bluuebunny/crossref_metadata_2025 huggingface dataset:
La percepción del alumnado de educación secundaria sobre el desarrollo del pensamiento histórico en el proceso evaluador
Authors: Trigueros Cano Francisco Javier , Molina Jorge Ortuño , Molina Puche Sebastián
Published: June 2015

Middle school students’ perception of the assessment of the history courses they take allows us to analyze the relationship between the way history is taught and competent learning that develops historical thinking. This quantitative exploratory study presents the results of a survey conducted among 1,117 students in the 3rd and 4th levels of Obligatory Secondary Education in the Region of Murcia (Spain), who expressed their opinion of the instruments and criteria of evaluation by responding to a questionnaire. The results showed the need to change the cognitive model used for teaching history and to find a form of assessment that will promote and evaluate historical thinking, since the current approach consists basically of memorizing facts and answering repetitive questions, instead of learning how to identify the significance of historical events, explain their causes and consequences, and form reasoned judgments about the past independently.
Competencias y narrativas históricas: el pensamiento histórico de estudiantes y futuros profesores españoles de educación secundaria
Authors: Sáiz Serrano Jorge , López-Facal Ramón
Published: June 2015

This paper examines the competencies in historical thinking of high school students and pre-service teachers in Spain, as well as their narratives about Spanish History. Qualitative methods are used in order to identify: a) their historical thinking, including substantive knowledge and use of meta-concepts; b) the narratives, the cognitive gradation (SOLO taxonomy), and the narrative subject employed. The findings show that a majority of secondary school students do not use meta-concepts. The degree of complexity of historical thinking among pre-service teachers is related to their use of substantive content. The results point to the need to improve history education, including substantive knowledge and the development of specific historical competencies.
La enseñanza de las ciencias sociales en Colombia: lugar de las disciplinas y disputa por la hegemonía de un saber
Authors: Arias Gómez Diego H.
Published: June 2015

This paper presents some episodes that illustrate how the teaching of history and the social sciences in Colombia has been a source of conflict among intellectuals, academics and the state. This body of knowledge is presented as an attractive field that can be capitalized on by different approaches to knowledge and power. The change in the names and periodic invocations of social actors who seek to recover their relevance in relation to the educational needs of the country actually highlight chapters of such tensions, in which professional historians have played a leading role.
Ciencias sociales, pensamiento histórico y ciudadanía: entre lo alegórico y lo virtual (Colombia, 1910-2010)
Authors: Serna Dimas Adrián
Published: June 2015

In recent decades, the role of history in citizen education has moved from a regime of the allegorical to a regime of the virtual. The regime that showed history as an established exemplary order that should enlighten a homogeneous public arena through allegory, has given way to a regime that showed history as an unfinished critical order that can support a public arena of diversities in virtualized form. This displacement has had an impact on cognitive, didactic, social, cultural and political dimensions of historical thought in the teaching of the social sciences. This situation has been complex in contexts with profound social conflicts where the educational system lies within the scope of transitional justice.
Single-fluorophore membrane transport activity sensors with dual-emission read-out
Authors: Ast Cindy , De Michele Roberto , Kumke Michael U , Frommer Wolf B
Published: June 2015

We recently described a series of genetically encoded, single-fluorophore-based sensors, termed AmTrac and MepTrac, which monitor membrane transporter activity in vivo (De Michele et al., 2013). However, being intensiometric, AmTrac and Meptrac are limited in their use for quantitative studies. Here, we characterized the photophysical properties (steady-state and time-resolved fluorescence spectroscopy as well as anisotropy decay analysis) of different AmTrac sensors with diverging fluorescence properties in order to generate improved, ratiometric sensors. By replacing key amino acid residues in AmTrac we constructed a set of dual-emission AmTrac sensors named deAmTracs. deAmTracs show opposing changes of blue and green emission with almost doubled emission ratio upon ammonium addition. The response ratio of the deAmTracs correlated with transport activity in mutants with altered capacity. Our results suggest that partial disruption of distance-dependent excited-state proton transfer is important for the successful generation of single-fluorophore-based dual-emission sensors.
Quantitative measurement of high intensity focused ultrasound pressure field by optical phase contrast method applying non-continuous phase unwrapping algorithm
Authors: Syahid Mohd , Oyama Seiji , Yasuda Jun , Yoshizawa Shin , Umemura Shin-ichiro
Published: June 2015

A fast and accurate ultrasound pressure field measurement is necessary for the progress of ultrasound application in medicine. In general, a hydrophone is used to measure the ultrasound field, which takes a long measurement time and might disturb the ultrasound field. Hence, we proposed a new method categorized in an optical method called Phase Contrast method to overcome the drawback in the hydrophone method. The proposed method makes use of the spatial DC spectrum formed in the focal plane to measure the modulated optical phase induced by ultrasound propagation in water. In this study, we take into account the decreased intensity of the DC spectrum at high ultrasound intensity to increase the measurement accuracy of the modulated optical phase. Then, we apply a non-continuous phase unwrapping algorithm to unwrap the modulated optical phase at high ultrasound intensity. From, the unwrapped result, we evaluate the quantitativeness of the proposed method.
Spatial and temporal occurrence of fin whales (Balaenoptera physalus) and euphausiids (Nyctiphanes simplex) in the Ballenas Channel, Gulf of California, Mexico
Authors: Ladrón-de-Guevara Paloma , Heckel Gisela , Lavaniegos Bertha E
Published: June 2015

