bluuebunny/crossref_metadata_2025 huggingface dataset:
Mouthguards: difference in longitudinal dimensional stability between single‐ and double‐laminated fabrication techniques
Authors: Miura Jiro , Maeda Yoshinobu , Machi Hiroyuki , Matsuda Shinsuke
Published: October 2006

Abstract –  Though the use of mouthguards (MGs) has increased with the increase in sporting activities, little is known about the influence of their fabrication methods on longitudinal dimensional stability. The objective of this study was to compare the difference in the longitudinal dimensional stability between single and laminated MGs. Single‐layer MGs were made from a 4.0 mm thick ethylene vinyl acetate (EVA) sheet and laminated MGs were made from two 2.0 mm thick sheets of EVA. MGs were kept in a 37°C water bath for 60 h, equivalent to the time period of 3‐months inter‐oral use. MG deformation was analyzed by measuring designated points on the MG border using a profile projector (J‐12, Nikon Inc., Tokyo, Japan) before and after the water immersion. A finite‐element model was also created to examine the time course of stress accumulation during the sheet forming process using Finite Element software. Longitudinal deformation was smaller in the laminated MGs than in the single‐layer MGs in the anterior area (P < 0.05). Finite element method (FEM) analysis also showed the largest stress accumulation in the anterior incisal area where deformations were mainly observed. Laminated double layer MGs have advantages over single‐layer MGs in terms of longitudinal stability due to lower stress accumulation during the fabrication process.
Isoquinoline‐1,3,4‐trione and its derivatives attenuate β‐amyloid‐induced apoptosis of neuronal cells
Authors: Zhang Ya‐Hui , Zhang Hua‐Jie , Wu Fang , Chen Yi‐Hua , Ma Xue‐Qin , Du Jun‐Qin , Zhou Zhong‐Liang , Li Jing‐Ya , Nan Fa‐Jun , Li Jia
Published: October 2006

Caspase‐3 is a programmed cell death protease involved in neuronal apoptosis during physiological development and under pathological conditions. It is a promising therapeutic target for treatment of neurodegenerative diseases. We reported previously that isoquinoline‐1,3,4‐trione and its derivatives inhibit caspase‐3. In this report, we validate isoquinoline‐1,3,4‐trione and its derivatives as potent, selective, irreversible, slow‐binding and pan‐caspase inhibitors. Furthermore, we show that these inhibitors attenuated apoptosis induced by β‐amyloid(25–35) in PC12 cells and primary neuronal cells.
Judicial Activism and the Origins of Parental Choice: The Court's Role in the Institutionalization of Compulsory Education in the United States, 1891–1925
Authors: Provasnik Stephen
Published: October 2006

A considerable body of scholarship has examined the history of compulsory attendance in the United States in an effort to explain why compulsory attendance laws were enacted, what effects they had on school attendance rates, and what made enforcement of these laws effective eventually. Recent research has revealed that some long-standing assumptions and conclusions about compulsory attendance warrant reconsideration. For example, the assumptions that educators promoted compulsory attendance and that compulsory attendance laws were enacted when state legislators responded to educators' demands disregard the historical reality that educators and state teachers' associations generally did not support compulsory attendance and that the biggest proponent of compulsory attendance legislation was a faction of the Republican Party. Similarly, the conventional periodization of compulsory attendance laws into two phases—“symbolic” and “bureaucratic”—obscures several facts. The conventional periodization holds that before the 1890s compulsory attendance laws were merely symbolic because the laws enacted were “unenforced and probably unenforceable.” During the bureaucratic phase, between the 1890s and 1920s, new compulsory attendance laws —“strong laws” with teeth—were passed, which finally made compulsory attendance effective. This periodization obscures the facts that (1) compulsory attendance did not develop in any linear or progressive fashion as much as in a “two steps forward, one step back” manner; (2) the state had limited power to enforce even “enforceable” compulsory attendance laws in the early twentieth century when most funding was local not state funding; and (3) compulsory attendance laws were not tremendously effective, accounting for no more than 5 percent of the increase in school attendance in the first half of the twentieth century.
WATER DEMAND AND THE URBAN POOR: A STUDY OF THE FACTORS INFLUENCING WATER CONSUMPTION AMONG HOUSEHOLDS IN CAPE TOWN, SOUTH AFRICA
Authors: Jansen Ada , Schulz Carl‐erik
Published: October 2006

Water demand management is a key focus area for most water managers and even more so in developing countries since improved access to water is important to the poor. Different policies have been introduced to ensure a water management system th at cares for the poor, among them the Increasing Block Tariff (IBT) structure. Studies demonstrate that it is very important to know the shape of the demand curve when deciding on the IBT structure. This paper adds to the understanding of the factors that influence water consumption. The focus is on how water demand patterns vary with the level of income among urban dwellers. The results support the hypothesis that pricing is an ineffective measure to manage water consumption among the poor, while it is relatively more effective for the richest group. Therefore, redistribution using water pricing policy will hardly work.
On the use of poroelastic materials for the control of the sound radiated by a cavity backed plate
Authors: Bécot François-Xavier , Sgard Franck
Published: October 2006

