bluuebunny/crossref_metadata_2025 huggingface dataset:
Production and correlation of reactive oxygen and nitrogen species in gas- and liquid-phase generated by helium plasma jets under different pulse widths
Authors: Liu Zhijie , Zhou Chunxi , Liu Dingxin , Xu Dehui , Xia Wenjie , Cui Qingjie , Wang Bingchuan , Kong Michael G
Published: January 2018

In this paper, we present the effects of the pulse width (PW) on the plasma jet's discharge characteristics, particularly focusing on the production and correlation of the reactive oxygen and nitrogen species (RONS) in gas- and liquid-phase. It is found that the length of plasma jet plume first increases before the PW of 10 μs, then gradually decreases and finally almost remains unchanged beyond 150 μs. The plasma bullet disappears after the falling edge of the voltage pulse at low PW, while it terminates far ahead of the falling edge of voltage pulse at high PW. This is mainly attributed to accumulation of space charges that lead to weakening of the reduced electric field with an increase of PW from low to high. More important, it is found that the excited reactive species, the positive and negative ions from plasma jet, and the concentrations of NO2– and NO3– in deionized water exposed to plasma jet also display the first increasing and then decreasing change trend with increase of PW, while the concentration of H2O2 in water almost displays the linearly increasing trend. This mainly results from the formation of the H3O+ and HO2–, as well as their ion water clusters that can produce more OH radicals to be converted into H2O2, while the NO2– and NO3– in gas phase can transport into water and exist most stably in water. The water cluster formation at gas-liquid interface is an important key process that can affect the chemical nature and dose of aqueous RONS in water; this is beneficial for understanding how the RONS are formed in liquid-phase.
Numerical analysis of effects of ion-neutral collision processes on RF ICP discharge
Authors: Nishida K. , Mattei S. , Lettry J. , Hatayama A.
Published: January 2018

The discharge process of a radiofrequency (RF) inductively coupled plasma (ICP) has been modeled by an ElectroMagnetic Particle-in-Cell Monte Carlo Collision method (EM PIC-MCC). Although the simulation had been performed by our previous model to investigate the discharge mode transition of the RF ICP from a kinetic point of view, the model neglected the collision processes of ions (H+ and H2+) with neutral particles. In this study, the RF ICP discharge process has been investigated by the latest version of the model which takes the ion-neutral collision processes into account. The basic characteristics of the discharge mode transition provided by the previous model have been verified by the comparison between the previous and present results. As for the H-mode discharge regime, on the other hand, the ion-neutral collisions play an important role in evaluating the growth of the plasma. Also, the effect of the ion-neutral collisions on the kinetic feature of the plasma has been investigated, which has highlighted the importance of kinetic perspective for modeling the RF ICP discharge.
In-plane electrical conduction mechanisms of highly dense carbon nanotube forests on silicon carbide
Authors: Matsuda Keita , Norimatsu Wataru , Bao Jianfeng , Kawarada Hiroshi , Kusunoki Michiko
Published: January 2018

We have investigated the length-dependence of the in-plane electrical resistivity of vertically aligned and highly dense carbon nanotube (CNT) films that were dense enough to conduct electrons. The in-plane conductivity is well accounted for by a combination of inter-tube hopping (variable range hopping, VRH) and graphitic conduction. VRH conduction was dominant in the thinner CNT films, and the films showed negative temperature dependence of resistivity. The dimension of the VRH component varied depending on the CNT length. In the thicker CNT films, the graphitic conduction appeared, and then, the localization length spread, leading to the positive temperature dependence of resistivity. This behavior can be explained by the presence of a labyrinthine arrangement of graphene walls among aligned CNTs, which was confirmed by transmission electron microscopy observations.
Enhanced gel formation in binary mixtures of nanocolloids with short-range attraction
Authors: Harden James L. , Guo Hongyu , Bertrand Martine , Shendruk Tyler N. , Ramakrishnan Subramanian , Leheny Robert L.
Published: January 2018

Colloidal suspensions transform between fluid and disordered solid states as parameters such as the colloid volume fraction and the strength and nature of the colloidal interactions are varied. Seemingly subtle changes in the characteristics of the colloids can markedly alter the mechanical rigidity and flow behavior of these soft composite materials. This sensitivity creates both a scientific challenge and an opportunity for designing suspensions for specific applications. In this paper, we report a novel mechanism of gel formation in mixtures of weakly attractive nanocolloids with modest size ratio. Employing a combination of x-ray photon correlation spectroscopy, rheometry, and molecular dynamics simulations, we find that gels are stable at remarkably weaker attraction in mixtures with size ratio near two than in the corresponding monodisperse suspensions. In contrast with depletion-driven gelation at larger size ratio, gel formation in the mixtures is triggered by microphase demixing of the species into dense regions of immobile smaller colloids surrounded by clusters of mobile larger colloids that is not predicted by mean-field thermodynamic considerations. These results point to a new route for tailoring nanostructured colloidal solids through judicious combination of interparticle interaction and size distribution.
Approximating hidden chaotic attractors via parameter switching
Authors: Danca Marius-F. , Kuznetsov Nikolay V. , Chen Guanrong
Published: January 2018

