bluuebunny/crossref_metadata_2025 huggingface dataset:
IF YOU CANNOT TAKE THE HEAT, GET OUT OF THE CERRADO … RECOVERING THE EQUILIBRIUM AMENITY COST OF NONMARGINAL CLIMATE CHANGE IN BRAZIL*
Authors: Timmins Christopher
Published: February 2007

ABSTRACT This paper presents an empirical technique for valuing large changes in nonmarketed local attributes (e.g., climate amenities) without data describing prices of locally traded commodities like housing. A model of endogenous sorting is used to identify individuals' indirect utility functions, from which the value of the change in the local attribute is recovered while accounting for equilibrium impacts on markets for labor and locally traded commodities. Annual amenity costs of Brazilian climate change are estimated to be between $1.6 and $8.1 billion for a moderate climate change scenario, depending upon the role of migration costs.
THE IMPACT OF POLICIES TO CONTROL MOTOR VEHICLE EMISSIONS IN MUMBAI, INDIA*
Authors: Takeuchi Akie , Cropper Maureen , Bento Antonio
Published: February 2007

ABSTRACTThis paper examines the impacts of measures to reduce emissions from buses, cars, and two‐wheelers in Mumbai, India. We have considered three possible policies: conversion of diesel buses to CNG, an increase in the price of gasoline and a tax on vehicle ownership.

Our results suggest that the most effective policy to reduce emissions from passenger vehicles—in terms of the total number of tons of PM10 reduced—is to convert diesel buses to CNG. The conversion of 3,391 diesel buses to CNG would result in an emissions reduction of 663 tons of PM10 per year, 14 percent of total emissions from transport.
ROAD INVESTMENTS, SPATIAL SPILLOVERS, AND DEFORESTATION IN THE BRAZILIAN AMAZON*
Authors: Pfaff Alexander , Robalino Juan , Walker Robert , Aldrich Steven , Caldas Marcellus , Reis Eustaquio , Perz Stephen , Bohrer Claudio , Arima Eugenio , Laurance William , Kirby Kathryn
Published: February 2007

ABSTRACT Understanding the impact of road investments on deforestation is part of a complete evaluation of the expansion of infrastructure for development. We find evidence of spatial spillovers from roads in the Brazilian Amazon: deforestation rises in the census tracts that lack roads but are in the same county as and within 100 km of a tract with a new paved or unpaved road. At greater distances from the new roads the evidence is mixed, including negative coefficients of inconsistent significance between 100 and 300 km, and if anything, higher neighbor deforestation at distances over 300 km.
AVIATION NOISE AND ENVIRONMENTAL JUSTICE: THE BARRIO BARRIER*
Authors: Sobotta Robin R. , Campbell Heather E. , Owens Beverly J.
Published: February 2007

ABSTRACTAviation noise is a harmful pollutant, which has yet to be studied in the environmental justice literature. This paper uses Tobit and logit multivariate regression analyses to analyze noise pollution exposure from a major commercial‐service airport. It addresses the issue of whether people moved to the aviation noise‐impacted areas or the noise encroached on the people, and controls for economic and political costs as well as the possibility of racial and ethnic prejudice. The results indicate that ethnicity is the primary cause of the disproportionate burden of aviation noise pollution borne by Hispanics in the area analyzed.
Immune reactivity towards insulin, its amyloid and protein S100B in blood sera of Parkinson's disease patients
Authors: Wilhelm K. R. , Yanamandra K. , Gruden M. A. , Zamotin V. , Malisauskas M. , Casaite V. , Darinskas A. , Forsgren L. , Morozova‐Roche L. A.
Published: February 2007

Peripheral immune responses can be sensitive indicators of disease pathology. We evaluated the autoimmune reactions to endocrine (insulin) and astrocytical (S100B) biomarkers in the blood sera of 26 Parkinson's disease (PD) patients compared with controls by using ELISA. We found a statistically significant increase of the autoimmune responses to both antigens in PD patients compared with controls with a mean increase of 70% and 50% in the autoimmune reactions towards insulin and S100B, respectively. Heterogeneity of the immune responses observed in patients may reflect the modulating effect of multiple variables associated with neurodegeneration and also changes in the basic mechanisms of individual autoimmune reactivity. We did not detect any pronounced immune reactions towards insulin amyloid fibrils and oligomers in PD patients, indicating that an amyloid‐specific conformational epitope is not involved in immune recognition of this amyloid type, while sequential epitope of native insulin is hidden within the amyloid structures. Immune reactions towards S100B and insulin may reflect the neurodegenerative brain damaging processes and impaired insulin homeostasis occurring in PD.
This is my story: I've got cancer
Authors: Tuffrey‐Wijne Irene , Davies John
Published: February 2007

Accessible summary

This is the story of John Davies. John has learning disabilities. He has cancer. He tells his story in his own words.

John found a lump on his penis (willie). It was cancer. He didn't go to the doctor. He left it too late. Now he is very ill with cancer. Maybe he will die of it. If he had gone to the doctor sooner, he could have got better.

This is what John is telling you: If you find something wrong with you, you should tell someone. You should go to the doctor.

We are doing a study. We want to find out what it is like to have cancer. We want to find out what helps people who have cancer. We are listening to their stories. There will be 20 people in our study. John is one of them. His story helps us to look after people with cancer better.

