bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Velocity Gradient on Optimisation of the Aggregation Process and Properties of Formed Aggregates
Authors: Polášek Pavel
Published: September 2011

Influence of Velocity Gradient on Optimisation of the Aggregation Process and Properties of Formed Aggregates

The follow up research into the IHDS process was carried out with a Couette device. The outcome of this study provides a comprehensive understanding of the effect that both the agitation intensity and the agitation time have on the kinetics and the mechanism of the aggregation process. The results obtained confirm the very favourable influence of high agitation intensity for the formation of more compact and dense aggregates than those formed by the accustomed flocculation conditions with low agitation intensity. This research also proved that the agitation intensity and time are the inherent means profoundly influencing the properties of the resultant aggregates such as their size, shape, density and homogeneity. Further, it was confirmed that the aggregation process passes through a minimum. Furthermore, it was verified that the aggregation process takes place in four consecutive phases, namely a) the phase of formation, b) the phase of compaction, c) the phase of a steady (equilibrium) state and d) most probably the phase of inner restructuring. The pattern of the aggregates development in these phases remains the same irrespective of the magnitude of the velocity gradient applied but the time at which these phases are completed is velocity gradient dependent. Last but not least this study proved that the dimensionless productCa=G T= const. has no general validity.
Self-Study and Cooperation of Pupils in Project Based Instruction
Authors: Kostelník Jan , Horňáková Veronika
Published: September 2011

Self-Study and Cooperation of Pupils in Project Based Instruction

This paper is focused on the use of cooperative and individualized concepts of instruction in project based learning. Part of the paper includes partial results of the questionnaire survey carried out within the grant project KEGA No. 031-035 SUT — 4 "Project models of teaching at the secondary vocational schools".
Quality and Dynamic Characteristics of Control System Visualization in Control Web
Authors: Michaľčonok German , Strémy Maximilián , Eliáš Andrej
Published: September 2011

Quality and Dynamic Characteristics of Control System Visualization in Control Web

Progress of information technologies and their applications create the necessary need to explore the analysis of techniques to estimate the impact of architecture control system on dynamic characteristics of control. Major impact factors on dynamics and quality of visualization, control modes selection and impact analysis are described in the article.
Size and Return Periods of Extreme Disasters
Authors: Rusko Miroslav , Procházková Dana
Published: September 2011

Size and Return Periods of Extreme Disasters

Extreme disasters occur rarely and altogether occasionally, and therefore, the determination of maximum possible size or maximum expected size of natural and other disasters is important for the safety management and for the insurance domain, and considerable attention is paid to it. Systematic methodology development has been supported by professional papers since 70s of the last century or so. At present, the extreme value methods based on the great numbers of law, fuzzy sets etc. are used. The example shows the high differences in the extreme values existing in the application of old concepts and new methods. By use of the extreme value methods, it is also possible to calculate the return period of extreme disasters. The example showing return periods for different disaster sizes is given.
Appraising Internationality in Spanish Communication Journals
Authors: Fernández-Quijada David
Published: September 2011

This article explores how journals published in a language other than English achieve a degree of internationality and can increase our knowledge of scientific publication patterns. This author offers a case study focused on Spanish communication journals from a sample of 1182 articles published from 2007 to 2009. The article examines three variables in this sample: the number of non-Spanish scholars, the use of languages other than Spanish, and how often non-Spanish journals are referred to. The results show that (a) these journals find it difficult to attract foreign scholars, (b) open-language policies have had a limited effect, and (c) internationality is constrained to the Spanish geolinguistic region.
Validation Techniques for Region-Level Microscopic Mass Evacuation Traffic Simulations
Authors: Dixit Vinayak , Montz Thomas , Wolshon Brian
Published: September 2011

The experiences of several recent evacuations have demonstrated how a mass evacuation of a major city can affect traffic throughout an entire region. This realization has brought the need for analyzing and evaluating evacuation plans at a regional level. Numerous recent studies have devoted themselves to the topic of simulating large-scale evacuations. However, few studies have developed procedures for the validation of large-scale models. This paper discusses validation within the context of the recent development of the regional multimodal evacuation model for New Orleans, Louisiana. The New Orleans model is unique because it is among the first ever to incorporate qualitative and quantitative model validation procedures based on field data collected during an actual mass evacuation. The paper discusses the various statistics considered for validation, including their inherent advantages and disadvantages. It also presents the results obtained from the validation exercises of the New Orleans model. The study concluded that regression analyses were the most appropriate for statistically analyzing the spatial and temporal data correlations between the traffic patterns produced within the simulation and those actually observed during the Hurricane Katrina evacuation. From a qualitative standpoint, colorized spatiotemporal maps were also found to be quite effective for visualizing traffic speed and volume patterns. The maps were also invaluable for quickly identifying and analyzing bottleneck areas at both the local and regional levels.
Exploiting the Capacity of Managed Lanes in Diverting Traffic around an Incident
Authors: Chou Chih-Sheng , Miller-Hooks Elise
Published: September 2011

