bluuebunny/crossref_metadata_2025 huggingface dataset:
The loricariid catfish genus Lasiancistrus (Siluriformes) with descriptions of two new species
Authors: Armbruster Jonathan W.
Published: December 2007

Lasiancistrus (Loricariidae: Hypostominae: Ancistrini) is diagnosed by the unique presence of a ventral strut of the pterotic and the presence of whiskerlike odontodes on the snout. Lasiancistrus has about 16 species assigned to it; however, only four are valid (L. schomburgkii, L. caucanus, L. guacharote, and L. heteracanthus), L. nationi is an Ancistrus, and L. trinitatus is incertae sedis in the Loricariidae. Lasiancistrus maracaiboensis and L. mystacinus are synonyms of L. guacharote; L. pictus, L. castelnaui, L. caquetae, L. guapore, L. multispinis, and L. scolymus are synonyms of L. schomburgkii; and L. planiceps, L. mayoloi, and L. volcanensis are synonyms of L. caucanus. Two new species are described: L. tentaculatus from the río Orinoco basin and L. saetiger from the rio Guama. The species can largely be told apart via color (L. schomburgkii has no or white spots on the fins, L. saetiger has entirely gray fins, and the rest have black spots in the fins), the presence of abdominal plates (L. caucanus, L. saetiger, and L. tentaculatus have naked abdomens, L. guacharote has a few small plates near the insertion of the pectoral fin, L. heteracanthus has a large patch of small plates, and L. schomburgkii is variable), and nuptial male condition (L. tentaculatus has small tentacles along the edge of the snout and the other species have a patch of whisker-like odontodes at the corners of the snout). Most species are widespread in piedmont regions of South America with L. schomburgkii occurring in the Amazon, Orinoco, and Essequibo basins.
A new cave species of Rhamdia (Siluriformes: Heptapteridae) from Serra do Ramalho, northeastern Brazil, with notes on ecology and behavior
Authors: Bichuette Maria Elina , Trajano Eleonora
Published: December 2007

Rhamdia enfurnada, a new troglobitic (exclusively subterranean) catfish, is described from the Gruna do Enfurnado, Serra do Ramalho, southwestern Bahia State, middle São Francisco River basin. It differs from epigean congeners from the São Francisco River basin by the variable eye size, ranging from reduced to externally invisible (bilateral asymmetry in development of eyes is frequently observed), with a conspicuous orbital concavity (orbital diameter varying from 6.4 to 13.6% of head length in R. enfurnada and from 14.5 to 24.4% in the epigean species); by the dark pigmentation reduced due to a decrease in density of melanophores, and also variable. In comparison to other cave species, R. enfurnada presents a low degree of troglomorphism regarding development of eyes and pigmentation, indicating a relatively short time evolving in isolation in the subterranean environment: R. reddelli is described as lacking eyes and with almost no pigmentation; likewise, R. macuspanensis and R. laluchensis as having rudimentary eyes, covered with skin and not visible externally, and with reduced body pigmentation; R. zongolicensis is also almost devoid of dark pigmentation, but eyes are less reduced than in R. reddelli. R. quelen urichi, also does not present any trace of eyes externally, but the body coloration is described as pale yellowish brown. Rhamdia guasarensis has a concave dorsal profile of head and a complete absence of pigmentation and eyes. The population density (preliminarily estimated in 0.1-0.2 individuals m-2 in average, and reaching 10 individuals m-2, in the dry season and size (several thousands of individuals) of R. enfurnada may be considered high for cave fish standards. Rhamdia enfurnada exhibited an increased midwater activity when compared to their typically bottom-dwelling epigean relatives; are mostly indifferent to light and moderately aggressive.
Brachyplatystom a promagdalena, new species, a fossil goliath catfish (Siluriformes: Pimelodidae) from the Miocene of Colombia, South America
Authors: Lundberg John G.
Published: December 2007

A fossil Weberian complex of a large pimelodid catfish from the middle Miocene La Venta fauna of central Colombia originally identified as Brachyplatystoma sp. is described as a new, extinct species. Brachyplatystoma promagdalena, new species, is diagnosed by three autapomorphic characters: fifth centrum with a massive midventral expansion containing deep cavities and heavy ridges; first and compound centra contribute to a pair of prominent anterolateral processes before the ventral ends of the ossa suspensoria; and compound centrum with an anteriorly concave low ridge crossing its ventral surface posterior to aortic canal foramen. Brachyplatystoma promagdalena is compared to modern congeneric species and placed in the subgenus Malacobagrus with B. filamentosum, B. capapretum and B. rousseauxii. This group is characterized by synapomorphies of the texture and form of the first vertebra; texture and form of the dorsal side of the fourth transverse process; and presence of a bony gas bladder platform on the ventral side of the fourth transverse process. Today Brachyplatystoma ranges widely across the lowland Orinoco and Amazon and some river basins of the Guianas. The genus does not occur west or north of the Andes or Venezuelan coastal ranges. The Miocene species of Brachyplatystoma signals the former large river and biotic connection between the paleo-Amazonas-Orinoco system and central Colombia, a region now drained by the río Magdalena. Other fossils of aquatic vertebrates from the La Venta fauna show this same biogeographic relationship.
Revision of genus Steindachneridion (Siluriformes: Pimelodidae)
Authors: Garavello Julio Cesar
Published: December 2007

