Showing papers by "Clemson University published in 2013"

Self-healing polymeric materials

Abstract: Inspired by nature, self-healing materials represent the forefront of recent developments in materials chemistry and engineering. This review outlines the recent advances in the field of self-healing polymers. The first part discusses thermodynamic requirements for self-healing networks in the context of conformation changes that contribute to the Gibbs free energy. The chain flexibility significantly contributes to the entropy changes, whereas the heat of reaction and the external energy input are the main contributors to enthalpy changes. The second part focuses on chemical reactions that lead to self-healing, and the primary classes are the covalent bonding, supramolecular assemblies, ionic interactions, chemo-mechanical self-healing, and shape memory polymers. The third part outlines recent advances using encapsulation, remote self-healing and the role of shape memory polymers. Recent developments in the field of self-healing polymers undeniably indicate that the main challenge will be the designing of high glass transition (Tg) functional materials, which also exhibit stimuli-responsive attributes. Build-in controllable hierarchical heterogeneousness at various length scales capable of remote self-healing by physical and chemical responses will be essential in designing future materials of the 21st century.

The high-quality draft genome of peach ( Prunus persica ) identifies unique patterns of genetic diversity, domestication and genome evolution

Abstract: Rosaceae is the most important fruit-producing clade, and its key commercially relevant genera (Fragaria, Rosa, Rubus and Prunus) show broadly diverse growth habits, fruit types and compact diploid genomes. Peach, a diploid Prunus species, is one of the best genetically characterized deciduous trees. Here we describe the high-quality genome sequence of peach obtained from a completely homozygous genotype. We obtained a complete chromosome-scale assembly using Sanger whole-genome shotgun methods. We predicted 27,852 protein-coding genes, as well as noncoding RNAs. We investigated the path of peach domestication through whole-genome resequencing of 14 Prunus accessions. The analyses suggest major genetic bottlenecks that have substantially shaped peach genome diversity. Furthermore, comparative analyses showed that peach has not undergone recent whole-genome duplication, and even though the ancestral triplicated blocks in peach are fragmentary compared to those in grape, all seven paleosets of paralogs from the putative paleoancestor are detectable.

SEIPS 2.0: A human factors framework for studying and improving the work of healthcare professionals and patients

Abstract: Healthcare practitioners, patient safety leaders, educators and researchers increasingly recognise the value of human factors/ergonomics and make use of the discipline's person-centred models of sociotechnical systems. This paper first reviews one of the most widely used healthcare human factors systems models, the Systems Engineering Initiative for Patient Safety (SEIPS) model, and then introduces an extended model, 'SEIPS 2.0'. SEIPS 2.0 incorporates three novel concepts into the original model: configuration, engagement and adaptation. The concept of configuration highlights the dynamic, hierarchical and interactive properties of sociotechnical systems, making it possible to depict how health-related performance is shaped at 'a moment in time'. Engagement conveys that various individuals and teams can perform health-related activities separately and collaboratively. Engaged individuals often include patients, family caregivers and other non-professionals. Adaptation is introduced as a feedback mechanism that explains how dynamic systems evolve in planned and unplanned ways. Key implications and future directions for human factors research in healthcare are discussed.

Carbon “quantum” dots for optical bioimaging

Abstract: Carbon dots, generally referring to small carbon nanoparticles with various levels of surface passivation, have emerged as a new class of quantum dot-like fluorescent nanomaterials. Since the original report in 2006, carbon dots have been investigated by many research groups worldwide, with major advances already made in their syntheses, structural and mechanistic understandings, and evaluations for biocompatibilities and potential bio-applications. In this article, representative studies responsible for these advances in the development and understanding of carbon dots are reviewed, and those targeting the use of carbon dots as high-performance yet nontoxic fluorescence agents for optical bioimaging in vitro and in vivo are highlighted and discussed.

Photoluminescence properties of graphene versus other carbon nanomaterials.

