bluuebunny/crossref_metadata_2025 huggingface dataset:
The energetic consequences of dietary specialization in populations of the garter snake, Thamnophis elegans
Authors: Britt E. J. , Hicks J. W. , Bennett A. F.
Published: August 2006

We investigated the intraspecific variation in digestive energetics between dietary specialist and generalist populations of the Western Terrestrial garter snake (Thamnophis elegans) in northern California. Coastal populations have a specialized diet of slugs and inland populations have a generalized diet of fish, anurans, mice and leeches. The difference in prey preference between the two populations is congenital, heritable and ontogenetically stable. To examine energetic specializations and trade-offs in these populations, we measured the net assimilation efficiency of each snake population on both slug (Ariolimax columbianus) and fish(Rhinichthys osculus) diets. The net assimilation efficiency was measured during digestion of a meal and continued until metabolic rate re-attained prefeeding levels. Coastal snakes were able to utilize 62% more of the ingested energy towards production from slug diets through both increased assimilation of nutrients and reduced digestive costs. For fish, assimilation and digestive costs were the same in both coastal and inland populations. These results support the hypothesis that snakes with specialized diets can evolve physiological traits to extract nutrients more efficiently. However,there was no apparent trade-off on the more generalized diet that was associated with this specialization.
Exploring with damaged antennae: do crayfish compensate for injuries?
Authors: Koch L. M. , Patullo B. W. , Macmillan D. L.
Published: August 2006

Appendages are important sources of sensory information for all animals that possess them but they are commonly damaged in nature. We describe how the tactile system of the crayfish Cherax destructor functioned when subjected to the kind of damage found in wild-caught or cultured animals. Touch information was methodically varied by the removal of antennae and chelae. The resulting behaviour was analysed in a T-maze. Crayfish with a single antenna ablated turned toward the intact appendage, however, those with only a partial ablation did not, suggesting that a tactile information threshold exists for normal behaviour. When exposed to the same environment after an antennal ablation but with no prior experience in that terrain,crayfish also turned toward the side of the intact antenna. By contrast, when animals with experience obtained in a previous trial with intact antennae were tested after ablation of one antenna, they did not turn into one arm of the maze more than the other. These two outcomes indicate that behaviour is affected by an interaction between the time at which an injury occurs and an animal's knowledge of the topography, and that an injury may affect learning. We also tested to see if other appendages could provide tactile information to compensate for antennal loss. Input from the chelae did not affect the turning behaviour of crayfish in the maze.
Seasonal modulation of sickness behavior in free-living northwestern song sparrows (Melospiza melodia morphna)
Authors: Owen-Ashley Noah T. , Wingfield John C.
Published: August 2006

A variety of vertebrate species modulate immune function on a seasonal basis to cope with seasonal energy deficits and competing life-history demands, such as reproduction. Most studies to date have focused upon seasonal variation of cellular and humoral immunity, while neglecting behavioral responses to infection. These behavioral strategies are collectively termed sickness behaviors and are hypothesized to divert energy away from normal activities to combat and overcome infection. Sickness behavior can be triggered experimentally by injecting bacterial lipopolysaccharide (LPS). In this study, we provide the first evidence for seasonal modulation of sickness behavior in a free-living animal. Male song sparrows of western Washington state (Melospiza melodia morphna) are sedentary and territorial year round, except for a brief time during molt. Treatment with LPS decreased territorial aggressive behavior of males in the winter (nonbreeding), but not in the spring (breeding). Subjects were recaptured approx. 25 h after treatment. Recaptured LPS males in the winter lost more body mass than saline-injected controls while LPS males in the spring did not. These data indicate that birds in breeding condition were relatively insensitive to the effects of LPS. On a proximate level, suppression of sickness behavior during breeding is likely mediated by seasonal differences in energy allocation, as wintering sparrows were significantly heavier and had larger subcutaneous fat reserves and lower baseline corticosterone levels than breeding birds. Ultimately, suppression of sickness behavior may represent an allocation strategy to balance current reproductive opportunities with the life-history costs of self-defense.
Hydrogen sulfide mediates hypoxia-induced relaxation of trout urinary bladder smooth muscle
Authors: Dombkowski Ryan A. , Doellman Meredith M. , Head Sally K. , Olson Kenneth R.
Published: August 2006

