bluuebunny/crossref_metadata_2025 huggingface dataset:
Alluvial plain dynamics in the southern Amazonian foreland basin
Authors: Lombardo U.
Published: October 2015

Abstract. Alluvial plains are formed with sediments that rivers deposit on the adjacent flood-basin, mainly through crevasse splays and avulsions. These result from a combination of processes, some of which push the river towards the crevasse threshold, while others act as triggers. Based on the floodplain sedimentation patterns of large rivers in the southern Amazonian foreland basin, it has been suggested that alluvial plain sediment accumulation is primarily the result of river crevasse splays triggered by above normal precipitation events due to La Niña. However, more than 90 % of the Amazonian river network is made of small rivers and it is unknown whether small river floodplain sedimentation is influenced by the ENSO cycle as well. Using Landsat images from 1984 to 2014, here I analyse the behaviour of all the twelve tributaries of the Río Mamoré with a catchment in the Andes. I show that these are very active rivers and that the frequency of crevasses is not linked to ENSO activity. I found that most of the sediments eroded from the Andes by the tributaries of the Mamoré are deposited in the alluvial plains, before reaching the parent river. The mid- to late Holocene paleo-channels of these rivers are located tens of kilometres further away from the Andes than the modern crevasses. I conclude that the frequency of crevasses is controlled by intrabasinal processes that act on a year to decade time scale, while the average location of the crevasses is controlled by climatic or neo-tectonic events that act on a millennial scale. Finally, I discuss the implications of river dynamics on rural livelihoods and biodiversity in the Llanos de Moxos, a seasonally flooded savannah covering most of the southern Amazonian foreland basin and the world's largest RAMSAR site.
3-D radiative transfer in large-eddy simulations – experiences coupling the TenStream solver to the UCLA–LES
Authors: Jakub F. , Mayer B.
Published: October 2015

Abstract. The recently developed three-dimensional TenStream radiative transfer solver was integrated into the UCLA–LES cloud resolving model. This work documents the overall performance of the TenStream solver as well as the technical challenges migrating from 1-D schemes to 3-D schemes. In particular the employed Monte-Carlo-Spectral-Integration needed to be re-examined in conjunction with 3-D radiative transfer. Despite the fact that the spectral sampling has to be performed uniformly over the whole domain, we find that the Monte-Carlo-Spectral-Integration remains valid. To understand the performance characteristics of the coupled TenStream solver, we conducted weak- as well as strong-scaling experiments. In this context, we investigate two matrix-preconditioner (GAMG and block-jacobi ILU) and find that algebraic multigrid preconditioning performs well for complex scenes and highly parallelized simulations. The TenStream solver is tested for up to 4096 cores and shows a parallel scaling efficiency of 80–90 % on various supercomputers. Compared to the widely employed 1-D δ-Eddington two-stream solver, the computational costs for the radiative transfer solver alone increases by a factor of five to ten.
The Occult Urothelial Cancer
Authors: Ragonese Mauro , Racioppi Marco , D'Agostino Daniele , Di Gianfrancesco Luca , Lenci Niccolò , Bientinesi Riccardo , Palermo Giuseppe , Sacco Emilio , Pinto Francesco , Bassi Pier Francesco
Published: October 2015

Transitional cell carcinoma (TCC) is the tumor that most frequently affects the urinary tract. The most common location is in the bladder; the diagnosis, as the follow-up, is based on urine cytology, endoscopic, and radiological examinations. Urinary cytology is an important non invasive tool used in the diagnosis and follow-up of patients with TCC. A positive urine cytology result is highly predictive of the presence of TCC, even in the presence of normal cystoscopy, because malignant cells may appear in the urine long time before any cystoscopically visible lesion becomes apparent. The presence of a positive urinary cytology, in the absence of clinical or endoscopic evidence of a TCC, can identify an occult urothelial cancer, located in any site of the urinary tract (upper urinary tract, bladder, prostatic urethra). Most of the urothelial tumors of the renal pelvis and ureters are diagnosed by radiological examinations, but we can observe a high rate of false negatives. In order to improve the diagnostic role of urinary cytology and other conventional examinations, numerous molecular markers have been identified; however, the real clinical application remains unclear. Photodynamic diagnosis and narrow band imaging (NBI) cystoscopy increase the diagnostic accuracy of endoscopic examinations in the presence of lesions not easily detectable. The aim of this review is to analyze the current diagnostic standards in the presence of occult urothelial cancer.
To Flip or Not to Flip: The Challenges and Benefits of Using Flipped Classroom in Geography Lessons in Brunei Darussalam
Authors: Nawi Naafi'ah , Jawawi Rosmawijah , Matzin Rohani , Jaidin Jainatul Halida , Shahrill Masitah , Mundia Lawrence
Published: October 2015

