bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and characterization of alkylated carbon nanotube/polyimide nanocomposites
Authors: Zhang Qinghua , Li Jing , Zhao Xin , Chen Dajun
Published: March 2009

BACKGROUND: The development of carbon nanotube‐reinforced composites has been impeded by the difficult dispersion of the nanotubes in polymers and the weak interaction between the nanofiller and matrices. Efficient dispersion of carbon nanotubes is essential for the formation of a functional nanotube network in a composite matrix.

RESULTS: Multiwalled carbon nanotubes (MWNTs) were incorporated into a polyimide matrix to produce MWNT/polyimide nanocomposites. To disperse well the MWNTs in the matrix and thus improve the interfacial adhesion between the nanotubes and the polymer, ‘branches’ were grafted onto the surface of the nanotubes by reacting octadecyl isocyanate with carboxylated MWNTs. The functionalized MWNTs were suspended in a precursor solution, and the dispersion was cast, followed by drying and imidization to obtain MWNT/polyimide nanocomposites.

CONCLUSION: The functionalized MWNTs appear as a homogeneous dispersion in the polymer matrix. The thermal stability and the mechanical properties are greatly improved, which is attributed to the strong interactions between the functionalized MWNTs and the polyimide matrix. Copyright © 2009 Society of Chemical Industry
Modeling a linear electric molten zone in a silicon ribbon
Authors: Brito Miguel C. , Amaral Ana , Alves J. Maia , Serra João M. , Costa Ivo , Vallêra A. M.
Published: March 2009

The linear electric molten zone produced by passing an electric current in a silicon ribbon may be used to create a floating molten zone specially suited for a recrystallization process. A one‐dimensional heat transfer numerical model of a linear electric molten zone is developed. Simulation results show the electric current concentration mechanism, and describe the effect of parameters such as the auxiliary radiative input power, or the ribbon thermal conditioning and geometry on the temperature profile and the molten zone width. It is shown that producing a linear molten zone electrically, is about half as energy intensive as if this were done solely by radiative heating. Copyright © 2009 John Wiley & Sons, Ltd.
Reducing the heterotic supergravity on nearly‐Kähler coset spaces
Authors: Chatzistavrakidis A. , Manousselis P. , Zoupanos G.
Published: March 2009

We study the dimensional reduction of the 𝒩 = 1, ten‐dimensional Heterotic Supergravity to four dimensions, at leading order in α', when the internal space is a nearly‐Kähler manifold. Nearly‐Kähler manifolds in six dimensions are all the non‐symmetric coset spaces and a group manifold. Here we reduce the theory using as internal manifolds the three six‐dimensional non‐symmetric coset spaces, omitting the case of the group manifold in the prospect of obtaining chiral fermions when the gauge fields will be included. We determine the effective actions for these cases, which turn out to describe 𝒩 = 1 four‐dimensional supergravities of the no‐scale type and we study the various possibilities concerning their vacuum.
On the effective theory of type IIA AdS4 compactifications
Authors: Körs S.
Published: March 2009

This is a summary of [1], where the low energy effectiv theory of type IIA AdS4 𝒩 = 1 flux compactifications on nilmanifolds and cosets has been analyzed.
Lightlike branes as natural candidates for wormhole throats
Authors: Guendelman E.I. , Kaganovich A. , Nissimov E. , Pacheva S.
Published: March 2009

We first briefly present a consistent world‐volume Lagrangian description of lightlike p‐branes (LL‐branes) in two equivalent forms – a Polyakov‐type and a dual to it Nambu‐Goto‐type formulations. The most important characteristic features of LL‐brane dynamics are: (i) the brane tension appears as a non‐trivial additional dynamical degree of freedom; (ii) consistency of LL‐brane dynamics in a spherically or axially symmetric gravitational background of codimension one requires the presence of an event horizon which is automatically occupied by the LL‐brane (“horizon straddling”). Next we consider a bulk Einstein‐Maxwell system interacting self‐consistently with a codimension one LL‐brane. We find spherically symmetric traversable wormhole solutions of Misner‐Wheeler type produced by the LL‐brane sitting at the wormhole throat with wormhole parameters being functions of the dynamical LL‐brane tension.
Free string evolution across plane wave singularities
Authors: Craps B. , De Roo F. , Evnin O.
Published: March 2009

In these proceedings, we summarize our studies of free string propagation in (near‐)singular scale‐invariant plane wave geometries. We analyze the singular limit of the evolution for the center‐of‐mass motion and all excited string modes. The requirement that the entire excitation energy of the string should be finite excludes consistent propagation across the singularity, in case no dimensionful scales are introduced at the singular locus (in an otherwise scale‐invariant space‐time).
Towards effective Lagrangians for adelic strings
Authors: Dragovich B.
Published: March 2009

p‐Adic strings are important objects of string theory, as well as of p‐adic mathematical physics and nonlocal cosmology. By a concept of adelic string one can unify and simultaneously study various aspects of ordinary and p‐adic strings. By this way, one can consider adelic strings as a very useful instrument in the further investigation of modern string theory. It is remarkable that for some scalar p‐adic strings exist effective Lagrangians, which are based on real instead of p‐adic numbers and describe not only four‐point scattering amplitudes but also all higher ones at the tree level. In this work, starting from p‐adic Lagrangians, we consider some approaches to construction of effective field Lagrangians for p‐adic sector of adelic strings. It yields Lagrangians for nonlinear and nonlocal scalar field theory, where spacetime nonlocality is determined by an infinite number of derivatives contained in the operator‐valued Riemann zeta function. Owing to the Riemann zeta function in the dynamics of these scalar field theories, obtained Lagrangians are also interesting in themselves.
Inflation and string cosmology
Authors: Linde A.
Published: March 2009

