bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Soil Solution's Constituents on Proton NMR Relaxometry of Soil Samples
Authors: Jaeger Fabian , Rudolph Nicole , Lang Friederike , Schaumann Gabriele E.
Published: November 2008

Proton nuclear magnetic resonance (1H NMR) relaxometry has been used to analyze pore size distributions of wet porous samples. To make this method applicable to soil samples, knowledge about contribution from the soil solution to the total proton relaxation is needed. We extracted soil solutions from nine soil samples and determined transverse proton relaxation rates, the concentration of Fe, Mn, and total organic C (TOC), and the pH of the solutions. The effects of Fe, Mn, and TOC on the proton relaxation in the soil solution were compared with those of dissolved Fe2+, Fe3+, and Mn2+ and of glucose, d‐cellobiose, potassium hydrogen phthalate, sodium alginate, and agar in model solutions. Proton relaxation rates in the soil solutions were up to 20 times larger than in pure water, which was mainly due to dissolved Fe(III) and Mn(II) species. The relaxivities of Fe and Mn in soil solution were reduced to 40 and 70% compared with Fe(III) and Mn(II) in a model solution, respectively. Smaller relaxivities were primarily due to the formation of metal–organic complexes. We conclude that the proton relaxation in soil samples is generally accelerated by the soil solution, and its contribution must be considered to estimate pore sizes from relaxation times. By using the calculated relaxivities of Fe and Mn in soil solution, the contribution of the soil solution to the total proton relaxation can be estimated from the Fe and Mn concentration in the soil solution.
Nutrient Sorption Dynamics of Resin Membranes and Resin Bags in a Tropical Forest
Authors: Meason Dean F. , Idol Travis W.
Published: November 2008

Plant root simulator (PRS) probes, a resin membrane technology, are increasingly used to measure soil nutrient availability in agricultural and nonagricultural systems. Like other resin technologies, the charged surface is meant to sorb nutrients until saturation; however, there is evidence that it acts as a dynamic exchanger in soils with low nutrient availability. This study compared the nutrient sorption dynamics of PRS probes during an 8‐wk period in a young Andisol forest soil on the island of Hawaii with and without P fertilization. Resin bags, a more established technology, were used to measure nutrient availability as a comparison. The PRS probe sorption dynamics differed for the six nutrients measured. Except for NO3, nutrient sorption appeared to reach equilibrium with the soil labile pools after 4 wk. Resin bags acted as an infinite sink for NH4+, NO3−, and PO43− and sorbed more than the PRS probes. Both technologies detected an increase in P availability due to fertilization. A comparison of nutrient availability from PRS probes and resin bags correlated poorly. Isolation of the PRS probes and resin bags from root activity did not improve measurements of labile nutrients. More research is required to understand the processes behind the apparent desorption of nutrients from the PRS probes in acidic forest soils. If used for a minimum of 4 wk, however, the PRS probes appear to provide an equilibrium measure of labile soil nutrients with high sensitivity to treatment differences.
Letter: Comment on Stiglitz's "Turn Left for Sustainable Growth"
Authors: Rao P. K.
Published: November 2008

P.K. Rao writes that Joseph Stiglitz is right that a truly accurate assessment of economic growth must reflect loss of environmental assets, excessive debt burdens, and related features, but points out that left-leaning policies are also susceptible to capture and corruption.
Research that Matters: Linking Researchers, Practitioners, Decision-Makers and the Public: Abstracts from the Fifth Annual IN-CAM Research Symposium November 7 to 9, 2008, Toronto, Canada
Authors: Verhoef Marja J. , Boon Heather
Published: November 2008

The following are abstracts of oral and poster presentations given at the Fifth Annual IN-CAM Research Symposium - Research that Matters: Linking Researchers, Practitioners, Decision-Makers and the Public, held on November 7, 8 & 9, 2008 at the Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada. The Symposium was held in collaboration with two IN-CAM partners, PedCAM and HomeoNet. The abstracts are grouped under: IN-CAM, PedCAM, and HomeoNet. For more information, please visit: www.incamresearch.ca.
Few-electron semiconductor quantum dots with Gaussian confinement
Authors: Gomez Sergio , Romero Rodolfo
Published: November 2008

We have performed Hartree-Fock calculations of the electronic structure of N ≤ 10 electrons in a quantum dot modeled with a confining Gaussian potential well. We discuss the conditions for the stability of N bound electrons in the system. We show that the most relevant parameter determining the number of bound electrons is V
0
R
2. Such a feature arises from widely valid scaling properties of the confining potential. Gaussian Quantum dots having N = 2, 5, and 8 electrons are particularly stable in agreement with the Hund rule. The shell structure becomes less and less noticeable as the well radius increases.
Independent trapping, manipulation and characterization by an all-optical biophotonics workstation
Authors: Ulriksen Hans-Ulrik , Thøgersen Jan , Keiding Søren R. , Perch-Nielsen Ivan R. , Dam Jeppe S. , Palima Darwin Z. , Stapelfeldt Henrik , Glückstad Jesper
Published: November 2008