In this paper, the problem of approximating hidden chaotic attractors of a general class of nonlinear systems is investigated. The parameter switching (PS) algorithm is utilized, which switches the control parameter within a given set of values with the initial value problem numerically solved. The PS-generated attractor approximates the attractor obtained by averaging the control parameter with the switched values, which represents the hidden chaotic attractor. The hidden chaotic attractors of a generalized Lorenz system and the Rabinovich-Fabrikant system are simulated for illustration.
Independent gate control of injected and detected spin currents in CVD graphene nonlocal spin valves
Authors: Anugrah Yoska , Hu Jiaxi , Stecklein Gordon , Crowell Paul A. , Koester Steven J.
Published: January 2018

Graphene is an ideal material for spintronic devices due to its low spin-orbit coupling and high mobility. One of the most important potential applications of graphene spintronics is for use in neuromorphic computing systems, where the tunable spin resistance of graphene can be used to apply analog weighting factors. A key capability needed to achieve spin-based neuromorphic computing systems is to achieve distinct regions of control, where injected and detected spin currents can be tuned independently. Here, we demonstrate the ability to achieve such independent control using a graphene spin valve geometry where the injector and detector regions are modulated by two separate bottom gate electrodes. The spin transport parameters and their dependence on each gate voltage are extracted from Hanle precession measurements. From this analysis, local spin transport parameters and their dependence on the local gate voltage are found, which provide a basis for a spatially-resolved spin resistance network that simulates the device. The data and model are used to calculate the spin currents flowing into, through, and out of the graphene channel. We show that the spin current flowing through the graphene channel can be modulated by 30% using one gate and that the spin current absorbed by the detector can be modulated by 50% using the other gate. This result demonstrates that spin currents can be controlled by locally tuning the spin resistance of graphene. The integration of chemical vapor deposition (CVD) grown graphene with local gates allows for the implementation of large-scale integrated spin-based circuits.
Probing spatial locality in ionic liquids with the grand canonical adaptive resolution molecular dynamics technique
Authors: Shadrack Jabes B. , Krekeler C. , Klein R. , Delle Site L.
Published: January 2018

We employ the Grand Canonical Adaptive Resolution Simulation (GC-AdResS) molecular dynamics technique to test the spatial locality of the 1-ethyl 3-methyl imidazolium chloride liquid. In GC-AdResS, atomistic details are kept only in an open sub-region of the system while the environment is treated at coarse-grained level; thus, if spatial quantities calculated in such a sub-region agree with the equivalent quantities calculated in a full atomistic simulation, then the atomistic degrees of freedom outside the sub-region play a negligible role. The size of the sub-region fixes the degree of spatial locality of a certain quantity. We show that even for sub-regions whose radius corresponds to the size of a few molecules, spatial properties are reasonably reproduced thus suggesting a higher degree of spatial locality, a hypothesis put forward also by other researchers and that seems to play an important role for the characterization of fundamental properties of a large class of ionic liquids.
Correlation analysis on volume vorticity and vortex in late boundary layer transition
Authors: Dong Xiangrui , Tian Shuling , Liu Chaoqun
Published: January 2018

In this paper, two functions are introduced to describe the turbulence generation in late flow transition. One is called the volume omega bar (volume Ω¯), which represents the flow rotation or vortex strength. The other is called the volume vorticity, which shows the flow statistical fluctuations. Although they have very different definitions, one is for fluctuation and the other is for rotation, volume Ω¯ and volume vorticity are found highly correlated with a correlation factor greater than 0.9, which means that there is a very close correlation between flow fluctuation and flow rotation (vortex). While the vorticity flux keeps constant in the late flow transition through the integration over any sections either parallel or perpendicular to the flow direction, the volume Ω¯ is greatly increased along the flow direction during the flow transition process. This means that the vortex structures are greatly built up and rotation becomes more and more dominant. On the other hand, the total volume vorticity is also quickly increased, which shows that the fluctuation is stronger. The flow transition is a process with significant volume vorticity increase, which is attributed to two of the following crucial factors: the first one is the lengthening of the vorticity tubes from side boundary due to the vorticity line stretching, distortion, and tangling; the second one is the generation of countless self-closed vorticity rings within the domain. Both the increase of the volume vorticity and the volume Ω¯ can be a significant symbol of the flow transition from the laminar flow to turbulent flow. It also shows that vorticity (tubes or lines) cannot directly represent vortex and should not be simply used as a signal of the turbulent transition process.
Spin transfer torque magnetization reversal in a hard/soft composite structures
Authors: Kuteifan M. , Lambert C.-H. , Lubarda M. V. , Lomakin V. , Fullerton E. E. , Mangin S.
Published: January 2018

