bluuebunny/crossref_metadata_2025 huggingface dataset:
Silyl‐Terminated Ethylene‐co‐Norbornene Copolymers by Organotitanium‐Based Catalysts
Authors: Marconi Roberto , Ravasio Andrea , Boggioni Laura , Tritto Incoronata
Published: November 2008

Ethylene (E) and norbornene (N) were copolymerized in the presence of PhSiH3 as chain‐transfer agent with [Ti(η5:η1‐C5Me4SiMe2NBut)(η1‐Me)2] precatalyst combined with [Ph3C][B(C6F5)4]. The silane was introduced at chain‐ends of E‐co‐N copolymers with concomitant reinitiation of the growing polymer chain. The concentrations of the silane and polymer molecular weight are inversely correlated. The characteristic signals of SiH2Ph chain‐ends were observed by 1H NMR. The Si heteroatom is predominantly adjacent to ethylene units in E‐co‐N copolymers with high N content.

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Nonnormality estimation in projection‐type system realization methods
Authors: Bazán F. S. V.
Published: November 2008

Using Henrici's departure from normality as a tool, we investigate the influence of nonnormality on the spectral sensitivity of system matrices of projection‐type system realization methods. Basically, we show that the system matrix of one of these methods is diagonally similar to the system matrix of the classical Kung's method and, we then conclude that the spectral sensitivity of all methods decreases significantly under conditions that are often met or easy to impose in practice. On the basis of these results, we conclude thatallprojection‐type realization methods have essentially the same spectral properties as Kung's method. Furthermore, a theoretical eigenvalue error bound is derived and illustrated by numerical simulations. Copyright © 2008 John Wiley & Sons, Ltd.
Foz2006 numerical linear algebra and optimization
Authors: Gonzaga Clovis Caesar , Yuan Jin Yun
Published: November 2008

The special issue contains five papers from Foz2006—Congress on Mathematics and its Applications, held in Foz do Iguaçu, Brazil, on 7–11 August 2006, chaired by Yuan Jin Yun. The papers address preconditioners for saddle point problems, iterative methods, new family of penalty functions for optimization and their applications. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and characterization of a new kind of immobilized Mn(salen) and catalytic epoxidation of styrene on the catalyst
Authors: Shen Hongsheng , Fu Xiangkai , Bao Hebin , Chen Junxian , Gong Biwei
Published: November 2008

A linear polystyrene‐isopropenyl phosphonic acid (PS‐IPPA) copolymer was newly synthesized by free radical reaction in solution with isopropenyl phosphonic acid (IPPA) and styrene. Zirconium poly(styrene‐isopropenyl phosphonate)‐phosphate acid (ZPS‐IPPA) was also synthesized. The benzene rings of ZPS‐IPPA were hydroxylated and then further reacted with Mn(salen)Cl. Thus the heterogeneous catalyst, Mn(salen) axially immobilized onto ZPS‐IPPA was synthesized. These substances were characterized by IR spectra, X‐ray diffraction (XRD), SEM, TEM, NMR, thermogravimetric analysis, and AAS. The catalyst showed good activity to epoxidation of styrene, which is close to that of the corresponding homogeneous catalyst. Copyright © 2008 John Wiley & Sons, Ltd.
A review on ternary immiscible polymer blends: morphology and effective parameters
Authors: Shokoohi Shirin , Arefazar Ahmad
Published: November 2008

In this paper a review of studies on ternary polymer blends, reported in the period from 1980s to 2007, is presented. This review covers the investigations carried out on the formation of morphologies observed in ternary blends including separated disperse, core–shell and co‐continuous morphologies; and also the parameters affecting the type of morphology and its distribution state. Copyright © 2008 John Wiley & Sons, Ltd.
Influences of poly(lactic acid)‐grafted carbon nanotube on thermal, mechanical, and electrical properties of poly(lactic acid)
Authors: Yoon Jin Tae , Jeong Young Gyu , Lee Sang Cheol , Min Byung Gil
Published: November 2008

Poly(lactic acid)‐grafted multiwalled carbon nanotubes (MWNT‐g‐PLA) were prepared by the direct melt‐polycondensation of L‐lactic acid with carboxylic acid‐functionalized MWNT (MWNT‐COOH) and then mixed with a commercially available neat PLA to prepare PLA/MWNT‐g‐PLA nanocomposites. Morphological, thermal, mechanical, and electrical characteristics of PLA/MWNT‐g‐PLA nanocomposites were investigated as a function of the MWNT content and compared with those of the neat PLA, PLA/MWNT, and PLA/MWNT‐COOH nanocomposites. It was identified from FE‐SEM images that PLA/MWNT‐g‐PLA nanocomposites exhibit good dispersion of MWNT‐g‐PLA in the PLA matrix, while PLA/MWNT and PLA/MWNT‐COOH nanocomposites display MWNT aggregates. As a result, initial moduli and tensile strengths of PLA/MWNT‐g‐PLA composites are much higher than those of neat PLA, PLA/MWNT, and PLA/MWNT‐COOH, which stems from the efficient reinforcing effect of MWNT‐g‐PLA in the PLA matrix. In addition, the crystallization rate of PLA/MWNT‐g‐PLA nanocomposites is faster than those of neat PLA, PLA/MWNT, and PLA/MWNT‐COOH, since MWNT‐g‐PLA dispersed in the PLA matrix serves efficiently as a nucleating agent. It is interesting that, unlike PLA/MWNT nanocomposites, surface resistivities of PLA/MWNT‐g‐PLA nanocomposites did not change noticeably depending on the MWNT content, demonstrating that MWNTs in PLA/MWNT‐g‐PLA are wrapped with the PLA chains of MWNT‐g‐PLA. Copyright © 2008 John Wiley & Sons, Ltd.
Managerial Complexity in Project-Based Operations: A Grounded Model and Its Implications for Practice
Authors: Maylor Harvey , Vidgen Richard , Carver Stephen
Published: November 2008

