bluuebunny/crossref_metadata_2025 huggingface dataset:
Initial Multi‐institutional Experience with Transoral Robotic Surgery
Authors: Vergez Sebastien , Lallemant Benjamin , Ceruse Philippe , Moriniere Sylvain , Aubry Karine , De Mones Erwan , Benlyazid Adil , Mallet Yann
Published: April 2012

Objective

To assess the initial experience for transoral robotic surgery (TORS), as observed in the French TORS group.

Study Design

A multi‐institutional prospective cohort study.

Setting

Seven tertiary referral centers.

Subjects and Methods

One hundred thirty consecutive patients who were scheduled for a TORS between October 2008 and March 2011 were included. The operative times, conversion rates, morbidity, and alternatives were described. The serious adverse effects encountered were analyzed, and recommendations for avoiding them are specified.

Results

Most of the patients (65%) had a laryngeal (supraglottic) and/or hypopharyngeal resection. Thirty‐nine of the 130 patients receiving TORS would have had a transoral laser resection as their alternative surgery. The tumor exposure was suboptimal in 26% of the cases. Six of the 130 patients needed conversion to an open approach. There were 15 postoperative hemorrhages and 2 deaths due to posthemorrhage complications in patients with significant comorbidities at 9 and 18 days after the surgery. The median setup and procedure times were 52 ± 46 and 90 ± 92 minutes, respectively. The learning curve was characterized by better selection and management of potential patients.

Conclusion

The visualization offered by the robotic assistance allowed transoral resections of tumors that were difficult to resect or unresectable by laser surgery. Self‐assessment of surgical exposure and a decrease in the need to convert to an open procedure over time suggested improvement in TORS‐related surgical skills. Nevertheless, strict patient selection is essential. Even with a minimally invasive approach, some patients will need a tracheostomy for safety reasons.
Age-Related Differences in Health Beliefs Regarding Cervical Cancer Screening Among Korean American Women
Authors: Lee Eunice E. , Eun Young , Lee Shin-Young , Nandy Karabi
Published: April 2012

Cervical cancer screening rates among older Korean American (KA) women are much lower than the rates for younger KA women, even though the overall cancer screening rates in the population continue to have one of the lowest Papanicolaou (Pap) test adherence rates compared with non-Hispanic White women. Variables based on the Health Belief Model related to cervical cancer screening were compared by age group among KA women. A telephone survey was conducted with 189 KA women living in the midwestern United States. Perceived barriers to having a Pap test predicted the outcome variable of having had Pap tests in the preceding 3 years in older KA women who were 65 or older, but not in younger women who were between 40 and 64 years old. Having physical examinations without symptoms in the preceding 2 years predicted the outcome variable in both age groups. Intervention strategies for all KA women should focus on encouraging them to receive routine physical examinations. In addition, attempts should be made to reduce perception of barriers in older KA women to improve their cervical cancer screening behaviors.
Pilot Intervention to Increase Physical Activity Among Sedentary Urban Middle School Girls
Authors: Robbins Lorraine B. , Pfeiffer Karin A. , Maier Kimberly S. , Lo Yun-Jia , Wesolek (LaDrig) Stacey M.
Published: April 2012

The primary purpose of the study was to determine whether girls in one school receiving nurse counseling plus an after-school physical activity club showed greater improvement in physical activity, cardiovascular fitness, and body composition than girls assigned to an attention control condition in another school ( N = 69). Linear regressions controlling for baseline measures showed no statistically significant group differences, but the directionality of differences was consistent with greater intervention group improvement for minutes of moderate to vigorous physical activity/hour ( t = 0.95, p = .35), cardiovascular fitness ( t = 1.26, p = .22), body mass index (BMI; t = −1.47, p = .15), BMI z score ( t = −1.19, p = .24), BMI percentile ( t = −0.59, p = .56), percentage body fat ( t = −0.86, p = .39), and waist circumference ( t = −0.19, p = .85). Findings support testing with a larger sample.
Continuing the Carbonatite Controversy Preface
Authors: Downes H. , Wall F. , Demény A. , Szabó Cs.
Published: April 2012

Carbonatites have always been controversial (Mitchell, 2005). Their magmatic origin was disputed in the early days of the last century, regardless of the fact that experiments clearly demonstrated the crystallization of magmatic calcite (Wyllie and Tuttle, 1960). The observation of the eruption of natrocarbonatite lava in Oldoinyo Lengai (Dawson 1962) finally convinced petrologists that they were dealing with the products of magmatic carbonate liquids. Since that time, further controversies have emerged, especially regarding the ultimate origin of carbonatite magmas, for which there are two ‘endmember’ hypotheses. The generally accepted hypothesis is based on isotopic evidence and suggests that carbonatites are from deep asthenospheric sources, such as mantle plumes (Bell, 2001; Bell et al., 2004). This fails to explain why carbonatites are essentially confined to the continental lithosphere and are extremely rare in the ocean basins (Woolley and Kjarsgaard, 2008; Woolley and Bailey, this issue), and leads to the alternative hypothesis of lithosphere-generated carbonatitic magmatism. It may be that this is simply because we have not yet understood how to identify carbonatites in oceanic regions (Bailey and Kearns, this volume), or there may be some more profound reason why carbonatites cannot form within or erupt through oceanic lithosphere.
Crossveinless 2 regulates bone morphogenetic protein 9 in human and mouse vascular endothelium
Authors: Yao Yucheng , Jumabay Medet , Ly Albert , Radparvar Melina , Wang Anthony H. , Abdmaulen Raushan , Boström Kristina I.
Published: April 2012