The purpose of this paper is to examine the potential of poroelastic materials to control the low frequency noise radiated outside a parallellepipedic cavity enclosing a point source. The enclosure consists of five rigid walls and one flexible plate, all of which may be treated with a porous slab. The Biot-Allard theory, three equivalent fluid approaches and a locally reacting assumption are used to model the porous medium. The response of the system is calculated using a finite element model for all the components. The two issues addressed are the modeling of a porous material in a complex structure and the control of the sound radiated outside the cavity. Concerning the first point, calculations confirmed the validity range of the locally reacting assumption and prove the relevance of a limp porous model for unbonded plate treatments. Regarding the second issue, the sound power reduction obtained with the treatment of nonvibrating walls is compared to that achieved when treating the plate. The efficiency of the different mounting conditions of the porous slab to the plate is also discussed. Finally, the calculation of the dissipated powers inside the system provides a crucial information to optimize the sound absorbing treatment.
Theory of sound propagation from a moving source in a three-layer Pekeris waveguide
Authors: Buckingham Michael J. , Giddens Eric M.
Published: October 2006

A theory is developed for the acoustic field in a three-layer waveguide, representing the atmosphere, shallow ocean and sediment. The unaccelerated source is moving horizontally in the atmosphere. Two solutions are presented. The first, for a line source normal to the direction of travel, is a single wavenumber integral yielding the two-dimensional (2-D) field in each layer; and the second, for a point source, is a double wavenumber integral for the 3-D field in each layer. In both cases, the moving-source dispersion relationship for the three-layer environment is derived. From the 2-D dispersion relation, asymmetries fore and aft of the source, due to source motion, are shown to exist in the field in all three layers. In the water column, complex Doppler effects modify asymmetrically the effective depth of the channel and hence also the mode shapes. Evidence of the fore-aft modal asymmetry appears in the high-resolution spectrum of the field in the channel, which exhibits several sharp peaks on either side of the unshifted frequency, each associated with an up- or downshifted mode. A numerical evaluation of the 3-D solution provides a graphic illustration of the asymmetrical character of the field in all three layers.
Effects of interaural time differences in fine structure and envelope on lateral discrimination in electric hearing
Authors: Majdak Piotr , Laback Bernhard , Baumgartner Wolf-Dieter
Published: October 2006

Bilateral cochlear implant (CI) listeners currently use stimulation strategies which encode interaural time differences (ITD) in the temporal envelope but which do not transmit ITD in the fine structure, due to the constant phase in the electric pulse train. To determine the utility of encoding ITD in the fine structure, ITD-based lateralization was investigated with four CI listeners and four normal hearing (NH) subjects listening to a simulation of electric stimulation. Lateralization discrimination was tested at different pulse rates for various combinations of independently controlled fine structure ITD and envelope ITD. Results for electric hearing show that the fine structure ITD had the strongest impact on lateralization at lower pulse rates, with significant effects for pulse rates up to 800 pulses per second. At higher pulse rates, lateralization discrimination depended solely on the envelope ITD. The data suggest that bilateral CI listeners benefit from transmitting fine structure ITD at lower pulse rates. However, there were strong interindividual differences: the better performing CI listeners performed comparably to the NH listeners.
Effects of directional microphone and adaptive multichannel noise reduction algorithm on cochlear implant performance
Authors: Chung King , Zeng Fan-Gang , Acker Kyle N.
Published: October 2006

Although cochlear implant (CI) users have enjoyed good speech recognition in quiet, they still have difficulties understanding speech in noise. We conducted three experiments to determine whether a directional microphone and an adaptive multichannel noise reduction algorithm could enhance CI performance in noise and whether Speech Transmission Index (STI) can be used to predict CI performance in various acoustic and signal processing conditions. In Experiment I, CI users listened to speech in noise processed by 4 hearing aid settings: omni-directional microphone, omni-directional microphone plus noise reduction, directional microphone, and directional microphone plus noise reduction. The directional microphone significantly improved speech recognition in noise. Both directional microphone and noise reduction algorithm improved overall preference. In Experiment II, normal hearing individuals listened to the recorded speech produced by 4- or 8-channel CI simulations. The 8-channel simulation yielded similar speech recognition results as in Experiment I, whereas the 4-channel simulation produced no significant difference among the 4 settings. In Experiment III, we examined the relationship between STIs and speech recognition. The results suggested that STI could predict actual and simulated CI speech intelligibility with acoustic degradation and the directional microphone, but not the noise reduction algorithm. Implications for intelligibility enhancement are discussed.
The ∕ problem in the Fuzzy-Logical Model of Perception
Authors: Schwartz Jean-Luc
Published: October 2006

The “Fuzzy-Logical Model of Perception” (FLMP) has often been questioned for its presumed ability to fit any data, but no clear-cut evidence has been presented yet. This paper demonstrates the ability of the FLMP to fit random data in the “McGurk region,” that is in conditions involving conflicting stimuli. This is due to the so-called “0∕0 problem,” consisting in the fact that any audio-visual response can be fitted by the FLMP if the audio and visual stimuli provide at least one null probability in each possible category. The consequence is a high instability of the root mean square error in the region of the best fit.
Acoustic roles of the laryngeal cavity in vocal tract resonance
Authors: Takemoto Hironori , Adachi Seiji , Kitamura Tatsuya , Mokhtari Parham , Honda Kiyoshi
Published: October 2006