This study examined the use of flipped classroom in geography lessons in one of the pre-university colleges in Brunei Darussalam. The benefits and challenges of using the flipped classroom as a pedagogical tool in geography were also investigated. Data were collected through action research adopting the use of a flipped classroom approach. This meant that learning geography as subject content was done outside the classroom. The findings of this study revealed that it was not necessary to apply flipped classroom for every lessons. Yet, this study found that flipped classroom was most beneficial when students worked on the application of geographical concepts where they learned to analyse and evaluate given scenarios. A significant improvement in the students’ academic achievement was also observed where through the interactive classroom activities, students developed a deeper understanding of the subject concepts. On the other hand, there were challenges in conducting a flipped classroom, for instance, some students had problems in accessing the lessons outside the classroom. This was one of the crucial elements conveyed in order to successfully implement a flipped classroom and to create an active learning environment during the class time. Without learning the concepts before the class time, the students reported the feeling of being lost, and thus could not fully participate in the classroom activities. Furthermore, a significant amount of time was wasted during the class time in teaching the students the concepts since they were supposed to have learned them prior to the lesson itself. Finally, the flipped classroom was also found to be a challenge to implement in a classroom known to have a passive learning environment.
Vidding: Remix as Affective Media Literacy
Authors: Stein Louisa Ellen
Published: October 2015

This essay explores the relationship between contemporary remix culture and inherited traditions of fan authorship: more specifically, fan-created music videos or “vids” and the practice of vidding. Through the individual and collective process of vidding, fans showcase their own media literacy, educate their viewers about how to read media, and demonstrate how to engage with and speak back to media and culture. Vids model an affective transmedia literacy, a mode of reading that is simultaneously investigative, critical, and engaged.
Regard intermédial sur le devenir numérique des archives
Authors: Besson Rémy
Published: October 2015

À travers l’étude d’un cas, le fonds de la troupe de théâtre yiddish Dora Wasserman, cet article porte sur la manière dont le numérique transforme les processus d’archivage et constitue un « contrepoint » au dossier thématique « Archiver/Archiving » paru dans Intermédialités no 18. La numérisation, phénomène d’abord technique, est appréhendée en plaçant au centre du questionnement les gestes archivistiques à la fois des personnes ayant manipulé les documents, de ceux qui les ont mis en archive et de ceux qui mettent en ligne ces traces du passé. Il s’agit de déterminer dans quelle mesure une forme d’archivage intermédiale peut permettre de rendre compte de l’imbrication entre ces trois gestes créateurs.
The development of Negative Self-Beliefs Inventory (NSBI): cultural adaptation and psychometric validation
Authors: Tang Xiaoqing , Duan Wenjie , Wang Ying , Guo Pengfei
Published: October 2015

Social anxiety is an emotional disorder common to various populations around the world. The newly developed Self-Beliefs Related to Social Anxiety Scale (SBSA) aims to assess three kinds of self-beliefs through 15 items that include self-related cognitive factors that evidently result in social anxiety. This study explored the psychometric characteristics of SBSA among 978 Chinese. An eight-item Negative Self-beliefs Inventory (NSBI) was developed through qualitative and quantitative analyses. Exploratory factor analysis, confirmatory factor analysis, and multi-group confirmatory factor analysis suggested that NSBI contained clear, meaningful, stable, and invariant three-factor structure consistent with the original SBSA. Further analyses showed that the three subscales and the entire scale exhibited high internal consistency (0.779–0.837), good criterion validity, and good convergent and divergent validity (i.e., negative associations with flourishing and positive associations with anxiety, depression, and stress). These findings indicated that NSBI is reliable and valid for measuring negative self-beliefs in the Chinese population. A higher total score of NSBI indicates the more serious negative self-beliefs. Limitations of the present study and implications for research and practice were also discussed. Further studies are needed to evaluate the predictive ability, incremental validity, and potential role of NSBI in clinical and large-scale populations.
Using Art to Tell Stories and Build Safe Spaces: Transforming Academic Research Into Action
Authors: Karabanow Jeff , Naylor Ted
Published: October 2015

This paper explores how art can be used to tell stories and actively build safe spaces, and grew out of reflections from a capacity-building and knowledge translation/mobilization project involving 7 young people living on the streets. The paper considers how research can contribute to an examination of anti-oppressive practice and methodology, and an application of it in the field through an arts-based agenda. Conceptually, the paper takes up the postmodern turn in methodological considerations by exploring how the “spectacle” of a research agenda can come to be undone by a more participatory research process. This paper speaks to the processes involved in creating an arts-based environment and, ultimately, the building of a community space for sharing, for reflection, and for mobilization—storytelling not only as a form of art, but as a critical methodology.
Very low frequency radio events with a reduced intensity observed by the low‐altitude DEMETER spacecraft
Authors: Záhlava J. , Němec F. , Santolík O. , Kolmašová I. , Parrot M. , Rodger C. J.
Published: October 2015

We present results of a systematic study of unusual very low frequency (VLF) radio events with a reduced intensity observed in the frequency‐time spectrograms measured by the low‐orbiting Detection of Electro‐Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) spacecraft. They occur exclusively on the nightside. During these events, the intensity of fractional hop whistlers at specific frequencies is significantly reduced. These frequencies are usually above about 3.4 kHz (second Earth‐ionosphere waveguide cutoff frequency), but about 20% of events extend down to about 1.7 kHz (first Earth‐ionosphere waveguide cutoff frequency). The frequencies of a reduced intensity vary smoothly with time. We have inspected 6.5 years of DEMETER data, and we identified in total 1601 such events. We present a simple model of the event formation based on the wave propagation in the Earth‐ionosphere waveguide. We apply the model to two selected events, and we demonstrate that the model is able to reproduce both the minimum frequencies of the events and their approximate frequency‐time shapes. The overall geographic distribution of the events is shifted by about 3000 km westward and slightly southward with respect to the areas with high long‐term average lightning activity. We demonstrate that this shift is related to the specific DEMETER orbit, and we suggest its qualitative explanation by the east‐west asymmetry of the wave propagation in the Earth‐ionosphere waveguide.
A Stereocontrolled Synthesis of the C11‐C24 Fragment of Inostamycin A via the Desymmetrization of Glycerols
Authors: Yu Guangri , Jung Byunghyuck , Lim Seolhee , Lee Hee‐Seung , Kang Sung Ho
Published: October 2015

