bluuebunny/crossref_metadata_2025 huggingface dataset:
Lessons From Privatization Task Forces
Authors: Korosec Ronnie LaCourse , Mead Timothy D.
Published: April 2005

This study provides evidence on an aspect of privatization that is increasing in popularity yet rarely considered in the literature: the effect that private‐sector task forces have on privatization efforts. It uses case studies from Charlotte and Raleigh, North Carolina, to provide evidence on the role of task forces in reengineering government and suggests how future privatization efforts can benefit from this knowledge. Specifically, it suggests that task forces need to establish realistic timetables, understand that there are fundamental differences between the public and private sectors, and work without predetermined biases to achieve desired ends. In addition, they need to identify services that are appropriate for privatization, understand the nature of privatization, and accept both the strengths and weaknesses of it. While the results of privatization endeavors may vary, they may be enhanced by adopting a new awareness of how private‐sector task forces influence privatization efforts.
Microsimulation Models and Labor Supply Responses to Welfare Reforms
Authors: Martini Alberto
Published: April 2005

While in principle including behavioral responses in microsimulation models is always desirable, the intrinsic difficulty of modeling individual behavior and the utilization of the results by a policy audience argue for a cautious and motivated use of behavioral responses. We report simulations of the effect on labor supply of four welfare reforms that affect female heads of households. We find that ignoring behavioral responses understates the disposable income gain (or overstates the losses) incurred by these families. In some cases the differences are trivial, while in others (the expansion of the Earned Income Tax Credit and the imposition of time limits) ignoring the labor supply response might provide a distorted view of the effects of the reform.
User Fees and Family Policy: Attempting to Recover Costs for State‐Provided Child Support Enforcement Services
Authors: Garasky Steven
Published: April 2005

This study looks in depth at three family policy issues surrounding one state's attempt to recover costs for child support enforcement services provided to nonpublic assistance families. The issues are whether a cost recovery user fee should be assessed; to whom the fee should be assessed; and how to develop a fee structure to meet criteria established by the policy agents. The original study was mandated by the state legislature. Recommendations were made to the legislature to continue one small fee, discontinue another unpopular fee, and institute three new broad‐based fees that would allow for nearly full cost recovery. In an election year the legislature accepted the first two recommendations but chose not to pursue the three new fees. Implications for policy development are drawn, focusing on the impact of user fees on service recipients and the role of the public sector in providing services that are available in the private sector in an era of tighter budgets.
A Potential Case of Social Bankruptcy: States' AFDC Payments and Their Teen Birth Rates
Authors: Zimmerman Shirley L. , Gager Constance T.
Published: April 2005

Based on a pooled time series analysis that covers a 30‐year period at five different time points—1960, 1970, 1980, 1985, and 1990—this research examines the relationship between states' Aid to Families with Dependent Children (AFDC) payments and teen birth rates. Drawing on rational choice theories, we expected the effects of states' AFDC payments on their teen birth rates to be positive, taking into account states' divorce rates, population change rates, unemployment rates, racial composition, and poverty rates. The effects of states'AFDC payments were significant in a negative direction in Model 1, a random effects model; they also were significant in a negative direction in Model 2 when we controlled for the effects of year; however, when we controlled for the effects of year and state in Model 3, they were not significant. The findings do not support assumptions regarding the incentive effects of welfare that underlie rational choice theories in states where teen birth rates are higher. If anything, teen birth rates are higher in states where AFDC payments are lower. Implications for policy and further research are discussed in relation to the positive effects of states' poverty and population change rates on the state teen birth rate problem.
Issue Definition in State Economic Development Policy
Authors: Boeckelman Keith
Published: April 2005

This paper examines whether an “issue definition” perspective developed by Baumgartner and Jones (1993) can account for the dynamics of state economic development policy. The analysis centers on a case study of Louisiana, and shows that efforts to redefine tax exemptions as a threat to the environment were only partially successful in leading to policy change. I speculate on the reasons for this failure, concluding with the fact that special conditions made it harder to redefine the economic development issue there. I argue further that the dynamics of issue redefinition differ by issue type and according to the level of government responsible for a particular policy.
Explaining A Paradox: The Alberta‐California Natural Gas Trade Dispute
Authors: Wilson Patrick Impero
Published: April 2005

For over 3 years the Alberta government and the California Public Utilities Commission engaged in a bitter dispute over the future of the Alberta‐California natural gas trade. This article examines how both sides sought to use their regulatory authority to control the substance of gas trade restructuring. It assesses the dispute as an exercise in deregulatory policymaking and suggests the need for increased study of the role and motivations of subnational regulatory actors.
From Zero‐Sum to Value‐Added Strategies: The Emergence of Knowledge‐Based Industrial Policy in the States of the United States
Authors: Etzkowitz Henry
Published: April 2005

