bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication and Intermolecular Interactions of Silk Fibroin/Hydroxybutyl Chitosan Blended Nanofibers
Authors: Zhang Kui-Hua , Yu Qiao-Zhen , Mo Xiu-Mei
Published: April 2011

The native extracellular matrix (ECM) is composed of a cross-linked porous network of multifibril collagens and glycosaminoglycans. Nanofibrous scaffolds of silk fibroin (SF) and hydroxybutyl chitosan (HBC) blends were fabricated using 1,1,1,3,3,3-hexaﬂuoro-2-propanol (HFIP) and trifluoroacetic acid (TFA) as solvents to biomimic the native ECM via electrospinning. Scanning electronic microscope (SEM) showed that relatively uniform nanofibers could be obtained when 12% SF was blended with 6% HBC at the weight ratio of 50:50. Meanwhile, the average nanoﬁbrous diameter increased when the content of HBC in SF/HBC blends was raised from 20% to 100%. Fourier transform infrared spectra (FTIR) and 13C nuclear magnetic resonance (NMR) showed SF and HBC molecules existed in hydrogen bonding interactions but HBC did not induce conformation of SF transforming from random coil form to β-sheet structure. X-ray diffraction (XRD) confirmed the different structure of SF/HBC blended nanofibers from both SF and HBC. Thermogravimetry-Differential thermogravimetry (TG-DTG) results demonstrated that the thermal stability of SF/HBC blend nanofibrous scaffolds was improved. The results indicated that the rearrangement of HBC and SF molecular chain formed a new structure due to stronger hydrogen bonding between SF and HBC. These electrospun SF/HBC blended nanofibers may provide an ideal tissue engineering scaffold and wound dressing.
Highly Unsaturated Binuclear Butadiene Iron Carbonyls: Quintet Spin States, Perpendicular Structures, Agostic Hydrogen Atoms, and Iron-Iron Multiple Bonds
Authors: Zeng Yi , Wang Shijian , Feng Hao , Xie Yaoming , King R. Bruce
Published: April 2011

The highly unsaturated binuclear butadiene iron carbonyls (C4H6)2Fe2(CO)n (n = 2, 1) have been examined using density functional theory. For (C4H6)2Fe2(CO)n (n = 2, 1), both coaxial and perpendicular structures are found. The global minima of (C4H6)2Fe2(CO)n (n = 2, 1) are the perpendicular structures 2Q-1 and 1Q-1, respectively, with 17- and 15-electron configurations for the iron atoms leading to quintet spin states. The Fe=Fe distance of 2.361 Å (M06-L) in the (C4H6)2Fe2(CO)2 structure 2Q-1 suggests a formal double bond. The Fe≡Fe bond distance in the (C4H6)2Fe2(CO) structure 1Q-1 is even shorter at 2.273 Å (M06-L), suggesting a triple bond. Higher energy (C4H6)2Fe2(CO)n (n = 2, 1) structures include structures in which a bridging butadiene ligand is bonded to one of the iron atoms as a tetrahapto ligand and to the other iron atom through two agostic hydrogen atoms from the end CH2 groups. Singlet (C4H6)2Fe2(CO) structures with formal Fe–Fe quadruple bonds of lengths ~2.05 Å were also found but at very high energies (~47 kcal/mol) relative to the global minimum.
Improving the Accuracy of Density Functional Theory (DFT) Calculation for Homolysis Bond Dissociation Energies of Y-NO Bond: Generalized Regression Neural Network Based on Grey Relational Analysis and Principal Component Analysis
Authors: Li Hong Zhi , Tao Wei , Gao Ting , Li Hui , Lu Ying Hua , Su Zhong Min
Published: April 2011

We propose a generalized regression neural network (GRNN) approach based on grey relational analysis (GRA) and principal component analysis (PCA) (GP-GRNN) to improve the accuracy of density functional theory (DFT) calculation for homolysis bond dissociation energies (BDE) of Y-NO bond. As a demonstration, this combined quantum chemistry calculation with the GP-GRNN approach has been applied to evaluate the homolysis BDE of 92 Y-NO organic molecules. The results show that the full-descriptor GRNN without GRA and PCA (F-GRNN) and with GRA (G-GRNN) approaches reduce the root-mean-square (RMS) of the calculated homolysis BDE of 92 organic molecules from 5.31 to 0.49 and 0.39 kcal mol−1 for the B3LYP/6-31G (d) calculation. Then the newly developed GP-GRNN approach further reduces the RMS to 0.31 kcal mol−1. Thus, the GP-GRNN correction on top of B3LYP/6-31G (d) can improve the accuracy of calculating the homolysis BDE in quantum chemistry and can predict homolysis BDE which cannot be obtained experimentally.
Multi-Step Usage of in Vivo Models During Rational Drug Design and Discovery
Authors: Williams Charles H. , Hong Charles C.
Published: April 2011

