bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring Pack-level Current-Split Strategies for Optimized Energy Distribution in Li-ion Battery Systems
Authors: Maddireddy Sandeep Riven Reddy
Published: July 2024

Pack-level current-split strategies play a crucial role in optimizing energy distribution within Li-ion battery systems, thereby enhancing their overall performance and reliability. In this study, we explore various current-split strategies and their impact on battery pack efficiency, energy utilization, and longevity. The efficiency of Li-ion battery systems heavily depends on how effectively current is distributed among individual cells within the battery pack. Traditional current-split strategies, such as passive balancing and uniform current distribution, may lead to suboptimal energy utilization and uneven cell degradation. To address these challenges, advanced current-split strategies, including active balancing, dynamic current allocation, and intelligent energy management algorithms, have been proposed. These strategies leverage real-time monitoring of cell voltages, temperatures, and state of charge (SOC) to dynamically adjust current distribution and ensure balanced cell operation. Additionally, innovative pack-level architectures, such as modular battery packs and multi-level current-split circuits, offer enhanced flexibility and scalability in optimizing energy distribution across large-scale battery systems. Through a comprehensive review of existing literature and case studies, we analyze the performance benefits, technical challenges, and practical considerations associated with different current-split strategies. By providing insights into the design, implementation, and optimization of current-split strategies, this study aims to contribute to the development of more efficient, reliable, and sustainable energy storage solutions for a wide range of applications, including electric vehicles, renewable energy integration, and grid-scale energy storage.
Student Perceptions on ICT Use in Teaching and Learning in Public Secondary Schools in Mbeya District, Tanzania
Authors: Minga Chrispin , Ghosh Saraswati
Published: July 2024

Global teaching and learning process modernization heavily depends on the use of information and communication technology (ICT) in the classroom. For educational methods to be implemented and improved in Tanzania, particularly in the Mbeya District, it is critical to comprehend how students view the incorporation of ICT in their education. This study explores how students in public secondary schools feel about using ICT for teaching and learning, as well as their experiences and preferences in this area.
The objectives of the study were to assess students' attitudes towards the integration of ICT in teaching and learning to examine students' experiences with ICT use in their educational environment, to identify the challenges students face in utilizing ICT for academic purposes and to explore the suggestions for improving the integration of ICT in education.
Several tools were used in the data collection namely questionnaire, interview and secondary data. In this study, a sample of a total 60 respondents were drawn from two secondary schools found in the Mbeya district. In this study 40 filled the questionnaires and 20 teachers were interviewed. The combination of these techniques provides a thorough comprehension of the viewpoints of students and teachers on ICT integration in the teaching and learning processes.
The study found that most of the students had a positive attitude towards ICT integration in in the teaching and learning process as it facilitates better access to learning materials, increased involvement via interactive learning environments, and the possibility of customised learning experiences.
The study recommended to hold interactive training sessions, put in place a strong feedback mechanism, and highlight effective case studies of ICT integration in education to boost student involvement and favourable perception on ICT use in teaching and learning process to secondary school students found in Mbeya district Tanzania.
Characterization of the 7475 Aluminium Alloy's Constitutive Behaviour
Authors: Biradar Nagaraj S. , Patil Sachinkumar
Published: July 2024

Aluminium alloys' high ratio of strength to weight and excellent fracture toughness have led to a sharp increase in their application in the aerospace and military sectors during the last several decades. It is necessary to conduct a thorough examination of the mechanical behaviour of aluminium alloys at elevated temperature and strain rate in order to forecast how structural elements will react to various severe loading scenarios, such as crashes and impacts. The impact of the process factors on the measurement of thermal-mechanical characteristics of aluminium alloys is crucial for the effective production of aluminium alloy panel components during hot forming. This research fully studied the thermal-mechanical characteristics of 7475 aluminium alloy sheets over hot forming circumstances. The investigation included conducting a variety of iso-thermal uniaxial tensile experiments at various temperatures and strain rates using an isothermal mechanical simulator i.e., Gleeble 3500. The split Hopkinson tensile bar (SHTB), the high velocity testing system, and the electronic universal testing machine were used in order to conduct test of dynamic tensile strength performed on the aluminium alloy 7475. These tests were conducted in order to assess the dynamic mechanical behaviours of the alloy at different strain rates. These stress–strain curves were collected at a variety of different speeds. The findings signify that the strain rate, hardening impact of the aluminium alloy 7475 contributes significantly to the overall impact. Through the modification of the strain rate hardening term inside the Johnson–Cook constitutive model of the 7475 aluminium alloy was successfully generated.
Oblique nonlinear whistler wave
Authors: Yoon Peter H. , Pandey Vinay S. , Lee Dong‐Hun
Published: March 2014

Motivated by satellite observation of large‐amplitude whistler waves propagating in oblique directions with respect to the ambient magnetic field, a recent letter discusses the physics of large‐amplitude whistler waves and relativistic electron acceleration. One of the conclusions of that letter is that oblique whistler waves will eventually undergo nonlinear steepening regardless of the amplitude. The present paper reexamines this claim and finds that the steepening associated with the density perturbation almost never occurs, unless whistler waves have sufficiently high amplitude and propagate sufficiently close to the resonance cone angle.
Analysis of fine ELF wave structures observed poleward from the ionospheric trough by the low‐altitude satellite DEMETER
Authors: Parrot Michel , Nĕmec František , Santolík Ondřej
Published: March 2014

