bluuebunny/crossref_metadata_2025 huggingface dataset:
Peculiarities of supermolecular structure of polyimides and polyester imides
Authors: Sidorovich A. V. , Baklagina Yu. G. , Kenarov A. V. , Nadezhin Yu. S. , Adrova N. A. , Florinsky F. S.
Published: June 2010

Supermolecular structures of fourteen heterocyclic thermally stable polymers of the polyimide (PI) and polyesterimide (PEI) class have been investigated by X‐ray scattering, optical, dilatometric and thermomechanical methods. Quasi‐crystalline structure of these polymers in the initial amorphous state of poly(amic acid) and poly(ester amic acid) and also after chemical imidization has been revealed. The quasi‐crystalline structure is characterized by a biaxial polarizability ellipsoid with a negative sign. This is indicated by distinct conoscopic figures recorded with a polarizing microscope. The effect of the number of oxyphenylene groups on the crystallizability of PI and PEI was investigated. For PEI the effect of self‐orientation of macromolecules induced by conformational transition was observed. Discrete small‐angle x‐ray scattering pattern (a long period) was also revealed for PEI. The appearance of long periods is caused by polymorphism of PEI uniquely determined for one of its types (PEI‐II). X‐ray scattering data confirmed by calculations of the lattice energy show that dianhydride pyromellitimide chain portion is the element determining the crystalline structure of PI. The structure is determined by van der Waals' forces and obeys the principle of dense packing. This leads to the appearance of layer structure with alternating layers of diamine and dianhydride portions. It was found that, depending on the rigidity of the diamine portion, PI and PEI exhibit different abilities of forming axial‐planar or axial textures in nonoriented films.
Excess volume and effect of pressure on the critical temperature
Authors: Onodera M.
Published: June 2010

The asymptotic method was applied to polymer solutions. The configurational partition function based on the lattice model was much improved by introducing free volumes into consideration. Consequently we were able to calculate the fractional volume change on mixing as the mean value through use of the configurational partition function, under the assumption of pairwise additivity of volume of mixing. The derived expression for the excess volume of mixing was compared with experimental results. Gibbs free energy was derived from Helmholtz free energy and the product of the volume of mixing and pressure, from this the critical pressure‐dependent composition and temperature was obtained. Thus we have the relation between pressure and critical temperature. The data are displayed figures that it might be compared with experimental results.
Entropy correlation theory and diffusion measurements for oriented polymers
Authors: Barker R. E. , Tsai R. C. , Willency R. A.
Published: June 2010

The entropy correlation theory predicts that any structural change which decreases the configurational entropy Sc of a complex molecular system will lead to an approximately equal increase in the activation entropy ΔS* for structurally controlled rate processes such as diffusion. In symbols, Δ(ΔS*) =‐ΔSc or ΔS*(A) = ΔS*(1)‐ΔSc, where, in the present case, the ordering parameter A is the elongation ratio L/L0. Although the theory is believed to be of wider scope, this paper deals with its confirmation for the case of gas diffusion in permanently stretched polymeric membranes. The systems investigated included representative poly(alkyl methacrylates) (viz. methyl, ethyl, isobutyl, and normal butyl methacrylate and a copolymer), and a selection of nonpolar and polar gases (Ar, O2, N2, CO). Diffusion and permeation measurements on the oriented films were made by the Daynes‐Barrer time lag method using a mass spectrometer for the detection instrument. The degree of orientation and its stability during an experiment were characterized by measurements of optical birefringence. For a comparison of the general theory with the specific data, it was found useful to prepare the samples in such a way that ΔSc ≈ a(A2 + (2/A)–3, corresponding to a quenched elastomer; then the data could be represented such that log DO is a linear function of ΔSc, where DO is the preexponental factor in the diffusion equation D = DO exp (‐ED/RT).
Properties of some rodlike polymers in solution
Authors: Wong C.‐P. , Ohnuma H. , Berry G. C.
Published: June 2010

The properties of poly (1, 4‐phenylene terephthalamide) (PPTA), Kevlar, and a poly(benzobisoxazole) (PBO) in solution are investigated. Molecular characterization using light scattering and viscometry on dilute solutions shows PBO and PPTA to have a rodlike conformation. Both are prone to interchain aggregation with the tendency for association apparently increasing with the ionic strength of the solvent. Rheological experiments are reported on disordered and ordered concentrated solutions of Kevlar and PBO. The dependence of the viscosity and recoverable compliance on shear rate is discussed and compared with that of flexible‐chain polymers. The dependence of the viscosity and recoverable compliance of PBO solutions on temperature and concentration is discussed.
Complex formation between poly(vinyl‐pyrrolidone) and poly(itaconic acid monomethylester) or its copolymer
Authors: Bimendina L. A. , Bekturov E. A. , Tleubaeva G. S. , Frolova V. A.
Published: June 2010

Complex formation in poly(vinylpyrrolidone)‐poly(itaconic acid monomethylester) and poly(vinylpyrrolidone)‐copolymer of maleic anhydride and monomethylitaconate systems has been investigated. It is shown that the interpolymer complexes are formed at interaction of macromolecular components. Data of conductometric, potentiometric, and viscometric titrations indicate that the molar composition of complexes is PVP:PMMI = 1:1 and PVP:MA/ MMI = 3:2. The complex particles are very compact with the intrinsic viscosity in water about 0.05‐0.10 dl/g not depending upon the molecular weight of polymer components. Complexes are destroyed both by inadequate organic solvent (30‐40 vol %) in mixed solvent water ‐dimethylsulfoxide, and by thermal action.
Fluorescent labeling of soluble polymers
Authors: Rypáček F. , Drobníak J. , Krejčoves J. , Kálal J.
Published: June 2010