The importance of morphogenetic proteins (BMPs) and their antagonists in vascular development is increasingly being recognized. BMP-4 is essential for angiogenesis and is antagonized by matrix Gla protein (MGP) and crossveinless 2 (CV2), both induced by the activin receptor like-kinase 1 (ALK1) when stimulated by BMP-9. In this study, however, we show that CV2 preferentially binds and inhibits BMP-9 thereby providing strong feedback inhibition for BMP-9/ALK1 signaling rather than for BMP-4/ALK2 signaling. CV2 disrupts complex formation involving ALK2, ALK1, BMP-4, and BMP-9 required for the induction of both BMP antagonists. It also limits VEGF expression, proliferation, and tube formation in ALK1-expressing endothelial cells. In vivo, CV2 deficiency translates into a dysregulation of vascular BMP signaling, resulting in an abnormal endothelium with increased endothelial cellularity and expression of lineage markers for mature endothelial cells. Thus, mutual regulation by BMP-9 and CV2 is essential in regulating the development of the vascular endothelium.
A genome-wide study of two-component signal transduction systems in eight newly sequenced mutans streptococci strains
Authors: Song Lifu , Sudhakar Padhmanand , Wang Wei , Conrads Georg , Brock Anke , Sun Jibin , Wagner-Döbler Irene , Zeng An-Ping
Published: April 2012

Background

Mutans streptococci are a group of gram-positive bacteria including the primary cariogenic dental pathogen Streptococcus mutans and closely related species. Two component systems (TCSs) composed of a signal sensing histidine kinase (HK) and a response regulator (RR) play key roles in pathogenicity, but have not been comparatively studied for these oral bacterial pathogens.

Results

HKs and RRs of 8 newly sequenced mutans streptococci strains, including S. sobrinus DSM20742, S. ratti DSM20564 and six S. mutans strains, were identified and compared to the TCSs of S. mutans UA159 and NN2025, two previously genome sequenced S. mutans strains. Ortholog analysis revealed 18 TCS clusters (HK-RR pairs), 2 orphan HKs and 2 orphan RRs, of which 8 TCS clusters were common to all 10 strains, 6 were absent in one or more strains, and the other 4 were exclusive to individual strains. Further classification of the predicted HKs and RRs revealed interesting aspects of their putative functions. While TCS complements were comparable within the six S. mutans strains, S. sobrinus DSM20742 lacked TCSs possibly involved in acid tolerance and fructan catabolism, and S. ratti DSM20564 possessed 3 unique TCSs but lacked the quorum-sensing related TCS (ComDE). Selected computational predictions were verified by PCR experiments.

Conclusions

Differences in the TCS repertoires of mutans streptococci strains, especially those of S. sobrinus and S. ratti in comparison to S. mutans, imply differences in their response mechanisms for survival in the dynamic oral environment. This genomic level study of TCSs should help in understanding the pathogenicity of these mutans streptococci strains.
Therapeutic implications of an enriched cancer stem-like cell population in a human osteosarcoma cell line
Authors: Martins-Neves Sara R , Lopes Áurio O , do Carmo Anália , Paiva Artur A , Simões Paulo C , Abrunhosa Antero J , Gomes Célia MF
Published: April 2012

Background

Osteosarcoma is a bone-forming tumor of mesenchymal origin that presents a clinical pattern that is consistent with the cancer stem cell model. Cells with stem-like properties (CSCs) have been identified in several tumors and hypothesized as the responsible for the relative resistance to therapy and tumor relapses. In this study, we aimed to identify and characterize CSCs populations in a human osteosarcoma cell line and to explore their role in the responsiveness to conventional therapies.

Methods

CSCs were isolated from the human MNNG/HOS cell line using the sphere formation assay and characterized in terms of self-renewal, mesenchymal stem cell properties, expression of pluripotency markers and ABC transporters, metabolic activity and tumorigenicity. Cell's sensitivity to conventional chemotherapeutic agents and to irradiation was analyzed and related with cell cycle-induced alterations and apoptosis.

Results

The isolated CSCs were found to possess self-renewal and multipotential differentiation capabilities, express markers of pluripotent embryonic stem cells Oct4 and Nanog and the ABC transporters P-glycoprotein and BCRP, exhibit low metabolic activity and induce tumors in athymic mice. Compared with parental MNNG/HOS cells, CSCs were relatively more resistant to both chemotherapy and irradiation. None of the treatments have induced significant cell-cycle alterations and apoptosis in CSCs.