DEMETER was a three‐axis stabilized Earth‐pointing spacecraft launched on 29 June 2004 into a low‐altitude (710 km) polar and circular orbit that was subsequently lowered to 650 km until the end of the mission in December 2010. DEMETER measured electromagnetic waves all around the Earth except at magnetic invariant latitudes >65°. The frequency range for the electric field was from DC up to 3.5 MHz and for the magnetic field from a few hertz up to 20 kHz. Electromagnetic ion cyclotron (EMIC) waves have been previously observed by DEMETER close to the ionospheric trough during high magnetic activity, and this paper describes another type of EMIC waves. These waves are also observed close to the trough, but they extend poleward, with the trough acting as a boundary. They are observed exclusively during the night and preferentially during geomagnetic substorms. The analysis of wave propagation shows that they propagate nearly along the ambient magnetic field and that they come from larger radial distances.
New aspects of the ionospheric response to the October 2003 superstorms from multiple‐satellite observations
Authors: Lei Jiuhou , Wang Wenbin , Burns Alan G. , Yue Xinan , Dou Xiankang , Luan Xiaoli , Solomon Stanley C. , Liu Yong C.‐M.
Published: March 2014

The total electron content (TEC) data measured by the Jason, CHAMP, GRACE, and SAC‐C satellites, the in situ electron densities from CHAMP and GRACE, and the vertical E × B drifts from the ROCSAT, have been utilized to examine the ionospheric response to the October 2003 superstorms. The combination of observations from multiple satellites provides a unique global view of ionospheric storm effects, especially over the Pacific Ocean and American regions, which were under sunlit conditions during the main phases of the October 2003 superstorms. The main results of this study are as follows: (1) There were substantial increases in TEC in the daytime at low and middle latitudes during both superstorms. (2) The enhancements were greater during the 30 October superstorm and occurred over a wider range of local times. (3) They also tended to peak at earlier local times during this second event. (4) These TEC enhancement events occurred at the local times when there were enhancements in the upward vertical drift. (5) The strong upward vertical drifts are attributed to penetration electric fields, suggesting that these penetration electric fields played a significant role in the electron density enhancements during these superstorms. Overall, the main contribution of this study is the simultaneous view of the storm time ionospheric response from multiple satellites, and the association of local time differences in ionospheric plasma response with measured vertical drift variations.
Path dependence of the potential for compaction banding: Theoretical predictions based on a plasticity model for porous rocks
Authors: Buscarnera Giuseppe , Laverack Reed T.
Published: March 2014

The paper presents a theoretical investigation of compaction banding based on a plasticity model for high‐porosity rocks. The selected model is featured by a nonassociated flow rule and two internal variables simulating the competition between softening and hardening in the brittle‐ductile transition. The parameters have been calibrated for two extensively studied rocks that exhibited localized compaction under laboratory conditions. In particular, the constants that control the compaction banding domain are defined by matching the stresses at which localized compaction was found in the experiments. The resulting parameters are used to simulate the stress‐strain response for two loading modes (i.e., triaxial compression and radially constrained deformation), thus exploring the role of stress paths and kinematic constraints on the evolution of the compaction banding potential. The analyses suggest that the loading paths able to mobilize the plastic resources of the rock alter the potential for compaction banding through irreversible effects. A notable example is oedometric compression, for which the potential to generate localized compaction tends to vanish during the initial stages of inelastic loading. These predictions suggest that constraints to the mode of deformation can hinder the occurrence of compaction bands in the field. Moreover, they suggest that the interplay between kinematic constraints and evolution of the compaction banding potential can be used for experimental characterization purposes. As a consequence, these results emphasize the importance of complementing stress‐controlled experiments with other tests able to explore different stress paths, thus providing additional data for an accurate characterization of rheological properties and strain‐localization characteristics.
Key parameters controlling OH‐initiated formation of secondary organic aerosol in the aqueous phase (aqSOA)
Authors: Ervens Barbara , Sorooshian Armin , Lim Yong B. , Turpin Barbara J.
Published: March 2014

Secondary organic aerosol formation in the aqueous phase of cloud droplets and aerosol particles (aqSOA) might contribute substantially to the total SOA burden and help to explain discrepancies between observed and predicted SOA properties. In order to implement aqSOA formation in models, key processes controlling formation within the multiphase system have to be identified. We explore parameters affecting phase transfer and OH(aq)‐initiated aqSOA formation as a function of OH(aq) availability. Box model results suggest OH(aq)‐limited photochemical aqSOA formation in cloud water even if aqueous OH(aq) sources are present. This limitation manifests itself as an apparent surface dependence of aqSOA formation. We estimate chemical OH(aq) production fluxes, necessary to establish thermodynamic equilibrium between the phases (based on Henry's law constants) for both cloud and aqueous particles. Estimates show that no (currently known) OH(aq) source in cloud water can remove this limitation, whereas in aerosol water, it might be feasible. Ambient organic mass (oxalate) measurements in stratocumulus clouds as a function of cloud drop surface area and liquid water content exhibit trends similar to model results. These findings support the use of parameterizations of cloud‐aqSOA using effective droplet radius rather than liquid water volume or drop surface area. Sensitivity studies suggest that future laboratory studies should explore aqSOA yields in multiphase systems as a function of these parameters and at atmospherically relevant OH(aq) levels. Since aerosol‐aqSOA formation significantly depends on OH(aq) availability, parameterizations might be less straightforward, and oxidant (OH) sources within aerosol water emerge as one of the major uncertainties in aerosol‐aqSOA formation.
Sponge‐Templated Preparation of High Surface Area Graphene with Ultrahigh Capacitive Deionization Performance
Authors: Yang Zhi‐Yu , Jin Lin‐Jian , Lu Guo‐Qian , Xiao Qing‐Qing , Zhang Yu‐Xia , Jing Lin , Zhang Xiao‐Xue , Yan Yi‐Ming , Sun Ke‐Ning
Published: March 2014