As people with learning disabilities live longer, and the incidence of cancer is rising, it is of increasing importance to understand the lived cancer experience of this group. Consideration of the viewpoints of people with learning disabilities themselves will facilitate the development of cancer support services that are appropriate and sensitive to their needs. This paper presents preliminary findings of an ethnographic study into the experiences of people with learning disabilities who have cancer. One of the study participants, John Davies (who has mild learning disabilities), relates his cancer experience in his own words. Having ignored his symptoms until it was too late, he now urges others to go to the doctor as soon as possible. The study is ongoing, but findings to date highlight the importance of listening to the story of people's lives and illness.
Aggressive Squamous Cell Carcinoma in Kindler Syndrome
Authors: Emanuel Patrick O. , Rudikoff Donald , Phelps Robert G.
Published: February 2007

A 57‐year‐old Hispanic man with a personal and family history of bullae and photosensitivity presented with a fungating, ulcerated squamous cell carcinoma on his left hand (Figure 1). Physical examination showed conjunctival injection, ectropion, symblepharon, urethral stricture, loss of teeth, short stature, and nail dystrophy. There was reticulated erythema, atrophy, hyperpigmentation and hypopigmentation, and telangiectasia of sun‐exposed skin of the face, neck, and hands consistent with poikiloderma (Figure 2). In addition, there was foreshortening of the left thumb and sclerodermoid changes of his hands (Figure 3). Radiation therapy was applied to shrink the tumor before a local excision was performed. However, a local recurrence followed and axillary lymph nodes became clinically palpable, necessitating amputation and lymph node dissection. Extensive histologic evaluation of the specimen obtained following left arm amputation and lymph node dissection showed moderate‐to‐poorly differentiated deeply invasive squamous cell carcinoma. Two of 3 axillary lymph nodes were positive for metastatic carcinoma. A random biopsy of the trunk showed epidermal atrophy, telangiectasia, a perivascular lymphocytic infiltration, and pigment‐laden macrophages consistent with poikiloderma. Electron microscopy illustrated extensive reduplication of the basement membrane, with loops, curls, and free extensions of the basal lamina in the superficial dermis; reduced numbers of hemidesmosomes and anchoring fibrils; and a basement membrane focally devoid of basal cells (Figure 4). On the basis of the clinical features and the characteristic basement zone changes, a diagnosis of Kindler syndrome was made.

Large vegetating tumor on the palm, necessitating amputation. Biopsy revealed poorly differentiated squamous cell carcinoma invading the bone.

image

Reticulated erythema, atrophy, hyperpigmentation and hypopigmentation, and telangiectasia of the face, neck, and hands (poikiloderma). Atrophy of the epidermis, postinflammatory pigment alteration, and telangiectasia are suggestive of poikiloderma.

image

Tight, shiny, scaly, poikilodermatous skin with erythema, hypopigmentation, and scale, consistent with sclerodermoid changes. Shortfall of the left thumb.

image

Electron microscopy showing reduplication of the basement membrane, reduced numbers of hemidesmosomes, and anchoring filaments (uranyl acetate and lead citrate; original magnification ×58,000).

image
Phase 2 Trial of the Continuous IV Administration of Interferon‐β in Patients With Disseminated Malignant Melanoma
Authors: Voelter‐Mahlknecht Susanne , Mahlknecht Ulrich , Letzel Stephan , Fierlbeck Gerhard
Published: February 2007

Background: Interferons have been reported to significantly contribute to tumor suppression via both induction of p53 gene expression and inhibition of angiogenesis.

Objective: The assessment of treatment toxicity and antitumoral effectiveness of continuous IV administration of interferon‐β based on an overall evaluation of laboratory, radiographic, and clinical parameters observed during the trial.

Methods: The authors treated patients with advanced malignant melanoma with continuous IV infusions of 1
×
106 IU interferon‐β daily (0.6
×
106 IU interferon‐β/m2 daily). Results: Continuous IV administration of interferon‐β had no significant effect on overall patient outcome. Interferon side effects were not a reason for treatment discontinuation in any of the patients observed during this trial.

Conclusions: Continuous IV interferon‐β had no significant effect on overall patient outcome in a group of patients with advanced malignant melanoma. To our knowledge, this is the first report on the continuous IV administration of interferon‐β in patients with advanced malignant melanoma.
Psoriasis and Pentoxifylline: A Clinical, Histopathologic, and Immunohistochemical Evaluation
Authors: Magalhães Geraldo Magela , Da Silva Carneiro Sueli Coelho , Do Amaral Karla Peisino , De Freire Cássia Flávia , Machado‐Pinto Jackson , Cuzzi Tullia
Published: February 2007

Objective. The aim of this study was to examine the clinical and histopathologic effects of pentoxifylline on psoriasis, compared with placebo.

Methods. Sixty‐one outpatients with active psoriasis were randomly assigned to either of 2 groups: one was given pentoxifylline 400 mg tid PO, and the other, placebo. Fifty‐six patients concluded the study. They were evaluated clinically and by laboratory parameters before and after 8 weeks of treatment. Pretreatment and posttreatment biopsies were taken. Initial sections were stained with hematoxylin‐eosin. Further cuts were immunostained for cytokeratins 10, 14, and 16.