Current induced magnetization manipulation in a spin valve structure where the free layer is a magnetic hard/soft composite structure is studied using micromagnetic simulations. In this structure where the hard layers has strong perpendicular magnetic anisotropy, a domain wall can be nucleated in the soft layer due to the spin transfer torque effect. Depending on the magnetic properties of the layers and the current intensity the domain wall can induce the free layer reversal or be pinned by the hard layer. For these non-uniform magnetic configurations both bulk and interface spin transfer torques need to be considered. The potential reduction of the critical current observed in this geometry is of potential technological interest.
Effects of aromaticity in cations and their functional groups on the temperature dependence of low-frequency spectrum
Authors: Kakinuma Shohei , Ramati Sharon , Wishart James F. , Shirota Hideaki
Published: January 2018

In this study, we investigate the temperature dependence of low-frequency spectra in the frequency range of 0.3–200 cm−1 for ionic liquids (ILs) whose cations possess two systematically different cyclic groups, using femtosecond Raman-induced Kerr effect spectroscopy. The target ILs are bis(trifluoromethylsulfonyl)amide [NTf2]– salts of 1-cyclohexylmethyl-1-methylpyrrolidinium [CHxmMPyrr]+, 1-cyclohexylmethyl-3-methylimidazolium [CHxmMIm]+, N-cyclohexylmethylpyridinium [CHxmPy]+, 1-benzyl-1-methylpyrrolidinium [BzMPyrr]+, 1-benzyl-3-methylimidazolium [BzMIm]+, and N-benzylpyridinium [BzPy]+ cations. The aim of this study is to better understand the effects of aromaticity in the cations’ constituent groups on the temperature-dependent low-frequency spectral features of the ILs. The low-frequency spectra of these ILs are temperature dependent, but the temperature-dependent spectrum of [CHxmMPyrr][NTf2] is different from that of other ILs. While [CHxmMPyrr][NTf2] shows spectral changes with temperature in the low-frequency region below 50 cm−1, the other ILs also show spectral changes in the high-frequency region above 80 cm−1 (above 50 cm−1 in the case of [BzMPyrr][NTf2]). We conclude that the spectral change in the low-frequency region is due to both the cation and anion, while the change in the high-frequency region is attributed to the red shift of the aromatic ring librations. On the basis of the plots of the first moment of the spectra vs. temperature, we found that the first moment of the low-frequency spectrum of the IL whose cation does not have an aromatic ring is less temperature dependent than that of the other ILs. However, the intrinsic first moment, the first moment at 0 K, of the low-frequency spectrum is governed by the absence or presence of a charged aromatic group, while a neutral aromatic group does not have much influence on determining the intrinsic first moment.
Temperature Dependence of Mineral Solubility in Water. Part 2. Alkaline and Alkaline Earth Bromides
Authors: Krumgalz B. S.
Published: January 2018

Databases of alkaline and alkaline earth bromide solubilities in water at various temperatures were created using experimental data from publications over about the last two centuries. Statistical critical evaluation of the created databases was produced since there were enough independent data sources to justify such evaluation. The reliable experimental data were adequately described by polynomial expressions over various temperature ranges. Using the Pitzer approach for ionic activity and osmotic coefficients, the thermodynamic solubility products for the discussed bromide minerals have been calculated at various temperature intervals and also represented by polynomial expressions.
Calculation of the orientational linear and nonlinear correlation factors of polar liquids from the rotational Dean-Kawasaki equation
Authors: Déjardin P. M. , Cornaton Y. , Ghesquière P. , Caliot C. , Brouzet R.
Published: January 2018

A calculation of the Kirkwood and Piekara-Kielich correlation factors of polar liquids is presented using the forced rotational diffusion theory of Cugliandolo et al. [Phys. Rev. E 91, 032139 (2015)]. These correlation factors are obtained as a function of density and temperature. Our results compare reasonably well with the experimental temperature dependence of the linear dielectric constant of some simple polar liquids across a wide temperature range. A comparison of our results for the linear dielectric constant and the Kirkwood correlation factor with relevant numerical simulations of liquid water and methanol is given.
Effect of electron injection on defect reactions in irradiated silicon containing boron, carbon, and oxygen
Authors: Makarenko L. F. , Lastovskii S. B. , Yakushevich H. S. , Moll M. , Pintilie I.
Published: January 2018

Comparative studies employing Deep Level Transient Spectroscopy and C-V measurements have been performed on recombination-enhanced reactions between defects of interstitial type in boron doped silicon diodes irradiated with alpha-particles. It has been shown that self-interstitial related defects which are immobile even at room temperatures can be activated by very low forward currents at liquid nitrogen temperatures. Their activation is accompanied by the appearance of interstitial carbon atoms. It has been found that at rather high forward current densities which enhance BiOi complex disappearance, a retardation of Ci annealing takes place. Contrary to conventional thermal annealing of the interstitial boron-interstitial oxygen complex, the use of forward current injection helps to recover an essential part of charge carriers removed due to irradiation.
Quenchable compressed graphite synthesized from neutron-irradiated highly oriented pyrolytic graphite in high pressure treatment at 1500 °C
Authors: Niwase Keisuke , Terasawa Mititaka , Honda Shin-ichi , Niibe Masahito , Hisakuni Tomohiko , Iwata Tadao , Higo Yuji , Hirai Takeshi , Shinmei Toru , Ohfuji Hiroaki , Irifune Tetsuo
Published: January 2018