Capacitive deionization (CDI) is a competent water desalination technique offering an appropriate route to obtain clean water. However, a rational designed structure of the electrode materials is essentially required for achieving high CDI performance. Here, a novel sponge‐templated strategy is developed for the first time to prepare graphene sheets with high specific surface area and suitable pore size distribution. Sponge is used as the support of graphene oxide to prevent the restack of graphene sheets, as well as to suppress the agglomerate during the annealing process. Importantly, the as‐fabricated graphene sheets possess high specific surface area of 305 m2 g−1 and wide pore size distribution. Ultrahigh CDI performance, a remarkable electrosorptive capacity of 4.95 mg g−1, and siginificant desorption rate of 25 min, is achieved with the sponge‐templated prepared graphene electrodes. This work provides an effective solution for the synthesis of rational graphene architectures for general applications in CDI, energy storage and conversion.
Separation of methanol‐tetrahydrofuran mixtures by heteroazeotropic distillation and pervaporation
Authors: Genduso Giuseppe , Amelio Antonio , Luis Patricia , Van der Bruggen Bart , Vreysen Steven
Published: March 2014

The experimental investigation of the separation of tetrahydrofuran‐methanol by heteroazeotropic‐batch‐distillation and methanol‐hexane by pervaporation is presented. In particular for this last task, four different specialty commercial membranes were tested (varying feed concentration and temperature). The “pore filling” PolyAn membranes show methanol permeance values higher than 5100 GPU (Typ M2®); separation factor of 19; and a selectivity of about 119 (Typ M1®). From the results, a coupling phenomenon was observed. An assessment of the temperature effect in the pervaporation process corroborates the hypothesis of the presence of a coupling phenomenon. Finally, a discussion is made on two industrial scale units for the separation of the same mixture: a system of a distillation column integrated with a decanter and stand‐alone pervaporation unit. The energetic comparison shows that when using pervaporation a large reduction of the energetic consumption compared to a conventional distillation system (up to 29%) can be obtained. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2584–2595, 2014
Gene mutations differently impact the prognosis of the myelodysplastic and myeloproliferative classes of chronic myelomonocytic leukemia
Authors: Cervera Nathalie , Itzykson Raphael , Coppin Emilie , Prebet Thomas , Murati Anne , Legall Stevan , Vey Norbert , Solary Eric , Birnbaum Daniel , Gelsi‐Boyer Véronique
Published: March 2014

Initially classified in the myelodysplastic syndromes (MDSs), chronic myelomonocytic leukemia (CMML) is currently considered as a MDS/myeloproliferative neoplasm. Two classes—myelodysplastic and myeloproliferative—have been distinguished upon the level of the white blood cell count (threshold 13 G/L). We analyzed mutations in 19 genes reported in CMML to determine if and how these mutations impacted the respective prognosis of the two classes. We defined four major mutated pathways (DNA methylation, ASXL1, splicing, and signaling) and determined their prognostic impact. The number of mutated pathways impacted overall survival in the myelodysplastic class but not in the myeloproliferative class. The myeloproliferative class had a worse prognosis than the myelodysplastic class and was impacted by RUNX1 mutations only. Our results argue for a reclassification of CMML based on the myelodysplastic/myeloproliferative status. Am. J. Hematol. 89:604–609, 2014. © 2014 Wiley Periodicals, Inc.
Asymmetric Synthesis of Tetrahydroquinolines via Saegusa‐type Oxidative Enamine Catalysis/1,5‐Hydride Transfer/Cyclization Sequences
Authors: Suh Chang Won , Woo Saet Byeol , Kim Dae Young
Published: March 2014

Enantioselective organocatalytic synthesis of tetrahydroquinolines has been achieved via Saegusa‐type oxidative enamine catalysis/1,5‐hydride transfer/cyclization sequences. The feature of this research is a one‐pot transformation of 3‐aryl aldehydes into tetrahydroquinolines by using environmentally benign catalytic Saegusa oxidation and highly efficient internal redox reactions. The synthetically useful ring‐fused tetrahydroquinoline derivatives were obtained in moderate yields and high levels of enantioselectivity.
Organocatalytic Enantio‐ and Diastereoselective Assembly of Thiazolidine Scaffolds by Formal [3+2] Annulation
Authors: Qian Hui , Sun Jianwei
Published: March 2014

An organocatalytic enantio‐ and diastereoselective formal [3+2] annulation between imines and 1,4‐dithiane‐2,5‐diol is disclosed. The reaction provides rapid access to chiral thiazolidine‐based molecules starting from a readily available catalyst and achiral starting materials.
Aggregation, interregional interaction, and postmarital residence patterning: A study of biological variation in the late prehistoric middle Ohio Valley
Authors: Cook Robert A. , Aubry B. Scott
Published: March 2014