After several years collecting in the type-localities and studying representative samples of genus Steindachneridion Eigenmann & Eigenmann, 1919 from Brazilian and foreign museums, a taxonomic revision of the Recent species of the genus is presented, including the description of a new species from the rio Iguaçu, above the great falls. Steindachneridion species are large sized fishes, reaching 1000 mm total length or more, and sharing some anatomical characters that, at least tentatively, support the monophyly of the genus. In addition to the general features found in the Pimelodidae, the species S. amblyurum (Eigenmann & Eigenmann, 1888), S. parahybae (Steindachner, 1877), S. doceanum (Eigenmann & Eigenmann, 1889), S. scriptum (Miranda Ribeiro, 1918), S. punctatum (Miranda Ribeiro, 1918), and S. melanodermatum, new species, share the shape of the vomer tooth plates, six to eight branched rays in the dorsal-fin, and a low number of gill-rakers. All species, except fossil ones, are redescribed and a key for their identification is provided.
Plant Breeding in Times of Change
Authors: Bernardo Rex , Bohn Martin O.
Published: December 2007

This supplement to Crop Science includes 22 of the 28 papers presented during the 2006 International Plant Breeding Symposium, held on 21–26 August 2006 in Mexico City (One of the 28 papers has been previously published in Crop Science [Löffler et al. (2005), Crop Sci. 45:1708–1716]). The symposium served as a global forum for current plant breeding research in major row‐crop species and honored Professor John W. Dudley of the University of Illinois for his 49 years of research, teaching, and service in plant breeding and genetics. A total of 356 scientists and students from 60 different countries participated in the symposium. Participation by many scientists from developing countries was made possible by generous financial support primarily from CIMMYT, Generation Challenge Program, HarvestPlus, Iowa State University, Monsanto, Pioneer Hi‐Bred, Renessen, Syngenta Seeds, USDA, and the University of Illinois.
Assessment of the National Plant Breeding and Associated Biotechnology Capacity Around the World
Authors: Guimarães Elcio P. , Kueneman Eric , Paganini Michela
Published: December 2007

Developing countries rely on agriculture and in particular on plant breeding for economic growth, poverty alleviation, and income generation. Therefore, knowledge of countries' capacity to develop improved cultivars is essential. The objective of this article is to present and discuss the results of the national plant breeding and associated biotechnology assessment performed worldwide by the Food and Agriculture Organization of the United Nations (FAO), and to propose actions to strengthen national capacity in the use of plant genetic resources for food and agriculture (PGRFA). Data were collected on countries' capacity to carry out plant breeding activities, including the application of biotechnology tools, through a questionnaire submitted to each institution involved in the sector. Data gathered through the questionnaire are checked for quality and completeness and analyzed at country and regional levels. Results reveal variable numbers and trends: the number of plant breeders and biotechnologists and the trends vary among countries and regions without a global upward or downward tendency; the capacity to use biotechnology tools varies but the lack of linkages with applied plant breeding is a major issue; allocations vary from crop to crop and from region to region; and even within a given region there is not necessarily coincidence in priority crops regarding the allocation of resources. To extend awareness coming out of these surveys, and to further discuss and design appropriate strategies to strengthen capacity to use PGRFA, national and regional workshops were held. The main issues stressed in these events were capacity building must have the highest priority, followed by access to PGRFA, access to biotechnology tools, and awareness of plant breeding characteristics and their impact. The Global Partnership Initiative for Plant Breeding Capacity Building (GIPB) was recently launched to further support countries in strengthening their competence through promoting capacity building.
Bridging Genomics and Genetic Diversity: Linkage Disequilibrium Structure and Association Mapping in Maize and Other Cereals
Authors: Veyrieras Jean‐Baptiste , Camus‐Kulandaivelu Letizia , Gouesnard Brigitte , Manicacci Domenica , Charcosset Alain
Published: December 2007

Linkage disequilibrium (LD) and association mapping is receiving considerable attention in the plant genetics community for its potential to use existing genetic resources collections to fine map quantitative trait loci (QTL), validate candidate genes, and identify alleles of interest. Based on investigations in maize (Zea mays L.) either published or recently conducted in our group, we discuss three elements of particular importance for conducting association mapping or interpreting the results: (i) the analysis of population structure into subgroups, (ii) its use to control for spurious associations and consequences in the specific case of differential selection among subgroups, and (iii) the analysis of the local structure of LD into haplotypes and its consequences on the resolution and the application of LD mapping. Consequences and perspectives for plant breeding are briefly discussed.
Insights and Innovations from Wide Crosses: Examples from Canola and Tomato
Authors: Osborn Thomas C. , Kramer Chad , Graham Elaine , Braun Carl J.
Published: December 2007

