bluuebunny/crossref_metadata_2025 huggingface dataset:
The Proposed Yucca Mountain Repository from a Corrosion Perspective
Authors: Payer Joe H.
Published: April 2011

In this paper, the proposed Yucca Mountain Repository is viewed from a corrosion perspective. A major component of the long-term strategy for safe disposal of nuclear waste at the Yucca Mountain Repository is first to completely isolate the radionuclides in the waste packages for long times and to greatly retard the egress and transport of radionuclides from penetrated packages. Therefore, long-lived waste packages are important. The corrosion resistance of the waste package outer canister is reviewed, and a framework for the analysis of localized corrosion processes is presented. An overview is presented of the Materials Performance targeted thrust of the U.S. Department of Energy/Office of Civilian Radioactive Waste Management's Office of Science and Technology and International. The thrust program strives for increased scientific understanding, enhanced process models and advanced technologies for corrosion control.
Leach Resistant Cesium and Strontium-bearing Wasteforms from Hexagonal Tungsten Bronze-Polyacrylonitrile Composite Adsorbers
Authors: Griffith Christopher S. , Luca Vittorio , Sebesta Ferdinand , Yee Patrick , Drabarek Elizabeth
Published: April 2011

Immobilization of adsorbed Cs+ and Sr2+ on a molybdenum-doped, hexagonal tungsten bronze (HTB)-polyacrylonitrile (PAN) composite adsorbent can be achieved by heating in air at temperatures in the range 600 – 1200 °C. Thermal treatment of the parent composite material at 800 – 1000 °C undergoes a ca. 60% reduction in volume and retains its spherical morphology. For materials prepared at 800 – 1200 °C the full complement of Cs+ and the majority of Sr2+ partition into HTB phases (A∼0.16-0.3MO3; A = Cs, Sr, Na; M = Mo,W), along with sodium cations. The presence of high concentrations of Na+ relative to either Cs+ or Sr2+ does not appear to interfere with the formation of the HTB phase. The fraction (f) of Cs+ and Sr2+ leached from the tungstate phase assemblages is better or comparable with cesium hollandite (Cs0.8Ba0.4Ti8O18; f = ca. 8 × 10−5; rate = <1.2 × 10−4 g m−2d−1) and strontium titanate (SrTiO3; f = 3.1 × 10−3; rate = 2.63 × 10−4 g m−2 day×1), respectively, using a modified PCT test. Furthermore, where aggressive leaching conditions are employed (0.1M HNO3; 150 oC; 4 days), the tungstate phase assemblages display leach resistance orders of magnitude better than the reference phases (Cs+ - f = ca. 5 × 10−3; rate = ca. 1.4 × 10−3 g m−2 day−1; Sr2+ - f = ca. 8 × 10−2; rate = ca. 2.5 × 10−2 g m−2 day−1).
Analysis Interaction Field Strength and Spectrum from Microhysteresis Loops
Authors: Ye Lin-Xiu , Lee Jia-Mou , Wu Te-ho
Published: April 2011

In this paper, we present a direct method to analyze the mechanism of magnetic domain reversal for a series of amorphous Dyx(FeCo)1-x magnetic thin films and whereby we obtained the distributions of the coercivities and interaction fields from 90,000 measurements of the microhysteresis loops. The standard deviations of the coercivity and the interaction field distributions, σi and σk, can be estimated by fitting the experimental data with the Gaussian- Preisach function. The results show that the interaction field decreases as Dy composition approaches the compensation point. The reversal mechanism is dominated by nucleation when σi is smaller than σk. The relationships between the magnetization reversal and interaction field strength are discussed
Percent Spotted Knapweed (Centaurea stoebe) in the Diets of Grazing Sheep
Authors: Surber Lisa M. M. , Rude Mark E. , Roeder Brent L. , Mosley Tracy K. , Grove Allison V. , Walker John W. , Kott Rodney W.
Published: April 2011

The objective of this study was to use fecal near-infrared reflectance spectroscopy (NIRS) to estimate the percent spotted knapweed in the diet of grazing ewes to fine tune grazing prescriptions. In trial 1, five ewes were randomly selected from a band of 900 ewes to estimate weekly variation in percent spotted knapweed in the diet. Fecal samples from these ewes were collected weekly from June 22 through August 17 (nine collections per ewe for a total of 45 observations). In trial 2, fecal samples were collected from 89 ewes in the band to estimate variability in percent spotted knapweed in the diet among sheep at two sampling dates corresponding to the bud (July 13) and postflowering (August 15) stages of spotted knapweed phenology. In trial 1, the percent spotted knapweed in the diet was similar (P > 0.05) on June 22, June 29, July 13, and July 20 but was greater (P < 0.05) on July 6 than June 22 and 29. Percent spotted knapweed in the diet was also greater (P < 0.05) from July 27 through August 17 than from June 22 through July 20. On July 13 in trial 2, 55% of ewes had 0 to 5% spotted knapweed in their diets, whereas 44% of ewes had 5 to 20% spotted knapweed in their diets. On August 15, only 1% of ewes had < 10% spotted knapweed in their diets, whereas 44% of ewes had 20 to 25% spotted knapweed in their diets. The estimated percent spotted knapweed in the diet of the 89 ewes in trial 2 was similar to that of the five ewes during the same time period in sampling trial 1 (5.3% compared with 5.0% for sampling trials 1 and 2, respectively, on July 13 and 22.0% compared with 20.7% on August 15 and 17 for trials 1 and 2, respectively). This is the first study to estimate percent spotted knapweed in the diet of individual grazing ewes. These data suggest that the best time to graze spotted knapweed–infested pastures would be in late July or early August, when spotted knapweed is flowering, but before viable seed production.
Mislocalization of CDK11/PITSLRE, a regulator of the G2/M phase of the cell cycle, in Alzheimer disease
Authors: Bajić Vladan , Su Bo , Lee Hyoung-Gon , Kudo Wataru , Siedlak Sandra , Živković Lada , Spremo-Potparević Biljana , Djelic Ninoslav , Milicevic Zorana , Singh Avneet , Fahmy Lara , Wang Xinglong , Smith Mark , Zhu Xiongwei
Published: April 2011

