bluuebunny/crossref_metadata_2025 huggingface dataset:
A Selective Increase in Plasma Soluble Vascular Cell Adhesion Molecule‐1 Levels in Preeclampsia
Authors: Daniel Yair , Kupferminc Michael J. , Baram Amiram , Geva Eli , Fait Gideon , Lessing Joseph B.
Published: September 2011

PROBLEM: The study was conducted to determine whether altered plasma levels of soluble intercellular adhesion molecule (ICAM)‐1 and soluble vascular cell adhesion molecule (VCAM)‐1 are involved in the pathogenesis of preeclampsia.

METHOD OF STUDY: Maternal plasma samples were collected from 20 patients with preeclampsia, 20 matched normotensive patients with uncomplicated pregnancies, and ten healthy nonpregnant women. Samples were assayed for soluble VCAM‐1 and soluble ICAM‐1 by specific enzyme‐linked immunosorbent assay.

RESULTS: Both soluble VCAM‐1 and soluble ICAM‐1 were detectable in the plasma of all preeclamptic, normotensive pregnant, and nonpregnant women. The mean plasma level of soluble VCAM‐1 was significantly higher in preeclamptic women compared to normotensive pregnant women (1831 ng/mL ± 534 ng/mL vs. 1254 ng/mL ± 386 ng/mL, respectively; P < 0.05). However, the plasma level of soluble VCAM‐1 was unchanged during the third‐trimester of normal pregnancy compared to nonpregnant women. The mean plasma level of soluble ICAM‐1 in preeclamptic and normotensive pregnant women were increased when compared to nonpregnant women. However, the mean plasma level of soluble ICAM‐1 was comparable in women with preeclampsia and normotensive pregnancy.

CONCLUSIONS: The selective increased plasma levels of soluble VCAM‐1 in patients with preeclampsia provide evidence for endothelial activation and suggest distinct pathways for neutrophil and endothelial activation in preeclampsia.
Mucosal Immunity in the Genital Tract: Prospects for Vaccines Against Sexually Transmitted Diseases—A Review
Authors: Russell Michael W. , Hedges Spencer R. , Wu Hong‐Yin , Hook Edward W. , Mestecky Jiri
Published: September 2011

PROBLEM: Consistent with the absence of protective immunity resulting from previous infection with Neisseria gonorrhoeae, the genital mucosal immune response in human gonorrhea is weak: only low levels of immunoglobulin G (IgG) and immunoglobulin A (IgA) antibodies are detectable against gonococci, and inflammatory cytokine responses are poor.

METHOD OF STUDY: Mucosal immunization strategies designed to induce persisting genital antibody responses might afford protection against infection, if appropriate conserved antigens can also be identified.

RESULTS: Intragastric or intranasal immunization with bacterial antigens expressed as recombinant chimeric proteins with cholera toxin A2/B subunits induced persisting IgA antibodies in genital and other secretions, and circulating IgG antibodies.

CONCLUSION: Although gonococci may avoid inducing or even suppress immune responses during natural infection, alternative approaches to vaccine development may be successful. However, inadequate understanding of the origins of antibodies in the genital tract, and their effector mechanisms, will need to be rectified to make this possible.
RANTES Production by Cultured Primate Endometrial Epithelial Cells
Authors: Altman Gaylene Bouska , Gown Allen M. , Luchtel Daniel L. , Baker Coralie
Published: September 2011

PROBLEM: RANTES (regulated upon activation, normal T cell expressed and secreted), is a chemokine with monocyte, macrophage, T lymphocyte, and eosinophil attractant and activating activities. This mediator has been detected in the peritoneal fluid of patients with endometriosis and in cultures of stromal cells from human endometrial and endometriotic tissue. To determine if endometrial epithelial cells were also a potential source of this mediator, primate endometrial epithelial cells were cultured in vitro and the constitutive and stimulated production of RANTES in these cultures was measured.

METHOD OF STUDY: Uterine tissue was obtained from Macaca nemestrina monkeys and the endometrial epithelial cells were isolated and placed in culture for 24–72 hr. RANTES was measured in cell extracts and culture fluids by enzyme‐linked immunosorbent assay (ELISA).

RESULTS: Constitute release of RANTES was low, ranging from 28–52 ng/mL but addition of interferon γ (INF‐γ) or the combination of IFN‐γ and tumor necrosis factor α (TNF‐α) produced a marked increase in RANTES production. The greatest release, which was nearly 500‐fold greater than the basal level, was observed at 72 hr with the combined addition of TNF‐α and INF‐γ. Nearly 90% of the stimulated RANTES was released into culture fluids, while cell associated RANTES was minimal constituting only 11.2% of the total.

CONCLUSION: These findings indicate that endometrial epithelial cells can produce and release RANTES. This chemokine may be an important attractant and activator of macrophages, T lymphocytes and/or eosinophils in the uterus during the reproductive cycle or implantation.
CD8 Membrane Expression Is Down‐regulated by Transforming Growth Factor (TGF)‐β1, TGF‐β2, and Prostaglandin E2
Authors: Ouellette Marie‐Josée , St‐Jacques Sylvie , Lambert Raymond D. , OUELLETTE MARIE‐JOSÉE , ST‐JACQUES SYLVIE , LAMBERT RAYMOND D.
Published: September 2011

PROBLEM: CD8 T‐cells are present at a lower frequency in human decidua than in peripheral blood. Because transforming growth factor (TGF)‐β2 down‐regulates CD4 membrane expression, its contribution, as well as the contribution of TGF‐β1 and prostaglandin (PG) E2, to the modulation CD8 expression was studied using human peripheral blood lymphocytes (PBLs).