I give a brief review of inflationary theory and of its recent progress related to string cosmology.
Interval approach to assessing antitumor activity for tumor xenograft studies
Authors: Wu Jianrong , Houghton Peter J.
Published: March 2009

In preclinical cancer drug screening tumor xenograft experiments, the tumor growth inhibition ratio (T/C) is commonly used to assess the antitumor activity of the agents. Unfortunately, this measurement can discard useful data and result in a high false‐negative rate. Furthermore, the degree of antitumor activity based on the T/C ratio is assessed on the basis of an arbitrary cutoff point that does not reflect variations in different tumor lines. To overcome these drawbacks, we propose an adjusted area‐under‐the‐curve (aAUC) ratio to quantify tumor growth inhibition. A nonparametric bootstrap t‐interval of the aAUC ratio is also proposed for assessing the significance of the antitumor activity of the agents. The proposed method is then applied to a real tumor xenograft study. Copyright © 2009 John Wiley & Sons, Ltd.
Monitoring a fraction with easy and reliable settings of the false alarm rate
Authors: Duran Rodrigo I. , Albin Susan L.
Published: March 2009

Monitoring a fraction arises in many manufacturing applications and also in service applications. The traditional p‐chart is easy to use and design but is difficult to achieve the desired false alarm rate. We propose a two‐sided CUSUM Arcsine method that achieves both large and small desired false alarm rates for an in‐control probability anywhere between 0 and 1. The parameters of the new method are calculated easily, without tables, simulation, or Markov chain analysis used by many of the existing methods. The proposed method detects increases and decreases and works for constant and Poisson distributed sample sizes. The CUSUM Arcsine also has a superior sensitivity compared with other easily designed existing methods for monitoring Binomial distributed data. This paper includes an extensive literature review and a taxonomy of the existing monitoring methods for a fraction. Copyright © 2009 John Wiley & Sons, Ltd.
A thermal decomposition study of polymers by tunable synchrotron vacuum ultraviolet photoionization mass spectrometry
Authors: Li Jiao , Cai Jianghuai , Yuan Tao , Guo Huijun , Qi Fei
Published: March 2009

The thermal decomposition of polymers (poly(vinyl chloride) (PVC) and polystyrene (PS)) has been studied with synchrotron VUV photoionization mass spectrometry at low pressure. Pyrolysis products formed at different temperatures have been identified by the measurement of photoionization mass spectra at different photon energies. The experimental results demonstrate the variation of the pyrolysis product pool of PVC at different temperatures, dividing the thermal decomposition process into two stages: the low‐temperature stage to form HCl and benzene, and the high‐temperature stage to form numerous large aromatic hydrocarbons. For the thermal decomposition of PS, four reaction categories are determined. This work reports a new application of synchrotron VUV photoionization mass spectrometry in the study of the thermal decomposition of polymers, and demonstrates its good performance in product analysis, which is expected to help understand the thermal decomposition mechanism of PVC, PS and other synthesized polymers. Copyright © 2009 John Wiley & Sons, Ltd.
Fragmentation reactions of some peptide b3 ions: an energy‐resolved study
Authors: Harrison Alex G.
Published: March 2009

The fragmentation reactions of b3 ions of nominal structure AAAoxa, YAAoxa, AYAoxa and AAYoxa have been studied as a function of collision energy, allowing the construction of breakdown graphs expressing in a qualitative way the energy dependence of the fragmentation reactions. The primary fragmentation reactions of the AAAoxa b3 ion involve formation of the a3* (a3 – NH3) ion and the b2 ion, with the latter becoming the dominant product at higher internal energies. For both YAAoxa and AYAoxa b3 ions the pathway to a3* is relatively minor with formation of b2 the dominant primary fragmentation reaction. For the AAYoxa b3 ion, in addition to a3*, abundant formation of the tyrosine (Y) iminium ion is observed with only minor formation of the b2 ion. The results support and expand upon the detailed mechanism of fragmentation of b3 ions proposed by Cooper et al. (J. Am. Soc. Mass Spectrom. 2006; 17: 1654). Copyright © 2009 John Wiley & Sons, Ltd.
Wip1 Regulates the Generation of New Neural Cells in the Adult Olfactory Bulb through p53-Dependent Cell Cycle Control
Authors: Zhu Yun-Hua , Zhang Cheng-Wu , Lu Li , Demidov Oleg N. , Sun Li , Yang Lan , Bulavin Dmitry V. , Xiao Zhi-Cheng
Published: March 2009