Fin whales (Balaenoptera physalus) are observed year-round in the Ballenas Channel and Bahía de los Ángeles region, Gulf of California, where their main food item is the euphausiid Nyctiphanes simplex. This investigation was designed under the hypothesis that the spatial and temporal occurrence of whales and euphausiids coincides. The aim was to establish the geographic, seasonal, and interannual changes in the abundance of the fin whale and its main prey in the region during 2003 and 2004. Four field trips were carried out per year. Surveys to search for whales and carry out horizontal surface tows were conducted from small boats. Fin whales and euphausiids were mainly observed off the coast of Baja California and in the southern Ballenas Channel. Their abundance varied significantly from one season to another in both years. The highest relative abundance of whales occurred in July (warm season), followed by June (cold–warm transition period) and March–April (cold season), and the lowest in October (late warm season). Euphausiid abundance was significantly higher in June (cold–warm transition period), followed by July (warm season). There was no direct correlation between weekly abundances of both species, probably because whale peak abundance occurred four weeks later than euphausiid peak abundance. Fin whale relative abundance was significantly higher in 2004 than in 2003 (2.22 and 0.46 whales h–1, respectively), but euphausiid abundance remained almost the same (geometric means 255 and 174 ind/1000 m3). Even though there was no weekly correlation between both species, their geographic distribution did overlap.
Effect of irradiance and nitrate levels on the relationship between gross photosynthesis and electron transport rate in the seagrass Cymodocea nodosa
Authors: Cabello-Pasini Alejandro , Abdala-Díaz Roberto T , Macías-Carranza Víctor , Figueroa Félix L
Published: June 2015

The relationship between gross photosynthesis (GPS) and electron transport rate (ETR) in marine algae has been shown to vary as a function of irradiance; however, little is known about the effect of nutrients on the this relationship in seagrasses. The objective of this study was to evaluate the effect of nitrate concentration on the GPS (measured as O2 evolution) vs ETR (estimated by fluorescence quenching analysis) relationship of the seagrass Cymodocea nodosa from the Spanish Mediterranean Sea. Carbon levels in the tissue increased 6.5% when nitrate in the culture medium augmented from 0 to 100 µM. Nitrogen in the tissue, however, increased more than 60% when nitrate concentration in the medium reached 100 µM. Chlorophyll a + b levels increased approximately 30%, while absorptance augmented 15% when nitrate increased from 0 to 100 µM. In general, maximum oxygenic photosynthesis and maximum ETR values increased when nitrate in the medium increased. The relationship between GPS and ETR did not show a linear response at low nitrate levels and high irradiances. In contrast, a linear relationship was observed at nitrate levels above 50 µM, even at high irradiances. The results from this study suggest that the lack of correlation between ETR and GPS is the result of low nitrogen levels in the tissue of marine macrophytes. They also suggest that seasonal fluctuations in nitrate levels or nitrogen pulses, such as those observed during upwelling events, may affect the relationship between GPS and ETR in C. nodosa or other marine macrophytes.
Prediction of solute transport in a heterogeneous aquifer utilizing hydraulic conductivity and specific storage tomograms
Authors: Jiménez S. , Brauchler R. , Hu R. , Hu L. , Schmidt S. , Ptak T. , Bayer P.
Published: June 2015

A sequential procedure of hydraulic tomographical inversion is applied to characterize at high resolution the spatial heterogeneity of hydraulic conductivity and specific storage at the field test site Stegemühle, Germany. The shallow aquifer at this site is examined by five short‐term multilevel pumping tests with 30 pumping‐observation pairs between two wells. Utilizing travel time diagnostics of the recorded pressure response curves, fast eikonal‐based inversion is shown to deliver insight into the sedimentary structures. Thus, the structural information from the generated travel time tomogram is exploited to constrain full calibration of the pressure response curves. Based on lateral extrapolation from the measured inter‐well profile, a three‐dimensional reconstruction of the aquifer is obtained. It is demonstrated that calibration of spatially variable specific storage in addition to hydraulic conductivity can improve the fitting of the model while the structural features are only slightly changed. At the field site, two tracer tests with uranine and sodium‐naphthionate were also performed and their concentrations were monitored for 2 months. The measured tracer breakthrough curves are employed for independent validation of the hydraulic tomographical reconstruction. It is demonstrated that major features of the observed solute transport can be reproduced, and structures relevant for macrodispersive tracer spreading could be resolved. However, for the mildly heterogeneous aquifer, the tracer breakthrough curves can also be approximated by a simplified homogeneous model with higher dispersivity. Therefore, improved validation results that capture specific characteristics of the breakthrough curves would require additional hydraulic measurements.
Variations of the lithospheric strength and elastic thickness in North America
Authors: Tesauro Magdala , Kaban Mikhail K. , Mooney Walter D.
Published: June 2015

