bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of mechanical loading on insulin-like growth factor-I gene expression in rat tibia
Authors: Reijnders Christianne M A , Bravenboer Nathalie , Tromp Annechien M , Blankenstein Marinus A , Lips Paul
Published: January 2007

Mechanical loading plays an essential role in maintaining skeletal integrity. Mechanical stimulation leads to increased bone formation. However, the cellular and molecular mechanisms that are involved in the translation of mechanical stimuli into bone formation, are not completely understood. Growth factors and osteocytes, which act as mechanosensors, play a key role during the bone formation after mechanical stimulation. The aim of this study was to characterize the role of IGF-I in the translation of mechanical stimuli into bone formation locally in rat tibiae. Fifteen female Wistar rats were randomly assigned to three groups (n = 5): load, sham-loaded, and control. The four-point bending model of Forwood and Turner was used to induce a single period of mechanical loading on the tibia shaft. The effects of mechanical loading on IGF-I mRNA expression were determined with non-radioactive in situ hybridization on decalcified tibiae sections, 6 h after the loading session. Endogenous IGF-I mRNA was expressed in trabecular and cortical osteoblasts, some trabecular and sub-endocortical osteocytes, intracortical endothelial cells of blood vessels, and periosteum. Megakaryocytes, macrophages, and myeloid cells also expressed IGF-I mRNA. In the growth plate, IGF-I mRNA was located in proliferative and hypertrophic chondrocytes. Mechanical loading did not affect the IGF-I mRNA expression in osteoblasts, bone marrow cells, and chondrocytes, but the osteocytes at the endosteal side of the shaft showed a twofold increase of IGF-I mRNA expression. The proportion of IGF-I mRNA positive osteocytes in loaded tibiae was 29.3 ± 12.9% (mean ± s.d.; n = 5), whereas sham-loaded and contra-lateral control tibiae exhibited 16.7 ± 4.4% (n = 5) and 14.7 ± 4.2% (n = 10) respectively (P < 0.05). Lamellar bone formation after a single mechanical loading session was observed at the endosteal side of the shaft. In conclusion, a single loading session results in a twofold up-regulation of IGF-I mRNA synthesis in osteocytes which are present in multiple layers extending into the cortical bone of mechanically stimulated tibia shaft 6 h after loading. This supports the hypothesis that IGF-I, which is located in osteocytes, is involved in the translation of mechanical stimuli into bone formation.
Autocrine proliferative effect of ghrelin on leukemic HL-60 and THP-1 cells
Authors: De Vriese Carine , Delporte Christine
Published: January 2007

Ghrelin is a 28 amino acid peptide hormone that is mainly produced by the stomach, but also by several tissues and tumors. Ghrelin is octanoylated on the Ser3, but is also detected as a des-acylated form. Only the acylated ghrelin activates the GH secretagogue receptor (GHS-R) type 1a to stimulate GH release, and regulate food intake and energy metabolism. For the first time, we report that ghrelin and des-acyl ghrelin are present in human promyelocytic HL-60, monocytic THP-1 and lymphoblastic SupT1 cell lines. The human leukemic cell lines did not express the functional GHS-R 1a, whereas they expressed GHS-R 1b, a truncated variant of the receptor. Leukemic cell proliferation was not modified by the addition of octanoylated or des-acyl ghrelins. However, THP-1 and HL-60 cell proliferations were inhibited by SB801, an antibody directed against the N-terminal octanoylated portion of ghrelin, suggesting that octanoylated ghrelin stimulates cell proliferation via an autocrine pathway involving an as yet unidentified ghrelin receptor. Both octanoylated and des-acyl ghrelins did not alter the basal adenylate cyclase activity. Treatments of THP-1 and SupT1 cells by both octanoylated and des-acyl ghrelins did not modify the adenylate cyclase activity in response to vasoactive intestinal peptide, suggesting that ghrelin is unlikely to modulate the anti-inflammatory and differentiating properties of vasoactive intestinal peptide.
Distinct glucose-dependent stress responses revealed by translational profiling in pancreatic β-cells
Authors: Greenman Isabel C , Gomez Edith , Moore Claire E J , Herbert Terence P
Published: January 2007

In pancreatic β-cells, following an acute (within 1 h) increase in glucose concentration, there are rapid changes in the expression of a large subset of proteins. The change in the expression of many of these proteins is mediated by a post-transcriptional mechanism through either increases or decreases in the rate of translation from pre-existing transcripts. These proteins, whose synthesis is rapidly up- or down-regulated in response to glucose, are likely important in mounting the correct response to changes in plasma glucose concentrations. However, the vast majority of these proteins remain unidentified. Therefore, in order to identify these proteins, we analysed changes in the levels of mRNAs associated with polysomes (i.e. actively translating mRNAs) isolated from mouse insulinoma 6 cells incubated at either 0.5 or 20 mM glucose for 1 h. Changes in the levels of polysomal mRNAs in response to glucose were analysed using affymetrix oligonucleotide microarrays (translational profiling). This work revealed that, in response to a change in glucose concentration, the abundance of 313 transcripts associated with polysomes changed by more than 1.5-fold, of which the abundance of 37 changed by more than twofold. The majority of these transcripts encoded proteins associated with metabolism or gene expression. More detailed analysis showed that a number of mRNAs encoding proteins associated with the induction of oxidative stress, including thioredoxin-2 and thioredoxin-interacting protein were rapidly redistributed onto heavier polysomes at high glucose concentration, indicating an increase in their expression. At low glucose concentration, when the general rate of protein synthesis is low, a number of mRNAs encoding integrated stress response proteins, including ATF4 and CHOP10, associate with heavier polysomes, indicating that their expression is up-regulated. In conclusion, translational profiling has revealed that, at either low or at high glucose concentration, β-cells rapidly increase the synthesis of a specific subset of proteins that are likely important in maintaining β-cell integrity and survival during conditions of nutritional stress.
Sexual dimorphism in thyroid function and type 1 iodothyronine deiodinase activity in pre-pubertal and adult rats
Authors: Marassi Michelle P , Fortunato Rodrigo S , da Silva Alba C Matos , Pereira Valmara S , Carvalho Denise P , Rosenthal Doris , da Costa Vânia M Corrêa
Published: January 2007