Possibilities of polymer‐analogous labeling of soluble polymers with covalently bound fluorochrome in the side chain were investigated, using N(2‐aminoethylcarbonyl)‐5(6)‐aminofluorescein (I), 4‐aminomethyl‐7‐hydroxycoumarine (II), and fluoresceinisothiocyanate (FITC) as labels. The properties of polyaspartamides labeled with I and FITC were compared with regard to their bond stability and intensity of fluorescence.
Localized combined chemotherapy of solid gardner lymphosarcoma by methotrexate bound to synthetic polymeric carriers
Authors: Motyčka K. , Slavíková V. , Špaček P. , Kubín M. , Slavík K.
Published: June 2010

A chemically modified poly‐2‐hydroxyethyl methacrylate was used as a carrier of methotrexate and 3′,5′‐dibromoaminopterin. Intratumorously implanted carrier with graded doses of sorbed methotrexate has prolonged the survival of treated mice. Best results were achieved if toxicity of higher doses of sorbed methotrexate was reversed by leukovorin. Increased toxicity and decrease of the survival time and of the detoxicating potency of leukovorin were found if using an advanced experimental tumor. A promising result in mice with advanced tumors by using sorbed 3′,5′‐dibromoaminopterin is reported.
Dependence of albumin–fibrinogen simple and competitive adsorption on surface properties of biomaterials
Authors: Brash J. L. , Uniyal S.
Published: June 2010

Adsorption of fibrinogen and albumin from solutions of the proteins singly and in mixtures was studied. A variety of surfaces with varying degrees of hydrophilicity and thrombogenicity was investigated. Adsorption behavior shows a strong dependence on surface properties. All surfaces show a preference for fibrinogen, and the degree of preference appears to correlate with thrombogenic tendency and platelet reactivity.
The hydrolysis of α‐N‐benzoyl‐L‐arginine ethyl ester by monolayers of papain and trypsin
Authors: Graham N. B. , Novosel B.
Published: June 2010

The hydrolysis of α‐N‐Benzoyl‐L‐arginine ethyl ester (BAEE) as a substrate under monolayers of papain and trypsin at the air–water interface was studied using an automated Lauda film balance to characterize the monolayers and a small resin‐flask reactor with movable barriers for surface‐layer compression. The rates of reaction were followed by UV spectrophotometry. The hydrolysis rate increased with moderate increases in surface pressure and temperature.
Metal‐catalyzed oligomerization reactions of organosiloxanes
Authors: Curtis M. David
Published: June 2010

Transition metal complexes, e.g., L2Pt(C2H4), L3RhCl, and L2Ir(CO)Cl (L = Ph3P), react with tetraalkyldisiloxanes, (HRR'Si)2O, to produce metallacycles featuring the transition metal, two silicons, and the oxygen in a four‐membered ring, MSiOSi. When R = Me and R' = Ph, stereoselectivity in the formation of the metallacycle from a mixture of stereoisomers of the starting disiloxane is observed. The catalytic activity of these complexes for the oligomerization of the disiloxanes has been investigated in the hope of obtaining stereoregular silicones. It has been found that extensive rearrangements occur which redistribute the groups on the silicon atoms. Increased selectivity for the desired exchange type (SiO groups for Si — H) was found when the catalysts were adsorbed on oxide supports. Although the goal of synthesizing stereoregular silicones has not yet been achieved, the results warrant further investigation.
Heat capacity of water absorbed in methylcellulose
Authors: Kinard D. A. , Hoeve C. A. J.
Published: June 2010

The heat capacity of methylcellulose is determined at various water contents over a wide range of temperatures, down to 125 K. From the data, the partial specific heat capacity of water has been obtained. The results show that water should be considered as a single, mobile phase. No evidence exists for bound water. Near 130 K water becomes immobilized in a glassy state.
Underwater stress relaxation studies of nafion (perfluorosulfonate) ionomer membranes
Authors: Kyu Thein , Eisenberg Adi
Published: June 2010

In an effort to elucidate the nature of ionic aggregation and its effect on the primary relaxation (α process) in the Nafion polymers (EW = 1200), underwater and undermethanol stress relaxation tests were conducted at various temperatures (20–70°C). Both semicrystalline and amorphous Nafion‐Na relax faster in the presence of water than in the dry state. In marked contrast to the behavior observed for Nafions in the dry condition, the kind of countercations is insignificant in the underwater stress relaxation. The great similarity in the underwater stress relaxation curves for different cations is attributable to the reduction of ionic interaction between the bound anions and unbound cations, probably associated with the water shielding around the ionic species. This leads to the suggestion that the primary α relaxation may be relevant to the ionic groups rather than to the matrix Tg, representing a reversal of the original assignment of the mechanical α and β relaxations. Increased swelling in methanol shows a modulus being one order of magnitude lower than that in the underwater runs. However, little or no difference is seen in the rates of stress relaxation in the underwater and undermethanol stress relaxation experiments. It is postulated that methanol also interacts with the interracial regions or with the fluorocarbon matrix in the Nafions, not just with the ionic regions.
Confinedrandom‐flightpolymerchainsinsolution: exclusion from micropores and distribution near barriers
Authors: Casassa Edward F.
Published: June 2010

