bluuebunny/crossref_metadata_2025 huggingface dataset:
„Gestatten, Obelix!”︁
Authors: Burgard Wolfram , Stachniss Cyrill
Published: April 2013

160 Zentimeter groß, 100 Kilogramm schwer, vollgepackt mit modernster Sensorik: So navigiert sich ein autonomer Roboter selbst durch eine belebte Fußgängerzone. Doch Freiburger Informatiker denken sogar noch weiter.
Implementation of pro‐poor exemption policy in Tanzania: policy versus reality
Authors: Idd Aisha , Yohana Odongo , Maluka Stephen Oswald
Published: April 2013

Like many other African countries, Tanzania has been implementing user fee policy in its health sector since the early 1990s. Accompanying user fee, mechanisms were designed that exempted the poor and vulnerable groups of the society from paying user charges. Although studies on the implementation of exemption policies in Tanzania exist, very few have documented the actual process of translating exemption policies into actions—the process of implementation. Drawing from policy analysis and implementation theories, this paper documents the implementation of the waiver (need‐based exemptions) policy in Tanzania. The findings indicate that waiver systems, while potentially effective in principle, were ineffective in implementation. Lack of specification of criteria by which the poor could be identified made policy implementers at different levels to implement the policy in their own style. Low level of public awareness about the existence of waiver mechanisms hindered the poor to demand exemptions. Furthermore, fear of loss of revenue at the health facilities and ineffective enforcement mechanisms provided little incentives for local government leaders and health workers to communicate the policy to beneficiaries. It is concluded from this study that to better achieve the objectives of the pro‐poor exemption policy, it is important to engage policy implementers more actively in the management and implementation of policies. Additionally, it is imperative to understand the behaviour and practices of policy implementers, especially district health managers, health workers and village and ward leaders, who may react negatively to new policies and implement the policies in ways contrary to what policy makers had intended. Copyright © 2013 John Wiley & Sons, Ltd.
Surface properties and wear performances of siloxane‐hydrogel contact lenses
Authors: Bettuelli Michela , Trabattoni Silvia , Fagnola Matteo , Tavazzi Silvia , Introzzi Laura , Farris Stefano
Published: April 2013

The low surface roughness of disposable contact lenses made of a new siloxane‐hydrogel loaded with hyaluronic acid is reported, as studied by atomic force microscopy (AFM). Before the wear, the surface is characterized by out‐of‐plane and sharp structures, with maximum height of about 10 nm. After a wear of 8 h, evidence of two typical morphologies is provided and discussed. One morphology (sharp type) has a similar aspect as the unworn lenses with a slight increase in both the height and the number of the sharp peaks. The other morphology (smooth type) is characterized by troughs and bumpy structures. Wettability and clinical performances are also discussed, the latter deduced by the ocular‐surface‐disease index (OSDI). The main finding arising from this work is the indication of correlation between the change of the OSDI before and after wear and the lens surface characteristics obtained by AFM. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1585–1593, 2013.
Synthesis and Antimicrobial Activity of New Derivatives of 1,3,4‐Thiadiazoles and 1,2,4‐Triazoles with 5‐Nitroindazole as Support
Authors: Cheptea Corina , Sunel Valeriu , Desbrieres Jacques , Popa Marcel
Published: April 2013

The synthesis of new derivatives of 1,3,4‐thiadiazoles and 1,2,4‐triazoles was achieved using the 1,4‐disubstituted thiosemicarbazides as intermediaries.
Differentiating hepatic abscess from malignant mimickers: Value of diffusion‐weighted imaging with an emphasis on the periphery of the lesion
Authors: Park Hyun Jeong , Kim Seong Hyun , Jang Kyung Mi , Lee Soon Jin , Park Min Jung , Choi Dongil
Published: April 2013

Purpose

To evaluate the efficacy of diffusion‐weighted imaging (DWI) in differentiating hepatic abscess from malignant mimickers with an emphasis on periphery of the lesions.

Materials and Methods

Thirty‐nine patients with hepatic abscess and 74 patients with malignant hepatic tumors were included, who underwent gadoxetic acid‐enhanced MRI. For qualitative and quantitative analysis, signal intensities and apparent diffusion coefficient (ADC) values of the periphery were assessed. Two observers reviewed DWI and ADC maps rated using a 5‐point scale. Diagnostic performance was evaluated using the receiver operating characteristics (ROC) curve analysis.

Results

The periphery of hepatic abscesses was T1‐hypointense, arterial hyperintense, and hypointense on hepatobiliary phase less frequently than that of malignant tumors (P < 0.05). No hepatic abscesses showed peripheral washout on 3‐min late phase compared with malignant tumors (59.5%) (P < 0.001). Both groups showed hyperintense rims on DWI, but, 37(94.9%) abscesses revealed rims with high ADC values compared with one (1.4%) malignant tumor (P < 0.001). Mean ADC values of abscesses (1.47 × 10−3 mm2/s ± 0.36 [standard deviation]) were significantly higher than those of malignancies (0.68 × 10−3 mm2/s ± 0.20). Diagnostic performance (area under the ROC curve [Az]) of DWI in identifying hepatic abscess was 0.986 and 0.982 for each observer.

