bluuebunny/crossref_metadata_2025 huggingface dataset:
Initial Usability Testing of Navigation and Interaction Methods in Virtual Environments: Developing Usable Interfaces for Brain Injury Rehabilitation
Authors: Wallergård Mattias , Lindén Anita , Davies Roy , Boschian Kerstin , Sonesson Bengt , Minör Ulf , Johansson Gerd
Published: January 2007

It is speculated that virtual environments (VE) might be used as a training tool in brain injury rehabilitation. The rehabilitation process often involves practicing so-called instrumental activities of daily living (IADL), such as shopping, cooking, and using a telephone. If a brain injury patient is to practice such activities in a VE, the patient must be able to navigate the viewpoint and interact with virtual objects in an understandable way. People with brain injury may be less tolerant to a poor interface and a VE might therefore become unusable due to, for example, an unsuitable input device. In this paper we present two studies aimed to do initial usability testing of VE interaction methods on people without experience of 3D computer graphics. In the first study four navigation input device configurations were compared: the IntelliKeys keyboard and the Microsoft Sidewinder joystick, both programmed with two and three degrees of freedom (DOF). The purpose of the second study was to evaluate a method for interaction with objects, and to find a sufficiently usable input device for this purpose. The keyboard was found to be more suitable for navigation tasks in which the user wants to give the viewpoint a more advantageous position and orientation for carrying out a specific task. No big differences could be found between two and three DOFs. The method for interaction with objects was found to work sufficiently well. No difference in performance could be found between mouse and touch screen, but some evidence was found that they affect the usability of the VE interface in different ways.
Airborne Retrievals of Snow Microwave Emissivity at AMSU Frequencies Using ARTS/SCEM-UA
Authors: Harlow R. Chawn
Published: January 2007

The remote sounding, by satellite, of atmospheric temperature and humidity is an important source of data for assimilation into operational weather forecasting routines. For retrievals of these variables near the surface, wavebands with low optical depths are monitored to allow penetration through the overlying atmosphere. Brightness temperatures in these relatively transparent bands are also sensitive to the land surface emissivity and effective temperature. Inadequate understanding of these land surface emissivities is a major issue when assimilating Advanced Microwave Sounding Unit data for the land-covered portion of the globe. One approach for estimating the emissivity of snow-covered surfaces is an empirical model derived from satellite-based and land-based retrievals of emissivity for a variety of snow types. The Met Office’s Hercules C-130 aircraft flew over snow-covered Arctic terrain of northern Finland during the Polar Experiment (POLEX) of March 2001. On these flights, microwave radiometers provided microwave brightness temperatures at 23.8, 50.3, 89.0, 157, and 183 GHz. The work presented here uses these data along with a robust multiparameter optimization routine [Shuffled Complex Evolution Metropolis (SCEM-UA)] coupled to the Atmospheric Radiative Transfer Simulator (ARTS) to retrieve emissivities at the measured frequencies. These results are then used to validate an empirical model. This latter model predicts 23.8–157-GHz emissivities with an RMSE of less than 0.02 and bias of less than 0.01 when compared with data at an incidence angle of 40°. Nonmonotonic behavior in the emissivity spectrum for this campaign, reported in earlier work, is confirmed by the retrievals presented here.
U.S. Political Culture and Hegemony
Authors: Martínez Jorge Hernández
Published: January 2007

Despite certain changes in character and direction, the political culture that is now being consolidated in the United States in an effort to regain the country’s lost hegemony and legitimize domestic policy is reproducing the themes and tools of the cold war. Terrorism has come to occupy the place that international communism once held. The repressive, intolerant, and violent atmosphere that characterized the cold war has resur-faced today as the new political culture is used to legitimize the use of violence both at home and abroad.
Inclusion and Segregation
Authors: Canales Alejandro I.
Published: January 2007

Immigrant Latin American workers are often subject to precarious working conditions and occupational segregation. On the one hand, even if they are as well-educated and as qualified as their U.S. peers, they are often relegated to lower positions. On the other, they systematically receive lower wages than the average U.S. worker in the same occupational fields. This constitutes a clear example of the inclusion of labor coupled with forms of social exclusion.
The New Pan-American Order
Authors: Suárez Salazar Luis
Published: January 2007

The past three U.S. administrations have employed a variety of strategies to establish a “new Pan-American order” that fits the nation’s hegemonic interests in Latin America and the Caribbean. They have also devised stratagems to counteract the revolutionary and reform-minded efforts in the region that challenge these U.S. attempts to create a new, univocal world order.
U.S. Hemispheric Security, Intellectual Property, and Biodiversity in the Andes
Authors: Pérez Catalina Toro
Published: January 2007

The negotiation of the Andean free-trade agreement consolidated the implementation phase of intellectual property regulation of biodiversity in Latin America, establishing new forms of control over societies and their strategic resources consistent with a strategy of territorial deployment of U.S. national security policies. Aspects of the agreement such as patents and public health, protection of information, patents for secondary uses, and the extension of patents to a 20-year period have become focal points of controversy in the specialized world of politicians, jurists, and economists.
U.S. Security Policies and United States–Colombia Relations
Authors: Nieto Jaime Zuluaga
Published: January 2007

