bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of polyethylene glycol for performing autologous adsorptions
Authors: Cid Joan , Ortín Xavier , Pinacho Asunción , Parra Rafael , Contreras Enric , Elies Enric 
Published: April 2005

BACKGROUND: Our reference adsorption procedure is to autoadsorb serum with ZZAP‐pretreated patients’ red cells (RBCs), although it is time‐consuming. The aim of this study was to evaluate the use of polyethylene glycol (PEG) for performing autologous adsorption procedures without pretreatment of patients’ RBCs.STUDY DESIGN AND METHODS: Equal volumes of patient's plasma, patient's RBCs, and PEG were mixed. This mixture was incubated for 15 minutes at 37°C, and the adsorbed plasma‐PEG mixture was immediately harvested to proceed to the antiglobulin test with anti‐immunoglobulin G. The ZZAP‐adsorption procedure was performed in our reference laboratory.RESULTS: Thirty‐one samples were detected with warm autoantibodies in pretransfusion testing. A total number of 58 autologous adsorption procedures were performed with PEG in 870 minutes (mean, 28 min) and alloantibodies were detected in 4 (13%) cases (anti‐E in 2 cases and anti‐E + K in 2 cases). Our reference laboratory performed a total number of 61 adsorption procedures with ZZAP in 3660 minutes (mean, 118 min) and detected the same alloantibodies specificities.CONCLUSION: The PEG autologous adsorption procedure is an efficient method of enhancing autoantibody adsorption and alloantibody detection and decreasing the labor‐intensive testing required by the presence of serum warm autoantibodies in pretransfusion samples.
Asymmetric Information in the IPO Aftermarket
Authors: Li Mingsheng , McInish Thomas H. , Wongchoti Udomsak 
Published: April 2005

AbstractUsing the adverse selection component of the spread as a measure of asymmetric information, we investigate how asymmetric information evolves after firms go public. We find that the level of asymmetric information is lower immediately after the initial public offering (IPO) compared with its level after a period of seasoning. In addition, we test the hypothesis that the greater the underpricing of an IPO, the more information is produced in its aftermarket, and the lower the aggregate level of asymmetric information. Our results are consistent with the hypothesis and are robust after controlling for other factors.
Recent Data Trends Show Welfare Reform to Be a Mixed Success: Significant Policy Changes Should Accompany Reauthorization
Authors: O’Neill Murray Kasia , Primus Wendell E. 
Published: April 2005

AbstractThe conventional wisdom is that the 1996 federal welfare reform law has been a stunning success. Welfare caseloads have declined significantly and employment among disadvantaged single mothers has increased more than anticipated. Also, more low‐income children were living with married couples in the late 1990s. However, welfare reform was enacted in the midst of exceptional economic, demographic, and other policy changes and it is impossible to disentangle the impact of federal welfare reform from these other factors. This article describes these factors and puts the income gains and losses among families with children between 1996 and 2000 into the historical context of the past twenty‐five years. This analysis provides substantial evidence that welfare reform may have “worked” for many low‐income families with children while failing other low‐income families. Furthermore, despite recent increases in poverty following the 2001 recession, welfare caseloads continued to decline, indicating a fundamental flaw in what has traditionally been a countercyclical program. Data also suggest that the significant increase over the 1990s in the share of low‐income children living with married couples has been reversed following the recent recession. These findings suggest that the 1996 welfare law needs to be considerably retooled.
Conducting Meta‐Analyses of Evaluations of Government‐Funded Training Programs
Authors: Greenberg David H. , Robins Philip K. , Walker Robert 
Published: April 2005

AbstractGovernment‐funded training programs in the United States have often been subject to rigorous evaluation. Indeed, many of these programs have been evaluated with random assignment, although sophisticated quasi‐experimental methods have also been used. Until very recently, however, there has been little systematic attempt to use the cumulative information vested in these evaluations to attempt determine which kinds of programs work best in which setting and with respect to which types of client. Meta‐analysis—a set of statistical procedures for systematically synthesizing findings from separate studies—can, in theory at least, address these and other topics that evaluation of individual programs cannot. This article discusses the steps in conducting such a synthesis, summarizes the results of three recently conducted meta‐analyses of training and welfare‐to‐work programs, identifies limitations to the meta‐analytic approach, and considers ways in which some of these limitations can be overcome.
Investing in Individuals for Independence
Authors: Rom Mark Carl 
Published: April 2005