Conclusion

In addition to conventional MRI, DWI is helpful in differentiating hepatic abscess from malignant mimickers. J. Magn. Reson. Imaging 2013;38:1333–1341. © 2013 Wiley Periodicals, Inc.
Diffusion tensor MRI evaluation of the corona radiata, cingulate gyri, and corpus callosum in HIV patients
Authors: Leite Sarah C.B. , Corrêa Diogo G. , Doring Thomas M. , Kubo Tadeu T.A. , Netto Tania M. , Ferracini Rafael , Ventura Nina , Bahia Paulo R.V. , Gasparetto Emerson L.
Published: April 2013

Purpose

To evaluate the white matter integrity of the corona radiata, cingulate gyri, and corpus callosum in patients with human immunodeficiency virus (HIV) infection through diffusion tensor imaging (DTI).

Materials and Methods

Thirty‐four patients with at least 5 years of HIV infection and 27 healthy controls underwent magnetic resonance imaging (MRI) in a 1.5 T scanner. A voxelwise‐based technique was used to analyze the DTI data.

Results

We found that in the body of corpus callosum the fractional anisotropy (FA) was significantly reduced, whereas mean diffusivity (MD) and radial diffusivity (RD) were increased in HIV patients. Analyzing the corona radiata, axial diffusivity (AD) and MD were significantly increased in the left superior region, MD and RD were increased in the left posterior area, and, furthermore, MD was also increased in the right posterior region. No significant abnormalities were found on the cingulate gyri. The white matter damage, related to FA reduction, was associated with increased RD, indicating that demyelization might be the pathophysiological result of this damage.

Conclusion

Since the DTI can detect abnormalities in the normal‐appearing white matter, this technique may play a role as an early marker of HIV disease progression, including clinical manifestations such as cognitive impairment. J. Magn. Reson. Imaging 2013;38:1488–1493. © 2013 Wiley Periodicals, Inc.
Adsorption in columns packed with porous adsorbent particles having partially fractal structures
Authors: Li Min , Liapis Athanasios I.
Published: April 2013

A mathematical model is constructed and solved that could describe the dynamic behavior of the adsorption of a solute of interest in single and stratified columns packed with partially fractal porous adsorbent particles. The results show that a stratified column bed whose length is the same as that of a single column bed, provides larger breakthrough times and a higher dynamic utilization of the adsorptive capacity of the particles than those obtained from the single column bed, and the superior performance of the stratified bed becomes especially more important when the superficial velocity of the flowing fluid stream in the column is increased to accommodate increases in the system throughput. This occurs because the stratified column bed provides larger average external and intraparticle mass transfer and adsorption rates per unit length of packed column. It is also shown that increases in the total number of recursions of the fractal and the ratio of the radii between larger and smaller microspheres that make up the partially fractal particles, increase the intraparticle mass transfer and adsorption rates and lead to larger breakthrough times and dynamic utilization of the adsorptive capacity of the particles. The results of this work indicate that highly efficient adsorption separations could be realized through the use of a stratified column comprised from a practically reasonable number of sections packed with partially fractal porous adsorbent particles having reasonably large (i) total number of recursions of the fractal and (ii) ratio of the radii between larger and smaller microspheres from which the partially fractal particles are made from. It is important to mention here that the physical concepts and modeling approaches presented in this work could be, after a few modifications of the model, applied in studying the dynamic behavior of chemical catalysis and biocatalysis in reactor beds packed with partially fractal porous catalyst particles.
Determination of phthalate esters in bottled water using dispersive liquid–liquid microextraction coupled with GC–MS
Authors: Mousa Amayreh , Basheer Chanbasha , Rahman Al‐Arfaj Abdul
Published: April 2013

Dispersive liquid–liquid microextraction method was developed for the determination of the amount of phthalate esters in bottled drinking water samples and dispersive liquid–liquid microextraction samples were analyzed by GC–MS. Various experimental conditions influencing the extraction were optimized. Under the optimized conditions, very good linearity was observed for all analytes in a range between 0.05 and 150 μg/L with coefficient of determination (R2) between 0.995 and 0.999. The LODs based on S/N = 3 were 0.005–0.22 μg/L. The reproducibility of dispersive liquid–liquid microextraction was evaluated. The RSDs were 1.3–5.2% (n = 3). The concentrations of phthalates were determined in bottled samples available in half shell. To understand the leaching profile of these phthalates from bottled water, bottles were exposed to direct sunlight during summer (temperature from 34–57°C) and sampled at different intervals. Result showed that the proposed dispersive liquid–liquid microextraction is suitable for rapid determination of phthalates in bottled water and di‐n‐butyl, butyl benzyl, and bis‐2‐ethylhexyl phthalate compounds leaching from bottles up to 36 h. Thereafter, degradation of phthalates was observed.
Dynamic permeability of an assemblage of soft spherical particles
Authors: Prakash Jai , Raja Sekhar G.P.
Published: April 2013

Under oscillatory Stokes flow, dynamic permeability of assemblage of soft spherical particles is derived. For the bed of soft particles, the fluid‐particle system is represented as an assemblage of uniform permeable spheres fixed in space. Each sphere, with a surrounding envelope of fluid, is uncoupled from the system and considered separately. This model is popularly known as cell model. Oscillatory Stokes equations are employed inside the fluid envelope, and oscillatory Brinkman equations are used inside the porous region. Four known boundary conditions namely: Happel's, Kuwabara's, Kvashnin's, and Cunningham's are considered on the outer boundary and results are compared. The behavior of dynamic permeability is analyzed with various parameters such as Darcy number (Da), frequency parameter (ϖ), porosity (φ), and viscosity ratio (δ). Copyright © 2013 John Wiley & Sons, Ltd.
Cervical softening occurs early in pregnancy: characterization of cervical stiffness in 100 healthy women using the aspiration technique
Authors: Badir Sabrina , Mazza Edoardo , Zimmermann Roland , Bajka Michael
Published: April 2013

Objective

To quantitatively describe the evolution of ectocervical stiffness in normal pregnancy.