Abstract: Photoluminescent nanomaterials continue to garner research attention becauseof their many applications. For many years, researchers have focused on quantum dots (QDs) of semiconductor nanocrystals for their excellent performance and predictable fluorescence color variations that depend on the sizes of the nanocrystals. Even with these advantages, QDs can present some major limitations, such as the use of heavy metals in the high-performance semiconductor QDs. Therefore, researchers continue to be interested in developing new QDs or related nanomaterials. Recently, various nanoscale configurations of carbon have emerged as potential new platforms in the development of brightly photoluminescent materials.As a perfect π-conjugated single sheet, graphene lacks electronic bandgaps andis not photoluminescent. Therefore, researchers have created energy bandgaps within graphene as a strategy to impart fluorescence emissions. Researchers have explored many experimental techniques to introduce bandgaps, such as cut...

Mixed-integer nonlinear optimization

Abstract: Many optimal decision problems in scientific, engineering, and public sector applications involve both discrete decisions and nonlinear system dynamics that affect the quality of the final design or plan. These decision problems lead to mixed-integer nonlinear programming (MINLP) problems that combine the combinatorial difficulty of optimizing over discrete variable sets with the challenges of handling nonlinear functions. We review models and applications of MINLP, and survey the state of the art in methods for solving this challenging class of problems.Most solution methods for MINLP apply some form of tree search. We distinguish two broad classes of methods: single-tree and multitree methods. We discuss these two classes of methods first in the case where the underlying problem functions are convex. Classical single-tree methods include nonlinear branch-and-bound and branch-and-cut methods, while classical multitree methods include outer approximation and Benders decomposition. The most efficient class of methods for convex MINLP are hybrid methods that combine the strengths of both classes of classical techniques.Non-convex MINLPs pose additional challenges, because they contain non-convex functions in the objective function or the constraints; hence even when the integer variables are relaxed to be continuous, the feasible region is generally non-convex, resulting in many local minima. We discuss a range of approaches for tackling this challenging class of problems, including piecewise linear approximations, generic strategies for obtaining convex relaxations for non-convex functions, spatial branch-and-bound methods, and a small sample of techniques that exploit particular types of non-convex structures to obtain improved convex relaxations.We finish our survey with a brief discussion of three important aspects of MINLP. First, we review heuristic techniques that can obtain good feasible solution in situations where the search-tree has grown too large or we require real-time solutions. Second, we describe an emerging area of mixed-integer optimal control that adds systems of ordinary differential equations to MINLP. Third, we survey the state of the art in software for MINLP.

Agriculture: Feeding the future

Abstract: Humanity depends on fewer than a dozen of the approximately 300,000 species of flowering plants for 80% of its caloric intake. And we capitalize on only a fraction of the genetic diversity that resides within each of these species. This is not enough to support our food system in the future. Food availability must double in the next 25 years to keep pace with population and income growth around the world. Already, food-production systems are precarious in the face of intensifying demand, climate change, soil degradation and water and land shortages. Farmers have saved the seeds of hundreds of crop species and hundreds of thousands of ‘primitive’ varieties (local domesticates called landraces), as well as the wild relatives of crop species and modern varieties no longer in use. These are stored in more than 1,700 gene banks worldwide. Maintaining the 11 international gene-bank collections alone costs about US$18 million a year.

On the Dielectric "Constant" of Proteins: Smooth Dielectric Function for Macromolecular Modeling and Its Implementation in DelPhi.

