bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterisation of lignin-carbohydrate complexes (LCCs) of spruce wood (Picea abies L.) isolated with two methods
Authors: Lawoko Martin , Henriksson Gunnar , Gellerstedt Göran
Published: March 2006

A method for the quantitative isolation of lignin-carbohydrate complexes (LCCs) in a softwood is presented. The isolation steps involve partial enzymatic hydrolysis of cellulose, subsequent swelling in urea, and quantitative dissolution into four major fractions: (1) a galactoglucomannan LCC containing ∼8% of the wood lignin; (2) a glucane LCC containing ∼4% of the wood lignin; (3) a xylan-lignin-glucomannan network LCC (xylan>glucomannan) containing ∼40% of the wood lignin; and (4) a glucomannan-lignin-xylan network LCC (glucoman-nan>xylan) containing ∼48% of the wood lignin. Endoglucanase Novozyme 476, with only cellulase activity, and Ecopulp XM, with only xylanase and mannanase activities, were used as an enzymatic tool. From mildly ball-milled wood, all the lignin was isolated as LCCs. As a control, LCC was prepared from partially chlorite-delignified wood meal without ball milling, also in a mild procedure. The results were very similar to those obtained after ball milling. Thus, it can be safely concluded that the formation of new chemical linkages between lignin and carbohydrates during ball milling is improbable. Studies on isolated milled wood lignin (MWL) supported this conclusion and clearly showed that covalent linkages between lignin and carbohydrates are present. The study provide conclusive evidence of covalent linkages between lignin and carbohydrates in the native lignin in wood. It is concluded that carbohydrate-free lignin, i.e., lignin without covalent bonds to carbohydrates, probably cannot be present in spruce wood.
Characterization of lignin-carbohydrate complexes from spruce sulfite pulp
Authors: Lawoko Martin , Henriksson Gunnar , Gellerstedt Göran
Published: March 2006

Lignin-carbohydrate complexes (LCCs) were isolated from unbleached acid sulfite pulp by selective enzymatic hydrolysis followed by fiber swelling and extraction. Approximately 80% of the lignin in the pulp was found to be chemically linked to carbohydrates in three major fractions, viz. as one glucan-lignin complex (with 8% lignin) and two hemicellulose-lignin complexes (with 72% lignin). The latter two were further separated into one glucomannan-lignin complex (with ∼25% lignin) and one xylan-lignin-glucomannan complex (with 45–50% lignin). Based on model experiments, it can be concluded that the lignin and carbohydrate moieties are probably linked together through benzyl ether linkages. Xylan is more stable towards acidic hydrolysis than galactoglucomannan, and this finding may explain the greater amount of xylan-rich LCC in the pulp.
Lignin antioxidants for preventing oxidation damage of DNA and for stabilizing polymeric composites
Authors: KoŠíková Božena , Lábaj Juraj , Gregorová Adriána , Slameňová Darina
Published: March 2006

The antioxidative behavior of various lignin preparations derived from chemical wood treatment for paper production was examined. All lignin samples exhibited higher antioxidant activity than Trolox. The protective effect of lignin antioxidants against H2O2-induced oxidative damage of DNA in human carcinoma cells and male rats was evaluated. Moreover, lignin was tested as a stabilizer in the processing of polypropylene composites, as well as in thermo-oxidative aging of styrene-butadiene vulcanizates. The results indicate that the lignin preparations show great potential as antioxidants in human diets and polymer blends. Lignin has the potential to protect living organisms against cancer diseases and contributes to the protection of polymers against degradation.
Glycerol-ω-hydroxyacid-ferulic acid oligomers in cork suberin structure
Authors: Santos Sara , Graça José
Published: March 2006

Cork suberin was partially depolymerised by methanolysis catalysed by Ca(OH)2. The solubilised depolymerisate was analysed by ESI-MS/MS. The compounds identified included monomers and “dimeric” and “trimeric” oligomers. Among the latter, an oligomer of glycerol esterified to a ω-hydroxyacid esterified to ferulic acid was identified. The “dimeric” structures of glycerol esterified to a ω-hydroxyacid and of a ω-hydroxyacid esterified to ferulic acid were also found in the partially depolymerised fraction. The identification of these molecules was confirmed by synthesis of model compounds and comparison of their ESI-MS/MS spectra. The glycerol-ω-hydroxyacid-ferulic acid trimeric oligomer could be an important constituent block in the suberin structure. Its function is probably to link the two main polymers present in suberised cell walls, namely, polyaliphatic polyesters and lignin-related polyaromatics. The glycerol-ω-hydroxyacid moiety is part of the polyaliphatic polyester and the ferulic acid moiety is esterified to the polyaromatics. These oligomers provide a new insight to understanding of the macromolecular structure of suberin, since they could allow cross-linking of the two structurally different biopolymers.
Yield and composition of lipophylic extracts of yellow birch (Betula alleghaniensis Britton) as a function of wood age and aging under industrial conditions
Authors: Lavoie Jean-Michel , Stevanovic Tatjana
Published: March 2006