The statistical basis of the entropic repulsion of dissolved random‐flight polymer chains from impenetrable passive barriers is described. The application of these ideas to the partial exclusion of linear and branched polymer chains from micropores and to the polymer concentration profile near a barrier is reviewed with emphasis on the mean projection of the chain as a measure of the exclusion effect.
Kinetics of particle nucleation and growth in the emulsion polymerization of acrylic monomers
Authors: Fitch Robert M. , Palmgren Tor H. , Aoyagi Tatsuhiro , Zuikov Aleksander
Published: June 2010

The rates of particle formation and growth during the earliest stages of the emulsion polymerization of several acrylic monomers have been studied as a function of surfactant concentration by means of the time‐dependence of light scattering from the reaction mixtures. Investigated were methyl methacrylate, and methyl, ethyl, and butyl acrylates at concentrations of SDS surfactant from zero to several times the CMC. Under continuous photoinitiation, the Rayleigh scattering intensities rose rapidly with slopes that increased with decreasing SDS concentration. The more water‐soluble the monomer, the more slowly was the rate of increase in scattering intensity.
Some evidence for the existence of the liquid‐liquid transition: Melt rheology studies
Authors: Maxwell Bryce , Cook Kevin S.
Published: June 2010

In 1963 Boyer proposed the existence of a liquid‐liquid transition, Tll, in polystyrene above the glass transition Tg. Since that time there has been considerable discussion and disagreement on the existence of this transition. Detailed shear modulus data as a function of temperature in the range 165–215°C will be presented for a series of polystyrenes of various molecular weights. In each case, as the temperature is increased, the modulus gradually decreases until a specific molecular weight dependent temperature is reached and then suddenly the modulus decreases rapidly over a few °C and then returns to its previous gradual decrease with increasing temperature. The response is reminiscent of the modulus behavior going through Tg. It is suggested that the temperature at which this sharp decreased in modulus takes place is Tll. The molecular weight effects on Tll will be discussed in terms of several rheological properties that measure the temperature of this transition.
Dynamics of rodlike macromolecules in semidilute solutions
Authors: Pecora R.
Published: June 2010

Experimental data on the rotation and translation of rigid rod macromolecules in the semi‐dilute region are discussed in the terms of the Doi‐Edwards theory. Available data indicate that the rotational diffusion coefficients vary approximately as the inverse concentration squared and the inverse length to a power between 7 and 8. The absolute value of the decrease of the rotational diffusion coefficient in the semidilute region relative to the infinite dilution value is about two orders of magnitude less than is predicted by the Doi‐Edwards theory. Some possible explanations for these deviations include:

The constraints on diffusion imposed in the Doi‐Edwards theory are too severe even for rigid rods.

The molecules studied exhibit some flexibility and thus do not conform to a model for rigid rods.
Dickblechclinchen – Innovatives Fügeverfahren für den Stahlbau
Authors: Israel Markus , Jesche Fred , Mauermann Reinhard , Trojer Andreas
Published: June 2010

Das auch unter dem Begriff Durchsetzfügen bekannte Clinchen ist eine Fügetechnologie, welche sich vor allem in den Bereichen der Automobilindustrie sowie der Geräte‐ und Elektroindustrie etabliert hat. Eine Vielzahl von Untersuchungen und Beispielen aus der industriellen Anwendung belegt die Universalität und Wirtschaftlichkeit, eine einfache Handhabbarkeit sowie die gute Automatisierbarkeit dieses Fügeverfahrens. Der Einsatz des Clinchens beschränkt sich zurzeit jedoch hauptsächlich auf den Feinblechbereich in den genannten Industriezweigen. Untersuchungen am Fraunhofer IWU zeigen, dass dieses hochgradig ökonomische und innovative Verfahren auch eingesetzt werden kann, wenn deutlich größere Blechdicken zu verbinden sind. Ein Einsatz im Schienenfahrzeug‐, Schiff‐ und Stahlbau sowie dem Nutzfahrzeugbau ist in naher Zukunft vorstellbar und aufgrund der besonderen Eigenschaften der Technologie erstrebenswert. Die Übertragung des Know‐how aus dem automobiltypischen Blechdickenbereich auf die Materialstärken im Stahlbau sowie die numerisch unterstützte Systementwicklung sind Schwerpunkte von Forschungsaktivitäten am Fraunhofer IWU.

Clinching of thick sheets – innovative joining technology for steelwork. Clinching, which is mechanical joining by upsetting, is above all established in the area of automotive industry as well as in appliance and electronic industry. The universality, economic efficiency, an easy manageability and the fact that the process is good automatable are documented by several research activities. Currently the process application is mainly restrained on connections of thin sheets in the named sector of industry. Investigations done by Fraunhofer IWU point out the possibility of using this high efficiency and innovative joining technology even for applications with distinctly higher sheet thicknesses. An adoption of clinching is conceivable and desirable for railway vehicle or truck manufacturing and shipbuilding as well as for steelwork generally in near future due to its specific technology characteristics. The transfer of knowledge from the thin sheet automotive sector to the sheet thicknesses used in steelwork as well as the numerical supported system development are focus of the research activities at Fraunhofer IWU.
Chest Radiographs Are Valuable in Demonstrating Clinically Significant Pacemaker Complications that Require Reoperation
Authors: Belvin Diane , Hirschl David , Jain Vineet R. , Godelman Alla , Stein Marjorie W. , Gross Jay N. , Haramati Linda B.
Published: June 2010

Purpose

To evaluate the utility of chest radiography in demonstrating clinically significant pacemaker complications that required reoperation.