Post-mitotic neurons are typically terminally differentiated and in a quiescent status. However, in Alzheimer disease (AD), many neurons display ectopic re-expression of cell cycle-related proteins. Cyclin-dependent kinase 11 (CDK11) mRNA produces a 110-kDa protein (CDK11p110) throughout the cell cycle, a 58-kDa protein (CDK11p58) that is specifically translated from an internal ribosome entry site and expressed only in the G2/M phase of the cell cycle, and a 46-kDa protein (CDK11p46) that is considered to be apoptosis specific. CDK11 is required for sister chromatid cohesion and the completion of mitosis. In this study, we found that the expression patterns of CDK11 vary such that cytoplasmic CDK11 is increased in AD cellular processes, compared to a pronounced nuclear expression pattern in most controls. We also investigated the effect of amyloid precursor protein (APP) on CDK11 expression in vitro by using M17 cells overexpressing wild-type APP and APP Swedish mutant phenotype and found increased CDK11 expression compared to empty vector. In addition, amyloid-β25–35 resulted in increased CDK11 in M17 cells. These data suggest that CDK11 may play a vital role in cell cycle re-entry in AD neurons in an APP-dependent manner, thus presenting an intriguing novel function of the APP signaling pathway in AD.
Stress-induced expression of p53 target genes is insensitive to SNW1/SKIP downregulation
Authors: Tolde Ondřej , Folk Petr
Published: April 2011

Pharmacological inhibition of protein kinases that are responsible for the phosphorylation of the carboxy-terminal domain (CTD) of RNA Pol II during transcription by 5,6-dichloro-1-beta-D-ribofuranosyl-benzimidazole (DRB) leads to severe inhibition of mRNA synthesis and activates p53. Transcription of the p53 effectors that are induced under these conditions, such as p21 or PUMA, must bypass the requirement for CTD phosphorylation by the positive elongation factor P-TEFb. Here, we have downregulated SNW1/SKIP, a splicing factor and a transcriptional co-regulator, which was found to interact with P-TEFb and synergistically affect Tat-dependent transcription elongation of HIV 1. Using the colon cancer derived cell line HCT116, we have found that both doxorubicin- and DRB-induced expression of p21 or PUMA is insensitive to SNW1 downregulation by siRNA. This suggests that transcription of stress response genes, unlike, e.g., the SNW1-sensitive mitosis-specific genes, can proceed uncoupled from regulators that normally function under physiological conditions.
Stereoselective synthesis of the polar part of mycestericins E and G
Authors: Martinková Miroslava , Gonda Jozef , Uhríková Alena , Kováčvá Margaréta
Published: April 2011

5-O-(t-Butyldimethylsilyl)-3-deoxy-3-C-hydroxymethyl-1,2-O-isopropylidene-3-(methoxycarbonylamino)-α-d-xylofuranose IV has been proved to be an appropriate building block in the stereoselective synthesis of methyl (4S)-4-[(1′R)-1′-acetoxy-4′-oxobutyl]-3-benzyl-2-oxooxazolidine-4-carboxylate III representing the polar part of the naturally occurring mycestericins E and mycestericins G.
Synthesis and crystal and molecular structures of N,N′-methylenedipyridinium tetrachlorozincate(II) and N,N′-methylenedipyridinium tetrachlorocadmate(II)
Authors: Al-Ktaifani Mahmoud , Rukiah Mwaffak
Published: April 2011

Treatment of N,N′-methylenedipyridinium dichloride [C5H5N-CH2-NC5H5]Cl2 with MCl2 (M = Zn or Cd) in aqueous solution gives the organic-inorganic hybrid ionic compounds [C5H5N-CH2-NC5H5] · [MCl4]. Both complex salts were fully characterised by multinuclear NMR spectroscopy, elemental analysis, and their molecular structures confirmed by powder X-ray diffraction studies. The most striking feature in both solid state structures was the presence of the C…Cl-M short contacts between the organic [C5H5N-CH2-NC5H5] dication and inorganic [MCl4] anion, which led to different crystal packing. For [C5H5N-CH2-NC5H5]·[ZnCl4], the C…Cl-Zn interactions led to the alternating arrangement of [C5H5N-CH2-NC5H5]2+[ZnCl4]2− to form 1-D chains in the direction [010], and each individual chain had a two-fold rotational axis along the b axis, while for [C5H5N-CH2-NC5H5] · [CdCl4] the C…Cl-Cd associations gave 2-D network. In both solid state structures, the presence of Cl-ring centroid distances gave a strong indication of some form of Cl-π interactions.
Properties of poly(γ-benzyl l-glutamate) membrane modified by polyurethane containing carboxyl group
Authors: Zhu Guo-Quan , Wang Fa-Gang , Gao Qiao-Chun , Li Guo-Chang , Wang Ping
Published: April 2011