Iodothyronine deiodinase activities are regulated by sex steroids; however, the mechanisms underlying the reported sexual dimorphism are poorly defined. In the present report, we aimed to investigate whether type 1 deiodinase (D1) sexual dimorphism exists early in sexual development by studying pre-pubertal male (Pm) and female (Pf) rats, as well as adult controls (C) and gonadectomized male and females rats. Adult male Wistar rats were studied 21 days after orchiectomy (Tex), and adult females were studied 21 days after ovariectomy (Ovx), and after estradiol benzoate (Eb) replacement. Serum total triiodothyronine (T3) was higher in pre-pubertal (P) rats than in the matching adults, with no difference between genders, although in adult males T3 was significantly lower than in females. There were no sex or age differences in serum total T4. Serum TSH in pre-pubertal (P) rats was within the adult female range, and both were significantly lower than in adult males. D1 activity in liver was greater in Pm than in Pf. In adult females, liver D1 activity was lower, while in adult males it was higher than in P rats. The same pattern of D1 activity was found in kidney. In thyroid and pituitary, D1 activity was similar in Pm, Pf, and adult females, which were all significantly lower than in the adult male. There were no differences in serum T3 and T4 between C and Tex males, but serum TSH was significantly decreased in Tex rats. Hepatic and renal D1 activities were lower in Tex than in C, but no changes were detected in thyroid and pituitary. In Ovx females, T3 was significantly lower than in the C group. Serum T4 was significantly decreased by estradiol replacement therapy in Ovx rats, in both doses used, whereas TSH was unchanged. Eb replacement increased liver and thyroid D1 activity, but in the kidney, only the highest estradiol dose promoted a significant D1 increase. In conclusion, in males, hepatic and renal D1 activity appears to be significantly influenced by gonadal hormones, in contrast to females, in which only exogenous Eb treatment stimulated D1 activity. The comparison between pre-pubertal and adult rats suggests that serum T3 is not the main regulator of D1 activity, and other factors, besides T3 and gonadal hormones, can modulate D1 activity during murine maturation.
Cell-specific expression of X-linked inhibitor of apoptosis in the anterior pituitary of streptozotocin-induced diabetic rats
Authors: Arroba Ana I , Lechuga-Sancho Alfonso M , Frago Laura M , Argente Jesús , Chowen Julie A
Published: January 2007

Cell death is increased in the anterior pituitary of poorly controlled diabetic rats, but anti-apoptotic mechanisms are also activated. We hypothesized that specific cell types are selectively protected against diabetes-induced cell death. To determine when anti-apoptotic mechanisms are activated, streptozotocin-induced diabetic rats were killed after 1, 4, 6 and 8 weeks of evolution. Anterior pituitaries were processed for western blot analysis to determine changes in the intrinsic cell death pathway and upstream kinases involved in cell protection mechanisms. An increase in cell death was detected by ELISA at 4 weeks of diabetes. TUNEL labelling demonstrated that this corresponded to death of primarily lactotrophs, a few somatotrophs, and no thyrotrophs, corticotrophs or gonadotrophs. Levels of phosphorylated (p) Akt were increased at 1 week of diabetes, while pERK1/2 levels increased at 4 weeks and pJNK at 6 weeks. Activation of caspase 3 decreased and anti-apoptotic members of the Bcl-2 protein family increased as early as 1 week after diabetes onset. These changes were coincident with increased IGF-I receptor levels. Levels of X-linked inhibitor of apoptosis protein (XIAP) increased significantly after 6 weeks of diabetes, as did activation of nuclear factor (NF)κB. Double immunohistochemistry indicated that XIAP was expressed in less than 1% of lactotrophs and gonadotrophs, approximately 50% of somatotrophs and more than 90% of corticotrophs and thyrotrophs. These results suggest that some cell survival mechanisms are rapidly activated in the anterior pituitary, even before increased cell death can be detected, while others are more delayed. Furthermore, both pituitary cell death and expression of protective mechanisms such as XIAP are cell-type specific.
Phosphorylated acidic serine–aspartate-rich MEPE-associated motif peptide from matrix extracellular phosphoglycoprotein inhibits phosphate regulating gene with homologies to endopeptidases on the X-chromosome enzyme activity
Authors: Liu Shiguang , Rowe Peter S N , Vierthaler Luke , Zhou Jianping , Quarles L Darryl
Published: January 2007

