bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seasonal changes of CLA isomers and other fatty acids of milk fat from grazing dairy herds in the Azores
Authors: Rego Oldemiro A , Rosa Henrique JD , Regalo Susana M , Alves Susana P , Alfaia Cristina MM , Prates José AM , Vouzela Carlos M , Bessa Rui JB 
Published: June 2008

AbstractBACKGROUND: Season of the year associated with dietary changes has been recognized as a factor implicated in milk fat fatty acid (FA) profile in dairy cows. However, a lack of information exists concerning cows grazing all year round as is practiced in the Azores, where cows are supplemented in winter with maize silage plus concentrates, while in spring the higher grass allowance only requires supplementation with concentrate. The main objective of this study was to detect any seasonal variation of FA profile of milk fat from milk sampled in bulk tanks of 12 Azorean dairy herds.RESULTS Compared to winter milk, milk fat from spring presented a higher proportion of CLA cis‐9,trans‐11 (14.3 versus 9.6 g kg−1 FA), C18:1 trans‐11 (32 versus 22 g kg−1 FA), C18:2 trans‐11,cis‐15 (3.7 versus 2.2 g kg−1 FA), CLA trans‐11,cis‐13 (0.34 versus 0.23 g kg−1 FA) and C18:3 n‐3 (5.7 versus 5.4 g kg−1 FA). The C18:2 n‐6/C18:3 n‐3 ratio was lower (P < 0.05) in spring. Branched‐chain FA, except the anteiso‐C15:0, were higher in spring, while odd‐chain FA (C15:0) were higher in winter.CONCLUSION: Dairy herd management in the Azores presents a seasonal variation of milk fat FA composition, where the spring milk may present increased potential benefits for human consumers. Copyright © 2008 Society of Chemical Industry
Poly(phenylacetylene)s Carrying Siloxy, Carbonate, and Hydroxy Groups: Synthesis and Properties
Authors: Saeed Irfan , Shida Yuichi , Khan Fareha Zafar , Shiotsuki Masashi , Masuda Toshio 
Published: June 2008

Abstractt‐Butyldimethylsilyl (t‐BDMS) and t‐butoxycarbonyl (t‐Boc) protected 3‐ and 4‐hydroxyphenylacetylene monomers were synthesized and polymerized using [(nbd)RhCl]2 (1) and [(nbd)RhBPh4] (2) catalysts. The t‐BDMS‐containing polymers [poly(3a) and poly(4a)] were obtained in good yield (45–69%) while the t‐Boc‐protected monomers polymerized in a high yield [poly(5a) and poly(6a): 80–100%]. The use of KN(SiMe3)2 as a cocatalyst in conjunction with 1 led to a dramatic increase in the molecular weight of the polymers. The acid‐catalyzed removal of the t‐BDMS group afforded the naked hydroxy‐containing polymers [poly(3b) and poly(4b)] which cannot be obtained directly by the polymerization of the corresponding monomers. The polymers containing protected OH moieties were more soluble in less polar solvents, whereas their deprotected counterparts displayed good solubility in polar protic or highly polar aprotic solvents. The attempts to accomplish the free‐standing membrane fabrication by solution casting were successful only for poly(3a) and an augmentation in the gas permeability was discerned in comparison with the unsubstituted poly(phenylacetylene) and poly(o‐methylphenylacetylene).magnified image
Two Coexisting Modes in Field‐Assisted AFM Nanopatterning of Thin Polymer Films
Authors: Xie Xian Ning , Chung Hong Jing , Bandyopadhyay Dipankar , Sharma Ashutosh , Sow Chorng Haur , Bettiol Andrew Anthony , Wee Andrew Thye Shen 
Published: June 2008

