bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphology, nanomechanical and thermodynamic surface characteristics of nylon 6/feather keratin blend films: an atomic force microscopy investigation
Authors: Akhlaghi Shahin , Sharif Alireza , Kalaee Mohammadreza , Nouri Ali , Manafi Mohammadreza
Published: February 2012

The surface structure and nanomechanical properties of solution‐cast nylon 6 (NY6)/feather keratin (FK) blend films were investigated using a combination of tapping‐mode atomic force microscopy (AFM) phase imaging and nanoscale indentation. A tendency for a nanoscale phase separation between NY6 and FK in their various blends was judged based on the blend phase images. The surface topography and roughness analysis of the AFM height images revealed that FK‐rich blends had coarser surfaces than NY6‐rich ones, possibly due to the heterogeneous nature of the FK chemical structure. Amplitude–phase–distance measurements involving the assignment of the darker and brighter regions of the phase images to NY6‐rich and FK‐rich, respectively, or vice versa led to the recognition of a phase inversion in the blend containing 40 wt% FK. The occurrence of the phase inversion phenomenon was related to the significant difference between the molecular weights of the blend constituents. Analysis of nanoindentation data showed that blending FK and NY6 at various ratios resulted in mixtures with modified mechanical and adhesion features. On the one hand, the NY6 component was responsible for an enhanced elastic modulus and stiffness of the blends, and on the other hand, the FK component provided higher pull‐off force and work of adhesion for the samples. A new approach is also proposed to directly determine the surface energy (γ) values of samples from the nanoindentation data. The excellent consistency between the calculated γ values and the results obtained from contact angle measurements lends credence to the proposed approach. Copyright © 2012 Society of Chemical Industry
Effect of nitrile functionalized graphene on the properties of poly(arylene ether nitrile) nanocomposites
Authors: Yang Xulin , Zhan Yingqing , Yang Jian , Tang Hailong , Meng Fanbing , Zhong Jiachun , Zhao Rui , Liu Xiaobo
Published: February 2012

In this study, novel nitrile functionalized graphene (GN‐nitrile)/poly(arylene ether nitrile) (PEN) nanocomposites were prepared by an easy solution‐casting method and investigated for the effect of surface modification on the dielectric, mechanical and thermal properties. Graphene (GN) was first functionalized by introduction of nitrile groups onto the GN plane, which was confirmed by scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, thermogravimetric analysis and dispersibility research. Compared with pure GN, the grafted nitrile groups on the GN‐nitrile can interact with nitrile groups in PEN and lead to flat but better dispersion and stronger adhesion in/to the PEN matrix. Consequently, GN‐nitrile had a more significant enhancement effect on the properties of PEN. The dielectric constant of the PEN/GN‐nitrile nanocomposite with 5 wt% GN‐nitrile reaches 11.5 at 100 Hz, which is much larger than that of the pure PEN matrix (3.1). Meanwhile, dielectric loss is quite small and stable and the dielectric properties showed little frequency dependence. For 5 wt% GN‐nitrile reinforced PEN composites, increases of 17.6% in tensile strength, 26.4% in tensile modulus and 21 °C in Td5% were obtained. All PEN/GN‐nitrile nanocomposite films can stand high temperature, up to 480 °C. Hence, novel dielectric PEN/GN‐nitrile nanocomposite films with excellent mechanical and thermal properties can be used as dielectric materials under some critical circumstances such as high wear and temperature. Copyright © 2012 Society of Chemical Industry
All the fundamental massless fields in bosonic string theory
Authors: Manoukian E.B.
Published: February 2012

A systematic analysis of the massless fields in the mass spectra of bosonic strings is carried in arbitrary spacetime dimension D > 2. The emphasis is put on the derivations of their propagators, their polarization aspects and the underlying constraints involved. The treatment is given, in the presence of external sources, in the celebrated Coulomb gauge for the second rank tensors and vector fields, which ensures positivity – a result which is also established in the process. No constraints are imposed on the external sources so that their components may be varied independently generating complete expressions for the propagators. This latter condition is an important one in the generation of dynamical theories with constraints involving such modifications as Faddeev‐Popov factors.
Non‐perturbative gauge couplings from holography
Authors: Billò M. , Frau M. , Giacone L. , Lerda A.
Published: February 2012

We show how D‐instanton corrections modify the dilaton‐axion profile emitted by an O7/D7 system turning it into the non‐singular F‐theory background which corresponds to the effective coupling on a D3 probe.
Asymptotically Lifshitz black holes in Einstein‐Maxwell‐dilaton theories
Authors: Tarrio J.
Published: February 2012

We study Einstein‐Maxwell‐dilaton theories with a cosmological constant and U(1)N gauge symmetry, considering metrics asymptotically approaching the Lifshiftz metric. We study the dependence of the phase diagram on the value of the dynamical exponent. Along the way, we apply holographic renormalization and propose a counterterm valid for arbitrary dimension and dynamical exponent in our setup.
Dimethyl disulfide is an induced systemic resistance elicitor produced by Bacillus cereus C1L
Authors: Huang Chien‐Jui , Tsay Jia‐Fang , Chang Shu‐Yu , Yang Hsiu‐Ping , Wu Wen‐Shi , Chen Chao‐Ying
Published: February 2012

BACKGROUND: Bacillus cereus C1L is a plant growth‐promoting rhizobacterium and can elicit induced systemic resistance (ISR) in plants against necrotrophic pathogens. However, little is known about ISR elicitors produced by B. cereus C1L, and no ISR elicitor has been identified and characterised. Therefore, the objective of this study is to identify volatile ISR elicitor(s) produced by B. cereus C1L.

