bluuebunny/crossref_metadata_2025 huggingface dataset:
Discussion: Kuhn's Evolutionary Analogy in The Structure of Scientific Revolutions and “The Road since Structure”
Authors: Reydon Thomas A. C. , Hoyningen-Huene Paul
Published: May 2010

Recently, Barbara Renzi argued that Kuhn's account of scientific change is undermined by mismatches in the analogy that Kuhn supposedly draws between scientific change and biological evolution. We argue that Renzi's criticism is inadequate to Kuhn's account of scientific change, as Kuhn does not draw any precise analogy between the mechanisms of scientific change and biological evolution nor aims to argue that the mechanisms of scientific change and biological evolution are similar in any important respects. Therefore, pointing to mismatches between the central concepts that feature in the descriptions of the two phenomena simply misses the point of Kuhn's analogy.
The G243D mutation (afsB mutation) in the principal sigma factor σ
HrdB alters intracellular ppGpp level and antibiotic production in Streptomyces coelicolor A3(2)
Authors: Wang Guojun , Tanaka Yukinori , Ochi Kozo
Published: May 2010

Deficient antibiotic production in an afsB mutant, BH5, of Streptomyces coelicolor A3(2) was recently shown to be due to a mutation (G243D) in region 1.2 of the primary sigma factor σ
HrdB. Here we show that intracellular ppGpp levels during growth, as well as after amino acid depletion, in the mutant BH5 are lower than those of the afsB+
parent strain. The introduction of certain rifampicin resistance (rif) mutations, which bypassed the requirement of ppGpp for transcription of pathway-specific regulatory genes, actII-ORF4 and redD, for actinorhodin and undecylprodigiosin, respectively, completely restored antibiotic production by BH5. Antibiotic production was restored also by introduction of a new class of thiostrepton-resistance (tsp) mutations, which provoked aberrant accumulation of intracellular ppGpp. Abolition of ppGpp synthesis in the afsB tsp mutant Tsp33 again abolished antibiotic production. These results indicate that intracellular ppGpp level is finely tuned for successful triggering of antibiotic production in the wild-type strain, and that this fine tuning was absent from the afsB mutant BH5, resulting in a failure to initiate antibiotic production in this strain.
Genome-wide gene expression regulation as a function of genotype and age in C. elegans
Authors: Viñuela Ana , Snoek L. Basten , Riksen Joost A.G. , Kammenga Jan E.
Published: May 2010

Gene expression becomes more variable with age, and it is widely assumed that this is due to a decrease in expression regulation. But currently there is no understanding how gene expression regulatory patterns progress with age. Here we explored genome-wide gene expression variation and regulatory loci (eQTL) in a population of developing and aging C. elegans recombinant inbred worms. We found almost 900 genes with an eQTL, of which almost half were found to have a genotype-by-age effect (gxaeQTL). The total number of eQTL decreased with age, whereas the variation in expression increased. In developing worms, the number of genes with increased expression variation (1282) was similar to the ones with decreased expression variation (1328). In aging worms, the number of genes with increased variation (1772) was nearly five times higher than the number of genes with a decreased expression variation (373). The number of cis-acting eQTL in juveniles decreased by almost 50% in old worms, whereas the number of trans-acting loci decreased by ∼27%, indicating that cis-regulation becomes relatively less frequent than trans-regulation in aging worms. Of the 373 genes with decreased expression level variation in aging worms, ∼39% had an eQTL compared with ∼14% in developing worms. gxaeQTL were found for ∼21% of these genes in aging worms compared with only ∼6% in developing worms. We highlight three examples of linkages: in young worms (pgp-6), in old worms (daf-16), and throughout life (lips-16). Our findings demonstrate that eQTL patterns are strongly affected by age, and suggest that gene network integrity declines with age.
Expression of ZmLEC1 and ZmWRI1 Increases Seed Oil Production in Maize
Authors: Shen Bo , Allen William B. , Zheng Peizhong , Li Changjiang , Glassman Kimberly , Ranch Jerry , Nubel Douglas , Tarczynski Mitchell C.
Published: May 2010

Increasing seed oil production is a major goal for global agriculture to meet the strong demand for oil consumption by humans and for biodiesel production. Previous studies to increase oil synthesis in plants have focused mainly on manipulation of oil pathway genes. As an alternative to single-enzyme approaches, transcription factors provide an attractive solution for altering complex traits, with the caveat that transcription factors may face the challenge of undesirable pleiotropic effects. Here, we report that overexpression of maize (Zea mays) LEAFY COTYLEDON1 (ZmLEC1) increases seed oil by as much as 48% but reduces seed germination and leaf growth in maize. To uncouple oil increase from the undesirable agronomic traits, we identified a LEC1 downstream transcription factor, maize WRINKLED1 (ZmWRI1). Overexpression of ZmWRI1 results in an oil increase similar to overexpression of ZmLEC1 without affecting germination, seedling growth, or grain yield. These results emphasize the importance of field testing for developing a commercial high-oil product and highlight ZmWRI1 as a promising target for increasing oil production in crops.
Endogenous Diterpenes Derived from ent-Kaurene, a Common Gibberellin Precursor, Regulate Protonema Differentiation of the Moss Physcomitrella patens
Authors: Hayashi Ken-ichiro , Horie Keisuke , Hiwatashi Yuji , Kawaide Hiroshi , Yamaguchi Shinjiro , Hanada Atsushi , Nakashima Tamotsu , Nakajima Masatoshi , Mander Lewis N. , Yamane Hisakazu , Hasebe Mitsuyasu , Nozaki Hiroshi
Published: May 2010