AbstractTwo coexisting mechanisms, i.e., electrohydrodynamic destabilization and electrostatic detachment, for polymer nanostructuring in field‐assisted atomic force microscope nanolithography are presented. The electrohydrodynamic destabilization mechanism is based on the surface instability of molten polymer film in the form of surface waves, and it leads to the formation of well defined polymeric wave patterns. The electrostatic detachment mechanism is associated with nano‐blister formation caused by pre‐existing defects, such as buried cavities in the polymer, and is responsible for the creation of hollow pillar‐like structures. Here, the coexistence and pattern formation probability of the two polymer patterning modes under similar nanolithographic conditions are discussed. It was found that the field strength and the efficiency of probe‐induced joule heating can significantly change the flow property of the polymer, which eventually leads to the occurrence of the two modes. The results presented here are useful in obtaining a complete picture of the diverse behaviors of polymers in AFM nanolithographic operations.magnified image
Can the First Addition of Alkyl Radicals Play a Role in the Fate of NMP?
Authors: Bagryanskaya Elena , Bertin Denis , Gigmes Didier , Kirilyuk Igor , Marque Sylvain R. A. , Reznikov Vladimir , Roshchupkina Galina , Zhurko Irina , Zubenko Dmitry 
Published: June 2008

AbstractValues of kd for the CON bond homolysis were measured for alkoxyamines based on imidazoline and imidazole nitroxides. They were analyzed in terms of polar/stabilization, steric, and entropic effects. kd decreased with increasing electron‐withdrawing capacities of the groups attached to the nitroxide, but increasing with both the bulkiness of the group attached to the nitroxide and the presence of substituents on the ring. With three alkoxyamines, it was shown that the fate of the NMP of styrene depended on the type of initiating alkyl radical: successful for initiating 1‐phenylethyl radicals and unsuccessful for initiating p‐nitrophenyloxycarbonyl‐2‐prop‐2‐yl radicals.magnified image
Synthesis of High Density Polymer Brushes on Nanoparticles by Combined RAFT Polymerization and Click Chemistry
Authors: Ranjan Rajesh , Brittain William J. 
Published: June 2008

AbstractIn the present paper, we report the successful preparation of high density, well‐defined polymer brushes by RAFT polymerization on silica nanoparticles. Our strategy includes (i) “grafting from” approach for brush formation, (ii) facile click reaction to immobilize RAFT agent, (iii) synthesis of R‐supported chain transfer agent (CTA) over Z‐supported CTA, and (iv) use of more active trithiocarbonate RAFT agent over conventional dithioester type RAFT agent. With the advantage of the properties of high‐density polymer brushes, these diblock copolymer‐modified silica nanoparticles open the route to the elaboration of a new family of nanocomposite colloids with potential applications in responsive or smart systems.magnified image
Aggregation Behavior of Homo‐PS/PS‐b‐P2VP Blends at the Air/Water Interface
Authors: Wen Gangyao , Chung Bonghoon , Chang Taihyun 
Published: June 2008

AbstractThe mixed Langmuir monolayers and Langmuir–Blodgett (LB) films of homo‐polystyrene (h‐PS) and the diblock copolymer polystyrene‐block‐poly(2‐vinylpyridine) (PS‐b‐P2VP) have been characterized by the Langmuir monolayer technique and tapping mode atomic force microscopy (AFM), respectively. When the content of h‐PS is below 80 wt.‐%, the mixed LB films of h‐PS/PS‐b‐P2VP mainly exhibit isolated circular nanoaggregates. With a further increase of the h‐PS content (80–95%), however, highly uniform and stable necklace‐network structures are observed in the mixed LB films.magnified image
Metal Salt‐Induced Ferroelectric Crystalline Phase in Poly(vinylidene fluoride) Films
Authors: Yoon Sun , Prabu Arun Anand , Kim Kap Jin , Park Cheolmin 
Published: June 2008

