bluuebunny/crossref_metadata_2025_split huggingface dataset:
Invasion and Extinction: The Last Three Million Years of North Sea Pelecypod History
Authors: VERMEIJ GEERAT J. 
Published: April 2005

Abstract:Biotic interchange occurs when two or more biotas with separate evolutionay histories come together as barriers between them become less effective. The idea that extinction of species often accompanies invasion of species during biotic interchange is rooted in the view that the success of invasion is controlled largely by competition or predation among newcomers and native species. An analysis of the stratigraphical ranges of pelecypod species from the Pliocene and Pleistocene of the North Sea Basin revealed that the magnitude of extinction is not cowelated with the absolute number of species invading from the North Pacific following the opening of the Bering Strait during the Middle Pliocene or from the Mediterranean during the Early Pleistocene, and that North Pacific invaders and native North Sea species were equally susceptible to extinction during the Early Pleistocene. I suggest that, although invasion may result in populational and ecological shifts in the recipient biota, it should rarely bring about extinction among marine species because marine competitors and predators are almost never 100 percent successful in locating and killing their victims, and because marine populations tend to be large. The fact that many invaders from the North Pacifc and Mediterranean first became established in the North Sea during the Pleistocene points to the possibility that the reoccupation of the North Sea by marine organisms following periods of emergence provided unusually good opportunities for the successful invasion of foreign species.
Cyclic Drought, Dispersal, and the Conservation of the Snail Kite in Florida: Lessons in Critical Habitat
Authors: TAKEKAWA JEAN E. , BEISSINGER STEVEN R. 
Published: April 2005

Abstract:Studies of the dispersal of the Florida Snail Kite, an endangered hawk that inhabits flooded wetlands and feeds almost solely on apple snails, illustrate the problems associated with protecting habitats for migratoty and wandering species with disjunct habitat requirements. Before a drought in 1985, most kites 2oere sighted in the large tracts of Everglades that were used for nesting. During the drought however, 60 percent of the sightings of kites reported to our sighting hotline were from smaller wetlands and other drought‐related habitats, mostly in Palm B e d and surrounding counties Although these small wetlands are important emergency habitats used by kites to suruive during drought, they are not designated as “critical habitat” and are being developed at a rapid rate We discuss the problems of uncertainty, cumulative effects, and compromise in theprocess of evaluating development proposals and protecting small; isolated habitats. We identify key sites used by kites during drought and suggest ways to conserve this species in Florida by mitigating drought‐induced population crashes The usefulness of sighting hotlines for assessing dispersal data is also evaluated.
The Population Dynamics and Conservation of Primate Populations
Authors: DOBSON ANDREW P. , LEES ANNA MARIE 
Published: April 2005

Abstract: Primates are among the most threatened taxa, with more than half of all species in jeopardy. In this paper we develop population models to use the kind of data on wild primates that primatologists actually collect. Our survey of recentprimate journals suggests that the average field study uses 1.5 years of data from 50 animals The models are based on the simple Leslie‐Lefkovitch matrix. They suggest a simple method that allows assessment from a few years’data, of whether a population is collapsing and requires intervention To a good approximation, populations will collapse when adult survival, per inter‐birth interval, is less than 70 percent.Modifications of the basic model incorporate more realistic assumptions about social organization and densitydependent resource limitation. These allow us to identify population densities at which potential Allee effects operate, and permit more precise estimates of the minimum population sizes and compositions required for successful reintroductions to the wild The most important result is that populations of primates that live in small family groups may be more prone to “demographic” extinction than are more promiscuous species that live in more extended groups.
Viable Populations, Reserve Size, and Federal Lands Management: A Critique
Authors: GRUMBINE R. EDWARD 
Published: April 2005

Abstract:An examination of current viable population theories and reserve size studies suggests that biological diversity for North American national parks and forests is inadequately protected This conclusion is further supported by reviews of federal agency management plans and policies. Preservation of biodiversity is thwarted by lack of landscape–level management, insufficient data, competition between federal land management agencies, and bureaucratic inertia, among other factors. To dress these problems, an ecosystem management model for reform is outlined New legislation is also suggested. Ethical and social choices are recognized as the basis for any restructuring of land management to protect biodiversity.
The development of a quantitative enzyme‐linked immunosorbent assay to detect human platelet factor 4
Authors: Schraw Todd , Whiteheart Sidney 
Published: April 2005