Methods

The stiffness of ectocervical tissue was measured by using the aspiration method. This non‐invasive technique allows to safely and objectively determine the pressure required to displace cervical tissue to a predefined deformation level (pcl). In this prospective study, 448 aspiration measurements were carried out on pregnant women (n = 50) at each of the eight routine pregnancy consultations and on nonpregnant subjects (reference, n = 50). pcl values were grouped as nonpregnant, first, second, third trimester, and postpartum.

Results

Stiffness in early pregnancy (first trimester) is significantly lower, by a factor >2 for the mean value than for the nonpregnant group. pcl continuously decreases during gestation, with significant differences between first and second trimester, but not between second and third trimester. After delivery, consistency is recovered to the level of early pregnancy.

Conclusions

The aspiration method allows an objective description of the consistency of the ectocervix during pregnancy, indicating that the tissue softens already at the beginning of gestation, transforms continuously to lower consistency in the first two trimesters, stabilizes at a low level in the third trimester, and recovers its stiffness after delivery. © 2013 John Wiley & Sons, Ltd.
The volume of the chorion villosum is associated with the location of the umbilical cord in the first trimester
Authors: Nakamura Masamitsu , Hasegawa Junichi , Hamada Shoko , Matsuoka Ryu , Ichizuka Kiyotake , Sekizawa Akihiko , Okai Takashi
Published: April 2013

Aims

To clarify whether villous placental volumes in cases with low cord insertion (CI) are smaller than those with normal cord insertion.

Methods

A prospective cohort study was conducted to evaluate the association between location of umbilical CI and placental volume at 11 to 13 weeks' gestation. An ultrasound examination was performed to measure the crown‐rump length, the distance between the histological internal cervical os and the CI site, the placental volume, and the uterine arterial blood flow. To standardize the distribution of the ultrasonographic measurements, we transformed data by crown‐rump length‐weighted linear regression.

Results

Six hundred fifty‐nine subjects were analyzed. Scatter plots showed a slightly positive correlation between the z‐scores of the distance from the CI site to the internal cervical os and villous placental volume (r = 0.102, p = 0.009) and a negative correlation between the z‐scores of the villous placental volume and the uterine arterial pulsatility index (r = −0.165, p < 0.001) as well as the uterine arterial resistance index (r = −0.187, p < 0.001).

Conclusion

The placental volume was likely to be smaller in cases with CI located in the lower uterine segment. © 2013 John Wiley & Sons, Ltd.
Radial heteroemitter solar cells based on VLS grown silicon nanowires
Authors: Eisenhawer Björn , Sill Ingo , Falk Fritz
Published: April 2013

Silicon nanowires (SiNWs) are an interesting system for the realization of solar cells, as they offer an enhanced light absorption compared to bulk Si. However, due to their large surface, nanowire solar cells suffer from high surface recombination which results in small carrier lifetimes. They therefore need perfect passivation. The use of an amorphous silicon heteroemitter on such structures enables a good surface passivation and therefore enables a higher open circuit voltage (VOC) than in crystalline core–shell structures. In this paper, we present the realization of radial junction SiNW solar cells by the vapor–liquid–solid (VLS) growth of n‐doped SiNWs and subsequent coating by amorphous silicon in a PECVD process. The cells were contacted using atomic layer deposition of a transparent conductive oxide (aluminum‐doped zinc oxide) as a front contact. The results of the SiNW solar cells are compared to a planar device to exclude the influence of the supporting wafer structure. The onset presented in this paper can possibly be used to realize SiNW based solar cells on low cost materials, as VLS enables the growth of SiNWs on almost any kind of surfaces.
A conservative adaptive wavelet method for the shallow‐water equations on staggered grids
Authors: Dubos T. , Kevlahan N. K‐R.
Published: April 2013

This article presents the first dynamically adaptive wavelet method for the shallow‐water equations (SWEs) on a staggered hexagonal C‐grid. Pressure is located at the centres of the primal grid (hexagons) and velocity is located at the edges of the dual grid (triangles). Distinct bi‐orthogonal second‐generation wavelet transforms are developed for the pressure and the velocity. These wavelet transforms are based on second‐order accurate interpolation and restriction operators. Together with compatible restriction operators for the mass flux and Bernoulli function, they ensure that mass is conserved and that there is no numerical generation of vorticity when solving the SWEs. Grid refinement relies on appropriate thresholding of the wavelet coefficients, allowing error control in both the quasi‐geostrophic and inertia–gravity wave regimes. The SWEs are discretized on the dynamically adapted multiscale grid using a mass and potential‐enstrophy‐conserving finite‐difference scheme. The conservation and error control properties of the method are verified by applying it to a propagating inertia–gravity wave packet and to rotating shallow‐water turbulence. Significant savings in the number of degrees of freedom are achieved even in the case of rotating shallow‐water turbulence. The numerical dissipation introduced by the grid adaptation is quantified. The method has been designed so it can be extended easily to the icosahedral subdivision of the sphere. This work provides important building blocks for the development of fully adaptive general circulation models.
Governance Mechanisms and New Venture Performance in China
Authors: Chen Chen , Zhu Xiumei , Ao Jiayue , Cai Li
Published: April 2013