Wild relatives and unadapted forms of crop plants are important reservoirs of allelic variation that can be accessed through wide crosses for improvement of crop plants. In this paper, we describe insights and innovations from the use of wide crosses to transfer favorable alleles from wild or unadapted forms of two crops: canola (oilseed Brassica napus L.) and tomato (Lycopersicon esculentum Mill.). The canola research involves the use of unadapted forms (winter types and resynthesized B. napus) in wide crosses to spring‐seeded types to increase seed yield of hybrids. The tomato research involves the use of wild tomato relatives to improve several traits, including disease resistance and fruit quality. These two crop plants provide a broad range of insights and innovations that have been gained from wide crosses in plant breeding research, including the impact of chromosomal rearrangements on allelic variation among unadapted forms of B. napus, and innovations that can be achieved from stacking elite alleles in tomato. The examples presented in this paper highlight the value of using DNA markers for understanding and applying the results of wide crosses.
Molecular Breeding to Enhance Ethanol Production from Corn and Sorghum Stover
Authors: Vermerris Wilfred , Saballos Ana , Ejeta Gebisa , Mosier Nathan S. , Ladisch Michael R. , Carpita Nicholas C.
Published: December 2007

Political and environmental concerns have resulted in a growing interest in renewable energy, especially transportation fuels. In the United States the majority of fuel ethanol is currently produced from corn (Zea mays L.) starch, but grain supplies will be insufficient to meet anticipated demands. Enzymatic hydrolysis of lignocellulosic biomass such as corn and sorghum [Sorghum bicolor (L.) Moench] stover can provide an abundant alternative source of fermentable sugars. While production of cellulosic ethanol from stover is feasible from an energy‐balance perspective, its production is currently not economically competitive. Along with improvements in bioprocessing, enhancing the yield and composition of the biomass has the potential to make ethanol production considerably more cost effective. This requires (i) a better understanding of how cell wall composition and structure affect the efficiency of enzymatic hydrolysis, (ii) the development of traits that enhance biomass conversion efficiency and increase biomass yield, and (iii) the development of rapid screening protocols to evaluate biomass conversion efficiency. Several genetic resources are available to improve maize and sorghum as sources of lignocellulosic biomass. This includes the use of existing mutants, forward and reverse genetics to obtain novel mutants, and transgenic approaches in which the expression of genes of interest is modified. Plant breeding can be implemented to improve biomass yield, biomass quality, and biomass conversion efficiency, either through selection among progeny obtained by crossing parents with desirable traits, or as a way to enhance the agronomic performance of promising mutants and transgenics. Examples from current research will be used to illustrate progress in these different areas.
Backcross versus Forward Breeding in the Development of Transgenic Maize Hybrids: Theory and Practice
Authors: Mumm Rita H.
Published: December 2007

Key factors affecting the choice of breeding methods employed in the development of transgenic maize (Zea mays L.) hybrids are identified and evaluated, particularly as these pertain to the use and balance of backcross and forward breeding in the overall design of a breeding program. These factors are type of trait, population(s) under selection, the predicted response to selection, stewardship of transgenic events, costs, and risks. Analysis suggested that simultaneous hybrid improvement and event integration via a forward breeding approach is not practical, given that some level of backcrossing is basic to event integration and the need to contain events not fully authorized by the local government for cultivation, food, and feed. Considering event integration conducted in a stream separate from hybrid improvement, a forward breeding component to event integration may be warranted, particularly if a threshold level of expression of the transgenic trait of interest is dependent on endogenous alleles that interact with the event, some of which may be influenced by the environment. For this situation, directives are given for determining the number of generations of backcrossing to be conducted to create partial conversions from which to select for favorable endogenous alleles via forward breeding. In addition, ways to maximize the advantages of a backcross‐only approach to event integration are discussed.
Education and Preparation of Plant Breeders for Careers in Global Crop Improvement
Authors: Bliss Fredrick A.
Published: December 2007

Plant breeding is essential to global food security and to a viable strategy for developing efficient plant sources for biofuels. Despite expanding demand for professionals educated in breeding fundamentals and able to integrate evolving new technology for crop improvement, public‐supported programs are diminishing. To meet future needs for breeders engaged in cultivar development, prebreeding and population improvement, biotechnology and applied genomics, and education and training, greater support must be forthcoming from public funding and businesses that are future employers. Colleges and universities with supporting curricula should work together to develop collaborative programs and courses of study that prepare new graduates for future employment, which will be largely in the private sector in developed countries and the public sector in developing countries. Broad‐based efforts to increase public awareness about the impact of plant breeding and inform students about career opportunities are needed to assure that highly qualified, dedicated new professionals replace the large numbers of current breeders nearing retirement.
The Use of Doubled Haploids in Recurrent Selection and Hybrid Development in Maize
Authors: Gallais A. , Bordes J.
Published: December 2007