Hydrogen sulfide (H2S) is a recently identified gasotransmitter that may mediate hypoxic responses in vascular smooth muscle. H2S also appears to be a signaling molecule in mammalian non-vascular smooth muscle, but its existence and function in non-mammalian non-vascular smooth muscle have not been examined. In the present study we examined H2S production and its physiological effects in urinary bladder from steelhead and rainbow trout (Oncorhynchus mykiss) and evaluated the relationship between H2S and hypoxia. H2S was produced by trout bladders, and its production was sensitive to inhibitors of cystathionineβ-synthase and cystathionine γ-lyase. H2S produced a dose-dependent relaxation in unstimulated and carbachol pre-contracted bladders and inhibited spontaneous contractions. Bladders pre-contracted with 80 mmol l-1 KCl were less sensitive to H2S than bladders contracted with either 80 mmol l-1KC2H3O2 (KAc) or carbachol, suggesting that some of the H2S effects are mediated through an ion channel. However, H2S relaxation of bladders was not affected by the potassium channel inhibitors, apamin, charybdotoxin, 4-aminopyridine, and glybenclamide, or by chloride channel/exchange inhibitors 4,4′-Diisothiocyanatostilbene-2,2′-disulfonic acid disodium salt,tamoxifen and glybenclamide, or by the presence or absence of extracellular HCO3-. Inhibitors of neuronal mechanisms, tetrodotoxin,strychnine and N-vanillylnonanamide were likewise ineffective. Hypoxia (aeration with N2) also relaxed bladders, was competitive with H2S for relaxation, and it was equally sensitive to KCl, and unaffected by neuronal blockade or the presence of extracellular HCO3-. Inhibitors of H2S synthesis also inhibited hypoxic relaxation. These experiments suggest that H2S is a phylogenetically ancient gasotransmitter in non-mammalian non-vascular smooth muscle and that it serves as an oxygen sensor/transducer, mediating the effects of hypoxia.
Performance and Clinical Utility of a Commercial von Willebrand Factor Collagen Binding Assay for Laboratory Diagnosis of von Willebrand Disease
Authors: Popov Joanna , Zhukov Olga , Ruden Susan , Zeschmann Terry , Sferruzza Anthony , Sahud Mervyn
Published: August 2006

Background: Von Willebrand disease (VWD) diagnosis and classification usually require a combination of nonspecific and VW-factor (VWF)-specific assays. We evaluated the analytical performance of a commercially available collagen-binding assay (CBA) and its usefulness in conjunction with other assays for laboratory diagnosis of VWD.

Methods: We used a commercial CBA ELISA (Life Technologies) to evaluate 3085 plasma samples. We used standard procedures to perform other assays, including factor VIII activity (FVIII:C), VWF antigen (VWF:Ag), ristocetin cofactor activity, VWF collagen binding capacity (VWF:CB), and VWF multimeric analysis.

Results: CBA intra- and interassay CVs were <6% and <13%, respectively. Reference intervals were 45%–198% for VWF:CB and 0.75–1.32 for the VWF:CB/Ag ratio. Of 3085 samples tested, 235 (8%) had results commonly associated with VWD. Multimer analysis and phenotypic data in 156 samples identified VWD types as: 91 (58%) type 1, 62 (40%) type 2, and 3 (2%) type 3. Of the 91 type 1 samples, proportional decreases in functional activity were seen in 75 samples (82%) according to CBA and in 63 samples (69%) according to the ristocetin cofactor assay. Of the type 2 samples, 10 were further identified as probable type 2A, 26 as probable type 2B, 12 as probable type 2M, and 14 could not be subtyped. VWF:CBA/Ag ratios <0.5 occurred in 83% of VWD type 2A and 2B samples, indicating characteristic functional discordance. Mean (SD) VWF:CB values were significantly higher in individuals without group O blood [113 (45)] than in those with group O blood [83 (32)] (t-test, P = 0.007).

Conclusions: The commercial CBA assay produces reliable results and is useful for laboratory diagnosis of VWD.
Immunolocalization of the hepatocyte growth factor (HGF) system in the rat ovary and the anti-apoptotic effect of HGF in rat ovarian granulosa cells in vitro
Authors: Uzumcu Mehmet , Pan Zui , Chu Yi , Kuhn Peter E , Zachow Rob
Published: August 2006

Hepatocyte growth factor (HGF) regulates granulosa cell (GC) steroidogenesis and suppresses apoptosis in non-ovarian cells. The hypothesis was thus developed that intraovarian HGF supports folliculogenesis by mediating steroidogenesis and suppressing apoptosis. To investigate the latter, the anti-apoptotic actions of HGF were tested in GCs and follicles isolated from immature rats. Results showed that HGF suppressed apoptosis in GC and follicle cultures as visualized using apoptosis indicator dye, YO-PRO-1. Immunohistochemistry was used to investigate the distribution of HGF, c-met, and HGF activator (HGFA) protein during folliculogenesis in equine chorionic gonadotropin (eCG)-primed rats. Immunoreactive HGF content was the greatest in GCs within preantral follicles. Following eCG, large antral follicles showed elevated HGF staining in theca and interstitial cells when compared with GCs. Intense c-met staining was observed in GCs within non-primed small preantral follicles; following eCG, the level of c-met was diminished in GCs, but increased within theca and interstitial cells. Theca, interstitium, and GCs in non-primed and primed ovaries contained HGFA. Following eCG, HGFA was more apparent in theca cells and the interstitium when compared to that in GCs within large antral follicles. The presence of HGF, c-met, and HGFA in preantral follicles would potentially enable the anti-apoptotic effects of HGF that were observed in vitro to occur in vivo. Advanced folliculogenesis led to a change in the cellular distribution of the HGF, c-met, and HGFA, suggesting that the ovarian HGF system is hormonally regulated in vivo.
Embryo-induced transcriptome changes in bovine endometrium reveal species-specific and common molecular markers of uterine receptivity
Authors: Bauersachs Stefan , Ulbrich Susanne E , Gross Karin , Schmidt Susanne E M , Meyer Heinrich H D , Wenigerkind Hendrik , Vermehren Margarete , Sinowatz Fred , Blum Helmut , Wolf Eckhard
Published: August 2006