Results. Clinical and histologic improvement did not show statistically significant differences between the groups. No laboratory abnormalities or serious reactions related to the drug were observed.

Conclusions. No statistical difference was seen when the treatment group was compared with the control group. Pentoxifylline is a well tolerated and safe drug, but its efficacy in psoriasis appears to be limited.
The effect of age on prostaglandin‐synthesizing enzymes in the development of gingivitis
Authors: Siegel B. , Weihe E. , Bette M. , Nüsing R. M. , Flores‐de‐Jacoby L. , Mengel R.
Published: February 2007

Background and Objective:  The aim of this study was to identify the expression of cyclooxygenase‐1, cyclooxygenase‐2, cyclooxygenase‐3, and microsomal prostaglandin E synthase‐1 in young and elderly subjects.

Material and Methods:  Periodontally healthy subjects were divided into young (18–30 years, n = 7) and elderly (46–77 years, n = 7). A gingival biopsy was taken at baseline. After experimental gingivitis, clinical examination was repeated and a second biopsy was taken. The expression of cyclooxygenase‐1, cyclooxygenase‐2, cyclooxygenase‐3, and microsomal prostaglandin E synthase‐1 was analyzed by means of immunohistochemistry.

Results:  In both healthy age groups, cyclooxygenase‐1 and microsomal prostaglandin E synthase‐1 were expressed in epithelial cells, endothelial cells and fibroblast‐like connective tissue cells. Cyclooxygenase‐1 was found in Langerhans' cells of the epithelium. Cyclooxygenase‐2 expression was observed in cells exhibiting the morphology of epithelial mitosis cells, and the expression of cyclooxygenase‐2 in periodontally healthy elderly subjects was significantly lower (p ≤ 0.05). Following experimental gingivitis, cyclooxygenase‐1 and microsomal prostaglandin E synthase‐1 expression did not change. However, the expression of cyclooxygenase‐2 was significantly increased in both age groups (p ≤ 0.05). Cyclooxygenase‐3 was not detected in any group investigated.

Conclusion:  Cyclooxygenase‐1 and microsomal prostaglandin E synthase‐1 were expressed constitutively in gingival tissue, and expression was unaffected by age or inflammation states. In contrast, the expression of cyclooxygenase‐2 was weaker in elderly subjects. In the course of experimental gingivitis, cyclooxygenase‐2 was induced in both age groups.
Defense mechanism of heme oxygenase‐1 against cytotoxic and receptor activator of nuclear factor‐κB ligand inducing effects of hydrogen peroxide in human periodontal ligament cells
Authors: Pi S.‐H. , Kim S.‐C. , Kim H.‐T. , Lee H.‐J. , Lee S.‐K. , Kim E.‐C.
Published: February 2007

Background and Objective:  Although induction of heme oxygenase‐1 by H2O2 has been reported, the protective role of heme oxygenase‐1 against the cytotoxic and osteoclastogenic effects of H2O2 have not been elucidated in human periodontal ligament cells. The aim of this work was to investigate the defense mechanism of heme oxygenase‐1 on H2O2‐induced cytotoxicity and to analyze the expression of receptor activator of nuclear factor‐κB ligand (RANKL) and osteoprotegerin as markers for osteoclast differentiation in periodontal ligament cells.

Material and Methods:  Using human periodontal ligament cells, cytotoxicity was measured by the 3,4,5‐dimethylthiazol‐2‐yl‐2,5‐diphenyl tetrazolium bromide (MTT) assay, and expression of heme oxygenase‐1, RANKL, and osteoprotegerin mRNA was determined by reverse transcription–polymerase chain reaction.

Results:  H2O2 produced a cytotoxic effect by reducing the cell viability and enhancing the expression of heme oxygenase‐1 and RANKL mRNAs in a concentration‐ and time‐dependent manner. Additional experiments revealed that heme oxygenase‐1 inducer (hemin), a membrane‐permeable cGMP analog (8‐bromo‐cGMP), carbon monoxide, extracellular signal‐regulated kinase, p38 mitogen‐activated protein kinase inhibitor, protein kinase inhibitor (KT5823), and nuclear factor‐κB inhibitor (pyrrolidine dithiocarbamate) also blocked the effects of H2O2 on cell viability and RANKL mRNA expression in periodontal ligament cells.

Conclusion:  These data suggest that heme oxygenase‐1 induction plays a protective role in periodontal ligament cells against the cytotoxic and RANKL‐inducing effects of H2O2, through multiple signaling pathways.
Diabetes‐related parameters and periodontal conditions in children
Authors: Lalla E. , Cheng B. , Lal S. , Kaplan S. , Softness B. , Greenberg E. , Goland R. S. , Lamster I. B.
Published: February 2007

Background and Objective:  The relationship between diabetes and periodontal diseases is well established. Our aim in this study was to explore the diabetes‐related parameters that are associated with accelerated periodontal destruction in diabetic youth.

Material and Methods:  Three‐hundred and fifty 6–18‐year‐old children with diabetes received a periodontal examination. Data on important diabetes‐related variables were collected. Analyses were performed using logistic regression, with gingival/periodontal disease as the dependent variable, for the whole cohort and separately for two subgroups (6–11 and 12–18 years of age).

