bluuebunny/crossref_metadata_2025 huggingface dataset:
Grid inhomogeneous solvation theory: Hydration structure and thermodynamics of the miniature receptor cucurbit[7]uril
Authors: Nguyen Crystal N. , Kurtzman Young Tom , Gilson Michael K.
Published: July 2012

The displacement of perturbed water upon binding is believed to play a critical role in the thermodynamics of biomolecular recognition, but it is nontrivial to unambiguously define and answer questions about this process. We address this issue by introducing grid inhomogeneous solvation theory (GIST), which discretizes the equations of inhomogeneous solvation theory (IST) onto a three-dimensional grid situated in the region of interest around a solute molecule or complex. Snapshots from explicit solvent simulations are used to estimate localized solvation entropies, energies, and free energies associated with the grid boxes, or voxels, and properly summing these thermodynamic quantities over voxels yields information about hydration thermodynamics. GIST thus provides a smoothly varying representation of water properties as a function of position, rather than focusing on hydration sites where solvent is present at high density. It therefore accounts for full or partial displacement of water from sites that are highly occupied by water, as well as for partly occupied and water-depleted regions around the solute. GIST can also provide a well-defined estimate of the solvation free energy and therefore enables a rigorous end-states analysis of binding. For example, one may not only use a first GIST calculation to project the thermodynamic consequences of displacing water from the surface of a receptor by a ligand, but also account, in a second GIST calculation, for the thermodynamics of subsequent solvent reorganization around the bound complex. In the present study, a first GIST analysis of the molecular host cucurbit[7]uril is found to yield a rich picture of hydration structure and thermodynamics in and around this miniature receptor. One of the most striking results is the observation of a toroidal region of high water density at the center of the host's nonpolar cavity. Despite its high density, the water in this toroidal region is disfavored energetically and entropically, and hence may contribute to the known ability of this small receptor to bind guest molecules with unusually high affinities. Interestingly, the toroidal region of high water density persists even when all partial charges of the receptor are set to zero. Thus, localized regions of high solvent density can be generated in a binding site without strong, attractive solute-solvent interactions.
Nonequilibrium molecular dynamics simulation of water transport through carbon nanotube membranes at low pressure
Authors: Wang Luying , Dumont Randall S. , Dickson James M.
Published: July 2012

Nonequilibrium molecular dynamics (NEMD) simulations are used to investigate pressure-driven water flow passing through carbon nanotube (CNT) membranes at low pressures (5.0 MPa) typical of real nanofiltration (NF) systems. The CNT membrane is modeled as a simplified NF membrane with smooth surfaces, and uniform straight pores of typical NF pore sizes. A NEMD simulation system is constructed to study the effects of the membrane structure (pores size and membrane thickness) on the pure water transport properties. All simulations are run under operating conditions (temperature and pressure difference) similar to a real NF processes. Simulation results are analyzed to obtain water flux, density, and velocity distributions along both the flow and radial directions. Results show that water flow through a CNT membrane under a pressure difference has the unique transport properties of very fast flow and a non-parabolic radial distribution of velocities which cannot be represented by the Hagen-Poiseuille or Navier-Stokes equations. Density distributions along radial and flow directions show that water molecules in the CNT form layers with an oscillatory density profile, and have a lower average density than in the bulk flow. The NEMD simulations provide direct access to dynamic aspects of water flow through a CNT membrane and give a view of the pressure-driven transport phenomena on a molecular scale.
Concept development for the ITER equatorial port visible/infrared wide angle viewing system
Authors: Reichle R. , Beaumont B. , Boilson D. , Bouhamou R. , Direz M.-F. , Encheva A. , Henderson M. , Huxford R. , Kazarian F. , Lamalle Ph. , Lisgo S. , Mitteau R. , Patel K. M. , Pitcher C. S. , Pitts R. A. , Prakash A. , Raffray R. , Schunke B. , Snipes J. , Diaz A. Suarez , Udintsev V. S. , Walker C. , Walsh M.
Published: July 2012

