bluuebunny/crossref_metadata_2025 huggingface dataset:
The products and validation of GAME reanalysis and JRA‐25 part 1: surface fluxes
Authors: Yatagai Akiyo , Yamazaki Nobuo , Kurino Toshiyuki
Published: July 2007

The Global Energy and Water Cycle Experiment (GEWEX) Asian Monsoon Experiment (GAME) reanalysis datasets are the products of four‐dimensional data assimilations (4DDA) of meteorological observations made from April 1998 to October 1998. These datasets were created using the most recently updated 4DDA schemes of the Japan Meteorological Agency (JMA) during the GAME reanalysis project (1999–2001) as well as radiosonde observations made during the intensive observation period of the GAME project (April 1998–October 1998). Two versions of reanalyses products have been released officially: Ver. 1.1 and Ver. 1.5.

One of the greatest differences between the two versions is the representation of snow cover: Ver. 1.1 used climatological snow data, while Ver. 1.5 used satellite‐derived snow information. Here, we describe how snow cover modifications and land surface schemes differ between the two versions and how changes in surface processes affect surface fluxes. The use of satellite‐derived snow information produced a difference in surface fluxes over the Tibetan Plateau, especially for May.

We also compare surface fluxes estimated by the long‐term reanalysis (JRA25) product of the JMA as well as GAME reanalysis product with in situ observations by the Asian Automatic Weather Station (AWS) Network (AAN). Radiosonde observations made 4 times daily were incorporated into the atmospheric field of the 4DDA GAME reanalysis and resulted in a good correspondence between the reanalyses products and surface observations, especially for July. The use of satellite‐derived snow information as a boundary condition also had improved flux results over the Tibetan Plateau in May. Copyright © 2007 John Wiley & Sons, Ltd.
A novel bone substitute composite composed of tricalcium phosphate, gelatin and drynaria fortunei herbal extract
Authors: Dong Guo‐Chung , Chen Hueih Min , Yao Chun‐Hsu
Published: July 2007

The Chinese herb, Gu‐Sui‐Bu (GSB) (Drynaria fortunei J. Sm.) has been anecdotally reported to enhance bone healing. We had previously confirmed in vitro the efficacy and safety of GSB in bone healing, and showed that it influenced both osteoblast and osteoclast activity. For clinically useful application of these bone regenerative effects, a satisfactory delivery system for GSB is required. In this study, we determined the optimal concentration of GSB for regenerative activity in rat bone cells via MTT, alkaline phosphatase (ALP), nodule formation and TRAP assays, and designed and tested a GSB‐rich bone composite material. The composite was fabricated by mixing a biodegradable GGT composite, containing genipin cross‐linked gelatin and tricalcium phosphate, with the predetermined concentration of GSB (GGT‐GSB). Neonatal rat calvarial culture and animal implantation were employed to evaluate and compare in vitro and in vivo the potential of GGT‐GSB and GGT in regeneration of defective bone tissue. The most effective concentration of GSB was 100 μg/mL, which significantly increased osteoblast numbers, intracellular ALP levels and nodule numbers, without influencing osteoclast activity. In vitro and in vivo tests also showed that GGT‐GSB accelerated bone regeneration compared to GGT. GGT‐GSB thus has great potential for improved bone repair. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
A novel polyrotaxane‐based intracellular delivery system for camptothecin: In vitro feasibility evaluation
Authors: Moon Cheol , Kwon Young Min , Lee Won Kyu , Park Yoon Jeong , Chang Li‐Chien , Yang Victor C.
Published: July 2007

Camptothecin (CPT) is a naturally occurring alkaloid that shows promise in antitumor activity in vitro against various tumor cell lines. Its potential clinical uses, however, are hindered by a lack of reaction selectivity and poor water solubility. Presented herein is a novel polyrotaxane (PR)‐based delivery system that could potentially lead to a highly effective yet less toxic CPT therapy. The approach involves the synthesis of the PR–CPT conjugates via hydrolyzable linkages. To enhance the therapeutic efficacy of CPT, a cell‐penetrating peptide, LMWP, is linked to the conjugate to allow specific, intratumoral delivery of CPT. To avoid nonselective uptake of the conjugates by normal tissues following administration, the cell‐penetrating function of LMWP on the conjugates is masked by heparin binding. This system was designed such that after accumulation at the tumor via the enhanced permeability and retention (EPR) effect, protamine can be subsequently administered to unmask heparin inhibition on LMWP, permitting intracellular uptake of the LMWP–PR–CPT conjugates. Once inside the tumor, CPT molecules are detached from the PR chain by hydrolysis, yielding a sustained concentration of CPT within tumor cells. In this paper, we demonstrated the in vitro feasibility of this delivery system. The LMWP–PR–CPT conjugates yielded a sevenfold increase in the overall CPT solubility, as well as a sustained release of CPT over a period of more than 7 days. Intracellular uptake of these conjugates by A2780 human ovarian cancer cells and regulation of such uptake by heparin and protamine were tested by MTT assay and confocal/flow cytometric methods, respectively. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Study on hemocompatibility and corrosion behavior of ion implanted TiNi shape memory alloy and Co‐based alloys
Authors: Liang Chenghao , Huang Naibao
Published: July 2007