Continual generation of new neural cells from adult neural stem/progenitor cells (NPCs) is an important component of life-long brain plasticity. However, the intrinsic regulation of this process remains poorly defined. Here we report that Wip1 phosphatase, previously studied in oncogenesis, functions as a crucial physiological regulator in adult neural cell generation. Wip1 deficiency resulted in a 90% decrease in new cell formation in adult olfactory bulb, accompanied by aberrantly decreased NPC amplification, stem cell frequency, and self-renewal. At a cellular level, Wip1 knockout NPCs exhibit a prolonged cell cycle, an accumulation at G2 to M phase transition, and enhanced p53 activity. Interestingly, the impaired M-phase entry and NPC amplification of Wip1-null mice can be reversed in Wip1/p53 double-null mice. Importantly, there is no difference in NPC amplification between p53-null and Wip1/p53 double-null mice. Our data demonstrate that Wip1 regulates the generation of new neural cells in adult olfactory bulb specifically through p53-dependent M-phase entry of the NPC cell cycle.

Disclosure of potential conflicts of interest is found at the end of this article.
Phenotypic and Functional Changes Induced in Hematopoietic Stem/Progenitor Cells After Gamma-Ray Radiation Exposure
Authors: Simonnet Arthur J. , Nehmé Johnny , Vaigot Pierre , Barroca Vilma , Leboulch Philippe , Tronik-Le Roux Diana
Published: March 2009

Ionizing radiation (IR) exposure causes rapid and acute bone marrow (BM) suppression that is reversible for nonlethal doses. Evidence is accumulating that IR can also provoke long-lasting residual hematopoietic injury. To better understand these effects, we analyzed phenotypic and functional changes in the stem/progenitor compartment of irradiated mice over a 10-week period. We found that hematopoietic stem cells (HSCs) identified by their repopulating ability continued to segregate within the Hoechst dye excluding “side population (SP)” early after IR exposure. However, transient phenotypic changes were observed within this cell population: Sca-1 (S) and c-Kit (K) expression levels were increased and severely reduced, respectively, with a concurrent increase in the proportion of SPSK cells positive for established indicators of the presence of HSCs: CD150 and CD105. Ten weeks after IR exposure, expression of Sca-1 and c-Kit at the SP cell surface returned to control levels, and BM cellularity of irradiated mice was restored. However, the c-Kit+Sca-1+Lin−/low (KSL) stem/progenitor compartment displayed major phenotypic modifications, including an increase and a severe decrease in the frequencies of CD150+Flk2− and CD150−Flk2+ cells, respectively. CD150+ KSL cells also showed impaired reconstituting ability, an increased tendency to apoptosis, and accrued DNA damage. Finally, 15 weeks after exposure, irradiated mice, but not age-matched controls, allowed engraftment and significant hematopoietic contribution from transplanted congenic HSCs without additional host conditioning. These results provide novel insight in our understanding of immediate and delayed IR-induced hematopoietic injury and highlight similarities between HSCs of young irradiated and old mice.

Disclosure of potential conflicts of interest is found at the end of this article.
Structural colored gels for tunable soft photonic crystals
Authors: Harun‐ur‐Rashid Mohammad , Seki Takahiro , Takeoka Yukikazu
Published: March 2009

A periodically ordered interconnecting porous structure can be embodied in chemical gels by using closest‐packed colloidal crystals as templates. The interconnecting porosity not only provides a quick response but also endows the porous gels with structural color arising from coherent Bragg optical diffraction. The structural colors revealed by porous gels can be regulated by several techniques, and thus, it is feasible to obtain desirable, smart, soft materials. A well‐known thermosensitive monomer, N‐isopropylacrylamide (NIPA), and other minor monomers were used to fabricate various structural colored gels. The selection of minor monomers depended on the targeted properties. This review focuses on the synthesis of templates, structural colored porous gels, and the applications of structural colored gel as smart soft materials for tunable photonic crystals. © 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 87–105; 2009: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20169
Flexible host frameworks with diverse cavities in inclusion crystals of bile acids and their derivatives
Authors: Nakano Kazunori , Aburaya Kazuaki , Hisaki Ichiro , Tohnai Norimitsu , Miyata Mikiji
Published: March 2009

We have systematically investigated structures and properties of inclusion crystals of bile acids and their derivatives. These steroidal compounds form diverse host frameworks having zero‐, one‐ and two‐dimensional cavities, causing various inclusion behaviors towards many organic compounds. The diverse host frameworks exhibit the following guest‐dependent flexibility. First, the frameworks mainly depend on the included guests in size and shape. The size‐dependence is quantitatively estimated by the parameter PCcavity, which is the volume ratio of a guest molecule to a host cavity. The resulting values of PCcavity lie in the range of 42–76%. Second, each of the host frameworks has its own range of the values. Some guests can employ two different frameworks with the boundary values, explaining formation of polymorphic crystals. Third, the host frameworks are selected by host–guest interactions through weak hydrogen bonds, such as NH/π and CH/O. The weak hydrogen bonds play an important role for various selective inclusion processes. Fourth, the host frameworks are dynamically exchangeable, resulting in intercalation and polymerization in the cavities. These static and dynamic structures of the frameworks demonstrate great potential of crystalline organic inclusion compounds as functional materials. © 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 124–135; 2009: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20171
Bifunctional transition metal‐based molecular catalysts for asymmetric CC and CN bond formation
Authors: Ikariya Takao , Gridnev Ilya D.
Published: March 2009

