bluuebunny/crossref_metadata_2025 huggingface dataset:
The efficacy of combining several risk factors as a screening test
Authors: Wald Nicholas J , Morris Joan K , Rish Simon
Published: December 2005

Objective: To determine the quantitative effect on overall screening performance (detection rate for a given false-positive rate) of using several moderately strong, independent risk factors in combination as screening markers.

Setting: Theoretical statistical analysis.

Methods: For the purposes of this analysis, it was assumed that all risk factors were independent, had Gaussian distributions with the same standard deviation in affected and unaffected individuals and had the same screening performance. We determined the overall screening performance associated with using an increasing number of risk factors together, with each risk factor having a detection rate of 10%, 15% or 20% for a 5% false-positive rate. The overall screening performance was estimated as the detection rate for a 5% false-positive rate.

Results: Combining the risk factors increased the screening performance, but the gain in detection at a constant false-positive rate was relatively modest and diminished with the addition of each risk factor. Combining three risk factors, each with a 15% detection rate for a 5% false-positive rate, yields a 28% detection rate. Combining five risk factors increases the detection rate to 39%. If the individual risk factors have a detection rate of 10% for a 5% false-positive rate, it would require combining about 15 such risk factors to achieve a comparable overall detection rate (41%).

Conclusion: It is intuitively thought that combining moderately strong risk factors can substantially improve screening performance. For example, most cardiovascular risk factors that may be used in screening for ischaemic heart disease events, such as serum cholesterol and blood pressure, have a relatively modest screening performance (about 15% detection rate for a 5% false-positive rate). It would require the combination of about 15 or 20 such risk factors to achieve detection rates of about 80% for a 5% false-positive rate. This is impractical, given the risk factors so far discovered, because there are too few risk factors and their associations with disease are too weak.
The West Midlands breast cancer screening status algorithm – methodology and use as an audit tool
Authors: Lawrence Gill , Kearins Olive , O'Sullivan Emma , Tappenden Nancy , Wallis Matthew , Walton Jackie
Published: December 2005

Objectives: To illustrate the ability of the West Midlands breast screening status algorithm to assign a screening status to women with malignant breast cancer, and its uses as a quality assurance and audit tool.

Methods: Breast cancers diagnosed between the introduction of the National Health Service [NHS] Breast Screening Programme and 31 March 2001 were obtained from the West Midlands Cancer Intelligence Unit (WMCIU). Screen-detected tumours were identified via breast screening units, and the remaining cancers were assigned to one of eight screening status categories. Multiple primaries and recurrences were excluded.

Results: A screening status was assigned to 14,680 women (96% of the cohort examined), 110 cancers were not registered at the WMCIU and the cohort included 120 screen-detected recurrences.

Conclusions: The West Midlands breast screening status algorithm is a robust simple tool which can be used to derive data to evaluate the efficacy and impact of the NHS Breast Screening Programme.
Estimating mean sojourn time and screening test sensitivity in breast cancer mammography screening: new results
Authors: Weedon-Fekjær Harald , Vatten Lars J , Aalen Odd O , Lindqvist Bo , Tretli Steinar
Published: December 2005

Objective: To assess if new screening techniques, increased use of hormone replacement therapy, or the transition from breast cancer screening trials to large scale screening programmes may influence the average time in preclinical screening detectable phase (mean sojourn time [MST]) or screening test sensitivity (STS).

Setting: Screening and interval data for 395,188 women participating in the Norwegian Breast Cancer Screening Programme (NBCSP).

Methods: Weighted non-linear least-square regression estimates using a tree step Markov chain model, and a sensitivity analysis of the possible impact by opportunistic screening between ordinary breast cancer screening rounds.

Results: MST was estimated to 6.1 (95% confidence interval [CI] 5.1–7.0) years for women aged 50–59 years, and 7.9 (95% CI 6.0–7.9) years for those aged 60–69 years. Correspondingly, STS was estimated to 58% (95% CI 52–64 %) and 73 % (67–78 %), respectively. Simulations revealed that opportunistic screening may give a moderate estimation bias towards higher MST and lower STS. Assuming a probable 21% higher background incidence, due to increased hormone replacement therapy use, MST estimates decreased to 3.9 and 5.0 years for the two age groups, and STS increased to 75 and 85%.

Conclusions: The new estimates indicate that screening detectable phase is longer than that found in previous mammography trials/programmes, but also that the sensitivity of the screening test is lower. Overall, the NBCSP detects more cancer cases than most previous trials/programmes.
UK Emissions Trading from 2002–2004: Corporate Responses
Authors: Hill Malcolm , McAulay Laurie , Wilkinson Adrian
Published: December 2005

The UK was the first country to implement emissions trading as a policy instrument to reduce greenhouse gas emissions across the whole of the economy. The paper therefore commences with a description of the UK Emissions Trading Scheme and then continues with a discussion of incentives for UK companies to engage in emissions trading. It then outlines a case for research of companies' experiences of “direct participation” in the Scheme, and presents results obtained from case studies of a set of companies which are “direct participants”. These illustrate the impact of emissions trading on income generation as well as cost savings. The paper then concludes with the observation that emissions trading will take on increased importance with the introduction of the EU Emissions Trading Scheme and the implementation of the Kyoto Protocol in 2005, and that further research is therefore required into energy and carbon costs and their possible influences on facilities location.
Indicators for the Assessment of Member States' GHG Emission Trends and Burden Sharing Commitments: The Cohesion Countries
Authors: del Río Pablo , Hernández Félix
Published: December 2005

