bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of mating behavior and temperature variation on the critical population density of a freshwater copepod
Authors: Kramer Andrew M. , Sarnelle Orlando , Yen Jeannette
Published: February 2011

At low density, population growth rates of dioecious zooplankton depend on the encounter rate of potential mates, resulting in a demographic Allee effect and a critical density for population establishment and persistence. Empirical evidence confirms a critical density for the calanoid copepod Hesperodiatomus shoshone, but existing estimates of the critical density span an order of magnitude. Combining three‐dimensional video analysis of mating behavior with life history data from natural populations we estimated H. shoshone critical density to be 0.44–1.44 m−3. The critical density was highly dependent on body size, primarily as a result of the latter's influence on swimming speed. Swimming speed also depended on temperature, increasing > 25% as temperature increased from 5°C to 16°C. Rapid swimming (1.25–2.4 cm s−1) and the ability to follow pheromone trails greatly improved the ability of H. shoshone to find mates. The large effect of temperature on mating behavior means that environmental variation can have a major effect on critical density and indicates that recovery or colonization events may be more likely to succeed in warmer lakes and/or warmer years. Considering the potential for critical densities to vary with environmental conditions is important for understanding how these thresholds determine population establishment and persistence in sexually reproducing aquatic organisms and other populations subject to Allee effects.
Air quality and emissions in the Yangtze River Delta, China
Authors: Li L. , Chen C. H. , Fu J. S. , Huang C. , Streets D. G. , Huang H. Y. , Zhang G. F. , Wang Y. J. , Jang C. J. , Wang H. L. , Chen Y. R. , Fu J. M.
Published: February 2011

Abstract. Regional trans-boundary air pollution has become an important issue in the field of air pollution modeling. This paper presents the results of the implementation of the MM5-CMAQ modeling system in the Yangtze River Delta (YRD) for the months of January and July of 2004. The meteorological parameters are obtained by using the MM5 model. A new regional emission inventory with spatial and temporal allocations based on local statistical data has been developed to provide input emissions data to the MM5-CMAQ modeling system. The pollutant concentrations obtained from the MM5-CMAQ modeling system have been compared with observational data from the national air pollution monitoring network. It is found that air quality in winter in the YRD is generally worse than in summer, due mainly to unfavorable meteorological dispersion conditions. In winter, the pollution transport from Northern China to the YRD reinforces the pollution caused by large local emissions. The monthly average concentration of SO2 in the YRD is 0.026 ± 0.011 mg m−3 in January and 0.017 ± 0.009 mg m−3 in July. Monthly average concentrations of NO2 in the YRD in January and July are 0.021 ± 0.009 mg m−3, and 0.014 ± 0.008 mg m−3, respectively. The monthly average concentration of PM10 in the YRD is 0.080 ± 0.028 mg m−3 in January and 0.025 ± 0.015 mg m−3 in July. Visibility is also a problem, with average deciview values of 26.4 ± 2.95 dcv in winter and 17.6 ± 3.3 dcv in summer. The ozone concentration in the downtown area of a city like Zhoushan can be very high, with the highest simulated value reaching 0.24 mg m−3. In January, the monthly average concentration of O3 in the YRD is 0.052 ± 0.011 mg m−3, and 0.054 ± 0.008 mg m−3 in July. Our results show that ozone and haze have become extremely important issues in the regional air quality. Thus, regional air pollution control is urgently needed to improve air quality in the YRD.
Spatial and vertical extent of nucleation events in the Midwestern USA: insights from the Nucleation In ForesTs (NIFTy) experiment
Authors: Pryor S. C. , Barthelmie R. J. , Sørensen L. L. , McGrath J. G. , Hopke P. , Petäjä T.
Published: February 2011

Abstract. Measurements of aerosol particle physical and chemical properties, gas phase concentrations and meteorological parameters were made along a transect in southern Indiana during the Nucleation In ForesTs (NIFTy) experiment conducted in May 2008. These measurements indicate nucleation was observed at all three measurement sites on almost half of all sampling days. The intensity of the nucleation events, as measured by the increase in ≥10 nm aerosol particle number concentrations of approximately 2×104 cm−3 over a layer of at least 300 m depth, is in good agreement with recent model results for the Midwestern USA derived using PMCAMx-UF. During the hour after termination of nucleation approximately half of the number concentration reduction is due to coagulation, while the remainder is due in equal parts to dry deposition and entrainment of relatively ultra-fine aerosol particle free troposphere air. Clear nucleation with continuous subsequent growth is only observed on days when the morning fractional cloud cover was less than 30%. It is associated with a clear transition from a strongly stratified atmosphere with low turbulence intensity and weak vertical velocities, to much a weaker vertical gradient of wind speed, increased turbulence intensity and stronger downwards vertical velocities, consistent with growth of the mixed layer and entrainment of air from the residual layer. Nucleation intensity is not very strongly determined by the prevailing condensational sink. However, there is a strong correlation between both a modified version of the Nucleation Parameter from Boy and Kulmala (2002) and ultrafine aerosol particle number concentrations, and mean morning H2SO4 concentrations and ultrafine aerosol particle number concentrations. Five A-class event days during NIFTy were characterized by values of the dimensionless nucleation parameter of Kuang et al. (2010) that are below 0.3, further indicating the applicability of their postulate that nucleation is favored by LΓ values below 0.7. Based on aerosol particle composition measurements it appears that aerosol particle formation and initial growth to approximately 30 nm diameter is dominated by ammonium and sulfate. Conservative estimates of the percent contribution of H2SO4 to aerosol particle growth (for sub-30 nm aerosol particles) on five A-class event days ranged from 23 to 85%.
On the origin of mesoscale TIDs at midlatitudes
Authors: Kelley M. C.
Published: February 2011