A robust and reproducible route has been developed for the synthesis of the C11‐C24 fragment of inostamycin A. Whilst the core scaffold of this compound was constructed via a series of addition reactions and an aldol condensation, the stereogenic centers were installed via a series of complex reactions involving a diastereoselective desymmetrization for the two quaternary carbons at C16 and C20, a crotylation for the carbons at C17 and C18, an aldol condensation for the carbons at C12 and C13, an allylation for the carbon at C21, and a chiral building block for the installation of the carbon at C14. All of these steps proceeded with high yield and stereoselectivity, and were also scalable.
Macronutrient balancing affects patch departure by guerezas (Colobus guereza)
Authors: Johnson Caley A. , Raubenheimer David , Chapman Colin A. , Tombak Kaia J. , Reid Andrea J. , Rothman Jessica M.
Published: October 2015

Foraging strategies are central in shaping social structure and grouping patterns in primates. We address Colobus guereza foraging strategies by investigating their patch departure decisions in relation to diet composition and nutrition. We examine whether guerezas are constrained in their intake of food in patches and thereby forage according to a fixed amount strategy that dictates patch departure. Additionally, we assess whether guereza employ a fixed time strategy or attempt to balance nutrients when foraging. We measured food patch occupancy time, intake rates, and analyzed foods for macronutrients, fiber, and condensed tannins. We determined that guerezas do not employ a fixed time foraging strategy; patch residence time varied widely between 1 and 290 min. They also did not depart patches or stop eating when they reached a specific intake of dry mass, macronutrients, or condensed tannins. However, guerezas maintained a macronutrient balance when feeding across patches, and the balance of protein to non‐protein energy (fats and carbohydrates) in patches is the best indicator of time adult guerezas spent feeding in patches. Previous studies have shown that the protein‐to‐fiber ratio is important in predicting food selection for folivores and their biomass; however, we found that guerezas did not maximize protein and minimize fiber intake while foraging in patches, nor did they stay longer in patches with the highest ratio of protein to fiber concentrations. This study raises questions about the nutritional and social implications of patch depletion as a foraging strategy in folivorous monkeys where food limitation predicts competitive and social regimes. Am. J. Primatol. 79:e22495, 2017. © 2015 Wiley Periodicals, Inc.
Structural evolution of recycled tire rubber in asphalt
Authors: Yao Hongru , Zhou Shuai , Wang Shifeng
Published: October 2015

The performance of recycled‐tire‐rubber‐modified asphalt mainly depends on the structure of rubber in the asphalt. The effects of the curing temperature, mixing time, and shearing on the evolution of the chemical structure and morphological structure of crumb rubber in asphalt were investigated. The crosslink density, compositions, and morphological evolution of the residual crumb rubber were characterized. The results show that the structure evolution of tire rubber in asphalt was greatly affected by the curing temperature. At a low curing temperature (180°C), the crosslinking network of the tire rubber was broken down, and this led to the partial dissolution of natural rubber (NR). However, at high curing temperature (240°C), the dissolution of NR, synthetic rubber, carbon black, and inorganic filler was observed. The released carbon black covered with a thin layer of bound rubber dispersed at a microstructured or nanostructured size in the asphalt. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42954.
Site‐Specific Zwitterionic Polymer Conjugates of a Protein Have Long Plasma Circulation
Authors: Bhattacharjee Somnath , Liu Wenge , Wang Wei‐Han , Weitzhandler Isaac , Li Xinghai , Qi Yizhi , Liu Jinyao , Pang Yan , Hunt Donald F. , Chilkoti Ashutosh
Published: October 2015

Many proteins suffer from suboptimal pharmacokinetics (PK) that limit their utility as drugs. The efficient synthesis of polymer conjugates of protein drugs with tunable PK to optimize their in vivo efficacy is hence critical. We report here the first study of the in vivo behavior of a site‐specific conjugate of a zwitterionic polymer and a protein. To synthesize the conjugate, we first installed an initiator for atom‐transfer radical polymerization (ATRP) at the N terminus of myoglobin (Mb‐N‐Br). Subsequently, in situ ATRP was carried out in aqueous buffer to grow an amine‐functionalized polymer from Mb‐N‐Br. The cationic polymer was further derivatized to two zwitterionic polymers by treating the amine groups of the cationic polymer with iodoacetic acid to obtain poly(carboxybetaine methacrylate) with a one‐carbon spacer (PCBMA; C1), and sequentially with 3‐iodopropionic acid and iodoacetic acid to obtain PCBMA(mix) with a mixture of C1 and C2 spacers. The Mb‐N‐PCBMA polymer conjugates had a longer in vivo plasma half‐life than a PEG‐like comb polymer conjugate of similar molecular weights (MW). The structure of the zwitterion plays a role in controlling the in vivo behavior of the conjugate, as the PCBMA conjugate with a C1 spacer had significantly longer plasma circulation than the conjugate with a mixture of C1 and C2 spacers.
Project WINGS (Women Initiating New Goals of Safety): A randomised controlled trial of a screening, brief intervention and referral to treatment (SBIRT) service to identify and address intimate partner violence victimisation among substance‐using women receiving community supervision
Authors: Gilbert Louisa , Shaw Stacey A. , Goddard‐Eckrich Dawn , Chang Mingway , Rowe Jessica , McCrimmon Tara , Almonte Maria , Goodwin Sharun , Epperson Matthew
Published: October 2015

Background

The high rate of intimate partner violence (IPV) victimisation found among substance‐using women receiving community supervision underscores the need for effective IPV victimisation screening, brief intervention and referral to treatment services (SBIRT) for this population.