This paper describes the recent advances in the conceptually new bifunctional Ir and Ru catalysts for asymmetric catalytic reactions. These reactions include the enantioselective Michael addition of 1,3‐dicarbonyl compounds to cyclic enones and nitroalkenes, and the enantioselective direct amination of α‐cyanoacetates with diazoesters. The outcome of these reactions in terms of reactivity and selectivity was delicately influenced by the catalyst structures and the reaction conditions including the solvents used. Even with a 1 : 1 molar ratio of donors to acceptors, the reactions proceeded smoothly to give the corresponding chiral adducts with an excellent yield and enantiomeric excess (ee). Preliminary mechanistic studies showed that the key stage of the catalytic cycle is the interaction of the bifunctional catalyst with a pronucleophilic reagent that leads to stereoselective formation of C‐, O‐, or N‐bound complexes. The resulting protonated catalyst bearing metal‐bound nucleophiles readily reacts with electrophiles to provide CC and CN bond formation products in a highly stereoselective manner. © 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 106–123; 2009: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20172
Microsurgical vasectomy reversal: results and predictors of success
Authors: Dohle Gert R. , Smit Marij
Published: March 2009

Microsurgical vasectomy reversal is a challenge for the physician but successful treatment depends on the experience and skills of the surgeon. Fertility can often be restored, thus avoiding the need for artificial reproductive techniques. Also, the surgical procedures can be combined with sperm aspiration and cryopreservation, to be used for Intracytoplasmic sperm injection (ICSI) in cases of surgical failure. We describe the results of 217 vasovasostomy procedures, with special emphasis on recent technical refinements and prognostic indicators.

Between 1998 and 2002 we performed 217 vasovasostomy-procedures in an outpatient clinic setting. Refertilisation was successful in 76.5%, spontaneous pregnancy occurred in 42% of the couples after, a follow-up of at least 1 year. The main prognostic factors determining the outcome of the surgery was the interval between vasectomy and refertilisation and the age of the female partner: patency was 89% after an interval of less than 5 years and pregnancy occurred in 56% of these couples. After an interval of more than 10 years patency decreased to 75% and pregnancy results dropped to 24%. Epididymal dysfunction with poor motility score and secondary epididymal obstruction appeared to be common after a long interval. Furthermore, in men with partners older than 35 years of age pregnancy was only 21%, indicating limited ovarian reserve as an important factor in determining the final outcome.

In men with a long obstructive interval between vasectomy and reversal an obstruction of the epididymis can be found due to a blow-out of the epididymal tubule with subsequent leakage of semen in the organ and fibrosis. A vaso-epididymostomy procedure is needed to treat the obstruction. Recently, surgical refinements, such as the invagination technique, have been introduced for the vaso-epididymostomy procedure, showing promising first results. This simplified technique enables less experienced microsurgeons to perform this difficult operation successfully. The results of vasectomy reversal procedures can be improved substantially if the surgeon is able to perform a vaso-epididymostomy in cases of a secondary epididymal obstruction, occurring in about 25% of men with an interval of more than 10 years.
Twenty-first century laparoscopic hysterectomy: should we not leave the vaginal step out?
Authors: Twijnstra A. R. H. , Kianmanesh Rad N. A. , Smeets M. J. G. H. , Admiraal J. F. , Jansen F. W.
Published: March 2009

The objective of this study was to compare surgical outcomes for laparoscopically assisted vaginal hysterectomy (LAVH) with total laparoscopic hysterectomy (TLH) in three teaching hospitals in the Netherlands. This study is a multicenter cohort retrospective analysis of consecutive cases (Canadian Task Force classification II-2). One hundred and four women underwent a laparoscopic hysterectomy between March 1995 and March 2005 at one of three teaching hospitals. This included 37 women who underwent LAVH and 67 who underwent TLH. Blood loss, operating time, and intraoperative complications such as bladder or ureteric injury as well as conversion to an open procedure were recorded. In the TLH group, average age was statistically significant lower, as well as the mean parity, whereas estimated uterus size was statistically significant larger, compared to the LAVH group. Main indication in both groups was dysfunctional uterine bleeding. In the TLH group, mean blood loss (173 mL) was significant lower compared to the LAVH group (457 mL), whereas length of surgery, uterus weight, and complication rates were comparable between the two groups. The method of choice at the start of the study period was LAVH, and by the end of the study period, it had been superceded by TLH. LAVH should not be regarded as the novice’s laparoscopic hysterectomy. Moreover, with regard blood loss, TLH shows advantages above LAVH. This might be due to the influence of the altered anatomy in the vaginal stage of the LAVH procedure. Therefore, when a vaginal hysterectomy is contraindicated, TLH is the procedure of choice. LAVH remains indicated in case of vaginal hysterectomy with accompanying adnexal surgery.
Genes, patients, families, doctors—Mutation analysis in clinical practice
Authors: Walter J. H.
Published: March 2009