Optical trapping has enabled a multitude of applications focusing, in particular, on non-invasive studies of cellular material. The full potential of optical trapping has, however, not yet been exploited due to restricted access to the trapped samples, caused by high numerical aperture objectives needed to focus the trapping laser beams. Here, we use our recently developed biophotonics workstation to overcome this limitation by introducing probing and spectroscopic characterization of optically trapped particles in a side-view geometry perpendicular to the trapping beams rather than in the traditional top-view geometry parallel to the trapping beams. Our method is illustrated by CARS and fluorescence spectroscopy of trapped polystyrene beads. The side-view geometry opens intriguing possibilities for accessing trapped particles with optical as well as other types of probe methods independent from the trapping process.
One Network or Two? French-Language Programming on the Canadian Radio Broadcasting Commission, 1932–36
Authors: Vipond Mary
Published: November 2008

During the four years of its existence, the Canadian Radio Broadcasting Commission (crbc), Canada's first public broadcaster, became a site where different conceptions of broadcasting and of Canada itself were contested and debated. One of the most significant controversies concerned the extent of French programming on the commission's national network, ultimately resolved by placing most French-language programs on a separate network covering only Quebec and nearby areas of Ontario and New Brunswick. This study argues that the controversy over French programming on the national network had a negative impact on the crbc's ability to build its credibility and legitimacy as a national cultural institution, but that the very ferocity of the debate reveals widespread agreement that a public broadcasting body potentially has the authority to shape the way Canadians imagine their country.
Toronto Society's Response to Celebrity Performers, 1887–1914
Authors: Walden Keith
Published: November 2008

The appearance of Toronto's Saturday Night magazine, founded in 1887, highlighted the competition between the city's social elite and outside figures of influence from the realm of commercial entertainment. It devoted considerable coverage both to the doings of local high society and to the city's theatrical and musical scene, which featured an unending succession of travelling stars. The blossoming of the culture of celebrity, which followed from the growing respectability of the stage in the nineteenth century, posed a challenge to the prestige and primacy of the beau monde. Its members reacted by trying to dominate performance halls from in front of the stage, incorporating suitable entertainers into local social circles, and most surprisingly, taking to the stage themselves in amateur productions that highlighted their own community leadership. None of these tactics could stem celebrity culture, and by the start of the First World War, the focus of elite strategies for securing status had shifted away from the playhouse.
Synthesis and Properties of Poly[p-(2,5-dihydroxy)- phenylenebenzobisoxazole] Fiber
Authors: Lin Hong , Huang Yu-Dong , Wang Feng
Published: November 2008

The novel polymer poly[p-(2,5-dihydroxy)-phenylenebenzobisoxazole] (PBOH) fiber was synthesized in the presence of 2,5-dihydroxyterephthalicacid (DHTA) and 4,6-diamino-1,3-benzenediol in poly(phosphoric acid) (PPA) using typical polycondensation conditions. The crystalline solutions of liquid PBOH in PPA were spun into fibers using dry-jet wet spinning. Furthermore, the thermostability and mechanical properties of PBOH were compared with poly(p-phenylene-2,6-benzoxazole) (PBO) in order to investigate the relationship between the chain structure and properties. The results indicated that the thermal degradation temperature of PBOH was above 750K and the tensile strength of the PBOH fiber was 3.1GPa, which were much lower than those of PBO fiber. The compressive strength of PBOH fiber was 331 M Pa, which was slightly higher than that of PBO fiber. In addition, molecular simulation was employed to explain why the compressive strength of PBOH fiber did not increase significantly compared to PBO fiber.
Assessment of Data Quality of and Staff Satisfaction with an Electronic Health Record System in a Developing Country (Uganda)
Authors: Ndira S.P. , Rosenberger K.D. , Wetter T.
Published: November 2008

Objectives:
To assess if electronic health record systems in developing countries can improve on timeliness, availability and accuracy of routine health reports and staff satisfaction after introducing the electronic system, compared to the paper-based alternative.

Methods:
The research was conducted with hospital staff of Tororo District Hospital in Uganda. A comparative intervention study with qualitative and quantitative methods was used to compare the paper-based (pre-test) to the electronic system (post-test) focusing on accuracy, availability and timeliness of monthly routine reports about mothers visiting the hospital; and staff satisfaction with the electronic system as outcome measures.

Results:
Timeliness: pre-test 13 of 19 months delivered to the district timely, delivery dates for six months could not be established; post-test 100%. Availability: pretest 79% of reports were present at the district health office; post-test 100%. Accuracy: pre-test 73.2% of selected reports could be independently confirmed as correct; post-test 71.2%. Difficulties were encountered in finding enough mothers through direct follow up to inquire on accuracy of information recorded about them. Staff interviews showed that the electronic system is appreciated by the majority of the hospital staff. Remaining obstacles include staff workload, power shortages, network breakdowns and parallel data entry (paper-based and electronic).

Conclusion:
While timeliness and availability improved, improvement of accuracy could not be established. Better approaches to ascertaining accuracy have to be devised, e.g. evaluation of intended use. For success, organizational, managerial and social challenges must be addressed beyond technical aspects.
PET/CT in Cancer
Authors: Vach W. , Høilund-Carlsen P.F. , Gerke O.
Published: November 2008

Objectives:
When the combined diagnostic imaging technique PET/CT is considered promising with respect to diagnosis/staging of a certain cancer type, a systematic investigation by means of clinical diagnostic studies in the target population is necessary to evaluate the usefulness of PET/CT compared to the current standard. It is often difficult to decide in advance whether it is appropriate to plan a superiority or non-inferiority study. We propose a statistical analysis strategy which is flexible enough to cope with both aims alike.