METHOD OF STUDY: PBLs were cultured with TGF‐β1, TGF‐β2, PGE 2, PGI 2, or day‐12 rabbit blastocoelic fluid (BF) that was or was not depleted of TGF‐β2 and/or PGE 2. Quantum Simply Cellular Microbeads™ were then used to evaluate CD8 membrane expression levels.

RESULTS: This study is the first demonstration that treatment of PBLs with TGF‐β1, TGF‐β2, and PGE 2 leads to a dose‐dependent decrease in CD8 expression. A significant inhibition was observed at 2.5 ng/mL for TGF‐β2, 5 ng/mL for TGF‐β1, and 10 ng/mL for PGE 2. In contrast, PGI 2 had no effect. Treatment of PBLs with BF day‐12 decreased CD8 expression. This effect, however, was not observed when BF was depleted of TGF‐β2 and/or PGE 2.

CONCLUSIONS: Our results suggest that TGF‐βs and PGE 2 are important modulators of CD8 membrane expression in human lymphocytes. Because TGF‐β1, TGF‐β2, and PGE 2 are produced by the conceptus and by uterine cells, and because the effect is observed after only 3 days of treatment, the present data suggest that these substances can locally modulate the phenotype of lymphocytes at the fetomaternal interface. Such modulation may explain, at least partly, the changes observed in the population of decidual lymphocytes during pregnancy.
Effect of Anticardiolipin Antibodies on Prolactin and Insulin‐Like Growth Factor Binding Protein‐1 Production by Human Decidual Cells
Authors: Pierro Emilia , Andreani Cristiana Laura , Lazzarin Natalia , Minici Francesca , Apa Rosanna , Miceli Florella , Ayala Glanfranco , Mancuso Salvatore , Lanzone Antonio
Published: September 2011

PROBLEM: The effect of anticardiolipin antibodies (ACAs) on basal‐ and growth factor‐stimulated prolactin and insulin‐like growth factor (IGF) binding protein (BP)‐l production by cultured human decidual cells was investigated.

METHOD OF THE STUDY: Decidual cells were cultured for 24, 48, or 96 hr in medium supplemented with 5% ACA‐containing or 5% control serum and increasing concentrations of insulin (1–10 μg/mL) or IGF‐I (10–100 ng/mL).

RESULTS: No significant increase in prolactin production was observed after addition of increasing doses of insulin and IGF‐I in the presence of ACA‐containing serum, while a dose‐dependent stimulation was seen with control serum. Time‐dependent prolactin accumulation was also reduced when cells were cultured in the former conditions. IGF BP‐1 release was not affected by insulin and IGF‐I in the presence of both sera. However, lower IGF BP‐1 levels and a less pronounced time‐dependent accumulation were observed in the presence of ACA‐positive serum.

CONCLUSIONS: Our data suggest that ACAs affect cellular transduction mechanisms regulating critical events, such as decidual cell differentiation. These cellular dysfunctions might be relevant in the induction of some obstetric disorders typical of this syndrome.
Monoclonal Antibodies Against Maternal Major Histocompatibility Complex Class I Molecules Induce Rapid Abortion in Mice
Authors: Knezevic Nikola , Nikolic Boris , Brajsa Karmen , Spaventi Radan , Jonjic Nives , Jonjic Stipan , Marusic Suzana
Published: September 2011

PROBLEM: The role of antibodies against fetal or maternal antigens in maintaining or losing pregnancy is not clear.

METHOD OF STUDY: Term‐pregnant mice were injected with monoclonal antibodies against only fetal or fetal and maternal major histocompatibility complex class I molecules. The development of pregnancy was then followed.

RESULTS: Antibodies against maternal, but not fetal, major histocompatibility complex class I molecules induced abortion in mice. The abortion occurred 6–8 hr after the administration of autoreactive antibodies. The abortion could only be induced after the formation of placenta. Antibodies against tumor necrosis factor‐α could not prevent or postpone the abortion. Extensive bleeding has been detected in the placenta of aborting mice 3 hr after the administration of the antibodies.

CONCLUSIONS: This study indicates that autoreactive antibodies present risk for pregnancy and that the damage leading to abortion induced by such antibodies most likely occurs at the maternal side of placenta.
Neonatal morbidity in singleton late preterm infants compared with full‐term infants
Authors: Leone A , Ersfeld P , Adams M , Meyer Schiffer P , Bucher HU , Arlettaz R
Published: September 2011

Aim:  The aim of this study was to test the hypothesis that singleton late preterm infants (34 0/7 to 36 6/7 weeks of gestation) compared with full‐term infants have a higher incidence of short‐term morbidity and stay longer in hospital.

Methods:  In this retrospective, multicentre study, electronic data of children born at five hospitals in Switzerland were recorded. Short‐term outcome of late preterm infants was compared with a control group of full‐term infants (39 0/7 to 40 6/7 weeks of gestation). Multiple gestations, pregnancies complicated by foetal malformations, maternal consumption of illicit drugs and infants with incomplete documentation were excluded. The results were corrected for gender imbalance.