Aims

This randomised controlled trial (RCT) aims to assess the feasibility, safety and efficacy of a single‐session computerised self‐paced IPV SBIRT (Computerised WINGS) in identifying IPV victimisation among women under community supervision and increasing access to IPV services, compared to the same IPV SBIRT service delivered by a case manager (Case Manager WINGS).

Methods

This RCT was conducted with 191 substance‐using women in probation and community court sites in New York City.

Results

No significant differences were found between Computerised and Case Manager WINGS arms on any outcomes. Both arms reported identical high rates of any physical, sexual or psychological IPV victimisation in the past year (77% for both arms) during the intervention. Both arms experienced significant increases from baseline to the 3‐month follow‐up in receipt of IPV services, social support, IPV self‐efficacy and abstinence from drug use.

Conclusions

Findings suggest that both modalities of WINGS show promise in identifying and addressing IPV victimisation among substance‐using women receiving community supervision.Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
Comment on “The Nature of the Fourth Bond in the Ground State of C2: The Quadruple Bond Conundrum”
Authors: Grunenberg Jörg
Published: October 2015

Is it time to reconsider the whole concept of quadruple bonding? Contrary to the conclusion of Shaik and co‐workers in Chem. Eur. J.­ 2014, 20, 6220–6232, there is no “deviation of C2 from the Badger Rule”.
Normal‐to‐Abnormal NHC Rearrangement of AlIII, GaIII, and InIII Trialkyl Complexes: Scope, Mechanism, Reactivity Studies, and H2 Activation
Authors: Schnee Gilles , Nieto Faza Olalla , Specklin David , Jacques Béatrice , Karmazin Lydia , Welter Richard , Silva López Carlos , Dagorne Samuel
Published: October 2015

The present contribution reports experimental and theoretical mechanistic investigations on a normal‐to‐abnormal (C2‐to‐C4‐bonded) NHC rearrangement processes occurring with bulky group 13 metal NHC adducts, including the scope of such a reactivity for Al compounds. The sterically congested adducts (nItBu)MMe3 (nItBu=1,3‐di‐tert‐butylimidazol‐2‐ylidene; M=Al, Ga, In; 1 a–c) readily rearrange to quantitatively afford the corresponding C4‐bonded complexes (aItBu)MMe3 (4 a–c), a reaction that may be promoted by THF. Thorough experimental data and DFT calculations were performed on the nNHC‐to‐aNHC process converting the Al‐nNHC (1 a) to its aNHC analogue 4 a. A nItBu/aItBu isomerization is proposed to account for the formation of the thermodynamic product 4 a through reaction of transient aItBu with THF–AlMe3. The reaction of benzophenone with (nItBu)AlMe3 afforded the zwitterionic species (aItBu)(CPh2‐O‐AlMe3) (6), reflecting the unusual reactivity that such bulky adducts may display. Interestingly, the nItBu/Al(iBu)3 Lewis pair behaves like a frustrated Lewis pair (FLP) since it readily reacts with H2 under mild conditions. This may open the way to future reactivity developments involving commonly used trialkylaluminum precursors.
Facile Alder‐Ene Reactions of Silylallenes Involving an Allenic C(sp2)H Bond
Authors: Sabbasani Venkata R. , Huang Genping , Xia Yuanzhi , Lee Daesung
Published: October 2015

Facile and selective Alder‐ene reactions of silylallenes involving the activation of an allenic C(sp2)H over an allylic C(sp3)H bond is described. In this ene reaction, the presence of a silyl substituent was found to be critical for the observed reactivity and selectivity since the corresponding alkyl‐substituted allenes show different reaction profiles. Computational studies show that the origin of this unusual reactivity is the lower bond dissociation energy of the α‐C(sp2)H bond in silylallenes compared to the corresponding nonsilylated allenes.
Quinine‐Based Zwitterionic Chiral Stationary Phase as a Complementary Tool for Peptide Analysis: Mobile Phase Effects on Enantio‐ and Stereoselectivity of Underivatized Oligopeptides
Authors: Ianni Federica , Sardella Roccaldo , Carotti Andrea , Natalini Benedetto , Lindner Wolfgang , Lämmerhofer Michael
Published: October 2015