This paper studies the potential benefits of traffic diversion in incident management for freeway operations of concurrent flow lane facilities. Techniques that exploit the capabilities of the component object module interface of the microscopic simulation tool, VISSIM, were devised for modeling freeway incidents and the implementation of diversion strategies. The potential for mobility improvement in general purpose lanes as a consequence of diverting traffic around an incident using existing managed lanes and the resulting degradation in managed lane performance are considered in a case study. Results from experiments employing the developed simulation tool show that the benefit to general traffic from implementation of a diversion strategy depends on the following factors: the location of the incident scene relative to the starting point of the diversion opening, the total length of access to the managed lane under the diversion strategy, incident duration, and number of lanes blocked (i.e., incident severity). When diversion implementation lags, travel time reductions achieved through diversion are diminished.
Pulmonary Embolism: Still a Diagnostic Quandary
Authors: Islam T
Published: September 2011

Objectives: The objective was to review the progress made in the diagnosis of pulmonary embolism over the past decade and the future direction of diagnostic modalities. Methods: Research studies, review articles and scientific meeting abstracts published were reviewed. Results: Significant progress has been made in the diagnosis of pulmonary embolism. Strategies have been developed to increase the sensitivity and specificity of the diagnostic tools. Conclusion: With the advances of the technology and better understanding of patho-physiology, offer the hope of improving the medical management of common and potentially life threatening condition like pulmonary embolism. Key words: Pulmonary embolism; diagnostic modalities; progress DOI: http://dx.doi.org/10.3329/jafmc.v7i1.8625 JAFMC Bangladesh. Vol 7, No 1 (June) 2011; 34-40
Device Closure of Patent Ductus Arteriosus in Complicated Patient
Authors: Begum NNF
Published: September 2011

Introduction: Congenital Rubella Syndrome is caused by the destructive action of the rubella virus on the fetus at a critical time in development. If the infection occurs at 0-12 weeks of conception, there is a 51% chance of effect on the infant. Along with eye problems, mental retardation, deafness, growth retardation and developmental delays, some patient who survive infection, takes birth with congenital heart disease. Patent ductus arteriosus (PDA) is the most commonly reported heart problem. Case Report: Two cases of congenital rubella syndrome with large patent ductus arteriosus and severe pulmonary hypertension are reported here, whose PDA's were closed with Lifetech PDA occluder devices. One of them had multiple peripheral pulmonary stenosis which were also dilated with balloons. Both of them had interventions in same day. Key words: Patent ductus arteriosus (PDA); congenital rubella syndrome; severe pulmonary hypertension DOI: http://dx.doi.org/10.3329/jafmc.v7i1.8627 JAFMC Bangladesh. Vol 7, No 1 (June) 2011; 43-45
Thyroid Dysfunction and Cardiovascular Abnormalities in a Young Patient with Turner Syndrome
Authors: Amin MR , Rana S , Hossain AR , Mohammad H , Chowdhury MAW , Kahhar MA
Published: September 2011

DOI: http://dx.doi.org/10.3329/jafmc.v7i1.8628 JAFMC Bangladesh. Vol 7, No 1 (June) 2011; 46-49
Adaptive Grid Use in Air Quality Modeling
Authors: Garcia-Menendez Fernando , Odman Mehmet Talat
Published: September 2011

The predictions from air quality models are subject to many sources of uncertainty; among them, grid resolution has been viewed as one that is limited by the availability of computational resources. A large grid size can lead to unacceptable errors for many pollutants formed via nonlinear chemical reactions. Further, insufficient grid resolution limits the ability to perform accurate exposure assessments. To address this issue in parallel to increasing computational power, modeling techniques that apply finer grids to areas of interest and coarser grids elsewhere have been developed. Techniques using multiple grid sizes are called nested grid or multiscale modeling techniques. These approaches are limited by uncertainty in the placement of finer grids since pertinent locations may not be known a priori, loss in solution accuracy due to grid boundary interface problems, and inability to adjust to changes in grid resolution requirements. A different approach to achieve local resolution involves using dynamic adaptive grids. Various adaptive mesh refinement techniques using structured grids as well as mesh enrichment techniques on unstructured grids have been explored in atmospheric modeling. Recently, some of these techniques have been applied to full blown air quality models. In this paper, adaptive grid methods used in air quality modeling are reviewed and categorized. The advantages and disadvantages of each adaptive grid method are discussed. Recent advances made in air quality simulation owing to the use of adaptive grids are summarized. Relevant connections to adaptive grid modeling in weather and climate modeling are also described.
Chemical Mechanism Solvers in Air Quality Models
Authors: Zhang Hong , Linford John C. , Sandu Adrian , Sander Rolf
Published: September 2011

The solution of chemical kinetics is one of the most computationally intensivetasks in atmospheric chemical transport simulations. Due to the stiff nature of the system,implicit time stepping algorithms which repeatedly solve linear systems of equations arenecessary. This paper reviews the issues and challenges associated with the construction ofefficient chemical solvers, discusses several families of algorithms, presents strategies forincreasing computational efficiency, and gives insight into implementing chemical solverson accelerated computer architectures.
Dielectrophoresis Aligned Single-Walled Carbon Nanotubes as pH Sensors
Authors: Li Pengfei , Martin Caleb M. , Yeung Kan Kan , Xue Wei
Published: September 2011