This study examines a perennial problem in anthropology, changes in postmarital residence patterning. Cross‐cultural patterns related to shifts from patrilocal to matrilocal patterns have been attributed to changes in subsistence and/or the result of migrants entering a populated region. Shifts from matrilocal to multilocal patterns have been found to be related to depopulation. This study examines these possibilities in an archeological context through morphometric analyses of human dentition. Comparisons in variability among males and females are made at four Fort Ancient sites in the Middle Ohio Valley that date to sequential time periods between circa A.D. 1000 and 1650. Results show that the earliest site (Turpin) that was occupied during the transition to maize agriculture was patrilocal, whereas two subsequent sites (Anderson and SunWatch) that were occupied after the transition to a maize‐focused diet reflect a matrilocal pattern. The most recently occupied site (Madisonville), occupied during a time of depopulation of the region after a decline in levels of maize consumption and a marked population shuffling contains a multilocal pattern. These results fit well with the various cross‐cultural findings regarding shifts in postmarital residence patterns. Am J Phys Anthropol 154:270–278, 2014. © 2014 Wiley Periodicals, Inc.
Case‐control analysis of survival outcomes in sinonasal acinic cell carcinoma
Authors: Biron Vincent L. , Lentsch Eric J. , Gerry Daniel R. , Bewley Arnaud F.
Published: March 2014

Background

Acinic cell carcinoma (AciCC) is an uncommon malignant‐epithelial salivary gland cancer. In very rare cases, this tumor may arise from sinonasal subsites, with only 19 cases described in the English‐language literature.

Methods

We performed a retrospective analysis of 18 cases of AciCC, obtained from searching the Surveillance, Epidemiology, and End Results (SEER) database between 1973 and 2009.

Results

Patient demographics, including age, gender, and race, were similar to AciCC cases found in more common locations. However, all patients had low‐grade tumors without regional or distant metastases. Comparing these patients to a stage, grade, and treatment–matched cohort of parotid AciCC, we found a lower 10‐year overall survival (52.3%) with no significant difference in disease‐specific survival (88.9%). Our meta‐analysis of survival from cases in the literature estimated 10‐year recurrence‐free survival at 92.9%.

Conclusion

To our knowledge, this is the largest cohort of patients with AciCC reported in the English‐language literature. Our results suggest that patients with sinonasal AciCC have excellent disease‐specific survival, comparable to matched patients with AciCC in more common salivary gland subsites.
Inverse Opalkugeln basierend auf polyionischen Flüssigkeiten als funktionelle Mikrokugeln mit steuerbaren optischen Eigenschaften und der Fähigkeit zur molekularen Erkennung
Authors: Cui Jiecheng , Zhu Wei , Gao Ning , Li Jian , Yang Haowei , Jiang Yin , Seidel Philipp , Ravoo Bart Jan , Li Guangtao
Published: March 2014

Basierend auf der Kombination der einzigartigen Eigenschaften von polyionischen Flüssigkeiten und kugelförmigen, kolloidalen Kristallen wurde eine neue Klasse von Opalkugeln mit einer Reihe besonderer Eigenschaften hergestellt. Diese photonischen Kugeln konnten nicht nur als responsive photonische Mikrogele verwendet werden, sondern auch als multifunktionelle Mikrokugeln, die die Haupteigenschaften herkömmlicher Moleküle wie optische Eigenschaften, spezifische molekulare Erkennung, Reaktivität, Derivatisierung und Anisotropie nachahmen.
Inverse Opal Spheres Based on Polyionic Liquids as Functional Microspheres with Tunable Optical Properties and Molecular Recognition Capabilities
Authors: Cui Jiecheng , Zhu Wei , Gao Ning , Li Jian , Yang Haowei , Jiang Yin , Seidel Philipp , Ravoo Bart Jan , Li Guangtao
Published: March 2014

Based on the combination of the unique features of both polyionic liquids and spherical colloidal crystals, a new class of inverse opaline spheres with a series of distinct properties was fabricated. It was found that such photonic spheres could not only be used as stimuli‐responsive photonic microgels, but also serve as multifunctional microspheres that mimic the main characteristics of conventional molecules, including intrinsic optical properties, specific molecular recognition, reactivity and derivatization, and anisotropy.
Substrate Specificity and Stereoselectivity of Two Sulfolobus 2‐Keto‐3‐deoxygluconate Aldolases towards Azido‐Substituted Aldehydes
Authors: Schurink Marloes , Wolterink‐van Loo Suzanne , van der Oost John , Sonke Theo , Franssen Maurice C. R.
Published: March 2014

The 2‐keto‐3‐deoxygluconate aldolases (KDGAs) isolated from Sulfolobus species convert pyruvate and glyceraldehyde reversibly into 2‐keto‐3‐deoxygluconate and ‐galactonate. As a result of their high thermostability and activity on nonphosphorylated substrates, KDGA enzymes have potential as biocatalysts for the production of building blocks for fine chemical and pharmaceutical applications. Up to now, wild‐type enzymes have only shown moderate stereocontrol for their natural reaction. However, if a set of azido‐functionalized aldehydes were applied as alternative acceptors in the reaction with pyruvate, the stereoselectivity was strongly increased to give enantiomeric or diastereomeric excess values up to 97 %. The Sulfolobus acidocaldarius KDGA displayed a higher stereoselectivity than Sulfolobus solfataricus KDGA for all tested reactions. The azido‐containing products are useful chiral intermediates in the synthesis of nitrogen heterocycles.
Water‐Resistant Poly(vinyl alcohol)‐Silica Hybrids through Sol‐Gel Processing
Authors: Pirzada Tahira , Shah Syed Sakhawat
Published: March 2014