In this article we propose a systematic development method for rational drug design while reviewing paradigms in industry, emerging techniques and technologies in the field. Although the process of drug development today has been accelerated by emergence of computational methodologies, it is a herculean challenge requiring exorbitant resources; and often fails to yield clinically viable results. The current paradigm of target based drug design is often misguided and tends to yield compounds that have poor absorption, distribution, metabolism, and excretion, toxicology (ADMET) properties. Therefore, an in vivo organism based approach allowing for a multidisciplinary inquiry into potent and selective molecules is an excellent place to begin rational drug design. We will review how organisms like the zebrafish and Caenorhabditis elegans can not only be starting points, but can be used at various steps of the drug development process from target identification to pre-clinical trial models. This systems biology based approach paired with the power of computational biology; genetics and developmental biology provide a methodological framework to avoid the pitfalls of traditional target based drug design.
Glass Formation, Chemical Properties and Surface Analysis of Cu-Based Bulk Metallic Glasses
Authors: Qin Chunling , Zhao Weimin , Inoue Akihisa
Published: April 2011

This paper reviews the influence of alloying elements Mo, Nb, Ta and Ni on glass formation and corrosion resistance of Cu-based bulk metallic glasses (BMGs). In order to obtain basic knowledge for application to the industry, corrosion resistance of the Cu–Hf–Ti–(Mo, Nb, Ta, Ni) and Cu–Zr–Ag–Al–(Nb) bulk glassy alloy systems in various solutions are reported in this work. Moreover, X-ray photoelectron spectroscopy (XPS) analysis is performed to clarify the surface-related chemical characteristics of the alloy before and after immersion in the solutions; this has lead to a better understanding of the correlation between the surface composition and the corrosion resistance.
Characterization of a Deswapped Triple Mutant Bovine Odorant Binding Protein
Authors: Polverini Eugenia , Lardi Paolo , Mazzini Alberto , Sorbi Robert T. , Virna Conti , Ramoni Roberto , Favilla Roberto
Published: April 2011

The stability and functionality of GCC-bOBP, a monomeric triple mutant of bovine odorant binding protein, was investigated, in the presence of denaturant and in acidic pH conditions, by both protein and 1-aminoanthracene ligand fluorescence measurements, and compared to that of both bovine and porcine wild type homologues. Complete reversibility of unfolding was observed, though refolding was characterized by hysteresis. Molecular dynamics simulations, performed to detect possible structural changes of the monomeric scaffold related to the presence of the ligand, pointed out the stability of the β-barrel lipocalin scaffold.
Molecular Recognition of Arginine by Supramolecular Complexation with Calixarene Crown Ether Based on Surface Plasmon Resonance
Authors: Chen Hongxia , Gu Limin , Yin Yongmei , Koh Kwangnak , Lee Jaebeom
Published: April 2011

Arginine plays an important role in cell division and the functioning of the immune system. We describe a novel method by which arginine can be identified using an artificial monolayer based on surface plasmon resonance (SPR). The affinity of arginine binding its recognition molecular was compared to that of lysine. In fabrication of an arginine sensing interface, a calix[4]crown ether monolayer was anchored onto a gold surface and then characterized by Fourier Transform infrared reflection absorption spectroscopy, atomic force microscopy, and cyclic voltammetry. The interaction between arginine and its host compound was investigated by SPR. The calix[4]crown ether was found to assemble as a monolayer on the gold surface. Recognition of calix[4]crown monolayer was assessed by the selective binding of arginine. Modification of the SPR chip with the calix[4]crown monolayer provides a reliable and simple experimental platform for investigation of arginine under aqueous conditions.
Individual Variations in Inorganic Arsenic Metabolism Associated with AS3MT Genetic Polymorphisms
Authors: Agusa Tetsuro , Fujihara Junko , Takeshita Haruo , Iwata Hisato
Published: April 2011

Individual variations in inorganic arsenic metabolism may influence the toxic effects. Arsenic (+3 oxidation state) methyltransferase (AS3MT) that can catalyze the transfer of a methyl group from S-adenosyl-L-methionine (AdoMet) to trivalent arsenical, may play a role in arsenic metabolism in humans. Since the genetic polymorphisms of AS3MT gene may be associated with the susceptibility to inorganic arsenic toxicity, relationships of several single nucleotide polymorphisms (SNPs) in AS3MT with inorganic arsenic metabolism have been investigated. Here, we summarize our recent findings and other previous studies on the inorganic arsenic metabolism and AS3MT genetic polymorphisms in humans. Results of genotype dependent differences in arsenic metabolism for most of SNPs in AS3MT were Inconsistent throughout the studies. Nevertheless, two SNPs, AS3MT 12390 (rs3740393) and 14458 (rs11191439) were consistently related to arsenic methylation regardless of the populations examined for the analysis. Thus, these SNPs may be useful indicators to predict the arsenic metabolism via methylation pathways.
Distribution of “Characteristic” Terms in MEDLINE Literatures
Authors: Smalheiser Neil R. , Zhou Wei , Torvik Vetle I.
Published: April 2011

Given the occurrence frequency of any term within any set of articles within MEDLINE, we define “characteristic” terms as words and phrases that occur in that literature more frequently than expected by chance (at p < 0.001 or better). In this report, we studied how the cut-off criterion varied as a function of literature size and term frequency in MEDLINE as a whole, and have compared the distribution of characteristic terms within a number of journal-defined, affiliation-defined and random literatures. We also investigated how the characteristic terms were distributed among MEDLINE titles, abstracts, and last sentence of abstracts, including “regularized” terms that appear both in the title and abstract of the same paper for at least one paper in the literature. For a set of 10 disciplinary journals, the characteristic terms comprised 18% of the total terms on average. Characteristic terms are utilized in several of our web-based services (Anne O’Tate and Arrowsmith), and should be useful for a variety of other information-processing tasks designed to improve text mining in MEDLINE.
4-{[(4-Fluorophenyl)imino]methyl}-3-hydroxyphenyl 4-(Hexadecanoyloxy)benzoate
Authors: Ha Sie-Tiong , Yeap Guan-Yeow , Boey Peng-Lim
Published: April 2011