Since its birth as a nation, the United States has espoused an imperialist vocation rooted in the universalism of republican principles. These principles inspired the Monroe Doctrine and the big-stick policy and turned the nation into an international police force. From the end of World War II to the collapse of the socialist bloc, U.S. security policies in Latin America led to interventions directed against insurgency. In the post-cold war context, interventionism has also played a key role in Colombia, where a policy based on the war against drugs was maintained until 2001. Since the September 11, 2001, attacks, the United States has geared its national security policies toward fighting the terrorist threat.
Hegemony in the Coordinates of U.S. Policy
Authors: Figueredo Darío Salinas
Published: January 2007

The reordering of the international system has deepened asymmetries and allowed the East-West dispute to continue in terms of a North-South or center-periphery axis. The new geostrategic order is overwhelmingly unilateral. U.S. conceptions of security and economic-commercial policy constitute an integrated geostrategic whole; the expansion of global commerce is part of the security strategy of the United States. Latin America is an essential area for the United States because of the importance of its “great southern border.” Although there is no concerted regional strategy for avoiding the imposition of unilateralism, countertrends are arising and new forms of interaction and collaboration are emerging. The challenge for regional politics is to entertain the possibility of prioritizing common problems and interests and making what unites Latin America and the Caribbean prevail.
The Asamblea Popular de los Pueblos de Oaxaca
Authors: Esteva Gustavo
Published: January 2007

The Popular Assembly of the Peoples of Oaxaca (Asamblea Popular de los Pueblos de Oaxaca—APPO) grew out of the violent repression of a teachers’ strike in Oaxaca during the late spring of 2006. This chronicle is a description from inside, by a participant, of APPO’s process of decision making and increasingly popular representation of citizens’ discontent with federal and Oaxacan state authorities during the critical months from August 2006 to the violent confrontations with federal police and the military in late October and early November 2006.
The Power of Prime Ministers: Results of an Expert Survey
Authors: O'Malley Eoin
Published: January 2007

Prime ministers are self-evidently important actors in the politics of parliamentary democracies. While there has been an ongoing debate about prime ministerial power in the political science literature, progress has been slow in a debate dating from the 1960s. This lack of progress is because of two connected factors. One is the lack of a theoretical framework to study prime ministerial power. A framework is less likely to be developed because of the lack of data on which hypotheses could be tested. This article reports in detail the methodology and results of an expert survey that was conducted to measure prime ministerial power. These data will provide a significant resource for the future study of prime ministers, cabinets, and the core executive.
Political Science at the Edge of Chaos? The Paradigmatic Implications of Historical Institutionalism
Authors: Ma Shu-Yun
Published: January 2007

Over the past decade, historical institutionalism has emerged as one of the major research pillars of contemporary political science. However, most historical institutionalists seem to be unaware of the paradigmatic implications of this approach for political studies. The theoretical underpinnings of historical institutionalism, namely, the ideas of path dependence and the economics of increasing returns, are based on a new science called complexity science. The worldview of complexity science is largely inconsistent with the scientific foundation of current mainstream political science, namely, Newtonianism. The emergence of historical institutionalist analyses in political studies thus means serious paradigmatic challenges for the discipline.
Determinants of Trust and Cooperation
Authors: Diwakara H.
Published: January 2007

This article examines trust and cooperation between farming communities using groundwater resource for irrigation in northern Gujarat. Trust and cooperation play a crucial role in building social capital, which is critical for good governance and economic development. Recent studies have focused on whether socio-economic and demographic differences between individuals affect degree of trust and cooperation. This study reports survey evidence on trust and cooperation from 150 farm households from 50 self-governed tubewell organizations across five villages in northern Gujarat. The field data is analysed in a regression-based quantitative framework. The major finding is that difference in economic and demographic attributes of individuals is likely to impact trust and cooperation. While ethnic (caste) heterogeneity has no significant impact on trust and cooperation behaviour at a micro level, the demographic attribute (age) of an individual has significant influence on trusting behaviour. The household data shows that at the individual level, trusting and cooperating behaviour varies with economic and demographic attributes of individuals. Policies aiming at economic development of farming communities need to consider these variables with other conditions under which trust and cooperation become imperative.
Using the Delphi Technique to Identify Topics for a Protected Area Co-Management Capacity Building Programme
Authors: De Urioste-Stone S. , McLaughlin W.J. , Sanyal N.
Published: January 2007

Co-management and co-administration are increasingly being promoted as protected area governance tools to encourage local involvement in protected area management in the Mesoamerican region. This increase has exposed the need to strengthen co-management capacities of institutions and organizations. We contend that creating capacity building programmes in co-management should reflect the wisdom of experts and practising co-managers from around the world. This study used the Delphi Technique and the Internet to assemble information from such experts. The purpose of this study was to better understand co-management capacity building needs. The panel of experts comprised of 30 professionals with vast experience in co-management in developing countries. Three rounds of questionnaires were sent to the experts. Twelve topic categories were identified and rated in terms of their importance. Power sharing, negotiating co-management agreements, financing co-management, and understanding the co-management idea were rated as the most important categories. Scoring of final topic categories were analysed using the Wilcoxon, Median, and Kruskall-Wallis non-parametric statistical tests. These results are being used to refine the development of a dynamic re-source web-based database to support co-management capacity building programmes. Results are also informing the development, implementation, and evaluation of a co-administration capacity building programme in Guatemala.
Shaping Democracy through Organizational Practice
Authors: Kudva Neema
Published: January 2007