RESULTS: The volatile metabolites produced by B. cereus C1L were extracted, separated and identified by solid‐phase microextraction, gas chromatography and mass spectrometry. Dimethyl disulfide (DMDS) was the only separated metabolite being determined. Afterwards, application of DMDS by means of soil drench significantly protected tobacco and corn plants against Botrytis cinerea and Cochliobolus heterostrophus, respectively, under greenhouse conditions. The results reveal that DMDS could play an important role in ISR by B. cereus C1L.

CONCLUSION: This is the first report of DMDS as an elicitor produced by an ISR‐eliciting B. cereus strain and its ability to suppress plant fungal diseases under greenhouse conditions. It is suggested that DMDS has potential for practical use in controlling plant foliar diseases besides soil fumigation. Copyright © 2012 Society of Chemical Industry
Effects of non‐repellent termiticides on the tunneling and walking ability of the eastern subterranean termite (Isoptera: Rhinotermitidae)
Authors: Quarcoo Franklin Y , Hu Xing Ping , Appel Arthur G
Published: February 2012

BACKGROUND: Non‐repellent insecticides, including fipronil and indoxacarb, are becoming increasingly important for soil treatments to manage the eastern subterranean termite, Reticulitermes flavipes (Kollar). The effects of these insecticides on termite walking and tunneling behavior could significantly reduce their efficacy against colonies.

RESULTS: Groups of R. flavipes were exposed to several concentrations of commercial formulations of fipronil and indoxacarb, and the ability of treated termites to tunnel in soil and walk was assessed. Increasing insecticide concentration resulted in a reduction in the ability of R. flavipes to walk, tunnel and form tunnel branches; the importance of these effects on the use of non‐repellent insecticides is discussed.

CONCLUSION: Exposure of R. flavipes to 1, 10 or 50 mg L−1 of fipronil or 50, 100 or 200 mg L−1 of indoxacarb significantly reduced termite walking and tunneling and the number of tunnel branches. Distance walked (ca 73 mm) by untreated control termites did not change over time for at least 16 h after treatment; control termites formed ca 150 cm of tunnels with ca 40 branches. Copyright © 2012 Society of Chemical Industry
Evaluation of dazomet as fumigant for the control of brown root rot disease
Authors: Fu Chuen‐Hsu , Hu Bau‐Yuan , Chang Tun‐Tschu , Hsueh Kai‐Leen , Hsu Wei‐Tse
Published: February 2012

BACKGROUND: Brown root rot disease caused by Phellinus noxius is widespread in approximately 216 tree and plant species in tropical and subtropical countries. No direct means of protection against P. noxius infection have thus far been developed. Therefore, in this field survey, a method was developed for preventing and controlling brown root rot disease using fumigation with dazomet.

RESULTS: Tracers were used to monitor the effect of dazomet fumigation. The results from field surveys and phytotoxicity tests showed that dazomet is able to kill P. noxius without any side effects on plants.

CONCLUSION: The use of an environmentally friendly agent to control brown root rot disease is needed, and prevention of the disease is more important than treatment. Hence, chemical fumigation with 60 g m−2 of 98% dazomet may be a possible means of preventing P. noxius incursion in agriculture, gardening and agroforestry. Copyright © 2012 Society of Chemical Industry
Entropy‐change measurement of electrocaloric effect of BaTiO3 single crystal
Authors: Bai Yang , Ding Kai , Zheng Guang‐Ping , Shi San‐Qiang , Qiao Lijie
Published: February 2012

We demonstrated a characterization method of entropy‐change measurement for the study of the electrocaloric effect (ECE). After the specific heat capacity was measured under different applied fields using a differential scanning calorimeter (DSC) accompanied with DC power supply, the electrocaloric ΔS was calculated from the temperature integral of specific heat capacities based on the basic definition of entropy. The ΔS–T curve of BaTiO3 single crystal showed a sharp peak around Tc, which increased gradually and shifted to higher temperature with the rise of applied field. A high ECE with ΔS = 1.9 J/kg K and ΔT = 1.6 K is achieved under a quite low field of 10 kV/cm. The results agreed with the thermodynamic calculation. It provides a direct, precise, and time‐efficient method for the electrocaloric studies.
Design and maskless fabrication of ultrathin suspended membranes of GaN
Authors: Tiginyanu I. M. , Popa V. , Stevens‐Kalceff M. A. , Gerthsen D. , Brenner P. , Pavlidis D.
Published: February 2012

We report the maskless fabrication of ultrathin suspended GaN membranes designed by focused ion beam treatment of the GaN epilayer surface with subsequent photoelectrochemical etching. This technological approach allows the fabrication of ultrathin membranes, as well as supporting micro/nanocolumns in a controlled fashion. The analysis of the spatial and spectral distribution of microcathodoluminescence demonstrates that the membranes exhibit mainly yellow luminescence. These results pave the way for the fabrication of ultrathin suspended GaN membranes for MEMS/NEMS applications.

magnified image

(© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time‐dependent schrödinger equation with Markovian outgoing wave boundary conditions: Applications to quantum tunneling dynamics and photoionization
Authors: Chou Chia‐Chun , Wyatt Robert E.
Published: February 2012

