bluuebunny/crossref_metadata_2025 huggingface dataset:
Association between dense CADM1 promoter methylation and reduced protein expression in high‐grade CIN and cervical SCC
Authors: Overmeer RM , Henken FE , Snijders PJF , Claassen‐Kramer D , Berkhof J , Helmerhorst TJM , Heideman DAM , Wilting SM , Murakami Y , Ito A , Meijer CJLM , Steenbergen RDM
Published: April 2008

We previously showed that silencing of TSLC1, recently renamed CADM1, is functionally involved in high‐risk HPV‐mediated cervical carcinogenesis. CADM1 silencing often results from promoter methylation. Here, we determined the extent of CADM1 promoter methylation in cervical (pre)malignant lesions and its relation to anchorage‐independent growth and gene silencing to select a CADM1‐based methylation marker for identification of women at risk of cervical cancer. Methylation‐specific PCRs targeting three regions within the CADM1 promoter were performed on high‐risk HPV‐containing cell lines, PBMCs, normal cervical smears, and (pre)malignant lesions. CADM1 protein expression in cervical tissues was analysed by immunohistochemistry. All statistical tests were two‐sided. Density of methylation was associated with the degree of anchorage‐independent growth and CADM1 gene silencing in vitro. In cervical squamous lesions, methylation frequency and density increased with severity of disease. Dense methylation (defined as ≥ 2 methylated regions) increased from 5% in normal cervical samples to 30% in CIN3 lesions and 83% in squamous cell carcinomas (SCCs) and was significantly associated with decreased CADM1 protein expression (p < 0.00005). The frequency of dense methylation was significantly higher in ≥ CIN3 compared with ≤ CIN1 (p = 0.005), as well as in SCCs compared with adenocarcinomas (83% versus 23%; p = 0.002). Detection of dense CADM1 promoter methylation will contribute to the assembly of a valuable marker panel for the triage of high‐risk HPV‐positive women at risk of ≥ CIN3. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Chronic wound state exacerbated by oxidative stress in Pax6+/− aniridia‐related keratopathy
Authors: Ou J , Walczysko P , Kucerova R , Rajnicek AM , McCaig CD , Zhao M , Collinson JM
Published: April 2008

Heterozygosity for the transcription factor PAX6 causes eye disease in humans, characterized by corneal opacity. The molecular aetiology of such disease was investigated using a Pax6+/− mouse model. We found that the barrier function of uninjured Pax6+/− corneas was compromised and that Ca2+–PKC/PLC–ERK/p38 signalling pathways were abnormally activated, mimicking a ‘wounded’ epithelial state. Using proteomic analysis and direct assay for oxidized proteins, Pax6+/− corneas were found to be susceptible to oxidative stress and they exhibited a wound‐healing delay which could be rescued by providing reducing agents such as glutathione. Pax6 protein was oxidized and excluded from the nucleus of stressed corneal epithelial cells, with concomitant loss of corneal epithelial markers and expression of fibroblast/myofibroblast markers. We suggest a chronic wound model for Pax6‐related corneal diseases, in which oxidative stress underlies a positive feedback mechanism by depleting nuclear Pax6, delaying wound healing, and activating cell signalling pathways that lead to metaplasia of the corneal epithelium. The study mechanistically links a relatively minor dosage deficiency of a transcription factor with potentially catastrophic degenerative corneal disease. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Peripherally inserted central venous catheters are a good option for prolonged venous access in children with cancer
Authors: Abedin Sarfraz , Kapoor Gauri
Published: April 2008

Background

A long term venous access device is essential in children with malignancies for the safe administration of medication and to avoid repeated painful venipunctures. The advantage of peripherally inserted central venous catheters (PICC) over conventional central venous catheter (CVC) is easy bedside insertion without need for general anesthesia and theatre time. The purpose of this study was to evaluate our experience with PICCs particularly with regard to catheter life, reason for removal and complications in children suffering from various malignancies.

Procedure

A retrospective analysis of all PICCs inserted in children with cancer was done with regard to the demographic data, catheter life, reason for removal, and complications. The latter two were evaluated in association with patient age, catheter days, and year of insertion.

Results

Of 127 catheters inserted in 127 children, median catheter life was 161 days with a total of 18,955 catheter days (for 124 patients, 3 lost to follow‐up). Elective removal occurred in 63/101 (62.4%) PICCs and removal due to complications resulted in a complication rate of 2.41 per 1,000 catheter days. The common reasons for catheter removal were suspected infection, breakage/leakage, dislodgement, phlebitis, and occlusion with rates of 1.27, 0.57, 0.31, 0.06, and 0.06 per 1,000 catheter days, respectively.

