bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterizing the isotopic composition of atmospheric ammonia emission sources using passive samplers and a combined oxidation‐bacterial denitrifier approach
Authors: David Felix J. , Elliott Emily M. , Gish Timothy J. , McConnell Laura L. , Shaw Stephanie L.
Published: September 2013

RATIONALE

Ammonia (NH3) emissions are a substantial source of nitrogen pollution to sensitive terrestrial, aquatic, and marine ecosystems and dependable quantification of NH3 sources is of growing importance due to recently observed increases in ammonium (NH4+) deposition rates. While determination of the nitrogen isotopic composition of NH3 (δ15N‐NH3) can aid in the quantification of NH3 emission sources, existing methods have precluded a comprehensive assessment of δ15N‐NH3 values from major emission sources.

METHODS

We report an approach for the δ15N‐NH4+ analysis of low concentration NH4+ samples that couples the bromate oxidation of NH4+ to NO2– and the microbial denitrifier method for δ15N‐NO2– analysis. This approach reduces the required sample mass by 50‐fold relative to standard elemental analysis (EA) procedures, is capable of high throughput, and eliminates toxic chemicals used in a prior method for the analysis of low concentration samples. Using this approach, we report a comprehensive inventory of δ15N‐NH3 values from major emission sources (including livestock operations, marine sources, vehicles, fertilized cornfields) collected using passive sampling devices.

RESULTS

The δ15N‐NH4+ analysis approach developed has a standard deviation of ±0.7‰ and was used to analyze passively collected NH3 emissions with a wide range of ambient NH3 concentrations (0.2 to 165.6 µg/m3). The δ15N‐NH3 values reveal that the NH3 emitted from volatilized livestock waste and fertilizer has relatively low δ15N values (–56 to –23‰), allowing it to be differentiated from NH3 emitted from fossil fuel sources that are characterized by relatively high δ15N values (–15 to +2‰).

CONCLUSIONS

The isotopic source signatures presented in this emission inventory can be used as an additional tool in identifying NH3 emission sources and tracing their transport across localized landscapes and regions. The insight into the transport of NH3 emissions provided by isotopic investigation is an important step in devising strategies to reduce future NH3 emissions, a mounting concern for air quality scientists, epidemiologists, and policy‐makers. Copyright © 2013 John Wiley & Sons, Ltd.
Too Many PhD Graduates or Too Few Academic Job Openings: The Basic Reproductive Number R0 in Academia
Authors: Larson Richard C. , Ghaffarzadegan Navid , Xue Yi
Published: September 2013

The academic job market has become increasingly competitive for PhD graduates. In this note, we ask the basic question of ‘Are we producing more PhDs than needed?’ We take a systems approach and offer a ‘birth rate’ perspective: professors graduate PhDs who later become professors themselves, an analogue to how a population grows. We show that the reproduction rate in academia is very high. For example, in engineering, a professor in the US graduates 7.8 new PhDs during his/her whole career on average, and only one of these graduates can replace the professor's position. This implies that in a steady state, only 12.8% of PhD graduates can attain academic positions in the USA. The key insight is that the system in many places is saturated, far beyond capacity to absorb new PhDs in academia at the rates that they are being produced. Based on the analysis, we discuss policy implications. Copyright © 2013 John Wiley & Sons, Ltd.
Metallaxis‐FL: mutation‐based fault localization
Authors: Papadakis Mike , Le Traon Yves
Published: September 2013

Fault localization methods seek to identify faulty program statements based on the information provided by the failing and passing test executions. Spectrum‐based methods are among the most popular ones and assist programmers by assigning suspiciousness values on program statements according to their probability of being faulty. This paper proposes Metallaxis, a fault localization approach based on mutation analysis. The innovative part of Metallaxis is that it uses mutants and links them with the faulty program places. Thus, mutants that are killed mostly by failing tests provide a good indication about the location of a fault. Experimentation using Metallaxis suggests that it is significantly more effective than statement‐based approaches. This is true even in the case where mutation cost‐reduction techniques, such as mutant sampling, are facilitated. Additionally, results from a controlled experiment show that the use of mutation as a testing technique provides benefits to the fault localization process. Therefore, fault localization is significantly improved by using mutation‐based tests instead of block‐based or branch‐based test suites. Finally, evidence in support of the methods’ scalability is also given. Copyright © 2013 John Wiley & Sons, Ltd.
Systems biology approaches to epidemiological studies of complex diseases
Authors: Li Hongzhe
Published: September 2013

Systems biology approaches to epidemiological studies of complex diseases include collection of genetic, genomic, epigenomic, and metagenomic data in large‐scale epidemiological studies of complex phenotypes. Designs and analyses of such studies raise many statistical challenges. This article reviews some issues related to integrative analysis of such high dimensional and inter‐related datasets and outline some possible solutions. I focus my review on integrative approaches for genome‐wide genetic variants and gene expression data, methods for joint analysis of genetic and epigenetic variants, and methods for analysis of microbiome data. Statistical methods such as mediation analysis, high‐dimensional instrumental variable regression, sparse signal recovery, and compositional data regression provide potential frameworks for integrative analysis of these high‐dimensional genomic data.WIREs Syst Biol Med2013, 5:677–686. doi: 10.1002/wsbm.1242

This article is categorized under:

Analytical and Computational Methods > Analytical Methods

Laboratory Methods and Technologies > Genetic/Genomic Methods
Integrative approaches for modeling regulation and function of the respiratory system
Authors: Ben‐Tal Alona , Tawhai Merryn H.
Published: September 2013