State science policy is industrial policy, shaped by local research and industrial strengths or, conversely, lack of same. States with research strengths relevant to local declining industries attempt to link them in an effort to revive the latter; states lacking research strengths attempt to develop them, especially in areas relevant to local natural resources that have the potential to be the basis of new high‐tech industries. Such knowledge‐based industrial policies supplement, even if they do not replace, traditional strategies focused upon: (a) creating economic activity based upon natural resources such as harbors or mineral deposits, (b) improving the business climate by lowering taxes, or (c) attracting industry to relocate by offering subsidies. The role of the federal government in science‐based industrial policy is still controversial even as it is widely accepted in the states as part of traditional responsibilities for their citizen's economic welfare.
Using Technology Absorption as an Evaluation Criterion: Case Studies from a State Research and Development Program
Authors: Kingsley Gordon , Farmer Michael C.
Published: April 2005

State agencies sponsoring local research and development projects often finance the development of technologies in partnership with other organizations. These contracting partners develop and demonstrate the new technology. This study distinguishes between two types of outcomes from such projects. Technology absorption is the adoption of a technology by an organization participating in the project. Technology transfer is the process by which outcomes are adopted by organizations outside the project (i.e., nonparticipants). From an evaluation perspective, research and development projects that result in the absorption of technology, without any subsequent transfer, are difficult to assess. Often these outcomes are counted the same as a transfer even though the process is subsidized by the state.

Three case studies of absorption outcomes are presented. Absorption projects tend to be distinctive because: (a) they develop technologies that are very large in scale and very complex; (b) project leadership typically is provided by an end‐user who attempts to employ the technology for commercial purposes; (c) success is measured through the technological accomplishment and ongoing commercial venture rather than by the number of adopting organizations; and (d) they produce spillover benefits in the cohesion of the social networks formed among project participants.
A View of Their Own: Women's Committee Leadership Styles and State Legislatures
Authors: Rosenthal Cindy Simon
Published: April 2005

Analysis of survey data from 291 state legislative committee chairs suggests that professionalization has important gender implications not previously explored. Legislatures are gendered in the sense that culturally masculine and feminine committee management styles are more at home in some legislatures than in others. “Citizen” legislatures seem to be more hospitable to “feminine” behaviors of inclusion and a motivation focused on people‐oriented concerns. Professionalized legislatures–promoted in large part on the basis of a masculine vocabulary of independence, rationality, expertise, and competition with the executive–discourage inclusive or collegial committee strategies and public‐minded motives. Professional legislatures may be positive environments in which to nurture policy leadership, but their committee leaders eschew public participation.
Legislator Gender and Legislator Policy Priorities in the Argentine Chamber of Deputies and the United States House of Representatives
Authors: Jones Mark P.
Published: April 2005

This paper suggests that the findings of the literature on gender differences in legislator policy priorities in advanced industrial democracies very well may be generalizable to nations in the developing world, particularly those in Latin America. Previous studies of gender differences in legislator policy priorities have been confined to a small number of advanced industrial democracies. These studies have found women legislators to give a higher degree of priority than men to policies in the thematic areas of women's rights and children and families. Employing data on bill introduction, this paper tests for and finds similar gender differences in the Argentine Chamber of Deputies and the United States House of Representatives. Significant gender differences were found in both national legislatures in the areas of women's rights and children and families. No significant gender differences were found in other areas widely considered to be of traditional interest to women.
Book Notes
Authors: Donoher William J.
Published: April 2005

Books reviewed in this article:

Donald L. Alexander (Ed.), Telecommunications Policy: Have Regulators Dialed the Wrong Number?

John J. Audley, Green Politics and Global Trade: NAFTA and the Future of Environmental Politics.

William I. Bacchus, The Price of American Foreign Policy: Congress, the Executive, and International Affairs Funding.

Arnold Birenbaum, Managed Care: Made in America.

Thomas A. Birkland, After Disaster; Agenda Setting, Public Policy, and Focusing Events.

James Bowman and Donald Menzel (Eds.), Teaching Ethics and Values in Public Administration Programs.

Robert J. Duffy, Nuclear Politics in America: A History and Theory of Government Regulation.

Marianne Githens and Dorothy McBride Stetson (Eds.), Abortion Politics: Public Policy in Cross‐Cultural Perspective.

Christopher Howard, The Hidden Welfare State: Tax Expenditures and Social Policy in the United States

Joan Johnson‐Freese and Roger Handberg, Space, The Dormant Frontier: Changing the Paradigm for the 21st Century.

Jennie Jacobs Kronenfeld, The Changing Federal Role in U.S. Health Care Policy.

Yong S. Lee (Ed.), Technology Transfer and Public Policy.

James Midgley, Social Welfare in Global Context.

Nancy C. Roberts and Paula J. King, Transforming Public Policy: Dynamics of Policy Entrepreneurs hip and Innovation.

Denise Scheberle, Federalism and Environmental Policy: Trust and the Politics of Implementation.