Biomedical TiNi shape memory alloy and Co‐based alloys were ion implanted, and corrosion resistance and hemocompatibility of these had been investigated with electrochemical method, dynamic clotting time, and hemolysis rate tests. The results indicated that the electrochemical stability and anodic polarization behavior of the materials were improved significantly after ion implantation. When TiNi, Co‐based alloys were implanted Mo + C and Ti + C, respectively, the corrosion potentials were enhanced more than 200 mV, passive current densities decreased, and passive ranges were broadened. Dynamic clotting time of the ion implanted substances was prolonged and hemolysis rate decreased. All the results pointed out that corrosion resistance and hemocompatibility of the alloys were improved by ion implantation, and effects of dual implantation was better than that of C single implantation. X‐ray diffraction analysis of the alloys after dual implantation revealed that TiC, Mo2C, Mo9Ti4, and Mo appeared on the surface of TiNi alloy, and CoCx, Co3Ti, TiC, and TiO on the surface of Co‐based alloys. These phases dispersing on the alloy surface formed amorphous film, prevented dissolving of alloy elements and improved the corrosion resistance and hemocompatibility of the alloys. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Formulating the alginate–polyornithine biocapsule for prolonged stability: Evaluation of composition and manufacturing technique
Authors: Thanos C.G. , Calafiore R. , Basta G. , Bintz B.E. , Bell W.J. , Hudak J. , Vasconcellos A. , Schneider P. , Skinner S.J.M. , Geaney M. , Tan P. , Elliot R.B. , Tatnell M. , Escobar L. , Qian H. , Mathiowitz E. , Emerich D.F.
Published: July 2007

Alginate encapsulation is one of the most widely used techniques for introducing cell‐based therapeutics into the body. Numerous encapsulation methodologies exist, utilizing a variety of alginates, purification technologies, and unique polycationic membrane components. The stability of a conventional alginate formulation encapsulated using a commercially available technique and apparatus has been characterized extensively. The current study employs an encapsulation protocol and ultra‐pure alginate pioneered at the University of Perugia. The enhanced microcapsules were produced, characterized, and implanted into the brain, peritoneal cavity, and subcutaneous space of Long‐Evans rats. After 14, 28, 60, 90, 120, and 180 or 215 days, capsules were explanted and the surface was analyzed using Fourier‐transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Image analysis was carried out to measure changes in diameter and wall thickness. FTIR peak analysis and surface morphology from SEM indicated that the enhanced encapsulation technique and formulation produced a stable biocapsule capable of survival in all sites, including the harsh peritoneal environment, for at least 215 days. Preimplant analysis showed a marked increase in the structural integrity of the enhanced formulation with improved elasticity and burst strength compared with the baseline formulation, which remained stable for less than 60 days. The enhanced microcapsule composition showed advantages in physical strength and longevity, indicating that small changes in encapsulation methodologies and materials selection can dramatically impact the stability and longevity of alginate microcapsules and their contents. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
McLafferty rearrangement of the radical cations of butanal and 3‐fluorobutanal: A theoretical investigation of the concerted and stepwise mechanisms
Authors: Norberg Daniel , Salhi‐Benachenhou Nessima
Published: July 2007

The stepwise and concerted pathways for the McLafferty rearrangement of the radical cations of butanal (Bu+) and 3‐fluorobutanal (3F‐Bu+) are investigated with density functional theory (DFT) and ab initio methods in conjunction with the 6‐311+G(d,p) basis set. A concerted transition structure (TS) for Bu+, (H), is located with a Gibbs barrier height of 37.7 kcal/mol as computed with CCSD(T)//BHandHLYP. Three pathways for the stepwise rearrangement of Bu+ have been located, which are all found to involve different complexes. The barrier height for the Hγ transfer is found to be 2.2 kcal/mol, while the two most favorable TSs for the Cα–Cβ cleavage are located 8.9 and 9.2 kcal/mol higher. The energies of the 3F‐Bu+ system have been calculated with the promising hybrid meta‐GGA MPWKCIS1K functional of DFT. Interestingly, the fluorine substitution yields a barrier height of only 20.5 kcal/mol for the concerted TS, (3F‐H). A smaller computed dipole moment, 12.1 D, for (3F‐H) compared with 103.2 D for (H) might explain the stabilization of the substituted TS. The Hγ transfer, with a barrier height of 4.9 kcal/mol, is found to be rate‐determining for the stepwise McLafferty rearrangement of 3F‐Bu+, in contrast to the unsubstituted case. By inspection of the spin and charge distributions of the stationary points, it is noted that the bond cleavages in the concerted rearrangements are mainly of heterolytic nature, while those in the stepwise channels are found to be homolytic. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008
The MET receptor tyrosine kinase in invasion and metastasis
Authors: Benvenuti Silvia , Comoglio Paolo M.
Published: July 2007