Progress made around the in situ gynogenesis technique allows production in a great number of maize (Zea mays L.) doubled‐haploid (DH) lines. Doubled haploids are now largely used in maize breeding. To optimize their use in breeding schemes, it is first required to know whether genetic variation expressed at the level of DH lines is the same as at the level of lines from self‐fertilization. In several experiments, with evaluation for testcross performance, good agreement appears between variance expressed in selfed progenies and DH variance for grain yield. Recurrent selection (RS) for testcross performance using doubled haploids (DH‐RS) can then be compared to the use of Sn (SnT) plants (S0, S1, S2, …). From a theoretical approach by numerical application, it was shown that, with the same selection intensity and without off‐season nurseries, DH‐RS in four years gives the highest genetic advance per year. With the use of off‐season nurseries, the same investment in trials and the same rate of reduction of effective population size, to have the advantage of DH‐RS the cycle length must be reduced to three years and for traits of low heritability. In an experiment comparing two cycles of RS‐S0T selection in four years to one cycle of DH‐RS (in three or four years), considering the expected gain per year with a DH‐RS cycle in four years, there was an advantage to RS‐S0T, whereas with a three‐year cycle for the DH method both methods were expected to be equivalent. The observed genetic gains were similar for one DH‐RS cycle and the two RS‐S0T cycles in four years. In conclusion, there is not a greater advantage from using doubled haploids in RS. However, DH‐RS has the advantage of simultaneously producing lines that are directly usable as parents of a hybrid. From a theoretical approach, it is shown that DH‐RS is expected to be the best method at the level of genetic advance in variety development, even for medium heritabilities. Furthermore, the whole process appears to be less costly than conventional methods. Use of doubled haploids can thus be very efficient in maize breeding.
Evaluating Potential Genetic Gains in Wheat Associated with Stress‐Adaptive Trait Expression in Elite Genetic Resources under Drought and Heat Stress
Authors: Reynolds Matthew P. , Pierre Carolina Saint , Saad Abu S.I. , Vargas Mateo , Condon Anthony G.
Published: December 2007

While genetic resources provide an invaluable gene pool for crop breeding, the majority of accessions in germplasm collections remain uncharacterized and their potential to improve stress adaptation is not quantified. A selection of 25 elite genetic resources for wheat (Triticum aestivum L.) were characterized for agronomic and physiological trait expression in drought‐ and heat‐stressed environments. Under drought, the physiological traits best associated with yield were canopy temperature, associated with water uptake, and carbon isotope discrimination, associated with transpiration efficiency. Under heat stress stomatal conductance, leaf chlorophyll content, and canopy temperature (associated with radiation use efficiency in this environment) were well correlated with yield. Theoretical yield gains based on extrapolating the best trait expression to the highest yielding backgrounds were also estimated. Under drought, the best expression of canopy temperature and carbon isotope discrimination suggested potential yield gains of approximately 10 and 9% above the best yielding cultivars, respectively; under heat stress, canopy temperature and remobilization of stem carbohydrates suggested potential yield gains of approximately 7 and 9%, respectively. Other physiological trait expression was associated with potential yield gains to varying degrees. When considering agronomic traits, the best expression of harvest index suggested yield gains of approximately 14 and 24% in drought and hot environments, respectively, while the combined best expression of both harvest index and final aboveground biomass suggested yield gains of 30 and 34%, respectively. Principal component analysis indicated that many of the physiological traits that were associated with yield and biomass were not strongly associated with each other, suggesting potential cumulative gene action for yield if traits were combined. When comparing trait expression across drought and hot environments, several physiological traits (e.g., canopy temperature) showed closer association with each other than did performance traits, supporting the idea that such stress‐adaptive traits have generic value across stresses.
Effects of Retinoic Acid on Proliferation and Differentiation of HepG2
Cells
Authors: Burley Michelle R. , Roth Charles M.
Published: December 2007

Hepatoma cell lines have characteristics derived from both their hepatic lineage and their transformation. We
examined the potential of retinoic acid to enhance the function of a hepatoma cell line, HepG2, under conditions of reduced
serum as are desired for bioreactor cultivation. We found that retinoic acid drastically slows the growth of HepG2
cells and induces a more spread morphology. Retinoic acid also augments the differentiated function of the cells, as measured
by albumin and urea secretion rates. Expression levels of a panel of liver-enriched transcription factor were increased
from retinoic acid exposure. Overall, we demonstrate that retinoic acid has significant effects on HepG2 growth and differentiated
function. These results have implications for the use of retinoic acid both as a chemotherapeutic agent and as a
medium component for cells of hepatic origin.
An Experimental Method for Stereolithic Mandible Fabrication and Image Preparation
Authors: Russett Shawn , Major Paul , Carey Jason , Toogood Roger , Boulanger Pierre
Published: December 2007

Reproduction of anatomical structures by rapid prototyping has proven to be a valid adjunct for craniofacial surgery, providing alternative methods to produce prostheses and development of surgical guides. The aim of this study was to introduce a methodology to fabricate asymmetric human mandibles by rapid prototyping to be used in future studies for evaluating mandibular symmetries. Stereolithic models of human mandibles were produced with varying amounts of asymmetry in the condylar neck, ramus and body of the mandible by means of rapid prototyping. A method for production of the synthetic mandibles was defined. Model preparation, landmark description and development of the experimental model were described. A series of synthetic mandibles ranging in asymmetry were accurately produced from a scanned human mandible. A method for creating the asymmetries, fabricating, coating and landmarking the synthetic mandibles was formulated. A description for designing a reproducible experimental model for image acquisition was also outlined. Production of synthetic mandibles by stereolithic modeling is a viable method for creating skeletal experimental models with known amounts of asymmetry.
Artificial Heart Rejects High Tech? Lessens Learnt from Non-pulsatile VAD with Straight Impeller Vanes
Authors: Qian Kun-xi
Published: December 2007