BACKGROUND: Platelet factor 4 (PF4) is a marker for in vitro and in vivo tests of platelet (PLT) activation and α‐granule secretion. PF4 is also a major CXC cytokine released during storage. Cytokines released during PLT storage are a potential cause of nonhemolytic transfusion reactions. Quantitative measurement of PF4 requires an assay that is both reliable and sensitive. To achieve this goal, a sensitive, cost‐effective, sandwich enzyme‐linked immunosorbent assay (ELISA) was developed with commercially available antibodies to human PF4.STUDY DESIGN AND METHODS: An ELISA was developed for measuring PF4 from whole human PLTs or secreted from activated PLTs. Optimal concentrations of capture antibody, detection antibody, and enzyme‐conjugate were determined with serial twofold dilutions of recombinant PF4. This assay was used to determine the ideal sample dilutions needed for reliable quantitation of PF4 in releasates or from whole PLT extracts.RESULTS: Serial dilutions of recombinant PF4 resulted in a sigmoid titration curve with a maximal sensitivity of 10 pg and a dynamic quantitative range from 100 to 2500 pg. This ELISA was used to measure secretion from permeabilized PLTs stimulated with free calcium. In a secretion experiment with 2.5 × 10|*bsup*|8|*esup*| PLTs per mL, samples required a 1:10‐fold dilution to reliably evaluate α‐granule release.CONCLUSION: The parameters described yield an ELISA method with low background and high sensitivity over a range of PF4 concentrations. Using the commercial reagents described makes this assay cost‐effective and therefore suitable for analyzing multiple samples in the research setting.
Detection of bacteria in platelet concentrates: comparison of broad‐range real‐time 16S rDNA polymerase chain reaction and automated culturing
Authors: Mohammadi Tamimount , Pietersz Ruby N.I. , Vandenbroucke‐Grauls Christina M.J.E. , Savelkoul Paul H.M. , Reesink Henk W. 
Published: April 2005

BACKGROUND: Based on real‐time polymerase chain reaction (PCR) technology, a broad‐range 16S rDNA assay was validated and its performance was compared to that of an automated culture system to determine its usefulness for rapid routine screening of platelet concentrates (PCs).STUDY DESIGN AND METHODS: The presence of bacteria in pooled PCs was routinely assessed in an automated culturing system (BacT/ALERT, bioMérieux). The PCR assay was performed with DNA extracted from the same samples as used for culturing. DNA extraction was performed with a automated extraction system (MagNA Pure, Roche Diagnostics). PCR amplification was performed with a set of universal primers and probe targeting eubacterial 16S rDNA.RESULTS: A total of 2146 PCs were tested. Eighteen (0.83%) samples were found to be contaminated. These samples were positive for the presence of bacteria by both methods. All contaminants were identified as bacteria belonging to the common human skin flora. These included Propionibacterium spp. (n = 7), Staphylococcus spp. (n = 6), Bacillus spp. (n = 2), Micrococcus spp. (n = 2), and Peptostreptococcus spp. (n = 1). Estimation of the bacterial load in PCs by real‐time PCR showed that the initial levels of contamination varied between 13.6 and 9 × 104 colony‐forming unit equivalents per PCR procedure.CONCLUSIONS: Compared to culture in the BacT/ALERT system, the PCR assay had a sensitivity of 100 percent and a specificity of 100 percent. This real‐time PCR assay has a much shorter turnaround time of 4 hours, which offers the possibility to test and obtain results on PCs before release or the day they are transfused. This would permit the withdrawal of contaminated PCs before transfusion.
Pilot Study: Noninvasive Monitoring of Oral Flecainide's Effects on Atrial Electrophysiology during Persistent Human Atrial Fibrillation Using the Surface Electrocardiogram
Authors: Husser Daniela , Binias Karl‐Heinz , Stridh Martin , Sornmo Leif , Olsson S. Bertil , Molling Jochen , Geller Christoph , Klein Helmut U. , Bollmann Andreas 
Published: April 2005

