bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic imaging of contrast‐enhanced coronary vessels with a magnetization prepared rotated stripe keyhole acquisition
Authors: Gui Dawei , Tsekos Nikolaos V.
Published: November 2006

Purpose

To evaluate dynamic coronary imaging based on a magnetization prepared contrast‐enhanced (CE) rotated stripe keyhole acquisition scheme.

Materials and Methods

Background suppression of long T1 tissue was used so that the k‐space would be selectively dominated by the contribution of the CE vessel. The phase‐encoding axis was then adjusted parallel to the long axis of the vessel to sample the significant power spectrum of the vessel. The performance of this approach was evaluated by means of computer simulations and experimental studies on phantoms and a pig model instrumented with an intracoronary catheter for infusion of contrast media.

Results

Computer simulations and phantom studies demonstrated that by rotating the gradient axes to match the k‐space pattern of the frequency spectrum, one can reduce the keyhole band to 20% of the full k‐space while preserving the structure's lumen width and sharpness. In vivo studies validated those findings, and dynamic angiograms of the CE coronary arteries were obtained as rapidly as 140 msec per image, with an in‐plane spatial resolution of 1.5 mm.

Conclusion

With efficient background suppression, a rotated stripes keyhole acquisition can efficiently acquire the significant k‐space of a CE vessel, and provide improved vessel definition with a reduced acquisition matrices scheme. J. Magn. Reson. Imaging 2007. © 2006 Wiley‐Liss, Inc.
Acute, chronic and withdrawal effects of the cannabinoid receptor agonist WIN55212‐2 on the sequential activation of MAPK/Raf‐MEK‐ERK signaling in the rat cerebral frontal cortex: Short‐term regulation by intrinsic and extrinsic pathways
Authors: Moranta David , Esteban Susana , García‐Sevilla Jesús A.
Published: November 2006

The cannabinoids (CB) modulate the extracellular signal‐regulated kinase (ERK), leading to various forms of plasticity in the brain. Little is known, however, on the in vivo short‐ and long‐term activation and regulation of the components of mitogen‐activated protein kinase (MAPK)/ERK signaling by CB. The CB agonist WIN55212‐2 (8 mg/kg) increased the immunodensities of phosphorylated c‐Raf‐1 (42%), MEK1/2 (63%), ERK1 (24%), and ERK2 (28%) in the rat cerebral frontal cortex. These effects were antagonized by SR141716A (rimonabant, 10 mg/kg), a selective CB1 receptor antagonist. Repeated WIN55212‐2 treatment (2–8 mg/kg for 5 days) resulted in tachyphylaxis to the acute activation of Raf‐MEK‐ERK signaling. Acute WIN55212‐2 also induced a hypothermic effect in rats, which was reduced after repeated administration (tolerance). Treatment with SR141716A after chronic WIN55212‐2 resulted in the expected cannabinoid withdrawal syndrome, without concomitant alterations in the phosphorylation state of c‐Raf‐1, MEK1/2, or ERK1/2. Pretreatment with SL327 (20 mg/kg, a MEK1/2 inhibitor) increased the basal phosphorylation of c‐Raf‐1 (40%) and MEK1/2 (74%; feedback regulation) and fully prevented the up‐regulation of ERK1/2 (23–31%) induced by WIN55212‐2. Pretreatment with MK801 (1 mg/kg, a NMDA receptor antagonist) effectively blocked the up‐regulation c‐Raf‐1 (41%), MEK1/2 (57%) and ERK1/2 (25–30%) induced by the CB agonist. The main findings demonstrate that the acute stimulation of CB1 receptors in the frontal cortex results in the sequential phosphorylation of Raf‐MEK‐ERK cascade, in which c‐Raf‐1 activation (rate‐limiting process) plays a crucial role. Moreover, the in vivo stimulating effect of WIN55212‐2 on Raf‐MEK‐ERK signaling is under the extrinsic regulation of an excitatory glutamatergic mechanism. © 2006 Wiley‐Liss, Inc.
How does alcohol impair neuronal migration?
Authors: Kumada Tatsuro , Jiang Yulan , Cameron D. Bryant , Komuro Hitoshi
Published: November 2006

Maternal alcohol consumption during pregnancy can cause serious birth defects, of which fetal alcohol syndrome (FAS) is the most devastating. Recognized by characteristic craniofacial abnormalities and growth deficiency, this condition produces severe alcohol‐induced damage in the developing brain. FAS children experience ataxia; deficits in intellectual functioning; and difficulties in learning, memory, problem solving, and attention. Multiple aspects of central nervous system development can be affected by alcohol exposure, but the most striking abnormalities are neuronal and glial migration. Little is known about cellular mechanisms by which alcohol affects the migration of immature neurons. Recently, it has been found that Ca2+ signaling and cyclic nucleotide signaling are the central targets of the action of alcohol in neuronal cell migration. Most importantly, the aberrant migration of immature neurons caused by alcohol exposure is significantly ameliorated by controlling the activity of these second‐messenger pathways. In this Mini‐Review, we first describe how alcohol exposure impairs the migration of cerebellar granule cells and then discuss the signaling mechanisms involved. © 2006 Wiley‐Liss, Inc.
Procedural justice's relationship with turnover: explaining past inconsistent findings
Authors: Posthuma Richard A. , Maertz Carl P. , Dworkin James B.
Published: November 2006

