bluuebunny/crossref_metadata_2025 huggingface dataset:
Auditory Performance Characteristics of the Computerized Revised Token Test (CRTT)
Authors: Eberwein Cynthia A. , Pratt Sheila R. , McNeil Malcolm R. , Fossett Tepanta R. D. , Szuminsky Neil J. , Doyle Patrick J.
Published: August 2007

Purpose

To assess the Computerized Revised Token Test (CRTT) performance of individuals with normal hearing under several intensity conditions and under several spectral and temporal perturbation conditions.

Method

Sixty normal-hearing listeners were randomly assigned to 1 of 3 groups. Group 1 provided performance-intensity information about CRTT performance using uncompressed acoustic stimuli. Groups 2 and 3 completed the CRTT using temporally and spectrally compressed and expanded stimuli. CRTT performance functions were plotted for each group.

Results

Group 1 required minimal audibility to perform maximally on this task. As expected, Groups 2 and 3 showed significant differences across subtests, regardless of distortion condition. Mean differences in performance between successive conditions for Group 2 increased beyond 40% time compressed. There was 1 significant difference for the time-expanded condition. There were no differences across frequency compressed and expanded conditions.

Conclusion

Young listeners require limited signal gain on the CRTT to achieve maximum performance. Time and frequency compression and expansion results were consistent with previous findings with varying types of speech stimuli. The results have implications for administration and interpretation of the CRTT administered to persons from other populations and will help in the development of a normative database for the CRTT.
The Language Experience and Proficiency Questionnaire (LEAP-Q): Assessing Language Profiles in Bilinguals and Multilinguals
Authors: Marian Viorica , Blumenfeld Henrike K. , Kaushanskaya Margarita
Published: August 2007

Purpose

To develop a reliable and valid questionnaire of bilingual language status with predictable relationships between self-reported and behavioral measures.

Method

In Study 1, the internal validity of the Language Experience and Proficiency Questionnaire (LEAP-Q) was established on the basis of self-reported data from 52 multilingual adult participants. In Study 2, criterion-based validity was established on the basis of standardized language tests and self-reported measures from 50 adult Spanish–English bilinguals. Reliability and validity of the questionnaire were established on healthy adults whose literacy levels were equivalent to that of someone with a high school education or higher.

Results

Factor analyses revealed consistent factors across both studies and suggested that the LEAP-Q was internally valid. Multiple regression and correlation analyses established criterion-based validity and suggested that self-reports were reliable indicators of language performance. Self-reported reading proficiency was a more accurate predictor of first-language performance, and self-reported speaking proficiency was a more accurate predictor of second-language performance. Although global measures of self-reported proficiency were generally predictive of language ability, deriving a precise estimate of performance on a particular task required that specific aspects of language history be taken into account.

Conclusion

The LEAP-Q is a valid, reliable, and efficient tool for assessing the language profiles of multilingual, neurologically intact adult populations in research settings.
Does the Auditory Saltation Stimulus Distinguish Dyslexic From Competently Reading Adults?
Authors: Kidd Joanna C. , Hogben John H.
Published: August 2007

Purpose

Where the auditory saltation illusion has been used as a measure of auditory temporal processing (ATP) in dyslexia, conflicting results have been apparent (cf. R. Hari & P. Kiesilä, 1996; M. Kronbichler, F. Hutzler, & H. Wimmer, 2002). This study sought to re-examine these findings by investigating whether dyslexia is characterized by poor saltation task performance and whether saltation thresholds are related to reading and phonological processing within groups of either dyslexic or competent readers.

Method

Nineteen dyslexic and 20 competently reading adults (18–64 years of age) participated. Participants completed 2 runs of a 2-alternative forced-choice saltation task, along with standard measures of reading and phonological processing.

Results

Although overall poorer saltation thresholds were apparent in the dyslexic group, the threshold distributions overlapped considerably, with thresholds alone unable to predict group membership at a level significantly greater than chance. Neither strong nor significant correlations were observed among saltation thresholds, reading, and phonological processing skills within either group.

Conclusion

The results of this study do not support suggestions of impaired ATP in dyslexia or associations among ATP, reading, and phonological processing. However, it is proposed that increased within- and between-subject variability in auditory thresholds might be a more valuable marker of dyslexia than the thresholds themselves. Implications of this observation for dyslexia research are discussed.
The Acquisition of Speech Rhythm by Bilingual Spanish- and English-Speaking 4- and 5-Year-Old Children
Authors: Bunta Ferenc , Ingram David
Published: August 2007

Purpose

In this study, the authors investigated speech rhythm acquisition by bilingual Spanish–English-speaking children, comparing their performance with functionally monolingual peers in both languages and to monolingual and bilingual adults.

Method

Participants included younger children (3;9 [years;months] to 4;5.15[years;months.days]), older children (4;6.18 to 5;2), and adults (over 18 years). Twenty-six sentences were elicited and analyzed using the normalized vocalic and intervocalic Pairwise Variability Indices (PVIs) that express the level of variability in successive duration measurements, on the basis of E. Grabe and E. L. Low (2002).

