bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimized Preparation of Elastically Soft, Highly Piezoelectric, Cellular Ferroelectrets from Nonvoided Poly(ethylene Terephthalate) Films
Authors: Wirges W. , Wegener M. , Voronina O. , Zirkel L. , Gerhard‐Multhaupt R.
Published: January 2007

Electrically charged cellular polymer films can exhibit very high piezoelectric activity and are therefore more and more often employed in advanced electromechanical and electro‐acoustical transducers. In this paper, we report an optimized sequence of steps for preparing such ferroelectrets from commercial nonvoided poly(ethylene terephthalate) (PETP) films by means of foaming with CO2, biaxial mechanical stretching, controlled void inflation, and bipolar electric charging. The nonvoided PETP films were foamed with supercritical CO2 at a suitably high pressure and subsequently annealed for stabilization. The cellular foam structure was further optimized by means of well‐controlled biaxial stretching in a commercial stretcher and sometimes subsequent inflation in a pressure chamber. Bipolar electric charging of the internal voids was achieved through the application of high electric fields in an SF6 atmosphere. The new optimized PETP ferroelectrets exhibit quite large piezoelectric coefficients up to almost 500 pC N–1, for which unusually low elastic stiffnesses of only around 0.3 MPa are essential. The PETP‐foam ferroelectrets possess unclamped thickness‐extension resonance frequencies between approximately 120 and 250 kHz, and are thus highly suitable for several established as well as novel ultrasonic‐transducer applications.
N∧C∧N‐Coordinated Platinum(II) Complexes as Phosphorescent Emitters in High‐Performance Organic Light‐Emitting Devices
Authors: Cocchi M. , Virgili D. , Fattori V. , Rochester D. L. , Williams J. A. G.
Published: January 2007

A series of terdentate cyclometallated PtII complexes with remarkable luminescence properties are used as new phosphorescence‐emitting dopants in a blended host matrix as the emitting layer, resulting in very high electroluminescence efficiencies. Because of the high phosphorescence quantum yields of these Pt complexes and the efficient energy transfer from both singlet and triplet excited states of the host to the emitting guest, external electroluminescence quantum efficiencies as high as 4–16 % photons per carrier and luminous efficiencies of 15–40 cd A–1 are achieved. Moreover, these high efficiency values were maintained over a four‐decade current intensity span with no significant roll‐off. Tuning of the electroluminescence spectra from the yellow to the green‐bluish region of the chromaticity diagram is obtained simply by changing the substituents at the central 5‐position of the cyclometallating ligand.
Optimal off‐line trajectory planning of hybrid fuel cell/gas turbine power plants
Authors: Kameswaran Shivakumar , Biegler L. T. , Junker S. Tobias , Ghezel‐Ayagh Hossein
Published: January 2007

A nonlinear programming (NLP) framework is developed to determine optimal operating policies for hybrid fuel cell/gas turbine power systems. The approach consists of a dynamic model of the power plant, reformulated as an index one differential algebraic equation (DAE) system. A dynamic optimization framework is developed where the constraints include the dynamic model of the plant. The system model is then discretized using Radau collocation on finite elements and formulated in the AMPL modeling environment. This allows for the straightforward solution of dynamic optimization problems using large‐scale NLP solvers. IPOPT is the NLP solver used in this study. Program links were provided to Matlab/Simulink to visualize and interpret the results. The formulation of a dynamic optimization problem was focused on determination of optimal operating trajectories for tracking power plant load variations. Efficiency measures were also included as a part of the dynamic optimization problem to maximize efficiency while tracking the desired load profile. Results from 18 case studies show that the dynamic optimization can be performed quickly with excellent results. The applicability of the dynamic optimization framework for the estimation of feed fuel concentrations is also demonstrated. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Synthesis of New 4‐Heteroaryl‐2‐Phenylquinolines and Their Pharmacological Activity as NK‐2/NK‐3 Receptor Ligands
Authors: Borioni Anna , Mustazza Carlo , Sestili Isabella , Sbraccia Maria , Turchetto Luciana , Del Giudice Maria Rosaria
Published: January 2007

Substituted 4‐heteroaryl‐2‐phenylquinolines were synthesized and tested on NK‐2 and NK‐3 receptors in order to get a better insight in the structure‐activity relationship. On the whole, these molecules, which can be regarded as bioisosters of the NK‐3 antagonist SB 218795, displayed a lower activity than the template. Ring electronic distribution and H‐bond donor and acceptor positions played some role in selectivity, 2‐imidazolyl substituted 2a showing affinity mainly towards NK‐3 while 3‐pyrazolyl substituted 4 displayed a preferential interaction with NK‐2 receptor. Structural characterization of the synthesized compounds was achieved by NMR and mass techniques. Bidimensional 1H‐NOESY experiments were a helpful tool for the assignment of the isomeric structures of compounds 9 and 11b–c.
Cell division of Giardia intestinalis: Assembly and disassembly of the adhesive disc, and the cytokinesis
Authors: Tůmová Pavla , Kulda Jaroslav , Nohýnková Eva
Published: January 2007