We evaluate the effect of temperature variations on strength and effective elastic thickness (Te) of the lithosphere of the North American (NA) continent. To this purpose, we use two thermal models that are corrected for compositional variations and anelasticity effects in the upper mantle. These thermal models are obtained from a joint inversion of gravity data and two recent seismic tomography models (NA07 and SL2013sv). The crustal rheology was defined using NACr14, the most recent NA crustal model. This model specifies seismic velocities and thickness for a three‐layer model of the crystalline crust. Strength in the lithosphere and in the crust has similar distributions, indicating that local geotherms play a dominant role in determining strength rather than crustal composition. A pronounced contrast is present in strength between cratonic and off‐cratonic regions. Lithospheric strength in the off‐cratonic regions is prevalently localized within the crust and Te shows low values (<20 km), while the inner part of the cratons is characterized by a strong lithosphere with large Te (>150 km). In contrast to previous results, our models indicate that Phanerozoic regions located close to the edge of the cratons, as the Appalachians, are characterized by low strength. We also find that locally weak zones exist within the cratons (e.g., beneath the intracratonic Illinois Basin and Midcontinent rift). Seismic tomography models NA07 and SL2013sv differ mainly in some peripheral parts of the cratons, as the Proterozoic Canadian Platform, the Grenville, and the western part of the Yavapai‐Mazatzal province, where the integrated strength for the model NA07 is 10 times larger than in model SL2013sv due to a temperature difference (>200°C) in the uppermost mantle. The differences in Te between the two models are less pronounced. In both models, Proterozoic regions reactivated by Meso‐Cenozoic tectonics (e.g., Rocky Mountains and the Mississippi Embayment) are characterized by a weak lithosphere due to the absence of the mechanically strong part of the mantle lithospheric layer. Intraplate earthquakes are distributed along the edges of the cratons, demonstrating that tectonic stress accumulates there, while the cores of the cratons remain undeformed. In both models, intraplate earthquakes occur in weak lithosphere (∼0.5 × 1013 Pa s, Te ∼ 15 km) or near the edges of strong cratonic blocks, characterized by pronounced contrasts of strength and Te.
Climate and agricultural land use change impacts on streamflow in the upper midwestern United States
Authors: Gupta Satish C. , Kessler Andrew C. , Brown Melinda K. , Zvomuya Francis
Published: June 2015

Increased streamflow and its associated impacts on water quality have frequently been linked to changes in land use and land cover (LULC) such as tile drainage, cultivation of prairies, and increased adoption of soybeans (Glycine max) in modern day cropping systems. This study evaluated the relative importance of changes in precipitation and LULC on streamflow in 29 Hydrologic Unit Code 008 watersheds in the upper midwestern United States. The evaluation was done by statistically testing the changes in slope and intercept of the relationships between ln(annual streamflow) versus annual precipitation for the periods prior to 1975 (prechange period) and after 1976 (postchange period). A significant shift either in slope or intercept of these relationships was assumed to be an indication of LULC changes whereas a lack of significant shift suggested a single relationship driven by precipitation. All 29 watersheds showed no statistical difference in slope or intercept of the relationships between the two periods. However, a simpler model that kept the slope constant for the two periods showed a slight upward shift in the intercept value for 10 watersheds in the postchange period. A comparison of 5 year moving averages also revealed that the increased streamflows in the postchange period are mainly due to an increase in precipitation. Minimal or the lack of LULC change impact on streamflow results from comparable evapotranspiration in the two time periods. We also show how incorrect assumptions in previously published studies minimized precipitation change impacts and heightened the LULC change impacts on streamflows.
African Political Philosophy
Authors: Metz Thaddeus
Published: June 2015

The field of African political philosophy as an academic discipline is new, with systematic argumentation expressed in a corpus of written texts having appeared for the first time only in the postwar era. “African” in this context means thought informed by the indigenous mores salient among black peoples in the sub‐Saharan region, which differ from, say, the Islamic religious practices so predominant above the Sahara desert. Although professional African political philosophy has originated only recently, it has invariably drawn on ideas and practices that have been widely held below the Sahara desert for many centuries. Much of the sub‐Saharan project of philosophizing normatively about government consists of mining intellectual resources from traditional black African peoples with an eye to seeing what might be relevant to understanding and advancing justice today.
Fanon, Frantz
Authors: Gordon Lewis
Published: June 2015

Frantz Fanon's contribution to ethics is, like that of Simone de Beauvoir, Friedrich Nietzsche, and Jean‐Paul Sartre, primarily metaethical in the form of a critique of Western moral philosophy and its relation to politics. Fanon offers, however, important critical considerations in the framework of what is today called global Southern thought and its many correlates, such as Africana (that is, African diasporic) philosophy, through his explorations of radical existential humanism. This approach has many creative twists and turns that emerge out of his efforts in what is now called decolonial thought and its complement, decolonial ethics. In Fanon, one finds the effort to decolonize not only knowledge and the organization of society, but also normative life.
Chemistry of Pyruvate Enolates: anti‐Selective Direct Aldol Reactions of Pyruvate Ester with Sugar Aldehydes Promoted by a Dinuclear Zinc Catalyst
Authors: Molenda Marta A. , Baś Sebastian , El‐Sepelgy Osama , Stefaniak Matylda , Mlynarski Jacek
Published: June 2015