Results:  Data from 530 late preterm and 1686 full‐term infants were analysed. Compared with full‐term infants, late preterm infants had a significant higher morbidity: respiratory distress (34.7% vs. 4.6%), hyperbilirubinaemia (47.7% vs. 3.4%), hypoglycaemia (14.3% vs. 0.6%), hypothermia (2.5% vs. 0.6%) and duration of hospitalization (mean, 9.9 days vs. 5.2 days). The risk to develop at least one complication was 7.6 (95% CI: 6.2–9.6) times higher among late preterm infants (70.8%) than among full‐term infants (9.3%).

Conclusion:  Singleton late preterm infants show considerably higher rate of medical complications and prolonged hospital stay compared with matched full‐term infants and therefore need more medical and financial resources.
TRANSIENT SERVITUDE AND WORK IN THE TWENTY‐FIRST CENTURY
Authors: Vogel Richard D.
Published: September 2011

This article focuses on the dilemma that labor finds itself in at the beginning of the twenty‐first century. Working people everywhere have been undermined by neoliberal labor policy which has been aimed at managing labor migration. Workers in labor‐sending countries often face the choice of working in the informal economy of their own country or of submitting to conditions of transient servitude in a developed nation, while citizen‐workers in labor‐receiving countries have to compete with a reserve service and industrial workforce maintained by a regulated flow of temporary migrant labor that has no prospect of citizenship in the host country.
Mannose‐binding lectin (MBL2) polymorphisms and inflammation in hypertensive patients
Authors: Schreiber R. , Campos‐Coelho A. V. , Brandão L. , Guimarães R. L. , Kamada A. J. , Ferreira‐Sae M. C. , Matos‐Souza J. R. , Cipolli J. A. , de Lima‐Filho J. L. , Crovella S. , Nadruz W.
Published: September 2011

We investigated the possible role of Mannose binding lectin 2 (MBL2) functional polymorphisms in the prevalence of hypertension and hypertensive end‐organ damage in 300 hypertensive patients and 313 normotensive individuals from Southern Brazil. Hypertensive subjects with MBL2 AO/OO genotypes presented lower C‐reactive protein levels than AA individuals and consequently lower inflammatory status.
MICRONIZATION AND ENCAPSULATION OF FUNCTIONAL PIGMENTS USING SUPERCRITICAL CARBON DIOXIDE
Authors: SANTOS DIEGO T. , MEIRELES M. ANGELA A.
Published: September 2011

This research involves experimental studies of supercritical fluid (SCF)‐based micronization and encapsulation processes exploiting both solvent and antisolvent properties of supercritical CO2 for diverse functional pigments to extend the application of these natural functional pigments. First, the reliability of homemade experimental apparatuses designed and constructed by our research group was tested. Quercetin and β‐carotene were used as model substances in the micronization process via supercritical antisolvent (SAS). Bixin‐rich extract with polyethylene glycol (PEG) 10,000 as encapsulant material was used in the encapsulation process via SAS, while rutin and anthocyanin‐rich extract with PEG 10,000 and ethanol as cosolvents were applied to the formation of polymeric microcapsules via rapid expansion of supercritical solutions (RESS). The processing parameters and the used levels were based on the literature data. SAS process successfully reduced the particle size of quercetin by 4.1 times, while conventional micronization process only reduced the particle size by 1.8 times. Furthermore, it was demonstrated that SAS process can be successfully utilized to coprecipitate microparticles of PEG loaded with bixin‐rich extract. RESS process using ethanol as cosolvent was employed effectively to encapsulate rutin and anthocyanin‐rich extract in the PEG matrix. The data obtained in this study are in good agreement with the previous values reported by several authors using similar operational conditions and equipment. Core material : encapsulant material ratio, core material physical properties, such as solubility in supercritical CO2 and in CO2 + ethanol, and viscosity were key parameters for these processes.

PRACTICAL APPLICATIONS

The application of natural food colorants with relevant antioxidant activities, such as carotenoids and flavonoids, as food additives in various food products is seriously hampered by their fast degradation triggered by light, temperature, presence of oxygen, insolubility in aqueous systems and low dispersibility, among others. Their particle size reduction and/or encapsulation have been successfully used to overcome all these drawbacks. SCFs have become an attractive alternative solvent due to their environmentally friendly properties. SCFs may be conveniently used for various applications such as extraction, reactions, micronization and encapsulation, among others. Studies showing the use of SCFs and/or the construction of apparatuses that use these green solvents for solubility enhancement of functional pigments with poor water solubility and/or avoiding degradation of these compounds are extremely important.
DESIGN AND PERFORMANCE OF CONVENTIONAL AND FUZZY CONTROLS FOR A HIGH TEMPERATURE SHORT TIME PASTEURIZATION SYSTEM
Authors: BERTO MARIA ISABEL , SILVEIRA, JUNIOR VIVALDO
Published: September 2011

Fuzzy control was applied in a high‐temperature short time (HTST) pasteurization system and experimentally evaluated and compared with proportional‐integral‐derivative (PID)/feedback and PID/feedback/feedforward controllers. The product, a juice model solution, was pasteurized for 91C/40 s in a three‐stage plate heat exchange (regeneration, heating and cooling sections). Hot water and propylene glycol were responsible to heat and cool the product, respectively. A control system was designed to assure the pasteurization temperature manipulating the hot fluid flow rate. Controllers were evaluated by means of dynamic behavior of the pasteurization temperature and performance criteria after the imposed step changes of the product inlet temperature. Configured controllers kept the process temperature within HTST requirements, having a variation of ±0,5C, and the similar values of performance criteria indicate an efficiency for all three tested controllers.