Do Member States (MS) show clear signs that they are abating their GHG emissions? In view of recent trends in emissions, are the Burden Sharing Agreement targets too ambitious for the MS and, particularly, for the cohesion countries? Would this provide an argument for the revision of these targets? This paper tries to answer these questions, which have been asked in Europe at both the policy and academic level. It proposes and develops a set of indicators and applies them to the EU context, assessing the likely trends in GHG emissions in Europe. The main conclusion is that the cohesion countries should not ask for a renegotiation of targets. Their emissions have increased beyond their economic growth patterns because of the weak implementation of both institutional and technological measures aimed at GHG mitigation.
Book Review: Acoustic Absorbers and Diffusers: Theory, Design and Application
Authors: Cox Trevor J , D'Antonio Peter
Published: December 2005

This book is concerned with factors that affect the way in which sound is reflected from a surface with particular emphasis on those surfaces found in auditoria. The two aspects, absorption and diffusion, are covered but the main novelty is the treatment of diffusion. Both authors have achieved well deserved international recognition for undertaking fundamental research on this topic over the last fifteen years. Trevor Cox has concentrated on the aspects of modelling, prediction and measurement whilst Peter D'Antonio has first hand experience of the application of diffusion in a range of highly significant and high profile projects. The distinct backgrounds of the two authors complement each other well, resulting in a book that will be valuable to both practitioners and researchers.
Development of Sound Absorbers for Large Spaces
Authors: Kobayashi Yoshihito , Kitamura Toshiya , Yamada Shinji
Published: December 2005

Moulded chairs have been developed, in which sound absorption at low frequency bands is increased by using the seat section and/or the back section as a resonator. In addition, a translucent sound absorption panel has been developed for application in large spaces. In the case of the chairs the resonance frequency, determined by the position, number, and depth of the holes, was examined. Prototypes were constructed, and the equivalent absorption area was measured in a reverberation room. The resonators of the chairs achieved an equivalent absorption area of 0.15 m2/seat, in the 125 Hz band.

For the case of the translucent material, sound absorption was measured and compared with conventional sound absorption materials. The panels were designed in order to control sound fields in large spaces. The panels achieved a sound absorption coefficient of 0.6 to 1.0 at middle and high frequency bands.
Measurements of Acoustical Properties in Cistercian Abbeys
Authors: Magrini Ugo , Magrini Anna
Published: December 2005

The work reports the results of measurements of acoustical parameters obtained in six abbeys of the Cistercian order (XIIth century). Three of them, Silvacane, Senanque and Le Thoronet, are in the South of France. They have the original layout both outside and inside the building, and are finished in local stone. The values of the reverberation time RT, measured in these abbeys, are higher than in other religious buildings of almost the same volume.

The other three abbeys, at Tiglieto, Morimondo and Chiaravalle, in Northern Italy, have similar characteristics as regards the plan and the simplicity of the interiors, but their inner surfaces are of bricks and stones, in different proportions. The measured RT values are lower than those of the French abbeys.

In the abbey at Le Thoronet, the RT values are higher at low and middle frequencies, which corresponds to the range of liturgical and mainly Gregorian choral music, played in Cistercian abbeys without musical instruments. This effect could have been the aim of the Cistercian architects, experienced in architectural acoustics, or is the consequence of the use of a special kind of stone, that has lower absorbing properties than the materials used in the other churches.
Modelling the Acoustical and Airflow Performance of Simple Lined Ventilation Apertures
Authors: Oldham D J , Kang Jian , Brocklesby M W
Published: December 2005

The pressure differences that can be used to drive a natural ventilation system are very small and thus large apertures are required to allow sufficient air to enter and leave a building to ensure good air quality or thermal comfort. Large apertures are potential acoustic weak points on a façade and may require some form of acoustic treatment such as absorbent linings, in which case the ventilator is similar to a short section of lined duct. In ducts, the performance of absorbent linings increases with the length of lining and the ratio of the length of lined perimeter to the cross sectional area of the duct. Thus, for a duct of a given cross sectional area, a lining is more effective for a duct with a high aspect ratio than for a duct with a square cross section. However, the high aspect ratio cross section will result in greater flow resistance and impede the airflow performance. In this paper numerical methods are employed to investigate the effect of different configurations of a lined aperture on the acoustical and ventilation performance of the aperture in order to establish the optimum configurations.
Evaluation of Acoustic Sources in an Excited Unstable Laminar Shear Layer
Authors: Hu Z.W. , Morfey C.L. , Sandham N.D.
Published: December 2005