The acoustic effects of the laryngeal cavity on the vocal tract resonance were investigated by using vocal tract area functions for the five Japanese vowels obtained from an adult male speaker. Transfer functions were examined with the laryngeal cavity eliminated from the whole vocal tract, volume velocity distribution patterns were calculated, and susceptance matching analysis was performed between the laryngeal cavity and the vocal tract excluding the laryngeal cavity (vocal tract proper). It was revealed that the laryngeal cavity generates one of the formants of the vocal tract, which is the fourth in the present study. At this formant, the resonance of the laryngeal cavity (the 1∕4 wavelength resonance) induces the open-tube resonance of the vocal tract proper (the 3∕2 wavelength resonance). At the other formants, on the other hand, the vocal tract proper acts as a closed tube, because the laryngeal cavity has only a small contribution to generating these formants and the effective closed end of the whole vocal tract is the junction between the laryngeal cavity and the vocal tract proper.
Broadband passive synthetic aperture: Experimental results
Authors: Sullivan Edmund J. , Holmes Jason D. , Carey William M. , Lynch James F.
Published: October 2006

Bearing estimation using an acoustically short towed array can be enhanced by the incorporation of a realistic signal model. By casting the problem as a joint estimation of bearing and source frequency, the bearing estimation performance, as measured by the variance of the bearing estimate, can exceed that of the conventional array processor. Experimental results based on the radiated noise of a ferry are shown. Bearing estimation results using an array of acoustic length of approximately two wavelengths are compared to results using the same data but with a conventional frequency domain beamformer. A significant improvement in performance is demonstrated.
Factors affecting masking release for speech in modulated noise for normal-hearing and hearing-impaired listeners
Authors: George Erwin L. J. , Festen Joost M. , Houtgast Tammo
Published: October 2006

The Speech Reception Threshold for sentences in stationary noise and in several amplitude-modulated noises was measured for 8 normal-hearing listeners, 29 sensorineural hearing-impaired listeners, and 16 normal-hearing listeners with simulated hearing loss. This approach makes it possible to determine whether the reduced benefit from masker modulations, as often observed for hearing-impaired listeners, is due to a loss of signal audibility, or due to suprathreshold deficits, such as reduced spectral and temporal resolution, which were measured in four separate psychophysical tasks. Results show that the reduced masking release can only partly be accounted for by reduced audibility, and that, when considering suprathreshold deficits, the normal effects associated with a raised presentation level should be taken into account. In this perspective, reduced spectral resolution does not appear to qualify as an actual suprathreshold deficit, while reduced temporal resolution does. Temporal resolution and age are shown to be the main factors governing masking release for speech in modulated noise, accounting for more than half of the intersubject variance. Their influence appears to be related to the processing of mainly the higher stimulus frequencies. Results based on calculations of the Speech Intelligibility Index in modulated noise confirm these conclusions.
Mechanisms of generation of the 2f2–f1 distortion product otoacoustic emission in humans
Authors: Wilson Hanna K. , Lutman Mark E.
Published: October 2006

The 2f1–f2 distortion product otoacoustic emission (DPOAE) is considered to consist of two components in normally hearing ears, one having constant phase with changing DP frequency (wave fixed) and one having an increasing phase lag with increasing frequency (place fixed). The aim was to identify the wave-fixed and place-fixed components of both 2f1–f2 and 2f2–f1 DPs, and, in particular, to show whether a wave-fixed 2f2–f1 DP exists in normally hearing adults. DPOAE recordings were made in 20 ears of normally hearing young adults. Four frequency ratios were used and recording entailed fixed frequency-ratio sweeps. A separation into wave-fixed and place-fixed components was carried out using a time-window separation method. A method for estimating the noise floor after data processing was developed. Results confirmed the presence of wave-fixed and place-fixed components for 2f1–f2, consistent with previous studies. Both components were also present for 2f2–f1 in virtually all subjects. This latter finding conflicts with current models of DPOAE generation, and so a modified model is proposed. Unlike the 2f1–f2 emission, which has a wave-fixed component that is strongly dependent on the frequency ratio, neither component of the 2f2–f1 emission showed such a dependence. The proposed model explains these findings in terms of the overlap of the primary frequency traveling waves.
Synchronized and noise-robust audio recordings during realtime magnetic resonance imaging scans
Authors: Bresch Erik , Nielsen Jon , Nayak Krishna , Narayanan Shrikanth
Published: October 2006

This letter describes a data acquisition setup for recording, and processing, running speech from a person in a magnetic resonance imaging (MRI) scanner. The main focus is on ensuring synchronicity between image and audio acquisition, and in obtaining good signal to noise ratio to facilitate further speech analysis and modeling. A field-programmable gate array based hardware design for synchronizing the scanner image acquisition to other external data such as audio is described. The audio setup itself features two fiber optical microphones and a noise-canceling filter. Two noise cancellation methods are described including a novel approach using a pulse sequence specific model of the gradient noise of the MRI scanner. The setup is useful for scientific speech production studies. Sample results of speech and singing data acquired and processed using the proposed method are given.
Scattering of the fundamental torsional mode by an axisymmetric layer inside a pipe
Authors: Ma J. , Simonetti F. , Lowe M. J. S.
Published: October 2006