Results

Younger bilingual children displayed distinct speech rhythm patterns for their target languages, and they deviated from their monolingual English-speaking peers. Older bilingual children also separated speech rhythm by language, and differences between older bilingual children and their monolingual peers speaking English were also found. Younger and older bilingual children differed on the vocalic PVI, but not the intervocalic PVI, providing partial support for age differences. Bilingual adults showed separation of their languages and performed similarly to their monolingual peers.

Conclusion

Bilingual children show distinct speech rhythm patterns for their target languages but with some early equal timing bias that diminishes over time, on the basis of the vocalic measurements. Overall, the vocalic PVI is more robust than the intervocalic PVI, but further research is necessary.
Will They Catch Up? The Role of Age at Cochlear Implantation in the Spoken Language Development of Children With Severe to Profound Hearing Loss
Authors: Nicholas Johanna Grant , Geers Ann E.
Published: August 2007

Purpose

The authors examined the benefits of younger cochlear implantation, longer cochlear implant use, and greater pre-implant aided hearing to spoken language at 3.5 and 4.5 years of age.

Method

Language samples were obtained at ages 3.5 and 4.5 years from 76 children who received an implant by their 3rd birthday. Hierarchical linear modeling was used to identify characteristics associated with spoken language outcomes at the 2 test ages. The Preschool Language Scale (I. L. Zimmerman, V. G. Steiner, & R. E. Pond, 1992) was used to compare the participants' skills with those of hearing age-mates at age 4.5 years.

Results

Expected language scores increased with younger age at implant and lower pre-implant thresholds, even when compared at the same duration of implant use. Expected Preschool Language Scale scores of the children who received the implant at the youngest ages reached those of hearing age-mates by 4.5 years, but those children implanted after 24 months of age did not catch up with hearing peers.

Conclusion

Children who received a cochlear implant before a substantial delay in spoken language developed (i.e., between 12 and 16 months) were more likely to achieve age-appropriate spoken language. These results favor cochlear implantation before 24 months of age, especially for children with aided pure-tone average thresholds greater than 65 dB prior to surgery.
The Relationship Among Receptive and Expressive Vocabulary, Listening Comprehension, Pre-Reading Skills, Word Identification Skills, and Reading Comprehension by Children With Reading Disabilities
Authors: Wise Justin C. , Sevcik Rose A. , Morris Robin D. , Lovett Maureen W. , Wolf Maryanne
Published: August 2007

Purpose

Some researchers (F. R. Vellutino, F. M. Scanlon, & M. S. Tanzman, 1994) have argued that the different domains comprising language (e.g., phonology, semantics, and grammar) may influence reading development in a differential manner and at different developmental periods. The purpose of this study was to examine proposed causal relationships among different linguistic subsystems and different measures of reading achievement in a group of children with reading disabilities.

Methods

Participants were 279 students in 2nd to 3rd grade who met research criteria for reading disability. Of those students, 108 were girls and 171 were boys. In terms of heritage, 135 were African and 144 were Caucasian. Measures assessing pre-reading skills, word identification, reading comprehension, and general oral language skills were administered.

Results

Structural equation modeling analyses indicated receptive and expressive vocabulary knowledge was independently related to pre-reading skills. Additionally, expressive vocabulary knowledge and listening comprehension skills were found to be independently related to word identification abilities.

Conclusion

Results are consistent with previous research indicating that oral language skills are related to reading achievement (e.g., A. Olofsson & J. Niedersoe, 1999; H. S. Scarborough, 1990). Results from this study suggest that receptive and expressive vocabulary knowledge influence pre-reading skills in differential ways. Further, results suggest that expressive vocabulary knowledge and listening comprehension skills facilitate word identification skills.
Electrical conduction model for polycrystalline GaAs films
Authors: Sharma M. K. , Joshi D. P.
Published: August 2007

An electrical conduction model for polycrystalline (PX) GaAs is presented to explain the electrical properties of this material. It is predicted that these properties cannot be explained without considering an additional rectangular potential barrier (qϕ) at the grain boundary and an additional mechanism of carrier transport (two-step tunneling process via grain boundary states) across the grain boundaries. It is demonstrated that the grain-boundary material in polycrystalline GaAs films is disordered in nature. Present computations have shown that the dependence of qϕ on doping density is very complicated and it is controlled by the processes of As clustering, and segregation of dopant as well as As atoms at the grain boundaries. It is also shown that the dopant segregation mechanism is present only in n-type PX-GaAs films, whereas it is absent in p-type samples. The dependence of carrier mobility and resistivity of this material on the doping density, temperature, and grain size has also been studied. A satisfactory agreement is observed between the theoretically computed results and available experimental data.
Numerically stable optimized effective potential method with balanced Gaussian basis sets
Authors: Heßelmann Andreas , Götz Andreas W. , Della Sala Fabio , Görling Andreas
Published: August 2007

A solution to the long-standing problem of developing numerically stable optimized effective potential (OEP) methods based on Gaussian basis sets is presented by introducing an approach consisting of an exact exchange OEP method with an accompanying construction and balancing scheme for the involved auxiliary and orbital Gaussian basis sets that is numerically stable and that properly represents an exact exchange Kohn-Sham method. The method is a purely analytical method that does not require any numerical grid, scales like Hartree-Fock or B3LYP procedures, is straightforward to implement, and is easily generalized to take into account orbital-dependent density functionals other than the exact exchange considered in this work. Thus, the presented OEP approach opens the way to the development and application of novel orbital-dependent exchange-correlation functionals. It is shown that adequately taking into account the continuum part of the Kohn-Sham orbital spectrum is crucial for numerically stable Gaussian basis set OEP methods. Moreover, it is mandatory to employ orbital basis sets that are converged with respect to the used auxiliary basis representing the exchange potential. OEP calculations in the past often did not meet the latter requirement and therefore may have led to erroneously low total energies.
Classical trajectory study of the formation of XeH+ and XeCl+ in the Xe++HCl collision
Authors: Ree J. , Kim Y. H. , Shin H. K.
Published: August 2007