AbstractIndividual Development Accounts (IDAs) are tax‐protected, matched savings accounts designed to help those with low incomes and few assets buy a home, capitalize a business, or fund higher education. Originally authorized through the Personal Responsibility and Work Opportunity Reconciliation Act (PRWORA), IDAs are designed, implemented, and evaluated through public‐private partnerships. In January 2003 over 500 IDA programs had been created, with more than 10,000 low‐income individuals making contributions. This paper outlines the rationale for IDA as an asset building strategy for the poor, describes the design and operation of IDAs, and provides results of early program evaluations. It concludes by arguing that IDAs are a smart practice that can and should be expanded.
Root herbivory reduces growth and survival of the shoot feeding specialist Pieris rapae on Brassica nigra
Authors: Van Dam Nicole M. , Raaijmakers Ciska E. , Van Der Putten Wim H. 
Published: April 2005

AbstractPlants may respond to herbivore attacks by changing their chemical profile. Such induced responses occur both locally and systemically throughout the plant. In this paper we studied how Brassica nigra (L.) Koch (Brassicaceae) plants respond to two different root feeders, the endoparasitic nematode Pratylenchus penetrans Cobb (Tylenchida: Pratylenchidae) and the larvae of the cabbage root fly Delia radicum L. (Diptera: Anthomyiidae). We tested whether the activities of the root feeders affected the survival and development of the shoot feeding crucifer specialist Pieris rapae (L.) (Lepidoptera: Pieridae) via systemically induced changes in the shoots. Overall, P. rapae larvae grew slower and produced fewer pupae on plants that were infested with root feeders, especially on plants infested with P. penetrans. This effect could not be attributed to lower water or protein levels in these plants, as the percentage of water in the controls and root infested shoots was similar, and protein content was even higher in root infested plants. Both glucosinolate as well as phenolic levels were affected by root feeding. Initially, glucosinolate levels were the lowest in root infested plants, but on P. penetrans infested plants they increased more rapidly after P. rapae started feeding than in controls or D. radicum infested plants. Plants with D. radicum feeding on their roots had the highest phenolic levels at all harvest dates. Our results indicate that root feeding can significantly alter the nutritional quality of shoots by changes in secondary metabolite levels and hence the performance of a specialist shoot feeder.
Leaf surface wax layers of Brassicaceae lack feeding stimulants for Phaedon cochleariae
Authors: Reifenrath Kerstin , Riederer Markus , Müller Caroline 
Published: April 2005

AbstractNumerous reports have indicated that glucosinolates are important stimulants for specialist herbivores feeding on Brassicaceae, and that these metabolites might be present on the plant surface and thereby detectable by an alighting insect. We investigated the outermost layer of leaves of two species of Brassicaceae, Brassica napus L. var. ‘Martina’ and Nasturtium officinale R. Br., using two highly selective extraction methods. When the epicuticular wax layer was mechanically removed with gum arabic, no glucosinolates were detectable in the lower and upper leaf surfaces. Extracting the leaf surfaces with a threefold short rinse with chloroform/methanol/water (2 : 1 : 1 vol/vol/vol) led to varying results, depending on the light conditions under which plants had been kept in the period prior to extraction. In plants kept under light, glucosinolates were detectable in a first extraction in minor concentrations, with increasing amounts in a second and third extraction. In plants kept in darkness, glucosinolates were almost absent in the first extraction. We postulate that the polar glucosinolates are washed from the inner leaf tissue through open stomata to the outside during solvent extraction, but are not naturally present in the outermost wax layer. The response of the crucifer specialist Phaedon cochleariae (F.) (Coleoptera: Chrysomelidae) to leaf surfaces of the host plants B. napus and N. officinale and to a glucosinolate was tested. Adults preferred both the adaxial and abaxial leaf surfaces of host plants that had been treated with gum arabic in order to remove the epicuticular waxes over intact surfaces. Waxes may therefore prevent direct contact with the stimulants. Sinigrin (allyl glucosinolate) and/or surface extracts of N. officinale leaves applied on Pisum sativum leaf discs did not evoke feeding, but feeding did occur when total leaf extracts of B. napus or N. officinale were applied on this non‐host. We conclude that glucosinolates might only act as feeding stimulants for P. cochleariae in concert with compounds other than surface waxes.
Ecological speciation without host plant specialization; possible origins of a recently described crypticPapiliospecies
Authors: Scriber J. Mark , Ording Gabriel J. 
Published: April 2005