Markovian outgoing wave boundary conditions are introduced as an approximate method to reduce the size of the computational grid for time integration of the time‐dependent Schrödinger equation. The ratio and polynomial methods developed as open boundary conditions are applied to the wave function at the boundaries of the computational grid. This computational method is used to study the wave packet dynamics for a metastable well, a double well, and strong‐field ionization of a model atom. Accurate results demonstrate that this method can significantly reduce the number of grid points required in a dynamical calculation for quantum dynamical problems. © 2012 Wiley Periodicals, Inc.
Reactivity of amines with hypochlorous acid: Computational study of steric, electronic, and medium effects
Authors: Tarade Tena , Vrček Valerije
Published: February 2012

N‐Chlorination reactions of alkyl‐, cycloalkyl‐, heterocyclic, and aromatic amines by HOCl have been investigated in the gas and aqueous phase. Density functional (B3LYP), double hybrid (B2PLYPD), and composite theoretical model (G3B3) have been used to assess steric, electronic, and solvent effects on the reactivity of different families of amines toward HOCl. When solvent effects are included by using CPCM/UAHF model, all computational methods predict the same order of reactivity within each group of amines. In agreement with experimental data, heterocyclic amines have the highest reactivity, with energy barriers calculated between 160 and 225 kJ mol−1 (B2PLYPD/AUG‐cc‐pVTZ//B3LYP/6‐31G(d) level). The substituted anilines are the least reactive species, with energy barriers calculated as high as 300 kJ mol−1. Two different reaction mechanisms of N‐chlorination have been considered in the gas phase: the one which includes the transition state TSa with cyclic arrangement of four atoms (N, Cl, O, and H) involved in an intramolecular rearrangement, and the second in which the hydrogen‐bridged structure TSb is characterized with the linear NClO moiety. The former is energetically more feasible (ca. 120 kJ mol−1) for alkyl‐, cycloalkyl‐, and heterocyclic amines, whereas the latter is operative in the case of aromatic amines. If two water molecules are explicitly included in the calculations, the rate‐determining transition state TSw has been located for N‐chlorination of all amines under study. It is characterized by eight‐membered ring geometry in which water molecules assist the simultaneous transfer of the three hydrogen atoms coupled with the NCl bond formation. To reproduce the experimentally observed trends in reactivity of amines, the inclusion of bulk and specific solvent effects is mandatory. Steric effects have been found to govern the reactivity of alkylamines, that is, more bulkier amines react slower with HOCl. It has been found that electronic structure parameters (HOMO–LUMO gap, natural bond orbital occupancy, and NPA charge on N atom) can be successfully used as descriptors for the reactivity of heterocyclic and aromatic amines. These results indicate the predictive power of our computational approach, which can be applied to calculate nucleophilic reactivities of more complex structures of environmentally or biologically relevant amines. © 2012 Wiley Periodicals, Inc.
Theoretical studies on structural and spectroscopic properties of photoelectrochemical cell ruthenium sensitizers, derivatives of AR20
Authors: Chen Jie , Wang Jian , Bai Fu‐Quan , Pan Qing‐Jiang , Zhang Hong‐Xing
Published: February 2012

Special efforts were devoted to improve the absorption behavior of AR20 in visible region. Density functional theory (DFT)‐based approaches were applied to explore the electronic structure properties of AR20 and its derivatives. Time‐dependent DFT results indicate that the ancillary ligand controls the molecular orbital (MO) energy levels and masters the absorption transition nature. The deprotonation of anchoring ligand not only affects the frontier MO energy levels but also determines the energy gaps of highest occupied MO–lowest unoccupied MO (LUMO) and LUMO–LUMO+1. Introducing thiophene groups into ancillary ligands would enhance the efficiency of the final dye‐sensitized solar cell (DSSC). The absorption intensity of the thiophene substituted derivatives of AR20 is irrelevant with environment circumstance change, such as pH value. This special nature prognosticates the thiophene‐substituted derivatives of AR20 which would have a broad application in DSSC. © 2012 Wiley Periodicals, Inc.
Combination of approximate spin‐projection and spin‐restricted calculations based on ONIOM method for geometry optimization of large biradical systems
Authors: Kitagawa Y. , Yasuda N. , Hatake H. , Saito T. , Kataoka Y. , Matsui T. , Kawakami T. , Yamanaka S. , Okumura M. , Yamaguch K.
Published: February 2012

In this article, we combine the approximate spin projection (AP) and the spin‐restricted (R) calculations based on ONIOM method for a geometry optimization of large biradical systems such as polynuclear metal complexes. This two‐layer quantum mechanics/quantum mechanics′ (QM/QM′) (AP/R) method treats atoms of an inner layer around the spin sources with the AP method, whereas the whole atoms including the peripheral ligands are calculated by the R method. The AP/R method is applied for the geometry optimizations of chromium(II) ions in Cr2(O2CCH3)4(OH2)2 (1) and Cr2{O2CPh(CHMe2)3}4 (2) complexes that involve quadruple CrCr bonds. The optimized structural parameters indicate that the error of the two‐layer combination is smaller than 0.01 Å in the optimized CrCr bond length on both complexes. The error is only 12.3% of the spin contamination error and 1.7% of the static correlation correction in the complex 1. The error of the two‐layer combination in a total energy is also estimated to be lower than 1 kcal mol−1 in both complexes. © 2012 Wiley Periodicals, Inc.
On induced Folkman numbers
Authors: Dudek Andrzej , Ramadurai Reshma , Rödl Vojtěch
Published: February 2012