Despite arguments for a significant negative relationship, there have been ambiguous findings on the empirical relationship between procedural justice and turnover behavior. This study attempts to clarify these past findings by examining the effects of multiple dimensions of procedural justice on the voluntary turnover behavior of nurses in a work‐scheduling context (N = 190). The advance notice and consistency dimensions were significantly and negatively correlated with turnover behavior. Two dimensions of procedural justice had divergent effects on actual turnover behaviors in a logistic regression model. Advance notice was negatively related to turnover, while representativeness of views was positively related to turnover. Copyright © 2006 John Wiley & Sons, Ltd.
Biotransformation enzymes in Cunninghamella blakesleeana (NCIM‐687)
Authors: Bhosale Sanjyot , Saratale Ganesh , Govindwar Sanjay
Published: November 2006

Presence of higher enzyme levels of aminopyrine N‐demethylase, aniline hydroxylase and 11‐β hydroxylase activities were observed in Cunninghamella blakesleeana grown in potato‐dextrose medium for 96 h. The enzyme activity preferred NADPH as a cofactor and showed inhibition with CO, indicating cytochrome P450 mediated reactions. A significant increase in aniline hydroxylase enzyme activity was observed when mycelia incubated in incubation medium containing different inducers (viz. camphor, cholesterol, naphthalene, veratrole, phenobarbital, n ‐hexadecane and ethyl alcohol) when compared with mycelia incubated in same way but in absence of inducers. Cunninghamella blakesleeana (NCIM 687) have shown the ability to degrade cholesterol, camphor and naphthalene when 96 h grown mycelia incubated in incubation medium containing these organic compounds. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The influence of extracellular H2O2 production on decolorization ability in fungi
Authors: Eichlerová Ivana , Homolka Ladislav , Lisá Ludmila , Nerud František
Published: November 2006

A set of 50 randomly chosen fungal strains belonging to different basidiomycete species was tested for H2O2 and ligninolytic enzyme production and for decolorization of synthetic dyes Orange G and Remazol Brilliant Blue R. The decolorization capacity of individual strains was influenced by the level of H2O2 and laccase activity. The strains producing H2O2 at a concentration of 1.0–1.5 µM exhibited the most efficient decolorization; higher or lower H2O2 concentration reduced this ability. None of the strains without a detectable laccase activity was able to decolorize the tested dyes. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ecto‐glycanases and metabolic stability of the capsule in Cryptococcus neoformans
Authors: Maceková Danka , Farkaš Vladimír , Kishida Eriko , Takeo Kanji
Published: November 2006

We have identified a number of ecto‐glycanases (glycosylhydrolases) associated with the capsule and/or the cell wall of Cryptococcus neoformans. The enzyme activities detected included α ‐mannosidase, α ‐, and β ‐glucosidase, α ‐, and β ‐galactosidase, β ‐xylosidase, β ‐glucuronidase, and endo‐β ‐1,3‐glucanase. Small portions of the enzymes were also secreted into the growth medium. Cell‐wall associated endo‐β ‐1,3‐glucanases exhibited highest activity in the acidic range between pH 2.5 and 5.0. The products of laminarin hydrolysis by the enzymes located on the cell surface were glucose and β ‐1,3‐linked glucooligosaccharides. The same products were released from isolated cell walls incubated in the buffer. Endo‐β ‐1,3‐glucanase activity extracted from the cell surfaces by mild sonication consisted of six isoforms separable by isoelectric focusing. In spite of the presence of the whole array of glycanase activities on the cell surfaces, capsular polysaccharides released from C. neoformans cells into the growth medium were practically metabolically stable. From the defined polysaccharides tested, only laminarin (β ‐1,3‐glucan) and to some extent also mixed‐linkage β ‐1,3/β ‐1,4‐glucan and/or 4‐O‐methyl‐D‐glucurono‐D‐xylan were able to support the yeast growth. The activities of majority of identified ecto‐glycanases were low when the yeast was grown on glucose but were considerably elevated when the cells were grown on glycerol indicating that their synthesis is regulated by catabolite repression. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of mutations in the GanB/RgsA G protein mediated signalling on the autolysis of Aspergillus nidulans
Authors: Molnár Zsolt , Emri Tamás , Zavaczki Erzsébet , Pusztahelyi Tünde , Pócsi István
Published: November 2006

Physiological changes taking place in carbon‐starved, autolysing cultures of Aspergillus (Emericella) nidulans strains with mutations in the GanB/RgsA heterotrimeric G protein signalling pathway were studied and compared. Deletion of the ganB, rgsA or both genes did not alter markedly either the autolytic loss of biomass or the extracellular chitinase production. However, they caused a significant decrease in the proteinase formation, which was detected by measuring both extracellular enzyme activity and the transcription of the prtA gene. The deletion mutants also showed significantly higher specific γ ‐glutamyltranspeptidase activities than the control strain. Deletion of the rgsA gene affected the glutathione peroxidase and catalase formation, as well as the peroxide content of the cells. The concomitant initiations of cell death and developmental genomic programmes may be interconnected via heterotrimeric G‐protein signalling and subsequent changes in intracellular ROS levels in ageing A. nidulans. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulated changes in fatty acid intake in humans through n‐3 fatty acid enrichment of foods from animal origin
Authors: De Henauw Stefaan , Van Camp John , Sturtewagen Geert , Matthys Christophe , Bilau Maaike , Warnants Nathalie , Raes Katleen , Van Oeckel Monique , De Smet Stefaan
Published: November 2006