Methods:
In opposition to clinical studies on drugs, each patient can be subjected to both PET/CT and the current standard, leading to paired observations of binary data (e.g., cancer = yes/no, stage = 0/1+). The analysis strategy focuses on point estimates and confidence intervals for the difference (or relative increase) in accuracy measures.

Results:
Formulas for approximate 95% confidence intervals for the differences in sensitivity, specificity, positive and negative predictive values between PET/CT and the standard procedures are given, respectively. The strategy can also be applied if results obtained with a golden standard are not available in patients in whom both PET/CT and the standard procedure gave negative results. Sample sizes can and should be determined in an adaptive manner.

Conclusions:
Diagnostic studies to assess the merit of PET/CT in the diagnostic work-up of cancer patients can and should start with phase II studies focusing on 95% confidence intervals for differences in diagnostic measures. Even if the gold standard procedure is incomplete, the statistical analysis strategy given here may still be applicable.
Using a Java Dynamic Tree to Manage the Terminology in a Suite of Medical Applications
Authors: Evens M.W. , Trace D. A. , Yang K.
Published: November 2008

Objectives:
Now that the National Library of Medicine has made SNOMED-CT widely available, we are trying to manage the terminology of a whole suite of medical applications and map our terminology into that in SNOMED.

Methods:
This paper describes the design and implementation of the Java Dynamic Tree that provides structure to our medical terminology and explains how it functions as the core of our system.

Results:
The tree was designed to reflect the stages in a patient interview, so it contains components for identifying the patient and the provider, a large set of chief complaints, review of systems, physical examination, several history modules, medications, laboratory tests, imaging, and special procedures. The tree is mirrored in a commercial DBMS, which also stores multi-encounter patient data, disorder patterns for our Bayesian diagnostic system, and the data and rules for other expert systems. The DBMS facilitates the import and export of large terminology files.

Conclusions:
Our Java Dynamic Tree allows the health care provider to view the entire terminology along with the structure that supports it, as well as the mechanism for the generation of progress notes and other documents, in terms of a single hierarchical structure. Changes in terminology can be propagated through the system under the control of the expert. The import/ export facility has been a major help by replacing our original terminology by the terminology in SNOMED-CT.
Prediction of Disease-associated Single Nucleotide Polymorphisms Using Virtual Genomes Constructed from a Public Haplotype Database
Authors: Miyashita A. , Kitamura N. , Kuwano R. , Akazawa K. , Toyabe S.
Published: November 2008

Objectives:
Simultaneous dealing of hundreds of thousands of single nucleotide polymorphisms (SNPs) in genome-wide association studies is laborious. The aim of our study is to develop a method to decrease the number of candidate SNPs prior to the genotyping of study subjects.

Methods:
We created virtual genotype data on case and control subjects from data of the International HapMap Project by using haplotype-based simulation method. We repeated virtual case-control association studies and selected candidate SNPs. We applied the selected SNPs to previously published genetic casecontrol studies. Sensitivity to detect association with causative genes using our method was compared to the original studies and results using tag SNPs.

Results:
We found a discrete distribution pattern of SNPs, which was able to produce significant results in case-control association studies. The number of candidate SNPs that we selected was 24.7% of the number of the original set of SNPs. We applied this method to previously published genetic case-control studies and found that the use of candidate SNPs improved the sensitivity for detecting significant alleles, both compared to the original studies and to the use of tag SNPs. The results were not affected by the difference of the diseases and genes involved.

Conclusions:
Our simulation-based approach has advantages of reducing costs and improving performance to detect significant alleles. This method can be used without considering the specific disease and genes involved.
Use of Kullback–Leibler divergence for forgetting
Authors: Kárný Miroslav , Andrýsek Josef
Published: November 2008

Non‐symmetric Kullback–Leibler divergence (KLD) measures proximity of probability density functions (pdfs). Bernardo (Ann. Stat.1979;7(3):686–690) had shown its unique role in approximation of pdfs. The order of the KLD arguments is also implied by his methodological result. Functional approximation of estimation and stabilized forgetting, serving for tracking of slowly varying parameters, use the reversed order. This choice has the pragmatic motivation: recursive estimator often approximates the parametric model by a member of exponential family (EF) as it maps prior pdfs from the set of conjugate pdfs (CEF) back to the CEF. Approximations based on the KLD with the reversed order of arguments preserves this property. In the paper, the approximation performed within the CEF but with the proper order of arguments of the KLD is advocated. It is applied to the parameter tracking and performance improvements are demonstrated. This practical result is of importance for adaptive systems and opens a way for improving the functional approximation. Copyright © 2008 John Wiley & Sons, Ltd.
Matching a system behavior with a known set of models: A quadratic optimization‐based adaptive solution
Authors: Bonilla Moisés , Martínez‐García J. C. , Pacheco‐Martínez J. , Malabre M.
Published: November 2008