The lipophylic extracts of yellow birch (Betula alleghaniensis) have been investigated to detect the effect of tree age and wood storage time on extract composition. A total of 17 wood disks were cut from trees belonging to different age groups at 1 m above ground and the wood was milled as usual for extraction (laboratory samples). In addition, 49 sawdust samples were collected in a lumber mill to study the effect of industrial processing on the extractives (industrial samples). All laboratory and industrial samples were extracted with dichloromethane under sonication. The chemical composition of the lipophilic extracts obtained was analyzed by GC-MS. A systematic (quasi-linear) relationship was found between the lipophilic extract yield and specimen age. A total of 30 constituents from yellow birch extracts have been identified, 26 of which have never been previously reported for B. alleghaniensis wood.
Treatment of wood with aminofunctional silanes for protection against wood destroying fungi
Authors: Donath Steffen , Militz Holger , Mai Carsten
Published: March 2006

Different aminofunctional silanes were tested for their suitability to preserve wood against basidiomycetes in a mini-block experiment according to EN 113. High effectiveness against the brown rot fungusConiophora puteanawas maintained over prolonged exposure times of up to 18 weeks. Resistance against the white rot fungusTrametes versicolorwas only enhanced in the initial phase of exposure (6 weeks); after longer exposure times of 18 weeks, considerable mass losses were observed. It was shown that the antifungal resistance was caused by the amino groups of the oligomeric silane systems, while alkyl groups, which influence the water uptake of wood, only had a minor impact. For effective protection, acidic conditions of the treatment solution were important; this promotes the formation of cationised amino groups (ammonium). The silane quaternary ammonium compound (Si-QAC) 3-(trimethoxysilyl)propyldimethyloctadecyl ammonium chloride was applied in combination with an oligomeric silane system to incorporate quaternary ammonium sites into a SiO2matrix via a sol-gel process. This combined treatment significantly enhanced the decay resistance of pine wood againstC. puteana.
Effect of Sample Geometry on Regression Rate of the Melting Interface for Carbon Steel Burned in Oxygen
Authors: Suvorovs T , Ward NR , Wilson R , Steinberg TA
Published: February 2006

Promoted-ignition testing on carbon steel rods of varying cross-sectional area and shape was performed in high pressure oxygen to assess the effect of sample geometry on the regression rate of the melting interface. Cylindrical and rectangular geometries and three different cross sections were tested and the regression rates of the cylinders were compared to the regression rates of the rectangular samples at test pressures around 6.9 MPa. Tests were recorded and video analysis used to determine the regression rate of the melting interface by a new method based on a drop cycle which was found to provide a good basis for statistical analysis and provide excellent agreement to the standard averaging methods used. Both geometries tested showed the typical trend of decreasing regression rate of the melting interface with increasing cross-sectional area; however, it was shown that the effect of geometry is more significant as the sample's cross sections become larger. Discussion is provided regarding the use of 3.2-mm square rods rather than 3.2-mm cylindrical rods within the standard ASTM test and any effect this may have on the observed regression rate of the melting interface.
Evaluation of Residual Stress in Fiber-Textured Films by X-ray Diffraction
Authors: Zhang J-M , Xu K-W , Ji V
Published: March 2006

The X-ray method is used extensively to determine the residual stress in bulk or thin film materials on the assumptions that the material is composed of fine crystals with random orientation and the stress state is biaxial and homogeneous through the X-ray penetrating region. But the method cannot be used in textured films due to oscillations in ε -sin2 Ψ relation. In this paper, a new method is proposed for measuring residual stress in cubic films with any [hkl] fiber texture.
Disarmed and Dangerous: The Strange Career of Bras-Coupé
Authors: WAGNER BRYAN
Published: March 2006

ABSTRACT This essay assesses the origin myths that have attached to Congo Square and its most famous dancer, Bras-Coupé, inorder to reflect upon their import within modern theories of blackness.
The Indigent Sublime: Specters of Irish Hunger
Authors: LLOYD DAVID
Published: March 2006

ABSTRACT This essay shows how the Irish Famine (1845–1851)constituted a crisis of representation and memory not only for those who underwent and witnessed it but also for those who live in its wake. The Famine and its untold victims project specters that haunt the processes of modernization and progressive rationalization that catastrophe is often held to have enabled. For contemporary observers, the scenes of mass starvation produce the effect of an “indigent sublime”; the spectacle on a vast scale of humanity reduced to “bare life” exceeds the possibility of realistic representation, but the excess of representation is not accompanied by an enhancement of the powers of the subject.
“Sons of Adam”: Text, Context, and the Early Modern African Subject
Authors: BENNETT HERMAN L.
Published: March 2006

ABSTRACT Seeking to dislodge the prism that a singular political practice—represented as the story from savage to slave—informed the slave trade, this essay points to a distinct genealogy shaping the earliest encounters between Europeans and Africans.
Legal Terrors
Authors: DAYAN COLIN
Published: March 2006

ABSTRACT This essay examines the conditions under which categories of identity are legally reconstructed. It argues that legal practice and spiritual belief in colonial North America and certain parts of the Caribbean shed light on current rituals of dispossession and torture in the United States.
The Accursed Share: Genealogy, Temporality, and the Problem of Value in Black Reparations Discourse
Authors: WESTLEY ROBERT
Published: March 2006