A chiral dinuclear zinc complex can effectively catalyse the direct aldol reactions of pyruvic acid ester with various chiral sugar aldehydes, thus functionally mimicking the pyruvate‐dependent type II aldolases. Application of sterically hindered aryl esters allows for the elusive aldol reaction of the pyruvate donor with controlled anti‐selectivity en route to the short and efficient synthesis of 3‐deoxy‐2‐ulosonic acids. Pyruvic acid ester is here used as a chemical equivalent of phosphoenol pyruvate (PEP) in imitation of the synthetic principle used in nature. The presented biomimetic methodologies use enol formation for the highly efficient and flexible formation of various C6–C9 ulosonic acids. Particularly, efficient and concise syntheses of 3‐deoxy‐D‐erythro‐hex‐2‐ulosonic acid (KDG, overall 50% yield), 3‐deoxy‐D‐ribo‐hept‐2‐ulosonic acid (DRH, overall 53% yield) and 3‐deoxy‐D‐glycero‐D‐talo‐non‐2‐ulosonic acid (4‐epi‐KDN, overall 78% yield) are described. This direct efficient application of pyruvic esters does not require additional demasking steps and thus surpassess previously methodologies utilising masked pyruvic synthons such 2‐acetylthiazole and pyruvic aldehyde dimethyl acetal.

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Metal‐Free Oxidative Decarbonylative Coupling of Aliphatic Aldehydes with Azaarenes: Successful Minisci‐Type Alkylation of Various Heterocycles
Authors: Tang Ren‐Jin , Kang Lei , Yang Luo
Published: June 2015

A metal‐free oxidative decarbonylative coupling of aliphatic aldehydes with various electron‐deficient heterocycles has been developed. This reaction is supposed to be realized via a Minisci‐type mechanism, based on the substrate scope, regioselectivity and radical trapping experiments. The ready availability of aliphatic aldehydes, metal‐free conditions and broad substrate scope should make this method attractive for the late‐stage alkylation of bioactive heterocycles.

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Edge magnetotransport in graphene: A combined analytical and numerical study
Authors: Stegmann Thomas , Lorke Axel
Published: June 2015

The current flow along the boundary of graphene stripes in a perpendicular magnetic field is studied theoretically by the nonequilibrium Green's function method. In the case of specular reflections at the boundary, the Hall resistance shows equidistant peaks, which are due to classical cyclotron motion. When the strength of the magnetic field is increased, anomalous resistance oscillations are observed, similar to those found in a nonrelativistic 2D electron gas [New. J. Phys. 15:113047 (2013)]. Using a simplified model, which allows to solve the Dirac equation analytically, the oscillations are explained by the interference between the occupied edge states causing beatings in the Hall resistance. A rule of thumb is given for the experimental observability. Furthermore, the local current flow in graphene is affected significantly by the boundary geometry. A finite edge current flows on armchair edges, while the current on zigzag edges vanishes completely. The quantum Hall staircase can be observed in the case of diffusive boundary scattering. The number of spatially separated edge channels in the local current equals the number of occupied Landau levels. The edge channels in the local density of states are smeared out but can be made visible if only a subset of the carbon atoms is taken into account.

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Chain‐Growth Click Polymerization of AB2 Monomers for the Formation of Hyperbranched Polymers with Low Polydispersities in a One‐Pot Process
Authors: Shi Yi , Graff Robert W. , Cao Xiaosong , Wang Xiaofeng , Gao Haifeng
Published: June 2015

Hyperbranched polymers are important soft nanomaterials but robust synthetic methods with which the polymer structures can be easily controlled have rarely been reported. For the first time, we present a one‐pot one‐batch synthesis of polytriazole‐based hyperbranched polymers with both low polydispersity and a high degree of branching (DB) using a copper‐catalyzed azide–alkyne cycloaddition (CuAAC) polymerization. The use of a trifunctional AB2 monomer that contains one alkyne and two azide groups ensures that all Cu catalysts are bound to polytriazole polymers at low monomer conversion. Subsequent CuAAC polymerization displayed the features of a “living” chain‐growth mechanism with a linear increase in molecular weight with conversion and clean chain extension for repeated monomer additions. Furthermore, the triazole group in a linear (L) monomer unit complexed CuI, which catalyzed a faster reaction of the second azide group to quickly convert the L unit into a dendritic unit, producing hyperbranched polymers with DB=0.83.
Selective Photooxidation of a Mustard‐Gas Simulant Catalyzed by a Porphyrinic Metal–Organic Framework
Authors: Liu Yangyang , Howarth Ashlee J. , Hupp Joseph T. , Farha Omar K.
Published: June 2015

The photooxidation of a mustard‐gas simulant, 2‐chloroethyl ethyl sulfide (CEES), is studied using a porphyrin‐based metal–organic framework (MOF) catalyst. At room temperature and neutral pH value, singlet oxygen is generated by PCN‐222/MOF‐545 using an inexpensive and commercially available light‐emitting diode. The singlet oxygen produced by PCN‐222/MOF‐545 selectively oxidizes CEES to the comparatively nontoxic product 2‐chloroethyl ethyl sulfoxide (CEESO) without formation of the highly toxic sulfone product. In comparison to current methods, which utilize hydrogen peroxide as an oxidizing agent, this is a more realistic, convenient, and effective method for mustard‐gas detoxification.
Oxygen‐Sensing Methods in Biomedicine from the Macroscale to the Microscale
Authors: Roussakis Emmanuel , Li Zongxi , Nichols Alexander J. , Evans Conor L.
Published: June 2015