The matching process between a time‐domain external behavior of a lumped single‐input single‐output dynamical system and a known set of linear continuous time‐invariant models is tackled in this paper. The proposed online solution is based on an adaptive structure detector, which in finite time locates in the known set of models the one corresponding to the observed external behavior; the detector results from the solution of a constrained quadratic optimization problem. The problem is expressed in terms of the time‐domain activity of a family of discriminating filters and is solved via a normalized gradient algorithm, which avoids mismatching due to the presence of structural zeros in the filters and can take into account band‐limited high‐frequency measurement noise. A failure detection problem concerning a simulated servomechanism is included in order to illustrate the proposed solution. Copyright © 2008 John Wiley & Sons, Ltd.
A Delivery System for Self‐Healing Inorganic Films
Authors: Liu Harvey A. , Gnade Bruce E. , Balkus Kenneth J.
Published: November 2008

Multilayer composites that utilize polymeric and brittle inorganic films are essential components for extending the lifetimes and exploiting the flexibility of many electronic devices. However, crack formation within the brittle inorganic layers that arise from defects as well as the flexing of these multilayer composite materials allows the influx of atmospheric water, a major source of device degradation. Thus, a composite material that can initiate self‐healing upon the influx of environmental water through defects or stress‐induced cracks would find potential applications in multilayer composite materials for permeation barriers. In the present study, the reactive metal oxide precursor TiCl4 is encapsulated within the pores of a degradable polymer, poly(lactic acid) (PLA). Electrospun PLA fibers are found to be reactive to atmospheric water leading to the hydrolysis of the degradable polymer shell and subsequent release of the reactive metal oxide precursor. Release of the reactive TiCl4 from the pores results in hydrolysis of the metal oxide precursor, forming solid titanium oxides at the surface of the fibers. The efficacy of this self‐healing delivery system is also demonstrated by the integration of these reactive fibers in the polymer planarization layer, poly(methyl methacrylate), of a multilayer film, upon which an alumina barrier layer is deposited. The introduction of nanocracks in the alumina barrier layer lead to the release of the metal oxide precursor from the pores of the fibers and the formation of titanium dioxide nanoparticles within the crack and upon the thin film surface. In this study the first delivery system that may find utility for the self‐healing of multilayer barrier films through the site‐specific delivery of metal oxide nanoparticles through smart reactive composite fibers is established.
Controllable Soluble Protein Concentration Gradients in Hydrogel Networks
Authors: Peret Brian J. , Murphy William L.
Published: November 2008

Here, controlled formation of sustained, soluble protein concentration gradients within hydrated polymer networks is reported. The approach involves spatially localizing proteins or biodegradable, protein‐loaded microspheres within hydrogels to form a protein‐releasing “depot.” Soluble protein concentration gradients are then formed as the released protein diffuses away from the localized source. Control over key gradient parameters, including maximum concentration, gradient magnitude, slope, and time dynamics, is achieved by controlling the release of protein from the depot and subsequent transport through the hydrogel. Results demonstrate a direct relationship between the amount of protein released from the depot and the source concentration, gradient magnitude, and slope of the concentration gradient. In addition, an inverse relationship exists between the diffusion coefficient of protein within the hydrogel and the slope of the concentration gradient. The time dynamics of the concentration gradient profile can be directly correlated to protein release from the localized source, providing a mechanism for temporarily controlling gradient characteristics. Therefore, each key biologically relevant parameter associated with the protein concentration gradient can be controlled by defining protein release and diffusion. It is anticipated that the resulting materials may be useful in 3D cell culture systems, and in emerging tissue engineering approaches that aim to regenerate complex, functional tissues.
Highly Porous Crosslinkable PLA‐PNB Block Copolymer Scaffolds
Authors: Wang Yiqing , Noga David E. , Yoon Kunsang , Wojtowicz Abigail M. , Lin Angela S. P. , García Andrés J. , Collard David M. , Weck Marcus
Published: November 2008

Poly(lactic acid) (PLA)‐block‐poly(norbornene) (PNB) copolymers which bear photocrosslinkable cinnamate side‐chains are synthesized by combining the ring‐opening metathesis polymerization (ROMP) of norbornenes with the ring‐opening polymerization (ROP) of lactides. Highly porous 3D scaffolds with tunable pore sizes ranging from 20 to 300 µm are fabricated through liquid–solid phase separation. Scaffolds with an average pore size around 250 µm, which are under investigation as bone grafting materials, are reproducibly obtained from freeze‐drying 5% w/v benzene solutions of PLA‐b‐PNB copolymers at −10 °C. As a demonstration of the impact of photocrosslinking of cinnamate side‐chains, scaffolds are exposed to UV radiation for 8 h, resulting in a 33% increase in the compressive modulus of the polymeric scaffold. The foams and the methodology described herein represent a new strategy toward polymeric scaffolds with potential for use in regenerative medicine applications.
An Electrochemical Bottom‐Up Approach to Producing Nanostructured Electrodes Based on Nanocolumnar ZnO Acting as a Self‐Assembled Template
Authors: Finke Alexandre , Poizot Philippe , Guéry Claude , Mazouzi Driss , Tarascon Jean‐Marie
Published: November 2008