NGOs are legitimized by their role in creating empowered citizens who will demand state accountability and good governance, build a strong and vibrant civil society, and deepen democracy. By charting the chronological evolution of the tribal struggle in southern Karnataka and by applying an analytical framework that accounts for positional as well as conditional changes within communities, this article explores the ways in which organizational strategies and practices produce uneven empowerment and varied ‘thickening’ of civil society. Further, it highlights the role of local NGOs in enabling tribal communities to take advantage of openings created by the state for articulating demands for self-rule. The article draws on the experiences of four local NGOs, their informal but longstanding network, the Tribal Joint Action Committee, and associated peoples' organizations to emphasize the impact of everyday organizational practice in shaping democracy.
Personal and Economic Empowerment in Rural Indian Women
Authors: Moyle Tracey L. , Dollard Maureen , Biswas Saswata Narayan
Published: January 2007

The present study examined the empowerment of women by addressing two dimensions: economic empowerment and personal empowerment. One hundred women, aged between 16 and 65 years, participating in self-help groups from two rural Indian villages in North-West India took part in the study. Both quantitative and qualitative data were gathered through self-report surveys and interviews, with the analysis yielding contradictory findings. The quantitative data found that working women reported moderate to high levels on collective efficacy, proactive attitude, self-esteem and self-efficacy with no significant reporting of psychological distress. In contrast, examination of the qualitative data revealed positive appraisals of self-worth, purpose and independence and negative appraisals of pressure, challenge and stress. The implications of these findings and the importance of this study are discussed.
News Grazers, Television News, Political Knowledge, and Engagement
Authors: Morris Jonathan S. , Forgette Richard
Published: January 2007

This study examines the modern-day television “news grazer” in American politics. We define news grazers as those individuals who watch television news with remote control in hand and switch to another channel when an uninteresting topic comes up. Using survey data from the Pew Research Center, we find that news grazers differ significantly from nongrazers in news-gathering habits, political knowledge, and behavior. These effects remain significant even when controlling for other factors associated with news-grazing frequency, such as age and gender. The implications for the present and future of democratic political engagement are discussed.
Sore Losers: News Frames, Policy Debates, and Emotions
Authors: Gross Kimberly , Brewer Paul R.
Published: January 2007

This study examined whether news framing of policy debates shapes audience members’ emotions. An experiment revolving around the issue of campaign finance reform tested the effects of conflict and substance coverage on anger and disgust among participants. Conflict coverage produced a conditional effect on these emotions, whereas substance coverage did not. Specifically, the extent to which conflict coverage provoked anger and disgust increased with prior support for the losing side of the debate (in this case, the pro-campaign finance reform side). Such effects may carry implications for political journalism and democratic politics.
Global Angling with a Local Angle: How U.S., British, and Dutch Newspapers Frame Global and Local Terrorist Attacks
Authors: Ruigrok Nel , van Atteveldt Wouter
Published: January 2007

The 9/11 terrorist attacks and later attacks such as those in London and Madrid shocked the world and found their way into the newspapers of many countries. The authors study the international coverage of these events in the context of globalization versus localization and the creation of the dominant post-cold war frame of the War on Terror. Using automatic co-occurrence analysis based on the notion of associative framing, they investigate whether these events were mainly framed in a local or global way in the American, British, and Dutch press. The authors found that although proximity is still a strong determinant of attention for events, the framing of these events was more affected by the global event of 9/11 than by local considerations.
What Media Bias? Conservative and Liberal Labeling in Major U.S. Newspapers
Authors: Eisinger Robert M. , Veenstra Loring R. , Koehn John P.
Published: January 2007

This article tests the hypothesis that major U.S. newspapers disproportionately label conservative politicians. We quantitatively analyze ideological labels of U.S. congresspersons and senators in newspaper articles. We then qualitatively review these articles, seeking to discern if any patterns exist, and if so, why. Disproportionate labeling of conservatives exists but not in a way that constitutes “bias,” as newspapers often label liberals, at times more than they do conservatives. These labeling patterns may be explained by the rise of conservatives who entered Congress in 1994, the political pejorativization of the word liberal, and the increased conservative ideological tenor of the Congress during the past fifteen years. We conclude by discussing possible implications of our findings.
A Short History of Journalism for Journalists: A Proposal and Essay
Authors: Carey James W.
Published: January 2007