Mathematical models have been central to understanding the interaction between neural control and breathing. Models of the entire respiratory system—which comprises the lungs and the neural circuitry that controls their ventilation—have been derived using simplifying assumptions to compartmentalize each component of the system and to define the interactions between components. These full system models often rely—through necessity—on empirically derived relationships or parameters, in addition to physiological values. In parallel with the development of whole respiratory system models are mathematical models that focus on furthering a detailed understanding of the neural control network, or of the several functions that contribute to gas exchange within the lung. These models are biophysically based, and rely on physiological parameters. They include single‐unit models for a breathing lung or neural circuit, through to spatially distributed models of ventilation and perfusion, or multicircuit models for neural control. The challenge is to bring together these more recent advances in models of neural control with models of lung function, into a full simulation for the respiratory system that builds upon the more detailed models but remains computationally tractable. This requires first understanding the mathematical models that have been developed for the respiratory system at different levels, and which could be used to study how physiological levels of O2 and CO2 in the blood are maintained. WIREs Syst Biol Med 2013, 5:687–699. doi: 10.1002/wsbm.1244

This article is categorized under:

Models of Systems Properties and Processes > Mechanistic Models

Physiology > Mammalian Physiology in Health and Disease

Models of Systems Properties and Processes > Organ, Tissue, and Physiological Models
Social influences on the estrous cycle of the captive sun bear (Helarctos Malayanus)
Authors: Frederick Cheryl , Hunt Kathleen , Kyes Randall , Collins Darin , Durrant Barbara , Ha James , Wasser Samuel K.
Published: September 2013

We examined the potential influences of existing social housing arrangements on captive sun bear female reproductive cycling. Three social conditions were studied: 1.2, 1.1, and 0.2. Fecal hormone metabolites of total estrogens, progestins and glucocorticoids were compared between the three social conditions and were analyzed along with vaginal cytology data in individuals that experienced a change in social condition. Behavioral data were collected on females in each of the social conditions and summarized into agonistic, affiliative and sexual categories. Results indicated that sun bears are spontaneous ovulators, but that the presence of a male does influence hormone metabolite concentrations and cytological profiles. Male presence was also associated with a greater proportion of females cycling. In most female pairs, only one female cycled, typically the younger, subordinate female. The presence of a second female appeared to have a suppressive influence on both cycling and mating behavior. Agonistic behavior and associated stress may be a mechanism for lowering progesterone. In contrast, high estrogen levels were associated with low levels of agonistic interactions; thus, reproductive cycle monitoring could facilitate social introductions with either sex. Females in 1.2 social groupings had significantly higher GC metabolite concentrations and agonistic behavior, suggesting that 1.2 social groupings may not be advisable for captive breeding programs. Data from the North American historical captive population indicate that at most 32% of all sun bear pairs and only 18.5% of females have successfully reproduced. Implications of these social and reproductive patterns for captive management are discussed. Zoo Biol. 32:581–591, 2013. © 2013 Wiley Periodicals Inc.
Cognitive enrichment for bottlenose Dolphins (Tursiops truncatus): Evaluation of a novel underwater maze device
Authors: Clark Fay E. , Davies Samuel L. , Madigan Andrew W. , Warner Abby J. , Kuczaj Stan A.
Published: September 2013

Cognitive enrichment is gaining popularity as a tool to enhance captive animal well‐being, but research on captive cetaceans is lacking. Dolphin cognition has been studied intensively since the 1950s, and several hundred bottlenose dolphins are housed in major zoos and aquaria worldwide, but most dolphin enrichment consists of simple floating objects. The aim of this study was to investigate whether a novel, underwater maze device (UMD) was cognitively enriching for one group of male and one group of female dolphins at Six Flags Discovery Kingdom, CA. The dolphin's task was to navigate a rubber ball through a maze of pipes, towards an exit pipe. We also tested a modification where an edible gelatine ball fell into the pool once the UMD was solved. The UMD was provided to each group between 8 and 11 times over a 4‐week period. Male dolphins used the UMD without prior training, whereas females did not use the UMD at all. Two male dolphins solved the UMD 17 times, using a variety of problem‐solving strategies. The UMD had no significant effect on circular (repetitive) swimming patterns, but males spent significantly more time underwater when the UMD was present. Males used the UMD significantly more when it contained the rubber ball, but the gelatine ball stimulated social play. The UMD is a safe and practical device for captive dolphins. It now requires further testing on other dolphins, particularly females, to in order to examine whether the sex differences we observed are a general phenomenon. Zoo Biol. 32:608–619, 2013. © 2013 Wiley Periodicals Inc.
EFFECT OF ALKALINE POTASSIUM AND SODIUM SALTS ON GROWTH, PHOTOSYNTHESIS, IONS ABSORPTION AND SOLUTES SYNTHESIS OF WHEAT SEEDLINGS
Authors: LI XIAOYU , MU CHUNSHENG , LIN JIXIANG , WANG YING , LI XIUJUN
Published: September 2013