Conclusion

We found PICC to be a convenient, cheap, safe, and reliable device for long term intravenous access in children with malignancies. This was possible with the help of dedicated catheter care nurses. Pediatr Blood Cancer 2008;51:251–255. © 2008 Wiley‐Liss, Inc.
Familial hemophagocytic lymphohistiocytosis in two brothers with X‐linked agammaglobulinemia
Authors: Schultz Kris Ann P. , Neglia Joseph P. , Smith Angela R. , Ochs Hans D. , Torgerson Troy R. , Kumar Ashish
Published: April 2008

Hemophagocytic lymphohistiocytosis (HLH) is often familial and is associated with high mortality. Primary (familial) HLH is known to occur in children with mutations in perforin, Munc13‐4, or syntaxin 11. We describe a case series of two brothers who developed HLH in the setting of X‐linked agammaglobulinemia (XLA, Bruton's disease) and adenovirus infection. Further studies revealed absence of Bruton's tyrosine kinase (BTK) protein expression and a novel BTK mutation. Pediatr Blood Cancer 2008;51:293–295. © 2008 Wiley‐Liss, Inc.
Neuropsychological outcome following intensity‐modulated radiation therapy for pediatric medulloblastoma
Authors: Jain Neelam , Krull Kevin R. , Brouwers Pim , Chintagumpala Murali M. , Woo Shiao Y.
Published: April 2008

Background

Combined cisplatin chemotherapy and cranial irradiation for treatment of medulloblastoma in children can cause significant ototoxicity and impair cognitive function and quality of life. We have previously demonstrated the conformal technique of intensity‐modulated radiation therapy (IMRT) to reduce ototoxicity, however, it has been suggested that IMRT may increase risk of cognitive deficits compared to conventional radiation therapy (CRT). This study compared the impact of the two treatments on measures of neurocognitive functioning.

Procedure

Twenty‐five pediatric patients with medulloblastoma were treated either with CRT or IMRT. In addition they received neurocognitive assessments to evaluate long‐term functional outcome. Statistical analyses between the two groups were conducted to compare levels and profiles of performance on tests not confounded with hearing loss.

Results

When compared to CRT, children treated with IMRT did not perform more poorly on any of the measures. Both groups' mean performance was significantly lower than published norms on several of the measures employed.

Conclusion

The benefit of reduced ototoxicity with IMRT does not appear to be at the cost of a decline in nonverbal intellectual abilities, visual‐spatial skills, processing speed, or fine motor dexterity when compared to CRT in children with medulloblastoma. Pediatr Blood Cancer 2008;51:275–279. © 2008 Wiley‐Liss, Inc.
Effect of electron beam irradiation on physico–mechanical properties of wood flour–polyethylene composites
Authors: Younes M.M. , Abdel‐Rahman H.A. , Orabi W. , Ismail M.R.
Published: April 2008

Agricultural lignocellulosic fiber (wood flour)‐waste was used to prepare composite materials through partial replacement of wood flour with low density polyethylene powder (LDPE) ranged from 10 to 20% by weight; these composites were made with and without electron beam irradiation (EB). The results obtained showed that, flexural strength, modulus of elasticity, modulus of rupture, and impact strength increase with increasing content of LDPE up to 20%. While, the percentages of thickness swelling and water absorption are decreased directly with increasing content of LDPE. Furthermore, the EB irradiation improves the physico‐mechanical properties of composite materials from 10 to 50 kGy. The results obtained are also confirmed by scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Preparation and shear properties of carbon nanotubes/poly(butyl methacrylate) hybrid material
Authors: Li Wen‐Hua , Chen Xiao‐Hua , Chen Chuan‐Sheng , Xu Long‐Shan , Yang Zhi , Wang Yan‐Guo
Published: April 2008

Composites containing carbon nanotubes (CNTs) in a poly(butyl methacrylate) (PBMA) have been prepared by in situ polymerization. Scanning electron microscopy and high‐resolution transmission electron microscope showed that CNTs were well dispersed into PBMA matrix and wrapped with PBMA. The infrared spectrum illustrated that CNTs were covalently linked with PBMA through a CC bond. Owing to this covalent linkage, the composites had a better solubility in organic solvents and had higher thermal stability over pure PBMA. The direct shear testing showed strong mechanical behavior with up to 200% increase in Young's modulus. The possible strengthening mechanism was discussed. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
The influence of matrix viscosity and composition on the morphology, rheology, and mechanical properties of thermoplastic elastomer nanocomposites based on EPDM/PP
Authors: Naderi Ghasem , Lafleur Pierre G. , Dubois Charles
Published: April 2008

The morphological and rheological properties of thermoplastic elastomer nanocomposites (TPE nanocomposites) were studied using different viscosities of polypropylene (PP) and ethylene‐propylene‐diene monomer (EPDM) rubber content (20, 40, 60 wt%). The components, namely EPDM, PP, Cloisite 15A, and maleic anhydride‐modified PP as compatibilizer, were compounded by a one‐step melt mixing process in a laboratory internal mixer. The structure of the nanocomposites was characterized with X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and rheometry in small amplitude oscillatory shear. The distribution state of the clay between the two phases (PP and EPDM) was found to be dependent on the viscosity ratio of PP to EPDM. In the nanocomposites prepared based on low viscosity PP (LVP) and EPDM, the clay was mostly dispersed into the PP phase and the size of the dispersed rubber particles decreased in comparison with unfilled but otherwise similar blends. However, the dispersed elastomer droplet size in the high viscosity PP (HVP) blends containing 40 and 60% EPDM increased with the introduction of the clay. For TPE nanocomposites, the dependence of the storage modulus (G′) on angular frequency (ω) followed a clear nonterminal behavior. The increase in the storage modulus and the decrease in the terminal zone slope of the elastic modulus curve were found to be larger in the LVP nanocomposite in comparison with the HVP sample. The yield stress of nanoclay‐filled blends prepared with LVP increased more than that of HVP samples. The tensile modulus improved for all nanocomposites but a higher percentage of increase was observed in the case of LVP samples. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Effect of bifunctional modifiers of the clay on the morphology of novolac cured epoxy resin/clay nanocomposites
Authors: Tsai Tsung‐Yen , Lu Shau‐Tai , Li Chih‐Hung , Huang Chin‐Jei , Liu Jia‐Xiang , Chen Li‐Chun
Published: April 2008