The collision-induced reaction of Xe+ with HCl has been studied by use of classical dynamics procedures at collision energies 2–20eV using empirical potential parameters. The principal reaction pathway on the potential energy surface is the formation of XeH+ with the maximum reaction cross section, 1.2Å2, occurring at E=9eV. At lower energies, the cross section for the charge transfer process Xe++HCl→Xe+HCl+ is comparable to that for XeH+ formation, but at higher energies, it is larger by a factor of 2. The cross section of the XeCl+ formation is an order of magnitude smaller than that of XeH+. For both XeH+ and XeCl+ formations, the reaction threshold is ≈2eV. The XeH+ formation takes place immediately following the turning point in a direct-mode mechanism, whereas an indirect-mode mechanism operates in the formation of XeCl+. Both XeH+ and XeCl+ formations come mainly from the perpendicular configuration, Xe+⋯HCl, at the turning point. Product vibrational excitation is found to be strong in both XeH+ and XeCl+.
Density functional theory of inhomogeneous liquids. I. The liquid-vapor interface in Lennard-Jones fluids
Authors: Lutsko James F.
Published: August 2007

A simple model is proposed for the direct correlation function (DCF) for simple fluids consisting of a hard-core contribution, a simple parametrized core correction, and a mean-field tail. The model requires as input only the free energy of the homogeneous fluid, obtained, e.g., from thermodynamic perturbation theory. Comparison to the DCF obtained from simulation of a Lennard-Jones fluid shows this to be a surprisingly good approximation for a wide range of densities. The model is used to construct a density functional theory for inhomogeneous fluids which is applied to the problem of calculating the surface tension of the liquid-vapor interface. The numerical values found are in good agreement with simulation.
Polarization of light emission by 460nm GaInN∕GaN light-emitting diodes grown on (0001) oriented sapphire substrates
Authors: Schubert Martin F. , Chhajed Sameer , Kim Jong Kyu , Fred Schubert E. , Cho Jaehee
Published: August 2007

Measurements on the polarization of top- and side-emitted light as a function of direction are performed for 460nm GaInN unpackaged and packaged light-emitting diode (LED) chips with a multiquantum well (MQW) GaInN∕GaN active region grown on (0001) oriented sapphire substrates. Side emission is found to be highly polarized with the electric field in the plane of the MQW. Intensity ratios for in-plane to normal-to-plane polarization reach values as high as 7:1, while the total intensity for the in-plane polarization is more than twice as large compared to the normal-to-plane polarization. Despite these measured polarization characteristics, conventional packaged LEDs are found to be virtually unpolarized due to packaging.
Self-consistent electronic subband structure of undoped InAs/GaSb-based type II and broken-gap quantum well systems
Authors: Xu W. , Folkes P. A. , Gumbs Godfrey
Published: August 2007

Motivated by a very recent experimental work on investigating electronic properties of InAs/GaSb-based type II and broken-gap quantum well structures, in this article we present a simple and transparent theoretical approach to calculate electronic subband structure in such device systems. The theoretical model is developed on the basis of solving self-consistently the Schrödinger equation for the eigenfunctions and eigenvalues coupled with the Poisson equation for the confinement potentials, in which the effects such as charge distribution and depletion are considered. In particular, we examine the effect of a GaSb cap layer on electronic properties of the quantum well systems in conjunction with experiments and experimental findings. The results obtained from the proposed self-consistent calculation can be used to understand important experimental findings and are in line with those measured experimentally.
Dynamic scaling in ion etching of tungsten films
Authors: Peverini Luca , Ziegler Eric , Kozhevnikov Igor
Published: August 2007

Grazing incidence x-ray scattering is employed in situ and in real time to investigate quantitatively the time-dependent roughening of an ion bombarded tungsten layer. The evolution of surface morphology is analyzed in terms of power spectral density functions extracted directly from the measured scattering diagrams. In the [1×10−4,4.6×10−2]nm−1 spatial frequency range, roughness spectra for progressive thickness are shown to obey a universal scaling form leading to scaling exponents consistent with the prediction of the Kardar-Parisi-Zhang equation in 2+1 dimensions.
Suspended heated silicon platform for rapid thermal control of surface reactions with application to carbon nanotube synthesis
Authors: van Laake Lucas , Hart Anastasios John , Slocum Alexander H.
Published: August 2007