Oxygen monitoring has been a topic of exhaustive study given its central role in the biochemistry of life. The ability to quantify the physiological distribution and real‐time dynamics of oxygen from sub‐cellular to macroscopic levels is required to fully understand the mechanisms associated with both normal physiology and disease states. This Review will present the most significant recent advances in the development of oxygen‐sensing materials and techniques, including polarographic, nuclear medicine, magnetic resonance, and optical approaches, that can be applied specifically for the real‐time monitoring of oxygen dynamics in cellular and tissue environments. As some of the most exciting recent advances in synthetic methods and biomedical applications have been in the field of optical oxygen sensors, a major focus will be on the development of these toolkits.
Hydrogen Production from a Methanol–Water Solution Catalyzed by an Anionic Iridium Complex Bearing a Functional Bipyridonate Ligand under Weakly Basic Conditions
Authors: Fujita Ken‐ichi , Kawahara Ryoko , Aikawa Takuya , Yamaguchi Ryohei
Published: June 2015

An efficient catalytic system for the production of hydrogen from a methanol–water solution has been developed using a new anionic iridium complex bearing a functional bipyridonate ligand as a catalyst. This system can be operated under mild conditions [weakly basic solution (0.046 mol L−1 NaOH) below 100 °C] without the use of an additional organic solvent. Long‐term continuous hydrogen production from a methanol–water solution catalyzed by the anionic iridium complex was also achieved.
Self‐Replenishable Anti‐Waxing Organogel Materials
Authors: Yao Xi , Wu Shuwang , Chen Lie , Ju Jie , Gu Zhandong , Liu Mingjie , Wang Jianjun , Jiang Lei
Published: June 2015

Solid deposition, such as the formation of ice on outdoor facilities, the deposition of scale in water reservoirs, the sedimentation of fat, oil, and grease (FOG) in sewer systems, and the precipitation of wax in petroleum pipelines, cause a serious waste of resources and irreversible environmental pollution. Inspired by fish and pitcher plants, we present a self‐replenishable organogel material which shows ultra‐low adhesion to solidified paraffin wax and crude oil by absorption of low‐molar‐mass oil from its crude‐oil environment. Adhesion of wax on the organogel surface was over 500 times lower than adhesion to conventional material surfaces and the wax was found to slide off under the force of gravity. This design concept of a gel with decreased adhesion to wax and oil can be extended to deal with other solid deposition problems.
Patterning of conducting layers on breathable substrates using laser engraving for gas sensors
Authors: Kolodziejczyk Bartlomiej , Winther‐Jensen Orawan , Pereira Brooke A. , Nair Santhosh S. , Winther‐Jensen Bjorn
Published: June 2015

Most of the techniques used for micro and nano‐patterning currently are of high quality and reproducibility, but they require expensive equipment and involve many time‐consuming steps to achieve the desired results. We herein report a patterning method of conducting layers on breathable substrates using a fast, simple, and mask‐less laser engraving technique. A resolution in the range of 30 μm has been successfully achieved in this report. The method is fast and the pattern can be easily changed or redesigned within a few minutes. The patterning time for a 25 cm2 sample is approximately 3 minutes. In comparison, patterning a sample of the same size using photolithography requires up to 4 hours. In this manuscript, we describe the laser patterning process, how to improve the patterning resolution, the calibration steps involved as well as an application for organic electrochemical transistors as gas sensors for detecting oxygen or sulphur dioxide. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42359.
Remazol‐Catalyzed Hydroperoxyarylation of Styrenes
Authors: Chen Ying‐Ho , Lee Ming , Lin Yi‐Zhen , Leow Dasheng
Published: June 2015

A mild photocatalytic hydroperoxyarylation of styrenes has been developed, in which a novel photocatalyst, remazol brilliant blue R (RBBR), is employed at low catalytic loading (1 mol %). The operationally easy procedure uses air as the dioxygen source. Simple mono‐substituted styrenes react with aryl hydrazines in moderate‐to‐good yields. RBBR is proposed to act as a photosensitizer for the generation of singlet oxygen.
Do mothers’ and fathers’ work involvement matter for teenagers’ school outcomes?
Authors: Rokicka Magdalena
Published: June 2015

This paper addresses the issue of parental employment and hours of work and their impact on children's educational outcomes at the age of 16. I contribute to existing research by applying more accurate measures of parental time spent outside the household—using direct measures of hours spent at work and commuting, and by examining the independent effect of mothers’ and fathers’ work involvement, as well as their joint effect. Additionally, I use longitudinal datasets that allow for the examination of the impact of parental hours of work in the preceding year on the child's exam results in the following year. In contrast to previous studies, which focus on the early development of the child, I examine the parental employment while the child is preparing for a final secondary school certificate. My results show that there is a statistically significant and positive association between parental engagement in the labour market and number of final secondary school exams taken by the child. In contrast, I found that children whose parents work very long hours perform worse at the GCSE (General Certificate of Secondary Education) level. This result holds even if unobservable family characteristics are taken into account in family‐fixed effects’ and siblings’ estimations.
Studying while doing time: understanding inmates’ conceptions of learning
Authors: Rosário Pedro , Núñez José Carlos , Pereira Joana , Fuentes Sonia , Gaeta Martha , Cunha Jennifer , Polydoro Soely
Published: June 2015