In 1970, Folkman proved that for any graph G there exists a graph H with the same clique number as G. In addition, any r ‐coloring of the vertices of H yields a monochromatic copy of G. For a given graph G and a number of colors r let f(G, r) be the order of the smallest graph H with the above properties. In this paper, we give a relatively small upper bound on f(G, r) as a function of the order of G and its clique number. © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 40, 493–500, 2012
Direct and Transmission Milling of Suspended Silicon Nitride Membranes With a Focused Helium Ion Beam
Authors: Marshall Michael M. , Yang Jijin , Hall Adam R.
Published: February 2012

Helium ion milling of suspended silicon nitride thin films is explored. Milled squares patterned by scanning helium ion microscope are subsequently investigated by atomic force microscopy and the relation between ion dose and milling depth is measured for both the direct (side of ion incidence) and transmission (side opposite to ion incidence) regimes. We find that direct‐milling depth varies linearly with beam dose while transmission‐milling depth varies with the square of the beam dose, resulting in a straightforward method of controlling local film thickness. SCANNING 34: 101‐106, 2012. © 2012 Wiley Periodicals, Inc.
Use of Multiphoton Microscopy to Diagnose Liver Cancer and Lung Metastasis in an Orthotopic Rat Model
Authors: Yan Jun , Zhuo Shuangmu , Chen Gang , Tan Changjun , Zhu Weifeng , Lu Jianping , Fan Jia , Chen Jianxin , Zhou Jian
Published: February 2012

Liver or lung biopsy for suspicious lesions has several disadvantages such as bleeding, bile leak or pneumothorax, needle track seeding, and time‐consuming histopathological procedure. The ability to directly observe cellular and subcellular details and then perform “optical biopsy” is a major goal in the development of new interventional techniques. Multiphoton microscopy (MPM) enables real‐time noninvasive visualization of tissue architecture and cell morphology in live tissue. We performed a study to evaluate whether MPMcan make real‐time optical diagnosis for liver cancer and lung metastasis using an orthotopic rat model with Morris hepatoma. We found that real‐time high‐resolution MPMimaging could clearly show tissue architecture and cell morphology. In the normal liver tissue, MPMimaging clearly revealed the blood‐filled sinusoids and cords of hepatocytes. In the cancerous tissue, MPMimaging clearly illustrated that cancer cells displayed marked cellular and nuclear pleomorphism. MPMimages were comparable to golden standard hematoxylin‐eosin staining images. Moreover, MPMimaging had deep penetration with the capability of optical sectioning. In short, MPMcan make real‐time optical diagnosis for liver cancer and lung metastasis. This study provides the groundwork for further using multiphoton endoscopy to perform real‐time noninvasive “optical biopsy” for liver cancer and lung metastasis in the near future. SCANNING 34: 271‐277, 2012. © 2012 Wiley Periodicals, Inc.
Second‐order competences and Schumpeterian rents
Authors: Danneels Erwin
Published: February 2012

Second‐order competences, a type of dynamic capability, enable firms to engage in a process of Schumpeterian competition. This study examines the effects of marketing and R&D second‐order competences (the abilities to create new market‐related and technological resources) on firm profitability. Based on multiple informant surveys and archival data from U.S. public manufacturing firms, competitive turbulence is found to present contrasting contingencies for the effects of these competences on return on assets (ROA). The effect of marketing competence on ROA was positive under stable and moderate competitive conditions, whereas the effect of R&D competence on ROA was positive under volatile competitive conditions. Copyright © 2012 Strategic Management Society.
Magnetic‐Nanoparticle‐Doped Carbogenic Nanocomposite: An Effective Magnetic Resonance/Fluorescence Multimodal Imaging Probe
Authors: Srivastava Sachchidanand , Awasthi Rishi , Tripathi Deepak , Rai Mohit K. , Agarwal Vikas , Agrawal Vinita , Gajbhiye Namdeo S. , Gupta Rakesh K.
Published: February 2012

A novel and facile approach is developed to synthesize a magnetic nanoparticle (iron oxide)‐doped carbogenic nanocomposite (IO‐CNC) for magnetic resonance (MR)/fluorescence imaging applications. IO‐CNC is synthesized by thermal decomposition of organic precursors in the presence of Fe3O4 nanoparticles with an average size of 6 nm. IO‐CNC shows wavelength‐tunable fluorescence properties with high quantum yield. Magnetic studies confirm the superparamagnetic nature of IO‐CNC at room temperature. IO‐CNC shows MR contrast behavior by affecting the proton relaxation phenomena. The measured longitudinal (r1) and transverse (r2) relaxivity values are 4.52 and 34.75 mM−1 s−1, respectively. No apparent cytotoxicity is observed and the nanocomposite shows a biocompatible nature. In vivo MR studies show both T1 and T2* contrast behavior of the nanocomposite. Fluorescence imaging indicates selective uptake of IO‐CNC by macrophages in spleen.
Tumor-Initiating Label-Retaining Cancer Cells in Human Gastrointestinal Cancers Undergo Asymmetric Cell Division
Authors: Xin Hong-Wu , Hari Danielle M. , Mullinax John E. , Ambe Chenwi M. , Koizumi Tomotake , Ray Satyajit , Anderson Andrew J. , Wiegand Gordon W. , Garfield Susan H. , Thorgeirsson Snorri S. , Avital Itzhak
Published: February 2012