AbstractIn this Communication, the effect of varying mass fractions (0–20 wt.‐%) of calcium chloride (CaCl2) salt on the α‐ and β‐phase content of poly(vinylidene fluoride) (PVDF) as‐cast films were investigated. Spectral and X‐ray studies revealed the maximum ferroelectric β‐phase for the addition of 15 wt.‐% of CaCl2 in PVDF compared to neat PVDF samples. The dense β‐phase dominant PVDF–CaCl2 (15 wt.‐%) thick film used as a ferroelectric insulator in one‐capacitor (1C) type random access memory device exhibited a remnant polarization of 3.1 µC · cm2, and is a good indication that the unoriented PVDF–CaCl2 films can be used in electronic applications without further stretching process.magnified image
Click Chemistry: A Powerful Tool to Create Polymer‐Based Macromolecular Chimeras
Authors: Le Droumaguet Benjamin , Velonia Kelly 
Published: June 2008

AbstractThe combination of polymeric with biological materials, to create biohybrid macromolecules that merge the properties of both the natural and synthetic components, is a flourishing area in both life sciences and biotechnology. The click chemistry philosophy has recently provided a powerful tool in this direction, leading to a plethora of novel, tailor‐made biomacromolecules with unprecedented structural characteristics and properties. The different synthetic strategies, using the alkyne–azide click cycloadditions to bioorthogonally achieve the coupling of synthetic polymers with nucleic acids, peptides, sugars, proteins or even viruses and cells is described. The review covers the latest developments in this very dynamic and rapidly expanding field.magnified image
A “Click” Strategy for Tuning in situ the Hydrophilic–Hydrophobic Balance of AB Macrosurfactants
Authors: Zarafshani Zoya , Akdemir Özgür , Lutz Jean‐François 
Published: June 2008

AbstractThe self‐organization of amphiphilic block copolymers in water strongly depends on their molecular structure, in particular on their hydrophilic–hydrophobic balance. Herein, a simple method for tuning the amphiphilicity of polymeric macrosurfactants in aqueous medium is proposed. This concept relies on the “click” ligation of an amphiphilic block copolymer (AB type) and a hydrophilic homopolymer (B type). In the present communication, the validity of this approach was examined with model polymers based on polystyrene (PS) and poly[oligo (ethylene glycol) acrylate] (POEGA) segments. A well‐defined ω‐azido functional diblock copolymer PS‐b‐POEGA and an α‐alkyne functional homopolymer POEGA were prepared using atom transfer radical polymerization. These two polymers could be efficiently coupled to each other via copper‐catalyzed azide–alkyne click chemistry in aqueous medium. Moreover, in this coupling strategy, an ester group was introduced at the junction between AB and B segments. This labile moiety may be “cut” by hydrolysis.magnified image
Access to Three‐Arm Star Block Copolymers by a Consecutive Combination of the Copper(I)‐Catalyzed Azide–Alkyne Cycloaddition and the RAFT Hetero Diels–Alder Concept
Authors: Sinnwell Sebastian , Inglis Andrew J. , Stenzel Martina H. , Barner‐Kowollik Christopher 
Published: June 2008

AbstractThree‐arm star block copolymers have been synthesized from linear polystyrene (PS) and poly(ε‐caprolactone) (PCL) building blocks. Through the use of an α‐diene‐ω‐alkyne functionalized PCL, the PS‐b‐PCL stars have been synthesized via either forming the PS‐b‐PCL arms first with the hetero Diels–Alder (HDA) cycloaddition and their subsequent coupling to a triazide coupling agent through a copper(I)‐catalyzed azide–alkyne cycloaddition (CuAAC) (arm‐first) or via forming the basic star structure first through the CuAAC of the coupling agent and the PCL, with the diblock stars achieved by the subsequent HDA cycloaddition with the PS (core‐first). The use of the two consecutive reactions has facilitated high conversions and a good control over the multiple reaction sites. In both examples, the CuAAC proceeded to quantitative conversion whereas the HDA cycloaddition proceeded to 94% conversion in the arm‐first approach and 81% in the core‐first approach.magnified image
Local Viscosity in the Vicinity of a Wall Coated by Polymer Brush from Green–Kubo Relations
Authors: Dimitrov Dimitar I. , Milchev Andrey , Binder Kurt 
Published: June 2008