Inactivating PHEX (phosphate regulating gene with homologies to endopeptidases on the X chromosome) mutations cause X-linked hypophosphatemia in humans and mice (Hyp) through overproduction of fibroblast growth factor 23 (FGF23) a phosphaturic factor, by osteocytes. Matrix extracellular phosphoglycoprotein (MEPE) is also elevated in Hyp and other hypophosphatemic disorders. In addition, the administration of an ASARM (acidic serine–aspartate rich MEPE-associated motif) peptide derived from MEPE causes phosphaturia and inhibits bone mineralization in mice, suggesting that MEPE also plays a role in phosphate homeostasis. Since recent studies found that MEPE binds specifically to PHEX in vitro, we tested the effect of recombinant-MEPE and its ASARM peptide on PHEX enzyme activity in vitro and FGF23 expression in bone marrow stromal cell cultures ex vivo. We found that both recombinant MEPE and synthetic phosphorylated ASARM peptide (ASARM-PO4) inhibit PHEX enzyme activities in an in vitro fluorescent-quenched PHEX enzyme activity assay. The ASARM-PO4 peptide inhibits PHEX enzyme activity in a dose-dependent manner with a Ki of 128 nM and Vmax−i of 100%. Recombinant MEPE also inhibits PHEX activity (Ki = 2 nM and Vmax−i = 26%). Long-term bone marrow stromal cell cultures supplemented with 10 μ M ASARM-PO4 peptide resulted in significant elevation of FGF23 transcripts and inhibition of mineralization. These findings suggest that MEPE inhibits mineralization and PHEX activity and leads to increased FGF23 production. The resulting coordination of mineralization and release of a phosphaturic factor by MEPE may serve a physiological role in regulating systemic phosphate homeostasis to meet the needs for bone mineralization.
Protein kinase C activation increases endothelial nitric oxide release in mesenteric arteries from orchidectomized rats
Authors: Blanco-Rivero Javier , Sagredo Ana , Balfagón Gloria , Ferrer Mercedes
Published: January 2007

The aim of the present study was to assess the effect of endogenous male sex hormones on endothelial nitric oxide synthase (eNOS) expression, release and function of the endothelial nitric oxide (NO), as well as to assess the regulatory action of protein kinase C (PKC) on acetylcholine (ACh)-induced endothelial NO release. For this purpose, superior mesenteric arteries from control and orchidectomized male Sprague–Dawley rats were used. eNOS expression and basal-and ACh-induced NO release were similar in arteries from both groups of rats. Orchidectomy decreased the vasodilator effect induced by ACh but did not alter that induced by sodium nitroprusside (SNP). The superoxide anion scavenger, superoxide dismutase (SOD), or the membrane-permeable mimetic of SOD, tempol, only enhanced ACh-induced relaxation in arteries from orchidectomized rats. ACh-induced TXA2 formation was higher in arteries from orchidectomized than from control rats. Neither the PKC activator, phorbol 12,13-dibutyrate (PDBu), nor the non-selective PKC inhibitor, calphostin C, modified basal- or ACh-induced NO release in arteries from control rats. In arteries from orchidectomized rats, basal- and ACh-induced endothelial NO release were increased by PDBu but decreased by calphostin C. Both Gö6976, a PKC inhibitor that is partially selective for conventional PKC isoforms, as well as PKCζ pseudosubstrate inhibitor (PKCζ-PI) decreased both basal- and ACh-induced NO release in arteries from orchidectomized rats. Neither PDBu nor calphostin C modified the vasodilator response induced by ACh in arteries from control rats. In segments from orchidectomized rats, PDBu enhanced the ACh-induced response, but this response was not modified by calphostin C, Gö6976 or PKCζ-PI. The vasodilator response induced by SNP was not altered by the PKC activators or inhibitors in any artery from either group. These results show that endogenous male sex hormone deprivation does not affect the eNOS expression or the endothelial NO release induced by ACh, but does decrease the vasodilator action of ACh, by increasing NO metabolism and TXA2 formation. In addition, PKC seems to modulate eNOS activity only in mesenteric arteries from orchidectomized rats, in which conventional and PKCζ isoforms are involved in the positive regulation of eNOS.
Tangent Poisson's ratio of high-strength concrete in triaxial compression
Authors: Lu X. , Hsu C.-T. T.
Published: January 2007

Based on a carefully arranged experimental programme, the paper studies the variation of the tangent Poisson's ratio of high-strength concrete with a uniaxial compressive strength of 67 MPa (100 × 200 mm cylinder) under various confining pressures in triaxial compression. It shows that the high lateral confinement can significantly reduce the initial value of the tangent Poisson's ratio as compared with that of the uniaxial compression, and the tangent Poisson's ratio at failure also decreases notably with the increase of the lateral confining pressure. Therefore the tangent Poisson's ratio of high-strength concrete depends on not only the axial stress but also the lateral confinement. A simplified expression based on the experimental results is then proposed to define this variation. The influence of cyclic loading in triaxial compression is also investigated; this shows that the lateral versus axial strain relation of high-strength concrete during the cyclic loading essentially follows the general trend of the monotonic loading.
The effect of FLCoS‐display hold time on the perceived blur of moving imagery
Authors: Geri George A. , Morgan William D.
Published: January 2007

Abstract—The on‐ and off‐times of LCDs have decreased significantly over the past few years. However, long hold times, while increasing light output, have limited the temporal resolution of these devices. We have varied hold time and used a perceptual technique to assess the resulting change in blur of a moving test target presented on an FLCoS display. The technique requires observers to adjust the gap between two vertical lines that move across the display at various speeds. It was found that for a 13.4‐msec hold time, the threshold gap width, and thus by implication the perceived blur, increased significantly from about 3 to 22 pixels as line speed was increased. For hold times of 8, 6, 4, and 2 msec, threshold gap width remained approximately constant at between about 2 and 5 pixels as line speed was increased. The results of the perceptual test used here suggest that reducing FLCoS hold time to 8 msec significantly improves the quality of moving imagery. Further, decreasing the hold time to 2 msec results in perceptual blur that extends over as little as 6 arc‐minutes.
Five Year‐Round Forage Systems in a Dairy Effluent Sprayfield
Authors: Woodard Kenneth R. , Sollenberger Lynn E. , Sweat Lewin A. , Graetz Donald A. , Rymph Stuart J. , Joo Yongsung
Published: January 2007