The ITER equatorial port visible/infrared wide angle viewing system concept is developed from the measurement requirements. The proposed solution situates 4 viewing systems in the equatorial ports 3, 9, 12, and 17 with 4 views each (looking at the upper target, the inner divertor, and tangentially left and right). This gives sufficient coverage. The spatial resolution of the divertor system is 2 times higher than the other views. For compensation of vacuum-vessel movements, an optical hinge concept is proposed. Compactness and low neutron streaming is achieved by orienting port plug doglegs horizontally. Calibration methods, risks, and R&D topics are outlined.
Stand-off filament-induced ablation of gallium arsenide
Authors: Weidman Matthew , Lim Khan , Ramme Mark , Durand Magali , Baudelet Matthieu , Richardson Martin
Published: July 2012

Using femtosecond filaments for the ablation of GaAs in air, we have observed that the diameter and volume of the resulting ablation craters remained almost constant with propagation distance. This constant mass removal along the propagation of a filament in both focused and non-focused configurations is valuable for applications such as material processing and stand-off laser-ablation based spectroscopy.
An improved carrier rate model to evaluate internal quantum efficiency and analyze efficiency droop origin of InGaN based light-emitting diodes
Authors: Wang Jiaxing , Wang Lai , Wang Lei , Hao Zhibiao , Luo Yi , Dempewolf Anja , Müller Mathias , Bertram Frank , Christen Jürgen
Published: July 2012

A carrier rate model taking carrier delocalization into account is presented to analyze current dependent internal quantum efficiency of InGaN based light-emitting diodes (LEDs). By fitting normalized experimental internal quantum efficiency-current curves, both injection efficiency and radiative recombination efficiency depending on current can be obtained. Based on the fitting results from two LED samples with and without the InGaN interlayer beneath the active regions of 5 InGaN quantum wells (QWs), carrier delocalization and carrier leakage are believed to lead to the efficiency droop effect under considerable and even larger injection, respectively. By investigating two LED samples with 8 and 10 QWs, it is found that the 8-QWs LED has the highest radiative recombination efficiency over 80% and the 10-QWs one has the highest injection efficiency over 50% under 120 A/cm2. This means that increasing QW number is an effective method to suppress droop effect.
Electronic structures of WAlOy and WAlOy− (y = 2–4) determined by anion photoelectron spectroscopy and density functional theory calculations
Authors: Mann Jennifer E. , Waller Sarah E. , Jarrold Caroline Chick
Published: July 2012

The anion photoelectron spectra of WAlOy− (y = 2–4) are presented and assigned based on results of density functional theory calculations. The WAlO2− and WAlO3− spectra are both broad, with partially resolved vibrational structure. In contrast, the WAlO4− spectrum features well-resolved vibrational structure with contributions from three modes. There is reasonable agreement between experiment and theory for all oxides, and calculations are in particular validated by the near perfect agreement between the WAlO4− photoelectron spectrum and a Franck-Condon simulation based on computationally determined spectroscopic parameters. The structures determined from this study suggest strong preferential W-O bond formation, and ionic bonding between Al+ and WOy−2 for all anions. Neutral species are similarly ionic, with WAlO2 and WAlO3 having electronic structure that suggests Al+ ionically bound to WOy− and WAlO4 being described as Al+2 ionically bound to WO4−2. The doubly-occupied 3sp hybrid orbital localized on the Al center is energetically situated between the bonding O-local molecular orbitals and the anti- or non-bonding W-local molecular orbitals. The structures determined in this study are very similar to structures recently determined for the analogous MoAlOy−/MoAlOy cluster series, with subtle differences found in the electronic structures [S. E. Waller, J. E. Mann, E. Hossain, M. Troyer, and C. C. Jarrold, J. Chem. Phys. 137, 024302 (2012)10.1063/1.4731345].
The dual modified Korteweg-de Vries–Fokas–Qiao equation: Geometry and local analysis
Authors: Bies Piotr Michał , Górka Przemysław , Reyes Enrique G.
Published: July 2012