Potassium (K) is an essential nutrient and abundant cation in plant cells. The application of K+could alleviate abiotic stress. However, it was reported that the alleviation of K+on salt-stressed plants only happened when K+concentration was low. Most studies were focused on effects of sodium salts on plants in salty soils, and little information was reported about potassium salts, especially a higher level of potassium in alkaline salts. To explore the effects of K+in alkaline salts on plant growth, and whether it had a same destructive impact as Na+, we mixed two alkaline sodium salts (ASS) (NaHCO3:Na2CO3= 9:1) and two alkaline potassium salts (APS) (KHCO3:K2CO3= 9:1) to treat 10-day-old wheat seedlings. Effects of ASS and APS on growth, photosynthesis, ions absorption and solutes accumulation were compared. Results indicated that effects of potassium salts in soil on plants growth were related to K+concentration. Both growth and photosynthesis of wheat seedlings decreased, and the reduction was higher in APS treatment than in ASS treatment at 40 mM alkalinity. ASS treatment absorbed Na+, competing with K+and free Ca2+, and inhibited the absorption of inorganic anions. APS treatments accumulated K+and reduced the absorption of anions, with no competition with other cations. Both APS and ASS treatments promoted free Mg2+accumulation and inhibited H2PO4−uptake. The reduction of H2PO4−promoted organic acid synthesis indirectly. Soluble sugar and proline accumulation were also related to the alkaline condition and extra K+addition. In conclusion, excess potassium ions in soil, especially in alkaline soils, were harmful to plants. APS was another severe salt stress, intensity of which was higher than ASS. The growth and physiological response mechanisms of wheat seedlings to APS were similar to ASS. Both inorganic ions and organic solutes took part in the osmotic adjustment. Differences for APS depended on K+, but ASS on Na+.
Lay Catholicism and Religious Policy in Cromwellian Ireland
Authors: CUNNINGHAM JOHN
Published: September 2013

The conquest of Ireland between 1649 and 1653 created almost as many problems as it solved for the English government of the country. Not least of these was how, if at all, the majority Catholic population was to be won over to Protestantism. This article reassesses Cromwellian religious policy towards the Catholic laity and traces its evolution up to the end of the decade, taking account also of Catholic responses to official measures. It argues that the supposed leniency of government policy has been overstated and that Catholics who refused to conform to Protestantism in fact risked heavy penalties.
Thrombotic events in critically ill children with myocarditis
Authors: Lin Kimberly Y. , Kerur Basavaraj , Witmer Char M. , Beslow Lauren A. , Licht Daniel J. , Ichord Rebecca N. , Kaufman Beth D.
Published: September 2013

Background: Children with myocarditis have multiple risk factors for thrombotic events, yet the role of antithrombotic therapy is unclear in this population. We hypothesised that thrombotic events in critically ill children with myocarditis are common and that children with myocarditis are at higher risk for thrombotic events than children with non-inflammatory dilated cardiomyopathy. Methods: This is a retrospective chart review of all children presenting to a single centre cardiac intensive care unit with myocarditis from 1995 to 2008. A comparison group of children with dilated cardiomyopathy was also examined. Antithrombotic regimens were recorded. The primary outcome of thrombotic events included intracardiac clots and any thromboembolic events. Results: Out of 45 cases with myocarditis, 40% were biopsy-proven, 24% viral polymerase chain reaction-supported, and 36% diagnosed based on high clinical suspicion. There were two (4.4%) thrombotic events in the myocarditis group and three (6.7%) in the dilated cardiomyopathy group (p = 1.0). Neither the use of any antiplatelet or anticoagulation therapy, use of intravenous immune globulin, presence of any arrhythmia, nor need for mechanical circulatory support were predictive of thrombotic events in the myocarditis, dilated cardiomyopathy, or combined groups. Conclusions: Thrombotic events in critically ill children with myocarditis and dilated cardiomyopathy occurred in 6% of the combined cohort. There was no difference in thrombotic events between inflammatory and non-inflammatory cardiomyopathy groups, suggesting that the decision to use antithrombotic prophylaxis should be based on factors other than the underlying aetiology of a child's acute decompensated heart failure.
Automatic Identification and Validation of Planar Collagen Organization in the Aorta Wall with Application to Abdominal Aortic Aneurysm
Authors: Polzer Stanislav , Gasser T. Christian , Forsell Caroline , Druckmüllerova Hana , Tichy Michal , Staffa Robert , Vlachovsky Robert , Bursa Jiri
Published: September 2013

Arterial physiology relies on a delicate three-dimensional (3D) organization of cells and extracellular matrix, which is remarkably altered by vascular diseases like abdominal aortic aneurysms (AAA). The ability to explore the micro-histology of the aorta wall is important in the study of vascular pathologies and in the development of vascular constitutive models, i.e., mathematical descriptions of biomechanical properties of the wall. The present study reports and validates a fast image processing sequence capable of quantifying collagen fiber organization from histological stains. Powering and re-normalizing the histogram of the classical fast Fourier transformation (FFT) is a key step in the proposed analysis sequence. This modification introduces a powering parameterw, which was calibrated to best fit the reference data obtained using classical FFT and polarized light microscopy (PLM) of stained histological slices of AAA wall samples. The values ofw= 3 and 7 give the best correlation (Pearson's correlation coefficient larger than 0.7,R2about 0.7) with the classical FFT approach and PLM measurements. A fast and operator independent method to identify collagen organization in the arterial wall was developed and validated. This overcomes severe limitations of currently applied methods like PLM to identify collagen organization in the arterial wall.
DO SOULS EXIST?
Authors: Johnson David Kyle
Published: September 2013

‘The soul hypothesis’ (the belief that souls exist and humans have them) enjoys near unanimous support in the general population. Among philosophers and scientists, however, belief in the soul is far less common. The purpose of this essay to explain why many philosophers and scientists reject the soul hypothesis and to consider what the non-existence of the soul would entail.
Genetic design of enhanced valley splitting towards a spin qubit in silicon
Authors: Zhang Lijun , Luo Jun-Wei , Saraiva Andre , Koiller Belita , Zunger Alex
Published: September 2013