Abstract. A recent breakthrough experiment by Ogawa et al. (2009) showed that Mesoscale Traveling Ionospheric Disturbances (MSTIDs), a common phenomenon at midlatitudes, originate in the auroral zone as gravity waves. Curiously, however, the latter do not seem to be related to magnetic activity. These atmospheric waves are common at high latitudes (Bristow and Greenwald, 1996; Bristow et al., 1996), and we argue here that, as they propagate to lower latitudes, Joule damping reduces the gravity wave spectrum to waves suffering the weakest damping. The direction of weakest damping corresponds to the direction predicted by the Perkins instability (Perkins, 1973) for nighttime MSTIDs. The daytime features reported by Ogawa et al. (2009) are very likely due to classical gravity wave interaction with the F-region ionosphere.
Mega fire emissions in Siberia: potential supply of soluble iron from forests to the ocean
Authors: Ito A.
Published: February 2011

Abstract. Significant amounts of carbon and nutrients are released to the atmosphere due to large fires in forests. Characterization of the spatial distribution and temporal variation of the intense fire emissions is crucial for assessing the atmospheric loadings of aerosols and trace gases. This paper discusses issues of the representation of forest fires in the estimation of emissions and the application to an atmospheric chemistry transport model (CTM). The potential contribution of forest fires to the deposition of soluble iron (Fe) into the ocean is highlighted, with a focus on mega fires in eastern Siberia. Satellite products of burned area, active fire, and land cover are used to estimate biomass burning emissions in conjunction with a biogeochemical model. Satellite-derived plume height from MISR is used for the injection height of boreal forest fire emissions. This methodology is applied to quantify fire emission rates in each three-dimensional grid location in the high latitude Northern Hemisphere (> 30° N latitude) over a 5-year period from 2001 to 2005. There is large interannual variation in forest burned area during 2001–2005 (13–51 × 103 km2 yr−1) which results in a corresponding variation in the annual emissions of carbon monoxide (CO) (12–78 Tg CO yr−1). Satellite observations of CO from MOPITT are used to evaluate the model performance in simulating the spatial distribution and temporal variation of the fire emissions. During the major Siberian fire seasons in the summer of 2002 and in the spring of 2003, the model results for CO enhancements due to intense fires are in good agreement with MOPITT observations. These fire emission rates are applied to the aerosol chemistry transport model to examine the relative importance of biomass burning sources of soluble iron compared to those from dust sources. Compared to the dust sources without the atmospheric processing by acidic species, extreme fire events contribute to a significant deposition of soluble iron (10–60%) to downwind regions over the western North Pacific Ocean. It may imply that the supply of nutrients from large forest fires plays a role as a negative biosphere-climate feedback with regards to the ocean fertilization.
Soil organic carbon (SOC) accumulation in rice paddies under long-term agro-ecosystem experiments in southern China – VI. Changes in microbial community structure and respiratory activity
Authors: Liu D. , Liu X. , Liu Y. , Li L. , Pan G. , Crowley D. , Tippkötter R.
Published: February 2011

Abstract. Biological stabilization within accumulated soil organic carbon (SOC) has not been well understood, while its role in physical and chemical protection as well as of chemical recalcitrance had been addressed in Chinese rice paddies. In this study, topsoil samples were collected and respiratory activity measured in situ following rice harvest under different fertilization treatments of three long-term experimental sites across southern China in 2009. The SOC contents, microbial biomass carbon (SMBC) and nitrogen (SMBN) were analysed using chemical digestion and microbial community structure assessment via clony dilute plate counting methods. While SOC contents were consistently higher under compound chemical fertilization (Comp-Fert) or combined organic and inorganic fertilization (Comb-Fert) compared to N fertilization only (N-Fert), there was significantly higher fungal-bacterial ratio under Comb-Fert than under N-Fert and Comp-Fert. When subtracting the background effect under no fertilization treatment (Non-Fert), the increase both in SMBC and SMBN under fertilization treatment was found very significantly correlated to the increase in SOC over controls across the sites. Also, the ratio of culturable fungal to bacterial population numbers (F/B ratio) was well correlated with soil organic carbon contents in all samples across the sites studied. SOC accumulation favoured a build-up the microbial community with increasing fungal dominance in the rice paddies under fertilization treatments. While soil respiration rates were high under Comb-Fert as a result of enhanced microbial community build-up, the specific soil respiratory activity based on microbial biomass carbon was found in a significantly negatively correlation with the SOC contents for overall samples. Thus, a fungal-dominated microbial community seemed to slow SOC turnover, thereby favouring SOC accumulation under Comp-Fert or under Comb-Fert in the rice paddies. Therefore, the biological stabilization process is of importance in SOC sequestration in the rice paddies, operating with physical and chemical protection and chemical recalcitrance. However, sufficient understanding and prediction of SOM dynamics needs further quantitative characterization of the simultaneous operation of several mechanisms.
Geomorphometry of drainage basins: a global view from the Shuttle Radar Topography Mission
Authors: Guth P. L.
Published: February 2011