The radiation of sound from artificial sources in a developing shear layer is studied numerically, in order to address an issue that arises in acoustic analogy models of jet noise: namely whether the unstable response of the mean-flow shear layer has a significant effect on sound radiation. Direct numerical simulation of a forced two-dimensional compressible laminar mixing layer has been carried out at a Reynolds number of 250, based on the mixing layer initial vorticity thickness and the upper free-stream velocity. The free-stream Mach numbers of the mixing layer are 0.9 and 0.45. The flow is excited with a single-frequency body force field that is acoustically compact and is derived from an applied-stress distribution. Sound radiation from the mixing layer is calculated at the forcing frequency, and compared with radiation from a uniform flow under the same forcing. Comparisons are shown for the most-unstable forcing frequency over a wide amplitude range. The pressure radiated on either side of the mixing layer differs very little from that radiated into a uniform flow of the same Mach number under the same forcing, although the higher forcing amplitudes used are sufficient to trigger the non-linear process of vortex roll-up in the case of the mixing layer. The dominant source position for the radiated pressure at the forcing frequency is estimated via a wavenumber-frequency domain analysis. It is found to be close to the location of the applied forcing, with little contribution from mixing-layer vortical structures that develop downstream.
Rotor Wake Vortex Definition-Evaluation of 3-C PIV Results of the HART-II Study
Authors: Burley Casey L. , Brooks Thomas F. , Rozier Kristen Y. , Wall Berend van der , Richard Hughes , Raffel Markus , Beaumier Philippe , Delrieux Yves , Lim Joon W. , Yu Yung H. , Tung Chee , Pengel Kurt , Mercker Edzard
Published: December 2005

An evaluation is made of extensive three-component (3-C) particle image velocimetry (PIV) measurements within the wake across a rotor disk plane. The model is a 40 percent scale BO-105 helicopter main rotor in forward flight simulation. This study is part of the HART II test program conducted in the German-Dutch Wind Tunnel (DNW). Included are wake vortex field measurements over the advancing and retreating sides of the rotor operating at a typical descent landing condition important for impulsive blade-vortex interaction (BVI) noise. Also included are advancing side results for rotor angle variations from climb to steep descent. Using detailed PIV vector maps of the vortex fields, methods of extracting key vortex parameters are examined and a new method was developed and evaluated. An objective processing method, involving a center-of-vorticity criterion and a vorticity “disk” integration, was used to determine vortex core size, strength, core velocity distribution characteristics, and unsteadiness. These parameters are mapped over the rotor disk and offer unique physical insight for these parameters of importance for rotor noise and vibration prediction.
Inexacting Whiteness: Blanqueamiento as a Gender-Specific Trope in the Nineteenth Century
Authors: Guevara Gema R
Published: January 2006

In Cuba, race, nation, and popular music were inextricably linked to the earliest formulations
of a national identity. This article examines how the racialized discourse of
blanqueamiento, or whitening, became part of a nineteenth-century literary narrative in
which the casi blanca mulata, nearly white mulatta, was seen as a vehicle for whitening
black Cubans. However, as the novels of Cirilo Villaverde and Ramón Meza reveal, the
mulata's inability to produce entirely white children established the ultimate unattainability
of whiteness by nonwhites. This article analyzes the fluidity of these racial
constructs and demonstrates that, while these literary texts advocated the lightening of
the nation's complexion over time, they also mapped the progressive "darkening" of
Cuban music as popular culture continued to borrow from black music.

En Cuba, y desde un principio, los discursos sobre raza, nación y música popular se
vinculan a los conceptos de una identidad nacional. En este artículo se examina la
incorporación del proceso discursivo del blanqueamiento a la narrativa literaria del siglo
xix. Dicho discurso asignó a "la mulata casi blanca" el papel de agente homogenizador,
responsable de fomentar el blanqueamiento del negro cubano. Sin embargo, como las
novelas de Cirilo Villaverde y Ramón Meza revelan, el poder reproductivo de la mulata
se ve limitado al no poder traspasar las fronteras raciales que establecían lo que implicaba
ser "blanco" en Cuba. Este artículo analiza la fluidez que caracteriza estas
construcciones raciales y demuestra que, mientras que estos textos literarios abogaban
por el blanqueamiento de la futura nación, también señalan cómo la música cubana se
fue "oscureciendo" progresivamente a medida que el elemento Afrocubano fue influyendo
en la cultura popular.
Fleeing the Revolution: The Exodus of Cuban Jewry in the Early 1960s
Authors: Kaplan Dana Evan
Published: January 2006

The Cuban Revolution's economic policies destroyed the island's Jewish community as
it had been in the 1950s, leaving only a small contingent remaining on the island. Most
Jews were middle-class businessmen and the revolution's socialist policies undermined
the economic basis of the community. This article describes the events that led up to the
mass emigration, the process of the emigration itself, and the financial consequences of
the emigration for those who left and those who remained behind. As more restrictive
laws governing emigration were passed, it became more difficult to leave the country
and certainly to take out assets. The Hebrew Immigrant Aid Society (HIAS) organized a
registration process in Havana and facilitated flights and resettlement. Of particular note
were a small number of Jewish children who emigrated without their parents as part of
Operación Pedro Pan. In recent years, some of the Cuban Jews who fled Castro have
returned to visit the remaining Jewish community and in some cases contribute to its
redevelopment.