The long spin coherence time and microelectronics compatibility of Si makes it an attractive material for realizing solid-state qubits. Unfortunately, the orbital (valley) degeneracy of the conduction band of bulk Si makes it difficult to isolate individual two-level spin-1/2 states, limiting their development. This degeneracy is lifted within Si quantum wells clad between Ge-Si alloy barrier layers, but the magnitude of the valley splittings achieved so far is small—of the order of 1 meV or less—degrading the fidelity of information stored within such a qubit. Here we combine an atomistic pseudopotential theory with a genetic search algorithm to optimize the structure of layered-Ge/Si-clad Si quantum wells to improve this splitting. We identify an optimal sequence of multiple Ge/Si barrier layers that more effectively isolates the electron ground state of a Si quantum well and increases the valley splitting by an order of magnitude, to ∼9 meV.
A fluorescent peroxidase probe increases the sensitivity of commercial ELISAs by two orders of magnitude
Authors: Acharya Abhinav P. , Nafisi Parsa M. , Gardner Austin , MacKay Joanna L. , Kundu Kousik , Kumar Sanjay , Murthy Niren
Published: September 2013

This manuscript demonstrates that hydrocyanines are substrates for horseradish peroxidase, and enhance the quantification sensitivity of ELISAs by two orders of magnitude.
White light emission based on a single component Sm(iii) framework and a two component Eu(iii)-doped Gd(iii) framework constructed from 2,2′-diphenyl dicarboxylate and 1H-imidazo[4,5-f][1,10]-phenanthroline
Authors: Zhang Yi-Hua , Li Xia , Song Shuang
Published: September 2013

1D frameworks were constructed from 2,2′-diphenyl dicarboxylate and 1H-imidazo[4,5-f][1,10]-phenanthroline. White light emission was realized by Sm(iii) or Eu(iii)-doped Gd(iii) frameworks.
Microwave, infrared-microwave double resonance, and theoretical studies of C2H4⋯H2S complex
Authors: Goswami M. , Neill J. L. , Muckle M. , Pate B. H. , Arunan E.
Published: September 2013

In this manuscript, rotational spectra of four new isotopologues of the S–H⋯π bonded C2H4⋯H2S complex, i.e., C2D4⋯H2S, C2D4⋯D2S, C2D4⋯HDS, and 13CCH4⋯H2S have been reported and analyzed. All isotopologues except C2D4⋯HDS show a four line pattern whereas a doubling of the transition frequencies was observed for C2D4⋯HDS. These results together with our previous report on the title complex [M. Goswami, P. K. Mandal, D. J. Ramdass, and E. Arunan, Chem. Phys. Lett. 393(1–3), 22–27 (2004)10.1016/j.cplett.2004.06.015] confirm that both subunits (C2H4 and H2S) are involved in large amplitude motions leading to a splitting of each rotational transition to a quartet. Further, the results also confirm that the motions which are responsible for the observed splittings involve both monomers. Molecular symmetry group analysis, considering the interchange of equivalent H atoms in H2S and C2H4 could explain the observed four line pattern and their intensities in the microwave spectrum. In addition, hydride stretching fundamentals of the complex were measured using coherence-converted population transfer Fourier Transform Microwave-infrared (IR-MW double resonance) experiments in the S–H and C–H stretch regions. Changes in the tunneling splittings upon vibrational excitation are consistent with the isotopic dependence of pure rotational transitions. A complexation shift of 2.7–6.5 cm−1 has been observed in the two fundamental S–H stretching modes of the H2S monomer in the complex. Vibrational pre-dissociation in the bound S–H stretch has been detected whereas the instrument-limited line-shapes in other S–H and C–H stretches indicate slower pre-dissociation rate. Some local perturbations in the vibrational spectra have been observed. Two combination bands have been observed corresponding to both the S–H stretching fundamentals and what appears to be the intermolecular stretching mode at 55 cm−1. The tunneling splitting involved in the rotation of C2H4 unit has been deduced to be 1.5 GHz from the IR-MW results. In addition, ab initio barrier heights derived for different motions of the monomers support the experimental results and provide further insight into the motions causing the splitting.
Pathways and kinetics of methane and ethane C–H bond cleavage on PdO(101)
Authors: Antony Abbin , Asthagiri Aravind , Weaver Jason F.
Published: September 2013

We used conventional density functional theory (DFT) and dispersion-corrected DFT (DFT-D3) calculations to investigate C–H bond activation pathways for methane and ethane σ-complexes adsorbed on the PdO(101) surface. The DFT-D3 calculations predict lower and more physically realistic values of the apparent C–H bond cleavage barriers, which are defined relative to the gas-phase energy level, while giving nearly the same energy differences between stationary states as predicted by conventional DFT for a given reaction pathway. For the stable CH4 η2 complex on PdO(101), DFT-D3 predicts that the C–H bond cleavage barriers are 55.2 and 16.1 kJ/mol relative to the initial molecularly adsorbed and gaseous states, respectively. We also predict that dehydrogenation of the resulting CH3 groups and conversion to CH3O species are significantly more energetically demanding than the initial C–H bond activation of CH4 on PdO(101). Using DFT-D3, we find that an η2 and an η1 ethane complex can undergo C–H bond cleavage on PdO(101) with intrinsic energy barriers that are similar to that of the methane complex, but with apparent barriers that are close to zero. We also investigated the dissociation kinetics of methane and ethane on PdO(101) using microkinetic models, with parameters derived from the DFT-D3 relaxed structures. We find that a so-called 3N – 2 model, in which two frustrated adsorbate motions are treated as free motions, predicts desorption pre-factors and alkane dissociation probabilities that agree well with estimates obtained from the literature. The microkinetic simulations demonstrate the importance of accurately describing entropic contributions in kinetic simulations of alkane dissociative chemisorption.
Slow photoelectron velocity-map imaging spectroscopy of the C9H7 (indenyl) and C13H9 (fluorenyl) anions
Authors: Kim Jongjin B. , Weichman Marissa L. , Yacovitch Tara I. , Shih Corey , Neumark Daniel M.
Published: September 2013