Poly(vinyl alcohol) (PVA)‐silica hybrids with exceptionally reduced solubility in water were synthesized. The hybrid xerogels were fabricated through sol‐gel processing of a mixture of PVA and the acid‐catalyzed silica precursor tetraethoxysilane. The effects of varying ratios of PVA and silica precursor on the surface structure, thermal properties, crystallinity, and solubility of the hybrids were investigated. Unlike the highly water‐soluble nature of PVA, all the hybrids displayed considerably reduced solubility in water. This anomalous behavior of PVA in the hybrids can be attributed to the unavailability of its pendant –OH groups. Water‐resistant PVA‐silica hybrids can find applications in various technologies requiring biocompatible systems that are stable in aqueous environments.
A Supramolecular Vesicle Based on the Complexation of p‐Sulfonatocalixarene with Protamine and its Trypsin‐Triggered Controllable‐Release Properties
Authors: Wang Kui , Guo Dong‐Sheng , Zhao Meng‐Yao , Liu Yu
Published: March 2014

Enzyme‐responsive assembly represents one of the increasingly significant topics in biomaterials research and finds feasible applications to the controlled release of therapeutic agents at specific sites at which the target enzymes are located. In this work, based on the concept of host–guest chemistry, a trypsin‐responsive supramolecular vesicle using p‐sulfonatocalix[4]arene as the macrocyclic host and natural serine protease trypsin‐cleavable cationic protein protamine as the guest molecule, is reported. The complexation of p‐sulfonatocalix[4]arene with protamine directs the formation of a supramolecular binary vesicle, which is dissipated by trypsin with high selectivity. Therefore, the present system represents a principle‐of‐concept to build a controlled‐release carrier at trypsin‐overexpressed sites.
The Synthesis of Functionalised Diaryltetraynes and Their Transport Properties in Single‐Molecule Junctions
Authors: Gulcur Murat , Moreno‐García Pavel , Zhao Xiaotao , Baghernejad Masoud , Batsanov Andrei S. , Hong Wenjing , Bryce Martin R. , Wandlowski Thomas
Published: March 2014

The synthesis and characterisation is described of six diaryltetrayne derivatives [Ar‐(CC)4‐Ar] with Ar=4‐NO2‐C6H4‐ (NO24), 4‐NH(Me)C6H4‐ (NHMe4), 4‐NMe2C6H4‐ (NMe24), 4‐NH2‐(2,6‐dimethyl)C6H4‐ (DMeNH24), 5‐indolyl (IN4) and 5‐benzothienyl (BTh4). X‐ray molecular structures are reported for NO24, NHMe4, DMeNH24, IN4 and BTh4. The stability of the tetraynes has been assessed under ambient laboratory conditions (20 °C, daylight and in air): NO24 and BTh4 are stable for at least six months without observable decomposition, whereas NHMe4, NMe24, DMeNH24 and IN4 decompose within a few hours or days. The derivative DMeNH24, with ortho‐methyl groups partially shielding the tetrayne backbone, is considerably more stable than the parent compound with Ar=4‐NH2C6H4 (NH24). The ability of the stable tetraynes to anchor in Au|molecule|Au junctions is reported. Scanning‐tunnelling‐microscopy break junction (STM‐BJ) and mechanically controllable break junction (MCBJ) techniques are employed to investigate single‐molecule conductance characteristics.
All‐Atom Molecular Dynamics Simulation of Structure and Diffusion of Hydrophilic Antistatic Agents in Polypropylene
Authors: Long Lianhua , Yang Yingzi , Qiu Feng
Published: March 2014

Glycerol monostearate (GMS) is an additive widely used in plastic industry for its good ability to improve the wettability and antistatic property of polymer surfaces. Based on GMS, we propose five additives of different polarity by attuning the number of oxyethyl groups. All‐atom molecular dynamics simulations of these additives in polypropylene (PP) matrix are carried out at temperatures of 300 K, 350 K and 400 K. Detailed molecular conformations are obtained and analyzed. Due to the gauche effect of the dihedral angles, the polar parts of these additives form helix structures. The diffusion coefficient of the additives depends on their molecular conformations and decreases monotonously with increasing polarity. These results are expected to be helpful in rational design of hydrophilic antistatic agents in polymeric materials.
Efficient Acid‐Catalyzed 18F/19F Fluoride Exchange of BODIPY Dyes
Authors: Keliher Edmund J. , Klubnick Jenna A. , Reiner Thomas , Mazitschek Ralph , Weissleder Ralph
Published: March 2014