This article reports an investigation into project managers’ perceptions of managerial complexity. Based on a multistage empirical study, elements of “what makes a project complex to manage” were identified and classified under the dimensions of mission, organization, delivery, stakeholder, or team—the MODeST model. Further, the data showed that these elements had both structural and dynamic qualities and that the elements are interdependent. Project managers are shown to be embedded in this complexity. The practical implications of the research include the ability to describe managerial complexity in a manner consistent with the actuality of the lived project environment. This provides a framework for the description of the level of managerial challenge or difficulty, which will allow the assessment of individual and organizational responses to it in the future. Further, the opportunity exists for active management of complexity.
Lagomizing, Organic Integration, and Systems Emergency Wards: Innovative Practices in Managing Complex Systems Development Projects
Authors: Berggren Christian , Järkvik Jack , Söderlund Jonas
Published: November 2008

In complex systems development, project management is a key factor for innovation, for bringing together system capabilities to actually working systems and taking them to the customer. The critical question then is: How can successful project management in this field be conceptualized, practiced, and understood? In the extant literature, there is a plethora of suggested tools for advanced planning and scheduling, for system decomposition and modularization, and for reducing interdependencies and avoiding errors. There is also a growing criticism of these “planning approaches,” suggesting various contingency and flexibility approaches, to reflect and adapt to complexity and change. This critique, however, tends to lack grounded suggestions for effective managerial practices and does not distinguish between general flexibility needs and specific project structures required to make complex systems development at all possible. This article centers on the development of large, complex systems with an empirical focus on the telecom industry. Key challenges here, it is argued, are to understand complexity, reduce complexity, and rapidly act on the consequences of complexity to ensure timely delivery of reliable and predictable systems to highly demanding customers. To cope with these challenges, a set of innovative practices has been developed within Ericsson, a world leader in mobile network systems. We focus on three such practices, which together represent examples of a “neo-realistic” approach to project management: (1) lagomizing, a top-down redefinition of project goals to reduce complexity and transform expectations; (2) organic integration, an articulation and visualization of a shared understanding of system capabilities; and (3) Systemakut, the Systems Emergency Ward, a real-time, high-visibility agora for managing integration, handling errors, and making swift decisions and in public. The study is based on a research methodology involving knowledge coproduction, where the team of authors represents both academic knowledge and practitioner experience of managing innovations in complex systems development projects.
Investigation of high‐T luminescence processes in ZnO nanorods grown catalytically by vapor‐transport method
Authors: Gupta A. , Omari M. , Kouklin N.
Published: November 2008

High‐T luminescence properties of ZnO nanorods/nanowires grown on c‐Si by a catalyst‐assisted vapor‐liquid‐solid (VLS) method have been studied spectroscopically at the T‐range of 123‐573 K. The performed T‐dependent photoluminescence (PL) measurements confirm the presence of strong ultra‐violet (UV) and visible emission associated with excitonic and donor‐acceptor pair recombinations, respectively. A red shift in the UV peak position was analyzed within the framework of a three‐parameter model, with the results suggesting a stronger role of phonons behind the band gap renormalization effect at high T. The ratio of excitonic to defect integral PL intensities was observed to increase exponentially with T which is attributed to a strong increase in the net ionization rate of deep‐defects at T exceeding ∼400 K. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chitosan tailor‐made films: the effects of additives on barrier and mechanical properties
Authors: Yoshida Cristiana M. P. , Oliveira Junior Enio Nazaré , Franco Telma Teixeira
Published: November 2008

With the aim of achieving ‘tailor‐made’ chitosan films, the effects of several variables on the properties of chitosan films were studied. These variables were chitosan concentration and molecular weight of thermally depolymerized chitosan, addition of lipids (palmitic acid, beeswax or carnauba wax) and plasticizer (glycerol). The water vapour transmission rate (WVTR) and mechanical properties of these films were measured. The innovative feature of this study is that it provides specific information to support the design of tailor‐made films. These can only be formulated when the effects of the important variables are well understood. It was found that WVTR was reduced by 57% in film made from chitosan that had been thermally treated for 7 h at 100°C (molecular mass 13.7 kDa), while in the emulsion films, the WVTR was increased by incorporation of palmitic acid, beeswax or carnauba wax incorporation. The mechanical properties (tensile strength and elongation at break) were improved when glycerol was used as plasticizer, resulting in more elastic films (increasing the elongation at break by 62%). Copyright © 2008 John Wiley & Sons, Ltd.
QSAR Modeling of HIV‐1 Protease Inhibition on Six‐ and Seven‐membered Cyclic Ureas
Authors: Takkis Kalev , Sild Sulev
Published: November 2008