AbstractWhen fluids are confined in slit pores between parallel walls, their static structures and their dynamical properties exhibit inhomogeneity in the z‐direction perpendicular to the wall. Of particular interest are local bulk viscosity ηb(z) and shear viscosity ηs(z). Here, we discuss an algorithm to estimate these quantities from Green–Kubo relations using equilibrium molecular dynamics. As an application example, a polymer brush (macromolecules end‐grafted to a substrate at z = 0) interacting with a solvent formed from point‐like particles is given.magnified image
Quality of life in Parkinson's disease: The relative importance of the symptoms
Authors: Rahman Shibley , Griffin Harry J. , Quinn Niall P. , Jahanshahi Marjan 
Published: June 2008

AbstractA body of literature now exists, which demonstrates that idiopathic Parkinson's disease (PD) has a major negative impact on quality of life (QoL), and that depression and cognitive impairment are among the main predictors of poor QoL in this disorder. Relatively little work has been done to assess the differential contribution of the specific symptoms of PD to QoL, which was the aim of this study. One hundred thirty patients with PD completed a booklet of questionnaires, which included the PDQ39 as a disease‐specific measure of QoL, a symptom checklist, a mobility checklist, as well as patient ratings of disease stage and disability. The results indicated that the contribution of physical, medication‐related, and cognitive/psychiatric symptoms to QoL can be significant. Sudden unpredictable on/off states, difficulty in dressing, difficulty in walking, falls, depression, and confusion were PD symptoms, which significantly influenced QoL scores. Among the mobility problems associated with PD, start hesitation, shuffling gait, freezing, festination, propulsion, and difficulty in turning had a significant effect on QoL scores. In addition to depression and anxiety, the major predictors of QoL were shuffling, difficulty turning, falls, difficulty in dressing, fatigue, confusion, autonomic disturbance particularly urinary incontinence, unpredictable on/off fluctuations, and sensory symptoms such as pain. The implications of these results for the medical management of PD are discussed. © 2007 Movement Disorder Society
Determination of sex and scrapie resistance genotype in preimplantation ovine embryos
Authors: Guignot Florence , Baril Gerard , Dupont Francis , Cognie Yves , Folch Jose , Alabart Jose Luis , Poulin Naty , Beckers Jean‐Francois , Bed'hom Bertrand , Babilliot Jean‐Marc , Mermillod Pascal 
Published: June 2008

AbstractThe aim of this study was to test the accuracy of genotype diagnosis after pre‐amplification of DNA extracted from biopsies obtained by microblade cutting of ovine embryos and to evaluate the viability of biopsied embryos after vitrification/warming and transfer to recipients. Sex and PrP genotypes were determined. Sex diagnosis was done by PCR amplification of ZFX/ZFY and SRY sequences after PEP‐PCR while PrP genotype determination was performed after specific pre‐amplification of specific target including codons 136, 154 and 171. Embryos were collected at Day 7 after oestrus. Blastocysts and expanded blastocysts were biopsied immediately after collection whereas compacted morulae were biopsied after 24 hr of in vitro culture. Eighty‐nine biopsied embryos were frozen by vitrification. Fresh and vitrified whole embryos were kept as control. DNA of biopsies was extracted and pre‐amplified. Sex diagnosis was efficient for 96.6% of biopsies and PrP genotyping was determined in 95.8% of codons. After embryo transfer, no significant difference was observed in lambing rate between biopsied, vitrified control and fresh embryos (54.5%, 60% and 66.6%, respectively). Embryo survival rate was not different between biopsied and whole vitrified embryos (P = 0.38). At birth, 96.7% of diagnosed sex and 95.4% of predetermined codons were correct. Lamb PrP profiles were in agreement with parental genotype. PEP‐PCR coupled with sex diagnosis and nested PCR coupled with PrP genotype predetermination are very accurate techniques to genotype ovine embryo before transfer. These original results allow planning of selection of resistant genotype to scrapie and sex of offspring before transfer of cryopreserved embryo. Mol. Reprod. Dev. 76: 183–190, 2009. © 2008 Wiley‐Liss, Inc.
Gonadotropin‐dependent regulation of the prostaglandin E2 receptor in equine preovulatory follicles during the ovulatory process in mares
Authors: Sayasith Khampoune , Bouchard Nadine , Doré Monique , Sirois Jean 
Published: June 2008