The ratio of n‐6 over n‐3 fatty acids (FA) in the Western diet is today on average between 10 and 15, while evidence suggests that humans would benefit substantially from a more balanced intake. Different strategies to reverse this trend can potentially be adopted. This paper explores the effect of n‐3 enrichment at the level of primary animal production on human FA intake. Consumption data from adolescents were linked to ‘currently available’ and to simulated ‘enriched’ FA profiles of foods from animal origin (by feeding α‐linolenic‐rich diets to pigs, dairy and beef cattle, and broiler and layer chickens). Under enriched conditions, population intakes for α‐linolenic acid and for all n‐3 FA shifted to recommended values. For long‐chain n‐3 polyunsaturated FA, the favourable trend in intake was not sufficient to meet recommendations. The effect on other FA was small. The n‐6/n‐3 ratio decreased considerably from an average value of 6.6 to 4.6. It is concluded that feasible and realistic n‐3 FA enrichments of foods from animal origin can add substantially to the overall efforts for reducing the n‐6/n‐3 intake ratio in the population. However, foods rich in long‐chain n‐3 FA remain essential in the human diet under such conditions. Copyright © 2006 Society of Chemical Industry
Modelling the effect of super‐atmospheric oxygen and carbon dioxide concentrations on the respiration of fresh‐cut butterhead lettuce
Authors: Geysen Sabine , Escalona Victor H , Verlinden Bert E , Nicolaï Bart M
Published: November 2006

For the design of high oxygen modified atmosphere packages, knowledge and modelling of respiration rates at both low and super‐atmospheric oxygen levels is required. Fresh‐cut butterhead lettuce was stored in glass jars at three different temperatures (1 °C, 5 °C and 9 °C), three carbon dioxide levels (0, 10 and 20 kPa) and eight different levels of oxygen partial pressures (0, 2, 5, 10, 20, 50, 70 and 100 kPa). Oxygen consumption and carbon dioxide production rates were measured. The respiration rates were significantly reduced by low temperatures and elevated carbon dioxide concentrations up to 10 kPa. At carbon dioxide concentrations of 20 kPa the respiration rates were comparable to those at 0 kPa CO2 probably due to an injury response. Oxygen concentrations had to be below 2 kPa to significantly reduce the respiration rates compared to air conditions. Respiration rates were also slightly lower under super‐atmospheric (50, 70 and 100 kPa) oxygen partial pressures than at air conditions. Additionally, a Michaelis–Menten based model to describe the respiration rates as a function of oxygen, carbon dioxide and temperature was constructed. Models that include respiration rates at super‐atmospheric oxygen levels have not previously been described. The inhibitive effects of carbon dioxide and high oxygen concentrations were incorporated by an uncompetitive and a non‐competitive inhibition term respectively. Temperature effects were described using Arrhenius' law. The model gave a good description (R2adj = 0.82) of the oxygen consumption and carbon dioxide production rates over the temperature, oxygen and carbon dioxide range tested. Copyright © 2006 Society of Chemical Industry
Chemical composition and in vitro antimicrobial activity of the essential oil of Origanum minutiflorum O Schwarz & PH Davis
Authors: Vardar‐Ünlü Gülhan , Ünlü Mehmet , Dönmez Erol , Vural Nilüfer
Published: November 2006

The essential oil obtained by hydrodistillation from the aerial parts of Origanum minutiflorum O Schwarz & PH Davis, an endemic species in Turkey, was analysed for its antimicrobial activity in vitro. Gas chromatography/mass spectrometry analysis of the essential oil resulted in the identification of 34 constituents accounting for 961.5 mL L−1 of the oil, the major compounds present being carvacrol (793.4 mL L−1), p‐cymene (32.6 mL L−1) and γ‐terpinene (21.4 mL L−1). The in vitro antimicrobial activity of the essential oil was investigated in order to evaluate its efficacy against 16 bacteria and two yeasts, using disc diffusion and minimum inhibitory concentration methods. The essential oil showed strong antimicrobial activity against all test micro‐organisms except Pseudomonas aeruginosa. Its main components carvacrol and p‐cymene were also assayed for their antimicrobial activities. Carvacrol exhibited comparable activity to the crude oil, proving it to be the main component responsible for the biological activity observed. This study demonstrates the in vitro antimicrobial activity of the essential oil of this endemic remedy against a wide spectrum of clinically important micro‐organisms, including pathogenic yeasts, being the first report on the anticandidal properties of the essential oil of O. minutiflorum. Copyright © 2006 Society of Chemical Industry
On the extender algebra being complete
Authors: Ketchersid Richard , Zoble Stuart
Published: November 2006

We show that a Woodin cardinal is necessary for the extender algebra to be complete. Our proof is relatively simple and does not use fine structure. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Unique solutions
Authors: Schuster Peter
Published: November 2006