Gibberellins (GAs) are a group of diterpene-type plant hormones biosynthesized from ent-kaurene via ent-kaurenoic acid. GAs are ubiquitously present in seed plants. The GA signal is perceived and transduced by the GID1 GA receptor/DELLA repressor pathway. The lycopod Selaginella moellendorffii biosynthesizes GA and has functional GID1-DELLA signaling components. In contrast, no GAs or functionally orthologous GID1-DELLA components have been found in the moss Physcomitrella patens. However, P. patens produces ent-kaurene, a common precursor for GAs, and possesses a functional ent-kaurene synthase, PpCPS/KS. To assess the biological role of ent-kaurene in P. patens, we generated a PpCPS/KS disruption mutant that does not accumulate ent-kaurene. Phenotypic analysis demonstrates that the mutant has a defect in the protonemal differentiation of the chloronemata to caulonemata. Gas chromatography-mass spectrometry analysis shows that P. patens produces ent-kaurenoic acid, an ent-kaurene metabolite in the GA biosynthesis pathway. The phenotypic defect of the disruptant was recovered by the application of ent-kaurene or ent-kaurenoic acid, suggesting that ent-kaurenoic acid, or a downstream metabolite, is involved in protonemal differentiation. Treatment with uniconazole, an inhibitor of ent-kaurene oxidase in GA biosynthesis, mimics the protonemal phenotypes of the PpCPS/KS mutant, which were also restored by ent-kaurenoic acid treatment. Interestingly, the GA9 methyl ester, a fern antheridiogen, rescued the protonemal defect of the disruption mutant, while GA3 and GA4, both of which are active GAs in angiosperms, did not. Our results suggest that the moss P. patens utilizes a diterpene metabolite from ent-kaurene as an endogenous developmental regulator and provide insights into the evolution of GA functions in land plants.
Pattern analysis and interpretation of scattering from short-range order stacking in the layered composite crystal 2H-NaxCoO2·yD2O (x≃ 0.35,y≃ 1.3)
Authors: Onoda Mitsuko , Takada Kazunori , Sasaki Takayoshi
Published: May 2010

Information about the features of Bragg reflections and/or diffuse streaks was obtained through simulation of a neutron powder diffraction pattern based on the model used in a successful analysis of the superconductor 2H-NaxCoO2·yD2O (x≃ 0.35,y≃ 1.3). Intensity distributions were calculated based on a superstructure expression of a commensurate composite crystal model, where the structures of the CoO2part (a1=b1= 2.82 Å) and the guest (a2 =b2= 3.26 Å) with short-range order stacking are described on a cell ofA=B= 2a1= 31/2a2= 5.64 Å, and with alternate stacking based onc= 4.9 Å. It is shown that the most conspicuous diffuse reflection band corresponds to the main reflection scattering of the guest sheet, with local maxima at half-integer positions of ζ′ based on the stacking distance 2c, and that the Bragg diffraction components of the host and guest are coherent in terms of the peak height at integer ζ′′ based on 4c.
LauePt, a graphical-user-interface program for simulating and analyzing white-beam X-ray diffraction Laue patterns
Authors: Huang X. R.
Published: May 2010

LauePtis a robust and extremely easy-to-use Windows application for accurately simulating, indexing and analyzing white-beam X-ray diffraction Laue patterns of any crystals under arbitrary diffraction geometry. This program has a user-friendly graphic interface and can be conveniently used by nonspecialists with little X-ray diffraction or crystallography knowledge. Its wide range of applications include (1) determination of single-crystal orientation with the Laue method, (2) white-beam topography, (3) white-beam microdiffraction, (4) X-ray studies of twinning, domains and heterostructures, (5) verification or determination of crystal structures from white-beam diffraction, and (6) teaching of X-ray crystallography.
A new Guinier–Porod model
Authors: Hammouda Boualem
Published: May 2010

Small-angle scattering (SAS) curves are characterized by two main features: the Guinier region and the Porod region. Standard linear plots are available to fit SAS data and obtain a radius of gyration and a Porod exponent. A new Guinier–Porod empirical model is introduced to fit SAS data from spherical as well as nonspherical objects such as rods or platelets. It also applies to shapes intermediate between spheres and rods or between rods and platelets. The new model is used to fit SAS data from a Pluronic solution that sequentially forms unimers, then spherical micelles, then cylindrical micelles, then lamellar micelles upon heating. This single model can fit structures associated with all four phases as well as the intermediate structures.
Safety, pharmacokinetics and efficacy of factor VIIa formulated with PEGylated liposomes in haemophilia A patients with inhibitors to factor VIII – an open label, exploratory, cross‐over, phase I/II study
Authors: SPIRA J. , PLYUSHCH O. , ZOZULYA N. , YATUV R. , DAYAN I. , BLEICHER A. , ROBINSON M. , BARU M.
Published: May 2010