The endometrium plays a central role among the reproductive tissues in the context of early embryo–maternal communication and pregnancy. This study investigated transcriptome profiles of endometrium samples from day 18 pregnant vs non-pregnant heifers to get insight into the molecular mechanisms involved in conditioning the endometrium for embryo attachment and implantation. Using a combination of subtracted cDNA libraries and cDNA array hybridisation, 109 mRNAs with at least twofold higher abundance in endometrium of pregnant animals and 70 mRNAs with higher levels in the control group were identified. Among the mRNAs with higher abundance in pregnant animals, at least 41 are already described as induced by interferons. In addition, transcript levels of many new candidate genes involved in the regulation of transcription, cell adhesion, modulation of the maternal immune system and endometrial remodelling were found to be increased. The different expression level was confirmed with real-time PCR for nine genes. Localisation of mRNA expression in the endometrium was shown by in situ hybridisation for AGRN, LGALS3BP, LGALS9, USP18, PARP12 and BST2. A comparison with similar studies in humans, mice, and revealed species-specific and common molecular markers of uterine receptivity.
Naturally suppressed apoptosis prevents follicular atresia and oocyte reserve decline in the adult ovary of Lagostomus maximus (Rodentia, Caviomorpha)
Authors: Jensen Federico , Willis Miguel A , Albamonte Mirta S , Espinosa María B , Vitullo Alfredo D
Published: August 2006

It has been widely accepted that mammalian females are born with a non-renewing, finite pool of oocytes that will be continuously cleared by atresia, with only a small proportion of them reaching ovulation. Apoptosis regulates this mass germ cell death, especially through the balance between pro- and anti-apoptotic proteins encoded by the BCL-2 gene family. The caviomorph rodent Lagostomus maximus, the South American plains viscacha, displays the highest ovulation rate known for a mammal releasing 400–800 eggs per cycle. We tested the hypothesis that in L. maximus massive polyovulation is a consequence of reduced apoptosis resulting in suppressed follicular atresia. We found that anti-apoptotic BCL-2 gene is markedly expressed in all kind of follicles from primordial to fully mature antral stages in the adult ovary of L. maximus. On the other hand, pro-apoptotic BAX gene showed weak signals or was undetectable by immunohistochemical examination. Western blot against both proteins confirmed immunohistochemical results. Screening for DNA fragmentation by TUNEL assay was conspicuously negative in ovaries from both pregnant and non-pregnant females. In addition, α-oestrogen receptor also showed an enhanced expression from primordial stage to fully mature antral follicles. Our results show that natural preferential expression of BCL-2 and restricted BAX expression greatly suppresses apoptosis in the ovary of L. maximus. This prevents the decline of the oocyte reserve by abolishing follicular atresia and enables the highest ovulation rate known for a mammal, 400–800 or more eggs per cycle.
The structural basis of TGF-β, bone morphogenetic protein, and activin ligand binding
Authors: Lin S Jack , Lerch Thomas F , Cook Robert W , Jardetzky Theodore S , Woodruff Teresa K
Published: August 2006

The transforming growth factor-β (TGF-β) superfamily is a large group of structurally related growth factors that play prominent roles in a variety of cellular processes. The importance and prevalence of TGF-β signaling are also reflected by the complex network of check points that exist along the signaling pathway, including a number of extracellular antagonists and membrane-level signaling modulators. Recently, a number of important TGF-β crystal structures have emerged and given us an unprecedented clarity on several aspects of the signal transduction process. This review will highlight these latest advances and present our current understanding on the mechanisms of specificity and regulation on TGF-β signaling outside the cell.
Pituitary actions of ligands of the TGF-β family: activins and inhibins
Authors: Bilezikjian Louise M , Blount Amy L , Donaldson Cindy J , Vale Wylie W
Published: August 2006

Activins, as members of the transforming growth factor-β superfamily, control and orchestrate many physiological processes and are vital for the development, growth and functional integrity of most tissues, including the pituitary. Activins produced by pituitary cells work in conjunction with central, peripheral, and other local factors to influence the function of gonadotropes and maintain a normal reproductive axis. Follistatin, also produced by the pituitary, acts as a local buffer to bind activin and modulate its bioactivity. On the other hand, inhibins of gonadal origin provide an endocrine feedback signal to antagonize activin signaling in cells that express the inhibin co-receptor, betaglycan, such as gonadotropes. This review highlights the pituitary roles of activin and the mechanisms through which these actions are modulated by inhibin and follistatin.
TGF-β superfamily members and ovarian follicle development
Authors: Knight Phil G , Glister Claire
Published: August 2006