ABSTRACT In this article the author discusses the procedural hurdles erected by courts to limit litigation of Black reparations claims based on slavery. By examining the policy justifications that underlie the procedural doctrines, the author challenges the view that the current impasse in Black reparations litigation is a matter of doctrinal limits rather than a matter of social devaluation of the litigants. Basing his argument on a review of nineteenth-century restitution cases involving wrongful enslavement, the author posits that the continued refusal by courts to hear Black reparations claims on the merits reflects a millenarian process of subordination and social devaluation of people of African descent.
An In Vivo Study of Free Radicals Generated in Murine Skin by Protoporphyrin IX and Visible Light
Authors: Nakai Kozo , Motten Ann G. , Chignell Colin F.
Published: March 2006

Lipids extracted from the skin of C57BL/6J mice injected subcutaneously with α‐(4‐pyridyl‐1‐oxide)‐N‐tert‐butylnitrone (POBN) and exposed to topical protoporphyrin IX (PPIX) and visible light had significantly higher levels of POBN spin adducts compared with dark PPIX exposed or vehicle‐treated controls. Computer analysis of the POBN adduct electron paramagnetic (spin) resonance (EPR) spectra indicated that two radical species were present in each extract, one of which was a lipid‐derived carbon‐centered adduct (1, aN= 14.8 G and aH= 2.6 G), whereas the other (2, aN= 13.8 G and aH= 1.8 G) was probably oxygen centered. Adduct 2 was present in greater proportion in lipids extracted from PPIX/light‐exposed mice compared with dark or vehicle‐treated controls. These findings suggest that PPIX/light generates free radicals in mouse skin, thus providing a radical mechanism for PPIX‐induced photosensitivity. Our approach may be useful for the detection of free radicals generated by other skin photosensitizers and may also provide a means for testing putative skin‐protecting agents.
Behavioral Thermoregulation and Slowed Migration by Adult Fall Chinook Salmon in Response to High Columbia River Water Temperatures
Authors: Goniea Thomas M. , Keefer Matthew L. , Bjornn Theodore C. , Peery Christopher A. , Bennett David H. , Stuehrenberg Lowell C.
Published: February 2006

The relationships between lower Columbia River water temperatures and migration rates, temporary tributary use, and run timing of adult fall Chinook salmonOncorhynchus tshawytschawere studied using historical counts at dams and recently collected radiotelemetry data. The results from more than 2,100 upriver bright fall Chinook salmon radio‐tagged over 6 years (1998, 2000–2004) showed that mean and median migration rates through the lower Columbia River slowed significantly when water temperatures were above about 20°C. Slowed migration was strongly associated with temporary use of tributaries, which averaged 2–7°C cooler than the main stem. The proportion of radio‐tagged salmon using tributaries increased exponentially as Columbia River temperatures rose within the year, and use was highest in the warmest years. The historical passage data showed significant shifts in fall Chinook salmon run timing distributions concomitant with Columbia River warming and consistent with increasing use of thermal refugia. Collectively, these observations suggest that Columbia River fall Chinook salmon predictably alter their migration behaviors in response to elevated temperatures. Coolwater tributaries appear to represent critical habitat areas in warm years, and we recommend that both main‐stem thermal characteristics and areas of refuge be considered when establishing regulations to protect summer and fall migrants.
Mortality Estimates of Juvenile Spring–Summer Chinook Salmon in the Lower Columbia River and Estuary, 1992–1998: Evidence for Delayed Mortality?
Authors: Schreck Carl B. , Stahl Thomas P. , Davis Lawrence E. , Roby Daniel D. , Clemens Benjamin J.
Published: March 2006

Recovery of Endangered Species Act—listed salmonids in the Columbia River basin has relied upon the efficacy of the U.S. Army Corps of Engineer's juvenile salmon transportation program to move fish past Snake and Columbia River hydropower dams. The effectiveness of this program has been assessed by the indirect method of comparing smolt‐to‐adult returns. We present some of the first data and mortality estimates of barged and run‐of‐river (ROR) radio‐tagged juvenile spring–summer Chinook salmon Oncorhynchus tshawytscha after release in the lower Columbia River, representing years of study. Our data suggest that smolt mortality (1) is very low for ROR and barged fish between Bonneville Dam and the estuary proper, a migratory distance of 180 river kilometers (rkm); (2) occurs in the lower estuary (rkm 0–46); (3) varies more across dates within a year than between years or between passage types (barged or ROR); (4) increases with time within a season and increasing numbers of avian predators, including Caspian terns Sterna caspia and double‐crested cormorants Phalacrocorax auritus; and (5) is estimated to be 11–17% of all smolts annually. Preliminary evidence suggests that at least some smolt mortality is influenced by differential predation by avian predators on Chinook salmon infected with Renibacterium salmoninarum and possessing low smoltification levels (relatively low gill Na+,K+‐ATPase activity). Fish type (barged or ROR) did not appear to influence mortality because of avian predation. This project was also the first to identify avian predators as a major source of mortality for out‐migrant Columbia River basin salmonids.
PDX-1 can repress stimulus-induced activation of the INGAP promoter
Authors: Taylor-Fishwick David A , Shi Wenjing , Pittenger Gary L , Vinik Aaron I
Published: March 2006