An Fe3O4/Cu nanostructured prototype electrode was developed from a 100% bottom‐up approach thanks to an original three‐step electrodeposition procedure that enlists 1) the growth of a ZnO nanocolumnar template, 2) the filling of the template voids by copper prior to the dissolution of the zincite nanopillars, and 3) the plating on the remaining copper nanodots of the Fe3O4 phase. The key technological point is that ZnO readily forms nanorod arrays by self‐assembly when an aqueous solution of ZnII, saturated by dioxygen, is cathodically polarized. The as‐obtained inorganic solid template is sufficiently stable for further deposition steps of any kind (metals, oxides, polymers, and so on) but is easy to remove in both acidic and alkaline media. The self‐supported Fe3O4/Cu nanostructured electrode shows, besides sustained capacity retention, outstanding rate capability when electrochemically tested versus Li. This original and soft process, derived from template‐assisted synthesis, avoids fixing (mechanically) a nanoporous membrane on the substrate, thus, enabling nanostructural design on shapeless surfaces.
A Simple, One‐Step Approach to Durable and Robust Superhydrophobic Textiles
Authors: Zimmermann Jan , Reifler Felix A. , Fortunato Giuseppino , Gerhardt Lutz‐Christian , Seeger Stefan
Published: November 2008

Superhydrophobic textile fabrics are prepared by a simple, one‐step gas phase coating procedure by which a layer of polymethylsilsesquioxane nanofilaments is grown onto the individual textile fibers. A total of 11 textile fabrics made from natural and man made fibers are successfully coated and their superhydrophobic properties evaluated by the water shedding angle technique. A thorough investigation of the commercially relevant poly(ethylene terephthalate) fabric reveals an unparalleled long‐term water resistance and stability of the superhydrophobic effect. Because of the special surface geometry generated by the nanoscopic, fibrous coating on the microscopic, fibrous textiles, the coated fabric remains completely dry even after two months of full immersion in water and stays superhydrophobic even after continuous rubbing with a skin simulating friction partner under significant load. Furthermore, important textile parameters such as tensile strength, color, and haptics are unaffected by the silicone nanofilament coating. For the first time, an in‐depth characterization of the wetting properties, beyond simple contact angle measurements, as well as a thorough evaluation of the most important textile parameters is performed on a superhydrophobic fabric, which reveals a true potential for application.
Ionic Liquid Effect on the Reversal of Configuration for the Magnesium(II) and Copper(II) Bis(oxazoline)‐Catalysed Enantioselective Diels–Alder Reaction
Authors: Goodrich P. , Hardacre C. , Paun C. , Pârvulescu V. I. , Podolean I.
Published: November 2008

Ionic liquids have been used to support a range of magnesium‐ and copper‐based bis(oxazoline) complexes for the enantioselective Diels–Alder reaction between N‐acryloyloxazolidinone and cyclopentadiene. Compared with reaction performed in dichloromethane or diethyl ether, an enhancement in ee is observed with a large increase in reaction rate. In addition, for non‐sterically hindered bis(oxazoline) ligands, that is, phenyl functionalised ligands, a reversal in configuration is found in the ionic liquid, 1‐ethyl‐3‐methylimidazolium bis[(trifluoromethanesulfonyl)imide], compared with molecular solvents. Supported ionic liquid phase catalysts have also been developed using surface‐modified silica which show good reactivity and enantioselectivity for the case of the magnesium‐based bis(oxazoline) complexes. Poor ees and conversion were observed for the analogous copper‐based systems. Some drop in ee was found on supporting the catalyst due a drop in the rate of reaction and, therefore, an increase in the contribution from the uncatalysed achiral reaction.
Suppressing the segregation of granular mixtures in rotating tumblers
Authors: Vargas Watson L. , Hajra Suman K. , Shi Deliang , McCarthy J. J.
Published: November 2008

While an understanding of the dynamics of segregation has begun to emerge, controlling segregation continues to be a complicated problem. The use of time‐modulation—via selective baffle placement—in order to suppress segregation in rotating tumblers is explored. Bidisperse (size or density), cohesionless granular materials in quasi‐two‐dimensional (2‐D) rotating containers are studied by means of simulations and experiments. Results are presented in two main configurations for the placement of the baffles, (1) axial placement, and (2) attached to the periphery of the tumbler. Both experiments and simulations indicate that baffles attached at the periphery are ineffective in reducing segregation, while baffles axially located in the tumbler generate periodic flow inversions and dramatically reduce both density and size segregation. Qualitative and quantitative evidence is presented, in terms of the intensity of segregation. Theoretical and scale‐up arguments are provided for the practical implementation of this approach. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Exudates as a fallback food forCallimico goeldii
Authors: Porter Leila M. , Garber Paul A. , Nacimento Edilio
Published: November 2008