Label-retaining cells (LRCs) have been proposed to represent adult tissue stem cells. LRCs are hypothesized to result from either slow cycling or asymmetric cell division (ACD). However, the stem cell nature and whether LRC undergo ACD remain controversial. Here, we demonstrate label-retaining cancer cells (LRCCs) in several gastrointestinal (GI) cancers including fresh surgical specimens. Using a novel method for isolation of live LRCC, we demonstrate that a subpopulation of LRCC is actively dividing and exhibits stem cells and pluripotency gene expression profiles. Using real-time confocal microscopic cinematography, we show live LRCC undergoing asymmetric nonrandom chromosomal cosegregation LRC division. Importantly, LRCCs have greater tumor-initiating capacity than non-LRCCs. Based on our data and that cancers develop in tissues that harbor normal-LRC, we propose that LRCC might represent a novel population of GI stem-like cancer cells. LRCC may provide novel mechanistic insights into the biology of cancer and regenerative medicine and present novel targets for cancer treatment.

Disclosure of potential conflicts of interest is found at the end of this article.
Problem management process, filling the gap in the systems engineering processes between the risk and opportunity processes
Authors: Olson Bill A. , Mazzuchi Thomas A. , Sarkani Shahram , Forsberg Kevin
Published: February 2012

Problem Management is not recognized as a Systems Engineering process. Unlike risk management, where risks could impact a project at some future date, problems impact the project now. Therefore, a robust Problem Management process should be established (similar to the risk management process described in Chapter 5 of the INCOSE handbook [Hamelin, Walden, and Krueger, INCOSE systems engineering handbook v3.2: Improving the process for SE practitioners, INCOSE, Seattle, WA, 2010]) early in a projects formulation. The process should be continuous throughout all phases of the project life cycle and should be included as a part of the project System Engineering Management Plan. The process should, at a minimum, address: problem identification, problem assessment, problem root cause investigation, problem corrective action planning, reporting, a roll‐up of all current problems, problem closure, and a strong interface with the project's knowledge management system. This paper proposes a Problem Management process based on the foundations of risk and opportunity management which could be used by corporations, government agencies, and programs to establish a robust problem management process for use on their projects. © 2012 Wiley Periodicals, Inc. Syst Eng
Hochpräzise Fügungen mittels reaktiven Nanometermultischichten
Authors: Dietrich Georg , Rühl Maximilian , Braun Stefan , Leson Andreas
Published: February 2012

Etablierte Fügetechniken wie Schweißen oder Löten bewirken im Allgemeinen einen großen Wärmeeintag in die zu fügenden Bauteile. Vor allem bei wärmempfindlichen Bauteilen, wie zum Beispiel MEMS, kann dies zu spannungsinduzierten Verformungen bzw. zur Beschädigung der Bauteile führen. Es wird daher eine Fügemethode benötigt, welche durch einen lokal definierten und kurzzeitigen Wärmeeintrag eine Schädigung der Bauteile vermeidet. Die sogenannten reaktiven Multischichtsysteme (RMS) bieten einen vielversprechenden Ansatz diese Forderung zu erreichen. RMS bestehen aus einigen hundert bis mehreren tausend alternierenden Schichten mit Dicken im Bereich von einigen Nanometern, wobei die Materialien der verschiedenen Schichten exotherm miteinander reagieren können. Wird eine mit einer Lot‐Schicht beschichtete RMS zwischen zwei Oberflächen gebracht, kann diese als kontrollierbare lokale Wärmequelle zum Fügen verwendet werden.

Die verschiedenen Anwendungsmöglichkeiten von RMS haben in den letzten Jahren intensive FuE‐Aktivitäten erforderlich gemacht. Aufbauend auf einer früheren Veröffentlichung aus dem Jahr 2009 [1], in der theoretische Untersuchungen und grundlegende Anwendungsmöglichkeiten der RMS diskutiert wurden, werden im folgenden Artikel die neuesten Entwicklungen auf den Gebieten Herstellung, Charakterisierung und Anwendung der RMS zum Fügen präsentiert.
Gastrointestinal Stromal Tumors: Case Series of 29 Patients Defining the Role of Imatinib Prior to Surgery
Authors: Shrikhande Shailesh V. , Marda Sachin S. , Suradkar Kunal , Arya Supreeta , Shetty Guruprasad S. , Bal Munita , Shukla Parul J. , Goel Mahesh , Mohandas K. M.
Published: February 2012

Background

The aim of this study was to assess the role of neoadjuvant imatinib in redefining treatment for gastrointestinal stromal tumors (GISTs).

Methods

A total of 76 patients were reviewed. Among them, 29 patients who were administered neoadjuvant imatinib for borderline resectable and locally advanced GISTs followed by surgery were analyzed. Adjuvant imatinib was administered based on risk stratification.