Fluorine‐containing fluorochromes are important validation agents for positron emission tomography imaging compounds, as they can be readily validated in cells by fluorescence imaging. In particular, the 18F‐labeled BODIPY‐FL fluorophore has emerged as an important platform, but little is known about alternative 18F‐labeling strategies or labeling on red‐shifted fluorophores. In this study we explore acid‐catalyzed 18F/19F exchange on a range of commercially available N‐hydroxysuccinimidyl ester and maleimide BODIPY fluorophores. We show this method to be a simple and efficient 18F‐labeling strategy for a diverse span of fluorescent compounds, including a BODIPY‐modified PARP‐1 inhibitor, and amine‐ and thiol‐reactive BODIPY fluorophores.
NSF workshop report: Discovering general principles of nervous system organization by comparing brain maps across species
Authors: Striedter Georg F. , Belgard T. Grant , Chen Chun‐Chun , Davis Fred P. , Finlay Barbara L. , Güntürkün Onur , Hale Melina E. , Harris Julie A. , Hecht Erin E. , Hof Patrick R. , Hofmann Hans A. , Holland Linda Z. , Iwaniuk Andrew N. , Jarvis Erich D. , Karten Harvey J. , Katz Paul S. , Kristan William B. , Macagno Eduardo R. , Mitra Partha P. , Moroz Leonid L. , Preuss Todd M. , Ragsdale Clifton W. , Sherwood Chet C. , Stevens Charles F. , Stüttgen Maik C. , Tsumoto Tadaharu , Wilczynski Walter
Published: March 2014

Efforts to understand nervous system structure and function have received new impetus from the federal Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative. Comparative analyses can contribute to this effort by leading to the discovery of general principles of neural circuit design, information processing, and gene‐structure‐function relationships that are not apparent from studies on single species. We here propose to extend the comparative approach to nervous system ‘maps' comprising molecular, anatomical, and physiological data. This research will identify which neural features are likely to generalize across species, and which are unlikely to be broadly conserved. It will also suggest causal relationships between genes, development, adult anatomy, physiology, and, ultimately, behavior. These causal hypotheses can then be tested experimentally. Finally, insights from comparative research can inspire and guide technological development. To promote this research agenda, we recommend that teams of investigators coalesce around specific research questions and select a set of ‘reference species' to anchor their comparative analyses. These reference species should be chosen not just for practical advantages, but also with regard for their phylogenetic position, behavioral repertoire, well‐annotated genome, or other strategic reasons. We envision that the nervous systems of these reference species will be mapped in more detail than those of other species. The collected data may range from the molecular to the behavioral, depending on the research question. To integrate across levels of analysis and across species, standards for data collection, annotation, archiving, and distribution must be developed and respected. To that end, it will help to form networks or consortia of researchers and centers for science, technology, and education that focus on organized data collection, distribution, and training. These activities could be supported, at least in part, through existing mechanisms at NSF, NIH, and other agencies. It will also be important to develop new integrated software and database systems for cross‐species data analyses. Multidisciplinary efforts to develop such analytical tools should be supported financially. Finally, training opportunities should be created to stimulate multidisciplinary, integrative research into brain structure, function, and evolution. J. Comp. Neurol. 522:1445–1453, 2014. © 2014 Wiley Periodicals, Inc.
The rise of new psychoactive substance use in Australia
Authors: Burns Lucy , Roxburgh Amanda , Matthews Allison , Bruno Raimondo , Lenton Simon , Van Buskirk Joe
Published: March 2014

New Psychoactive Substances are now a feature of Australia's recreational drug market. Little is known, however, about the prevalence of use, the characteristics of people who use them and the relationship between the NPS and ecstasy markets. This study examined the prevalence and correlates of NPS use amongst a group of regular ecstasy users in Australia. Participants were recruited if they had used ecstasy at least six times in the previous six months, lived in a capital city and were over 16 years of age. Purposive sampling was used, recruiting through universities and colleges, word of mouth and street press. 654 participants were recruited in 2013. Respondents who had used an NPS in the past six months were compared to those who had not. NPS were used by 44% of the total sample. In 2013 2C‐I (14%) and 2C‐B (8%) were the most prevalent NPS. Respondents in the NPS group were younger and reported more frequent use of more types of drugs. They were also more likely to rate the purity of ecstasy as low relative to those in the no NPS group. NPS are now an established part of Australia's recreational drug scene and NPS with hallucinogenic effects are now used most commonly. Monitoring systems need to develop capacity to monitor this highly dynamic market. Copyright © 2014 John Wiley & Sons, Ltd.
Temporal changes of soil physic‐chemical properties at different soil depths during larch afforestation by multivariate analysis of covariance
Authors: Wang Hui‐Mei , Wang Wen‐Jie , Chen Huanfeng , Zhang Zhonghua , Mao Zijun , Zu Yuan‐Gang
Published: March 2014

Soil physic‐chemical properties differ at different depths; however, differences in afforestation‐induced temporal changes at different soil depths are seldom reported. By examining 19 parameters, the temporal changes and their interactions with soil depth in a large chronosequence dataset (159 plots; 636 profiles; 2544 samples) of larch plantations were checked by multivariate analysis of covariance (MANCOVA). No linear temporal changes were found in 9 parameters (N, K, N:P, available forms of N, P, K and ratios of N: available N, P: available P and K: available K), while marked linear changes were found in the rest 10 parameters. Four of them showed divergent temporal changes between surface and deep soils. At surface soils, changing rates were 262.1 g·kg−1·year−1 for SOM, 438.9 mg·g−1·year−1 for C:P, 5.3 mg·g−1·year−1 for C:K, and −3.23 mg·cm−3·year−1 for bulk density, while contrary tendencies were found in deeper soils. These divergences resulted in much moderated or no changes in the overall 80‐cm soil profile. The other six parameters showed significant temporal changes for overall 0–80‐cm soil profile (P: −4.10 mg·kg−1·year−1; pH: −0.0061 unit·year−1; C:N: 167.1 mg·g−1·year−1; K:P: 371.5 mg·g−1 year−1; N:K: −0.242 mg·g−1·year−1; EC: 0.169 μS·cm−1·year−1), but without significant differences at different soil depths (P > 0.05). Our findings highlight the importance of deep soils in studying physic‐chemical changes of soil properties, and the temporal changes occurred in both surface and deep soils should be fully considered for forest management and soil nutrient balance.
Design of FIR Filters with Discrete Coefficients Using Ant Colony Optimization
Authors: Tsutsumi Shuntaro , Suyama Kenji
Published: March 2014