Peptide stereoisomer analysis is of importance for quality control of therapeutic peptides, the analysis of stereochemical integrity of bioactive peptides in food, and the elucidation of the stereochemistry of peptides from a natural chiral pool which often contains one or more D‐amino acid residues. In this work, a series of model peptide stereoisomers (enantiomers and diastereomers) were analyzed on a zwitterionic ion‐exchanger chiral stationary phase (Chiralpak ZWIX(+) 5 µm), in order to investigate the retention and separation performance for such compounds on this chiral stationary phase and elucidate its utility for this purpose. The goal of the study focused on 1) investigations of the effects of the sample matrix used to dissolve the peptide samples; 2) optimization of the mobile phase (enabling deriving information on factors of relevance for retention and separation); and 3) derivation of structure–selectivity relationships. It turned out that small di‐ and tripeptides can be well resolved under optimized conditions, typically with resolutions larger than 1.5. The optimized mobile phase often consisted of methanol–tetrahydrofuran–water (49:49:2; v/v/v) with 25 mM formic acid and 12.5 mM diethylamine. This work proposes some guidance on which mobile phases can be most efficiently used for peptide stereoisomer separations on Chiralpak ZWIX. Chirality 28:5–16, 2016. © 2015 Wiley Periodicals, Inc.
Monitoring 2‐phenylethanamine and 2‐(3‐hydroxyphenyl)acetamide sulfate in doping controls
Authors: Sigmund Gerd , Dib Josef , Tretzel Laura , Piper Thomas , Bosse Christina , Schänzer Wilhelm , Thevis Mario
Published: October 2015

2‐Phenylethanamine (phenethylamine, PEA) represents the core structure of numerous drugs with stimulant‐like properties and is explicitly featured as so‐called specified substance on the World Anti‐Doping Agency (WADA) Prohibited List. Due to its natural occurrence in humans as well as its presence in dietary products, studies concerning the ability of test methods to differentiate between an illicit intake and the renal elimination of endogenously produced PEA were indicated. Following the addition of PEA to the Prohibited List in January 2015, retrospective evaluation of routine doping control data of 10 190 urine samples generated by combined gas chromatography‐mass spectrometry and nitrogen phosphorus‐specific detection (GC‐MS/NPD) was performed. Signals for PEA at approximate concentrations > 500 ng/mL were observed in 31 cases (0.3%), which were subjected to a validated isotope‐dilution liquid chromatography‐tandem mass spectrometry (ID‐LC‐MS/MS) test method for accurate quantification of the target analyte. Further, using elimination study urine samples collected after a single oral administration of 250 mg of PEA hydrochloride to two healthy male volunteers, two tentatively identified metabolites of PEA were observed and evaluated concerning their utility as discriminative markers for PEA intake. The ID‐LC‐MS/MS approach was extended to allow for the simultaneous detection of PEA and 2‐(3‐hydroxyphenyl)acetamide sulfate (M1), and concentration ratios of M1 and PEA were calculated for elimination study urine samples and a total of 205 doping control urine samples that returned findings for PEA at estimated concentrations of 50–2500 ng/mL. Urine samples of the elimination study with PEA yielded concentration ratios of M1/PEA up to values of 9.4. Notably, the urinary concentration of PEA did increase with the intake of PEA only to a modest extent, suggesting a comprehensive metabolism of the orally administered substance. Conversely, doping control urine samples with elevated (>50 ng/mL) amounts of PEA returned quantifiable concentrations of M1 only in 3 cases, which yielded maximum ratios of M1/PEA of 0.9, indicating an origin of PEA other than an orally ingested drug formulation. Consequently, the consideration of analyte abundance ratios (e.g. M1/PEA) is suggested as a means to identify the use of PEA by athletes, but further studies to support potential decisive criteria are warranted. Copyright © 2015 John Wiley & Sons, Ltd.
Astragalus podlechii, a new name for Astragalus insularis Maassoumi & Podlech (Fabaceae)
Authors: Kottaimuthu R. , Vasudevan N.
Published: October 2015

A new name Astragalus podlechii is proposed to replace the illegitimate later homonym Astragalus insularis Maassoumi & Podlech. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
3D scaffold alters cellular response to graphene in a polymer composite for orthopedic applications
Authors: Kumar Sachin , Azam Dilkash , Raj Shammy , Kolanthai Elayaraja , Vasu K.S. , Sood A.K. , Chatterjee Kaushik
Published: October 2015

Graphene‐based polymer nanocomposites are being studied for biomedical applications. Polymer nanocomposites can be processed differently to generate planar two‐dimensional (2D) substrates and porous three‐dimensional (3D) scaffolds. The objective of this work was to investigate potential differences in biological response to graphene in polymer composites in the form of 2D substrates and 3D scaffolds. Polycaprolactone (PCL) nanocomposites were prepared by incorporating 1% of graphene oxide (GO) and reduced graphene oxide (RGO). GO increased modulus and strength of PCL by 44 and 22% respectively, whereas RGO increased modulus and strength by 22 and 16%, respectively. RGO increased the water contact angle of PCL from 81° to 87° whereas GO decreased it to 77°. In 2D, osteoblast proliferated 15% more on GO composites than on PCL whereas RGO composite showed 17% decrease in cell proliferation, which may be attributed to differences in water wettability. In 3D, initial cell proliferation was markedly retarded in both GO (36% lower) and RGO (55% lower) composites owing to increased roughness due to the presence of the protruding nanoparticles. Cells organized into aggregates in 3D in contrast to spread and randomly distributed cells on 2D discs due to the macro‐porous architecture of the scaffolds. Increased cell‐cell contact and altered cellular morphology led to significantly higher mineralization in 3D. This study demonstrates that the cellular response to nanoparticles in composites can change markedly by varying the processing route and has implications for designing orthopedic implants such as resorbable fracture fixation devices and tissue scaffolds using such nanocomposites. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 732–749, 2016.
Pentafluorophenyl Ester‐based Polymersomes as Nanosized Drug‐Delivery Vehicles
Authors: Scherer Martin , Fischer Karl , Depoix Frank , Fritz Thomas , Thiermann Raphael , Mohr Kristin , Zentel Rudolf
Published: October 2015