Abstract. A suite of 42 geomorphometric parameters for each of 26 272 drainage basins larger than 100 km2 from the Hydrosheds Shuttle Radar Topography digital elevation model shows the global distribution of Strahler order for streams and drainage basins; the largest basins are order 9. Many common parameters depend both on the size of the basin, and the scale of the digital elevation model used for the computations. These drainage basins display the typical longitudinal stream profiles, but the major basins tend to be more convex than the smaller basins.
Stories from the Front Line
Authors: Smith Paul J. , Scott Jonathan M.
Published: February 2011

This paper explores the views that students and employers have on innovative work-based learning (WBL) programmes in English higher education. The experiences of both students and employers were analysed methodologically, using the organizational story-telling framework (Gabriel, 1999). The themes that have emerged are learning support, organizational issues, links between the WBL programme and the workplace and barriers to change. The paper concludes with recommendations for future policy and research.
‘Can't String a Sentence Together’? UK Employers' Views of Graduates' Writing Skills
Authors: Kotzee Ben , Johnston Roger
Published: February 2011

Concern exists among both academics and employers regarding the quality of graduates' writing. The complaint, as it is most commonly phrased, is that young graduates can no longer ‘string a simple sentence together’. If true, this is a problem: the quality of students' writing seriously affects their chances in the job market. In this small-scale study, the authors investigated employers' complaints about graduates' writing and attempted to identify the typical writing problems graduates encounter. Answers were sought by reviewing the literature on graduates' writing skills and by surveying members of the Association of Graduate Recruiters regarding their estimation of new graduate employees' writing skills. Important conclusions are that concern among employers regarding graduates' writing skills is serious and that complaints are often about basic skills such as grammar and punctuation. However, employers do not seem to see much difference between the writing skills of business graduates and other graduates and are uncertain as to whether universities pay sufficient attention to writing.
From Entrepreneurial Fission to Entrepreneurial Fusion
Authors: Curley Martin G. , Formica Piero , Nicolò Vincenzo
Published: February 2011

Incubators are embedded in the culture of the economics of (value-added) services. To date, at least in Europe, they have operated in a manner analogous to the generation of nuclear power; that is, attempting to produce ‘entrepreneurial energy’ through a process of fission that creates a division between the aspiring entrepreneurs' demands for, and the corresponding supply of, support and services. The process has been artificially fuelled by the provision of subsidies and grants from the European Union and elsewhere. However, the outcomes, in terms of high-expectation start-ups and their long-term sustainability, have been mediocre. In contrast, experience in the USA – where the incubation process has been more successful, qualitatively, than in Europe – points to a new route: that of ‘proof of concept’, of which the Kauffman Foundation is the strongest advocate (Mitchell, 2009, p 57). We can use the concept of nuclear fusion – not yet a commercial reality for the generation of power – as a metaphor for the present situation regarding entrepreneurial innovation. On the one hand, there is the failure of incubators and, on the other, the need to expand the incubation process beyond the limits of the business plan, to encompass experimentation and the simulation of new business concepts in an experimental laboratory environment. Such experimental labs are attuned to and conversant with the economics of experimentation. This proposed innovative shift requires the fusion (that is, in the terminology of nuclear physics, production of a single, heavier nucleus) rather than the separation or fission (production of several lighter nuclei), of the demand for and supply of experimentation – of which the services currently provided are only a part.
Entrepreneurship as a Gendered Process
Authors: Hovorka Alice J. , Dietrich Dawn
Published: February 2011

This paper conceptualizes entrepreneurship as a gendered process shaped by dynamic, context-specific structures in order to balance the underestimation of external factors and overestimation of individual factors in existing gender and entrepreneurship studies. It presents research from Botswana that reveals striking differences between men, women and their businesses in terms of capital, access to resources and business outcomes. It explores the broader cultural, legal–institutional and political factors that are inherently gendered and that manifest themselves in the entrepreneurial sector. In both instances, women's business endeavours are consistently subordinate to those of men and gender dynamics constantly reproduce themselves to the detriment of female entrepreneurs.
Innovation and NGOs
Authors: Luxmore Stephen R. , Hull Clyde Eiríkur
Published: February 2011