In recent years, exciting progress has been made towards unravelling the complex intraovarian control mechanisms that, in concert with systemic signals, coordinate the recruitment, selection and growth of follicles from the primordial stage through to ovulation and corpus luteum formation. A plethora of growth factors, many belonging to the transforming growth factor-β (TGF-β ) superfamily, are expressed by ovarian somatic cells and oocytes in a developmental, stage-related manner and function as intraovarian regulators of folliculogenesis. Two such factors, bone morphogenetic proteins, BMP-4 and BMP-7, are expressed by ovarian stromal cells and/or theca cells and have recently been implicated as positive regulators of the primordial-to-primary follicle transition. In contrast, evidence indicates a negative role for anti-Mullerian hormone (AMH, also known as Mullerian-inhibiting substance) of pre-granulosa/granulosa cell origin in this key event and subsequent progression to the antral stage. Two other TGF-β superfamily members, growth and differentiation factor-9 (GDF-9) and BMP-15 (also known as GDF-9B) are expressed in an oocyte-specific manner from a very early stage and play key roles in promoting follicle growth beyond the primary stage; mice with null mutations in the gdf-9 gene or ewes with inactivating mutations in gdf-9 or bmp-15 genes are infertile with follicle development arrested at the primary stage. Studies on later stages of follicle development indicate positive roles for granulosa cell-derived activin, BMP-2, -5 and -6, theca cell-derived BMP-2, -4 and -7 and oocyte-derived BMP-6 in promoting granulosa cell proliferation, follicle survival and prevention of premature luteinization and/or atresia. Concomitantly, activin, TGF-β and several BMPs may exert paracrine actions on theca cells to attenuate LH-dependent androgen production in small to medium-size antral follicles. Dominant follicle selection in monovular species may depend on differential FSH sensitivity amongst a growing cohort of small antral follicles. Changes in intrafollicular activins, GDF-9, AMH and several BMPs may contribute to this selection process by modulating both FSH- and IGF-dependent signalling pathways in granulosa cells. Activin may also play a positive role in oocyte maturation and acquisition of developmental competence. In addition to its endocrine role to suppress FSH secretion, increased output of inhibin by the selected dominant follicle(s) may upregulate LH-induced androgen secretion that is required to sustain a high level of oestradiol secretion during the pre-ovulatory phase. Advances in our understanding of intraovarian regulatory mechanisms should facilitate the development of new approaches for monitoring and manipulating ovarian function and improving fertility in domesticated livestock, endangered species and man.
TGF-β superfamily expression and actions in the endometrium and placenta
Authors: Jones Rebecca L , Stoikos Chelsea , Findlay Jock K , Salamonsen Lois A
Published: August 2006

Transforming growth factor β (TGFβ) superfamily members are closely associated with tissue remodelling events and reproductive processes. This review summarises the current state of knowledge regarding the expression and actions of TGFβ superfamily members in the uterus, during the menstrual cycle and establishment of pregnancy. TGFβs and activin β subunits are abundantly expressed in the endometrium, where roles in preparation events for implantation have been delineated, particularly in promoting decidualisation of endometrial stroma. These growth factors are also expressed by epithelial glands and secreted into uterine fluid, where interactions with preimplantation embryos are anticipated. Knockout models and embryo culture experiments implicate activins, TGFβs, nodal and bone morphogenetic proteins (BMPs) in promoting pre- and post-implantation embryo development. TGFβ superfamily members may therefore be important in the maternal support of embryo development. Following implantation, invasion of the decidua by fetal trophoblasts is tightly modulated. Activin promotes, whilst TGFβ and macrophage inhibitory cytokine-1 (MIC-1) inhibit, trophoblast migration in vitro, suggesting the relative balance of TGFβ superfamily members participate in modulating the extent of decidual invasion. Activins and TGFβs have similar opposing actions in regulating placental hormone production. Inhibins and activins are produced by the placenta throughout pregnancy, and have explored as a potential markers in maternal serum for pregnancy and placental pathologies, including miscarriage, Down’s syndrome and pre-eclampsia. Finally, additional roles in immunomodulation at the materno-fetal interface, and in endometrial inflammatory events associated with menstruation and repair, are discussed.
Minimizing environmental impacts of hydropower development: transferring lessons from past projects to a proposed strategy for Chile
Authors: Goodwin Peter , Jorde Klaus , Meier Claudio , Parra Oscar
Published: August 2006

Large dams have provided extensive benefits during the past 60 years but have also resulted in ecological and social consequences that were unexpected or were deemed to have a lower societal importance than the design benefits. The management of large dams is still a relatively new scientific issue, compared to the timeframe necessary to detect and understand all the consequences occurring at the watershed scale. This paper summarizes the unforeseen or unanticipated environmental consequences of these projects and potential ramifications to the overall project performance. The value of a central knowledge base and the importance of a system-wide monitoring program to assess pre- and post-implementation conditions and adapt operational rules are presented. Knowledge developed in several basins is reviewed in the context of future strategies for Chile. Chile has a strong economy, looming energy crisis and is faced with balancing the long-term value of a renowned natural landscape with unique ecology and the largest salmon aquaculture industry in the world against the prospect of low cost hydropower to drive other sectors of the economy. This paper outlines the hydroinformatics technologies and scientifically based management approaches that can be applied to this complex issue.
Application of an Eulerian–Lagrangian–Agent method (ELAM) to rank alternative designs of a juvenile fish passage facility
Authors: Weber L. J. , Goodwin R. A. , Li S. , Nestler J. M. , Anderson J. J.
Published: August 2006