Islet neogenesis associated protein (INGAP) promotes the generation of new islet mass in adult animal models. It is not understood what factors control the expression of INGAP. In this study, factors that regulate the expression of INGAP promoter activity are reported. To determine factors that regulate INGAP expression, we previously cloned the promoter region for INGAP. Analysis of the INGAP promoter suggested that candidate regulators of INGAP expression include the transcription factors PDX-1, NeuroD, PAN-1, STAT and AP-1. Using gene addition experiments in the 293 cell line the activity of these transcription factors on an INGAP-promoter construct linked to the β-galactosidase reporter has been determined. Induction of AP-1 activity or STAT activity using PMA or LIF stimulation respectively, or direct expression of PAN-1 specifically up-regulates INGAP promoter activity. In contrast, co-expression of PDX-1 but not NeuroD inhibits activation of the INGAP-promoter driven by PAN-1, PMA or LIF stimulation. PDX-1 binds directly to the INGAP promoter as determined in electromobility shift and antibody supershift assays. Expression of the INGAP-promoter-reporter construct in the HIT-T15 beta-cell line, a cell line that expresses endogenous PDX-1, did not reveal PMA-mediated stimulation of INGAP promoter activity. HIT-T15 cells however did efficiently transfect (> 68%) and respond (2-fold) to PMA-induced signal transduction to a transfected AP-1-CAT reporter. Partial reduction of PDX-1 expression in HIT-T15 cells was associated with recovery of PMA induced INGAP promoter activity. These data suggest that expression of PDX-1 is associated with a repression of stimulus-induced INGAP promoter activity that appears to be mediated by a direct DNA interaction. These findings implicate PDX-1 in a possible feedback loop to block unbridled islet expansion.
Stimulation of pancreatic β-cell replication by incretins involves transcriptional induction of cyclin D1 via multiple signalling pathways
Authors: Friedrichsen Birgitte N , Neubauer Nicole , Lee Ying C , Gram Vivian K , Blume Niels , Petersen Jacob S , Nielsen Jens H , Møldrup Annette
Published: March 2006

The incretin hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), have been suggested to act as β-cell growth factors and may therefore be of critical importance for the maintenance of a proper β-cell mass. We have investigated the molecular mechanism of incretin-induced β-cell replication in primary monolayer cultures of newborn rat islet cells. GLP-1, GIP and the long-acting GLP-1 derivative, lira-glutide, increased β-cell replication 50–80% at 10–100 nM upon a 24 h stimulus, whereas glucagon at a similar concentration had no significant effect. The stimulatory effect of GLP-1 and GIP was efficiently mimicked by the adenylate cyclase activator, forskolin, at 10 nM (~90% increase) and was additive (~170–250% increase) with the growth response to human growth hormone (hGH), indicating the use of distinct intracellular signalling pathways leading to mitosis by incretins and cytokines, respectively. The response to both GLP-1 and GIP was completely blocked by the protein kinase A (PKA) inhibitor, H89. In addition, the phosphoinositol 3-kinase (PI3K) inhibitor wortmannin and the mitogen-activated protein kinase kinase (MEK) inhibitor PD98059, both inhibited GLP-1- and GIP-stimulated proliferation. The p38 mitogen-activated protein kinase (MAPK) inhibitor, SB203580, had no inhibitory effect on either GLP-1 or GIP stimulated proliferation. Cyclin Ds act as molecular switches for the G0/G1-S phase transition in many cell types and we have previously demonstrated hGH-induced cyclin D2 expression in the insulinoma cell line, INS-1. GLP-1 time-dependently induced the cyclin D1 mRNA and protein levels in INS-1E, whereas the cyclin D2 levels were unaffected. However, minor effect of GLP-1 stimulation was observed on the cyclin D3 mRNA levels. Transient transfection of a cyclin D1 promoter-luciferase reporter construct into islet monolayer cells or INS-1 cells revealed approximately a 2–3 fold increase of transcriptional activity in response to GLP-1 and GIP, and a 4–7 fold increase in response to forskolin. However, treatment of either cell type with hGH had no effect on cyclin D1 promoter activity. The stimulation of the cyclin D1 promoter by GLP-1 was inhibited by H89, wortmannin, and PD98059. We conclude that incretin-induced β-cell replication is dependent on cAMP/PKA, p42 MAPK and PI3K activities, which may involve transcriptional induction of cyclin D1. GLP-1, GIP and liraglutide may have the potential to increase β-cell replication in humans which would have significant impact on long-term diabetes treatment.
A transient microenvironment loaded mainly with macrophages in the early developing human pancreas
Authors: Banaei-Bouchareb L , Peuchmaur M , Czernichow P , Polak M
Published: March 2006

We have previously shown that the human developing pancreas, as a tissue under construction and remodeling, is composed of epithelial ducts and differentiated endocrine cells surrounded by mesenchyme. The physiologic importance of resident tissue leukocytes, expected to enter through the mesenchyme in remodeling functions, prompted us to investigate human developing pancreases for the presence of leukocyte lineages and for expression of cytokines and receptors involved in their recruitment and differentiation. Immunohistochemistry studies were performed on 69 human, paraffin-embedded pancreases at 6–12 weeks of development (WD). Cytokines and receptor transcripts were monitored by reverse transcription (RT)–PCR, by immunohistochemistry when antibodies were available or by in situ hybridization (ISH). We show that numerous cells expressing CD45RA, HLADR and CD68 antigens are cellular components of the mesenchyme of all the pancreases at 6–12 WD. So-called constitutive chemokines (SLC (CCL19), stromal-derived factor 1 (SDF1) (CXCL12)) and a macrophage-specific growth/survival factor, colony-stimulating factor 1 (CSF1), were detected in epithelial duct cells. Both epithelial and mesenchymal cells expressed chemokine receptors, suggesting a role in leukocyte recruitment and possibly in early pancreatic development. In conclusion, we demonstrated the presence of CD45RA resident leukocyte-derived lineages, mostly macrophages, in the early human pancreatic mesenchyme. These cells may have migrated in the tissue through the vascular system, attracted by constitutively expressed chemokines, and locally surviving through CSF1 signaling. The role of macrophages in epithelium/mesenchyme interaction-mediated pancreatic development remains to be demonstrated.
A sex difference in the cortisol response to tail docking and ACTH develops between 1 and 8 weeks of age in lambs
Authors: Turner A I , Hosking B J , Parr R A , Tilbrook A J
Published: March 2006