Conclusions

MNNG/HOS osteosarcoma cells contain a stem-like cell population relatively resistant to conventional chemotherapeutic agents and irradiation. This resistant phenotype appears to be related with some stem features, namely the high expression of the drug efflux transporters P-glycoprotein and BCRP and their quiescent nature, which may provide a biological basis for resistance to therapy and recurrence commonly observed in osteosarcoma.
Clinical scale rapid expansion of lymphocytes for adoptive cell transfer therapy in the WAVE® bioreactor
Authors: Somerville Robert PT , Devillier Laura , Parkhurst Maria R , Rosenberg Steven A , Dudley Mark E
Published: April 2012

Background

To simplify clinical scale lymphocyte expansions, we investigated the use of the WAVE®, a closed system bioreactor that utilizes active perfusion to generate high cell numbers in minimal volumes.

Methods

We have developed an optimized rapid expansion protocol for the WAVE bioreactor that produces clinically relevant numbers of cells for our adoptive cell transfer clinical protocols.

Results

TIL and genetically modified PBL were rapidly expanded to clinically relevant scales in both static bags and the WAVE bioreactor. Both bioreactors produced comparable numbers of cells; however the cultures generated in the WAVE bioreactor had a higher percentage of CD4+ cells and had a less activated phenotype.

Conclusions

The WAVE bioreactor simplifies the process of rapidly expanding tumor reactive lymphocytes under GMP conditions, and provides an alternate approach to cell generation for ACT protocols.
Implementation of legal abortion in Nepal: a model for rapid scale-up of high-quality care
Authors: Samandari Ghazaleh , Wolf Merrill , Basnett Indira , Hyman Alyson , Andersen Kathryn
Published: April 2012

Unsafe abortion's significant contribution to maternal mortality and morbidity was a critical factor leading to liberalization of Nepal's restrictive abortion law in 2002. Careful, comprehensive planning among a range of multisectoral stakeholders, led by Nepal's Ministry of Health and Population, enabled the country subsequently to introduce and scale up safe abortion services in a remarkably short timeframe. This paper examines factors that contributed to rapid, successful implementation of legal abortion in this mountainous republic, including deliberate attention to the key areas of policy, health system capacity, equipment and supplies, and information dissemination. Important elements of this successful model of scaling up safe legal abortion include: the pre-existence of postabortion care services, through which health-care providers were already familiar with the main clinical technique for safe abortion; government leadership in coordinating complementary contributions from a wide range of public- and private-sector actors; reliance on public-health evidence in formulating policies governing abortion provision, which led to the embrace of medical abortion and authorization of midlevel providers as key strategies for decentralizing care; and integration of abortion care into existing Safe Motherhood and the broader health system. While challenges remain in ensuring that all Nepali women can readily exercise their legal right to early pregnancy termination, the national safe abortion program has already yielded strong positive results. Nepal's experience making high-quality abortion care widely accessible in a short period of time offers important lessons for other countries seeking to reduce maternal mortality and morbidity from unsafe abortion and to achieve Millennium Development Goals.
Low back pain during pregnancy caused by a sacral stress fracture: a case report
Authors: Pishnamaz Miguel , Sellei Richard , Pfeifer Roman , Lichte Philipp , Pape Hans C , Kobbe Philipp
Published: April 2012

Introduction

Sacral stress fractures are a rare but well known cause of low back pain. This type of fracture has also been observed as a postpartum complication. To date, no cases of intrapartum sacral stress fractures have been described in the literature.

Case presentation

We report the case of a 26-year-old Caucasian European primigravid patient (30 weeks and two days of gestation) who presented to our outpatient clinic with severe low back pain that had started after a downhill walk 14 days previously. She had no history of trauma. A magnetic resonance imaging scan revealed a non-displaced stress fracture of the right lateral mass of her sacrum. Following her decision to opt for non-operative treatment, our patient received an epidural catheter for pain control. The remaining course of her pregnancy was uneventful and our patient gave birth to a healthy child by normal vaginal delivery.

Conclusions

We conclude that a sacral stress fracture must be considered as a possible cause of low back pain during pregnancy.
Plant polyphenols as electron donors for erythrocyte plasma membrane redox system: validation through in silico approach
Authors: Kesharwani Rajesh Kumar , Singh Durg Vijay , Misra Krishna , Rizvi Syed Ibrahim
Published: April 2012

Background

The plasma membrane redox system (PMRS) has extensively been studied in erythrocytes. The PMRS plays an important role in maintaining plasma redox balance and provides a protective mechanism against oxidative stress. Earlier it was proposed that only NADH or NADPH provided reducing equivalents to PMRS; however, now it is acknowledged that some polyphenols also have the ability to donate reducing equivalents to PMRS.

Methods

Two different docking simulation softwares, Molegro Virtual Docker and Glide were used to study the interaction of certain plant polyphenols viz. quercetin, epigallocatechin gallate, catechin epicatechin and resveratrol with human erythroyte NADH-cytochrome b5 reductase, which is a component of PMRS and together with the identification of minimum pharmacophoric feature using Pharmagist.

Results

The derived common minimum pharmacophoric features show the presence of minimum bioactive component in all the selected polyphenols. Our results confirm wet lab findings which show that these polyphenols have the ability to interact and donate protons to the Human NADH-cytochrome b5 reductase.