We study a bi-hamiltonian equation with cubic nonlinearity shown to appear in the theory of water waves by Fokas, derived by Qiao using the two-dimensional Euler equation, and also known to arise as the dual of the modified Korteweg-de Vries equation thanks to work by Fokas, Fuchssteiner, Olver, and Rosenau. We present a quadratic pseudo-potential, we compute infinite sequences of local and nonlocal conservation laws, and we construct an infinite-dimensional Lie algebra of symmetries which contains a semi-direct sum of the $sl(2,\mathbb {R})$sl(2,R)-loop algebra and the centerless Virasoro algebra. As an application we prove a theorem on the existence of smooth solutions, and we construct some explicit examples. Moreover, we consider the Cauchy problem and we prove existence and uniqueness of weak solutions in the Sobolev space $H^{q+2}({\mathbb R})$Hq+2(R), q > 1/2.
Restricted diffusion in NMR in arbitrary inhomogeneous magnetic fields and an application to circular layers
Authors: Laun Frederik Bernd
Published: July 2012

The multiple correlation function technique is a versatile approach for the computation of the nuclear magnetic resonance (NMR) magnetization of spins diffusing in inhomogeneous fields. The difficulties in deriving the required interaction matrices are one of the main limitations of this technique. In this work, methods to compute the interaction matrices of general magnetic field profiles from those of linear fields by basic matrix manipulations are presented. As an example, susceptibility induced magnetic field profiles that are generated by cylindrical capillaries residing in homogeneous magnetic fields are considered.
Metal particle nucleation in laminar jets
Authors: Liu Jun , Garrick Sean C.
Published: July 2012

Gas to particle conversion in the form of nucleation within various flow systems plays a significant role in a variety of industrial and natural processes. Recently developed surface tension models offer increased accuracy in the modeling of metal particle nucleation. These models facilitate the probing of the effects of fluid, scalar, and thermal transport on nucleation in an accurate manner. In this work we investigate the formation of metal nanoparticles in laminar flows. The flows consist of metal vapor diluted in argon issuing into a cooler argon stream. The fluid, thermal, and chemical fields are obtained by solving the Navier Stokes, enthalpy, and mass-fraction transport equations while nucleation is simulated via a homogeneous nucleation model with size-dependent surface tension. This approach is attractive in that it promises to be more accurate than the classical nucleation theory (CNT) while maintaining much of its simplicity when coupling with fluid dynamics. The results show that the size-dependent surface tension nucleation model is more accurate than CNT and agrees well with physical data. Physically, the sensitivity of the saturation ratio to changes in temperature is shown to be greater than its sensitivity to mass fraction, highlighting the significance of differential molecular transport of energy and mass and the significance of non-unity Lewis numbers. More significantly, the size-dependent surface tension approach suggests that certain metals may have a maximum nucleation rate and further cooling—a strategy employed to increase particle nucleation rates—will actually decrease particle nucleation.
Measurement of xenon plasma properties in an ion thruster using laser Thomson scattering technique
Authors: Yamamoto N. , Tomita K. , Sugita K. , Kurita T. , Nakashima H. , Uchino K.
Published: July 2012

This paper reports on the development of a method for measuring xenon plasma properties using the laser Thomson scattering technique, for application to ion engine system design. The thresholds of photo-ionization of xenon plasma were investigated and the number density of metastable atoms, which are photo-ionized by a probe laser, was measured using laser absorption spectroscopy, for several conditions. The measured threshold energy of the probe laser using a plano-convex lens with a focal length of 200 mm was 150 mJ for a xenon mass flow rate of 20 μg/s and incident microwave power of 6 W; the probe laser energy was therefore set as 80 mJ. Electron number density was found to be (6.2 ± 0.4) × 1017 m−3 and electron temperature was found to be 2.2 ± 0.4 eV at a xenon mass flow rate of 20 μg/s and incident microwave power of 6 W. The threshold of the probe laser intensity against photo-ionization in a miniature xenon ion thruster is almost constant for various mass flow rates, since the ratio of population of the metastable atoms to the electron number density is little changed.
Low energy electron induced damage to plasmid DNA pQE30
Authors: Kumar S. V. K. , Pota Tasneem , Peri Dinakar , Dongre Anushka D. , Rao Basuthkar J.
Published: July 2012