Innovations that antagonize non-governmental organizations (NGOs) will face significantly greater challenges than those that do not. The impact of non-governmental organizations on the commercialization of new technology is evolving from the more traditional indirect approach of lobbying governments. The new NGO approach is to pursue private politics, in which the NGO seeks to exert direct influence over entrepreneurial companies that commercialize radical new technology. The authors use the industry study approach to explore how this new NGO role affects innovation. They present a theoretical framework that encompasses the emerging role of NGOs and set out the practical managerial implications that emerge from their analysis.
Blowing Agents
Authors: Heck Rhomie L. , Peascoe Warren J.
Published: February 2011

Blowing agents, sometimes referred to as foaming agents, produce gas and thus may be used to generate cells (gas packets) in polymeric materials. They are classified as either physical or chemical blowing agents (CBAs). Physical blowing agents form cells by a phase change, eg, a liquid may be volatilized or a gas dissolved in a polymer under high pressure may be desorbed by decompression. Chemical blowing agents produce gas by thermal decomposition and, in a few instances, via a chemical reaction with other components of the polymer system. Properties of several blowing agents of both types, as well as test methods, are reviewed.
Vinylidene Chloride Polymers
Authors: Howell B. A. , Beyer D. E.
Published: February 2011

This article covers the uniqueness and versatility of these thermoplastics. The unique morphology of vinylidene chloride polymers is covered in detail and related to both polymerization and production processes and also to subsequent processing at the customer end. Each of the main polymerization processes of suspension, mass, and emulsion are described in detail with particular emphasis on how the morphology of each different product is created. Other aspects such as environmental protection, barrier properties, quality and testing, processing, and economic aspects complete the story of these fascinating polymers.
Craniomicromelic syndrome: First report in a male
Authors: Gambhir Prakash S. , Gambhir Sunita
Published: February 2011

We report on craniomicromelic syndrome in a male fetus. This case had the previously reported features of prenatal onset growth retardation, underossified cranial bones, wide sutures and fontanels, small face as compared to head, small palpebral fissures, pinched nose, microstomia, micrognathia, and narrow thorax. The consistent combination of these features with short appearing limbs as observed in this case establishes this syndrome as a distinct entity. © 2011 Wiley‐Liss, Inc.
Toward a cross‐species neuroscientific understanding of the affective mind: do animals have emotional feelings?
Authors: Panksepp Jaak
Published: February 2011

Do we need to consider mental processes in our analysis of brain functions in other animals? Obviously we do, if such BrainMind functions exist in the animals we wish to understand. If so, how do we proceed, while still retaining materialistic–mechanistic perspectives? This essay outlines the historical forces that led to emotional feelings in animals being marginalized in behavioristic scientific discussions of why animals behave the way they do, and why mental constructs are generally disregarded in modern neuroscientific analyses. The roots of this problem go back to Cartesian dualism and the attempt of 19th century physician–scientists to ground a new type of medical curriculum on a completely materialistic approach to body functions. Thereby all vitalistic principles were discarded from the lexicon of science, and subjective experience in animals was put in that category and discarded as an invalid approach to animal behavior. This led to forms of rigid operationalism during the era of behaviorism and subsequently ruthless reductionism in brain research, leaving little room for mentalistic concepts such as emotional feelings in animal research. However, modern studies of the brain clearly indicate that artificially induced arousals of emotional networks, as with localized electrical and chemical brain stimulation, can serve as “rewards” and “punishments” in various learning tasks. This strongly indicates that animal brains elaborate various experienced states, with those having affective contents being easiest to study rigorously. However, in approaching emotional feelings empirically we must pay special attention to the difficulties and vagaries of human language and evolutionary levels of control in the brain. We need distinct nomenclatures from primary (unconditioned phenomenal experiences) to tertiary (reflective) levels of mind. The scientific pursuit of affective brain processes in other mammals can now reveal general BrainMind principles that also apply to human feelings, as with neurochemical predictions from preclinical animal models to self‐reports of corresponding human experiences. In short, brain research has now repeatedly verified the existence of affective experience—various reward and punishment functions—during artificial arousal of emotional networks in our fellow animals. The implications for new conceptual schema for understanding human/primate affective feelings and how such knowledge can impact scientific advances in biological psychiatry are also addressed. Am. J. Primatol. 73: 545–561, 2011. © 2011 Wiley‐Liss, Inc.
The Structure‐Based Design of Mdm2/Mdmx–p53 Inhibitors Gets Serious
Authors: Popowicz Grzegorz M. , Dömling Alexander , Holak Tad A.
Published: February 2011