Rapid continuous thermal control of chemical reactions such as those for chemical vapor deposition (CVD) growth of nanotubes and nanowires cannot be studied using traditional reactors such as tube furnaces, which have large thermal masses. We present the design, modeling, and verification of a simple, low-cost reactor based on resistive heating of a suspended silicon platform. This system achieves slew rates exceeding 100°C∕s, enabling studies of rapid heating and thermal cycling. Moreover, the reaction surface is available for optical monitoring. A first-generation CVD apparatus encapsulates the heated silicon platform inside a sealed quartz tube, and initial experiments demonstrate growth of films of tangled single-wall and aligned multiwall carbon nanotubes using this system. The reactor can be straightforwardly scaled to larger or smaller substrate sizes and may be extended for a wide variety of reactions, for performing in situ reaction diagnostics, for chip-scale growth of nanostructures, and for rapid thermal processing of microelectronic and micromechanical devices.
Revisit to the finite element modeling of electromigration for narrow interconnects
Authors: Tan Cher Ming , Hou Yuejin , Li Wei
Published: August 2007

Electromigration (EM) is an important reliability concern in ultralarge-scale integration interconnects. A refined EM model based on a driving force approach is proposed in this work. The distribution of atomic flux divergence is computed by an finite element method to predict the void nucleation site in interconnects. It is demonstrated that the proposed model is more accurate than the conventional counterpart for narrow interconnects. The validity of the proposed model is verified through the study of the reservoir effect in EM. The predicted critical reservoir length agrees well with the reported values.
Microstructure, phase transition, and electrical properties of (K0.5Na0.5)1−xLix(Nb1−yTay)O3 lead-free piezoelectric ceramics
Authors: Lin Dunmin , Kwok K. W. , Chan H. L. W.
Published: August 2007

Lead-free ceramics (K0.5Na0.5)1−xLix(Nb1−yTay)O3 have been prepared by an ordinary sintering technique. Our results reveal that Li+ and Ta5+ diffuse into the K0.5Na0.5NbO3 lattices to form a solid solution with a perovskite structure. The substitution of Li+ induces an increase in the Curie temperature (TC) and a decrease in the ferroelectric tetragonal–ferroelectric orthorhombic phase transition temperature (TO-T). On the other hand, both TC and TO-T decrease after the substitution of Ta5+. A coexistence of the orthorhombic and tetragonal phases is formed at 0.03<x<0.06 and 0.10<y<0.25 near room temperature, leading to significant enhancements of the piezoelectric properties. For the ceramic with x=0.04 and y=0.225, the piezoelectric properties become optimum, giving a piezoelectric coefficient d33=208pC∕N, electromechanical coupling factors kP=48% and kt=49%, remanent polarization Pr=14.2μC∕cm2, coercive field Ec=1.21kV∕mm, and Curie temperature TC=320°C.
Resonant x-ray emission spectroscopy of multiferroic TbMnO3
Authors: Chen J. M. , Chen C. K. , Chou T. L. , Jarrige I. , Ishii H. , Lu K. T. , Cai Y. Q. , Liang K. S. , Lee J. M. , Huang S. W. , Yang T. J. , Shen C. C. , Liu R. S. , Lin J. Y. , Jeng H. T. , Kao C.-C.
Published: August 2007

The Mn 3d valence states in single-crystalline TbMnO3 were probed using x-ray absorption spectroscopy and resonant x-ray emission spectroscopy (RXES). The polarized Mn K-edge x-ray absorption spectra show a strong polarization dependence, particularly for the white line region, indicating the strong anisotropic Mn–O bonding within the ab plane in TbMnO3. The RXES data obtained at the Mn K edge clearly reveal that unoccupied Mn 3d states exhibit a relatively delocalized character, stemming from hybridization of the Mn 3d states with the neighboring Mn 4p orbitals. The authors demonstrated that resonant x-ray emission spectroscopy is able to characterize the degree of localization of the unoccupied states or hole carriers in manganites.
Excitonic luminescence of polycrystalline CuInS2 solar cell material under the influence of strain
Authors: Eberhardt J. , Metzner H. , Schulz K. , Reislöhner U. , Hahn Th. , Cieslak J. , Witthuhn W. , Goldhahn R. , Hudert F. , Kräußlich J.
Published: August 2007

Using molecular beams, polycrystalline CuInS2 (CIS) films were deposited on Mo-covered Si substrates. In order to investigate the influence of growth-induced strain on the optical and structural properties, detailed photoluminescence, photoreflectance and x-ray diffraction (XRD) measurements were performed. The transition energy of the free A-exciton (FXA) transition decreases with (i) decreasing thickness of the CIS layer at a constant thickness of the Mo buffer layer and (ii) increasing thickness of the Mo buffer layer at a constant CIS layer thickness. This appreciable redshift of FXA is accompanied by an increase of the energetic splittings between FXA, FXB, and FXC. When we compare theoretically predicted valence band splittings as a function of the crystal field—obtained from the calculated relative valence band energies—to our experimental values, a completely coherent picture is obtained. We also derived the structure of the conduction band as a function of crystal field, based on the theoretically expected valence band structures combined with the measured transition energies of FXA, FXB, and FXC. The XRD data show the increasing strain to occur with decreasing lattice spacings in growth direction.
High permittivity in Zr doped NiO ceramics
Authors: Chen K. , Yuan S. K. , Li P. L. , Gao F. , Liu J. , Li G. L. , Zhao A. G. , Lu X. M. , Liu J. M. , Zhu J. S.
Published: August 2007