La comunidad judía de Cuba de los años cincuenta quedó destrozada por las políticas
económicas de la revolución. Apenas un número muy reducido de judíos permaneció en
la isla. La mayoría de los judíos eran hombres de negocios de clase media y las políticas
socialistas de la revolución minaron la base económica de esta comunidad. Este artículo
describe los acontecimientos que condujeron a la emigración masiva, el proceso de
emigración en sí y las consecuencias financieras del éxodo, tanto para los emigrantes
como para aquellos que se quedaron. A medida que se aprobaron leyes de emigración
cada vez más restrictivas, salir del país y sacar bienes resultaba más difícil. La Sociedad
Hebrea de Ayuda al Inmigrante (HIAS) organizó un proceso de registro en La Habana y
facilitó vuelos y el reasentamiento de judíos cubanos fuera de la isla. En particular, se
destaca un grupo pequeño de niños judíos que emigraron sin sus padres como parte de la
Operación Pedro Pan. En años más recientes, algunos de los judíos cubanos que huyeron
del régimen de Castro han regresado al país para visitar la comunidad judía y, en algunos
casos, contribuir a su reconstrucción.
Stretching the Limits of Gendered Spaces: Black and Mulatto Women in 1830s Havana
Authors: Mena Luz
Published: January 2006

In a city mapped out by the elites to resemble nineteenth-century Paris, European and
American visitors showed surprise at the scarcity of white women in Havana's public
spaces. Meanwhile, black and mulatto women filled Havana's streets and plazas. They
needed to in order to survive and to better themselves. What is more, their economic and
social participation was indispensable to the daily functioning of the city. They constituted
the majority of the city's peddlers, artisans, midwives, caretakers and preschool
teachers. There were also business owners among them. And they were the wives and
consorts of both black and white men. They integrated themselves in almost every
aspect of daily city life by using tactics that helped them get around racial and gender
discrimination. One important tactic was the use of prejudice to their advantage: they
filled the economic and social gaps left by the racial prejudice and archaic gender
conventions of the Cuban elites. This article will examine how, through their daily
economic and social practices, women of color stretched the limits of the gendered and
racialized spaces in early modern Havana.

La escasez de mujeres blancas en las áreas públicas se hacía palpable para los visitantes
europeos y americanos en una Habana planificada por las élites para rememorar el Paris
del siglo xix. Mientras tanto, mujeres negras y mulatas llenaban las calles y las plazas de
la ciudad. Lo hacían no sólo por necesidad, sino también para mejorar su situación. Por
otro lado, su participación social y económica era indispensable para el buen funcionamiento
de la ciudad. Constituían la mayoría de las vendedoras, artesanas, parteras,
cuidaderas, y maestras de primeras letras de la ciudad. Algunas hasta eran dueñas de
negocios, así como esposas y compañeras, tanto de hombres blancos como negros. Con
la ayuda de ciertas tácticas, lograron evadir la discriminación racial y de género, integrándose
en casi todos los aspectos de la vida diaria. Una táctica clave fue la de sacarle
ventaja al prejuicio, llenando las brechas económicas y sociales que quedaban por el
prejuicio racial de las élites y sus convenciones arcaicas con respecto al género. Este
artículo examina cómo, a través de sus prácticas diarias, las mujeres de color rebasaron
los límites de los espacios delimitados por convenciones de género y raza en La Habana
del siglo xix.
Prensa, politica y prostitucion en La Habana finisecular: El caso de La Cebolla y la "polemica de las meretrices"
Authors: Calvo Pena Beatriz
Published: January 2006

Este trabajo analiza e interpreta los diferentes textos que polemizaron en torno a la
prostitución hacia finales del siglo xix y los relaciona con el conflicto cubano-español y
con la formación del discurso nacionalista cubano. Centra su atención en el periódico La
Cebolla, publicado a lo largo del mes de septiembre de 1888 en la ciudad de La Habana.
El estudio pretende demostrar que la autoría de tal periódico no es atribuible a las
prostitutas, sino a Victorino Reineri, un periodista español que en el mismo año firmaba
en otros periódicos isleños de tendencias anarquistas. Dicho periodista tendría un objetivo
político a la hora de publicar el semanario, pues La Cebolla creaba un contradiscurso
capaz de desmantelar los valores sobre los que se basaba el discurso nacional
defendido por las élites criollas. La Cebolla y el conjunto de textos sobre la prostitución
(a lo cual he llamado "la polémica de las meretrices") demuestra que el discurso sexual
se entretejió a fines del siglo xix con el discurso político y ayuda a comprender cómo fue
utilizada la sexualidad femenina para la creación de un discurso de identidad nacional
por parte de todos los grupos sociales en un momento histórico tan convulso.