Trophozoites of Giardia are equipped with a special organelle of attachment, essential for parasite survival and pathogenicity, the ventral disc. Although its basic structure is well established, its reorganization and assembly during cell replication is poorly understood. We addressed some of these problems with aid of conventional, confocal and electron microscopy. We found that dividing Giardia alternates attached and free swimming phases in accordance with functional competence of the parent or newly assembled discs. The division started in attached cells by detachment of the disc microtubules from basal bodies. Shortening and eventual loss of the giardin microribbons, and unfolding of the microtubular layer resulting in collapse of the disc chamber and parasite detachment underlined gradual disassembly of the parent disc skeleton. Two daughter discs assembled on the dorsal side of the attached cell, with their ventral sides exposed on the parent cell surface and their microtubular skeletons growing in counter‐clockwise direction. A depression between the assembling discs marked the cleavage plane. The splitting continued during the free‐swimming phase with ventral‐ventral axial symmetry in a plane of the daughter discs. Finally, the daughter cells with fully developed discs but still connected tail to tail by a cytoplasmic bridge, attached to a substrate and terminated the division by a process resembling adhesion‐dependent cytokinesis. The mode of assembly of the daughter discs and plane of the division is compatible with maintenance of the left‐right asymmetry of the Giardia cytoskeleton in progeny, which cannot be satisfactorily explained by alternative models proposed so far. Cell Motil. Cytoskeleton 2007. © 2007 Wiley‐Liss, Inc.
Bile duct proliferation in liver-specific Jag1 conditional knockout mice: Effects of gene dosage
Authors: Loomes Kathleen M. , Russo Pierre , Ryan Matthew , Nelson Anthony , Underkoffler Lara , Glover Curtis , Fu Hong , Gridley Thomas , Kaestner Klaus H. , Oakey Rebecca J.
Published: January 2007

The Notch signaling pathway is involved in determination of cell fate and control of cell proliferation in multiple organ systems.

Jag1

encodes a ligand in the Notch pathway and has been identified as the disease-causing gene for the developmental disorder Alagille syndrome. Evidence from the study of human disease and mouse models has implicated

Jag1

as having an important role in the development of bile ducts. We have derived a conditional knockout allele (

Jag1

loxP) to study the role of

Jag1

and Notch signaling in liver and bile duct development. We crossed

Jag1

loxP mice with a transgenic line carrying Cre recombinase under the control of the albumin promoter and α-fetoprotein enhancer to ablate

Jag1

in hepatoblasts. The liver-specific

Jag1

conditional knockout mice showed normal bile duct development. To further decrease Notch pathway function, we crossed the

Jag1

conditional knockout mice with mice carrying the hypomorphic

Notch2

allele, and bile duct anatomy remained normal. When

Jag1

conditional mice were crossed with mice carrying the

Jag1

null allele, the adult progeny exhibited striking bile duct proliferation.

Conclusion:

These results indicate that Notch signaling in the liver is sensitive to

Jag1

gene dosage and suggest a role for the Notch pathway in postnatal growth and morphogenesis of bile ducts.
Hypoxic conformance of metabolism in primary rat hepatocytes: A model of hepatic hibernation
Authors: Subramanian Ram M. , Chandel Navdeep , Budinger Scott G. R. , Schumacker Paul T.
Published: January 2007

Following prolonged hypoxia, mammalian cells invoke adaptive mechanisms to enhance oxygen delivery and promote energy conservation. We previously reported that hepatocytes subjected to prolonged moderate hypoxia (PO2 = 20-50 mmHg for >3 hours) demonstrated a reversible inhibition of cellular respiration with maintenance of cell viability, associated with a decrease in mitochondrial adenosine triphosphate (ATP) synthesis; acute hypoxia (similar PO2 for <30 minutes) did not induce a similar suppression of respiration and ATP synthesis. In the current study, using an

in vitro

model of primary rat hepatocytes, we measured the changes in metabolic demand for ATP during hypoxic conformance, and tested whether viability is maintained by preferentially suppressing nonessential processes while sustaining processes essential for maintaining cell homeostasis. In addition, the rate of recovery of oxygen consumption and ATP concentrations following reoxygenation after prolonged and acute hypoxia/anoxia was compared. Oxygen consumption and ATP concentrations decreased during prolonged hypoxia compared with acute hypoxia. However, ouabain-inhibitable respiration did not decrease during prolonged hypoxia, indicating that membrane Na+/K+ ATPase activity, an essential process for cell viability, was maintained. In contrast, ATP-dependent glucuronidation and sulfation of acetaminophen, deemed “non-essential” processes, were decreased significantly compared with normoxic cells. After reoxygenation, cells exposed to prolonged moderate hypoxia demonstrated a more rapid recovery of respiration compared to acute hypoxia/anoxia.