We report on measurements of the dielectric permittivity of NiO-based ceramics doped with Zr (ZNO). Samples were prepared by the traditional solid-state reaction method. The concentration of Zr has an effect on the dielectric properties of ZNO ceramics. High permittivity values (∼104) were observed which remain almost constant from 200 K to 350 K at low frequencies. The high-dielectric-constant response of the ZNO ceramics is attributed mainly to a grain boundary (internal) barrier layer capacitance.
Method for calibrating a Rogowski coil of fast time response
Authors: Liu Rui , Wang Xinxin , Zou Xiaobing , Yuan Jianqiang , Zou Naigong , He Luya
Published: August 2007

A new method was designed for calibrating a Rogowski coil of fast time response. The method is based on the cable pulser method except that the voltage signal pick-off output was moved to a position with a distance l from the load. If 2l∕v is longer than the time duration of the forward voltage pulse uf(t), the reflected voltage pulse ur(t) could be separated from uf(t) and directly measured. Using the formula i(t)=[uf(t)−ur(t)]∕50 to calculate the primary current of the Rogowski coil, the coil could be more accurately calibrated.
Superionic PbSnF4: A giant dielectric constant material
Authors: Ahmad Mohamad M. , Yamada Koji
Published: August 2007

In this letter, the authors report on the giant dielectric constant properties in a hitherto unexplored material, the superionic conductor lead tin fluoride PbSnF4. Despite its superionic behavior, PbSnF4 is surprisingly found to exhibit extraordinary high dielectric constant (ε′∼105). ε′ is almost independent of temperature and frequency over wide ranges. The authors find that the high value of ε′ originates from an internal effect, such as internal barrier layer capacitor, rather than from a surface barrier layer capacitor formed at the electrode/sample interface.
Silver oxide Schottky contacts on n-type ZnO
Authors: Allen M. W. , Durbin S. M. , Metson J. B.
Published: August 2007

A method of fabricating highly rectifying Schottky contacts on n-type ZnO using silver oxide has been developed and used to compare diode performance on hydrothermal and melt grown, bulk, single crystals. Silver oxide diodes on hydrothermal ZnO have lower ideality factors, lower reverse current voltage dependence, higher series resistance, and larger surface-polarity related differences in barrier height, compared to those on melt ZnO. These effects are explained by the large difference in resistivity between hydrothermal and melt ZnO. Barrier heights of 1.20eV were achieved on the Zn-polar face of hydrothermal ZnO which are the highest reported for n-type ZnO.
US condensed-matter community grapples with availability of crystalline samples
Authors: Feder Toni
Published: August 2007

Crystal growing for physics measurements has fallen between the cracks in the US; without a turnaround, the country can't help but lag in the discovery of new materials and their applications.
Saturn's dynamical rings
Authors: Murray Carl D.
Published: August 2007

Gravitational interactions among the particles in Saturn's rings lead to a variety of novel structures, including propeller-like features, wavy perturbations, and co-orbital rings around embedded satellites.
Dis/Abling Spaces of Calculation: Blindness and Money in Everyday Life
Authors: Schillmeier Michael
Published: August 2007

In this paper I attempt to explore how ‘ordinary acts’ of dealing with money and with money technologies fabricate enabling and disabling—dis/abling—spaces of calculation. Rather than referring to money merely as a general symbolic medium of exchange, I highlight the materiality and the sensory practices involved in handling money and shaping the practice of sociality. Drawing on empirical material, I explicate some of the ways in which everyday practices with money are distinctively important for visually disabled people. Combining sociological and social philosophical thoughts with insights from science and technology studies, I rethink the social understanding of money and disability. I explore how (visual) dis/ability is situated in everyday practices and suggest that it can be understood neither as an individual bodily impairment nor as a socially attributed disability. Both money and blindness become visible as complex sets of calculate practices, linking bodies, material objects, and technologies with sensory practices. These practices, I conclude, draw attention to the heterogeneous fabrication of sociality and to the emerging dis/abling spaces of calculation that unfold in the course of everyday life.
Fanon and Space: Colonization, Urbanization, and Liberation from the Colonial to the Global City
Authors: Kipfer Stefan
Published: August 2007

Stimulated by recent controversies about the headscarf in France, this paper offers a fresh look at the spatial and urban dimensions of the work of Frantz Fanon. While there is widespread agreement that the work of Fanon (which preceded the so-called ‘spatial turn’ in social theory) includes powerful spatial dimensions, there is no consensus about the status of ‘space’ in Fanon's texts. Postcolonial theorists, whose reading of Fanon dominated the Anglo-American academic world until recently, have applauded the prevalence of spatial metaphors in Fanon's work as a sign for the latter's discomfort with dialectical thought and matters of historical transformation and thus as a sign for ‘third-space’ thinking. Representing a new, heterodox wave of Fanon interpretation and insisting on Fanon's Hegelian–Marxist, radical Black, and phenomenological preoccupations with liberation, other readers have detected a shift from spatial to temporal concerns in Fanon's work. While building on this latter reading of Fanon, I argue that the spatial aspects in Fanon's work are neither a function of a philosophical imperative of nonrepresentability nor in contradiction with his concerns about temporal transformation. Fanon analyzed everyday racism as an alienating spatial relation, treated colonization as spatial organization, and viewed decolonization in part as a form of reappropriating and transforming spatial relations in the colonial city and through the construction of nationwide sociospatial alliances. Fanon's complex historical-geographical perspective on everyday racism, the colonial issue, and national liberation makes it possible to link his work to Henri Lefebvre's insights into the processes by which postwar French urbanization mediated a shift from colonial war to the ‘colonization’ of everyday life in the metropole. Given the growing role of controlling urban space in the core and peripheries of our neo-imperial world, excavating an urban and spatial Fanon is promising for strategies to emphasize the urban dimensions, microaspects and macroaspects, and multiple scales of what colonization means today.
Disruption of
Plasmodium falciparum
development by antibodies against a conserved mosquito midgut antigen
Authors: Dinglasan Rhoel R. , Kalume Dario E. , Kanzok Stefan M. , Ghosh Anil K. , Muratova Olga , Pandey Akhilesh , Jacobs-Lorena Marcelo
Published: August 2007