A new Schiff base ester, 4-{[(4-fluorophenyl)imino]methyl}-3-hydroxyphenyl 4-(hexadecanoyloxy)benzoate was synthesized and its IR, 1H NMR, 13C NMR and EI-MS spectroscopic data are presented.
Effects of High Salt Stress on Secondary Metabolite Production in the Marine-Derived Fungus Spicaria elegans
Authors: Wang Yi , Lu Zhenyu , Sun Kunlai , Zhu Weiming
Published: April 2011

To obtain structurally novel and bioactive natural compounds from marine-derived microorganisms, the effect of high salt stress on secondary metabolite production in the marine-derived fungal strain, Spicaria elegans KLA-03, was investigated. The organism, which was isolated from marine sediment, produced different secondary metabolites when cultured in 3% and 10% saline conditions. Four characteristic metabolites, only produced in the 10% salinity culture, were isolated, and their structures were identified as (2E,2'Z)-3,3'-(6,6'-dihydroxybiphenyl-3,3'-diyl)diacrylic acid (1), aspulvinone E (2), aspochalasin E (3) and trichodermamide B (6), according to their 1D and 2D NMR spectra. Compound 1 is a new compound. High salt stress may therefore be a promising means to induce the production of new and chlorinated compounds in halotolerant fungi. Compound 1 showed moderate antibacterial activity against Pseudomonas aeruginosa and Escherichia coli with minimum inhibitory concentration (MIC) values of 0.038 and 0.767 mM, respectively.
FISHprep: A Novel Integrated Device for Metaphase FISH Sample Preparation
Authors: Shah Pranjul , Vedarethinam Indumathi , Kwasny Dorota , Andresen Lars , Skov Søren , Silahtaroglu Asli , Tümer Zeynep , Dimaki Maria , Svendsen Winnie E.
Published: April 2011

We present a novel integrated device for preparing metaphase chromosomes spread slides (FISHprep). The quality of cytogenetic analysis from patient samples greatly relies on the efficiency of sample pre-treatment and/or slide preparation. In cytogenetic slide preparation, cell cultures are routinely used to process samples (for culture, arrest and fixation of cells) and/or to expand limited amount of samples (in case of prenatal diagnostics). Arguably, this expansion and other sample pretreatments form the longest part of the entire diagnostic protocols spanning over 3–4 days. We present here a novel device with an integrated expansion chamber to culture, arrest and fix metaphase cells followed by a subsequent splashing protocol leading to ample metaphase chromosome spreads on a glass slide for metaphase FISH analysis. The device provides an easy, disposable, low cost, integrated solution with minimal handling for metaphase FISH slide preparation.
Bismuth(III) Reagents in Steroid and Terpene Chemistry
Authors: Salvador Jorge A. R. , Silvestre Samuel M. , Pinto Rui M. A.
Published: April 2011

Steroid and terpene chemistry still have a great impact on medicinal chemistry. Therefore, the development of new reactions or “greener” processes in this field is a contemporaneous issue. In this review, the use of bismuth(III) salts, as “ecofriendly” reagents/catalysts, on new chemical processes involving steroids and terpenes as substrates will be focused. Special attention will be given to some mechanistic considerations concerning selected reactions.
A New Diterpene Glycoside from Stevia rebaudiana
Authors: Prakash Chaturvedula Venkata Sai , Prakash Indra
Published: April 2011

From the commercial extract of the leaves of Stevia rebaudiana, a new diterpene glycoside was isolated besides the known steviol glycosides including stevioside, rebaudiosides A-F, rubusoside and dulcoside A. The new compound was identified as 13-[(2-O-β-D-glucopyranosyl-3-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-(2-O-α-L-rhamnopyranosyl-β-D-glucopyranosyl) ester (1) on the basis of extensive spectroscopic (NMR and MS) and chemical studies.
Multiblock Copolymers of Styrene and Butyl Acrylate via Polytrithiocarbonate-Mediated RAFT Polymerization
Authors: Ebeling Bastian , Vana Philipp
Published: April 2011

When linear polytrithiocarbonates as Reversible Addition-Fragmentation chain Transfer (RAFT) agents are employed in a radical polymerization, the resulting macromolecules consist of several homogeneous polymer blocks, interconnected by the functional groups of the respective RAFT agent. Via a second polymerization with another monomer, multiblock copolymers—polymers with alternating segments of both monomers—can be prepared. This strategy was examined mechanistically in detail based on subsequent RAFT polymerizations of styrene and butyl acrylate. Size-exclusion chromatography (SEC) of these polymers showed that the examined method yields low-disperse products. In some cases, resolved peaks for molecules with different numbers of blocks (polymer chains separated by the trithiocarbonate groups) could be observed. Cleavage of the polymers at the trithiocarbonate groups and SEC analysis of the products showed that the blocks in the middle of the polymers are longer than those at the ends and that the number of blocks corresponds to the number of functional groups in the initial RAFT agent. Furthermore, the produced multiblock copolymers were analyzed via differential scanning calorimetry (DSC). This work underlines that the examined methodology is very well suited for the synthesis of well-defined multiblock copolymers.
Regional Mapping of the Geoid Using GNSS (GPS) Measurements and an Artificial Neural Network
Authors: Veronez Mauricio Roberto , Florêncio de Souza Sérgio , Matsuoka Marcelo Tomio , Reinhardt Alessandro , Macedônio da Silva Reginaldo
Published: April 2011