David E. Wildasin (Ed.), Fiscal Aspects of Evolving Federations.
Supply response of U.K. milk producers
Authors: Colman David , Solomon Alexander , Gill Len
Published: April 2005

Short‐run own‐price response elasticities are estimated from two samples of panel data for specialist dairy farms in the Northwest and Southwest of England. Although these farms are subject to milk marketing quotas, the free tradability of quotas enables them individually to adjust the output quite rapidly. Model specifications have been chosen to test the ability of panel data to directly reveal behavioral responses without the imposition of theoretical restrictions. Significantly, the two independent samples generate quite similar results, especially in terms of supply response measures. Stable and promising estimates are obtained with simultaneous models giving higher elasticities than single equation models.
Bacterial plasmids in the oral and endodontic microflora
Authors: Sedgley Christine , Clewell Don B.
Published: April 2005

Bacterial plasmids typically represent covalently closed circular, double‐stranded, supercoiled DNA molecules that replicate independently of chromosomal DNA. Plasmids are frequently not essential to the bacterial host, but can confer traits facilitating survival under atypical conditions e.g. resistance to antibiotics and heavy metals. Plasmids have been identified in clinical and environmental bacteria from all over the world, and range in size from ∼1 to >200 kb. Their copy number in the cell can range from one or two copies per chromosome, to well over 30; the number is usually characteristic for the particular plasmid. Clinical strains of Enterococcus faecalis, a species commonly associated with root canal infections, can carry as many as six co‐resident plasmids with different sizes and copy numbers. In part because of their ability to replicate autonomously, plasmids are used as tools or shuttle vectors in basic molecular biological research. Many plasmids can transfer copies of themselves from one bacterial cell to another by a process called conjugation. In some cases, small peptides called pheromones act as mating signals in this process. Conjugative plasmids that make use of pheromones have been identified previously in E. faecalis and the related plasmids tend to exhibit a narrow host range. Conjugative plasmids in E. faecalis that do not make use of pheromones usually have a much broader host range. Pheromone‐responding plasmids in E. faecalis can carry genes relating to antibiotic resistance as well as virulence traits. In general, plasmids are capable of adaptability and stable maintenance in a wide spectrum of bacterial hosts. The potential role of plasmids in oral and endodontic microbiology is discussed.
Clinical aspects related to endodontic yeast infections
Authors: Waltimo Tuomas M. T. , Haapasalo Markus , Zehnder Matthias , Meyer Jürg
Published: April 2005

Yeasts can be detected in 7–18% of infected root canals. They are commonly associated with persistent cases of apical periodontitis, but yeasts can also be isolated in primary apical periodontitis. Their relative proportion of the root canal flora is low, usually below 1%. Therefore, yeast detection with conventional microbiological methods may be difficult. Selective culture media such as Sabouraud dextrose agar combined with cultivation from undiluted sample should be used for primary isolation of yeasts in endodontic infections. Preliminary identification of yeasts is based on typical colony and cellular morphology and a positive catalase test. Detection by molecular biological methods is sensitive, but may occasionally also give false‐positive results. Candida albicans is the most commonly detected yeast species from infected root canals. It is typically found together with Gram‐positive bacteria such as streptococci, but can also be isolated in pure culture, which is an indication of its pathogenicity. A variety of virulence factors enable C. albicans to adhere to and penetrate into dentine. Furthermore, C. albicans tolerates harsh ecological conditions including high alkalinity. Calcium hydroxide is generally not efficient against oral yeasts in vitro; the in vivo effectiveness of calcium hydroxide is not known. However, sodium hypochlorite, iodine compounds, and chlorhexidine have proven effective against yeasts both in experimental conditions as well as in vivo and may offer effective treatment possibilities against endodontic yeast infections.
The grassland farming system and sustainable agricultural development in China
Authors: Nan Zhibiao
Published: April 2005

Grassland is the largest terrestrial ecosystem in China, at about 39 280 × 104 ha and covers 41% of the total land area. Grasslands not only provide forage to feed livestock, but also play a critical role in alleviating many of the most challenging environmental and ecological problems that humankind is facing. About 90% of the total usable grassland in China has been degraded to various extents and this is the number one problem facing agricultural production, rural development and environmental improvement. Research on grassland degradation has been carried out since the early 1950s. Enormous achievements have been made and theory and a technical system for pastoral agriculture have been developed. This pastoral agriculture system is a well‐organized modern farming system including four production levels, that is, preplant, plant, animal and postbiotic levels, and is linked by three interfaces, including vegetation‐site, grassland‐animal and production‐management. The system capacity and productivity could be improved by system coupling. Since it emerged, this pastoral agriculture system has been established in various ecological regions in China and significant improvements in agricultural sustainability, farmer's income and environmental stability have been obtained. In the future, it will play a more critical role in developing sustainable agriculture in China.
Comparing MODIS vegetation indices with AVHRR NDVI for monitoring the forage quantity and quality in Inner Mongolia grassland, China
Authors: Kawamura Kensuke , Akiyama Tsuyoshi , Yokota Hiro‐omi , Tsutsumi Michio , Yasuda Taisuke , Watanabe Osamu , Wang Shiping
Published: April 2005