Developments in mutation analysis have led to significant benefits for patients with inherited metabolic disorders and their families. This is particularly the case where new methodologies have prevented the need for invasive tissue biopsies or have allowed carrier detection or first trimester prenatal testing to be undertaken. Whereas in the past it may have only been possible to identify specific ‘common’ mutations, the availability of techniques, such as automated sequencing, and novel technologies including mutation scanning techniques, multiplex ligation dependent probe amplification, and array technologies, have vastly improved the diagnostic efficiency of molecular testing.
Total Distal Radioulnar Joint Arthroplasty in Adults with Symptomatic Madelung's Deformity
Authors: Coffey Michael J. , Scheker Luis R. , Thirkannad Sunil M.
Published: March 2009

Madelung's deformity is a well-known congenital anomaly of the wrist. A number of procedures have been described to correct the deformity and thus improve function at the wrist. Most of these procedures have to a large extent addressed the alignment and consequent function of the radiocarpal joint but not the persistent problem of painful stiffness at the distal radioulnar joint (DRUJ). The availability of a total DRUJ prosthesis appears to provide a solution to this problem. This article discusses our early experience with total DRUJ arthroplasty using the Scheker prosthesis for managing pain and decreased range of motion in three adult patients with symptomatic Madelung's deformity.
Nerve Allotransplantation as it Pertains to Composite Tissue Transplantation
Authors: Moore Amy M. , Ray Wilson Z. , Chenard Kristofer E. , Tung Thomas , Mackinnon Susan E.
Published: March 2009

Nerve allografts provide a temporary scaffold for host nerve regeneration and allow for the repair of significant segmental nerve injuries. From rodent, large animal, and nonhuman primate studies, as well as clinical experience, nerve allografts, with the use of immunosuppression, have the capacity to provide equal regeneration and function to that of an autograft. In contrast to solid organ transplantation and composite tissue transfers, nerve allograft transplantation requires only temporary immunosuppression. Furthermore, nerve allograft rejection is difficult to assess, as the nerves are surgically buried and are without an immediate functional endpoint to monitor. In this article, we review what we know about peripheral nerve allograft transplantation from three decades of experience and apply our current understanding of nerve regeneration to the emerging field of composite tissue transplantation.
Advances and Prospect of Nanotechnology in Stem Cells
Authors: Wang Zheng , Ruan Jing , Cui Daxiang
Published: March 2009

In recent years, stem cell nanotechnology has emerged as a new exciting field. Theoretical and experimental studies of interaction between nanomaterials or nanostructures and stem cells have made great advances. The importance of nanomaterials, nanostructures, and nanotechnology to the fundamental developments in stem cells-based therapies for injuries and degenerative diseases has been recognized. In particular, the effects of structure and properties of nanomaterials on the proliferation and differentiation of stem cells have become a new interdisciplinary frontier in regeneration medicine and material science. Here we review some of the main advances in this field over the past few years, explore the application prospects, and discuss the issues, approaches and challenges, with the aim of improving application of nanotechnology in the stem cells research and development.
Structure and Photoluminescent Properties of ZnO Encapsulated in Mesoporous Silica SBA-15 Fabricated by Two-Solvent Strategy
Authors: Lu Qingshan , Wang Zhongying , Li Jiangong , Wang Peiyu , Ye Xialei
Published: March 2009

The two-solvent method was employed to prepare ZnO encapsulated in mesoporous silica (ZnO/SBA-15). The prepared ZnO/SBA-15 samples have been studied by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, nitrogen adsorption–desorption isotherm, and photoluminescence spectroscopy. The ZnO/SBA-15 nanocomposite has the ordered hexagonal mesostructure of SBA-15. ZnO clusters of a high loading are distributed in the channels of SBA-15. Photoluminescence spectra show the UV emission band around 368 nm, the violet emission around 420 nm, and the blue emission around 457 nm. The UV emission is attributed to band-edge emission of ZnO. The violet emission results from the oxygen vacancies on the ZnO–SiO2interface traps. The blue emission is from the oxygen vacancies or interstitial zinc ions of ZnO. The UV emission and blue emission show a blue-shift phenomenon due to quantum-confinement-induced energy gap enhancement of ZnO clusters. The ZnO clusters encapsulated in SBA-15 can be used as light-emitting diodes and ultraviolet nanolasers.
Antioxidant Activity of Added Phenolic Compounds in Freeze‐Dried Microencapsulated Sunflower Oil
Authors: Velasco Joaquín , Holgado Francisca , Dobarganes Carmen , Márquez‐Ruiz Gloria
Published: March 2009