Various cytokines and soluble growth factors upon interaction with their membrane receptors are responsible for inducing cellular proliferation, differentiation, movement, and protection from anoikis (a planned suicide activated by normal cells in absence of attachment to neighboring cells or extracellular matrix (EMC)). Among those soluble factors a major position is exerted by hepatocyte growth factor (HGF) together with its receptor MET and macrophage‐stimulating protein (MSP) in cooperation with its receptor RON. J. Cell. Physiol. 213: 316–325, 2007. © 2007 Wiley‐Liss, Inc.
Inhibition of the mitogenic, angiogenic and tumorigenic activities of pleiotrophin by a synthetic peptide corresponding to its C‐thrombospondin repeat‐I domain
Authors: Hamma‐Kourbali Yamina , Bernard‐Pierrot Isabelle , Heroult Mélanie , Dalle Sophie , Caruelle Danièle , Milhiet Pierre Emmanuel , Fernig David G. , Delbé Jean , Courty José
Published: July 2007

Pleiotrophin (PTN), is a heparin‐dependent growth factor involved in angiogenesis and tumor growth. PTN contains a thrombospondin repeat‐I (TSR‐I) motif in its two β‐sheet domains that are involved in its binding to heparin and its neurite outgrowth activity. Based on the importance of the binding of PTN to heparin in its dimerization and biological activities, we have designed two synthetic peptides, P(13–39) and P(65–97) corresponding to a part of the N‐terminal and C‐terminal TSR‐I motif of PTN, respectively. P(65–97) inhibited the mitogenic, tumorigenic and angiogenic activities of PTN, as well as the mitogenic and an angiogenic activity of fibroblast growth factor‐2 (FGF‐2). However, P(65–97) had no effect on the mitogenic activity of epidermal growth factor, which does not bind heparin. P(65–97) but not P(13–39) inhibited the binding of PTN and to a lesser extent of FGF‐2 to heparin using an immunoassay and an optical biosensor assay and bound directly to heparin with a Kd of 120 nM. These findings suggest that P(65–97), containing amino acids 65–97 of the TSR‐I motif of the C‐terminal domain of PTN, inhibits the activities of PTN and FGF‐2 by virtue of its ability to bind heparin very effectively and so compete with the growth factors for their polysaccharide co‐receptor. J. Cell. Physiol. 214:250–259, 2008. © 2007 Wiley‐Liss, Inc.
Effect of LED optical characteristics on temporal behavior of o‐cresol decomposition by UV/TiO2 process
Authors: Chen Hua‐Wei , Ku Young , Wu Chang‐Yen
Published: July 2007

BACKGROUND: An ultraviolet light‐emitting diode (UV‐LED) was used in this investigation as the light source for the photocatalytic decomposition of o‐cresol in aqueous solution because of its efficiency, design flexibility, and durability. The UV light intensities of the corn‐shaped LED tube designed in this investigation were relatively uniform due to the correct arrangement of LEDs.

RESULTS: For experiments conducted with initial o‐cresol concentrations of 9 mg L−1 and pH 3, more than 80% of o‐cresols were decomposed after 8 h of irradiation. The calculated photonic efficiency (about 1·06%) for experiments conducted with continuous illumination was much lower than those (1·69–6·27%) obtained with periodic illumination.

CONCLUSION: The proposed Langmuir–Hinshelwood kinetic model with modification of UV light intensity attenuation could be adequately applied to describe the temporal behavior of the o‐cresol decomposition in aqueous solution by the UV‐LED/TiO2 process. Copyright © 2007 Society of Chemical Industry
Bacterial magnetic particles (BMPs)‐PEI as a novel and efficient non‐viral gene delivery system
Authors: Xiang Li , Bin Wang , Huali Jin , Wei Jiang , Jiesheng Tian , Feng Guan , Ying Li
Published: July 2007

Background Non‐viral methods of gene delivery, especially using polyethylenimine (PEI), have been widely used in gene therapy or DNA vaccination. However, the PEI system has its own drawbacks, which limits its applications.

Methods We have developed a novel non‐viral delivery system based on PEI coated on the surface of bacterial magnetic nanoparticles (BMPs). The ability of BMPs‐PEI complexes to bind DNA was determined by retardation of plasmid DNA in agarose gel electrophoresis. The transfection efficiency of BMPs‐PEI/DNA complexes into eukaryotic cells was determined by flow cytometric analysis. The MTT assay was invited to investigate the cytotoxicity of BMPs‐PEI/DNA complexes. The expression efficiency in vivo of BMPs‐PEI bound to the plasmid pCMVβ encoding β‐galactosidase was evaluated intramuscularly inoculated into mice. The immune responses of in vivo delivery of BMPs‐PEI bound plasmid pcD‐VP1 were determined by MTT assay for T cell proliferation and ELISA for detecting total IgG antibodies.

Results BMPs‐PEI complexes could bind DNA and provide protection from DNase degradation. The transfection efficiency of BMPs‐PEI/DNA complexes was higher than that in PEI/DNA complexes. Interestingly, in contrast to PEI, the BMPs‐PEI complex was less cytotoxic to cells in vitro. We further demonstrated that the BMPs‐PEI system can deliver an exogenous gene to animals and allow it to be expressed in vivo. Such expression resulted in higher levels of humoral and cellular immune responses against the target antigen compared to controls.