PRACTICAL APPLICATIONS

The continuous need for better food products, standardized within the consumer demands, has expanded the applications and the search for solutions using automation and control techniques. The use of control strategies and automation in chemical, petroleum and other industrial processes are more intensive as compared with the same applications in food industries. The complex execution of experimental tests in lab‐scale or pilot plants is the main reason for the great number of simulations in the process control area. Based on the importance of accomplishing experimental errors and uncertainties, this paper results from an extensive research developed in a pilot plant of HTST process. Theoretical methods for tuning controllers were applied and evaluated. Conventional controllers (PID/feedback and PID/feedback/feedforward) were tuned and compared with fuzzy control, one of the most recognized nonconventional controllers. Results showed that the requirements to maintain pasteurization temperature after changes in inlet process conditions were performed in all three strategies, indicating the accomplishment of the research purpose.
Ultrasonography of small intestinal obstructions: a contemporary approach
Authors: Garcia D. A. A. , Froes T. R. , Vilani R. G. D. O. C. , Guérios S. D. , Obladen A.
Published: September 2011

Objectives: To assess the accuracy of intestinal ultrasound for diagnosis of intestinal obstruction in dogs and cats.

Methods: A prospective clinical study was performed. Inclusion criteria were dogs and cats with clinical signs suggestive of gastrointestinal obstruction. Animals with no obstruction detected on ultrasound were excluded if they could not be monitored for 48 hours to confirm absence of obstruction. Sonographic diagnosis of small intestinal obstruction was based on identification of at least two findings suggestive of intestinal obstruction.

Results: Ninety‐two patients suspected of having intestinal obstruction were included. Correct diagnosis of intestinal obstruction was made in 21 cases (23%), and in 68 (74%) this diagnosis was excluded. Interpretation of the images on prospective analysis had sensitivity, positive predictive, specificity and negative predictive values of 100%, 87.5%, 95.8% and 100%, respectively.

Clinical Significance: Ultrasonography is an excellent method for investigation of animals with gastrointestinal disorders, and is particularly useful for excluding obstructive processes.
A statistics primer
Authors: Scott Marian , Flaherty Derek , Currall James
Published: September 2011

Statistical input into an experimental study is often not considered until the results have already been obtained. This is unfortunate, as inadequate statistical planning ‘up front’ may result in conclusions which are invalid. This review will consider some of the statistical considerations that are appropriate when planning a research study.
Adolescent attention deficit hyperactivity disorder and susceptibility to psychosis in adulthood: a review of the literature and a phenomenological case report
Authors: Jandl Martin , Steyer Jürgen , Kaschka Wolfgang P.
Published: September 2011

Aim: In contrast to affective disorders, some forms of personality disorders and drug addiction, schizophrenia is commonly not considered to be a sequela of attention deficit hyperactivity disorder. However, attention deficit hyperactivity disorder and the prodromal stages of schizophrenia spectrum disorders do exhibit a number of common central features. To facilitate the early treatment of schizophrenic symptoms, the detection of discrete and subtle alterations in the prodromal stages of incipient psychoses is particularly important.

Methods: We review the literature on the prodromal symptoms of psychosis and present a case report, in which a phenomenological approach was used to identify subtle alterations linked to anomalous self‐experience.

Results: Using the Examination of Anomalous Self‐Experience symptom checklist, the case report presented here reveals attention deficit hyperactivity disorder symptoms in adolescence as a precursor state of psychosis in adulthood.

Conclusions: The characteristics of this schizophrenia spectrum disorder case and its time course are derived from the specific distribution pattern of Examination of Anomalous Self‐Experience items. When treating adolescent attention deficit hyperactivity disorder patients, the rare possibility of the development of schizophrenia spectrum disorder from attention deficit hyperactivity disorder like symptoms should be kept in mind.
A novel antimicrobial protein for plant protection consisting of aXanthomonas oryzaeharpin and active domains of cecropin A and melittin
Authors: Che Yi‐Zhou , Li Yu‐Rong , Zou Hua‐Song , Zou Li‐Fang , Zhang Bing , Chen Gong‐You
Published: September 2011

Discoveries about antimicrobial peptides and plant defence activators have made possible thede novoand rational design of novel peptides for use in crop protection. Here we report a novel chimeric protein, Hcm1, which was made by linking the active domains of cecropin A and melittin to the hypersensitive response (HR)‐elicitor Hpa1 ofXanthomonas oryzaepv.oryzicola, the causal agent of rice bacterial leaf streak. The resulting chimeric protein maintained not only the HR‐inducing property of the harpin, but also the antimicrobial activity of the cecropin A‐melittin hybrid. Hcm1 was purified from engineeredEscherichia coliand evaluated in terms of the minimal inhibitory concentration (MIC) and the 50% effective dose (ED50) against important plant pathogenic bacteria and fungi. Importantly, the protein acted as a potential pesticide by inducing disease resistance for viral, bacterial and fungal pathogens. This designed drug can be considered as a lead compound for use in plant protection, either for the development of new broad‐spectrum pesticides or for expression in transgenic plants.
Mediators of Opportunity: High School Counselors in the 21st Century
Authors: Smith Vicki
Published: September 2011

