bluuebunny/crossref_metadata_2025 huggingface dataset:
Fortification of Shrimp Shell Flour as a Source of Calcium on the Preference Level of Bread
Authors: Rizkiyanda Hafidz , Liviawaty Evi , Rostini Iis , Pratama Rusky Intan
Published: February 2024

This research aim was to find the most preferred percentage of shrimp shell flour fortification on white bread. This research used an experimental method with 20 semi-trained panelists and 5 treatments of shrimp shell flour percentages which were 0%; 2,5%; 5%; 7,5%; and 10%. The parameters in this research were yield of shrimp shells, bread volume development, and calcium content which were analyzed with a comparative descriptive method; and preference level which was analyzed using the Friedman test. Fisheries Product Processing Laboratory, Faculty of Fisheries and Marine Science and Test Service Laboratory, Faculty of Agro-Industrial Technology, Padjadjaran University, between January and June 2023. Yield and volume development were tested by the ratio of the mass of shrimp shells flour and shrimp shells (yield test) and dough volume and white bread loaf (volume development test) times 100%. The Preference test used an organoleptic test with each panelist being given a test sheet to test 5 treatments of white bread fortified with shrimp shell flour and to test their preference level on 4 characteristics; which were color, aroma, texture, and taste. Calcium content was tested using the atomic absorption spectrophotometer method on the control treatment (0%) and the most preferred treatment. Yield result from shrimp shell flour was 27.8% (139 gr) from its initial mass (500 gr). Volume development of white bread showed decreases in volume with each treatment from 136.433% to 111.504%. The most preferred fortification of shrimp shell flour on white bread was treatment 2.5% with an alternative value of 7.22 and characteristic value of color 9, aroma 7, taste 7, and texture 7, which means overall still preferred. The calcium content within treatment 2.5% was 30.095 mg/100gr which is significantly higher than the calcium of treatment 0% (1.465 mg/100gr) and could assist humans meet their calcium needs.
Effect of Microclimate Modification on Growth and Yield of Basmati Rice under Punjab Conditions
Authors: Anand Shubham , Dhaliwal L. K.
Published: February 2024

The field experiments were conducted at the Research Farm, Department of Climate Change and Agricultural Meteorology, Punjab Agricultural University, Ludhiana during kharif 2018. Pusa Basmati variety was transplanted on 5th July (D1) and 15th July (D2) under three spacing (25 cm x12 cm, 20 cm x 15 cm and 30 cm x 10 cm). The micrometeorological data on photosynthetically active radiation (PAR) was recorded at different phenological stages. The periodic biometric observations on leaf area index were recorded. Growing degree days (GDD) were calculated at different phenological stages. The results indicate that PAR interception and leaf area index was higher under wider spacing (30 cm x 10 cm) followed by closer spacing (20 cm x 15 cm and 25 cm x 12 cm). The leaf area index was higher under wider spacing (30 cm x 10 cm) followed by closer spacing (20 cm x 15 cm and 25 cm x 12 cm). Correlation coefficients were worked out between periodic number of tillers of rice and temperature (maximum and minimum) and sunshine hours/day. In both dates of transplanting, maximum temperature showed a significant negative correlation with tiller number in most of the cases. The sunshine hours in both dates of transplanting showed a positive and significant correlation under different treatments. The first date of transplanting reported higher grain yield (30.61 q/ha) as compared to second date of transplanting (27.20 q/ha). The higher grain yield (30.57 q/ha) was recorded in basmati rice transplanted under wider spacing (30 cm x 10 cm) in comparison to closer spacing of 20 cm x 15 cm (29.25 q/ha) and 25 cm x 12 cm (26.89 q/ ha). Hence, microclimate modification through dates of transplanting and spacing is cost effective measure for increasing basmati rice yield.
Assessing the Productivity of Forage Based Cropping System under Different Farming Practices in the Western Himalayan Region
Authors: Narwal Kunal , Sharma Gurbhan D. , Kumar Naveen , Sankhyan Narender Kumar , Manuja Sandeep , Rana Bharat Bhushan , Hetta Gaytri
Published: February 2024

A field experiment was conducted at CSK Himachal Pradesh, Krishi Vishwavidyalaya Palampur, Department of Organic Agriculture and Natural Farming, College of Agriculture, during 2019-20 to study the effect of conventional, organic and natural farming practices on growth and yield of fodder oat. The experiment was laid out in split plot design with three replications with comprising of 5 farming practices (F0: Absolute control, F1: Organic farming package of practices, F2: Natural farming package of practices (SPNF), F3: 10 t FYM + Natural farming package of practices (SPNF), F4: Recommended fertilizer dose and 3 cropping system (CS1: Oat, CS2: Oat + Fodder Sarson, CS3: Oat + Berseem). The results concluded that, among the farming practices, higher number of shoots per meter square, dry matter accumulation, green fodder yield and dry fodder yield was recorded with recommended dose of fertilizer followed by 10 t FYM + natural farming package of practices (SPNF). In case of cropping systems, significantly higher number of shoots per square meter, dry matter accumulation, green and dry fodder yield was observed with oat + berseem cropping system as compared to oat alone.
Correlation, Heritability and Genetic Advance Analysis of Rice (Oriza sativa L.) Genotypes
Authors: Kumar Sunil , Vimal S. C. , Singh Jay , Gupta Mohit , Katiyar Dheeraj , Sharma Saurabh , Dubey Ravisankar , Verma Anuj Kumar
Published: February 2024