James W. Carey was a Shorenstein Center Fellow on leave from his faculty position at Columbia University when he wrote this article in 2003. Carey, who died on May 23, 2006, was a preeminent journalism theorist. He is noted for his “ritual theory” of journalism, which posits that journalism is a type of drama as opposed simply to a means of public communication. Carey joined the Columbia Journalism School’s faculty in 1992 after having been professor and dean of the College of Communication at the University of Illinois. Few scholars could match his writing skills and fewer still could match his intellect. All that was combined in a thoroughly decent man who, though teaching in New York City, held tight to a lifelong devotion to the Boston Red Sox. The Shorenstein Center is fortunate to have had him as one of its fellows, and through its Harvard International Journal of Press/Politics, to have the honor of publishing one of the last articles he wrote.
Community Empowerment: A Partnership Approach to Public Health Program Implementation
Authors: Hanks Carole A.
Published: January 2007

Public policy implementation models reflect who makes decisions, how success is defined, and whether learning is built into decision making. The extant implementation models capture many important features of public policy implementation, including the desire of large public bureaucracies to impose order and rationality on implementation structures that include many public and private organizations. Analysis of the three-decades-long process of implementation of the Special Supplemental Nutrition Program for Women, Infants, and Children suggests that a new public policy implementation model is needed. The new model builds on the iterative learning cycles and shared decision making of community participatory research and better addresses the transactional relationship between program targets and providers than do current implementation models.
Decision Making for Nurse Staffing: Canadian Perspectives
Authors: Hall Linda McGillis , Pink Leah , Lalonde Michelle , Murphy Gail Tomblin , O'Brien-Pallas Linda , Laschinger Heather K. Spence , Tourangeau Ann , Besner Jeanne , White Debbie , Tregunno Deborah , Thomson Donna , Peterson Jessica , Seto Lisa , Akeroyd Jennifer
Published: January 2007

The effectiveness of methods for determining nurse staffing is unknown. Despite a great deal of interest in Canada, efforts conducted to date indicate that there is a lack of consensus on nurse staffing decision-making processes. This study explored nurse staffing decision-making processes, supports in place for nurses, nursing workload being experienced, and perceptions of nursing care and outcomes in Canada. Substantial information was provided from participants about the nurse staffing decision-making methods currently employed in Canada including frameworks for nurse staffing, nurse-to-patient ratios, workload measurement systems, and “gut” instinct. A number of key themes emerged from the study that can form the basis for policy and practice changes related to determining appropriate workload for nursing in Canada. These include the use of (a) staffing principles and frameworks, (b) nursing workload measurement systems, (c) nurse-to-patient ratios, and (d) the need for uptake of evidence related to nurse staffing.
Nurse Work Environments and Occupational Safety in Intensive Care Units
Authors: Stone Patricia W. , Gershon Robyn R. M.
Published: January 2007

Using data collected from 39 intensive care units (ICUs) in 23 hospitals across the United States, the purpose of this study was to examine hospital structural characteristics, nurse characteristics, and nurses' working conditions' impact on occupational safety outcomes. ICU with more positive organizational climates had lower rates of occupational injuries and blood and body fluid exposures (p < .05). Similarly, ICUs in hospitals that had attained magnet accreditation had lower rates of negative occupational health incidents (p < .05). Hospital profitability was inversely related to rates of blood and body fluid exposure (p < .05). Monitoring nurses' working conditions and improving the organizational climate of hospitals is likely to improve the safety of the employee and the profitability of the hospital through improved system outcomes (such as lower turnover of the employees) as well as improve the quality of patient care delivered.
Nursing Cost by DRG: Nursing Intensity Weights
Authors: Knauf Robert A. , Ballard Karen , Mossman Philip N. , Lichtig Leo K.
Published: January 2007

Although diagnosis-related group (DRG) reimbursement is used for Medicare and many other payors, nursing—the largest portion of hospital costs—is not specifically identified and quantified in deriving payments in any of the DRG reimbursement systems except that of New York State. In New York, nursing costs are allocated to each DRG in payment rate formulation by means of nursing intensity weights (NIWs)—relative values reflecting the quantity and types of nursing services provided to patients in each DRG. In the absence of charges for nursing services, these NIWs are derived from scores for each DRG provided by a representative panel of nurses through a modified Delphi technique. NIWs have been shown to correlate with hospitals' nursing costs per day. They are used to set cost-based payment weights, thereby avoiding compression caused by using flat cost-to-charge or cost-per-day averages for all acute and intensive care patients.
Business Policy Practices That Predict Sales of Tobacco
Authors: Gangeness Jeanine E. , Evanson Tracy , Webb Derek
Published: January 2007

This pilot study with tobacco merchants asked how policy practices may influence sales of tobacco to youth. This study compared tobacco merchant new employee training and business policies and practices to business compliance data. Licensed tobacco merchants in a rural Minnesota county were mailed surveys regarding their new employee training and business policies practices. The returned surveys (75.9%, N = 44) were compared with tobacco compliance results that indicated if the business sold tobacco to youth during a county compliance check. The major finding from this study was that the survey respondents who did not sell tobacco to youth provided training on fake identification cards (68.0%, n = 17). Tobacco merchants who provided additional information on fake identification cards (40%,n = 6),α2(2, n = 43) 6.66, p = .036, were more likely to not sell tobacco to youth than the merchants who did not provide fake identification card information.
Revised Response Criteria for Malignant Lymphoma
Authors: Cheson Bruce D. , Pfistner Beate , Juweid Malik E. , Gascoyne Randy D. , Specht Lena , Horning Sandra J. , Coiffier Bertrand , Fisher Richard I. , Hagenbeek Anton , Zucca Emanuele , Rosen Steven T. , Stroobants Sigrid , Lister T. Andrew , Hoppe Richard T. , Dreyling Martin , Tobinai Kensei , Vose Julie M. , Connors Joseph M. , Federico Massimo , Diehl Volker
Published: January 2007

Purpose

Standardized response criteria are needed to interpret and compare clinical trials and for approval of new therapeutic agents by regulatory agencies.