Over the second half of the 20th century sociologists of education and inequality variously criticized high school counselors (seeing them as stratifying gatekeepers) or downplayed their significance (seeing them as impartial but ineffective). Today, sociologists of education might predict that counselors have little ability to shape students’ long‐run educational or occupational trajectories. This essay outlines two models that have led to this prediction: the concerted gatekeeping and the impartial cultivator models. It then identifies a set of trends that suggest that high school counselors – whether by serving students in one‐on‐one interactions or serving them more collectively – should be viewed as intermediaries, occupying a place in the broader population of intermediaries in our society. Specifically, like other intermediaries, school counselors have the organizational capacity and the professional mandate to take responsibility for their clients’ well‐being and mobility and are structurally positioned to do so.
Prediction of Streamflow Regime and Annual Runoff for Ungauged Basins Using a Distributed Monthly Water Balance Model1
Authors: Moore R.D. (Dan) , Trubilowicz J.W. , Buttle J.M
Published: September 2011

Moore, R.D. (Dan), J.W. Trubilowicz, and J.M. Buttle, 2011. Prediction of Streamflow Regime and Annual Runoff for Ungauged Basins Using a Distributed Monthly Water Balance Model. Journal of the American Water Resources Association (JAWRA) 48(1): 32‐42. DOI: 10.1111/j.1752‐1688.2011.00595.x

Abstract:  Prediction of streamflow in ungauged basins is a global challenge, but is particularly an issue in physiographically complex regions like British Columbia (BC), Canada. The objective of this study was to assess the accuracy of a simple water balance model that can be run using existing spatial datasets. The model was developed by modifying an existing monthly water balance model to account for interception loss from forest canopy, glacier melt, and evaporation from lakes. The model was run using monthly climate normals from the ClimateBC application, which have a horizontal resolution of 400 m. Each ClimateBC grid cell was classified as forest, open land, glacier or water surface based on provincial scale digital maps of biogeoclimatic zones, glaciers, and water. The output was monthly mean runoff from each grid cell. These values were integrated within the catchment boundaries for streams gauged by the Water Survey of Canada. Annual runoff was predicted with modest accuracy: after updating the predicted runoff by interpolating errors from neighboring gauged streams, the mean absolute error was 25.4% of the gauged value, and 52% of the streams had errors less than 20%. However, the model appears to be quite robust in distinguishing between pluvial, hybrid, and melt‐dominated hydroclimatic regimes, and therefore has promise as a tool for catchment classification.
When scoring algorithms matter: Effects of working memory load on different IAT scores
Authors: Schmitz Florian , Teige‐Mocigemba Sarah , Voss Andreas , Klauer Karl C.
Published: September 2011

In most process accounts of the Implicit Association Test (IAT), it is assumed that compatible and incompatible IAT blocks require different amounts of working memory capacity (WMC) and recruit executive functions such as task switching and inhibition to different extents. In the present study (N= 120), cognitive load during the completion of an IAT was experimentally manipulated by means of an oral random‐number generation secondary task. Cognitive load led to slower latencies and more errors, especially in the incompatible block. However, different IAT scores, including conventional scores and D‐scores, were affected differentially by the load manipulation: scores based on raw data of task performance such as latencies and errors were increased whereas scores that use transformations such as log‐latency scores and D‐scores were decreased. A number of analyses shed light on the reasons for the unexpected dissociation between scoring algorithms. Remarkably, external correlations of the IAT scores were not affected by the experimental manipulation.
Trajectory Control of Miniature Helicopters Using a Unified Nonlinear Optimal Control Technique
Authors: Xin Ming , Xu Yunjun , Hopkins Ricky
Published: September 2011

It is always a challenge to design a real-time optimal full flight envelope controller for a miniature helicopter due to the nonlinear, underactuated, uncertain, and highly coupled nature of its dynamics. This paper integrates the control of translational, rotational, and flapping motions of a simulated miniature aerobatic helicopter in one unified optimal control framework. In particular, a recently developed real-time nonlinear optimal control method, called the θ-D technique, is employed to solve the resultant challenging problem considering the full nonlinear dynamics without gain scheduling techniques and timescale separations. The uniqueness of the θ-D method is its ability to obtain an approximate analytical solution to the Hamilton–Jacobi–Bellman equation, which leads to a closed-form suboptimal control law. As a result, it can provide a great advantage in real-time implementation without a high computational load. Two complex trajectory tracking scenarios are used to evaluate the control capabilities of the proposed method in full flight envelope. Realistic uncertainties in modeling parameters and the wind gust condition are included in the simulation for the purpose of demonstrating the robustness of the proposed control law.
Design Optimization of Scaffold Microstructures Using Wall Shear Stress Criterion Towards Regulated Flow-Induced Erosion
Authors: Chen Yuhang , Schellekens Michiel , Zhou Shiwei , Cadman Joseph , Li Wei , Appleyard Richard , Li Qing
Published: September 2011