The super hard material of “compressed graphite” (CG) has been reported to be formed under compression of graphite at room temperature. However, it returns to graphite under decompression. Neutron-irradiated graphite, on the other hand, is a unique material for the synthesis of a new carbon phase, as reported by the formation of an amorphous diamond by shock compression. Here, we investigate the change of structure of highly oriented pyrolytic graphite (HOPG) irradiated with neutrons to a fluence of 1.4 × 1024 n/m2 under static pressure. The neutron-irradiated HOPG sample was compressed to 15 GPa at room temperature and then the temperature was increased up to 1500 °C. X-ray diffraction, high-resolution transmission electron microscopy on the recovered sample clearly showed the formation of a significant amount of quenchable-CG with ordinary graphite. Formation of hexagonal and cubic diamonds was also confirmed. The effect of irradiation-induced defects on the synthesis of quenchable-CG under high pressure and high temperature treatment was discussed.
Argon impact on the quantification accuracy of a QMS in gas mixtures with nitrogen or carbon monoxide at very low partial pressures
Authors: Nemanič Vincenc , Žumer Marko
Published: January 2018

Quantification accuracy of nitrogen and carbon monoxide in argon used as the matrix gas was studied by quadrupole mass spectrometers (QMS) at very low partial pressures when no interference between ions was expected. The effect of mutual ion interactions within the ionization cell is well recognized, but it arises at much higher pressures. Our measurements were performed in an UHV system designed for pressure gauge calibrations. In two in situ calibrated QMSs with different ion source designs, the argon leak rate noticeably increased the QMS signal of a trace gas: at low leak rates, nitrogen was increased for a factor of up to ∼3, and carbon monoxide signal for a factor of up to ∼2.8 at the first QMS, while this effect was much smaller in the other QMS. The anomaly was not observed at high leak rates of trace gases. The underlying physical process seems to be the argon-assisted charge transfer to nitrogen and carbon monoxide molecules adsorbed on the quadrupole rods in the filter section. Despite the fact that this physical effect is manifested as an instrumental error, the accuracy of quantification of unknown gas mixtures containing these gases can be substantially improved after numerical correction factors for particular QMS device have been determined.
Nanoporous distributed Bragg reflectors on free-standing nonpolar m-plane GaN
Authors: Mishkat-Ul-Masabih Saadat , Luk Ting Shan , Rishinaramangalam Ashwin , Monavarian Morteza , Nami Mohsen , Feezell Daniel
Published: January 2018

We report the fabrication of m-plane nanoporous distributed Bragg reflectors (DBRs) on free-standing GaN substrates. The DBRs consist of 15 pairs of alternating undoped and highly doped n-type ([Si] = ∼3.7 × 1019 cm−3) GaN. Electrochemical (EC) etching was performed to convert the highly doped regions into a porous material, consequently reducing the effective refractive index of the layers. We demonstrate a DBR with peak reflectance greater than 98% at 450 nm with a stopband width of ∼72 nm. The polarization ratio of an incident polarized light source remains identical after reflection from the DBR, verifying that there is no drop in the polarization ratio due to the interfaces between the porous layers. We also quantify the porosity under various EC bias conditions for layers with different doping concentrations. The bias voltage controls the average pore diameter, while the pore density is primarily determined by the doping concentration. The results show that nanoporous DBRs on nonpolar free-standing GaN are promising candidates for high-reflectance, lattice-matched DBR mirrors for GaN-based resonant cavity devices.
Formation of pseudo-microgravity environment for dusty plasmas in supercritical carbon dioxide
Authors: Sakakibara Noritaka , Matsubayashi Yasuhito , Ito Tsuyohito , Terashima Kazuo
Published: January 2018

We realized a pseudo-microgravity environment for dusty plasmas in a ground-based experiment, using the field-emitting regime of a surface dielectric barrier discharge in high-pressure carbon dioxide (CO2) including supercritical conditions. Using the high and adjustable density of high-pressure CO2, the balance between gravitational force and buoyancy was controlled. When changing the density of CO2 in the range of 0.234 g/cm3 to 0.668 g/cm3, i.e., smaller and larger than that of the particles (0.5 g/cm3), a particle arrangement in the direction of the gravitational force was formed only when the density of CO2 was in the range of ±0.17 g/cm3 with respect to that of the particles. This experimentally demonstrates that the pseudo-microgravity that emerges due to the buoyancy from the high-pressure CO2 contributes to the particle arrangement in the gravitational direction, and hence, it compensates the gravity-induced anisotropy.
The role of Minkowski functionals in the thermodynamics of two-phase systems
Authors: Eder Gerhard
Published: January 2018