The present study compared the abilities of the spectral vegetation indices (VI) of Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) sensors in accurately detecting seasonal vegetation changes (phenology) with regard to forage quantity and quality. The normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) were computed with a 10‐day maximum value composite from April 1 to October 31, 2002. The study sites included four meadow steppes and six typical steppes in the Xilingol steppe area of central Inner Mongolia, China. Comparisons of the MODIS‐NDVI and AVHRR‐NDVI profiles revealed that the MODIS‐NDVI temporal profile had a higher fidelity. The dynamic range of the MODIS‐NDVI was then analyzed and its sensitivity in discriminating between vegetation differences was evaluated in sparsely and densely vegetated areas. Estimations of the live, dead standing, total biomass and crude protein (CP) concentration and standing CP were obtained using AVHRR‐NDVI (1.1 km pixels), MODIS‐NDVI and ‐EVI (500 m pixels). Regression analysis revealed that the MODIS‐VI showed a good coefficient of determination (R2 = 0.77–0.83) with regard to estimations of the total and live biomass. Furthermore, the MODIS‐EVI was a good predictor of standing CP (R2 = 0.74) compared with AVHRR (R2 = 0.53). These results suggest that the MODIS‐VI can reliably detect the phenology and forage quantity and quality of grassland steppe areas.
Co‐segregation of AFLP and RAPD markers to apospory in Guineagrass (Panicum maximum Jacq.)
Authors: Ebina Masumi , Nakagawa Hitoshi , Yamamoto Toshiya , Araya Hiroshi , Tsuruta Sin‐ichi , Takahara Manabu , Nakajima Kousuke
Published: April 2005

Synopsis

A genetic linkage map of guinea grass (Panicum maximum Jacq.) was generated with nine of the AFLP markers found to be associated with apospory. These apospory‐associated markers were assigned to a linkage group having previous association with microsporogenesis of the aposporous guineagrass cultivar ‘Natsukaze’. An aposporous linkage group was constructed utilizing 38 AFLP markers. Embryo sac analysis revealed that sexual and apomictic embryo sacs occurred at a frequency of 1 : 1, indicating simple inheritance of a single major gene controlling apospory in guineagrass. In addition, utilizing 56 AFLP primer combinations and 41 RAPD primers, 39 linkage groups and 360 simplex marker loci were assigned to the genetic map of the ‘Natsukaze’ cultivar. These markers covered 1703.5 cM of the autotetraploid guineagrass genome (2n = 4x = 32), with an average spacing of 4.7 cM. These tightly linked markers to apospory locus in guineagrass could be a powerful tool for marker‐assisted selection of apospory and map‐based cloning of the apospory gene.
Integrated Pyrolysis Regenerated Plant (IPRP): An Efficient and Scalable Concept for Gas Turbine Based Energy Conversion From Biomass and Waste
Authors: Fantozzi Francesco , D’Alessandro Bruno , Desideri Umberto
Published: April 2005

A massive effort towards sustainability is necessary to prevent global warming and energy sources impoverishment: both biomass and waste to energy conversion may represent key actions to reach this goal. At the present, state of the art available technologies for biomass and waste to energy conversion are similar and include low to mid efficiency grate incineration or fluidized bed combustion with steam power cycles or mid to high efficiency gas turbine based cycles through integrated gasification technology. Nevertheless, these plants are all available from mid-to-high scale range that can be highly intrusive on protected areas and socially unacceptable. This paper proposes an innovative, low cost, high efficiency plant in which the residue is gasified in the absence of oxygen (pyrolysis), in a rotary kiln, by means of a highly regenerative gas turbine based cycle. Pyrolysis is preferred to gasification, because the syngas obtained has a higher low heating value and produces char or tar as a by-product with an interesting energy content to be re-utilized inside the cycle. Different plant configurations are proposed and discussed through principal thermodynamic variables parametric analysis. Results show that very interesting efficiencies are obtainable in the 30–40% range for every plant scale. This fact shows how IPRP technology can provide an interesting alternative to traditional technologies, especially for the small size (below 5MW). Moreover, the IPRP technology provides a unique solution for microscale (below 500 kW) power plants, opening a new and competitive possibility for distributed biomass or waste to energy conversion systems where low environmental and social impact turns into higher interest and positive dissemination effect.
Unique Challenges for Bolted Joint Design in High-Bypass Turbofan Engines
Authors: Czachor Robert P.
Published: April 2005

Bolted joints are used at numerous locations in the rotors and carcass structure of modern aircraft turbine engines. This application makes the design criteria and process substantially different from that used for other types of machinery. Specifically, in addition to providing engine alignment and high-pressure gas sealing, aircraft engine structural joints can operate at high temperatures and may be required to survive very large applied loads which can result from structural failures within the engine, such as the loss of a fan blade. As engine bypass ratios have increased in order to improve specific fuel consumption, these so-called “Ultimate” loads increasingly dominate the design of bolted joints in aircraft engines. This paper deals with the sizing and design of both bolts and lever flanges to meet these demanding requirements. Novel empirical methods, derived from both component test results and correlated analysis have been developed to perform strength evaluation of both flanges and bolts. Discussion of analytical techniques in use includes application of the LS-DYNA™ code for modeling of high-speed blade impact events as related to bolted joint behavior.
Diversity of the Human Intestinal Microbial Flora
Authors: Eckburg Paul B. , Bik Elisabeth M. , Bernstein Charles N. , Purdom Elizabeth , Dethlefsen Les , Sargent Michael , Gill Steven R. , Nelson Karen E. , Relman David A.
Published: April 2005