Background: The relation between flecainide's plasma level and its influence on human atrial electrophysiology during acute and maintenance therapy of atrial fibrillation (AF) is unknown. Therefore, this study determined flecainide plasma levels and atrial fibrillatory rate obtained from the surface ECG during initiation and early maintenance of oral flecainide in patients with persistent lone AF and assessed their relationship. Methods and Results: In 10 patients (5 males, mean age 63 ± 14 years, left atrial diameter 46 ± 3 mm) with persistent lone AF, flecainide was administered as a single oral bolus (day 1) followed by 200–400 mg/day (days 2–5). The initial 300 mg flecainide bolus resulted in therapeutic plasma levels in all patients (range 288–629 ng/ml) with no side effects. Flecainide plasma levels increased on day 3 and remained stable thereafter. Day 5 plasma levels were lower (508 ± 135 vs 974 ± 276 ng/ml, P = 0.009) in patients with daily mean flecainide doses of 200 mg compared to patients with higher maintenance doses. Fibrillatory rate obtained from the surface electrocardiogram measuring 378 ± 17 fpm at baseline was reduced to 270 ± 18 fpm (P < 0.001) after the flecainide bolus but remained stable thereafter. Fibrillatory rate reduction was independent of flecainide plasma levels or clinical variables. Conclusion: A 300 mg oral flecainide bolus is associated with electrophysiologic effects that are not increased during early maintenance therapy in persistent human lone AF. In contrast to drug plasma levels, serial analysis of fibrillatory rate allows monitoring of individual drug effects on atrial electrophysiology.
Abiotic induction of susceptibility in insect‐resistant willow
Authors: Höglund Solveig , Larsson Stig 
Published: April 2005

AbstractPlants are mosaics of resource quality to insect herbivores. Some leaves are superior to others, resulting in variable insect performance. Certain Salix viminalis L. (Salicaceae) genotypes show an unusually strong resistance to the gall midge Dasineura marginemtorquens Bremi (Diptera: Cecidomyiidae). A few leaves are frequently galled on such resistant willows, whereas on the great majority of leaves all larvae die before any galls are formed. We performed a series of greenhouse and field experiments in order to understand in more detail the observed intraplant heterogeneity. First, we tested whether random events (biotic or abiotic) can induce a susceptibility that is expressed later (next season), i.e., delayed induced susceptibility. Second, we performed a combined field and greenhouse experiment to test the possibility that susceptibility was induced by abiotic factors at the time of gall induction (within days), i.e., rapid induced susceptibility. We found support for rapid induced susceptibility, but not for delayed induced susceptibility. Although resistance remained strong, significantly more leaves with surviving larvae and galls were found on potted plants moved to the field compared with identical plants that remained in the greenhouse. Potted field plants were exposed to field conditions during a very short period in connection with gall initiation. Thus, we can exclude soil moisture, nutrient availability, and the history of the plant as factors explaining the induction of susceptibility. We tentatively suggest that radiation interferes with the expression of resistance. Our findings suggest that plasticity in plant resistance may be linked to ambient light conditions, and that heterogeneity in leaf suitability can be of ecological significance in plants that are considered resistant.
Influence of leaf trichome density on the efficiency of two polyphagous insect predators
Authors: Björkman Christer , Ahrné Karin 
Published: April 2005