Abstract: Implicit methods for modeling protein electrostatics require dielectric properties of the system to be known, in particular, the value of the dielectric constant of protein. While numerous values of the internal protein dielectric constant were reported in the literature, still there is no consensus of what the optimal value is. Perhaps this is due to the fact that the protein dielectric constant is not a "constant" but is a complex function reflecting the properties of the protein's structure and sequence. Here, we report an implementation of a Gaussian-based approach to deliver the dielectric constant distribution throughout the protein and surrounding water phase by utilizing the 3D structure of the corresponding macromolecule. In contrast to previous reports, we construct a smooth dielectric function throughout the space of the system to be modeled rather than just constructing a "Gaussian surface" or smoothing molecule-water boundary. Analysis on a large set of proteins shows that (a) the average dielectric constant inside the protein is relatively low, about 6-7, and reaches a value of about 20-30 at the protein's surface, and (b) high average local dielectric constant values are associated with charged residues while low dielectric constant values are automatically assigned to the regions occupied by hydrophobic residues. In terms of energetics, a benchmarking test was carried out against the experimental pKa's of 89 residues in staphylococcal nuclease (SNase) and showed that it results in a much better RMSD (= 1.77 pK) than the corresponding calculations done with a homogeneous high dielectric constant with an optimal value of 10 (RMSD = 2.43 pK).

Majorana fermions in semiconductor nanowires: fundamentals, modeling, and experiment.

Abstract: After a recent series of rapid and exciting developments, the long search for the Majorana fermion?the elusive quantum entity at the border between particles and antiparticles?has produced the first positive experimental results, but is not over yet. Originally proposed by E?Majorana in the context of particle physics, Majorana fermions have a condensed matter analogue in the zero-energy bound states emerging in topological superconductors. A promising route to engineering topological superconductors capable of hosting Majorana zero modes consists of proximity coupling semiconductor thin films or nanowires with strong spin?orbit interaction to conventional s-wave superconductors in the presence of an external Zeeman field. The Majorana zero mode is predicted to emerge above a certain critical Zeeman field as a zero-energy state localized near the order parameter defects, namely, vortices for thin films and wire ends for the nanowire. These Majorana bound states are expected to manifest non-Abelian quantum statistics, which makes them ideal building blocks for fault-tolerant topological quantum computation. This review provides an update on the current status of the search for Majorana fermions in semiconductor nanowires by focusing on the recent developments, in particular the period following the first reports of experimental signatures consistent with the realization of Majorana bound states in semiconductor nanowire?superconductor hybrid structures. We start with a discussion of the fundamental aspects of the subject, followed by considerations on the realistic modeling, which is a critical bridge between theoretical predictions based on idealized conditions and the real world, as probed experimentally. The last part is dedicated to a few intriguing issues that were brought to the fore by the recent encouraging experimental advances.

Corporate Social Responsibility, Customer Orientation, and the Job Performance of Frontline Employees

Abstract: A study involving a Global 500 company finds that frontline employees’ perceptions of corporate social responsibility (CSR) can contribute to their customer orientation (self-rated) and objective job performance (supervisor-rated) by activating social identification processes. Employees identify with the organization based in part on the extent to which CSR is supported by salient and job-relevant others both internal and external to the organization. Looking internally, employees identify with the organization to the extent that they perceive management to support CSR. Looking externally, employees can identify with customers (called employee-customer identification) to the extent they perceive customers to support the company’s CSR. Both effects are enhanced when employees feel CSR is an important (versus non-important) part of their self-concept. Organizational identification directly drives job performance while employee-customer identification contributes to job performance through its effects on organizational identification and customer orientation.

Estimation and Inference in Nonparametric Frontier Models: Recent Developments and Perspectives

Abstract: Nonparametric estimators are widely used to estimate the productive efficiency of firms and other organizations, but often without any attempt to make statistical inference. Recent work has provided statistical properties of these estimators as well as methods for making statistical inference, and a link between frontier estimation and extreme value theory has been established. New estimators that avoid many of the problems inherent with traditional efficiency estimators have also been developed; these new estimators are robust with respect to outliers and avoid the well-known curse of dimensionality. Statistical properties, including asymptotic distributions, of the new estimators have been uncovered. Finally, several approaches exist for introducing environmental variables into production models; both two-stage approaches, in which estimated efficiencies are regressed on environmental variables, and conditional efficiency measures, as well as the underlying assumptions required for either approach, are examined.

