bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Short Glass-Fiber Volume Fractions in Compression Molded Thermoset Composites—Numerical
Authors: Cheon Jae-Seung , Kim Soo-Young , Im Yong-Taek
Published: April 2011

In this paper, a fiber content prediction model was investigated in order to numerically determine the glass-fiber volume fraction distributions by approximating the compression molded thermoset composites as a rigid-thermoviscoplastic material. The current approach of fiber distribution prediction was compared to the results based on mass balance and isothermal analysis, respectively, for the case of simple flat-plate compression molding of sheet molding compounds (SMC). From this comparison it was found to better reproduce the trend of fiber distributions observed in experimental findings. The two flow coefficients involved with the current model in characterizing the flow of fibers during compression molding were determined by a numerical search scheme in the present investigation, based on minimizing the errors between the numerically predicted values and the measured data obtained from the image processing. Comparison of isothermal and non-isothermal finite element simulations revealed the importance of the effects of heat transfer during compression molding and showed that the current approach provides useful information about the local variation of fiber volume fractions. Following this approach, it will be possible to make better estimates of the distribution of fibers in compression molded thermoset composites parts with complex geometries.
Axial Compression of Empty and Foam Filled Composite Conical Shells
Authors: Gupta N. K. , Velmurugan R.
Published: April 2011

Experimental and theoretical studies of axial compression of both empty and foam filled glass fibre/polyester resin truncated conical shells are presented.

An analysis is carried out to determine the mean crushing load and the crush length, i.e., the shell length crushed in a cycle of progressive crushing of the shell. The mean crushing load is obtained by equating the total energy involved in a crush cycle to the work done by the applied load. The expression for crush length is obtained by minimizing the total potential energy with respect to the crush length.

The shells were made of short, randomly oriented glass fibre mats with polyester resin, and their cone angles were 9.50°, 140°, 18.40°, 21° and 450°. These were subjected to axial compression in the Instron machine at a cross head velocity of 2 mm/min. Their typical deformation histories, load-deformation behaviour and energy absorption characteristics are presented and influence thereon of the infill foam is discussed. Standard tensile specimens were made with the same lay up sequence and number of layers as in the actual conical shells. These were subjected to uni-axial tension test in Instron machine to obtain their tensile properties. The analytical results obtained compared well with the experimental results.
Transient Analysis and Measurement of Anisotropic Heat Conduction in Transversely Isotropic Composite Materials
Authors: Shuler S. F. , Advani S. G. , Kaliakin Victor N.
Published: April 2011

This study focuses on modeling the transient and steady state temperature distribution within a unidirectional fiber reinforced thermoplastic composite laminate beam after it has been inserted into a hot platen forming appartus. In the forming prodedure of interest, a room temperature sheet laminate is placed within hot platens that melt the matrix and allow the beam to be formed successfully. The heating process is dependent upon the convection conditions along the beam. The arrangement, volume fraction and individual conductivities of the matrix and fiber components of the beam determine its anisotropic thermal conductivity which, in turn, governs the heat flow. A two-dimensional steady state analytic series solution is developed for the beam/platen geometry and presented to model the heat conduction along the beam's length. In addition, two-dimensional numerical steady state and transient heat tranfer models are obtained using a finite element code. Finally, to validate these models, surface temperature measurements taken from a unidirectional laminate beam placed within the hot platens of the forming apparatus are compared to the analytic and numerical solutions.
A Finite Element Based Modal Method for Determination of Plate Stiffnesses Considering Uncertainties
Authors: Kuttenkeuler Jakob
Published: April 2011

A method for determination of orthotropic elastic material properties of plates using resonance frequencies is developed and verified. The elastic properties are found through minimization of the difference between experimentally measured resonance frequencies and the eigenfrequencies obtained by finite element (FE) analysis using the plate stiffnesses as parameters. Mindlin type plate theory is used. Emphasis is on the practical use of knowledge about uncertainties to compute bounds of the obtained stiffnesses. Variations of the optimization problem formulation incorporating the known uncertainties, combined with a suitable scalar stiffness norm, enables the calculation of the upper and lower bounds of the stiffnesses. Further, an advantage with the present (FE-based) method is that more complex plate shapes can be analyzed than for similar methods based on Rayleigh-Ritz displacement field assumptions. This is verified with good results on orthotropic composite laminates using specimen geometries including comer singularities. The method is successfully validated against another, but similar, vibration technique.
An Impregnation Model for the Consolidation of Thermoplastic Composites Made from Commingled Yarns
Authors: Bernet N. , Michaud V. , Bourban P. E. , Manson J. A.E.
Published: April 2011

A model for the consolidation of thermoplastic composites based on commingled yarns was developed. The evolution of composite void content during consolidation was related to the processing parameters and the material properties. Additionally, the analysis relied on experimental investigation of the yarn structure, taking into account a distribution in dry fiber bundle sizes. Residual porosity was considered to result from pore closing at a given stage during fiber bundle impregnation. The accuracy of the model was assessed by conducting consolidation experiments using a unidirectional commingled yarn fabric made of polyamide 12 resin and carbon fibers. Excellent correlation was found between predicted and experimental void contents. The model aided prediction of suitable processing conditions and identification of the main physical and geometrical parameters influencing the consolidation rate.
A Finite Element Model for Predicting Time-Dependent Deformations and Damage Accumulation in Laminated Composite Bolted Joints
Authors: Kallmeyer Alan R. , Stephens Ralph I.
Published: April 2011