It is folklore that if a continuous function on a complete metric space has approximate roots and in a uniform manner at most one root, then it actually has a root, which of course is uniquely determined. Also in Bishop's constructive mathematics with countable choice, the general setting of the present note, there is a simple method to validate this heuristic principle. The unique solution even becomes a continuous function in the parameters by a mild modification of the uniqueness hypothesis. Moreover, Brouwer's fan theorem for decidable bars turns out to be equivalent to the statement that, for uniformly continuous functions on a compact metric space, the crucial uniform “at most one” condition follows from its non‐uniform counterpart. This classification in the spirit of the constructive reverse mathematics, as propagated by Ishihara and others, sharpens an earlier result obtained jointly with Berger and Bridges. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quasi‐completeness and functions without fixed‐points
Authors: Batyrshin Ilnur I.
Published: November 2006

We prove a completeness criterion for quasi‐reducibility and generalize it to higher levels of the arithmetical hierarchy. As an application of the criterion we obtain Q‐completeness of the set of all pairs (x,n) such that the prefix‐free Kolmogorov complexity ofxis less thann. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effective Borel degrees of some topological functions
Authors: Gherardi Guido
Published: November 2006

The focus of this paper is the incomputability of some topological functions (with respect to certain representations) using the tools of Borel computability theory, as introduced by V. Brattka in [3] and [4]. First, we analyze some basic topological functions on closed subsets of ℝn , like closure, border, intersection, and derivative, and we prove for such functions results of Σ02‐completeness and Σ03‐completeness in the effective Borel hierarchy. Then, following [13], we re‐consider two well‐known topological results: the lemmas of Urysohn and Urysohn‐Tietze for generic metric spaces (for the latter we refer to the proof given by Dieudonné). Both lemmas define Σ02‐computable functions which in some cases are even Σ02‐complete. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Brand name influence on brand perception
Authors: Wänke Michaela , Herrmann Andreas , Schaffner Dorothea
Published: November 2006

The impact of hotel names on the evaluation of the hotels by customers prior to their stay was investigated. In general, hotels were rated higher on attributes consistent with the semantic associations of the name than on inconsistent attributes. This name effect was somewhat reduced—but still strong—when actual feature information was given, when consumers were explicitly told that the hotels bearing different names had exactly the same features, when consumers were provided with testimonials from former hotel guests, when consumers were informed that the name had changed in the past or would change in the future, and when the actual features were in with the image evoked by the name. The results corroborate the widely accepted assertion that consumers use brand names as diagnostic and legitimate search attributes. Most notably, the findings imply that the effects are robust and resistant to elimination. Four hundred clients of a travel agency participated in this research. © 2007 Wiley Periodicals, Inc.
Fast multidimensional NMR by polarization sharing
Authors: Kupče Eriks , Freeman Ray
Published: November 2006

The speed of multidimensional NMR spectroscopy can be significantly increased by drastically shortening the customary relaxation delay between scans. The consequent loss of longitudinal magnetization can be retrieved if ‘new’ polarization is transferred from nearby spins. For correlation spectroscopy involving heteronuclei (X = 13C or 15N), protons not directly bound to X can repeatedly transfer polarization to the directly bound protons through Hartmann–Hahn mixing. An order of magnitude increase in speed has been observed for the 600 MHz two‐dimensional HMQC spectra of amikacin and strychnine using this technique, and it also reduces the noisy F1 ridges that degrade many heteronuclear correlation spectra recorded with short recovery times. Copyright © 2007 John Wiley & Sons, Ltd.
Erratum: Solution conformation of longifolene and its precursor by NMR and ab initio calculations
Authors: Subramaniam Gopal , Karimi Sasan , Phillips David
Published: November 2006

The original article to which this Erratum refers was published in Magnetic Resonance in Chemistry, in Volume 44 issue 12.
Optimization of blood–myocardial contrast in 3D true FISP cardiac imaging at 1.5 T
Authors: Martirosian Petros , Greil Gerald F. , Fenchel Michael , Kramer Ulrich , Miller Stefan , Greiser Andreas , Claussen Claus D. , Schick Fritz , Sieverding Ludger
Published: November 2006

Three‐dimensional (3D) steady‐state free precession (SSFP) MRI sequences are often applied to visualize both intra‐ and extracardiac pathologies. In the present study the contrast behavior of 3D true fast imaging with steady precession (True‐FISP) sequences for cardiac imaging was optimized in numerical simulations and compared with measurements obtained in eight healthy volunteers on a 1.5 T whole‐body scanner. Two SS preparation schemes in combination with and without a T2 preparation were assessed to improve contrast between blood and myocardium using a navigator‐gated and ECG‐triggered 3D True‐FISP sequence. Numerical simulations and experimental studies in volunteers showed that an SS preparation using a constant flip angle (CFA) is preferable to a linear flip angle (LFA) preparation in terms of contrast between blood and myocardium. The optimized 3D True‐FISP sequence provides a reliable, accurate, and time‐efficient means of obtaining a morphological cardiac diagnosis. Magn Reson Med 57:213–219, 2007. © 2006 Wiley‐Liss, Inc.
Metastatic carcinoma: palaeopathology and differential diagnosis
Authors: Marks M. K. , Hamilton M. D.
Published: November 2006