This paper analyzes and interprets various polemical texts on prostitution published
toward the end of the nineteenth century, tying them to the Cuban-Spanish conflict and
the formation of a Cuban nationalist discourse. Of particular interest here is the newspaper
La Cebolla, published during the month of September, 1888, in Havana. The
study seeks to demonstrate that the newspaper's content cannot be attributed to prostitutes
but rather to Victorino Reineri, a Spanish journalist who during the same year
wrote in other anarchist-leaning Cuban newspapers. He had a political objective in
publishing the weekly newspaper, since La Cebolla espoused a position that countered
values at the heart of the national discourse defended by the criollo elite. La Cebolla and
other texts about prostitution (what I have called "the polemic of the harlots") show that
sexual discourse at the end of the nineteenth century was intertwined with political
discourse and shed light on how female sexuality was utilized by all social groups in the
creation of a discourse of national identity during this tumultuous historical moment.
Prosperity, Progress, and Wealth: Cuban Enterprise during the Early Republic, 1902-1927
Authors: Speck Mary
Published: January 2006

Many historians see the first decades of the twentieth century in Cuba as a time of
frustration and failure. An unhealthy dependence on U.S. trade and investment distorted
Cuba's economy, they argue, while the incessant barrage of U.S. goods and culture
undermined its national identity. The business and political classes in pre-Revolutionary
Republic of Cuba are portrayed as accepting the imposition of U.S. interests and the
dictates of U.S. culture out of weakness, venality, or both. This article argues that native
investment and entrepreneurship were crucial to Cuba's rapid economic growth during
the first decades after the war for independence. As heirs to the liberal, Creole economic
elite that had modernized the sugar industry in the nineteenth century, Cuban entrepreneurs
during the Republic were more than capable of collaborating with and competing
against foreign capitalists to create one of the world's most dynamic export economies.

Según la perspectiva de muchos historiadores, las primeras décadas del siglo xx en
Cuba fueron una época de frustración y fracaso. Una dependencia poco saludable del
comercio e inversión de los Estados Unidos distorsionó el desarrollo de la economía
cubana, argumentan, mientras que la afluencia de productos y de la cultura norteamericanos
socavaron la identidad nacional. Según esta interpretación, la élite política y
económica aceptaba la imposición de intereses económicos estadounidenses y de su
cultura por razones de debilidad, venalidad o ambas cosas. Este artículo sostiene que el
capital y la experiencia de los empresarios cubanos fueron cruciales para el rápido
crecimiento económico de Cuba durante las primeras décadas después de la Guerra de la
Independencia. Como herederos de la élite liberal criolla que había modernizado la
industria azucarera en el siglo xix, los empresarios cubanos, durante la Republica,
fueron más que capaces de colaborar y competir con los capitalistas extranjeros para
crear una de las economías exportadoras más dinámicas del mundo.
Audit Committees, Boards, and the Quality of Reported Earnings*
Authors: Vafeas Nikos
Published: January 2006

I use data on 252 U.S. firms between 1994 and 2000 to study the relationship between audit committees and boards of directors with financial reporting quality. I initially document several changes in committee and board profile during the sample period. Results from logistic regressions suggest that measures of audit committee and board structure are related to earnings quality in a manner that is generally consistent with the predictions of agency theory. This study contributes to extant knowledge by employing different earnings quality measures from prior studies, and by expanding the range of audit committee attributes deemed important in determining audit committee performance.
Evidence of Choice Avoidance in Capital‐Investment Judgements*
Authors: Sawers Kimberly M.
Published: January 2006

Evaluating capital‐investment decisions is an important function of managerial accountants. There is anecdotal evidence, however, that managers avoid making decisions or delay decisions, which is costly in terms of time, effort, and lost opportunities. Prior research has shown that choice avoidance among nonprofessionals making personal decisions is associated with having to choose between alternatives with very different features or that require trade‐offs of very important goals (choice difficulty). It is unclear, however, whether experienced managers, using the analytical decision tools at their disposal, respond in the same way as nonprofessionals when making accounting decisions. Hence, this study examines whether increased choice difficulty increases negative affect in the capital‐investment decision‐making process and, as a result, the tendency of managers to avoid choice even when analytical decision tools are used. In an experiment with 120 executives, participants facing more difficult decisions reported they felt more worried, nervous, uneasy, and anxious and had a greater desire to postpone making the decision than participants in a control group. Participants provided with a decision aid designed to help them focus their cognitive effort reported a lower desire to postpone making the decision than participants in the choice‐difficulty conditions without the decision aid. I conclude by discussing the result's implications for managers and accountants.
Determinants of Managerial Earnings Guidance Prior to Regulation Fair Disclosure and Bias in Analysts' Earnings Forecasts*
Authors: Hutton Amy P.
Published: January 2006

Prior to Regulation Fair Disclosure (“Reg FD”), some management privately guided analyst earnings estimates, often through detailed reviews of analysts' earnings models. In this paper I use proprietary survey data from the National Investor Relations Institute to identify firms that reviewed analysts' earnings models prior to Reg FD and those that did not. Under the maintained assumption that firms conducting reviews guided analysts' earnings forecasts, I document firm characteristics associated with the decision to provide private earnings guidance. Then I document the characteristics of “guided” versus “unguided” analyst earnings forecasts. Findings demonstrate an association between several firm characteristics and guidance practices: managers are more likely to review analyst earnings models when the firm's stock is highly followed by analysts and largely held by institutions, when the firm's market‐to‐book ratio is high, and its earnings are important to valuation but hard to predict because its business is complex. A comparison of guided and unguided quarterly forecasts indicates that guided analyst estimates are more accurate, but also more frequently pessimistic. An examination of analysts' annual earnings forecasts over the fiscal year does not distinguish between guidance and no‐guidance firms; both experience a “walk‐down” in annual estimates. To distinguish between guidance and no‐guidance firms, one must examine quarterly earnings news: unguided analysts walk down their annual estimates when the majority of the quarterly earnings news is negative; guided analysts walk down their annual estimates even though the majority of the quarterly earnings news is positive.
The Link between Earnings Conservatism and the Price‐to‐Book Ratio*
Authors: PAE JINHAN , THORNTON DANIEL B. , WELKER MICHAEL
Published: January 2006