This study was aimed at evaluating the effectiveness of phenolic antioxidants with a similar structure but having a different polarity in dried microencapsulated sunflower oil. The antioxidants tested were, on one hand, α‐tocopherol and its water soluble analogue, Trolox, and on the other, gallic acid and its ester derivatives, propyl gallate and dodecyl gallate. At a moderate temperature (40 °C), the samples were oxidized under accelerated conditions by using Cu(II) as an oxidation catalyst. The progress of oxidation was followed up over time in the free and encapsulated oil fractions. The peroxide value, the total content of polymers and, when appropriate, the content of α‐tocopherol were determined. Quantitative analysis of the total fraction of the non‐volatile oxidation products and their distribution in oligomers, dimers and monomers was applied to samples to obtain a complete evaluation of oxidation. Finally, as a complementary measure, the antioxidants were also assessed by direct application of the Rancimat test at 100 °C on the dried microencapsulated oil samples. Results showed that the antioxidants of lower polarity in each series, i.e. tocopherol and dodecyl gallate, were to a great extent the most protective antioxidants. The results obtained by the Rancimat test were consistent with those found during oxidation at moderate temperature. Furthermore, the addition of Cu(II) reduced proportionally the oxidative stability index of the dried microencapsulated samples.
Assembly of a chimeric respiratory chain from bovine heart submitochondrial particles and cytochrome bd terminal oxidase of Escherichia coli
Authors: Gavrikova Eleonora V. , Grivennikova Vera G. , Borisov Vitaliy B. , Cecchini Gary , Vinogradov Andrei D.
Published: March 2009

Cytochrome bd is a terminal quinol oxidase in Escherichia coli. Mitochondrial respiration is inhibited at cytochrome bc
1 (complex III) by myxothiazol. Mixing purified cytochrome bd oxidase with myxothiazol‐inhibited bovine heart submitochondrial particles (SMP) restores up to 50% of the original rotenone‐sensitive NADH oxidase and succinate oxidase activities in the absence of exogenous ubiquinone analogs. Complex III bypassed respiration and is saturated at amounts of added cytochrome bd similar to that of other natural respiratory components in SMP. The cytochrome bd tightly binds to the mitochondrial membrane and operates as an intrinsic component of the chimeric respiratory chain.
Stroke and Neurodegenerative Disorders: 1. Stroke Management in the Acute Care Setting
Authors: Reddy Cara Camiolo , Moroz Alex , Edgley Steven R. , Lew Henry L. , Chae John , Lombard Lisa A.
Published: March 2009

Objective

This self‐directed learning module highlights management of stroke in the acute care setting. It is part of the study guide on stroke and neurodegenerative disorders in the Self‐Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. Using a case vignette format, this article specifically focuses on initial assessment and management of acute ischemic and hemorrhagic stroke, descriptions of posterior circulation and lacunar stroke, and criteria for admission to acute inpatient rehabilitation after stroke and secondary stroke prevention. The goal of this article is to improve the learner's ability to identify, treat and manage a patient with a stroke in the acute care setting.
Stroke and Neurodegenerative Disorders: 2. Poststroke Medical Complications
Authors: Lombard Lisa A. , Reddy Cara Camiolo , Moroz Alex , Lew Henry L. , Chae John , Edgley Steven R.
Published: March 2009

Objective

This self‐directed learning module highlights common poststroke medical complaints encountered on an inpatient rehabilitation unit. It is part of the study guide on stroke and neurodegenerative disorders in the Self‐Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. Using a case vignette format, this article specifically focuses on the differential diagnosis, evaluation and management of chest pain, mental status changes, weight loss and poor motivation in stroke patients. The goal of this article is to expand the learner's knowledge of how to diagnose and manage common medical complications of stroke patients in rehabilitation.
Sports and Performing Arts Medicine: 1. Upper Extremity Injuries
Authors: Akau Cedric K. , Harrast Mark A. , Storm Seneca A. , Finnoff Jonathan T. , Willick Stuart
Published: March 2009

Objective

This self‐directed learning module highlights upper limb sports and performing arts injuries. It is part of the study guide on sports and performing arts medicine in the Self‐Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. Using a case vignette format, this article specifically focuses on shoulder, elbow and finger pain in athletes and wrist pain in musicians. The goal of this article is to enhance the learner's understanding on how to approach common upper limb pain conditions and injuries in these populations.
Sports and Performing Arts Medicine: 3. Spine and Neurologic Injuries
Authors: Storm Seneca A. , Finnoff Jonathan T. , Willick Stuart , Akau Cedric K. , Harrast Mark A.
Published: March 2009

Objective

This self‐directed learning module highlights select spine and neurological injuries in athletes and performing arts injuries. It is part of the study guide on sports and performing arts medicine in the Self‐Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. Using a case vignette format, this article specifically focuses on sports‐induced concussion, stingers and transient myelopathy, and buttock pain in athletes, and hand dystonia and hand numbness in musicians. The goal of this article is to facilitate the learner's ability to diagnose and treat spine and neurologic injuries in athletes and performing artists.
Stroke and Neurodegenerative Disorders: 4. Community Integration
Authors: Edgley Steven R. , Lew Henry L. , Moroz Alex , Chae John , Lombard Lisa A. , Reddy Cara Camiolo
Published: March 2009