To assess and predict the long-term durability of advanced composite joints, a general, nonlinear finite element program was developed and implemented to model the localized time-dependent deformations and damage accumulation in the vicinity of a fastener hole in a polymer matrix composite (PMC) laminate. This code incorporates an elastic-viscoplastic constitutive model for unidirectional, orthotropic laminae, coupled with classical lamination theory, to determine the time-dependent stresses and deformations in the laminate. The accumulation of damage in the composite, and the subsequent deterioration of mechanical properties, is predicted by a set of ply failure criteria and an associated property degradation model. The results from this analysis were compared to experimental data and were found to provide reasonable correlation with time-dependent bolt-hole elongation measurements obtained from a graphite fiber reinforced PMC.
Modeling and Control of an Injection Pultrusion Process
Authors: Voorakaranam Srikanth , Joseph Babu , Kardos John L.
Published: April 2011

Injection Pultrusion (IP) is a novel process that combines the best features of traditional Resin Transfer Molding (RTM) and wet bath pultrusion for manufacturing polymer composites. Few researchers have dealt with the quality control aspects of this process which is extremely crucial to the plant economics. The main contribution of this paper is the study of the IP process from the point of view of product quality control while maximizing production rates. A mathematical model that includes resin flow and cure, and heat transfer in the part and the die is used to determine sensitivity of the quality variables to important processing variables and parameters. Similarities and differences with traditional pultrusion process are pointed out. Control-relevant features of the process are identified and the requirements necessary for a control system are presented. A cascaded control strategy which uses an on-line process model is proposed.
Knowledge-Based Expert System for Optimal Stacking Sequence Design of Composite Structures
Authors: Kim Jung-Seok , Kim Chun-Gon , Hong Chang-Sun
Published: April 2011

This paper expounds the development of a knowledge-based expert system for the optimal strength design of composite structures subjected to various loading conditions and rules of design heuristics. The optimal stacking sequences are obtained by integration of a knowledge-based expert system, genetic algorithm and finite element analysis. Because this expert system in optimal stacking sequence design adopts a finite element method as a stress analysis tool, it isn't limited to laminate design but can be applied to a general composite structure. The optimal stacking sequence combination is drawn from discrete ply angles and rules of design heuristics stored in the knowledge-base for the given application of interest. Results of this study were verified through comparison with quasi-isotropic lay-ups.
A Study of Negative Poisson's Ratio in Randomly Oriented Quasi-Isotropic Composite Laminates
Authors: Yeh Hsien-Liang , Yeh Hsien-Yang , Zhang Ruguang
Published: April 2011

In isotropic materials, it is known that values of Poisson's ratio larger than one half are thermodynamically inadmissible, for such values would lead to negative strain energy under certain loads. Although a negative Poisson's ratio is not forbidden by thermodynamics, it is rare in crystalline solids. With the development of modem fiber reinforced composite materials, the effective Poisson's ratio of laminated fiber reinforced composites shows a peculiar behavior as it becomes larger than one half or less than zero.

In this article, a study of negative in-plane Poisson's ratio for a general class of randomly-oriented composite laminates is presented. A simple random statistical analysis has been presented. It is demonstrated that composite laminates with negative in-plane Poisson's ratio could be achieved by using the specific values of independent elastic constants E1, E2, G12, and v12 in each lamina. Also, the influence of the lamina material properties to the negative in-plane Poisson's ratio of the composite laminates is presented. The results from this statistical analysis provide a set of general guidelines for designing composite laminates with a special character-the negative in-plane Poisson's ratio.
Strength of Adhesively-Bonded Thbular Single Lap Carbon/Epoxy Composite-Steel Joints
Authors: Kim Young Goo , Oh Je Hoon , Lee Dai Gil
Published: April 2011

The static tensile load bearing capability of adhesively-bonded tubular single lap joints if calculated using the linear mechanical adhesive properties is usually less than the experimentally determined one because the majority of the load transfer of adhesively-bonded joints is accomplished by the nonlinear behavior of the rubber-toughened epoxy adhesive.

In this paper, both nonlinear mechanical properties and fabrication residual thermal stresses of adhesive were included in the stress calculation of adhesively-bonded tubular single lap carbon/epoxy composite-steel joints. During calculation, nonlinear tensile properties of adhesive were approximated by an exponential equation that was represented by the initial tensile modulus and ultimate tensile strength of adhesive obtained from tensile tests.