Methods

In this retrospective case-controlled series, we identified 14 consecutive adults who required pacemaker reoperation and who had chest radiographs available for review (6 men, 8 women; mean age, 71 years [range, 43–95 years]). Ten patients had pacemakers implanted at our institution, and 4 were referred for reoperation. Forty-two controls, 3 for each patient, had postoperative chest radiographs and normal device function (25 men, 17 women; mean age 76 years [range, 37–96 years]). All postoperative chest radiographs, including 1-year follow-ups, were blindly reviewed by at least 2 of 4 radiologists for lead perforation and position of right atrial and right ventricular leads. Follow-up radiographs were assessed for lead perforation, lead displacement, and lead fracture. Data were analysed by using the Fisher exact test.

Results

Of the patients, 1.7% (10/581) required reoperation for pacemaker dysfunction (noncapture, oversensing, abnormal atrial and ventricular thresholds, failing impedance), extracardiac stimulation, and lead perforation and/or displacement. There were no lead fractures. Chest radiographs demonstrated pacemaker complications in 57% of patients (8/14) at a median of 2 days (<1–32 days) after implantation and in 5% of the controls (2/42) ( P < .0001). None of the abnormalities were noted on the official reports. Among subgroups, chest radiographs were abnormal for the following indications: pacemaker dysfunction in 4 of 7 patients versus 0 of 21 controls ( P = .0017), extracardiac stimulation in 1 of 3 patients vs 0 of 9 controls ( P = .25), and lead perforation and/or displacement in 3 of 4 patients vs 2 of 12 controls ( P = .06).

Conclusions

Chest radiographs are useful after pacemaker placement and demonstrate the majority of complications that require reoperation. Familiarity with the expected normal position of the leads, appearances of pacemaker complications, and comparison with prior radiographs is crucial in rendering a correct diagnosis that guides patient management.
“Active Labor” Duration and Dilation Rates Among Low‐Risk, Nulliparous Women With Spontaneous Labor Onset: A Systematic Review
Authors: Neal Jeremy L. , Lowe Nancy K. , Ahijevych Karen L. , Patrick Thelma E. , Cabbage Lori A. , Corwin Elizabeth J.
Published: June 2010

Introduction: Laboring women are often admitted to labor units under criteria that are commonly associated with the onset of active‐phase labor (i.e., cervical dilatation of 3–5 cm in the presence of regular contractions). Beginning with these criteria through complete dilatation, this systematic review describes labor duration and cervical dilation rates among low‐risk, nulliparous women with spontaneous labor onset.

Methods: Studies published in English (between 1990 and 2008) were identified via MEDLINE and CINAHL searches. Data were abstracted and weighted “active labor” durations (i.e., from 3–5 cm through complete dilatation) and linear dilation rates were calculated.

Results: Eighteen studies (n = 7009) reported mean “active labor” duration. The weighted mean duration was 6.0 hours, and the calculated dilation rate was 1.2 cm per hour. These findings closely parallel those found at the median. At the statistical limits, the weighted “active labor” duration was 13.4 hours (mean + 2 standard deviations) and the dilation rate was 0.6 cm per hour (mean − 2 standard deviations).

Discussion: These findings indicate that nulliparous women with spontaneous labor onset have longer “active” labors and therefore slower dilation rates than are traditionally associated with active labor when commonly used criteria are applied as the starting point. Revision of existing active labor expectations and/or criteria used to prospectively identify active phase onset is warranted.
The Effects of Perceived Stress and Attitudes Toward Menopause and Aging on Symptoms of Menopause
Authors: Nosek Marcianna , Kennedy Holly Powell , Beyene Yewoubdar , Taylor Diana , Gilliss Catherine , Lee Kathryn
Published: June 2010

Introduction: As part of a longitudinal study of midlife women, the aim of this investigation was to describe the intensity of menopausal symptoms in relation to the level of perceived stress in a woman's life and her attitudes toward menopause and aging.

Methods: Data were collected on 347 women between 40 and 50 years of age in Northern California who began the study while premenopausal. Women self‐identified as African American, European American, or Mexican/Central American. Data collected over three time points in the first 12 months were used for this analysis. An investigator‐developed tool for the perception of specific types of stress was used. Attitudes toward menopause and aging were measured using the Attitudes Toward Menopause and Attitude Toward Aging scales. Attitudes toward aging and menopause, perceived stress, and income were related to intensity of symptoms.

Results: There was no ethnic group difference in perceived stress or attitude toward menopause. However, European and African Americans had a more positive attitude toward aging than Mexican/Central Americans.

Discussion: A lower income, higher perceived stress, a more negative attitude toward aging, and a more positive attitude toward menopause influenced menopausal symptom experience.
The Use of Complementary and Alternative Medicines Among a Sample of Canadian Menopausal‐Aged Women
Authors: Lunny Carole A. , Fraser Shawn N.
Published: June 2010

Introduction: Despite questionable efficacy and safety, many women use a variety of complementary and alternative medicine (CAM) therapies to relieve menopause symptoms.

Methods: We examined the determinants and use of CAM therapies among a sample of menopausal‐aged women in Canada by using a cross‐sectional Web‐based survey.

Results: Four hundred twenty‐three women who were contacted through list serves, e‐mail lists, and Internet advertisements provided complete data on demographics, use of CAM, therapies, and menopausal status and symptoms. Ninety‐one percent of women reported trying CAM therapies for their symptoms. Women reported using an average of five kinds of CAM therapies. The most common treatments were vitamins (61.5%), relaxation techniques (57.0%), yoga/meditation (37.6%), soy products (37.4%), and prayer (35.7%). The most beneficial CAM therapies reported were prayer/spiritual healing, relaxation techniques, counseling/therapy, and therapeutic touch/Reiki. Demographic factors and menopausal symptoms contributed to 14% of the variance (P < .001) in the number of CAM therapies tried.