Within this work quite old concepts from integral geometry are applied to classical equilibrium thermodynamics of two-phase systems. In addition to the area as basic interfacial quantity the full geometric characterization of the interface is used, which includes the two remaining Minkowski functionals, the mean curvature integral and the Euler Poincaré characteristic. The basic energetic characteristic of the interface (i.e. the interfacial tension) is extended by two additional properties: edge force as (up to a factor 4/π) the work necessary to form a right-angled edge of unit length, and item energy as the work to form an additional item in the phase morphology. Both quantities are of increasing importance, when going to micro- and nano-scales. They are subsequently used for interfaces of arbitrary shape to derive a relationship extending the classical Young-Laplace equation. The supplementary contribution is proportional to the Gaussian curvature, with the edge force as proportionality constant. Furthermore, both edge force and item energy are shown to be applicable to the description of crystal nucleation in liquids (extending the classical Becker Döring theory). It turns out, that even above the thermodynamic melting temperature stable nuclei can be present in the liquid phase. They immediately are able to grow when quenched to a temperature below a characteristic temperature. This temperature of spontaneous homogeneous nucleation is simply connected to the edge force, whereas the number of stable clusters per unit volume is dominated by the item energy. Finally, the additional energetic interfacial properties are used in a similar way to characterize the stability of emulsions.
Measurement of Soret coefficients in a ternary mixture of toluene–methanol–cyclohexane in convection-free environment
Authors: Mialdun A. , Ryzhkov I. , Khlybov O. , Lyubimova T. , Shevtsova V.
Published: January 2018

We report on the measurement of Soret (ST) coefficients in the ternary system toluene (T)–methanol (M)–cyclohexane (Ch) onboard the International Space Station in the experiment selectable optical diagnostic instrument/DCMIX2 (Diffusion Coefficients Measurement in ternary mIXtures). Nine experiments were conducted in the range of mean temperatures between 298.15 K and 306.15 K in the mixture with composition 0.62 (T)–0.31 (M)–0.07 (Ch) in mass fractions. A linear dependence of the Soret coefficients on temperature was established for the ternary mixture. It has also been found that, over considered range of mean temperatures, the Soret coefficients of toluene are small and positive, while the Soret coefficients for methanol are negative and, at least, two times larger. The present work also presents a comprehensive study of possible methodologies to process raw data from the Soret experiment in ternary mixtures. All the experiments were processed by seven different schemes and two of them were identified as the most reliable. We also investigate the error propagation and explain the reasons for the discrepancy of the results obtained by different schemes.
Communication: Electronic flux induced by crossing the transition state
Authors: Jia Dongming , Manz Jörn , Yang Yonggang
Published: January 2018

We present a new effect of chemical reactions, e.g., isomerizations, that occurs when the reactants pass along the transition state, on the way to products. It is based on the well-known fact that at the transition state, the electronic structure of one isomer changes to the other. We discover that this switch of electronic structure causes a strong electronic flux that is well distinguishable from the usual flux of electrons that travel with the nuclei. As a simple but clear example, the effect is demonstrated here for bond length isomerization of Na2 (21Σu+), with adiabatic crossing the barrier between the inner and outer wells of the double minimum potential that support different “Rydberg” and “ionic” type electronic structures, respectively.
Null boundary controllability of a one-dimensional heat equation with an internal point mass and variable coefficients
Authors: Ben Amara Jamel , Bouzidi Hedi
Published: January 2018

In this paper, we consider a linear hybrid system which is composed by two non-homogeneous rods connected by a point mass with Dirichlet boundary conditions on the left end and a boundary control acts on the right end. We prove that this system is null controllable with Dirichlet or Neumann boundary controls. Our approach is mainly based on a detailed spectral analysis together with the moment method. In particular, we show that the associated spectral gap in both cases (Dirichlet or Neumann boundary controls) is positive without further conditions on the coefficients other than the regularities.
On randomness
Authors: Cohen Imogen
Published: January 2018

AndrewChesterman’s 2008article “On Explanation” examines what it means to explain translational phenomena. In doing so, it explores the nature of explanation itself and raises one crucial question: How much is beyond explanation? In other words, to what extent could translational phenomena be due to mere chance? This article addresses this question by drawing on six landmark experiments within the field of psychology. These experiments suggest (1) that we, as translators, might unknowingly be injecting random elements into our translations, and (2) that we, as Translation Studies scholars, might be ‘seeing’ causes in that randomness where there are none. This article also draws on psychologist Daniel Kahneman’s ideas about the ‘illusion of causation’ and on Nassim Taleb’s definition of randomness within the humanities and social sciences. It concludes by arguing that retrospective explanations of translations should pay far more than lip service to the notion of chance.
A medium manganese steel designed for water quenching and partitioning
Authors: Hou Z. R. , Zhao X. M. , Zhang W. , Liu H. L. , Yi H. L.
Published: January 2018