Constitutive Expression of a miR319 Gene Alters Plant Development and Enhances Salt and Drought Tolerance in Transgenic Creeping Bentgrass

Abstract: MicroRNA319 (miR319) is one of the first characterized and conserved microRNA families in plants and has been demonstrated to target TCP (for TEOSINTE BRANCHED/CYCLOIDEA/PROLIFERATING CELL FACTORS [PCF]) genes encoding plant-specific transcription factors. MiR319 expression is regulated by environmental stimuli, suggesting its involvement in plant stress response, although experimental evidence is lacking and the underlying mechanism remains elusive. This study investigates the role that miR319 plays in the plant response to abiotic stress using transgenic creeping bentgrass (Agrostis stolonifera) overexpressing a rice (Oryza sativa) miR319 gene, Osa-miR319a. We found that transgenic plants overexpressing Osa-miR319a displayed morphological changes and exhibited enhanced drought and salt tolerance associated with increased leaf wax content and water retention but reduced sodium uptake. Gene expression analysis indicated that at least four putative miR319 target genes, AsPCF5, AsPCF6, AsPCF8, and AsTCP14, and a homolog of the rice NAC domain gene AsNAC60 were down-regulated in transgenic plants. Our results demonstrate that miR319 controls plant responses to drought and salinity stress. The enhanced abiotic stress tolerance in transgenic plants is related to significant down-regulation of miR319 target genes, implying their potential for use in the development of novel molecular strategies to genetically engineer crop species for enhanced resistance to environmental stress.

Nanobiotechnology can boost crop production and quality: first evidence from increased plant biomass, fruit yield and phytomedicine content in bitter melon (Momordica charantia)

Abstract: Recent research on nanoparticles in a number of crops has evidenced for enhanced germination and seedling growth, physiological activities including photosynthetic activity and nitrogen metabolism, mRNA expression and protein level, and also positive changes in gene expression indicating their potential use in crop improvement. We used a medicinally rich vegetable crop, bitter melon, as a model to evaluate the effects of seed treatment with a carbon-based nanoparticle, fullerol [C60(OH)20], on yield of plant biomass and fruit characters, and phytomedicine contents in fruits. We confirmed the uptake, translocation and accumulation of fullerol through bright field imaging and Fourier transform infra-red spectroscopy. We observed varied effects of seed treatment at five concentrations, including non-consequential and positive, on plant biomass yield, fruit yield and its component characters, and content of five phytomedicines in fruits. Fullerol-treatment resulted in increases up to 54% in biomass yield and 24% in water content. Increases of up to 20% in fruit length, 59% in fruit number, and 70% in fruit weight led to an improvement up to 128% in fruit yield. Contents of two anticancer phytomedicines, cucurbitacin-B and lycopene, were enhanced up to 74% and 82%, respectively, and contents of two antidiabetic phytomedicines, charantin and insulin, were augmented up to 20% and 91%, respectively. Non-significant correlation inter se plant biomass, fruit yield, phytomedicine content and water content evidenced for separate genetic control and biosynthetic pathways for production of plant biomass, fruits, and phytomedicines in fruits, and also no impact of increased water uptake. While our results indicated possibility of improving crop yield and quality by using proper concentrations of fullerol, extreme caution needs to be exercised given emerging knowledge about accumulation and toxicity of nanoparticles in bodily tissues.