Conclusion

With the help of these comparative results of docking simulation and pharmacophoric features, novel potent molecules can be designed with higher efficacy for activation of the PMRS system.
A Conversation “Overflowing with Memory”
Authors: Allen Jafari S. , Tinsley Omise'eke Natasha
Published: April 2012

This conversation between Jafari S. Allen and Omise'eke Natasha Tinsley (with Natalie Bennett, Rosamond S. King, Rinaldo Walcott, and Michelle Wright) follows a lively debate during the Black/Queer/Diaspora Work(ing) Group symposium in 2009. This debate centered on the promise and pitfalls associated with pushing beyond disciplinary frameworks and methodological conventions toward, for example, narrative theorizing and creative responses as a legitimate way to represent black women's (erotic) histories. Whither interdisciplinarity? What are the limits of various approaches and genres? This conversation serves as a preface to an excerpt from Tinsley's work of historical fiction. The conversation takes up scholars' responses to the impossibility of knowing some of the particularities of historical experience and subjectivity, as Tinsley's contribution attempts to revindicate the theoretics of those who, in Barbara Christian's words, “have always been a race for theory.”
Chatting Back an Epidemic
Authors: Gill Lyndon K.
Published: April 2012

The popular presumption of a particularly vicious homophobia in the anglophone Caribbean has nearly rendered (especially male) homosexuality implausible for anyone living in the region. However, Caribbean men who have sex with men (MSM) are disturbingly omnipresent in the public health discourses circulating throughout the region. These MSM are nearly always overrepresented by a subgrouping of openly gay Caribbean men. Yet the forbidding absence of Caribbean homosexuality in popular discourses and the dangerously pervasive presence of Caribbean MSM in public health discourses both indicate a failure to recognize not only the existence of decidedly gay Caribbean men but also—and more important—the work these men have been doing for three decades to survive the HIV/AIDS pandemic. This analysis sits with Friends For Life—one of the only HIV/AIDS nongovernmental organizations in the Caribbean region run by and for self-identified gay men—to see how these men have used the erotic to survive.
Highly Efficient Aqueous Oxidation of Furfural to Succinic Acid Using Reusable Heterogeneous Acid Catalyst with Hydrogen Peroxide
Authors: Choudhary Hemant , Nishimura Shun , Ebitani Kohki
Published: April 2012

Green oxidation of inedible biomass-based 2-furaldehyde (furfural) to succinic acid (SA), one of the most important building blocks, was successfully achieved using Amberlyst-15 as a reusable solid acid catalyst in water at 353 K in the presence of hydrogen peroxide (H2O2).
Synthesis and Adsorption Properties of Azulene-containing Porous Interdigitated Framework
Authors: Kishida Keisuke , Horike Satoshi , Nakagawa Keiji , Kitagawa Susumu
Published: April 2012

A porous interdigitated 2D coordination framework {[Zn(azdc)(bpy)]·DMF}n (azdc: 1,6-azulenedicarboxylate; bpy: 4,4′-bipyridyl; DMF: N,N-dimethylformamide) was synthesized and structurally characterized. By comparing with its constitutional isomer, [Zn(azdc)(bpy)]n showed stronger H2O interaction which was induced by polarized azulene moiety.
Possibility of Vitamin C to Induce the Formation of Lecithin Organogel
Authors: Hashizaki Kaname , Watanabe Naohito , Imai Miko , Taguchi Hiroyuki , Saito Yoshihiro
Published: April 2012

We investigated the formation of a new lecithin organogel composed of reverse worm-like micelles. The organogel is a mixed organic solution containing lecithin and vitamin C (i.e., ascorbic acid). The highly viscoelastic reverse worm-like micelles were formed upon addition of a small amount of ascorbic acid.
Microwave-assisted Synthesis of Highly Crystalline Mesoporous Hydroxyapatite with a Rod-shaped Morphology
Authors: Benzigar Mercy R , Mane Gurudas P , Talapaneni Siddulu N , Varghese Shaji , Anand Chokkalingam , Aldeyab Salem S , Balasubramanian Veerappan V , Vinu Ajayan
Published: April 2012

Mesoporous hydroxyapatite (MHA) with a rod-shaped morphology has been successfully synthesized for the first time employing cetyltrimethylammonium bromide (CTAB) as a template and CaCl2 and K2HPO4 as the precursors for hydroxyapatite under alkaline medium at the reaction temperature of 120 °C via microwave method. The obtained material exhibits a disordered mesoporous structure with a high crystallinity and highly uniform rod-like morphology with an average size of ca. 25 nm in width and 100 nm in length.
Quantification of Human Discomfort in a Vehicle Using a Four-Post Rig Excitation
Authors: Ibicek T , Thite A N
Published: April 2012