Summary.  Recombinant activated factor VIIa (FVIIa) is a bypassing agent used to treat bleeding episodes in haemophilia patients with inhibitors to factor VIII (FVIII) and factor IX. The pharmacological effect of FVIIa is short‐lived and therefore with the recommended dose of 90 μg kg−1, a bleeding episode is treated with multiple injections. A long‐acting form of FVIIa that can ensure adequate haemostasis with a single infusion, without increasing the thrombotic risk, would therefore be beneficial. PEGylated liposomes (PEGLip) have been shown to bind FVIIa and to improve haemostatic efficacy in preclinical experiments. In the present phase I/II clinical trial, we assessed the safety and efficacy of PEGLip‐formulated FVIIa in severe haemophilia A patients (FVIII ≤ 1%) with inhibitors to FVIII. Each patient received one prophylactic infusion of standard FVIIa and one prophylactic infusion of PEGLip‐formulated FVIIa. The order of the infusions was randomized and the two infusions were separated by a ten‐day washout period. Efficacy assessed by thromboelastography revealed that PEGLip‐FVIIa induced significantly shorter clotting times and produced higher clot firmnesses than standard FVIIa. Thrombin generation assays showed that PEGLip‐FVIIa induced faster thrombin generation and higher peak levels of thrombin than standard FVIIa. These effects lasted up to 5 h postinfusion. Measurements of D‐dimer, prothrombin fragment 1 + 2 and fibrinogen showed no significant differences between the PEGLip‐FVIIa and standard FVIIa treatments. PEGLip‐FVIIa therefore showed improved haemostatic efficacy without increased risk of thrombosis and may be further developed for the treatment for bleeding episodes in haemophilia patients with inhibitors.
Steroid minimization for sirolimus‐treated renal transplant recipients
Authors: Matas Arthur J. , Granger Darla , Kaufman Dixon B. , Sarwal Minnie M. , Ferguson Ronald M. , Woodle E. Steve , Gill John S.
Published: May 2010

Matas AJ, Granger D, Kaufman DB, Sarwal MM, Ferguson RM, Woodle ES, Gill JS. Steroid minimization for sirolimus‐treated renal transplant recipients. Clin Transplant 2011: 25: 457–467. © 2010 John Wiley & Sons A/S.

Abstract: Steroids are associated with a myriad of post‐transplant side effects. Therefore, as new immunosuppressive drugs have been developed, attempts have been made to minimize steroid exposure. Sirolimus (SRL) has been demonstrated to have efficacy in early and late post‐transplant immunosuppression. Accordingly, numerous trials have studied steroid minimization (early and late post‐transplant) in the context of SRL‐containing protocols (either with or without a calcineurin inhibitor). We herein review these trials and show that recent studies have determined that both late steroid withdrawal and early rapid discontinuation can be successful with SRL immunosuppression.
A fatigue life prediction model for Chopped Strand Mat GRP at elevated temperatures
Authors: SUL JUNG‐HOON , PRUSTY B. GANGADHARA , PAN JAN WEI
Published: May 2010

Experimental and analytical investigations for the low cycle‐fatigue life prediction of Glass‐Reinforced Polymer (GRP) in Chopped Strand Mat (CSM) form are studied. Based on the theories of modulus degradation and residual strength degradation, a novel model is proposed for the prediction of progressive stiffness loss in terms of tension–tension fatigue load and the number of cycles. The proposed model involves various loadings and environmental variables, which makes the reliable predictions suitable for structural analysts. Experiments were carried out at room and elevated temperatures to evaluate the validity of the proposed prediction model for the characterisation of temperature‐dependent behaviour in fatigue. Predictions using the proposed model are in good agreement with the experiments that justify the use of the model to determine the extent of low‐cycle fatigue damage accumulation in GRP–CSM at room and elevated temperatures.
“There Is Something in That Water”: Race, Nationalism, and Legal Violence
Authors: Murdocca Carmela
Published: May 2010

This article analyzes the issue of water contamination in Kashechewan, Ontario, Canada. Through an inquiry into the way in which water contamination in one Aboriginal community was handled by the local and federal governments, this article examines processes of ongoing colonialism in Canada. Drawing on an array of sources, this article explores three features pertinent to this water crisis: historical forms of legal violence, symbolic forms of representation concerning the relationship between nationalism and the governance of race in liberal democracies, and the importance of the case study approach when examining legalized forms of violence. By examining connections between race, nationalism, and legal violence, this article explores the ways in which biopolitical forms of racial governance require an analysis that links legal violence and structural violence to historical and symbolic forms of representation.
Oxygen Requirements for Growth of Young Coho (Oncorhynchus kisutch) and Sockeye (O. nerka) Salmon at 15 °C
Authors: Brett J. R. , Blackburn J. M.
Published: May 2010

The growth rate and food conversion efficiency of young coho and sockeye salmon on a full ration were determined in freshwater at oxygen concentrations ranging from 2 to 15 mg/L (15 °C). The data, and a reanalysis of selected published records for bass, carp, and coho, were examined critically in relation to the Limiting Factor hypothesis. It was concluded for all species that above a critical level ranging from 4.0 to 4.5 mg O2/L, growth and conversion efficiency were not limited when tested for relatively short periods (6–8 wk) under the pristine conditions of laboratory tanks. A slight but significant trend to exhibit higher hematocrits at lower oxygen levels revealed the possible presence of an adaptive mechanism for improved respiratory capacity at subcritical oxygen concentrations.Key words: limiting oxygen, growth rate, blood hematocrits, salmon tolerance
Complex Interactions of Multiple Aquatic Consumers: An Experimental Mesocosm Manipulation
Authors: Richardson William B. , Threlkeld Stephen T.
Published: May 2010