A 62 year‐old contemporary white female diagnosed with metastatic carcinoma of the breast was examined after skeletonisation. She never received chemical, hormonal or radiation therapy. Because of the confirmed clinical diagnosis, lack of medicinal intervention, and quality of bone preservation, this specimen provides a comparative standard for metastatic carcinoma and differential diagnosis of idiopathic dry bone pathology. We detail gross and radiographic bone response to this disease and differentially diagnose the skeleton against Langerhans cell histiocytosis and multiple myeloma, conditions capable of modifying bone in characteristic patterns that may mimic metastatic carcinoma. Copyright © 2006 John Wiley & Sons, Ltd.
The frequency of os acromiale in the Robert J. Terry Collection
Authors: Hunt D. R. , Bullen L.
Published: November 2006

Normal fusion of the acromion process in humans begins at about age 15 and should complete ossification by age 22–25. Os acromiale occurs when fusion of the acromial epiphysis does not follow its normal ossification pattern, resulting in the retention of a separate epiphyseal end to the acromial process. Depending on how the metaphyseal junctures fuse, differential size and shape of the unattached acromial segment is produced. As a result of shoulder anatomy and the mobile epiphysis, os acromiale is associated with shoulder impingement and rotator cuff problems. The purpose of this study is to document the frequency of os acromiale in the Robert J. Terry Collection and gain a perspective on the occurrence of os acromiale in this specific US population. The overall frequency of os acromiale in the sample of 1594 skeletons was 8.34%. This study also evaluates the prevalence of os acromiale between sexes and ancestral groups in the Terry Collection. Significant frequency differences in the expression of os acromiale were found between both ancestry and sex; the black male sample has the highest frequency (12.47%), with a lower occurrence in the black female sample (9.22%). The white sample exhibited observably lower frequencies, with the white males at 6.8%, and white females at 3.2%. Size and shape and side expression (laterality) showed no significant differences between the sexes. However, significant differences in laterality by ancestry were observed; black males exhibited 48.3% bilateral expression, while white males exhibited bilateral expression only 29% of the time and 54.8% had a right lateral expression. Based on the results presented in this study, it is suggested that there is a genetic causation for os acromiale, which may or may not be exacerbated by physical activity. The use of this anomaly as an additional non‐metric feature in inferring familial relationships and personal identification is discussed. Copyright © 2006 John Wiley & Sons, Ltd.
School choice, racial segregation, and test‐score gaps: Evidence from North Carolina's charter school program*
Authors: Bifulco Robert , Ladd Helen F.
Published: November 2006

Using panel data that track individual students from year to year, we examine the effects of charter schools in North Carolina on racial segregation and black‐white test score gaps. We find that North Carolina's system of charter schools has increased the racial isolation of both black and white students, and has widened the achievement gap. Moreover, the relatively large negative effects of charter schools on the achievement of black students is driven by students who transfer into charter schools that are more racially isolated than the schools they have left. Our analysis of charter school choices suggests that asymmetric preferences of black and white charter school students (and their families) for schools of different racial compositions help to explain why there are so few racially balanced charter schools. © 2006 by the Association for Public Policy Analysis and Management.
Employment, privatization, and managerial choice: Does contracting out reduce public sector employment?
Authors: Fernandez Sergio , Smith Craig R. , Wenger Jeffrey B.
Published: November 2006

We examine the effects of governments' use of alternative service provision on public employment using panel data from a nationally representative sample of local governments. We model the effects of alternative service provision on the size of the public workforce and hypothesize that alternative provision jointly impacts both full‐ and part‐time employment. We find evidence of an inter‐relationship between these employment types. Our results from seemingly unrelated and 3SLS regressions indicate that full‐time employment in the public sector declines when additional services are provided by for‐profit providers, while part‐time employment increases. The net employment effect in the public sector is negative when government services are moved to the for‐profit sector. These combined effects result in a compositional shift toward more part‐time public sector employment. © 2006 by the Association for Public Policy Analysis and Management
The impact of child support enforcement policy on nonmarital childbearing
Authors: Plotnick Robert D. , Garfinkel Irwin , McLanahan Sara S. , Ku Inhoe
Published: November 2006

The interaction of welfare and child support regulations has created a situation in which child support policy's incentives that discourage unwed fatherhood tend to be stronger than its incentives that encourage unwed motherhood. This suggests that more stringent child support enforcement creates incentives that reduce the likelihood of nonmarital childbearing, particularly among women with a significant chance of needing public assistance in the event of a nonmarital birth and their male partners. We investigate this hypothesis with a sample of women from the Panel Study of Income Dynamics, to which we add information on state child support enforcement. We examine childbearing behavior between the ages of 15 and 44 before marriage and during periods of non‐marriage following divorce or widowhood. The estimates indicate that women living in states with more effective child support enforcement are less likely to bear children when unmarried, especially if they are young, never‐married, or black. The findings suggest that improved child support enforcement may be a potent intervention for reducing nonmarital childbearing. © 2006 by the Association for Public Policy Analysis and Management.
Earned income credit utilization by welfare recipients: A case study of Minnesota's earned income credit program
Authors: Hirasuna Donald P. , Stinson Thomas F.
Published: November 2006