Methods

The International Working Group response criteria (Cheson et al, J Clin Oncol 17:1244, 1999) were widely adopted, but required reassessment because of identified limitations and the increased use of [18F]fluorodeoxyglucose-positron emission tomography (PET), immunohistochemistry (IHC), and flow cytometry. The International Harmonization Project was convened to provide updated recommendations.

Results

New guidelines are presented incorporating PET, IHC, and flow cytometry for definitions of response in non-Hodgkin's and Hodgkin's lymphoma. Standardized definitions of end points are provided.

Conclusion

We hope that these guidelines will be adopted widely by study groups, pharmaceutical and biotechnology companies, and regulatory agencies to facilitate the development of new and more effective therapies to improve the outcome of patients with lymphoma.
Physics of ultra-thin surface films on molecularly smooth surfaces
Authors: Teodorescu M , Balakrishnan S , Rahnejat H
Published: January 2007

This paper investigates the physics of ultra-thin surface films in nano-scale counterformal conjunctions. A novel approach is proposed in which the transient behaviour of the fluid film is integrated with the contact mechanics of the approaching bodies. The method predicts film thickness and pressure distribution, as well as local elastic deflection and resulting sub-surface stress tensor. It is found that inertial dynamics of bodies, as determined by local squeeze film effect, prevents diminution of film below certain thickness and reduces the solvation effect. This approach has direct applications for micro-scale mechanisms, where prediction of thin surface adhered film thickness is required for tribological purposes, as well as structural in-service integrity of contacts of vanishing dimensions.
A General Model to Explore Complex Dominance Patterns in Plant Sporophytic Self-Incompatibility Systems
Authors: Billiard Sylvain , Castric Vincent , Vekemans Xavier
Published: January 2007

We developed a general model of sporophytic self-incompatibility under negative frequency-dependent selection allowing complex patterns of dominance among alleles. We used this model deterministically to investigate the effects on equilibrium allelic frequencies of the number of dominance classes, the number of alleles per dominance class, the asymmetry in dominance expression between pollen and pistil, and whether selection acts on male fitness only or both on male and on female fitnesses. We show that the so-called “recessive effect” occurs under a wide variety of situations. We found emerging properties of finite population models with several alleles per dominance class such as that higher numbers of alleles are maintained in more dominant classes and that the number of dominance classes can evolve. We also investigated the occurrence of homozygous genotypes and found that substantial proportions of those can occur for the most recessive alleles. We used the model for two species with complex dominance patterns to test whether allelic frequencies in natural populations are in agreement with the distribution predicted by our model. We suggest that the model can be used to test explicitly for additional, allele-specific, selective forces.
Selective Sweeps Reveal Candidate Genes for Adaptation to Drought and Salt Tolerance in Common Sunflower, Helianthus annuus
Authors: Kane Nolan C , Rieseberg Loren H
Published: January 2007

Here we report the results of an analysis of variation at 128 EST-based microsatellites in wild Helianthus annuus, using populations from the species' typical plains habitat in Kansas and Colorado, as well as two arid desert and two distinct brackish marsh areas in Utah. The test statistics lnRV and lnRH were used to find regions of the genome that were significantly less variable in one population relative to the others and thus are likely to contain genes under selection. A small but detectable percentage (1.5–6%) of genes showed evidence for selection from both statistics in any particular environment, and a total of 17 loci showed evidence of selection in at least one environment. Distance-based measures provided additional evidence of selection for 15 of the 17 loci. Global FST-values were significantly higher for candidate loci, as expected under divergent selection. However, pairwise FST-values were lower for populations that shared a selective sweep. Moreover, while spatially separated populations undergoing similar selective pressures showed evidence of divergence at some loci, they evolved in concert at other loci. Thus, this study illustrates how selective sweeps might contribute both to the integration of conspecific populations and to the differentiation of races or species.
Mlh1 Deficiency in Zebrafish Results in Male Sterility and Aneuploid as Well as Triploid Progeny in Females
Authors: Feitsma Harma , Leal Marcelo C , Moens Peter B , Cuppen Edwin , Schulz Rüdiger W
Published: January 2007