In 7-m3 outdoor tanks filled with lake water, the presence/absence of omnivorous young-of-the-year Micropterus salmoides, zooplanktivorous Menidia beryllina, and herbivorous larval Hyla chrysocelis was experimentally manipulated. A cross-classified design was used to assess the interactive effects of these vertebrate consumers on the experimental food webs. Large zooplankters and large, actively swimming macroinvertebrates (Ceriodaphnia, Simocephalus, Corixidae, Notonectidae, and Dytiscidae) were particularly susceptible to depletion by both fish species. Micropterus tanks contained greater numbers of Keratella quadrata and Hebridae but fewer benthic cyclopoid copepods. Menidia tanks contained more Synedra and algal filaments. Hyla exerted only minor direct effects on the tank communities. When both fish species were in the same tank, both had elevated mortality. Micropterus, in tanks with Menidia and Hyla, were larger and in better condition than in tanks without Hyla. The primary effects of the experimental manipulations on food web components were two- and three-way interactions in which the effect of a given treatment was dependent on the presence of another treatment. Results suggest that the addition or removal of consumers may not cause linear, additive changes in food webs.
Prey Aggregation Is Correlated with Increased Predation Pressure in Lake Fish Communities
Authors: Johannes Mark R. S.
Published: May 2010

Aggregations of prey fish, golden shiner (Notemigonus crysoleucas), were examined during 7 yr of predator manipulations in two lakes to determine whether they responded to changes in predation pressure and varied with time-of-day, age, and habitat. Regression analysis was used to examine aggregation in 12 replicate prey densities from two time periods, two ages, two habitats, three sample series, and seven predator densities. Aggregation was assessed as the variance of mean densities for each treatment combination. Multiple regression and ANCOVA analyses indicated that (1) golden shiner aggregated more during day than night, (2) their aggregation was positively related to predator density, (3) young shiner aggregated more than older ones at low predator densities, and (4) aggregation in older shiner was more responsive to increased predator densities than aggregation in younger shiner. These results provide empirical evidence that golden shiner aggregation patterns respond to predation pressure and the response varies with time and age. These results also suggest that variance in net catches can provide an index of fish aggregation and that aggregation observed at the population level is not solely dependent on species and density, but is a behavioural response mediated by several factors including predators.
Nutrient and Energy Transport between Estuaries and Coastal Marine Ecosystems by Fish Migration
Authors: Deegan Linda A.
Published: May 2010

Biomass accumulation and changes in body energy and nutrient (carbon, nitrogen, and phosphorus) composition were evaluated relative to the migration pattern of gulf menhaden (Brevoortia patronus) to determine if biotic transport by fish is an important source of energy and nutrients to coastal marine ecosystems. Gulf menhaden transported significant quantities of energy, C, N, and P from a Louisiana estuary to the nearshore Gulf of Mexico. Transport was always out of the estuary to the marine system, although the magnitude depended on the balance between growth and mortality rates and abundance of fish. Average export per year was 38 g biomass, 930 kJ, 22.5 g C, 3.1 g N, and 0.9 g P∙m−2 out of estuaries. This is roughly 5–10% of the total primary production of these estuarine areas. N and P export by fish is of the same magnitude as passive waterborne export; however it is higher quality. This indicates that fish migration can play an important role in exporting the productivity of estuaries to coastal marine ecosystems.
Mitochondrial DNA Variation in Striped Bass (Morone saxatilis) from Canadian Rivers
Authors: Wirgin Isaac I. , Ong Tun-Liang , Maceda Lorraine , Waldman John R. , Moore David , Courtenay Simon
Published: May 2010

Mitochondrial DNA(mtDNA)was analysed to determine the genetic relatedness of striped bass (Morone saxatilis) populations in tributaries to the Gulf of St. Lawrence and the Bay of Funday. Mitochondrial DNA genotype frequencies were compared with those of striped bass from the Shubenacadie River (Bay of Fundy) and the Miramichi and Tabusintac rivers (Gulf of St. Lawrence). These mtDNA genotype frequencies were compared with those of striped bass representative of the Atlantic coastal migratory stock originating in the Hudson River and Chesapeake Bay. Differences in the frequencies of mtDNA length variants permitted discrimination of the Shubenacadie River from the Miramichi River and Tabusintac River populations and all three Canadian populations from the U S. spawned costal migratory stock. No difference in the frequency of mtDNA length variants was observed between Tabusintac River and Miramichi River striped bass. Heteroplasmy for mtDNA length variants was observed in 35% of Gulf of St. Lawrence fish, the highest frequency observed in any striped bass population. These results highlight the genetic heterogeneity of these Canadian striped bass populations and their distinctiveness from U S. stocks. Future efforts to restore these depleted Canadian striped bass populations should consider the impact of stock transfer on endemic striped bass gene pools.
Accumulation of PCBs by Lake Trout (Salvelinus namaycush): An Individual-Based Model Approach
Authors: Madenjian Charles P. , Carpenter Stephen R. , Eck Gary W. , Miller Michael A.
Published: May 2010

To explain the variation in growth and in concentration of polychlorinated biphenyls (PCBs) among individual fish, an individual-based model (IBM) was applied to the lake trout (Salvelinus namaycush) population in Lake Michigan. The IBM accurately represented the variation in growth exhibited by the different age classes of lake trout. Uncertainty analysis of the IBM revealed that mean PCB concentration for the lake trout population was most sensitive to PCB concentration in their prey. The variability in PCB concentration among lake trout individuals was not adequately explained by the IBM, unless variation in prey fish PCBs was included in the model. To accomplish this, the simulated lake trout population was divided into subsets subjected to different levels of PCB concentration in the prey fish. Thus, model results indicated that variability in prey fish PCB concentration was an important component of the variation in PCB concentration observed among individual lake trout comprising the Lake Michigan population.
Sediment pH and Redox Potential Affect the Bioavailability of Al, Cu, Fe, Mn, and Zn to Rooted Aquatic Macrophytes
Authors: Jackson Leland J. , Kalff Jacob , Rasnnussen Joseph B.
Published: May 2010