Malaria parasites must undergo development within mosquitoes to be transmitted to a new host. Antivector transmission-blocking vaccines inhibit parasite development by preventing ookinete interaction with mosquito midgut ligands. Therefore, the discovery of novel midgut antigen targets is paramount. Jacalin (a lectin) inhibits ookinete attachment by masking glycan ligands on midgut epithelial surface glycoproteins. However, the identities of these midgut glycoproteins have remained unknown. Here we report on the molecular characterization of an
Anopheles gambiae
aminopeptidase N (AgAPN1) as the predominant jacalin target on the mosquito midgut luminal surface and provide evidence for its role in ookinete invasion. α-AgAPN1 IgG strongly inhibited both
Plasmodium berghei
and
Plasmodium falciparum
development in different mosquito species, implying that AgAPN1 has a conserved role in ookinete invasion of the midgut. Molecules targeting single midgut antigens seldom achieve complete abrogation of parasite development. However, the combined blocking activity of α-AgAPN1 IgG and an unrelated inhibitory peptide, SM1, against
P. berghei
was incomplete. We also found that SM1 can block only
P. berghei
, whereas α-AgAPN1 IgG can block both parasite species significantly. Therefore, we hypothesize that ookinetes can evade inhibition by two potent transmission-blocking molecules, presumably through the use of other ligands, and that this process further partitions murine from human parasite midgut invasion models. These results advance our understanding of malaria parasite–mosquito host interactions and guide in the design of transmission-blocking vaccines.
Quadrantic deficit reveals anatomical constraints on selection
Authors: Carlson Thomas A. , Alvarez George A. , Cavanagh Patrick
Published: August 2007

Our conscious experience is of a seamless visual world, but many of the cortical areas that underlie our capacity for vision have a fragmented or asymmetrical representation of visual space. In fact, the representation of the visual field is fragmented into quadrants at the level of V2, V3, and possibly V4. In theory, this division could have no functional consequences and therefore no impact on behavior. Contrary to this expectation, we find robust quadrant-level interference effects when attentively tracking two moving targets. Performance improves when target objects appear in separate quadrants (straddling either the horizontal or vertical meridian) compared with when they appear the same distance apart but within a single quadrant. These quadrant-level interference effects would not be predicted by cognitive theories of attention and tracking that do not take anatomical constraints into account. Quadrant-level interference strongly suggests that cortical areas containing a noncontiguous representation of the four quadrants of the visual field (i.e., V2, V3, and V4) impose an important constraint on attentional selection and attentive tracking.
Oncogenic
PIK3CA
mutations occur in epidermal nevi and seborrheic keratoses with a characteristic mutation pattern
Authors: Hafner Christian , López-Knowles Elena , Luis Nuno M. , Toll Agustí , Baselga Eulàlia , Fernández-Casado Alex , Hernández Silvia , Ribé Adriana , Mentzel Thomas , Stoehr Robert , Hofstaedter Ferdinand , Landthaler Michael , Vogt Thomas , Pujol Ramòn M. , Hartmann Arndt , Real Francisco X.
Published: August 2007

Activating mutations of the p110 α subunit of PI3K (
PIK3CA
) oncogene have been identified in a broad spectrum of malignant tumors. However, their role in benign or preneoplastic conditions is unknown. Activating FGF receptor 3 (
FGFR3
) mutations are common in benign skin lesions, either as embryonic mutations in epidermal nevi (EN) or as somatic mutations in seborrheic keratoses (SK).
FGFR3
mutations are also common in low-grade malignant bladder tumors, where they often occur in association with
PIK3CA
mutations. Therefore, we examined exons 9 and 20 of
PIK3CA
and
FGFR3
hotspot mutations in EN (
n
= 33) and SK (
n
= 62), two proliferative skin lesions lacking malignant potential. Nine of 33 (27%) EN harbored
PIK3CA
mutations; all cases showed the E545G substitution, which is uncommon in cancers. In EN, R248C was the only
FGFR3
mutation identified. By contrast, 10 of 62 (16%) SK revealed the typical cancer-associated
PIK3CA
mutations E542K, E545K, and H1047R. The same lesions displayed a wide range of
FGFR3
mutations. Corresponding unaffected tissue was available for four EN and two mutant SK: all control samples displayed a WT sequence, confirming the somatic nature of the mutations found in lesional tissue. Forty of 95 (42%) lesions showed at least one mutation in either gene.
PIK3CA
and
FGFR3
mutations displayed an independent distribution; 5/95 lesions harbored mutations in both genes. Our findings suggest that, in addition to their role in cancer, oncogenic
PIK3CA
mutations contribute to the pathogenesis of skin tumors lacking malignant potential. The remarkable genotype–phenotype correlation as observed in this study points to a distinct etiopathogenesis of the mutations in keratinocytes occuring either during fetal development or in adult life.
Modulation of NR2B-regulated contextual fear in the hippocampus by the tissue plasminogen activator system
Authors: Norris Erin H. , Strickland Sidney
Published: August 2007