Despite increasing attention have been paid to the role of external relationship management, some studies have been concerned about established firms’ relationship management; however, only few studies have explicitly discussed the role of relationship management for new venture performance in a transition economy. Trust and contracts are two kinds of governance mechanisms to manage external relationship. This research focuses on trust and contracts and examines their impacts on new ventures’ performance. Moreover, we argue that resource acquisition mediates the relationship between governance mechanisms and new venture performance. By using survey data from 188 questionnaires, this study finds that trust and contracts are positively associated with relationship performance and economic performance. New ventures also obtain more relationship and economic performance through resource acquisition. In addition, trust and contracts are substitutable that affect economic performance, but the interaction is not associated with relationship performance. Copyright © 2013 John Wiley & Sons, Ltd.
Repression of Zeb1 and Hypoxia Cause Sequential Mesenchymal-to-Epithelial Transition and Induction of Aid, Oct4, and Dnmt1, Leading to Immortalization and Multipotential Reprogramming of Fibroblasts in Spheres
Authors: Liu Yongqing , Mukhopadhyay Partha , Pisano M. Michele , Lu Xiaoqin , Huang Li , Lu Qingxian , Dean Douglas C.
Published: April 2013

In this study, we demonstrate that sphere formation triggers immortalization and stable reprogramming of mouse fibroblasts. Cell contact signaling in spheres causes downregulation of the epithelial-to-mesenchymal transition transcription factor Zeb1 leading to rapid mesenchymal-to-epithelial transition. Hypoxia within spheres together with loss of Zeb1 repression synergize to cause superinduction of Hif1a, which in turn leads to induction of the DNA demethylase Aid/Aicda, demethylation of the Oct4 promoter/enhancer and multipotency. Oct4 and Nanog expression diminish when cells are removed from the hypoxic environment of spheres and placed in monolayer culture, but the cells retain multipotential capacity, demonstrating stable reprogramming and a gene expression pattern resembling adult stem cells. Oct4 has been shown to induce Dnmt1 in mesenchymal stem cells, and we link Oct4 and Dnmt1 to silencing of cell cycle inhibitory cyclin dependent kinase inhibitors and Arf, and immortalization of the reprogrammed fibroblasts. Sphere formation then represents a novel and rapid protocol for immortalization and stable reprogramming of fibroblasts to multipotency that does not require exogenous expression of a stem cell factor or a lineage-specifying transcription factor.
Measurement of tennis player's stroke form by ground reaction forces
Authors: Nosu Kiyoshi , Goshima Akira , Imamura Takayuki , Mitsumoto Kenji
Published: April 2013

This letter proposes a tennis instruction support system to provide stroke‐form information obtained through measurement and analysis of ground reaction forces. The originality of the proposed method can be summarized as follows: (i) simultaneous outdoor measurements of ground reaction forces on the front part (toes) and back part (heels) of both feet are conducted for visual recognition of the center of gravity of a tennis player's body during a stroke, and (ii) the comparison between experienced players and beginners is examined so that the system can be used for training beginners. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Climate change and human rights
Authors: Bell Derek
Published: April 2013

Human rights have not played a significant role in the international law and politics of climate change to date. However, there has been increasing interest among legal scholars and moral and political philosophers in a human rights approach to climate change. This review focuses on the new literature in moral and political philosophy that has begun to explore the connections between human rights and climate change. The attractions of a human rights approach to climate change are explained. The idea of a moral conception of human rights is introduced and distinguished from human rights recognized in international and national law. The key features of moral human rights are identified and an important distinction between negative and positive rights is explained. The three main arguments in the literature connecting human rights and climate change are introduced and critical discussions of them are presented. The first argument (associated with Steve Vanderheiden) claims that there is a human right to a stable climate, which can be derived from a human right to an adequate environment. The second argument (associated with Simon Caney) claims that anthropogenic climate change violates basic human (negative) rights to life, health, and subsistence. The third argument claims that there is a human right to emit greenhouse gases. This argument has two versions. The first version claims that there is a human right to equal per capita emissions. The second version claims that there is a human right to subsistence emissions. WIREs Clim Change 2013, 4:159–170. doi: 10.1002/wcc.218

This article is categorized under:

Climate, Nature, and Ethics > Climate Change and Global Justice

Climate, Nature, and Ethics > Climate Change and Human Rights

Climate, Nature, and Ethics > Ethics and Climate Change
Developing semianalytical solutions for multispecies transport coupled with a sequential first‐order reaction network under variable flow velocities and dispersion coefficients
Authors: Suk Heejun
Published: April 2013

Key Points

semianalytical method for solving a multispecies reactive‐transport equation

sequential first‐order reaction under spatially or temporally varying flow

GITT and general linear‐transformation method by Clement (2001)
Renormalization group scaling of Higgs operators and h → γγ decay
Authors: Grojean Christophe , Jenkins Elizabeth E. , Manohar Aneesh V. , Trott Michael
Published: April 2013