We hypothesize and find that (1) earnings conservatism, the tendency of firms to recognize bad news in earnings on a more timely basis than good news, is substantially greater in portfolios of firms with lower price‐to‐book ratios than in portfolios of firms with higher price‐to‐book ratios; and (2) the negative association between earnings conservatism and the price‐to‐book ratio stems primarily from the accrual component of earnings, not the operating cash flow component of earnings. Our results suggest that studies using earnings‐returns associations to investigate cross‐sectional or time‐series differences in earnings conservatism risk drawing erroneous inferences unless the research designs control for cross‐sectional or time‐series variation in price‐to‐book ratios.
Aggregation, Dividend Irrelevancy, and Earnings‐Value Relations*
Authors: YEE KENTON K.
Published: January 2006

In this paper I show that the aggregation of operating and financial income imposes three conditions on earnings‐based value functions. These three conditions provide a shortcut way to identify dividend irrelevant value functions. For example, consider any value function Vt of book value bt, earnings xt, and dividends dt. The aggregation conditions imply that Vt must be of the form Vt = (1 − k)bt + k [f xt − dt]. f is the permanent earnings capitalization factor and undetermined weight k may be any function of Δt ≡[φxt − dt] − bt. The Ohlson 1995 model is the special case when k is constant. But generally k does not have to be constant to maintain dividend irrelevancy. Whenk varies with Δt, Vt is nonlinear in earnings. Hence, this result specifies how Vt may be nonlinear in earnings in settings with limited liability or production or abandonment options and still be dividend‐irrelevant.

An even more remarkable feature of this result is that it holds whether accounting is clean surplus or not. One must conclude that accounting‐based valuation properly builds from accounting aggregation and Δt, and not from the clean surplus relation and abnormal earnings as many now believe.
Conditional Coalescent Trees With Two Mutation Rates and Their Application to Genomic Instability
Authors: Emily Mathieu , François Olivier
Published: December 2005

Humans have invested several genes in DNA repair and fidelity replication. To account for the disparity between the rarity of mutations in normal cells and the large number of mutations present in cancer, an hypothesis is that cancer cells must exhibit a mutator phenotype (genomic instability) during tumor progression, with the initiation of abnormal mutation rates caused by the loss of mismatch repair. In this study we introduce a stochastic model of mutation in tumor cells with the aim of estimating the amount of genomic instability due to the alteration of DNA repair genes. Our approach took into account the difficulties generated by sampling within tumoral clones and the fact that these clones must be difficult to isolate. We provide corrections to two classical statistics to obtain unbiased estimators of the raised mutation rate, and we show that large statistical errors may be associated with such estimators. The power of these new statistics to reject genomic instability is assessed and proved to increase with the intensity of mutation rates. In addition, we show that genomic instability cannot be detected unless the raised mutation rates exceed the normal rates by a factor of at least 1000.
The Broad-Spectrum Blast Resistance Gene Pi9 Encodes a Nucleotide-Binding Site–Leucine-Rich Repeat Protein and Is a Member of a Multigene Family in Rice
Authors: Qu Shaohong , Liu Guifu , Zhou Bo , Bellizzi Maria , Zeng Lirong , Dai Liangying , Han Bin , Wang Guo-Liang
Published: December 2005

The broad-spectrum rice blast resistance gene Pi9 was cloned using a map-based cloning strategy. Sequencing of a 76-kb bacterial artificial chromosome (BAC) contig spanning the Pi9 locus led to identification of six tandemly arranged resistance-like genes with a nucleotide-binding site (NBS) and leucine-rich repeats (LRRs) (Nbs1-Pi9–Nbs6-Pi9). Analysis of selected Pi9 deletion mutants and transformation of a 45-kb fragment from the BAC contig into the susceptible rice cultivar TP309 narrowed down Pi9 to the candidate genes Nbs2-Pi9 and Nbs3-Pi9. Disease evaluation of the transgenic lines carrying the individual candidate genes confirmed that Nbs2-Pi9 is the Pi9 gene. Sequence comparison analysis revealed that the six paralogs at the Pi9 locus belong to four classes and gene duplication might be one of the major evolutionary forces contributing to the formation of the NBS–LRR gene cluster. Semiquantitative reverse transcriptase (RT)–PCR analysis showed that Pi9 was constitutively expressed in the Pi9-resistant plants and was not induced by blast infection. The cloned Pi9 gene provides a starting point to elucidate the molecular basis of the broad-spectrum disease resistance and the evolutionary mechanisms of blast resistance gene clusters in rice.
Pheromones and Pheromone Receptors Are Required for Proper Sexual Development in the Homothallic Ascomycete Sordaria macrospora
Authors: Mayrhofer Severine , Weber Jan M , Pöggeler Stefanie
Published: December 2005