It is important to understand factors that may influence responses to stress, as these factors may also influence vulnerability to pathologies that can develop when stress responses are excessive or prolonged. It is clear that, in adults, the sex of an individual can influence the cortisol response to stress in a stressor specific manner. Nevertheless, the stage of development at which these sex differences emerge is unknown. We tested the hypothesis that there are sex differences in the cortisol response to tail docking and ACTH in lambs of 1 and 8 weeks of age. We also established cortisol responses in males when tail docking was imposed alone and in combination with castration at these ages. In experiment 1, 1 and 8 week old male and female lambs were subjected to sham handling, tail docking or, in males, a combination of tail docking and castration. In experiment 2, we administered ACTH (1.0 IU/kg) to male and female lambs at 1 and 8 weeks of age. There were significant cortisol responses to all treatments at both ages. Sex differences in the cortisol responses to tail docking and ACTH developed between 1 and 8 weeks of age, with females having greater responses than males. The data suggest that the mechanism for the sex difference in response to tail docking may involve the adrenal glands. At both ages, in males, the cortisol response to the combined treatment of tail docking and castration was significantly greater than that for tail docking alone.
Effects of 8-prenylnaringenin on the hypothalamo-pituitary-uterine axis in rats after 3-month treatment
Authors: Christoffel J , Rimoldi G , Wuttke W
Published: March 2006

Phytoestrogens are increasingly consumed in artificially high doses as herbal preparations and nutritional supplements. The flavanone 8-prenylnaringenin (8PN) is a potent phytoestrogen, but its benefits and risks after long-term application are poorly identified. Therefore, we tested two doses of 8PN and 17β-estradiol-3-benzoate (E2B) (effective doses: 6.8 and 68.4 mg/kg body weight (BW) of 8PN, and 0.17 and 0.7 mg/kg BW of 17β-estradiol (E2)) and compared their effects on uterine weight, pituitary hormones (LH, FSH and prolactin) and the expression of estrogen-regulated genes and of estrogen receptor (ER)α and ERβ in the hypothalamus, pituitary and uterus. Both doses of E2 and the high dose of 8PN suppressed serum LH and FSH, and stimulated serum prolactin levels, uterine weight, and progesterone receptor, insulin-like growth factor I and complement protein C3 mRNA transcripts. In the preoptic and the mediobasal areas of the hypothalamus, all treatments had negligible effects on ERα and ERβ and gonadotropin-releasing hormone (GnRH) receptor gene expression, while ERβ and GnRH receptor transcripts in the anterior pituitary were reduced under both E2 doses and the high 8PN dose. The mRNA concentrations of the LHα and -β subunits in the pituitary were suppressed by E2 and 8PN. In summary, 8PN had very similar though milder effects than E2 on all tested parameters. Inhibition of climacteric complaints by E2 takes place in the hypothalamus, where it inhibits the overactive GnRH pulse generator. Hence, 8PN may be used to inhibit climacteric symptoms effectively. Human pharmacologic studies will show whether the stimulatory effect on the uterus that was found in the present animal model would require the concomitant administration of progestins to prevent endometrial overstimulation.
Molecular cloning and differential expression of three GnRH mRNAs in discrete brain areas and lymphocytes in red drum
Authors: Mohamed J Shaik , Khan I A
Published: March 2006

Three gonadotropin releasing hormones, seabream GnRH (GnRH-I), chicken GnRH-II (GnRH-II) and salmon GnRH (GnRH-III) cDNAs were isolated from the brain of the red drum, Sciaenops ocellatus. The GnRH cDNA sequences of red drum showed more similarity to those of Atlantic croaker, sea bass and sea bream. The real-time quantitative RT-PCR study revealed expression of GnRH-I and GnRH III mRNAs in the olfactory bulb plus telencephalon (OB+TEL), and preoptic-anterior hypothalamic area (POAH), indicating an overlap of the GnRH-I and GnRH-III systems in these forebrain regions. However, GnRH-II mRNA expression was detected only in the midbrain tegmentum (MT). The GnRH-I mRNA expression in the POAH in fish undergoing gonadal recrudescence was significantly higher than that in gonadally immature individuals, suggesting involvement of the POAH GnRH-I in gonadal maturation. On the other hand, GnRH-III mRNA expression was significantly higher in the OB+TEL region compared with that in the POAH. Moreover, the demonstration of GnRH-I mRNA and peptide expression in red drum lymphocytes indicates that the GnRH-I is synthesized in these cells of the immune system similar to the situation in mammals.
Exendin-4 induction of cyclin D1 expression in INS-1 β-cells: involvement of cAMP-responsive element
Authors: Kim M-J , Kang J-H , Park Y G , Ryu G R , Ko S H , Jeong I-K , Koh K-H , Rhie D-J , Yoon S H , Hahn S J , Kim M-S , Jo Y-H
Published: March 2006

