bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of the VDR Translation Start Site Polymorphism and Fracture Risk in Older Women
Authors: Moffett Susan P , Zmuda Joseph M , Cauley Jane A , Ensrud Kristine E , Hillier Teresa A , Hochberg Marc C , Li Jia , Cayabyab Shelia , Lee Jocelyn M , Peltz Gary , Cummings Steven R
Published: February 2007

We evaluated the association between the VDR translation start site polymorphism and osteoporotic phenotypes among 6698 older white women. Women with the C/C genotype had lower wrist BMD and an increased risk of wrist and all non-spine/low-trauma fractures. The high frequency of this variant confers a population attributable risk that is similar to several established risk factors for fracture.

Introduction: The vitamin D receptor (VDR) is a nuclear receptor that regulates bone formation, bone resorption, and calcium homeostasis. A common C to T polymorphism in exon 2 of the VDR gene introduces a new translation start site and a protein that differs in length by three amino acids (T = 427aa, C = 424aa; rs10735810).

Materials and Methods: We conducted genetic association analyses of this polymorphism, BMD, and fracture outcomes in a prospective cohort of 6698 white American women ≥65 years of age. Incident fractures were confirmed by physician adjudication of radiology reports. There were 2532 incident nontraumatic/nonvertebral fractures during 13.6 yr of follow-up including 509 wrist and 703 hip fractures.

Results: Women with the C/C genotype had somewhat lower distal radius BMD compared with those with the T/T genotype (CC = 0.358 g/cm2, CT = 0.361 g/cm2, TT = 0.369 g/cm2, p = 0.003). The C/C genotype was also associated with increased risk of non-spine, low traumatic fractures (HR: 1.18; 95% CI: 1.04, 1.33) and wrist fractures (HR: 1.33; 95% CI: 1.01, 1.75) compared with the T/T genotype in age-adjusted models. Further adjustments for distal radius BMD only slightly attenuated these associations. The VDR polymorphism was not associated with hip fracture. The population attributable risk (PAR) of the C/C genotype for incident fractures was 6.1%. The PAR for established risk factors for fracture were: low femoral neck BMD (PAR = 16.3%), maternal history of fracture (PAR = 5.1%), low body weight (PAR = 5.3%), corticosteroid use (PAR = 1.3%), and smoking (PAR = 1.6%). Similar PAR results were observed for wrist fractures.

Conclusions: The common and potentially functional VDR translation start site polymorphism confers a modestly increased relative risk of fracture among older white women. However, the high frequency of this variant confers a population attributable risk that is similar to or greater than several established risk factors for fracture.
Effect of 2-Methylene-19-nor-(20S)-1α-Hydroxy-Bishomopregnacalciferol (2MbisP), an Analog of Vitamin D, on Secondary Hyperparathyroidism
Authors: Slatopolsky Eduardo , Finch Jane L , Brown Alex J , Ritter Cynthia S , Mizobuchi Masahide , Plum Lori A , Clagett-Dame Margaret , Sicinski Rafal R , DeLuca Hector F
Published: February 2007

Vitamin D analogs are being developed that retain therapeutic effects but are less calcemic and phosphatemic, a concern in CKD patients who are prone to vascular calcification. We tested a new analog of vitamin D, 2MbisP, and found that it suppresses PTH at doses that do not affect serum Ca or P.

Introduction: Calcitriol is used for the treatment of secondary hyperparathyroidism. However, its use is often limited by the development of hypercalcemia and hyperphosphatemia, an important consideration in patients with chronic kidney disease (CKD) because they are prone to vascular calcification. To minimize this toxicity, structural modifications in the vitamin D molecule have led to the development of calcitriol analogs with selective actions.

Materials and Methods: In this study, we compared the effects of 1,25(OH)2D3 and a new analog, 2-methylene-19-nor-(20S)-1α-hydroxy-bishomopregnacalciferol (2MbisP), on the development of secondary hyperparathyroidism and established secondary hyperparathyroidism in uremic rats and on mobilization of calcium and phosphorus from bone in parathyroidectomized rats. The clearance from circulation, half-life, and binding affinities to the vitamin D–binding protein and vitamin D receptor of this compound were also evaluated.

Results: Uremia produced a marked rise in plasma PTH, but treatment every other day for 2 wk with either 1,25(OH)2D3 (4 ng) or 2MbisP (250, 750, 1500, or 3000 ng) suppressed this increase by >50%. The suppression by 1,25(OH)2D3, however, was accompanied by increases in ionized calcium, phosphorus, and the calcium × phosphorus product, whereas these three parameters were unchanged by 2MbisP. The binding affinity of 2MbisP was 10–20 times less for the vitamin D receptor and 1000 times less for the serum vitamin D–binding protein compared with 1,25(OH)2D3. Also, 2MbisP was cleared more rapidly from the circulation (t½ = 10 min) than 1,25-(OH)2D3 (t½=7–9 h). In parathyroidectomized rats fed calcium-or phosphorus-deficient diets, daily injections of 2MbisP (1500 or 3000 ng), unlike 1,25(OH)2D3 (50 ng), had no effect on calcium or phosphorus mobilization from bone.