AbstractPlant characteristics, such as leaf structure or hairiness, are important for the movement and attachment of insects. It has been suggested that increased trichome density on new Salix cinerea L. (Salicaceae) leaves, produced after grazing by the willow leaf beetle Phratora vulgatissima L. (Coleoptera: Chrysomelidae), function as an inducible defence against the beetle and especially its larvae. Here we studied whether and how two of the main natural enemies of P. vulgatissima, viz., Anthocoris nemorum L. (Heteroptera: Anthocoridae) and Ortothylus marginalis L. (Heteroptera: Miridae), were influenced by trichome density on S. cinerea leaves. The effect of trichome density on these two predators was studied on plants with different trichome densities, comparing natural enemy efficiency, measured as number of P. vulgatissima eggs consumed or larvae missing and/or killed. To obtain different trichome densities, cuttings of several different clones of S. cinerea were used. In the experiment using eggs as prey, an increase in trichome density was, in addition, induced through leaf beetle defoliation on half of the plants of each willow clone. Furthermore, a field study was performed to investigate whether trichome density was correlated with natural enemy abundance. The results indicate that neither the efficiency of these two natural enemies in the greenhouse, nor their abundance in the field was influenced by trichome density. A well‐known behavioural difference between the two predator species could probably account for the higher disappearance of larvae after exposure to the more active predator. These findings are relevant for the development of pest management programs, not least because the enemies are polyphagous predators. It is concluded that an induced increase in leaf hairiness in willows in response to leaf beetle grazing could be a plant resistance trait worthy of further study in this system, because no negative effects on the main natural enemies were observed.
Inheritance and plasticity of adult host acceptance in Yponomeuta species: implications for host shifts in specialist herbivores
Authors: Hora Katja H. , Roessingh Peter , Menken Steph B.J. 
Published: April 2005

AbstractChanges in host acceptance is an important factor in the host specialization of phytophagous insects, and knowledge of the genetic organization of this behaviour is necessary in order to understand how host shifts occur. Here we describe the inheritance of adult host acceptance (oviposition) in three closely related species of Yponomeuta Latreille (Lepidoptera: Yponomeutidae), and their interspecific hybrids. Yponomeuta cagnagellus (Hübner), a specialist on Euonymus europaeus L. (Celastraceae), Y. malinellus Zeller, a specialist on Malus spp. (Rosaceae), and Y. padellus (L.), oligophagous on a number of Rosaceae, were tested for their acceptance of parental hosts in choice tests. Acceptance of E. europaeus is semi‐dominant in hybrids of Y. cagnagellus×Y. padellus, and in hybrids of Y. cagnagellus×Y. malinellus. The dominance of this acceptance was confirmed in oviposition tests with backcross hybrids: backcross hybrids F1 × Y. cagnagellus oviposited mainly on E. europaeus and F1 × Y. padellus still deposited more than half of their egg masses on E. europaeus. Reciprocal hybrids did not differ in their host acceptance, indicating that the trait is autosomal. We further studied the effect of larval food on adult host acceptance (‘Hopkins host selection principle’) in split full‐sib F1 families. Larval diet influenced oviposition only in one of two hybrid crosses. The F1 hybrid of Y. padellus× Y. cagnagellus, reared on Prunus spinosa L., deposited a significantly lower percentage of egg masses on E. europaeus compared to their full‐sib sisters fed with E. europaeus. We did not find this in the reciprocal cross. However, still more than half of the egg masses are deposited on E. europaeus by hybrids that have no experience on this host. We conclude that the semi‐dominant character of acceptance of E. europaeus and a tendency of Rosaceae‐feeding Yponomeuta to deposit egg masses on this host may have created the opportunity for the host shift of the predecessor of Y. cagnagellus from Rosaceae to the Celastraceae. This shift may have been further facilitated by a weak tendency of adults to oviposit on their larval food source.
The Canadian Keiretsu
Authors: Buckley F.H. 
Published: April 2005

This article describes the Canadian keiretsu, in which a main Chartered Bank dominates an interlocking group of corporate clients, investment dealers, trust companies, and professional advisors. Such a network facilitates information‐sharing and monitoring among group members, while also reducing the agency costs of banker misbehavior. Most major Canadian firms are members of a keiretsu, and stock ownership of Canadian corporations is far more concentrated than ownership of U.S. companies.Given their many similarities of history, law, and geography, Canada and the United States should have ended up with similar corporate ownership and governance structures. But they did not, and the difference was Canada's less restrictive banking and bankruptcy laws, which in turn can be traced to Canada's distinctly non‐populist historical experience.The Canadian keiretsu arose primarily for two reasons: (1) the larger concentration of commercial banking (the six largest Canadian banks today account for 98% of the industry's assets) allowed by Canadian law; and (2) the greater powers of Canadian secured lenders in the event of default. Unlike a U.S. Chapter 11 filing, in a Canadian bankruptcy the lender's right to assume control of the assets was not stayed until quite recently. And, even with the recent change in Canadian bankruptcy law, Canadian secured lenders have much stronger protection of their claims in bankruptcy than their U.S. counterparts in Chapter 11.
SECONDARY MARKET STABILIZATION OF IPOs
Authors: Wilhelm William J. 
Published: April 2005