Low energy electrons (LEEs) are produced in copious amounts by the primary radiation used in radiation therapy. The damage caused to the DNA by these secondary electrons in the energy range 5–22 eV has been studied to understand their possible role in radiation induced damage. Electrons are irradiated on dried films of plasmid DNA (pQE30) and analysed using agarose gel electrophoresis. Single strand breaks (SSBs) induced by LEE to supercoiled plasmid DNA show resonance structures at 7, 12, and 15 eV for low doses and 6, 10, and ∼18 eV at saturation doses. The present measurements have an overall agreement with the literature that LEEs resonantly induce SSBs in DNA. Resonant peaks in the SSBs induced by LEEs at 7, 12, and 15 eV with the lowest employed dose in the current study are somewhat different from those reported earlier by two groups. The observed differences are perhaps related to the irradiation dose, conditions and the nature of DNA employed, which is further elaborated.
Self-consistent simulation of the initiation of the flashover discharge on vacuum insulator surface
Authors: Cai L. B. , Wang J. G. , Zhang D. H. , Du T. J. , Zhu X. Q. , Wang Y.
Published: July 2012

A 2D particle-in-cell code, including the space charge effects of insulator surface charge, is established to simulate the initiation of insulator surface flashover. The simulation is started with a field electron emission, which provides the seed electrons of the surface flashover discharge. Then the secondary electron emission is caused by the seed electrons on the insulator surface, gets into an avalanche, and saturates rapidly in a region between the cathode and anode. And the saturation region spreads to the anode at a speed of ∼107 m/s, which is coincident with the experiment measurement.
Local atomic structure in equilibrium and supercooled liquid Zr75.5Pd24.5
Authors: Mauro N. A. , Fu W. , Bendert J. C. , Cheng Y. Q. , Ma E. , Kelton K. F.
Published: July 2012

Atomic structures were obtained in equilibrium and supercooled eutectic Zr75.5Pd24.5 liquids by in situ high-energy synchrotron diffraction measurements using the beamline electrostatic levitation (BESL) technique, which provides a high-vacuum, containerless, environment. Reverse Monte Carlo fits to the x-ray static structure factors, constrained using partial pair correlation functions obtained from ab initio molecular dynamics simulations, indicate the presence of medium-range order (MRO) in the form of a strong tendency for Pd-Pd (solute-solute) avoidance. This order persists over the entire temperature range studied, from 170 °C above the equilibrium liquidus temperature to 263 °C below it. Further, a quantitative analysis of the atomic structures obtained indicates a modest degree of icosahedral-like local order around Pd atoms, with the clusters showing an increased tendency for face-sharing to form more extended structures with decreasing temperature.
Transient chaotic rotating waves in a ring of unidirectionally coupled symmetric Bonhoeffer-van der Pol oscillators near a codimension-two bifurcation point
Authors: Horikawa Yo , Kitajima Hiroyuki
Published: July 2012

Propagating waves in a ring of unidirectionally coupled symmetric Bonhoeffer-van der Pol (BVP) oscillators were studied. The parameter values of the BVP oscillators were near a codimension-two bifurcation point around which oscillatory, monostable, and bistable states coexist. Bifurcations of periodic, quasiperiodic, and chaotic rotating waves were found in a ring of three oscillators. In rings of large numbers of oscillators with small coupling strength, transient chaotic waves were found and their duration increased exponentially with the number of oscillators. These exponential chaotic transients could be described by a coupled map model derived from the Poincaré map of a ring of three oscillators. The quasiperiodic rotating waves due to the mode interaction near the codimension-two bifurcation point were evidently responsible for the emergence of the transient chaotic rotating waves.
Role of the substrate in the electrical transport characteristics of focused ion beam fabricated nanogap electrode
Authors: Rajput Nitul S. , Singh Abhishek K. , Verma H. C.
Published: July 2012