Conclusions We have developed a novel BMPs‐PEI gene delivery system with a high transfection efficiency and low toxicity, which presents an attractive strategy for gene therapy and DNA vaccination. Copyright © 2007 John Wiley & Sons, Ltd.
Consistency between chemotyping of single filaments of Planktothrix rubescens (cyanobacteria) by MALDI‐TOF and the peptide patterns of strains determined by HPLC‐MS
Authors: Welker Martin , Erhard Marcel
Published: July 2007

The high metabolic diversity of potentially toxigenic cyanobacteria has been recently demonstrated for several bloom‐forming genera. To understand the dynamics of cyanobacterial blooms and fluctuations in toxin content, techniques are required that allow the distinction of clones in field samples on a subspecific taxonomic level. We evaluated the possibility to analyze single filaments of a common toxigenic taxon, Planktothrix rubescens, by comparing peptide profiles obtained from HPLC/MS analyses of bulk biomass to mass spectra of single filaments for 11 clonal strains. For all strains a significant relationship of chromatogram peak area to mass spectrum peak height was found for individual peptides. Individual peptide's response in mass spectrometry compared to HPLC, however, differed, likely attributable to the presence of particular moieties with high proton affinities in the molecules. Thirty‐four individual peptides detected in HPLC fractions of all strains could also be detected in the corresponding single filaments. In conclusion, MALDI‐TOF MS analysis of single filaments is shown to be an efficient tool for the study of chemotype diversity and dynamics in field studies and laboratory experiments. The good correspondence between peak area and peak height in chromatograms and mass spectra, respectively, is promising with respect to the use of MALDI‐TOF MS as a quantitative analytical tool for natural products studies and cyanotoxin research. Copyright © 2007 John Wiley & Sons, Ltd.
Raman spectroscopic and SEM analysis of sodium‐zippeite
Authors: Frost Ray L. , Čejka Jiří , Ayoko Godwin A. , Weier Matt L.
Published: July 2007

Raman at 298 and 77 K and infrared spectra of two samples of sodium‐zippeite were studied and interpreted. UO bond lengths in uranyl were calculated and compared with those inferred from the X‐ray single crystal structure data of a synthetic sodium‐zippeite analogue. Hydrogen‐bonding network in the studied samples is discussed. OH…O bond lengths were calculated and compared with those predicted from the X‐ray single crystal structure analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Raman spectroscopic analysis of breast cancer tissues: identifying differences between normal, invasive ductal carcinoma and ductal carcinoma in situ of the breast tissue
Authors: Rehman Shazza , Movasaghi Zanyar , Tucker Art T. , Joel Simon P. , Darr Jawwad A. , Ruban Alexander V. , Rehman Ihtesham U.
Published: July 2007

A relatively non‐destructive method employing Raman spectroscopy for the analysis of histopathological specimens is described. Raman spectroscopy has allowed qualitative analysis of the same specimen used for histopathological evaluation. Breast cancer tissues have been analysed to demonstrate the feasibility of the chemical changes taking place in the biological tissue, which can be identified precisely, and the results are reproducible.

Raman analysis of tissue sections provides distinct spectra that can be used to distinguish between the nuclear grades of ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) of the breast. Sixty cases of breast carcinoma including DCIS and IDC and seven cases of normal breast tissues were studied employing the Raman spectroscopic technique.

This study reports for the first time spectral differences between DCIS grades. It is concluded that Raman spectroscopy can objectively distinguish between DCIS and IDC grades and is non‐destructive and reproducible. It should become possible in future to use Raman spectroscopy as an informative and quantitative method suitable for classification of grades and diagnosis of breast carcinoma. Copyright © 2007 John Wiley & Sons, Ltd.
Raman spectroscopic study of calf thymus DNA: an effect of proton‐ and γ‐irradiation
Authors: Synytsya Alla , Alexa Petr , de Boer Jorrit , Loewe Markus , Moosburger Martin , Würkner Michael , Volka Karel
Published: July 2007

Raman spectroscopy was applied to analyse structural changes in calf thymus double‐stranded deoxyribonucleic acid (dsDNA) after proton‐ and γ‐irradiation (0.5, 5 and 50 Gy). Characteristic Raman bands of phosphodiester linkages, nucleic bases and deoxyribose moieties were sensitive to irradiation. A significant damage of the macromolecules was observed only at the highest dose (50 Gy) of both types of radiations. Spectral changes confirmed a radiation‐induced alteration of the native structure of dsDNA. Nucleic bases, especially pyrimidines, were the most sensitive to radiation, while some alterations in the sugar–phosphate backbone were also detected. The differences in the dose‐dependent effects of proton vs γ‐irradiation on studied biomolecule are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Self‐assembled silver nanoparticle monolayer on glassy carbon: an approach to SERS substrate
Authors: Chen Hongjun , Wang Yuling , Qu Jianying , Dong Shaojun
Published: July 2007

In this paper, the fabrication of an active surface‐enhanced Raman scattering (SERS) substrate by self‐assembled silver nanoparticles on a monolayer of 4‐aminophenyl‐group‐modified glassy carbon (GC) is reported. Silver nanoparticles are attached to the substrate through the electrostatic force between the negatively charged silver nanoparticles and the positively charged 4‐aminophenyl groups on GC. The active SERS substrate has been characterized by means of tapping‐mode atomic force microscopy (AFM), indicating that large quantities of silver nanoparticles are uniformly coated on the substrate. Rhodamine 6G (R6G) and p‐aminothiophenol (p‐ATP) are used as the probe molecules for SERS, resulting in high sensitivity to the SERS response, with the detection limit reaching as low as 10−9 M. This approach is easily controlled and reproducible, and more importantly, can extend the range of usable substrates to carbon‐based materials for SERS with high sensitivity. Copyright © 2007 John Wiley & Sons, Ltd.
Observation of the ν3 Raman band of S3− inserted into sodalite cages
Authors: Ledé B. , Demortier A. , Gobeltz‐Hautecœur N. , Lelieur J.‐P. , Picquenard E. , Duhayon C.
Published: July 2007