Conclusions: In uremic rats, 2MbisP can suppress PTH at doses that do not affect plasma calcium, phosphorus, and calcium × phosphorus product. This new vitamin D analog may represent an important tool in the treatment of secondary hyperparathyroidism in patients with CKD.
Novelmad2Alleles Isolated in aSchizosaccharomyces pombeγ-Tubulin Mutant Are Defective in Metaphase Arrest Activity, but Remain Functional for Chromosome Stability in Unperturbed Mitosis
Authors: Tange Yoshie , Niwa Osami
Published: February 2007

A previously isolated fission yeast γ-tubulin mutant containing apparently stabilized microtubules proliferated at an approximately identical rate as wild type, yet the mutant mitosis spindle dynamics were aberrant, particularly the kinetochore microtubule dynamics. Progression through mitosis in the mutant, however, resulted in mostly accurate chromosome segregation. In the absence of the spindle assembly checkpoint gene, mad2+, the spindle dynamics in the γ-tubulin mutant were greatly compromised, leading to a high incidence of chromosome missegregation. Unlike in wild-type cells, green fluorescent protein (GFP)-tagged Mad2 protein often accumulated near one of the poles of an elongating spindle in the γ-tubulin mutant. We isolated novel mad2 mutants that were defective in arresting mitotic progression upon gross perturbation of the spindle formation but remained functional for the viability of the γ-tubulin mutant. Further, the mad2 mutations did not appreciably destabilize minichromosomes in unperturbed mitoses. When overexpressed ectopically, these mutant Mad2 proteins sequestered wild-type Mad2, preventing its function in mitotic checkpoint arrest, but not in minichromosome stability. These results indicated that the Mad2 functions required for checkpoint arrest and chromosome stability in unperturbed mitosis are genetically discernible. Immunoprecipitation studies demonstrated that GFP-fused mutant Mad2 proteins formed a Mad1-containing complex with altered stability compared to that formed with wild-type Mad2, providing clues to the novel mad2 mutant phenotype.
Role of themod(mdg4)Common Region in Homolog Segregation in Drosophila Male Meiosis
Authors: Soltani-Bejnood Morvarid , Thomas Sharon E , Villeneuve Louisa , Schwartz Kierstyn , Hong Chia-sin , McKee Bruce D
Published: February 2007

Homologous chromosomes must pair and establish stable connections during prophase I of meiosis to segregate reliably from each other at anaphase I. In most organisms, the stable connections, called chiasmata, arise from crossovers. In Drosophila males, homologs pair and segregate without crossing over. Chiasmata are replaced by a homolog conjunction complex that includes the Stromalin in Meiosis (SNM) and Modifier of Mdg4 in Meiosis (MNM) proteins. MNM is one of 31 alternative splice products of mod(mdg4), all of which share a common 402-amino-acid N terminus and differ at their C termini. Previous data demonstrated that an MNM-specific exon is required for homolog conjunction, but did not address whether the N-terminal common region, which includes a BTB domain that can mediate coalescence of protein-DNA complexes, is also required. Here we describe a mutation in the common region of mod(mdg4), Z3-3401, that causes qualitatively similar phenotypes as the MNM-specific alleles but disrupts X–Y segregation much more drastically than autosomal segregation. The mutant MNM protein in Z3-3401 is expressed throughout prophase I in spermatocytes but the protein is confined to the cytoplasm, suggesting that the Z3-3401 mutation disrupts a signal required for nuclear localization or retention. Z3-3401 fails to complement a large battery of lethal and semilethal alleles in the common region for meiotic nondisjunction, including an allele containing an amino acid substitution at a conserved residue in the BTB/POZ domain, consistent with a general requirement for the mod(mdg4) common region in homolog segregation.
Rampant Gene Exchange Across a Strong Reproductive Barrier Between the Annual Sunflowers,Helianthus annuusandH. petiolaris
Authors: Yatabe Yoko , Kane Nolan C , Scotti-Saintagne Caroline , Rieseberg Loren H
Published: February 2007

Plant species may remain morphologically distinct despite gene exchange with congeners, yet little is known about the genomewide pattern of introgression among species. Here we analyze the effects of persistent gene flow on genomic differentiation between the sympatric sunflower species Helianthus annuus and H. petiolaris. While the species are strongly isolated in testcrosses, genetic distances at 108 microsatellite loci and 14 sequenced genes are highly variable and much lower (on average) than for more closely related but historically allopatric congeners. Our analyses failed to detect a positive association between levels of genetic differentiation and chromosomal rearrangements (as reported in a prior publication) or proximity to QTL for morphological differences or hybrid sterility. However, a significant increase in differentiation was observed for markers within 5 cM of chromosomal breakpoints. Together, these results suggest that islands of differentiation between these two species are small, except in areas of low recombination. Furthermore, only microsatellites associated with ESTs were identified as outlier loci in tests for selection, which might indicate that the ESTs themselves are the targets of selection rather than linked genes (or that coding regions are not randomly distributed). In general, these results indicate that even strong and genetically complex reproductive barriers cannot prevent widespread introgression.
A Balance Between Two Nuclear Localization Sequences and a Nuclear Export Sequence Governs Extradenticle Subcellular Localization
Authors: Stevens Katherine E , Mann Richard S
Published: February 2007