In this work, activated ester chemistry is employed to synthesize biocompatible and readily functionalizable polymersomes. Via aminolysis of pentafluorophenyl methacrylate‐based precursor polymers, an N‐(2‐hydroxypropyl) methacrylamide (HPMA)‐analog hydrophilic block is obtained. The precursor polymers can be versatile functionalized by simple addition of suitable primary amines during aminolysis as demonstrated using a fluorescent dye. Vesicle formation is proven by cryoTEM and light scattering. High encapsulation efficiencies for hydrophilic cargo like siRNA are achieved using dual centrifugation and safe encapsulation is demonstrated by gel electrophoresis. In vitro studies reveal low cytotoxicity and no protein adsorption‐induced aggregation in human blood serum occurs, making the vesicles interesting candidates as nanosized drug carriers.

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Determining Free‐Radical Propagation Rate Coefficients with High‐Frequency Lasers: Current Status and Future Perspectives
Authors: Kockler Katrin B. , Haehnel Alexander P. , Junkers Tanja , Barner‐Kowollik Christopher
Published: October 2015

Detailed knowledge of the polymerization mechanisms and kinetics of academically and industrially relevant monomers is mandatory for the precision synthesis of tailor‐made polymers. The IUPAC‐recommended pulsed‐laser polymerization–size exclusion chromatography (PLP–SEC) approach is the method of choice for the determination of propagation rate coefficients and the associated Arrhenius parameters for free radical polymerization processes. With regard to specific monomer classes—such as acrylate‐type monomers, which are very important from a materials point of view—high laser frequencies of up to 500 Hz are mandatory to prevent the formation of mid‐chain radicals and the occurrence of chain‐breaking events by chain transfer, if industrially relevant temperatures are to be reached and wide temperature ranges are to be explored (up to 70 °C). Herein the progress and state‐of‐the‐art of high‐frequency PLP–SEC with pulse repetition rates of 500 Hz is reported, with a critical collection of to‐date investigated 500 Hz data as well as future perspectives for the field.

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Atomic‐Level Sculpting of Crystalline Oxides: Toward Bulk Nanofabrication with Single Atomic Plane Precision
Authors: Jesse Stephen , He Qian , Lupini Andrew R. , Leonard Donovan N. , Oxley Mark P. , Ovchinnikov Oleg , Unocic Raymond R. , Tselev Alexander , Fuentes‐Cabrera Miguel , Sumpter Bobby G. , Pennycook Stephen J. , Kalinin Sergei V. , Borisevich Albina Y.
Published: October 2015

The atomic‐level sculpting of 3D crystalline oxide nanostructures from metastable amorphous films in a scanning transmission electron microscope (STEM) is demonstrated. Strontium titanate nanostructures grow epitaxially from the crystalline substrate following the beam path. This method can be used for fabricating crystalline structures as small as 1–2 nm and the process can be observed in situ with atomic resolution. The fabrication of arbitrary shape structures via control of the position and scan speed of the electron beam is further demonstrated. Combined with broad availability of the atomic resolved electron microscopy platforms, these observations suggest the feasibility of large scale implementation of bulk atomic‐level fabrication as a new enabling tool of nanoscience and technology, providing a bottom‐up, atomic‐level complement to 3D printing.
Animal traction and household economies in Neolithic Europe
Authors: Bogucki Peter
Published: October 2015

Most archaeological interest in the story of European social evolution has looked to the grand picture, as the bands combine and climb at last to achieve states and empires. What about the structure of European Neolithic as it was experienced at home, when the OX, the pig, the sheep and the goat came to live in the domestic unit of the single household?
China's strategy in the Arctic: threatening or opportunistic?
Authors: Lasserre Frédéric , Huang Linyan , Alexeeva Olga V.
Published: October 2015

In a context of rapid climatic change in the Arctic, the fast melting of permafrost, the decline of glaciers and the melting of sea ice created perceived strategic and economic opportunities for the littoral states. The attention of states beyond the region was also attracted. For example China, without direct access to the Arctic, displays an interest in Arctic research, natural resources, and shipping potential. However, its diplomatic, economic, political and scientific efforts in this region arouse negative reactions among western media. They often draw up a portrait of an ambitious and arrogant China, ready to push aside the sovereignty of the Arctic countries to defend its own interests in the Arctic. From this perspective, it seems relevant to analyse China's activities in the region and to try to assess Beijing's strategy, which seems more driven by opportunism than by a long-term desire to challenge the littoral states’ sovereignty.
Ambulantes Assessment in der Schule: Den schulischen Alltag erfahrbar machen
Authors: Bugl Petra , Schmid Johanna , Gawrilow Caterina
Published: October 2015