Here we report the fabrication and characterization of pH sensors using aligned single-walled carbon nanotubes (SWNTs). The SWNTs are dispersed in deionized (DI) water after chemical functionalization and filtration. They are deposited and organized on silicon substrates with the dielectrophoresis process. Electrodes with “teeth”-like patterns—fabricated with photolithography and wet etching—are used to generate concentrated electric fields and strong dielectrophoretic forces for the SWNTs to deposit and align in desired locations. The device fabrication is inexpensive, solution-based, and conducted at room temperature. The devices are used as pH sensors with the electrodes as the testing pads and the dielectrophoretically captured SWNTs as the sensing elements. When exposed to aqueous solutions with various pH values, the SWNTs change their resistance accordingly. The SWNT-based sensors demonstrate a linear relationship between the sensor resistance and the pH values in the range of 5–9. The characterization of multiple sensors proves that their pH sensitivity is highly repeatable. The real-time data acquisition shows that the sensor response time depends on the pH value, ranging from 2.26 s for the pH-5 solution to 23.82 s for the pH-9 solution. The long-term stability tests illustrate that the sensors can maintain their original sensitivity for a long period of time. The simple fabrication process, high sensitivity, and fast response of the SWNT-based sensors facilitate their applications in a wide range of areas.
Distinct Redox Profiles of Selected Human Prostate Carcinoma Cell Lines: Implications for Rational Design of Redox Therapy
Authors: Chaiswing Luksana , Zhong Weixiong , Oberley Terry D.
Published: September 2011

The effects of several cancer chemotherapeutic drugs and radiation are mediated, at least in part, by oxidative stress. To better understand this process, we analyzed certain biochemical properties affecting reduction-oxidation (redox) balance in normal prostate epithelial cells and several prostate cancer cell lines. Highly aggressive androgen-independent prostate cancer PC3 cells demonstrated significantly higher levels of total antioxidant capacity (AC) and intra- and extracellular glutathione (GSH)/glutathione disulfide (GSSG) ratios when compared with normal prostate epithelial PrEC cells. WPE1-NB26 cells, a prostate cancer cell line derived from immortalized RWPE1 human prostate epithelial cells, demonstrated significantly higher levels of total AC and intra- and extracellular GSH/GSSG ratios, but lower levels of intracellular reactive oxygen/nitrogen species and lipid peroxidation compared with RWPE1 cells. LNCaP-C4-2 cells, a more aggressive prostate cancer derived from less aggressive androgen-responsive LNCaP cells, exhibited higher levels of AC and extracellular GSH/GSSG ratio when compared to LNCaP cells. Specific cell types showed distinct cytotoxic responses to redox-modulating compounds. WPE1-NB26 cells were more sensitive to phenethyl isothiocyanate and tumor necrosis factor (TNF) than RWPE1 cells, while PC3 cells were more sensitive to TNF than PrEC cells. These results are consistent with the hypothesis that cancer cell redox state may modulate responses to redox-modulating therapeutic regimens.
Traveling Wave Reactor and Condition of Existence of Nuclear Burning Soliton-Like Wave in Neutron-Multiplying Media
Authors: Rusov Vitaliy D. , Linnik Elena P. , Tarasov Victor A. , Zelentsova Tatiana N. , Sharph Igor V. , Vaschenko Vladimir N. , Kosenko Sergey I. , Beglaryan Margarita E. , Chernezhenko Sergey A. , Molchinikolov Pavel A. , Saulenko Sergey I. , Byegunova Olga A.
Published: September 2011

Physical fundamentals of traveling wave reactor are considered. We show that the condition of existence of nuclear burning soliton-like wave in a neutron-multiplying medium is determined in general by two conditions. The first condition (necessary) is determined by relationship between the equilibrium concentration and critical concentration of active (fissionable) isotope that is a consequence of the Bohr–Sommerfeld quantization condition. The second condition (sufficient) is set by the so-called Wigner quantum statistics, or more accurately, by a statistics of the Gaussian simplectic ensembles with respect to the parameter that describes the squared width of burning wave front of nuclear fuel active component.
Temporal and Spatial Analysis of Integrated Energy and Environment Efficiency in China Based on a Green GDP Index
Authors: Lin Weibin , Yang Jin , Chen Bin
Published: September 2011