The S3− radical anion is observed in several systems: non‐aqueous polysulfides solutions, doped alkali halides, ultramarine pigments (UP) for which S3− is the blue chromophore and S2− is the yellow one and pigments of zeolite 4A structure. The S3− ion has C2V symmetry, and therefore its three vibrational modes should be observed in the Raman and in IR spectra. In resonance Raman spectroscopy, only the symmetric stretching mode ν1 and the bending mode ν2 have been observed, whereas the anti‐symmetric stretching mode ν3 has never been observed whatever the system. In this work, we confirm that ν3 is not observed in solutions with resonance Raman spectroscopy. However, our investigation of several blue UP, with various concentrations of S2−, shows that there is a superposition of two bands at ca 590 cm−1: the first is assigned to ν (S2−) and the second to ν3 (S3−). With the 457.9 nm excitation line, for which the resonance conditions are simultaneously fulfilled for S2− and S3−, the band at ca 590 cm−1 is the sum of the contributions of both ν (S2−) and ν3 (S3−) vibrations, while, with the 647.1 nm line, which only satisfies the resonance conditions of S3−, the band at ca 584 cm−1 must be assigned only to ν3 (S3−). Furthermore, ν3 (S3−) is observed in green UP and in pigments of zeolite structure. The ν3 vibration of S3−, which is observed neither in polysulfide solutions nor in doped alkali halides in resonance Raman conditions, can therefore be observed when this species is inserted into the β‐cages of the sodalite or of the zeolite 4A structures. So, the band at ca 590 cm−1 cannot always be assigned to S2− in these systems. This implies that the concentration of S2− in UP must be reconsidered. Copyright © 2007 John Wiley & Sons, Ltd.
Disruption of the developing female reproductive system by phytoestrogens: Genistein as an example
Authors: Jefferson Wendy N. , Padilla‐Banks Elizabeth , Newbold Retha R.
Published: July 2007

Studies in our laboratory have shown that exposure to genistein causes deleterious effects on the developing female reproductive system. Mice treated neonatally on days 1–5 by subcutaneous injection of genistein (0.5–50 mg/kg) exhibited altered ovarian differentiation leading to multioocyte follicles (MOFs) at 2 months of age. Ovarian function and estrous cyclicity were also disrupted by neonatal exposure to genistein with increasing severity observed over time. Reduced fertility was observed in mice treated with genistein (0.5, 5, or 25 mg/kg) and infertility was observed at 50 mg/kg. Mammary gland and behavioral endpoints were also affected by neonatal genistein treatment. Further, transgenerational effects were observed; female offspring obtained from breeding genistein treated females (25 mg/kg) to control males had increased MOFs. Thus, neonatal treatment with genistein at environmentally relevant doses caused adverse consequences on female development which is manifested in adulthood. Whether adverse effects occur in human infants exposed to soy‐based products such as soy infant formulas is unknown but the neonatal murine model may help address some of the current uncertainties since we have shown that many effects obtained from feeding genistin, the glycosolated form of genistein found in soy formula, are similar to those obtained from injecting genistein.
Perinatal exposure to environmental estrogens and the development of obesity
Authors: Newbold Retha R. , Padilla‐Banks Elizabeth , Snyder Ryan J. , Jefferson Wendy N.
Published: July 2007

Dietary substances and xenobiotic compounds with hormone‐like activity can disrupt the programming of endocrine signaling pathways that are established during perinatal differentiation. The consequences of this disruption may not be apparent until later in life but increasing evidence implicates developmental exposure to environmental hormone‐mimics with a growing list of adverse health effects including reproductive problems and increased cancer risks. Obesity has recently been proposed to be yet another adverse health consequence of exposure to endocrine disrupting substances during development. There is a renewed focus on identifying contributions of environmental factors to the development of obesity since it is reaching worldwide epidemic proportions, and this disease has the potential to overwhelm healthcare systems with associated illnesses such as diabetes and cardiovascular disease. Here, we review the literature that proposes an association of perinatal exposure to endocrine disrupting chemicals, in particular those with estrogenic activity, with the development of obesity later in life. We further describe an animal model of developmental exposure to diethylstilbestrol (DES) to study mechanisms involved in programming for obesity. Our experimental data support the idea that adipocytes and the mechanisms involved in weight homeostasis are novel targets of abnormal programming of environmental estrogens, some of which are found in our foods as naturally occurring substances or inadvertently as contaminants.
Women get the answers
Authors: Lindenmayer Blanche S.
Published: July 2007

Grinnell, lowa, group gets many testimonials on manager plan from officials, editors, others to sell own city.
A combined state and state estimate feedback solution to the ship positioning control problem
Authors: Grimble M. J.
Published: July 2007

A stochastic linear quadratic optimal control problem is considered in which some of the plant states may be measured without a measurement noise component. This set of states are assumed to be associated with the plant inputs and force transducers. The optimal controller is shown to include state feedback from this part of the system. The states which cannot be measured are assumed to be combined in noisy output signal. The optimal controller corresponding to this second subsystem is shown to include a Kalman filter and state‐estimate feedback.