In this paper, we propose a new design method for linear phase finite impulse response (FIR) filters with discrete coefficients. In a hardware implementation, filter coefficients must be represented as discrete values. The design problem of digital filters with discrete coefficients is formulated as an integer programming problem. But an enormous amount of computational time is required to solve the problem in a strict solver. Recently, ant colony optimization (ACO), a heuristic approach, has been used widely for solving combinational problems such as the traveling salesman problem. In our method, we formulate the design problem as a 0‐1 integer programming problem and solve it by using ACO. Several design examples are presented to show the effectiveness of the proposed method.
Evaluation of Triplet Aromaticity by the Indene–Isoindene Isomerization Stabilization Energy Method
Authors: An Ke , Zhu Jun
Published: March 2014

Aromaticity, one of the most important concepts in chemistry, has attracted considerable interest from both experimentalists and theoreticians. According to Baird's rule, triplet annulenes with 4n π electrons are aromatic. However, the approach to evaluate the magnitude of the triplet aromaticity is less developed. Herein we apply the indene–isoindene isomerization stabilization energy (ISE) method to evaluate the aromaticity in the triplet state. The reliability of this approach can be demonstrated by the strong correlation of these indene–isoindene ISE values with nucleus‐independent chemical shifts [NICS(1)zz] as well as methyl–methylene ISE values. Large [4n]annulenes have the tendency to be planar to achieve aromaticity in the T1 state. Steric effects play an important role in the stabilities of large [4n]annulene isomers.
Integrated approach to the in vivo genotoxic effects of a titanium dioxide nanomaterial using LacZ plasmid‐based transgenic mice
Authors: Louro Henriqueta , Tavares Ana , Vital Nádia , Costa Pedro M. , Alverca Elsa , Zwart Edwin , de Jong Wim H. , Fessard Valérie , Lavinha João , Silva Maria J.
Published: March 2014

Titanium dioxide (TiO2) nanomaterials (NMs) are widely used in a diversity of products including cosmetics, pharmaceuticals, food, and inks, despite uncertainties surrounding the potential health risks that they pose to humans and the environment. Previous studies on the genotoxicity of TiO2 have reported discrepant or inconclusive findings in both in vitro and in vivo systems. This study explores the in vivo genotoxic potential of a well‐characterized uncoated TiO2 NM with an average diameter of 22 nm (NM‐102, from JRC repository) using several genotoxicity endpoints in the LacZ plasmid‐based transgenic mouse model. Mice were exposed by intravenous injection to two daily doses of NM‐102: 10 and 15 mg/kg of body weight/day. Micronuclei were analyzed in peripheral blood reticulocytes 42 hr after the last treatment. DNA strand breaks (comet assay) and gene mutations were determined in the spleens and livers of the same animals 28 days after the last treatment. Histopathological and cytological analyses were also performed in liver samples. Genotoxic effects were not detected in mice exposed to the nanosized TiO2 under the experimental conditions used, despite a moderate inflammatory response that was observed in the liver. Considering the biopersistence of TiO2 in mouse liver and the moderate inflammatory response, the possibility of a secondary genotoxic effect at higher doses and in conditions that result in a stronger inflammatory response, for example, within a longer time window, should be investigated further. Environ. Mol. Mutagen. 55:500–509, 2014. © 2014 Wiley Periodicals, Inc.
Energy and throughput efficient cooperative spectrum sensing in cognitive radio sensor networks
Authors: Ejaz Waleed , Shah Ghalib A. , Hasan Najam ul , Kim Hyung Seok
Published: March 2014

The sensing‐throughput trade‐off and the sensing‐energy trade‐off for cooperative spectrum sensing have been the subject of recent research. Two important, but often conflicting, design objectives for low‐power devices are throughput and energy efficiency. These have not been comprehensively investigated jointly in cognitive radio networks for the design of spectrum sensing algorithms. This paper examines the energy‐throughput trade‐off for cooperative spectrum sensing and formulates an optimisation problem for the trade‐off between energy and throughput for secondary users based on spectrum sensing efficiency. The objective is to minimise the energy consumed in spectrum sensing, reporting cooperative decisions to a central entity and data transmission while satisfying reliability constraints and providing a given throughput to secondary users. A heuristic solution is developed that determines the optimal sensing, reporting and transmission duration. Analysis and simulation results reveal the optimal value for sensing, reporting and transmission duration in order to achieve the best trade‐off between energy consumption and throughput for secondary users. Copyright © 2014 John Wiley & Sons, Ltd.
New results on perfect channel shortening schemes for MIMO‐OFDM systems
Authors: Singh Istdeo , Giridhar K.
Published: March 2014