This paper examines utilization of a state earned income credit by AFDC and TANF recipients. Although utilization percentages are increasing, we find that among TANF recipients in 1999, 45.7 percent of all households and 34.8 percent of eligible households did not receive the state earned income credit. Moreover, we find that utilization may depend upon TANF requirements and incentives, information resources, and barriers to work and filing of income tax returns. Finally, we investigate whether low utilization is because of little or no benefit from the state earned income credit and find this may be true for some with barriers or less incentive to work under TANF. © 2006 by the Association for Public Policy Analysis and Management.
The effects of state policy design features on take‐up and crowd‐out rates for the state children's health insurance program
Authors: Bansak Cynthia , Raphael Steven
Published: November 2006

We evaluate the effects of state policy design features on SCHIP take‐up rates and on the degree to which SCHIP benefits crowd out private benefits. The results indicate overall program take‐up rates of approximately 10 percent. However, there is considerable heterogeneity across states, suggesting a potential role of inter‐state variation in policy design. We find that several design mechanisms have significant and substantial positive effects on take‐up. For example, eliminating asset tests, offering continuous coverage, simplifying the application and renewal processes, and extending benefits to parents all have sizable and positive effects on take‐up rates. Mandatory waiting periods, on the other hand, consistently reduce take‐up rates. In all, inter‐state differences in outreach and anti‐crowd‐out efforts explain roughly one‐quarter of the crossstate variation in take‐up rates. Concerning the crowding out of private health insurance benefits, we find that between one‐quarter and one‐third of the increase in public health insurance coverage for SCHIP‐eligible children is offset by a decline in private health coverage. We find little evidence that the policy‐induced variation in take‐up is associated with a significant degree of crowd out, and no evidence that the negative effect on private coverage caused by state policy choices is any greater than the overall crowding‐out effect. This suggests that states are not augmenting take‐up rates by enrolling children that are relatively more likely to have private health insurance benefits. © 2006 by the Association for Public Policy Analysis and Management.
Epithelial–mesenchymal interactions in keloid pathogenesis modulate vascular endothelial growth factor expression and secretion
Authors: Ong CT , Khoo YT , Tan EK , Mukhopadhyay A , Do DV , Han HC , Lim IJ , Phan TT
Published: November 2006

Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis during the wound healing process. As epithelial–mesenchymal interactions have been shown to regulate a plethora of genes in wound healing, we hypothesized that these interactions might have a role in modulating VEGF expression and angiogenesis. A two chamber co‐culture model was used, wherein normal and keloid keratinocytes and fibroblasts were physically separated by membrane inserts while allowing cytokine diffusion. Cell lysates obtained from keratinocytes co‐cultured with fibroblasts demonstrated increased expression of VEGF. An enzyme‐linked immunosorbent assay (ELISA) showed significant increase in VEGF expression in co‐culture conditioned media compared with controls. Additionally, the conditioned medium from keloid keratinocyte and fibroblast co‐cultures increased proliferation and formation of complex three‐dimensional capillary‐like structures in human umbilical vein endothelial cells, emphasising the importance of epithelial–mesenchymal interactions in the angiogenic process. Immunostaining of keloid tissue localized VEGF in the basal layer of the epidermis and also demonstrated higher blood vessel density than normal skin. Keloid tissue extract also demonstrated increased expression of VEGF compared with normal skin. It is likely that epidermal VEGF exerts significant paracrine control over the dynamics and expression profile of underlying dermal fibroblasts. Addition of the inhibitors WP631, mitoxantrone, and Rapamycin to keloid keratinocyte and fibroblast co‐cultures, downregulated secreted VEGF expression in a dose‐dependent manner, suggesting therapeutic potential for these compounds in the treatment of keloid scars. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Hypermethylation of CpG island loci and hypomethylation of LINE‐1 and Alu repeats in prostate adenocarcinoma and their relationship to clinicopathological features
Authors: Cho N‐Y , Kim B‐H , Choi M , Yoo EJ , Moon KC , Cho Y‐M , Kim D , Kang GH
Published: November 2006

Promoter CpG island hypermethylation is an important carcinogenic event in prostate adenocarcinoma. Regardless of tissue type, human cancers have in common both focal CpG island hypermethylation and global genomic hypomethylation. The present study evaluated CpG island loci hypermethylation and LINE‐1 and Alu repeat hypomethylation in prostate adenocarcinoma, analysed the relationship between them, and correlated these findings with clinicopathological features. We examined 179 cases of prostate adenocarcinoma and 30 cases of benign prostate hypertrophy for the methylation status of 22 CpG island loci and the methylation levels of LINE‐1 and Alu repeats using methylation‐specific polymerase chain reaction and combined bisulphite restriction analysis, respectively. The following 16 CpG island loci were found to display cancer‐related hypermethylation: RASSF1A, GSTP1, RARB, TNFRSF10C, APC, BCL2, MDR1, ASC, TIG1, RBP1, COX2, THBS1, TNFRSF10D, CD44, p16, and RUNX3. Except for the last four CpG island loci, hypermethylation of each of the remaining 12 CpG island loci displayed a close association with one or more of the prognostic parameters (ie preoperative serum prostate specific antigen level, Gleason score sum, and clinical stage). Prostate adenocarcinoma with hypermethylation of each of ASC, COX2, RARB, TNFRSF10C, MDR1, TIG1, RBP1, NEUROG1, RASSF1A, and GSTP1 showed a significantly lower methylation level of Alu or LINE‐1 than prostate adenocarcinoma without hypermethylation. In addition, hypomethylation of Alu or LINE‐1 was closely associated with one or more of the above prognostic parameters. These data suggest that in tumour progression a close relationship exists between CpG island hypermethylation and the hypomethylation of repetitive elements, and that CpG island hypermethylation and DNA hypomethylation contribute to cancer progression. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The soft‐solid model for liquids. Application to biodiesel and other materials of technological interest
Authors: Castellón‐Elizondo Erick , Lutz Giselle , Mata‐Segreda Julio F.
Published: November 2006