Montmorillonite type clay, (PK‐802) is modified by the bifunctional modifiers (2‐phenylimidazole/benzalkonium chloride, PI/BEN or 2‐methylimidazole/benzalkonium chloride, MI/BEN) with different ratio, which contain a curing agent, BEN, and the promoters/accelerator (PI and MI). These two modifying agents are simultaneously intercalated into the gallery space of pure PK‐802. The novolac cured epoxy nanocomposites are prepared with this modified clay by crosslinking polymerization reaction. Wide‐angle X‐ray diffraction is used to measure the resulting d‐spacing of modified PK‐802 and the nanocomposites. Thermo‐gravimetric analysis is used to characterize the thermal properties of the nanocomposites. The morphology of the nanocomposites is investigated using transmission electron microscopy techniques. Well dispersion of clay into the novolac cured epoxy‐clay nanocomposites resulted when simultaneously both the modifying agents with 5:5 mole ratios are used to modify the clay instead of using single modified agent. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Identification of key climatic factors regulating the transport of pesticides in leaching and to tile drains
Authors: Nolan Bernard T , Dubus Igor G , Surdyk Nicolas , Fowler Hayley J , Burton Aidan , Hollis John M , Reichenberger Stefan , Jarvis Nicholas J
Published: April 2008

BACKGROUND: Key climatic factors influencing the transport of pesticides to drains and to depth were identified. Climatic characteristics such as the timing of rainfall in relation to pesticide application may be more critical than average annual temperature and rainfall. The fate of three pesticides was simulated in nine contrasting soil types for two seasons, five application dates and six synthetic weather data series using the MACRO model, and predicted cumulative pesticide loads were analysed using statistical methods.

RESULTS: Classification trees and Pearson correlations indicated that simulated losses in excess of 75th percentile values (0.046 mg m−2 for leaching, 0.042 mg m−2 for drainage) generally occurred with large rainfall events following autumn application on clay soils, for both leaching and drainage scenarios. The amount and timing of winter rainfall were important factors, whatever the application period, and these interacted strongly with soil texture and pesticide mobility and persistence. Winter rainfall primarily influenced losses of less mobile and more persistent compounds, while short‐term rainfall and temperature controlled leaching of the more mobile pesticides.

CONCLUSIONS: Numerous climatic characteristics influenced pesticide loss, including the amount of precipitation as well as the timing of rainfall and extreme events in relation to application date. Information regarding the relative influence of the climatic characteristics evaluated here can support the development of a climatic zonation for European‐scale risk assessment for pesticide fate. Copyright © 2008 Society of Chemical Industry
Application timing and efficacy of alternatives for the insecticidal control of Tipula paludosa Meigen (Diptera: Tipulidae), a new invasive pest of turf in the northeastern United States
Authors: Peck Daniel C , Olmstead Daniel , Morales Anuar
Published: April 2008

BACKGROUND: Two invasive crane flies, Tipula paludosa Meigen and Tipula oleracea L. (Diptera: Tipulidae), were detected in New York State for the first time in 2004. Both are damaging pests of turfgrass and other horticultural systems in North America where establishment has already been documented. To develop management recommendations for the Northeast and define opportunities for preventive (autumn) and curative (spring) control, four insecticide trials targeting T. paludosa larvae were conducted over a 2 year period.

RESULTS: The most efficacious (≥70% control in both trials) products against early instars in autumn were bifenthrin, carbaryl, chlorantraniliprole, clothianidin and trichlorfon. Results varied for azadirachtin, Beauveria bassiana, cyfluthrin, dinotefuran, imidacloprid, imidacloprid + bifenthrin and indoxacarb. Clothianidin and dinotefuran were most efficacious against fourth instars in spring; results varied for imidacloprid, indoxacarb and trichlorfon.

CONCLUSION: Several insecticides offer alternatives for preventive and curative control of T. paludosa, but, because there is little overlap with application windows for scarab larvae pests, management may entail an entirely new insecticide treatment window, implying new economic and environmental burdens to the turfgrass industry. Moreover, curtailing the impact and spread of these invasives may be severely hampered because the best performing alternatives (clothianidin, dinotefuran) are not registered in New York. Copyright © 2008 Society of Chemical Industry
Magnetotransport properties of GaMnAs with ferromagnetic nanodots
Authors: Suh Jooyoung , Chang Joonyeon , Kim Eun Kyu , Sapozhnikov M. V. , Mironov V. L. , Fraerman A. A.
Published: April 2008

The new hybrid device consisting of single array of Co nanodots on top of GaMnAs is presented to explore a new functionality of GaMnAs diluted magnetic semiconductor (DMS). Magnetic state of Co dots was observed by magnetic force microscopy (MFM). Magnetoresistance of pure GaMnAs microbridge strongly depends on the orientation of applied magnetic field. Magnetization reversal of the single domain state definitely affects the longitudinal magnetoresistance of GaMnAs. Inhomogeneous magnetic field induced by Co nanodot is a dominant contribution to the resistance change. This field was regarded to act as an effective potential that may affect the spin polarized carriers in GaMnAs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diamond: a material for acoustic devices
Authors: Mortet V. , Williams O. A. , Haenen K.
Published: April 2008