The scattering of the fundamental guided torsional mode by a local axisymmetrical layer coated inside a pipe, referred to as a bilayered pipe, is studied. In a prescribed frequency range, the number of torsional modes which can propagate in an empty pipe is increased by the presence of the coating layer, including new cutoff frequencies that depend on the layer thickness and shear acoustic properties. This principle suggests the potential for detecting, and perhaps characterizing layers inside pipes, which may be exploited in two ways using either remote or local measurements. A remote measurement may be employed to measure the reflection from the entry point of the layer inside the pipe. Such a measurement shows that the reflection coefficient spectrum exhibits periodic maxima that occur at the cutoff frequencies of the torsional modes in the bilayered pipe. On the other hand, when the location of the coating layer is accessible, the local guided wave measurement can be made to measure the dispersion curves of the torsional modes in the bilayered pipe by applying a reassigned spectrogram analysis. The idea is investigated through theoretical analysis and finite element modeling and is validated by experimental measurements.
A prototype acoustic gas sensor based on attenuation
Authors: Petculescu Andi , Hall Brian , Fraenzle Robert , Phillips Scott , Lueptow Richard M.
Published: October 2006

Acoustic attenuation provides the potential to identify and quantify gases in a mixture. We present results for a prototype attenuation gas sensor for binary gas mixtures. Tests are performed in a pressurized test cell between 0.2 and 32atm to accommodate the main molecular relaxation processes. Attenuation measurements using the 215-kHz sensor and a multiseparation, multifrequency research system both generally match theoretical predictions for mixtures of CO2 and CH4 with 2% air. As the pressure in the test cell increases, the standard deviation of sensor measurements typically decreases as a result of the larger gas acoustic impedance.
Cross-language sensitivity to phonotactic patterns in infants
Authors: Kajikawa Sachiyo , Fais Laurel , Mugitani Ryoko , Werker Janet F. , Amano Shigeaki
Published: October 2006

This study explored sensitivity to word-level phonotactic patterns in English and Japanese monolingual infants. Infants at the ages of 6, 12, and 18months were tested on their ability to discriminate between test words using a habituation-switch experimental paradigm. All of the test words, neek, neeks, and neekusu, are phonotactically legitimate for English, whereas the first two words are critically noncanonical in Japanese. The language-specific phonotactical congruence influenced infants’ performance in discrimination. English-learning infants could discriminate between neek and neeks at the age of 18months, but Japanese infants could not. There was a similar developmental pattern for infants of both language groups for discrimination of neek and neeks, but Japanese infants showed a different trajectory from English infants for neekusu/neeks. These differences reflect the different status of these word patterns with respect to the phonotactics of both languages, and reveal early sensitivity to subtle phonotactic and language input patterns in each language.
Experimental investigation of the effects of water saturation on the acoustic admittance of sandy soils
Authors: Horoshenkov Kirill V. , Mohamed Mostafa H. A.
Published: October 2006

A novel technique for the laboratory characterization of the frequency-dependent acoustic surface admittance of partly saturated samples of sands is presented. The technique is based on a standard laboratory de-watering apparatus coupled with a standard acoustic impedance tube. The dependence of the surface admittance on the degree of water saturation is investigated for two samples of sand with widely different flow resistivities. It is shown that a relatively small change (e.g., from 0% to 11% by volume) in the degree of water saturation can result in a much larger change (e.g., twofold) in the acoustic surface admittance. An empirical relationship is found between the peaks observed in the real part of admittance spectra for the low flow resistivity sand and the degree of water saturation. The data are compared with predictions of two widely used ground impedance models: a semiempirical single parameter model and a two parameter model. A modified two-parameter version of a single-parameter model is found to give comparable fit to the two-parameter model. However, neither model provides an accurate fit.
Perception of native and non-native affricate-fricative contrasts: Cross-language tests on adults and infants
Authors: Tsao Feng-Ming , Liu Huei-Mei , Kuhl Patricia K.
Published: October 2006

Previous studies have shown improved sensitivity to native-language contrasts and reduced sensitivity to non-native phonetic contrasts when comparing 6–8 and 10–12-month-old infants. This developmental pattern is interpreted as reflecting the onset of language-specific processing around the first birthday. However, generalization of this finding is limited by the fact that studies have yielded inconsistent results and that insufficient numbers of phonetic contrasts have been tested developmentally; this is especially true for native-language phonetic contrasts. Three experiments assessed the effects of language experience on affricate-fricative contrasts in a cross-language study of English and Mandarin adults and infants. Experiment 1 showed that English-speaking adults score lower than Mandarin-speaking adults on Mandarin alveolo-palatal affricate-fricative discrimination. Experiment 2 examined developmental change in the discrimination of this contrast in English- and Mandarin-leaning infants between 6 and 12months of age. The results demonstrated that native-language performance significantly improved with age while performance on the non-native contrast decreased. Experiment 3 replicated the perceptual improvement for a native contrast: 6–8 and 10–12-month-old English-learning infants showed a performance increase at the older age. The results add to our knowledge of the developmental patterns of native and non-native phonetic perception.
Identification of PhIL1, a Novel Cytoskeletal Protein of the
Toxoplasma gondii
Pellicle, through Photosensitized Labeling with 5-[
125
I]Iodonaphthalene-1-Azide
Authors: Gilk Stacey D. , Raviv Yossef , Hu Ke , Murray John M. , Beckers Con J. M. , Ward Gary E.
Published: October 2006