The human endogenous intestinal microflora is an essential “organ” in providing nourishment, regulating epithelial development, and instructing innate immunity; yet, surprisingly, basic features remain poorly described. We examined 13,355 prokaryotic ribosomal RNA gene sequences from multiple colonic mucosal sites and feces of healthy subjects to improve our understanding of gut microbial diversity. A majority of the bacterial sequences corresponded to uncultivated species and novel microorganisms. We discovered significant intersubject variability and differences between stool and mucosa community composition. Characterization of this immensely diverse ecosystem is the first step in elucidating its role in health and disease.
New Dinopanorpidae (Insecta: Mecoptera) from the Eocene Okanagan Highlands (British Columbia, Canada and Washington State, USA)
Authors: Archibald S Bruce
Published: April 2005

Six new species of the extinct family Dinopanorpidae (Mecoptera) are described in the new genus Dinokanaga gen. nov. from five Early (and early Middle?) Eocene Okanagan Highlands localities in British Columbia and Washington State. These are Dinokanaga hillsi sp. nov., D. wilsoni sp. nov., D. dowsonae sp. nov., D. andersoni sp. nov., D. sternbergi sp. nov., and D. webbi sp. nov. The family Dinopanorpidae is previously known only from a hind wing of Dinopanorpa megarche Cockerell, and an undescribed species of Dinopanorpa, both from the Paleogene of Primorye (Maritime Province) in Pacific coastal far-eastern Russia. The family includes mostly large species, with forewings up to 43 mm in length. Dinopanorpidae is particularly distinguished by a long R1 vein in both the fore- and hind wings, extending almost to the wing apex and bending posteriad distally. Their wings are mostly dark with light bands and spots; have many to extremely dense crossveins; and an expanded costal space in the basal quarter of the forewing, which is more developed in larger species. The rostrum is extended; the medigynium is without tongue-shaped structures.
Regional and local vegetation community dynamics of the Eocene Okanagan Highlands (British Columbia  Washington State) from palynology
Authors: Moss Patrick T , Greenwood David R , Archibald S Bruce
Published: April 2005

Palynofloras from the middle Early to early Middle Eocene Okanagan Highlands (northern Washington State and southern British Columbia) are used to reconstruct vegetation across a broad upland Eocene landscape. In this preliminary report, forest floristic composition is reconstructed using palynological analysis of sediments from Republic, Washington; localities of the Allenby Formation in the Princeton region (Hospital Hill, One Mile Creek and Summers Creek Road), Hat Creek, McAbee, Falkland, Horsefly, and Driftwood Canyon, British Columbia. Wind-dispersed taxa were dominant in all samples, consistent with floras preserved in lacustrine and paludal depositional environments. Pseudolarix was dominant in five of the floras, but Abies (Falkland) or Ulmus (Republic Corner Lot site) were dominant in individual samples for some floras. Betulaceae were dominant for McAbee (Alnus) and Allenby Formation (Betula), matching megafloral data for these sites. Some taxa common to most sites suggest cool conditions (e.g., Abies, other Pinaceae; Alnus, other Betulaceae). However, all floras contained a substantive broad-leaved deciduous element (e.g., Fagaceae, Juglandaceae) and conifers (e.g., Metasequoia) indicative of mesothermal conditions. Palms were only abundant in the Hat Creek coal flora, with very low counts recorded for the Falkland, McAbee, and Allenby Formation sites, suggesting that they were rare in much of the landscape and likely restricted to specialized habitats. Thermophilic (principally mesothermal) taxa, including palms (five sites) and "taxodiaceous" conifers, may have occurred at their climatic limits. The limiting factor controlling the regional distribution of thermophilic flora, which include primarily wetlands taxa, may be either climatic or edaphic.
Diatomaceous origin of siliceous shale in Eocene lake beds of central British Columbia
Authors: Mustoe George E
Published: April 2005

The abundance of diatoms in Neogene lacustrine sediments and their apparent scarcity in Paleogene deposits have long perplexed geoscientists, but siliceous shales from Eocene lake beds of central British Columbia provide new insights. Major element geochemistry, X-ray diffraction patterns, and relict diatom frustules suggest that Eocene beds at Horsefly, McAbee, and Princeton originated as lacustrine diatomite that underwent diagenetic alteration to produce siliceous shale. The combination of high SiO2and low Al2O3values and the presence of opal-CT X-ray diffraction peaks provide a distinctive geochemical fingerprint for biogenic silica deposits that have been remineralized. The discovery of diatomaceous geochemical signatures in siliceous shales may prove to be a useful tool for extending the geologic record of diatoms, perhaps helping to reduce the apparent discrepancy between fossil evidence and evolutionary interpretations based extant species.
Early genetic testing of coastal Douglas-fir for Swiss needle cast tolerance
Authors: Temel Fatih , Johnson G R , Adams W T
Published: April 2005