Underwriting syndicates routinely “stabilize” the secondary market price for poorly received initial public offerings. Price stabilization practices, particularly the use of “penalty bids” aimed at discouraging immediate resale or “flipping” of IPO shares, recently have triggered litigation and attracted the attention of the regulatory community. Much of the attention has focused on the allegation that a disproportionate share of the burden of price stabilization efforts is borne by individual investors.After describing the various practices that fall under the rubric of price stabilization, this article provides several economic rationales for what is by definition a manipulative but legal practice. It also summarizes recently published evidence characterizing the winners and losers from price stabilization and presents a number of conclusions from a recent roundtable discussion among practitioners, regulators, and academics held at the Boston College Carroll School of Management that might serve as a guide to policymakers.
HOW CHANGES IN BOND CALL FEATURES AFFECT COUPON RATES
Authors: Stanhouse Bryan , Stock Duane 
Published: April 2005

In April 1998, Level 3, a telecommunications company, sold $2 billion of 9.19%, ten‐year bonds to finance the building of a fiber‐optic network. Like most below‐investment‐grade issues, as well as many investment‐grade issues, the Level 3 issue contained an embedded call option that gave the company the right to repurchase the bonds after five years at par value plus the (semi‐annual) coupon rate, with the call price declining to par two years before maturity.Because issuers must pay for the call provision in the form of a higher coupon rate, the choice of whether or not to include a call option can be a difficult one. And, once management decides to include a call option, it must then decide how to structure the call. The most important call structure decisions are how long to make the call protection period and how to set the call price—both of which can have a significant impact upon the coupon yields required to attract investors. Using a well‐known option pricing model, the authors of this article summarize their recent research on how variations in bond call features can be expected to affect par coupon yields of new issues under different market circumstances—circumstances that include market conditions relevant to option valuation such as the shape of the term structure and the volatility of interest rates.
Outer Membrane Protein P6 of NontypeableHaemophilus influenzaeIs a Potent and Selective Inducer of Human Macrophage Proinflammatory Cytokines
Authors: Berenson Charles S. , Murphy Timothy F. , Wrona Catherine T. , Sethi Sanjay 
Published: April 2005

ABSTRACTInteractions of nontypeableHaemophilus influenzae(NTHI) with human macrophages contribute to the pathogenesis of NTHI-induced infection in humans. However, the immunologic mechanisms that initiate and perpetuate NTHI-mediated macrophage responses have not been well explored. Outer membrane protein (OMP) P6 is a conserved lipoprotein expressed by NTHI in vivo that possesses a Pam3Cys terminal motif, characteristic of immunoactive bacterial lipoproteins associated with Toll-like receptor signaling. We theorized that OMP P6 is a potent immunomodulator of human macrophages. To test this hypothesis, we purified OMP P6 as well as OMP P2, the predominant NTHI outer membrane protein, and lipooligosaccharide (LOS), the specific endotoxin of NTHI, from NTHI strain 1479. Human blood monocyte-derived macrophages, purified from healthy donors, were incubated with each outer membrane constituent, and cytokine production of macrophage supernatants interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), IL-10, IL-12, and IL-8 was measured. OMP P6 selectively upregulated IL-10, TNF-α, and IL-8. While OMP P6 (0.1 μg/ml for 8 h) elicited slightly greater concentrations of IL-10, it resulted in over ninefold greater concentrations of TNF-α and over fourfold greater concentrations of IL-8 than did OMP P2. OMP P6 at doses as low as 10 pg/ml was still effective at induction of macrophage IL-8, while OMP P2 and LOS were not. OMP P6 of NTHI is a specific trigger of bacteria-induced human macrophage inflammatory events, with IL-8 and TNF-α as key effectors of P6-induced macrophage responses.