Tissue scaffolds aim to provide a cell-friendly biomechanical environment for facilitating cell growth. Existing studies have shown significant demands for generating a certain level of wall shear stress (WSS) on scaffold microstructural surfaces for promoting cellular response and attachment efficacy. Recently, its role in shear-induced erosion of polymer scaffold has also drawn increasing attention. This paper proposes a bi-directional evolutionary structural optimization (BESO) approach for design of scaffold microstructure in terms of the WSS uniformity criterion, by downgrading highly-stressed solid elements into fluidic elements and/or upgrading lowly-stressed fluidic elements into solid elements. In addition to this, a computational model is presented to simulate shear-induced erosion process. The effective stiffness and permeability of initial and optimized scaffold microstructures are characterized by the finite element based homogenization technique to quantify the variations of mechanical properties of scaffold during erosion. The illustrative examples show that a uniform WSS is achieved within the optimized scaffold microstructures, and their architectural and biomechanical features are maintained for a longer lifetime during shear-induced erosion process. This study provides a mathematical means to the design optimization of cellular biomaterials in terms of the WSS criterion towards controllable shear-induced erosion.
Effect of Implanting a Soft Tissue Autograft in a Central-Third Patellar Tendon Defect: Biomechanical and Histological Comparisons
Authors: Kinneberg Kirsten R. C. , Galloway Marc T. , Butler David L. , Shearn Jason T.
Published: September 2011

Previous studies by our laboratory have demonstrated that implanting a stiffer tissue engineered construct at surgery is positively correlated with repair tissue stiffness at 12 weeks. The objective of this study was to test this correlation by implanting a construct that matches normal tissue biomechanical properties. To do this, we utilized a soft tissue patellar tendon autograft to repair a central-third patellar tendon defect. Patellar tendon autograft repairs were contrasted against an unfilled defect repaired by natural healing (NH). We hypothesized that after 12 weeks, patellar tendon autograft repairs would have biomechanical properties superior to NH. Bilateral defects were established in the central-third patellar tendon of skeletally mature (one year old), female New Zealand White rabbits (n = 10). In one limb, the excised tissue, the patellar tendon autograft, was sutured into the defect site. In the contralateral limb, the defect was left empty (natural healing). After 12 weeks of recovery, the animals were euthanized and their limbs were dedicated to biomechanical (n = 7) or histological (n = 3) evaluations. Only stiffness was improved by treatment with patellar tendon autograft relative to natural healing (p = 0.009). Additionally, neither the patellar tendon autograft nor natural healing repairs regenerated a normal zonal insertion site between the tendon and bone. Immunohistochemical staining for collagen type II demonstrated that fibrocartilage-like tissue was regenerated at the tendon-bone interface for both repairs. However, the tissue was disorganized. Insufficient tissue integration at the tendon-to-bone junction led to repair tissue failure at the insertion site during testing. It is important to re-establish the tendon-to-bone insertion site because it provides joint stability and enables force transmission from muscle to tendon and subsequent loading of the tendon. Without loading, tendon mechanical properties deteriorate. Future studies by our laboratory will investigate potential strategies to improve patellar tendon autograft integration into bone using this model.
A Novel Approach to the Generation of Sustainable Energy From Biomass and Wastes
Authors: Paisley Mark A. , Millspaugh Mark
Published: September 2011

Recent price increases for various forms of energy along with projected shortages of supply have resulted in renewed interest in alternative fuels. Biomass gasification provides a renewable basis for supplying electric power and also a broad suite of chemicals such as Fisher-Tropsch liquids as well as hydrogen. The Taylor gasification process, being developed by Taylor Biomass Energy is a biomass gasification process that produces a MCV gas. The Taylor gasification process provides improvements over currently available gasification processes by integrating improvements to reduce issues with ash agglomeration and provide in-situ destruction of condensable hydrocarbons (tars), an essential element in gas cleanup. The gas conditioning step integrated into the Taylor Gasification Process provides a unique method to convert the tars into additional synthesis gas and to adjust the composition of the synthesis gas. Taylor Biomass Energy has developed and refined a sorting and recycling process that can produce a clean feedstock for energy recovery from abundant residue materials such as construction and demolition residuals and MSW. The sorting and separating process can then be coupled to the Taylor gasification process to produce clean, sustainable energy. Construction is expected to start in mid 2011 for an integrated combined cycle power system incorporating the Taylor Gasification Process and utilizing biomass feedstocks recovered from municipal solid wastes (MSW) and construction and demolition wastes C&D). The Taylor Recycling Facility, LLC, located approximately 70 miles northwest of New York City in Montgomery, NY, is a leader in C&D and waste wood recycling. The development process including integration with a gas turbine based combined cycle system, connection into the New York ISO, and identification of renewable energy credit options is discussed along with a discussion of the Taylor Gasification Process, its modular design, and implementation into the commercial IGCC system in Montgomery, NY.
Novel Gas Cleaning With Integrated Energy Recovery
Authors: Herrlander Bo
Published: September 2011