In northern Florida, forages are grown in dairy effluent sprayfields to recover excess P. Our purpose was to evaluate five year‐round forage systems for their capacity to remove P from a dairy sprayfield. The soil is a Kershaw sand (thermic, uncoated Typic Quartzipsamment). Systems included bermudagrass (Cynodon spp.)‐rye (Secale cereale L.) (BR), perennial peanut (Arachis glabrata Benth.)‐rye (PR), corn (Zea mays L.)‐forage sorghum [Sorghum bicolor (L.) Moench]‐rye (CSR), corn‐bermudagrass‐rye (CBR), and corn‐perennial peanut‐rye (CPR). Forages were grown for five 12‐mo cycles. Effluent P rates were 80, 120, and 165 kg ha−1 cycle−1 The 5‐cycle P removal was 67 kg ha−1 cycle−1 for BR, 54 kg ha−1 for CBR, 52 kg for CSR, 45 kg for PR, and 43 for CPR. Removal of P by winter rye was low. There were differences in system rankings among cycles primarily due to changes in the performance of perennial forages. In the first two cycles, BR had the greatest P removal (91 kg ha−1 cycle−1) due to high bermudagrass yield and P concentration. In the first cycle, P removal was lowest for PR (36 kg ha−1) because perennial peanut was slow to establish. In later cycles, P removal for BR declined because bermudagrass yield and P concentration declined. It increased for PR because peanut yield increased. The yield of corn in CBR, CPR, and CSR was consistently high but P concentration was modest (avg. 2.2 g kg−1). Sorghum produced moderate but stable yield and had low P levels (avg. 1.8 g kg−1). Effluent rate marginally affected the performance of most grasses. For P recovery in dairy sprayfields in northern Florida, the best warm‐season forage would likely be a high yielding, persistent bermudagrass.
Time‐Dependent Distribution of Surface‐Applied Radionuclides and their Recovery in Maize during the Growing Season
Authors: Centofanti T. , Frossard E. , Flühler H.
Published: January 2007

The spatial and temporal heterogeneity of field soils influences the fate and behavior of strongly sorbing pollutants and their entry into the food chain. We studied the redistribution of surface‐applied54Mn,65Zn,57Co, and134Cs in the soil profile and their recovery in the aerial parts of maize grown on an untilled agricultural soil during the growing season. Radionuclides were more concentrated in the preferential flow paths (PFP) than in the soil matrix and their concentration decreased with time. The recovery of54Mn in the aerial plant parts increased between pollen shed and maturity, while the recovery of65Zn and57Co did not show any significant difference, and the recovery of134Cs decreased with time. The amount and distribution of rainfall, and the chemical, physical, and microbiological soil characteristics are the major factors influencing the variation of radionuclide recovery with time.
Passive Treatment of Acid Mine Drainage in Bioreactors using Sulfate‐Reducing Bacteria
Authors: Neculita Carmen‐Mihaela , Zagury Gérald J. , Bussière Bruno
Published: January 2007

Acid mine drainage (AMD), characterized by low pH and high concentrations of sulfate and heavy metals, is an important and widespread environmental problem related to the mining industry. Sulfate‐reducing passive bioreactors have received much attention lately as promising biotechnologies for AMD treatment. They offer advantages such as high metal removal at low pH, stable sludge, very low operation costs, and minimal energy consumption. Sulfide precipitation is the desired mechanism of contaminant removal; however, many mechanisms including adsorption and precipitation of metal carbonates and hydroxides occur in passive bioreactors. The efficiency of sulfate‐reducing passive bioreactors is sometimes limited because they rely on the activity of an anaerobic microflora [including sulfate‐reducing bacteria (SRB)] which is controlled primarily by the reactive mixture composition. The most important mixture component is the organic carbon source. The performance of field bioreactors can also be limited by AMD load and metal toxicity. Several studies conducted to find the best mixture of natural organic substrates for SRB are reviewed. Moreover, critical parameters for design and long‐term operation are discussed. Additional work needs to be done to properly assess the long‐term efficiency of reactive mixtures and the metal removal mechanisms. Furthermore, metal speciation and ecotoxicological assessment of treated effluent from on‐site passive bioreactors have yet to be performed.
Ground Cover Impacts on Nitrogen Export from Manured Riparian Pasture
Authors: Butler David M. , Ranells Noah N. , Franklin Dorcas H. , Poore Matthew H. , Green James T.
Published: January 2007

Maintaining ground cover of forages may reduce the export of nitrogen (N) from pastures. The objective of this work was to determine the effect of ground cover on N export from pastured riparian areas receiving simulated rainfall. Plots were established on two adjacent sites in the North Carolina Piedmont: one of 10% slope with Appling sandy loam soils and a second of 20% slope with Wedowee sandy loam soils. Both sites had existing mixed tall fescue (Festuca arundinaceaSchreb.)‐dallisgrass (Paspalum dilatatumPoir.) vegetation. Forage stands were modified to represent a range of ground cover levels: 0, 45, 70, and 95% (bare ground, low, medium, and high cover, respectively), and amended with beef steer (Bos taurus) feces and urine (∼200 kg N ha−1). For all rain events combined, mean nitrate N export was greatest from bare ground and was reduced by 34% at low cover, which did not differ from high cover. Mean ammonium N export was slightly elevated (∼1.37 kg N ha−1) in months when manures were applied and negligible (<0.02 kg N ha−1) in all other months. For all rain events combined, mean export of total N was greatest from bare ground and was reduced by at least 85% at all other cover levels. Whereas site did not impact N export, results indicated that cover and time of rainfall following manure deposition are important determinants of the impact of riparian grazing.
Denitrification in the Shallow Ground Water of a Tile‐Drained, Agricultural Watershed
Authors: Mehnert Edward , Hwang Hue‐Hwa , Johnson Thomas M. , Sanford Robert A. , Beaumont Will C. , Holm Thomas R.
Published: January 2007