Degradable natural polymer hydrogels for articular cartilage tissue engineering

Abstract: Articular cartilage has poor ability to heal once damaged. Tissue engineering with scaffolds of polymer hydrogels is promising for cartilage regeneration and repair. Polymer hydrogels composed of highly hydrated crosslinked networks mimic the collagen networks of the cartilage extracellular matrix and thus are employed as inserts at cartilage defects not only to temporarily relieve the pain but also to support chondrocyte proliferation and neocartilage regeneration. The biocompatibility, biofunctionality, mechanical properties, and degradation of the polymer hydrogels are the most important parameters for hydrogel-based cartilage tissue engineering. Degradable biopolymers with natural origin have been widely used as biomaterials for tissue engineering because of their outstanding biocompatibility, low immunological response, low cytotoxicity, and excellent capability to promote cell adhesion, proliferation, and regeneration of new tissues. This review covers several important natural proteins (collagen, gelatin, fibroin, and fibrin) and polysaccharides (chitosan, hyaluronan, alginate and agarose) widely used as hydrogels for articular cartilage tissue engineering. The mechanical properties, structures, modification, and structure–performance relationship of these hydrogels are discussed since the chemical structures and physical properties dictate the in vivo performance and applications of polymer hydrogels for articular cartilage regeneration and repair. © 2012 Society of Chemical Industry

Effect of Injection Routes on the Biodistribution, Clearance, and Tumor Uptake of Carbon Dots

Abstract: The emergence of photoluminescent carbon-based nanomaterials has shown exciting potential in the development of benign nanoprobes. However, the in vivo kinetic behaviors of these particles that are necessary for clinical translation are poorly understood to date. In this study, fluorescent carbon dots (C-dots) were synthesized and the effect of three injection routes on their fate in vivo was explored by using both near-infrared fluorescence and positron emission tomography imaging techniques. We found that C-dots are efficiently and rapidly excreted from the body after all three injection routes. The clearance rate of C-dots is ranked as intravenous > intramuscular > subcutaneous. The particles had relatively low retention in the reticuloendothelial system and showed high tumor-to-background contrast. Furthermore, different injection routes also resulted in different blood clearance patterns and tumor uptakes of C-dots. These results satisfy the need for clinical translation and should promote efforts to...

Blaming the organization for abusive supervision: The roles of perceived organizational support and supervisor's organizational embodiment

Abstract: Why do employees who experience abusive supervision retaliate against the organization? We apply organizational support theory to propose that employees hold the organization partly responsible for abusive supervision. Depending on the extent to which employees identify the supervisor with the organization (i.e., supervisor's organizational embodiment), we expected abusive supervision to be associated with low perceived organizational support (POS) and consequently with retribution against the organization. Across 3 samples, we found that abusive supervision was associated with decreased POS as moderated by supervisor's organizational embodiment. In turn, reduced POS was related to heightened counterproductive work behavior directed against the organization and lowered in-role and extra-role performance. These findings suggest that employees partly attribute abusive supervision to negative valuation by the organization and, consequently, behave negatively toward and withhold positive contributions to it.

Continuous Backbone “Continuum” Robot Manipulators

Abstract: This paper describes and discusses the history and state of the art of continuous backbone robot manipulators. Also known as continuum manipulators, these robots, which resemble biological trunks and tentacles, offer capabilities beyond the scope of traditional rigid-link manipulators. They are able to adapt their shape to navigate through complex environments and grasp a wide variety of payloads using their compliant backbones. In this paper, we review the current state of knowledge in the field, focusing particularly on kinematic and dynamic models for continuum robots. We discuss the relationships of these robots and their models to their counterparts in conventional rigid-link robots. Ongoing research and future developments in the field are discussed.

Axionic field theory of (3+1)-dimensional Weyl semimetals

Abstract: From a direct calculation of the anomalous Hall conductivity and an effective electromagnetic action obtained via Fujikawa's chiral rotation technique, we conclude that an axionic field theory with a nonquantized coefficient describes the electromagnetic response of the $(3+1)$-dimensional Weyl semimetal. The coefficient is proportional to the momentum space separation of the Weyl nodes. Akin to the Chern-Simons field theory of quantum Hall effect, the axion field theory violates gauge invariance in the presence of the boundary, which is cured by the chiral anomaly of the surface states via the Callan-Harvey mechanism. This provides a unique solution for the radiatively induced CPT-odd term in the electromagnetic polarization tensor of the Lorentz violating spinor electrodynamics, where the source of the Lorentz violation is a constant axial 4-vector term for the Dirac fermion. A direct linear response calculation also establishes anomalous thermal Hall effect and a Wiedemann-Franz law, but thermal Hall conductivity does not directly follow from the well known formula for the gravitational chiral anomaly.