We have evaluated the role of sediment pH (4.7–7.1) and redox potential (88–305 mV) in determining the bioavailability of five metals to four species of isoetoid macrophytes. The four species (Eleocharis acicularis, Eriocaulon septangulare With., Isoetes sp., and Sagittaria graminae) did not differ significantly in the relationship between the contents of metals in plants and sediment. When data for all species were pooled, 28–80% of the variation in the log of plant metal content was explained by the log of sediment metal (Al, Fe, and Mn) or by the log of sediment organic content (Cu and Zn). Sediment pH explained 45% (Al), 10% (Cu), 20% (Fe), 5% (Mn), and 12% (Zn) variation over and above that explained by the sediment metal content. These results demonstrate that lower sediment pH, in the presence of mildly oxic redox conditions, increases the bioavailability of these five trace metals to rooted aquatic plants. Rooted macrophytes subject to acidification contain higher metal concentrations which may be transferred by grazing to higher trophic levels.
Pelagic Food Web Structure in Adirondack Mountain, USA, Lakes of Varying Acidity
Authors: Havens Karl E.
Published: May 2010

Pelagic food web models were constructed for 50 softwater lakes of varying acidity (pH 4.17–7.32) in the Adirondack Mountains, and relationships between food web parameters and several abiotic variables (pH, monomeric Al, dissolved organic carbon (DOC), zmax, and area) were quantified. With declining pH, pelagic food web complexity was reduced, as the number of species, links, links per species, predator generalization, and prey vulnerability all declined. The declines were less pronounced in lakes having high DOC levels. Some web parameters, including the predator/prey ratio, the portion of basal, intermediate and top species, and species redundancy, did not decline with pH but were more variable among the acid lakes. Those trends are consistent with the view that at low pH, toxicity becomes the major factor controlling community structure.
Sedimentary Phosphorus in the Bay of Quinte, Lake Ontario
Authors: Oluyedun O. A. , Ajayi S. O. , VanLoon G. W. , Sly P.
Published: May 2010

Phosphorus distributions in sediments of the Bay of Quinte were measured. Principal fractions in most samples were (in order of decreasing concentration) P associated with CaCO3, residual organic P, associated with Fe and Al hydrous oxides, and P in the fulvic acid fraction. Concentrations of P in each fraction were followed at 3-wk intervals from May to October and on some additional dates at two or more sites. There were only two systematic changes in concentration over this time. The amount of P incorporated in the sedimentary biomass increased during the summer, probably at a time of high microbiological activity; this was followed by a sharp decrease and another slower increase in late summer. Available P steadily increased during the growing season, but returned to near the previous year's value 12 mo later. Dissolved P in water adjacent to the sediments showed a peak in concentration corresponding to the decrease in biomass P in midsummer. The results are consistent with a picture of P cycling in which forms of the element are first incorporated in the biomass, but are later released to the water column or to available sites on the sediment upon decomposition of the biomass.
Genetic and Morphological Differentiation between Dwarf and Normal Size Forms of Lake Whitefish (Coregonus clupeafotmis) in Como Lake, Ontario
Authors: Vuorinen J. A. , Bodaly R. A. , Reist J. D. , Bernatchez L. , Dodson J. J.
Published: May 2010

Normal and dwarf size forms of lake whitefish (Coregonus clupeaformis) from Como Lake, Ontario, were sampled at spawning time and examined for differences in electrophoretic, mtDNA, and morphological characteristics to test the hypothesis of reproductive isolation and provide clues regarding evolutionary origin. Of the 36 enzyme loci examined, 33 were fixed for the same alleles in both dwarf and normal lake whitefish. At the three polymorphic loci, allele frequencies were not statistically different between dwarfs and normals. mtDNA analysis revealed five different haplotypes. The same mtDNA haplotype was the most common in both dwarf and normal lake whitefish, but there was a statistically significant difference in haplotype frequencies between the two size forms. Discriminant and principal component analyses demonstrated highly significant morphological differences between dwarfs and normals. Because the two size morphs spawn in the same place at the same time, it is most likely that genetic differences, not different rearing environments, underly the observed morphological differences. mtDNA haplotypes derived from both the Mississippi and Atlantic glacial refugia are present in Como Lake lake whitefish, raising the possibility of an allopatric divergence for the two forms; however, this hypothesis requires testing by genetic comparisons of other sympatric populations in Ontario.
Improved Growth, Swimming Performance, and Muscular Development in Exercise-Conditioned Young-of-the-Year Striped Bass (Morone saxatilis)
Authors: Young Paciencia S. , Cech Jr. Joseph J.
Published: May 2010