China is experiencing a high speed economic development which may exert great pressure on the environment and energy systems. To measure the environmental and energy performance during the economic development process, this paper selected 30 provinces, cities or autonomous regions as the decision making unit (DMU), and proposed a Green GDP index (GGI) in view of energy intensity and pollution intensity using the generalized Data Envelopment Analysis (DEA) method, and the developing trends of integrated energy and environment efficiency of DMUs from 2006 to 2010 are also demonstrated by the Malmquist index. Results show that the integrated energy and environment efficiency varies for each DMU. GGI were both 1 in Beijing and Shanghai. GGI values for the developed cities in Eastern China, such as Guangdong, Fujian, Zhejiang, Tianjin, Jiangsu, and Hainan, ranked high, while those in the Northeast and Middle China remained relatively low. Moreover, there is a positive relationship between the GGI and per capita GDP with a correlation coefficient of 0.75. Increases in GGI are also observed in the results, representing great achievements are acquired in energy conservation and emission reduction. However, the GGIs do not converge to the green frontier across the provinces.
Simultaneous Isolation of Lactoferrin and Lactoperoxidase from Bovine Colostrum by SPEC 70 SLS Cation Exchange Resin
Authors: Liang Yafei , Wang Xuewan , Wu Mianbin , Zhu Wanping
Published: September 2011

In this work, simultaneous isolation of lactoferrin (Lf) and lactoperoxidase (Lp) from defatted bovine colostrum by one-step cation exchange chromatography with SPEC 70 SLS ion-exchange resin was investigated. A RP-HPLC method for Lf and Lp determination was developed and optimized as the following conditions: detection wavelength of 220 nm, flow rate of 1 mL/min and acetonitrile concentration from 25% to 75% within 20 min. The adsorption process of Lf on SPEC 70 SLS resin was optimized using Lf standard as substrate. The maximum static binding capacity of SPEC 70 SLS resin was of 22.0 mg/g resin at 15 °С, pH 7.0 and adsorption time 3 h. The Lf adsorption process could be well described by the Langmuir adsorption isotherm model, with a maximum adsorption capacity of 21.73 mg/g resin at 15 °С. In batch fractionation of defatted colostrum, the binding capacities of SPEC 70 SLS resin for adsorbing Lf and Lp simultaneously under the abovementioned conditions were 7.60 and 6.89 mg/g resin, respectively, both of which were superior to those of CM Sepharose F.F. or SP Sepharose F.F. resins under the same conditions. As a result, SPEC 70 SLS resin was considered as a successful candidate for direct and economic purification of Lf and Lp from defatted colostrum.
The Use of Thermal Techniques for the Characterization and Selection of Natural Biomaterials
Authors: Samouillan Valérie , Delaunay Florian , Dandurand Jany , Merbahi Nofel , Gardou Jean-Pierre , Yousfi Mohammed , Gandaglia Alessandro , Spina Michel , Lacabanne Colette
Published: September 2011

In this paper we explore the ability of thermal analysis to check elastin and collagen integrity in different biomaterial applications. Differential Scanning Calorimetry (DSC) has been used to analyze the first and second order transitions of the biological macromolecules in the hydrated and dehydrated state. First, we report the characterization of control cardiovascular tissues such as pericardium, aortic wall and valvular leaflet. Their thermal properties are compared to pure elastin and pure collagen. Second, we present results obtained on two collagen rich tissues: pericardia with different chemical treatments and collagen with physical treatments. Finally, more complex cardiovascular tissues composed of elastin and collagen are analyzed and the effect of detergent treatment on the physical structure of collagen and elastin is brought to the fore.
A Review of Gene Delivery and Stem Cell Based Therapies for Regenerating Inner Ear Hair Cells
Authors: Devarajan Keerthana , Staecker Hinrich , Detamore Michael S.
Published: September 2011

Sensory neural hearing loss and vestibular dysfunction have become the most common forms of sensory defects, affecting millions of people worldwide. Developing effective therapies to restore hearing loss is challenging, owing to the limited regenerative capacity of the inner ear hair cells. With recent advances in understanding the developmental biology of mammalian and non-mammalian hair cells a variety of strategies have emerged to restore lost hair cells are being developed. Two predominant strategies have developed to restore hair cells: transfer of genes responsible for hair cell genesis and replacement of missing cells via transfer of stem cells. In this review article, we evaluate the use of several genes involved in hair cell regeneration, the advantages and disadvantages of the different viral vectors employed in inner ear gene delivery and the insights gained from the use of embryonic, adult and induced pluripotent stem cells in generating inner ear hair cells. Understanding the role of genes, vectors and stem cells in therapeutic strategies led us to explore potential solutions to overcome the limitations associated with their use in hair cell regeneration.
4-({[4-(Methylthio)phenyl]methylene}amino)phenyl Dodecanoate
Authors: Ha Sie-Tiong , Lee Teck-Leong , Win Yip-Foo , Yeap Guan-Yeow
Published: September 2011

A new Schiff base ester, 4-({[4-(methylthio)phenyl]methylene}amino)phenyl dodecanoate was synthesized and its IR, 1H NMR, 13C NMR and EI-MS spectroscopic data are presented.
Anthracen-9-ylmethylene-(3,4-dimethylisoxazol-5-yl)amine
Authors: Asiri Abdullah M. , Khan Salman A.
Published: September 2011

The title compound, anthracen-9-ylmethylene-(3,4-dimethylisoxazol-5-yl)amine (3), was synthesized in high yield by reaction of anthracene-9-carbaldehyde and 5-amino-3,4-dimethyl­isoxazole in ethanol. The structure of this new compound was confirmed by elemental analysis, IR, 1H NMR, 13C NMR and GC-MS spectral analysis.
2-tert-Butyl-5,6,7,8,9,10-hexahydrocyclohepta[b]indole
Authors: Falke Hannes , Bumiller Katharina , Harbig Sabrina , Masch Andreas , Wobbe Janina , Kunick Conrad
Published: September 2011