A series of poly(γ-benzyl l-glutamate) (PBLG)/polyurethane (PU) containing carboxyl group blend membranes was prepared by casting the polymer blend solution in dimethylformamide (DMF). The surface morphology of the PBLG/PU blend membranes was investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of PBLG/PU blend membranes were studied by differential scanning calorimetry (DSC), tensile tests and other physical methods. It was revealed that the introduction of PU could exert outstanding effects on the morphology and the properties of PBLG membrane.
Patterns in Software Maintenance
Authors: Stevens Perdita
Published: April 2011

In software design, patterns—that is, structured, named descriptions of good solutions to common problems in context—have become a popular way of recording and transferring problem-solving expertise. The aim of this chapter is to describe how patterns can help in the field of software maintenance. There are two main uses of patterns in software maintenance. The first is to consider the introduction of a design pattern to an existing design. The second approach is to consider patterns for the maintenance process itself. For example, reengineering patterns describe solutions to common problems in the reengineering of a system, considering issues such as how to split the necessary changes into risk-minimizing steps. We discuss the advantages, pitfalls and practicalities of using patterns in both of these ways.
Software Maintenance Cost Estimation
Authors: Sneed Harry M.
Published: April 2011

This chapter deals with the subject of estimating the costs of software maintenance. It reviews the existing literature on the subject and summarises the various approaches taken to estimate maintenance costs starting with the original COCOMO approach in 1981. It then deals with the subject of impact analysis and why it is essential to estimate the scope of maintenance projects. Examples are given to illustrate this. It then goes on to describe some of the tools the author has developed in the past ten years to support his practice of maintenance project estimation including the tools SoftCalc and MainCost. For both of these tools empirical studies of industrial experiments are presented as proof of the need to automate the estimation process.
Structural Influences on Global E-Commerce Activity
Authors: Markus M. Lynne , Soh Christina
Published: April 2011

An important line of research on global information management examines the effects of national culture on information technology (IT) development, operations, management, and use. This chapter argues that global information management researchers should not lose sight of structural conditions related to business-to-business and business-to-consumer e-commerce activity. Structural conditions are physical, social, and economic arrangements that shape e-commerce business models and influence individual and organizational use of the Internet. Examples include geography (which affects the physical distribution of goods purchased online), space (which influences the choice of access technology for e-commerce), and financial infrastructure (which is related to credit card use). Structural conditions differ from country to country — and even from location to location within country, but they are not necessarily related to dimensions of natural culture. Therefore, valid explanations of global differences in e-commerce activity require a careful assessment of relevant structural factors.
The IS/IT Outsourcing Phenomenon in the Public Sector of a Developing Country
Authors: Khalfan Abdulwahed Moh. , Gough Tom G.
Published: April 2011

This chapter presents an overview of a national case study exploring the IS/IT outsourcing phenomenon in the public sector of a developing country. The study is empirically based and provides a logical extension to earlier research studies/endeavors in the field of IS/IT outsourcing. Kuwait, where the data collection for this study was carried out, has been used as an example of a developing country . The primary data on IS/IT outsourcing practices, obtained for the first time in Kuwait, were collected by means of survey questionnaires and semi-structured interviews supported by organizational documentation. The research seeks to identify the factors that give rise to the IS/IT outsourcing phenomenon, and the degree to which they influence the practices, procedures, and outcomes of IS/IT outsourcing arrangements in Kuwait. The overall research aimed to provide a comprehensive pragmatic picture of IS/IT outsourcing practices, including motivations, risk analysis, contract drafting and legal issues, vendor selection criteria, evaluation practices, decision-making processes, and post-evaluation experience. There is growing evidence within the Kuwaiti environment to suggest that public organizations are not achieving the desired benefits from their IS/IT outsourcing operations. IS/IT outsourcing projects in Kuwait are still undertaken in ways that are not clearly related to strategic change. It is clear that IS/IT outsourcing is a multi-faceted phenomenon that should be studied broadly in context. The lesson is that the solutions must make sense for the particular context in which they will be implemented, considering all cultural and environmental factors. It was found that culture plays an important role throughout the outsourcing process. The findings of this study also suggest that there will be an increasing utilisation of IT outsourcing services in the public sector of Kuwait.
The State of Teledensity Diffusion in Least Developed Countries
Authors: Mbarika Victor W.A.
Published: April 2011