The p53 protein is the cell’s principal bastion of defense against tumor‐associated DNA damage. Commonly referred as a “guardian of the genome”, p53 is responsible for determining the fate of the cell when the integrity of its genome is damaged. The development of tumors requires breaching this defense line. All known tumor cells either mutate the p53 gene, or in a similar number of cases, use internal cell p53 modulators, Mdm2 and Mdmx proteins, to disable its function. The release of functional p53 from the inhibition by Mdm2 and Mdmx should in principle provide an efficient, nongenotoxic means of cancer therapy. In recent years substantial progress has been made in developing novel p53‐activating molecules thanks to several reported crystal structures of Mdm2/x in complex with p53‐mimicking peptides and nonpeptidic drug candidates. Understanding the structural attributes of ligand binding holds the key to developing novel, highly effective, and selective drug candidates. Two low‐molecular‐weight compounds have just recently progressed into early clinical studies.
Anion‐binding properties of two calix[4]arene derivatives containing two ferrocene imine or ferrocene amine units at the upper rim
Authors: Shaabani Behrouz , Shaghaghi Zohreh
Published: February 2011

Calix[4]arene derivatives containing ferrocene units at the upper rim have been synthesized and their anion‐binding and sensing investigated towards anions such as chloride, bromide and hydrogen sulfate by cyclic voltammetry. Electrochemical studies show that these redox‐active ligands electrochemically recognize chloride and bromide anions. These compounds have excellent selectivity for chloride and bromide ions, in the comparison with hydrogen sulfate anion. With ferrocenyl Schiff base calix[4]arene 1 an anodic shift as large as 302 mV is observed on addition of four equivalents of Cl− anion. Also electrochemical and UV–vis spectroscopic titrations ferrocenyl calix[4]arene derivatives 1 with chloride and bromide ions and 2 (only with Cl−) indicate a 1:1 binding‐stiochiometry. Copyright © 2011 John Wiley & Sons, Ltd.
Monitoring of solid oxide fuel cell systems
Authors: Murshed AKM M. , Huang B. , Nandakumar K.
Published: February 2011

Fault detection and isolation of critical equipments as well as process operation is an important part of automation. Failure to detect fault can contribute to process safety incident, violation of environmental regulation and, as a result, reduce profit from the unit affected by the fault. Even though there has been a lot of work done on the modeling and control of the solid oxide fuel cell, little attention has been paid to its monitoring methodology. The need of reliable SOFC operations and current effort toward commercialization call for advanced monitoring technology, which constitutes one of the most important directions for SOFC research and development. In this article, as an attempt toward monitoring of SOFC systems a hybrid monitoring approach is developed which formulates the fault detection problem as a linear matrix inequality (LMI). The formulation is then illustrated through its application to the solid oxide fuel cell and its system to handle constraints and detect faults early. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
Optimal design of water networks involving multiple contaminants for global water operations
Authors: Bahiyah Handani Zainatul , Wan Alwi Sharifah Rafidah , Hashim Haslenda , Abdul Manan Zainuddin , Sayid Abdullah Sharifah Hanis Yasmin
Published: February 2011

This work presents the development of a systematic technique to target the minimum fresh water consumption and wastewater generation to achieve maximum water recovery (MWR) for systems involving multiple contaminants. A generic linear programing (LP) model has been developed based on water network superstructure to simultaneously set the targets and design the MWR network, for both mass transfer‐based (MTB) and non‐mass transfer‐based (NMTB) problems (i.e. global water‐using operations). This work also includes cases where fresh water concentrations for all contaminants are assumed to be either zero or non‐zero. The proposed method is superior since it can guarantee a global optimal solution. Application of the methodology on three case studies shows significant water savings, illustrating the effectiveness of the proposed approach. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
Research of styrene‐butadiene rubber/silicon‐aluminum oxides nanotube binary nanocomposites
Authors: Wang Qingguo , Gao Wenxiu , Zhang Liqun
Published: February 2011

A novel silicon‐aluminum oxides (Si‐Al) nanotubes with length ranging from 500 to 1000 nm were introduced to fabricate the styrene‐butadiene rubber (SBR)/Si‐Al nanotube binary nanocomposites. Scanning electron microscope observation showed the Si‐Al nanotubes up to 20 parts per hundred parts of rubber (phr) loading level were dispersed well in SBR matrix. Mechanical properties tests, thermogravimetry analysis and dynamic mechanical thermal analysis revealed that the Si‐Al nanotubes have the effects on improving shore A hardness, tensile strength, tear strength, initial decomposition temperature, and storage modulus while lower the maximum loss factor (tan δ) of the SBR/Si‐Al nanotube binary nanocomposites. FTIR spectra analysis showed that new SiO bond was generated between the hydroxyl group of Si‐Al nanotube and the coupling reagent Si69. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of styrene–acrylonitrile on the electrical resistivity of polycarbonate/multiwalled carbon nanotube composites
Authors: Sun Yao , Jia Ming‐Yin , Guo Zhao‐Xia , Yu Jian , Nagai Satoshi
Published: February 2011