Nonpoint‐source pollution of surface water by N is considered a major cause of hypoxia. Because Corn Belt watersheds have been identified as major sources of N in the Mississippi River basin, the fate and transport of N from midwestern agricultural watersheds have received considerable interest. The fate and transport of N in the shallow ground water of these watersheds still needs additional research. Our purpose was to estimate denitrification in the shallow ground water of a tile‐drained, Corn Belt watershed with fine‐grained soils. Over a 3‐yr period, N was monitored in the surface and ground water of an agricultural watershed in central Illinois. A significant amount of N was transported past the tile drains and into shallow ground water. The ground water nitrate was isotopically heavier than tile drain nitrate, which can be explained by denitrification in the subsurface. Denitrifying bacteria were found at depths to 10 m throughout the watershed. Laboratory and push‐pull tests showed that a significant fraction of nitrate could be denitrified rapidly. We estimated that the N denitrified in shallow ground water was equivalent to 0.3 to 6.4% of the applied N or 9 to 27% of N exported via surface water. These estimates varied by water year and peaked in a year of normal precipitation after 2 yr of below average precipitation. Three years of monitoring data indicate that shallow ground water in watersheds with fine‐grained soils may be a significant N sink compared with N exported via surface water.
Long‐Term Phosphorus Immobilization by a Drinking Water Treatment Residual
Authors: Agyin‐Birikorang Sampson , O'Connor George A. , Jacobs Lee W. , Makris Konstantinos C. , Brinton Scott R.
Published: January 2007

Excessive soluble P in runoff is a common cause of eutrophication in fresh waters. Evidence indicates that drinking water treatment residuals (WTRs) can reduce soluble P concentrations in P‐impacted soils in the short term (days to weeks). The long‐term (years) stability of WTR‐immobilized P has been inferred, but validating field data are scarce. This research was undertaken at two Michigan field sites with a history of heavy manure applications to study the longevity of alum‐based WTR (Al‐WTR) effects on P solubility over time (7.5 yr). At both sites, amendment with Al‐WTR reduced water‐soluble P (WSP) concentration by ≥60% as compared to the control plots, and the Al‐WTR‐immobilized P (WTR‐P) remained stable 7.5 yr after Al‐WTR application. Rainfall simulation techniques were utilized to investigate P losses in runoff and leachate from surface soils of the field sites at 7.5 yr after Al‐WTR application. At both sites, amendment with Al‐WTR reduced dissolved P and bioavailable P (BAP) by >50% as compared to the control plots, showing that WTR‐immobilized P remained nonlabile even 7.5 yr after Al‐WTR amendment. Thus, WTR‐immobilized P would not be expected to dissolve into runoff and leachate to contaminate surface waters or groundwater. Even if WTR‐P is lost via erosion to surface waters, the bioavailability of the immobilized P should be minimal and should have negligible effects on water quality. However, if the WTR particles are destroyed by extreme conditions, P loss to water could pose a eutrophication risk.
Phytostabilization Potential of Quailbush for Mine Tailings
Authors: Mendez Monica O. , Glenn Edward P. , Maier Raina M.
Published: January 2007

Abandoned mine tailings sites in semiarid regions remain unvegetated for extended periods of time and are subject to eolian dispersion and water erosion. This study examines the potential phytostabilization of a lead‐zinc mine tailings site using a native, drought‐tolerant halophyte, quailbush [Atriplex lentiformis (Torr.) S. Wats.]. In a greenhouse study germination, growth, and metal uptake was evaluated in two compost‐amended mine tailings samples, K4 (pH 3) and K6 (pH 6) at 75, 85, 90, 95, and 100% mine tailings, and two controls, off‐site and compost. Microbial community changes were monitored by performing MPN analysis of iron‐ and sulfur‐oxidizing bacteria as well as heterotrophic plate counts. Results demonstrate that germination is not a good indicator for phytostabilization since it was only inhibited in the unamended K4 treatment. Plant growth was significantly reduced in 95 and 100% mine tailings, while growth in 75, 85, and 90% treatments was similar to the off‐site control. Quailbush accumulated elevated levels of the nutrient metals Na, K, Mn, and Zn in the shoot tissues; however, metal accumulation was generally below the domestic animal toxicity limit. Initially, autotrophic population estimates were four to six logs higher than heterotrophic counts, indicating extremely stressed conditions. However, post‐harvest, heterotrophic bacterial counts increased to normal levels (∼106 CFU g−1 dry tailings) and dominated the rhizosphere. Therefore, with compost amendment, quailbush has good potential as a native species candidate for phytostabilization of mine tailings in semiarid environments.
Potentially Toxic Elements Contamination in Urban Soils
Authors: Biasioli M. , Grčman H. , Kralj T. , Madrid F. , Díaz‐Barrientos E. , Ajmone‐Marsan F.
Published: January 2007