This chapter reviews research from academic and major international organizational literature to examine and synthesize the current understanding of teledensity development in Least Developed Countries (LDCs). The obstacles to the growth of teledensity are discussed, and the importance and opportunities for growth of teledensity to solve priority problems and to realize sustainable development in LDCs are examined. The literature findings suggest that various policy, economical, financial, managerial, organizational, technological, political, and geographical factors are important determinants for growth of teledensity in LDCs. A variety of strategies to advance teledensity in LDCs are suggested.
A Graphical Approach for Reducing Spreadsheet Linking Errors
Authors: Morrison Charles E. , Morrison Joline , Melrose John , Wilson E. Vance
Published: April 2011

Spreadsheet programs are deceptively simple tools that are widely used by end user developers in organizations. However, recent studies have shown that spreadsheets often contain significant, decision-affecting errors. One study that addressed “linking errors,” i.e., incorrect references to spreadsheet cell values on separate work areas, found these errors to be a major error source in complex spreadsheets that use distinct work areas spread across multiple worksheets. This paper describes a code inspection approach that visually represents the structure of a linked spreadsheet and graphically identifies linked cells and their sources. We tested this approach in an experimental study where subjects created a complex spreadsheet. Results indicate that subjects who used the approach made significantly fewer errors and experienced no decrease in speed of spreadsheet production or satisfaction with the production process.
Initial E-Commerce Efforts in Nine Least Developed Countries
Authors: Wresch William
Published: April 2011

While e-commerce would seem to be a unique opportunity for poor countries with limited local markets to sell goods to richer nations, limited research is available on the current status of e-commerce efforts in Least Developed Countries (LDCs). This study reviewed the efforts of the nine countries identified by the UNDP as having the least technological capacity. Statistics provided by the UNDP demonstrate serious national infrastructure problems in each of the countries. Yet a survey of business web sites finds that all but one (Sudan) has some minimal e-commerce efforts underway. A survey sent to companies in three of these countries showed that many companies were being creative in where they were hosting their web sites and were able to keep their web costs low. Yet the vast majority also reported slow sales and a variety of local barriers to success. A review of the products they are offering on their sites found that the product mix might be particularly problematic. The author hopes the results of this study will suggest improved strategies for companies in LDCs seeking to use e-commerce to expand their markets.
Fuzzy Information Modeling with the UML
Authors: Ma Zongmin
Published: April 2011

Computer applications in nontraditional areas have put requirements on conceptual data modeling. Some conceptual data models, being the tool of design databases, were proposed. However, information in real-world applications is often vague or ambiguous. Currently, less research has been done in modeling imprecision and uncertainty in conceptual data models. The UML (Unified Modeling Language) is a set of object-oriented modeling notations and is a standard of the Object Data Management Group (ODMG). It can be applied in many areas of software engineering and knowledge engineering. Increasingly, the UML is being applied to data modeling. In this chapter, different levels of fuzziness are introduced into the class of the UML and the corresponding graphical representations are given. The class diagrams of the UML can hereby model fuzzy information.
Supporting the JAD Facilitator with the Nominal Group Technique
Authors: Duggan Evan W. , Thachenkary Cherian S.
Published: April 2011

Joint Application Development (JAD) was introduced in the late 1970s to solve many of the problems system users experienced with the conventional methods used in systems requirements determination (SRD) and has produced noteworthy improvements over these methods. However, a JAD session is conducted with freely interacting groups, which makes it susceptible to the problems that have curtailed the effectiveness of groups. JAD outcomes are also critically dependent on excellent facilitation for minimizing dysfunctional group behaviors. Many JAD efforts are not contemplated (and some fail) because such a person is often unavailable. The nominal group technique (NGT) was designed to reduce the impact of negative group dynamics. An integration of JAD and NGT is proposed here as a crutch to reduce the burden of the JAD facilitator in controlling group sessions during SRD. This approach, which was tested empirically in a laboratory experiment, appeared to outperform JAD alone in the areas tested and seemed to contribute to excellent group outcomes even without excellent facilitation.
Electronic Banking and Information Assurance Issues
Authors: Gupta Manish , Rao Raghav , Upadhyaya Shambhu
Published: April 2011

Information assurance is a key component in e-banking services. This article investigates the information assurance issues and tenets of e-banking security that would be needed for design, development, and assessment of an adequate electronic security infrastructure. The technology terminology and frameworks presented in the article are with the view to equip the reader with a glimpse of the state-of-art technologies that may help toward learning and better decisions regarding electronic security.
A TAM Analysis of an Alternative High-Security User Authentication Procedure
Authors: Warkentin Merrill , Davis Kimberly , Bekkering Ernst
Published: April 2011