During animal development, transcription factor activities are modulated by several means, including subcellular localization. The Hox cofactor Extradenticle (Exd) has a dynamic subcellular localization, such that Exd is cytoplasmic by default, but is nuclear when complexed with another homeodomain protein, Homothorax (Hth). These observations raise the question of whether dimerization with Hth simply induces Exd's nuclear localization or, alternatively, if Hth is also necessary for Exd activity. To address this question, we analyzed the nuclear transport signals in Exd, including a divergent nuclear export signal (NES) and two nuclear localization signals (NLSs). We show that, although these signals are weak compared to canonical signals, they balance each other in Exd. We also provide evidence that Exd contains an NLS mask that contributes to its cytoplasmic localization. With these signals characterized, we generated forms of Exd that are nuclear localized in the absence of Hth. Surprisingly, although these Exd forms are functional, they do not phenocopy Hth overexpression. These findings suggest that Hth is required for Exd activity, not simply for inducing its nuclear localization.
Evolutionary Framework for Protein Sequence Evolution and Gene Pleiotropy
Authors: Gu Xun
Published: February 2007

In this article, we develop an evolutionary model for protein sequence evolution. Gene pleiotropy is characterized by K distinct but correlated components (molecular phenotypes) that affect the organismal fitness. These K molecular phenotypes are under stabilizing selection with microadaptation (SM) due to random optima shifts, the SM model. Random coding mutations generate a correlated distribution of K molecular phenotypes. Under this SM model, we further develop a statistical method to estimate the “effective” number of molecular phenotypes (Ke) of the gene. Therefore, for the first time we can empirically evaluate gene pleiotropy from the protein sequence analysis. Case studies of vertebrate proteins indicate that Ke is typically ∼6–9. We demonstrate that the newly developed SM model of protein evolution may provide a basis for exploring genomic evolution and correlations.
Prospects for Association Mapping in Classical Inbred Mouse Strains
Authors: Payseur Bret A , Place Michael
Published: February 2007

The collection of classical inbred mouse strains displays heritable variation in a large number of complex traits. Many generations of historical recombination have contributed to the panel of classical strain genomes, raising the possibility that quantitative trait loci could be located with high resolution by correlating strain genotypes and phenotypes. Although this association mapping framework has been successful in several empirical applications, its expected performance remains unclear. We used computer simulations based on a publicly available, dense single-nucleotide polymorphism (SNP) map to measure the power and false-positive rate of association mapping on a genomic scale across 30 commonly used classical inbred strains. Expected power is (i) often low for phenotypic effect sizes that are realistic for complex traits, (ii) highly variable across the genome, and (iii) correlated with linkage disequilibrium, aspects of the allele frequency distribution, and haplotype characteristics, as predicted by theory. Simulations also demonstrate clear potential for spurious associations to be generated by unequal relatedness among the strains. These findings suggest that association mapping in the classical strains is best applied in combination with other procedures, such as QTL mapping.
Diversity in Mating Behavior of Hermaphroditic and Male–Female Caenorhabditis Nematodes
Authors: Garcia L Rene , LeBoeuf Brigitte , Koo Pamela
Published: February 2007

In this study, we addressed why Caenorhabditis elegans males are inefficient at fertilizing their hermaphrodites. During copulation, hermaphrodites generally move away from males before they become impregnated. C. elegans hermaphrodites reproduce by internal self-fertilization, so that copulation with males is not required for species propagation. The hermaphroditic mode of reproduction could potentially relax selection for genes that optimize male mating behavior. We examined males from hermaphroditic and gonochoristic (male–female copulation) Caenorhabditis species to determine if they use different sensory and motor mechanisms to control their mating behavior. Instead, we found through laser ablation analysis and behavioral observations that hermaphroditic C. briggsae and gonochoristic C. remanei and Caenorhabditis species 4, PB2801 males produce a factor that immobilizes females during copulation. This factor also stimulates the vulval slit to widen, so that the male copulatory spicules can easily insert. C. elegans and C. briggsae hermaphrodites are not affected by this factor. We suggest that sensory and motor execution of mating behavior have not significantly changed among males of different Caenorhabditis species; however, during the evolution of internal self-fertilization, hermaphrodites have lost the ability to respond to the male soporific-inducing factor.
Simulated Effects of Recruitment Variability, Exploitation, and Reduced Habitat Area on the Muskellunge Population in Shoepack Lake, Voyageurs National Park, Minnesota
Authors: Frohnauer Nick K. , Pierce Clay L. , Kallemeyn Larry W.
Published: February 2007