Multiwalled carbon nanotube (MWCNT)‐filled polycarbonate (PC)/styrene–acrylonitrile (SAN) blends with a wide range of blend compositions were prepared by melt mixing in a rotational rheometer, and the effect of SAN on the electrical properties of the PC/MWCNT composites was studied. The structure/electrical property relationship was investigated and explained by a combination of MWCNT localization and blend morphology. Transmission electron micrographs showed selective localization of MWCNTs in the PC phase, regardless of the blend morphology. When the SAN concentration was 10–40 wt %, which corresponded to sea‐island (10–30 wt %) and cocontinuous (40 wt %) blend morphologies (PC was continuous in both structures), the electrical resistivity decreased with increases in the SAN content. The concept of an effective volume concentration of MWCNTs was used to explain this effect. When the SAN concentration was 70 wt % or higher, the electrical resistivity was very high because MWCNTs were confined in the isolated PC particles. In addition, SAN was replaced by other polymers [polystyrene, methyl methacrylate/styrene, and poly(methyl methacrylate)]; these yielded similar blend morphologies and MWCNT localization and showed the generality of the concept of effective concentration in explaining a decrease in the electrical resistivity upon the addition of a second polymer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Selective separation and concentration of Pd(II) from Fe(III), Co(II), Ni(II), and Cu(II) ions using thiourea‐formaldehyde resin
Authors: Muslu Nazan , Gülfen Mustafa
Published: February 2011

Thiourea‐formaldehyde (TUF), a well‐known chelating resin, has been synthesized and it was used in the adsorption, selective separation, and concentration of Pd(II) ions from Fe(III), Co(II) Ni(II), and Cu(II) base metal ions. The composition of the synthesized resin was determined by elemental analysis. The effect of initial acidity/pH and the adsorption capacity for Pd(II) ions were studied by batch technique. The adsorption and separation of Pd(II) were then examined by column technique. FTIR spectra and SEM/EDS analysis were also recorded before and after the adsorption of Pd(II). The optimum pH was found to be 4 for the adsorption. The adsorption data fitted well to the Langmuir isotherm. The maximum adsorption capacity of the TUF resin for Pd(II) ions was found to be 31.85 mg g−1 (0.300 mmol g−1). Chelating mechanism was effective in the adsorption. Pd(II) ions could be separated efficiently from Fe(III), Cu(II), Ni(II), and Co(II) ions using TUF resin. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Thermo‐responsive albumin hydrogels with LCST near the physiological temperature
Authors: Spizzirri Umile Gianfranco , Cirillo Giuseppe , Iemma Francesca , Puoci Francesco , Curcio Manuela , Ilaria Parisi Ortensia , Picci Nevio
Published: February 2011

This paper deals with the synthesis of thermoresponsive microspheres with proteic structure exhibiting a transition temperature close to the body temperature. The hydrogels were synthesized by free radical polymerization of methacrylate Bovine Serum Albumin (BSA‐MA) as crosslinker, and 2‐hydroxyethyl methacrylate (HEMA) and/or N‐isopropylacrylamide (NIPAAm), as hydrophilic and thermoresponsive monomers, respectively. The modification of the hydrophilic/hydrophobic balance in the polymerization feed allows to modulate the volume phase transition temperature of the macromolecular network. The hydrogels were characterized by infrared spectroscopy and thermal analyses, which showed negative thermoresponsive behavior for all compositions and, by increasing the content of the hydrophilic moieties in the network, the transition temperature was ranged from 34.2 to 36.8°C. To test the preformed materials as drug carriers, diclofenac diethyl ammonium salt was chosen and drug entrapment percent was determined. Drug release profiles, in media at different temperature, depend on the crosslinking degree and on the composition of the hydrogels. By using semiempirical equations, the release mechanism was extensively studied and the diffusional contribute evaluated. The physic‐chemical characteristics of thermoresponsive materials confirm the applicability of the microspheres as drug delivery device. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation and properties of novel thermally stable pyridine‐based poly(amide imide amide)s
Authors: Mehdipour‐Ataei Shahram , Taremi Fatemeh
Published: February 2011

The 2,6‐bis(4‐nitrobenzamido)pyridine was prepared via reaction of 2,6‐diaminopyridine with two moles of 4‐nitrobenzoyl chloride in the presence of propylene oxide. Catalytic reduction of nitro groups of 2,6‐bis(4‐nitrobenzamido)pyridine with hydrazine yielded 2,6‐bis(4‐aminobenzamido)pyridine. Reaction of this diamine with two moles of trimellitic anhydride afforded a diacid with preformed amide and imide structures. Poly(amide imide amide)s were prepared by direct polycondensation reactions of the diacid with different diamines in the presence of triphenyl phosphite. All the precursors and polymers were fully characterized using common spectroscopic methods and elemental analysis and physical properties of the polymers including solution viscosity, thermal stability, thermal behavior, and solubility were studied. According to the obtained results the polymers showed high thermal stability and enhanced solubility. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Carboxymethylcellulose–Chitosan‐coated microneedles with modulated hydration properties
Authors: Marin Alexander , Andrianov Alexander K.
Published: February 2011