Discussion: Results support previous research showing that menopausal women have high user rates of CAM therapy and show that specific demographic factors and somatic symptomatology relate to use of CAM therapies. Health care providers can benefit from understanding the determinants and use of CAM by women during the menopause transition if they are to help and provide quality care for this population.
A numerical nonlinear analysis of two-dimensional ventilating entry of surface-piercing hydrofoils with effects of gravity
Authors: VINAYAN VIMAL , KINNAS SPYROS A.
Published: June 2010

The presence of the free surface adds an element of difficulty to the development of numerical and theoretical methods for the performance prediction of surface-piercing hydrofoils. Existing methods of analysis for two-dimensional surface-piercing hydrofoils or blade sections of a surface-piercing propeller solve either a linear problem, assuming a thin section and ventilated surface along with linear free-surface boundary conditions, or a nonlinear problem in a self-similar setting. Both these approaches cannot be used when the effects of gravity are important, which is the case when a craft is operating at low speeds. A two-dimensional boundary-element-method-based numerical scheme is presented here that overcomes these drawbacks by solving the fully ventilated flow past a surface-piercing hydrofoil of finite dimensions and includes the whole gamut of nonlinear free-surface interactions. The unique aspect of the numerical scheme is that fully nonlinear boundary conditions are applied on the free surface which allows for the accurate modelling of the jet generated on the wetted boundary and the ventilated surface formed on the suction side as a result of the passage of the hydrofoil through the free surface. Moreover, the effects of gravity can be considered to take into account the influence of the Froude number. Ventilated-surface shapes predicted by the present scheme are compared with existing experimental results and are shown to be in good agreement.
A study on phytoplankton following ‘Volgoneft-248’ oil spill on the north-eastern coast of the Sea of Marmara
Authors: Taş Seyfettin , Okuş Erdoğan , Ünlü Selma , Altiok Hüsne
Published: June 2010

Following the ‘Volgoneft-248’ oil spill, phytoplankton distribution within the affected area was investigated for two years. Simultaneously measured physical variables such as salinity, temperature, Secchi disc, current speed and direction, and total petroleum hydrocarbons (TPH) were evaluated together with phytoplankton data. At the time of the accident, the TPH concentration in surface water was measured as 2.17 mg l−1and decreased to 88.5 µg l−1after five days. In the first sampling period, no diatoms were detected in surface water, while dinoflagellates were dominant in the phytoplankton community. The species composition of phytoplankton changed rapidly in two months and the diatoms increased in terms of abundance and diversity. This indicated that the diatoms might be more sensitive to oil pollution than the dinoflagellates. In comparison with the historical datasets, the low phytoplankton abundance following the oil spill should be considered as the small effect of oil on the phytoplankton rather than natural variability of the ecosystem. High oil concentration in the water column caused stress on the phytoplankton and influenced the species composition negatively depending on the sensitivity of groups and the natural variability of the ecosystem.
Reproductive effort of an endemic major reef builder along an inshore–offshore gradient in south-western Atlantic
Authors: Pires Débora O. , Segal Bárbara , Caparelli Alice C.
Published: June 2010

Mussismilia braziliensisis endemic to the south-western Atlantic, where it plays an important role as a major reef builder. It occurs in a wide range of sediment conditions between coastal and offshore environments. Here, we investigated its reproductive effort along an inshore–offshore gradient. Three sites were sampled with varying distances (15 to 60 km) from the mainland in the Abrolhos Reef Complex (18° S). Reproductive effort was estimated as fecundity (number of eggs per: polyp, cm2, mm3, and mesenteries). Mean fecundity per polyp was 338.7 (±73.5 SD) and the highest number of eggs per polyp was 987. Percentages of fertile mesenteries per polyp were similar among sites. However, the fecundity per mesentery varied among colonies and among sites. Fecundity per polyp increased as its area, volume, height and number of fertile mesenteries increases. The area closest to the coast (‘Pedra de Leste’) presented the highest mean fecundity per polyp (410 eggs ± 159.2 SD), cm2(233.47 eggs ± 219.44 SD), mm3(4.95 eggs ± 2.34 SD) and mesentery (10.6 eggs ± 4.3 SD). Corals closest to the coast had 55% higher fecundity per polyp and 64% higher fecundity per cm2than corals offshore. This area presented the highest contribution of non-carbonate sediments deposited on the reefs. Therefore, we suggest that colonies ofM. braziliensismay present higher uptake rates of particulate matter at inshore reefs, which allow for higher rates of tissue growth (less nutrient limitation) and energy allocation to reproduction.
Detrimental effects of antibiotics on mouse embryos in chromatin integrity, apoptosis and expression of zygotically activated genes
Authors: Liu Jun , Tang Shuang , Xu Wei , Wang Yongsheng , Yin Baoying , Zhang Yong
Published: June 2010

The effects of specific components in culture medium on embryo physiology have been extensively investigated to optimizein vitroculture systems; however, little attention has been paid to antibiotics, the reagents used most commonly in culture systems to prevent contamination. To investigate the potential effects of routine use of antibiotics on cultured embryos, mouse zygotes were cultured with or without antibiotics. In both groups, the developmental rate and cell number of blastocysts appear to be normal. The proportion of embryos with blastomere fragmentation increased slightly when embryos were cultured with antibiotics. In contrast, the presence of antibiotics in the embryo culture system significantly disturbs expression of zygotically activated genes, damages chromatin integrity and increases apoptosis of cultured embryos. These results provide evidence that, when cultured with antibiotics, embryos with normal appearance may possess intrinsic physiological and genetic abnormalities. We demonstrate that the adverse effects of antibiotics on mammalian embryos are more severe than we previously presumed and that antibiotics are not essential for sterility of embryo culture system therefore abolishing antibiotic supplementation during embryo culture.
South Korean Attitudes toward the ROK–U.S. Alliance: Group Analysis
Authors: Chae Haesook
Published: June 2010