Despite the progresses in developing pulsatile impeller pump and impeller total heart, as well as in applying streamlined impeller vanes, the best results in application of artificial heart pumps have been achieved by nonpulsatile univentricular assist pump with straight impeller vanes until now. It seems all efforts and successes have been done in vain because artificial heart rejects Hi-Tech! This paper recalls some important achievements in R&D of artificial heart in past 25 years and shares author’s experiences with the readers.
Texture Analysis and Radial Basis Function Approximation for IVUS
Image Segmentation
Authors: Maria Papadogiorgaki , Vasileios Mezaris , Yiannis S Chatzizisis , George D Giannoglou , Ioannis Kompatsiaris
Published: December 2007

>Intravascular ultrasound (IVUS) has become in the last years an important tool in both clinical and research applications. The detection of lumen and media-adventitia borders in IVUS images represents a first necessary step in the utilization of the IVUS data for the 3D reconstruction of human coronary arteries and the reliable quantitative assessment of the atherosclerotic lesions. To serve this goal, a fully automated technique for the detection of lumen and media-adventitia boundaries has been developed. This comprises two different steps for contour initialization, one for each corresponding contour of interest, based on the results of texture analysis, and a procedure for approximating the initialization results with smooth continuous curves. A multilevel Discrete Wavelet Frames decomposition is used for texture analysis, whereas Radial Basis Function approximation is employed for producing smooth contours. The proposed method shows promising results compared to a previous approach for texture-based IVUS image analysis.
Extraction of Clove and Vetiver Oils with Supercritical Carbon Dioxide: Modeling and Simulation
Authors: Martínez Julian , Rosa Paulo T.V. , Meireles M. Angela A.
Published: December 2007

The kinetics of supercritical fluid extraction (SFE) of clove and vetiver oils using carbon dioxide as solvent was
studied, in order to establish an efficient method to predict extraction curves on large scale. The mass transfer model of
Sovová was used to adjust the experimental SFE data, which were obtained at 100 bar and 35 °C for clove and 200 bar
and 40 °C for vetiver, using extraction columns of different geometry and solvent flow rates. Some other process parameters,
such as bed density and porosity, solvent to feed ratio and solvent velocity were kept constant from one experiment
to another, in order to verify if the mass transfer coefficients adjusted by the model varied. The results show that the
model of Sovová was able to predict an overall extraction curve for clove from data obtained with twenty times less raw
material, since the mass transfer coefficients remained the same and the predicted curves were similar to the observed
ones. For vetiver, the simulation was not as effective, probably due to the effects of transport properties on the process.
Carotid Body AT4 Receptor Expression and its Upregulation in Chronic Hypoxia
Authors: Fung Man-Lung , Lam Siu-Yin , Wong Tung-Po , Tjong Yung-Wui , Leung Po-Sing
Published: December 2007

Hypoxia regulates the local expression of angiotensin-generating system in the rat carotid body and the me-tabolite angiotensin IV (Ang IV) may be involved in the modulation of carotid body function. We tested the hypothesis that Ang IV-binding angiotensin AT4 receptors play a role in the adaptive change of the carotid body in hypoxia. The expression and localization of Ang IV-binding sites and AT4 receptors in the rat carotid bodies were studied with histochemistry. Specific fluorescein-labeled Ang IV binding sites and positive staining of AT4 immunoreactivity were mainly found in lobules in the carotid body. Double-labeling study showed the AT4 receptor was localized in glomus cells containing tyrosine hydroxylase, suggesting the expression in the chemosensitive cells. Intriguingly, the Ang IV-binding and AT4 immunoreactivity were more intense in the carotid body of chronically hypoxic (CH) rats (breathing 10% oxygen for 4 weeks) than the normoxic (Nx) control. Also, the protein level of AT4 receptor was doubled in the CH comparing with the Nx group, supporting an upregulation of the expression in hypoxia. To examine if Ang IV induces intracellular Ca2+ response in the carotid body, cytosolic calcium ([Ca2+]i) was measured by spectrofluorimetry in fura-2-loaded glomus cells dissociated from CH and Nx carotid bodies. Exogenous Ang IV elevated [Ca2+]i in the glomus cells and the Ang IV response was significantly greater in the CH than the Nx group. Hence, hypoxia induces an upregulation of the expression of AT4 receptors in the glomus cells of the carotid body with an increase in the Ang IV-induced [Ca2+]i elevation. This may be an additional pathway enhancing the Ang II action for the activation of chemoreflex in the hypoxic response during chronic hypoxia.
The disjunction and related properties for constructive Zermelo-Fraenkel set theory
Authors: Rathjen Michael
Published: December 2007

This paper proves that the disjunction property, the numerical existence property. Church's rule, and several other metamathematical properties hold true for Constructive Zermelo-Fraenkel Set Theory, CZF, and also for the theory CZF augmented by the Regular Extension Axiom.