In most eukaryotes, recombination of homologous chromosomes during meiosis is necessary for proper chromosome pairing and subsequent segregation. The molecular mechanisms of meiosis are still relatively unknown, but numerous genes are known to be involved, among which are many mismatch repair genes. One of them, mlh1, colocalizes with presumptive sites of crossing over, but its exact action remains unclear. We studied meiotic processes in a knockout line for mlh1 in zebrafish. Male mlh1 mutants are sterile and display an arrest in spermatogenesis at metaphase I, resulting in increased testis weight due to accumulation of prophase I spermatocytes. In contrast, females are fully fertile, but their progeny shows high rates of dysmorphology and mortality within the first days of development. SNP-based chromosome analysis shows that this is caused by aneuploidy, resulting from meiosis I chromosomal missegregation. Surprisingly, the small percentage of progeny that develops normally has a complete triploid genome, consisting of both sets of maternal and one set of paternal chromosomes. As adults, these triploid fish are infertile males with wild-type appearance. The frequency of triploid progeny of mlh1 mutant females is much higher than could be expected for random chromosome segregation. Together, these results show that multiple solutions exist for meiotic crossover/segregation problems.
Circadian Rhythms in Neurospora crassa: Clock Mutant Effects in the Absence of a frq-Based Oscillator
Authors: Lombardi Laura , Schneider Kevin , Tsukamoto Michelle , Brody Stuart
Published: January 2007

In Neurospora, the circadian rhythm is expressed as rhythmic conidiation driven by a feedback loop involving the protein products of frq (frequency), wc-1 (white collar-1), and wc-2, known as the frq/wc (FWC) oscillator. Although strains carrying null mutations such as frq10 or wc-2Δ lack a functional FWC oscillator and do not show a rhythm under most conditions, a rhythm can be observed in them by the addition of geraniol or farnesol to the media. Employing this altered media as an assay, the effect of other clock mutations in a frq10- or wc-2Δ-null background can be measured. It was found that the existing clock mutations fall into three classes: (1) those, such as prd-3 or prd-4 or frq1, that showed no effect in a clock null background; (2) those, such as prd-1 or prd-2 or prd-6, that did have a measurable effect in the frq10 background; and (3) those, such as the new mutation ult, that suppressed the frq10 or wc-2Δ effect, i.e., geraniol/farnesol was not required for a visible rhythm. This classification suggests that some of the known clock mutations are part of a broader multioscillator system.
S Locus F-Box Brothers: Multiple and Pollen-Specific F-Box Genes WithSHaplotype-Specific Polymorphisms in Apple and Japanese Pear
Authors: Sassa Hidenori , Kakui Hiroyuki , Miyamoto Mayu , Suzuki Yusuke , Hanada Toshio , Ushijima Koichiro , Kusaba Makoto , Hirano Hisashi , Koba Takato
Published: January 2007

Although recent findings suggest that the F-box genes SFB/SLF control pollen-part S specificity in the S-RNase-based gametophytic self-incompatibility (GSI) system, how these genes operate in the system is unknown, and functional variation of pollen S genes in different species has been reported. Here, we analyzed the S locus of two species of Maloideae: apple (Malus domestica) and Japanese pear (Pyrus pyrifolia). The sequencing of a 317-kb region of the apple S9 haplotype revealed two similar F-box genes. Homologous sequences were isolated from different haplotypes of apple and Japanese pear, and they were found to be polymorphic genes derived from the S locus. Since each S haplotype contains two or three related genes, the genes were named SFBB for S locus F-box brothers. The SFBB genes are specifically expressed in pollen, and variable regions of the SFBB genes are under positive selection. In a style-specific mutant S haplotype of Japanese pear, the SFBB genes are retained. Apart from their multiplicity, SFBB genes meet the expected characteristics of pollen S. The unique multiplicity of SFBB genes as the pollen S candidate is discussed in the context of mechanistic variation in the S-RNase-based GSI system.
Epigenetic Mechanisms for Breakdown of Self-Incompatibility in Interspecific Hybrids
Authors: Nasrallah June B , Liu Pei , Sherman-Broyles Susan , Schmidt Renate , Nasrallah Mikhail E
Published: January 2007

As a major agent of rapid speciation, interspecific hybridization has played an important role in plant evolution. When hybridization involves species that exhibit self-incompatibility (SI), this prezygotic barrier to self-fertilization must be overcome or lost to allow selfing. How SI, a normally dominant trait, is lost in nascent hybrids is not known, however. Here we demonstrate that hybrid self-fertility can result from epigenetic changes in expression of the S-locus genes that determine specificity in the SI response. We analyzed loss of SI in synthetic hybrids produced by crossing self-fertile and self-incompatible species in each of two crucifer genera. We show that SI is lost in the stigmas of A. thaliana–lyrata hybrids and their neo-allotetraploid derivatives and in the pollen of C. rubella–grandiflora hybrids and their homoploid progenies. Aberrant processing of S-locus receptor kinase gene transcripts as detected in Arabidopsis hybrids and suppression of the S-locus cysteine-rich protein gene as observed in Capsella hybrids are two reversible mechanisms by which SI might break down upon interspecific hybridization to generate self-fertile hybrids in nature.
Adrenal Insufficiency: Still a Cause of Morbidity and Death in Childhood
Authors: Shulman Dorothy I. , Palmert Mark R. , Kemp Stephen F. ,   for the Lawson Wilkins Drug and Therapeutics Committee
Published: January 2007