The present investigation was conducted at Seed Testing Laboratory of Seed Technology Section, Acharya Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya (U.P.). The study was based on the germplasm evaluation of 45 germplasm including three checks viz., NDR-2065, BPT 5204 and Sambha sub1. The high estimates (> 40 %) of phenotypic (PCV) and genotypic (GCV) coefficients of variation was registered in case of shoot length (PCV=18.1129 %, GCV=17.1129 %).  The magnitude of heritability in broad sense varied between 0.7947 per cent in case of seedling length to 0.9567 per cent in case of vigour index-I. The high estimates of h2 (>0.8564) were noted for vigour index-I (0.9567) followed by root length (0.8845), speed of germination (0.8749), seed weight (0.8596). Vigour index-I noticed highly significant and positive correlation with shoot length (0.454), root length (0.419), seedling dry weight (0.333), germination per cent (0.319), seed weight (0.315), seedling length (0.312), seed width (0.308), root length (0.292), speed of germination (0.281) and L/B ratio (0.216).
Simultaneous input and parameter estimation with input observers and set‐membership parameter bounding: theory and an automotive application
Authors: Kolmanovsky I. , Sivergina I. , Sun J.
Published: March 2006

The paper addresses an on‐line, simultaneous input and parameter estimation problem for a first‐order system affected by measurement noise. This problem is motivated by practical applications in the area of engine control. Our approach combines an input observer for the unknown input with a set‐membership algorithm to estimate the parameter. The set‐membership algorithm takes advantage ofa prioriavailable information such as (i) known bounds on the unknown input, measurement noise and time rate of change of the unknown input; (ii) the form of the input observer in which the unknown parameter affects only the observer output; and (iii) the input observer error bounds for the case when the parameter is known exactly. The asymptotic properties of the algorithm as the observer gain increases are delineated. It is shown that for accurate estimation the unknown input needs to approach the known bounds a sufficient number of times (these time instants need not be known). Powertrain control applications are discussed and a simulation example based on application to engine control is reported. A generalization of the basic ideas to higher order systems is also elaborated. Copyright © 2006 John Wiley & Sons, Ltd.
Urban Remote Sensing: Global Comparisons
Authors: Small Christopher
Published: March 2006

Over three decades of satellite remote sensing has supplied a rich, largely untapped archive for urban designers and thinkers. Existing and concurrent images have the potential to allow us not only to trace through multitemporal observations of urban agglomerations, but also to predict emerging urban trends. Christopher Small of the Lamont‐Doherty Earth Observatory of Columbia University provides some essential insights into the applications of remote‐sensing technology, while also outlining its capabilities and limitations. Copyright © 2005 John Wiley & Sons, Ltd.
Urban Field Guide Baltimore, Maryland
Authors: Svendsen Erika , Marshall Victoria , Ufer Manolo F
Published: March 2006

A changing economy and different lifestyles have altered the meaning of the forest in the Northeastern United States, prompting scientists to reconsider the spatial form, stewardship and function of the urban forest. Erika Svendsen, Victoria Marshall and Manolo F Ufer describe how social observation techniques and the employment of a novel, locally based, participatory hand‐held monitoring system could aid the exposure of more positive socially orientated patterns of land use. Copyright © 2005 John Wiley & Sons, Ltd.
Urban Simulacra: London
Authors: Batty Michael , Hudson‐Smith Andrew
Published: March 2006

As the digital revolution deepens and pervades every aspect of daily life, virtual realities begin to penetrate one another in a multiplicity of ways. The amount of sensing data being compiled on the city grows, enabling the construction of virtual realities that can, in turn, be transformed for diverse purposes. Here, Michael Batty and Andrew Hudson‐Smith from the Centre for Advanced Spatial Analysis, University College London, outline how they went about the construction of a virtual city in central London. A conventional 3‐D‐GIS/CAD model was used as the basis on which to build a digital realm in which designers are cast as avatars and populations as agents, so as to define new ways in which to understand and plan the city. Copyright © 2005 John Wiley & Sons, Ltd.
The 21st‐Century Welfare City: Aalborg + Copenhagen, Denmark
Authors: Kiib Hans , Marling Gitte
Published: March 2006

Under the scientific eye of satellite surveillance, the world's urban conglomerations often appear heterogeneous. On the ground, differences and special features of a city remain of utmost importance to the quality of life of its citizens. Hans Kiib and Gitte Marling assess how the welfare system in Denmark, which is so dear to many Danes, is holding up. If the physical, Modernist urban model of the welfare city is to endure, can it withstand the irresistible, less tangible pull of consumption and aspirational individualised lifestyles that are penetrating the globe worldwide? Copyright © 2005 John Wiley & Sons, Ltd.
With Satellites: Dubai + India
Authors: Easterling Keller
Published: March 2006

By juxtaposing the histories of satellite transmission and remote sensing in India and Dubai, Keller Easterling unpacks the notion of the unified global village. Rather than a true internationalism, she reveals a complex picture of commercial and political alliances and networks that operate between national jurisdictions. Copyright © 2005 John Wiley & Sons, Ltd.
Cochin, India: Notes from a Nerve of the World
Authors: Joseph May
Published: March 2006

May Joseph draws a poetic portrait of Cochin, in southern India, a contemporary city overlaid with history and successive migrations. Old and new collide with the local and regional pulls of cultures and peoples, the diaspora being further heightened by the possibilities of telecommunications matrixes and media transmission. Copyright © 2005 John Wiley & Sons, Ltd.
National Security Sprawl: Washington DC
Authors: Natsios Deborah
Published: March 2006