AbstractThe objectives of the study were to clone the primary structure of the prostaglandin E2 receptor subtype 2 (PTGER2) cDNA and to characterize its regulation in equine follicles during gonadotropin‐induced ovulation. Results from DNA isolation indicated that the equine PTGER2 cDNA encodes a predicted 353‐amino acid protein, which is highly similar (76–85%) to known mammalian homologues. The regulation of PTGER2 was studied by semi‐quantitative RT‐PCR/Southern blot using preparations of theca interna and mural granulosa cells isolated from equine follicles 0–39 hr post‐treatment with human chorionic gonadotropin (hCG). Results indicated that a significant increase of PTGER2 mRNA occurred at 24 and 39 hr post‐hCG in granulosa cells, and 30 and 33 hr post‐hCG in theca cells (P < 0.05). Immunohistochemical staining and immunoblotting performed on equine follicular samples showed a corresponding increase of PTGER2 protein in both cell types after treatment with hCG. Levels of PTGER2 mRNA were also high in uterus, thymus and spleen, but moderate to low in other tested tissues. In the ovary, the expression of PTGER4 mRNA was observed and predominantly occurred in granulosa cells, with highest abundance of transcripts observed at 12 and 39 hr post‐hCG. Thus, this study reports for the first time in mares that the ovulatory process is accompanied by the gonadotropin‐dependent up‐regulation of PTGER2 and PTGER4, which may in turn regulate PGE2‐mediated preovulatory effects. Mol. Reprod. Dev. 76: 191–201, 2009. © 2008 Wiley‐Liss, Inc.
Efficient production of nuclear transferred rat embryos by modified methods of reconstruction
Authors: Popova Elena , Bader Michael , Krivokharchenko Alexander 
Published: June 2008

AbstractIn this study we investigated spontaneous oocyte activation and developmental ability of rat embryos of the SD‐OFA substrain. We also tried to improve the somatic cell nuclear transfer (SCNT) technique in the rat by optimizing methods for the production of reconstructed embryos. About 20% of oocytes extruded the second polar body after culture for 3 hr in vitro and 84% of oocytes were at the MII stage. MG132 blocked spontaneous activation but decreased efficiency of parthenogenetic activation. Pronuclear formation was more efficient in strontium‐activated oocytes (66.1–80.9%) compared to roscovitine activation (24.1–54.5%). Survival rate after enucleation was significantly higher (89.4%) after slitting the zona pellucida and then pressing the oocyte with a holding pipette in medium without cytochalasin B (CB) compared to the conventional protocol using aspiration of the chromosomes after CB treatment (67.7%). Exposure of rat ova to UV light for 30 sec did not decrease their in vitro developmental capacity. Intracytoplasmic cumulus cell injection dramatically decreased survival rate of oocytes (42%). In contrast, 75.9% of oocytes could be successfully electrofused. Development to the 2‐cell stage was reduced after SCNT (24.6% compared 94.6% in controls) and none from 244 reconstructed embryos developed in vitro beyond this stage. After overnight in vitro culture, 74.4% of the SCNT embryos survived and 56.1% formed pronuclei. The pregnancy rate of 33 recipients after the transfer of 695 of these cloned embryos was, however, very low (18.2%) and only six implantation sites could be detected (0.9%) without any live fetuses and offspring. Mol. Reprod. Dev. 76: 208–216, 2009. © 2008 Wiley‐Liss, Inc.
Polymerisable Miniemulsions Using Rotor‐Stator Homogenisers
Authors: El‐Jaby Ula , Cunningham Michael , Enright Tom , McKenna Timothy F. L. 
Published: June 2008