2-tert-Butyl-5,6,7,8,9,10-hexahydrocyclohepta[b]indole was synthesized by reaction of cycloheptanone and (4-tert-butylphenyl)hydrazine hydrochloride in the presence of sodium acetate and sulfuric acid in glacial acetic acid via Fischer indole synthesis.
Antioxidant Capacities and Total Phenolic Contents Increase with Gamma Irradiation in Two Types of Malaysian Honey
Authors: Hussein Saba Zuhair , Yusoff Kamaruddin Mohd , Makpol Suzana , Yusof Yasmin Anum Mohd
Published: September 2011

Two types of monofloral Malaysian honey (Gelam and Nenas) were analyzed to determine their antioxidant activities and total phenolic and flavonoid contents, with and without gamma irradiation. Our results showed that both types of honey can scavenge free radicals and exhibit high antioxidant-reducing power; however, Gelam honey exhibited higher antioxidant activity (p < 0.05) than Nenas honey, which is in good correlation (r = 0.9899) with its phenolic contents. Interestingly, we also noted that both irradiated honeys have higher antioxidant activities and total phenolic and flavonoid contents compared to nonirradiated honeys by Folin-Ciocalteu and UV-spectrophotometry methods, respectively. However, HPLC analysis for phenolic compounds showed insignificant increase between irradiated and nonirradiated honeys. The phenolic compounds such as: caffeic acid, chlorogenic acid, ellagic acid, p- coumaric acid, quercetin and hesperetin as indicated by HPLC method were found to be higher in Gelam honey versus Nenas honey. In conclusion, irradiation of honey causes enhanced antioxidant activities and flavonoid compounds.
RFamide Peptides: Structure, Function, Mechanisms and Pharmaceutical Potential
Authors: Findeisen Maria , Rathmann Daniel , Beck-Sickinger Annette G.
Published: September 2011

Different neuropeptides, all containing a common carboxy-terminal RFamide sequence, have been characterized as ligands of the RFamide peptide receptor family. Currently, five subgroups have been characterized with respect to their N-terminal sequence and hence cover a wide pattern of biological functions, like important neuroendocrine, behavioral, sensory and automatic functions. The RFamide peptide receptor family represents a multiligand/multireceptor system, as many ligands are recognized by several GPCR subtypes within one family. Multireceptor systems are often susceptible to cross-reactions, as their numerous ligands are frequently closely related. In this review we focus on recent results in the field of structure-activity studies as well as mutational exploration of crucial positions within this GPCR system. The review summarizes the reported peptide analogs and recently developed small molecule ligands (agonists and antagonists) to highlight the current understanding of the pharmacophoric elements, required for affinity and activity at the receptor family. Furthermore, we address the biological functions of the ligands and give an overview on their involvement in physiological processes. We provide insights in the knowledge for the design of highly selective ligands for single receptor subtypes to minimize cross-talk and to eliminate effects from interactions within the GPCR system. This will support the drug development of members of the RFamide family.
An Excursion into the Intriguing World of Polymeric Tl(I) and Ag(I) Cyanoximates
Authors: Gerasimchuk Nikolay
Published: September 2011

The reaction of hot (~95 °C) aqueous solutions of Tl2CO3 with solid HL (HL = NC-C(=N-OH)-R is a cyanoxime, and R is an electron-withdrawing group; 37 ligands are known up-to-date) leads to crystalline yellow/orange TlL. Similarly, the reaction between AgNO3 and ML (M = K+, Na+; L = anion of the monodeprotonated cyanoxime) this time at room temperature in mixed ethanol/aqueous solutions leads to sparingly soluble, colored AgL in high-yield. All synthesized monovalent Tl and Ag complexes were characterized using a variety of spectroscopic methods and X-ray analysis, which revealed the formation of primarily 2D coordination polymers of different complexity. In all cases cyanoxime mono-anions act as bridging ligands. Thallium(I) cyanoximates adopt in most cases a double-stranded motif that is originated from centrosymmetric (TlL)2 dimers in which two Tl2O2 rhombs are fused into infinite “ladder-type” structure. There are very short (3.65–3.85 Å) intermetallic distances in (TlL)n, which are close to that (3.46 Å) in metallic thallium. This opens the possibility for the electrochemical or chemical generation of mixed valence Tl(I)/Tl(III) polymers that may exhibit electrical conductivity. Synthesized silver(I) compounds demonstrate a very significant (for multiple years!) stability towards visible light. There are three areas of potential practical applications of these unusual complexes: (1) battery-less detectors of UV-radiation, (2) non electrical sensors for gases of industrial importance, (3) antimicrobial additives to light-curable acrylate polymeric glues, fillers and adhesives used during introduction of indwelling medical devices. Chemical, structural, technological and biological aspects of application of Tl(I) and Ag(I) cyanoximes-based coordination polymers are reviewed.
Activity and Mechanism of Antimicrobial Peptide-Mimetic Amphiphilic Polymethacrylate Derivatives
Authors: Sovadinova Iva , Palermo Edmund F. , Urban Michael , Mpiga Philomene , Caputo Gregory A. , Kuroda Kenichi
Published: September 2011