Diamond has been foreseen to replace silicon for high power, high frequency electronic applications or for devices that operates in harsh environments. However, diamond electronic devices are still in the laboratory stage due to the lack of large substrates and the complexity of diamond doping. On another hand, surface acoustic wave filters based on diamond are commercially available. Diamond is especially suited for acoustic applications because of its exceptional mechanical properties. The other properties of diamond such as bio‐inertness and chemical stability certainly make of diamond a key material for the next generation of acoustic sensors. In this article, we try to detail the interest of diamond films in composite acoustic applications and review the different type of acoustic devices/sensors. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Very low dislocation density, resistive GaN films obtained using transition metal nitride interlayers
Authors: Moram M. A. , Kappers M. J. , Zhang Y. , Barber Z. H. , Humphreys C. J.
Published: April 2008

A threading dislocation density (TDD) reduction method for GaN films is described. Thin amorphous layers of Sc, Hf, Nb, Zr and Cr were deposited on MOVPE‐grown GaN‐on‐sapphire templates with a TDD of 5 × 109 cm–2 and annealed in NH3 to form metal nitrides. The ScN layer remained continuous, with a very low pinhole density, while the HfN layer contained a high pinhole density of approximately 3 × 109 cm–2. The NbN and ZrN layers formed oriented holey network structures. The Cr layer did not nitride. Coalesced GaN epilayers grown on the ScN layers had the lowest dislocation density of 3 × 107 cm–2 (un‐coalesced GaN on ScN had TDDs as low as 5 × 106 cm–2). Unlike GaN films grown using multiple SiNx interlayers, which contain a similar proportion of edge and mixed dislocations, the GaN‐on‐ScN layers contain substantially fewer mixed than edge dislocations, a proportion similar to that of the high‐TDD template. The low‐TDD GaN epilayers grown on ScN are also highly electrically resistive. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical polarization of m ‐plane In‐GaN/GaN light‐emitting diodes characterized via confocal microscope
Authors: Masui Hisashi , Yamada Hisashi , Iso Kenji , Hirasawa Hirohiko , Fellows Natalie N. , Speck James S. , Nakamura Shuji , DenBaars Steven P.
Published: April 2008

A confocal microscope was applied to characterize near‐field optical polarization of light emission from InGaN‐based light‐emitting diodes prepared on a nonpolar orientation. Detection of stray light was significantly reduced as a result of the confocal technique compared to broad‐area measurements. The confocal measurement required no special sample preparation and obtained data was directly interpretable. A polarization ratio of 0.83 was measured on long‐wavelength emitting devices and was sustained over two orders of magnitude of low current range. Energy shifts and separation of emission peaks for the two polarization components were evaluated to discuss the valence‐band structure. Energy shifts indicated that the topmost band |X 〉 had a heavier effective mass than the lower band |Z 〉. Splitting energy of InGaN was estimated to be 30 meV. Results were consistent with the past reports, thus it was confirmed that the confocal microscope is a valid technique to characterize near‐field optical polarization. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Consultants' forum: should post hoc sample size calculations be done?
Authors: Walters Stephen J
Published: April 2008

Pre‐study sample size calculations for clinical trial research protocols are now mandatory. When an investigator is designing a study to compare the outcomes of an intervention, an essential step is the calculation of sample sizes that will allow a reasonable chance (power) of detecting a pre‐determined difference (effect size) in the outcome variable, at a given level of statistical significance. Frequently studies will recruit fewer patients than the initial pre‐study sample size calculation suggested. Investigators are faced with the fact that their study may be inadequately powered to detect the pre‐specified treatment effect and the statistical analysis of the collected outcome data may or may not report a statistically significant result. If the data produces a “non‐statistically significant result” then investigators are frequently tempted to ask the question “Given the actual final study size, what is the power of the study, now, to detect a treatment effect or difference?” The aim of this article is to debate whether or not it is desirable to answer this question and to undertake a power calculation, after the data have been collected and analysed. Copyright © 2008 John Wiley & Sons, Ltd.
Mass spectra of tetrahydroisoquinoline‐fused 1,3,2‐O,N,P‐ and 1,2,3‐O,S,N‐heterocycles: influence of ring size and fusion, of present heteroatoms, substituent effects and of the stereochemistry on fragmentation
Authors: Starke Ines , Schuster Ildikó , Fülöp Ferenc , Kleinpeter Erich
Published: April 2008

The electron ionization (EI) mass spectra of a variety of stereoisomeric tricyclic 1,3,2‐oxazaphosphino[4,3‐a]isoquinolines (1–4), 1,2,3‐oxathiazino[4,3‐a]isoquinoline‐4‐oxides (5–7) and the ‐4,4‐dioxides (8–10) of oxazaphospholo‐ and oxathiazolo[4,3‐a]‐ (11, 12, 15 and 16) and ‐[3,4‐b]isoquinolines (13, 14 and 17) were recorded. Ring size and fusion, the different heteroatoms (P and S) and substituents on the ring systems strongly influence the mass spectra. In addition, mass spectra of the stereoisomers of compounds 1, 2 and 13, 14 revealed stereochemically relevant differences which are not observed for the other pairs of isomers. Copyright © 2008 John Wiley & Sons, Ltd.
Effects of stream hydraulics and other environmental variables on density of Narapa bonettoi (Oligochaeta) in the Paraná River system
Authors: Blettler Martín , Amsler Mario , de Drago Inés Ezcurra , Marchese Mercedes
Published: April 2008