This article focuses on South Korean attitudes toward the South Korean-U.S. alliance by comparing three political groups. Using a nationwide survey of South Koreans conducted in 2007, it performs two quantitative analyses: cluster analysis to identify distinct political groups and regression analysis to test hypotheses drawn from literature about what influences public attitudes toward the alliance. This study draws four major conclusions about attitudes toward the alliance: (1) There is strong support for the alliance among South Koreans, including anti-American progressives. (2) For conservatives and centrists, the traditional rationale for the alliance—deterrence of North Korean aggression—remains a basic foundation for the alliance. (3) Among the three groups, there is a developing consensus on a new rationale for the alliance of promoting inter-Korean reconciliation. (4) The younger generation, which constitutes a large majority of the voting public, exhibits moderation and pragmatism in its ideological orientation, contradicting the commonly held view that it heavily slants progressive. These findings can offer important guidance for the future of the alliance.
TRIBUTES TO JOHN HOPE FRANKLIN
Authors: Carson Clayborne
Published: June 2010

Since meeting him three decades ago, John Hope Franklin has served as my best model for what a professional historian should be. Even as a graduate student, his writings were my beacon—a standard of scholarly excellence and social relevance to which I could aspire. Having never taken a course in African American history before entering graduate school, his authoritative text, From Slavery to Freedom, provided an overview of what I wanted to study as well as a challenging reminder of how much I still needed to learn. W. E. B. Du Bois, Thurgood Marshall, and Martin Luther King, Jr., had helped to remove the racial barriers that had once restricted the opportunities of Black scholars, but for my generation of Black students who entered graduate school in the late 1960s and 1970s, Franklin's writings demonstrated that we could use our training to produce scholarship that not only advanced our understanding of our racial past but also exhibited the highest standards of the historical profession.
MEXICAN MIGRATION AND SETTLEMENT
Authors: Vasquez Jessica M.
Published: June 2010

Literature on international migration, assimilation, and transnationalism continues to be concerned with questions about ties that migrants and their descendents have with their homelands, coethnics, and the native-born population. Tomás R. Jiménez'sReplenished Ethnicity: Mexican Americans, Immigration, and Identityand Joanna Dreby'sDivided by Borders: Mexican Migrants and their Childrenprovide important perspectives on different aspects of the larger phenomenon of international migration from Mexico to the United States that is a consequence of labor demand in the United States, economic need and job scarcity in Mexico, and a global economy. Both books deal with social life that takes place across ethnic boundaries, within ethnic groups, and across national borders. Taking qualitative approaches and dealing with the perennial tension between inclusion and exclusion, these books analyze the experiences and perspectives of Mexican migrants, Mexican children, and Mexican Americans.
Prediction of Infarct Volume and Neurologic Outcome by using Automated Multiparametric Perfusion-Weighted Magnetic Resonance Imaging in a Primate Model of Permanent Middle Cerebral Artery Occlusion
Authors: Sasaki Makoto , Kudo Kohsuke , Honjo Kaneyoshi , Hu Jin-Qing , Wang Hai-Bin , Shintaku Katsuya
Published: June 2010

By optimizing thresholds, we identified the perfusion-weighted magnetic resonance imaging (PWI) parameters that accurately predict final infarct volume and neurologic outcome in a primate model of permanent middle cerebral artery (MCA) occlusion. Ten cynomolgus monkeys underwent PWI and diffusion-weighted imaging (DWI) at 3 and 47 hours, respectively, after right MCA occlusion using platinum coils, and were killed at 48 hours. Volumes of the hypoperfused areas on PWI were automatically measured using different thresholds and 11 parametric maps to determine the optimum threshold (at which least difference was found between the average volumes on PWI and those determined using specimens or DWI). In the case of arrival time (AT), cerebral blood volume (CBV), time to peak (TTP), time to maximum ( Tmax), and cerebral blood flow (CBF) determined using deconvolution techniques, the volume of the hypoperfused area significantly correlated with the infarct volumes and the neurologic deficit scores with small variations, whereas in the case of mean transit time and nondeconvolution CBF, relatively poor correlations with large variations were seen. At optimum threshold, AT, CBV, TTP, Tmax, and deconvolution CBF can accurately predict the final infarct volume and neurologic outcome in monkeys with permanent MCA occlusion.
PET Scan Perfusion Imaging in the Prader–Willi Syndrome: New Insights into the Psychiatric and Social Disturbances
Authors: Mantoulan Carine , Payoux Pierre , Diene Gwenaëlle , Glattard Mélanie , Rogé Bernadette , Molinas Catherine , Sevely Annick , Zilbovicius Monica , Celsis Pierre , Tauber Maïthé
Published: June 2010