The genetically unique population of muskellunge Esox masquinongy inhabiting Shoepack Lake in Voyageurs National Park, Minnesota, is potentially at risk for loss of genetic variability and long-term viability. Shoepack Lake has been subject to dramatic surface area changes from the construction of an outlet dam by beavers Castor canadensis and its subsequent failure. We simulated the long-term dynamics of this population in response to recruitment variation, increased exploitation, and reduced habitat area. We then estimated the effective population size of the simulated population and evaluated potential threats to long-term viability, based on which we recommend management actions to help preserve the long-term viability of the population. Simulations based on the population size and habitat area at the beginning of a companion study resulted in an effective population size that was generally above the threshold level for risk of loss of genetic variability, except when fishing mortality was increased. Simulations based on the reduced habitat area after the beaver dam failure and our assumption of a proportional reduction in population size resulted in an effective population size that was generally below the threshold level for risk of loss of genetic variability. Our results identified two potential threats to the long-term viability of the Shoepack Lake muskellunge population, reduction in habitat area and exploitation. Increased exploitation can be prevented through traditional fishery management approaches such as the adoption of no-kill, barbless hook, and limited entry regulations. Maintenance of the greatest possible habitat area and prevention of future habitat area reductions will require maintenance of the outlet dam built by beavers. Our study should enhance the long-term viability of the Shoepack Lake muskellunge population and illustrates a useful approach for other unique populations.
Gulf Sturgeon Movements in the Pearl River Drainage and the Mississippi Sound
Authors: Rogillio Howard E. , Ruth Ronald T. , Behrens Elizabeth H. , Doolittle Cedric N. , Granger Whitney J. , Kirk James P.
Published: February 2007

A study of the seasonal movements of Gulf sturgeon Acipenser oxyrinchus desotoi was conducted in the Pearl River system and the Mississippi Sound from 2000 through 2003. We captured or recaptured, marked, and released 503 Gulf sturgeon, 98 adults being tagged with internal or external telemetry tags. Movement chronologies were generally similar to those reported in other studies. Summer habitats were found in the Pearl and Bogue Chitto rivers (Louisiana–Mississippi), and these habitats were occupied from April through November. Adults and subadults were spatially separated, the adults being concentrated in the Bogue Chitto River and the subadults in the Pearl River. Tagged adults began to leave the summer habitat during September and to arrive at the mouth of the Pearl River and the Rigolets Pass. The last departure from this location was in late November. Wintering habitat between Cat, Ship, Horn, and Petit Bois islands in the Mississippi Sound was used between November and early March. Gulf sturgeon returned to the Rigolets Pass from March through June. Despite extensive sampling and the use of multiple collection gears, no eggs, larvae, or age-0 fish were captured and Gulf sturgeon spawning sites within this system remain unknown. The identification of summer and wintering habitats is essential for critical habitat designation for this species, which is federally listed as threatened.
Dual-acting peptide with prolonged glucagon-like peptide-1 receptor agonist and glucagon receptor antagonist activity for the treatment of type 2 diabetes
Authors: Claus Thomas H , Pan Clark Q , Buxton Joanne M , Yang Ling , Reynolds Jennifer C , Barucci Nicole , Burns Michael , Ortiz Astrid A , Roczniak Steve , Livingston James N , Clairmont Kevin B , Whelan James P
Published: February 2007

Type 2 diabetes is characterized by reduced insulin secretion from the pancreas and overproduction of glucose by the liver. Glucagon-like peptide-1 (GLP-1) promotes glucose-dependent insulin secretion from the pancreas, while glucagon promotes glucose output from the liver. Taking advantage of the homology between GLP-1 and glucagon, a GLP-1/glucagon hybrid peptide, dual-acting peptide for diabetes (DAPD), was identified with combined GLP-1 receptor agonist and glucagon receptor antagonist activity. To overcome its short plasma half-life DAPD was PEGylated, resulting in dramatically prolonged activity in vivo. PEGylated DAPD (PEG-DAPD) increases insulin and decreases glucose in a glucose tolerance test, evidence of GLP-1 receptor agonism. It also reduces blood glucose following a glucagon challenge and elevates fasting glucagon levels in mice, evidence of glucagon receptor antagonism. The PEG-DAPD effects on glucose tolerance are also observed in the presence of the GLP-1 antagonist peptide, exendin(9–39). An antidiabetic effect of PEG-DAPD is observed in db/db mice. Furthermore, PEGylation of DAPD eliminates the inhibition of gastrointestinal motility observed with GLP-1 and its analogues. Thus, PEG-DAPD has the potential to be developed as a novel dual-acting peptide to treat type 2 diabetes, with prolonged in vivo activity, and without the GI side-effects.
Interplay of PI3K and cAMP/PKA signaling, and rapamycin-hypersensitivity in TGFβ1 enhancement of FSH-stimulated steroidogenesis in rat ovarian granulosa cells
Authors: Chen Yun-Ju , Hsiao Pei-Wen , Lee Ming-Ting , Mason J Ian , Ke Ferng-Chun , Hwang Jiuan-Jiuan
Published: February 2007

Transforming growth factor (TGF) β1 facilitates FSH-induced differentiation of rat ovarian granulosa cells. The signaling crosstalk between follicle stimulating hormone (FSH) and TGFβ receptors remains unclear. This study was to investigate the interplay of cAMP/protein kinase A (PKA) and phosphatidylinositol-3-kinase (PI3K) signaling including mammalian target of rapamycin (mTOR)C1 dependence in FSH- and TGFβ1-stimulated steroidogenesis in rat granulosa cells. To achieve this aim, inhibitors of PKA (PKAI), PI3K (wortmannin), and mTORC1 (rapamycin) were employed. PKAI and wortmannin suppressions of the FSH-increased progesterone production were partly attributed to decreased level of 3β-HSD, and their suppression of the FSH plus TGFβ1 effect was attributed to the reduction of all the three key players, steroidogenic acute regulatory (StAR) protein, P450scc, and 3β-HSD. Further, FSH activated the PI3K pathway including increased integrin-linked kinase (ILK) activity and phosphorylation of Akt(S473), mTOR(S2481), S6K(T389), and transcription factors particularly FoxO1(S256) and FoxO3a(S253), which were reduced by wortmannin treatment but not by PKAI. Interestingly, PKAI suppression of FSH-induced phosphorylation of cAMP regulatory element-binding protein (CREB(S133)) disappeared in the presence of wortmannin, suggesting that wortmannin may affect intracellular compartmentalization of signaling molecule(s).