Abstract

We compute the renormalization of dimension six Higgs-gauge boson operators that can modify the h → γγ rate at tree-level. Operator mixing is shown to lead to an important modification of new physics effects which has been neglected in past calculations. We also find that the usual formula for the S oblique parameter contribution of these Higgs-gauge boson operators needs additional terms to be consistent with renormalization group evolution. We study the implications of our results for Higgs phenomenology and for new physics models which attempt to explain a deviation in the h → γγ rate. We derive a new relation between the S parameter and the h → γγ and h → Zγ decay rates.
Algebraic cycles satisfying the Maurer-Cartan equation and the unipotent fundamental group of curves
Authors: Hadian Majid
Published: April 2013

We address the question of lifting the étale unipotent fundamental group of curves to the level of algebraic cycles and show that a sequence of algebraic cycles whose sum satisfies the Maurer-Cartan equation would do the job. For any elliptic curve with the origin removed and the curve $\double-struck(G)_m\$, we construct such a sequence of algebraic cycles whose image under the cycle map gives rise to the étale unipotent fundamental group of the curve.
The Imagery ofthe Persians
Authors: Anderson Michael
Published: April 2013

‘If, almost a hundred years ago,’ writes the critic Martin Esslin, Walter Pater could sum up the then prevailing trend in his famous epigram, “All art constantly aspires towards the condition of music”, the dominant tendency of our own age might be described as an aspiration of all the arts to attain the condition ofimages' Certainly it is true that the study of imagery has been a fashionable method of literary criticism for some time and, employed with the proper blend of caution and imagination, has proved itself of service in the interpretation of a number of poets, most notably perhaps Shakespeare. It has long been recognized that Aeschylus is a poet who often works through ‘key’ or ‘dominant’ images; indeed, I suspect that classical scholarship may take some modest pride in having been the first in this field of study, even if it has yet to reach the dizzy heights (and sometimes the excesses) achieved by the Shakespearians.
“High” and “low” in urban Danish speech styles
Authors: Madsen Lian Malai
Published: April 2013

This article approaches on-going sociolinguistic processes in Copenhagen by focusing on the overt metalinguistic activities of a group of adolescents. The article sheds light on how social power differences are refracted in the metalinsguistic activities of these adolescents in spite of the relatively homogenous (or hegemonic) sociolinguistic conditions of Danish society. In the article, I investigate how social status relations understood as cultural interpretations of societal “high” and “low” are relevant to on-going social value ascriptions to the contrasting ways of speaking labelled “integrated” and “street language.” The metalinguistic data I present points to a sociolinguistic transformation. Linguistic signs that used to be seen as related to migration, on an insider/outsider dimension of comparison, are now related to status on a high/low dimension as well. (Sociolinguistic transformation, ethnicity, social class, enregisterment, metalinguistic reflections)*
Racist Hysteria to Pragmatic Rapprochement? The German Debate about Rhenish ‘Occupation Children’, 1920–30
Authors: ROOS JULIA
Published: April 2013

This essay revisits 1920s German debates over the illegitimate children of the Rhineland occupation to examine hitherto neglected fluctuations in the relationship between nationalism and racism in Weimar Germany. During the early 1920s, nationalist anxieties focused on the alleged racial ‘threats’ emanating from the mixed-race children of colonial French soldiers. After 1927, plans for the forced sterilisation and deportation of the mixed-race children were dropped; simultaneously, officials began to support German mothers’ paternity suits against French soldiers. This hitherto neglected shift in German attitudes towards the ‘Rhineland bastards’ sheds new light on the role of debates over gender and the family in the process of Franco–German rapprochement. It also enhances our understanding of the contradictory political potentials of popularised foreign policy discourses about women's and children's victimisation emerging from World War I.
Pleasure and Duty
Authors: WEEKS JEFFREY
Published: April 2013

Three obvious, superficially simple but actually intensely complex questions embodied in the title immediately confront the reader of Dagmar Herzog's important new book. First, what do we mean by the ‘sexuality’ that constitutes the subject matter? Second, what is demarcated by the Europe that provides the geo-political boundaries of this study? Third, does the ‘twentieth century’ provide a useful temporal unity for the narrative and analysis that is at the heart of the book? Such questions are not mere scholarly nit-picking or academic point scoring, but a tribute to the problematising of the body in space and time that has been a hallmark of the deconstructive and reconstructive energy of recent scholarship on the sexual, and that is now making a welcome entry into mainstream history.
Annular Dark-Field Transmission Electron Microscopy for Low Contrast Materials
Authors: Leroux F. , Bladt E. , Timmermans J.-P. , Van Tendeloo G. , Bals S.
Published: April 2013

Imaging soft matter by transmission electron microscopy (TEM) is anything but straightforward. Recently, interest has grown in developing alternative imaging modes that generate contrast without additional staining. Here, we present a dark-field TEM technique based on the use of an annular objective aperture. Our experiments demonstrate an increase in both contrast and signal-to-noise ratio in comparison to conventional bright-field TEM. The proposed technique is easy to implement and offers an alternative imaging mode to investigate soft matter.
Inhibition of Plasmodium falciparum CDPK1 by conditional expression of its J-domain demonstrates a key role in schizont development
Authors: Azevedo Mauro F. , Sanders Paul R. , Krejany Efrosinia , Nie Catherine Q. , Fu Ping , Bach Leon A. , Wunderlich Gerhard , Crabb Brendan S. , Gilson Paul R.
Published: April 2013