The objective of information system security management is information assurance, which means to maintain confidentiality (privacy), integrity, and availability of information resources for authorized organizational end users. User authentication is a foundation procedure in the overall pursuit of these objectives, and password procedures historically have been the primary method of user authentication. There is an inverse relationship between the level of security provided by a password procedure and ease of recall for users. The longer the password and the more variability in its characters, the higher the level of security is that is provided by the password, because it is more difficult to violate or crack. However, such a password tends to be more difficult for an end user to remember, particularly when the password does not spell a recognizable word or when it includes non-alphanumeric characters such as punctuation marks or other symbols. Conversely, when end users select their own more easily remembered passwords, the passwords also may be cracked more easily. This study presents a new approach to entering passwords that combines a high level of security with easy recall for the end user. The Check-Off Password System (COPS) is more secure than self-selected passwords and high-protection, assigned-password procedures. The present study investigates tradeoffs between using COPS and three traditional password procedures, and provides a preliminary assessment of the efficacy of COPS. The study offers evidence that COPS is a valid alternative to current user authentication systems. End users perceive all tested password procedures to have equal usefulness, but the perceived ease of use of COPS passwords equals that of an established high-security password, and the new interface does not negatively affect user performance compared to a high-security password. Further research will be conducted to investigate long-term benefits.
Migration of Persistent Object Models Using XMI
Authors: Fromming Rainer , Rausch Andreas
Published: April 2011

Embrace the change! Change is a constant reality of software development, a reality that must be reflected in not only our software process but also our software production environment. With ever-changing customer requirements, modifications to the object model are required during software development as well as after product distribution. The associated migration of existing persistent object data is a nontrivial problem. This chapter presents the conceptualization and implementation of a tool for the automated migration of persistent object models. The migration is controlled by an XMI-based description of the difference between the old and the new object model. Both, the schema and the data of the persistent object model are migrated efficiently and reliably.
A Reuse Definition, Assessment, and Analysis Framework for UML
Authors: Needham Donald , Caballero Rodrigo , Demurjian Steven , Eickhoff Felix , Zhang Yi
Published: April 2011

This chapter examines a formal framework for reusability assessment of development-time components and classes via metrics, refactoring guidelines, and algorithms. It argues that software engineers seeking to improve design reusability stand to benefit from tools that precisely measure the potential and actual reuse of software artifacts to achieve domain-specific reuse for an organization’s current and future products. The authors consider the reuse definition, assessment, and analysis of a UML design prior to the existence of source code, and include dependency tracking for use case and class diagrams in support of reusability analysis and refactoring for UML. The integration of these extensions into the UML tool Together Control Center to support reusability measurement from design to development is also considered.
Cultural Differences, Information and Code Systems
Authors: Corbitt Brian J. , Peszynski Konrad J. , Inthanond Saranond , Hill Byron
Published: April 2011

This paper explores an alternative way of framing information systems research on the role and impact of national culture. It argues that the widely accepted structural framework of Hofstede reduces interpretation to a simplistic categorical description which in many cases ignores differentiation within cultures. The alternative model suggests, that national culture can be better understood by seeking out the dominant codes that frame the discourse pervasive in a culture and understanding how that discourse affects the obvious social codes of ritual, custom and behavior and the textual codes which express the nature of that culture. This framework is applied to two different case studies — one in New Zealand and one in Thailand — to demonstrate its applicability.
Evaluating the Factors Affecting DSS Usage by Senior Managers in Local Authorities in Egypt
Authors: Elbeltagi Ibrahim , McBride Neil , Hardaker Glenn
Published: April 2011

The study of factors influencing the adoption and use of information systems in less-developed countries is an important area to address since differences in culture, social structure, and business approaches may have significant effects on the benefits derived from importing Western-influenced IT technology, concepts, and management approaches. This study examines the usage of a decision support system (DSS) in Egyptian local authorities using an adapted Technology Acceptance Model (TAM). The centrally-developed DSS had been rolled out to 27 governorates in Egypt for use by chief executive officers. The results demonstrated that TAM could be applied to a specific system within a developing country. Both perceived ease of use (PEU) and perceived usefulness (PU) had a significant direct effect on DSS usage. PEU dominated over PU whose effect on DSS usage was negative.
A Template-Based Analysis of GRL
Authors: Heymans Patrick , Saval Germain , Dallons Gautier
Published: April 2011

This chapter applies the template proposed by Opdahl and Henderson-Sellers to the Goal-oriented Requirements Engineering Language (GRL). It proposes a metamodel of GRL that identifies the constructs of the language and the links between them. Each construct is then described through the template in order to extract and formalise detailed syntactic and semantic information. The latter takes the form of a mapping between a construct and its meaning, defined in terms of the Bunge-Wand-Weber ontology. Evaluations of both GRL and the template are provided as well as suggestions for improvements. The purpose of our work is to improve the quality of goal modelling. Indeed, despite the increasing popularity of the goal-oriented paradigm, especially in requirements engineering and enterprise modelling, the central notion of goal remains one of the most controversial. A possible cause might be that researchers have devoted too little attention to studying the ontological foundations of goal-oriented languages. This chapter addresses such issues for GRL.
A Case Study
Authors: Chu Sauman , Arango Mauricio , Yust Charles Earl Love
Published: April 2011

This chapter addresses the design and procedural variables of creating a bilingual Web site information portal for an audience of culturally diverse immigrants. A Web site developed as a resource for a diverse Somali community (http://www.somaliresource. net) is used as a case study for this chapter. The Somali community, which includes immigrants, refugees, and asylees, faces difficulties associated with language barriers. They struggle with the adjustment of life in a completely new system in Minnesota. The aim of this resource is to address some of the Somali’s informational needs in the form of a one-stop bilingual Web site. It is our goal to describe our design process, and offer recommendations on design and procedural variables for working with the Somali cultural group. We envision that graphic designers and other researchers will find it useful to reference this material when they address design issues related to different cultural groups.
It Can’t Be December Already: A Real Life Simile to Jeffery Archer’ Short Story
Authors: Kumar Sarwan , Gupta Deepak , Rau Shiva S.
Published: April 2011