From the tensile tests and the stress analyses of adhesively-bonded tubular single lap carbon/epoxy composite-steel joints with respect to stacking angles of carbon/epoxy composite adherends, the failure model for the adhesively-bonded tubular single lap carbon/epoxy composite-steel joint under the axial tensile load was proposed with considering fabrication residual thermal stresses.
Characterization of Reinforcing Web Structures in Needle Punched Nonwoven Composites
Authors: Kang Tae Jin , Lee Sung Ho
Published: April 2011

The structural parameters of needle punched nonwoven composites have been examined using image analysis system. Fourteen plies of carded webs of E Glass fiber were stacked and needle punched at different punching densities of 15, 30, 45, 60, and 90 penetrations per square centimeter. The needle punched webs were formed into composites with unsaturated polyester resin. The structural parameters examined include the fiber orientation distribution as well as the length changes during the punching process. The mean fiber length was substantially decreased up to 30% with increasing punching densities and the fibers were more randomly distributed at the high punching densities. The fiber orientation factor of the nonwoven composite was decreased with punching densities, which means more random distribution of fibers at higher punching densities.
Sleep Quality and Quality of Life in Adults With Type 2 Diabetes
Authors: Luyster Faith S. , Dunbar-Jacob Jacqueline
Published: April 2011

Purpose

The purpose of this study was to examine the relationship between sleep quality and health-related and diabetes-related quality of life in adults with type 2 diabetes.

Methods

Three hundred individuals with type 2 diabetes (mean age 63.9 years) completed questionnaires assessing sleep quality, health-related quality of life, diabetes-related quality of life, comorbidities, and depressive symptoms.

Results

More than half of the participants (55%) were “poor sleepers” according to the Pittsburgh Sleep Quality Index. After controlling for covariates, poor sleep quality was found to be a significant predictor of lower health-related quality of life as indicated by lower scores on both the physical and mental component scores of the Medical Outcomes Study 36-item Short Form health survey (SF-36). Poor sleep quality was also associated with worse diabetes-related quality of life, in particular lower scores on the Diabetes Quality of Life measure total score and the Satisfaction With Treatment and Diabetes Impact subscale scores.

Conclusions

These results suggest that poor sleep is common in type 2 diabetes and may adversely impact quality of life. Interventions to improve sleep hygiene can be suggested to patients by diabetes educators as part of diabetes self-management education programs.
Nursing Practice Patterns: Timing of Insulin Administration and Glucose Monitoring in the Hospital
Authors: Freeland Barbara , Penprase Barbara B. , Anthony Maureen
Published: April 2011

Purpose

The purpose of this study was to describe diabetes nursing practice patterns related to the timing of morning insulin administration, blood glucose monitoring, and meal intake for patients with type 2 diabetes and to report how frequently nurses were able to meet the expected standard of care.

Methods

Observations were made of 50 incidents of morning diabetes care on medical-surgical units in an acute care setting. Timeliness of rapid-acting insulin administration and glucose monitoring in relation to the morning meal were evaluated, as were the subsequent prelunch glucose levels.

Results

Patients did not receive rapid-acting insulin with in the standard recommended time of 10 minutes premeal/postmeal 84% of the time, nor did they receive glucose monitoring within the recommended 30 minutes premeal 57% of the time. There was no significant relationship found between timely insulin administration and glucose monitoring. There were no significant relationships found between care activities and prelunch glucose control or glucose variability.

Conclusions

Coordinating insulin administration, glucose monitoring, and meal delivery within the tight time frames required for rapid-acting insulin is a significant challenge not being met. Timeliness of diabetes nursing care is not the sole determining factor to good glucose control in hospitalized patients. Standards regarding timing of these activities need to be evaluated.
The Self-Care Deficit Nursing Theory as a Curriculum Conceptual Framework in Baccalaureate Education
Authors: Berbiglia Violeta A.
Published: April 2011

Although Dorothea Orem’s Self-Care Deficit Nursing Theory has been used for curricula framework for years, it was not until 2001 that Orem identified the nursing practice sciences and the foundational nursing sciences and specified the appropriate content for the two sciences. The broad purpose of this paper is to reinforce the importance of utilizing nursing theories as curricular conceptual frameworks. The specific purpose is to delineate the appropriate content for baccalaureate programs that adopt a Self-Care Deficit Nursing Theory conceptual framework for their curriculum.
“Trauma of Rape” Discourse: A Double-Edged Template for Everyday Understandings of the Impact of Rape?
Authors: Gavey Nicola , Schmidt Johanna
Published: April 2011

We map a discourse of the trauma of rape that was widely drawn upon by 29 “lay” New Zealand women and men in focus group discussions about the impact of rape. Using a discursiv e approach, we identify the key interlocking elements of this discourse. It centers on the contention that rape is traumatic, and depicts this trauma as unique, sev ere, long lasting, and in need of healing. We discuss the ways in which this ostensibly more enlightened and sensitiv e framework of meaning brings forth its own ways of potentially othering, stigmatizing, v iolating, and obstructing av enues of support and understanding for women who hav e experienced rape.
Effects of Structured Teaching on the Behavior of Young Children With Disabilities
Authors: Bennett Katherine , Reichow Brian , Wolery Mark
Published: April 2011