The ride comfort of a vehicle is a vital aspect determining competitiveness of vehicles. The comfort is intricately related to feelings of discomfort due to vibration. The discomfort depends on various dynamic aspects of the suspension-seat and surrounding system. In industry, the discomfort due to vibration is assessed by road testing on various surfaces; these road tests may not be accurately repeatable. Discomfort, in general, can be assessed by measurements based on a shaker table and seat combination. These results when used for “in vehicle situations” may not accurately indicate the level of human discomfort in a vehicle. In view of this, to quantify seated human discomfort in a vehicle, measurements were performed using a four-post rig simulator; the setup allows controlled in-situ experiments to be conducted. A group of six subjects were exposed to sinusoidal vibration at five magnitudes in the vertical direction for heave, roll and pitch motion. The objective is to develop a discomfort metric which could be used to compare vehicles. The preliminary results show varying significance of roll, pitch and heave motion. The results, however, confirm the nonlinear variation of perception as a function of the physical stimulus. The test setup can be used to study the effects of complex road inputs and eventually may contribute towards reduced reliance on road tests.
Numerical Assessment of One-Chamber Plenums Lined with Multi-Layer Sound Absorbers Using a Particle Swarm Method
Authors: Chiu Min-Chie
Published: April 2012

High noise levels can be harmful to workers and can lead to psychological and physiological ailments. Consequently, noise control in an industrial setting is vital. Acoustical plenums have been widely used in depressing industrial venting noise. Because of the constrainment problem in practical engineering work, there is a growing need to optimize acoustical performance within a fixed space. However, research work of shape optimization on a space-constrained acoustical plenum by adjusting the design parameters has been neglected. In addition, the optimal mechanism of internal sound absorbers within the plenum has been ignored. In order to efficiently design a better performancing acoustical plenum with minumum manufacturing costs, a numerical assessment used to search for an optimally shaped one-chamber acoustical plenum lined with four kinds of multi-layer sound absorbers (one-layer, two-layer, three layer, and four-layer) in conjunction with a particle swarm method ( PSO) will be introduced. Before dealing with a broadband noise, a reliability check of the PSO method by maximizing the sound absorption coefficient ( α) for a three-layer sound absorber at a pure tone (500 Hz) will be performed.

Consequently, this paper provides a quick economical, and effective method for reducing noise levels by optimally designing a shaped one-chamber acoustical plenum lined with multi-layer sound absorbers using a particle swarm method.
Model Error and Structural Reliability for Reinforced Concrete Block Masonry Walls in Shear
Authors: Zhai Ximei , Zhong Zhifeng , Stewart Mark G.
Published: April 2012

The present paper develops a probabilistic model to calculate the structural reliability of typical reinforced grouted concrete block masonry walls designed to Chinese standards, loaded in horizontal shear. The statistical parameters for model error used for the structural reliability analysis are obtained from a database of wall test data from China. The effect of probability distribution of model error, the compressive strength for grouted concrete block masonry, live load type, load effect ratio, reinforcement ratio, wall length, wall size or strength discretization, vertical compressive load and ratio of shear span to depth were considered when calculating the structural reliability of reinforced masonry walls in shear. The structural reliability for reinforced concrete block masonry walls in shear is sensitive to the probability distribution of model error. The recommended lognormal distribution of model error based on test data provided a high reliability index, and when using Gamma and Gumbel distributions for typical structures the existing (design) safety levels were also found to exceed the target reliability of 3.7, whereas the safety levels were less than the target reliability using Normal and Weibull distributions of model error.
On Temperature Gradients in High-Performance Concrete Box Girder under Solar Radiation
Authors: Song Zhiwen , Xiao Jianzhuang , Shen Luming
Published: April 2012

This paper investigates the characteristics of temperature gradients in a high-performance concrete (HPC) box girder with unconventional cross section under the solar radiation in Shanghai, China. The comparisons of thermal effects calculated according to the Chinese and foreign design code provisions show that the temperature gradient models of the current codes are not appropriate for the HPC box girder with unconventional cross section. In this paper, a new method is proposed to determine the solar temperature actions based on the stationary binomial probability model of random process. For the HPC box girder, the design standard value of equivalent linear temperature differences and cross-section temperature differences in the design reference period are obtained from the proposed method. Finally, the solar temperature gradients in the HPC box girder with unconventional cross section are gained based on the suggested design standard values.
Research on the Process of Pre-Stressing Construction of Suspen-Dome considering Temperature Effect
Authors: Liu Hongbo , Chen Zhihua , Zhou Ting
Published: April 2012

Suspen-dome is a highly efficient pre-stressing spatial structure. The pre-stressing force in cable has a significant effect on its structural performance. During pre-stressing construction, the temperature variation due to solar radiation and seasonal change might affect the pre-stressing force in cables. However, the construction tensile method which is widely adopted in engineering project does not cope with the effect of temperature change on the cable force. As a result, it is expected that the actual cable force differs from the designed cable force. In this study, the effect of temperature change during pre-stressing construction on pre-stressing force in cable is firstly studied. A significant difference of cable force, up to 212%, is observed between cases considering temperature change and cases not considering temperature change. It is therefore necessary to take the effect of temperature changing on pre-stressing force into account in design of suspen-dome. In this purpose, a new construction pre-stressing control method and a simplified calculation formula are proposed and verified.
An Experimental Study of Multi-Grid Composite Walls
Authors: Liu Pei , Guo Meng
Published: April 2012