The possibility of early testing coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) for Swiss needle cast (SNC; caused by Phaeocryptopus gaeumannii (Rohde) Petrak) tolerance was investigated using 55 Douglas-fir families from western Oregon. Seedlings were inoculated with P. gaeumannii naturally in the field and were visually scored for a variety of SNC symptom traits (i.e., needle and foliage color, and retention) at the seedling stage (age 2) and in "mature" (ages 10 and 12) trees at two test sites for both the seedling and mature ages. Seedlings were also assessed in the laboratory for SNC symptom traits, for proportion of needle stomata occluded with pseudothecia (PSOP), and for amount of P. gaeumannii DNA in needles. Although families differed significantly at both ages for all SNC symptom traits and for PSOP, they did not differ for amount of fungal DNA. Thus, genetic variation in SNC symptoms appears to be primarily due to differences in tolerance to the disease rather than to resistance to infection per se. Estimated individual-tree heritabilities for SNC symptom traits were low to moderate (mean hi2 = 0.19, range 0.060.37) at both ages, and within each age-class these traits were moderately to strongly genetically correlated (mean rA = 0.69, range 0.420.95). Type B genetic correlations between SNC symptom traits in seedlings and mature trees ranged from 0 to 0.83 and were weakest for traits measured in the laboratory. Genetic gain estimates indicated that family selection for SNC tolerance (i.e., greener needles or greater foliage retention) at the seedling stage can be very effective in increasing tolerance in older trees.
Tree-size diversity between single- and mixed-species stands in three forest types in western Canada
Authors: Varga Pàl , Chen Han YH , Klinka Karel
Published: April 2005

Mixed-species stands are hypothesized to be more structurally diverse because of inherent differences in growth rates between tree species. We investigated three combinations of even-aged, single- and mixed-species coniferous stands in western Canada: (i) shade-tolerant western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata (Donn ex D. Don) Spach), (ii) shade-intolerant lodgepole pine (Pinus contorta Dougl. ex Loud.) and western larch (Larix occidentalis Nutt.), and (iii) shade-intolerant lodgepole pine and shade-tolerant black spruce (Picea mariana (Mill.) BSP). We quantified stand structural diversity based on tree diameter and height by using Shannon's index and the coefficient of variation. Regression analysis was applied to examine the relationships between structural diversity, species composition, and stand age. Mixed-species stands of western hemlock and western redcedar had similar structural diversity to their respective single-species stands. Pinelarch and pinespruce mixed-species stands had higher tree-size diversity than their respective single-species stands. Stand age was a significant factor for tree-size diversity, but its effect changed in different ways depending on the type of mixtures and index used to measure diversity.
Long-term differential stem growth responses in mature eastern white pine following release from competition
Authors: Bevilacqua Eddie , Puttock David , Blake Terence J , Burgess Darwin
Published: April 2005

The magnitude and duration of the growth response in residual trees following silvicultural release treatments are measures used to assess the success of silvicultural practices. Eighty-eight eastern white pine (Pinus strobus L.) trees, representing three different dominance classes, were sampled destructively from stands from a single study site that included areas of both unharvested (control) and silvicultural release treatments. The study area consisted of several pine mixedwood stands with understory white pine growing in association with an overstory of predominantly intolerant hardwoods. Annual height, diameter, basal area, stem and sawtimber volume increment, pattern of stem increment allocation along the bole, stem form, and heightdiameter ratio were reconstructed over a postrelease period of 23 years using detailed stem analysis. Within 3 years of release, white pine in all dominance classes showed significant increases in diameter, basal area, and volume increment compared with control trees. Differences in the volume increment between released and control trees varied with canopy position, with emergent trees showing the greatest increased volume growth, followed by dominant and intermediate classes, respectively. A temporary shift in the growth allocation pattern along the bole varied depending on crown class, suggesting a period of growth adjustment during which trees are acclimating to changes in resource availability and wind exposure. The shift in growth allocation contributed to increased stem taper, resulting in decreased form class and heightdiameter ratios in the released trees.
Probabilities of small-gap capture by sugar maple saplings based on height and crown growth data from felled trees
Authors: Cole William G , Lorimer Craig G
Published: April 2005

We simulated the probability that Acer saccharum Marsh. saplings in single-tree gaps would reach the overstory before lateral gap closure. The model was calibrated with height and crown growth data from destructively sampled trees that ranged from 1 to 27 m tall. Each of the major initial conditions and growth processes was evaluated separately to determine its effect on gap-capture probabilities. Factors such as sapling height at the time of gap formation, continued height growth of border trees, and stochastic growth variation had pronounced effects on the outcome. Stochastic variation generally increased chances of sapling success by delaying closure times in some of the gaps and allowing some saplings to grow at above-average rates. In stochastic simulations with continued (asymptotic) border-tree height growth, probabilities of successful gap capture ranged from <20% of saplings 12 m tall to 35%86% for saplings 78 m tall. The results suggest that some saplings may be able to capture gaps after one gap event, but probabilities are low for small saplings and for all saplings in small and medium gaps. Based on the mechanisms simulated here, most of the larger single-tree gaps (78 m2) are captured by advance regeneration more than 4 m tall.
Balsam fir and white spruce seedling recruitment in response to understory release, seedbed type, and litter exclusion in trembling aspen stands
Authors: Wang G. Geoff , Kemball Kevin J
Published: April 2005