As regards the proof technique, it features a self-validating semantics for CZF that combines realizability for extensional set theory and truth.
Cofinal families of Borel equivalence relations and quasiorders
Authors: Rosendal Christian
Published: December 2007

Families of Borel equivalence relations and quasiorders that are cofinal with respect to the Borel reducibility ordering. ≤B, are constructed. There is an analytic ideal on ω generating a complete analytic equivalence relation and any Borel equivalence relation reduces to one generated by a Borel ideal. Several Borel equivalence relations, among them Lipschitz isomorphism of compact metric spaces, are shown to beKσcomplete.
Subsimple groups
Authors: Wagner Frank
Published: December 2007

We define a notion of genericity for arbitrary subgroups of groups interpretable in a simple theory, and show that a type generic for such a group is generic for the minimal hyperdefinable supergroup (the definable hull). In particular, at least one generic type of the definable hull is finitely satisfiable in the original subgroup. If the subgroup is a subfield. then the additive and the multiplicative definable hull both have bounded index in the smallest hyperdefinable superfield.
On a conjecture of Dobrinen and Simpson concerning almost everywhere domination
Authors: Binns Stephen , Kjos-Hanssen Bjørn , Lerman Manuel , Solomon Reed
Published: December 2007

Dobrinen and Simpson [4] introduced the notions of almost everywhere domination and uniform almost everywhere domination to study recursion theoretic analogues of results in set theory concerning domination in generic extensions of transitive models of ZFC and to study regularity properties of the Lebesgue measure on 2ω in reverse mathematics. In this article, we examine one of their conjectures concerning these notions.

Throughout this article, ≤T denotes Turing reducibility and μ denotes the Lebesgue (or “fair coin”) probability measure on 2ω given by

A property holds almost everywhere or for almost all X ∈ 2ω if it holds on a set of measure 1. For f, g ∈ ωω, f dominatesg if ∃m∀n < m(f(n) > g(n)).

(Dobrinen, Simpson). A set A ∈ 2ωis almost everywhere (a.e.) dominating if for almost all X ∈ 2ω and all functions g ≤TX, there is a function f ≤TA such that f dominates g. A is uniformly almost everywhere (u.a.e.) dominating if there is a function f ≤TA such that for almost all X ∈ 2ω and all functions g ≤TX, f dominates g.

There are several trivial but useful observations to make about these definitions. First, although these properties are stated for sets, they are also properties of Turing degrees. That is, a set is (u.)a.e. dominating if and only if every other set of the same degree is (u.)a.e. dominating. Second, both properties are closed upwards in the Turing degrees. Third, u.a.e. domination implies a.e. domination. Finally, if A is u.a.e. dominating, then there is a function f ≤TA which dominates every computable function.
Hyperfine structure theory and gap 1 morasses
Authors: Friedman Sy-David , Koepke Peter , Piwinger Boris
Published: December 2007

Using the Friedman-Koepke Hyperfine Structure Theory of [2]. we provide a short construction of a gap 1 morass in the constructible universe.
Generix never gives up
Authors: Jaligot Eric
Published: December 2007

We prove conjugacy and generic disjointness of generous Carter subgroups in groups of finite Morley rank. We elaborate on groups with a generous Carter subgroup and on a minimal counterexample to the Genericity Conjecture.
On supersimplicity and lovely pairs of cats
Authors: Ben-Yaacov Itay
Published: December 2007

We prove that the definition of supersimplicity in metric structures from [7] is equivalent to an a priori stronger variant. This stronger variant is then used to prove that if T is a supersimple Hausdorff cat then so is its theory of lovely pairs.
Correspondences between gentzen and hilbert systems
Authors: Raftery J.G.
Published: December 2007

Most Gentzen systems arising in logic contain few axiom schemata and many rule schemata. Hilbert systems, on the other hand, usually contain few proper inference rules and possibly many axioms. Because of this, the two notions tend to serve different purposes. It is common for a logic to be specified in the first instance by means of a Gentzen calculus, whereupon a Hilbert-style presentation ‘for’ the logic may be sought—or vice versa. Where this has occurred, the word ‘for’ has taken on several different meanings, partly because the Gentzen separator ⇒ can be interpreted intuitively in a number of ways. Here ⇒ will be denoted less evocatively by ⊲.

In this paper we aim to discuss some of the useful ways in which Gentzen and Hilbert systems may correspond to each other. Actually, we shall be concerned with thededucibility relationsof the formal systems, as it is these that are susceptible to transformation in useful ways. To avoid potential confusion, we shall speak of Hilbert and Gentzenrelations. By aHilbert relationwe mean any substitution-invariant consequence relation onformulas—this comes to the same thing as the deducibility relation of a set of Hilbert-style axioms and rules. By aGentzen relationwe mean the fully fledged generalization of this notion in whichsequentstake the place of single formulas. In the literature, Hilbert relations are often referred to assentential logics. Gentzen relations as defined here are their exactsequentialcounterparts.
Measure theory aspects of locally countable orderings
Authors: Yu Liang
Published: December 2007

We prove that for any locally countable partial order ℙ = (2ε, ≤p, there exists a nonmeasurable antichain in ℙ. Some applications of the result are also presented.
Abstract Beth definability in institutions
Authors: Petria Marius , Diaconescu Răzvan
Published: December 2007

This paper studies definability within the theory of institutions, a version of abstract model theory that emerged in computing science studies of software specification and semantics. We generalise the concept of definability to arbitrary logics, formalised as institutions, and we develop three general definability results. One generalises the classical Beth theorem by relying on the interpolation properties of the institution. Another relies on a meta Birkhoff axiomatizability property of the institution and constitutes a source for many new actual definability results, including definability in (fragments of) classical model theory. The third one gives a set of sufficient conditions for ‘borrowing’ definability properties from another institution via an ‘adequate’ encoding between institutions.