The effects of structured work systems based on the principles of structured teaching were evaluated with 3 preschool-aged children with developmental disabilities (2 children had autism). A withdrawal design was used with 2 participants, and a multiple baseline across stimuli was used with the other. During baseline, children were given 3 tasks to do with no structure or guidance. During intervention, a structured work system was provided, including organization of the physical structure, visual schedule, and predictable routines. Graduated guidance was used to teach the children use of the system. Use of the structured work system produced increases in engagement and the speed and accuracy of task completion along with decreases in stereotypic behavior and escape attempts.
Effects of Technology Enhancements and Type of Teacher Support on Assessing Spanish-Speaking Children’s Oral Reading Fluency in Second Grade
Authors: York Mary J. , Foorman Barbara R. , Santi Kristi L. , Francis David J.
Published: April 2011

We examined student-, classroom-, and school-level effects in predicting second-grade Spanish-speaking children’s oral reading fluency in Spanish. Teachers in 67 randomly selected urban schools administered the Tejas LEE to 1,537 first- and second-grade students. Oral reading fluency was measured in the passages students read for comprehension. Covariates were mean fluency in Grade 1, variability in fluency in Grade 1, degree of grouping in the school, and the proportion of second-grade students in the classroom and/or the school taking the Tejas LEE. Treatment effects were administration format (paper, desktop, handheld) and type of teacher support (no mentoring, web mentoring, and on-site plus web mentoring). Second-grade teachers positively affected students’ reading fluency when (a) they administered the Tejas LEE on paper with the associated paper reports in classrooms of bilingual students, and (b) they either received web mentoring and had relatively homogeneous classrooms or received on-site or no mentoring and had ability-grouped classes. Implications for interpreting assessment results are discussed in the context of the type of support provided to teachers and the grouping of bilingual students by language and/or by ability.
Looking Across Domains to Understand Infant Representation of Emotion
Authors: Quinn Paul C. , Anzures Gizelle , Izard Carroll E. , Lee Kang , Pascalis Olivier , Slater Alan M. , Tanaka James W.
Published: April 2011

A comparison of the literatures on how infants represent generic object classes, gender and race information in faces, and emotional expressions reveals both common and distinctive developments in the three domains. In addition, the review indicates that some very basic questions remain to be answered regarding how infants represent facial displays of emotion, including (a) whether infants form category representations for discrete classes of emotion, (b) when and how such representations come to incorporate affective meaning, (c) the developmental trajectory for representation of emotional expression at different levels of inclusiveness (i.e., from broad to narrow or narrow to broad?), and (d) whether there is superior discrimination ability operating within more frequently experienced emotion categories.
Socioemotional Information Processing in Human Infants: From Genes to Subjective Construals
Authors: Johnson Susan C. , Chen Frances S.
Published: April 2011

This article examines infant attachment styles from the perspective of cognitive and emotional subjectivity. We review new data that show that individual differences in infants’ attachment behaviors in the traditional Strange Situation are related to (a) infants’ subjective construals of infant—caregiver interactions, (b) their attention to emotional expressions, and (c) polymorphisms in the oxytocin receptor (OXTR) gene. We use these findings to argue that individual differences in infants’ attachment styles reflect, in part, the subjective outcomes of objective experience as filtered through genetic biases in socioemotional information processing.
Emotion Development in Infancy through the Lens of Culture
Authors: Halberstadt Amy G. , Lozada Fantasy T.
Published: April 2011

The goal of this review is to consider how culture impacts the socialization of emotion development in infancy, and infants’ and young children’s subsequent outcomes. First, we argue that parents’ socialization decisions are embedded within cultural structures, beliefs, and practices. Second, we identify five broad cultural frames (collectivism/individualism; power distance; children’s place in family and culture; ways children learn; and value of emotional experience and expression) that help to organize current and future research. For each frame, we discuss the impact on parents’ socialization practices and infants’ subsequent outcomes relating to emotion-related experience, expression, and understanding. We also generate testable hypotheses to further our understanding of the relationships between the five frames and emotion development in infancy.
Potential for Using 3D Technology to Image the Origins of the Coronary Arteries
Authors: Weber JoAnne
Published: April 2011

When young patients present to the echocardiography laboratory with chest pain, one consideration is that there may be an anomalous coronary artery. For this reason, it is critical that the sonographer evaluate the origins of the coronary arteries and map them with color Doppler flow to ensure that the blood is going in the correct direction. Although this may sound simple, not all sonographers have been trained to image the coronary arteries in detail and map them as far as possible. This pilot study investigated the feasibility of using volume acquisition from the parasternal short-axis and apical views. The results demonstrated that coronary artery origins can be successfully identified in adults using reconstruction of 3D volume data sets without adding significant time to the examination.
Using Sonography to Characterize Renal Cell Carcinoma: Case Study of a Large Renal Mass
Authors: Singleton Jenna Elizabeth
Published: April 2011

Renal cell carcinoma (RCC) is both the most common—and deadly—renal tumor in the adult population. It is categorized into various subtypes, with clear cell RCC being the most common of those. Sonography, in addition to other imaging modalities, is important in discovering, describing, staging, and ultimately predicting the outcome of RCC. This article presents a case study of a woman in her 60s diagnosed with late clear cell RCC with multiple metastases. It also addresses recent literature regarding outcomes for this disease.
BCL-2 (-938C > A) polymorphism is associated with breast cancer susceptibility
Authors: Zhang Ning , Li Xiaoyan , Tao Kai , Jiang Liyu , Ma Tingting , Yan Shi , Yuan Cunzhong , Moran Meena S , Liang Faming , Haffty Bruce G , Yang Qifeng
Published: April 2011

Background

BCL-2 (B-cell leukemia/lymphoma 2) gene has been demonstrated to be associated with breast cancer development and a single nucleotide polymorphism (SNP; -938C > A) has been identified recently. To investigate whether this polymorphism functions as a modifier of breast cancer development, we analyzed the distribution of genotype frequency, as well as the association of genotype with clinicopathological characteristics. Furthermore, we also studied the effects of this SNP on Bcl-2 expression in vitro.