The combination of state and state‐estimate feedback has the advantage that the dimension of the Kalman filter is equal to that of the second subsystem mentioned above. In the conventional solution to this problem, no states are assumed measurable, and the dimension of the Kalman filter is equal to the dimension of the complete system. In many industrial control problems, the combined control law enables a significant reduction in the dimension of the filter to be achieved. The technique has been proposed for use in dynamic ship positioning control systems, and this problem is discussed.
The geometry of the barrier in the ‘game of two cars’
Authors: Pachter Meir , Getz Wayne M.
Published: July 2007

A complete open barrier surface is constructed in the ‘Game of two cars’ differential game of kind with a circular target set. Our geometric approach has the advantages, among others, that it yields the explicit barrier termination conditions and that it highlights the geometric meaning of the universal and dispersal curves on the barrier.
The game of two elliptical ships
Authors: Miloh T.
Published: July 2007

Isaacs' formulation of the game of two cars, which assumes players of circular shape, is extended to include the effect of elongated players and elliptical shapes in particular. The geometry is used to model the problem of ship‐collision avoidance as a differential game which suggests the name of ‘game of two ships’. The game of two ships is formulated as a free‐time unbounded game of kind. A general solution for the optimal controls on the terminal manifold is given and is also used to derive a model analytical solution for the primary optimal path emanating from the target set. The occurrence of singular arcs as well as the condition for switching are also discussed. Finally, a capture criterion for the pursuit‐evasion game between a faster elliptical pursuer and a more manoeuvrable circular evader is also derived. This capture criterion is given in the form of a relationship between the geometrical dimensions of the players, their speed and acceleration ratios, and the maximum range that the manoeuvrable, yet slower, evader can indefinitely guarantee without being captured. If both players have circular shapes, our solution reduces to an already‐known capture criterion for the ‘game of two cars’.
Robust and well‐conditioned eigenstructure assignment via sylvester's equation
Authors: Iii R. K. Cavin , Bhattacharyya S. P.
Published: July 2007

An algorithmic solution is given for the problem of calculating a pole assignment matrix F that makes the eigenvector matrix of A + BF well‐conditioned with respect to inversion, or equivalently, maximally orthonormal. This causes A + BF to have low eigenvalue sensitivity. The algorithm relies on a solution of Sylvester's equation and does not involve co‐ordinate transformations or canonical forms. These results are steps in the direction of transforming pole assignment theory into an effective design tool for control systems.
Optimal non‐linear feedback regulation of spacecraft angular momentum
Authors: Salehi S. V. , Ryan E. P.
Published: July 2007

Optimal non‐linear feedback laws are presented for the regulation of spacecraft angular momentum by using flywheels and by using fixed on‐off reaction jets. The control law for the flywheels takes the form of a linear combination of functions of the state, each positively homogeneous of degree 2p‐1 (p1/2); whereas the control law for the reaction jets is of bang‐bang form. The range (of the initial disturbance) over which the flywheels are capable of regulating the system and the problem of momentum dumping are also discussed with regard to flywheel saturation constraints. Finally, a control scheme combining the merits of reaction jets and flywheels is proposed.
Stabilizing optimal control of bilinear systems with a generalized cost
Authors: Tzafestas S. G. , Anagnostou K. E. , Pimenides T. G.
Published: July 2007

Stabilizing and optimizing feedback control policies are derived for the important class of bilinear systems with generalized quadratric cost functions. These policies as well as the resulting optimal costs are quadratic in the state. The optimal cost function is shown to be a Lyapunov function for the bilinear system at hand. The resulting optimal and stabilized closed‐loop system is of third order with respect to the state. One illustrative example is included.
Optimal control problems with differential inclusions: Sufficiency conditions and an application to a production‐inventory model
Authors: Hartl Richard F. , Sethi Suresh P.
Published: July 2007

In this paper we derive useful sufficiency optimality conditions for a class of optimal control problems subject to differential inclusions and involving non‐differentiable functions. A production‐inventory problem is solved to illustrate our results.
A decoupling pole placement self‐tuning controller for a class of multivariable processes
Authors: McDermott P. E. , Mellichamp D. A.
Published: July 2007

This paper describes a new multivariable self‐tuning controller that specifically handles different time delays between each of the input‐output pairs (multiple delays), and deals with unknown or varying time delay (variable dead time compensation) without requiring an explicit estimate of each delay. The new algorithm can control unstable and/or non‐minimum phase processes; it eliminates both set‐point and load offsets without having to maintain integral action continuously; it decouples the loops, both dynamically and at steady state. The effective decoupling algorithm not only minimizes significant interactions among the control loops, it permits the use of a very simple design criterion, namely the approximate assignment of the primary closed‐loop poles to prespecified locations. A straightforward autotuning technique locates the closed‐loop poles on‐line so as to optimize the system set‐point step responses. One desirable side‐effect is to account for inexact decoupling.