The determination of the orthometric height from geometric leveling has practical difficulties that, despite a number of scientific and technological advances, passed a century without substantial modifications or advances. Currently, the Global Navigation Satellite System (GNSS) has been used with reasonable success for orthometric height determination. With a sufficient number of benchmarks with known horizontal and vertical coordinates, it is often possible to adjust using the least squares method mathematical expressions that allow interpolation of geoid heights. The objective of this study is to present an alternative method to interpolate geoid heights based on the technique of Artificial Neural Networks (ANNs). The study area is the Brazilian state of São Paulo, and for training the ANN the authors have used geoid height information from the EGM08 gravity model with a grid spacing of 10 minutes of arc. The efficiency of the model was tested at 157 points with known geoid heights distributed across the study area. The results were also compared with the Brazilian Geoid Model (MAPGEO2004). Based on those 157 benchmarks it was possible to verify that the model generated by ANNs provided a mean absolute error of 0.24 m in obtaining a geoid height value. Statistical tests have shown that there was no difference between the means from known geoid heights and geoid heights provided by the neural model for a significance level of 5%. It was also found that ANNs provided an improvement of 2.7 times in geoid height estimates when compared with the MAPGEO2004 geoid model.
MERIS Retrieval of Water Quality Components in the Turbid Albemarle-Pamlico Sound Estuary, USA
Authors: Sokoletsky Leonid G. , Lunetta Ross S. , Wetz Michael S. , Paerl Hans W.
Published: April 2011

Two remote-sensing optical algorithms for the retrieval of the water quality components (WQCs) in the Albemarle-Pamlico Estuarine System (APES) were developed and validated for chlorophyll a (Chl). Both algorithms were semi-empirical because they incorporated some elements of optical processes in the atmosphere, water, and air/water interface. One incorporated a very simple atmospheric correction and modified quasi-single-scattering approximation (QSSA) for estimating the spectral Gordon’s parameter, and the second estimated WQCs directly from the top of atmosphere satellite radiance without atmospheric corrections. A modified version of the Global Meteorological Database for Solar Energy and Applied Meteorology (METEONORM) was used to estimate directional atmospheric transmittances. The study incorporated in situ Chl data from the Ferry-Based Monitoring (FerryMon) program collected in the Neuse River Estuary (n = 633) and Pamlico Sound (n = 362), along with Medium Resolution Imaging Spectrometer (MERIS) satellite imagery collected (2006–2009) across the APES; providing quasi-coinciding samples for Chl algorithm development and validation. Results indicated a coefficient of determination (R2) of 0.70 and mean-normalized root-mean-squares errors (NRMSE) of 52% in the Neuse River Estuary and R2 = 0.44 (NRMSE = 75 %) in the Pamlico Sound—without atmospheric corrections. The simple atmospheric correction tested provided on performance improvements. Algorithm performance demonstrated the potential for supporting long-term operational WQCs satellite monitoring in the APES.
An Enhanced Reservation-Based MAC Protocol for IEEE 802.15.4 Networks
Authors: Afonso José A. , Silva Helder D. , Macedo Pedro , Rocha Luis A.
Published: April 2011

The IEEE 802.15.4 Medium Access Control (MAC) protocol is an enabling standard for wireless sensor networks. In order to support applications requiring dedicated bandwidth or bounded delay, it provides a reservation-based scheme named Guaranteed Time Slot (GTS). However, the GTS scheme presents some drawbacks, such as inefficient bandwidth utilization and support to a maximum of only seven devices. This paper presents eLPRT (enhanced Low Power Real Time), a new reservation-based MAC protocol that introduces several performance enhancing features in comparison to the GTS scheme. This MAC protocol builds on top of LPRT (Low Power Real Time) and includes various mechanisms designed to increase data transmission reliability against channel errors, improve bandwidth utilization and increase the number of supported devices. A motion capture system based on inertial and magnetic sensors has been used to validate the protocol. The effectiveness of the performance enhancements introduced by each of the new features is demonstrated through the provision of both simulation and experimental results.
From Sensor to Observation Web with Environmental Enablers in the Future Internet
Authors: Havlik Denis , Schade Sven , Sabeur Zoheir A. , Mazzetti Paolo , Watson Kym , Berre Arne J. , Mon Jose Lorenzo
Published: April 2011