Methods

We genotyped the BCL-2 (-938C > A) in 114 patients and 107 controls, and analyzed the estrogen receptor (ER), progestogen receptor (PR), C-erbB2 and Ki67 status with immunohistochemistry (IHC). Different Bcl-2 protein levels in breast cancer cell lines were determined using western blot. Logistic regression model was applied in statistical analysis.

Results

We found that homozygous AA genotype was associated with an increased risk (AA vs AC+CC) by 2.37-fold for breast cancer development and significant association was observed between nodal status and different genotypes of BCL-2 (-938C > A) (p = 0.014). AA genotype was more likely to develop into lobular breast cancer (p = 0.036). The result of western blot analysis indicated that allele A was associated with the lower level of Bcl-2 expression in breast cancer cell lines.

Conclusions

AA genotype of BCL-2 (-938C > A) is associated with susceptibility of breast cancer, and this genotype is only associated with the nodal status and pathological diagnosis of breast cancer. The polymorphism has an effect on Bcl-2 expression but needs further investigation.
Plasmodium Cysteine Repeat Modular Proteins 3 and 4 are essential for malaria parasite transmission from the mosquito to the host
Authors: Douradinha Bruno , Augustijn Kevin D , Moore Sally G , Ramesar Jai , Mota Maria M , Waters Andrew P , Janse Chris J , Thompson Joanne
Published: April 2011

Background

ThePlasmodiumCysteine Repeat Modular Proteins (PCRMP) are a family of four conserved proteins of malaria parasites, that contain a number of motifs implicated in host-parasite interactions. Analysis of mutants of the rodent parasitePlasmodium bergheilacking expression of PCRMP1 or 2 showed that these proteins are essential for targeting ofP. bergheisporozoites to the mosquito salivary gland and, hence, for transmission from the mosquito to the mouse.

Methods

In this work, the role of the remaining PCRMP family members, PCRMP3 and 4, has been investigated throughout thePlasmodiumlife cycle by generation and analysis ofP. bergheigene deletion mutants, Δpcrmp3 and Δpcrmp4. The role of PCRMP members during the transmission and hepatic stages of thePlasmodiumlifecycle has been evaluated by light- and electron microscopy and by analysis of liver stage development in HEPG2 cellsin vitroand by infecting mice with mutant sporozoites. In addition, mice were immunized with live Δpcrmp3 and Δpcrmp4 sporozoites to evaluate their immunization potential as a genetically-attenuated parasite-based vaccine.

Results

Disruption ofpcrmp3andpcrmp4inP. bergheirevealed that they are also essential for transmission of the parasite through the mosquito vector, although acting in a distinct way topbcrmp1and2. Mutants lacking expression of PCRMP3 or PCRMP4 show normal blood stage development and oocyst formation in the mosquito and develop into morphologically normal sporozoites, but these have a defect in egress from oocysts and do not enter the salivary glands. Sporozoites extracted from oocysts perform gliding motility and invade and infect hepatocytes but do not undergo further development and proliferation. Furthermore, the study shows that immunization with Δcrmp3and Δcrmp4sporozoites does not confer protective immunity upon subsequent challenge.

Conclusions

PCRMP3 and 4 play multiple roles during thePlasmodiumlife cycle; they are essential for the establishment of sporozoite infection in the mosquito salivary gland, and subsequently for development in hepatocytes. However, although Δpcrmp3and Δpcrmp4parasites are completely growth-impaired in the liver, immunization with live sporozoites does not induce the protective immune responses that have been shown for other genetically-attenuated parasites.
Stability and rheology of dilute TiO2-water nanofluids
Authors: Penkavova Vera , Tihon Jaroslav , Wein Ondrej
Published: April 2011

The apparent wall slip (AWS) effect, accompanying the flow of colloidal dispersions in confined geometries, can be an important factor for the applications of nanofluids in heat transfer and microfluidics. In this study, a series of dilute TiO2 aqueous dispersions were prepared and tested for the possible presence of the AWS effect by means of a novel viscometric technique. The nanofluids, prepared from TiO2 rutile or anatase nanopowders by ultrasonic dispersing in water, were stabilized by adjusting the pH to the maximum zeta potential. The resulting stable nanofluid samples were dilute, below 0.7 vol.%. All the samples manifest Newtonian behavior with the fluidities almost unaffected by the presence of the dispersed phase. No case of important slip contribution was detected: the Navier slip coefficient of approximately 2 mm Pa-1 s-1 would affect the apparent fluidity data in a 100-μm gap by less than 1%.
Absorption and scattering properties of carbon nanohorn-based nanofluids for direct sunlight absorbers
Authors: Mercatelli Luca , Sani Elisa , Zaccanti Giovanni , Martelli Fabrizio , Di Ninni Paola , Barison Simona , Pagura Cesare , Agresti Filippo , Jafrancesco David
Published: April 2011