In addition, TGFβ1 had no effect on FSH-activated CREB and PI3K signaling mediators. We further found that rapamycin reduced the TGFβ1-enhancing effect of FSH-stimulated steroidogenesis, yet it exhibited no effect on FSH action. Surprisingly, rapamycin displayed a suppressive effect at concentrations that had no effect on mTORC1 activity. Together, this study demonstrates a delicate interplay between cAMP/PKA and PI3K signaling in FSH and TGFβ1 regulation of steroidogenesis in rat granulosa cells. Furthermore, we demonstrate for the first time that TGFβ1 acts in a rapamycin-hypersensitive and mTORC1-independent manner in augmenting FSH-stimulated steroidogenesis in rat granulosa cells.
Assessment of Intrinsic Bioremediation of a Coal‐Tar‐Affected Aquifer Using Two‐Dimensional Reactive Transport and Biogeochemical Mass Balance Approaches
Authors: Rogers Shane W. , Ong Say Kee , Stenback Greg A. , Golchin Johanshir , Kjartanson Bruce H.
Published: February 2007

Expedited site characterization and groundwater monitoring using direct‐push technology and conventional monitoring wells were conducted at a former manufactured gas plant site. Biogeochemical data and heterotrophic plate counts support the presence of microbially mediated remediation. By superimposing solutions of a two‐dimensional reactive transport analytical model, first‐order degradation rate coefficients (day −1) of various compounds for the dissolved‐phase plume were estimated (i.e., benzene [0.0084], naphthalene [0.0058], and acenaphthene [0.0011]). The total mass transformed by aerobic respiration, nitrate reduction, and sulfate reduction around the free‐phase coal‐tar dense‐nonaqueous‐phase‐liquid region and in the plume was estimated to be approximately 4.5 kg/y using a biogeochemical mass‐balance approach. The total mass transformed using the degradation rate coefficients was estimated to be approximately 3.6 kg/y. Results showed that a simple two‐dimensional analytical model and a biochemical mass balance with geochemical data from expedited site characterization can be useful for rapid estimation of mass‐transformation rates.
Coupling Permanganate Oxidation with Microbial Dechlorination of Tetrachloroethene
Authors: Sahl Jason W. , Munakata‐Marr Junko , Crimi Michelle L. , Siegrist Robert L.
Published: February 2007

For sites contaminated with chloroethene non‐aqueous‐phase liquids, designing a remediation system that couples in situ chemical oxidation (ISCO) with potassium permanganate (KMnO 4) and microbial dechlorination may be complicated because of the potentially adverse effects of ISCO on anaerobic bioremediation processes. Therefore, one‐dimensional column studies were conducted to understand the effect of permanganate oxidation on tetrachloroethene (PCE) dechlorination by the anaerobic mixed culture KB‐1. Following the confirmation of PCE dechlorination, KMnO 4 was applied to all columns at a range of concentrations and application velocities to simulate varied distances from oxidant injection. Immediately following oxidation, reductive dechlorination was inhibited; however, after passing several pore volumes of sterile growth medium through the columns after oxidation, a rebound of PCE dechlorination activity was observed in every inoculated column without the need to reinoculate. The volume of medium required for a rebound of dechlorination activity differed from 1.1 to 8.1 pore volumes (at a groundwater velocity of 4 cm/d), depending on the specific condition of oxidant application.
Effectiveness of Zerovalent Iron and Nickel Catalysts for Degrading Chlorinated Solvents and n‐Nitrosodimethylamine in Natural Groundwater
Authors: Schaefer Charles E. , Topoleski Corinne , Fuller Mark E.
Published: February 2007

Laboratory batch experiments were performed to evaluate the effectiveness of nickel catalysts, nanoscale zerovalent iron (nZVI) doped with palladium, and microscale ZVI for treatment of tetrachloroethene, trichloroethene, and n‐nitrosodimethylamine (NDMA) in soil‐groundwater slurries. Results indicated that the presence of NDMA inhibited degradation of chlorinated solvents. Although both the nickel catalyst and nZVI were able to degrade NDMA in deionized water, neither of these metals was effective at degrading NDMA in the soil–groundwater system evaluated in this study. The effectiveness of the nickel catalyst and nZVI, with respect to treatment of the chlorinated solvents, also appeared to be highly dependent on the groundwater geochemical conditions. Overall results of this study suggest that the degradation mechanisms involving nickel catalysts and nZVI in natural soil/groundwater systems are not well‐understood, and addition of metal catalysts to ZVI may not necessarily enhance observed degradation rates in natural systems.
Reactive Oxygen Species Responsible for the Enhanced Desorption of Dodecane in Modified Fenton's Systems
Authors: Corbin Joseph F. , Teel Amy L. , Allen‐King Richelle M. , Watts Richard J.
Published: February 2007