Objective

This self‐directed learning module highlights common rehabilitation issues in stroke survivors with chronic impairments with emphasis on community integration. It is part of the study guide on stroke and neurodegenerative disorders in the Self‐Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. Using a case vignette format, this article specifically focuses on management of shoulder pain, management of hypertonia, secondary stroke prevention, vocational reintegration including strategies for return to driving, and treatment of sexual dysfunction following stroke. The goal of this article is to improve the learner's ability to implement community integration strategies after a stroke.
Lichenometric dating using Rhizocarpon subgenus Rhizocarpon in the Patagonian Andes, Argentina
Authors: Garibotti Irene Adriana , Villalba Ricardo
Published: March 2009

This study represents the first attempt to develop and apply lichenometric dating curves of Rhizocarpon subgenus Rhizocarpon for dating glacier fluctuations in the Patagonian Andes. Six glaciers were studied along the Patagonian Andes. Surfaces of known ages (historical evidences and tree-ring analyses) were used as control sites to develop indirect lichenometric dating curves. Dating curves developed for the studied glaciers show the same general logarithmic form, indicating that growth rate of subgenus Rhizocarpon decreases over time. The strong west–east precipitation gradient across the Andean Cordillera introduces statistically significant differences in the growth curves, with faster growth rates in the moist west sites than the drier eastern sites. Latitudinal difference among the studied glaciers does not appear to be a major factor regulating lichen growth rates. Therefore, we developed two lichenometric curves for dating glacier fluctuations in wetter and drier sites in the Patagonian Andes during the past 450 yrs. Application of the developed curves to moraine dating allowed us to complement glacial chronologies previously obtained by tree-ring analyses. A first chronosequence for moraine formation in the Torrecillas Glacier (42°S) is presented. Our findings confirm the utility of lichenometry to date deglaciated surfaces in the Patagonian Andes.
Whose Right to Rest? Contesting the Family Vacation in the Postwar Soviet Union
Authors: Koenker Diane P.
Published: March 2009

The idea of leisure and vacations in the Soviet Union at first glance suggests a paradox. As a system based on the labor theory of value, the USSR emphasized production as the foundation of wealth, personal worth, and the path to a society of abundance for all. Work—physical or mental—was the obligation of all citizens. But work took its toll on the human organism, and along with creating the necessary incentives and conditions for productive labor a socialist system would also include reproductive rest as an integral element of its economy. The eight-hour work day, a weekly day off from work, and an annual vacation constituted the triad of restorative and healthful rest opportunities in the emerging Soviet system of the 1920s and 1930s.
Sex, attachment, and the development of reproductive strategies
Authors: Del Giudice Marco
Published: March 2009

This target article presents an integrated evolutionary model of the development of attachment and human reproductive strategies. It is argued that sex differences in attachment emerge in middle childhood, have adaptive significance in both children and adults, and are part of sex-specific life history strategies. Early psychosocial stress and insecure attachment act as cues of environmental risk, and tend to switch development towards reproductive strategies favoring current reproduction and higher mating effort. However, due to sex differences in life history trade-offs between mating and parenting, insecure males tend to adopt avoidant strategies, whereas insecure females tend to adopt anxious/ambivalent strategies, which maximize investment from kin and mates. Females are expected to shift to avoidant patterns when environmental risk is more severe. Avoidant and ambivalent attachment patterns also have different adaptive values for boys and girls, in the context of same-sex competition in the peer group: in particular, the competitive and aggressive traits related to avoidant attachment can be favored as a status-seeking strategy for males. Finally, adrenarche is proposed as the endocrine mechanism underlying the reorganization of attachment in middle childhood, and the implications for the relationship between attachment and sexual development are explored. Sex differences in the development of attachment can be fruitfully integrated within the broader framework of adaptive plasticity in life history strategies, thus contributing to a coherent evolutionary theory of human development.
Lijphart expanded: three dimensions of democracy in advanced OECD countries?
Authors: Vatter Adrian
Published: March 2009

This article attempts to examine the relationship between the most important political institutions and direct democracy in 23 modern OECD democracies by expanding Lijphart’s concept of majoritarian and consensus democracy. The article updates Lijphart’s data collection for the most recent period (1997–2006); it responds to criticisms of Lijphart’s measurement of a number of variables and of case selection, and it integrates direct democracy as an additional variable. Based on factor analysis, the main finding is that there are not just two, but three dimensions of democracy in advanced democracies. The horizontal dimension comprises the disproportionality of the electoral system, the number of parties, the executive–legislative relationship, the interest groups, and the degree of central bank independence. In the vertical dimension of democracy, we find federalism, decentralization, bicameralism, the rigidity of constitutional provisions, and the strength of judicial review. The top-to-bottom dimension of democracy comprises the type of cabinet government and the strength of direct democracy. In contrast to earlier research, our empirical analysis furnishes the hypothesis that direct democracy is not a variable that is independent of all other political institutions. While active direct democracy goes hand-in-hand with broadly supported multi-party governments, purely representative constitutions frequently appear in conjunction with minimal winning cabinets.
Equivocal evidence for a thermostat and unusually low levels of coral bleaching in the Western Pacific Warm Pool
Authors: van Hooidonk Ruben , Huber Matthew
Published: March 2009