Hydraulic and substratum conditions have been identified as two stream features which affect the benthic community composition, abundance and distribution. However, little attention has been given to the influence of hydraulic variables in large river beds. The aim of this study was to analyse the incidence of the near‐bottom hydraulic conditions and other environmental variables on the density of Narapa bonettoi (Oligochaeta, Narapidae), a typical and dominant species found in sandy bed rivers of diverse hierarchy of the Paraná River basin. A large amount of existing and available benthic data were used. The highest correlations among N. bonettoi densities and environmental variables were obtained with the hydraulic variables of friction Reynolds number (R*) and shear stress (τ0); the substratum type (sand, silt and clay) and organic matter content. The results show that N. bonettoi density would be related with the hydraulic variables following a ‘bell‐shaped’ tendency, e.g. with the friction Reynolds number, N. bonettoi would have a preference for transition values of turbulence (∼40 < R* < ∼50), which is equivalent to τ0 between ∼0.6 and ∼0.8 kg −2. Densities show a slight decreasing tendency toward the maximum R* values, suggesting that the species does not support a completely developed turbulence (R* > ∼70). Significant but negative correlations were reported in the literature between benthic macroinvertebrates typical of smaller and steeper streams and R* values far beyond the threshold 70 value. N. bonettoi shows a clear preference for a completely sandy substratum and for sand particles sizes around 300 µm. Finally, considering the important role played by the hydraulic variables on the benthic community studied herein, the contagious distribution pattern of N. bonettoi, reported by other authors, would be principally linked with the interactions between current and sediment near the bottom rather than with the mobility of these organisms. Copyright © 2008 John Wiley & Sons, Ltd.
The effect of the Grand Ditch on the abundance of benthic invertebrates in the Colorado River, Rocky Mountain National Park
Authors: Clayton Jordan A. , Westbrook Cherie J.
Published: April 2008

We investigate herein the hypothesis that there is a significant relationship between bed particle mobility and benthic invertebrate abundance in the gravel‐bed channel of the upper Colorado River in Rocky Mountain National Park. A large diversion channel called the Grand Ditch normally diverts a significant portion (∼50%) of the annual snowmelt runoff from the watershed northward out of the basin. In May 2003, a ∼30‐m section of the ditch was breached, contributing substantially to the magnitude and duration of discharge in the Colorado River until the ditch breach was repaired in July of that year. As a result, all grain sizes in the river channel were mobilized, which contrasted sharply with the minimal gravel transport experienced during the exceptional drought of the previous year. Benthic macroinvertebrates were collected in the field using a Surber sampler at the same six locations for both years, and the number of individuals of the orders ephemeroptera (mayflies), plecoptera (stoneflies), trichoptera (caddisflies) and diptera (e.g. chironomids) was counted in the laboratory. The total number of individuals was 240% higher in 2003, and the proportion of mayflies in the samples increased from 25% in 2002 to 40% in 2003. In 2003, samples were also taken immediately upstream and downstream of a large flow obstruction in the channel in order to further isolate the relative importance of sediment transport against other variables affecting the stream habitat. Numbers of individuals for all taxa collected (particularly ephemeroptera and plecoptera) were nearly an order of magnitude higher at the upstream site than at the downstream, protected location. These results have important implications for the ecosystem management of streams within Rocky Mountain National Park and elsewhere. Copyright © 2008 John Wiley & Sons, Ltd.
When does entrepreneurial self‐efficacy enhance versus reduce firm performance?
Authors: Hmieleski Keith M. , Baron Robert A.
Published: April 2008

The entrepreneurial self‐efficacy of lead founders has been generally considered to be a robust predictor of the performance of their firms. Few studies, however, have considered variables that might moderate this relationship. The current study attempts to fill this gap in the literature by examining two possible moderators of the effects of entrepreneurial self‐efficacy on firm performance: dispositional optimism and environmental dynamism. Results indicate that these factors do indeed moderate the effects of entrepreneurial self‐efficacy; in fact, a three‐way interaction between self‐efficacy, optimism, and environmental dynamism was observed with respect to firm performance. Consistent with predictions, in dynamic environments, the effects of high entrepreneurial self‐efficacy on firm performance were positive when combined with moderate optimism, but negative when combined with high optimism. In stable environments, in contrast, the effects of self‐efficacy were relatively weak, and were not moderated by optimism. Overall, results suggest that high self‐efficacy is not always beneficial for entrepreneurs and may, in fact, exert negative effects under some conditions. Copyright © 2008 Strategic Management Society.
A two‐level structural equation model approach for analyzing multivariate longitudinal responses
Authors: Song Xin‐Yuan , Lee Sik‐Yum , Hser Yih‐Ing
Published: April 2008