Fallback foods have been defined as resources for which a species has evolved specific masticatory and digestive adaptations, and are consumed principally when preferred foods are scarce. In the present field investigation, we examine fungi, fruit, and exudate consumption in one group ofCallimico goeldiiin order to determine the importance of exudates as a fallback food for this species. Based on a total of 1,198 hr of quantitative behavioral data collected between mid‐November 2002–August 2003, we found that pod exudates ofParkia velutinaaccounted for 19% of callimico feeding time in the dry season. This resource was not consumed in the wet season when fruits and fungi were the most common items in the diet. In the dry season of 2005 (July), the same callimico study group did not consumeParkiapod exudates. Instead, the group ate exudates obtained from holes gouged in tree trunks by pygmy marmosets and exudates resulting from natural weathering and insect damage on trunks, roots, and lianas. Pod exudates are reported to contain greater amounts of readily available energy than do trunk and root exudates, and were consumed throughout all periods of the day, particularly in the late afternoon. Trunk and root exudates were consumed principally in the morning. We propose that digestive adaptations of the hindgut, which enable callimicos to exploit fungi (a resource high in structural carbohydrates) year‐round, predispose them to efficiently exploit and process exudates as fallback foods when other resources, such as ripe fruits, are scarce. Am. J. Primatol. 71:120–129, 2009. © 2008 Wiley‐Liss, Inc.
Evidences of solvent‐induced miscibility in polychloroprene‐co‐ethylene‐propene diene terpolymer blends
Authors: Dubey K. A. , Bhardwaj Y. K. , Chaudhari C. V. , Kumar Virendra , Goel N. K. , Sabharwal S.
Published: November 2008

Solvent dependent changes in the compatibility behavior of Polychloroprene/Ethylene–propylene–diene terpolymer blends (CR/EPDM) have been investigated using dilute solution viscometry and solvent permeability analysis. To predict the compatibility of rubber blends of different compositions in solvents of different cohesive energy densities, Huggins interaction parameter (ΔB), hydrodynamic interaction (Δη) and Sun's parameter (α) were evaluated from the analysis of the specific and reduced viscosity data of two and three‐component polymer solutions. Miscibility criteria were not satisfied for CR/EPDM blends over the entire composition range in toluene, xylene, and carbon tetrachloride (CCl4), however, a narrow miscibility domain was observed in chloroform (CHCl3) for CR/EPDM/CHCl3 system. These results were further corroborated with the analysis of heat of mixing (ΔHm) and polymer–polymer interaction parameter (χ12), for all rubber blend compositions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Kinetics of the thermal degradation of hyperbranched poly(phenylene sulfide)
Authors: Bo Yan , Yanmo Chen , Hao You , Bin Sun , Meifang Zhu
Published: November 2008

An advanced heat‐resistant hyperbranched poly(phenylene sulfide) (HPPS) had been subjected to dynamic thermogravimetric analysis (TGA) in nitrogen. The presence of a single peak in the DTG cures suggested that weight loss occurs in a single stage. The thermal decomposition kinetics had been analyzed by applying the Kissinger, Friedman and Ozawa‐Flynn methods. The E values determined for the hyperbranched PPS using these analyses were found to be 183.1, 189.2, 193.9 kJ mol−1, respectively. Coats‐Redfern method was used to discuss the probable degradation mechanisms. The solid‐state decomposition mechanism followed by the degradation stage of HPPS was Phase boundary controlled mechanism (R1). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of silane coupling agent on swelling behaviors and mechanical properties of thermosensitive hybrid gels
Authors: Huang Wei‐Jen , Lee Wen‐Fu
Published: November 2008

A series of organic–inorganic hybrid thermosensitive gels with three different structures were prepared from N‐isopropylacrylamide (NIPAAm), and N, N′‐methylenebisacrylamide (NMBA) and tetraethoxysilane (TEOS) [N‐IPN]; NIPAAm, 3‐(trimethoxysilyl) propyl methacrylate (TMSPMA) as coupling agent and TEOS [NT‐IPN]; and NIPAAm, TMSPMA, and TEOS [NT‐semi‐IPN] by emulsion polymerization and sol–gel reaction in this study. The effect of different gel structures and coupling agent on the swelling behavior, mechanical properties, and morphologies of the present gels was investigated. Results showed that the properties of the gels would be affected by the gel networks such as IPN or semi‐IPN and with or without existence of TMSPMA as the bridge chain between networks. The NT‐semi‐IPN gel had higher swelling ratio and faster diffusion rate because poly(NIPAAm) moiety in the semi‐IPN gels was not restricted by NMBA network. However, the IPN gels such as N‐IPN and NT‐IPN had good mechanical properties and lower swelling ratio, but had a poor thermosensitivity due to the addition of coupling agent, TMSPMA, into the gel system that resulted in denser link between organic and inorganic components. The morphology showed that IPN gels had partial aggregation (siloxane domain) and showed some denser phases. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Markers of acculturation and risk of NTDs among Hispanic women in California
Authors: Carmichael Suzan L. , Shaw Gary M. , Song Jun , Abrams Barbara
Published: November 2008