Battlements and fortifications are most often associated with the historic cities of the Old World. Here, Deborah Natsios gives an account of the physical and virtual transformations that have affected Greater Washington DC since 9/11. Copyright © 2005 John Wiley & Sons, Ltd.
Just‐in‐Time Planning: New York + Houston
Authors: Kwartler Michael
Published: March 2006

Michael Kwartler counters the rigid determinism of urban planning policy with a just‐in‐time approach. He describes a new planning, design and regulatory model that harnesses information technologies, such as geographic information systems (GIS) and emerging planning and design‐decision support (PDDS), which ‘learn’ from experience and provide the means to be self‐organising and adjusting, responding to rather than anticipating or even trying to direct change. Copyright © 2005 John Wiley & Sons, Ltd.
The Boutique Apartment
Authors: Kellogg Craig
Published: March 2006

In New York, the gap between living lofts and boutique hotels is being eclipsed. The organisation of rooms in new apartment blocks is becoming complicated. Craig Kellogg reveals how a brave new world of designer floor plans has begun to introduce a welcome complexity. Copyright © 2005 John Wiley & Sons, Ltd.
Albion Wharf
Authors: Archer Stephen
Published: March 2006

The conspicuous glazed volume, which houses the luxury private flats of Foster and Partners' Albion Riverside, have become a prominent landmark on the River Thames, in full view from London's Chelsea Embankment. Stephen Archer describes how this signature building contrasts with, and is reinforced by, a new block of affordable housing, also by Fosters, for the Peabody Trust. Copyright © 2005 John Wiley & Sons, Ltd.
Piercy Conner
Authors: Bullivant Lucy
Published: March 2006

Piercy Conner first came to broader public attention with its prototype for the Microflat. Displayed in the windows of Selfridges on London's Oxford Street, it ignited discussions in the press about means of realising affordable urban housing. Lucy Bullivant describes this young practice's enduring commitment to high‐density public‐housing solutions and the work it has undertaken in communication techniques. Copyright © 2005 John Wiley & Sons, Ltd.
The Peace Hotel
Authors: Denison Edward
Published: March 2006

Edward Denison recounts the story of one of Shanghai's modern landmarks, the Sassoon House, now known as the Peace Hotel, which has come to represent the city's early 20th‐century heyday. Copyright © 2005 John Wiley & Sons, Ltd.
Structural and Electrostatic Complexity at a Pentacene/Insulator Interface
Authors: Puntambekar K. , Dong J. , Haugstad G. , Frisbie C. D.
Published: March 2006

The properties of organic‐semiconductor/insulator (O/I) interfaces are critically important to the operation of organic thin‐film transistors (OTFTs) currently being developed for printed flexible electronics. Here we report striking observations of structural defects and correlated electrostatic‐potential variations at the interface between the benchmark organic semiconductor pentacene and a common insulator, silicon dioxide. Using an unconventional mode of lateral force microscopy, we generate high‐contrast images of the grain‐boundary (GB) network in the first pentacene monolayer. Concurrent imaging by Kelvin probe force microscopy reveals localized surface‐potential wells at the GBs, indicating that GBs will serve as charge‐carrier (hole) traps. Scanning probe microscopy and chemical etching also demonstrate that slightly thicker pentacene films have domains with high line‐dislocation densities. These domains produce significant changes in surface potential across the film. The correlation of structural and electrostatic complexity at O/I interfaces has important implications for understanding electrical transport in OTFTs and for defining strategies to improve device performance.
Effect of processing conditions on compatibility of nylon 6/polystyrene blend
Authors: Choi Jin‐Hwan , Kim Ho‐Gyum , Han Dong‐Hee , Lim Jeong‐Cheol , Oh Dae‐Hee , Min Kyung‐Eun
Published: March 2006

The morphology of nylon 6 and polystyrene (PS) blend with styrene‐maleic anhydride copolymer (SMA) as a compatibilizing agent was studied. The long‐time mixing of blends exhibited slight decrease in storage modulus and larger domain size. This may be caused by imidization between amine end‐group of nylon 6, and SMA produce the water, which hydrolyzes an amide group of nylon 6 and results in the decrease of viscosity. As the morphology change in blend influence on physical properties, it is found that modification of nylon 6 by SMA has a better morphology and good physical properties with shorter mixing time. However, the morphology investigation in nylon 6/PS blends reveals that the effect of mixing time was negligibly small. Addition of small amount of SMA into nylon 6/PS blend has proved to give improvement in physical properties. This behavior is based on the concentration of water derived from imidization. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1–7, 2006
Classical cationic polymerization of styrene in a spinning disc reactor using silica‐supported BF3 catalyst
Authors: Boodhoo Kamelia V. K. , Dunk William A. E. , Vicevic Marija , Jachuck Roshan J. , Sage Valerie , Macquarrie Duncan J. , Clark James H.
Published: March 2006

The carbo‐cationic polymerization of styrene has been studied in a Spinning Disc Reactor (SDR) and the results were compared to those observed in a conventional Stirred Tank Reactor (STR). Addition of styrene to a slurry of silica‐supported boron trifluoride (BF3/SiO2) in 1,2‐dichloroethane led to uncontrollable reactions in the STR at monomer concentrations > 25%w/w and initial temperatures of 20–25°C. By comparison, monomer concentrations of 75% w/w were safely and controllably polymerized in the SDR at 40°C to yield polymers with molecular weights comparable to those reported in the literature for polymer prepared at −60°C. Exceptional heat transfer rates achieved in the SDR are sufficient to deal with the heat evolved when styrene is polymerized at concentrations as high as 75% w/w, the reaction proceeding under essentially isothermal conditions. In the present study, the effects of monomer/solvent feed rates, monomer concentrations, disc size, and disc speed on monomer conversions, polymer molecular weights, and polydispersities achieved in the SDR are investigated. Speculative explanations of the observed results are presented in terms of enhanced mixing effects on the polymerization mechanisms in the SDR. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 8–19, 2006
Study on blooming of tetrabromobisphenol a bis(2,3‐dibromopropyl ether) in blends with polypropylene
Authors: Li Xiang‐Mei , Yang Rong‐Jie
Published: March 2006