This paper outlines the grand challenges in global sustainability research and the objectives of the FP7 Future Internet PPP program within the Digital Agenda for Europe. Large user communities are generating significant amounts of valuable environmental observations at local and regional scales using the devices and services of the Future Internet. These communities’ environmental observations represent a wealth of information which is currently hardly used or used only in isolation and therefore in need of integration with other information sources. Indeed, this very integration will lead to a paradigm shift from a mere Sensor Web to an Observation Web with semantically enriched content emanating from sensors, environmental simulations and citizens. The paper also describes the research challenges to realize the Observation Web and the associated environmental enablers for the Future Internet. Such an environmental enabler could for instance be an electronic sensing device, a web-service application, or even a social networking group affording or facilitating the capability of the Future Internet applications to consume, produce, and use environmental observations in cross-domain applications. The term “envirofied” Future Internet is coined to describe this overall target that forms a cornerstone of work in the Environmental Usage Area within the Future Internet PPP program. Relevant trends described in the paper are the usage of ubiquitous sensors (anywhere), the provision and generation of information by citizens, and the convergence of real and virtual realities to convey understanding of environmental observations. The paper addresses the technical challenges in the Environmental Usage Area and the need for designing multi-style service oriented architecture. Key topics are the mapping of requirements to capabilities, providing scalability and robustness with implementing context aware information retrieval. Another essential research topic is handling data fusion and model based computation, and the related propagation of information uncertainty. Approaches to security, standardization and harmonization, all essential for sustainable solutions, are summarized from the perspective of the Environmental Usage Area. The paper concludes with an overview of emerging, high impact applications in the environmental areas concerning land ecosystems (biodiversity), air quality (atmospheric conditions) and water ecosystems (marine asset management).
Multi-Hop Localization Algorithm Based on Grid-Scanning for Wireless Sensor Networks
Authors: Wan Jiangwen , Guo Xiaolei , Yu Ning , Wu Yinfeng , Feng Renjian
Published: April 2011

For large-scale wireless sensor networks (WSNs) with a minority of anchor nodes, multi-hop localization is a popular scheme for determining the geographical positions of the normal nodes. However, in practice existing multi-hop localization methods suffer from various kinds of problems, such as poor adaptability to irregular topology, high computational complexity, low positioning accuracy, etc. To address these issues in this paper, we propose a novel Multi-hop Localization algorithm based on Grid‑Scanning (MLGS). First, the factors that influence the multi-hop distance estimation are studied and a more realistic multi-hop localization model is constructed. Then, the feasible regions of the normal nodes are determined according to the intersection of bounding square rings. Finally, a verifiably good approximation scheme based on grid-scanning is developed to estimate the coordinates of the normal nodes. Additionally, the positioning accuracy of the normal nodes can be improved through neighbors’ collaboration. Extensive simulations are performed in isotropic and anisotropic networks. The comparisons with some typical algorithms of node localization confirm the effectiveness and efficiency of our algorithm.
Novel Mechano-Luminescent Sensors Based on Piezoelectric/Electroluminescent Composites
Authors: Jia Yanmin , Tian Xiangling , Wu Zheng , Tian Xiaojuan , Zhou Jiayi , Fang Yunzhang , Zhu Chenchen
Published: April 2011

A high-sensitivity mechano-luminescent sensor was fabricated on the basis of piezoelectric/electroluminescent composites. The working principle of this mechano-luminescent sensor was elucidated by analyzing the relationship between the piezoelectric-induced charges and the electroluminescent effects. When a stress is applied on the piezoelectric layer, electrical charges will be induced at both the top and bottom sides of the piezoelectric layer. The induced electrical charges will lead to a light output from the electroluminescent layer, thus producing a mechano-luminescence effect. By increasing the vibration strength or frequency applied, the mechano-luminescence output can be obviously enhanced. Mechano-luminescence sensors have potential in smart stress-to-light devices, such as foot-stress-distribution-diagnosis systems and dynamic-load-monitors for bridge hanging cables.
Metallo-Graphene Nanocomposite Electrocatalytic Platform for the Determination of Toxic Metal Ions
Authors: Willemse Chandre M. , Tlhomelang Khotso , Jahed Nazeem , Baker Priscilla G. , Iwuoha Emmanuel I.
Published: April 2011

A Nafion-Graphene (Nafion-G) nanocomposite solution in combination with an in situ plated mercury film electrode was used as a highly sensitive electrochemical platform for the determination of Zn2+, Cd2+, Pb2+ and Cu2+ in 0.1 M acetate buffer (pH 4.6) by square-wave anodic stripping voltammetry (SWASV). Various operational parameters such as deposition potential, deposition time and electrode rotation speed were optimized. The Nafion-G nanocomposite sensing platform exhibited improved sensitivity for metal ion detection, in addition to well defined, reproducible and sharp stripping signals. The linear calibration curves ranged from 1 µg L−1 to 7 µg L−1 for individual analysis. The detection limits (3σ blank/slope) obtained were 0.07 µg L−1 for Pb2+, Zn2+ and Cu2+ and 0.08 µg L−1 for Cd2+ at a deposition time of 120 s. For practical applications recovery studies was done by spiking test samples with known concentrations and comparing the results with inductively coupled plasma mass spectrometry (ICP-MS) analyses. This was followed by real sample analysis.
Integration of Social Aspects in Decision Support, Based on Life Cycle Thinking
Authors: Lehmann Annekatrin , Russi Daniela , Bala Alba , Finkbeiner Matthias , Fullana-i-Palmer Pere
Published: April 2011