Results:  Regression analyses, adjusting for age, gender, ethnicity, frequency of prior dental visits, dental plaque, and dental examiner, revealed a strong positive association between mean hemoglobin A1c over the 2 years prior to inclusion in the study and periodontitis (odds ratio = 1.31, p = 0.030). This association approached significance in the younger subgroup (odds ratio = 1.56, p = 0.052, n = 183). There was no significant relationship between diabetes duration or body mass index‐for‐age and measures of gingival/periodontal disease in this cohort.

Conclusion:  These findings suggest that accelerated periodontal destruction in young people with diabetes is related to the level of metabolic control. Good metabolic control may be important in addressing periodontal complications in young patients with diabetes, similarly to what is well established for other systemic complications of this disease.
Lipid A‐associated proteins from Porphyromonas gingivalis stimulate release of nitric oxide by inducing expression of inducible nitric oxide synthase
Authors: Choi E.‐Y. , Hwang Y.‐M. , Lee J.‐Y. , Choi J.‐I. , Choi I.‐S. , Jin J.‐Y. , Ko J. S. , Kim S.‐J.
Published: February 2007

Background and Objective:  The purpose of this study was to examine the effects of lipid A‐associated proteins from Porphyromonas gingivalis, a major cause of inflammatory periodontal disease, on the production of nitric oxide and expression of inducible nitric oxide synthase in the murine macrophage cell line, RAW264.7. We also attempted to throw light on the signaling mechanisms involved in P. gingivalis lipid A‐associated protein‐induced nitric oxide production.

Material and Methods:  The lipid A‐associated proteins from P. gingivalis 381 were prepared by standard hot phenol‐water extraction of endotoxin isolated by the butanol method. Nitric oxide production was assayed by measuring the accumulation of nitrite in culture supernatants. Western blot analysis of inducible nitric oxide synthase and analysis of reverse transcription‐polymerase chain reaction products were carried out.

Results:  We found that P. gingivalis lipid A‐associated proteins can induce inducible nitric oxide synthase expression and stimulate the release of nitric oxide without additional stimuli, and we demonstrated that multiple signaling pathways, such as nuclear factor‐κB, microtubule polymerization, protein tyrosine kinase, protein kinase C, and mitogen‐activated protein kinase cascades, are involved in P. gingivalis lipid A‐associated protein‐stimulated nitric oxide production. The production of nitric oxide required l‐arginine.

Conclusion:  The present study clearly shows that P. gingivalis lipid A‐associated proteins fully induced inducible nitric oxide synthase expression and nitric oxide production in RAW264.7 cells in the absence of other stimuli. The ability of P. gingivalis lipid A‐associated proteins to promote the production of nitric oxide may be important in the pathogenesis of inflammatory periodontal disease.
IDEALS, EDUCATION, AND HAPPY FLOURISHING
Authors: De Ruyter Doret
Published: February 2007

Abstract In this essay, Doret J. de Ruyter defends the claim that parents as well as professional educators need to impart ideals to children in order to realize their wish that children become happy and flourishing adults. The argument consists of two parts. First, de Ruyter shows how ideals are important to construing the meaning of objective goods. Second, she contends that educating children with ideals is important to motivating them to strive for something higher or better. De Ruyter’s analysis rests on two key concepts: “ideals,” which refer to things one believes to be superb, excellent, or perfect, but that are as yet unrealized, and “happy flourishing,” which describes the fulfillment of objectively identifiable generic goods and the person’s satisfactory meaningful interpretation of these goods.
ETHICS AND EDUCATION FORTY YEARS LATER
Authors: Warnick Bryan R.
Published: February 2007

Abstract R.S. Peters’s 1966 book Ethics and Education is one of the most significant works in twentieth‐century philosophy of education. At least in the United States, however, it is now rarely read or discussed. In this essay, Bryan Warnick looks at the virtues and vices of Ethics and Education, examining some major criticisms of the book in light of key developments in philosophy and educational theory that have occurred since it was first published. He finds that some of the criticisms seem unjustified and overstated, while others can be met with a reading of the text that places its language analysis within a framework of communitarian ethics, a move made possible by rejecting Peters’s fact/value dichotomy. This way of reading Ethics and Education reveals an interesting conception of what philosophy of education can be: namely, a sort of normative analytic anthropology. It also shows the value of engaging more with the recent history of philosophy of education.
THE MAKING OF THE MODERN SUBJECT: A CROSS‐CULTURAL ANALYSIS
Authors: Zhao Guoping
Published: February 2007

Abstract The postmodern critique of modernity has focused on the construction of the modern subject and the self‐disciplining and self‐cancellation tendencies within it. This critique, however, fails to consider what happens during the early years of children’s development — the period during which the modern subject is made, and the one in which the paradoxes and ambiguities inherent in modern subjectivity are established. In this essay Guoping Zhao analyzes how children’s developmental process affects the definition and formation of the self in the United States. She uses a cross‐cultural lens, comparing the dominant cultural ideas and practices associated with child development in the United States (stemming from the ideology of liberal individualism) with those influenced and supported by Confucianism. Zhao argues that children’s paths of development are not natural but cultural ones guided by underlying ideologies, and ultimately concludes that this cultural process determines the shapes and forms of the modern subject and the nature of individual freedom and autonomy.
LINKING MARXISM, GLOBALIZATION, AND CITIZENSHIP EDUCATION: TOWARD A COMPARATIVE AND CRITICAL PEDAGOGY POST 9/11
Authors: Ibrahim Awad
Published: February 2007