Cationic amphiphilic polymethacrylate derivatives (PMAs) have shown potential as a novel class of synthetic antimicrobials. A panel of PMAs with varied ratios of hydrophobic and cationic side chains were synthesized and tested for antimicrobial activity and mechanism of action. The PMAs are shown to be active against a panel of pathogenic bacteria, including a drug-resistant Staphylococcus aureus, compared to the natural antimicrobial peptide magainin which did not display any activity against the same strain. The selected PMAs with 47–63% of methyl groups in the side chains showed minimum inhibitory concentrations of ≤2–31 µg/mL, but cause only minimal harm to human red blood cells. The PMAs also exhibit rapid bactericidal kinetics. Culturing Escherichia coli in the presence of the PMAs did not exhibit any potential to develop resistance against the PMAs. The antibacterial activities of PMAs against E. coli and S. aureus were slightly reduced in the presence of physiological salts. The activity of PMAs showed bactericidal effects against E. coli and S. aureus in both exponential and stationary growth phases. These results demonstrate that PMAs are a new antimicrobial platform with no observed development of resistance in bacteria. In addition, the PMAs permeabilized the E. coli outer membrane at polymer concentrations lower than their MIC values, but they did not show any effect on the bacterial inner membrane. This indicates that mechanisms other than membrane permeabilization may be the primary factors determining their antimicrobial activity.
Loading of Two Related Metal-Organic Frameworks (MOFs), [Cu2(bdc)2(dabco)] and [Cu2(ndc)2(dabco)], with Ferrocene
Authors: Heck Romain , Shekhah Osama , Zybaylo Olexandra , Weidler Peter G. , Friedrich Frank , Maul Robert , Wenzel Wolfgang , Wöll Christof
Published: September 2011

We have studied the loading of two related, similar porous metal-organic frameworks (MOFs) [Cu2(bdc)2(dabco)] (1), and [Cu2(ndc)2(dabco)] (2) with ferrocene by exposing bulk powder samples to the corresponding vapor. On the basis of powder X-ray diffraction data and molecular dynamics (MD) calculations we propose that each pore can store one ferrocene molecule. Despite the rather pronounced similarity of the two MOFs a quite different behavior is observed, for 1 loading with ferrocene leads to an anisotropic 1% contraction, whereas for 2 no deformation is observed. Mössbauer spectroscopy studies reveal that the Fe oxidation level remains unchanged during the process. Time dependent studies reveal that the diffusion constant governing the loading from the gas-phase for 1 is approximately three times larger than the value for 2.
Integrating Millimeter Wave Radar with a Monocular Vision Sensor for On-Road Obstacle Detection Applications
Authors: Wang Tao , Zheng Nanning , Xin Jingmin , Ma Zheng
Published: September 2011

This paper presents a systematic scheme for fusing millimeter wave (MMW) radar and a monocular vision sensor for on-road obstacle detection. As a whole, a three-level fusion strategy based on visual attention mechanism and driver’s visual consciousness is provided for MMW radar and monocular vision fusion so as to obtain better comprehensive performance. Then an experimental method for radar-vision point alignment for easy operation with no reflection intensity of radar and special tool requirements is put forward. Furthermore, a region searching approach for potential target detection is derived in order to decrease the image processing time. An adaptive thresholding algorithm based on a new understanding of shadows in the image is adopted for obstacle detection, and edge detection is used to assist in determining the boundary of obstacles. The proposed fusion approach is verified through real experimental examples of on-road vehicle/pedestrian detection. In the end, the experimental results show that the proposed method is simple and feasible.
Viral Determinants of FeLV Infection and Pathogenesis: Lessons Learned from Analysis of a Natural Cohort
Authors: Bolin Lisa L. , Levy Laura S.
Published: September 2011

Detailed analysis has been performed over many years of a geographic and temporal cohort of cats naturally infected with feline leukemia virus (FeLV). Molecular analysis of FeLV present in the diseased tissues and application of those viruses to experimental systems has revealed unique isolates with distinctive disease potential, previously uncharacterized virus-receptor interactions, information about the role of recombinant viruses in disease induction, and novel viral and cellular oncogenes implicated in pathogenesis, among other findings. The studies have contributed to an understanding of the selective forces that lead to predominance of distinctive FeLV isolates and disease outcomes in a natural population.
Water Recycling in Australia
Authors: Apostolidis Nick , Hertle Chris , Young Ross
Published: September 2011