Results

The median age of the neoadjuvant imatinib group was 51 years. The median duration of neoadjuvant imatinib administration was 8.5 months. The response rate with neoadjuvant imatinib was 79.3%. Five patients, initially considered to have locally unresectable lesions, ultimately underwent resection (three R0, two R2). Another three patients, who had M1 disease, underwent R2 resection (due to the presence of metastasis) with complete resection of the primary lesion. In 19 patients, who would have originally required extensive surgery, underwent conservative surgery (R0). In two patients, neoadjuvant imatinib did not influence the final procedure. The postoperative complication rate was 13.8%, and there were no postoperative deaths. There was one locoregional recurrence and two cases of distant metastasis. The 1‐, 2‐, and 3‐year overall survivals were each 100%.

Conclusions

Neoadjuvant imatinib for locally advanced GISTs is a safe concept for downsizing, improving resectability, and aiding organ‐preserving surgery. It also improves the chance of long‐term survival. Surgery, however, remains the cornerstone of curative treatment of GISTs even after neoadjuvant imatinib.
The Evolution of Breast Reconstruction: A Historical Perspective
Authors: Champaneria Manish C. , Wong Wendy W. , Hill Michael E. , Gupta Subhas C.
Published: February 2012

Plastic surgeons have been performing operations to improve the aesthetic aspect of the breast for centuries. Throughout ancient times, great controversy produced many theories of how breast cancer occurred and the best treatment. Because of beliefs that closure of mastectomy sites could conceal tumor recurrence, breast reconstruction did not gain wide acceptance until the mid‐1900s. Today, plastic surgeons have a variety of techniques to reconstruct the breast. The first autologous muscle flap for breast reconstruction was the latissimus dorsi myocutaneous flap, described in 1896 by Iginio Tansini. The introduction of Carl Hartrampf’s transverse rectus abdominis myocutaneous flap and Robert J. Allen’s deep inferior epigastric perforator flap have also provided excellent reconstructive options. With regard to augmentation, Vincenz Czerny attempted to enhance a woman’s breast in 1895 with implantation of a lumbar lipoma. Soon after, surgeons used paraffin injections and polyvinylic alcohol sponge implantation, which yielded disastrous results. In 1961, Thomas Cronin and Frank Gerow promoted the first silicone implant, paving the way for today’s silicone and saline prototypes. Although reduction mammaplasty techniques had originated centuries earlier than mastopexy methods, the advancements of both have largely paralleled one another. In 1949, the Wise pattern was introduced to preoperatively plan safer and predictable outcomes in breast reductions. Efforts to minimize scars were achieved with Claude Lassus’ introduction and Madeleine Lejour’s subsequent modification of the vertical scar mammaplasty. In hopes of fostering an understanding of current post‐mastectomy procedures and instilling passion for innovating future techniques, we provide a near‐complete, surgically focused historical account of the primary contributors to breast reconstruction.
A defined growth medium with very low background carbon for culturingClostridium thermocellum
Authors: Holwerda Evert K , Hirst Kyle D , Lynd Lee R
Published: February 2012

A growth medium was developed for cultivation of Clostridium thermocellum ATCC 27405 in which “background” carbon present in buffers, reducing agents, chelating agents, and growth factors was a small fraction of the carbon present in the primary growth substrate. Background carbon was 1.6% of primary substrate carbon in the low-carbon (LC) medium, whereas it accounts for at least 40% in previously reported media. Fermentation of cellulose in LC medium was quite similar to Medium for Thermophilic Clostridia (MTC), a commonly used growth medium that contains background carbon at 88% of primary substrate carbon. Of particular note, we found that the organism can readily be cultivated by eliminating some components, lowering the concentrations of others, and employing a tenfold lower concentration of reducing agent. As such, we were able to reduce the amount of background carbon 55-fold compared to MTC medium while reaching the same cell biomass concentration. The final mass ratios of the products acetate:ethanol:formate were 5:3.9:1 for MTC and 4.1:1.5:1 for LC medium. LC medium is expected to facilitate metabolic studies involving identification and quantification of extracellular metabolites. In addition, this medium is expected to be useful in studies of cellulose utilization by anaerobic enrichment cultures obtained from environmental inocula, and in particular to diminish complications arising from metabolism of carbon-containing compounds other than cellulose. Finally, LC medium provides a starting point for industrial growth media development.
Crossing Boundaries: Nativity, Ethnicity, and Mate Selection
Authors: Qian Zhenchao , Glick Jennifer E. , Batson Christie D.
Published: February 2012

The influx of immigrants has increased diversity among ethnic minorities and indicates that they may take multiple integration paths in American society. Previous research on ethnic integration has often focused on panethnic differences, and few have explored ethnic diversity within a racial or panethnic context. Using 2000 U.S. census data for Puerto Rican–, Mexican-, Chinese-, and Filipino-origin individuals, we examine differences in marriage and cohabitation with whites, with other minorities, within a panethnic group, and within an ethnic group by nativity status. Ethnic endogamy is strong and, to a lesser extent, so is panethnic endogamy. Yet, marital or cohabiting unions with whites remain an important path of integration but differ significantly by ethnicity, nativity, age at arrival, and educational attainment. Meanwhile, ethnic differences in marriage and cohabitation with other racial or ethnic minorities are strong. Our analysis supports that unions with whites remain a major path of integration, but other paths of integration also become viable options for all ethnic groups.
Effect of non-parallel mean flow on the Green’s function for predicting the low-frequency sound from turbulent air jets
Authors: Goldstein M. E. , Sescu Adrian , Afsar M. Z.
Published: February 2012