Through reinforcing autoclaved aerated concrete block wall by reinforced concrete members, a new force-resisting structural component, namely multi-grid composite wall, is proposed in this paper. The composite wall is made up of RC edge frame, RC grids and autoclaved aerated concrete in-filled blocks. The purpose of this research is to investigate the behavior of multi-grid composite walls under cyclic lateral loading simulating seismic action. 1/2 scale six multi-grid composite wall specimens were tested. Experimental parameters that were studied for the six specimens were numbers of RC grid beams and columns and aspect ratio (ratio of wall height to width). A description of observed behavior of the specimens during the tests was offered. Strains of longitudinal bars, load carrying capacity, stiffness and ductility of the specimens were investigated. Results indicated the presence of RC grid columns and beams restricted propagation of the cracks in the autoclaved aerated concrete in-filled blocks, and then the mechanical characteristics of the in-filled blocks were improved significantly. The load carrying capacity, stiffness and ductility of the typical multi-grid composite wall specimen were much larger than those of the reference specimen that was considered as the commonly used member in the confined masonry structure. Multi-grid composite walls possess good seismic performance and offer a new way for the application of autoclaved aerated concrete block walls as force-resisting structural components in practice, especially in Chinese towns and villages.
Hybrid Analytical/Numerical Prediction of Propeller Broadband Noise in the Time Domain
Authors: Barbarino Mattia , Casalino Damiano
Published: April 2012

This work deals with the numerical prediction of the trailing edge noise from rotating blades. A semi-empirical model of the wall pressure spectrum in proximity of the trailing edge is used in connection with an analytical flat-plate aerodynamic response function to compute the acoustic pressure fluctuations on the surface of the blade. Pressure signals with a broadband spectral content are generated by superimposing Fourier components of the blade pressure waves with a stochastic phase distribution. Finally, the far-field noise is computed through a numerical integration of the Ffowcs-Williams and Hawkings equation in the time domain. The hybrid analytical/numerical broadband noise prediction method is verified by computing the trailing-edge noise from a flat plate and comparing its spectrum to the one obtained through a direct analytical extrapolation of the wall pressure spectrum in the frequency domain. The same flat-plate results are then validated against measurements of trailing edge noise spectrum from a NACA-0012 airfoil. The method is finally used to compute the broadband noise from an aircraft propeller and results are compared with analytical results obtained through a blade strip approach. The method and the results described in this paper have been presented at the 14th CEAS-ASC workshop held on 7–8 October 2010 at the Institute of Aviation in Warsaw, Poland.
Far-Field Sound Radiation Due to an Installed Open Rotor
Authors: McAlpine A. , Kingan M.J.
Published: April 2012

Future single rotation propeller and contra-rotating advanced open rotor concepts promise a significant fuel efficiency advantage over current generation turbofan engines. The development of rotors which produce a minimum level of noise is a critical technical issue which needs to be resolved in order for these concepts to become viable aircraft propulsors. Noise and emissions are subject to stringent legislative requirements, thus accurate models are required in order to predict the noise radiated from aircraft engines. In this article, the development of a theoretical model to predict noise levels of an installed open rotor is reported. First a canonical problem is examined: how to predict the pressure field produced by a rotating ring of point sources adjacent to a rigid cylinder. Analytic expressions for the far-field pressure from a rotating ring of single-frequency monopole and dipole point sources, located near an infinitely long rigid cylinder, immersed in a constant axial mean flow, are explicitly formulated. Illustrative results show how the far-field pressure is affected by varying the source rotational direction, source location and source radius. Next the solution of the canonical problem is utilized to formulate a more advanced model to predict the noise due to an installed open rotor. In this model, the rotor noise sources are represented by a distribution of rotating sources. The adjacent aircraft fuselage is modeled by the rigid cylinder, and the effect of the fuselage boundary layer and other steady distortions are neglected. Also neglected is the scattering from other surfaces such as the pylon, wing and centerbody. This distributed source model can be used to calculate the effect of scattering of open rotor noise by an adjacent cylindrical fuselage. The model can be used to calculate both rotor-alone tones and tones produced by periodic unsteady loading on the rotor blades. Practical examples are provided which show how the effect of blade rotational direction and propeller location relative to the fuselage affect the sound produced by the interaction of a pylon wake with a rotor in a pusher configuration.
Digital Girih, a Digital Interpretation of Islamic Architecture
Authors: Riether Gernot , Baerlecken Daniel
Published: April 2012

The relation between texture, pattern and massing is a fundamental question in architecture. Classical architecture, as Leon Battista Alberti states in De Re Aedificatoria, Book VI, Chapter 2, is developed through massing and structure first; texture is added afterwards to give the bold massing and structure beauty [1]. This hierarchy has of course been challenged throughout architecture history. This paper will provide a different thinking of the relationship of massing and texture in Islamic Architecture from a digital point of view. An analysis of Islamic patterns challenged this relationship in Islamic architecture. Digital design and fabrication methods for a series of studies and an installation were used to respond to the findings of the analysis.
Potential Use of Structural Layout Optimization at the Conceptual Design Stage
Authors: Park Peter , Gilbert Matthew , Tyas Andy , Popovic-Larsen Olga
Published: April 2012