Microneedles containing sodium carboxymethylcellulose (CMC) formulations were fabricated to include an external chitosan (CS) layer to modulate their hydration profile, an important parameter affecting their application as intradermal delivery devices and their storage. The microfabrication process was carried out under conditions that enabled the formation of polyelectrolyte complexes between these oppositely charged macromolecules. CMC–CS microneedles were characterized by water uptake in a humid environment, contact angle measurements, dissolution in aqueous solutions, and protein‐release profiles. The results demonstrate that the microneedles containing CMC–CS formulations displayed suppressed moisture sensitivity in water vapors compared to their unmodified CMC counterparts while the maintaining quick protein‐release characteristics required for their uses. This approach also showed the potential for sustained protein‐release applications, as the CMC–CS formulations could be combined in layers to fabricate multicompartment microneedle coatings with delayed release characteristics. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and characterization of the biomaterial poly(lactic acid‐co‐Nε‐carbobenzoyloxy‐L‐lysine) via direct melt copolymerization
Authors: Ye Ruirong , Wang Zhaoyang , Luo Shihe , Yang Liting , Xiao Xin
Published: February 2011

With D,L‐lactic acid and Nϵ‐carbobenzoyloxy‐L‐lysine [Lys(Z)] as the starting monomer material and tin dichloride as the catalyst, the drug carrier material poly(lactic acid‐co‐Nϵ‐carbobenzoyloxy‐L‐lysine) was synthesized via direct melt polycondensation. The copolymer was systematically characterized with intrinsic viscosity testing, Fourier transform infrared spectroscopy, 1H‐NMR, gel permeation chromatography, differential scanning calorimetry, and X‐ray diffraction. The influences of different feed molar ratios were examined. With increasing molar feed content of Lys(Z), the intrinsic viscosity, weight‐average molecular weight, and polydispersity index (weight‐average molecular weight/number‐average molecular weight) gradually decreased. Because of the introduction of Lys(Z) with a big aromatic ring into the copolymer, the glass‐transition temperature gradually increased with increasing feed charge of Lys(Z), and all of the copolymers were amorphous. The copolymers, with weight‐average molecular weights from 10,500 to 6900 Da, were obtained and could reach the molecular weight level of poly(lactic acid) modified by Lys(Z) via the ring‐opening polymerization of the cyclic intermediates, such as lactide and morpholine‐2,5‐dione. However, a few terminal carboxyl groups might have been deprotected during the polymerization reaction under high temperatures. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Working with activity theory: Context, technology, and information behavior
Authors: Allen David , Karanasios Stan , Slavova Mira
Published: February 2011

Over the last 7 years, the AIMTech Research Group in the University of Leeds has used cultural‐historical activity theory (CHAT) to inform a range of research activities in the fields of information behavior and information systems. In this article, we identify certain openings and theoretical challenges in the field of information behavior, which sparked our initial interest in CHAT: context, technology, and the link between practice and policy. We demonstrate the relevance of CHAT in studying information behavior and addressing the identified openings and argue that by providing a framework and hierarchy of activity‐action‐operation and semantic tools, CHAT is able to overcome many of the uncertainties concerning information behavior research. In particular, CHAT provides researchers a theoretical lens to account for context and activity mediation and, by doing so, can increase the significance of information behavior research to practice. In undertaking this endeavour, we have relied on literature from the fields of information science and others where CHAT is employed. We provide a detailed description of how CHAT may be applied to information behavior and account for the concepts we see as relevant to its study.
Learning outcomes of information literacy instruction at business schools
Authors: Detlor Brian , Julien Heidi , Willson Rebekah , Serenko Alexander , Lavallee Maegen
Published: February 2011

This paper reports results from an exploratory study investigating the factors affecting student learning outcomes of information literacy instruction (ILI) given at business schools. Specifically, the potential influence of student demographics, learning environment factors, and information literacy program components on behavioral, psychological, and benefit outcomes were examined. In total, 79 interviews with library administrators, librarians, teaching faculty, and students were conducted at three business schools with varying ILI emphases and characteristics. During these interviews, participants discussed students' ILI experiences and the outcomes arising from those experiences. Data collection also involved application of a standardized information literacy testing instrument that measures student information literacy competency. Analysis yielded the generation of a new holistic theoretical model based on information literacy and educational assessment theories. The model identifies potential salient factors of the learning environment, information literacy program components, and student demographics that may affect ILI student learning outcomes. Recommendations for practice and implications for future research are also made.
Solving the logistic problems with optimal resource assignment using fuzzy logic methods
Authors: Moškon Miha , Novak Štefan , Medeot Marino , Bajec Iztok Lebar , Zimic Nikolaj , Mraz Miha
Published: February 2011

Fuzzy approach of optimal resource assignment regarding the given demands in the scope of transportation will be presented in the article. The basis of the research is the crisp solution which is also presented in the article. The basic solution was upgraded in order to be able to handle vaguely (i.e. fuzzily) defined requirements and resource properties. The optimal resource configuration is calculated with the aid of Hungarian algorithm which uses the data calculated with the fuzzy methods for its inputs. The approach described is presented on the example of a military convoy formation. Copyright © 2011 John Wiley & Sons, Ltd.
The silkmoth eggshell as a natural amyloid shield for the safe development of insect oocyte and embryo: Insights from studies of silkmoth chorion protein peptide‐analogues of the B famil
Authors: Iconomidou Vassiliki A. , Cordopatis Paul , Hoenger Andreas , Hamodrakas Stavros J.
Published: February 2011