A Quantitative Structure–Activity Relationship (QSAR) analysis was carried out on a dataset of 135 six‐ and seven‐membered cyclic urea‐based Human Immunodeficiency Virus Type 1 (HIV‐1) protease inhibitors. Using a larger and more diverse dataset than previous studies reported in literature allowed a more comprehensive analysis. A large set of molecular descriptors, calculated with CODESSA PRO, was used in Multiple Linear Regression (MLR) analysis and the resulting four‐parameter model enabled accurate prediction of inhibitory activity for the structures both in training and external validation sets. The squared correlation coefficient for both sets combined is 0.824. Descriptors in the final model characterize the size and shape of the molecule and its charge distribution. Non‐linear relationships between the HIV‐1 protease inhibition activity and some descriptors are significant and described with simple non‐linear transformations. After the model development, another dataset of 45 compounds was collected and additional external validation was performed.
ONIOM study of the nonbonding interaction of the 2PU inhibitor with the CDK2 and CDK4 cyclin‐dependant kinases
Authors: Li Aixiao , Maurel François , Delamar Michel , Wang Baoshan
Published: November 2008

We discuss in this article, the applicability of hybrid techniques [especially the our‐own N‐layered integrated molecular orbital and molecular mechanics (ONIOM) method] to weak chemical interactions in large systems, such as the interaction of cyclin‐dependant kinases, CDK4, and CDK2, with a specific ligand (2PU) showing selectivity for CDK4. Our results show that the energies from the ONIOM calculations perfectly match our former molecular dynamics results, both for determining the amino acids which have strongest interactions with the ligand and for explaining the selectivity of 2PU towards CDK4, as compared with CDK2. We show that the ONIOM method is a good candidate for studying such interactions in large systems, even though there are still some technical and theoretical problems to solve. The calculation details will be presented together with the methodology we devised for using the ONIOM approach in such a context. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Stepwise inter‐frame correlation‐based steganalysis system for video streams
Authors: Liu Bin , Liu Fenlin , Yang Chunfang
Published: November 2008

stage‐wise steganalysis system that utilizes the collusion scheme among sucessive video frames is proposed. The effect of local motion interfering detection precision is studied. The local motion and message embedded in video frame is treated as a bimodal noise. To detect the existence of the embedded message, blockwise correlation‐based feature extraction scheme is proposed to reduce the local motion interfering effect. The video steganalysis process is divided into two stages. In the first stage, suspicious video frames will be recognized by decision module employing features extracted with a light‐weight collusion scheme, for the real‐time requirement. In the second stage, suspicious frames will be analyzed critically by the present powerful image steganalysis algorithms. Moreover, the determined principle is also studied to reduce the false positive rate in the first stage. Experimental results show the satisfying performance of the proposed system. Copyright © 2008 John Wiley & Sons, Ltd.
Surface characterization of the SiOx films prepared by a remote atmospheric pressure plasma jet
Authors: Huang Chun , Liu Chi‐Hung , Wu Shin‐Yi
Published: November 2008

The deposition rate and surface properties of SiOx films were prepared and investigated using remote atmospheric pressure plasma (APP) jet. The APP, generated with low frequency power at 16 kHz, was fed with tetraethoxysilane (TEOS)/air gas mixture. After deposition, the SiOx films were analyzed for chemical characteristics, elemental composition, surface morphology, and hardness. It was found that the deposition substrate temperature is the key factor to affect the deposition rate of remote APP chemical vapor deposition process. Fourier transform infrared (FTIR) spectra indicated that APP deposited SiOx films are an inorganic feature. XPS examination revealed that the SiOx films contained approximately 30% silicon, 58% oxygen and 12% carbon. Atomic forced microscopy (AFM) analysis results indicated a smooth surface of SiOx films in deposition under higher substrate temperature. Also, pencil hardness tests indicated that the hardness of APP deposited SiOx films was greatly improved with increasing substrate temperatures. Copyright © 2008 John Wiley & Sons, Ltd.
Improved efficiency of the sputtering technique for pyrite surface and its effect on reduction of electron beam damage
Authors: Moslemzadeh N. , Tamara M. , Raval R. , Prior D. , Preston M. R.
Published: November 2008

A quick and highly efficient method is described for the preparation of clean and well‐characterised (100) pyrite surfaces on natural crystals based on a sputter/annealing procedure in an ultra‐high vacuum (UHV) chamber. The improvement has been achieved by controlling the ingress of the key contaminants water and oxygen and restricting the annealing temperature to 560 K, which is below the SO2 dissociation temperature. Low‐energy electron diffraction (LEED) and X‐ray photoelectron spectroscopy (XPS) data were used to study the surface. As well as improving the efficiency of the sputtering technique for this surface, a further major benefit is its high stability against electron beam damage as investigated by a quantitative LEED study. Copyright © 2008 John Wiley & Sons, Ltd.
Recent developments in composite connections
Authors: Demonceau Jean‐François , Jaspart Jean‐Pierre , Klinkhammer Ralf , Oerder Ralf , Weynand Klaus , Labory Françoise , Cajot Louis‐Guy
Published: November 2008

Eurocode 4 [1] suggests design rules for the evaluation of the mechanical properties of steel‐concrete beam‐to‐column composite joints (rotational stiffness, resistance and ductility). These rules cover situations where the joints are subjected to moments and shear forces, but in hogging regions only (negative bending moments). Recently, researches have been conducted on the behaviour of composite joints (Fig. 1) subjected to positive bending moments (called “sagging moments” in the following) and combined bending moments and axial loads; for instance, these loading situations may appear in composite sway frames under conventional loading and exceptional actions (impact, explosion …) leading to the loss of a structural column [2].