Despite recent developments in computer-aided design in architecture, both in terms of form generation techniques and performance-based design tools, there still appears to be polarization between the ‘visual’ and the ‘technical’ elements of design. Two causes of this are discussed: long-standing tradition within the discipline and perception of design as primarily a visual exercise. Structural layout optimization is a technique which enables automatic identification of optimal arrangements of structural elements in frames. As the technique appears to have the potential to help reduce the polarization between the visual and the technical elements of design, it can be considered as an ‘integrative’ form generation tool. Applications of the technique are considered via three design examples, demonstrating both its potential and areas where refinement is required before it is suitable for application in practice.
Programming Languages for Generative Design: A Comparative Study
Authors: Leitão António , Santos Luís , Lopes José
Published: April 2012

In the field of Generative Design (GD), Visual Programming Languages (VPLs), such as Grasshopper, are becoming increasingly popular compared to the traditional Textual Programming Languages (TPLs) provided by CAD applications, such as RhinoScript. This reaction is explained by the relative obsolescence of these TPLs and the faster learning curve of VPLs. However, modern TPLs offer a variety of linguistic features designed to overcome the limitations of traditional TPLs, making them hypothetical competitors to VPLs. In this paper, we reconsider the role of TPLs in the design process and we present a comparative study of VPLs and modern TPLs. Our findings show that modern TPLs can be more productive than VPLs, especially, for large-scale and complex design tasks. Finally, we identify some problems of modern TPLs related to portability and sharing of programs and we propose a solution.
Kinetic Hybrid Structure Development and Simulation
Authors: Phocas Marios C. , Kontovourkis Odysseas , Matheou Maria
Published: April 2012

Supported through technological advances, the concept of kinetic architecture is internationally increasingly acknowledged in the past years in the development of adaptable buildings as to differing functional requirements, or external loading conditions. Most decisive factor is the structure in terms of materials and geometrical configurations, and the control system integrated within. Based on general principles of tensegrity structures, a hybrid system has been developed that consists of continuous hinge connected compression members, strengthened by an internal system of struts and continuous cable diagonals with closed loop. The kinetic mechanism is achieved through alteration of the cables length and the respective relative inclination of any adjacent compression members. In this way the transformability of the system arises primarily from the inherent integrative composition and dual capabilities of its members. Following the construction design of the prototype structure, the interactive development, as regards geometric properties and structural configurations, is presented analytically, as based on a parametric-associative design approach applied. Along this line, the specific syntax of structural development and simulation through parametric design is suggested to support in real terms the control design of the innovative structure in an integrated interactive context.
TetraScript: A Responsive Pavilion, from Generative Design to Automation
Authors: Henriques Gonçalo Castro
Published: April 2012

This research is part of a broader investigation into the use of digital technologies in the Architecture, Engineering and Construction (AEC) sector. The intention is to improve the ability of buildings to respond to context by proposing a skylight system that can adjust to external environmental conditions and internal functional demands. We call this responsive ability customisation. The proposed skylight system can adapt to different geometries, uses, locations, times of day and other contextual conditions. Customisation can be achieved by static and dynamic processes. Static customisation is achieved during the design process by selecting the form and size of the building, as well as the number, arrangement and size of the skylights, among other features. Dynamic customisation is accomplished after construction by changing the skylight aperture in real-time to control interior conditions. This paper focuses on the static process to find an adequate skylight configuration for a case-study pavilion.
A Practical Perspective on Decision Making Influences in Sports Officiating
Authors: MacMahon Clare , Mildenhall Bill
Published: April 2012

The objective of this article is to reflect on the sport science research findings related to decision making and decision-making errors in sports officials (judges, umpires, referees). Specifically, we reflect on the mechanisms that have been discussed as influential in leading to these errors, and the responses to these errors. We present the general view that officials are human information processors both vulnerable to, and in some cases benefitting from the limitations of their system. We advocate that most cases of errors are due to missing information and uncertainty pertaining to the judgment, and that rather than removing information, where possible, more certainty, and/or more information should be provided. This article also bridges the science with informal practices, highlighting the ways in which more certainty and information are naturally sought and provided in sports officiating.
Understanding Motivational Processes in University Rugby Players: A Preliminary Test of the Hierarchical Model of Intrinsic and Extrinsic Motivation at the Contextual Level
Authors: Pope Jacqueline Paige , Wilson Philip M.
Published: April 2012

The purpose of this study was to examine the relationship between perceptions of autonomy support, structure and involvement provided by the head coach and motivational processes at mid- and late-season in competitive rugby players. Participants ( Mage = 20.17 years, SD = 1.61 years, Range = 18 to 27 years) completed assessments of perceived coaching style and psychological need fulfillment at the mid-season point ( n mid-season = 102; 47.05% female) and motivation to continue playing rugby and perceived effort spent playing rugby at the late-season assessment ( N late-season = 82; 53.64% female). Structural equation modeling analyses provided support for a conceptual model whereby global perceptions of coach support predicted greater need fulfillment which, in turn, was associated with autonomous sport motivation and greater perceived effort. Overall, the results of this study lend partial support for Vallerand's contentions regarding the importance of motivation processes in sport and imply structure and involvement may be important components of a coach's interactional style that impact athletes' motivation.
Power Generation Using Mechanical Wave Energy Converter
Authors: Chandrasekaran Srinivasan , Harender
Published: April 2012