High-resolution photoelectron spectra are reported of the cryogenically cooled indenyl and fluorenyl anions, ${\rm C}_9 {\rm H}_7^ - $C9H7− and ${\rm C}_{13} {\rm H}_9^ - $C13H9−, obtained with slow electron velocity-map imaging. The spectra show well-resolved transitions to the neutral ground states, giving electron affinities of 1.8019(6) eV for indenyl and 1.8751(3) eV for fluorenyl. Numerous vibrations are observed and assigned for the first time in the radical ground states, including several transitions that are allowed only through vibronic coupling. The fluorenyl spectra can be interpreted with a Franck-Condon simulation, but explaining the indenyl spectra requires careful consideration of vibronic coupling and photodetachment threshold effects. Comparison of high- and low-resolution spectra along with measurements of photoelectron angular distributions provide further insights into the interplay between vibronic coupling and the photodetachment dynamics. Transitions to the neutral first excited states are also seen, with term energies of 0.95(5) eV and 1.257(4) eV for indenyl and fluorenyl, respectively. Those peaks are much wider than the experimental resolution, suggesting that nearby conical intersections must be considered to fully understand the vibronic structure of the neutral radicals.
Structural and vibrational properties of phenanthrene under pressure
Authors: Huang Qiao-Wei , Zhang Jiang , Berlie Adam , Qin Zhen-Xing , Zhao Xiao-Miao , Zhang Jian-Bo , Tang Ling-Yun , Liu Jing , Zhang Chao , Zhong Guo-Hua , Lin Hai-Qing , Chen Xiao-Jia
Published: September 2013

The structural and vibrational properties of phenanthrene are measured at high pressures up to 30.2 GPa by Raman spectroscopy and synchrotron X-ray diffraction techniques. Two phase transitions are observed in the Raman spectra at pressures of 2.3 GPa and 5.4 GPa which correspond to significant changes of intermolecular and intramolecular vibrational modes. Above 10.2 GPa, all the Raman peaks are lost within the fluorescence background; however, upon further compression above 20.0 GPa, three broad peaks are observed at 1600, 2993, and 3181 cm−1, indicating that phenanthrene has transformed into amorphous phase. Using X-ray diffraction, the structures of corresponding phases observed from Raman spectra are indexed with space groups of P21 for phase I (0-2.2 GPa), P2/m for phase II (2.2-5.6 GPa), P2/m+Pmmm for phase III (5.6-11.4 GPa) which has a coexistence of structures, and above 11.4 GPa the structure is indexed with space group of Pmmm. Although phenanthrene has transformed to a hydrogenated amorphous carbon structure above 20.0 GPa, these amorphous clusters still show characteristic crystalline behavior based on our X-ray diffraction patterns. Our results suggest that the long-range periodicity and the local disorder state coexist in phenanthrene at high pressures.
Unprecedented grain size effect on stacking fault width
Authors: Hunter A. , Beyerlein I. J.
Published: September 2013

Using an atomistic-phase field dislocation dynamics model, we isolate and investigate grain size and stress effects on the stacking fault width created by partial dislocation emission from a boundary. We show that the nucleation stress for a Shockley partial is governed by size of the boundary defect and insensitive to grain size. We reveal a grain size regime in which the maximum value the stacking fault width attains increases with grain size.
Methodology for vetting heavily doped semiconductors for intermediate band photovoltaics: A case study in sulfur-hyperdoped silicon
Authors: Sullivan J. T. , Simmons C. B. , Krich J. J. , Akey A. J. , Recht D. , Aziz M. J. , Buonassisi T.
Published: September 2013

We present a methodology for estimating the efficiency potential for candidate impurity-band photovoltaic materials from empirical measurements. This methodology employs both Fourier transform infrared spectroscopy and low-temperature photoconductivity to calculate a “performance figure of merit” and to determine both the position and bandwidth of the impurity band. We evaluate a candidate impurity-band material, silicon hyperdoped with sulfur; we find that the figure of merit is more than one order of magnitude too low for photovoltaic devices that exceed the thermodynamic efficiency limit for single band gap materials.
Noncontact manipulation using a transversely magnetized rolling robot
Authors: Tung Hsi-Wen , Peyer Kathrin E. , Sargent David F. , Nelson Bradley J.
Published: September 2013

A type of magnetic, wireless microrobot has been designed for non-contact manipulation of micro-objects in liquids. The agent, named the RodBot, has typical dimensions of 300 μm × 60 μm × 50 μm. The RodBot is transversely magnetized and rolls around its long axis on a surface in a rotating external magnetic field. In liquid environments, the RodBot generates a rising flow in front of it and a vortex above its body. The flow and vortex are efficient for picking-up and trapping micro-objects of sizes ranging from microns to one millimeter. In viscous solutions, a RodBot can transport objects many times its own size and weight.
Ultra-bright, ultra-broadband hard x-ray driven by laser-produced energetic electron beams
Authors: Shi Yin , Shen Baifei , Zhang Xiaomei , Wang Wenpeng , Ji Liangliang , Zhang Lingang , Xu Jiancai , Yu Yahong , Zhao Xueyan , Wang Xiaofeng , Yi Longqing , Xu Tongjun , Xu Zhizhan
Published: September 2013