An aluminium-containing medium manganese steel has been designed to undergo intercritical annealing followed by quenching in water and subsequent partitioning. Water quenching, replacing the quenching temperature (QT) between 150 and 300°C in conventional quenching and partitioning steels, is therefore adopted in QP alloys, in order to guarantee the precise QT in practice. The low intercritical annealing temperature of 750°C refines both ferrite and prior austenite grains into submicron size. The large fraction of ultra-fine ferrite, as well as the transformation-induced plasticity effect of retained austenite, improves the overall ductility of this water-quenched and partitioned steel. The alloy has achieved excellent mechanical properties of 1130 MPa ultimate tensile strength combined with 19.2% total elongation.
Psychological Stress and Cellular Aging
Authors: Shalev Idan , Hastings Waylon J.
Published: January 2018

Stress is a multistage process during which an organism perceives, interprets, and responds to threatening environmental stimuli. Physiological activity in the nervous, endocrine, and immune systems mediates the biological stress response. Although the stress response is adaptive in the short term, exposure to severe or chronic stressors dysregulates these biological systems, promoting maladaptive physiology and an accelerated aging phenotype, including aging on the cellular level. Two structures implicated in this process of stress and cellular aging are telomeres, whose length progressively decreases with age, and mitochondria, whose respiratory activity becomes increasingly inefficient with advanced age. Stress in its various forms is suggested to influence the maintenance and stability of these structures throughout life. Elucidating the interrelated connection between telomeres and mitochondria and how different types of stressors are influencing these structures to drive the aging process is of great interest. A better understanding of this subject can inform clinical treatments and intervention efforts to reduce (or even reverse) the damaging effects of stress on the aging process.
History of Sport, Exercise, and Performance Psychology in Australia
Authors: Bond Jeffrey , Morris Tony
Published: January 2018

Australian sport psychology was effectively “launched” in conjunction with the establishment of the Australian Institute of Sport (AIS) in 1981. Prior to this date, sport psychology sat within the realm of a small number of research academics in tertiary institutions and many more unqualified practitioners with backgrounds in sport, hypnotherapy, medicine, and marketing and sales. The commencement of the legitimacy of the profession in the early 1980s correlated with the co-location of the AIS Sport Psychology Department with other sports medicine and sports science disciplines. From this rather humble but significant beginning, Australian sport psychology quickly became integrated into the training and competition plans of the vast majority of Australian Olympic sports and the developing professional football, tennis, golf, and cricket codes.

The rapid growth of the AIS and its team of qualified and experienced sport psychology practitioners, combined with international competition exposure, international conference presentations, reciprocal visits to international sports institutes, and Olympic training centers culminated in the inclusion of sport psychology within the auspices of the Australian Psychological Society (APS) and the accreditation of undergraduate and postgraduate tertiary programs in Australian universities. Applied sport psychology services are now a regular inclusion in most, if not all, Australian sports programs. An increasing emphasis on athlete and coach mental health in conjunction with the performance enhancement capability associated with sport psychology support has firmly entrenched the profession within the Australian sporting milieu.
Arousal Control in Sport
Authors: Turner Martin , Jones Marc
Published: January 2018

Sport and stress are intertwined. Muhammad Ali once said, “I always felt pressure before a big fight, because what was happening was real.” As this quote attests, sport is real, unscripted, with the potential for psychological, and often physical, harm. The response to stress, commonly described as “flight or fight,” is an evolutionary adaptation to dangerous situations. It guides behavior and readies a person to respond, to fight, or flee. However, the stress response is not evoked solely in situations of mortal danger; it occurs in response to any situation with the potential for physical or psychological harm, such as sport. For example, the possibility of missing out on a life-changing gold-medal win in an Olympic Games, or losing an important competition that you were expected to win.

Stress in sport is often illustrated by the archetypal image of an athlete choking; snatching defeat from the jaws of victory. But stress can also help athletes perform well. Stress also plays a role in behavior away from the competition arena, influencing interactions with significant others, motivation and performance in training, and how athletes experience and manage injury and retirement from sport. In sport stress, the psychophysiological responses to stress are not just abstract theoretical concepts removed from the real world; they reflect the thoughts, feelings, and experiences of athletes.

It is important to understand the arousal response to stress in sport. Both theory and research suggest a connection between arousal and athletic performance. Recent approaches propose ideas about how the nature of arousal may differ depending on whether the athlete feels positively (as a challenge) or negatively (as a threat) about the stressor. The approach to seeing stress as a challenge supports a series of strategies that can be used to help control arousal in sport.
The Role of Mental Processes in Elite Sports Performance
Authors: Vickers Joan N. , Williams A. Mark
Published: January 2018

Considerable debate has arisen about whether brain activity in elite athletes is characterized by an overall quieting, or neural efficiency in brain processes, or whether elite performance is characterized by activation of two simultaneous networks. One network exercises cognitive control using increased theta activation of premotor and cingulate gyrus, whereas the second reduces alpha activation in an inhibitory network that prevents the intrusion of debilitating thoughts emanating from the temporal lobe and other areas. Also, there is controversy about how a long-duration “quiet eye” (QE) can fit within a single efficient neural system, or whether a dual system where both increased cognitive control and reduced inhibitory processes has advantages. The literature on neural efficiency, the QE, and theta cognitive control, suggest that a long-duration QE promotes both an increase in theta band activation of the medial prefrontal cortex and anterior cingulate and reduced activation and inhibition of the temporal regions during high-pressure situations when a high level of focused, cognitive control is essential.
Pecuniary Punishments
Authors: Faraldo-Cabana Patricia
Published: January 2018