The coefficient of cubic expansion of liquids (α) correlates inversely with the corresponding value of enthalpy of vaporisation. The theoretical interpretation is based on the molecular view of liquids as modified solids made of molecules packed in a way that a few neighbouring molecules have been removed. The general equation for the coefficient of cubic expansion of solids was modified to describe the case of liquids regarded as soft solids. The empirical equation α = 0.087/ΔHvap was obtained for long‐chain liquids of low polarity such as biodiesel materials, when the enthalpy value is given in kJ/mol. Copyright © 2006 John Wiley & Sons, Ltd.
Thermodynamics of the partitioning of poly(propylene oxide) between aqueous and chlorinated organic phases compared to poly(ethylene oxide) and other hydrophilic polymers
Authors: Anselmo Aletéia G. , Sassonia Rogério C. , Loh Watson
Published: November 2006

Thermodynamic functions associated with the partitioning of poly(propylene oxide), PPO, between aqueous and organic (chloroform, dichloromethane, and chlorobenzene) phases were determined and analyzed in comparison with those for the partitioning of poly(ethylene oxide), PEO, and poly(vinyl pyrrolidone), PVP. Amounts of water accompanying the partitioning of PPO to the organic phases were also measured. These results reveal that PPO partitioning is controlled by hydrophobic effects (entropic contribution), which was confirmed by the release of a significant amount of water molecules following the partitioning. Hydrophilic polymers like PVP and polyacrylamide, on the other hand, remain almost quantitatively in the aqueous phase. PEO remains a unique example of a polymer displaying high affinity for water, but that can be extracted to certain organic solvents (which should display hydrogen bond donating capacity). Copyright © 2006 John Wiley & Sons, Ltd.
Kinetics and mechanism of reactions of substituted (methylthio)benzylidene Meldrum's acids with primary amines in aqueous DMSO
Authors: Ali Mahammad , Biswas Supriya , Rappoport Zvi , Bernasconi Claude F.
Published: November 2006

A kinetic study of the aminolysis of substituted (methylthio)benzylidene Meldrum's acids, 2‐SMe‐Z with the aliphatic primary amines, n‐butylamine, glycinamide, methoxyethylamine, and aminoacetonitrile, in aqueous DMSO at 20 °C is reported. With all amines the reaction is strictly second‐order, that is, first‐order in 2‐SMe‐Z and first‐order in the amine. A three steps mechanism has been proposed. The first step is a rate‐limiting attachment of the amine to form the tetrahedral intermediate (T), and the subsequent steps are a fast acid–base equilibrium followed by a fast R‴CH2NH or H2O catalyzed expulsion of the leaving group. The Brönsted plot for k1 for the reaction of 2‐SMe‐H with four primary amines showed a good correlation between log k1 and pK with βnuc = 0.32 ± 0.02, a slightly lower value than that for the reactions of secondary amines (βnuc = 0.41 ± 0.01). The Hammett plot for n‐butylamine yields ρ(k1) = 0.40 ± 0.05 which is smaller than that for the reaction of piperidine with the same substrates (ρ(k1) = 0.72 ± 0.07) and also for the reactions of HOCH2CH2S− (ρ(k1) = 1.18), CF3CH2O− (ρ(k1) = 1.14) and OH− (ρ(k1) = 1.11) addition to 2‐H‐H (ρ(k1) = 1.11). All these observations are consistent with the suggested mechanism. Copyright © 2006 John Wiley & Sons, Ltd.
Kinetics and mechanism of the reaction of benzyl halides with zinc in dimethylformamide
Authors: Egorov Anatoly M.
Published: November 2006

The reaction of metal zinc with various benzyl halides in dimethylformamide has been studied. The low‐temperature ESR‐spectroscopy is used to show that reaction of zinc with benzyl bromide and benzyl iodide occurs to form benzyl radicals. Benzyl chloride reacts with zinc at 77 K to form benzyl radicals and ion‐radical pairs${\rm RX}^{\mathop \cdot \limits^ - } - {\rm Zn}^{\mathop \cdot \limits^ + }$. Nevertheless these pairs disappear at temperatures higher than 110 K. The investigation of the reaction stereochemistry and the use of a radical trap provide evidence in favor of a radical mechanism. The optical activity has been proved in the course of the formation of organozinc halide from (+)‐R‐1‐halogen‐1‐phenylethane at low temperature. The kinetic features of the reaction have been studied. Benzyl iodide reacts with zinc at transport‐controlled rate. The reaction of zinc with benzyl chloride and benzyl bromide in DMF occurs according to Langmuir–Hinshelwood scheme, the adsorption of reagents taking place on similar active centers of metal. The kinetic and thermodynamic parameters of the reaction have been clarified. The comparison of kinetic parameters with those reported in literature evidences that the limiting step of reaction is halogen atom transfer (inner sphere electron transfer). Copyright © 2006 John Wiley & Sons, Ltd.
Combining estimates from multiple early studies to obtain estimates of response: using shrinkage estimates to obtain estimates of response
Authors: Kathman Steven J. , Hale Michael D.
Published: November 2006