BACKGROUND: Prevalences of NTDs are typically 50–100% greater among Hispanic women compared to non‐Hispanic Whites. This article examines whether markers of acculturation such as “language preference” allow the identification of high‐risk groups within the Hispanic population. It also examines whether known NTD risk factors explain observed differences in risk among Hispanic women who are more and less acculturated. METHODS: This population‐based case‐control study of deliveries in selected California counties from 1999–2003 included 337 NTD cases and 626 nonmalformed, liveborn controls. RESULTS: Relative to less acculturated US‐born Hispanic women (i.e., women who preferred reading and speaking Spanish), other subgroups (i.e., US‐born Hispanic women who preferred English, foreign‐born Hispanic women regardless of “language preference”, and non‐Hispanic White women) had approximately twofold increased risks of spina bifida. Only the less acculturated foreign‐born women (i.e., women with a preference for Spanish) had substantially increased risk of anencephaly (OR 1.7; 95% CI 0.9, 3.4). Adjustment for several NTD risk factors (maternal intake of folic acid‐containing supplements, dietary folate intake, body mass index, food insecurity, stressful life events, smoking, alcohol intake, education, income, and neighborhood education and poverty) resulted in modest or no reductions in most of the ORs. CONCLUSIONS: The explanation for variability in NTD risks among Hispanic and non‐Hispanic White women therefore likely extends beyond most known NTD risk factors. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.
A case control population‐based study investigating smoking as a risk factor for gastroschisis in Utah, 1997–2005
Authors: Feldkamp Marcia L. , Alder Stephen C. , Carey John C.
Published: November 2008

BACKGROUND:Smoking in pregnancy increases the risk for many different adverse pregnancy outcomes, including birth defects. Gastroschisis, a birth defect most commonly associated with young maternal age has been associated with smoking, but findings are inconsistent. We assessed whether smoking increases the risk for gastroschisis using population‐based data from Utah.METHODS:Gastroschisis cases (n= 189) were identified from the Utah Birth Defect Network and all live births without birth defects (n= 423,499) occurring in Utah from January 1, 1997 through December 31, 2005 served as controls. Exposure data were derived from birth certificates and fetal death certificates and, for terminated pregnancies, the Utah Birth Defect Network.RESULTS:Women who smoked during the first trimester of pregnancy had an increased risk of gastroschisis (OR 1.6; 95% CI: 1.1, 2.3) after adjusting for maternal age and preconception BMI. Discordance between birth certificate data and data from structured interviews increased exposure prevalence from 16.9 to 22.2% for case mothers and 7.4 to 13.2% for control mothers. Accounting for this misclassification, the crude OR decreased by 24%, 1.9 (1.3, 2.7).CONCLUSIONS:Though first trimester cigarette smoking was reported on birth certificates by more mothers of gastroschisis cases than controls, adjustment for confounders (maternal age and preconception BMI) and smoking misclassification suggests the association is weak. Despite a decrease in smoking prevalence among all women of childbearing years in Utah between 1997 and 2005, the prevalence of gastroschisis has not followed a similar trend. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.
Starch phosphorylation—Maltosidic restrains upon 3′‐ and 6′‐phosphorylation investigated by chemical synthesis, molecular dynamics and NMR spectroscopy
Authors: Hansen Peter I. , Spraul Manfred , Dvortsak Peter , Larsen Flemming H. , Blennow Andreas , Motawia Mohammed S. , Engelsen Søren B.
Published: November 2008

Phosphorylation is the only known in vivo substitution of starch, yet no structural evidence has been provided to explain its implications of the amylosidic backbone and its stimulating effects on starch degradation in plants. In this study, we provide evidence for a major influence on the glucosidic bond in starch specifically induced by the 3‐O‐phosphate. Two phosphorylated maltose model compounds were synthesized and subjected to combined molecular dynamics (MD) studies and 950 MHz NMR studies. The two phosphorylated disaccharides represent the two possible phosphorylation sites observed in natural starches, namely maltose phosphorylated at the 3′‐ and 6′‐position (maltose‐3′‐O‐phosphate and maltose‐6′‐O‐phosphate). When compared with maltose, both of the maltose‐phosphates exhibit a restricted conformational space of the α(1→4) glycosidic linkage. When maltose is phosphorylated in the 3′‐position, MD and NMR show that the glucosidic space is seriously restricted to one narrow potential energy well which is strongly offset from the global potential energy well of maltose and almost 50°degrees from the Φ angle of the α‐maltose crystal structure. The driving force is primarily steric, but the configuration of the structural waters is also significantly altered. Both the favored conformation of the maltose‐3′‐phosphate and the maltose‐6′‐phosphate align well into the 6‐fold double helical structure of amylopectin when the effects on the glucosidic bond are not taken into account. However, the restrained geometry of the glucosidic linkage of maltose‐3′‐phosphate cannot be accommodated in the helical structure, suggesting a major local disturbing effect, if present in the starch granule semi‐crystalline lattice. © 2008 Wiley Periodicals, Inc. Biopolymers 91: 179–193, 2009.