Conclusion:

This “hepatic hibernation” during prolonged moderate hypoxia may represent an anticipatory adaptation that seeks to maintain cell viability while delaying or preventing the onset of lethal hypoxia, and facilitates rapid recovery after the resumption of normoxia.
Mitochondrial protection by the JNK inhibitor leflunomide rescues mice from acetaminophen-induced liver injury
Authors: Latchoumycandane Calivarathan , Goh Catherine W. , Ong Michie M.K. , Boelsterli Urs A.
Published: January 2007

Acetaminophen (APAP) is a widely used analgesic and antipyretic drug that is safe at therapeutic doses but which can precipitate liver injury at high doses. We have previously found that the antirheumatic drug leflunomide is a potent inhibitor of APAP toxicity in cultured human hepatocytes, protecting them from mitochondria-mediated cell death by inhibiting the mitochondrial permeability transition. The purpose of this study was to explore whether leflunomide protects against APAP hepatotoxicityin vivoand to define the molecular pathways of cytoprotection. Male C57BL/6 mice were treated with a hepatotoxic dose of APAP (750 mg/kg, ip) followed by a single injection of leflunomide (30 mg/kg, ip). Leflunomide (4 hours after APAP dose) afforded significant protection from liver necrosis as assessed by serum ALT activity and histopathology after 8 and 24 hours. The mechanism of protection by leflunomide was not through inhibition of cytochrome P450 (CYP)–catalyzed APAP bioactivation or an apparent suppression of the innate immune system. Instead, leflunomide inhibited APAP-induced activation (phosphorylation) of c-jun NH2-terminal protein kinase (JNK), thus preventing downstream Bcl-2 and Bcl-XL inactivation and protecting from mitochondrial permeabilization and cytochromecrelease. Furthermore, leflunomide inhibited the APAP-mediated increased expression of inducible nitric oxide synthase and prevented the formation of peroxynitrite, as judged from the absence of hepatic nitrotyrosine adducts. Even when given 8 hours after APAP dose, leflunomide still protected from massive liver necrosis.

Conclusion:

Leflunomide afforded protection against APAP-induced hepatotoxicity in mice through inhibition of JNK-mediated activation of mitochondrial permeabilization.
Role of second trimester sonography in detecting trisomy 18: A review of 70 cases
Authors: Papp Csaba , Ban Zoltan , Szigeti Zsanett , Csaba Akos , Beke Artur , Papp Zoltan
Published: January 2007

Purpose.

To investigate the role of second‐trimester sonographic examination in the prenatal diagnosis of trisomy 18.

Methods.

Out of 22,150 fetal chromosomal analyses performed between 1990 and 2004, 70 trisomy 18 fetuses were found. The sonographic findings of this aneuploidy were analyzed.

Results.

The average maternal age was 32.4 years; the average gestational age was 19.5 weeks. Major anomalies were seen in 61 (87.1%) of the 70 fetuses with trisomy 18; among these, cardiac anomalies were the most common (47.1%), with a 27.1% incidence of ventricular septal defects. Anomalies of the central nervous system were seen in 35.7% of cases; abnormal head shape was the most frequently detected anomaly in this group (12.9%). Fifty‐six (80%) of the fetuses had at least 1 minor anomaly; of these, choroid plexus cyst was the most common (38.6%). Increased nuchal fold thickness was detected in 17.1% of cases.

Conclusion.

The vast majority of trisomy 18 fetuses have sonographically detectable abnormalities in the second trimester. Both the 87.1% frequency of major anomalies and the 80% frequency of minor anomalies are substantially higher than multiple biochemical marker tests could achieve. It was also demonstrated that fetal echocardiography plays a pivotal role in the diagnosis of trisomy 18. © 2006 Wiley Periodicals, Inc. J Clin Ultrasound 35:, 2007
Cross‐national job stress: a quantitative and qualitative study
Authors: Liu Cong , Spector Paul E. , Shi Lin
Published: January 2007

Using both quantitative and qualitative methods, this study contrasted employees' job stress perceptions and their relationships to strains in China and the United States. Significant job stressor–strain correlations were found in both countries. However, hierarchical regression analyses revealed significant interactions of country by job stressors in predicting job strains, indicating the unique patterns of stressor–strain relationships in China and the United States. In the qualitative analyses, American employees reported significantly more incidents of lack of job control, direct interpersonal conflict, lack of team coordination, anger, frustration, feeling overwhelmed, and stomach problems than the Chinese. Chinese employees reported significantly more incidents of job evaluations, work mistakes, indirect conflict, employment conditions, lack of training, anxiety, helplessness, sleep problems, and feeling hot than the Americans. The qualitative approach contributed above and beyond the quantitative results in that it revealed culture‐specific job stressors of job evaluations, work mistakes, and indirect conflict that had been overlooked in western‐based stress research. Copyright © 2007 John Wiley & Sons, Ltd.
Pyridoxamine, a scavenger agent of carbohydrates
Authors: Adrover Miquel , Vilanova Bartolomé , Muñoz Francisco , Donoso Josefa
Published: January 2007

Pyridoxamine has been found to inhibit protein glycation and to avoid the formation of advanced glycation end‐products (AGEs). One of the mechanisms by which pyridoxamine can inhibit glycation involves the scavenger of carbonyl groups with glycation capacity. In this work, we conducted a kinetic study of the reactions of pyridoxamine with various carbohydrates under physiological pH and temperature. The reactions involving hexoses were found to give a tricyclic compound (5) in addition to pyridoxal and pyridoxine. Such a tricyclic compound inhibits the Amadori rearrangement and the formation of other carbonyl compounds with glycating properties. The reactions involving pentoses gave compound 7 and pyridoxal—by transamination of the Schiff base. The transamination reaction enhances the inhibitory action of pyridoxamine. The formation rate constants for the Schiff base, k3, were found to be similar to those for the reactions of D‐glucose with amino acids, which suggests competition between pyridoxamine and terminal amino residues in proteins for glycating sites in sugars. These constants are dependent on the electrophilic character of the carbonyl carbon in the carbohydrate. © 2007 Wiley Periodicals, Inc. 39: 154–167, 2007
Clinical evaluation of a hyaluronan‐based gel following microsurgical reconstruction of peripheral nerves of the hand
Authors: Atzei Andrea , Calcagni Maurizio , Breda Bruno , Fasolo Giampaolo , Pajardi Giorgio , Cugola Landino
Published: January 2007