Estimation and Inference in Nonparametric Frontier Models: Recent Developments and Perspectives

Abstract: Nonparametric estimators are widely used to estimate the productive efficiency of firms and other organizations, but often without any attempt to make statistical inference. Recent work has provided statistical properties of these estimators as well as methods for making statistical inference, and a link between frontier estimation and extreme value theory has been established. New estimators that avoid many of the problems inherent with traditional efficiency estimators have also been developed; these new estimators are robust with respect to outliers and avoid the well-known curse of dimensionality. Statistical properties, including asymptotic distributions, of the new estimators have been uncovered. Finally, several approaches exist for introducing environmental variables into production models; both two-stage approaches, in which estimated efficiencies are regressed on environmental variables, and conditional efficiency measures, as well as the underlying assumptions required for either approach, are examined. (This abstract was borrowed from another version of this item.)

A longitudinal study of herd behavior in the adoption and continued use of technology

Abstract: Herd literature suggests that people tend to discount their own beliefs and imitate others when making adoption decisions and that the resulting adoption decisions are fragile and can be easily reversed during the post-adoptive stage This helps explain why the adoption of a number of new technologies--from Amazon's Kindle, to Apple's iPod, iPhone, and iPad, to various types of Web 20 technologies--appears to have adoption patterns similar to those of new fashion trends (i e, an initial en masse acquisition followed by subsequent abandonment) It is important to understand these phenomena because they are strongly related to the staying power of technology From a herd behavior perspective, this study proposes two new concepts, namely discounting one's own information and imitating others, to describe herd behavior in technology adoption A research model is developed to describe the conditions under which herd behavior in technology adoption occurs, how it impacts technology adoption decision making, and how it influences post-adoptive system use A longitudinal study is conducted to examine the research model Findings from this research suggest that the discounting of one's own beliefs and the imitating of others when adopting a new technology are provoked primarily by the observation of prior adoptions and perceptions of uncertainty regarding the adoption of new technology Herd behavior has a significant influence on user technology adoption; however, it does not necessarily lead to the collapse of the user base, as predicted in the herd literature Instead, imitation can help reduce post-adoption regret and thus serve as a legitimate strategy for choosing a good enough technology, which may or may not be the best option to enhance job performance People tend to adjust their beliefs when herding and also to revive their discounted initial beliefs to modify their beliefs about the technology at the post-adoptive stage Findings from this study have significant research and practical implications

Rheological Properties and Chemical Bonding of Asphalt Modified with Nanosilica

Abstract: The objective of this study is to evaluate the rheological properties and chemical bonding of nano-modified asphalt binders blended with nanosilica In this study, the nanosilica was added to the control asphalt at contents of 4% and 6% based on the weight of asphalt binders Superpave binder and mixture tests were utilized in this study to estimate the characteristics of the nano-modifed asphalt binder and mixture The rotational viscosity (RV), dynamic shear rheometer (DSR), bending beam rhometer (BBR), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), asphalt pavement analyzer (APA), dynamic modulus (DM) and flow number (FN) tests were used to analyze rheological properties and chemical bonding changes of the nano-modified asphalt binder and the performance of the nano-modified asphalt mixture In addition, the performance of nano-modified asphalt after rolling thin-film oven (RTFO) short-term and pressure-aging vessel (PAV) long-term aging was assessed as well

Oil and Conflict: What Does the Cross Country Evidence Really Show?