The analysis of longitudinal data to study changes in variables measured repeatedly over time has received considerable attention in many fields. This paper proposes a two‐level structural equation model for analyzing multivariate longitudinal responses that are mixed continuous and ordered categorical variables. The first‐level model is defined for measures taken at each time point nested within individuals for investigating their characteristics that are changed with time. The second level is defined for individuals to assess their characteristics that are invariant with time. The proposed model accommodates fixed covariates, nonlinear terms of the latent variables, and missing data. A maximum likelihood (ML) approach is developed for the estimation of parameters and model comparison. Results of a simulation study indicate that the performance of the ML estimation is satisfactory. The proposed methodology is applied to a longitudinal study concerning cocaine use. Copyright © 2008 John Wiley & Sons, Ltd.
Nanomosaic Network for the Detection of Proteins Without Direct Electrical Contact
Authors: Gamby Jean , Abid Jean‐Pierre , Tribollet Bernard , Girault Hubert H.
Published: April 2008

A nanomosaic network of metallic nanoparticles for the detection of ultralow concentrations of proteins is reported, which uses two planar microelectrodes embedded in a microchip that permit generation of capacitive coupling to the nanomosaic system without the need for direct electrical contact with the channel. By tailoring the microchannel surface using a sandwich configuration of polyethylene terephthalate/gold nanoparticles/poly(L‐lysine), the surface charge can be modified following biomolecular interactions and monitored using a noncontact admittance technique. This nanodevice system behaves like a tunable capacitor and can be employed for the detection of any kind of molecule. The femtomolar detection of an anionic protein, such as β‐lactoglobulin in phosphate‐buffered saline medium, is taken as an example.
Micro‐organism‐Triggered Release of Silver Nanoparticles from Biodegradable Oxide Carriers Allows Preparation of Self‐Sterilizing Polymer Surfaces
Authors: Loher Stefan , Schneider Oliver D. , Maienfisch Tobias , Bokorny Stefan , Stark Wendelin J.
Published: April 2008

The antimicrobial activity of silver has attracted significant research interest and contributes to an exponentially growing use of this noble metal in commodity products. In this investigation, we describe a general approach to increase the antimicrobial activity of a silver‐containing surface by two to three orders of magnitude. The use of 1–2‐nm silver particles decorating the surface of 20–50‐nm carrier particles consisting of a phosphate‐based, biodegradable ceramic allows the triggered release of silver in the presence of a growing microorganism. This effect is based on the organism's requirements for mineral uptake during growth creating a flux of calcium, phosphate, and other ions to the organism. The growing micro‐organism dissolves the carrier containing these nutrients and thereby releases the silver nanoparticles. Further, we demonstrate the rapid self‐sterilization of polymer surfaces containing silver on calcium phosphate nanoparticles using a series of human pathogens. Colony‐forming units (viable bacteria or fungi counts) have been routinely reduced below detection limit and suggest application of these self‐sterilizing surfaces in hospital environments, food and pharmaceutical processing, and personal care.
Aggregation of proteins having Golgi apptus sorting determinant induces large globular structures derived from the endoplasmic reticulum in plant seed cells
Authors: Maruyama Nobuyuki , Okuda Eiko , Tatsuhara Miyuki , Utsumi Shigeru
Published: April 2008

Endoplasmic reticulum (ER)‐derived compartments are found in many plant species. Although it has been assumed that aggregation induces formation of the ER‐derived compartments in plant seed cells, the effect of aggregation on the trafficking from the ER to the Golgi has not yet been elucidated. In this study, we used an aggregated type of red fluorescent protein (DsRED) to investigate the effect of aggregation on sorting in seed cells. DsRED fused to the Golgi sorting determinant was found mainly in large globular structures derived from the ER where ER‐resident proteins were excluded. These results indicate that aggregation of the Golgi protein blocks transport from the ER to the Golgi.
Nuclear actin dynamics – From form to function
Authors: Vartiainen Maria K.
Published: April 2008

Cell biological functions of actin have recently expanded from cytoplasm to nucleus, with actin implicated in such diverse processes as gene expression, transcription factor regulation and intranuclear motility. Actin in the nucleus seems to behave differently than in the cytoplasm, raising new questions regarding the molecular mechanisms by which actin functions in cells. In this review, I will discuss dynamic properties of nuclear actin that are related to its polymerization cycle and nucleocytoplasmic shuttling. By comparing the behaviour of nuclear and cytoplasmic actin and their regulators, I try to dissect the underlying differences of these equally important cellular actin pools.
Unequal tissue expression of proteins from the PA/PAI system, myoma necrosis, and uterus survival after uterine artery occlusion
Authors: Cheng Zhongping , Xie Yan , Dai Hong , Hu Liping , Zhu Yu , Gong Jun
Published: April 2008

Objective

To further the understanding of the mechanism behind myoma necrosis and uterus survival after uterine artery occlusion.

Method

Myomal and myometrial gene transcription and protein expression of tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), and plasminogen activator inhibitor type 1 (PAI‐1) were investigated in 30 uteri.

Results

Compared with myometrial expression, myomal expression was less for uPA mRNA (1.34% ± 2.18% vs 2.84% ± 2.97%; P < 0.05) and greater for PAI‐1 mRNA (2.67% ± 1.82% vs 1.27% ± 1.99%; P < 0.05), but the difference in tPA mRNA expression was not significant. Accordingly, compared with myometrial expression, myomal expression was less for the uPA protein (P < 0.05) and greater for the PAI‐1 protein (P < 0.05), but the difference in tPA protein was not significant.