In the present work, we investigated the scattering and spectrally resolved absorption properties of nanofluids consisting in aqueous and glycol suspensions of single-wall carbon nanohorns. The characteristics of these nanofluids were evaluated in view of their use as sunlight absorber fluids in a solar device. The observed nanoparticle-induced differences in optical properties appeared promising, leading to a considerably higher sunlight absorption with respect to the pure base fluids. Scattered light was found to be not more than about 5% with respect to the total attenuation of light. Both these effects, together with the possible chemical functionalization of carbon nanohorns, make this new kind of nanofluids very interesting for increasing the overall efficiency of the sunlight exploiting device.

PACS

78.40.Ri, 78.35.+c, 78.67.Bf, 88.40.fh, 88.40.fr, 81.05.U.
Multicolor fluorescent in situ hybridization to define abutting and overlapping gene expression in the embryonic zebrafish brain
Authors: Lauter Gilbert , Söll Iris , Hauptmann Giselbert
Published: April 2011

Background

In recent years, mapping of overlapping and abutting regulatory gene expression domains by chromogenic two-color in situ hybridization has helped define molecular subdivisions of the developing vertebrate brain and shed light on its basic organization. Despite the benefits of this technique, visualization of overlapping transcript distributions by differently colored precipitates remains difficult because of masking of lighter signals by darker color precipitates and lack of three-dimensional visualization properties. Fluorescent detection of transcript distributions may be able to solve these issues. However, despite the use of signal amplification systems for increasing sensitivity, fluorescent detection in whole-mounts suffers from rapid quenching of peroxidase (POD) activity compared to alkaline phosphatase chromogenic reactions. Thus, less strongly expressed genes cannot be efficiently detected.

Results

We developed an optimized procedure for fluorescent detection of transcript distribution in whole-mount zebrafish embryos using tyramide signal amplification (TSA). Conditions for hybridization and POD-TSA reaction were optimized by the application of the viscosity-increasing polymer dextran sulfate and the use of the substituted phenol compounds 4-iodophenol and vanillin as enhancers of POD activity. In combination with highly effective bench-made tyramide substrates, these improvements resulted in dramatically increased signal-to-noise ratios. The strongly enhanced signal intensities permitted fluorescent visualization of less abundant transcripts of tissue-specific regulatory genes. When performing multicolor fluorescent in situ hybridization (FISH) experiments, the highly sensitive POD reaction conditions required effective POD inactivation after each detection cycle by glycine-hydrochloric acid treatment. This optimized FISH procedure permitted the simultaneous fluorescent visualization of up to three unique transcripts in different colors in whole-mount zebrafish embryos.

Conclusions

Development of a multicolor FISH procedure allowed the comparison of transcript gene expression domains in the embryonic zebrafish brain to a cellular level. Likewise, this method should be applicable for mRNA colocalization studies in any other tissues or organs. The key optimization steps of this method for use in zebrafish can easily be implemented in whole-mount FISH protocols of other organisms. Moreover, our improved reaction conditions may be beneficial in any application that relies on a TSA/POD-mediated detection system, such as immunocytochemical or immunohistochemical methods.
Papillary renal cell carcinoma with metastatic laparoscopic port site and vaginal involvement: a case report
Authors: Chuang Xue En , Loh Hwai Liang , Sim Hong Gee , Fong Kah Leng , Tan Min-Han
Published: April 2011

Introduction

Laparoscopic port-site metastasis is a rare but well recognized outcome following surgery in urological cancers, with its etiology not clearly understood. Additionally, vaginal metastasis in clear cell renal cell carcinoma is rare, and has not been previously reported in the setting of papillary renal cell carcinoma.

Case presentation

We present the case of a 71-year-old Chinese woman with metastatic type II papillary renal cell carcinoma with histologically verified vaginal involvement and a concurrent laparoscopic port-site metastasis. This was also associated with a unique constellation of widely disseminated metastatic sites, which include a local relapse, the peritoneum and the urethra.

Conclusion

Laparoscopic port-site metastases are associated with the presence of advanced cancer with multiple sites of metastasis. We hypothesize from the findings of our report and background data that this phenomenon is more likely to be related to tumor factors rather than operative factors. We also present what is, to the best of our knowledge, the first reported case in the literature of vaginal and urethral metastasis and the second reported case of laparoscopic port-site recurrence.
Synergy between inhibitors of androgen receptor and MEK has therapeutic implications in estrogen receptor-negative breast cancer
Authors: Naderi Ali , Chia Kee Ming , Liu Ji
Published: April 2011

Introduction

Estrogen receptor-negative (ER-) breast cancer is a heterogeneous disease with limited therapeutic options. The molecular apocrine subtype constitutes 50% of ER-tumors and is characterized by overexpression of steroid response genes including androgen receptor (AR). We have recently identified a positive feedback loop between the AR and extracellular signal-regulated kinase (ERK) signaling pathways in the molecular apocrine subtype. In this feedback loop, AR regulates ERK phosphorylation through the mediation of ErbB2 and, in turn, ERK-CREB1 signaling regulates the transcription of AR in molecular apocrine cells. In this study, we investigated the therapeutic implications of the AR-ERK feedback loop in molecular apocrine breast cancer.