The pellicle of the protozoan parasite
Toxoplasma gondii
is a unique triple bilayer structure, consisting of the plasma membrane and two tightly apposed membranes of the underlying inner membrane complex. Integral membrane proteins of the pellicle are likely to play critical roles in host cell recognition, attachment, and invasion, but few such proteins have been identified. This is in large part because the parasite surface is dominated by a family of abundant and highly immunogenic glycosylphosphatidylinositol (GPI)-anchored proteins, which has made the identification of non-GPI-linked proteins difficult. To identify such proteins, we have developed a radiolabeling approach using the hydrophobic, photoactivatable compound 5-[
125
I]iodonaphthalene-1-azide (INA). INA can be activated by photosensitizing fluorochromes; by restricting these fluorochromes to the pellicle, [
125
I]INA labeling will selectively target non-GPI-anchored membrane-embedded proteins of the pellicle. We demonstrate here that three known membrane proteins of the pellicle can indeed be labeled by photosensitization with INA. In addition, this approach has identified a novel 22-kDa protein, named PhIL1 (
ph
otosensitized
I
NA-
l
abeled protein
1
), with unexpected properties. While the INA labeling of PhIL1 is consistent with an integral membrane protein, the protein has neither a transmembrane domain nor predicted sites of lipid modification. PhIL1 is conserved in apicomplexan parasites and localizes to the parasite periphery, concentrated at the apical end just basal to the conoid. Detergent extraction and immunolocalization data suggest that PhIL1 associates with the parasite cytoskeleton.
Transcriptome Analysis of
Aspergillus nidulans
Exposed to Camptothecin-Induced DNA Damage
Authors: Malavazi Iran , Savoldi Marcela , Di Mauro Sônia Marli Zingaretti , Menck Carlos Frederico Martins , Harris Steven D. , Goldman Maria Helena de Souza , Goldman Gustavo Henrique
Published: October 2006

We have used an
Aspergillus nidulans
macroarray carrying sequences of 2,787 genes from this fungus to monitor gene expression of both wild-type and
uvsB
ATR
(the homologue of the ATR gene) deletion mutant strains in a time course exposure to camptothecin (CPT). The results revealed a total of 1,512 and 1,700 genes in the wild-type and
uvsB
ATR
deletion mutant strains that displayed a statistically significant difference at at least one experimental time point. We characterized six genes that have increased mRNA expression in the presence of CPT in the wild-type strain relative to the
uvsB
ATR
mutant strain:
fhdA
(encoding a forkhead-associated domain protein),
tprA
(encoding a hypothetical protein that contains a tetratrico peptide repeat),
mshA
(encoding a MutS homologue involved in mismatch repair),
phbA
(encoding a prohibitin homologue),
uvsC
RAD51
(the homologue of the RAD51 gene), and
cshA
(encoding a homologue of the excision repair protein ERCC-6 [Cockayne's syndrome protein]). The induced transcript levels of these genes in the presence of CPT require
uvsB
ATR
. These genes were deleted, and surprisingly, only the
ΔuvsC
mutant strain was sensitive to CPT; however, the others displayed sensitivity to a range of DNA-damaging and oxidative stress agents. These results indicate that the selected genes when inactivated display very complex and heterogeneous sensitivity behavior during growth in the presence of agents that directly or indirectly cause DNA damage. Moreover, with the exception of UvsC, deletion of each of these genes partially suppressed the sensitivity of the
ΔuvsB
strain to menadione and paraquat. Our results provide the first insight into the overall complexity of the response to DNA damage in filamentous fungi and suggest that multiple pathways may act in parallel to mediate DNA repair.
Upstream and Downstream Regulation of Asexual Development in
Aspergillus fumigatus
Authors: Mah Jae-Hyung , Yu Jae-Hyuk
Published: October 2006

The opportunistic human pathogen
Aspergillus fumigatus
produces a large quantity of asexual spores (conidia), which are the primary agent causing invasive aspergillosis in immunocompromised patients. We investigated the mechanisms controlling asexual sporulation (conidiation) in
A. fumigatus
via examining functions of four key regulators, GpaA (Gα), AfFlbA (RGS), AfFluG, and AfBrlA, previously studied in
Aspergillus nidulans
. Expression analyses of
gpaA
, Af
flbA
, Af
fluG
, Af
brlA
, and Af
wetA
throughout the life cycle of
A. fumigatus
revealed that, while transcripts of Af
flbA
and Af
fluG
accumulate constantly, the latter two downstream developmental regulators are specifically expressed during conidiation. Both loss-of-function Af
flbA
and dominant activating GpaA
Q204L
mutations resulted in reduced conidiation with increased hyphal proliferation, indicating that GpaA signaling activates vegetative growth while inhibiting conidiation. As GpaA is the primary target of AfFlbA, the dominant interfering GpaA
G203R
mutation suppressed reduced conidiation caused by loss of Af
flbA
function. These results corroborate the hypothesis that functions of G proteins and RGSs are conserved in aspergilli. We then examined functions of the two major developmental activators AfFluG and AfBrlA. While deletion of Af
brlA
eliminated conidiation completely, null mutation of Af
fluG
did not cause severe alterations in
A. fumigatus
sporulation in air-exposed culture, implying that, whereas the two aspergilli may have a common key downstream developmental activator, upstream mechanisms activating
brlA
may be distinct. Finally, both Af
fluG
and Af
flbA
mutants showed reduced conidiation and delayed expression of Af
brlA
in synchronized developmental induction, indicating that these upstream regulators contribute to the proper progression of conidiation.
A Peroxisomal Glutathione Transferase of
Saccharomyces cerevisiae
Is Functionally Related to Sulfur Amino Acid Metabolism
Authors: Barreto Lina , Garcerá Ana , Jansson Kristina , Sunnerhagen Per , Herrero Enrique
Published: October 2006