Blends of polypropylene/tetrabromobisphenol A bis(2,3‐dibromopropyl ether) (PP/TBAB) were prepared by twin‐screw extruder, and then were molded into PP/TBAB plaques. Blooming of TBAB on the surface of PP/TBAB plaques were studied through heat aging test and theoretical calculation. The heat aging test at 70°C for 45 days was performed. Mass of the blooming TBAB on the surface of the plaque was measured every day in the period. Based on Fick's second law of diffusion, a mathematical method was developed to achieve concentration profile of TBAB dependent on time in the PP/TBAB plaques. Diffusion coefficients of TBAB were calculated by using the set concentration equation of TBAB with the experimental data. It was obtained that the diffusion coefficient of TBAB in PP/18 wt % TBAB is larger than that in PP/45 wt % TBAB. For the sample of PP/18 wt % TBAB, diffusion of TBAB reached an equilibrium after the heat aging for 40 days at 70°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 20–24, 2006
Vulcanization kinetic of styrene–butadiene rubber by sulfur/TBBS
Authors: Marzocca A. J. , Mansilla M. A.
Published: March 2006

Torque curves, measured with a moving die rheometer at temperatures between 413 and 473 K, were used to characterize the vulcanization of styrene–butadiene rubber with different cure systems based on sulfur and TBBS (N‐t‐butyl‐2‐benzothiazole sulfenamide). Several compounds were prepared varying the amount of sulfur and accelerator between 0.5 and 2.5 phr in the formulation. By means of normalized torque curves, the kinetic of cure of these samples was evaluated considering the model of isothermal curing proposed by Kamal and Sourour. In this frame, the parameters of the kinetic model were obtained. The effect of the amount of sulfur and accelerator in the compound on the kinetic parameters was investigated and a maximum of the rate parameter k for the compound with formulation with 1.0 phr of sulfur and 2.0 phr of accelerator was found. A marked decrease in the activation energy of the cure process of the elastomer was observed at higher levels of TBBS in the compound. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 35–41, 2006
High temperature zone‐drawing of nylon 66 microfiber prepared by CO2 laser‐thinning
Authors: Suzuki Akihiro , Hasegawa Toshinori
Published: March 2006

A high temperature zone‐drawing method was applied to a nylon 66 microfiber, obtained by using CO2 laser‐thinning, to develop its mechanical properties. The microfiber used for the high temperature zone‐drawing was prepared by winding at 150 m min−1 the microfiber obtained by irradiating the laser at 4.0 W cm−2 to an original fiber with a diameter of 50 μm, and had a diameter of 9.6 μm and a birefringence of 0.019. The high temperature zone‐drawing was carried out in two steps; the first drawing was carried out at a temperature of 230°C at supplying and winding speeds of 0.266 and 0.797 m min−1, the second at 250°C at supplying and winding speeds of 0.266 and 0.425 m min−1, respectively. The diameter of the microfiber decreased, and its birefringence increased stepwise with the processing. The high temperature zone‐drawn microfiber finally obtained had a diameter of 4.2 μm, a birefringence of 0.079, total draw ratio of 4.8, tensile modulus of 12 GPa, and tensile strength of 1.0 GPa. The wide‐angle X‐ray diffraction photograph of the drawn microfiber showed the existence of highly oriented crystallites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 42–47, 2006
An investigation on wear mechanism of POM/LLDPE blends
Authors: Chen Jinyao , Cao Ya , Li Huilin
Published: March 2006

The friction and wear properties of polyoxymethylene/linear low‐density polyethylene/ethylene‐acrylic acid (POM/LLDPE/EAA) blends are investigated on a MM‐200 wear tester. The results show that the addition of LLDPE and EAA obviously improves the friction and wear properties of POM. The friction coefficient and wear scar width of POM/LLDPE/EAA blends are much lower than those of pure POM. SEM analysis reveals that POM appears to wear by thermal softening and melting of worn surface when sliding against the stainless steel, while no severe damage but wear debris can be observed on the worn face of POM/LLDPE/EAA blend. Long‐time sliding causes the removal of molten POM from the worn surface, while the formation of the lubricated layer occurs on the worn surface for POM/LLDPE/EAA blend. DSC analysis shows that the melting temperature and the crystallinity of the worn surface for POM are improved after a long‐time sliding. Molecular orientation on the worn surface of POM is affirmed by WAXD. For POM/LLDPE/EAA blend, the improvement of the friction and wear properties is mainly owed to wear debris and lubricant layer existing between the contact surfaces. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 48–53, 2006
Cleavage and survival of Xenopus embryos exposed to 8 T static magnetic fields in a rotating clinostat
Authors: Eguchi Yawara , Ueno Shoogo , Kaito Chikara , Sekimizu Kazuhisa , Shiokawa Koichiro
Published: March 2006