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
Biochemical and biophysical characterization of a novel plant protein disulfide isomerase
Authors: Gruber Christian W. , Čemažar Maša , Mechler Adam , Martin Lisandra L. , Craik David J.
Published: November 2008

We recently isolated a protein disulfide isomerase (PDI) from the Rubiaceae (coffee family) plant Oldenlandia affinis (OaPDI) and demonstrated that it facilitates the production of disulfide‐knotted defense proteins called cyclotides. PDIs are major folding catalysts in the eukaryotic ER where they are responsible for formation, breakage, or shuffling of disulfide bonds in substrate polypeptides and are important chaperones in the secretory pathway. Here, we report the first detailed analysis of the oligomerization behavior of a plant PDI, based on characterization of OaPDI using various biochemical and biophysical techniques, including size‐exclusion chromatography, NMR spectroscopy, surface plasmon resonance and atomic force microscopy. In solution at low concentration OaPDI comprises mainly monomers, but fractions of dimers and/or higher‐order oligomers were observed at increased conditions, raising the possibility that dimerization and/or oligomerization could be a mechanism to adapt to the various‐sized polypeptide substrates of PDI. Unlike mammalian PDIs, oligomerization of the plant PDI is not driven by the formation of intermolecular disulfide bonds, but by noncovalent interactions. The information derived in this study advances our understanding of the oligomerization behavior of OaPDI in particular but is potentially of broader interest for understanding the mechanism and role of oligomerization, and hence the catalytic and physiological mechanism, of the ubiquitous folding catalyst PDI. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 35–43, 2009.

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
Liquid–liquid extraction of fermentation inhibiting compounds in lignocellulose hydrolysate
Authors: Zautsen R.R.M. , Maugeri‐Filho F. , Vaz‐Rossell C.E. , Straathof A.J.J. , van der Wielen L.A.M. , de Bont J.A.M.
Published: November 2008

Several compounds that are formed or released during hydrolysis of lignocellulosic biomass inhibit the fermentation of the hydrolysate. The use of a liquid extractive agent is suggested as a method for removal of these fermentation inhibitors. The method can be applied before or during the fermentation. For a series of alkanes and alcohols, partition coefficients were measured at low concentrations of the inhibiting compounds furfural, hydroxymethyl furfural, vanillin, syringaldehyde, coniferyl aldehyde, acetic acid, as well as for ethanol as the fermentation product. Carbon dioxide production was measured during fermentation in the presence of each organic solvent to indicate its biocompatibility. The feasibility of extractive fermentation of hydrolysate was investigated by ethanolic glucose fermentation in synthetic medium containing several concentrations of furfural and vanillin and in the presence of decanol, oleyl alcohol and oleic acid. Volumetric ethanol productivity with 6 g/L vanillin in the medium increased twofold with 30% volume oleyl alcohol. Decanol showed interesting extractive properties for most fermentation inhibiting compounds, but it is not suitable for in situ application due to its poor biocompatibility. Biotechnol. Bioeng. 2009;102: 1354–1360. © 2008 Wiley Periodicals, Inc.
Functional characterization of a bacterial expansin from Bacillus subtilis for enhanced enzymatic hydrolysis of cellulose
Authors: Kim Eun Sil , Lee Hee Jin , Bang Won‐Gi , Choi In‐Geol , Kim Kyoung Heon
Published: November 2008

Expansin is a plant protein family that induces plant cell wall‐loosening and cellulose disruption without exerting cellulose‐hydrolytic activity. Expansin‐like proteins have also been found in other eukaryotes such as nematodes and fungi. While searching for an expansin produced by bacteria, we found that the BsEXLX1 protein from Bacillus subtilis had a structure that was similar to that of a β‐expansin produced by maize. Therefore, we cloned the BsEXLX1 gene and expressed it in Escherichia coli to evaluate its function. When incubated with filter paper as a cellulose substrate, the recombinant protein exhibited both cellulose‐binding and cellulose‐weakening activities, which are known functions of plant expansins. In addition, evaluation of the enzymatic hydrolysis of filter paper revealed that the recombinant protein also displayed a significant synergism when mixed with cellulase. By comparing the activity of a mixture of cellulase and the bacterial expansin to the additive activity of the individual proteins, the synergistic activity was found to be as high as 240% when filter paper was incubated with cellulase and BsEXLX1, which was 5.7‐fold greater than the activity of cellulase alone. However, this synergistic effect was observed when only a low dosage of cellulase was used. This is the first study to characterize the function of an expansin produced by a non‐eukaryotic source. Biotechnol. Bioeng. 2009;102: 1342–1353. © 2008 Wiley Periodicals, Inc.
Sensitivity Study on Modeling an Internal Airlift Loop Reactor Using a Steady 2D Two‐Fluid Model
Authors: Huang Q. , Yang C. , Yu G. , Mao Z.‐S.
Published: November 2008

The sensitivity study of bubbly flow in an internal airlift loop reactor is presented using a steady Reynolds averaging two‐fluid model. Comparative evaluation of different drag formulations, drag coefficient correlations, turbulence effect on the drag coefficient, outlet slip velocity, and bubble size is performed and the respective influence to the simulation results is highlighted. It is found that a complicated drag formulation may not result in reliable predictions. All the drag coefficient correlations underpredict the gas holdup if the influence of turbulence on the drag coefficient is not well incorporated. Fortunately, the global hydrodynamics is not sensitive to the outflow slip velocity for a wide range, so a steady two‐fluid model can be used to simulate the bubbly flow when the flow field is fully developed. The correct estimation of bubble size with properly selected correlations play an important role in successful simulation of gas‐liquid bubbly flow in airlift loop reactors.