Saccharomyces cerevisiae
cells contain three omega-class glutathione transferases with glutaredoxin activity (Gto1, Gto2, and Gto3), in addition to two glutathione transferases (Gtt1 and Gtt2) not classifiable into standard classes. Gto1 is located at the peroxisomes, where it is targeted through a PTS1-type sequence, whereas Gto2 and Gto3 are in the cytosol. Among the
GTO
genes,
GTO2
shows the strongest induction of expression by agents such as diamide, 1-chloro-2,4-dinitrobenzene,
tert
-butyl hydroperoxide or cadmium, in a manner that is dependent on transcriptional factors Yap1 and/or Msn2/4. Diamide and 1-chloro-2,4-dinitrobenzene (causing depletion of reduced glutathione) also induce expression of
GTO1
over basal levels. Phenotypic analyses with single and multiple mutants in the
S. cerevisiae
glutathione transferase genes show that, in the absence of Gto1 and the two Gtt proteins, cells display increased sensitivity to cadmium. A
gto1
-null mutant also shows growth defects on oleic acid-based medium, which is indicative of abnormal peroxisomal functions, and altered expression of genes related to sulfur amino acid metabolism. As a consequence, growth of the
gto1
mutant is delayed in growth medium without lysine, serine, or threonine, and the mutant cells have low levels of reduced glutathione. The role of Gto1 at the
S. cerevisiae
peroxisomes could be related to the redox regulation of the Str3 cystathionine β-lyase protein. This protein is also located at the peroxisomes in
S. cerevisiae
, where it is involved in transulfuration of cysteine into homocysteine, and requires a conserved cysteine residue for its biological activity.
RacG Regulates Morphology, Phagocytosis, and Chemotaxis
Authors: Somesh Baggavalli P. , Vlahou Georgia , Iijima Miho , Insall Robert H. , Devreotes Peter , Rivero Francisco
Published: October 2006

RacG
is an unusual member of the complex family of Rho GTPases in
Dictyostelium
. We have generated a knockout (KO) strain, as
well as strains that overexpress wild-type (WT), constitutively active
(V12), or dominant negative (N17) RacG. The protein is targeted to the
plasma membrane, apparently in a nucleotide-dependent manner, and
induces the formation of abundant actin-driven filopods. RacG is
enriched at the rim of the progressing phagocytic cup, and
overexpression of RacG-WT or RacG-V12 induced an increased rate of
particle uptake. The positive effect of RacG on phagocytosis was
abolished in the presence of 50 μM LY294002, a phosphoinositide
3-kinase inhibitor, indicating that generation of phosphatidylinositol
3,4,5-trisphosphate is required for activation of RacG. RacG-KO cells
showed a moderate chemotaxis defect that was stronger in the RacG-V12
and RacG-N17 mutants, in part because of interference with signaling
through Rac1. The in vivo effects of RacG-V12 could not be reproduced
by a mutant lacking the Rho insert region, indicating that this region
is essential for interaction with downstream components. Processes like
growth, pinocytosis, exocytosis, cytokinesis, and development were
unaffected in Rac-KO cells and in the overexpressor mutants. In a
cell-free system, RacG induced actin polymerization upon GTPγS
stimulation, and this response could be blocked by an Arp3 antibody.
While the mild phenotype of RacG-KO cells indicates some overlap with
one or more
Dictyostelium
Rho GTPases, like Rac1 and RacB, the
significant changes found in overexpressors show that RacG plays
important roles. We hypothesize that RacG interacts with a subset of
effectors, in particular those concerned with shape, motility, and
phagocytosis.
TOS9 Regulates White-Opaque Switching in
Candida
albicans
Authors: Srikantha Thyagarajan , Borneman Anthony R. , Daniels Karla J. , Pujol Claude , Wu Wei , Seringhaus Michael R. , Gerstein Mark , Yi Song , Snyder Michael , Soll David R.
Published: October 2006