This case reflects the difficulties arising out of the patients autonomy to choose the type, timing, and extent of the medical management even though in some clinical scenarios, like the case presented, the patient was not able to communicate his physiological needs for a safe and protected shelter from the extreme weather, and was unable to follow up with the medical plan offered at the emergency room during each of his prior visits before the catastrophic event of unwitnessed hypoglycemic seizure and severe hypothermia.
On the Behavior of Periodic Solutions of Planar Autonomous Hamiltonian Systems with Multivalued Periodic Perturbations
Authors: Makarenkov Oleg , Malaguti Luisa , Nistri Paolo
Published: April 2011

Aim of the paper is to provide a method to analyze the behavior of

T

-periodic solutions

x_\varepsilon

,

\varepsilon>0

, of a perturbed planar Hamiltonian system near a cycle

x_0

, of smallest period

T

, of the unperturbed system. The perturbation is represented by a

T

-periodic multivalued map which vanishes as

\varepsilon\to 0

. In several problems from nonsmooth mechanical systems this multivalued perturbation comes from the Filippov regularization of a nonlinear discontinuous

T

-periodic term. Through the paper, assuming the existence of a

T

-periodic solution

x_\varepsilon

for

\varepsilon>0

small, under the condition that

x_0

is a nondegenerate cycle of the linearized unperturbed Hamiltonian system we provide a formula for the distance between any point

x_0(t)

and the trajectories

x_\varepsilon([0,T])

along a transversal direction to

x_0(t)

.
Singular Perturbations of Curved Boundaries in Three Dimensions. The Spectrum of the Neumann Laplacian
Authors: Laurain Antoine , Nazarov Sergei A. , Sokolowski Jan
Published: April 2011

We calculate the main asymptotic terms for eigenvalues, both simple and multiple, and eigenfunctions of the Neumann Laplacian in a three-dimensional domain

\Omega(h)

perturbed by a small (with diameter

O(h)

) Lipschitz cavern

\overline{\omega_h}

in a smooth boundary

\partial\Omega=\partial\Omega(0)

. The case of the hole

\overline{\omega_h}

inside the domain but very close to the boundary

\partial\Omega

is under consideration as well. It is proven that the main correction term in the asymptotics of eigenvalues does not depend on the curvature of

\partial\Omega

while terms in the asymptotics of eigenfunctions do. The influence of the shape of the cavern to the eigenvalue asymptotics relies mainly upon a certain matrix integral characteristics like the tensor of virtual masses. Asymptotically exact estimates of the remainders are derived in weighted norms.
On the Convergence to Stationary Solutions for a Semilinear Wave Equation with an Acoustic Boundary Condition
Authors: Frigeri Sergio
Published: April 2011

We consider a semilinear wave equation equipped with an acoustic boundary condition. More precisely, we study a system consisting of the wave equation for the evolution of an unknown function in a three-dimensional domain

\Omega

, i.e., the velocity potential

u

, coupled with an ordinary differential equation for the evolution of an unknown function on

\partial\Omega

, i.e., the normal displacement

\delta

. The system is completed with a third condition expressing the impenetrability of the boundary. This problem, inspired on a model for acoustic wave motion of a fluid in a domain with locally reacting boundary surface, originally proposed by J.T. Beale and S.I. Rosencrans in [Bull. Amer. Math. Soc. 80 (1974), 1276–1278], has been studied by S. Frigeri in [J. Evol. Equ. 10 (2010), 29–58] from the point of view of the global asymptotic analysis. The goal of this paper is to analyze the asymptotic behavior of single trajectories, proving that, when the nonlinearity

f(u)

is analytic, every weak solution converges to a stationary state. The result is obtained by suitably using an argument due to Haraux-Jendoubi and based on the Simon–Lojasiewicz inequality. Furthermore, we provide an estimate for the decay rate to equilibrium.
On the Parabolicity of the Muskat Problem: Well-Posedness, Fingering, and Stability Results
Authors: Escher Joachim , Matioc Bogdan-Vasile
Published: April 2011

We study the Muskat problem in a periodic geometry and incorporate capillary as well as gravity effects in the modelling. The problem is rewritten as an abstract evolution equation. By analysing this evolution equation we prove wellposedness of the problem and we establish exponential stability of some flat equilibrium. Using bifurcation theory we also find finger shaped steady-states which are all unstable.
The Riesz Potential Operator in Optimal Couples of Rearrangement Invariant Spaces
Authors: Capone Claudia , Fiorenza Alberto , Karadzhov G. E. , Nazeer Waqas
Published: April 2011

We prove continuity of the Riesz potential operator in optimal couples of rearrangement invariant function spaces defined in

{\mathbf R}^n

with the Lebesgue measure. An application is given to the Hardy–Littlewood maximal operator.
Endogeny for the Logistic Recursive Distributional Equation
Authors: Bandyopadhyay Antar
Published: April 2011