Glucagon-like peptide-1 (GLP-1) and its analog exendin-4 (EX) have been considered as a growth factor implicated in pancreatic islet mass increase and β-cell proliferation. This study aimed to investigate the effect of EX on cyclin D1 expression, a key regulator of the cell cycle, in the pancreatic β-cell line INS-1. We demonstrated that EX significantly increased cyclin D1 mRNA and subsequently its protein levels. Although EX induced phosphorylation of Raf-1 and extracellular-signal-regulated kinase (ERK), both PD98059 and exogenous ERK1 had no effect on the cyclin D1 induction by EX. Instead, the cAMP-elevating agent forskolin induced cyclin D1 expression remarkably and this response was inhibited by pretreatment with H-89, a protein kinase A (PKA) inhibitor. Promoter analyses revealed that the cAMP-responsive element (CRE) site (at position −48; 5′-TAACGTCA-3′) of cyclin D1 gene was required for both basal and EX-induced activation of the cyclin D1 promoter, which was confirmed by site-directed mutagenesis study. For EX to activate the cyclin D1 promoter effectively, CRE-binding protein (CREB) should be phosphorylated and bound to the putative CRE site, according to the results of electrophoretic mobility shift and chromatin immunoprecipitation assays. Lastly, a transfection assay employing constitutively active or dominant-negative CREB expression plasmids clearly demonstrated that CREB was largely involved in both basal and EX-induced cyclin D1 promoter activities. Taken together, EX-induced cyclin D1 expression is largely dependent on the cAMP/PKA signaling pathway, and EX increases the level of phosphorylated CREB and more potently trans-activates cyclin D1 gene through binding of the CREB to the putative CRE site, implicating a potential mechanism underlying β-cell proliferation by EX.
Mechanisms regulating prostaglandin H2 synthase-2 mRNA level in the amnion and chorion during pregnancy
Authors: Johnson Renée F , Mitchell Carolyn M , Giles Warwick B , Bisits Andrew , Zakar Tamas
Published: March 2006

Increasing prostaglandin H2 synthase (PGHS)-2 expression in the fetal membranes is implicated in the production of prostaglandins (PGs) that stimulate labour. We have determined the activity of the PGHS-2 gene in the amnion and chorion throughout gestation and defined the contribution of transcriptional and post-transcriptional mechanisms to the increase of PGHS-2 mRNA levels. We also measured PGHS-1 mRNA abundance to assess the participation of the two isoenzymes in fetal membrane PG-production during pregnancy. Amnion and chorion were collected from non-labouring women at 10–19 weeks (early), at 28–36 weeks (preterm) and at term (37–41 weeks). We determined PGHS-1 and -2 mRNA abundance and assessed PGHS-2 gene activity by measuring PGHS-2 heterogeneous nuclear RNA levels using real-time RT-PCR. PGHS-2 gene activity and mRNA levels were up-regulated in both tissues with advancing gestation. Path analysis demonstrated that the PGHS-2 mRNA up-regulation involved both transcriptional and post-transcriptional components. PGHS-2 mRNA abundance increased 9–11 fold between the early (10–19 weeks) and preterm (28–36 weeks) groups and remained high at term. The underlying mechanism was predominantly transcriptional in the amnion and post-transcriptional in the chorion. PGHS-1 mRNA expression precipitously decreased between early gestation and term. Thus, PGHS-2 mRNA abundance is up-regulated well in advance of term and is not a trigger for labour. There is a switch in PGHS mRNA expression during pregnancy with PGHS-1 dominating in the early period and PGHS-2 dominating at term.
The effects of testosterone and oestrogen on gonadectomised and intact male rat anterior pituitary mitotic and apoptotic activity
Authors: Nolan L A , Levy A
Published: March 2006

We have used a direct, non-immunochemical and highly accurate method to quantify the effects of testosterone and oestrogen on mitotic and apoptotic activity in the young, male rat anterior pituitary in vivo. Surgical gonadectomy resulted in a 3-fold increase in mitotic activity by the fourth post-operative day, which returned gradually to levels seen in intact animals over the subsequent 3–4 weeks. Both a single dose of Sustanon, a mixture of long-acting testosterone esters in arachis oil, and the same dose divided over 7 days (starting 6 days after gonadectomy), initially suppressed mitotic activity to levels seen in intact animals, but was associated after 48–96 h with a wave of increased mitotic activity. The latter was blocked by co-administration of Sustanon with the non-steroidal aromatase inhibitor letrozole and was not seen when the non-aromatisable androgen dihydrotestosterone was substituted for Sustanon. Oestrogen alone in gonadectomised and intact rats produced a marked increase in mitosis as expected. With the exception of a transient increase in response to a single high-dose injection of Sustanon in gonadectomised animals, apoptotic activity was unaffected by all of the above. This study suggests that pituitary mitotic activity is tonically inhibited by gonadal hormone production (at least in the short term) in adult male rats. The study also suggests that supraphysiological testosterone treatment – while unable to reduce anterior pituitary mitotic activity in untreated, intact animals –suppresses the early increase in mitotic activity induced by gonadectomy. Oestrogen, either exogenous or generated locally by aromatisation, stimulates anterior pituitary mitotic activity in a time-dependent manner.
Reconsideration of the proposed luteotropic and luteoprotective actions of ovine placental lactogen in sheep: in vivo and in vitro studies
Authors: Al-Gubory K H , Camous S , Germain G , Bolifraud P , Nicole A , Ceballos-Picot I
Published: March 2006