The power of our general definability results is illustrated with several applications to (many-sorted) classical model theory and partial algebra, leading for example to definability results for (quasi-)varieties of models or partial algebras. Many other applications are expected for the multitude of logical systems formalised as institutions from computing science and logic.
On the available partial respects in which an axiomatization for real valued arithmetic can recognize its consistency
Authors: Willard Dan E.
Published: December 2007

Gödel's Second Incompleteness Theorem states axiom systems of sufficient strength are unable to verify their own consistency. We will show that axiomatizations for a computer's floating point arithmetic can recognize their cut-free consistency in a stronger respect than is feasible under integer arithmetics. This paper will include both new generalizations of the Second Incompleteness Theorem and techniques for evading it.
Glivenko theorems for substructural logics over FL
Authors: Galatos Nikolaos , Ono Hiroakira
Published: December 2007

It is well known that classical propositional logic can be interpreted in intuitionistic prepositional logic. In particular Glivenko's theorem states that a formula is provable in the former iff its double negation is provable in the latter. We extend Glivenko's theorem and show that for every involutive substructural logic there exists a minimum substructural logic that contains the first via a double negation interpretation. Our presentation is algebraic and is formulated in the context of residuated lattices. In the last part of the paper, we also discuss some extended forms of the Koltnogorov translation and we compare it to the Glivenko translation.
Intensional models for the theory of types
Authors: Muskens Reinhard
Published: December 2007

In this paper we defineintensionalmodels for the classical theory of types, thus arriving at an intensional type logic ITL. Intensional models generalize Henkin's general models and have a natural definition. As a class they do not validate the axiom of Extensionality. We give a cut-free sequent calculus for type theory and show completeness of this calculus with respect to the class of intensional models via a model existence theorem. After this we turn our attention to applications. Firstly, it is argued that, sinceITLis truly intensional, it can be used to model ascriptions of propositional attitude without predictinglogical omniscience. In order to illustrate this a small fragment of English is defined and provided with anITLsemantics. Secondly, it is shown thatITLmodels contain certain objects that can be identified withpossible worlds. Essential elements of modal logic become available within classical type theory once the axiom of Extensionality is given up.
Relation algebra reducts of cylindric algebras and complete representations
Authors: Hirsch Robin
Published: December 2007

We show, for any ordinalγ≥ 3, that the classℜaCAγis pseudo-elementary and has a recursively enumerable elementary theory. ScKdenotes the class of strong subalgebras of members of the classK. We devise games,Fn(3 ≤n≤ω),G, H, and show, for an atomic relation algebrawith countably many atoms, that

for 3 ≤n<ω. We use these games to show, forγ> 5 and any classKof relation algebras satisfying

thatKis not closed under subalgebras and is not elementary. For infiniteγ, the inclusion ℜaCAγ⊂ScℜaCAγis strict.

For infiniteγand for a countable relation algebrawe show thathas a complete representation if and only ifis atomic and ∃ has a winning strategy inF(At()) if and only ifis atomic and∈ScℜaCAγ.
On notions of genericity and mutual genericity
Authors: Truss J. K.
Published: December 2007

Generic automorphisms of certain homogeneous structures are considered, for instance, the rationals as an ordered set, the countable universal homogeneous partial order, and the random graph. Two of these cases were discussed in [7], where it was shown that there is a generic automorphism of the second in the sense introduced in [10], In this paper, I study various possible definitions of ‘generic’ and ‘mutually generic’, and discuss the existence of mutually generic automorphisms in some cases. In addition, generics in the automorphism group of the rational circular order are considered.
Reconstruction of homogeneous relational structures
Authors: Barbina Silvia , Macpherson Dugald
Published: December 2007

This paper contains a result on the reconstruction of certain homogeneous transitive ω-categorical structures from their automorphism group. The structures treated are relational. In the proof it is shown that their automorphism group contains a generic pair (in a slightly non-standard sense, coming from Baire category).

Reconstruction results give conditions under which the abstract group structure of the automorphism group Aut() of an ω-categorical structure determines the topology on Aut(), and hence determines up to bi-interpretability, by [1]; they can also give conditions under which the abstract group Aut() determines the permutation group ⟨Aut (), ⟩. so determines up to bi-definability. One such condition has been identified by M. Rubin in [12], and it is related to the definability, in Aut(), of point stabilisers. If the condition holds, the structure is said to have a weak ∀∃ interpretation, and Aut() determines up to bi-interpretability or, in some cases, up to bi-definability.