In the present paper, the Eurocode 4 design rules are extended to joints in sagging regions and to joints subjected to combined bending moments and axial loads and the proposed methods are validated through comparisons with experimental test results. An easy‐to‐use and freely available software for the design of composite joints according to the Eurocode 4 principles is also described.
High‐strength steel fillet welded connections
Authors: Kuhlmann Ulrike , Günther Hans‐Peter , Rasche Christina
Published: November 2008

This paper presents the results of a research project analysing the strength and ductility of welded high‐strength steel connections. Existing design rules according to Eurocode 3 are introduced and discussed showing that these rules are inadequate for high‐strength steel connections for various reasons. Quasi‐static strength tests on fillet welded connections together with numerical simulations are presented. Based on these tests, recommendations for updating the rules of Eurocode 3 are suggested.
Whole‐brain thinking in systems architecting
Authors: Carlo Tony Di , Khoshnevis Behrokh , Udwadia Firdaus
Published: November 2008

This position paper†explores the role of whole‐brain thinking in the context of systems architecting. Brain research indicates that the brain is dual and that each of its hemispheres interprets the world differently; the concept is commonly referred to as right‐brain and left‐brain thinking, or sometimes R‐mode and L‐mode for short. L‐mode denotes step‐by‐step linear thinking. R‐mode is integrative and holistic. It pays to extend this to systems architecting. For example, there may be two ways to look at complexity, analytically and holistically. Step‐by‐step analysis is well suited for low‐dimensional complexity. As complexity increases methodical analytical skills become overwhelmed and we are bogged down, maybe even forced into complacent partial representation—tunnel vision. Learning to “see” the complex may benefit from a shift from the analytical to the holistic, from L‐mode to R‐mode thinking, or a better blending of the two. We begin with a cursory review of brain theory and applications thereof in drawing, management and creativity theory, and then follow up with observations of blended L/R‐mode thinking in the context of systems architecting. Our hope is to distill from these sources whole‐brain mental strategies that may be relevant to systems architects. © 2008 Wiley Periodicals, Inc. Syst Eng
Risk management capability maturity model for complex product systems (CoPS) projects
Authors: Yeo K. T. , Ren Yingtao
Published: November 2008

This paper aims at conceptualizing and developing a multilevel framework for the Risk Management Capability Maturity Model (RM‐CMM), specifically for Complex Product Systems (CoPS) projects. CoPS is a special class of projects, which are high‐value, technology‐ and engineering‐intensive products or systems that are typically used to produce consumer goods and services. The embedded and inherent complexity in terms of task and human relations in CoPS projects can be a major source of risk and can contribute to persistent project challenges, failure, and impairment. There is a need to build a progressive risk management capability to deal with the unique characteristics of these complex projects. The proposed CoPS‐RM‐CMM model defines two broad layers in systems “security” and organizational “robustness.” The understanding of complexity inherent in CoPS projects is drawn from the science of complexity and emergence, which provides additional insights into the management of both predictable and emergent risk in CoPS implementation. The proposed model is also built upon a change management framework, which addresses the risk planning and control processes, organizational and people contexts, and technology contents of CoPS. © 2008 Wiley Periodicals, Inc. Syst Eng
Tricuspid regurgitation in screening for trisomies 21, 18 and 13 and Turner syndrome at 11 + 0 to 13 + 6 weeks of gestation
Authors: Kagan K. O. , Valencia C. , Livanos P. , Wright D. , Nicolaides K. H.
Published: November 2008

Objective

To investigate the performance of first‐trimester screening for aneuploidies by including assessment of tricuspid blood flow in the combined test of maternal age, fetal nuchal translucency (NT) thickness, fetal heart rate (FHR) and serum free β‐human chorionic gonadotropin (β‐hCG) and pregnancy‐associated plasma protein A (PAPP‐A).

Method

Screening by the combined test was performed in singleton pregnancies, including 19 614 with chromosomally normal fetuses or the delivery of a phenotypically normal baby (euploid group), 122 with trisomy 21, 36 with trisomy 18, 20 with trisomy 13 and eight with Turner syndrome. In all cases tricuspid flow was assessed to determine if there was tricuspid regurgitation. We examined the performance of two screening strategies: firstly, assessment of tricuspid flow in all patients and secondly, first‐stage screening using the combined test in all patients followed by second‐stage assessment of tricuspid flow only in those with an intermediate risk of 1 in 51 to 1 in 1000 after the first stage.

Results

Tricuspid regurgitation was observed in 0.9% of the euploid fetuses and 55.7%, 33.3% and 30% of the fetuses with trisomies 21, 18 and 13, respectively, and in 37.5% of those with Turner syndrome. In a screening policy based on maternal age, fetal NT, FHR, serum free β‐hCG and PAPP‐A, for a fixed false positive rate of 3% the standardized detection rates were 91% for trisomy 21 and 100% for trisomy 18, trisomy 13 and Turner syndrome. Assessment of tricuspid flow in all pregnancies would increase the detection rate of trisomy 21 to 96%, and the detection rates of trisomy 18, trisomy 13 and Turner syndrome would be 92%, 100% and 100%, respectively. The same detection rates were achieved with the two‐stage strategy—in which it was necessary to assess tricuspid flow in only 15% of the total population—at a false positive rate of 2.4%.