Studies on several cities around the world confirm that urban soils are subject to heavy anthropogenic disturbance. However, these surveys are difficult to compare due to a lack of common sampling and analytical protocols. In this study the soils of Ljubljana (Slovenia), Sevilla (Spain), and Torino (Italy) were extensively sampled and analyzed using common procedures. Results highlighted similarities across the cities, despite their differences in geography, size, climate, etc. Potentially toxic elements (PTE) showed a wide range in concentration reflecting a diffuse contamination. Among the “urban” elements Pb exceeded the legislation threshold in 45% of Ljubljana, 43% of Torino, and 11% of Sevilla samples while Zn was above the limits in 20, 43, and 2% of the soils of Ljubljana, Torino, and Sevilla, respectively. The distribution of PTE showed no depth‐dependant changes, while general soil properties seemed more responsive to anthropogenic influences. Multivariate statistics revealed similar associations between PTE in the three cities, with Cu, Pb, and Zn in a group, and Ni and Cr in another, suggesting an anthropogenic origin for the former group and natural one for the latter. Chromium and Ni were unaffected by land use, except for roadside soils, while Cu, Pb, and Zn distribution appeared to be more dependent on the distance from emission sources. Regardless of the location, climate, and size, the “urban” factor—integrating type and intensity of contaminant emission and anthropogenic disturbance—seems to prevail in determining trends of PTE contamination.
Frances Power Cobbe's Life and the Rules for Women's Autobiography
Authors: Mitchell Sally
Published: January 2007

The aberrations of memory have in them this peculiarity: we never remember that our remembrance is habitually, not merely fallible, but faulty. We treat all mistakes as exceptional, rather than instantial. We assume that when error is detected, there is either intentional falsehood or culpable inexactitude—or at the least, some singular accidental lapse.â¦ Over and over again the same result occurs whenever we have occasion to verify any particular recollection by reference to memoranda, or to return to the scene of a past occurrence, or to discuss with another witness the details of any event.â¦ Nevertheless, in the face of such experiences a hundred times repeated, we remark complacently again and again: "How strange that I should have mistaken such a fact! how singular that my memory (generally so accurate) should have made me fancy that house so much larger than it is!"1
The inter‐relations of mother and father attachment, self‐esteem and aggression during late adolescence
Authors: Gomez Rapson , McLaren Suzanne
Published: January 2007

This study examined three models depicting the relations between mother and father attachment, self‐esteem and aggression. A total of 385 participants (173 males and 212 females), aged from 18 to 20 years, completed self‐rating questionnaires covering mother and father attachment, self‐esteem and aggression. Results showed that self‐esteem had additive and mediation effects on both the father attachment–aggression and mother attachment–aggression relationships, and also moderated the mother attachment–aggression relation. These findings are discussed in terms of different models for the inter‐relations of mother and father attachment, self‐esteem and aggression in late adolescence. Aggr. Behav. 33:1–10, 2007. © 2006 Wiley‐Liss, Inc.
4‐Hydroxyphenylglycine‐Based Oxazaborolidines for Enantioselective Reductions of Ketones
Authors: Braun Manfred , Sigloch Michael , Cremer Jens
Published: January 2007

Amino alcohols 6 featuring the diphenylhydroxymethyl group are prepared from the commercial amino acid (R)‐4‐hydroxyphenylglycine 3. Oxazaborolidines generated in situ from the amino alcohols 6 and borane‐dimethyl sulfide serve as catalysts in enantioselective reductions of acetophenone. The para‐substituents of the phenyl ring at the stereogenic carbon atom have a substantial influence on the enantioselectivity. When mediated by the nonaflate 6d, the reduction of ketones 7, 9, 11, and 13 leads to the carbinols 8, 10, 12, and 14 in 90 to 96 % ee.
Palladium‐Catalyzed N‐Arylation of N,N‐Dialkylhydrazines with Aryl Chlorides
Authors: Cacchi Sandro , Fabrizi Giancarlo , Goggiamani Antonella , Sgalla Simona
Published: January 2007

N,N‐Dialkyl‐N′‐arylhydrazines have been prepared usually in high to excellent yields via the reaction of N,N‐dialkylhydrazines with aryl chlorides in the presence of Pd2(dba)3, Xphos and NaO‐t‐Bu in dioxane at 120 °C. With ortho‐substituted aryl chlorides best results have been obtained by using 2‐(2′,6′‐dimethoxybiphenyl)dicyclohexylphosphine (ligand d) as the ligand.
Asymmetric Cyanoethoxycarbonylation of Aldehydes Catalyzed by Heterobimetallic Aluminum Lithium Bis(binaphthoxide) and Cinchonine
Authors: Gou Shaohua , Wang Jun , Liu Xiaohua , Wang Wentao , Chen Fu‐Xue
Published: January 2007

Highly efficient catalytic asymmetric cyanoethoxycarbonylation of aldehydes was achieved by 10 mol % cinchonine with 10 mol % heterometallic (S)‐aluminum lithium bis(binaphthoxide), which gave the cyanohydrins ethyl carbonates in excellent isolated yields (up to 99 %) with moderate to high enantioselectivities (up to 95 % ee) under mild conditions (at −20 °C). Especially, the solid aluminum lithium bis(binaphthoxide) free of tetrahydrofuran was obtained by a new procedure using (S)‐bi(2‐naphthol), aluminum isopropoxide and n‐butyllithium in dichloromethane, which was insensitive to air and moisture and was very convenient to store and use. A catalytic cycle based on experimental phenomena was proposed to explain the nature of the asymmetric induction.
Desulfitative Carbon–Carbon Cross‐Coupling of Thioamide Fragments with Boronic Acids
Authors: Prokopcová Hana , Kappe C. Oliver
Published: January 2007