Experimental seeding of balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) was implemented in three mature trembling aspen (Populus tremuloides Michx.) stands in southeastern Manitoba to test (i) the effect of vegetation (light) competition and seedbed type (undisturbed forest floor, exposed mineral soil, and rotten logs) on seedling recruitment over the first 2 years and (ii) the effect of broadleaf litter exclusion on seedling mortality during the first winter. The study indicated that, with adequate seed supply, seedbed type was the most important factor limiting seedling recruitment, especially the recruitment of white spruce, in trembling aspen stands. Seedling recruitment on the best and the worst seedbeds differed by 1.8 times for balsam fir but by 19 times for white spruce. Significant differences in soil moisture and temperature were found between seedbed types. Broadleaf litter exclusion also facilitated the recruitment of balsam fir and white spruce, but only on undisturbed forest floor. Vegetation (light) competition, however, did not limit seedling recruitment. On the contrary, the presence of understory vegetation benefited seedling recruitment on rotten logs. Compared with white spruce, balsam fir is better adapted to regenerate in trembling aspen stands. Balsam fir was about 4, 12, and 36 times better than white spruce when regenerating on exposed mineral soil, rotten log, and undisturbed forest floor, respectively.
Testing for variation in the western Oregon softwood log price structure
Authors: Størdal Ståle , Adams Darius M
Published: April 2005

Timber owners in western Oregon have been concerned about the erosion of price premiums for higher quality grades of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) sawlogs over the past decade. Time series tests indicate that the ratio of 3Saw (lower quality) to 2Saw (higher quality) sawlog prices did rise over the 19902000 period, suggesting convergence between the prices. To identify causes of this trend, we estimate reduced form equations for Douglas-fir sawlog prices with time-varying coefficients using flexible least squares. Log grade prices were related to prices of lumber by grade, prices of chipped residues, labor wage rates, and volumes of public timber supplied. Changes in the relation of log grade prices are reflected through changes in both reduced form coefficients and levels of the exogenous variables. Changes in the coefficients, in turn, may derive from shifts in the distribution of log qualities within grade categories and from grade-specific changes in sawing and log production technologies. Coefficient trends showed that higher quality lumber grades became more important for 3Saw logs during the sample period, while lower quality lumber grades and chips became more important for 2Saw, moving the log grade prices closer together. Comparison of simulated 2Saw and 3Saw prices with and without historical time patterns in the exogenous variables had little impact on their relationship, suggesting that factors shifting the coefficients may have been the primary drivers of price convergence.
NONLINEAR SQUEEZED VACUUM STATES: NONCLASSICAL PROPERTIES
Authors: DARWISH M.
Published: April 2005

Some of the properties of nonlinear squeezed vacuum states associated with trapped ions are considered, especially the photon number distribution, the phase properties, the Husimi–Kano Q function and the Wigner–Moyal W function of these nonlinear squeezed vacuum states. The structure of these functions is shown to depend on the nonlinearity parameter, its functional dependence and the squeezing parameter. It is shown that increasing the nonlinearity parameter results in the photon number distribution being squeezed independent.
EFFECT OF INVERSION LAYER THICKNESS ON THE ACTIVATION ENERGY AND TURN-ON CHARACTERISTICS OF POLYSILICON THIN-FILM TRANSISTORS
Authors: GUPTA NAVNEET , TYAGI B. P.
Published: April 2005

The influence of inversion layer thickness on the activation energy and turn-on characteristics of a polycrystalline silicon thin-film transistor (poly- Si TFT) have been investigated theoretically by developing an analytical model. It is observed that activation energy decreases as the gate bias increases and is larger for a larger poly- Si inversion layer thickness. It is also observed that effective carrier mobility and drain current increase rapidly with the increase in gate voltage for all values of inversion layer thickness and are larger for lower inversion layer thickness. The computed results are in reasonable agreement with the experimental observations.
SUM FREQUENCY GENERATION VIBRATIONAL SPECTROSCOPY STUDIES ON MOLECULAR CONFORMATION AND ORIENTATION OF BIOLOGICAL MOLECULES AT INTERFACES
Authors: CHEN XIAOYUN , CLARKE MATTHEW L. , WANG JIE , CHEN ZHAN
Published: April 2005

Sum frequency generation (SFG) vibrational spectroscopy has been employed to study a variety of interesting biological phenomena occurring at interfaces. This review summarizes recent SFG studies on proteins, lipid monolayers and bilayers, and other biological molecules. Molecular level details revealed by SFG in these studies show that SFG is a powerful technique for characterizing conformation, orientation and ordering of biological molecules at interfaces.
THEORETICALLY MODELING MICROARRAY WITH THE CHEMICAL EQUILIBRIUM AND THERMODYNAMICS
Authors: XU MEI
Published: April 2005

To date, the idea that microarray may shed the light on cellular processes by identifying groups of genes that appear to be co-expressed seems to remain a dream. This is partly because that there are some blank (meaning the knowledge is unavailable) or even erroneous areas in the fundamental theory in this field. This paper attempts to present the digest of microarray hybridization system with chemical thermodynamics, theoretically clarifying some misunderstandings and looking for answers to some critical questions around this technology, such as the mechanisms and conditions of quantitative measuring by hybridization reaction, the reasons of inconsistency of the data and the analysis results and the solutions, how to analyze the data, etc. A theoretical model for the next generation of microarray is proposed. We believe that this model is universal, laying the foundation for microarray technology from array design through the data analysis.
U–Pb SIMS dating of synkinematic granites: timing of core-complex formation in the northern Anatolide belt of western Turkey
Authors: Ring Uwe , Collins Alan S.
Published: April 2005