The Prader–Willi syndrome (PWS), a rare multisystem genetic disease, leads to severe disabilities, such as morbid obesity, endocrine dysfunctions, psychiatric disorders, and social disturbances. We explored the whole brain of patients with PWS to detect abnormalities that might explain the behavioral and social disturbances, as well as the psychiatric disorders of these patients. Nine patients with PWS (six males, three females; mean age 16.4 years) underwent a positron emission tomography (PET) scan with H215O as a tracer to measure regional cerebral blood flow (rCBF). The images were compared with those acquired from nine controls (six males, three females; mean age 21.2 years). A morphologic magnetic resonance imaging (MRI) was also performed in PWS patients, and their cognitive and behavioral skills were assessed with Wechsler Intelligence Scale for Children III and the Child Behavior Check List (CBCL). The MRI images showed no evident anatomic abnormalities, whereas PET scans revealed hypoperfused brain regions in PWS patients compared with controls, particularly in the anterior cingulum and superior temporal regions. We observed a significant relationship ( P<0.05) between rCBF in the hypoperfused regions and CBCL scores. The functional consequences of these perfusion abnormalities in specific brain regions might explain the behavioral and social problems observed in these individuals.
Cerebral Dynamics and Metabolism of Hyperpolarized [1-13C]pyruvate Using Time-Resolved MR Spectroscopic Imaging
Authors: Hurd Ralph E , Yen Yi-Fen , Tropp James , Pfefferbaum Adolf , Spielman Daniel M , Mayer Dirk
Published: June 2010

Dynamic hyperpolarized [1-13C]pyruvate metabolic imaging in the normal anesthetized rat brain is demonstrated on a clinical 3-T magnetic resonance imaging scanner. A 12-second bolus injection of hyperpolarized [1-13C]pyruvate is imaged at a 3-second temporal resolution. The observed dynamics are evaluated with regard to cerebral blood volume (CBV), flow, transport, and metabolic exchange with the cerebral lactate pool. A model for brain [1-13C]lactate, based on blood–brain transport kinetics, CBV, and the observed pyruvate dynamics is described.
Economics of reducing methane emissions from beef cattle in extensive grazing systems in Queensland
Authors: Rolfe John
Published: June 2010

Beef cattle contribute ~7% of anthropocentric greenhouse gas emissions in Australia through the release of methane into the atmosphere. Cattle in northern Australia produce more methane per unit of beef produced because tropical grasses are generally of poor quality and elicit slower average growth rates. In this paper the level of emissions from different herds and some strategies to reduce emissions are estimated with a daily time-step model. The results indicate that few options exist to reduce methane emissions from extensive grazing systems without reducing beef production. Options to improve production or feed conversion efficiencies can generate lower levels of emissions per kg of beef produced, but can be expected to lead to increased livestock numbers and higher overall methane emissions. A woodland grazing case study from central Queensland suggests the opportunity cost of reducing each kg of methane emissions by reducing stocking rates ranges from 1.0 to 1.2 kg of liveweight beef production. A price of $23 per t of carbon dioxide equivalent would indicate that opportunity costs (ignoring fixed costs of production) of reducing emissions by adjusting stocking rates would range between $0.39 and $0.49 per kg of beef produced.
miRNA malfunction causes spinal motor neuron disease
Authors: Haramati Sharon , Chapnik Elik , Sztainberg Yehezkel , Eilam Raya , Zwang Raaya , Gershoni Noga , McGlinn Edwina , Heiser Patrick W. , Wills Anne-Marie , Wirguin Itzhak , Rubin Lee L. , Misawa Hidemi , Tabin Clifford J. , Brown Robert , Chen Alon , Hornstein Eran
Published: June 2010

Defective RNA metabolism is an emerging mechanism involved in ALS pathogenesis and possibly in other neurodegenerative disorders. Here, we show that microRNA (miRNA) activity is essential for long-term survival of postmitotic spinal motor neurons (SMNs) in vivo. Thus, mice that do not process miRNA in SMNs exhibit hallmarks of spinal muscular atrophy (SMA), including sclerosis of the spinal cord ventral horns, aberrant end plate architecture, and myofiber atrophy with signs of denervation. Furthermore, a neurofilament heavy subunit previously implicated in motor neuron degeneration is specifically up-regulated in miRNA-deficient SMNs. We demonstrate that the heavy neurofilament subunit is a target of miR-9, a miRNA that is specifically down-regulated in a genetic model of SMA. These data provide evidence for miRNA function in SMN diseases and emphasize the potential role of miR-9–based regulatory mechanisms in adult neurons and neurodegenerative states.
Optical and thermal energy transport from a NSOM probe to a pure silicon target under intense ns pulsed light
Authors: Wen Sy-Bor
Published: June 2010

An integrated wave-based optical analysis and diffusion-based thermal analysis are constructed to understand the optical and thermal energy transport from a near-field scanning optical microscope (NSOM) probe to a pure silicon target. Based on a comparison between the simulated results and experimentally observed melting structure on the silicon targets in the previous study, it is concluded that a direct contact between the NSOM probes and the target occurs when high intense nanosecond (ns) laser pulses are carried with NSOM probes. Significant thermal energy transport from the NSOM probe to the Si target occurs during the direct contact and is responsible for the melted structure on silicon targets observed in previous experiments. It is also predicted from the integrated optical-thermal analysis for the NSOM probes that (a) the thermal energy transport from the NSOM probe to the target can be orders higher than the near-field optical energy transport under intense ns laser pulses, (b) light transport efficiency from the NSOM probe to the Si target is a strong function of the tapering angle, aperture size and the constructing material of the metal cladding of the probe, (c) the highest temperature of the NSOM probe is a weak function of the tapering angle and aperture diameter of the NSOM probe. However, the maximum temperature of the NSOM can be significantly changed by selecting the appropriate cladding material of the NSOM probe.
A necessary condition for principal cluster sets to be void
Authors: Belna C. L.
Published: June 2010