High-energy recovery combined with low emissions to air and water was targeted when Jo¨nko¨ping Energi planned their new Waste to Energy plant at Torsvik in Sweden. The plant is compliant with the new EU Industry Directive and the Waste Frame Directive R-formula, which defines energy recovery levels for recycle of energy. In total about 160 000 tons of municipal (40%) and commercial waste (60%) is annually converted into usable energy. The average heat value is 11,7 MJ/kg. The energy produced is a combination of electricity (14 MWe) and heat (42–56 MWth, depending on electricity production). The heat is recovered both in a boiler and in a condenser. The flue gas condensing system is combined with a heat pump (10 MWth) to optimize the heat recovery rate. The plant is designed to fulfill the requirements set by the Swedish authorities, which are more stringent than the EU emission requirements. Some examples of the plant emissions to air guarantees: dust 5, HCl 5, SO2 20, HF1, Hg 0,03, Cd+Tl 0,05, other HM 0,5 all in mg/Nm3 and dioxin 0,05 ng/Nm3. The flue gas cleaning upstream of the condenser consists of a combination of a semi-dry system and a wet scrubber. The gas cleaning system operating range goes from 60 000 up to 127 000 Nm3/h depending on load and fuel heat value. The semi-dry system is carrying out the major part of the gas cleaning and is sufficient to comply with the air regulations. However, in order to minimize the treatment of the condensate from the condenser the wet scrubber is installed after the semi-dry system and upstream the condenser. The blow down from the scrubber is reused within the plant. Thus the polishing scrubber secures minimal treatment of the condensate to comply with the local stringent limits, particular chlorides, before release to the recipient lake Munksjo¨n. Emissions to water were 2010 nitrogen 1,7 mg/l, Cl <3,6 mg/l, As 0,66 μg/l, Cd <0,07 μg/l, Cr <6 μg/l, Cu 0,8 μg/l, Hg <0,4 μg/l, Ni <0,66 μg/l, Pb<1,2 μg/l, Tl<1,3 μg/l, Zn<7,2 μg/l and PCDD/PCDF 0,0088 ng/l. In the wet scrubber acid stage residual HCl and excess ammonia from the SNCR system are removed. The latter compound is important to capture in order to prevent eutrophication. The combination of a semidry and a wet system enables an optimization of the flue gas cleaning with regard to the different operating situations, taking into account seasonal demand variations as well as fuel alterations. The concept has demonstrated very low emissions combined with low consumption of lime. The possibility to optimize the flue gas cleaning performance is a prerequisite for minimal condensate treatment and optimal energy recovery. The paper will describe the system and the operating experiences.
New Contract Provisions to Assure Timely Maintenance of Publicly Owned WTE Facilities
Authors: Stoller Paul J. , Crellin William
Published: September 2011

When the initial generation of U.S. municipal waste combustor (WTE) facilities was developed during the 1980s and early 1990s, the only tools that were included in the service agreement to deal with a contract operator that was not meeting the contract terms was either dispute resolution or default and termination. After 20 years of administering these service agreements, those two provisions have proved inadequate for publicly owned WTE facilities particularly as it relates to ongoing maintenance. Additional provisions have recently been developed and incorporated into the next generation of service agreements to address this need. Contract operators of publicly owned WTE facilities typically focus their attention on facility performance and less on long-term facility asset preservation, especially for the portions of the facility that are not critical to production. If a contract operator is meeting all of its performance guarantees, but is falling behind on the general upkeep of facility buildings and/or infrastructure, owners will likely not invest the time and money in dispute resolution to try to get those items repaired. Additionally, neglect of those items does not rise to the level that the operator can be defaulted and terminated. As a result, conditions generally deteriorate to the point where the relations between the owner and contract operator are adversely affected. If the deferral of maintenance continues until the end of the service agreement term, the public owner will be faced with added capital costs and/or increased operating costs under a new service agreement for items that he already paid the previous operator for. This paper describes the new contractual provisions that have been developed in the latest generation of service agreements aimed at helping public owners of WTE facilities resolve these types of problems at minimal cost. Instead of only having the “nuclear weapons” (e.g., formal—and expensive—dispute resolution or default and termination), a series of mechanisms have been developed that provide owners with some “small arms weapons” to assure that the timely and proper maintenance is performed on all aspects of the WTE facility, thereby assuring its long-term preservation. This paper also sets forth case studies of three WTE facilities in the Tampa Bay, Florida area where these latest contractual provisions are being implemented and the results to date.
Recommitting to a Long Term Waste to Energy Future Through a Comprehensive Refurbishment Program
Authors: Schauer Raymond H. , Krupa Joseph
Published: September 2011

Created in 1978, the Solid Waste Authority of Palm Beach County (Authority) has developed an “award winning” solid waste management system that includes franchised solid waste collections and the following facilities to service the residents and businesses in Palm Beach County, Florida: • North County Resource Recovery Facility (NCRRF); • Residential and Commercial Recovered Materials Processing Facility; • Five Transfer Stations; • Class I Landfill; • Class III Landfill; • Biosolids Pelletization Facility; • Ferrous Processing Facility; • Woody Waste Recycling Facility; • Composting Facility; and • Household Hazardous Waste Facility. The Authority has proactively planned and implemented its current integrated solid waste management program to ensure disposal capacity through 2021. However, like many communities, the Authority anticipates continued population growth and associated new development patterns that will significantly increase demands on its solid waste system, requiring it to reevaluate and update its planning to accommodate future growth. The NCRRF, the Authority’s refuse derived fuel waste-to-energy facility, has performed very well since its start up in 1989 processing over 13 million tons of MSW, saving valuable landfill space and efficiently producing clean, renewable energy. As the NCRRF approached the end of its first 20 year operating term, it became necessary to complete a comprehensive refurbishment to ensure its continued reliable service for a second 20 year term and beyond providing for continued disposal capacity and energy production for the Authority’s customers. The Authority renegotiated and extended its operating agreement with the Palm Beach Resource Recovery Corporation (PBRRC), a Babcock & Wilcox Company, for an additional 20-year term. The Authority selected BE&K Construction Company (BE&K) and entered into an Engineering, Procurement, and Construction contract (EPC Contract) to perform the refurbishment. The Authority, with assistance from its Consulting Engineer, Malcolm Pirnie, Inc., developed the minimum technical requirements and negotiated the EPC Contract with BE&K. The design and procurement efforts were completed in early 2009 and on-site construction refurbishment activities commenced in November 2009. The refurbishment has a total estimated cost of $205 million. The refurbishment work is sequenced with the intent that one boiler train will remain operational to reduce the impact to the Authority’s landfill and maximize electrical production and revenues during the refurbishment period. This presentation will focus on the improvements to operations as a result of the refurbishment and its positive effects on the Authority’s integrated solid waste management system.
NOx Reduction: The Challenge for Innovative Concepts in Europe
Authors: Koralewska Ralf
Published: September 2011