Conclusions

Assessment of tricuspid flow improves the performance of first‐trimester screening for trisomy 21. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Ag3Bi14Br21: ein Subbromid mit Bi24+‐Hanteln und Bi95+‐Polyedern – Synthese, Kristallstruktur und Chemische Bindung
Authors: Wahl Bernhard , Ruck Michael
Published: November 2008

Ag3Bi14Br21: a Subbromide with Bi24+ Dumbbells and Bi95+ Polyhedra – Synthesis, Crystal Structure and Chemical Bonding

Black crystals of Ag3Bi14Br21 = (Bi95+)[Ag3Bi3Br153−](Bi2Br62−), the first argentiferous bismuth subhalide, were obtained from a stoichiometric melt of Ag, Bi, and BiBr3. The compound crystallizes in the monoclinic space group P21/m with lattice parameters a = 1277.78(5) pm, b = 1466.87(6) pm, c = 1342.62(5) pm, and β = 108.47(1)° at 110(5) K. In contrast to all other bismuth subhalides that contain an electron‐rich transition metal, the silver atoms are not bonded to bismuth atoms. Instead they are integrated into the anionic bromometallate network, which consists of [MBr6]‐octahedra (M = Ag, Bi) that share edges and vertices. These corrugated $_{\infty}^{2}\rm [Ag_{3}Bi_{3}Br_{15}]^{3-}$ sheets alternate with tessellated layers formed by Bi95+ polycations and hitherto unknown (BiII2Br6)2− groups. The latter anions contain Bi24+ dumbbells (299 pm) and can be represented by the structured formula [Br2BiII(μ–Br)2BiIIBr2]2−. The multi‐center bonding within the Bi95+ cluster and the bent single‐bond in the Bi2 dumbbell can be visualized using the electron localization indicator (ELI‐D).
Synthese und strukturchemische Untersuchungen an molekularen Oxovanadiumphosphonaten
Authors: Wulff‐Molder Dirk , Meisel Manfred
Published: November 2008

Synthesis and Structural Studies on Molecular Oxovanadium Phosphonates

Solvothermal syntheses at 373 K in the system (MePPh3)[VO2Cl2]/ RPO3H2 (R = tBu; Ph)/Template (T= Cl−, HCl, OH−; Br−) /MeCN have lead to the already known compound [(VO)6(tBuPO3)8 ⊂ Cl−] (1) [1] as well as to [(VO)6(tBuPO3)8 ⊂ T](T: HCl (2) OH− 3), [(VO)6(PhPO3)8 ⊂ Br−]×solv (4), (Ph3PMe)2[(VO)6(PhPO3)8 ⊂ Cl−]3 (5) with an identical VPO‐core, and [(V3O5)(VO)4(tBuPO3)8 ⊂ NO3−] (6) with seven metal centres. The renewed X‐ray structure analysis of 1 produced evidence, that the {V6P8O24}‐core shows some flexibility and belongs to the enantiomorphic point group O (≡ 432). With the structure data from the compounds 1–5 a geometric model for the flexible contraction of the {V6P8O24}‐core was developed. The calculation of the diameter of the host shell for different degrees of contraction shows that the {V6P8O24}‐core is always too small to incorporate a nitrate ion. This leads to the formation of [(V3O5)(VO)4(tBuPO3)8 ⊂ NO3−] (6) which can be derived topologically from 1. There is no structural similarity between 6 and the seven oxovanadium units containing anion of (Ph4P)2[(V4O7)(V3O5)(PhPO3)6 ⊂ Cl−] [2].

The thermal degradation of 1 in air starts at 590 K with the oxidation of the organic groups followed by the formation of β‐(VO)(PO3)2. Possibly these results offer new ways to use oxovanadium phosphonates as precursors of oxovanadium phosphate catalysts.
MicroRNAs: Control and Loss of Control in Human Physiology and Disease
Authors: Li Min , Marin‐Muller Christian , Bharadwaj Uddalak , Chow Kwong‐Hon , Yao Qizhi , Chen Changyi
Published: November 2008

Analysis of the human genome indicates that a large fraction of the genome sequences are RNAs that do not encode any proteins, also known as non‐coding RNAs. MicroRNAs (miRNAs) are a group of small non‐coding RNA molecules 20–22 nucleotides (nt) in length that are predicted to control the activity of approximately 30% of all protein‐coding genes in mammals. miRNAs play important roles in many diseases, including cancer, cardiovascular disease, and immune disorders. The expression of miRNAs can be regulated by epigenetic modification, DNA copy number change, and genetic mutations. miRNAs can serve as a valuable therapeutic target for a large number of diseases. For miRNAs with oncogenic capabilities, potential therapies include miRNA silencing, antisense blocking, and miRNA modifications. For miRNAs with tumor suppression functions, overexpression of those miRNAs might be a useful strategy to inhibit tumor growth. In this review, we discuss the current progress of miRNA research, regulation of miRNA expression, prediction of miRNA targets, and regulatory role of miRNAs in human physiology and diseases, with a specific focus on miRNAs in pancreatic cancer, liver cancer, colorectal cancer, cardiovascular disease, the immune system, and infectious disease. This review provides valuable information for clinicians and researchers who want to recognize the newest advances in this new field and identify possible lines of investigation in miRNAs as important mediators in human physiology and diseases.
Metacarpal Neck Fractures: Results of Treatment with Traction Reduction and Cast Immobilization
Authors: Harris Albert R. , Beckenbaugh Robert D. , Nettrour John F. , Rizzo Marco
Published: November 2008