The Eulerian–Lagrangian–Agent method (ELAM) couples three modelling approaches into a single, integrated simulation environment: (i) Eulerian descriptions, (ii) Lagrangian formulations, and (iii) agent reference frameworks. ELAMS are particularly effective at decoding and simulating the motion dynamics of individual aquatic organisms, using the output of high fidelity computational fluid dynamics (CFD) models to represent complex flow fields. Here we describe the application of an ELAM to design a juvenile fish passage facility at Wanapum Dam on the Columbia River in the United States. This application is composed of three parts: (1) an agent-based model, that simulates the movement decisions made by individual fish, (2) an Eulerian CFD model that solves the 3D Reynolds-averaged Navier–Stokes (RANS) equations with a standard k–ɛ turbulence model with wall functions using a multi-block structured mesh, and (3) a Lagrangian particle-tracker used to interpolate information from the Eulerian mesh to point locations needed by the agent model and to track the trajectory of each virtual fish in three dimensions. We discuss aspects of the computational mesh topology and other CFD modeling topics important to this and future applications of the ELAM model for juvenille salmon, the Numerical Fish Surrogate. The good match between forecasted (virtual) and measured (observed) fish passage proportions demonstrates the value-added benefit of using agent-based models (i.e. the Numerical Fish Surrogate model) as part of common engineering practice for fish passage design and, more fundamentally, to simulate complex ecological processes.
Environmental and ecological hydroinformatics to support the implementation of the European Water Framework Directive for river basin management
Authors: van Griensven A. , Breuer L. , Di Luzio M. , Vandenberghe V. , Goethals P. , Meixner T. , Arnold J. , Srinivasan R.
Published: August 2006

Research and development in hydroinfomatics can play an important role in environmental impact assessment by integrating physically-based models, data-driven models and other Information and Communication Tools (ICT). An illustration is given in this paper describing the developments around the Soil and Water Assessment Tool (SWAT) to support the implementation of the EU Water Framework Directive. SWAT operates on the river basin scale and includes processes for the assessment of complex diffuse pollution; it is open-source software, which allows for site-specific modifications to the source and easy linkage to other hydroinformatics tools. A crucial step in the world-wide applicability of SWAT was the integration of the model into a GIS environment, allowing for a quick model set-up using digital information on terrain elevation, land use and management, soil properties and weather conditions. Model analysis tools can be integrated with SWAT to assist in the tedious tasks of model calibration, parameter optimisation, sensitivity and uncertainty analysis and allows better understanding of the model before addressing scientific and societal questions. Finally, further linkage of SWAT to ecological assessment tools, Land Use prediction tools and tools for Optimal Experimental Design shows that SWAT can play an important role in multi-disciplinary eco-environmental impact assessment studies.
The effects of hydraulic and organic shock loads on the robustness of upflow anaerobic sludge blanket reactors treating sewage
Authors: Leitão R.C. , Santaellla S.T. , van Haandel A.C. , Zeeman G. , Lettinga G.
Published: August 2006

In this investigation, the robustness and stability of UASB reactors was evaluated on the basis of four indicators: (i) COD removal efficiency; (ii) effluent variability; (iii) pH stability; and (iv) recovery time. The experiments were carried out using six pilot-scale UASB reactors fed with domestic sewage and operated under different operational conditions. After establishment of a “steady-state”, organic and hydraulic shock loads (six times the loading rate during six hours) were imposed. The results show that the UASB reactors are robust systems with regards to COD removal efficiency and pH stability when exposed to shock loads. However, this reactor cannot attenuate the imposed fluctuation in the influent COD. A secondary treatment unit is needed to retain the expelled sludge occurring as a result of a hydraulic shock load, or prior to the shock, a sufficient amount of sludge needs to be discharged from the reactor.
A hydrogen-based variable-gain controller for anaerobic digestion processes
Authors: Rodríguez J. , Ruiz G. , Molina F. , Roca E. , Lema J.M.
Published: August 2006

An easy-to-implement controller based on gas phase measurements for anaerobic digestion processes was developed. The controller is based on the indirect control of COD in the effluent by means of controlling the hydrogen concentration in the biogas. The fast response of hydrogen under destabilizations, such as those caused by overloads, guarantees an early actuation on the system before it destabilizes. The controller is designed such that it brings the anaerobic digestion process to maximum capacity by pushing it to maximum methane production as long as hydrogen remains low. Experiments have been conducted to test the controller under organic over- and underload situations and promising performance was achieved. Further experiments must be carried out to validate the controller under a wider spectrum of situations to enable its robust industrial application.
Mathematical modelling of the anaerobic hybrid reactor
Authors: Soroa S. , Gomez J. , Ayesa E. , Garcia-Heras J.L.
Published: August 2006

This paper presents a new mathematical model for the anaerobic hybrid reactor (AHR) (a UASB reactor and an anaerobic filter in series) and its experimental calibration and verification. The model includes a biochemical part and a mass transport one, which considers the AHR as two contact reactors in series. The anaerobic process transformations are described by the model developed by Siegrist et al. The fraction (F) of solids in the clarification zone of the UASB reactor that leaves this first reactor is the key physical parameter to be estimated. The main parameters of the model were calibrated using experimental results from a bench-scale AHR fed with real slaughterhouse wastewater. The fraction of inert particulate COD in the influent and the factor F were estimated by a trial and error procedure comparing experimental and simulated results of the mass of solids in the lower tank and the VSS concentration in the AHR effluent. A good fit was obtained. The final verification was carried out by comparing a set of experiments with simulated data. The model's capability to predict the process performance was thus proved.
Bio-layer management in anaerobic membrane bioreactors for wastewater treatment
Authors: Jeison D. , van Lier J.B.
Published: August 2006