A novel and general carbon–carbon cross‐coupling reaction between cyclic thioamides and boronic acids is described. The reaction is catalytic in palladium(0) and requires stoichiometric amounts of a copper(I) carboxylate as metal cofactor. The mode of cross‐coupling in the reaction of cyclic thioamides with boronic acids is easily tunable between carbon–carbon and carbon–sulfur cross‐coupling. While the catalytic palladium(0)/copper(I) system provides carbon–carbon bond formation with extrusion of sulfur, stoichiometric quantities of copper(II) under air mediate carbon–sulfur bond formation.
Hb Indianapolis [β112 (G14) Cys→Arg] as the probable cause of moderate hemolytic anemia and renal damage in a Brazilian patient
Authors: Fattori A. , Kimura E.M. , Albuquerque D.M. , Oliveira D.M. , Costa F.F. , Sonati M.F.
Published: January 2007

Hemoglobin (Hb) Indianapolis [β112 (G14) Cys→Arg] is a rare and slightly unstable β‐globin variant. All carriers described to date were clinically normal with only mild reticulocytosis. We report here a case of a Brazilian patient in whom hemolytic anemia and acute renal failure were probably caused by the presence of this variant. Am. J. Hematol., 2007. © 2007 Wiley‐Liss, Inc.
Follow‐up: Deliverables for ABA mediation quality task force begin to emerge
Authors: Bleemer Russ
Published: January 2007

Two follow‐ups: The American Bar Association Section of Dispute Resolution's Task Force on Quality in Mediation is getting results from its focus group effort, and the direction of its work is taking shape. Possible focuses are detailed. Also, the American Arbitration Association completes the sale of its large conflict resolution library. Find out why it was sold to Pepperdine University
Diselenastanna‐, ‐sila‐ and ‐carbacycles with an annelated dicarba‐closo‐dodecaborane(12) unit
Authors: Wrackmeyer Bernd , Hernández Zureima García , Kempe Rhett , Herberhold Max
Published: January 2007

The reactions of the 1,2‐diselenolato‐1,2‐dicarba‐closo‐dodecaborane(12) dianion 1 with diorganoelement(IV) dichlorides (Ph2CCl2, Me2SiCl2, Ph2SiCl2, Me2SnCl2, Ph2SnCl2) gave novel five‐member heterocycles along with other products. The molecular structures of the five‐member rings containing CPh2 (2) and SnPh2 (9) moieties between the selenium atoms were determined by X‐ray analyses. In the case of the chlorosilanes, the analogous five‐member ring containing the SiPh2 unit (4) could be identified in mixtures. The expected reaction was accompanied by rearrangement leading to formation of another five‐member ring 6 containing the Ph2SiSeSe moiety. Oxidative addition of the five‐member heterocycles containing tin (7, 9) to ethene‐bis(triphenylphosphane)platinum(0) gave at low temperature the bis(triphenylphosphane)platinum(II) complexes 12 and 13, where the Pt(PPh3)2 fragment had been inserted into one of the SnSe bonds. Extensive decomposition of these complexes was observed above − 20 °C. The proposed solution‐state structures of the new compounds are supported by multinuclear magnetic resonance data (1H, 11B, 13C, 29Si, 31P, 77Se, 119Sn and 195Pt NMR). Copyright © 2007 John Wiley & Sons, Ltd.
Ground‐penetrating radar investigations into the construction techniques of the Concordia Temple (Agrigento, Sicily, Italy)
Authors: Barone P. M. , Graziano F. , Pettinelli E. , Corradini R. Ginanni
Published: January 2007

Over the past decade, ground‐penetrating radar (GPR) has been recognized as being particularly well adapted to the non‐destructive survey of archaeological sites. The present work discusses such an application of the GPR to the study of the foundation geometry of the Concordia Temple in Agrigento (Sicily, southern Italy).

Radar data were collected using a pulse EKKO 1000 unit (Sensors and Software, Inc.) with 225 MHz antennae. The GPR data show a regular sequence of short reflectors alternating with ‘signal blanked’ areas located at approximately 50 ns in the peristyle and a continuous horizontal reflector at approximately 30 ns within the inner part of the temple (the cell). These results may indicate that the construction technique used in the temple was not a compact and homogeneous retaining wall, consisting of an outside layer of bricks and various grouting materials, as was previously thought. The two‐dimensional images indicate, instead, that the Greeks made use of the geomorphology of the surrounding area, which involved exploiting the surrounding landscape to obtain foundations (artificial and natural) capable of supporting such monumental and stately buildings. Furthermore, the paper demonstrates the validity of this technique to investigate the foundation geometry of an ancient temple, where it is undesirable to apply a destructive technique. Copyright © 2007 John Wiley & Sons, Ltd.
Kojic acid–tripeptide amide as a new tyrosinase inhibitor
Authors: Noh Jin‐Mi , Kwak Seon‐Yeong , Kim Do‐Hyun , Lee Yoon‐Sik
Published: January 2007

Twenty two kojic acid–tripeptide amides were prepared using a solid‐phase Fmoc/tBu strategy with Rink Amide SURE® resin. To effectively obtain kojic acid–tripeptide amide conjugates, the coupling conditions of kojic acid to the tripeptide on the resin were optimized. The tyrosinase inhibitory activity of kojic acid–tripeptide amides and the effect of the amino acid sequence on the activity were compared with those of kojic acid–tripeptide acids. The stability of kojic acid–tripeptide amides were then compared with those of kojic acid and kojic acid–tripeptides acids. As a consequence, kojic acid‐FWY‐NH2 proved to be the best compound, with the highest inhibitory activity, which was maintained over different storage times under various temperatures and pHs. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 88: 300–307, 2007.