Recently increasing attention has been paid to complementing environmental Life Cycle Assessment (LCA) with social aspects. The paper discusses the selection of social impacts and indicators from existing frameworks like Social Life Cycle Assessment (SLCA) and Social Impact Assessment (SIA). Two ongoing case studies, addressing sustainability assessment within decision support, were considered: (1) Integrated Water Resources Management (IWRM) in Indonesia; and (2) Integrated Packaging Waste Management in Spain and Portugal (FENIX). The focus was put on social impacts occurring due to decisions within these systems, such as choice of technologies, practices or suppliers. Thus, decision makers—here understood as intended users of the studies’ results—are not consumers that buy (or do not buy) a product, such as in recent SLCA case-studies, but mainly institutions that decide about the design of the water or packaging waste management system. Therefore, in the FENIX project, a list of social impacts identified from literature was sent to the intended users to be ranked according to their priorities. Finally, the paper discusses to what extent the entire life cycle is reflected in SLCA impact categories and indicators, and explains how both life-cycle and on-site-related social impacts were chosen to be assessed. However, not all indicators in the two projects will assess all stages of the life cycle, because of their varying relevance in the different stages, data availability and practical interest of decision makers.
Understanding the Future of Change Agency in Sustainability Through Cellular Automata Scenarios: The Role of Timing †
Authors: Sosa Ricardo
Published: April 2011

One of the main interdisciplinary challenges today is to understand and change the dominant social perceptions and values that support and perpetuate unsustainable practices. Social computational simulations have been conceived in recent years to understand emergent results from complex systems. These dynamic social models are of interest to sustainability researchers because they provide a means to implement hypotheses and explore scenarios that could help extend our understanding of the future role of change agency in society. Change agents are individuals who directly or indirectly enable sustainable behaviors or inhibit practices that damage the environment and large social groups. Evidence-based strategies, guidelines and methods are necessary in order to manage creative change agency more effectively. This paper presents work with computational simulations, known as cellular automata, in order to explore the role of timing in triggering social change through uncoordinated, autonomous individual action. The paper identifies a number of issues related to creative change agency and proposes associated guidelines for practitioners. As a means of early validation, these findings are portrayed against empirical studies in the literature.
Quantisation, Representation and Reduction; How Should We Interpret the Quantum Hamiltonian Constraints of Canonical Gravity?
Authors: Thébault Karim P. Y.
Published: April 2011

Hamiltonian constraints feature in the canonical formulation of general relativity. Unlike typical constraints they cannot be associated with a reduction procedure leading to a non-trivial reduced phase space and this means the physical interpretation of their quantum analogues is ambiguous. In particular, can we assume that “quantisation commutes with reduction” and treat the promotion of these constraints to operators annihilating the wave function, according to a Dirac type procedure, as leading to a Hilbert space equivalent to that reached by quantisation of the problematic reduced space? If not, how should we interpret Hamiltonian constraints quantum mechanically? And on what basis do we assert that quantisation and reduction commute anyway? These questions will be refined and explored in the context of modern approaches to the quantisation of canonical general relativity.
The Use of Convection-Enhanced Delivery with Liposomal Toxins in Neurooncology
Authors: Fiandaca Massimo S. , Berger Mitchel S. , Bankiewicz Krystof S.
Published: April 2011

Liposomes have long been effective delivery vehicles for transport of toxins to peripheral cancers. The combination of convection-enhanced delivery (CED) with liposomal toxins was originally proposed to circumvent the limited delivery of intravascular liposomes to the central nervous system (CNS) due to the blood-brain-barrier (BBB). CED offers markedly improved distribution of infused therapeutics within the CNS compared to direct injection or via drug eluting polymers, both of which depend on diffusion for parenchymal distribution. This review examines the basis for improved delivery of liposomal toxins via CED within the CNS, and discusses preclinical and clinical experience with these therapeutic techniques. How CED and liposomal technologies may influence future neurooncologic treatments are also considered.
Detection of Ricin Contamination in Ground Beef by Electrochemiluminescence Immunosorbent Assay
Authors: Brandon David L.
Published: April 2011

Ricin is a highly toxic protein present in the seeds of Ricinus communis (castor), grown principally as a source of high quality industrial lubricant and as an ornamental. Because ricin has been used for intentional poisoning in the past and could be used to contaminate food, there is a need for analytical methodology to detect ricin in food matrices. A monoclonal antibody-based method was developed for detecting and quantifying ricin in ground beef, a complex, fatty matrix. The limit of detection was 0.5 ng/g for the electrochemiluminescence (ECL) method and 1.5 ng/g for enzyme-linked immunosorbent assay (ELISA). The detection of nanogram per gram quantities of ricin spiked into retail samples of ground beef provides approximately 10,000-fold greater sensitivity than required to detect a toxic dose of ricin (>1 mg) in a 100 g sample.
Climate Change and Classic Maya Water Management
Authors: Lucero Lisa J. , Gunn Joel D. , Scarborough Vernon L.
Published: April 2011

The critical importance of water is undeniable. It is particularly vital in semitropical regions with noticeable wet and dry seasons, such as the southern Maya lowlands. Not enough rain results in decreasing water supply and quality, failed crops, and famine. Too much water results in flooding, destruction, poor water quality, and famine. We show not only how Classic Maya (ca. A.D. 250–950) society dealt with the annual seasonal extremes, but also how kings and farmers responded differently in the face of a series of droughts in the Terminal Classic period (ca. A.D. 800–950). Maya farmers are still around today; kings, however, disappeared over 1,000 years ago. There is a lesson here on how people and water managers responded to long-term climate change, something our own society faces at present. The basis for royal power rested in what kings provided their subjects materially—that is, water during annual drought via massive artificial reservoirs, and spiritually—that is, public ceremonies, games, festivals, feasts, and other integrative activities. In the face of rulers losing their powers due to drought, people left. Without their labor, support and services, the foundation of royal power crumbled; it was too inflexible and little suited to adapting to change.
La Bibliographie internationale (1891-1991), témoin d'un siècle de géographie : quelques enseignements d'analyse formelle
Authors: Robic Marie-Claire
Published: April 2011