Ovine placental lactogen (oPL) is produced by the conceptus trophectoderm and is secreted into both the maternal and fetal circulations. The present study was designed to examine in vivo the luteotropic effect of recombinant oPL (roPL), as determined by monitoring progesterone concentration and cycle length (experiment 1), and the antioxidative and antiapoptotic effects of roPL, as determined respectively by monitoring antioxidant enzymatic activity and apoptosis in the corpus luteum (CL) of cyclic ewes (experiment 2). We also studied whether roPL is capable of stimulating progesterone secretion in vitro by cultured luteal tissue of functionally active CL obtained from day-10 cyclic ewes (experiment 3) and day-60 pregnant ewes (experiment 4). Circulating concentrations of progesterone and cycle length were not affected by treatment of ewes with 80 μg/kg body weight per day of roPL (n = 4 ewes) for 10 days beginning on day 11 post-estrus, as compared with saline-treated ewes (n = 4 ewes). Luteolysis occurred between days 15 and 16 post-estrus in the four saline-treated ewes and in 3/4 roPL-treated ewes. The activities of the key antioxidant enzymes copper-zinc superoxide dismutase (Cu,Zn-SOD), manganese SOD (Mn-SOD), glutathione peroxidase (GPX), glutathione reductase (GSR) and glutathione S-transferase (GST) were unaffected by treatment of ewes with 80 μg/kg per day of roPL (n = 4 ewes) for 3 days, between days 11 and 14 post-estrus, as compared with saline-treated ewes (n = 4 ewes). In situ TUNEL method revealed that the number of apoptotic cells was not different between the two groups of ewes. There was no significant change in progesterone secretion by explants from day-10 estrous cycle (n = 3 ewes) or day-60 pregnancy (n = 3 ewes) CL cultured with different concentrations (10, 100 and 1000 ng/ml) of roPL, whereas treatment with oLH at the concentration of 100 or 1000 ng/ml caused a significant increase in progesterone secretion by explants from day-10 estrous cycle CL (P < 0.05) and by explants from day-60 pregnancy CL (P < 0.01). In conclusion, our results demonstrate that oPL has no luteotropic and/or luteoprotective actions in sheep, either in vivo or in vitro.
Procurement of ethical construction products
Authors: Mustow S. E.
Published: March 2006

A number of methods have been devised to assess the environmental performance of construction materials. Less attention, however, has been paid to social and economic issues associated with different construction products, which are frequently sourced from a wide range of countries. The extraction and manufacture of construction products can have positive effects by creating jobs, increasing skills and boosting economies. Negative impacts have, however, also been known to arise, which at their most extreme may involve the confiscation of land, use of child labour, corruption and dangerous working conditions. Given that the global construction industry is worth approximately US$3·2 trillion, there is great potential for positive action by specifiers to drive significant improvements in social, economic and environmental conditions on an international scale. There is also increasing pressure for organisations to reduce corporate risk through adopting ethical procurement practices. The lack of information and understanding relating to social and economic issues makes it hard for architects, surveyors, engineers, building managers, property owners and others to make informed choices regarding ‘ethical procurement’. This paper reviews initiatives, organisations and tools that are relevant to the ethical procurement of construction products.
Sustainable landslide risk reduction in poorer countries
Authors: Anderson M. G. , Holcombe L.
Published: March 2006

In developing countries many houses are built by the most vulnerable persons in unplanned settlements on land that is marginal in construction terms and often subject to high landslide risk. This paper outlines a low-cost, community-based approach to landslide risk reduction undertaken in St Lucia, West Indies. The process of establishing a Government management team integrated with joint community implementation is described. Three key elements comprising a mapping methodology for landslide risk, identification of dominant slope instability controls and implementation of low-cost sustainable measures are described. The successful pilot project demonstrates the feasibility of such a low-cost approach to landslide risk reduction and offers a major step forward in establishing appropriate preventative measures for minimising landslide risk in vulnerable communities.
Sustainable supply chains for rural water supplies in Africa
Authors: Harvey P. A. , Reed R. A.
Published: March 2006

Many rural water supplies in sub-Saharan Africa demonstrate high operational failure rates, particularly those using handpumps to extract groundwater. The supply of spare parts for pump maintenance is one of the weak links in the quest for sustainability and there are very few examples of sustainable supply chains throughout the subcontinent. There are a number of key reasons for this, which are specific to the rural African context. These include: the separation of the supply of pumps from the supply of associated spares; low pump density resulting in low profits; poverty and immobility among end-users; inflexible approaches to technology choice; and restrictive policies and maintenance systems. Field research in four African countries—Ghana, Kenya, Uganda and Zambia—indicated that the supply of handpump spare parts to rural areas is not a viable stand-alone commercial activity, despite many initiatives with this ultimate aim. There is a critical need for realism in the rural water sector and for implementers to move away from the perceived wisdom that the private-sector alone is the solution to the spare parts conundrum. Integrated service provision, appropriate technology choice and, where necessary, non-profit sector options provide a multifaceted solution that must be embraced if present and future rural water services are to be sustained.
A comparative study on the interpretation of concrete core strength results
Authors: Ariöz Ö. , Tuncan M. , Ramyar K. , Tuncan A.
Published: February 2006