A controlled clinical trial was performed to investigate the safety and efficacy of the hyaluronate‐based gel polymer Hyaloglide® after microsurgical reconstruction of peripheral nerves of the hand. Thirty patients were randomized to receive either no postsurgical treatment (n = 16) or Hyaloglide® (n = 14) and were clinically evaluated at various intervals for 1 year. The application of Hyaloglide® posed no safety concerns. Efficacy was assessed by the recovery of sensitivity, measurement of pain, and progression of Tinel's sign. The Hyaloglide®‐treated group showed better improvement in recovery from pain, approaching statistical significance during the first 3 months postsurgery. Likewise, recovery of sensitivity was also higher in the Hyaloglide®‐treated group throughout the entire follow‐up period, and the distance of Tinel's sign was longer in the Hyaloglide®‐treated group (P < 0.05 at day 30). The application of Hyaloglide® may improve recovery of sensitivity and decrease pain following microsurgical repair of the peripheral nerves of the hand. © 2007 Wiley‐Liss, Inc. Microsurgery 27, 2007.
Origin and history of end‐to‐side neurorrhaphy
Authors: Papalia I. , Geuna S. , D'alcontres F. Stagno , Tos P.
Published: January 2007

This historical note offers a perspective concerning the origin of the employment of end‐to‐side (termino‐lateral) anastomosis for nerve repair and summarizes the works that have been published on this surgical technique through the first part of the 20th Century. While the origin of end‐to‐side neurorrhaphy is usually dated to the beginning of the 20th Century, some works referring to this technique were published earlier, the first of which dates as far back as 1873. A number of interesting clinical and experimental studies have been carried out on end‐to‐side nerve anastomosis during the first years of the twentieth century. However, this literature is not easily detectable through current online scientific databases. In this paper we will give an overview of these early works. This history contributes interesting information to the debate surrounding this surgical concept and adds perspective to the use of a technique that has attracted a great deal of attention over the last 15 years. © 2007 Wiley‐Liss, Inc. Microsurgery, 2007.
Urtica ferox neuropathy
Authors: Hammond‐Tooke Graeme D. , Taylor Peter , Punchihewa Saman , Beasley Michael
Published: January 2007

A 21‐year‐old student developed an acute, symmetrical, predominantly motor polyneuropathy within 48 h of walking through a patch of nettles (Urtica ferox). Two companions had similar but less severe symptoms. Nerve conduction studies demonstrated markedly reduced compound muscle action potentials and prolonged distal motor latencies. Recovery occurred over a period of a few weeks. This case demonstrates that cutaneous exposure to Urtica ferox can cause an acute polyneuropathy and that its stinging hairs contain an unidentified neurotoxin. Muscle Nerve, 2007
An extended finite element library
Authors: Bordas Stéphane , Nguyen Phu Vinh , Dunant Cyrille , Guidoum Amor , Nguyen‐Dang Hung
Published: January 2007

This paper presents and exercises a general structure for an object‐oriented‐enriched finite element code. The programming environment provides a robust tool for extended finite element (XFEM) computations and a modular and extensible system. The programme structure has been designed to meet all natural requirements for modularity, extensibility, and robustness. To facilitate mesh–geometry interactions with hundreds of enrichment items, a mesh generator and mesh database are included. The salient features of the programme are: flexibility in the integration schemes (subtriangles, subquadrilaterals, independent near‐tip, and discontinuous quadrature rules); domain integral methods for homogeneous and bi‐material interface cracks arbitrarily oriented with respect to the mesh; geometry is described and updated by level sets, vector level sets or a standard method; standard and enriched approximations are independent; enrichment detection schemes: topological, geometrical, narrow‐band, etc.; multi‐material problem with an arbitrary number of interfaces and slip‐interfaces; non‐linear material models such as J2 plasticity with linear, isotropic and kinematic hardening. To illustrate the possible applications of our paradigm, we present 2D linear elastic fracture mechanics for hundreds of cracks with local near‐tip refinement, and crack propagation in two dimensions as well as complex 3D industrial problems. Copyright © 2007 John Wiley & Sons, Ltd.
Detection and identification of bacterial cell surface proteins by fluorescent labeling
Authors: Anaya Cecilia , Church Nadia , Lewis Janina P.
Published: January 2007

A rapid method of detection and identification of bacterial cell surface proteins is needed to better understand the interaction of bacteria with host components. To detect cell surface proteins, we have labeled cells of the Gram‐negative anaerobic bacterium, Porphyromonas gingivalis, with fluorescent cyanine dyes, Cy3 and Cy5. We demonstrate that only cell surface proteins were labeled, indicating the method applied in our study is suitable for detection and identification of cell surface proteins in Gram‐negative bacteria and possibly other organisms.
Estimating the predictive quality of dose–response after model selection
Authors: Hu Chuanpu , Dong Yingwen
Published: January 2007