Zusammenfassung. Der Alltag von Schülerinnen und Schülern ist geprägt von Schwankungen des Lernertrags und des Lerngeschehens. Ziel dieses Beitrags ist es, das ambulante Assessment als Methode vorzustellen, die Zugang zu kurzfristig ablaufenden Schwankungen psychischer und physischer Prozesse innerhalb von Schülerinnen und Schülern oder Lehrkräften bietet. Durch zeitlich eng aufeinanderfolgende wiederholte Messungen wird ein neuer Blick auf den Schulalltag möglich. Besonders hervorzuheben ist das Potenzial ambulanten Assessments, Lernprozesse im Kontext eingebettet aus einer intraindividuellen Perspektive heraus zu betrachten. Erste empirische Evidenzen zu Schwankungen des Lerngeschehens als Bedingungen der schulischen Leistung verdeutlichen die Relevanz und den Nutzen ambulanten Assessments. Für eine Anwendung im Klassenzimmer sprechen viele Vorteile. Die konkrete Umsetzung bleibt herausfordernd und verlangt eine Kooperation zwischen Wissenschaft und Praxis. Zukünftige Studien im Schulkontext sind für alle Beteiligten gewinnbringend.
Landscape simplification filters species traits and drives biotic homogenization
Authors: Gámez-Virués Sagrario , Perović David J. , Gossner Martin M. , Börschig Carmen , Blüthgen Nico , de Jong Heike , Simons Nadja K. , Klein Alexandra-Maria , Krauss Jochen , Maier Gwen , Scherber Christoph , Steckel Juliane , Rothenwöhrer Christoph , Steffan-Dewenter Ingolf , Weiner Christiane N. , Weisser Wolfgang , Werner Michael , Tscharntke Teja , Westphal Catrin
Published: October 2015

Biodiversity loss can affect the viability of ecosystems by decreasing the ability of communities to respond to environmental change and disturbances. Agricultural intensification is a major driver of biodiversity loss and has multiple components operating at different spatial scales: from in-field management intensity to landscape-scale simplification. Here we show that landscape-level effects dominate functional community composition and can even buffer the effects of in-field management intensification on functional homogenization, and that animal communities in real-world managed landscapes show a unified response (across orders and guilds) to both landscape-scale simplification and in-field intensification. Adults and larvae with specialized feeding habits, species with shorter activity periods and relatively small body sizes are selected against in simplified landscapes with intense in-field management. Our results demonstrate that the diversity of land cover types at the landscape scale is critical for maintaining communities, which are functionally diverse, even in landscapes where in-field management intensity is high.
Artemisinin-resistant Plasmodium falciparum clinical isolates can infect diverse mosquito vectors of Southeast Asia and Africa
Authors: St. Laurent Brandyce , Miller Becky , Burton Timothy A. , Amaratunga Chanaki , Men Sary , Sovannaroth Siv , Fay Michael P. , Miotto Olivo , Gwadz Robert W. , Anderson Jennifer M. , Fairhurst Rick M.
Published: October 2015

Artemisinin-resistant Plasmodium falciparum parasites are rapidly spreading in Southeast Asia, yet nothing is known about their transmission. This knowledge gap and the possibility that these parasites will spread to Africa endanger global efforts to eliminate malaria. Here we produce gametocytes from parasite clinical isolates that displayed artemisinin resistance in patients and in vitro, and use them to infect native and non-native mosquito vectors. We show that contemporary artemisinin-resistant isolates from Cambodia develop and produce sporozoites in two Southeast Asian vectors, Anopheles dirus and Anopheles minimus, and the major African vector, Anopheles coluzzii (formerly Anopheles gambiae M). The ability of artemisinin-resistant parasites to infect such highly diverse Anopheles species, combined with their higher gametocyte prevalence in patients, may explain the rapid expansion of these parasites in Cambodia and neighbouring countries, and further compromise efforts to prevent their global spread.
Structural isomerism in gold nanoparticles revealed by X-ray crystallography
Authors: Tian Shubo , Li Yi-Zhi , Li Man-Bo , Yuan Jinyun , Yang Jinlong , Wu Zhikun , Jin Rongchao
Published: October 2015

Revealing structural isomerism in nanoparticles using single-crystal X-ray crystallography remains a largely unresolved task, although it has been theoretically predicted with some experimental clues. Here we report a pair of structural isomers, Au38T and Au38Q, as evidenced using electrospray ionization mass spectrometry, X-ray photoelectron spectroscopy, thermogravimetric analysis and indisputable single-crystal X-ray crystallography. The two isomers show different optical and catalytic properties, and differences in stability. In addition, the less stable Au38T can be irreversibly transformed to the more stable Au38Q at 50 °C in toluene. This work may represent an important advance in revealing structural isomerism at the nanoscale.
Flexible and High Performance Supercapacitors Based on NiCo2O4for Wide Temperature Range Applications
Authors: Gupta Ram K. , Candler John , Palchoudhury Soubantika , Ramasamy Karthik , Gupta Bipin Kumar
Published: October 2015