Abstract: This paper re-examines the effect of oil wealth on political violence. Using a unique historical panel dataset of oil discoveries, we show that simply controlling for country fixed effects removes the statistical association between the value of oil reserves and civil war onset. Other macro-political violence measures, such as coup attempts, are also uncorrelated with oil wealth. To further address endogeneity concerns, we exploit changes in oil reserves due to randomness in the success of oil explorations. We find little robust evidence that oil discoveries increase the likelihood of political violence. Rather, oil discoveries increase military spending in nondemocratic countries. (JEL D74, H56, O17, Q34, Q41) D oes oil wealth corrupt or strengthen regimes? The conventional wisdom dating back to at least Malthus is that resource scarcity triggers conflict. Since the end of the Cold War, however, resource abundance—particularly when that resource is oil—has been blamed for many civil wars in developing countries, and for political instability in the Middle East. If civil strife is caused by resource scarcity and poverty, why should oil revenues weaken states by fueling separatism and causing political instability? The puzzle is intensified by another popular argument for the oil curse—oil wealth enhances the stability and durability of authoritarian regimes because it strengthens dictators by funding patronage and repressive apparatuses. This paper uses data on historical oil explorations and discoveries to provide new evidence on the effect of oil wealth on political violence. In particular, we re-examine the “oil-fuels-war” hypothesis, and provide the first systematic analysis of the impact of oil wealth on coup attempts, irregular leadership transitions, and military spending, using a unique industrial dataset describing worldwide oil explorations, discoveries, extractions, and endowments since 1930.

Multitissue Molecular, Genomic, and Developmental Effects of the Deepwater Horizon Oil Spill on Resident Gulf Killifish (Fundulus grandis)

Abstract: The Deepwater Horizon oil rig disaster resulted in crude oil contamination along the Gulf coast in sensitive estuaries. Toxicity from exposure to crude oil can affect populations of fish that live or breed in oiled habitats as seen following the Exxon Valdez oil spill. In an ongoing study of the effects of Deepwater Horizon crude oil on fish, Gulf killifish (Fundulus grandis) were collected from an oiled site (Grande Terre, LA) and two reference locations (coastal MS and AL) and monitored for measures of exposure to crude oil. Killifish collected from Grande Terre had divergent gene expression in the liver and gill tissue coincident with the arrival of contaminating oil and up-regulation of cytochrome P4501A (CYP1A) protein in gill, liver, intestine, and head kidney for over one year following peak landfall of oil (August 2011) compared to fish collected from reference sites. Furthermore, laboratory exposures of Gulf killifish embryos to field-collected sediments from Grande Terre and Barataria Bay, LA, a...

The genome sequence of the most widely cultivated cacao type and its use to identify candidate genes regulating pod color

Abstract: Background Theobroma cacao L. cultivar Matina 1-6 belongs to the most cultivated cacao type. The availability of its genome sequence and methods for identifying genes responsible for important cacao traits will aid cacao researchers and breeders.

Social Sustainability Considerations during Planning and Design: Framework of Processes for Construction Projects

Abstract: This research identifies 50 processes and categorizes them into a framework for integrating and evaluating social considerations in construction projects. These processes focus on the planning and design phases because they offer the greatest potential for influencing project performance. The concept mapping research method was applied to develop this framework on the basis of input from 25 experts in academia, industry, and government. Multidimensional scaling and hierarchical cluster analyses were used to organize the experts' input into six categories defining social sustainability in construction projects: stakeholder engagement, user considerations, team formation, man- agement considerations, impact assessment, and place context. Although previous research has recognized social sustainability as a series of processes, this study is the first to integrate them into a comprehensive framework. Practitioners can benefit from this framework, which will enhance existing sustainability assessment methods and help address the challenge of developing truly sustainable projects. This framework also provides academics with a tool for introducing students to social sustainability in construction projects. Future research could use this framework as a baseline, developing metrics using the processes included in the framework. DOI: 10.1061/(ASCE)CO.1943-7862.0000566. © 2013 American Society of Civil Engineers. CE Database subject headings: Sustainable development; Social factors; Design; Planning; Construction; Safety. Author keywords: Sustainable development; Social factors; Design; Planning; Construction; Safety.