Adrenal insufficiency is relatively rare in childhood and adolescence. Signs and symptoms may be nonspecific; therefore, the diagnosis may not be suspected early in the course. If unrecognized, adrenal insufficiency may present with life-threatening cardiovascular collapse. Adrenal crisis continues to occur in children with known primary or secondary adrenal insufficiency during intercurrent illness because of failure to increase glucocorticoid dosage. In this article, current knowledge of the incidence, diagnosis, and treatment of adrenal insufficiency in children and factors precipitating adrenal crisis are summarized. Suggestions for prevention of adrenal crisis in patients at risk are provided for health care professionals and families.
Molecular cloning of equine 17β-hydroxysteroid dehydrogenase type 1 and its downregulation during follicular luteinization in vivo
Authors: Brown Kristy A , Sayasith Khampoune , Bouchard Nadine , Lussier Jacques G , Sirois Jean
Published: January 2007

The type 1 form of 17β-hydroxysteroid dehydrogenase (17βHSD1) was the first isoform to be identified and is capable of converting estrone to 17β-estradiol. This study was aimed at characterizing the molecular structure of the equine 17βHSD1 gene and cDNA, as well as its molecular regulation during human chorionic gonadotropin (hCG)-induced follicular luteinization/ovulation in vivo. The equine 17βHSD1 gene was cloned from an equine genomic library and shown to have a conserved genomic structure composed of six exons. Its cDNA sequence was also identified and coded for a 308 amino acid protein, 72.1–74.5% homologous to other mammalian orthologs. RT-PCR/Southern blot analyses were performed to study the regulation of the 17βHSD1 transcript in equine preovulatory follicles isolated between 0 and 39 h after hCG treatment. Results demonstrated the presence of high 17βHSD1 mRNA expression prior to hCG treatment with a marked decrease observed 12 h after hCG (P < 0.05). Analyses on isolated preparations of granulosa and theca interna cells identified the granulosa cell layer as the site of 17βHSD1 transcript expression and downregulation (P < 0.05). A 1412 bp fragment of the equine 17βHSD1 proximal promoter was sequenced and shown to contain many putative transcription factor binding sites. Electromobility shift assays (EMSA) using a fragment of the proximal promoter (−230/−30) and nuclear extracts prepared from granulosa cells isolated prior to hCG (0 h post-hCG) revealed the presence of a major complex, and results from competition assays suggest that steroidogenic factor-1 (SF-1), NFκB, GATA, and Sp1 cis-elements are involved. Supershift assays using an antibody against the p65 subunit of NFκB led to the displacement of the binding nuclear proteins to the DNA probe, whereas the use of an anti-equine SF-1 antibody demonstrated the clear formation of a DNA–protein–antibody complex, confirming the potential role of these transcription factors in EMSA results. Interestingly, a notable decrease in DNA binding was observed when granulosa cell nuclear extracts isolated 30 h post-hCG were used, which paralleled the decrease in 17βHSD1 transcript after hCG treatment. Thus, this study is the first to report the gonadotropin-dependent downregulation of 17βHSD1 transcript expression in a monoovulatory species, the presence and regulation of protein/DNA interactions in the proximal region of the 17βHSD1 promoter during gonadotropin treatment, and the characterization of the primary structure of equine 17βHSD1 cDNA and gene.
Identification of Urop11, a novel leptin-modulated gene that is upregulated in the hypothalamus of mice with virus-induced obesity
Authors: Verlaeten O , Casery C , Cavagna S , Naville D , Giraudon P , Belin M F , Begeot M , Bernard A
Published: January 2007

Obesity results from disturbances of tightly regulated interactions between the nervous, endocrine, and metabolic systems that can be caused by external factors, such as viral infections. A mouse model of obesity induced by brain infection with a morbillivirus, canine distemper virus, allowed us to identify obesity-related genes. Using a subtractive library for the hypothalamus, the main brain structure regulating energy homeostasis, we identified a new gene on mouse chromosome 19 which we named upregulated obese product (Urop) 11 and, which has no homology with any known mRNA. A step-by-step molecular approach allowed us to isolate the full-length mRNA, predict the protein sequence, and identify consensus sites. Urop11 was mainly detected in the hypothalamus and adipocytes, and was dramatically upregulated in these central and peripheral structures in obese mice. Urop11 was also expressed in human neural and lymphoid samples and its expression seemed to be regulated by the state of lymphocyte activation. Interestingly, Urop11 expression was strongly upregulated both in vivo in mouse hypothalamus and in vitro in mouse neural cell lines, after leptin treatment. Taken together, our data show that Urop11 is a target of leptin, the satiety factor produced by adipocytes, in physiological and pathological conditions, including obesity. This new gene can be considered a key molecule in the hypothalamic integration pathway and demonstrates the importance of Urop11 as a target of leptin action.
Altered endocytosis of epidermal growth factor receptor in androgen receptor positive prostate cancer cell lines
Authors: Bonaccorsi Lorella , Nosi Daniele , Muratori Monica , Formigli Lucia , Forti Gianni , Baldi Elisabetta
Published: January 2007