We propose a new method of obtaining a compact ultra-bright, ultra-broadband hard X-ray source. This X-ray source has a high peak brightness in the order of 1022 photons/(s mm2 mrad2 0.1\%BW), an ultrashort duration (10 fs), and a broadband spectrum (flat distribution from 0.1 MeV to 4 MeV), and thus has wide-ranging potential applications, such as in ultrafast Laue diffraction experiments. In our scheme, laser-plasma accelerators (LPAs) provide driven electron beams. A foil target is placed oblique to the beam direction so that the target normal sheath field (TNSF) is used to provide a bending force. Using this TNSF-kick scheme, we can fully utilize the advantages of current LPAs, including their high charge, high energy, and low emittance.
A dynamical systems approach to the control of chaotic dynamics in a spatiotemporal jet flow
Authors: Narayanan Satish , Gunaratne Gemunu H. , Hussain Fazle
Published: September 2013

We present a strategy for control of chaos in open flows and provide its experimental validation in the near field of a transitional jet flow system. The low-dimensional chaotic dynamics studied here results from vortex ring formation and their pairings over a spatially extended region of the flow that was excited by low level periodic forcing of the primary instability. The control method utilizes unstable periodic orbits (UPO) embedded within the chaotic attractor. Since hydrodynamic instabilities in the open flow system are convective, both monitoring and control can be implemented at a few locations, resulting in a simple and effective control algorithm. Experiments were performed in an incompressible, initially laminar, 4 cm diameter circular air jet, at a Reynolds number of 23 000, housed in a low-noise, large anechoic chamber. Distinct trajectory bundles surrounding the dominant UPOs were found from experimentally derived, time-delayed embedding of the chaotic attractor. Velocity traces from a pair of probes placed at the jet flow exit and farther downstream were used to empirically model the UPOs and compute control perturbations to be applied at the jet nozzle lip. Open loop control was used to sustain several nearly periodic states.
Strong secondary piezoelectric effect in ferroelectric 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 crystal
Authors: Wu Zheng , Ma Ke , Cao Yi , Jia Yanmin , Xie A'Xi , Chen Jianrong , Zhang Yihe , Li Huamei , Zheng R. K. , Luo Haosu
Published: September 2013

In this work, the secondary piezoelectric effect in the ferroelectric 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 crystal was measured and characterized. The reverse internal electric field induced by the secondary piezoelectric effect shows a good linear response to the applied external electric field over the measured frequency range of 40 Hz ∼ 4 kHz. The measured secondary piezoelectric coefficient (i.e., the ratio of the induced reverse internal electric field to the applied external electric field) is 0.4. This strong secondary piezoelectric phenomenon will lower the primary piezoelectric effect and should be taken into account for accuracy in practical piezoelectric sensor/actuator applications.
Phase mixing and nonlinearity in geodesic acoustic modes
Authors: Hung C. P. , Hassam A. B.
Published: September 2013

Phase mixing and nonlinear resonance detuning of geodesic acoustic modes in a tokamak plasma are examined. Geodesic acoustic modes (GAMs) are tokamak normal modes with oscillations in poloidal flow constrained to lie within flux surfaces. The mode frequency is sonic, dependent on the local flux surface temperature. Consequently, mode oscillations between flux surfaces get rapidly out of phase, resulting in enhanced damping from the phase mixing. Damping rates are shown to scale as the negative 1/3 power of the large viscous Reynolds number. The effect of convective nonlinearities on the normal modes is also studied. The system of nonlinear GAM equations is shown to resemble the Duffing oscillator, which predicts resonance detuning of the oscillator. Resonant amplification is shown to be suppressed nonlinearly. All analyses are verified by numerical simulation. The findings are applied to a recently proposed GAM excitation experiment on the DIII-D tokamak.
Making activity-based funding work for mental health
Authors: Rosenberg Sebastian P. , Hickie Ian B.
Published: September 2013

The implementation of activity-based funding (ABF) in mental health from 1 July 2013 has significant risks and benefits. It is critical that the process of implementation is consistent with Australia’s cherished goal of establishing a genuine and effective model of community-based mental health care. The infrastructure to support the application of ABF to mental health is currently weak and requires considerable development. States and territories are struggling to meet existing demand for largely hospital-based acute mental health care. There is a risk that valuable ABF-driven Commonwealth growth funds may be used to prop up these systems rather than drive the emergence of new models of community-based care. Some of these new models exist now and this article provides a short description. The aim is to help the Independent Hospital Pricing Authority better understand the landscape of mental health into which it now seeks to deploy ABF.
Origins of Travelling Stock Routes. 1. Connections to Indigenous traditional pathways
Authors: Spooner P. G. , Firman M. , Yalmambirra
Published: September 2013

Travelling Stock Routes (TSRs) are networks of grazing routes and reserves situated throughout much of south-eastern Australia, and thought to have originated from the informal tracks of early European explorers, pastoralists and settlers. However, the historic development of TSRs has been poorly documented, and mostly confined to the classic pastoral account. An alternative perspective is that many TSRs may have originated from previous Indigenous traditional pathways, which are known to have existed before European settlement. By examining available literature and maps, we found evidence which suggests that several TSRs, which follow the routes of early explorers, settlers or pastoralists, have developed from previous traditional pathways. Adoption of Indigenous pathways into the present-day stock route system has most likely occurred by (1) ‘passing on’ of knowledge of pathways by Indigenous guides and trackers, (2) observations of physical evidence of pathways by early Europeans, and their subsequent adoption, and (3) shared development of some TSRs as a result of Indigenous people working in the pastoral industry. These findings highlight the significant cultural heritage values of the TSR network, and the need to appropriately protect and manage this important national asset.
Evaluation of camera traps for monitoring European rabbits before and after control operations in Otago, New Zealand
Authors: Latham A. David M. , Nugent Graham , Warburton Bruce
Published: September 2013

Context
European rabbits (Oryctolagus cuniculus) are reaching plague proportions again in some parts of New Zealand as the effect of rabbit haemorrhagic disease begins to wane. Effective monitoring techniques are required to quantify the success of alternative methods of controlling rabbits, such as poisoning.