Exercise conditioning at 1.2–2.4 body lengths∙s−1for 60 d significantly improved final weights, specific growth rates (SGR), 2-min critical swimming velocities, red muscle cross-sectional areas at 80% standard length (SL), and red:white muscle ratio at 80% SL in both cultured and wild young-of-the-year striped bass (Morone saxatilis). Moreover, wild fish had final weights and SGR greater than cultured fish in both exercised and unexercised groups. Exercise conditioning also increased white muscle cross-sectional areas at all sections (50, 65, and 80% SL) in the cultured but not in the wild fish, although white muscle areas of exercised wild fish were significantly greater than in the unexercised cultured fish. It is suggested that exercise-conditioned striped bass used for stocking purposes might show increased survival rates in the wild.
Shape of Zooplankton and Retention in Filter-Feeding: A Quantitative Comparison between Industrial Sieves and the Branchial Sieves of Common Bream (Abramis brama) and White Bream (Blicca bjoerkna)
Authors: Berg Coen van den , Boogaart Jos G.M. van den , Sibbing Ferdinand A. , Lammens Eddy H.R.R. , Osse Jan W.M.
Published: May 2010

Industrial sieves retained all cycloid copepods with a width larger than their mesh size, but Daphnia, with a width up to 1.4 times the mesh size, still passed through them. Daphnia have a lower depth/width ratio than copepods (0.599 and 0.882, respectively). Therefore, Daphnia could pass through the square meshes diagonally. In filter-feeding experiments with common bream (Abramis brama), the smallest retained copepods correspondingly were about 35% less wide than the smallest retained Daphnia. White bream (Blicca bjoerkna) did not retain copepods smaller than Daphnia. In the reducible-channel model of filter-feeding, particles are retained in the channels between the medial gill rakers. The mesh size can be reduced by lowering the lateral rakers into these channels. We calculated that zooplankton depth is the critical size parameter in reduced channels and zooplankton width in unreduced channels. We found that white bream was feeding with unreduced channels and common bream with reduced channels. The depth/width ratio (35% lower in Daphnia than in copepods) therefore explains the difference in retention of copepods and Daphnia by common bream whereas no such difference was expected for white bream. The shape of zooplankton thus affects the trophic segregation and the exploitation of food resources by fish.
Estimation of the Functional Form of Selectivity by Baited Hooks: A Graphical Approach
Authors: Kenchington T. J.
Published: May 2010

A recently proposed graphical technique for exploring the selectivity of hooked fishing gears, involving the plotting of catch ratios against fish length, is further developed and illustrated. This technique can provide first estimates of the functional form of selectivity curves and sometimes estimates of some parameter values as well. It is therefore a useful preliminary to nonlinear estimation of hook selectivities.
Host Response of Atlantic Salmon (Salmo salar) to Infection by Sea Lice (Caligus elongatus)
Authors: MacKinnon Barbara M.
Published: May 2010

Atlantic salmon (Salmo salar), naturally infected with Caligus elongatus in seapen cages in Brandy Cove, St. Andrews, N.B., were examined histologically and ultrastructurally for signs of pathology associated with the attached chalimus larvae. Naturally -infected fish and fish that had never been exposed to sea lice infections were examined serologically for altered white blood cell counts and for any antibody response to the adult parasite. The chalimus larva feeds on the epidermal cells of the scale to which it is attached and denudes the epidermis down to the basement membrane. Ruptured and pycnotic cells line the hole created by the larva, and there is some evidence of hyperplasia around stage IV chalimus larvae. Little other damage or host reaction is evident. There is no seral antibody response to the patent infection as assayed by electroimmuno transfer blot, and white blood cell counts from infected and control groups of fish are statistically the same.
INDEX POLYNOMIAL INVARIANT OF VIRTUAL LINKS
Authors: IM YOUNG HO , LEE KYEONGHUI , LEE SANG YOUL
Published: May 2010

We introduce a polynomial invariant of virtual links that is non-trivial for many virtuals, but is trivial on classical links. Also this polynomial is sometimes useful to find the virtual crossing number of virtual knots. We give various properties of this polynomial and examples.
μ-Opioid receptor stimulation in the medial subnucleus of the tractus solitarius inhibits gastric tone and motility by reducing local GABA activity
Authors: Herman Melissa A. , Alayan Alisa , Sahibzada Niaz , Bayer Barbara , Verbalis Joseph , Dretchen Kenneth L. , Gillis Richard A.
Published: May 2010

We examined the effects of altering μ-opioid receptor (MOR) activity in the medial subnucleus of the tractus solitarius (mNTS) on several gastric end points including intragastric pressure (IGP), fundus tone, and the receptive relaxation reflex (RRR). Microinjection of the MOR agonist [d-Ala2,MePhe4,Gly(ol)5]enkephalin (DAMGO; 1–10 fmol) into the mNTS produced dose-dependent decreases in IGP. Microinjection of the endogenous MOR agonists endomorphin-1 and endomorphin-2 (20 fmol) into the mNTS mimicked the effects of 10 fmol DAMGO. Microinjection of 1 and 100 pmol DAMGO into the mNTS produced a triphasic response consisting of an initial decrease, a transient increase, and a persistent decrease in IGP. The increase in IGP appeared to be due to diffusion to the dorsal motor nucleus of the vagus. The effects of 10 fmol DAMGO in the mNTS were blocked by vagotomy and by blockade of MORs, GABAAreceptors, and ionotropic glutamate receptors in the mNTS. The RRR response was abolished by bilateral microinjection of the opioid receptor antagonist naltrexone into the mNTS and reduced by intravenous administration of naltrexone. Our data demonstrate that 1) activation of MORs in the mNTS with femtomole doses of agonist inhibits gastric motility, 2) the mechanism of MOR effects in the mNTS is through suppression of local GABA activity, and 3) blockade of MORs in the mNTS prevents the RRR response. These data suggest that opioids play an important role in mediating a vagovagal reflex through release of an endogenous opioid in the mNTS, which, in turn, inhibits ongoing local GABA activity and allows vagal sensory input to excite second-order mNTS neurons.
S100A4 expression is increased in stricture fibroblasts from patients with fibrostenosing Crohn's disease and promotes intestinal fibroblast migration
Authors: Cunningham Michael F. , Docherty Neil G. , Burke John P. , O'Connell P. Ronan
Published: May 2010