Prediction of dose–response is important in dose selection in drug development. As the true dose–response shape is generally unknown, model selection is frequently used, and predictions based on the final selected model. Correctly assessing the quality of the predictions requires accounting for the uncertainties caused by the model selection process, which has been difficult. Recently, a new approach called data perturbation has emerged. It allows important predictive characteristics be computed while taking model selection into consideration. We study, through simulation, the performance of data perturbation in estimating standard error of parameter estimates and prediction errors. Data perturbation was found to give excellent prediction error estimates, although at times large Monte Carlo sizes were needed to obtain good standard error estimates. Overall, it is a useful tool to characterize uncertainties in dose–response predictions, with the potential of allowing more accurate dose selection in drug development. We also look at the influence of model selection on estimation bias. This leads to insights into candidate model choices that enable good dose–response prediction. Copyright © 2007 John Wiley & Sons, Ltd.
Understanding R&D value creation with organizational simulation
Authors: Bodner Douglas A. , Rouse William B.
Published: January 2007

Research and development functions are fundamental drivers of value creation in technology‐based enterprises. Successful R&D is a function of invention and R&D management. This paper studies R&D management issues from the perspective of their effect on value creation. The particular issues studied are: (i) How does one attach a value to a particular proposed R&D activity, and (ii) how does one allocate funding over the various stages comprising an R&D value stream? Organizational simulation is used in an experiment to determine the value creation effectiveness of alternative investment policies. Experimental results indicate the superiority of valuation methods (options pricing vs. traditional net present value approaches) and budget allocation strategies under differing conditions and differing value‐oriented performance measures. An application of the model to R&D in the forest products industry is presented. © 2007 Wiley Periodicals, Inc. Syst Eng 10: 64–82, 2007
Reforming practice or modifying reforms?: Elementary teachers' response to the tools of reform
Authors: Smith Leigh K. , Southerland Sherry A.
Published: January 2007

Understanding the interaction between internally constructed and externally imposed aspects of the teaching context may be the missing link between calls for school reform and teachers' interpretation and implementation of that reform. Although the context of the local school culture has a profound impact on teachers, there are other external forces that are specifically aimed at influencing teachers' pedagogical and curricular decisions. These externally imposed aspects of context include some of the existing tools of reform, such as national standards, mandated state core curricula, and related criterion‐referenced testing. However, little is known about how these reform tools impact teachers' thinking about science and science teaching or how teachers respond to such tools. This study examined the interactions between individual teachers' beliefs about teaching and learning science in elementary school and the tools of reform that are imposed upon them. Comparative case studies were conducted in which two elementary teachers' science instruction, teaching context, and related beliefs were examined, described, and analyzed. In this study, the teachers' fundamental beliefs about science and what it means to teach and learn science influenced their interpretations of the sometimes contradictory messages of reform as they are represented in the standards, mandated curriculum, and end‐of‐level tests. Suggestions about what these findings mean for needed aspects of teacher professional development are offered. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 396–423, 2007
The estimation of population size, migration rates and survival in a stratified population
Authors: Neil Arnason A.
Published: January 2007

Estimates of survival, migration rates, and population size are developed for a triple catch marking experiment on n (n>‐2) areas with migration among all areas and death in all areas occurring, but no recruitment (birth). This repressents the extension to three sampling times of the method ofChapman andJunge (1956) for estimates in a stratified population. The method is further extented to allow for ‘losses on capture’.
A preliminary study on collembolan populations in a pine forest
Authors: Takeda Hiroshi
Published: January 2007

A study was made of the populations of Collembola in the pine forest. Among the eight species commonly found, Folsomia octoculataHandschin was numerically dominant.

Seasonal population changes of these eight species were described over a year. It was found that many species show two peaks in number. As for F. octoculata, the dominant species, the changes in number was discussed in connection with the variation in age structure.

The census data for each species were examined for the distribution pattern by using the regression method. None of these eight species was distributed at random in the soil and they could be classified into three groups based on the differences in the degree of aggregation in terms of coefficient β of the regression. It was suggested that such differences in the distribution pattern are largely due to differences in the response to heterogeneity of the habitat. In the case of F. octoculata, the changes of distribution pattern in the course of post‐embryonic development were examined and it was found that (a) the component of distribution is a single individual rather than a colony, and (b) the degree of aggregation is decreased with the development of individuals.

Using the relationship, the relation of the necessary sample size to the population density was derived for a fixed level of presision (D=S.E./m=0.2) and some suggestions were given concerning sampling plans for these insects.
An analysis of the kinematics of swarming of Anarete pritchardi kim (Diptera: Cecidomyiidae)
Authors: Okubo Akira , Chiang H. C.
Published: January 2007

Movies of swarming of a cecidomyiid midge Anarete pritchardiKim, are analysed to provide kinematic data for swarming. Statistical characteristics calculated from the basic data are the mean, variance, standard deviation, skewness, and kurtosis of the insect coordinates; insect number‐density distribution in space, frequency distribution of insect velocities; velocity autocorrelation coefficients; effective advective velocity and diffusivity for swarming, among others.