In
Candida albicans
, the
a
1-α2 complex
represses white-opaque switching, as well as mating. Based upon the
assumption that the
a
1-α2 corepressor complex binds to
the gene that regulates white-opaque switching, a chromatinimmunoprecipitation-microarray analysis strategy was used to identify
52 genes that bound to the complex. One of these genes,
TOS9
,
exhibited an expression pattern consistent with a “master
switch gene.”
TOS9
was only expressed in opaque cells,
and its gene product, Tos9p, localized to the nucleus. Deletion of the
gene blocked cells in the white phase, misexpression in the white phase
caused stable mass conversion of cells to the opaque state, and
misexpression blocked temperature-induced mass conversion from the
opaque state to the white state. A model was developed for the
regulation of spontaneous switching between the opaque state and the
white state that includes stochastic changes of Tos9p levels above and
below a threshold that induce changes in the chromatin state of an
as-yet-unidentified switching locus.
TOS9
has also been
referred to as
EAP2
and
WOR1
.
LIMITATIONS OF GADOLINIUM ALLOYS IN CANCER TREATMENT AND RADIATION SHIELDING
Authors: MAQBOOL MUHAMMAD , AHMAD IFTIKHAR
Published: October 2006

Characteristic emission from gadolinium-doped amorphous aluminum nitride thin films deposited on Si (111) substrate are studied, with cathodoluminescence and photoluminescence, for their suitability as tissue compensators in radiation treatment planning. These films are deposited by reactive sputtering at liquid nitrogen temperature, using 100–200 W rf power, 5–8 mTorr nitrogen, and a metal target of aluminum and gadolinium. Thermal annealing was performed at a temperature of 900°C. A sharp ultraviolet peak is observed at 314 nm, corresponding to 6 P 7/2 → 8 S 7/2 transition. The ultraviolet emission is intense enough to harm human tissues if it is used as a tissue compensator. Thermal annealing further enhances the intensity of ultraviolet emission, indicating that its longer use as tissue compensator will provide more harm and damage to the human body.
Mitochondrial Oxidative Stress: Implications for Cell Death
Authors: Orrenius Sten , Gogvadze Vladimir , Zhivotovsky Boris
Published: October 2006

In addition to the established role of the mitochondria in energy metabolism, regulation of cell death has emerged as a second major function of these organelles. This seems to be intimately linked to their generation of reactive oxygen species (ROS), which have been implicated in mtDNA mutations, aging, and cell death. Mitochondrial regulation of apoptosis occurs by mechanisms, which have been conserved through evolution. Thus, many lethal agents target the mitochondria and cause release of cytochrome c and other pro-apoptotic proteins into the cytoplasm. Cytochrome c release is initiated by the dissociation of the hemoprotein from its binding to the inner mitochondrial membrane. Oxidation of cardiolipin reduces cytochrome c binding and increases the level of soluble cytochrome c in the intermembrane space. Subsequent release of the hemoprotein occurs by pore formation mediated by pro-apoptotic Bcl-2 family proteins, or by Ca2+and ROS-triggered mitochondrial permeability transition, although the latter pathway might be more closely associated with necrosis. Taken together, these findings have placed the mitochondria in the focus of current cell death research.
Differentiation of the Gastric Mucosa II. Role of gastrin in gastric epithelial cell proliferation and maturation
Authors: Jain Renu N. , Samuelson Linda C.
Published: October 2006

Gastrin is the principal hormonal inducer of gastric acid secretion. The cellular targets for gastrin in the stomach are the acid-secreting parietal cell and histamine-producing enterochromaffin-like (ECL) cell. Gastrin is also a growth factor, with hypergastrinemia resulting in increased proliferation of gastric progenitor cells and a thickened mucosa. This review presents insights into gastrin function revealed by genetically engineered mouse models, demonstrating a new role for gastrin in the maturation of parietal and ECL cells. Thus, gastrin regulates many aspects of gastric physiology, with tight regulation of gastrin levels required to maintain balanced growth and function of gastric epithelial cells.
Paralongidorus sacchari Siddiqi, Hooper & Khan, 1963 and Paraxiphidorus michelluci Coomans & Chaves, 1995 (Nematoda: Longidoridae) from Chile
Authors: Rios Alejandra , Roca Francesco
Published: October 2006

Specimens from soil samples collected at Cocalan, Chile, from the rhizosphere of the Chilean wine palm, Jubaea chilensis, were sent to the Plant Protection Institute, Bari, Italy. The identification revealed the presence of large numbers of Paralongidorus sacchari and a few specimens of Paraxiphidorus michelluci, including several juveniles. Populations were studied morphologically and morphometrically and results are reported herein. Both species represent new records for Chile. Juveniles of Paraxiphidorus michelluci are described for the first time.
Spatial and temporal distribution of Heterorhabditis indica in their natural habitats of Guadeloupe
Authors: Briand Sophie , Denon Dominique , Mauléon Hervé
Published: October 2006

The presence of Heterorhabditis indica in the littoral zone of continental Guadeloupe was assessed by the Galleria trap technique. A total of 309 samples from 192 sampling sites were analysed. Heterorhabditis indica was found in 74 samples from 53 sites (45 beaches and eight limestone cliffs). The ecological characteristics of these places (climate, soil, flora and fauna) were described and the arthropods occupying these locations were tested for their ability to support nematode development. The spatial distribution of H. indica showed that the colonisation of these sites by nematodes is due to a permanent occurrence of patches generally found under the canopy of trees. An annual monitoring (performed in the wet season from 1996-2005) showed that these patches were regularly recovered (10 consecutive years). The population dynamics of H. indica was studied monthly in two sites for 28 months. In both sites, the abundance of nematodes was directly correlated to rainfall. In the dry season, when the soil moisture was lower than 3.5%, nematodes were not detected by the insect traps. The infective juveniles can survive about 6-7 months in such an environment. Field experiments with sterilised soil showed that nematode-free soil is normally recolonised by active migration but recolonisation can also occur when this route is excluded, indicating either infected insects or passive transport (human or animal) as alternative routes.
Managing incidents of work-family conflict: A decision-making perspective
Authors: Powell Gary N. , Greenhaus Jeffrey H.
Published: October 2006