During combustion, most of the waste’s nitrogen content is transferred to the flue gases as nitrogen oxide, NOx. The EU Waste Incineration Directive defines a maximum emission limit value for NOx of 200 mg/Nm3 as a daily average value referred to 11% O2. Based on National Emission Ceilings (NEC) defined by the Gothenburg Protocol, it can be expected that the limit values for NOx in the EU will become even more stringent. In some European countries (e.g. The Netherlands, Austria, Switzerland) a lower emission limit has already been introduced. Selective Catalytic Reduction (SCR) technologies are used in many cases to achieve the above-mentioned NOx limits. However, there are drawbacks to SCR systems such as high investment cost. Operation cost is also quite high due to the energy consumption necessary for the reheating of the flue gas as well as the increased pressure loss. Innovative technologies are therefore required to make it possible to reconcile both requirements: reduced emissions and increased energy efficiency. Selective Non-Catalytic Reduction (SNCR) systems are based on the selective reaction of ammonia or urea injected into the upper furnace. In many cases SNCR technologies are limited by the ammonia slip which increases in case of more stringent NOx requirements. According to the relevant BREF document, an ammonia slip limit of 10 mg/Nm3 is generally required at the stack. In order to achieve reduced NOx values, it is necessary to implement measures to reduce ammonia slip, by means of either a wet scrubber or a High-dust catalytic converter. EfW plants in Mainz (Germany) and Brescia (Italy) are examples of operational plants combining SNCR with such a catalytic converter type. In addition R&D activities are carried out on the development of simplified reaction mechanisms to be implemented in Computational Fluid Dynamics (CFD) codes. With these tools it will be possible to describe the interaction between turbulent mixing, radiation and chemical reaction rates. Another option to achieve low NOx values (below 100 mg/Nm3) is the reduction of NOx by so-called primary measures, e.g. the Very Low NOx process (VLN), which has been developed by MARTIN jointly with its cooperation partners. The VLN process is based on a grate-based combustion system. The “VLN gas” is drawn off at the rear end of the grate and is reintroduced into the upper furnace in the vicinity of the SNCR injection positions. NOx will be reduced significantly, ensuring low NOx emission values at the stack as required, at low values for ammonia slip. The new EfW plant in Honolulu (USA) will be equipped with the VLN process. In Coburg (Germany), the VLN process will be retrofitted in an existing installation. This paper documents the potential and the limitations of different measures for NOx reduction as well as examples of recent innovative EfW plants in Europe using MARTIN technologies successfully.
Improving Refractories for Waste to Energy Challenges
Authors: Stephan Patrick M. , Burak William H.
Published: September 2011

Operating conditions in steam generating units (boilers) in the waste-to-energy market present a wide range of operating conditions which challenge materials used throughout the units. While operators attempt to operate within a narrow range of conditions, the variability of fuel types, heating values and water content specifically affect refractory life throughout the units. In recent years, many operators have modified combustion conditions in order to reduce controlled emissions, resulting in higher temperatures, larger thermal gradients and different gas chemistries, with potentially harmful effects on refractory performance. Refractory manufacturers have responded through material developments and installation improvements which are meeting the new operating challenges.
Modeling and Measuring Impacts From Ash Landfilling: Using Data to Inform Regulatory Policy
Authors: Zemba Stephen G. , Ames Michael R. , Green Laura C.
Published: September 2011

Most ash generated by waste-to-energy (WTE) facilities in the U.S. is landfilled. Studies undertaken in the late 1980’s and early 1990’s indicated no significant environmental concerns associated with ash landfilling. However, in 2001, policy-makers at the Massachusetts Department of Environmental Protection (MA DEP) became concerned that the “cumulative” impacts of landfills, including ash landfills, might pose a risk to human health. To address this concern, we performed an in-depth assessment of impacts to air quality, and theoretical risks to health, from fugitive emissions associated with an ash landfill. Nine sources of fugitive ash emissions were modeled using methods that coupled detailed information about the site operations, ash properties, and meteorological conditions on an hour-by-hour basis. The results of these assessments, combined with ambient air data collected by others, demonstrated that the impacts from fugitive emissions of the ash were no more than negligible. Accordingly, in 2006, MA DEP revised its policy, exempting ash disposal landfills from the requirement to demonstrate no significant impact, effectively granting presumptive certainty to ash landfills that employ best management practices. Detailed analyses such as described herein, combined with robust data sets, can form the basis of more efficient regulatory policies.
Focus Issue: Series on Computational and Systems Biology
Authors: Gough Nancy R.
Published: September 2011

The month of September includes research, teaching materials, and methods that exemplify themes in computational and systems biology.