Although fractures of the fifth metacarpal neck (boxer's fractures) are common, their treatment can be problematic. A description of a technique utilizing traction reduction is presented in this paper. The records and radiographs of 59 patients who underwent reduction using longitudinal traction and subsequent immobilization in a specially molded cast were retrospectively reviewed. On average, 80% of initial fracture angulation in the sagittal plane was corrected, and only 1° of this correction was lost at the discontinuation of casting (3–4 weeks). We have found this technique to be highly effective in the treatment of boxer's fractures. Advantages of this treatment include its efficacy, ease, and improved patient tolerance over other casting techniques.
Cu-Doping Effects in CdI2Nanocrystals: The Role of Cu-Agglomerates
Authors: Miah M Idrish
Published: November 2008

Cu-doping effects in CdI2nanocrystals are studied experimentally. We use the photostimulated second harmonic generation (PSSHG) as a tool to investigate the effects. It is found that the PSSHG increases with increasing Cu content up to 0.6% and then decreases due to the formation of the Cu-agglomerates. The PSSHG for the crystal with Cu content higher than 1% reduces to that for the undoped CdI2crystal. The results suggest that a crucial role of the Cu-metallic agglomerates is involved in the processes as responsible for the observed effects.
A solution to limitations of cognitive testing in children with intellectual disabilities: the case of fragile X syndrome
Authors: Hessl David , Nguyen Danh V. , Green Cherie , Chavez Alyssa , Tassone Flora , Hagerman Randi J. , Senturk Damla , Schneider Andrea , Lightbody Amy , Reiss Allan L. , Hall Scott
Published: November 2008

Intelligence testing in children with intellectual disabilities (ID) has significant limitations. The normative samples of widely used intelligence tests, such as the Wechsler Intelligence Scales, rarely include an adequate number of subjects with ID needed to provide sensitive measurement in the very low ability range, and they are highly subject to floor effects. The IQ measurement problems in these children prevent characterization of strengths and weaknesses, poorer estimates of cognitive abilities in research applications, and in clinical settings, limited utility for assessment, prognosis estimation, and planning intervention. Here, we examined the sensitivity of the Wechsler Intelligence Scale for Children (WISC-III) in a large sample of children with fragile X syndrome (FXS), the most common cause of inherited ID. The WISC-III was administered to 217 children with FXS (age 6–17 years, 83 girls and 134 boys). Using raw norms data obtained with permission from the Psychological Corporation, we calculated normalized scores representing each participant’s actual deviation from the standardization sample using az-score transformation. To validate this approach, we compared correlations between the new normalized scores versus the usual standard scores with a measure of adaptive behavior (Vineland Adaptive Behavior Scales) and with a genetic measure specific to FXS (FMR1protein or FMRP). The distribution of WISC-III standard scores showed significant skewing with floor effects in a high proportion of participants, especially males (64.9%–94.0% across subtests). With the z-score normalization, the flooring problems were eliminated and scores were normally distributed. Furthermore, we found correlations between cognitive performance and adaptive behavior, and between cognition and FMRP that were very much improved when using these normalized scores in contrast to the usual standardized scores. The results of this study show that meaningful variation in intellectual ability in children with FXS, and probably other populations of children with neurodevelopmental disorders, is obscured by the usual translation of raw scores into standardized scores. A method of raw score transformation may improve the characterization of cognitive functioning in ID populations, especially for research applications.
Proceedings of the Fortieth Meeting of the Agricultural Research
Modellers' Group
Authors: CROMPTON L. A. , WHEELER T. R.
Published: November 2008

This group, which is concerned with the applications of mathematics to
agricultural science, was formed in 1970 and has since met at approximately
yearly intervals in London for one-day meetings. The fortieth meeting of the
group, chaired by Dr John Thornley of Henley-on-Thames, UK and the Centre for
Nutrition Modelling, University of Guelph, Canada, was held in the Kohn Centre
at the Royal Society, 6 Carlton House Terrace, London on Friday, 11 April 2008
when the following papers were read.
Predicting the metabolizable energy intake of ruminants using digestibility, ruminal methane production and fermentation data
Authors: McPHEE M. J. , HEGARTY R. S.
Published: November 2008