The enhanced treatment of sorbed contaminants has been documented in modified Fenton's reactions; contaminants are desorbed and degraded more rapidly than they desorb by fill‐and‐draw or gas‐purge desorption. The reactive species responsible for this process was investigated using dodecane as a model sorbent. Hydroxyl radical, hydroperoxide anion, and superoxide radical anion were generated separately to evaluate their roles in enhanced dodecane desorption. Dodecane desorption from silica sand over 180 minutes was negligible in gas‐purge systems and in the hydroxyl radical and hydroperoxide anion systems. In contrast, enhanced desorption of dodecane occurred in superoxide systems, with >80% desorption over 180 minutes. Scavenging of superoxide eliminated the enhanced desorption of dodecane in both superoxide and modified Fenton's systems, confirming that superoxide is the desorbing agent in modified Fenton's reactions. Conditions that promote superoxide generation in Fenton's reactions may enhance their effectiveness for in situ subsurface remediation of sorbed hydrophobic contaminants.
Influencing Factors and a Proposed Evaluation Methodology for Predicting Groundwater Contamination Potential from Stormwater Infiltration Activities
Authors: Clark Shirley E. , Pitt Robert
Published: February 2007

To offset the detrimental effects of urbanization on groundwater recharge, stormwater managers are focusing on infiltrating much of the runoff from a site that was generated because of development. For this to be effective, tools are required to predict the potential for contamination resulting from this infiltration for many site conditions, because infiltration should be stressed in areas where the least potential for causing groundwater contamination exists. Factors that influence contamination potential include the pollutant concentration in the runoff directed to the infiltration device and the ability of the underlying soil to remove the pollutant. The groundwater contamination potential of some pollutants, even those with high concentrations and moderate‐to‐high mobilities, can be reduced with proper pretreatment before infiltration. This paper presents a methodology that can be used to evaluate infiltration as an management option and introduces two different levels of models that could be used to evaluate contamination potential.
A River is Reborn—Use Attainability Analysis for the Lower Des Plaines River, Illinois
Authors: Novotny Vladimir , O'Reilly Neal , Ehlinger Timothy , Frevert Toby , Twait Scott
Published: February 2007

The goal of the Use Attainability Analysis (UAA) of the Lower Des Plaines River was to upgrade the designated “Secondary Contact Recreation and Indigenous Aquatic Life Use” to a higher use that would be commensurate with the goals of the Clean Water Act (CWA). In Illinois, the water body use in compliance with the goals of the CWA is named “General Use”. The river has been extensively modified and receives most point‐source and urban runoff discharges from the Chicago metropolitan area (9.5 million inhabitants). The study included an extensive assessment of the physical, chemical, biological, and bacteriological integrity status of the water body and sediments. The UAA found that the water quality situation of the river has improved significantly since the 1970s, when the Illinois Pollution Control Board defined and assigned the Secondary Contact Recreation and Indigenous Aquatic Life Use designation to the Lower Des Plaines River. The study defined and suggested a “Modified Impounded Use” for one highly modified reach, with adjusted standards for dissolved oxygen and recreation. The study also recommended adoption of the General Use standards, some of them in a modified form, for other water quality parameters. Standards for limited recreation were also developed. The UAA also outlines a suggested action plan that will bring UAA segments of the Lower Des Plaines River in compliance with UAA goals.
Dynamic optimization of electric arc furnace operation
Authors: MacRosty Richard D. M. , Swartz Christopher L. E.
Published: February 2007

The main objective of this work is the development of a computational procedure for determining optimal operating strategies for an industrial electric arc furnace (EAF). These goals are achieved by incorporating a detailed mechanistic model into a mathematical optimization framework. The model used in this work includes mass and energy balances, and contains sufficient detail to describe the melting process, chemical changes, and material and energy flows. Mathematical optimization is used to determine the optimal input trajectories based on an economic criterion; process limitations are accounted for by including them within the optimization problem as constraints. This optimization procedure considers trade‐offs between all the process inputs and processing time, so as to maximize the profit. Several case studies illustrating the use of mathematical optimization in the enhancement of process performance are given. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Predicting the phase equilibria of petroleum fluids with the SAFT‐VR approach
Authors: Sun Lixin , Zhao Honggang , McCabe Clare
Published: February 2007

The SAFT‐VR equation of state is combined with a semi‐continuous thermodynamic approach to model several synthetic and crude oil systems. In our approach, the oil fractions are defined by a continuous distribution that is then represented as discrete pseudo‐components using the Gaussian quadrature method. The SAFT‐VR parameters for the pseudo‐components are obtained from simple linear relationships that were defined in earlier work, which allows the approach to be easily applied to undefined oil systems. Good agreement between the theoretical predictions and experimental data is obtained for bubble point pressure calculations of several gas condensates and the solubility of gases such as methane, ethane, and carbon dioxide in several crude oils. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Congenital nystagmus: Randomized, controlled, double‐masked trial of memantine/gabapentin
Authors: McLean Rebecca , Proudlock Frank , Thomas Shery , Degg Chris , Gottlob Irene
Published: February 2007

Objective

Nystagmus consists of involuntary to and fro movements of the eyes. Although studies have shown that memantine and gabapentin can reduce acquired nystagmus, no drug treatment has been systematically investigated in congenital nystagmus.