In this work, we explore further aspects of the zero‐forcing or perfect channel shortening algorithms described in literature for single‐input multi‐output orthogonal frequency division multiplexing (OFDM) systems. Firstly, we propose a novel perfect channel shortening prefilter (CSP) for multi‐input multi‐output OFDM that admits a CSP of significantly lower order when compared to the perfect shorteners. Secondly, new analytical results are derived for perfect channel shortening algorithms, namely, their post‐shortening signal‐to‐noise ratio (SNR) and their post‐processing SNR. The analytical and simulated results are in close match. Using simulations, we show that the proposed technique outperforms the perfect CSP (zero‐forcing), while performing similar to the optimal channel shortening algorithms based on maximum shortened SNR and the linear minimum mean square error. Our results also indicate that the proposed perfect CSP in MIMO‐OFDM systems is less sensitive to the choice of decoding delay when compared to the linear minimum mean square error CSP, and it can yield substantial gain in practical scenarios where the delay is chosen in an ad‐hoc manner by the CSP. Copyright © 2014 John Wiley & Sons, Ltd.
Onset of hippocampus‐dependent memory impairments in 5XFAD transgenic mouse model of Alzheimer's disease
Authors: Girard Stéphane D. , Jacquet Marlyse , Baranger Kévin , Migliorati Martine , Escoffier Guy , Bernard Anne , Khrestchatisky Michel , Féron François , Rivera Santiago , Roman François S. , Marchetti Evelyne
Published: March 2014

The 5XFAD mice are an early‐onset transgenic model of Alzheimer's disease (AD) in which amyloid plaques are first observed between two and four months of age in the cortical layer five and in the subiculum of the hippocampal formation. Although cognitive alterations have been described in these mice, there are no studies that focused on the onset of hippocampus‐dependent memory deficits, which are a hallmark of the prodromal stage of AD. To identify when the first learning and memory impairments appear, 5XFAD mice of two, four, and six months of age were compared with their respective wild‐type littermates using the olfactory tubing maze, which is a very sensitive hippocampal‐dependent task. Deficits in learning and memory started at four months with a substantial increase at six months of age while no olfactory impairments were observed. The volumetric study using magnetic resonance imaging of the whole brain and specific areas (olfactory bulb, striatum, and hippocampus) did not reveal neuro‐anatomical difference. Slight memory deficits appeared at 4 months of age in correlation with an increased astrogliosis and amyloid plaque formation. This early impairment in learning and memory related to the hippocampal dysfunction is particularly suited to assess preclinical therapeutic strategies aiming to delay or suppress the onset of AD. © 2014 Wiley Periodicals, Inc.
Authentically Engaged Learning Through Live Supervision: A Phenomenological Study
Authors: Moody Steven , Kostohryz Katie , Vereen Linwood
Published: March 2014

This phenomenological study explored the experiential learning of 5 master's‐level counseling students undergoing live supervision in a group techniques course. Multiple themes were identified to provide a textural‐structural description of how students authentically engaged in the learning process. Implications for counselor education and directions for future research are presented.
A Moderated Mediation Model of Planned Happenstance Skills, Career Engagement, Career Decision Self‐Efficacy, and Career Decision Certainty
Authors: Kim Boram , Jang Sun Hee , Jung Sun Hwa , Lee Bo Hyun , Puig Ana , Lee Sang Min
Published: March 2014

This study examined how college students’ levels of planned happenstance skills influenced the relationships among career engagement, career decision self‐efficacy, and career decision certainty. Moderated mediation analysis was used with a sample of 217 Korean undergraduate students. The results indicated that career decision self‐efficacy mediated the relationship between career engagement and career decision certainty. Moreover, the positive indirect effect of career engagement on career decision through career decision self‐efficacy was strengthened as the level of planned happenstance skills increased. In conclusion, college students’ career engagement strengthens their career decision certainty via career decision self‐efficacy when they have enough planned happenstance skills to discover unexpected career opportunities.
Examining Differential Effects of Internal and External Resources on Counselor Burnout Symptoms in South Korea
Authors: Choi Hyunju , Puig Ana , Kim Keunhwa , Lee Seongchan , Lee Sang Min
Published: March 2014

This study aims to bring to light the relationship between internal/external resources and counselors’ burnout depending on the type of clients (traumatized/bereaved vs. personal growth issues). Moderated mediation analysis was conducted with 165 counselors in South Korea. The results indicated that counselors of traumatized or bereaved clients were more likely to be affected by internal resources (countertransference management ability), whereas counselors of clients with personal growth issues were more likely to be affected by external resources (environmental resources). Implications and limitations of this study are discussed.
The use of compliant layer prosthetic components in orthopedic joint repair and replacement: A review
Authors: St. John Kenneth R.
Published: March 2014

The surgical repair or treatment of degenerative joint disease has traditionally involved the substitution of synthetic materials for one or both surfaces of the joint. Engineering thermoplastics, metals, and ceramics have either been widely accepted or experimentally evaluated for use as bearing surfaces in these prostheses. When engineering thermoplastics are used, the opposing surface is a metal or a ceramic, but metal‐on‐metal, metal‐on‐ceramic, and ceramic‐on‐ceramic have also been used or tested. Researchers have sought the opportunity to utilize materials with compressive mechanical properties more closely matching those of the natural articular cartilage. This review discusses the theory, testing, and application of elastomers for one bearing component of articular joint prostheses. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1332–1341, 2014.