In this study, we examined cleavage and survival of fertilized Xenopus embryos exposed to 8 T static magnetic fields (SMFs). We investigated fertilized Xenopus embryos exposed to magnetic field either in static chamber or in a rotating culture system. Our results showed that the exposure to the strong magnetic field of 8 T changed the third cleavage furrow from the usual horizontal one to a perpendicular one; however, when the direction of gravity was randomized by exposing embryos to magnetic field in a rotating culture system, the third cleavage furrow were formed horizontally, a finding which suggests that the observed distortion of the third cleavage furrow in magnetism‐exposed embryos was accomplished by altering gravity effects which were elicited by diamagnetic force due to high gradient magnetic field. Our results also showed that the exposure to the strong magnetic field did not damage survival. These results demonstrate that SMF and altering gravity cause distortion of the third cleavage furrow and show that effects of exposing cleavage embryos to magnetic field were transient and did not affect the post‐cleavage development. We also showed that strong magnetic field is not hazardous to the cleavage and blastula‐gastrula transition of developing embryonic cells. Bioelectromagnetics 27:307–313, 2006. © 2006 Wiley‐Liss, Inc.
Bayesian Analysis for the Meiosis I Non‐disjunction Fraction in Numerical Chromosomal Anomalies
Authors: Loschi Rosangela H. , Franco Glaura C.
Published: March 2006

The main causes of numerical chromosomal anomalies, including trisomies, arise from an error in the chromosomal segregation during the meiotic process, named a non‐disjunction. One of the most used techniques to analyze chromosomal anomalies nowadays is the polymerase chain reaction (PCR), which counts the number of peaks or alleles in a polymorphic microsatellite locus. It was shown in previous works that the number of peaks has a multinomial distribution whose probabilities depend on the non‐disjunction fraction F . In this work, we propose a Bayesian approach for estimating the meiosis I non‐disjunction fraction F in the absence of the parental information. Since samples of trisomic patients are, in general, small, the Bayesian approach can be a good alternative for solving this problem. We consider the sampling/importance resampling technique and the Simpson rule to extract information from the posterior distribution of F . Bayes and maximum likelihood estimators are compared through a Monte Carlo simulation, focusing on the influence of different sample sizes and prior specifications in the estimates. We apply the proposed method to estimate F for patients with trisomy of chromosome 21 providing a sensitivity analysis for the method. The results obtained show that Bayes estimators are better in almost all situations. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Simple Imputation Method for Longitudinal Studies with Non‐ignorable Non‐responses
Authors: Wang Molin , Fitzmaurice Garrett M.
Published: March 2006

Missing data are a common problem in longitudinal studies in the health sciences. Motivated by data from the Muscatine Coronary Risk Factor (MCRF) study, a longitudinal study of obesity, we propose a simple imputation method for handling non‐ignorable non‐responses (i.e., when non‐response is related to the specific values that should have been obtained) in longitudinal studies with either discrete or continuous outcomes. In the proposed approach, two regression models are specified; one for the marginal mean of the response, the other for the conditional mean of the response given non‐response patterns. Statistical inference for the model parameters is based on the generalized estimating equations (GEE) approach. An appealing feature of the proposed method is that it can be readily implemented using existing, widely‐available statistical software. The method is illustrated using longitudinal data on obesity from the MCRF study. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Conformational studies of vasopressin analogues modified with N‐methylphenylalanine enantiomers in dimethyl sulfoxide solution
Authors: Sikorska Emilia , Ślusarz Magdalena J. , Lammek Bernard
Published: March 2006

The conformations of [Arg8]vasopressin (AVP) analogues substituted at positions 2 and 3 with N‐methylphenylalanine (MePhe) enantiomers were earlier investigated by using nuclear magnetic resonance (NMR) spectroscopy in aqueous solution. A comparison of the results obtained in H2O/D2O (9:1) and DMSO‐d6 has shown the structures in the first solution to be more flexible than those in DMSO‐d6. This is manifested by a higher percentage of minor conformations in H2O/D2O. The largest differences between the NMR spectra in both solvents were noticed for [MePhe2, D‐MePhe3]AVP (II) and [D‐Cys1,MePhe2,D‐MePhe3]AVP (III). Namely, in the ROESY spectra in aqueous solution, the cis/trans isomerization between MePhe2–DMePhe3 and D‐Cys1–MePhe2 for II and III, respectively, is observed, while in DMSO‐d6, the appropriate cross peaks indicate isomerization across the Cys6–Pro7 peptide bond. In the case of the remaining peptides, the position of cis/trans isomerization is the same in aqueous solution and in dimethyl sulfoxide. [D‐MePhe2,MePhe3]AVP (V) displays low antiuterotonic and antipressor activities, while [D‐MePhe2,3]AVP (IV) is a weak but selective blocker of oxytocin (OT) receptors in the uterus. The former shows similar conformational preferences as another antagonist of V1a and OT receptors—namely, [Acc2,D‐Arg8]VP (Acc: 1‐aminocyclohexane‐1‐carboxylic acid)—investigated by us. In the case of IV, the cis peptide bond between residues at positions 2 and 3 might be the reason for selectivity. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 603–614, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Proton transfer pathways in the mutant His‐64–Ala of human carbonic anhydrase II
Authors: Roy Arijit , Taraphder Srabani
Published: March 2006