The International Geographical Bibliography (IGB), 1891-1991, a testimony of a century of geography : some results of a formal analysis. The durability of the Bibliographie, which was created by the Annales de Géographie as the major document of a scientific scheme, shows the relatively good success of French academic geography for the past century. Its history follows the evolution of the institutionalization of geography. Strong and lasting ties with the publishing house Armand Colin were developed ; the Bibliographie started out as part of the Annales de Géographie ; then, in 1921 it became a publication of the Association de géographes français. The Centre national de la recherche scientifique (CNRS) progressively took it over in the fifties. The international network of academics that contributed to the reviews has been relayed since 1976 by the INTERGEO CNRS team. The Bibliographie has now become a database. For the last few years the INTERGEO team has been collaborating with a national center of documentation, the Institut de l'information scientifique et technique (INIST). A work of French geographers at first, the Bibliographie has always received international support, as it is testified by the patronage of the IGU in the thirties when it became the Bibliographie géographique internationale (1932).

Thus the history of the journal shows a remarquable institutional continuity, in spite of the changes that go with the transformations of scientific research during the 20th century. Selected recension is still the aim ; there has been a great stability in the editorship and in the classification scheme for at least three quarters of a century. Still several periods can be pointed out. They show recent changes in documentary methods on one hand, and a chronology truly epistemological on the other hand. Following the decisive innovations of the end of the 19th century that give way to stability for half a century, the fifties are a time of adjustments, while the seventies undertake a reorganisation of the geographic material.
Lamarck, Darwin et Vidal : aux fondements naturalistes de la géographie
Authors: Berdoulay Vincent , Soubeyran Olivier
Published: April 2011

Un des objectifs de Vidal de la Blache lors de la fondation Annales de Géographie était d'acclimater les sciences naturelles à sa discipline. La fréquentation assidue de la pensée des naturalistes lui a permis de tirer parti des grands modèles de la nature pour formuler la géographie humaine. Darwinisme et néo-lamarckisme s'y combinent à des degrés divers, selon les dimensions théorique, méthodologique ou rhétorique du projet géographique.
The Recomposition of Rural Europe : a Review Les milieux deltaïques et leurs aménagements
Authors: Clout Hugh D.
Published: April 2011

Long established trends of socio-economic change in rural Europe have been reversed in recent decades. In many areas depopulation has been replaced by repopulation, and the revised Common Agricultural Policy now aims at reducing outputs of agricultural production rather than increasing them. The European countryside is contested space in which land development clashes with conservation, and environmentalism challenges many taken-for- granted features of agricultural activity. The EC's revised structural funds offer threats to the rural environment as well as promises for socio-economic development. Pluriactivity , despecialisation, extensification, set-aside, and farm-based diversification are key themes for the 1990s.
Les villes moyennes européennes et l'échéance de 1993
Authors: Bouinot Jean
Published: April 2011

« Medium-sized towns and the opening up of the european market in 1993. » — The building of a united Europe, and in particular the perspective of a single European market in 1993, bring specific threats to bear on the future of the Community's medium-sized towns.

Certain factors penalize medium-sized towns in general : for example, the construction of a single financial market results in economies of scale in management costs which are only to the advantage of major towns. Other factors have a more selective effect : for instance, when firms join forces to ensure competitivity at European level this leads to the geographical concentration of their production and distribution sites, thus increasing disparities in tax resources between towns.

The local politicians questioned in seven of the E.E.C. countries are, on the whole, aware of these threats. Nevertheless, their comments and expectations reveal that the largest of the medium-sized towns are those in the best position to take up the challenge that the building of a united Europe offers them, since they are the ones most actively developing policies of cooperation in a climate of incrased competitivity.
Les deltas et leur aménagement
Authors: Verger Fernand
Published: April 2011

Deltas are measured by length, width, surface and protruding area. The fundamental geomorphometrical property of a delta can be expressed by the protuberance index proposed here as the ratio of the two latter parameters.

In the delta seen as river ending, the radial distribution of the hydrographie network will be simple, cross-connected or tree-structured depending on different river discharge partitionnings. In the delta seen as a coastline, the layout is concentric with a succession disposal of sandy bars and shallow depressions usually briny or saline.

The relative influences of tide, waves and river discharge are used to define a classification of embouchures based on W.G. Galloway's and extended to many cases.

Delta resource management can be broken down into the river streams and the deltas themselves. In the latter areas, resources can be developed without altering the geomorphometrical and hydrological environment (fishing, hunting, extensive cattle farming...), with some environmental changes (rice fields, irrigated agriculture, salt flats...) or completely obliterating the natural features (industrial land reclamation, deep-water harbours...).
Le désert du Namib central
Authors: Lageat Yannick
Published: April 2011

The middle Namib desert. On both sides of the Kuiseb Valley, the Namib coastal desert, which is less known than the chiloperuvian desert, shows a strong contrast between the southern erg which is made up of three dune systems (barchan, linear and star dunes), the age of which, while increasing eastwards, is regarded as Pleistocene, and a northern reg the coarse débris of which suffer active salt weathering and eolian corrasion. This desert, which could be the oldest in the world, presents a great number of typical processes, formations and forms under a « humid » and non- pluvial climate which is more dependent of the structure of the maritime Trades than of the Benguela cold current.
Spécificité de l'organisation spatiale des bassins de main-d'œuvre et d'emploi des petites villes
Authors: Troufleau Pascal
Published: April 2011