Methods

We examined a synergy between the AR inhibitor flutamide and the MEK inhibitor CI-1040 in the molecular apocrine cell lines MDA-MB-453, HCC-1954 and HCC-202 using MTT cell viability and annexin V apoptosis assays. Synergy was measured using the combination index (CI) method. Furthermore, we examined in vivo synergy between flutamide and the MEK inhibitor PD0325901 in a xenograft model of the molecular apocrine subtype. The effects of in vivo therapies on tumor growth, cell proliferation and angiogenesis were assessed.

Results

We demonstrate synergistic CI values for combination therapy with flutamide and CI-1040 across three molecular apocrine cell lines at four dose combinations using both cell viability and apoptosis assays. Furthermore, we show in vivo that combination therapy with flutamide and MEK inhibitor PD0325901 has a significantly higher therapeutic efficacy in reducing tumor growth, cellular proliferation and angiogenesis than monotherapy with these agents. Moreover, our data suggested that flutamide and CI-1040 have synergy in trastuzumab resistance models of the molecular apocrine subtype. Notably, the therapeutic effect of combination therapy in trastuzumab-resistant cells was associated with the abrogation of an increased level of ERK phosphorylation that was developed in the process of trastuzumab resistance.

Conclusions

In this study, we demonstrate in vitro and in vivo synergies between AR and MEK inhibitors in molecular apocrine breast cancer. Furthermore, we show that combination therapy with these inhibitors can overcome trastuzumab resistance in molecular apocrine cells. Therefore, a combination therapy strategy with AR and MEK inhibitors may provide an attractive therapeutic option for the ER-/AR+ subtype of breast cancer.
Stimulation of Activin A/Nodal signaling is insufficient to induce definitive endoderm formation of cord blood-derived unrestricted somatic stem cells
Authors: Filby Caitlin E , Williamson Robert , van Kooy Peter , Pébay Alice , Dottori Mirella , Elwood Ngaire J , Zaibak Faten
Published: April 2011

Introduction

Unrestricted somatic stem cells (USSC) derived from umbilical cord blood are an attractive alternative to human embryonic stem cells (hESC) for cellular therapy. USSC are capable of forming cells representative of all three germ line layers. The aim of this study was to determine the potential of USSC to form definitive endoderm following induction with Activin A, a protein known to specify definitive endoderm formation of hESC.

Methods

USSC were cultured for (1) three days with or without 100 ng/ml Activin A in either serum-free, low-serum or serum-containing media, (2) three days with or without 100 ng/ml Activin A in combination with 10 ng/ml FGF4 in pre-induction medium, or (3) four days with or without small molecules Induce Definitive Endoderm (IDE1, 100 nM; IDE2, 200 nM) in serum-free media. Formation of definitive endoderm was assessed using RT-PCR for gene markers of endoderm (Sox17, FOXA2 and TTF1) and lung epithelium (surfactant protein C; SPC) and cystic fibrosis transmembrane conductance regulator; CFTR). The differentiation capacity of Activin A treated USSC was also assessed.

Results

Activin A or IDE1/2 induced formation of Sox17+ definitive endoderm from hESC but not from USSC. Activin A treated USSC retained their capacity to form cells of the ectoderm (nerve), mesoderm (bone) and endoderm (lung). Activin A in combination with FGF4 did not induce formation of Sox17+ definitive endoderm from USSC. USSC express both Activin A receptor subunits at the mRNA and protein level, indicating that these cells are capable of binding Activin A.

Conclusions

Stimulation of the Nodal signaling pathway with Activin A or IDE1/2 is insufficient to induce definitive endoderm formation from USSC, indicating that USSC differ in their stem cell potential from hESC.
Colonial Aphasia: Race and Disabled Histories in France
Authors: Stoler Ann Laura
Published: April 2011

If the Republic and Empire are now difficult to view as mutually exclusive categories in contemporary France, few scholars have sought to address the conventions of knowledge production that have made France's own history of a racialized polity so rarely a subject for the French academic elite. The term “colonial aphasia” is invoked to supplant the notions of “amnesia” or “forgetting,” to focus rather on three features: an occlusion of knowledge, a difficulty generating a vocabulary that associates appropriate words and concepts with appropriate things, and a difficulty comprehending the enduring relevancy of what has already been spoken.
Postcolonizing France
Authors: Baneth-Nouailhetas Emilienne
Published: April 2011