It is now well-known that there is an exact formula relating the far-field jet noise spectrum to the convolution product of a propagator (that accounts for the mean flow interactions) and a generalized Reynolds stress autocovariance tensor (that accounts for the turbulence fluctuations). The propagator depends only on the mean flow and an adjoint vector Green’s function for a particular form of the linearized Euler equations. Recent numerical calculations of Karabasov, Bogey & Hynes (AIAA Paper 2011-2929) for a Mach 0.9 jet show use of the true non-parallel flow Green’s function rather than the more conventional locally parallel flow result leads to a significant increase in the predicted low-frequency sound radiation at observation angles close to the downstream jet axis. But the non-parallel flow appears to have little effect on the sound radiated at $9{0}^{\ensuremath{\circ} } $ to the downstream axis. The present paper is concerned with the effects of non-parallel mean flows on the adjoint vector Green’s function. We obtain a low-frequency asymptotic solution for that function by solving a very simple second-order hyperbolic equation for a composite dependent variable (which is directly proportional to a pressure-like component of this Green’s function and roughly corresponds to the strength of a monopole source within the jet). Our numerical calculations show that this quantity remains fairly close to the corresponding parallel flow result at low Mach numbers and that, as expected, it converges to that result when an appropriately scaled frequency parameter is increased. But the convergence occurs at progressively higher frequencies as the Mach number increases and the supersonic solution never actually converges to the parallel flow result in the vicinity of a critical- layer singularity that occurs in that solution. The dominant contribution to the propagator comes from the radial derivative of a certain component of the adjoint vector Green’s function. The non-parallel flow has a large effect on this quantity, causing it (and, therefore, the radiated sound) to increase at subsonic speeds and decrease at supersonic speeds. The effects of acoustic source location can be visualized by plotting the magnitude of this quantity, as function of position. These ‘altitude plots’ (which represent the intensity of the radiated sound as a function of source location) show that while the parallel flow solutions exhibit a single peak at subsonic speeds (when the source point is centred on the initial shear layer), the non-parallel solutions exhibit a double peak structure, with the second peak occurring about two potential core lengths downstream of the nozzle. These results are qualitatively consistent with the numerical calculations reported in Karabasov et al. (2011).
Turbulence dynamics near a turbulent/non-turbulent interface
Authors: Teixeira M. A. C. , da Silva C. B.
Published: February 2012

The characteristics of the boundary layer separating a turbulence region from an irrotational (or non-turbulent) flow region are investigated using rapid distortion theory (RDT). The turbulence region is approximated as homogeneous and isotropic far away from the bounding turbulent/non-turbulent (T/NT) interface, which is assumed to remain approximately flat. Inviscid effects resulting from the continuity of the normal velocity and pressure at the interface, in addition to viscous effects resulting from the continuity of the tangential velocity and shear stress, are taken into account by considering a sudden insertion of the T/NT interface, in the absence of mean shear. Profiles of the velocity variances, turbulent kinetic energy (TKE), viscous dissipation rate ($\varepsilon $), turbulence length scales, and pressure statistics are derived, showing an excellent agreement with results from direct numerical simulations (DNS). Interestingly, the normalized inviscid flow statistics at the T/NT interface do not depend on the form of the assumed TKE spectrum. Outside the turbulent region, where the flow is irrotational (except inside a thin viscous boundary layer),$\varepsilon $decays as${z}^{\ensuremath{-} 6} $, where$z$is the distance from the T/NT interface. The mean pressure distribution is calculated using RDT, and exhibits a decrease towards the turbulence region due to the associated velocity fluctuations, consistent with the generation of a mean entrainment velocity. The vorticity variance and$\varepsilon $display large maxima at the T/NT interface due to the inviscid discontinuities of the tangential velocity variances existing there, and these maxima are quantitatively related to the thickness$\delta $of the viscous boundary layer (VBL). For an equilibrium VBL, the RDT analysis suggests that$\delta \ensuremath{\sim} \eta $(where$\eta $is the Kolmogorov microscale), which is consistent with the scaling law identified in a very recent DNS study for shear-free T/NT interfaces.
Is Discussion of the “United States of Africa” Premature? Analysis of ECOWAS and SADC Integration Efforts
Authors: Forere Malebakeng
Published: February 2012

For integration to succeed, the intending bloc of nations must begin with integration efforts that are based on gradual, continuous and concrete achievements, to create de facto solidarity among community members. This is the theoretical premise on which this article is based. This perspective is also drawn from the normative framework of both the Constitutive Act of the African Union (AU) and the Treaty Establishing the African Economic Community. According to its objectives, the AU aims to form a union government, to be preceded by successful economic integration through regional economic communities (RECs). While there are several RECs in Africa, this article examines those in west and southern Africa, being among the more developed. The article discusses whether the RECs have achieved their objectives to the extent that would warrant discussion of, and efforts towards, the imminent formation of the “United States of Africa”.
Female Genital Mutilation in Uganda: A Glimpse at the Abolition Process
Authors: Mujuzi Jamil Ddamulira
Published: February 2012