Abstract In a post‐9/11 world, where the politics of “us” versus “them” has reemerged under the umbrella of “terrorism,” especially in the United States, can we still envision an éducation sans frontières: a globalized and critical praxis of citizenship education in which there are no borders? If it is possible to conceive it, what might it look like? In this review essay, Awad Ibrahim looks at how these multilayered and complex questions have been addressed in three books: Peter McLaren and Ramin Farahmandpur’s Teaching Against Global Capitalism and the New Imperialism, Nel Noddings’s Educating Citizens for Global Awareness, and Gita Steiner‐Khamsi’s The Global Politics of Educational Borrowing and Lending. Ibrahim concludes that, through creating a liminal, dialogical space between humanism, environmentalism, materialism, philosophy, and comparative education, the authors in these books offer a critical pedagogy in which éducation sans frontières is possible — a project that is as visionary as it is hopeful.
RECONSTITUTING THE DEMOCRATIC SUBJECT: SEXUALITY, SCHOOLING, AND CITIZENSHIP
Authors: Rhoads Robert A. , Calderone Shannon M.
Published: February 2007

Abstract In this review essay, Robert Rhoads and Shannon Calderone consider how liberalism, as a guiding principle for school practices and educational policy making, reinforces heteronormativity through a doctrine of professed neutrality that circumscribes sexual expression and subjectivity. Through an analysis of Carol Vincent’s Social Justice, Education, and Identity; Cris Mayo’s Disputing the Subject of Sex: Sexuality and Public School Controversies; and Susan Birden’s Rethinking Sexual Identity in Education, Rhoads and Calderone argue that the form of liberalism espoused by schools operates in contradiction to any pluralistic democratic project emphasizing social justice and inclusion of the “other.” By highlighting the discursive contradictions and structural conditions of schools that lead to the marginalization and disenfranchisement of lesbian, gay, bisexual, transgendered, and queer students, each book proposes alternative forms of educational praxis that attempt to disrupt the liberal status quo of schools. Such praxis, Rhoads and Calderone argue, offers possibilities for new forms of democratic organization within schools that conform with a more robust and inclusive notion of citizenship.
Presidential Authority to Gather Foreign Intelligence
Authors: FEIN BRUCE
Published: February 2007

President George W. Bush has claimed inherent constitutional authority to collect foreign intelligence on his say‐so alone in contravention of the warrant requirements stipulated in the Foreign Intelligence Surveillance Act of 1978 (FISA), as amended six times since 9/11. The constitutionality of FISA, however, is incontestable. It is justified by the Necessary and Proper Clause of Article I, section 8, clause 18 in light of the massive foreign intelligence abuses compiled during forty years of absolute executive power. FISA leaves the separation of powers undisturbed. It regulates only a microscopic percentage of foreign intelligence collection. To sustain President Bush's constitutional claims would “trust me” the measure of our civil liberties, not the checks and balances intended by the Constitution's architects.
Inherent Presidential Power and Constitutional Structure
Authors: KINKOPF NEIL
Published: February 2007

Much current debate about presidential power revolves around the phrase “inherent power.” This phrase has a loose signification, but disputes often involve the question of whether presidential power is subject to limitation by Congress. This essay identifies four different constitutional constructions that might lead to such unchecked presidential power. The essay also assesses each of these four constructions from the standpoint of the Constitution's structure, concluding in each case that the assertion of unchecked power is inconsistent with constitutional structure.
The Commander in Chief and the Courts
Authors: LOBEL JULES
Published: February 2007

The Bush administration claims to have sweeping, inherent, and unchecked war powers to conduct its war against terror. These claims are inconsistent with the text of the Constitution, the Framers' intent, and the practice of the early leaders of the Republic. Judicial decisions in the first few decades after the Constitution's adoption affirmed the Framers' narrow view of executive war powers. This article will address the extent of the president's inherent powers to prosecute a war, whether Congress can regulate and limit the president's commander‐in‐chief power, and the role of the courts in deciding whether the president has overstepped his power in conducting warfare.
Taking the Prerogative out of the Presidency: An Originalist Perspective
Authors: RAKOVE JACK N.
Published: February 2007

Claims for the inherent authority of the executive over issues of national security imply that the adopters of the Constitution relied on prior British definitions equating executive power and royal prerogative. These claims cannot survive the scrutiny of key sources, including Locke's treatment of the federative power in his Second Treatise, the Federal Convention's debates over the presidency, and the famous 1793 exchange between Hamilton and Madison over the nature and sources of presidential power. When Hamilton relied on the Vesting Clause to stake his claim, he was engaging in interpretive innovatio, not providing a historically faithful account of how the presidency had been contrived.
Presidential Power and National Security
Authors: SOFAER ABRAHAM D.
Published: February 2007

Recent claims of unilateral, independent executive power have renewed the debate over presidential authority. The Framers, however, adopted a system of separate branches with predominantly mixed rather than independent powers. President George Washington's proclamation of 1793 demonstrated how the system works. The system's inherent ambiguities led Justice Robert H. Jackson to describe executive power by the standards used to evaluate its exercise. Jackson's description remains accurate, and the system of concurrent authorities remains necessary to protect against tyranny while enabling the president to lead.
The Contemporary Presidency: The Greats and the Great Debate: President William J. Clinton's Use of Presidential Exemplars
Authors: BROWN LARA M.
Published: February 2007