This article isolates a few flashpoints in the debating space opened up by the copresence, within a volume, of contributions by Jean-François Bayart, Achille Mbembe, and Ann Laura Stoler. The concepts or notions discussed are useful as core samplings of the multiple layers of the postcolonial argument unfolding within a group of French scholars. At the heart of the postcolonial debate are the very definitions of the “social sciences” and “humanities” and the remapping of the knowledge they contain and produce. These repeated disjunctions among enunciative spaces, the discrepancies among apparently common signifiers rooted in radically differing tropologies, reveal this debate as a crucible of and for postcolonial thought.
Mediating Memories. The Ethics of Post-9/11 Spectatorship
Authors: Smelik Anneke
Published: April 2011

What is the notion of ‘mediated memory’ in relation to films and other media about 9/11? Media technologies invariably shape our memories of past and present life. Rather than simply representing the past, even the recent past of an event like the attack on the Twin Towers, television, computers, cinema and other media enable and produce particular memories with the use of specific techniques. Representations of 9/11 constituted a case of ‘real virtuality' that turned the disaster into a media spectacle. The question then becomes how later films can avoid spectacularization; how they can visualize a disaster that is already settled in cultural memory. How can spectators assume an ethical position in a global media culture that promotes a theme park of disaster?
The Violin Player, the Soccer Game and the Wall-Graffiti. Rhetorical Strategies in the Border-Regions between Israel and Palestine
Authors: Rokem Freddie
Published: April 2011

This contribution examines an incident at a roadblock which took place in November 2004, documented in a short video and was also reproduced as a still in Israeli media. This image immediately became broadly discussed and contested. It shows a young Palestinian man playing a violin at a check point while a group of Israeli soldiers are standing and guarding the place. This image was drawn into larger clusters of signification where the rhetorical strategies employed become both quite complex and ambiguous. The image became contextualized within discourses of conflict, creating what Walter Benjamin in his Passagenwerk termed “constellations.” – Besides presenting this notion and its hermeneutic potentials my article examines the historical associations of the image, arguing that the associations with the Holocaust are actually a way to minimize the pain and suffering of the Palestinians under Israeli occupation rather than highlighting them in a broader universal context. – Another aspect of this image is connected to the technologies of creating and disseminating images of conflict/occupation and how they affect the ethical discussions surrounding this incident. I will argue that historical constellations tend to obscure rather than sharpen the ethical dimensions of images like the Palestinian violin player at the check point. – A number of graffiti paintings on the separation wall, in particular by the British graffiti artist Bansky, as well as a cellphone advertisement featuring the separation wall will be examined in order to contextualize the discourses of conflict and occupation.
Beyond Medusa. Recovering History on Stage
Authors: Röttger Kati
Published: April 2011

The theatre work of the Austrian Elfriede Jelinek is known for its critique of mythology. In her recent “work in progress”, which closely follows media reports about the Iraq war and the tortures in Abu Ghraib, Jelinek concentrates on the mythologizing effects of a “wartainment” that a supposedly alert, educated population can witness as little more than a spectacular television melodrama. According to Jelinek this rapidly erases the event from public memory. In the second step of her progressing work, “Babel” (2005), she deconstructs these telematic strategies of forgetting, ignoring and blinding traumatic experiences by creating what she in a slightly ironical way calls an “artwork of morality”. Jelinek is pleading with her work for a concept of performing history (on stage) that inscribes what does not let inscribe itself: the contingency of events of terror, war and torture that ruptures continuity and signification.
Unclaimed and Unclaimable. Memories of the RAF
Authors: Siegmund Gerald
Published: April 2011

This essay deals with the traumatic memory of the RAF, a German terrorist group from the 1970s, as staged by two theatre productions, Klaus Michael Grüber's Winterreise from 1977 and Nicolas Stemann's Ulrike Maria Stuart from 2006. Despite their very different aesthetics, Grüber and Stemann share artistic strategies of dealing with history in the theatre in general and the history of the RAF in particular. Rather than creating a fictional world that remembers and represents past events as completed acts, both directors use metonymic devices to deconstruct space and character, situation and speech. They transpose historic events into a performative play with absences rather than presences, thereby spectralising the past and asking the audience to assume its position in the unfolding spectrum of remaining questions and contradictions. Thus the essay proposes a form of memory specific to the aesthetic experience: ‘aesthetic memory’ is not primarily concerned with creating continuity and stabilizing identities, but with keeping the questions of the past open.
Afterimages. Post-Holocaust, Posttraumatic, and Postcolonial Cinemas
Authors: Hirsch Joshua
Published: April 2011

Based on the author's previous work, which posited a posttraumatic form of cinema emerging in France after the Second World War, this article focuses primarily on the representation of the Holocaust in films like Night and Fog, The Pawnbroker, and Shoah. These films not only represented traumatic events, they also developed new aesthetic strategies that encouraged a posttraumatic historical consciousness in the audience. More recent work of the author compares this posttraumatic cinema of the Holocaust with the cinematic responses of filmmakers from other cultures to other historical traumas. To what extent are these cinematic responses to trauma influenced by or similar to the posttraumatic cinema of the Holocaust, and to what extent do they differ? The article summarizes the posttraumatic cinema of the Holocaust, and then compares and contrasts it to two other posttraumatic films: Sankofa (about African-American slavery) and History and Memory (about the Japanese American internment camps). History and Memory – made by Rea Tajiri, a woman – can be used to problematize the relationship between trauma and gender in the other films.