Although androgens and the androgen receptor (AR) are involved in tumorigenesis of prostate cancer (PC) in initial phases, less clear is the role played in advanced androgen-independent (AI) stages of the disease. Several recent reports indicated that re-expression of AR in PC-derived cell lines determines a less aggressive phenotype of the cells. We have previously demonstrated that re-expression of AR decreases the invasion ability of PC3 cells in vitro by affecting signalling and internalization processes of epidermal growth factor receptor (EGFR). Here, we show that reduced EGFR internalization is also a characteristic of AR positive PC cell lines LNCaP and 22Rv1. Reduced internalization in PC3-AR cells is associated to a defective interaction between the EGFR and two adaptor proteins which mediate the endocytotic process, Grb2 and c-Cbl. As a consequence of such reduced interaction, ubiquitination of the receptor, which is mainly mediated by c-Cbl, is also altered. In addition, we show that internalized EGFR co-localizes with early endosome antigen-1, a marker of clathrin-mediated endocytosis, in PC3-Neo cells but not in AR positive cell lines. Conversely, EGFR maintains co-localization with caveolin-1 after EGF stimulation in PC3-AR cells. These data suggest that expression of AR affects clathrin-mediated endocytosis pathway of EGFR, which, according to recent findings, plays an essential role in the completeness of signalling of the receptor. Taken together, these data emphasize the role of AR in the regulation of EGFR endocytotic trafficking and active signalling in PC cells. In view of the role of EGFR signalling in invasion of carcinoma cells, our data may explain the lower invasive phenotype observed in AR-positive cell lines.
Identification, tissue expression, and glucocorticoid responsiveness of alternative first exons of the human glucocorticoid receptor
Authors: Presul Elisabeth , Schmidt Stefan , Kofler Reinhard , Helmberg Arno
Published: January 2007

Transcripts for the human glucocorticoid receptor (NR3C1) are known to contain alternative first exons 1A1, 1A2, and 1A3 from the distal promoter or 1D, 1E, 1B, 1F, 1C, or 1H from the proximal promoter. Here, we report two additional alternative first exons identified by Rapid amplification of cDNA ends (RACE)-PCR. The first, exon 1I, starts approximately 700 bp downstream of the splice donor site of the longest form of exon 1A, 1A3, considerably extending the known distal promoter region with a region containing conserved transcription factor-binding sites as well as a potential glucocorticoid response element (GRE) that differs from the consensus GRE in only two positions. The second, exon 1J, is part of the proximal promoter region and resides between exons 1D and 1E. Since this has been determined by quantitative real-time reverse transcriptase (RT)-PCR, exon 1I is used foremost in cells of the T-lymphocyte lineage. In the T-ALL cell line CEM-C7H2, which is sensitive to glucocorticoid-induced apoptosis, transcripts containing alternative first exons from the distal as well as the proximal promoter regions were markedly autoinduced by glucocorticoid treatment, with more pronounced relative induction in the distal promoter. Neither transcript was autoinduced in the related, resistant cell lines CEM-C1, and CEM-C7R5. In contrast, the glucocorticoid-sensitive PreB697 cell line strongly autoinduced transcripts from the proximal promoter, but not transcripts from the distal promoter, to relevant levels. Therefore, the autoinductive feedback loop implicated in glucocorticoid-induced apoptosis cannot universally rely on the distal promoter of the glucocorticoid receptor.
High-Frequency Tsunami Signals of the Great Indonesian Earthquakes of 26 December 2004 and 28 March 2005
Authors: Hanson Jeffrey A. , Reasoner Colin L. , Bowman J. Roger
Published: January 2007

Tsunamis generated by the great Indonesian earthquakes of 26 December 2004 (Mw 9.3) and 28 March 2005 (Mw 8.6) produced high-frequency (>5 mHz) dispersed signals recorded by hydrophone stations offshore from Diego Garcia and Cape Leeuwin, Australia, and by many seismic stations in the Indian Ocean and on the coast of Antarctica. For the first and greater earthquake, the dispersed energy is commonly observed to 30 mHz and, in one case, to 60 mHz. The high-frequency signals are consistent with being generated at pointlike sources. The earliest arriving tsunami signals originate from a point near 4.3° N, 93.8° E, determined using event- to-station distances estimated by matching predicted dispersion to observations. The location is further constrained with azimuth estimates from an array of hydrophones. Fine structure in the tsunami signal indicates a second high-frequency source just south of Great Nicobar Island near 6.5° N, 93.6° E. The point sources are located close to the maximum slip area determined in several other seismic and tsunami studies. The dispersion of much later-arriving energy is consistent with travel over longer paths, and matches predictions for reflections of the tsunami from bathymetric features in the Indian Ocean basin. For the 28 March 2005 tsunami, the high- frequency dispersion is observed at the Diego Garcia hydrophone station and the AIS seismic station, and tsunami signals without apparent dispersion are seen at four other seismic stations. Phase velocities estimated at hydroacoustic stations agree with linear dispersion theory at frequencies above 12 mHz.