Ocean wave energy plays a significant role in meeting the growing demand of electric power. Economic, environmental, and technical advantages of wave energy set it apart from other renewable energy resources. Present study describes a newly proposed Mechanical Wave Energy Converter (MEWC) that is employed to harness heave motion of floating buoy to generate power. Focus is on the conceptual development of the device, illustrating details of component level analysis. Employed methodology has many advantages such as i) simple and easy fabrication; ii) easy to control the operations during rough weather; and iii) low failure rate during normal sea conditions. Experimental investigations carried out on the scaled model of MWEC show better performance and its capability to generate power at higher efficiency in regular wave fields. Design Failure Mode and Effect Analysis (FMEA) shows rare failure rates for all components except the floating buoy.
Nearshore Currents along the Karnataka Coast, West Coast of India
Authors: Kumar V. Sanil , Dora G. Udhaba , Philip C. Sajiv , Pednekar P. , Singh Jai
Published: April 2012

Measured current data at 7 locations and tide data at 3 locations during the pre-summer monsoon period along the west coast of India is used in the study. The surface currents during March showed a predominant northward trend and during April it was towards south. Estimated tidal currents were upto 25 cm s−1 with an average value of 8 cm s−1. Current tidal form number varied from 0.56 to 1 at different locations indicating currents are mixed. M2 and S2 tidal current constituents rotated clock wise at all location. Near surface, the alongshore current was 2.6 to 5.9% of the alongshore wind and near bottom it was 1.9 to 3.6% of the alongshore wind.
Supply Portfolio Concentration in Outsourced Knowledge-Based Services
Authors: Moeen Mahka , Somaya Deepak , Mahoney Joseph T.
Published: April 2012

In the extant vertical integration literature, the question of how a firm's portfolio of outsourced work is managed across suppliers has been relatively understudied. We seek to advance this area of research by examining factors that influence how concentrated the firm's outsourcing is among its set of suppliers. Using data on the outsourcing of patent legal services, we find empirical evidence that outsourced knowledge-based service work is concentrated in the hands of fewer suppliers when (1) it requires greater firm-specific knowledge, (2) there is a higher level of interrelatedness across outsourced projects, (3) the firm's reliance on outsourcing is high, (4) its outsourced projects are focused on a narrower (capability) domain, and (5) the technological dynamism of this domain is low. Our study suggests that examining portfolio-level phenomena in outsourcing is a useful complement to the predominant focus on transaction-level outcomes in prior research because it provides insights into how firms manage trade-offs across their entire set of outsourced projects.
Forming and Exploiting Opportunities: The Implications of Discovery and Creation Processes for Entrepreneurial and Organizational Research
Authors: Alvarez Sharon A. , Barney Jay B. , Anderson Philip
Published: April 2012

Research on opportunities has received significant attention in entrepreneurship in the last decade. However, recently the focus has shifted from opportunities themselves to the processes that form and exploit them. This paper traces the history of opportunity origins and draws upon the implications of opportunity types to suggest associated entrepreneurial processes. This paper then suggests future research and applications based on processes used to form and exploit opportunities.
Family Firm Governance, Strategic Conformity, and Performance: Institutional vs. Strategic Perspectives
Authors: Miller Danny , Breton-Miller Isabelle Le , Lester Richard H.
Published: April 2012

A fundamental schism divides the family firm and strategy literatures, on the one hand, and the institutional literature, on the other, regarding both the situational prevalence and the utility of conforming behavior. The first two schools, respectively, view strategic differentiation as especially common among family firms and an important source of competitive advantage. By contrast, the reasoning of institutionalists would suggest that family firms will be subject to unusually powerful motivations to conform, in part because of their pursuit of socioemotional wealth objectives. Unfortunately, the relationships between conformity and family firm governance—and, in fact, governance in general—have not been amply studied. This analysis of Fortune 1000 firms finds considerable support for the institutional perspective: family involvement is related to greater, not lesser, conformity in many aspects of strategy. Although strategic conformity related to superior returns on assets, it did not enhance firm market valuations.
Greener Pastures: Outside Options and Strategic Alliance Withdrawal
Authors: Greve Henrich R. , Mitsuhashi Hitoshi , Baum Joel A. C.
Published: April 2012

Departing from prior work that demonstrates the stickiness and stability of alliance networks resulting from embeddedness, we extend matching theory to study firms' withdrawal from alliances. Viewing alliance withdrawal as a result of firms' pursuit of more promising alternative partners (outside options) rather than failures in collaboration, we predict that a firm is more likely to withdraw from an alliance when there is a higher density of outside options that have better match quality than the current partners. We also propose that, because matching is two-sided, outside options have a greater impact on a firm's withdrawal when they are more likely to initiate new alliances. Using data on alliances in the global liner shipping industry, we show that, controlling for internal tensions in the alliance, outside options predict alliance withdrawals. Thus, despite the alliance stickiness and stability, firms alter their alliances in response to the availability of promising outside options, even leaving alliances that appear successful.