Development of anti‐cancer therapies usually involve small to moderate size studies to provide initial estimates of response rates before initiating larger studies to better quantify response. These early trials often each contain a single tumor type, possibly using other stratification factors. Response rate for a given tumor type is routinely reported as the percentage of patients meeting a clinical criteria (e.g. tumor shrinkage), without any regard to response in the other studies. These estimates (called maximum likelihood estimates or MLEs) on average approximate the true value, but have variances that are usually large, especially for small to moderate size studies. The approach presented here is offered as a way to improve overall estimation of response rates when several small trials are considered by reducing the total uncertainty.

The shrinkage estimators considered here (James–Stein/empirical Bayes and hierarchical Bayes) are alternatives that use information from all studies to provide potentially better estimates for each study. While these estimates introduce a small bias, they have a considerably smaller variance, and thus tend to be better in terms of total mean squared error. These procedures provide a better view of drug performance in that group of tumor types as a whole, as opposed to estimating each response rate individually without consideration of the others. In technical terms, the vector of estimated response rates is nearer the vector of true values, on average, than the vector of the usual unbiased MLEs applied to such trials. Copyright © 2006 John Wiley & Sons, Ltd.
Role of resonances in building cross sections: Comparison between the Mittag–Leffler and the T‐matrix Green function expansion approaches
Authors: Shilyaeva Ksenia , Elander Nils , Yarevsky Evgeny
Published: November 2006

Peaks in collision cross sections are often interpreted as resonances. The complex dilation method, as well as other methods relying on analytic continuation of the scattering formalism, can be used to clarify whether these structures are true resonances in the sense that they are poles of the S‐matrix and the associated Green function. The performance of the Mittag–Leffler expansion and T‐matrix Green function expansion methods are formally and computationally compared. The two methods are applied to two model potentials. Eigenenergies, s‐wave residues, and cross sections are computed with both methods. The resonance contributions to the cross sections are further analyzed by removing the residue contributions from the Mittag–Leffler and Green function expansion sums, respectively. It is suggested that the contribution of a resonance to a cross section should be defined through its S‐matrix residue. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Time‐resolved measurement of X‐ray emission from Al2O3 targets induced by low‐energy ion bombardment
Authors: Song Minghui , Takeguchi Masaki , Furuya Kazuo
Published: November 2006

Dependence of X‐ray emission on ion current in low‐energy ion‐induced X‐ray emission (LIIXE) was investigated for irradiation with 30‐keV Ga+ ions. Time‐resolved measurement of the X‐ray emission from Al2O3 samples revealed that the X‐ray emission fluctuated in intensity with time, but there was a tendency for the fluctuation to become smaller with increasing irradiation ion current. The fluctuation for irradiation with an ion current of 0.867 nA was much smaller than that for irradiation with an ion current of 0.087 nA. The main reason for the larger fluctuation for ion irradiation with smaller current was that high pulses of X‐ray emission emerged irregularly with time. For the X‐ray emission induced by irradiation with an ion current of 0.862 nA, a collection time of 50 s gave measured values with a deviation from the average of less than 13% for O K peak count, 28% for Al peak count, and 14% for the peak count ratio of Al K to O K. It is suggested that by choosing ion currents and collection time, X‐ray peak counts can be measured with a deviation of about 10%, and that ratio of characteristic peak counts can be used to evaluate the relative content of elements in a sample. Copyright © 2006 John Wiley & Sons, Ltd.
Characterisation of alumina–silica films deposited by ALD
Authors: Prince K. E. , Evans P. J. , Triani G. , Zhang Z. , Bartlett J.
Published: November 2006

Atomic layer deposition (ALD) is a surface mediated chemical vapour deposition method that is capable of producing uniform films over large areas. In addition, the technique has been used to deposit highly conformal films on high aspect ratio structures. The applicability of any film deposition technique is dependent upon the properties of the final product. Many applications, such as optical coatings, require films of constant composition, low levels of impurities, and adherent interfaces. The latter may derive its strength from some form of interfacial mixing but this should not have an adverse effect on film performance. Dynamic SIMS (D‐SIMS) offers a versatile tool for monitoring film and interface compositions as a function of depth. Sputtering the surface with Cs+ primary ions and detecting MCs+ secondary ions was found to offer the best analytical conditions for ALD films. In the present study, D‐SIMS has been used to characterise films grown with silicon‐containing precursors at temperatures between 200 and 300 °C. The D‐SIMS results have been complemented with data obtained from XPS and an in situ quartz crystal microbalance (QCM). This combination of analytical techniques enabled the effects of different ALD process conditions to be evaluated. With this approach, it was possible to compare the relative amounts of Si in the films, determined by SIMS and XPS, with the mass gains measured for different pulsing sequences with the QCM. Copyright © 2006 John Wiley & Sons, Ltd.