Methods

We performed a randomized, double‐masked, placebo‐controlled study investigating the effects of memantine and gabapentin on congenital nystagmus over a period of 56 days. The primary outcome measure was logarithmic minimum angle of resolution (logMAR) visual acuity; the secondary outcome measures were nystagmus intensity and foveation, subjective questionnaires about visual function (VF‐14) and social function. Analyses were by intention to treat.

Results

Forty‐eight patients were included in the study. One patient in the placebo group dropped out. Patients were randomized into either a memantine group (n = 16), gabapentin group (n = 16), or placebo group (n = 15). Mean visual acuity improvements showed a significant effect between treatment groups (F = 6.2; p = 0.004, analysis of variance) with improvement in both memantine and gabapentin groups. Participants with afferent visual defects showed poorer improvements in visual acuity to medication than those with apparently normal visual systems. However, eye movement recordings showed that both nystagmus forms improved in nystagmus intensity (F = 7.7; p = 0.001) and foveation (F = 8.7; p = 0.0007). Participants subjectively reported an improvement in vision after memantine and gabapentin treatment more often than in the placebo group (p = 0.03). However, there were no significant differences between the treatment groups with visual function (VF‐14) or social function questionnaires because all groups reported improvements.

Interpretation

Our findings show that pharmacological agents such as memantine and gabapentin can improve visual acuity, reduce nystagmus intensity, and improve foveation in congenital nystagmus. Ann Neurol 2007
Complex aerohydrodynamic research and the effectiveness of arresting dispersed particles for barbotage‐rotation
Authors: Panov A. K. , Usmanova R. R. , Zaikov V. G. , Zaikov G. E.
Published: February 2007

The design of barbotage‐rotation installation with different profiles of blades of the rotator has been created on the basis of modeling method. As a result of the complex of aerohydrodynamic research in the system “gas–liquid” carried out on the barbotage‐rotation unit, certain recommendations on the improvement of the construction and operating conditions have been developed with a view to a rise in the effectiveness of dust removal. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
The Aral Sea: Recent limnological changes and their conservation significance
Authors: Williams W. D. , Aladin N. V.
Published: February 2007

1. Limnological changes to the Aral Sea, a large saline lake in central Asia, are considered. Important changes include the decreased water‐level (c. 15 m), the recession of the shoreline (up to 120 km in places), the exposure of large areas of lake bed, the increased salinity (from c. 10 to 30 g 1−1), and the marked alteration in the nature of the lacustrine biota involving decreases in diversity and biomass and the introduction of species.

2. Fish have virtually disappeared from the lake and the diversity of associated bird and wildlife communities has decreased.

3. The major cause of the limnological changes is the diversion of water, mainly for agricultural purposes, from inflowing rivers (the Amu‐ and Syr‐Darya), and, to a lesser degree, species introductions.

4. Limnological changes have been accompanied by changes to regional rivers and terrestrial environments, groundwaters, climate, and to agricultural productivity.

5. It is concluded that four major values of the lake (economic, cultural, scientific, and environmental) have been seriously diminished by recent changes to it. The need to continue limnological studies is stressed.
Conservation of freshwater fish in the British Isles: The current status and biology of threatened species
Authors: Maitland Peter S. , Lyle Alex A.
Published: February 2007

1. The objective of this paper is to review the status of all freshwater fishes in the British Isles and to identify theatened species, races and communities which are in need of conservation.

2. Using objective criteria to assess the degree of threat, two of the 55 freshwater species known in the British Isles are thought to be extinct here and eight are believed to be under significant threat.

3. The biology of these ten species is reviewed. They are: Sturgeon Acipenser sturio, Allis Shad Alosa alosa, Twaite Shad Alosa fallax, Arctic Charr Salvelinus alpinus, Houting Coregonus oxyrinchus (extinct), Powan Coregonus lavaretus, Pollan Coregonus autumnalis, Vendace Coregonus albula, Smelt Osmerus eperlanus and Burbot Lota lota (extinct).

4. In addition, there are several races of commoner species which are believed to be worthy of special conservation measures. These fish include the purely freshwater race of River Lamprey Lampetra fluviatilis in Loch Lomond, dwarf Brook Lampreys Lampetra planeri in the Inner Hebrides, spineless Three‐spined Sticklebacks Gasterosteus aculeatus in the Outer Hebrides and a number of important races of Brown Trout Salmo trutta in various waters in Ireland and Scotland.

5. There is also a range of fish communities in individual rivers and lakes which merit conservation attention. These are important for a variety of reasons, including high (and very low) diversity, unique assemblages, pristine stocks and highly characteristic communities.

6. The major threats to these species and communities include industrial and domestic pollution, acidification, land use changes, river barriers, drainage, fish farming, fishery management and the introduction of new species.