The controller is demonstrated using a simulated paper machine head box having an unusually large amount of (off‐diagonal) interaction, a simulated two‐input, two‐output distillation column with time‐varying parameters (varying gains and time delays), and a highly interacting unstable and non‐minimum phase system on which the autotuning technique is demonstrated. These three processes place stringent requirements on any control method, and two of them have been used extensively in the literature to test various multivariable and/or self‐tuning algorithms. Hence, the success of the new technique indicates that it is a very promising candidate to deal with intransigent processes, i.e. those characterized as unstable, non‐minimum phase, time‐varying (non‐linear), and interacting.
A simplified algorithm for optimization of large‐scale gas networks
Authors: Osiadacz A. J. , Bell D. J.
Published: July 2007

A number of sophisticated algorithms exist for the optimization of large‐scale systems. However, from a practical viewpoint one must always balance the cost of such optimization in applications with the saving that results. This paper presents a simplified algorithm for large‐scale gas networks which, although yielding a suboptimal energy saving, is nevertheless simple to apply and demands only moderate back‐up facilities. To illustrate the proposed method an example is chosen in which there are fifty nodes and three compressors.
Optimal control problems with multiple goal objectives
Authors: Levary Reuven R.
Published: July 2007

Solution procedures for optimal control problems having multiple objectives are developed by using the concepts of goal programming. The solutions to optimal control problems having conflicting objectives and multidimensional decision criteria are in the form of a set of optimum levels of achievement of some target goals.
Real‐time computation of feedback controls for constrained optimal control problems. part 2: A correction method based on multiple shooting
Authors: Pesch Hans Josef
Published: July 2007

On the basis of Part 1 of this paper, a numerical method is developed for the real‐time computation of neighbouring optimal feedback controls for constrained optimal control problems. We use the idea of multiple shooting to develop a numerical method which has the following properties:

1. The method is applicable to optimal control problems with constraints (differential equations, boundary conditions, inequality constraints, problems with discontinuities, etc.).

2. The control variables and the switching points are computed for the remaining time interval of the process.

3. All constraints are checked.

4. The method is appropriate for real‐time computations on onboard computers of space vehicles.

5. The scheme is robust in that controllable deviations from a precalculated flight path are much larger than deviations typical for perturbations occuring in space vehicles.

The re‐entry of a space vehicle is investigated as an example. One problem contains a control variable inequality constraint with a large variety of different switching structures, including problems with a corner. A second problem contains a state variable inequality constraint with one or two boundary points or one boundary arc. The different switching structures depend on the tightness of the constraints.
Robust approximate non‐interacting control design for a class of non‐linear stochastic systems
Authors: Bamani Ali H. , Iskanderani Ahmed I.
Published: July 2007

A technique for the approximate decoupling of a class of non‐linear stochastic systems which has parameter variation in the plant is presented. First, nominal decoupling is obtained. Then a sensitivity model representing the plant variation is formulated and incorporated into a performance index. Minimization of this index with respect to the free parameters in the feedback matrix results in a robust feedback controller which can reduce the effect of noise and perturbations on the output. An example demonstrating the feasibility of the approach for practical problems is presented.
Minimum‐time turn trajectories to fly‐to points
Authors: Clements John C.
Published: July 2007

The existence of a (global) optimal control u* is established which ensures the execution of a constant‐altitude, minimum‐time flight trajectory to a specified fly‐to point, given the aircraft maximum performance turn radius and the wind speed W and direction tHw. Fast, accurate numerical procedures based on elementary geometry and the solution of a fixed‐point equation are derived for the calculation of u* and the associated optimal trajectory (x*, y*). An example is given and the application of these results to the real‐time solution of the case where the aircraft roll rate is also incorporated into the flight dynamics is discussed.
Eigenstructure assignment with control gains optimization
Authors: Zhang Qiang , Slater G. L.
Published: July 2007

Eigenstructure assignment using output feedback is reformulated using an auxiliary principle of minimization of control effort. In the general eigenstructure assignment procedure, the feedback gain matrix is uniquely determined for a set of explicitly specified desired eigenvalues and eigenvectors. However, for the controller design proposed in this paper, only the most necessary constraints are imposed on the desired eigenvalues and eigenvectors, and the unspecified model parameters of the closed‐loop system are determined by minimizing the control effort. Numerical examples are presented for comparison of the proposed method with standard eigenstructure assignment methods, and an experimental example gives an insight into the feasibility of the proposed control algorithm with application to the vibration control of flexible structures undergoing forced vibration.
Discrete computer control of a triple‐inverted pendulum
Authors: Meier Farwig H. Zu , Unbehauen H.
Published: July 2007

Stabilization of a triple‐inverted pendulum is studied in this paper. The overall control structure is based on a state space approach and employs the computer‐aided design package ‘KEDDC’. The complete set of state variables needed for state feedback are provided by a reduced‐order observer. Theoretical analysis, supported by successful experimental results, shows that our stabilization objective can be achieved by measuring the angles of the three arms of the pendulum as well as the position and velocity of the supporting cart.
Shape optimization analysis: First‐ and second‐order necessary conditions
Authors: Cabuk H. , Modi V.
Published: July 2007