Precise metallic nanogap structure is fabricated on a glass substrate by using a 30 keV focused Ga ion beam. While investigating the I-V behavior of the nanogap structure, tunneling through the substrate has been found to play a vital role in the electrical transportation process. Substrate breakdown occurs at a certain applied voltage and a metal vapor state is initiated through intense heat generation at the nanogap region. The experimental observation confirms the role of the substrate in the explosion process. Metallic spherical particles are formed during cooling/condensation of the metal vapors or splashing of the liquid droplets showing a wide distribution of size from few tens of nanometers to few microns.
Synergistic co-processing/co-cracking of Jatropha oil, petroleum vacuum residue, and high density polyethylene
Authors: Biswas Shelly , Sharma D. K.
Published: July 2012

Co-processing behavior of the blended mixture of Jatropha oil (JO), petroleum vacuum residue (VR), and high density polyethylene (HDPE) was studied by using thermogravimetric analysis under nitrogen atmosphere and was compared with those of their individual components. The blended samples studied are VR:JO (1:1), VR:HDPE (1:1), JO:HDPE (1:1), and VR:JO:HDPE (1:1:1). The pyrolysis was carried out from an ambient temperature of 30 °C to 800 °C in an inert atmosphere of nitrogen with a heating rate of 10 K/min. The value of activation energy was found to vary within the three temperature ranges studied <400, 400–500, >500. A reduction in the activation energy of the blended mixture was observed, which clearly indicates the synergism in the co-cracking/co-processing reactions when they are co-cracked/co-processed together. Thermodynamics parameters of the binary and ternary mixture of fuels were derived which further support the feasibility of co-cracking reactions.
Electronic structures of the SrTiO3(110) surface in different reconstructions
Authors: Cao Yanwei , Wang Shuai , Liu Shuming , Guo Qinlin , Guo Jiandong
Published: July 2012

The surface of SrTiO3(110) single crystal is prepared in monophase with different reconstructions. The increase of surface Ti concentration is responsible for the evolution of the reconstruction from (4×1) to (2×8), and to a new (1×10) structure. It also induces the enhancement of the surface metallicity, characterized by the appearance of the in-gap states and the increasing Drude weight as measured by the electron and photoelectron spectroscopies. We attribute the metallicity to the reduced Ti ions, which is consistent with the observed band structures and the shift of the phonon energy. It is indicated that a heterointerface between a reduced titanate layer and SrTiO3 crystal with unique electronic structure can be obtained by the simple treatment.
White metal-like omnidirectional mirror from porous silicon dielectric multilayers
Authors: Ariza-Flores A. David , Gaggero-Sager L. M. , Agarwal V.
Published: July 2012

We report the design and fabrication of the complete visible range omnidirectional mirror, with a dielectric multilayered structure based on porous silicon (PS). The refractive index profile consisted of Bragg type chirped layers with an increasing thicknesses modulated by a potential envelop function f(x)=Cxk. The omnidirectional photonic band gap (OPBG) was measured from 396 to 805 nm, with more than 95% of the reflectivity, for 8° and 68°. The theoretical simulations based on the transfer matrix method along with a photographic sequence of the sample confirmed the OPBG for higher incident angles. It was enhanced by a factor of 19 as compared to the last reported visible region OPBG by PS dielectric multilayered structure.
A study of vibration system characteristics based on laser self-mixing interference effect
Authors: Huang Yang , Du Zhengting , Deng Jialiang , Cai Xuguang , Yu Benli , Lu Liang
Published: July 2012