Let

f
f

be an arbitrary function from the open unit disk

D
D

into the Riemann sphere

W
W

, and let

p
p

be a point on the unit circle

C
C

. We prove that if the principal cluster set of

f
f

at

p
p

is void, then either

p
p

is an ambiguous point of

f
f

or the diameter of each arc-cluster set of

f
f

at

p
p

is greater than a fixed positive number.
Fatou’s lemma in several dimensions
Authors: Schmeidler David
Published: June 2010

In this note the following generalization of Fatou’s lemma is proved: Lemma. Let

(

f
n

)

n
−
1

∞

({f_n})_{n - 1}^\infty

be a sequence of integrable functions on a measure space

S
S

with values in

R
+
d

R_ + ^d

, the nonnegative orthant of a

d
d

-dimensional Euclidean space, for which

∫

f
n

→
a
∈

R
+
d

\int {{f_n} \to a \in R_ + ^d}

. Then there exists an integrable function

f
f

, from

S
S

to

R
+
d

R_ + ^d

, such that a.e.

f
(
s
)

f(s)

is a limit point of

(

f
n

(
s
)

)

n
−
1

∞

({f_n}(s))_{n - 1}^\infty

and

∫

f
≦
a

\int {f \leqq a}

.
On embedding of lattices belonging to the same genus
Authors: Jacobinski H.
Published: June 2010

If

R
R

is an order in a semisimple algebra over a Dedekind ring and

M
,

N

M,\;N

two

R
R

-lattices in the same genus, an upper bound for the length of the composition series of

M

/

N
′

M/N’

for

N
′

≅
N

N’ \cong N

, is given. This answers a question posed by Roĭter.
An elementary Tauberian theorem of nonlinear type
Authors: Pollard Harry , Saari D. G.
Published: June 2010

We find a nonlinear condition on

f
∈

C
2

(
0
,
∞
)

f \in {C^2}(0,\infty )

which, when coupled with the assumption

lim
inf

|

f
(
t
)

|

/

t
>
∞

\lim \inf |f(t)|/t > \infty

, implies

f
∼
A
t

f \sim At

and

f
′

→
A

f’ \to A

.

A
A

is some constant and

t
→
∞

t \to \infty

or

t
→
0
+

t \to 0 +

.
An unsolvable equation
Authors: Garabedian P. R.
Published: June 2010

A linear partial differential equation that is not solvable is obtained by a very simple transformation of the Cauchy-Riemann equations.
A note on finite metabelian 𝑝-groups
Authors: Gillam J. D.
Published: June 2010

Let

A
A

be an abelian subgroup of maximal order in the finite metabelian

p
p

-group

P
P

. It is shown that there exists a normal abelian subgroup

A
1

{A_1}

of

P
P

such that the order of

A
1

{A_1}

is equal to the order of

A
A

.
Asymptotic values of normal light interior functions defined in the unit disk
Authors: Mathews J. H.
Published: June 2010

Lehto and Virtanen have extended Lindelöf’s theorem for the class of normal meromorphic functions. It is shown that Lindelöf’s theorem cannot be extended for the class of bounded normal light interior functions. A generalization of Lindelöf’s theorem is given.
The Perron integral and existence and uniqueness theorems for a first order nonlinear differential equation
Authors: Manougian Manoug N.
Published: June 2010

The Perron integral is used to establish an existence and uniqueness theorem concerning the initial value problem

y
′

(
t
)
=
f
(
t
,
y
(
(
t
)
)

y’(t) = f(t,y((t))

, and

y
(

t
0

)
=
α

y({t_0}) = \alpha

, for

t
t

on the interval

I
=
{
t

|

0
≦
t
≦
1
}

I = \{ t|0 \leqq t \leqq 1\}

. The existence and uniqueness of the solution is obtained by use of a generalized Lipschitz condition, and a Picard sequence which is equiabsolutely continuous on

I
I

. Also, we prove a theorem on the uniqueness of solution by a generalization of Gronwall’s inequality.
Annulus conjecture and stability of homeomorphisms in infinite-dimensional normed linear spaces
Authors: McCoy R. A.
Published: June 2010

If

E
E

is an arbitrary infinite-dimensional normed linear space, it is shown that if all homeomorphisms of

E
E

onto itself are stable, then the annulus conjecture is true for

E
E

. As a result, this confirms that the annulus conjecture for Hilbert space is true. A partial converse is that for those spaces

E
E

which have some hyperplane homeomorphic to

E
E

, if the annulus conjecture is true for

E
E

and if all homeomorphisms of

E
E

onto itself are isotopic to the identity, then all homeomorphisms of

E
E

onto itself are stable.
Note on the homology of a fiber product of groups
Authors: Rinehart G. S.
Published: June 2010

Spectral sequences are derived for the homology and cohomology of a fiber product of groups with coefficients in a tensor product module. These generalize the Hochschild-Serre spectral sequences, and, in the case of a full product of groups, give Künneth formulas. The latter are used to make easy explicit computations of the homology and cohomology of an arbitrary finitely generated
Polynomial approximation on 𝑦=𝑥^{𝛼}
Authors: Passow E. , Raymon L.
Published: June 2010

We show that on the curve

y
=

x
α

,
α

y = {x^\alpha },\alpha

any irrational,

0
≦
x
≦
1

0 \leqq x \leqq 1

, the degree of approximation by

n
n

th degree polynomials in

x
x

and

y
y

in the

L
2

{L^2}

norm has order of magnitude

1

/

n

3

/

2

1/{n^{3/2}}

.