We have investigated the possible proton transfer pathways from the surface of the protein to the zinc‐bound water molecule in the mutant His‐64–Ala of human carbonic anhydrase II. Starting with an input of known crystallographic structures of the mutant, we model the proton pathways as hydrogen‐bonded networks of proton conducting groups and bound solvent molecules. No proton path is detected in the mutant, in close agreement with the experimental observation of a 20‐fold decrease in its catalytic efficiency compared to the wild‐type enzyme. We also investigate in detail changes in hydration structure at the active site of the mutant and the resulting proton paths in the presence of an exogenous proton donor 4‐methylimidazole (4‐MI). The proton transfer pathways thus detected are correlated to the observed chemical rescue of catalytic activity by 4‐MI. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 623–630, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Conformational Fluctuations versus Constraints in Amino Acid Side Chains: The Evolution of Information Content from Free Amino Acids to Proteins
Authors: Bojarski Andrzej J. , Nowak Mateusz , Testa Bernard
Published: March 2006

Like all other complex biological systems, proteins exhibit properties not found in free amino acids (i.e., emergent properties). Here, we explore top‐down constraints experienced by the residue side chains in proteins compared to amino acids in increasingly complex molecular environments: free amino acids, end‐capped amino acids, and the central residue in an α‐helical nonapeptide. The crystalline structure of the contractile protein profilin Ib and the enzyme trypsin were chosen as objects of study, and submitted to 10 ns molecular dynamics (MD) simulations. The results revealed increased conformational constraints on the side chains when going from the simpler to the more complex compounds. A Shannon entropy (SE) analysis of the conformational behavior of the side chains showed in most cases a progressive and marked decrease in the SE of the χ1 and χ2 dihedral angles. This is equivalent to stating that conformational constraints on the side chain of residues increase their information content and, hence, recognition specificity compared to free amino acids. In other words, the vastly increased information content of a protein relative to its free monomers is embedded not only in the tertiary structure of the backbone, but also in the conformational behavior of the side chains. The postulated implication is that both backbone and side chains, by virtue of being conformationally constrained, contribute to the protein's recognition specificity toward other macromolecules and ligands.
Synthesis and Characterization of a C(6) Nucleoside Analogue for the in vivo Imaging of the Gene Expression of Herpes Simplex Virus Type‐1 Thymidine Kinase (HSV1 TK)
Authors: Johayem Anass , Raić‐Malić Silvana , Lazzati Katia , Schubiger Pius A. , Scapozza Leonardo , Ametamey Simon M.
Published: March 2006

The synthesis and biological evaluation of ‘6‐(1,3‐dihydroxyisobutyl)thymine’ (DHBT; 1), which corresponds to 6‐[3‐hydroxy‐2‐(hydroxymethyl)propyl]‐5‐methylpyrimidine‐2,4(1H,3H)‐dione, is reported. DHBT (1) was designed as a new substrate for herpes simplex virus type‐1 thymidine kinase (HSV1 TK). The compound was found to be exclusively phosphorylated by HSV1 TK, and to exhibit good binding affinity (Ki = 35.3±1.3 μM). Cell‐proliferation assays with HSV1‐TK‐transduced human osteosarcoma cells (143B‐TK+‐HSV1‐WT) and with both human‐thymidine‐kinase‐1‐negative (143B‐TK−) and non‐transduced parental (MG‐63) cells indicate that 1 is less cytotoxic than the standard drug Ganciclovir. Thus, DHBT (1) represents a promising precursor of a nontoxic reporter probe for the monitoring of HSV1 TK gene expression by means of positron‐emission tomography (PET).
Thermal Stability of Dehydrophenylalanine‐Containing Model Peptides as Probed by Infrared Spectroscopy: a Case Study of an α‐Helical and a 310‐Helical Peptide
Authors: Gupta Alka , Mehrotra Ranjana , Klimov Evgueni , Siesler Heinz Wilhelm , Joshi Ratanmani M. , Chauhan Virander Singh
Published: March 2006

The temperature‐dependent secondary‐structural changes in the two known helical model peptides Boc‐Val‐ΔPhe‐Ala‐Leu‐Gly‐OMe (1; α‐helical) and Boc‐Leu‐Phe‐Ala‐ΔPhe‐Leu‐OMe (2; 310‐helical), which both comprise a single dehydrophenylalanine (ΔPhe) residue, were investigated by means of FT‐IR spectroscopy (peptide film on KBr). Both the first‐order and the better‐resolved second‐order derivative IR spectra of 1 and 2 were analyzed. The ν(NH) (3240–3340 cm−1), the Amide‐I (1600–1700 cm−1), and the Amide‐II (1510–1580 cm−1) regions of 1 and 2 showed significant differences in thermal‐denaturation experiments (22°→144°), with the 310‐helical peptide (2) being considerably more stable. This observation was rationalized by different patterns and strengths of intramolecular H‐bonds, and was qualitatively related to the different geometries of the peptides. Also, a fair degree of residual secondary‐structural elements were found even in the ‘denatured’ states above 104° (1) or 134° (2).
Synthesis and Characterization of a New Macrocyclic Copper(II) Complex with an N‐Glycosidic Pendant Arm: in vitro Cytotoxicity and Binding Studies with Calf‐Thymus DNA
Authors: Mathur Suvigya , Tabassum Sartaj
Published: March 2006