The homothallic, filamentous ascomycete Sordaria macrospora is self-fertile and produces sexual fruiting bodies (perithecia) without a mating partner. Even so, S. macrospora transcriptionally expresses two pheromone-precursor genes (ppg1 and ppg2) and two pheromone-receptor genes (pre1 and pre2). The proteins encoded by these genes are similar to α-factor-like and a-factor-like pheromones and to G-protein-coupled pheromone receptors of the yeast Saccharomyces cerevisiae. It has been suggested that in S. macrospora, PPG1/PRE2 and PPG2/PRE1 form two cognate pheromone–receptor pairs. To investigate their function, we deleted (Δ) pheromone-precursor genes (Δppg1, Δppg2) and receptor genes (Δpre1, Δpre2) and generated single- as well as double-knockout strains. No effect on vegetative growth, fruiting-body, and ascospore development was seen in the single pheromone-mutant and receptor-mutant strains, respectively. However, double-knockout strains lacking any compatible pheromone-receptor pair (Δpre2/Δppg2, Δpre1/Δppg1) and the double-pheromone mutant (Δppg1/Δppg2) displayed a drastically reduced number of perithecia and sexual spores, whereas deletion of both receptor genes (Δpre1/Δpre2) completely eliminated fruiting-body and ascospore formation. The results suggest that pheromones and pheromone receptors are required for optimal sexual reproduction of the homothallic S. macrospora.
Cytogenetic and Molecular Evaluation of Centromere-Associated DNA Sequences From a Marsupial (Macropodidae:Macropus rufogriseus) X Chromosome
Authors: Bulazel Kira , Metcalfe Cushla , Ferreri Gianni C , Yu Jingwei , Eldridge Mark D B , O'Neill Rachel J
Published: December 2005

The constitution of the centromeric portions of the sex chromosomes of the red-necked wallaby, Macropus rufogriseus (family Macropodidae, subfamily Macropodinae), was investigated to develop an overview of the sequence composition of centromeres in a marsupial genome that harbors large amounts of centric and pericentric heterochromatin. The large, C-band-positive centromeric region of the X chromosome was microdissected and the isolated DNA was microcloned. Further sequence and cytogenetic analyses of three representative clones show that all chromosomes in this species carry a 178-bp satellite sequence containing a CENP-B DNA binding domain (CENP-B box) shown herein to selectively bind marsupial CENP-B protein. Two other repeats isolated in this study localize specifically to the sex chromosomes yet differ in copy number and intrachromosomal distribution. Immunocytohistochemistry assays with anti-CENP-E, anti-CREST, anti-CENP-B, and anti-trimethyl-H3K9 antibodies defined a restricted point localization of the outer kinetochore at the functional centromere within an enlarged pericentric and heterochromatic region. The distribution of these repeated sequences within the karyotype of this species, coupled with the apparent high copy number of these sequences, indicates a capacity for retention of large amounts of centromere-associated DNA in the genome of M. rufogriseus.
How Are Humans Related to Other Primates?: A Guided Inquiry Laboratory for Undergraduate Students
Authors: Kalinowski Steven T , Taper Mark L , Metz Anneke M
Published: December 2005

Understanding that phylogenies depict the evolutionary history of species is a critical concept for undergraduate biology students. We present an inquiry-based laboratory exercise exploring this concept in the context of the human phylogeny. This activity reinforces several important biological concepts and skills. Bolstered concepts include that evolution is descent with modification, that evolution is a genetic process, and that humans are closely related to apes. In terms of thinking skills, the lab gives students practice with hypothetical-deductive thinking, quantifying patterns from complex data, and evaluating evidence.
Quantitative Trait Locus Analysis of Atherosclerosis in an Intercross Between C57BL/6 and C3H Mice Carrying the Mutant Apolipoprotein E Gene
Authors: Su Zhiguang , Li Yuhua , James Jessica C , McDuffie Marcia , Matsumoto Alan H , Helm Gregory A , Weber James L , Lusis Aldons J , Shi Weibin
Published: December 2005

Inbred mouse strains C57BL/6J (B6) and C3H/HeJ (C3H) differ significantly in atherosclerosis susceptibility and plasma lipid levels on the apolipoprotein E-deficient (apoE−/−) background when fed a Western diet. To determine genetic factors contributing to the variations in these phenotypes, we performed quantitative trait locus (QTL) analysis using an intercross between the two strains carrying the apoE−/− gene. Atherosclerotic lesions at the aortic root and plasma lipid levels of 234 female F2 mice were analyzed after being fed a Western diet for 12 weeks. QTL analysis revealed one significant QTL, named Ath22 (42 cM, LOD 4.1), on chromosome 9 and a suggestive QTL near D11mit236 (20 cM, LOD 2.4) on chromosome 11 that influenced atherosclerotic lesion size. One significant QTL on distal chromosome 1, which accounted for major variations in plasma LDL/VLDL cholesterol and triglyceride levels, coincided with a QTL having strong effects on body weight. Plasma LDL/VLDL cholesterol or triglyceride levels of F2 mice were significantly correlated with body weight, but they were not correlated with atherosclerotic lesion sizes. These data indicate that atherosclerosis susceptibility and plasma cholesterol levels are controlled by separate genetic factors in the B6 and C3H mouse model and that genetic linkages exist between body weight and lipoprotein metabolism.
Regulation of the Oxidative Stress Response Through Slt2p-Dependent Destruction of Cyclin C in Saccharomyces cerevisiae
Authors: Krasley Elizabeth , Cooper Katrina F , Mallory Michael J , Dunbrack Roland , Strich Randy
Published: December 2005