Obtaining accurate estimates of the metabolizable energy (ME) intake (MEI; MJ/day) of individual grazing ruminants is an important requirement for effective nutritional management and genetic selection of energy efficient ruminants. Diet digestibility and the daily methane production rate (MPR; MJ/day) of ruminants can be closely linked with their MEI, so published data were examined to determine whether MEI could be accurately estimated from digestibility, MPR and other parameters able to be measured on grazing animals. Four modelling approaches were assessed or developed to estimate MEI: (i) a published fixed proportional relationship between the non-metabolizable losses of MPR and urinary energy (UE; MJ/day); (ii) the proportion of energy digestibility (EngDig); (iii) MPR and the ruminal factors that influence the stoichiometric relationships between MPR and MEI; and (iv) the calculated ME arising from rumen fermentation (MEf; MJ/day). Data to develop the models (n=61) were collected across three publications (Paper) where the Paper effect was treated as a random-effect variable. Each of the models (1–4) was challenged with an independent data set (n=19). The inclusion of MEf (P=0·01) to predict MEI [MEI=0·18 (2·03)+3·42 (0·36)×sqrt(MEf) (d.f.=57; residual log likelihood=173·6)] had the lowest mean square error of prediction (MSEP) when challenged with the independent data set; mean bias of −0·42 MJ/day (P<0·05), MSEP=0·68 MJ/day and the bias, slope and random components of the MSEP were, as a proportion, 0·26, 0·13 and 0·61, respectively. None of the models estimated MEI with sufficient accuracy to be useful for identifying individual animals with above average energetic efficiency. A critical limit to any model seeking to estimate MEI from MPR and fermentation traits appears to be the variation between animals and between diets, in the proportion of digested energy which is fermented relative to that which is made available by mammalian digestion, and this is evaluated.
The burden of rotavirus gastroenteritis in children presenting to a paediatric hospital
Authors: INGLIS E. , KESSON A. , NEWALL A. T. , MACARTNEY K. , MacINTYRE C. R.
Published: November 2008

The aim of this study was to determine the burden, management and outcomes of rotavirus infection in young children presenting to a tertiary paediatric hospital in Sydney, Australia. All laboratory-confirmed cases of rotavirus in children aged <5 years were identified and medical records reviewed. In 2004, 80 children aged <5 years presented to the hospital with rotavirus gastroenteritis confirmed by stool testing. Infants aged <24 months comprised 75% of cases, with more males than females affected. Most children (86%) acquired rotavirus infection in the community, with a mean length of hospital admission of 2·3 days. There were eight cases of nosocomial infection at a rate of 3/10 000 admissions. The rates of intravenous fluid management (46%) and antibiotic use (28%) were high, reflecting the severity of disease presenting in a hospital setting. These data will help inform the assessment of the recently introduced rotavirus vaccination programme in Australia.
Defending Limits on the Sacrifices We Ought To Make For Others
Authors: IGNESKI VIOLETTA
Published: November 2008

How much are we morally required to do to aid others? After articulating some of the main contributions to this debate, I defend the position that we are sometimes morally permitted to spend our time and resources satisfying our own interests and needs rather than using them to aid others who are in desperate need. I argue that the duty to aid the needy should not always take priority over every other end we have. Whatever else we value, we most highly value the ability and opportunity to live our lives on our own terms; this grounds both our obligation to aid others and places limits on how far these obligations ought to extend. Persons ought to respect others and fulfill their moral obligations but they must also be given the moral space to set ends and pursue those ends just because they are theirs.
An Augmented Buck-Passing Account of Reasons and Value: Scanlon and Crisp on What Stops the Buck
Authors: COOK PHILIP
Published: November 2008

Roger Crisp has inspired two important criticisms of Scanlon's buck-passing account of value. I defend buck-passing from the wrong kind of reasons criticism, and the reasons and the good objection. I support Rabinowicz and Rønnow-Rasmussen's dual role of reasons in refuting the wrong kind of reasons criticism, even where its authors claim it fails. Crisp's reasons and the good objection contends that the property of goodness is buck-passing in virtue of its formality. I argue that Crisp conflates general and formal properties, and that Scanlon is ambiguous about whether the formal property of a reason can stop the buck. Drawing from Wallace, I respond to Crisp's reasons and the good objection by developing an augmented buck-passing account of reasons and value, where the buck is passed consistently from the formal properties of both to the substantive properties of considerations and evaluative attitudes. I end by describing two unresolved problems for buck-passers.
Children in Regular and Special Needs Classes: Cognitive and Non-Cognitive Aspects
Authors: Michel Eva , Roebers Claudia M.
Published: November 2008

In the present study, systematic comparisons between Swiss children attending regular first grade classes and those enrolled in classes for children with special needs (so-called “Einführungsklassen”, in which the first grade curriculum is spread over two years) are reported. Different aspects of executive skills in the domain of short-term memory, attention, motor coordination, and achievement motivation are addressed. For most cognitive measures, children in special needs classes perform more poorly than children in regular classes. Deficits appeared to be pronounced in tasks of high complexity and with multiple demands, but there were no differences with respect to self-concept and school motivation. Follow-up analyses indicate that improvement in most of the tasks was minimal and that children in special needs classes do not catch up to their age-mates. The findings are discussed in terms of adequate placement of these children and the need for early and efficient prevention/intervention programs.
Evolution of unsaturated hydraulic conductivity of aggregated soils due to compressive forces
Authors: Berli M. , Carminati A. , Ghezzehei T. A. , Or D.
Published: November 2008