AbstractThe use of a rotor‐stator mixer as a homogenisation device to make miniemulsion droplets with industrially pertinent solid contents was investigated. Methyl methacrylate/butyl acrylate (50:50 w/w ratio) miniemulsions with droplet diameters from 2 µm to 300 nm and polydispersity indices from 1.2 to 3.6 were used. Miniemulsions with three different mean droplet diameters (300, 400, 600 nm) were polymerised and the evolution of particle size was observed. When 300 nm droplets were polymerised they yielded particles of similar diameter to the original droplets, whereas particle coalescence of the growing particles with a loss of control over the particle size distribution was observed for the 400 and 600 nm droplets. The influence of costabiliser, agitation speed, solid content, colloidal protectors and surface coverage on the evolution of the droplet size and size distribution as well as on the evolution of the average particle size and its distribution were examined. It was observed that changing the above parameters had no impact on the evolution of the particle size, suggesting we have a very robust miniemulsion system.magnified image
Quantitative methods, economics, and or models
Authors: Desai Anand 
Published: June 2008

AbstractTraining in quantitative methods is seen as essential for policy analysts, public administrators, and public managers if they are to make cogent and informed data‐based arguments. If our objective is to help students and future practitioners identify credible evidence, to make sense of that evidence, link it to their substantive knowledge, and thereby develop a defensible case for action, then this paper argues that our current approach to teaching methods is inappropriate. We need to take into consideration the learning styles and needs of our students in designing the delivery and content of our courses. Our current emphasis on teaching techniques needs to be replaced by an emphasis on teaching about the concepts underlying these tools and techniques. © 2008 by the Association for Public Policy Analysis and Management.
A strategic response to class size reduction: Combination classes and student achievement in California
Authors: Sims David 
Published: June 2008

AbstractThe California class size reduction program provided schools with cash rewards for K–3 classes of 20 or fewer students. I show how program rules made it possible for schools to save money by using mixed‐grade classes to meet class size reduction obligations while maintaining larger average class sizes. I also show that this smoothing of students across grades is associated with a significant test score gap for certain second and third grade students. My estimates suggest that class size reduction may lead to lower test scores for students placed in combination classes. Alternative explanations of teacher experience and credentialing changes cannot explain the test score pattern. This result spotlights both the underappreciated role of age heterogeneity in classroom learning and the difficulty of replicating the success of policy experiments in statewide reform. © 2008 by the Association for Public Policy Analysis and Management.
Causes of Urban Sprawl in the United States: Auto reliance as compared to natural evolution, flight from blight, and local revenue reliance
Authors: Wassmer Robert W. 
Published: June 2008

AbstractThis paper describes a statistical study of the contribution of theories previously offered by economists to explain differences in the degree of urban decentralization in the U.S. The focus is on a relative comparison of the influence of auto reliance. A regression analysis reveals that a 10 percent reduction in the percentage of households owning one or more autos would reduce the square mile size of an urban area by only 0.5 percent and raise its population density by only 0.7 percent. Factors falling under the categories of “natural evolution” and “flight from blight” exert a far greater magnitude of influence. For instance, a 10 percent reduction in per capita income would reduce the square mile size of an urban area by 11.4 percent and raise its population density by 10.1 percent, while a 10 percent decrease in the percentage central place(s) population poor would reduce the square mile size of an urban area by 2.6 percent and raise its population density by 1.7 percent. A significant increase in urban decentralization will require more than just reduced auto reliance. © 2008 by the Association for Public Policy Analysis and Management.