This article examines President William J. Clinton's use of presidential exemplars from 1991 to 2001. While many observers have called attention to the fact that Clinton made efforts to connect his presidency to Democratic “greats” Thomas Jefferson and Franklin Roosevelt, his rhetoric reveals a more complex pattern of identification and use of his predecessors. Not only did he reference Abraham Lincoln and Theodore Roosevelt—Republican “greats”—as often as Thomas Jefferson and Franklin Roosevelt, but he appears to have used them to talk across party lines and move his fellow partisans to the center. This rhetorical pattern became more prominent after the 1994 midterm election, when the Republicans won majority control of Congress. Hence, this article asserts that Clinton used his predecessors to help him carry out his political agenda and his constitutional duties. Further, he learned from his predecessors about how they had used ideological and partisan constructs during their administrations, and this led to his reconsidering the “great debate” between Jefferson and Hamilton. This research concludes that President William J. Clinton left a Hamiltonian—not Jeffersonian—legacy for the Democratic party.
The Polls: Cabinet Member and Presidential Approval
Authors: PANAGOPOULOS COSTAS
Published: February 2007

Are presidential approval and the level of approval of key administration officials linked? Previous findings reveal scant evidence of such a relationship and suggest presidential and subordinate approval are independently derived. This article examines this question further by assessing Americans' attitudes toward the secretaries of state during the George W. Bush presidency. I find no evidence of a causal connection between impressions of presidential performance and approval of the secretary of state or vice versa. Cabinet member approval appears to be driven by media coverage of their activities rather than the macropartisanship or economic performance that influence presidential approval.
THE EVOLUTION OF GENDER EARNINGS GAPS AND DISCRIMINATION IN URBAN CHINA, 1988–95
Authors: DÉMURGER Sylvie , FOURNIER Martin , CHEN Yi
Published: February 2007

This paper analyzes the impact of market liberalization on gender earnings differentials and discrimination against women in urban China at the beginning of the 1990s. The observed stability in the overall gender earnings gap between 1988 and 1995 is shown to result from a complex set of evolutions across enterprises, earnings distributions, and time. Our results highlight the interplay of opposing forces, with economic reforms contributing to changes in managers’ behaviors in different dimensions. On the one hand, by bringing more competition, liberalization favored a reduction in discriminating behaviors in both urban collectives and foreign‐invested enterprises; on the other hand, by relaxing institutional rules, it led to a loosening of the government's egalitarian wage‐setting policies, leaving more space for discrimination in state‐owned enterprises.
Multi‐species prostate implant treatment plans incorporating and using a Greedy Heuristic based 3D optimization algorithm
Authors: Chaswal V. , Yoo S. , Thomadsen B. R. , Henderson D. L.
Published: February 2007

The goals of interstitial implant brachytherapy include delivery of the target dose in a uniform manner while sparing sensitive structures, and minimizing the number of needles and sources. We investigated the use of a multi‐species source arrangement ( with ) for treatment in interstitial prostate brachytherapy. The algorithm utilizes an “adjoint ratio,” which provides a means of ranking source positions and is the criterion for the Greedy Heuristic optimization. Three cases were compared, each using seeds: case I is the base case using alone, case II uses seeds mixed with , and case III uses mixed with . Both multi‐species cases result in lower exposure of the urethra and central prostate region. Compared with the base case, the exposure to the rectum and normal tissue increases by a significant amount for case III as compared with the increase in case II, signifying the effect of slower dose falloff rate of higher energy gammas of in the tissue. The number of seeds and needles decreases in both multi‐species cases, with case III requiring fewer seeds and needles than case II. Further, the effect of on uniformity was investigated using the seeds in multi‐species implants. An increase in uniformity was observed with an increase in the number of seeds implanted. The effects of prostate size on the evaluation parameters for multi‐species implants were investigated using and , and an acceptable treatment plan with increased uniformity was obtained.
PET/CT imaging for treatment verification after proton therapy: A study with plastic phantoms and metallic implants
Authors: Parodi Katia , Paganetti Harald , Cascio Ethan , Flanz Jacob B. , Bonab Ali A. , Alpert Nathaniel M. , Lohmann Kevin , Bortfeld Thomas
Published: February 2007