Low levels of education and dropping out of school are associated with criminal involvement. The Portuguese prison system, similar to other prison systems (e.g. England), offers prison‐based educational programmes so inmates can complete compulsory education. However, the completion rate of these educational programmes is low, and the dropout rate is high. Deepening our understanding of how inmates conceptualise learning and how they engage in learning will improve the quality of the prison‐based educational services and promote school enrolment. Data from a phenomenographic study of 30 Portuguese inmate students, ranging from 20 to 58 years of age, revealed an understanding of learning focused on the instrumental role of knowledge and its application in the short‐term (e.g. learning how to read) and on integration in the prison system (e.g. learning how to play draughts to fit in the yard). Moreover, a broader understanding of learning that reflected particular forms of learning favoured within the prison context also emerged in the discourse. For example, learning was described as an opportunity to reflect upon their previous offence and behaviours and on the need to avoid violence. Participants also stressed the importance of setting an academic example for their children by engaging actively in learning and the significance of occupying one's time in prison in a positive and beneficial manner. Findings allow a first approach to prison students’ involvement in school learning by listening to the inmates’ opinions and thoughts, and they offer promising suggestions to improve the organisation of prison‐based educational programmes.
Vancomycin and maltodextrin affect structure and activity of Staphylococcus aureus biofilms
Authors: Kiamco Mia Mae , Atci Erhan , Khan Qaiser Farid , Mohamed Abdelrhman , Renslow Ryan S. , Abu‐Lail Nehal , Fransson Boel A. , Call Douglas R. , Beyenal Haluk
Published: June 2015

Hyperosmotic agents such as maltodextrin negatively impact bacterial growth through osmotic stress without contributing to drug resistance. We hypothesized that a combination of maltodextrin (osmotic agent) and vancomycin (antibiotic) would be more effective against Staphylococcus aureus biofilms than either alone. To test our hypothesis, S. aureus was grown in a flat plate flow cell reactor. Confocal laser scanning microscopy images were analyzed to quantify changes in biofilm structure. We used dissolved oxygen microelectrodes to quantify how vancomycin and maltodextrin affected the respiration rate and oxygen penetration into the biofilm. We found that treatment with vancomycin or maltodextrin altered biofilm structure. The effect on the structure was significant when they were used simultaneously to treat S. aureus biofilms. In addition, vancomycin treatment increased the oxygen respiration rate, while maltodextrin treatment caused an increase and then a decrease. An increased maltodextrin concentration decreased the diffusivity of the antibiotic. Overall, we conclude that (1) an increased maltodextrin concentration decreases vancomycin diffusion but increases the osmotic effect, leading to the optimum treatment condition, and (2) the combination of vancomycin and maltodextrin is more effective against S. aureus biofilms than either alone. Vancomycin and maltodextrin act together to increase the effectiveness of treatment against S. aureus biofilm growth. Biotechnol. Bioeng. 2015;112: 2562–2570. © 2015 Wiley Periodicals, Inc.
New 3,4‐Secocycloartane and 3,4‐Secodammarane Triterpenes from the Ecuadorian Plant Coussarea macrophylla
Authors: Gilardoni Gianluca , Chiriboga Ximena , Vita Finzi Paola , Vidari Giovanni
Published: June 2015

Coussarea macrophylla (Mart.) Müll.Arg. (Rubiaceae) was collected in Ecuador, and the bark was extracted with AcOEt. Chromatographic separation afforded six novel 3,4‐secocycloartane and 3,4‐secodammarane triterpenes, named macrocoussaric acids A–F, together with the known metabolites secaubryenol and 3,4‐secodammara‐4(28),20,24‐triene‐3,26‐dioic acid. The structures of the new compounds were determined on the basis of their spectroscopic data. This is the first report of 3,4‐secocycloartane and 3,4‐secodammarane triterpenes occurring in a Coussarea species. Macrocoussaric acids A and B (2 and 3, resp.) were found to be moderately cytotoxic against five different tumor cell lines.
Contact Toxicity and Repellency of the Essential Oil of Dictamnus dasycarpus Roots from China against Two Stored‐Product Insects
Authors: Yang Kai , Guo Shan‐Shan , Geng Zhu‐Feng , Du Shu‐Shan , Wang Cheng‐Fang , Deng Zhi‐Wei
Published: June 2015

During our screening program for new agrochemicals from traditional medicinal herbs, Dictamnus dasycarpus was found to possess contact toxicity and repellent activity against the cigarette beetle Lasioderma serricorne and the booklouse Liposcelis bostrychophila. The essential oil obtained by hydrodistillation of D. dasycarpus roots was characterized by GC‐FID and GC/MS analyses, and the main components identified were syn‐7‐hydroxy‐7‐anisylnorbornene (1, 49.9%), 1,3,4,5,6,7‐hexahydro‐2H‐inden‐2‐one (2, 11.6%), 5,6‐diethenyl‐1‐methylcyclohexene (3, 7.4%), and 3,9‐dimethyltricyclo[4.2.1.12,5]dec‐3‐en‐9‐ol (4, 6.35%). The D. dasycarpus root oil exhibited strong contact toxicity against L. serricorne adults and L. bostrychophila, with LD50 values of 12.4 μg/adult and 27.2 μg/cm2, respectively. Moreover, the essential oil also showed strong repellency against both stored‐product insects tested.
Botanical, Phytochemical, and Anticancer Properties of the Eucalyptus Species
Authors: Vuong Quan V. , Chalmers Anita C. , Jyoti Bhuyan Deep , Bowyer Michael C. , Scarlett Christopher J.
Published: June 2015