Membrane separation technology represents an alternative way to achieve biomass retention in anaerobic bioreactors for wastewater treatment. Due to high biomass concentrations of anaerobic reactors, cake formation is likely to represent a major cause of flux decline. In the presented research, experiments are performed on the effect of biomass concentration and level of gas sparging on the hydraulic capacity of a submerged anaerobic membrane bioreactor. Both parameters significantly affected the hydraulic capacity, with biomass exerting the most pronounced effect. After 50 days of continuous operation the critical flux remained virtually unchanged, despite an increase in membrane resistance, suggesting that biomass characteristics and hydraulic conditions determine the bio-layer formation rather than the membrane's fouling level. The concept of bio-layer management is introduced to describe the programmed combination of actions performed in order to control the formation of biomass layer over membranes.
The role of sulphate reduction on the reductive decolorization of the azo dye reactive orange 14
Authors: Cervantes F.J. , Enriquez J.E. , Mendoza-Hernandez M.R. , Razo-Flores E. , Field J.A.
Published: August 2006

The aim of this study was to investigate the impact of a broad range of sulphate concentrations (0–10 g SO4−2 L−1) on the reduction of an azo dye (reactive orange 14 (RO14)) by an anaerobic sludge. An increase in the sulphate concentration generally stimulated the reduction of RO14 by sludge incubations supplemented with glucose, acetate or propionate as electron donor. Sulphate and azo dye reductions took place simultaneously in all incubations. However, there was a decrease on the rate of decolorization when sulphate was supplied at 10 g SO4−2 L−1. Abiotic incubations at different sulphide concentrations (0–2.5 g sulphide L−1) promoted very poor reduction of RO14. However, addition of riboflavin (20 μM), as a redox mediator, accelerated the reduction of RO14 up to 44-fold compared to a control lacking the catalyst. Our results indicate that sulphate-reduction may significantly contribute to the reduction of azo dyes both by biological mechanisms and by abiotic reductions implicating sulphide as an electron donor. The contribution of abiotic decolorization by sulphide, however, was only significant when a proper redox mediator was included. Our results also revealed that sulphate-reduction can out-compete with azo reduction at high sulphate concentrations leading to a poor decolorising performance when no sufficient reducing capacity is available.
Degradation of acid orange 7 by a controlled anaerobic–aerobic sequencing batch reactor
Authors: Buitrón G. , Martínez K.M. , Vargas A.
Published: August 2006

The degradation of a mono azo dye in an automated and controlled anaerobic–aerobic sequencing batch reactor (SBR) is described in this work. The experiments were conducted with a synthetic wastewater containing acid orange 7 as the model compound to degrade and glucose as the co-substrate in a molar relationship 1:40 (substrate/co-substrate). It was possible to control the anaerobic and aerobic stages, using the redox potential (ORP) as the only control variable. The strategy detects an inflection point in the ORP signal, indicating the end of the reaction. The efficiency of removal of total organic carbon was between 85% and 90%. Azo dye was removed with 85% efficiency during the anaerobic stage.
Chromatographic characterization of dissolved organics in effluents from two anaerobic reactors treating synthetic wastewater
Authors: Aquino S.F. , Stuckey D.C.
Published: August 2006

This paper presents results on the quantification and chromatographic characterization of soluble microbial products (SMP) accumulated in two laboratory-scale reactors: a submerged anaerobic membrane reactor (SAMBR or MBR), and an anaerobic CSTR. The results obtained under steady-state conditions show that 2.1% of the substrate was channelled into the production of SMP in the CSTR, whilst in the SAMBR this was estimated to be 25%. Chromatographic characterization showed that more hydrophobic and high MW organics that absorb at 254 nm were detected in the SAMBR supernatant than in the CSTR. A comparison of chromatograms suggest that the release of extracellular polymers (ECP) and cell lysis may be important sources of SMP in the SAMBR. Electrophoresis results confirmed that there was more soluble protein inside the SAMBR, and showed that the release of ECP by shear or hydrolysis seemed to have contributed to the production of protein-like SMP in both systems.
Sequencing batch reactor as a post-treatment of anaerobically treated dairy effluent
Authors: Benítez A. , Ferrari A. , Gutierrez S. , Canetti R. , Cabezas A. , Travers D. , Menes J. , Etchebehere C.
Published: August 2006

Wastewater from dairy industries, characterized by its high COD content and relative high COD/TKN ratio, requires post-treatment after anaerobic treatment to complete the removal of organic matter and nutrients. Due to its simplicity, robustness and low maintenance costs, sequencing batch reactors (SBR) result in an attractive system, especially in case of small dairy industries in order to comply with the emission standards. The goal of this work was to determine the operational parameters, optimize the performance, and study the stability of the microbial population of a SBR system for the post-treatment of an anaerobic pond effluent. High and stable removal of COD and TKN was achieved in the reactor, which can easily be set up in dairy industries. An active nitrifying population was selected during reactor operation and maintained relatively stable, while the heterotrophic (total and denitrifying) communities were more unstable and susceptible to changes in the operating conditions.
Use of electrochemical oxidation process as post-treatment for the effluents of a UASB reactor treating cellulose pulp mill wastewater
Authors: Buzzini A.P. , Miwa D.W. , Motheo A.J. , Pires E.C.
Published: August 2006