AbstractNorth AmericanPapilio canadensisandP. glaucus(Lepidoptera: Papilionidae, thesePapilio = Pterourus) have previously been described as having allopatric distributions separated by a narrow hybrid zone running from Minnesota to southern New England, and southward in the Appalachian Mountains (possibly to northern Georgia). Recent patterns of hybridization and introgression suggest a more complex interaction between the two, possibly even resulting in the formation of a new species (Pterourus appalachiensisPavulaan & Wright, 2002). Recently, extensive northward interspecific introgression ofP. glaucus‐diagnostic traits has been observed in the hybrid zone. These include wing bands and other color patterns, the ability to feed on tulip tree leaves, andHk‐100allozymes; all are autosomally encoded. However, there has been little northward introgression of certain otherP. glaucustraits (such as facultative diapause and bivoltinism, andLdh‐100allozymes, both X‐linked; and the Y‐linked melanic mimicry gene in females). Interspecific recombination of the X‐chromosome has evidently occurred, as shown by discordant patterns of X‐linked markers. TheP. glaucusX‐linkedPgd‐100andPgd‐50alleles have introgressed 200–400 km north of the historical hybrid zone, yet theP. glaucusX‐linkedLdh‐100allele has not. The allele frequency shift for both genes is more closely related to the ‘thermal landscape’ (i.e., accumulated degree‐days above a developmental base threshold of 50 °F (=10 °C)) than to latitude. Delayed post‐diapause eclosion of cohorts within the hybrid zone, e.g., the New York/Vermont border area, has produced a natural ‘false‐second generation’ flight (a hybrid swarm of synchronous males and females, where 2300–2700 °F degree‐days have accumulated each year since 1998) that is reproductively isolated from flights of both parental species. Moreover, the newly describedP. appalachiensisexhibits a unique combination of traits. These include obligate diapause, a univoltine habit, and theLdh‐80orLdh‐40alleles (as forP. canadensis), thePgd‐100orPgd‐50alleles (as forP. glaucus), and a delayed ‘false‐second generation’ reproductive flight period (as observed in the hybrid zone). Since 2001, a rare allele or ‘hybrizyme’ (Ldh‐20) has appeared in this false second generation at high frequencies (40–50%). We hypothesize that strong selection against the facultative diapause (od‐)trait (and the linkedLdh‐100allele) in regions with 2800 °F degree‐days or less, and divergent selection in favor ofPgd‐100(or a closely linked trait) combined with allochronic reproductive isolation, has resulted in recombinational, parapatric, hybrid speciation. There is no evidence at present that host‐plant shifts or changes in sex pheromones have driven this process, in contrast to many other speciation events in the Lepidoptera.
The effect of fractionated Tagetes oil volatiles on aphid reproduction
Authors: Tomova Blagovesta S. , Waterhouse John S. , Doberski Julian 
Published: April 2005

AbstractThe biological activity of essential oil volatiles from Tagetes minuta L. (Mexican marigold) against three aphid species was investigated in a series of laboratory experiments. The aphid species (Homoptera: Aphididae) studied were: Acyrthosiphon pisum (Harris) (pea aphid), Myzus persicae (Sulzer) (peach‐potato aphid), and Aulacorthum solani (Kaltenbach) (glasshouse and potato aphid). Tagetes minuta oil volatiles significantly reduced aphid reproduction (up to 100% after 5 days of exposure). The effect depended on the quantity of essential oil used, and varied with the aphid species tested. Pea aphids were the most susceptible. Tagetes minuta oil was fractionated by vacuum distillation. Fractions and three pure compounds (limonene, (Z)‐ocimene, and β‐caryophyllene) were tested using the same experimental technique. The chemical composition of the volatiles was investigated by headspace–solid phase microextraction–gas chromatography mass spectrometry (HS‐SPME‐GCMS), and the main constituents of the oil were identified. Overall, applied in equal quantity, fractions predominantly containing sesquiterpenes and oxygenated monoterpenoids were more effective in restricting aphid population growth than fractions predominantly containing monoterpenes. When tested as a pure compound, the sesquiterpene β‐caryophyllene produced a greater effect than the monoterpenes limonene and ocimene. The study demonstrates that T. minuta oil volatiles have potential for aphid control.
Future directions in the study of induced plant responses to herbivory
Authors: Agrawal Anurag A. 
Published: April 2005