Aim
To evaluate camera traps as a method of estimating the percentage of rabbits killed in a poison control operation, and to compare results obtained from cameras with those from traditional monitoring methods (spotlight transects and vantage-point counts).

Methods
We deployed cameras and conducted vantage-point counts and spotlight transects to compare a priori statistical power. We then used these monitoring methods to estimate percentage kill from a case study rabbit-control operation using sodium fluoroacetate (compound 1080).

Key results
Cameras had good statistical power to detect large reductions in rabbit numbers (>90%) and the percentage kill estimated using cameras was comparable with spotlight transects and vantage-point counts.

Conclusions
Cameras set up at fixed sampling locations can be an effective method of quantitatively assessing rabbit population control outcomes. We recommend that ≥6 cameras per 100 ha should remain active for at least 5 days before and 5 days following control, so as to obtain reliable estimates of percentage kill.

Implications
Cameras may be preferable to conventional monitoring methods where there is insufficient area to walk or drive transects, terrain is too rugged or scrubby for transects, and there are no or few vantage points from which to count rabbits.
On the behavior of test ideals under finite morphisms
Authors: Schwede Karl , Tucker Kevin
Published: September 2013

We derive precise transformation rules for test ideals under an arbitrary finite surjective morphism

π
:
Y
→
X

\pi \colon Y \to X

of normal varieties in prime characteristic

p
>
0

p > 0

. Specifically, given a ℚ

-divisor

Δ

X

\Delta _{X}

on

X
X

and any

O

X

\mathcal {O}_{X}

-linear map

T

:
K
(
Y
)
→
K
(
X
)

\mathfrak {T} \colon K(Y) \to K(X)

, we associate a ℚ

-divisor

Δ

Y

\Delta _{Y}

on

Y
Y

such that
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="German upper T left-parenthesis pi Subscript asterisk Baseline tau left-parenthesis upper Y semicolon normal upper Delta Subscript upper Y Baseline right-parenthesis right-parenthesis equals tau left-parenthesis upper X semicolon normal upper Delta Subscript upper X Baseline right-parenthesis">

T

(

π

∗

τ
(
Y
;

Δ

Y

)
)
=
τ
(
X
;

Δ

X

)

\mathfrak {T} ( \pi _{*}\tau (Y;\Delta _{Y})) = \tau (X;\Delta _{X})

. When

π
\pi

is separable and

T

=

Tr

Y

/

X

\mathfrak {T} = \operatorname {Tr}_{Y/X}

is the field trace, we have

Δ

Y

=

π

∗

Δ

X

−

Ram

π

\Delta _{Y} = \pi ^{*} \Delta _{X} - \operatorname {Ram}_{\pi }

, where

Ram

π

\operatorname {Ram}_{\pi }

is the ramification divisor. If, in addition,

Tr

Y

/

X

⁡
(

π

∗

O

Y

)
=

O

X

\operatorname {Tr}_{Y/X}(\pi _{*}\mathcal {O}_{Y}) = \mathcal {O}_{X}

, we conclude that
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="pi Subscript asterisk Baseline tau left-parenthesis upper Y semicolon normal upper Delta Subscript upper Y Baseline right-parenthesis intersection upper K left-parenthesis upper X right-parenthesis equals tau left-parenthesis upper X semicolon normal upper Delta Subscript upper X Baseline right-parenthesis">

π

∗

τ
(
Y
;

Δ

Y

)
∩
K
(
X
)
=
τ
(
X
;

Δ

X

)

\pi _{*}\tau (Y;\Delta _{Y}) \cap K(X) = \tau (X;\Delta _{X})

and thereby recover the analogous transformation rule to multiplier ideals in characteristic zero. Our main technique is a careful study of when an

O

X

\mathcal {O}_{X}

-linear map

F

∗

O

X

→

O

X

F_{*} \mathcal {O}_{X} \to \mathcal {O}_{X}

lifts to an

O

Y

\mathcal {O}_{Y}

-linear map

F

∗

O

Y

→

O

Y

F_{*} \mathcal {O}_{Y} \to \mathcal {O}_{Y}

, and the results obtained about these liftings are of independent interest as they relate to the theory of Frobenius splittings. In particular, again assuming

Tr

Y

/

X

⁡
(

π

∗

O

Y

)
=

O

X

\operatorname {Tr}_{Y/X}(\pi _{*}\mathcal {O}_{Y}) = \mathcal {O}_{X}

, we obtain transformation results for

F
F

-pure singularities under finite maps which mirror those for log canonical singularities in characteristic zero. Finally, we explore new conditions on the singularities of the ramification locus, which imply that, for a finite extension of normal domains

R
⊆
S

R \subseteq S

in characteristic

p
>
0

p > 0

, the trace map

T

:
Frac
⁡
S
→
Frac
⁡
R

\mathfrak {T} : \operatorname {Frac} S \to \operatorname {Frac} R

sends

S
S

onto

R
R

.
Open innovation in an emerging economy
Authors: Scott Gregory , Chaston Ian
Published: September 2013

Purpose

The purpose of this paper is to examine the performance of firms in Peru in relation to open innovation.