An ocean “thermostat” was recently proposed that limits Western Pacific Warm Pool (WPWP) sea surface temperature (SST) causing anomalously low coral bleaching rates. We analyze WPWP SST trends and bleaching using HadISST data and a coral bleaching database and find no strong evidence for a thermostat or for anomalously low bleaching. A region within the WPWP has a trend of maximum SST near zero, but this signal is not robust – by using different data or periods the signal disappears. We do find a negative correlation between the average warmest month for the years 1950–1969 (average SST max) and the linear trend of maximum monthly temperatures for the years 1950–2006 (linear trend SST max). However this correlation is not unique to the WPWP, it is also observed in a cooler region. Consequently it can not be explained by a thermostat. The observed sparsity of bleaching observations in the WPWP is not in agreement with estimated bleaching likelihood. The sparsity of observations is more likely due to the WPWP's remoteness.
Can liquid water profiles be retrieved from passive microwave zenith observations?
Authors: Crewell Susanne , Ebell Kerstin , Löhnert Ulrich , Turner D. D.
Published: March 2009

The ability to determine the cloud boundaries and vertical distribution of cloud liquid water for single‐layer liquid clouds using zenith‐pointing microwave radiometers is investigated. Simulations are used to demonstrate that there is little skill in determining either cloud base or cloud thickness, especially when the cloud thickness is less than 500 m. It is also shown that the different distributions of liquid water content within a cloud with known cloud boundaries results in a maximum change in the brightness temperature of less than 1 K at the surface from 20 to 150 GHz, which is on the order of the instrument noise level. Furthermore, it is demonstrated using the averaging kernel that the number of degrees of freedom for signal (i.e., independent pieces of information) is approximately 1, which implies there is no information on vertical distribution of liquid water in the microwave observations.
D, E, and F layers in the daytime at high‐latitude terminator ionosphere of Mars: Comparison with Earth's ionosphere using COSMIC data
Authors: Haider S. A. , Abdu M. A. , Batista I. S. , Sobral J. H. , Luan Xiaoli , Kallio Esa , Maguire W. C. , Verigin M. I. , Singh V.
Published: March 2009

We report the first model result for ion production rates and densities of positive ions, negative ions, and electrons in the dayside Martian ionosphere from 0 to 220 km. These calculations are made at solar zenith angle 77° for low solar activity periods. The calculated electron density is compared with the radio occultation measurements made by Mars Global Surveyor (MGS) and Mars 4/5 on Mars and by Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) on Earth. Our calculation suggests that the daytime ionosphere of Mars can be divided into D, E, and F layers at altitude ranges ∼25–35 km, ∼100–112 km, and ∼125–145 km with the concentrations 7 × 101 cm−3, 2.4 × 104 cm−3, and 8.4 × 104 cm−3 owing to the impact of galactic cosmic rays, X rays (10–90 Å), and solar EUV (90–1026 Å) radiations, respectively. The water cluster ions H3O+(H2O)n, NO2−(H2O)n, and CO3−(H2O)n are dominated in the D region, while NO+, CO2+, and O2+ are major ions in the E and F regions. The calculated E and F peak heights are in good agreement with MGS observation. The value of D peak density is lowered by 1 and 2 orders of magnitude from the measurements on Mars and Earth, respectively. The height of F layer peak is lower by factor of 1.8 in the Martian ionosphere as compared to that observed in the ionosphere of Earth. E regions are created at nearly the same heights in the ionospheres of both planets, but the layer thickness is considerably less on Mars than on Earth. This implies that solar EUV energy is deposited within smaller‐altitude range in the upper ionosphere of Mars as compared to the corresponding altitude range in the upper ionosphere of Earth.
Evolution of asymmetric multifractal scaling of solar wind turbulence in the outer heliosphere
Authors: Macek Wiesław M. , Wawrzaszek Anna
Published: March 2009

The aim of this study is to examine the question of scaling properties of intermittent turbulence in the space environment. We analyze time series of velocities of the slow and fast speed streams of the solar wind measured in situ by Voyager 2 spacecraft in the outer heliosphere during solar minimum at various distances from the Sun (2.5, 25, and 50 AU). To quantify asymmetric scaling of solar wind turbulence, we consider a generalized two‐scale weighted Cantor set with two different scales describing nonuniform distribution of the kinetic energy flux between cascading eddies of various sizes. We investigate the resulting spectrum of generalized dimensions and the corresponding multifractal singularity spectrum depending on one probability measure parameter and two rescaling parameters, demonstrating that the multifractal scaling is often rather asymmetric. In particular, we show that the degree of multifractality for the solar wind during solar minimum is greater for fast streams' velocity fluctuations than that for the slow streams; the fast wind during solar minimum may exhibit strong asymmetric scaling. Moreover, we observe the evolution of multifractal scaling of the solar wind in the outer heliosphere. It is worth noting that for the model with two different scaling parameters a much better agreement with the solar wind data is obtained, especially for the negative index of the generalized dimensions. Therefore, we argue that there is a need to use a two‐scale cascade model. Hence, we propose this model as a useful tool for analysis of intermittent turbulence in various environments, and we hope that our new more general asymmetric multifractal model can shed light on the nature of turbulence.