Analyses show that the motion inside the swarm is more or less random although we occasionally notice some kind of interaction between individuals. An inward velocity is detected for insects flying at the edge of the swarm.

Mathematical models based on a combined process of diffusion and of nondiffusion are compared with the kinetic data to evaluate the parameters involved in the model. The result indicates that the mathematical model is realistic and useful.

A few features of midge behavior in swarming flight are also noted. The result obtained for midge kinetics should be applicable to swarms of some other insects and animals.
On interference among larvae of the greasy cutworm, Agrotis ypsilonrott. (lepidoptera: Noctuidae)
Authors: Murai Minoru
Published: January 2007

The greasy cut worm, Agrotis ypsilonRott., has a characteristic habit; the larva feeds on the small seedling of the host plant. Studies in a population in outbreak area suggested that the food shortage temporally took place, causing the reduction of weights of pupae and adults. The fact that this species depends on the small seedling as the host seemed to be responsible for this food shortage. However, it was found that the larval crowding also affected the body weight, even if the food was supplied in excess. It was further suggested that the weight reduction is due to the injury caused by the encounter of larvae.

The oviposition habit to lay small egg masses and the aggressive behaviour of the larva was considered to be responsible for the uniform distribution at the later larval stage. Probably, the larval dispersion enabled the larva to forage in the most effective way as well as it protected the larva from the attack of another ones. As a result, this would enable the maximum number of individuals to survive. It seemed that the functions noted above did not work in the population being under outbreak condition, because the larval density was unusually high due to mass‐invasion of moths.
Effects of molecular weight distribution of nonionic surfactants on stability of O/W emulsions
Authors: Saito Yoshihiro , Sato Takatoshi , Anazawa Ichiro
Published: January 2007

From the relationship between the distribution width of oxyethylene (OE) or alkyl chains and O/W emulsions stability, it became evident that even with the same average OE or alkyl chain lengths, the phase‐inversion temperature (PIT) and O/W emulsion stability depend on width. However, emulsification at the PIT invariably results in a very stable O/W emulsion. Emulsifiers with a large distribution width of OE or alkyl chains were also found to improve O/W emulsion stability.
Syntheses of 2‐(N‐alkyl‐N,N‐dimethylammonio)ethyl hydrogen phosphates and their physicochemical properties
Authors: Tsubone Kazuyuki , Uchida Noriko
Published: January 2007

A series of new amphoteric surfactants, having a quaternary ammonium group and a phosphoric acid group, 2‐(N‐alkyl‐N,N‐dimethylammonio)ethyl hydrogen phosphates (alkyl: dodecyl, tetradecyl, hexadecyl), were prepared by introducing a phosphoric acid group into N‐alkyl‐N,N‐dimethyl‐(N‐2‐hydroxyethyl) ammoniumiodide, followed by neutralization with sodium hydroxide and removal of inorganic salts. By the evaluation of the physicochemical properties, it was found that the phosphobetaines behave like “nonionic” surfactant in the zwitterionic region, having very small CMC values in comparison with sodium 2‐(N‐alkyl‐N‐methylamino)ethyl hydrogen phosphates. Additionally, similar trends were also observed in the experiments from the point of the effect of electrolyte and temperature on CMC, respectively. It should be considered that the hydrophobicity of the surfactant molecule is increased by the electronic interaction between the quaternary ammonium group and a phosphoric acid group. On the other hand, the phosphobetaines gave the smaller values of the occupied area per molecule at the air/water interface than sodium 2‐(N‐alkyl‐N‐methylamino)ethyl hydrogen phosphates. Therefore, it is clear that the phosphobetaines have higher surface‐active properties than the amphoteric surfactants.
Solubilization in mixed micelles
Authors: Weers Jeffry G.
Published: January 2007

Solubilization capacities for decane have been determined for a variety of mixed surfactant systems. Negative deviations from additivity are observed for nonionic/ionic mixtures where there are no attractive interactions between the surfactant headgroups. “Synergistic” positive deviations from additivity are observed for anionic/cationic mixtures, where strong attractive forces between the headgroups exist. The results are interpreted in terms of curvature effects using the Israelachvili, Mitchell and Ninhamv/aol model and a model based on Laplace pressures. Data are also presented for the C12TAB/C12EO6 system which clearly shows the differences in the solubilization sites for hexanol, which solubilizes in the palisade region, and decane, which solubilizes in the micellar core. The results indicate that any future modeling will have to include surfactant‐solubilizate interactions as well as surfactant‐surfactant interactions.
A new titrimetric analysis for ethylene oxide condensates
Authors: Weeks Lloyd E. , Lewis John T. , Ginn Martin E.
Published: January 2007

Summary and Conclusions

A critical review of the literature was made in search of suitable methods for analyzing ethylene oxide condensates. These studies led to the development of a rapid empirical titrimetric method for measuring nonionic hydrophobicity based on a water titration of a condensate dissolved in dimethylformamide (DMF) and benzene. The end‐point is identified by a definite solution turbidity. Calibration curves were prepared from known condensates.