Conclusion

The PA/PAI system was found to be expressed differently in myomas and the myometrium, which may play a role in uterus survival and myoma necrosis after uterine artery occlusion.
A NAHḌA OF CHARITABLE ORGANIZATIONS? HEALTH SERVICE PROVISION AND THE POLITICS OF AID IN PALESTINE
Authors: Challand Benoît
Published: April 2008

Until recently, the topic of charitable organizations seemed to have fallen in disgrace. Social scientists have given little attention to this sector of associational life. Instead, a great deal has been written on the issues of democratization through pressure groups or on the transformation of social movements into professional organizations while assessing the overall impact of development promoted by donors. Yet three signs point to the need for a better understanding of charitable organizations. First, new research studying Islamic activism through the lens of social-movement literature has offered innovative results. Second, studies on the impact of aid during the second intifada have revealed that charitable organizations as well as Islamic organizations offered a significant amount of emergency support, sometimes competing with professional nongovernmental organizations (NGOs). Finally, the fact that Hamas, also known for running a vast network of charitable organizations, achieved such a significant political success in the 2005 municipal and 2006 legislative elections should invite social scientists to consider whether and how political momentum can also be obtained through activism in the charitable sector.
Minimum sampling effort for reliable non-invasive estimations of excretion abundance of Elaphostrongylus cervi L1 in red deer (Cervus elaphus) populations
Authors: Tayce J. , Acevedo P. , Vicente J. , Gortazar C.
Published: April 2008

Faecal surveys are commonly used as non-invasive means to evaluate population abundance of animals as well as comparable indexes of prevalence and intensity of diseases between populations, especially macroparasites. While faecal surveys are among one of the simplest means to perform these evaluations, they are time consuming and labour intensive. The present study evaluated 80 red deer (Cervus elaphus) faecal samples collected in two study sites for the presence and abundance of first-stage larvae of the nematode Elaphostrongylus cervi and established pools of samples for epidemiological analysis. The analysis of 20–30 individual samples would produce a reliable estimate of the ‘true’ prevalence, and the error of the smaller sample size only doubled that of the 80 reference samples. The analysis of 5 pools of 5 pellet groups each, or of 4 pools of 10 pellet groups each, provided a reliable estimation of the ‘true’ excretion abundance estimated by the analysis of all 80 samples. These pools comprise a cost-effective and dependable alternative for measuring and obtaining comparable abundances of parasitic faecal excretion stages in red deer populations, which is very valuable for epidemiological and ecological research as well as for management purposes.
Facial nerve palsy secondary to middle-ear lipoma
Authors: Kasbekar A V , Donnelly N , Axon P
Published: April 2008

Objective:

We present the first reported case of a middle-ear lipoma presenting with facial nerve palsy. We review the available literature on middle-ear lipomas and alert the surgeon to the possibility of a lipoma occurring in this location.

Case report:

A 33-year-old man presented to our unit with a right-sided, House–Brackmann grade two, lower motor neurone facial palsy. A computed tomography scan revealed abnormal soft tissue in the epitympanic recess, extending to the region of the geniculate ganglion. At middle-ear exploration, a lump of fatty tissue was found filling the anterior middle-ear cleft, juxtaposed to the horizontal portion of the facial nerve. The patient's facial palsy resolved within a few weeks of surgery.

Conclusion:

Lipomas are a rare but real differential diagnosis of a mass in the middle ear. Early imaging is advised.
“That Ill, Tight Sound”: Telepresence and Biopolitics in Post-Timbaland Rap Production
Authors: CHAPMAN DALE
Published: April 2008

This article investigates the music created by current rap and R&B producers such as Timbaland and Pharrell Williams in order to understand how their works evoke certain constructions of sonic space. The opaque, spare, two-dimensional qualities of the virtual spaces assembled by these artists serve as a useful window onto broader cultural forces, such as the peculiar short circuit of space and temporality that Paul Virilio evokes in his concept of “telepresence.” The author argues that the sonic construction of telepresence allows contemporary black music to comment upon the notion of “biopolitics,” the reduction of the political to the horizon of the body.
The Avenging Angel of Creation/Destruction: Black Music and the Afro-technological in the Science Fiction of Henry Dumas and Samuel R. Delany
Authors: WASHINGTON SALIM
Published: April 2008

This essay explores the thematic use of music in the science-fiction writings of two African American authors, Henry Dumas and Samuel R. Delany. Each author visited this theme in more than one work, and in at least one work centered the Afro-technological focus upon a special musical instrument: the “afro horn” in Dumas's story “Will the Circle Be Unbroken?” and a machete/flute in Samuel R. Delany's novel The Einstein Intersection. Both writers treat music itself, without regard to a material instrument, as a technology. Dumas depicted black music as a tool that enabled black people to kill their enemies, and Delany represented music as a technology capable of avenging the wrongs committed against the politically and socially marginalized. Whereas Dumas's protagonists were more likely to be social pariahs because of their class or their sexual orientation than because of race, his descriptions specifically reference black music and its attendant rituals. Both writers portray music as a technology capable of creating and healing as well as avenging and destroying.
Geotail and LFM comparisons of plasma sheet climatology: 2. Flow variability
Authors: Guild Timothy B. , Spence Harlan E. , Kepko E. Larry , Merkin Viacheslav , Lyon John G. , Wiltberger Michael , Goodrich Charles C.
Published: April 2008