PfCDPK1 [Plasmodium falciparum CDPK1 (calcium-dependent protein kinase 1)] is highly expressed in parasite asexual blood and mosquito stages. Its role is still poorly understood, but unsuccessful gene knockout attempts suggest that it is essential for parasite replication and/or RBC (red blood cell) invasion. In the present study, by tagging endogenous CDPK1 with GFP (green fluorescent protein), we demonstrate that CDPK1 localizes to the parasite plasma membrane of replicating and invasive forms as well as very young intracellular parasites and does not appear to be exported into RBCs. Although a knockdown of endogenous CDPK1 was achieved using a destabilization domain, parasites tolerated reduced expression without displaying a phenotype. Because of this, the PfCDPK1 auto-inhibitory J (junction) domain was explored as a means of achieving inducible and specific inhibition. Under in vitro conditions, a fusion protein comprising a J–GFP fusion specifically bound to PfCDPK1 and inhibited its activity. This fusion protein was conditionally expressed in P. falciparum asexual blood stages under the regulation of a DD (destabilization domain) (J–GFP–DD). We demonstrate that J–GFP–DD binds to CDPK1 and that this results in the arrest of parasite development late in the cell cycle during early schizogony. These data point to an early schizont function for PfCDPK1 and demonstrate that conditionally expressing auto-inhibitory regions can be an effective way to address the function of Plasmodium enzymes.
Perpendicular magnetic anisotropy and perpendicular exchange bias in sputter-deposited CoO/CoPt multilayer
Authors: Wang J. , Sannomiya T. , Shi J. , Nakamura Y.
Published: April 2013

The structural and magnetic properties of room-temperature sputter-deposited CoO/CoPt multilayer have been investigated. It was found that the multilayers show strong perpendicular magnetic anisotropy (PMA) at room temperature. Moreover, after perpendicular field cooling below the Néel temperature of CoO layer, the multilayer with antiferromagnet (AF)/ferromagnet (FM) interfaces exhibits perpendicular exchange bias (PEB). And also the PMA of the multilayer is enhanced after field cooling process. This is considered due to the strong interfacial exchange coupling between the CoPt and CoO layers, which is further confirmed from the significantly enhanced perpendicular coercivity. Similar with the reported Co/noble-metal structures, the strong PMA found here also shows clear interface effect. However, with the multilayer structure studied here, the PMA can survive with relative thicker ferromagnetic layer (tFM ∼ 2.3 nm) at as-deposited state. Therefore, the PMA found in AF/FM multilayer could be partially attributed to the interfacial AF-FM exchange coupling. On the other hand, structural characterization results indicate a well-defined layer structure and strong (111) texture for CoPt layers. CoO layer here provides a good seed layer for the growth of textured CoPt layer. As [111] is one of the easy axis for the fcc CoPt, the (111) texture should also benefit the PMA. Such PMA and PEB originating from the interface would give new parameters to control the magnetic properties especially for multilayer systems.
High-overtone bulk acoustic resonator as passive ground penetrating RADAR cooperative targets
Authors: Friedt J.-M. , Saintenoy A. , Chrétien S. , Baron T. , Lebrasseur É. , Laroche T. , Ballandras S. , Griselin M.
Published: April 2013

RAdio-frequency Detection And Ranging instruments—RADARs—are widely used for applications aimed at measuring passive target velocity or ranging for various metrology applications such as ground position and localization. Within the context of using piezoelectric acoustic passive sensors as cooperative targets to RADARs probed through a radiofrequency link, this paper reports on investigating the compatibility of narrowband resonator architectures with the classical operation mode of wideband RADAR instruments. Since single mode resonators are hardly compatible due to the limited bandwidth of their spectrum, the investigation has been extended to High-overtone Bulk Acoustic Resonator (HBAR) whose comb of modes appears appropriate to the use with RADAR instruments. This analysis leads to consider HBARs as delay lines providing a comb of echos in the time domain rather than through the usual frequency comb considerations. Experimental measurements of HBAR responses are demonstrated using Ground Penetrating RADAR instruments fitted with a variety of antennas, and thus, operating in various frequency ranges, as well as the identification of the device temperature through the echo time delay computed as the cross correlation maximum position. Finally, the use of such cooperative targets for single reflector identification within a clutter of reflectors is theoretically considered with the proposal of a Finite-Difference Time-Domain-based simulation method encompassing both passive dielectric reflectors and the contribution of buried passive acoustic sensors.
Interplay of 3d-4f exchange interaction in Pr0.5-xNdxSr0.5CoO3
Authors: Kumar Pawan , Aparnadevi M. , Mahendiran R.
Published: April 2013