The genus Eucalyptus (Myrtaceae) is mainly native to Australia; however, some species are now distributed globally. Eucalyptus has been used in indigenous Australian medicines for the treatment of a range of aliments including colds, flu, fever, muscular aches, sores, internal pains, and inflammation. Eucalyptus oils containing volatile compounds have been widely used in the pharmaceutical and cosmetics industries for a multitude of purposes. In addition, Eucalyptus extracts containing nonvolatile compounds are also an important source of key bioactive compounds, and several studies have linked Eucalyptus extracts with anticancer properties. With the increasing research interest in Eucalyptus and its health properties, this review briefly outlines the botanical features of Eucalyptus, discusses its traditional use as medicine, and comprehensively reviews its phytochemical and anticancer properties and, finally, proposes trends for future studies.
Synthesis of Al‐Containing Spherical Mesocellular Silica Foams with Different Pore Sizes and Their Applications as Catalyst Supports for Hydrodesulfurization of Dibenzothiophene
Authors: Zhou Xiaofeng , Song Shaotong , Duan Aijun , Zhao Zhen , Gong Yanjun , Wang Xilong , Li Jianmei , Wei Yuechang , Jiang Guiyuan , Liu Jian
Published: June 2015

In the present work, a series of Al‐containing spherical mesostructured cellular silica foams (SMCFs) with different ultra‐large pore sizes were successfully synthesized by simply adjusting the mass ratio (x) of the swelling agent 1,3,5‐trimethylbenzene (TMB) to P123. The as‐synthesized Al‐SMCFs‐x were utilized as NiMo catalyst supports for the hydrodesulfurization of dibenzothiophene. The characterization results showed that, compared with other studied NiMo/Al‐SMCFs‐x catalysts, the NiMo/Al‐SMCFs‐1.25 catalyst exhibited higher sulfidation degree, higher dispersions of Ni and Mo species, shorter length, and lower stacking number of MoS2 slabs. It was also found that the NiMo/Al‐SMCFs‐1.25 catalyst possessed suitable physicochemical parameters [i.e., ultra‐large pore size (27.5 nm), high surface area (383 m2 g−1), and large pore volume (1.34 cm3 g−1), resulting in the formation of more type II active sites with more brim active sites. Consequently, the NiMo/Al‐SMCFs‐1.25 catalyst displayed outstanding catalytic performance for the hydrodesulfurization of dibenzothiophene.
Lithium Depletion and the Rechargeability of Li–O2 Batteries in Ether and Carbonate Electrolytes
Authors: Jang Il‐Chan , Ida Shintaro , Ishihara Tatsumi
Published: June 2015

Li metal is a highly promising candidate anode material because of its high energy density. However, Li depletion caused by the formation of a passivation layer and dendrites prevent the use of Li metal for rechargeable batteries. In this study, we investigate Li depletion in practical Li–O2 batteries by using two typical electrolytes, carbonate and ether, under high Li utilization. The ether‐based solvent tetraethylene glycol dimethyl ether (TEGDME) showed greatly increased levels of Li depletion through the formation of both solid electrolyte interphase (SEI) layers and dendrites than carbonated‐based solvents (ethylene carbonate/diethyl carbonate (EC/DEC)). Although TEGDME is known as a stable solvent for oxygen reduction species, it may be less appropriate as a solvent with respect to Li reactivity, which is very important for the cycle stability of Li–O2 battery systems. In contrast, although slight decomposition of EC‐DEC was observed, cells constructed with EC‐DEC were found to be more stable than those with TEGDME for Li–O2 batteries.
A Modular Approach To Study Protein Adsorption on Surface Modified Hydroxyapatite
Authors: Ozhukil Kollath Vinayaraj , Van den Broeck Freya , Fehér Krisztina , Martins José C. , Luyten Jan , Traina Karl , Mullens Steven , Cloots Rudi
Published: June 2015

Biocompatible inorganic nano‐ and microcarriers can be suitable candidates for protein delivery. This study demonstrates facile methods of functionalization by using nanoscale linker molecules to change the protein adsorption capacity of hydroxyapatite (HA) powder. The adsorption capacity of bovine serum albumin as a model protein has been studied with respect to the surface modifications. The selected linker molecules (lysine, arginine, and phosphoserine) can influence the adsorption capacity by changing the electrostatic nature of the HA surface. Qualitative and quantitative analyses of linker‐molecule interactions with the HA surface have been performed by using NMR spectroscopy, zeta‐potential measurements, X‐ray photoelectron spectroscopy, and thermogravimetric analyses. Additionally, correlations to theoretical isotherm models have been calculated with respect to Langmuir and Freundlich isotherms. Lysine and arginine increased the protein adsorption, whereas phosphoserine reduced the protein adsorption. The results show that the adsorption capacity can be controlled with different functionalization, depending on the protein–carrier selections under consideration. The scientific knowledge acquired from this study can be applied in various biotechnological applications that involve biomolecule–inorganic material interfaces.
Dynamic Formation of Noncovalent Calixsalen Aggregates
Authors: Petryk Małgorzata , Troć Anna , Gierczyk Błażej , Danikiewicz Witold , Kwit Marcin
Published: June 2015