Secondary ion mass spectrometry (SIMS) U–Th–Pb dating of magmatic zircon from the synkinematic Eğrigöz and Koyunoba granites and a leucogranite dyke dates core-complex formation in the northern Anatolide belt of western Turkey at 24–19 Ma. The granites intrude into the footwall of the Simav detachment and are strongly elongated in the NNE direction parallel to tectonic transport on the detachment. Although large parts of the granites are undeformed, localized mylonitic to ultramylonitic deformation occurs directly beneath the Simav detachment and preserves evidence of progressive deformation from ductile to brittle conditions. Oscillatory zoned rims of long-prismatic zircon from the Eğrigöz and Koyunoba granites yield identical and well-constrained intrusion ages of 20.7 ± 0.6 Ma and 21.0 ± 0.2 Ma, whereas inherited grains range from Palaeoproterozoic (2972 ± 13 Ma) to Neoproterozoic (653 ± 6 Ma to 500 ± 5 Ma) in age. A leucogranite dyke yields an intrusion age of 24.4 ± 0.3 Ma, with inherited Neoproterozoic (640 ± 7 Ma to 511 ± 6 Ma) grains. Our data, in conjunction with published
40
Ar/
39
Ar biotite ages, indicate very rapid cooling (greater than
c
. 200 °C Ma
−1
) for the granites during and after synkinematic emplacement.
Suppressor of cytokine signaling-2 modulates the fibrogenic actions of GH and IGF-I in intestinal mesenchymal cells
Authors: Fruchtman Shira , Simmons James G. , Michaylira Carmen Z. , Miller Megan E. , Greenhalgh Christopher J. , Ney Denise M. , Lund P. Kay
Published: April 2005

Growth hormone (GH) and IGF-I play important roles in wound healing during intestinal injury and inflammation, but there is also indirect evidence that locally expressed IGF-I may act to induce excessive collagen deposition, which can lead to intestinal fibrosis. Factors that dictate the balance between normal wound healing and excessive healing responses are unknown. Using RNase protection assay and in situ hybridization, we determined whether GH and/or IGF-I increase type I collagen deposition in the intestine of rats fed by total parenteral nutrition (TPN), a feeding modality used for many patients following intestinal surgery and resection. We also used an in vitro model system to confirm our in vivo effects and to directly evaluate the relative potency of GH and IGF-I on DNA synthesis and collagen deposition in intestinal myofibroblasts. Both GH and IGF-I stimulated collagen production in vivo and in vitro, and IGF-I, but not GH, stimulated DNA synthesis in vitro. In collagen production, GH was less potent than IGF-I. Suppressors of cytokine signaling (SOC) are cytokine-inducible proteins that negatively feedback to inhibit the actions of cytokines and we recently found that GH selectively upregulates SOC-2 in the intestine of TPN-fed rats. We examined whether SOC-2 may be responsible for the difference in magnitude of action of GH and IGF-I on collagen accumulation. GH, but not IGF-I, induced SOC-2 in isolated myofibroblasts, and overexpression of SOC-2 led to a suppression of GH- and IGF-I-induced collagen accumulation. SOC-2 null mice infused with IGF-I showed greater collagen gene expression compared with wild-type (WT) mice. Myofibroblasts isolated from SOC-2 null mice showed increased IGF-I-stimulated DNA synthesis compared with WT cells. Taken together, these findings suggest that SOC-2 induced by GH may play an important role in suppressing collagen accumulation and mesenchymal cell proliferation induced by GH or GH-induced IGF-I, providing a mechanism for the differing potencies of GH and IGF-I on intestinal mesenchyme and collagen synthesis.
Mitochondrial DNA mutations activate programmed cell survival in the mouse heart
Authors: Zhang Dekui , Mott Justin L. , Chang Shin-Wen , Stevens Melissa , Mikolajczak Peter , Zassenhaus H. Peter
Published: April 2005

Increased frequencies of mitochondrial DNA (mtDNA) mutations characterize the aging heart and are also found in idiopathic dilated cardiomyopathy and end-stage heart failure. The pathogenic potential of such mutations is unclear. Transgenic mice showing accelerated accumulation of mtDNA mutations and dilated cardiomyopathy due to expression of an error-prone mtDNA polymerase specifically in the heart were characterized by Western blot analysis and immunohistochemistry for the levels of pro- and antiapoptotic proteins. By 8 wk of age, when frequencies of mtDNA mutations were ∼0.01% and all transgenic mice showed four-chamber cardiac dilation, a vigorous prosurvival response was evident. Upregulated were Bcl-2, Bcl-xl, Bfl1, heat shock protein 27, and X-linked inhibitor of apoptosis protein, all of which function to inhibit apoptosis. Although translocation of Bax to mitochondria was also seen, it was not integrated into the mitochondrial membrane. Treatment of transgenic mice with doxorubicin failed to induce apoptosis, in contrast to controls, showing that the prosurvival response protected cardiomyocytes from a death stimulus. Increased apoptosis and release of cytochrome c appeared to precede the establishment of the prosurvival state suggesting that it may reflect a response to activation of programmed cell death pathways. It has been proposed that a programmed cell survival response is activated in the failing and aging heart. We show that elevated frequencies of mtDNA mutations may serve as one trigger for the activation of such a response.