7. The identification of these threatened fishes and important freshwater sites provides a foundation for a review of existing protection in the British Isles and a major fish conservation management programme. These will be described in subsequent papers.
European estuaries and lagoons: A personal overview of problems and possibilities for conservation and management
Authors: Barnes R. S. K.
Published: February 2007

1. European estuaries and lagoons fall into three categories in respect of their conservation status and potential for ecological management. (i) Small lagoons, although greatly reduced by natural and man‐made changes to the coastal environment, are relatively easily recreated behind longshore shingle barriers, but natural colonization of such habitats may have ceased and successful artificial introduction of species or whole assemblages is hampered by lack of knowledge of the processes structuring natural lagoonal communities. (ii) Small estuaries require very little conservation management, only control of further human exploitation especially in respect of the siting of marinas and other recreational usage. (iii) Large estuaries are in many cases already altered beyond recognition, and such is their economic importance that it is unlikely that the pressures for further reclamation, impoundment, and development will be resisted. Nevertheless, it is may be possible to protect areas within each such estuarine system that could serve as staging posts for migratory birds.

2. Integrated action is needed to assess the status and importance of the remaining European estuarine and lagoonal habitats, and to conserve and manage them in the future, if they are to continue to provide any significant habitats for organisms into the 21st Century and beyond.
Distribution of freshwater crayfish in the British Isles, with particular reference to crayfish plague, alien introductions and water quality
Authors: Holdich David M. , Reeve Ian D.
Published: February 2007

1. The distribution of native and alien crayfish in the British Isles, based on records from 1970–1991, is figured at the 10 km square level and that for Britain is tabulated regionally.

2. Since 1981 crayfish plague has been recorded from six catchments in Britain and one in Ireland, and suspected from an additional four catchments in Britain; 56.2% of native crayfish sites in Britain occur in catchments from which plague has been confirmed.

3. Since the mid‐1970s approximately 300 signal crayfish implants have been made in Britain. Only 117 “successful” implants of signals are known to the authors; 39 crayfish farmers were registered in 1986 and 68 by 1990. In 1989 declared production was approximately 7 tonnes.

4. Some mixed populations of natives and disease‐free signals exist. Evidence for exclusion of natives is being monitored.

5. Signal crayfish are found in the flowing waters of seven catchments; 58.1% of native crayfish sites are located in catchments which support farmed and wild populations of signals. Some rapidly‐expanding Turkish crayfish populations are known, particularly in the Thames catchment.

6. At least 87% of native crayfish records are from good quality waters.

7. Native populations from 88.6% of sites recorded in Britain since 1970 have either been eliminated, or are directly threatened, by crayfish plague infection, and/or habitat invasion by signals, and/or pollution.

8. The native crayfish was added to the list of species protected under the Wildlife and Countryside Act in 1986.

9. Recommendations to assist in the conservation of the native crayfish include a ban on future imports of alien crayfish, a reassessment of records, the setting up of “no‐go” areas, the protection of isolated sites, and a restocking programme.

10. There are many restrictedt, healthy populations of native crayfish in areas which could be protected by designating them as Sites of Special Scientific Interest (SSSIs).
A life table for powan, Coregonus lavaretus (L.) in Loch Lomond, Scotland: A basis for conservation strategy
Authors: Brown E. A. R. , Finnigan N. , Scott D. B. C.
Published: February 2007

1. A static life table for Loch Lomond powan, Coregonus lavaretus (L.) has been constructed from data obtained during 1980–1988, as a basis for monitoring any changes in the population which may ensue from exploitation of the Loch.

2. Mortality was 99.95% during the first year of life, and adult mortality highest at 5–6 years.

3. Average fecundity was 20.7 ova mm−1 fork length.

4. Mortality and fecundity have not changed in 25 years.

5. It is not yet possible to assess the effect of the recent introduction of ruffe, Gymnocephalus cernuus (L.) into Loch Lomond, but their effect on recruitment into the vulnerable 0–1 year‐class may be critical.
Biotic score and prediction to assess the effects of water abstractions on river macroinvertebrates for conservation purposes
Authors: Armitage P. D. , Petts G. E.
Published: February 2007

1. The possible impacts of abstraction of water from streams and rivers in the UK have generated concern in conservation bodies.

2. This paper examines the feasibility of using biotic scores and predictions from the computer‐based RIVPACS system to assess the effects of abstractions on benthic fauna.

3. Control and ‘impacted’ sites on 22 rivers which experienced abstractions for hydroelectric power generation, supply of drinking water (either directly or through groundwater abstraction), spray irrigation and fish farming, were examined.

4. The ratios of observed to predicted biotic scores and comparison of observed fauna with that predicted by RIVPACS were used to assess the biological quality of the sites.

5. Only 11 of the 51 sites on the 22 rivers showed signs of reduced environmental quality. These included eight sites on a small lowland stream which receives run‐off from fertilized agricultural land and is subject to spray irrigation; two sites on upland streams which had experienced severe spates prior to our survey and a small chalk stream, the Pang.

6. Discharge, baseflow, substrate and altitude were factors which explained most of the variation in faunal parameters such as biotic score, numbers of species, numbers of families and total abundance.

7. The main conclusions of the study are that upland streams did not appear to suffer adverse effects as a result of abstraction whereas lowland streams appeared to be more degraded, but with the exception of the Pang this could not necessarily be attributed to abstraction.

8. Biotic scores with RIVPACS cannot be used to set ‘minimum ecological flows’ but can be used either directly, to assess site‐quality and to identify areas of concern which may or may not be related to abstraction; or indirectly, by reference to the RIVPACS data‐base to assess the conservation interest of invertebrate assemblages.