The genealogy of pecuniary punishments is a story of constant reformulation in response to shifting political pressures, changes in institutional and administrative arrangements, and intellectual developments that changed ideological commitments of legislators and practitioners. Within this chronicle of reformulation, broad transformations since the late 17th century are discernible. These legal transformations, most of which have been widely discussed and debated, help delimitate old and new forms of punishment and, to some degree, different modes of constructing punishment inside the criminal law. Based on the notion that the legal discussions during the 19th century set the stage for the profound reforms initiated by the emergence of consumer societies, the discourses that unfolded from around the end of early modern times until now are analyzed, even though few could have predicted the increase in the use of fines and confiscation that would occur throughout the 20th century. For the fine to reach such a state of ubiquity, one of its most criticized characteristics derived from its monetary nature had to undergo a severe scrutiny: the unequal impact on offenders caused by the unequal distribution of money between individuals in society. Confiscation, on the other hand, after having being extensively used by the Nazi, fascist, and Francoist regimes against “people’s enemies” and political opponents, was rediscovered as one of the most powerful weapons in the fight against organized crime during the war on drugs in the 1980s. In the 21st century it has become increasingly important for countries to be able to freeze and confiscate property related to the committing of an offense, thus depriving criminals of their illicitly obtained assets.
Auditory Mechanisms of Echolocation in Bats
Authors: Moss Cynthia F.
Published: January 2018

Echolocating bats have evolved an active sensing system, which supports 3D perception of objects in the surroundings and permits spatial navigation in complete darkness. Echolocating animals produce high frequency sounds and use the arrival time, intensity, and frequency content of echo returns to determine the distance, direction, and features of objects in the environment. Over 1,000 species of bats echolocate with signals produced in their larynges. They use diverse sonar signal designs, operate in habitats ranging from tropical rain forest to desert, and forage for different foods, including insects, fruit, nectar, small vertebrates, and even blood. Specializations of the mammalian auditory system, coupled with high frequency hearing, enable spatial imaging by echolocation in bats. Specifically, populations of neurons in the bat central nervous system respond selectively to the direction and delay of sonar echoes. In addition, premotor neurons in the bat brain are implicated in the production of sonar calls, along with movement of the head and ears. Audio-motor circuits, within and across brain regions, lay the neural foundation for acoustic orientation by echolocation in bats.
Echinoderm Nervous System
Authors: Díaz-Balzac Carlos A. , García-Arrarás José E.
Published: January 2018

The nervous system of echinoderms has been studied for well over a century. Nonetheless, the information available is disparate, with in-depth descriptions for the nervous component of some groups or of particular organs while scant data is available for others. The best studied representatives to date are the nervous system of echinoid embryos and larva, and the adult holothurian nervous system. Although described sometimes inaccurately as a neural net, the echinoderm nervous system consists of well-defined neural structures. This is observed since early embryogenesis when activation of the anterior neuroectoderm gene regulatory networks initiate the formation of the embryonic nervous system. This system then undergoes expansion and differentiation to form the larval nervous system, which is centered on the ciliary bands. This “simpler” nervous system is then metamorphosed into the adult echinoderm nervous system. The adult echinoderm nervous system is composed of a central nervous system made up of a nerve ring connected to a series of radial nerve cords. Peripheral nerves extending from the radial nerve cords or nerve ring connect with the peripheral nervous system, located in other organs or effectors including the viscera, podia, body wall muscles, and connective tissue.

Both the central and peripheral nervous systems are composed of complex and diverse subdivisions. These are mainly characterized by the expression of neurotransmitters, namely acetylcholine, catecholamines, histamine, amino acids, GABA, and neuropeptides. Other areas of interest include the amazing regenerative capabilities of echinoderms that have been shown to be able to regenerate their nervous system components; and the analysis of the echinoderm genome that has provided essential insights into the molecular basis of how echinoderms develop an adult pentaradial symmetry from bilaterally symmetric larvae and the role of the nervous system in this process.
Prolactin: Regulation and Actions
Authors: Bridges Robert S.
Published: January 2018

Prolactin (PRL) is a protein hormone with a molecular weight of approximately 23 KD, although variants in size exist. It binds to receptor dimers on the cytoplasmic surface of its target cells and acts primarily through the activation of the STAT5 pathway, which in turn alters gene activity. Pituitary prolactin, while being the main, but not only, source of PRL, is primarily under inhibitory control by hypothalamic dopaminergic neurons. Release of dopamine (DA) into the hypothalamo-hypophyseal portal system binds on DA D2 receptors on PRL-producing lactotrophs within the anterior pituitary gland. Prolactin’s functions include the regulation of behaviors that include maternal care, anxiety, and feeding as well as lactogenesis, hepatic bile formation, immune function, corpora lutea function, and more generally cell proliferation and differentiation. Dysfunctional conditions related to prolactin’s actions include its role in erectile dysfunction and male infertility, mood disorders such as depression during the postpartum period, possible roles in breast and hepatic cancer, prostate hyperplasia, galactorrhea, obesity, immune function, and diabetes. Future studies will further elucidate both the underlying mechanisms of prolactin action together with prolactin’s involvement in these clinical disorders.
Neuroimmunology: Behavioral Effects
Authors: Neigh Gretchen N. , Bekhbat Mandakh , Rowson Sydney A.
Published: January 2018