AbstractThis paper reviews current progress and makes recommendations for future studies of induced plant responses to herbivory in three research areas: the role of induction in structuring herbivore communities, costs associated with the expression of induced responses, and theory and data on the macro‐evolution of induced responses. It is argued that although mechanistic approaches will be important for progress, it is also critical to maintain a holistic approach, including a consideration of field environments, multi‐species interactions, and patterns over ecological and evolutionary time.
RATCHET BONDS: MAXIMUM REFUNDING EFFICIENCY AT MINIMUM TRANSACTION COST
Authors: Kalotay Andrew , Abreo Leslie 
Published: April 2005

Callable bonds, which are widely used by corporate borrowers to manage interest rate risk, have several major drawbacks. Foremost is the transaction cost of refunding. In addition, poor execution—calling too early or too late—is common, causing a transfer of wealth from shareholders to bondholders.The Ratchet bond captures the advantages of a callable bond—the ability to lower interest costs when rates decline—while eliminating its undesirable features. If rates fall after issuance, the coupon of a Ratchet bond automatically resets to the yield of a specified Treasury bond plus some fixed spread. The resulting “step‐down” cash flow pattern resembles that of a sequence of callable bonds that are refunded to the same original maturity date.The Tennessee Valley Authority was the first to use this innovative structure. In June 1998, they sold $575 million 6.75%“PARRS” with a 30‐year maturity and annual rate resets beginning after five years. Moreover, as this article went to print, TVA announced its intent to sell another large Ratchet issue with features virtually identical to the PARRS described in this article.
THE MARKET'S PRICING OF DEBT IPOs
Authors: Datta Sudip , Iskandar‐Datta Mai , Patel Ajay 
Published: April 2005

Based on the authors' recent study published in the Journal of Financial Economics, this article summarizes new evidence on the first‐day and aftermarket price performance of a firm's first public offer of bonds after its equity IPO. Unlike equity IPOs, such bond IPOs are not underpriced on average. However, bonds that are more equity‐like (junk bonds) are underpriced at the initial offer whereas high‐grade debt is actually overpriced. This finding supports the view that riskier debt issues have a larger equity component and, as a consequence, a higher degree of information asymmetry.The authors' study also showed that less prestigious underwriters are associated with more underpriced offers, and that the issuer's stock market listing plays an important role in determining the first‐day price performance of bond IPOs. The degree of underpricing is lower for bonds issued by firms whose equity is listed on NYSE/AMEX than for bonds issued by firms listed on Nasdaq. Finally, the aftermarket performance for the full sample and various subsamples is consistent with bond market efficiency in the sense that, once prices adjust after the first day of trading, there are no clearly exploitable opportunities for excess returns.
Functional Roles of the Leg Muscles When Pedaling in the Recumbent Versus the Upright Position
Authors: Hakansson Nils A. , Hull M. L. 
Published: April 2005