We have investigated electrical and magnetic properties of Pr0.5-xNdxSr0.5CoO3 (x = 0.0, 0.1, 0.2, 0.3, and 0.5) samples. Upon cooling, field-cooled magnetization of Pr0.5Sr0.5CoO3 shows an anomalous increase at TA = 120 K within the ferromagnetic state coupled structural and magnetic anisotropy transitions. This anomaly shifts to 88 K for x = 0.1 but its magnetization starts decreasing below Tferri = 35 K, where Tferri signals the onset of ferrimagnetic interaction between Nd(4f) and Co(3d) moments. The structural transition is absent in x ≥ 0.2. While the ferromagnetic Curie temperature decreases with increasing Nd content by 8 K, Tferri increases from 35 K for x = 0.1 to 80 K for x = 0.5. The ferrimagnetic interaction does not affect the dc resistivity. All the studied samples are metallic and magnetoresistance decreases from −6.7% for x = 0 to −0.7% for x = 0.5.
Tailoring magnetism of multifunctional MnxGa films with giant perpendicular anisotropy
Authors: Zhu L. J. , Pan D. , Nie S. H. , Lu J. , Zhao J. H.
Published: April 2013

We report wide-range composition and annealing effects on magnetic properties of MnxGa films grown on GaAs (001) by molecular-beam epitaxy. We obtained single-crystalline MnxGa films in a surprisingly wide composition range from x = 0.76 to 2.6. We show that the magnetism could be effectively tailored by adjusting composition and annealing. Especially, when 0.76 ≤ x ≤ 1.75, MnxGa films simultaneously show magnetization from 130 to 450 emu/cc, perpendicular anisotropy from 8.6 to 21 Merg/cc, intrinsic coercivity from 4.38 to 20.1 kOe, normal coercivity to 3.6 kOe, energy product up to 3.4 MGOe, and thermal-stability up to at least 350 °C in contact with GaAs.
Effects of spermatozoa–oviductal cell coincubation time and oviductal cell age on spermatozoa–oviduct interactions
Authors: Aldarmahi Ahmed , Elliott Sarah , Russell Jean , Fazeli Alireza
Published: April 2013

The oviduct plays a crucial role in sperm storage, maintenance of sperm viability and sperm transport to the site of fertilisation. The aim of the present study was to investigate the effects of oviductal cell culture passage number, oviductal cell age and spermatozoa–oviduct coincubation times on gene expression in oviductal cells. Immortalised oviductal epithelial cells (OPEC) obtained from two different cell passages (36 and 57) were subcultured three times with and without spermatozoa for 24 h (control group). In a second study, OPEC were cocultured with spermatozoa for different time intervals (0, 4, 12 and 24 h). Expression of adrenomedullin (ADM), heat shock 70 kDa protein 8 (HSPA8) and prostaglandin E synthase (PGES) in OPEC was measured by quantitative polymerase chain reaction. The expression of ADM and HSPA8 was decreased significantly in OPEC cells from Passage 57, particularly in the later subculture group. These effects on HSPA8, but not ADM, expression in OPEC were further altered after coculture with spermatozoa for 24 h. We also demonstrated that spermatozoa–oviduct coculture for 12 and 24 h resulted in significantly higher expression of ADM, HSPA8 and PGES in OPEC. Overall, the data suggest that the OPEC lose some of their properties as a result of oviductal cell aging and that there are spermatozoa–oviduct interactions leading to increased oviductal cell gene expression.
Proteome-wide profiling of activated transcription factors with a concatenated tandem array of transcription factor response elements
Authors: Ding Chen , Chan Doug W. , Liu Wanlin , Liu Mingwei , Li Dong , Song Lei , Li Chonghua , Jin Jianping , Malovannaya Anna , Jung Sung Yun , Zhen Bei , Wang Yi , Qin Jun
Published: April 2013

Transcription factors (TFs) are families of proteins that bind to specific DNA sequences, or TF response elements (TFREs), and function as regulators of many cellular processes. Because of the low abundance of TFs, direct quantitative measurement of TFs on a proteome scale remains a challenge. In this study, we report the development of an affinity reagent that permits identification of endogenous TFs at the proteome scale. The affinity reagent is composed of a synthetic DNA containing a concatenated tandem array of the consensus TFREs (catTFRE) for the majority of TF families. By using catTFRE to enrich TFs from cells, we were able to identify as many as 400 TFs from a single cell line and a total of 878 TFs from 11 cell types, covering more than 50% of the gene products that code for the DNA-binding TFs in the genome. We further demonstrated that catTFRE pull-downs could quantitatively measure proteome-wide changes in DNA binding activity of TFs in response to exogenous stimulation by using a label-free MS-based quantification approach. Applying catTFRE on the evaluation of drug effects, we described a panoramic view of TF activations and provided candidates for the elucidation of molecular mechanisms of drug actions. We anticipate that the catTFRE affinity strategy will find widespread applications in biomedical research.
β1 integrin regulates Arg to promote invadopodial maturation and matrix degradation
Authors: Beaty Brian T. , Sharma Ved P. , Bravo-Cordero Jose J. , Simpson Mark A. , Eddy Robert J. , Koleske Anthony J. , Condeelis John
Published: April 2013

