Great Smoky Mountains National Park were examined in a photogrammetric study of temporal trends in landscape heterogeneity. Analysis of data from maps and aerial photographs showed that from 1940 to 1978, most areas outside the park borders experienced an increase in forest patch density and cleared patch density, a decrease in forest patch size and little change in percentage of forest cover Areas inside the park borders showed an increase in forest patch size and percentage of forest cover, and a decrease in density of forested and cleared patches.Significant differences in spatial continuity of vegetation existed between areas inside and outside the park borders at the time of the park's establishment. Land use changes since 1940 have increased differences in landscape heterogeneity between park and nonpark lands. The areas of greatest change haw generally been those in closest proximity to the legal park border, where relatively sharp gradients in patch size, patch density, and forest cover now exist. Differences in landscape heterogeneity between adjacent lands outside the park have decreased as have differences between adjacent park lands.Local variations in land use history have influenced the nature and intensity of boundary effects along the park border Different sections of the park border vary greatly in both spatial patterns and temporal trends in landscape heterogeneity. The results of the study point to the limited utility of the island biogeographic model in predicting management problems in this park.