Cores measuring 94 mm and 144 mm in diameter and having length-to-diameter ratios of 2·0, 1·0 and 0·75 were removed from beam specimens produced from different concrete mixtures. Standard cubes and cylinders were also produced from the same mixtures. Compressive strength tests were conducted on 216 standard and 530 core specimens. The test results obtained from core specimens were compared with those of standard specimens. The effects of maximum aggregate size in concrete mixture, core diameter and type and size of the standard specimens on the interpretation of the core test results were examined. The test results showed that the maximum size of the aggregate affects the strength of the cores even when the diameter of the core is larger than three times the maximum size of the aggregates. The age of the concrete was found to be an important factor in the interpretation of the core strength results. Although the cores with a length-to-diameter ratio of 0·75 gave higher strength values, they may be used for the evaluation of the core strength results.
Linking Riemann and storage cell models for flood prediction
Authors: Villanueva I. , Wright N. G.
Published: March 2006

As part of the nationally funded Flood Risk Management Research Consortium the use of linked one-dimensional and two-dimensional models has been investigated with a view to optimising the balance of accuracy, model complexity and run times. This has been developed in research software named TRENT using a Riemann approach for both dimensional representations. In this paper the details of the method are presented along with a storage cell scheme similar to that implemented in the software known as LISFLOOD-FP developed at the University of Bristol. Remotely sensed data are used to provide the digital terrain model for a test case at Upton-upon-Severn in the UK and airborne imagery is used for validation. The storage cell and Riemann approaches are compared and conclusions drawn.
Issues of using digital maps for catchment delineation
Authors: Hammond M. , Han D.
Published: March 2006

Digital elevation models (or maps) (DEMs) are increasingly becoming available to consulting engineers and academic researchers for delineating catchment boundaries. There are two important questions to be answered in using DEMs for generating those boundaries: first, how good are the computer-generated boundaries and second, what map resolution should be used from a host of data products on the market? This paper describes some explorations of these two topical issues through a case study for the Brue catchment in the south-west of England. The study concludes that computer-generated boundaries failed to delineate accurately or reliably the catchment border with all the available digital maps tested. This was mainly because the computer cannot pick up man-made features (highways, ditches, etc.), in addition to data quality and algorithm problems. With respect to map resolution, it has been found that although the discrepancy of the delineation increases with the grid size (i.e. poor resolution maps would generate lower-quality boundaries), there is a threshold which defines a zone where the clear relationship between the map resolution and discrepancy becomes very unstable. This is a very important conclusion since it indicates that higher map resolution may produce poorer results than lower map resolution, which is quite serious in practical projects for map users who face increased map costs, longer computing time and potentially poorer results. In the end, the paper proposes an integrated technique that uses the strengths of both manual and computer methods to produce an optimised boundary.
Future flood risk management in the UK
Authors: Evans E. , Hall J. , Penning-Rowsell E. , Sayers P. , Thorne C. , Watkinson A.
Published: March 2006

The Foresight Future Flooding project has analysed future flood risk in a scenario framework for the whole of the UK. The analysis predicts increasing flood risk unless current flood management policies and investment levels are changed, with up to a twentyfold increase in economic risk by the 2080s. The increase is attributable to a combination of climate change and increasing value of household, industrial and infrastructure assets. Potential responses are assessed in terms of the three pillars of sustainability: social, environmental and economic. The work described has formed much of the evidence base for the new government strategy for flood risk management in England, ‘Making space for water’.
Improved simulation of flood flows using storage cell models
Authors: Hunter N. M. , Bates P. D. , Horritt M. S. , Wilson M. D.
Published: March 2006

Storage cell codes for inundation modelling treat the floodplain as a series of discrete basins, with the flow between cells calculated using some analytical flow formulae such as the Manning equation. These codes have many of the advantages of full two-dimensional schemes but without the computational cost. However, with this class of model the propagation speed of the inundation front over the floodplain can be shown to be highly dependent on the model grid scale and insensitive to floodplain friction. To overcome these problems adaptive time step techniques have recently been proposed; however, to date these have only been tested against highly idealised analytical solutions. In this paper the authors compare fixed and adaptive time step storage cell codes for flood inundation modelling against a real world data set for the first time. The data consist of a satellite synthetic aperture radar image of inundation extent at ∼12·5 m spatial resolution taken during a 1-in-50-year flood, which occurred in 1998 on the upper River Severn in the UK; gauged flows at the upstream and downstream ends of an approximately 60 km reach of the river; and a digital elevation model developed from channel survey and an airborne laser altimeter survey of the floodplain topography. Results show that the adaptive model produces a modest improvement in simulation performance over the fixed time step code, yet is much better able to simulate realistically the drying of the floodplain in the upper reaches of the model domain. The adaptive code also demonstrates a more realistic sensitivity to floodplain friction which is likely to account for its markedly different dynamic behaviour and, in this respect, intuitively better performance.