Australia is the driest inhabited continent on earth and, more importantly, experiences the most variable rainfall of all the continents on our planet. The vast majority of Australians live in large cities on the coast. Because wastewater treatments plants were all located near the coast, it was thought that large scale recycling would be problematic given the cost of infrastructure and pumping required to establish recycled water schemes. This all changed when Australia experienced a decade of record low rainfall and water utilities were given aggressive targets to increase the volume of water recycled. This resulted in recycled water being accepted as a legitimate source of water for non-drinking purposes in a diversified portfolio of water sources to mitigate climate risk. To ensure community support for recycled water, Australia lead the world in developing national guidelines for the various uses of recycled water to ensure the protection of public health and the environment. Australia now provides a great case study of the developments in maximizing water recycling opportunities from policy, regulatory and technological perspectives. This paper explores the evolution in thinking and how approaches to wastewater reuse has changed over the past 40 years from an effluent disposal issue to one of recognizing wastewater as a legitimate and valuable resource. Despite recycled water being a popular choice and being broadly embraced, the concept of indirect potable reuse schemes have lacked community and political support across Australia to date.
Refus de la simplicité et individualisme cognitif
Authors: Wilcox Nathaniel T.
Published: September 2011

La neuroéconomie est un bel exemple d’investigation approfondie de la connaissance de l’individu. Cet outil est soutenu par l’hypothèse implicite selon laquelle « l'homme individuel » est le fameux « agent » de l'économie néoclassique. Nous soutenons ici que cette supposition n'est ni simplement correcte, ni d'une importance primordiale pour la société économique des hommes. En particulier nous suggérons que le principal génie du genre humain tient dans sa capacité à accumuler des artefacts cognitifs physiques et sociaux qui échouent en grande partie aux limitations biologiques innées des individus. C'est essentiellement pourquoi nos économies s’accroissent, et par conséquent nous devrions être plus intéressés par la connaissance distribuée dans des groupes que par la connaissance individuelle. Nous devrions aussi être davantage concernés par l'accumulation culturelle d'artefacts cognitifs comme les dispositifs computationnels et les médias, les structures sociales et les institutions économiques.
L’état actuel de la macroéconomie
Authors: Blanchard Olivier
Published: September 2011

The State of Macro.

For a long while after the explosion of macroeconomics in the 1970s, the field looked like a battlefield. Over time however, largely because facts do not go away, a largely shared vision both of fluctuations and of methodology has emerged. Not everything is fine. Like all revolutions, this one has come with the destruction of some knowledge, and suffers from extremism and herding. None of this deadly however. The state of macro is good. The first section sets the stage with a brief review of the past. The second argues that there has been broad convergence in vision, and the third reviews the specifics. The fourth focuses on convergence in methodology. The last looks at current challenges. not go away, a largely shared vision both of fluctuations and of methodology has emerged. Not everything is fine. Like all revolutions, this one has come with the destruction of some knowledge, and suffers from extremism and herding. None of this deadly however. The state of macro is good. The first section sets the stage with a brief review of the past. The second argues that there has been broad convergence in vision, and the third reviews the specifics. The fourth focuses on convergence in methodology. The last looks at current challenges.
Propriété immobilière et déqualifications dans l'emploi
Authors: Havet Nathalie , Brunet Carole
Published: September 2011

Homeownership and Job Downgrading.

Our empirical study stems from previous research on the effects of residential status on microeconomic labour market outcomes. It focuses on employees and assesses the a priori ambiguous impact of homeownership on job-downgrading. On the one hand, homeownership might reduce the set of employment opportunities, and thus increase job-downgrading ; on the other hand, homeowners might benefit from extended social networks and from professional stability, and thus reduce their downgrading risk. We use the French data set of the 1995-2001 European Community Household Panel to build botha statistical measure as well as a subjective measure of wage downgrading. We estimate a recursive bivariate probit that simultaneously models the residential status choice and the probability to be in a downgraded job. Our results show that other thing being equal, homeowners are more wage downgraded and feel more overeducated than renters. Consequently, homeownership could be a source of mismatch between workers and jobs on the French labour market.
Directed ortho,ortho'-dimetalation of hydrobenzoin: Rapid access to hydrobenzoin derivatives useful for asymmetric synthesis
Authors: Cho Inhee , Meimetis Labros , Belding Lee , Katz Michael J , Dudding Travis , Britton Robert
Published: September 2011

A variety of ortho,ortho'-disubstituted hydrobenzoin derivatives are readily accessible through a directed ortho,ortho'-dimetalation strategy in which the alcohol functions in hydrobenzoin are deprotonated by n-BuLi and the resulting lithium benzyl alkoxides serve as directed metalation groups. The optimization and scope of this reaction are discussed, and the utility of this process is demonstrated in the one-pot preparation of a number of chiral diols as well as a short synthesis of the chiral ligand Vivol.
Building Creative Competence in Globally Distributed Courses through Design Thinking
Authors: Steinbeck Reinhold
Published: September 2011

Helping students think creatively is consistently cited as one of the key goals of education. Yet, across universities around the world, alarms have been sounding off suggesting that students are not prepared for a world where they are expected to solve messy, unstructured problems that don't have easy answers. This paper introduces design thinking, a human-centered innovation methodology that has been implemented in a design innovation program at Stanford University as well as at one of the most successful design consultancies. After a brief overview of design thinking, the author illustrates the key elements of this innovation pedagogy through its implementation at a university in Colombia. Realizing the potential of this methodology for building creative competence and confidence among students from all disciplines, and recognizing the power of the next generation of information and collaboration technologies and social media, the author proposes new research and development projects that will bring more creativity to traditional distance and blended learning programs through an infusion of design thinking.