In this article we prove the endogeny and bivariate uniqueness property for a particular “max-type” recursive distributional equation (RDE). The RDE we consider is the so called logistic RDE, which appears in the proof of the ζ(2)-limit of the random assignment problem using the local weak convergence method proved by D. Aldous [Probab. Theory Related Fields 93 (1992)(4), 507–534]. This article provides a non-trivial application of the general theory developed by D. Aldous and A. Bandyopadhyay [Ann. Appl. Probab. 15 (2005)(2), 1047–1110]. The proofs involve analytic arguments, which illustrate the need to develop more analytic tools for studying such max-type RDEs.
Hydrogel for Cell Housing in the Brain and in the Spinal Cord
Authors: Perale Giuseppe , Giordano Carmen , Bianco Fabio , Rossi Filippo , Tunesi Marta , Daniele Francesco , Crivelli Filippo , Matteoli Michela , Masi Maurizio
Published: April 2011

Purpose

Neurons in the adult mammalian central nervous system do not proliferate or renew themselves and consequently strong interest in cell replacement therapies to repair brain and spinal cord damages has emerged in the last decade.

Methods

An injectable resorbable hydrogel with a controlled nanostructure, specifically designed for neural cell housing, was developed together with a new protocol for building three-dimensional (3D) biohybrid cell/hydrogel constructs: cells are housed within the polymeric matrix which is directly built with a specific cell culture media. This matrix was tested with standard glial populations, primary astrocytes and mesenchymal stem cells.

Results

Physico-chemical characterization of the hydrogel matrix confirmed a 2- week (+ 2 days) stability before massive degradation; mean mesh size of about 5 nm and thixotropic behavior with transition yield stress at 60+5 Pa. Cell survival within the hydrogel resulted in about 55±5% (minimum value) survivals, data also confirmed by optical assessments. Cell viability also remained high after extraction from the gel, indicating survival to inclusion latency period.

Conclusions

Since the intimate structure of the gel mimics extracellular matrix cells as would be expected to be found in an in vivo context, this polymeric formulation is a promising base for building 3D constructs for neural cell housing, in which cells are embedded and kept alive directly from the time of polycondensation.
A Validated Cfd Model to Predict O2 and Co2 Transfer Within Hollow Fiber Membrane Oxygenators
Authors: Hormes Marcus , Borchardt Ralf , Mager Ilona , Schmitz-Rode Thomas , Behr Marek , Steinseifer Ulrich
Published: April 2011

Hollow fiber oxygenators provide gas exchange to and from the blood during heart surgery or lung recovery. Minimal fiber surface area and optimal gas exchange rate may be achieved by optimization of hollow fiber shape and orientation (1). In this study, a modified CFD model is developed and validated with a specially developed micro membrane oxygenator (MicroMox). The MicroMox was designed in such a way that fiber arrangement and bundle geometry are highly reproducible and potential flow channeling is avoided, which is important for the validation. Its small size (VFluid=0.04 mL) allows the simulation of the entire bundle of 120 fibers. A non-Newtonian blood model was used as simulation fluid. Physical solubility and chemical bond of O2 and CO2 in blood was represented by the numerical model. Constant oxygen partial pressure at the pores of the fibers and a steady state flow field was used to calculate the mass transport. In order to resolve the entire MicroMox fiber bundle, the mass transport was simulated for symmetric geometry sections in flow direction. In vitro validation was achieved by measurements of the gas transfer rates of the MicroMox. All measurements were performed according to DIN EN 12022 (2) using porcine blood. The numerical simulation of the mass transfer showed good agreement with the experimental data for different mass flows and constant inlet partial pressures. Good agreement could be achieved for two different fiber configurations. Thus, it was possible to establish a validated model for the prediction of gas exchange in hollow fiber oxygenators.
Method for Autologous Single Skin Cell Isolation for Regenerative Cell Spray Transplantation with Non-Cultured Cells
Authors: Gerlach Jörg C. , Johnen Christa , Ottoman Christian , Bräutigam Kirsten , Plettig Jörn , Belfekroun Claudia , Münch Sandra , Hartmann Bernd
Published: April 2011

Background

There is a therapeutic gap for patients with deep partial-thickness wounds (Grade IIb) of moderate size that were initially not treated with split- or mesh grafting to avoid overgrafting, but developed delayed wound healing around two weeks after injury - at which time grafting is typically not indicated anymore. Delayed wound healing is often associated with esthetically unsatisfactory results and sometimes functional problems. An innovative cell isolation method for cell spray transplantation at the point of care, which eliminates cell culture prior to treatment, was implemented for this population of burn patients in our center.

Methods

Autologous skin cell spray transplantation was initiated by taking healthy skin. The dermal/epidermal layers were separated using enzymatic digestion with 40 min dispase application, followed by 15 min trypsin application for basal kerationcyte isolation, 7 min cell washing by centrifugation, followed by transferring the cells for spraying into Ringer lactate solution. The procedure was performed on site in a single session immediately following the biopsy. After sharp wound debridement, cells were immediately transplanted by deposition with a cell sprayer for even distribution of the cell suspension.