The main purpose of this study was to evaluate the performance of the electrochemical oxidation process as a post-treatment for the effluents of a bench-scale UASB reactor treating simulated wastewater from an unbleached pulp plant. The oxidation process was performed using a single compartment cell with two plates as electrodes. The anode was made of Ti/Ru0.3Ti0.7O2 and the cathode of stainless steel. The following variables were evaluated: current density (75, 150 and 225 mA cm−2) and recirculation flow rate in the electrochemical cell (0.22, 0.45 and 0.90 L h−1). The increase in current density from 75 to 225 mA cm−2 did not increased the color removal efficiency for the tested flow rates, 0.22, 0.45 and 0.90 L h−1, however the energy consumption increased significantly. The results indicated the technical feasibility of the electrochemical treatment as post-treatment for UASB reactors treating wastewaters from pulp and paper plants.
Stability and activity of anaerobic sludge from UASB reactors treating sewage in subtropical regions
Authors: Seghezzo L. , Cuevas C.M. , Trupiano A.P. , Guerra R.G. , González S.M. , Zeeman G. , Lettinga G.
Published: August 2006

The production of small amounts of well-stabilized biological sludge is one of the main advantages of upflow anaerobic sludge bed (UASB) reactors over aerobic wastewater treatment systems. In this work, sludge produced in three pilot-scale UASB reactors used to treat sewage under subtropical conditions was assessed for both stability and specific methanogenic activity. Stability of primary sludge from settling tanks and digested sludge from conventional sludge digesters was also measured for comparison purposes. Kinetic parameters like the hydrolysis rate constant and the decay rate constant were calculated. High stability was observed in sludge from UASB reactors. Methanogenic activity in anaerobic sludges was relatively low, probably due to the low organic matter concentration in influent sewage. Knowledge on sludge growth rate, stability, and activity might be very useful to optimize sludge management activities in full-scale UASB reactors.
Co-digestion of ruminal content and blood from slaughterhouse industries: influence of solid concentration and ammonium generation
Authors: López I. , Passeggi M. , Borzacconi L.
Published: August 2006

At the present time, organic solid wastes from industries and agricultural activities are considered to be promising substrates for biogas production via anaerobic digestion. Moreover solids stabilisation is required before reutilization or disposal. Slaughterhouses are among the most important industries in Uruguay and produce 150 000 tons of ruminal content (RC) and 30 000 tons of blood per year. In order to determine the influence of the solids and blood contents, the ammonia inhibition and the inoculum adaptation co-digestion batch tests were performed. A set of experiences with TS concentration of 2.5%, 5% and 7.5% and different ratios of RC/blood were carried out using an inoculum from an UASB reactor. In all experiences fast blood hydrolisation was observed. A higher methane production was detected in the experiences with higher TS content. However, the fraction of solids degradation was lower in these experiences. A plateau in the biogas production was found. The free ammonia level, which was above the reported inhibitory levels, could explain this behaviour. After the inhibition period the biogas production restarted probably due to the biomass acclimatisation to the ammonia. In order to determine the inoculum adaptation a new experiment was performed. The inoculum used was the sludge coming from the first set of experiences. Based upon batch tests a 3.5 m3 pilot reactor was designed and started up. Ammonia inhibition was avoided by the start-up strategy and in two weeks the biogas production was 3.5 m3/d. The VS stabilisation with a solid retention time of 20 days was of 43%. The pilot reactor working at steady state had a TS concentration of 3–4% with a ratio of RC/blood of 10:1 at the entrance.
Effect of H2O2 dose on the thermo-oxidative co-treatment with anaerobic digestion of excess municipal sludge
Authors: Cacho Rivero J.A. , Suidan M.T.
Published: August 2006

Thermo-oxidative treatment, applied at moderate temperatures below the boiling point of water and using hydrogen peroxide as oxidant, has been shown to enhance anaerobic digestion of excess municipal sludge. Due to the high economic impact of chemical addition on the process, a balance between process performance and economic cost has to be established. The effect of three low hydrogen peroxide dosages (0.1, 0.25 and 0.5 gH2O2/gVSSinfluent) applied at 90 °C was evaluated. Increases in solids destruction of 13.9, 18.9 and 25.6% with respect to a control were observed when the thermo-oxidative co-treatment was operated at 0.1, 0.25 and 0.5 gH2O2/gVSSinfluent, respectively.
A good life environment for all through conceptual, technological and social innovations
Authors: Lettinga G.
Published: August 2006

In conventional environmental protection the parallel development of advanced technical solutions alongside ever more stringent environmental standards increasingly conflicts with the moral and practical imperatives to ensure sustainability and drastically improve the life conditions of the world's poor. Such priorities are far better tackled by technological and social innovations based on relatively simple and highly sustainable concepts: e.g., applying Natural Biological Mineralization Routes (NBMR) for wastewater and waste treatment, implementing Decentralized Sanitation and Resource Recovery and Reuse (DESAR3) where transport of waste(water)s is kept to an optimum level and pollutants valorized, etc. With developing countries now taking a lead in applying these concepts in public sanitation, the more prosperous countries will gradually abandon the expensive, vulnerable and non-sustainable conventional approaches to wastes treatment and environmental protection.
Are They Hallucinations or are They Real? The Spirituality of Deathbed and Near-Death Visions
Authors: Betty L. Stafford
Published: August 2006