β1 integrin has been shown to promote metastasis in a number of tumor models, including breast, ovarian, pancreatic, and skin cancer; however, the mechanism by which it does so is poorly understood. Invasive membrane protrusions called invadopodia are believed to facilitate extracellular matrix degradation and intravasation during metastasis. Previous work showed that β1 integrin localizes to invadopodia, but its role in regulating invadopodial function has not been well characterized. We find that β1 integrin is required for the formation of mature, degradation-competent invadopodia in both two- and three-dimensional matrices but is dispensable for invadopodium precursor formation in metastatic human breast cancer cells. β1 integrin is activated during invadopodium precursor maturation, and forced β1 integrin activation enhances the rate of invadopodial matrix proteolysis. Furthermore, β1 integrin interacts with the tyrosine kinase Arg and stimulates Arg-dependent phosphorylation of cortactin on tyrosine 421. Silencing β1 integrin with small interfering RNA completely abrogates Arg-dependent cortactin phosphorylation and cofilin-dependent barbed-end formation at invadopodia, leading to a significant decrease in the number and stability of mature invadopodia. These results describe a fundamental role for β1 integrin in controlling actin polymerization–dependent invadopodial maturation and matrix degradation in metastatic tumor cells.
Biomechanical Comparison of Expansive Pedicle Screw and Polymethylmethacrylate-augmented Pedicle Screw in Osteoporotic Synthetic Bone in Primary Implantation
Authors: Liu Da , Shi Lei , Lei Wei , Wei Meng-Qi , Qu Bo , Deng Shao-Lin , Pan Xian-Ming
Published: April 2013

Study Design:

Expansive pedicle screws (EPS) and polymethylmethacrylate-augmented pedicle screws (PMMA-PS) were inserted into osteoporotic synthetic bones, which were then tested by radiographic and biomechanical examinations.

Objective:

To compare the stability of EPS and PMMA-PS with that of a conventional pedicle screw (CPS) in an osteoporotic synthetic bone.

Summary of Background Data:

It is a significant challenge for orthopedic surgeons performing transpedicular fixation in the osteoporotic spine. Prior studies have suggested that both EPS and PMMA-PS can increase the screw stability effectively. However, there are no biomechanical comparisons of EPS and PMMA-PS, especially in primary spinal surgery in osteoporosis.

Methods:

Thirty osteoporotic synthetic bone blocks were divided into 3 groups randomly. A pilot hole was prepared in advance in all samples by the same method. Then, the CPS was inserted directly into the pilot hole in the CPS group; the hole in the PMMA-PS group was first filled with polymethylmethacrylate (PMMA; 2.5 mL) and then inserted with CPS, and the EPS was inserted directly into the blocks in the EPS group. Twenty-four hours later, x-ray and computed tomography examination and axial pullout tests were performed on all samples; the block destructions were then recorded, and the hole diameters were measured.

Results:

In the CPS group, the screw was surrounded directly by the synthetic bone without any other materials, whereas in the PMMA-PS group, the screw was totally wrapped up by PMMA, and the PMMA was evenly distributed in the synthetic bone around the screw, indicating obvious improvement of the local density around the track. In the EPS group, the anterior part of the EPS presented an obvious expansion in synthetic bone and formed an unguiform structure pressing the surrounding synthetic bone. Screw stabilities in both the PMMA-PS and the EPS groups were significantly enhanced compared with those in the CPS group, and the screw stability in the PMMA-PS group was significantly higher than that in the EPS group. After the pullout tests, the block destructions were the most severe in the PMMA-PS group and the lightest in the CPS group. Hole diameters in the PMMA-PS and the EPS groups were significantly larger than that in the CPS group, whereas the diameter of the hole in the PMMA-PS group was significantly greater than that in the EPS group.

Conclusions:

EPS can significantly increase the strength of screw fixation compared with CPS in osteoporotic synthetic bone. Although EPS shows a weaker fixation strength compared with PMMA-PS in the osteoporotic synthetic bone, it may still provide an alternative option to prevent screw loosening in the clinical treatment of osteoporosis.
Capacity and Plasticity of Potassium Channels and High-Affinity Transporters in Roots of Barley and Arabidopsis
Authors: Coskun Devrim , Britto Dev T. , Li Mingyuan , Oh Saehong , Kronzucker Herbert J.
Published: April 2013

The role of potassium (K+) transporters in high- and low-affinity K+ uptake was examined in roots of intact barley (Hordeum vulgare) and Arabidopsis (Arabidopsis thaliana) plants by use of 42K radiotracing, electrophysiology, pharmacology, and mutant analysis. Comparisons were made between results from barley and five genotypes of Arabidopsis, including single and double knockout mutants for the high-affinity transporter, AtHAK5, and the Shaker-type channel, AtAKT1. In Arabidopsis, steady-state K+ influx at low external K+ concentration ([K+]ext = 22.5 µm) was predominantly mediated by AtAKT1 when high-affinity transport was inhibited by ammonium, whereas in barley, by contrast, K+ channels could not operate below 100 µm. Withdrawal of ammonium resulted in an immediate and dramatic stimulation of K+ influx in barley, indicating a shift from active to passive K+ uptake at low [K+]ext and yielding fluxes as high as 36 µmol g (root fresh weight)−1 h−1 at 5 mm  [K+]ext, among the highest transporter-mediated K+ fluxes hitherto reported. This ammonium-withdrawal effect was also established in all Arabidopsis lines (the wild types, atakt1, athak5, and athak5 atakt1) at low [K+]ext, revealing the concerted involvement of several transport systems. The ammonium-withdrawal effect coincided with a suppression of K+ efflux and a significant hyperpolarization of the plasma membrane in all genotypes except athak5 atakt1, could be sustained over 24 h, and resulted in increased tissue K+ accumulation. We discuss key differences and similarities in K+ acquisition between two important model systems and reveal novel aspects of K+ transport in planta.