In this paper, first‐ and second‐order necessary conditions for optimality are studied for a domain optimization problem. The optimization problem considered is the minimization of an objective function defined on the domain boundary through the solution of a boundary value problem. In order to derive the first and second variations of the objective function due to boundary variation, the first and second variations of the solution of the boundary value problem are calculated using a perturbation technique. An iterative shape optimization algorithm for potential flow problems in R2 with Dirichlet boundary conditions is presented. In the algorithm a boundary element method (BEM) is employed to solve the Laplace equation numerically. The validity and accuracy of the algorithm have been verified on a problem where the final solution is known. Finally, the problem of designing a 90° bend for two‐dimensional potential flow is solved.
Adaptive root‐locus control for siso processes with time delays
Authors: Wang Feng‐Sheng
Published: July 2007

Two adaptive root‐locus control schemes for processes with time delays have been developed. The control design methodologies are based on classical feedback control and Smith predictor structures with simple pole placement. The overall behaviour of both control systems is adapted along the root loci of the system in each control horizon. Since the Smith predictor structure includes time delay compensation, the tuning gain can be enlarged to improve the performance of the control system. The optimal tuning gain is repeatedly updated by an optimization technique when the estimated model is confirmed. A comparison with simplified model predictive control (SMPC) is also given. SMPC in SISO systems is a special case of the proposed control laws.
Relationship between åström control and the kalman linear regulator—caines revisited
Authors: Warwick Kevin
Published: July 2007

The relationship between minimum variance and minimum expected quadratic loss feedback controllers for linear univariate discrete‐time stochastic systems is reviewed by taking the approach used by Caines. It is shown how the two methods can be regarded as providing identical control actions as long as a noise‐free measurement state‐space model is employed.
A simple way to stabilize discrete systems with jump markov parameters
Authors: Yaz Engin
Published: July 2007

A new control method is proposed to stabilize, in the exponential mean‐square sense, linear discrete‐time systems with discrete‐time, discrete‐state jump Markov parameters. This method offers a substantial computational advantage in that it requires only finite‐time solutions of Riccati‐like equations to achieve stabilization.
A comparison of some robust eigenvalue assignment techniques
Authors: Burrows Simon P. , Patton Ron J.
Published: July 2007

Three techniques for robust eigenvalue assignment are presented. The first is well known and is based on iteratively assigning the closed‐loop eigenvectors so as to be maximally orthogonal to one another. The second has been recently presented by the authors and is an improvement of the first which gives better results for problems where complex‐conjugate eigenvalue pairs are to be assigned. The final method is new and is founded on the iterative replacement of the current closed‐loop eigenvector matrix with a new matrix which is the projection of the columns of the nearest orthogonal matrix into the allowable eigenvector subspaces. Some numerical examples are given which are used to illustrate the improved results obtained using the second technique in place of the first and to compare these with the performance of the last algorithm which is based on an alternative approach.
A turnpike improvement algorithm for piecewise deterministic control
Authors: Boukas K. , Haurie A. , van Delft Ch.
Published: July 2007

This paper proposes a numerical technique, called turnpike improvement, for the approximation of the solution of a class of piecewise deterministic control problems typically associated with manufacturing flow control models. This algorithm exploits the structure of Markov decision processes with continuous state and action spaces that can be associated with piecewise deterministic control systems. The numerical method is applicable whenever a turnpike property holds for some associated infinite horizon deterministic control problem. To illustrate the approach, we use a simple model fully studied from an analytic point of view in the literature. We compare the turnpike improvement technique with a direct approximation of the solution of the continuous‐time Hamilton‐Jacobi dynamic programming equations inspired by Kushner's work. The two approaches agree remarkably on this simple problem. We conclude with a discussion of the relative advantages of the two approaches.
Optimal digital redesign of cascaded analogue controllers
Authors: Shieh L. S. , Decrocq B. B. , Zhang J. L.
Published: July 2007

This paper presents a new, optimal digital redesign technique for finding an optimal cascaded digital controller from the given continuous‐time counterpart by minimizing a quadratic performance index. The control gains can be obtained by solving a set of Lyapunov equations. The developed optimal cascaded digital controller enables the state and/or outputs of the digitally controlled closed‐loop sampled‐data system to optimally match those of the original continuous‐time closed‐loop system at any instant between sampling periods. The developed control law can be implemented using inexpensive and reliable digital electronics with a relatively long sampling period.
Solving robot trajectory planning problems with uniform cubic B‐splines
Authors: Chen Yao‐Chon
Published: July 2007

Uniform cubic B‐splines are applied to solve the optimal trajectory planning problem for robotic manipulators. It is first shown that the trajectory planning problem can be formulated as an optimal control problem with state and control constraints. The resulting optimal control problem is then solved numerically.
A global cartesian space obstacle avoidance scheme for redundant manipulators
Authors: Khadem Siamak E. , Dubey Rajiv V.
Published: July 2007

Optimal control of kinematically redundant manipulators involves the use of extra degrees of freedom to improve their performance by energy minimization, singularity avoidance, obstacle avoidance, higher dexterity, etc. In this paper we deal with the obstacle avoidance problem by using modern control theory and choosing an integral‐type performance index which results in a global optimization scheme. Obstacles are expressed as Cartesian space constraints. The state constraint function and control effort are minimized globally as a performance index. The control effort which maximizes the Hamiltonian and minimizes the performance index is used to find the self‐motion of the manipulator. A simulation for a three‐degrees‐of‐freedom redundant planar robot is presented to demonstrate the effectiveness of the scheme.