The feasibility of off‐line positron emission tomography/computed tomography (PET/CT) for routine three dimensional in‐vivo treatment verification of proton radiation therapy is currently under investigation at Massachusetts General Hospital in Boston. In preparation for clinical trials, phantom experiments were carried out to investigate the sensitivity and accuracy of the method depending on irradiation and imaging parameters. Furthermore, they addressed the feasibility of PET/CT as a robust verification tool in the presence of metallic implants. These produce x‐ray CT artifacts and fluence perturbations which may compromise the accuracy of treatment planning algorithms. Spread‐out Bragg peak proton fields were delivered to different phantoms consisting of polymethylmethacrylate (PMMA), PMMA stacked with lung and bone equivalent materials, and PMMA with titanium rods to mimic implants in patients. PET data were acquired in list mode starting within after irradiation at a commercial luthetium‐oxyorthosilicate (LSO)‐based PET/CT scanner. The amount and spatial distribution of the measured activity could be well reproduced by calculations based on the GEANT4 and FLUKA Monte Carlo codes. This phantom study supports the potential of millimeter accuracy for range monitoring and lateral field position verification even after low therapeutic dose exposures of , despite the delay between irradiation and imaging. It also indicates the value of PET for treatment verification in the presence of metallic implants, demonstrating a higher sensitivity to fluence perturbations in comparison to a commercial analytical treatment planning system. Finally, it addresses the suitability of LSO‐based PET detectors for hadron therapy monitoring. This unconventional application of PET involves countrates which are orders of magnitude lower than in diagnostic tracer imaging, i.e., the signal of interest is comparable to the noise originating from the intrinsic radioactivity of the detector itself. In addition to PET alone, PET/CT imaging provides accurate information on the position of the imaged object and may assess possible anatomical changes during fractionated radiotherapy in clinical applications.
Study of increased radiation when an x‐ray tube is placed in a strong magnetic field
Authors: Wen Zhifei , Pelc Norbert J. , Nelson Walter R. , Fahrig Rebecca
Published: February 2007

When a fixed anode x‐ray tube is placed in a magnetic fieldthat is parallel to the anode‐cathode axis, the x‐ray exposure increases with increasing. It was hypothesized that the increase was caused by backscattered electrons which were constrained byand reaccelerated by the electric field onto the x‐ray tube target. We performed computer simulations and physical experiments to study the behavior of the backscattered electrons in a magnetic field, and their effects on the radiation output, x‐ray spectrum, and off‐focal radiation. A Monte Carlo program (EGS4) was used to generate the combined energy and angular distribution of the backscattered electrons. The electron trajectories were traced and their landing locations back on the anode were calculated. Radiation emission from each point was modeled with published data (IPEM Report 78), and thus the exposure rate and x‐ray spectrum with the contribution of backscattered electrons could be predicted. The point spread function for a pencil beam of electrons was generated and then convolved with the density map of primary electrons incident on the anode as simulated with a finite element program (Opera‐3d, Vector Fields, UK). The total spatial distribution of x‐ray emission could then be calculated. Simulations showed that for an x‐ray tube working at, about 54% of the electrons incident on the target were backscattered. In a magnetic field of, although the exposure would be increased by 33%, only a small fraction of the backscattered electrons landed within the focal spot area. The x‐ray spectrum was slightly shifted to lower energies and the half value layer (HVL) was reduced by about 6%. Measurements of the exposure rate, half value layer and focal spot distribution were acquired as functions of. Good agreement was observed between experimental data and simulation results. The wide spatial distribution of secondary x‐ray emission can degrade the MTF of the x‐ray system at low spatial frequencies for.
Dose dependence of mass and microcalcification detection in digital mammography: Free response human observer studies
Authors: Ruschin Mark , Timberg Pontus , Båth Magnus , Hemdal Bengt , Svahn Tony , Saunders Rob S. , Samei Ehsan , Andersson Ingvar , Mattsson Sören , Chakraborty Dev P. , Tingberg Anders
Published: February 2007

The purpose of this study was to evaluate the effect of dose reduction in digital mammography on the detection of two lesion types—malignant masses and clusters of microcalcifications. Two free‐response observer studies were performed—one for each lesion type. Ninety screening images were retrospectively selected; each image was originally acquired under automatic exposure conditions, corresponding to an average glandular dose of for a standard breast ( compressed breast thickness with 50% glandularity). For each study, one to three simulated lesions were added to each of 40 images (abnormals) while 50 were kept without lesions (normals). Two levels of simulated system noise were added to the images yielding two new image sets, corresponding to simulated dose levels of 50% and 30% of the original images (100%). The manufacturer's standard display processing was subsequently applied to all images. Four radiologists experienced in mammography evaluated the images by searching for lesions and marking and assigning confidence levels to suspicious regions. The search data were analyzed using jackknife free‐response (JAFROC) methodology. For the detection of masses, the mean figure‐of‐merit (FOM) averaged over all readers was 0.74, 0.71, and 0.68 corresponding to dose levels of 100%, 50%, and 30%, respectively. These values were not statistically different from each other (, ) but showed a decreasing trend. In contrast, in the microcalcification study the mean FOM was 0.93, 0.67, and 0.38 for the same dose levels and these values were all significantly different from each other (, ). The results indicate that lowering the present dose level by a factor of two compromised the detection of microcalcifications but had a weaker effect on mass detection.
Biomedical imaging research opportunities workshop IV: A white paper
Authors: Hendee William R. , Banovac Filip , Carson Paul L. , DeFronzo Ralph A. , Eckelman William C. , Fullerton Gary D. , Larson Steven M. , McLennan Gordon , Welch Michael J.
Published: February 2007

The Fourth Biomedical Imaging Research Opportunities Workshop (BIROW IV) was held on February 24–25, 2006, in North Bethesda, MD. The workshop focused on opportunities for research and development in four areas of imaging: imaging of rodent models; imaging in drug development; imaging of chronic metabolic disease: diabetes; and image guided intervention in the fourth dimension‐time. These topics were examined by four keynote speakers in plenary sessions and then discussed in breakout sessions devoted to identifying research opportunities and challenges in the individual topics. This paper synthesizes these discussions into a strategy for future research directions in biomedical imaging.
Subvoxel precise skeletons of volumetric data based on fast marching methods
Authors: Van Uitert Robert , Bitter Ingmar
Published: February 2007