A better-known approach to reconstruction is via the ‘small index property’: an ω-categorical stucture has the small index property if any subgroup of Aut() of index less than is open. This guarantees that the abstract group structure of Aut() determines the topology, so if is ω-categorical with Aut() ≅ Aut() then and are bi-interpretable.
Turing computable embeddings
Authors: Knight Julia F. , Miller Sara , Boom M. Vanden
Published: December 2007

In [3]. two different effective versions of Borel embedding are defined. The first, called computable embedding, is based on uniform enumeration reducibility. while the second, called Turing computable embedding, is based on uniform Turing reducibility. While [3] focused mainly on computable embeddings, the present paper considers Turing computable embeddings. Although the two notions are not equivalent, we can show that they behave alike on the mathematically interesting classes chosen for investigation in [3]. We give a “Pull-back Theorem”, saying that if Ф is a Turing computable embedding of K into K′, then for any computable infinitary sentence φ in the language of K′, we can find a computable infinitary sentence φ* in the language of K such that for all A ∈ K A ⊨ φ* iff Φ (A) ⊨ φ and φ* has the same “complexity” as φ (i.e., if φ is computable Σα or computable Πα, for α ≥ 1, then so is φ*). The Pull-back Theorem is useful in proving non-embeddability, and it has other applications as well.
Characterizing rosy theories
Authors: Ealy Clifton , Onshuus Alf
Published: December 2007

We examine several conditions, either the existence of a rank or a particular property of þ-forking that suggest the existence of a well-behaved independence relation, and determine the consequences of each of these conditions towards the rosiness of the theory. In particular we show that the existence of an ordinal valued equivalence relation rank is a (necessary and) sufficient condition for rosiness.
Π10 classes and strong degree spectra of relations
Authors: Chisholm John , Chubb Jennifer , Harizanov Valentina S. , Hirschfeldt Denis R. , Jockusch Carl G. , McNicholl Timothy , Pingrey Sarah
Published: December 2007

We study the weak truth-table and truth-table degrees of the images of subsets of computable structures under isomorphisms between computable structures. In particular, we show that there is a low c.e. set that is not weak truth-table reducible to any initial segment of any scattered computable linear ordering. Countable subsets of 2ω and Kolmogorov complexity play a major role in the proof.
Increasing Differential Mortality by Educational Attainment in Adults in the United States
Authors: Hadden Wilbur C. , Rockswold Paul D.
Published: December 2007

Economic inequality has increased substantially in the United States since the early 1970s. Inequality in mortality increased from 1960 to 1986. To assess the trend in inequality in mortality the authors calculate age-adjusted mortality rates by educational attainment for 2000 and compare them with rates from 1960 and 1986, using relative and absolute indexes of inequality. Rates are calculated for non-Hispanic white and black adults aged 25 to 64 years, using mortality data from U.S. Vital Statistics and population estimates from the Census Public Use Microdata Sample. The trend toward increasing inequality in mortality between 1960 and 1986 accelerated from 1986 to 2000. Improvements in mortality went disproportionately to those with the most education. Mortality rates for whites with low education, which declined from 1960 to 1986, actually rose from 1986 to 2000. The relative change was greatest for those with only a high school education. This change, however, is largely explained by shifts in the distribution of education, which left those with a high school education in a lower position. The increase in inequality was particularly strong in whites and stronger in men than in women. For black men there was a small decline in absolute inequality between 1986 and 2000.
Assessment of the FDA Backgrounder on Platinum in Silicone Breast Implants: Implications for Public Health Policy
Authors: Maharaj S. V. M.
Published: December 2007

A recent report by the U.S. Food and Drug Administration reviewed the literature on the subject of platinum in silicone gel–filled breast implants. In this study the author evaluates the FDA report for scientific accuracy and impartiality, and provides relevant discussions on financial conflicts of interest, an Institute of Medicine report, and public health policy. The study suggests that the FDA used discredited scientific practices in compiling its report. Reports by regulatory agencies should be scientifically accurate, with no partiality to industry. The current policy of one-way information flow from the FDA directly to those being informed needs to be revised. Greater importance should be placed on studies in which authors have no financial conflicts of interest.
Death in China: Market Reforms and Health
Authors: Reddy Sanjay G.
Published: December 2007

Has China's remarkable reduction in income poverty since 1980 been accompanied by comparable progress in health? The author's findings are fourfold. First, province-level rates of improvement in life expectancy (LE) were higher in the 1990s than in the 1970s and 1980s, and were lowest in the 1980s. Second, even in the 1990s, when the province-level rates of improvement in LE were highest, they were lower than for many countries with similar initial LE level (although higher than the average for all such countries). Third, China's LE improvement between 1980 and 2000 was achieved much more quickly by almost all other countries considered, and in particular by most lower-middle-income countries that had similar LE improvements; similar conclusions are drawn from an analysis of China's LE improvements relative to two other sets of comparator countries—selected presently rich countries and high-growth East Asian countries. Finally, even those Chinese provinces that performed best over the period experienced rates of improvement significantly lower than for comparator countries. China's experience of reducing health deprivations has been notably less impressive than its record of income poverty reduction. There is a need for China to invest in the redevelopment of its public health infrastructure, which has withered during the period of market-oriented reforms.