This article was originally published online as an accepted preprint. The ‘Published Online’ date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Chromatin dynamics of unfolding and refolding controlled by the nucleosome repeat length and the linker and core histones
Authors: Kobori Toshiro , Iwamoto Satoshi , Takeyasu Kunio , Ohtani Toshio
Published: January 2007

Chromatin is composed of genomic DNA and histones, forming a hierarchical architecture in the nucleus. The chromatin hierarchy is common among eukaryotes despite different intrinsic properties of the genome. To investigate an effect of the differences in genome organization, chromatin unfolding processes were comparatively analyzed using Schizosaccaromyces pombe, Saccharomyces cerevisiae, and chicken erythrocyte. NaCl titration showed dynamic changes of the chromatin. 400–1000 mM NaCl facilitated beads with ∼115 nm in diameter in S. pombe chromatin. A similar transition was also observed in S. cerevisiae chromatin. This process did not involve core histone dissociation from the chromatin, and the persistence length after the transition was ∼26 nm for S. pombe and ∼28 nm for S. cerevisiae, indicating a salt‐induced unfolding to “beads‐on‐a‐string” fibers. Reduced salt concentration recovered the original structure, suggesting that electrostatic interaction would regulate this discrete folding‐unfolding process. On the other hand, the linker histone was extracted from chicken chromatin at 400 mM NaCl, and AFM observed the “beads‐on‐a‐string” fibers around a nucleus. Unlike yeast chromatin, therefore, this unfolding was irreversible because of linker histone dissociation. These results indicate that the chromatin unfolding and refolding depend on the presence and absence of the linker histone, and the length of the linker DNA. © 2007 Wiley Periodicals, Inc. Biopolymers 85:295–307, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Intramolecular and intermolecular guanine quadruplexes of DNA in aqueous salt and ethanol solutions
Authors: Vorlíčková Michaela , Bednářová Klára , Kejnovská Iva , Kypr Jaroslav
Published: January 2007

DNA guanine quadruplexes are all based on stacks of guanine tetrads, but they can be of many types differing by mutual strand orientation, topology, position and structure of loops, and the number of DNA molecules constituting their structure. Here we have studied a series of nine DNA fragments (G3Xn)3G3, where X = A, C or T, and n = 1, 2 or 3, to find how the particular bases and their numbers enable folding of the molecule into quadruplex and what type of quadruplex is formed. We show that any single base between G3 blocks gives rise to only four‐molecular parallel‐stranded quadruplexes in water solutions. In contrast to previous models, even two Ts in potential loops lead to tetramolecular parallel quadruplexes and only three consecutive Ts lead to an intramolecular quadruplex, which is antiparallel. Adenines make the DNA less prone to quadruplex formation. (G3A2)3G3 folds into an intramolecular antiparallel quadruplex. The same is true with (G3A3)3G3 but only in KCl. In NaCl or LiCl, (G3A3)3G3 prefers to generate homoduplexes. Cytosine still more interferes with the quadruplex, which only is generated by (G3C)3G3, whereas (G3C2)3G3 and (G3C3)3G3 generate hairpins and/or homoduplexes. Ethanol is a more potent DNA guanine quadruplex inducer than are ions in water solutions. It promotes intramolecular folding and parallel orientation of quadruplex strands, which rather corresponds to quadruplex structures observed in crystals. © 2007 Wiley Periodicals, Inc. Biopolymers 86: 1–10, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Hydration study of homopolypeptides by 2H NMR
Authors: Peemoeller H. , Stanley J. A. , MacMillan M. B. , Weglarz W. P. , Bennett J. C. , Corbett J. M. , Hawton M. , Holly R.
Published: January 2007

Deuteron T1 and T2 was studied as a function of hydration in homopolyglycine (PG) and homopolyproline (PP). Water deuteron relaxation rates in PG conform to a hydration model involving two types of primary hydration sites where water is directly bonded to the polymer. Once these sites are filled, additional water only bonds to water molecules at the primary sites and in so doing affect their dynamics. PP exhibits an anomalous T1 and T2 hydration dependence which has been interpreted in terms of a cooperative water molecule–PP molecule helical conformational rearrangement which occurs once a certain hydration level is reached. The proposal of a water–PP structure is tested using molecular dynamics simulations. © 2007 Wiley Periodicals, Inc. Biopolymers 86: 11–22, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Sequence‐based modeling of Aβ42 soluble oligomers
Authors: Dulin Fabienne , Callebaut Isabelle , Colloc'h Nathalie , Mornon Jean‐Paul
Published: January 2007

Aβ fibrils, which are central to the pathology of Alzheimer's disease, form a cross‐β‐structure that contains likely parallel β‐sheets with a salt bridge between residues Asp23 and Lys28. Recent studies suggest that soluble oligomers of amyloid peptides have neurotoxic effects in cell cultures, raising the interest in studying the structures of these intermediate forms. Here, we present three models of possible soluble Aβ forms based on the sequences similarities, assumed to support local structural similarities, of the Aβ peptide with fragments of three proteins (adhesin, Semliki Forest virus capsid protein, and transthyretin). These three models share a similar structure in the C‐terminal region composed of two β‐strands connected by a loop, which contain the Asp23‐Lys28 salt bridge. This segment is also structurally well conserved in Aβ fibril forms. Differences between the three monomeric models occur in the N‐terminal region and in the C‐terminal tail. These three models might sample some of the most stable conformers of the soluble Aβ peptide within oligomeric assemblies, which were modeled here in the form of dimers, trimers, tetramers, and hexamers. The consistency of these models is discussed with respect to available experimental and theoretical data. © 2007 Wiley Periodicals, Inc. Biopolymers 85: 422–437, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com