A procedure for studying “dynamic structural behavior” of large chiral macrocycles is presented. Ion mobility MS, diffusion‐ordered NMR spectroscopy (DOSY NMR), and optical rotation (OR) measurements, supported by calculations, are used together as effective complementary methods to study dynamic formation of noncovalent aggregates. It is shown that the monomer–dimer equilibrium is driven by π–π or CH–π interactions and controlled largely by the substitution pattern of the calixsalen skeleton.
A Combined IM‐MS/DFT Study on [Pd(MPAA)]‐Catalyzed Enantioselective CH Activation: Relay of Chirality through a Rigid Framework
Authors: Cheng Gui‐Juan , Chen Ping , Sun Tian‐Yu , Zhang Xinhao , Yu Jin‐Quan , Wu Yun‐Dong
Published: June 2015

A combined ion‐mobility mass spectrometry (IM‐MS) and DFT study has been employed to investigate the mechanism and the origin of selectivity of palladium/mono‐N‐protected amino acid (MPAA)‐catalyzed enantioselective CH activation reactions of several prochiral substrates. We captured the [Pd(MPAA)(substrate)] complex at different stages, and demonstrated that the CH bond can be activated in the absence of an external base. DFT studies lead to the establishment of a significantly modified relay mechanism invoking a key conformational effect to account for the origin of enantioselectivity. This relay mechanism successfully accounts for the enantioselectivity for all the relevant reactions reported. The enantioselectivity originates from the rigid square‐planar Pd coordination in the CH activation transition state: Bidentate MPAA and substrate coordination.
From Polymer to Monomer: Cleavage and Rearrangement of Si‐O‐Si Bonds after Oxidation Yielded an Ordered Cyclic Crystallized Structure
Authors: Zuo Yujing , Gou Zhiming , Cao Jinfeng , Yang Zhou , Lu Haifeng , Feng Shengyu
Published: June 2015

Polymerization reactions are very common in the chemical industry, however, the reaction in which monomers are obtained from polymers is rarely invesitgated. This work reveals for the first time that oxone can break the Si‐O‐Si bond and induce further rearrangement to yield an ordered cyclic structure. The oxidation of P1, which is obtained by reaction of 2,2′‐1,2‐ethanediylbis(oxy)bis(ethanethiol) (DBOET) with 1,3‐divinyl‐1,1,3,3‐tetramethyldisiloxane (MMVi), with oxone yielded cyclic crystallized sulfone–siloxane dimer (P1‐ox) after unexpected cleavage and rearrangement of the Si‐O‐Si bond.
Modeling the HCOOH/CO2 Electrocatalytic Reaction: When Details Are Key
Authors: Steinmann Stephan N. , Michel Carine , Schwiedernoch Renate , Filhol Jean‐Sebastien , Sautet Philippe
Published: June 2015

Our first principles simulations of the electrooxidation of formic acid over nickel identify the reorientation of the formate intermediate and the desorption of CO2 as the rate‐limiting steps. Although they are not associated with an electron transfer, these barriers are strongly modified when the electrochemical potential is explicitly accounted for and when modeling the influence of the solvent. Hence, such a level of modeling is key to understand the kinetic limitations that penalize the reaction.
Use of the conditional marketing authorization pathway for oncology medicines in Europe
Authors: Hoekman J , Boon WPC , Bouvy JC , Ebbers HC , de Jong JP , De Bruin ML
Published: June 2015

Conditional marketing authorization (CMA) in the European Union (EU) is an early access pathway for medicines that show promising therapeutic effects, but for which comprehensive data are not available. Using a mixed quantitative‐qualitative research design, we evaluated how CMA has been used in marketing authorization of oncology medicines in the period 2006 to 2013. We show that compared to full marketing authorization, CMA is granted based on less comprehensive data. However, this is accompanied by significantly longer assessment times and less consensus among regulators about marketing authorization. Moreover, development time from first‐in‐human testing to marketing authorization did not differ between full marketing authorization and CMA, but was significantly longer for CMA compared to accelerated approved products in the United States (US). Results indicate that CMA is not used by companies as a prospectively planned pathway to obtain early access, but as a “rescue option” when submitted data are not strong enough to justify full marketing authorization.
Low‐Temperature Synthesis of Hierarchical Amorphous Basic Nickel Carbonate Particles for Water Oxidation Catalysis
Authors: Yang Yisu , Liang Fengli , Li Mengran , Rufford Thomas E. , Zhou Wei , Zhu Zhonghua
Published: June 2015

Amorphous nickel carbonate particles are catalysts for the oxygen evolution reaction (OER), which plays a critical role in the electrochemical splitting of water. The amorphous nickel carbonate particles can be prepared at a temperature as low as 60 °C by an evaporation‐induced precipitation (EIP) method. The products feature hierarchical pore structures. The mass‐normalized activity of the catalysts, measured at an overpotential of 0.35 V, was 55.1 A g−1, with a Tafel slope of only 60 mV dec−1. This catalytic activity is superior to the performance of crystalline NiOx particles and β‐Ni(OH)2 particles, and compares favorably to state‐of‐the‐art RuO2 catalysts. The activity of the amorphous nickel carbonate is remarkably stable during a 10 000 s chronoamperometry test. Further optimization of synthesis parameters reveals that the amorphous structure can be tuned by adjusting the H2O/Ni ratio in the precursor mixture. These results suggest the potential application of easily prepared hierarchical basic nickel carbonate particles as cheap and robust OER catalysts with high activity.