The Saccharomyces cerevisiae C-type cyclin and its cyclin-dependent kinase (Cdk8p) repress the transcription of several stress response genes. To relieve this repression, cyclin C is destroyed in cells exposed to reactive oxygen species (ROS). This report describes the requirement of cyclin C destruction for the cellular response to ROS. Compared to wild type, deleting cyclin C makes cells more resistant to ROS while its stabilization reduces viability. The Slt2p MAP kinase cascade mediates cyclin C destruction in response to ROS treatment but not heat shock. This destruction pathway is important as deleting cyclin C suppresses the hypersensitivity of slt2 mutants to oxidative damage. The ROS hypersensitivity of an slt2 mutant correlates with elevated programmed cell death as determined by TUNEL assays. Consistent with the viability studies, the elevated TUNEL signal is reversed in cyclin C mutants. Finally, two results suggest that cyclin C regulates programmed cell death independently of its function as a transcriptional repressor. First, deleting its corepressor CDK8 does not suppress the slt2 hypersensitivity phenotype. Second, the human cyclin C, which does not repress transcription in yeast, does regulate ROS sensitivity. These findings demonstrate a new role for the Slt2p MAP kinase cascade in protecting the cell from programmed cell death through cyclin C destruction.
The in Vivo Characterization of Translesion Synthesis Across UV-Induced Lesions in Saccharomyces cerevisiae: Insights Into Polζ- and Polη-Dependent Frameshift Mutagenesis
Authors: Abdulovic Amy L , Jinks-Robertson Sue
Published: December 2005

UV irradiation, a known carcinogen, induces the formation of dipyrimidine dimers with the predominant lesions being cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone adducts (6-4PPs). The relative roles of the yeast translesion synthesis DNA polymerases Polζ and Polη in UV survival and mutagenesis were examined using strains deficient in one or both polymerases. In addition, photoreactivation was used to specifically remove CPDs, thus allowing an estimate to be made of the relative contributions of CPDs vs. 6-4PPs to overall survival and mutagenesis. In terms of UV-induced mutagenesis, we focused on the +1 frameshift mutations detected by reversion of the lys2ΔA746 allele, as Polζ produces a distinct mutational signature in this assay. Results suggest that CPDs are responsible for most of the UV-associated toxicity as well as for the majority of UV-induced frameshift mutations in yeast. Although the presence of Polη generally suppresses UV-induced mutagenesis, our data suggest a role for this polymerase in generating some classes of +1 frameshifts. Finally, the examination of frameshift reversion spectra indicates a hierarchy between Polη and Polζ with respect to the bypass of UV-induced lesions.
A Versatile and Efficient Gene-Targeting System for Aspergillus nidulans
Authors: Nayak Tania , Szewczyk Edyta , Oakley C Elizabeth , Osmani Aysha , Ukil Leena , Murray Sandra L , Hynes Michael J , Osmani Stephen A , Oakley Berl R
Published: December 2005

Aspergillus nidulans is an important experimental organism, and it is a model organism for the genus Aspergillus that includes serious pathogens as well as commercially important organisms. Gene targeting by homologous recombination during transformation is possible in A. nidulans, but the frequency of correct gene targeting is variable and often low. We have identified the A. nidulans homolog (nkuA) of the human KU70 gene that is essential for nonhomologous end joining of DNA in double-strand break repair. Deletion of nkuA (nkuAΔ) greatly reduces the frequency of nonhomologous integration of transforming DNA fragments, leading to dramatically improved gene targeting. We have also developed heterologous markers that are selectable in A. nidulans but do not direct integration at any site in the A. nidulans genome. In combination, nkuAΔ and the heterologous selectable markers make up a very efficient gene-targeting system. In experiments involving scores of genes, 90% or more of the transformants carried a single insertion of the transforming DNA at the correct site. The system works with linear and circular transforming molecules and it works for tagging genes with fluorescent moieties, replacing genes, and replacing promoters. This system is efficient enough to make genomewide gene-targeting projects feasible.
Transposition of Regulatory Elements by P-Element-Mediated Rearrangements in Drosophila melanogaster
Authors: Pomerantseva Ekaterina , Biryukova Inna , Silicheva Rita , Savitskaya Ekaterina , Golovnin Anton , Georgiev Pavel
Published: December 2005

Previously we described highly unstable mutations in the yellow locus, induced by the chimeric element and consisting of sequences from a distally located 1A unique genomic region, flanked by identical copies of an internally deleted 1.2-kb P element. Here we show that a sequence, which is part of the yellow 1A region, can be transmitted to the AS-C by successive inversion and reinversion generated by yellow- and AS-C-located P elements. The chimeric element contains a regulatory element from the 1A region that specifically blocks yellow wing and body enhancers and simultaneously stimulates yellow expression in bristles. These results suggest that P-element-generated chimeric elements may play a certain role in rapid changes of regulatory regions of genes during evolution.