Contextual fear conditioning is regulated by the hippocampus, and NR2B, a subunit of the NMDA receptor (NR), is involved in this process. We show that acute stress modulates tissue plasminogen activator (tPA) activity in the hippocampus by inducing expression of its inhibitor, plasminogen activator inhibitor-1. Acute stress increases NR2B expression and ERK1/2 phosphorylation, a classical marker of postsynaptic plasticity, in the hippocampus. tPA forms a complex with NR2B and is necessary for binding NR2B to postsynaptic density-95, allowing for NR activation and membrane anchoring. Acute stress increases the interaction between NR2B and RACK-1, which is also dependent on tPA, further suggesting that tPA is an important factor in NMDA signaling and plasticity in the hippocampus. Finally, acutely stressed tPA
−/−
mice show a decrease in contextual fear conditioning compared with stressed WT mice. These results indicate that tPA is a key modulator in stabilizing the NR complex during stress and participates in changes in behavior and synaptic plasticity.
Far Western: Labeling GST Fusion Proteins
Authors: Einarson Margret B. , Pugacheva Elena N. , Orlinick Jason R.
Published: August 2007

INTRODUCTION

A far-Western blot (also known as an overlay assay) is used to detect the interaction of a recombinant GST fusion protein (produced and purified from bacteria) with a target protein on a membrane. Three methods are generally used to detect an interaction: radioactive labeling of the fusion protein, biotinylation of the fusion protein, and detection by anti-GST antibodies. This protocol describes the radioactive labeling of GST fusion proteins using a phosphorylation site that has been integrated into the fusion protein. This is rapid, easy, and because the phosphorylation site is in the fusion portion of the protein, labeling the fusion protein generally has little impact on subsequent activity. The fusion protein consists of a GST moiety, a protease cleavage site, and the phosphorylation target site for a known kinase, which are translated in-frame with the protein of interest. The purified protein is bound to glutathione beads and is radioactively labeled with 32P using a commercially available kinase. Unincorporated nucleotides are removed from the solution by washing, and the radioactively labeled protein is cleaved with protease (e.g., factor X or thrombin) or eluted with glutathione to remove the GST moiety, which eliminates the possibility of detecting proteins bound to GST during membrane probing.
Preparing DNA from Mammalian Sources for Genotyping
Authors: Sahota Amrik , Brooks Andrew I. , Tischfield Jay A.
Published: August 2007

INTRODUCTION

The availability of high-quality DNA from a large number of individuals is a prerequisite for the success of genetic variation studies. This requirement has spurred major technological advances in DNA extraction methodologies. Twenty years ago, large-scale manual extractions took >3 d to complete. Large-scale preparations can now be completed within 3 h using automated extraction platforms, without the need for toxic reagents and often with higher yields than in the past. This article introduces methods and considerations for the extraction of DNA for genotyping, and for the determination of DNA quantity and quality.
The Arf GEF GBF1 Is Required for GGA Recruitment to Golgi Membranes
Authors: Lefrançois Stéphane , McCormick Peter J.
Published: August 2007

The lysosomal trafficking of the mannose 6‐phosphate receptor and sortilin require that the Golgi‐localized, γ‐ear‐containing, ADP ribosylation factor (Arf)‐binding proteins (GGAs) be recruited to Golgi membranes where they bind a signal in the cytosolic tail of the receptors and recruit clathrin to form trafficking vesicles. GGA recruitment to membranes requires Arf1, a protein that cycles between a GDP‐bound inactive state and GTP‐bound active state. The guanine nucleotide exchange factors (GEFs) promote the formation of Arf–GTP, while the GTPase activating proteins induce hydrolysis of GTP to GDP. We provide evidence that the GEF, GBF1, colocalizes with the GGAs and interacts with the GGAs. Depletion of GBF1 or expression of an inactive mutant prevents recruitment of the GGAs to Golgi membranes and results in the improper sorting of cargo. In summary, we show that GBF1 is required for GGA recruitment to Golgi membranes and plays a role in the proper processing and sorting of lysosomal cargo.
The Hope of France
Authors: Benenson Mira
Published: August 2007

‘We, the writers, friends, readers of “Temps Nouveau” do not pretend to consider ourselves the only or the sufficient expression of the hope of France; but we are firmly convinced that our “little flock’ is one of the armies—of the vanguards—of the reconquest and the restoration of France…

My purpose, in this article, is to say something about this ‘little flock’ with whom I was privileged to work up till the capitulation, and whose activities I have tried to follow in spite of the prison walls which to-day surround their country.