Abstract
An understanding of the coordination of the leg muscles in recumbent pedaling would be useful to the design of rehabilitative pedaling exercises. The objectives of this work were to (i) determine whether patterns of muscle activity while pedaling in the recumbent and upright positions are similar when the different orientation in the gravity field is considered, (ii) compare the functional roles of the leg muscles while pedaling in the recumbent position to the upright position to the upright position and (iii) determine whether leg muscle onset and offset timing for recumbent and upright pedaling respond similarly to changes in pedaling rate. To fulfill these objectives, surface electromyograms were recorded from 10 muscles of 15 subjects who pedaled in both the recumbent and upright positions at 75, 90, and 105rpm and at a constant workrate of 250W. Patterns of muscle activation were compared over the crank cycle. Functional roles of muscles in recumbent and upright pedaling were compared using the percent of integrated activation in crank cycle regions determined previously for upright pedaling. Muscle onset and offset timing were also compared. When the crank cycle was adjusted for orientation in the gravity field, the activation patterns for the two positions were similar. Functional roles of the muscles in the two positions were similar as well. In recumbent pedaling, the uniarticular hip and knee extensors functioned primarily to produce power during the extension region of the crank cycle, whereas the biarticular muscles crossing the hip and knee functioned to propel the leg through the transition regions of the crank cycle. The adaptations of the muscles to changes in pedaling rate were also similar for the two body positions with the uniarticular power producing muscles of the hip and knee advancing their activity to earlier in the crank cycle as the pedaling rate increased. This information on the functional roles of the leg muscles provides a basis by which to form functional groups, such as power-producing muscles and transition muscles, to aid in the development of rehabilitative pedaling exercises and recumbent pedaling simulations to further our understanding of task-dependent muscle coordination.
Modulation of Host Cytoskeleton Function by the Enteropathogenic
Escherichia coli
and
Citrobacter rodentium
Effector Protein EspG
Authors: Hardwidge Philip R. , Deng Wanyin , Vallance Bruce A. , Rodriguez-Escudero Isabel , Cid Victor J. , Molina Maria , Finlay B. Brett 
Published: April 2005

ABSTRACT

EspG is a conserved protein encoded by the locus of enterocyte effacement (LEE) of attaching and effacing (A/E) pathogens, including enteropathogenic and enterohemorrhagic
Escherichia coli
and
Citrobacter rodentium
. EspG is delivered into infected host cells by a type III secretion system. The role of EspG in virulence has not yet been defined. Here we describe experiments that probe the virulence characteristics and biological activities of EspG in vitro and in vivo. A
C. rodentium espG
mutant displayed a significantly reduced ability to colonize C57BL/6 mice and to cause colonic hyperplasia. Epitope-tagged EspG was detected in the apical regions of infected colonic epithelial cells in infected mice, partially localizing with another LEE-encoded effector protein, Tir. EspG was found to interact with mammalian tubulin in both genetic screens and gel overlay assays. Binding to tubulin by EspG caused localized microtubule depolymerization, resulting in actin stress fiber formation through an undefined mechanism. Heterologous expression of EspG in yeast resulted in loss of cytoplasmic microtubule structure and function, preventing coordination between bud development and nuclear division. Yeast expressing EspG were also unable to control cortical actin polarity. We suggest that EspG contributes to the ability of A/E pathogens to establish infection through a modulation of the host cytoskeleton involving transient microtubule destruction and actin polymerization in a manner akin to the
Shigella flexneri
VirA protein.
Pertussis Toxin and Adenylate Cyclase Toxin Provide a One-Two Punch for Establishment of
Bordetella pertussis
Infection of the Respiratory Tract
Authors: Carbonetti Nicholas H. , Artamonova Galina V. , Andreasen Charlotte , Bushar Nicholas 
Published: April 2005

ABSTRACT

Previously we found that pertussis toxin (PT), an exotoxin virulence factor produced by
Bordetella pertussis
, plays an important early role in colonization of the respiratory tract by this pathogen, using a mouse intranasal infection model. In this study, we examined the early role played by another exotoxin produced by this pathogen, adenylate cyclase toxin (ACT). By comparing a wild-type strain to a mutant strain (ΔCYA) with an in-frame deletion of the
cyaA
gene encoding ACT, we found that the lack of ACT confers a significant peak (day 7) colonization defect (1 to 2 log
10
). In mixed-infection experiments, the ΔCYA strain was significantly outcompeted by the wild-type strain, and intranasal administration of purified ACT did not increase colonization by ΔCYA. These data suggest that ACT benefits the bacterial cells that produce it and, unlike PT, does not act as a soluble factor benefiting the entire infecting bacterial population. Comparison of lower respiratory tract infections over the first 4 days after inoculation revealed that the colonization defect of the PT deletion strain was apparent earlier than that of ΔCYA, suggesting that PT plays an earlier role than ACT in the establishment of
B. pertussis
infection. Examination of cells in the bronchoalveolar lavage fluid of infected mice revealed that, unlike PT, ACT does not appear to inhibit neutrophil influx to the respiratory tract early after infection but may combat neutrophil activity once influx has occurred.