This method should be useful for analysis of adducts in plant quality control and also for nonionics with known hydrophobes. Ether type adducts can not. (Ethylene oxide in esters can be calculated from their saponification values.) Examples of adducts which can be identified by the titrimetric method are those based on fatty alcohols and alkylphenols. Proprietary nonionics analyzed by the DMF method had ethylene oxide values in agreement with those claimed by the manufacturers. DMF data also compare favorably with that by hydriodic acid cleavage.
Problems arising in connection with the use of antioxidants in the food industry
Authors: Tollenaar F. D. , Vos H. J.
Published: January 2007

Investigations on the use of the gallic acid esters, butylated hydroxyanisole, and butylated hydroxytoluene as antioxidants in animal fats, vegetable oils, margarine, and bakery products are described. It was found that the gallates and BHT were highly effective in lard; BHA was of lesser importance.

In vegetable oils scarcely any effect was observed although some antioxidants might be able to suppress peroxide formation in these products; the flavor evaluations however are not always in accordance with these findings.

In margarine it was found that some antioxidants had a promising effect on the peroxide formation but only a slight effect on the flavor. Mixtures of antioxidants however could exercise a synergistic effect on the organoleptic qualities.

In bakery products,e.g., Dutch shortbread, BHT can afford good protection against flavor deterioration.

Mention is made of the fact that the dissociation of peroxides is governed primarily by their concentration and that fats with a peroxide value of 25 to 50 meq/kg. are very stable on heating at 100°C. without air‐passage.
A simplified and precise flavor evaluation procedure for determining oxidative rancidity in vegetable oils
Authors: Wyatt C. Jane , Day E. A.
Published: January 2007

High correlations were observed between the flavor evaluation procedure and objective chemical tests for measuring oxidative deterioration in stored corn, cottonseed, safflower, and soybean oils. The high correlations observed are believed to result from the precision of the flavor threshold testing procedure. Therefore, when suitable flavor testing methods are employed, the chemical methods become more valuable in assessing the quality of an oil. Milk is recommended as the testing media because of its desirable properties.
Preparation and phase behavior of positionally isomeric propylene glycol monoesters
Authors: Martin J. B. , Lutton E. S.
Published: January 2007

Primary even‐chain‐length monoesters of propylene glycol (1,2‐propanediol), myristate through behenate, have been prepared, and also the secondary monostearate. Phase behavior of the pure compounds and of the binary system of isomeric stearates has been studied. This behavior is one of considerable complexity. The highest‐melting stable form of the primary stearate is a single‐chain‐length (SCL) perpendicular form (Form II) of very weak long‐spacing intensities. A metastable perpendicular double‐chain‐length (DCL)a form occurs at the (metastable) melting point after chilling the primary esters; it transforms to a perpendicular DCL Form III on cooling. Low temp crystallization from dilute hexane gives a titled DCL Form I, the typical room temp form in crude preparations of primary ester. The secondary stearate exhibits a single similar DCL Form I at 25C and a perpendicular SCL a form just under the melting point of the chilled melt. Polymorphism is modified by mol wt and purity. Primary arachidate and behenate do not show Form II, hence show stable a at their (stable) melting points.

Repeated crystallization of the 80% primary ester obtained on direct esterification with stearic acid yields pure primary ester. Special synthesis via 1‐tetrahydropyranyl propylene glycol is necessary to prepare pure secondary ester. The pure primary monobehenate could be obtained only by acylation of 2‐tetrahydropyranyl propylene glycol obtained by reduction of tetrahydropyranyl ethyl lactate. Removal of the tetrahydropyranyl blocking groups was accomplished without acyl migration by using boric acid as a cleaving agent.
Hydrogenation of cottonseed oil with reused catalyst
Authors: Albright L. F. , Win M. M. , Woods J. M.
Published: January 2007

Cottonseed oil was hydrogenated using both new (Rufert catalyst flakes) and reused (up to five uses) catalysts at 130舑169C, at a pressure of 45 psig, and with high degrees of agitation.

The activity of the catalyst increased initially with use, especially at 130C, but with continued use the activity decreased. The selectivity of the hydrogenation decreased with reuse of the catalyst, especially at lower temp. Isomerization decreased slightly as the catalyst was used only at higher temps. The induction period found with fresh catalyst at 130C was eliminated in runs with second‐ and third‐use catalyst. A small induction period was noted with fifth‐use catalyst.

Treatment of once‐use catalyst with air severely reduced the catalyst activity. Steam‐ and vacuum‐treatment of the catalyst resulted in a slightly less active catalyst than a hydrogen‐treated catalyst. None of these treatments significantly affected selectivity or isomerization.

Results of this investigation can be explained in large part by the concn of hydrogen absorbed on the catalyst surface.
A simple and efficient method for the recovery of deodorizer distillates
Authors: Klingerman R. H. , West R. W.
Published: January 2007

An improved method has been developed to permit simple and efficient recovery of the distillates from oil deodorizer systems. A description of system and unit operation as well as design parameters are presented. Limited development experience is discussed and related to unit performance. Test methods used to determine unit performance are also discussed. Advantages resulting from use of this method to recover distillates are described to permit relative evaluation of similar systems.
Methods for methanolysis of sphingolipids and direct determination of long‐chain bases by gas chromatography
Authors: Gaver R. C. , Sweeley C. C.
Published: January 2007