The accurate calculation of the skeleton of an object is a problem not satisfactorily solved by existing approaches. Most algorithms require a significant amount of user interaction and use a voxel grid to compute discrete and often coarse approximations of this representation of the data. We present a novel, automatic algorithm for computing subvoxel precise skeletons of volumetric data based on subvoxel precise distance fields. Most voxel based centerline and skeleton algorithms start with a binary mask and end with a list of voxels that define the centerline or skeleton. Even though subsequent smoothing may be applied, the results are inherently discrete. Our skeletonization algorithm uses as input a subvoxel precise distance field and employs a number of fast marching method propagations to extract the skeleton at subvoxel precision. We present the skeletons of various three‐dimensional (3D) data sets and digital phantom models as validations of our algorithm.
Study of the performance of a novel resolution dual‐panel PET camera design dedicated to breast cancer imaging using Monte Carlo simulation
Authors: Zhang Jin , Olcott Peter D. , Chinn Garry , Foudray Angela M. K. , Levin Craig S.
Published: February 2007

We studied the performance of a dual‐panel positron emission tomography (PET) camera dedicated to breast cancer imaging using Monte Carlo simulation. The PET camera under development has two plates that are constructed from arrays of LSO crystals coupled to novel ultra‐thin silicon position‐sensitive avalanche photodiodes (PSAPD). In this design the photodetectors are configured “edge‐on” with respect to incoming photons which encounter a minimum of thick of LSO with directly measured photon interaction depth. Simulations predict that this camera will have photon sensitivity, for an panel separation. Detector measurements show intrinsic spatial resolution, energy resolution, and coincidence time resolution. By performing simulated dual‐panel PET studies using a phantom comprising active breast, heart, and torso tissue, count performance was studied as a function of coincident time and energy windows. We also studied visualization of hot spheres of diameter and various locations within the simulated breast tissue for , , , and LSO crystal resolutions and different panel separations. Images were reconstructed by focal plane tomography with attenuation and normalization corrections applied. Simulation results indicate that with an activity concentration ratio of tumor:breast:heart:torso of 10:1:10:1 and of acquisition time, only the dual‐plate PET camera comprising crystals could resolve diameter spheres with an average peak‐to‐valley ratio of 1.3.
Noise and resolution in images reconstructed with FBP and OSC algorithms for CT
Authors: Ziegler A. , Köhler Th. , Proksa R.
Published: February 2007

This paper presents a comparison between an analytical and a statistical iterative reconstruction algorithm for computed transmission tomography concerning their noise and resolution performance. The reconstruction of two‐dimensional images from simulated fan‐beam transmission data is performed with a filtered back‐projection (FBP) type reconstruction and an iterative ordered subsets convex (OSC) maximum‐likelihood method. A special software phantom, which allows measuring the resolution and noise in a nonambiguous way, is used to simulate transmission tomography scans with different signal‐to‐noise ratios (SNR). The noise and modulation transfer function is calculated for FBP and OSC reconstruction at several positions, distributed over the field‐of‐view (FOV). The reconstruction with OSC using different numbers of subsets shows an inverse linear relation to the number of iterations that are necessary to reach a certain resolution and SNR, i.e., increasing the number of subsets by a factorreduces the number of required iterations by the same factor. The OSC algorithm is able to achieve a nearly homogeneous high resolution over the whole FOV, which is not achieved with FBP. The OSC method achieves a lower level of noise compared with FBP at the same resolution. The reconstruction with OSC can save a factor of up to nine of x‐ray dose compared with FBP in the investigated range of noise levels.
Effects of seed migration on post‐implant dosimetry of prostate brachytherapy
Authors: Gao M. , Wang J. Z. , Nag S. , Gupta N.
Published: February 2007

Brachytherapy using permanent seed implants has been an effective treatment for prostate cancer. However, seeds will migrate after implant, thus making the evaluation of post‐implant dosimetry difficult. In this study, we developed a computer program to simulate seed migration and analyzed dosimetric changes due to seed migration at various migration amounts. The study was based on 14 patients treated with Pd‐103 at the James Cancer Hospital. Modeling of seed migration, including direction, distance as well as day of migration, was based on clinical observations. Changes of commonly used dosimetric parameters as a function of migration amount (2, 4, respectively), prostate size (from ), and prostate region (central vs peripheral) were studied. Change of biological outcome (tumor control probability) due to migration was also estimated. Migration reduced prostate D90 to of original value in migration, and the reduction increased to in migration. The reduction of prostate dose led to a 14% (40%) drop in the tumor control probability for migration, assuming radiosensitive tumors. However, migration has less effect on a prostate implanted with a larger number of seeds. Prostate V100 was less sensitive to migration than D90 since its mean value was still 99% of original value even in migration. Migration also showed a different effect in the peripheral region vs the central region of the prostate, where the peripheral mean dose tended to drop more significantly. Therefore, extra activity implanted in the peripheral region during pre‐plan can be considered. The detrimental effects of migration were more severe in terms of increasing the dose to normal structures, as rectum V50 may be 70% higher and urethra V100 may be 50% higher in the case of migration. Quantitative knowledge of these effects is helpful in treatment planning and post‐implant evaluation.