Silkmoth chorion is the major component of the silkmoth eggshell. The proteins that constitute more than 95% of its dry mass have remarkable mechanical and physicochemical properties forming a protective natural shield for the oocyte and the developing embryo from a wide range of environmental hazards. Peptide‐analogues of the central conservative domain of the two major families of silkmoth chorion proteins, the A's and the B's, form amyloid fibrils under a variety of conditions, which prompted us to propose, 10 years ago, that silkmoth chorion is an amyloid with protective properties. Following our finding, a number of studies verified the existence of several functional amyloids. In this study, we designed, synthesized and studied two peptide‐analogues of the central conservative domain of the B family of silkmoth chorion proteins, and we present experimental results, which show: (a) that the amyloidogenic properties of silkmoth chorion peptides are encoded into the tandemly repeating hexapeptides comprising the central domain of silkmoth chorion proteins, confirming our previous findings from peptide analogues of the A family of chorion proteins, and, (b) they suggest how silkmoth chorion proteins of the B family self‐assemble in vivo, for the formation of the helicoidal architecture of silkmoth chorion. © 2011 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 96: 723–733, 2011.
NMEGylation: A novel modification to enhance the bioavailability of therapeutic peptides
Authors: Park Minyoung , Jardetzky Theodore S. , Barron Annelise E.
Published: February 2011

We have evaluated “NMEGylation”—the covalent attachment of an oligo‐N‐methoxyethylglycine (NMEG) chain—as a new form of peptide/protein modification to enhance the bioavailability of short peptides. OligoNMEGs are hydrophilic polyethylene glycol‐like molecules made by solid‐phase synthesis, typically up to 40 monomers in length. They have been studied as nonfouling surface coatings and as monodisperse mobility modifiers for free‐solution conjugate capillary electrophoresis. However, polyNMEGs have not been demonstrated before this work as modifiers of therapeutic proteins. In prior published work, we identified a short peptide, “C20,” as a potential extracellular inhibitor of the fusion of human respiratory syncytial virus with mammalian cells. The present study was aimed at improving the C20 peptide's stability and solubility. To this end, we synthesized and studied a series of NMEGylated C20 peptide–peptoid bioconjugates comprising different numbers of NMEGs at either the N‐ or C‐terminus of C20. NMEGylation was found to greatly improve this peptide's solubility and serum stability; however, longer polyNMEGs (n > 3) deleteriously affected peptide binding to the target protein. By incorporating just one NMEG monomer, along with a glycine monomer as a flexible spacer, at C20's N‐terminus (NMEG‐Gly‐C20), we increased both solubility and serum stability greatly, while recovering a binding affinity comparable to that of unmodified C20 peptide. Our results suggest that NMEGylation with an optimized number of NMEG monomers and a proper linker could be useful, more broadly, as a novel modification to enhance bioavailability and efficacy of therapeutic peptides. © 2011 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 96: 688–693, 2011.
Reengineering the SLEEP simulator in a concurrent and distributed programming course
Authors: Radivojević Zaharije , Cvetanović Miloš , Jovanović Zoran
Published: February 2011

This article presents laboratory exercises and project assignments developed to teach concepts of concurrent and distributed programming in Java. The exercises and assignments cover important topics determined after an analysis of topics that are often taught in different universities. During the exercises, students reengineer the general purpose discrete event simulator named SLEEP (Simulation, Logic, Execution, prEsentation, Physics). A multilayer organization of the SLEEP simulator enables coverage of the important topics in a coherent manner. In order to support parallel execution in SLEEP students start to reengineer the simulator layers with an exercise related to concurrent programming, followed by two exercises related to distributed programming, and finish with an exercise related to grid computing. The exercises follow the principles of error management training and teach students what common errors are and how to overcome them. The article also describes a practical experience with the use of SLEEP on a concurrent and distributed programming course over a 3‐year period. The results show a positive impact on both students' satisfaction and performance. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22: 39–51, 2014
Alive after death: An exploratory cultural artifact analysis of the Merry Cemetery of Săpânţa
Authors: Curşeu Petru Lucian , Pop‐Curşeu Ioan
Published: February 2011

The paper uses insights from several Social Psychological theories to study the cultural artifacts of the Merry Cemetery (MC) of Săpânţa (Romania). In the first study we have content analysed the epitaphs written on the painted crosses of the MC and the results show that the epitaphs reflect personal as well as social identity (in which individuals are described as members of both the family and the community) and play two important roles for the community members: they serve as a message to the dear ones and as an external memory of the community's social norms and shared worldview. The second study explored the social representation of the MC in the local community. The results show that the social representation of the MC clusters around three main themes: its symbolic, economic and local identity value. Copyright © 2011 John Wiley & Sons, Ltd.