Fibroblasts represent the key cell type in fibrostenosing Crohn's disease (FCD) pathogenesis. S100A4 is an EF-hand calcium-binding protein family member, implicated in epithelial-mesenchymal transition and as a marker of activated T lymphocytes and fibroblasts in chronic tissue remodeling. The aim of this study was to examine the expression profile of S100A4 in the resected ileum of patients with FCD. Mucosa, seromuscular explants, and transmural biopsies were harvested from diseased and proximal, macroscopically normal margins of ileocecal resections from patients with FCD. Samples were processed for histochemistry, immunohistochemistry, real-time RT-PCR, Western blotting, and transmission electron microscopy. Primary explant cultures of seromuscular fibroblasts were exposed to transforming growth factor (TGF)-β1 (1 ng/ml), and S100A4 expression and scratch wound-healing activity were assessed at 24 h. CCD-18Co fibroblasts were transfected with S100A4 small interfering RNA, treated with TGF-β1 (1 ng/ml) for 30 min or 24 h, and then assessed for S100A4 and Smad3 expression and scratch wound-healing activity. S100A4 expression was increased in stricture mucosa, in the lamina propria, and in CD3-positive intraepithelial CD3-positive T lymphocytes. Fibroblastic S100A4 staining was observed in seromuscular scar tissue. Stricture fibroblast explant culture showed significant upregulation of S100A4 expression. TGF-β1 increased S100A4 expression in cultured ileal fibroblasts. In CCD-18Co fibroblasts, S100A4 small interfering RNA inhibited scratch wound healing and modestly inhibited Smad3 activation. S100A4 expression is increased in fibroblasts, as well as immune cells, in Crohn's disease stricture and induced by TGF-β1. Results from knockdown experiments indicate a potential role for S100A4 in mediating intestinal fibroblast migration.
Effects of Rivastigmine Transdermal Patch and Capsule on Aspects of Clinical Global Impression of Change in Alzheimer’s Disease: A Retrospective Analysis
Authors: Cummings Jeffrey L. , Ferris Steven H. , Farlow Martin R. , Olin Jason T. , Meng Xiangyi
Published: May 2010

Background: The Alzheimer’s Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC) scale is widely used in Alzheimer trials. It assesses cognition, activities of daily living (ADLs), behavior and global functioning. To advance the understanding of relationships between the ADCS-CGIC and scores from other commonly used tools, this analysis investigated the ability of each domain to measure change. This was a hypothesis-forming study, designed to provide a basis for possible future research. Methods: This retrospective analysis used data from a 24-week, randomized, placebo-controlled trial [study ENA713D2320 (IDEAL)] that evaluated rivastigmine patches and capsules in AD patients. Results: At week 24, significant treatment effects versus placebo were seen on the ADCS-CGIC cognitive domain with rivastigmine 17.4 mg/24 h patch (p < 0.01), 9.5 mg/24 h patch (p = 0.02) and capsules (p < 0.01); similarly on the ADCS-CGIC ADL domain. The cognition portion of the CGIC correlated with the Alzheimer’s Disease Assessment Scale cognitive subscale and the ADL section with the ADCS-ADL trial measures. Variance ascribable to these tools was small, indicating that CGIC detects changes not measured by the domain-specific tools. Conclusions: The results of this post hoc analysis suggest that the ADCS-CGIC accurately reflects changes in cognitive and functional domains measured by other tools; it captures changes not assessed by domain-specific instruments. Cognitive alterations show greatest correlation with total CGIC. These results may assist in analyzing and interpreting CGIC results in other trials.
Patients’ Perspectives of Constant-Site (Buttonhole) Cannulation for Haemodialysis Access
Authors: Ward Janice , Shaw Kate , Davenport Andrew
Published: May 2010

Introduction: The advent of blunt needles for arteriovenous fistula cannulation has led to a resurgence in the buttonhole technique. Although successful for home haemodialysis patients and those who self-cannulate, we introduced this technique into one of our satellite dialysis centres. Methods: Audit of buttonhole cannulation in 53 adult haemodialysis patients, 29 male, mean age 68.5 ± 1.9 years. Twelve (23%) patients started de novo and 41 (77%) had previously been using sharp needles with the rope ladder technique. Results: Typically, the needle tract was developed after 8–10 cannulations depending on the tracker nurse and vessel. Ninety-three percent of the patients reported shorter venepuncture bleeding times after needle removal, 81% less pain on needling and 80% improved appearance of the fistula compared to sharp needle rope ladder technique. Fistula recirculation rates fell from 9.3 ± 0.4 to 8.3 ± 0.3% (p = 0.016), as did fistuloplasty requirement during a median follow-up of 14 months (range, 9.5–22.5; χ2 = 5.6, p = 0.008). Conclusions: Buttonhole cannulation can be successfully introduced into a busy satellite dialysis centre. Patient satisfaction improved due to lower pain scores, shorter bleeding times after needle removal and improved appearance of the fistula. Recirculation rates and requirement for fistuloplasty were also reduced.
Pulse Wave Velocity Measurements Are Reproducible in Multiple Trained Observers: A Short Report
Authors: Sigrist M.K. , Chiarelli G. , Levin A. , Romann A. , Weber C.
Published: May 2010