On June 18th, 1940, I was driving south towards Bayonne. A little way ahead, on a hill, a small boy-scout was directing the traffic. He beckoned us on. And as we continued down the long, straight, poplar-studded roads of the Landes, I knew that that little boy would go on with his job, and that he represented the real France—youthful in its enterprise and energy and courage, mature in its perseverance and devotion. We talked then, my friends and I, of all those other young people whom we had seen or of whom we had heard, who were directing refugees, housing and feeding people, giving information, carrying luggage, delivering post, in fact, governing—that is, doing the real work of administration—a country whose official bureaucracy and civil service had collapsed. For those who knew the French youth movements this was less a cause for surprise than for admiration : it was to have been expected that France’s Catholic Action should fulfil its magnificent promise at the moment of France’s greatest tragedy.
Charles Péguy and the Spirit of France
Authors: Bethell Ruth
Published: August 2007

Péguy’s life practically covers the stretch of years between the Franco-Prussian war and the war of 1914. He was killed at the Marne in September, 1914. They are years when the attitude of Frenchmen to the problems of nationalism underwent fundamental changes, which are reflected in Péguy’s Cahiers de la Quinzaine.

For two generations after the Franco-Prussian war, defeat and determinism worked their separate corrosions and Frenchmen knew such depression of spirit that perhaps in all history no country has fallen so low in faith in its power to carry on. Since the beginning of the nineteenth century German ideas had become increasingly popular, and it seemed to some people that all that was vital in recent thought came from Germany. Tracing the reactions of two generations of young Frenchmen to the music of Wagner is a very good way of tracing a change of attitude for which Barrès was largely responsible. He felt the fatal attraction of the Tristan music : ‘It is in vain that I am bound to the mast, like the wise Odysseus. I tear my bonds asunder, and ardent even to despair I plunge beneath the waves to seek the sirens.’ Elsewhere, he speaks of Wagner’s creations as exerting harmful influences, demoralising and brutalising’ men’s minds.
Our Separated Brethren
Authors: Nissen Benedict Momme
Published: August 2007

By the very fact of baptism men are incorporated into the one Church of Christ. A large number of Christians, it is true, do not consider themselves members of the Mother Church. Yet all those who were baptised in the name of the triune God outside the pale of the Catholic Church belong to her. Everyone wishing to baptise and doing so in the prescribed way, baptises validly, and anyone may do so in case of emergency. The Council of Trent has laid down that whoever denies that baptism, even if administered by heretics, in the name of the Father, the Son, and the Holy Ghost, with the intention of doing what the Church does, is true baptism, shall be anathema. Anyone who has been validly baptised is and remains a member of the Apostolic Church. A son does not cease to be the child of his parents though he grows up far from his home. In like manner the character of regeneration and of membership in Christ, bestowed by baptism, is not obliterated, though a man be brought up in ignorance of Mother Church, without her instruction, and without receiving her other sacraments.

It has been said that baptism gives grace to live according to the precepts of the Gospel. Our separated brethren bear witness to this fact, in as much as they faithfully adhere to the Apostolic Creed, believe in the divinity of Christ, and keep the ten commandments; devoutly pray the Our Father, and in simplicity of heart make the teaching of Scripture the foundation of their lives.
Fables and Symbols—I
Authors: Sharrock Roger
Published: August 2007

Whatever future judgments may be on our contemporary Western culture and education, we cannot be accused of denying a major, even a predominating role, to the life of the artistic imagination (though when one turns from stated aim to present practice, in primary schools and elsewhere, the position may be less satisfactory). In the last forty years philistinism has quietly died after a few rearguard actions and many whimpers; the ultimate success of the opponents of censorship in the cases over Lady Chatterley and Last Exit to Brooklyn was due in the first place to this triumphant antiphilistinism and only secondly to a climate of increasing moral permissiveness: the argument that carried the day with people of all shades of ethical opinion was that the artist could get away with it.

The high claims made for poetry and the imagination by the Romantics and their successors have led us into a position where poets and novelists have been studied in a manner formerly thought suitable for moral teachers. Arnold’s plea for a poetry of the emotions which would provide a substitute for religion was a landmark along the way. Arnold declared that ‘the strongest part of our religion today is its unconscious poetry’: the increase in the authority granted to the insights of the artist has often advanced in a ratio with the declining authority of dogmatic belief.
Chemical and Biological Warfare
Authors: Synge Ann
Published: August 2007

In the 1930s there was a considerable interest in the possibility that chemical and biological weapons might be used in the war which many people realized was impending. When such weapons were not, in fact, used in the war, public interest in their potentialities died down and the use of thermonuclear weapons diverted the attention of those who would otherwise have been concerned with chemical and biological warfare by focussing it on the urgent need to prevent any further use of these catastrophic new armaments. From time to time there have been outbursts of indignation when reports of the use of gas or microbial agents have been made public but there has been little study outside military circles of the potentialities or implications of their use. During the past year or so, however, there has been a recrudescence of public interest in the subject. There have been many reasons for this but, undoubtedly, the international conference on chemical and biological warfare held in London last February under the auspices of the J. D. Bernal Peace Library had a stimulating effect. The contributors to this conference were able to speak authoritatively on various topics connected with chemical and biological warfare as they were mostly senior scientists, some with world-wide reputations, working in related fields, or else younger people who, for one reason or another, had made a special study of some aspect of the subject. Furthermore, the conference received considerable publicity on radio and television and in the newspapers and gave rise to questions in the House of Commons which, in turn, received publicity and helped to keep public interest alive.