A new, simple procedure is described for the direct gas chromatographic determination of sphingolipid bases as their trimethylsilyl derivatives. This method is used to study the nature of the mixture of bases produced by acidic methanolysis of ceramides, sphingomyelins, free sphingolipid bases, andN‐acetyl derivatives of the latter. Cleavage of sphingolipids with anhydrous methanolic hydrogen chloride results in the production of considerable quantities of secondary products from sphingosine, such as theO‐methyl ethers, which are not formed during methanolysis of free sphingosine. A modified reagent for methanolysis, containing methanol, water and hydrochloric acid, reduces the yield of these by‐products to low levels. Preliminary purification of the sphingolipid bases, before gas chromatography, is achieved by chromatographic procedures. Evidence is presented for the occurrence of C16‐sphingosine in sphingomyelin from human blood plasma.
The solubilities of seven gases in olive oil with references to theories of transport through the cell membrane
Authors: Battino R. , Evans F. D. , Danforth W. F.
Published: January 2007

The solubilities of He, Ne, Ar, N2, O2, CO and CO2 in olive oil have been determined in the temperature range 24–56 C. The gas solubility apparatus was a considerably improved version of the one reported by Morrison and Billett and gave a precision, depending on the gas solvent system of ±0.2% to ±1.0%. Plots of log L, the Ostwald coefficient, and log α, the Bunsen coefficient, against 1/TK were linear and showed a small temperature dependence for CO2. The enthalpy and entropy changes corresponding to the solution process were calculated. The partition coefficients of the gases between olive oil and water were calculated using reported values for the solubility of the gases in water. These results have been used to test and extend the Meyer‐Overton theory of transport through the cell membrane.
Preparation of high apparent bulk density clays by fluidized activation
Authors: Hasnuddin Siddiqui M. K.
Published: January 2007

Fluidizing a free‐flowing mixture of clay and concentrated sulfuric acid in a medium of hot air at 150 C yields an active product of high apparent bulk density (ABD) and consequent low oil retention unlike the conventional “wet” method of activation which yields a fluffy clay with high oil retention. Comparative data on bleaching capacity, ABD and oil retention of the products obtained by both methods are given.
Vulcanized meadowfoam oil
Authors: Erhan Sellm M. , Kleiman Robert
Published: January 2007

The factice gelation time for meadowfoam oil, along with hardness, color, acetone extract and free sulfur content of the gelled products were compared with gelation time and product properties of factice prepared from seed oils of rapeseed, crambe, soybean, castor,Lesquerella and jojoba. The effect of additives, specifically zinc oxide, magnesium oxide, triethylamine, dicyclohexylamine, 2‐mercaptobenzothiazole and iodine, was also investigated. Both white and brown factices could be prepared from meadowfoam oil and their properties were equivalent to or better than those from high erucic acid rapeseed oil used commercially for the highest quality factice.
Variation in lipid composition of niger seed (Guizotia abyssinica Cass.) Samples collected from different regions in ethiopia
Authors: Dutta Paresch Chandra , Helmersson Seved , Kebedu Eshetu , Alemaw Getinet , Appelqvist Lars‐Åke
Published: January 2007

Niger seed samples were collected from different regions in Ethiopia for determination of oil content, and of fatty acid, tocopherol and sterol composition in the seed oil by gas‐liquid chromatography and high‐performance liquid chromatography methods. There was a large variation in oil content, ranging from 29 to 39%. More than 70% of the fatty acids was linoleic acid (18∶2) in all samples analyzed. The other predominant fatty acids were palmitic (16∶0), stearic (18∶0) and oleic (19∶1) at a range of 6 to 11% each. Total polar lipids recovered after preparative thin‐layer chromatography comprised a small fraction of the total lipids. They had higher 16∶0 and lower 18∶2 contents than the triacylglycerols.α‐Tocopherol was the predominant tocopherol in all samples, 94–96% of the total amounting to 630–800 μg/g oil. More than 40% of the total sterols wasβ‐sitosterol,ca. 2000μg/g oil. The other major sterols were campesterol and stigmasterol, ranging from 11 to 14%. The Δ5‐ and Δ7‐avenasterols were in the range of 4 to 7%. From the samples studied, no conclusion could be drawn regarding the influence of altitude or location on oil content, tocopherol and/or sterol contents. The results of the present study on niger seed oil are discussed in comparison with known data for common oils from Compositae,viz, safflower and sunflower.
Effects of sugar, salt and water on soybean oil quality during deep‐frying
Authors: Chu Yan‐Hwa , Luo Shiuan
Published: January 2007

The effects of flour dough components (water, sugar and salt) on soybean oil deterioration during deep‐fat frying have been investigated. Flour dough sheets made from flour and water were used as the carrier of salt and sugar. Several analyses, including acid value, carbonyl value,p‐anisidine value, color, dielectric constant, Fritest, total polar compounds and polymer content, were used to evaluate deterioration of oil quality during deep‐fat frying. The relationship between frying time and analytical data was analyzed by Duncan's multiple range test. Oil quality after frying simple flour dough sheets without additives was inferior to that after frying dough sheets with added sugar or salt. The sugar and salt in the flour dough sheets may play a role as water‐binding substances during frying. Among the effects of water, salt and sugar, the rate of oil deterioration was found to be highest for water, followed by salt and sugar. The combined addition of salt and sugar had no enhancing effect on the oil deterioration during deep‐fat frying.