The present study proposed a decision process that people follow in incidents of work-family conflict and offered an initial test of factors that may influence their decisions. It distinguished between decisions regarding the mobilization of social support to avoid conflict and decisions regarding participation in a work and/or family activity if the conflict was not avoided. According to analyses of critical incidents provided by managers and professionals employed in full-time jobs, decisions were influenced by internal cues reflecting the individual’s priorities in the conflict situation, role sender cues reflecting the priorities of involved parties in the individual’s work and family roles, and role activity cues reflecting characteristics of the specific activities in conflict. Moreover, our findings suggest that the utilization of these cues often represents an attempt to preserve positive relationships with important role senders in the work and family domains.
Childhood Physical and Emotional Abuse by a Parent: Transference Effects in Adult Interpersonal Relations
Authors: Berenson Kathy R. , Andersen Susan M.
Published: October 2006

Extending research on transference and the relational self (Andersen & Chen, 2002), female undergraduates with or without a history of physical and emotional abuse by a loved parent participated in an experiment manipulating parental resemblance and threat-relevant interpersonal context in a new person. Transference elicited differences not evident in the control condition between abused and nonabused participants’ responses, with greater rejection expectancy, mistrust, dislike, and emotional indifference reported by abused participants. Immediate implicit affect was more positive in transference than in the control condition regardless of abuse history. Yet, abused participants in transference also reported increased dysphoria that was markedly attenuated when interpersonal threat was primed, and no such pattern occurred among nonabused participants. Evidence that interpersonally guarded and affectively complex responses are triggered in transference among previously abused individuals suggests that this social-cognitive process may underlie long-term interpersonal difficulties associated with parental abuse.
Bolstering Implementation Plans for the Long Haul: The Benefits of Simultaneously Boosting Self-Concordance or Self-Efficacy
Authors: Koestner Richard , Horberg E. J. , Gaudreau Patrick , Powers Theodore , Di Dio Pasqualina , Bryan Christopher , Jochum Ruth , Salter Nicholas
Published: October 2006

Recent studies suggest that implementation planning exercises may not be as helpful for long-term, self-initiated goals as for short-term, assigned goals. Two studies used the personal goal paradigm to explore the impact of implementation plans on goal progress over time. Study 1 examined whether administering implementation plans in an autonomy supportive manner would facilitate goal progress relative to a neutral, control condition and a condition in which implementation plans were administered in a controlling manner. Study 2 examined whether combining implementation plans with a self-efficacy boosting exercise would facilitate goal progress relative to a neutral, control condition and a typical implementation condition. The results showed that implementation plans alone did not result in greater goal progress than a neutral condition but that the combination of implementation plans with either autonomy support or self-efficacy boosting resulted in significantly greater goal progress.
The Role of Perceived Similarity in Supportive Responses to Victims of Negative Life Events
Authors: Westmaas J. Lee , Silver Roxane Cohen
Published: October 2006

The authors examined whether participants’ perceived similarity to an ostensible victim of a negative life event influenced their supportiveness during a live interaction. Two competing models were considered: (a) increased similarity would be associated with increased supportiveness through attraction to the target and (b) increased similarity would be associated with decreased supportiveness through anxiety (due to heightened vulnerability). Participants (N = 241) met individually with a confederate posing as a cancer patient. Reactions were assessed, including verbal and nonverbal behaviors, both before and after the interaction, by participants themselves and by observers of the interaction. Results supported a model based on the classic similarity/attraction paradigm: Perceived similarity indirectly predicted participant-reported supportiveness/warmth and smiling through its relationship to attraction. Results extend the literature on similarity and attraction to the stress and coping arena and suggest that emphasizing perceived similarities to victims would be beneficial.
The European Union's Strategy towards the Western Balkans: Exclusion or Integration?
Authors: Türkes Mustafa , Gökgöz Göksu
Published: October 2006

This article analyzes the European Union’s strategy towards the Western Balkans as a hegemonic project. The European Commission’s strategy is neither total exclusion nor rapid integration. The Commission’s aim is to restructure the Western Balkans in line with neoliberalism to prepare the region for the “preincorporation stage.” The Commission’s major initiatives show that this neoliberal restructuring need not end in full membership but remains an open-ended process. Two components of the Commission’s formula, neoliberal economy and democracy, have not fed one another; rather, the opposite has occurred. Local crises have exacerbated and been exacerbated by the Commission’s strategy, whereby existing social forces and structures have been dismantled, leading to the reproduction of authoritarianism. Despite the continuously shifting hegemonic discourses of ethnopolitical groups, their ultimate objective is integration with the EU. However, cycles of crises in the region have, in neo-Gramscian terms, undermined the formation of a historic bloc, and thus the EU’s hegemonic project is rather daunting.