The new macrocyclic complex 2‐amino‐2‐deoxy‐N‐[2‐(1,3,5,8,11‐pentaazacyclotridecan‐3‐yl)ethyl]‐β‐D‐glucopyranosylamine copper(II) dichloride (1a) was prepared and thoroughly characterized by various techniques. Molar‐conductance measurements showed that 1a (and its Ni analogue 1b) are ionic in nature. On the basis of spectroscopic data, both complexes were assigned a square‐planar geometry, and found to be highly stabile and hydrolytically robust in H2O over a wide range of pH, as confirmed by cyclic voltammetry (CV). The CuII complex 1a was found to bind to CT‐DNA, with a binding constant Kb of 2.4×103 M−1, as derived by UV/VIS titration, and confirmed by CV, circular dichroism (CD), and viscosity measurements. DNA binding seems to occur mostly via H‐bonding. In an in vitro antitumor MTT assay, 1a exhibited significant anticancer activity against the SY5Y and PC‐12 cell lines, with an estimated IC50 value in the micromolar range for SYSY, similar to the standard drug 5‐fluorouracil.
Synthesis of Fluoro Analogues of 3,4‐(Methylenedioxy)amphetamine (MDA) and Its Derivatives
Authors: Trachsel Daniel , Hadorn Marcel , Baumberger Franz
Published: March 2006

The role of the metabolism of the entactogen 3,4‐(methylenedioxy)methamphetamine (MDMA;1b) in neurotoxic or psychopharmacologic action is widely discussed, but not yet fully understood. To prompt further investigation into the role of MDMA metabolism, six new 3,4‐(difluoromethylenedioxy) analogues of MDMA (1b) were prepared and characterized. Although electronically very different, the fluoro analogues3–5should be sterically very similar to the non‐fluorinated parent compounds. The F‐atoms may prevent the formation of toxic metabolites producedviaa radical pathway (Scheme 1). Different theories regarding MDMA‐induced neurotoxicity are briefly reviewed and discussed. The novel compounds3–5may help to verify the hypothesis that MDMA‐induced neurotoxicity is the result of the formation of metabolites lacking the methylenedioxy bridge.
New Chemical Constituents from the Endophyte Streptomyces Species LR4612 Cultivated on Maytenus hookeri
Authors: Zhao Pei‐Ji , Li Guo‐Hong , Shen Yue‐Mao
Published: March 2006

From solid cultures of the biologically important endophyte Streptomyces species LR4612, cultivated on Maytenus hookeri, four new and two known compounds were isolated. The new compounds were identified as (2S*,3S*)‐5‐amino‐3‐hydroxy‐5‐oxopentan‐2‐yl 3‐(formylamino)‐2‐hydroxybenzoate (1), N‐[(3R*,4R*)‐3‐amino‐3,4‐dihydro‐4‐methyl‐2,6‐dioxo‐2H,6H‐1,5‐benzodioxocin‐10‐yl]formamide (2), (5β,6α)‐6,11‐dihydroxyeudesmane (3), and 5‐(6,7‐dihydroxy‐6‐methyloctyl)furan‐2(5H)‐one (4); the known compounds were elucidated as sorbicillin (5) and N‐acetyltyramine (6). The structures were established by HR‐ESI‐MS and in‐depth NMR analyses.
Antiviral Flavonoid‐Type C‐Glycosides from the Flowers of Trollius chinensis
Authors: Cai Shao‐Qing , Wang Rufeng , Yang Xiuwei , Shang Mingying , Ma Chaomei , Shoyama Yukihiro
Published: March 2006

Two new flavonoid‐type C‐glycosides, trollisin I (=(1S)‐1,5‐anhydro‐1‐[2‐(3,4‐dihydroxyphenyl)‐5‐hydroxy‐7‐methoxy‐4‐oxo‐4H‐[1]benzopyran‐8‐yl]‐2‐O‐(2‐methylbutanoyl)‐D‐glucitol; 1) and its 2‐O‐benzoyl congener trollisin II (2), were isolated from Trollius chinensis Bunge, together with the two known compounds 2″‐O‐(2′′′‐methylbutanoyl)isoswertisin (3) and vitexin galactoside (4). All compounds were identified by HR‐ESI‐MS and in‐depth NMR‐spectroscopic analyses. In antiviral assays, compound 3 was found to be moderately active towards influenza virus A.
Phylogeny of the Schisandraceae Based on cpDNA mat‐K and rpL16 Intron Data
Authors: Wang Yan‐Han , Zhang Shou‐Zhou , Gao Jian‐Ping , Chen Dao‐Feng
Published: March 2006

The chloroplast mat‐K region and rpL16 intron region were sequenced for 14 species of Schisandraceae, representing both genera Kadsura Kaempf. ex Juss. and Schisandra Michx, to discuss the phylogeny of this family. Analyses were performed both in separate and combined sequence data sets (including the rbc‐L sequence), with Illicium angustispealum A. C. Smith as the out‐group. The results showed that the Schisandraceae are monophyletic. In all the analyses, Schisandra propinqua var. chinensis Oliva and Schisandra plena A. C. Smith were nested within Kadsura, which implies that the genera Kadsura and Schisandra are closely related. They might have originated from a common ancestor, but then evolved via different routes. The result inferred from the combined data showed a greater resolution within Schisandra than those from the two separate data sets. High bootstrap values supported the monophyly of most subgenera according to Law's system (1996). A combination of morphological, anatomical, and chemical analyses indicates that S. chinensis and S. rubriflora may be the primitive taxa in Schisandra.
Model of a pH‐Based Potentiometric Biosensor Immobilizing Organophosphorus Hydrolase
Authors: Lihong W. , Lin Z. , Jinxing H. , Huanlin C.
Published: March 2006