Binder free nanostructured NiCo2O4 were grown using a facile hydrothermal technique. X-ray diffraction patterns confirmed the phase purity of NiCo2O4. The surface morphology and microstructure of the NiCo2O4 analyzed by scanning electron microscopy (SEM) showed flower-like morphology composed of needle-like structures. The potential application of binder free NiCo2O4 as an electrode for supercapacitor devices was investigated using electrochemical methods. The cyclic voltammograms of NiCo2O4 electrode using alkaline aqueous electrolytes showed the presence of redox peaks suggesting pseudocapacitance behavior. Quasi-solid state supercapacitor device fabricated by sandwiching two NiCo2O4 electrodes and separating them by ion transporting layer. The performance of the device was tested using cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The device showed excellent flexibility and cyclic stability. The temperature dependent charge storage capacity was measured for their variable temperature applications. Specific capacitance of the device was enhanced by ~150% on raising the temperature from 20 to 60 °C. Hence, the results suggest that NiCo2O4 grown under these conditions could be a suitable material for high performance supercapacitor devices that can be operated at variable temperatures.
Light-induced cell damage in live-cell super-resolution microscopy
Authors: Wäldchen Sina , Lehmann Julian , Klein Teresa , van de Linde Sebastian , Sauer Markus
Published: October 2015

Super-resolution microscopy can unravel previously hidden details of cellular structures but requires high irradiation intensities to use the limited photon budget efficiently. Such high photon densities are likely to induce cellular damage in live-cell experiments. We applied single-molecule localization microscopy conditions and tested the influence of irradiation intensity, illumination-mode, wavelength, light-dose, temperature and fluorescence labeling on the survival probability of different cell lines 20–24 hours after irradiation. In addition, we measured the microtubule growth speed after irradiation. The photo-sensitivity is dramatically increased at lower irradiation wavelength. We observed fixation, plasma membrane permeabilization and cytoskeleton destruction upon irradiation with shorter wavelengths. While cells stand light intensities of ~1 kW cm−2 at 640 nm for several minutes, the maximum dose at 405 nm is only ~50 J cm−2, emphasizing red fluorophores for live-cell localization microscopy. We also present strategies to minimize phototoxic factors and maximize the cells ability to cope with higher irradiation intensities.
A Novel Physical Approach for Cationic–Thiolate Protected Fluorescent Gold Nanoparticles
Authors: Ishida Yohei , Lee Chaiyathat , Yonezawa Tetsu
Published: October 2015

Knowledge on the synthesis of cationically charged fluorescent gold nanoparticles (Au NPs) is limited because the electrostatic repulsion between cationic ligands on the surface of NP hinders the formation of small Au NPs (usually less than ca. 2 nm) during nucleation in solvents. We herein propose a novel methodology for a synthesis of water-dispersible, cationic–thiolate protected fluorescent Au NPs by the sputtering of Au into liquid matrix containing thiolate ligands. By controlling mercaptan concentration the size and photophysical characteristics of Au NPs were directly controlled, resulting in near IR fluorescence with a 0.9% of absolute quantum yield. Cationically charged fluorescent metal NPs are promising, especially in biological fields and this work provides a novel methodology towards the synthesis of a new series of functional metal NPs.
Microhabitat locality allows multi-species coexistence in terrestrial plant communities
Authors: Tubay Jerrold M. , Suzuki Keisuke , Uehara Takashi , Kakishima Satoshi , Ito Hiromu , Ishida Atsushi , Yoshida Katsuhiko , Mori Shigeta , Rabajante Jomar F. , Morita Satoru , Yokozawa Masayuki , Yoshimura Jin
Published: October 2015

Most terrestrial plant communities exhibit relatively high species diversity and many competitive species are ubiquitous. Many theoretical studies have been carried out to investigate the coexistence of a few competitive species and in most cases they suggest competitive exclusion. Theoretical studies have revealed that coexistence of even three or four species can be extremely difficult. It has been suggested that the coexistence of many species has been achieved by the fine differences in suitable microhabitats for each species, attributing to niche-separation. So far there is no explicit demonstration of such a coexistence in mathematical and simulation studies. Here we built a simple lattice Lotka-Volterra model of competition by incorporating the minute differences of suitable microhabitats for many species. By applying the site variations in species-specific settlement rates of a seedling, we achieved the coexistence of more than 10 species. This result indicates that competition between many species is avoided by the spatial variations in species-specific microhabitats. Our results demonstrate that coexistence of many species becomes possible by the minute differences in microhabitats. This mechanism should be applicable to many vegetation types, such as temperate forests and grasslands.
Live fast die young life history in females: evolutionary trade-off between early life mating and lifespan in female Drosophila melanogaster
Authors: Travers Laura M. , Garcia-Gonzalez Francisco , Simmons Leigh W.
Published: October 2015

The trade-off between survival and reproduction is fundamental to life history theory. Sexual selection is expected to favour a ‘live fast die young’ life history pattern in males due to increased risk of extrinsic mortality associated with obtaining mates. Sexual conflict may also drive a genetic trade-off between reproduction and lifespan in females. We found significant additive genetic variance in longevity independent of lifetime mating frequency and in early life mating frequency. There was significant negative genetic covariance between these traits indicating that females from families characterized by high levels of multiple mating early in life die sooner than females that engage in less intense early life mating. Thus, despite heritable variation in both traits, their independent evolution is constrained by an evolutionary trade-off. Our findings indicate that, in addition to the well-known male-driven direct costs of mating on female lifespan (mediated by male harassment and harmful effects of seminal fluids), females with a genetic propensity to mate multiply live shorter lives. We discuss the potential role of sexual conflict in driving the evolutionary trade-off between reproduction and lifespan in Drosophila. More generally, our data show that, like males, females can exhibit a live fast die young life history strategy.