Results and Conclusions

Eight patients were treated (mean age 30.3 years, mean burn total body surface area 14%, mean Abbreviated Burn Severity Index (5 points). The mean time to complete re-epithelialization was 12.6 days. All patients exhibited wound healing with improved esthetic and functional quality. Our initial experience for the use of non-cultured cells using a two-enzyme approach with cell washing suggests shortened time for wound closure, suggesting that the method may potentially avoid longer-term complications.
Distributed Space-Time/Frequency Coding Schemes for Single-Carrier Frequency Division Multiple Access Systems
Authors: Al-nahari A. Y. , Abd El-Samie F. E. , Dessouky M. I.
Published: April 2011

The single carrier-frequency division multiple access (SC-FDMA) system is a new system that was adopted in the standardization of the upcoming 3GPP long-term evolution (LTE). Designing diversity-achieving schemes for the SC-FDMA system is a challenging task. The codes adopted should not affect the peak-to-average power ratio (PAPR) among other constraints. In this paper, we consider the design of cooperative diversity schemes for SC-FDMA systems in the uplink direction. Specifically, two relay-assisted distributed space-time/frequency codes are proposed. The proposed distributed space-frequency code (SFC) achieves full spatial diversity in the uplink fast-fading channels, where a diversity of order three can be achieved. The proposed code keeps a low PAPR, which is a good feature of the system. A minimum mean square error (MMSE) decoder is used at the receiver of the destination node. Moreover, we propose a bandwidth-efficient distributed space-time code (STC) for slow-fading relay channels. A decode-and-forward (DF) protocol is used at the relay node, and the possibility of erroneous decoding is taken into account. Simulation results demonstrate the performance improvement of the proposed schemes.
Fish Species Richness in Lowland Streams with a Geothermal Input Phenomenon, Sarapiquí de Heredia, Costa Rica
Authors: Golcher Benavides Jimena , Protti Quesada Maurizzio
Published: April 2011

Lowland streams of the Caribbean Costa Rican slope are naturally enriched by minerals and solutes such as phosphorus, a phenomenon known as geothermal input. The resulting stream phosphorus gradient affects the food web by altering primary production, leading to complex biotic and abiotic interactions. The objective of this study was to describe fish species richness patterns in relation to a naturally occurring phosphorus gradient in three lowland streams. We hypothesized that phosphorus input in La Selva Biological Station streams is correlated with species richness. 354 individuals were identified at 4 sites: Surá, El Salto, Sábalo and Jaguar, using a cast net, a total of 150 throws were made, distributed in 10 samplings, at each site. An estimation of species richness along with alpha and beta diversity indices were calculated in order to describe fish community structure. Species richness was estimated to be higher at Jaguar but presents a lower phosphorus enrichment. Jaguar and Sábalo, differed the most while Salto and Surá were the most similar as indicated by species turnover among streams. There is a non significant relationship between phosphorus levels and diversity; however, this interesting trend encourages further studies on species richness patterns and natural nutrient enrichment of streams.
Brief communication: Correcting overestimation when determining two‐dimensional occlusal area in human molars
Authors: Schmidt Christopher , Ousley Stephen , Schmidt Molly
Published: April 2011

The robustness index (RI) is determined by multiplying dental mesiodistal and buccolingual diameters, and is used to estimate occlusal area. However, because teeth are not rectangular its calculation consistently causes overestimations. Moreover, teeth, in particular molars, are not identically shaped so overestimations vary. The current study seeks to determine the extent to which overestimations are affected by tooth shape and to improve RI's efficacy. Initially, 120 molars were sorted into six shape groups, which were determined by hypocone/hypoconulid expression. Three maxillary and three mandibular shape groups were set using the Arizona State University Dental Anthropology System. ANOVA results determined that RI overestimations, which averaged around 20%, were not the same for each shape category. Maxillary molars with large hypocones and mandibular molars with no hypoconulids were overestimated significantly less than the other molar groups. Regression‐based correction formulae were generated and applied to the original sample. These formulae far more precisely estimated tooth area than RI and there were no differences in estimation based upon tooth shape. A subsequent validation study of 24 additional molars was undertaken to test the formulae on teeth not from the original sample. Overestimation/underestimation averaged 0.5% and was about the same for each of the tooth shape groups. Finally, six new correction formulae were generated using all 144 molars. The correction formulae provide, what is termed here, an adjusted robustness index (ARI), and it is recommended that ARI is used in future studies of molar occlusal area. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Degradation of thiram in water, soil and plants: a study by high‐performance liquid chromatography
Authors: Gupta Bina , Rani Manviri , Kumar Rahul
Published: April 2011

A comprehensive study was conducted to evaluate the persistence of thiram in water and soil under controlled conditions and on two plants, namely tomato and radish, in field conditions. In order to follow the decay of the pesticide, an HPLC procedure was developed employing an octadecyl endcapped RP‐C18 column using a mixture of acetonitrile and water as the mobile phase and an ultraviolet detector. Studies conducted in water at different temperature, pH and organic content revealed that the persistence of the pesticide decreases with the increase in all the three variables. In the three different types of soils studied, the effect of pH was more or less apparent on a similar line. On average a slower decay was observed in the case of plants than in water and soil. Copyright © 2011 John Wiley & Sons, Ltd.