We characterize the variability of central plasma sheet bulk flows with a 6‐year Geotail data set and a 2‐month Lyon‐Fedder‐Mobarry (LFM) global MHD simulation at two spatial resolutions. Comparing long databases of observed and simulated parameters enable rigorous statistical tests of the model's ability to predict plasma sheet properties during routine driving conditions and represent a new method of global MHD validation. In this study, we use probability density functions (PDFs) to compare the statistics of plasma sheet velocities in the Geotail observations with those in the LFM simulations. We find that the low‐resolution model grossly underestimates the occurrence of fast earthward and tailward flows. Increasing the simulation resolution inherently changes plasma sheet mass transport in the model, allowing the development of fast, bursty flows. These flows fill out the wings of the velocity distribution and bring the PDF into closer agreement with observations.
Insight into the geodynamics of cratonic reactivation from seismic analysis of the crust‐mantle boundary
Authors: Zheng T. Y. , Zhao L. , Zhu R. X.
Published: April 2008

The reactivation of craton is a crucial issue for the understanding of continent lithosphere. Although the partial loss of the thick lithospheric root of the North China Craton (NCC) was documented, its mechanism remains a contentious topic in the study of cratonic evolution. In this paper, we imaged the crust‐mantle structures by using the data from 36 permanent stations with fine spatial coverage in the Yanshan tectonic belt (YSTB) and the Taihangshan region (TSR) in the northern NCC. Two tectonic units with distinct crust‐mantle structures were recognized and their junction zone was identified. The results reveal distinct features of the crust‐mantle boundaries of the YSTB and the TSR which are characterized by a sharp interface and a thick transition zone, respectively. Based on the analysis of the seismic structures of the crust‐mantle boundary and the upper mantle, we propose that the NCC reactivation was possibly derived by a slow secular ascension of hydrated asthenospheric material atop the stagnant Pacific slab, which influenced the formation of crust‐mantle transition zone in the eastern NCC. On the other hand, regional delamination of the deep crust after orogenic thickened and/or magmatic underplating beneath the YSTB caused the spatial variation of the crust‐mantle boundary. Both of the mantle processes possibly changed the nature of the lithospheric mantle.
Stress and Sex Influences on Food‐seeking Behaviors
Authors: Pankevich Diana E. , Bale Tracy L.
Published: April 2008

Objective: Stress increases the drive to consume calorically dense preferred foods suggesting an exogenous factor that may induce caloric overconsumption and weight gain. As females show heightened stress sensitivity and present with increased rates of obesity, we hypothesized that stress‐induced increases in the motivation for preferred foods may be a sex‐specific predisposing factor for weight gain.

Methods and Procedures: To investigate this hypothesis, we have developed a buried food paradigm that permits the measurement of sex differences and effects of chronic variable stress (CVS) on the latency to uncover and the consumption of a preferred food pellet without the requisite caloric restriction required in traditional operant conditioning tasks.

Results: In our studies, females consistently showed latencies that were twice as fast as males to locate the buried pellet in limited access tests. Interestingly, during stress exposure, male latencies decreased to that of control female levels. Male and female mice showed a significant effect of stress, three‐ and fourfold, respectively, on increased consumption of the preferred food during testing.

Discussion: These results support a basal sex difference in behaviors toward a preferred food, and a possible role of stress sensitivity in the drive and intake of such foods. Sex differences in the role stress plays in these behaviors may provide insight into underlying mechanisms related to an increased obesity risk.
Weight Loss of Black, White, and Hispanic Men and Women in the Diabetes Prevention Program
Authors: West Delia S. , Prewitt T. Elaine , Bursac Zoran , Felix Holly C.
Published: April 2008

Objective: To provide the specific weight loss outcomes for African‐American, Hispanic, and white men and women in the lifestyle and metformin treatment arms of the Diabetes Prevention Program (DPP) by race‐gender group to facilitate researchers translating similar interventions to minority populations, as well as provide realistic weight loss expectations for clinicians.

Methods and Procedures: Secondary analyses of weight loss of 2,921 overweight participants (22% black; 17% Hispanic; 61% white; and 68% women) with impaired glucose tolerance randomized in the DPP to intensive lifestyle modification, metformin or placebo. Data over a 30‐month period are examined for comparability across treatment arms by race and gender.

Results: Within lifestyle treatment, all race‐gender groups lost comparable amounts of weight with the exception of black women who exhibited significantly smaller weight losses (P < 0.01). For example, at 12 months, weight losses for white men (−8.4%), white women (−8.1%), Hispanic men (−7.8%), Hispanic women (−7.1%), and black men (−7.1%) were similar and significantly higher than black women (−4.5%). In contrast, within metformin treatment, all race‐gender groups including black women lost similar amounts of weight. Race‐gender specific mean weight loss data are provided by treatment arm for each follow‐up period.

Discussion: Diminished weight losses were apparent among black women in comparison with other race‐gender groups in a lifestyle intervention but not metformin, underscoring the critical nature of examining sociocultural and environmental contributors to successful lifestyle intervention for black women.