Prediction of water flow and transport processes in soils susceptible to structural alteration such as compaction of tilled agricultural lands or newly constructed landfills rely on accurate description of changes in soil unsaturated hydraulic conductivity. Recent studies have documented the critical impact of aggregate contact characteristics on water flow rates and pathways in unsaturated aggregated soils. We developed an analytical model for aggregate contact size evolution as a basis for quantifying effects of compression on saturated and unsaturated hydraulic conductivity of aggregated soil. Relating confined one‐dimensional sample strain with aggregate deformation facilitates prediction of the increase in interaggregate contact area and concurrent decrease in macropore size with degree of sample compression. The hydrologic component of the model predicts unsaturated hydraulic conductivity of a pack of idealized aggregates (spheres) on the basis of contact size and saturation conditions under prescribed sample deformation. Calculated contact areas and hydraulic conductivity for pairs of aggregates agreed surprisingly well with measured values, determined from compaction experiments employing neutron and X‐ray‐radiography and image analysis. Model calculations for a unit cell of uniform spherical aggregates in cubic packing were able to mimic some of the differences in saturated and unsaturated hydraulic conductivity observed for aggregates and bulk soil.
New absolute paleointensity results from the Parana Magmatic Province (Uruguay) and the Early Cretaceous geomagnetic paleofield
Authors: Goguitchaichvili Avto , Cejudo Ruiz Ruben , Sanchez Bettucci Leda , Aguilar Reyes Bertha , Alva‐Valdivia Luis M. , Urrutia‐Fucugauchi Jaime , Morales Juan , Calvo Rathert Manuel
Published: November 2008

Thellier paleointensity experiments are carried out on the Early Cretaceous Arapey Formation, which belongs to the Parana Magmatic Province (PMP) in northern Uruguay. Twenty‐seven samples out of 225 analyzed yield reliable absolute intensity determinations. For these samples the NRM fraction f used for determination ranges between 0.33 to 0.83 and the quality factor q ranges from 4.5 to 14.1, being generally greater than 5. The flow‐mean paleointensity values obtained in this study range from 16.3 ± 2.3 to 41.5 ± 3.8 μT, with corresponding virtual dipole moments (VDMs) from 3.4 ± 0.6 to 8.2 ± 0.8 (1022 Am2). This corresponds to mean VDM value of 6.4 ± 2.3 × 1022 Am2. 40Ar/39Ar dating on the PMP sequence by Feraud et al. (1999) gave a mean age of 132.2 ± 0.5 Ma. Our results in conjunction with previous studies (Kosterov et al., 1998; Goguitchaichvili et al., 2002) suggest that the paleostrength during the early Cretaceous might be as variable and strong as Brunhes data and not anomalously low as previously suggested. The scatter observed in our study is similar to recent findings by Granot et al. (2007) for the Troodos Ophiolite.
Mass loss on Himalayan glacier endangers water resources
Authors: Kehrwald Natalie M. , Thompson Lonnie G. , Tandong Yao , Mosley‐Thompson Ellen , Schotterer Ulrich , Alfimov Vasily , Beer Jürg , Eikenberg Jost , Davis Mary E.
Published: November 2008

Ice cores drilled from glaciers around the world generally contain horizons with elevated levels of beta radioactivity including 36Cl and 3H associated with atmospheric thermonuclear bomb testing in the 1950s and 1960s. Ice cores collected in 2006 from Naimona'nyi Glacier in the Himalaya (Tibet) lack these distinctive marker horizons suggesting no net accumulation of mass (ice) since at least 1950. Naimona'nyi is the highest glacier (6050 masl) documented to be losing mass annually suggesting the possibility of similar mass loss on other high‐elevation glaciers in low and mid‐latitudes under a warmer Earth scenario. If climatic conditions dominating the mass balance of Naimona'nyi extend to other glaciers in the region, the implications for water resources could be serious as these glaciers feed the headwaters of the Indus, Ganges, and Brahmaputra Rivers that sustain one of the world's most populous regions.
PocketMatch: A new algorithm to compare binding sites in protein structures
Authors: Kalidas Yeturu , Chandra Nagasuma
Published: November 2008

Background:

Recognizing similarities and deriving relationships among protein molecules is a fundamentalrequirement in present-day biology. Similarities can be present at various levels which can be detected through comparison of protein sequences or their structural folds. In some cases similarities obscure at these levels could be present merely in the substructures at their binding sites. Inferring functional similarities between protein molecules by comparing their binding sites is still largely exploratory and not as yet a routine protocol. One ofthe main reasons for this is the limitation in the choice of appropriate analytical tools that can compare binding sites with high sensitivity. To benefit from the enormous amount of structural data that is being rapidly accumulated, it is essential to have high throughput tools that enable large scale binding site comparison.

Results:

Here we present a new algorithm PocketMatch for comparison of binding sites in a frame invariantmanner. Each binding site is represented by 90 lists of sorted distances capturing shape and chemical nature of the site. The sorted arrays are then aligned using an incremental alignment method and scored to obtain PMScores for pairs of sites. A comprehensive sensitivity analysis and an extensive validation of the algorithm have been carried out. Perturbation studies where the geometry of a given site was retained but the residue types were changed randomly, indicated that chance similarities were virtually non-existent. Our analysis also demonstrates that shape information alone is insufficient to discriminate between diverse binding sites, unlesscombined with chemical nature of amino acids.

Conclusions:

A new algorithm has been developed to compare binding sites in accurate, efficient andhigh-throughput manner. Though the representation used is conceptually simplistic, we demonstrate that alongwith the new alignment strategy used, it is sufficient to enable binding comparison with high sensitivity. Novel methodology has also been presented for validating the algorithm for accuracy and sensitivity with respect to geometry and chemical nature of the site. The method is also fast and takes about 1/250th second for one comparison on a single processor. A parallel version on BlueGene has also been implemented.