A model for predicting the steady‐state response of a pH‐based potentiometric biosensor immobilizing organophosphorus hydrolase (OPH) is developed. The model combines the processes of diffusion and enzymatic reaction in the membrane. Key factors influencing the system response, such as enzyme reaction order, Thiele modulus, and buffer concentration are discussed in detail. It is possible to obtain a good linear response by designing an enzyme electrode with a high enough Thiele modulus and by appropriately controlling added buffer concentrations. It is found that the model is in reasonable agreement with the experiment results.
Optimization of Fischer‐Tropsch Synthesis Using Neural Networks
Authors: Fernandes F. A. N.
Published: March 2006

Fischer‐Tropsch synthesis is an important chemical process for the production of liquid fuels and olefins. Optimization of hydrocarbon products such as diesel and gasoline produced by Fischer‐Tropsch synthesis usually requires the knowledge of the complex polymerization mechanism and the kinetic parameters associated with it in order to optimize production. The Fischer‐Tropsch reaction mechanism is still not fully understood, making optimization a hard task. In this work, a neural network was used in substitution to the reaction mechanism to optimize diesel and gasoline production based on few experimental data for the reaction. The neural network has yielded satisfactory predictions of the product distribution (with prediction errors lower than 5 %) and the optimum operating conditions for gasoline and diesel production were found for a commercial iron based catalyst.
Effect of Alternating Pumping of Two Reactants into a Microchannel on a Phase Transfer Reaction
Authors: Okamoto H.
Published: March 2006

Alternating pumping of two reactants into a microchannel was found to provide, in comparison with batch processes, a more effective mixing and an increased yield for a particular organic reaction which uses a phase transfer catalyst. The superiority of the microreactor method increased with the frequency of alternation of the pumping of the two liquids.
Variation of Cell Voltage with Reaction Time in Electrochemical Synthesis Process of Sodium Dichromate
Authors: Li C. W. , Qi T. , Wang F. , Zhang Y. , Yu Z. H.
Published: March 2006

To address the problems existing in the traditional production technique of sodium dichromate, a new green technology of producing sodium dichromate with an electrochemical synthesis method was studied. Using a self‐made electrosynthesis reactor of pure titanium and stainless steel, with a multiple‐unit metal oxides combination anode, a cathode of stainless steel, and a reinforcing combination cation exchange membrane with perfluorosulfonic and perfluorocarboxylic polymers, experiments were carried out on the direct electrochemical synthesis of sodium dichromate from sodium chromate. From the experimental results and electrochemical reaction principles, it was shown that the electrochemical synthesis reaction process of sodium dichromate may be quantitatively determined from the variation of the cell voltage measured macroscopically with reaction time. Cell voltages were experimentally measured at different initial sodium chromate concentrations in the anolyte, and the dependence of the cell voltage on reaction time was discussed. The mathematical model of the variation of cell voltage with reaction time and the change rate equation of cell voltage were established, and satisfactorily formulated the change law of cell voltage in the electrochemical synthesis process of sodium dichromate.
Experimental Study and Analysis on Drag Reduction Mechanisms of Reducing Pressure Drop Stick in a Cyclone Separator
Authors: Liu C. W. , Wang L. Z. , Liu Q. S.
Published: March 2006

The mechanisms of mean mechanical energy losses in a cyclone separator with a Repds (Reducing Pressure Drop Stick) are studied. The results show that the energy losses are mainly caused by direct viscous dissipation, turbulent diffusion, and turbulent energy production, which is the same as in a conventional cyclone separator. In particular, the direct viscous dissipation and the turbulent energy production are of importance. Laser Doppler Velocimetry (LDV) is used to measure the flow field in the cyclone body and the exit pipe of a cyclone separator with and without a Repds, respectively. The drag reduction mechanism of the Repds is analyzed by examining the effects of the Repds on flow parameters which are related to energy loss factors. The measured results and analysis reveal that the drag reduction results from decreases of the direct viscous dissipation, turbulent diffusion, and turbulent production as a whole when a Repds is inserted into a cyclone separator. The resultant drag reduction is a tradeoff between the increase and the decrease of energy losses caused by the Repds.
Study of the Dehydration of Isopropanol by a Pervaporation‐Based Hybrid Process
Authors: Sanz M. T. , Gmehling J.
Published: March 2006

The permeation characteristics of the commercial polymeric membrane PERVAP® 2201 were studied to carry out the dehydration of binary water/isopropanol mixtures. The influence of the composition (2–75 wt % H2O) and temperature of the feed (311.15–348.15 K) on the membrane performance was studied. The selected membrane showed a high selectivity towards water in the entire concentration range. It was found that the permeation rate increased with the water content and the operating temperature. The influence of the temperature on the flux can be described by an Arrhenius‐type expression. The commercial software Aspen Plus was used to simulate the dehydration of isopropanol by means of a hybrid process combining distillation and pervaporation.
Inferential Estimation of Polymer Melt Index Using Sequentially Trained Bootstrap Aggregated Neural Networks
Authors: Zhang J. , Jin Q. , Xu Y.
Published: March 2006

The inferential estimation of a polymer melt index in an industrial polymerization process using aggregated neural networks is presented in this paper. The difficult‐to‐measure polymer melt index is estimated from easy‐to‐measure process variables, and their relationship is estimated using aggregated neural networks. The individual networks are trained on bootstrap re‐samples of the original training data by a sequential training algorithm. In this training method, individual networks, within a bootstrap aggregated neural network model, are trained sequentially. The first network is trained to minimize its prediction error on the training data. In the training of subsequent networks, the training objective is not only to minimize the individual networks' prediction errors but also to minimize the correlation among the individual networks. Training is terminated when the aggregated network prediction performance on the training and testing data cannot be further improved. Application to real industrial data demonstrates that the polymer melt index can be successfully estimated using an aggregated neural network.