Design/methodology/approach

Data were acquired through a survey of Peruvian middle and senior managers.

Findings

Peruvian firms engaged in open innovation did report higher sales growth. The study indicated that involvement in open innovation included activities to reduce operating costs and improve internal processes, as well as exploiting the process to assist the development of new or improved products.

Practical implications

The practical implications of this paper, although restricted to Peruvian organizations, suggest that firms operating in an emerging economy may find involvement in open innovation which is an effective strategy for enhancing organizational performance.

Originality/value

The originality of the paper is the focus on open innovation in an emerging economy.
Population‐based determinants of radical prostatectomy operative time
Authors: Carter Stacey C. , Lipsitz Stuart , Shih Ya‐Chen T. , Nguyen Paul L. , Trinh Quoc‐Dien , Hu Jim C.
Published: September 2013

Objectives

To determine factors that influence radical prostatectomy (RP) operative times.

Operative time assessment is inherent to defining surgeon learning curves and evaluating quality of care.

Subjects/Patients and Methods

Population‐based observational cohort study using USA Surveillance, Epidemiology, and End Results (SEER)‐Medicare linked data of men diagnosed with prostate cancer during 2003–2007 who underwent robot‐assisted radical prostatectomy (RARP, 3458 men) and retropubic RP (RRP, 6993) through to 2009.

We obtained median operative time using anaesthesia administrative data for RP and used median regression to assess the contribution of patient, surgeon, and hospital factors to operative times.

Results

The median RARP operative time decreased from 315 to 247 min from 2003 to 2008–2009 (P < 0.001), while the median RRP operative time remained similar (195 vs 197 min, P = 0.90).

In adjusted analysis, RARP vs RRP (parameter estimate [PE] 70.9; 95% confidence interval [CI] 58, 84; P < 0.001) and obesity (PE 15; 95% CI 7, 23; P < 0.001) were associated with longer operative times while higher surgeon volumes were associated with shorter operative times (P < 0.001).

RPs performed by surgeons employed by group (parameter estimate [PE] –22.76; 95% CI –38, –7.49; P = 0.004) and non‐government (PE –35.59; 95% CI –68.15, –3.03; P = 0.032) vs government facilities and non‐profit vs government hospital ownership (PE –21.85; 95% CI –32.28, –11.42; P < 0.001) were associated with shorter operative times.

Conclusions

During our study period, RARP operative times decreased by 68 min while RRP operative times remained stagnant.

Higher surgeon volume was associated with shorter operative times, and selective referral or improved efficiency to the level of high‐volume surgeons would net almost $15 million (USA dollars) in annual savings.
Two Different Perspectives on Open Innovation – Libre versus Control
Authors: Wikhamn Björn Remneland
Published: September 2013

The concept of open innovation has successfully diffused in academia as well as in industry. However, criticisms have at the same time been raised regarding the lack of a precise definition and also similar past research has not been sufficiently recognized. This paper highlights two perspectives of openness related to innovation – open as ‘libre’ versus ‘controlled’ – arguing that they rest on different underlying assumptions and theoretical foundations related to knowledge and value production. The paper concludes that the general research on ‘open innovation’ implicitly utilizes both perspectives, which tends to give a somewhat fragmented and incoherent perception of what open innovation is and how it should be applied in practice.
Trans fatty acids exacerbate dextran sodium sulphate-induced colitis by promoting the up-regulation of macrophage-derived proinflammatory cytokines involved in T helper 17 cell polarization
Authors: Okada Y , Tsuzuki Y , Sato H , Narimatsu K , Hokari R , Kurihara C , Watanabe C , Tomita K , Komoto S , Kawaguchi A , Nagao S , Miura S
Published: September 2013

Numerous reports have shown that a diet containing large amounts of trans fatty acids (TFAs) is a major risk factor for metabolic disorders. Although recent studies have shown that TFAs promote intestinal inflammation, the underlying mechanisms are unknown. In this study, we examined the effects of dietary fat containing TFAs on dextran sodium sulphate (DSS)-induced colitis. C57 BL/6 mice were fed a diet containing 1·3% TFAs (mainly C16:1, C18:1, C18:2, C20:1, C20:2 and C22:1), and then colitis was induced with 1·5% DSS. Colonic damage was assessed, and the mRNA levels of proinflammatory cytokines and major regulators of T cell differentiation were measured. The TFA diet reduced survival and exacerbated histological damage in mice administered DSS compared with those fed a TFA-free diet. The TFA diet significantly elevated interleukin (IL)-6, IL-12p40, IL-23p19 and retinoic acid-related orphan receptor (ROR)γt mRNA levels in the colons of DSS-treated animals. Moreover, IL-17A mRNA levels were elevated significantly by the TFA diet, with or without DSS treatment. We also examined the expression of proinflammatory cytokines in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and peritoneal macrophages. These cells were exposed to TFAs (linoelaidic acid or elaidic acid) with or without LPS and the mRNA levels of various cytokines were measured. IL-23p19 mRNA levels were increased significantly by TFAs in the absence of LPS. Cytokine expression was also higher in LPS-stimulated cells exposed to TFAs than in unexposed LPS-stimulated cells. Collectively, our results suggest that TFAs exacerbate colonic inflammation by promoting Th17 polarization and by up-regulating the expression of proinflammatory cytokines in the inflamed colonic mucosa.