Background: Arterial stiffness, measured by pulse wave velocity (PWV), is highly predictive of mortality in dialysis patients. As such, PWV is frequently used in clinical research studies and may have a role in clinical practice if shown to be suitably reliable. Measurement of PWV using the SphygmoCor® system is known to be an observer-dependent technique. The aim of this study was to investigate the ability of 4 observers to acquire reproducible PWV and pulse wave analysis (PWA) measurements after a 6-week training period. Methods: Reproducibility of this technique was investigated using repeated measurements of the carotid-femoral PWV and PWA of the radial pulse by the 4 observers after a period of training. Both healthy volunteers and individuals with chronic kidney disease (CKD) were recruited for this study. Measurements were considered to have met quality control if 2 consecutive measurements were visually acceptable, within 1.5 m/s of each other and had a standard deviation of less than 10%. A fixed-effect analysis of variance was used to test the variation in measurements between the observers; the intraclass correlation coefficient (ICC) was used to assess the statistical agreement between the observers. Results: A total of 20 individuals volunteered for PWV and PWA measurements (13 with CKD and 7 without); the mean age was 58 years (range 24–83). The average PWV was 9.4 ± 3.6 m/s. There was no significant difference shown between the 4 observers’ measurements (p = 0.25). Further, there was good statistical agreement between the observers (ICC = 0.95). Conclusions: After a period of training it is possible for multiple observers to have reproducible measurements of PWV and PWA. Assurance of reproducibility is important when more than one individual is collecting data in a study, particularly when assessing changes over time.
The Immunopathological Spectrum of Crescentic Glomerulonephritis: A Survey of 106 Patients in a Single Chinese Center
Authors: Lin Wei , Chen Min , Cui Zhao , Zhao Ming-Hui
Published: May 2010

Background: Crescentic glomerulonephritis (CrGN) is a severe form of glomerular injury. We retrospectively analyzed data from Chinese patients with CrGN in our center to characterize the immunopathological spectrum of CrGN. Methods: A total of 106 consecutive patients with biopsy-proven CrGN were recruited. CrGN was classified into 3 types according to findings on immunofluorescence microscopy; type I was defined as a linear deposition of immunoglobulins along the glomerular basement membrane (GBM), type II as a glomerular deposition of immune-complex and type III as a pauci-immune deposition. Results: A total of 17/106 (16.0%) patients were classified as type I, 43/106 (40.6%) as type II and 46/106 (43.4%) as type III. Serum antineutrophil cytoplasmic antibodies (ANCA) could be detected in 1/17 (5.9%) patient with type I, 11/43 (25.6%) patients with type II and 29/46 (63.0%) patients with type III CrGN (p < 0.001). Serum anti-GBM antibodies could be detected in 14/17 (82.4%) patients with type I, 2/43 (4.7%) patients with type II and 3/46 (6.5%) patients with type III. In type II CrGN, ANCA-positive patients were older (p < 0.001), had more multi-system involvement (p < 0.001) and more fibrinoid necrosis in renal histopathology than ANCA-negative patients (p = 0.003). Conclusions: Pauci-immune CrGN might be the most common type of CrGN in Northern China. There was much heterogeneity within each type of CrGN.
Cholesteryl Ester Transfer Protein Polymorphism (TaqIB) Associates With Risk in Postinfarction Patients With High C-Reactive Protein and High-Density Lipoprotein Cholesterol Levels
Authors: Corsetti James P. , Ryan Dan , Rainwater David L. , Moss Arthur J. , Zareba Wojciech , Sparks Charles E.
Published: May 2010

Objective—

To investigate the roles of inflammation and a cholesteryl ester transfer protein (CETP) polymorphism potentially related to recent findings demonstrating coronary risk with increasing high-density lipoprotein cholesterol (HDL-C) level.

Methods and Results—

A novel graphical exploratory data analysis tool allowed the examination of coronary risk in postinfarction patients relating to HDL-C and C-reactive protein levels. Results demonstrated a high-risk subgroup, defined by high HDL-C and C-reactive protein levels, exhibiting larger HDL particles and lower lipoprotein-associated phospholipaseA
2
levels than lower-risk patients. Subgroup CETP-associated risk was probed using a functional
CETP
polymorphism (TaqIB,
rs708272
). In the high-risk subgroup, multivariable modeling revealed greater risk for
B2
allele carriers (less CETP activity) versus B1 homozygotes (hazard ratio, 2.41; 95% CI, 1.04 to 5.60;
P
=0.04). Within the high-risk subgroup,
B2
allele carriers had higher serum amyloid A levels than B1 homozygotes. Evidence also demonstrates that
CETP
genotypic differences in HDL subfraction distributions regarding non–HDL-C and lipoprotein-associated phospholipaseA
2
may potentially relate to impaired HDL remodeling.

Conclusion—

Postinfarction patients with high HDL-C and C-reactive protein levels demonstrate increased risk for recurrent events. Future studies should aim at characterizing altered HDL particles from such patients and at elucidating the mechanistic details related to inflammation and HDL particle remodeling. Such patients should be considered in drug trials involving an increase in HDL-C level.