Ayudar a los estudiantes a pensar de forma creativa suele considerarse uno de los objetivos clave de la educación. Sin embargo, muchas universidades de todo el mundo muestran cierta preocupación al respecto que sugiere que los estudiantes no están preparados para un mundo en el que necesitarán resolver problemas desordenados y desestructurados que no tienen fácil solución. Este artículo presenta el «design thinking» como una metodología para la innovación centrada en las personas, que se ha implementado en un programa para la innovación en el diseño de la Universidad de Stanford, así como en una de las consultoras de diseño más exitosas. Después de un breve resumen del concepto de design thinking, se ilustran los elementos clave de esta pedagogía para la innovación a través de su aplicación en una universidad en Colombia. Rendida cuenta del elevado potencial de esta metodología para la construcción de confianza y capacidad creativa en los estudiantes de todas las disciplinas, y del evidente poder de la próxima generación de tecnologías de la información y la colaboración, así como de los medios sociales, el autor propone nuevos proyectos de investigación y desarrollo que aportarán más creatividad a los programas de educación a distancia y semipresenciales gracias a la aplicación del «design thinking».
Digital Divide in Universities: Internet Use in Ecuadorian Universities
Authors: Torres-Díaz Juan-Carlos , Infante-Moro Alfonso
Published: September 2011

New technologies have transformed higher education whose application has implied changes at all levels. These changes have been assimilated by the university community in various ways. Subtle differences among university students have emerged; these differences determine that the resources the network offers have been used in different ways, thus creating gaps in the university population. This study seeks to determine the level of incidence of the variable of university students’ incomes on the uses and intensity of use of the Internet tools and resources. Students were classified using factor analysis complemented through cluster analysis in order to obtain user profiles; these profiles were verified by means of discriminant analysis. Finally, chi-square was applied to determine the relationship between income level and user profiles. As a result, three profiles were identified with different levels of use and intensity of use of the Internet tools and resources, and statistically the incidence of income in the creation of those profiles was proved. To conclude, we can say that the income level falls mainly on the variables that define the access possibilities; gender has a special behavior; however, since the profile of the highest level has a double proportion for men, though women have better performance in general terms.

Las tecnologías han transformado la educación superior impulsando cambios que han sido asimilados por la comunidad universitaria de distintas maneras. Como consecuencia, los estudiantes han presentado diversas formas y niveles de aprovechamiento de los recursos que nos ofrece Internet, delineándose brechas sutiles en la población universitaria. En este estudio se puntualizan algunas características de estas brechas; concretamente se analiza la incidencia de la variable ingresos del estudiante sobre los usos e intensidad de uso de las herramientas y recursos de Internet. Para lograrlo se clasificó a los estudiantes aplicando análisis factorial, complementado por análisis clúster para obtener perfiles de usuarios; estos perfiles se contrastaron con análisis discriminante y, finalmente, se aplicó chicuadrado para verificar la relación entre el nivel de ingresos y los perfiles de usuarios. Se determinaron tres perfiles con distintos niveles de las herramientas y recursos de Internet; y se comprobó estadísticamente la incidencia del nivel de ingresos en la conformación de estos perfiles. Se concluye que el nivel de ingreso incide mayormente en las variables que definen las posibilidades de acceso; el género tiene un comportamiento especial, puesto que, si bien el perfil más alto tiene el doble de proporción de hombres, las mujeres tienen un mejor desempeño en general.
Use of Dendrimers during the Synthesis of Pt-Ru Electrocatalysts for PEM Fuel Cells: Effects on the Physical and Electrochemical Properties
Authors: Calderón J. C. , Calvillo L. , Lázaro M. J. , Pastor E.
Published: September 2011

In this work, Pt-Ru catalysts were synthesized by a novel methodology which includes the use as encapsulating molecules of dendrimers of different generation: zero (DN-0), one (DN-1), two (DN-2), and three (DN-3). Synthesized catalysts were heat-treated at 350°C, and the effects of this treatment was established from the physical (X-ray dispersive energy (XDE) and X-ray diffraction (XRD)) and electrochemical characterization (cyclic voltammetry and chronoamperometry). Results showed that the heat-treatment benefits the catalytic properties of synthesized materials in terms of CO and methanol electrochemical oxidation. The curves for CO stripping were more defined for heat-treated catalysts, and methanol oxidation current densities were higher for these materials. These changes are principally explained from the removal of organic residues remaining on the surface of the Pt-Ru nanoparticles after the synthesis procedure. After the activation of the catalysts by heating at 350°C, the real importance of the use of these encapsulating molecules and the effect of the generation of the dendrimer become visible. From these results, it can be concluded that synthesized catalysts are good catalytic anodes for direct methanol fuel cells (DMFCs).