ENG : Commuting flows! small towns! employment poles! spatial interaction! regression analysis! gravity model!
La frontière entre protestantisme et catholicisme en Europe.
Authors: Boyer Jean-Claude
Published: April 2011

The frontier between protestantism and Catholicism in Europe. A fault line separates the protestant north of Europe from the catholic south. The break is clean along most of its length except where it runs erratically through Switzerland and Germany. This frontier, which mainly originates from the sixteenth century, no longer represents (except in Northern Ireland) a major discontinuity. Even so it still has a marked influence on economic, political and socio-cultural patterns and behaviours. This study highlights the specificities of the two Europes and the evolution of relationships between them. It will more specifically focus on the case of those states where the problems of two religions coexisting side by side have to be managed.
Auditory Risk to Unprotected Bystanders Exposed to Firearm Noise
Authors: Flamme Gregory A. , Stewart Michael , Meinke Deanna , Lankford James , Rasmussen Per
Published: April 2011

Background:What is the risk of hearing loss for someone standing next to a shooter? Friends, spouses, children, and other shooters are often present during hunting and recreational shooting activities, and these bystanders seem likely to underestimate the hazard posed by noise
from someone else's firearm. Hunters use hearing protection inconsistently, and there is little reason to expect higher use rates among bystanders. Acoustic characteristics and estimates of auditory risk from gunfire noise next to the shooter were assessed in this study.Research Design:This
was a descriptive study of auditory risk at the position of a bystander near a recreational firearm shooter.Data Collection and Analysis:Recordings of impulses from 15 recreational firearms were obtained 1 m to the left of the shooter outdoors away from reflective surfaces. Recordings
were made using a pressure-calibrated 1/4 inch measurement microphone and digitally sampled at 195 kHz (24 bit depth). The acoustic characteristics of these impulses were examined, and auditory risk estimates were obtained using three contemporary damage-risk criteria (DRCs) for unprotected
listeners.Results:Instantaneous peak levels at the bystander location ranged between 149 and 167 dB SPL, and 8 hr equivalent continuous levels (LeqA8) ranged between 64 and 83 dB SPL. Poor agreement was obtained across the three DRCs, and the DRC that was most conservative
varied with the firearm. The most conservative DRC for each firearm permitted no unprotected exposures to most rifle impulses and fewer than 10 exposures to impulses from most shotguns and the single handgun included in this study. More unprotected exposures were permitted for the guns with
smaller cartridges and longer barrel length.Conclusions:None of the recreational firearms included in this study produced sound levels that would be considered safe for all unprotected listeners. The DRCs revealed that only a few of the small-caliber rifles and the smaller-gauge shotguns
permitted more than a few shots for the average unprotected listener. This finding is important for professionals involved in hearing health care and the shooting sports because laypersons are likely to consider the bystander location to be inherently less risky because it is farther from
the gun than the shooter.
Decreased Mitochondrial Dna Content in Subcutaneous Fat from HIV-Infected Women Taking Antiretroviral Therapy as Measured at Delivery
Authors:   Group the Target Study, Nasi Milena , Pinti Marcello , Chiesa Elisabetta , Fiore Simona , Manzini Serena , Giovane Cinzia Del , D'Amico Roberto , Palai Nicoletta , Campatelli Carlo , Sabbatini Francesca , Roccio Marianna , Tibaldi Cecilia , Masuelli Giulia , Mussini Cristina , Ferrazzi Enrico , Monforte Antonella d'Arminio , Cossarizza Andrea
Published: April 2011

Background

Increasing numbers of pregnant HIV- positive women are receiving combination antiretroviral regimens for preventing mother-to-child virus transmission or for treating the infection itself. Several studies have demonstrated that nucleoside reverse transcriptase inhibitors (NRTIs) induce mitochondrial toxicity by several mechanisms, including depletion of mitochondrial DNA (mtDNA). By the quantification of mtDNA levels, we studied mitochondrial toxicity in HIV-positive women at delivery and the possible correlations with antiretroviral regimens, viroimmunological and metabolic parameters.

Methods

We analysed 68 HIV-positive women enrolled in the Italian Prospective Cohort Study on Efficacy and Toxicity of Antiretroviral in Pregnancy (TARGET Study); all were taking ≥1 NRTI. We quantified mtDNA copies per cell in subcutaneous fat samples collected during delivery. At the 3rd, 6th and 9th month of pregnancy, we collected data concerning CD4+ T-cell count, plasma HIV RNA, total and high-density lipoprotein (HDL) cholesterol, fasting plasma glucose and triglycerides. As a control, we analysed mtDNA levels in abdominal subcutaneous fat samples from 23 HIV-seronegative women at delivery.

Results

mtDNA content was significantly lower in HIV-infected women when compared with HIV-negative controls. mtDNA content varied independently from viroimmunological, lipid and glucose parameters at the different months, with the exceptions of triglycerides at the 9th month and of HDL at the 6th month of pregnancy.

Conclusions

In subcutaneous tissue from women taking NRTI-based antiretroviral regimens, we observed a signifcant decrease of mtDNA content, compared with uninfected women not on antiviral treatment. Moreover, a significant correlation was noted between mtDNA content and HDL cholesterol and triglycerides.