This article looks at three legal steps that have been taken in Uganda to abolish the practice of female genital mutilation: (1) a process during the drafting of the constitution that resulted in the enactment of different constitutional provisions that implicitly rendered female genital mutilation unconstitutional; (2) the declaration by the Constitutional Court in the case of Law and Advocacy for Women in Uganda v Attorney General in July 2010 that the practice is unconstitutional; and (3) the enactment in April 2010 of the Prohibition of Female Genital Mutilation Act. This article highlights some of the challenges that are likely to be encountered in enforcing both the Constitutional Court decision and the Prohibition of Female Genital Mutilation Act.
The Performance of Investment Bank-Affiliated Mutual Funds: Conflicts of Interest or Informational Advantage?
Authors: Hao (Grace) Qing , Yan Xuemin (Sterling)
Published: February 2012

Using a comprehensive sample of U.S. mutual funds from 1992 to 2004, we find strong evidence that investment bank-affiliated funds underperform unaffiliated funds. Consistent with the conflict of interest hypothesis, we find that affiliated funds hold disproportionately large amounts of stocks of their initial public offering and seasoned equity offering clients. Moreover, worse-performing clients are more likely to be held by affiliated funds. Our results are robust to alternative risk adjustments, portfolio weighting schemes, and regression methodologies. Overall, our findings are consistent with the idea that investment banks use affiliated funds to support underwriting business at the expense of fund shareholders.
‘Land for Those Who Work It’: A Visual Analysis of Agrarian Reform Posters in Velasco's Peru
Authors: CANT ANNA
Published: February 2012

Latin American military dictatorships of the twentieth century were often right-wing, elitist and violent. A marked exception was the left-wing Peruvian military government of Juan Velasco Alvarado. More exceptional still was the government's use of visual media. Between 1968 and 1970 it produced approximately 20 posters, printed in editions of 50,000 to 200,000, to promote the radical Agrarian Reform Law. These posters provide vibrant representations of the agrarian reform's ideological aspects, which have been under-studied. A detailed exploration of visual communication shows that the government deployed aesthetically sophisticated propaganda and symbols to encourage social participation in the reform.
From Insurgent to Transgressive Citizenship: Housing, Social Movements and the Politics of Rights in São Paulo
Authors: EARLE LUCY
Published: February 2012

This article examines the rhetoric and practice of a large social movement organised around low-income housing in the city of São Paulo, Brazil. Making explicit the relationship between housing and citizenship, the União de Movimentos de Moradia (Alliance of Housing Movements) articulates a ‘politics of rights’ with which it calls on the state to uphold the constitutional right to housing, and legitimates its high-profile occupations of abandoned buildings in the centre of the city. The article engages with James Holston's historical examination of homeowners’ struggles on the peripheries of São Paulo to assert themselves as rights-holders and to mobilise against threats of eviction. While Holston names these groups of residents ‘insurgent’ citizens for the way they have unsettled entrenched social inequalities, this article presents the concept of ‘transgressive’ citizenship to reflect the challenge the housing movement makes to the state as it uses text-based law to justify building occupations.
Visual servoing applied to real-time stabilization of a multi-rotor UAV
Authors: Romero Hugo , Salazar Sergio , Lozano Rogelio
Published: February 2012

In this paper we address the problem of stabilization and local positioning of a four-rotor rotorcraft using computer vision. Our approaches to estimate the orientation and position of the rotorcraft combine the measurements from an Inertial Measurement Unit (IMU) and a vision system composed of a single camera. In the first stage, the vision system is used to estimate the position and yaw angle of the rotorcraft, while in the second stage the vision system is used to estimate the translational velocity of the flying robot. In both cases the IMU gives the pitch and roll angles at a higher rate. The technique used to estimate the position of the rotorcraft in the first stage combines the homogeneous transformation approach for the camera calibration process with the plane-based pose method for estimating the position. In the second stage, a navigation system using the optical flow is also developed to estimate the translational velocity of the aircraft. We present real-time experiments of stabilization and location of a four-rotor rotorcraft.
Importance of shade trees (Grevillea robusta) in the dispersal of forest tree species in managed tea plantations of southern Western Ghats, India
Authors: Chetana H. C. , Ganesh T.
Published: February 2012

Abandoned plantations of coffee, tea and other commercial crops offer opportunities for understanding ecological processes in modified forest ecosystems. Unlike tree plantations tea is maintained as a shrub with a continuous dense short canopy that precludes large-frugivore activity thereby limiting dispersal of forest species to such areas. In this study we determine how location and density ofGrevillea robustaa shade tree in tea plantations and proximity of plantations to forests influences seed arrival from forests into the plantations. We also estimate the importance of dispersal modes in the colonization processes. We laid 10 × 10-m plots at three distance intervals from the forest edge in three different plantation types with varying shade tree densities. Within the plots we laid four 1× 1-m subplots at the corners of the plot. We estimated species richness, abundance and categorized the seeds into dispersal modes in these plots.Grevillea robustaincreased species richness of seeds by three times and abundance of seeds by 3–30 times compared with plantations without them. Higher density ofG. robustaincreased seed input changed species composition and altered species dominance in the plantations. Distance to forests influenced seed arrival in plantations withoutG. robustatrees and plots 95 m from the forest did not have any seeds in them. No such effect was seen in plantations withG. robustatrees. Seeds dispersed by birds or a combination of birds and mammals contribute 30% of the seeds reaching the plantations withG. robustaand this was not influenced by distance from the forest. In plantations withoutG. robustabird dispersal is restricted to 25 m from the forest edge. In general density of shade trees has a strong influence on seed arrival which can negate the forest proximity effect and enhance natural forest colonization.