The focus here is mainly on visions of deceased relatives and friends that persons near death often report. Are they visions of real people who live in an afterlife environment or are they hallucinations? Most social scientists assume they are hallucinations, but a thorough and careful analysis of the evidence does not point to this conclusion. The argument for the reality of such visions is muddied, however, by aspects of the visions that are dependent on the personal histories of the percipients and suggest, in some cases, illusory content. A theory that makes sense of all aspects of these visions is developed and defended, then tied into our theme: the spirituality of death.
Mapping Religion and Spirituality in an Irish Palliative Care Setting
Authors: MacConville Una
Published: August 2006

Kellehear's (2000) proposed theoretical model of spiritual care suggests that there is considerable interaction and overlap between situational, biographical and religious needs and the social and cultural contexts in which people are located. This article reports a study that used a cartographic approach to “map” understandings of religion and spirituality in an Irish palliative care setting (MacConville, 2004). Aspects of religion and spirituality have been explored within a multilayered Irish cultural setting to reveal a complex landscape—a landscape that is changing but which draws upon the past in shaping the present.
Time of Change? The Spiritual Challenges of Bereavement and Loss
Authors: Tedeschi Richard G. , Calhoun Lawrence G.
Published: August 2006

Coping with grief can include, in part, trying either to assimilate the loss into the existing worldview and its spiritual and religious components, or changing those components in congruence with the new reality. This spiritual or religious challenge can lead to loss of faith and a loss of spiritual meaning, but it can also provide a struggle that eventually leads to growth in the religious and spiritual domains. In a similar way, the bereaved person's experiences with their proximate culture and social world, particularly if their social systems include a religious community or shared spiritual beliefs with others, can lead to negative changes, but there is the possibility for growth in the social domain as well. Clinicians who work with bereaved persons need to be aware of the possibility that such themes may be important to their clients, and some suggestions are made to assist clinicians in this kind of work.
Immortal Organs: Spirituality in the Resurrected Lives of Organ Transplant Recipients
Authors: MaCdonald Arlene
Published: August 2006

At the heart of the scholarly critique of organ transplant is an unshakeable conviction that the zeal for transplantation stems from a misguided endeavour to resist death indefinitely and unnaturally. Based on ethnographic research with recipients about the religious or spiritual import of their transplant, this article argues that the immortality organ recipients seek is not a simple hunger to live longer but a complex rendering of eternal life founded on embodied experiences of illness and transplant and the social networks these experiences give rise to. Post modern medicine does not solve the problem of death, but it does contribute to new understandings of life after death.
Meaning Reconstruction in the Context of Religious Coping: Rebuilding the Shattered Assumptive World
Authors: Matthews Laura T. , Marwit Samuel J.
Published: August 2006

Recently research studies have begun to examine the theory that religion may help bereaved individuals to provide meaning (or an explanation) to an otherwise inconceivable event. In addition, there has been a growing understanding that bereavement forces individuals to restructure and rebuild previously held assumptions about the self and the world. The purpose of this paper is to examine the inter-relationship of religious coping, meaning reconstruction, and shattered assumptions by reviewing the literature of these three domains. Definitions surrounding “religious coping” and “meaning reconstruction” are clarified, and theoretical constructs are refined by exploring their relationships. Suggestions for future research are discussed, including methodological and conceptual considerations.
Particle wetting distribution in trickle‐bed reactors
Authors: van Houwelingen Arie Jan , Sandrock Carl , Nicol Willie
Published: August 2006

A novel technique is used to obtain the distribution of particle wetting in trickle‐bed reactors for different flow and prewetting conditions. Two prewetting methods were investigated: (1) Levec prewetting, in which the packed catalyst bed is completely flooded and then left to drain before steady state trickle‐flow is commenced; (2) Kan prewetting, in which the bed is prewetted by pulsing with the liquid before flow, after which the liquid flow is gradually set back to the required rate. It is shown that the method of prewetting has a major influence on average wetting efficiency and wetting distributions: Average wetting efficiencies differ with as much as 20% between the prewetting modes, and Levec prewetting leads to a considerable fraction of the bed that is not used (up to 7% at the investigated flow conditions), whereas the entire catalyst is used in Kan prewetted beds. It is shown that the particle wetting distributions can influence the modeling of Levec prewetted beds for liquid‐ and gas‐limited conditions. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Histone deacetylase inhibitor FK228 is a potent inducer of human fetal hemoglobin
Authors: Cao Hua , Stamatoyannopoulos George
Published: August 2006

We investigated the induction of the human fetal globin gene using five potent histone deacetylase (HDAC) inhibitors: FK‐228, HC‐Toxin, Trichostatin, MS‐275, and Apicidin, using in vitro assays and cultures of primary human erythroblasts. The results showed that FK228 is the most potent inducer of fetal hemoglobin and exhibits its effects in picomolar concentrations. FK228 should be considered as a potential therapeutic for induction of fetal hemoglobin in patients with β chain hemoglobinopathies. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.