Bidirectional interactions between the immune system and central nervous system have been acknowledged for centuries. Over the past 100 years, pioneering studies in both animal models and humans have delineated the behavioral consequences of neuroimmune activation, including the different facets of sickness behavior. Rodent studies have uncovered multiple neural pathways and mechanisms that mediate anorexia, fever, sleep alterations, and social withdrawal following immune activation. Furthermore, work conducted in human patients receiving interferon treatment has elucidated some of the mechanisms underlying immune-induced behavioral changes such as malaise, depressive symptoms, and cognitive deficits.

These findings have provided the foundation for development of treatment interventions for conditions in which dysfunction of immune-brain interactions leads to behavioral pathology. Rodent models of neuroimmune activation frequently utilize endotoxins and cytokines to directly stimulate the immune system. In the absence of pathogen-induced inflammation, a variety of environmental stressors, including psychosocial stressors, also lead to neuroimmune alterations and concurrent behavioral changes. These behavioral alterations can be assessed using a battery of behavioral paradigms while distinguishing acute sickness behavior from the type of behavioral outcome being assessed. Animal studies have also been useful in delineating the role of microglia, the neuroendocrine system, neurotransmitters, and neurotrophins in mediating the behavioral implications of altered neuroimmune activity. Furthermore, the timing and duration of neuroimmune challenge as well as the sex of the organism can impact the behavioral manifestations of altered neuroimmune activity. Finally, neuroimmune modulation through pharmacological or psychosocial approaches has potential for modulating behavior.
Youth and Media Culture
Authors: Poyntz Stuart R. , Pedri Jennesia
Published: January 2018

Media in the 21st century are changing when, where, what, and how young people learn. Some educators, youth researchers, and parents lament this reality; but youth, media culture, and learning nevertheless remain entangled in a rich set of relationships today. These relationships and the anxieties they produce are not new; they echo worries about the consequences of young people’s media attachments that have been around for decades.

These anxieties first appeared in response to the fear that violence, vulgarity, and sexual desire in early popular culture was thought to pose to culture. Others, however, believed that media could be repurposed to have a broader educational impact. This sentiment crept into educational discourses throughout the 1960s in a way that would shift thinking about youth, media culture, and education. For example, it shaped the development of television shows such as Sesame Street as a kind of learning portal. In addition to the idea that youth can learn from the media, educators and activists have also turned to media education as a more direct intervention. Media education addresses how various media operate in and through particular institutions, technologies, texts, and audiences in an effort to affect how young people learn and engage with media culture. These developments have been enhanced by a growing interest in a broad project of literacy. By the 1990s and 2000s, media production became a common feature in media education practices because it was thought to enable young people to learn by doing, rather than just by analyzing or reading texts. This was enabled by the emergence of new digital media technologies that prioritize user participation.

As we have come to read and write media differently in a digital era, however, a new set of problems have arisen that affect how media cultures are understood in relation to learning. Among these issues is how a participatory turn in media culture allows others, including corporations, governments, and predatory individuals, to monitor, survey, coordinate, and guide our activities as never before. Critical media literacy education addresses this context and continues to provide a framework to address the future of youth, media culture and learning.
Indigenous Peoples in Africa
Authors: Sylvain Renee
Published: January 2018

Moringe ole Parkipuny addressed the United Nations Working Group on Indigenous Populations (UNWGIP) in 1989 and, for the first time, opened up discussion of the idea that certain groups of hunter-gathers and pastoralists in Africa merited the status of indigenous peoples. Local activists and international organizations took up the cause in the following decades. Several international conferences resulted in new forms of activism, the reformulation of local identities, and a growing body of scholarship addressing African indigeneity. As NGOs built solidarity among relatively scattered groups of pastoralists and hunter-gatherers, often skeptical state governments initially resisted what they saw as demands for recognition of status and claims to “special rights.” Disagreements between state interests and newly organized indigenous groups were expressed at the United Nations during the process of adopting the Declaration on the Rights of Indigenous Peoples (UNDRIP); but as the idea of indigeneity evolved through such discussions, African governments gradually came on board. International activism and work done by the African Commission on Human and Peoples’ Rights play significant roles in convincing African states to accept the concept of “indigenous peoples.” The issue of developing a definition of “indigenous peoples” appropriate for Africa remains unsettled and continues to present challenges. Mobilization among marginalized groups on the African continent itself, however, has presented NGOs, activists, states, and courts with the opportunity, through well-publicized struggles and several landmark legal cases, to refine the category to better fit with African contexts.