For removing the limitations of traditional theoretical model and measurement technology of vibration system characteristics, a new vibration system extreme points (VSEP) model based on laser self-mixing interference (SMI) effect is proposed. The VSEP can be applied to study vibration systems due to compact, effective, and low cost. This paper derives the VSEP model from Lang-Kobayashi (L-K) rate equations and modifies the simplified half-cycle extreme points formula by using Monte Carlo stochastic simulation method. Finally, amplitude-frequency response curve which ω0 is 1.18595 × 103 rad, δ is 16.2460 s−2 and the piezoelectric coefficient of piezoelectric transducer which d33 is 0.66034 nm/V have been obtained by combining the modified VSEP model and SMI measurement method.
Transient measurement approaches to differentiate non-specific binding in affinity-based bioanalytical assays
Authors: Mao Yufei , On Chui Chi
Published: July 2012

Non-specific binding (NSB), especially due to cross-reactivity between specific capture probes and interferents, is a platform-independent issue that limits the detection selectivity of most affinity-based bioanalytical assays. The ability to differentiate and quantify NSB has thus been sought after particularly in label-free biomolecular detections. In this paper, the Langmuir formulation has been applied to understand the transient competitive binding between the target molecules and interferents with the capture probes in complex solutions. By tracking the deviation from the ideal interferent-free case, two NSB differentiation approaches have been proposed. The first one requires multiple measurements during the initial transient and has a short turnaround time. The second approach necessitates only one transient and one equilibrium sampling, which offers a better selectivity over the first approach. The applicability of each approach has been scrutinized depending on whether the interferents would contribute a signal comparable to that of the targets. Finally, the achievable detection selectivity has been correlated to the intrinsic sensitivity of the bioanalytical assay.
Disorder-free sputtering method on graphene
Authors: Qiu Xue Peng , Shin Young Jun , Niu Jing , Kulothungasagaran Narayanapillai , Kalon Gopinadhan , Qiu Caiyu , Yu Ting , Yang Hyunsoo
Published: July 2012

Deposition of various materials onto graphene without causing any disorder is highly desirable for graphene applications. Especially, sputtering is a versatile technique to deposit various metals and insulators for spintronics, and indium tin oxide to make transparent devices. However, the sputtering process causes damage to graphene because of high energy sputtered atoms. By flipping the substrate and using a high Ar pressure, we demonstrate that the level of damage to graphene can be reduced or eliminated in dc, rf, and reactive sputtering processes.
Karen Vousden: Getting the big picture on p53
Authors: Sedwick Caitlin
Published: July 2012

Vousden studies the activities and regulation of the tumor suppressor p53.
Subcanonical points on algebraic curves
Authors: Bullock Evan
Published: July 2012

If

C
C

is a smooth, complete algebraic curve of genus

g
≥
2

g\geq 2

over the complex numbers, a point

p
p

of

C
C

is subcanonical if

K
C

≅

O

C

(

(
2
g
−
2
)
p

)

K_C \cong \mathcal {O}_C\big ((2g-2)p\big )

. We study the locus

G

g

⊆

M

g
,
1

\mathcal {G}_g\subseteq \mathcal {M}_{g,1}

of pointed curves

(
C
,
p
)

(C,p)

, where

p
p

is a subcanonical point of

C
C

. Subcanonical points are Weierstrass points, and we study their associated Weierstrass gap sequences. In particular, we find the Weierstrass gap sequence at a general point of each component of

G

g

\mathcal {G}_g

and construct subcanonical points with other gap sequences as ramification points of certain cyclic covers and describe all possible gap sequences for

g
≤
6

g\leq 6

.
A neurotrophic hypothesis of depression: role of synaptogenesis in the actions of NMDA receptor antagonists
Authors: Duman Ronald S. , Li Nanxin
Published: July 2012

Molecular and cellular studies have demonstrated opposing actions of stress and antidepressant treatment on the expression of neurotrophic factors, particularly brain-derived neurotrophic factor, in limbic structures of the brain. These changes in neurotrophic factor expression and function result in structural alterations, including regulation of neurogenesis, dendrite length and spine density in hippocampus and prefrontal cortex (PFC). The deleterious effects of stress could contribute to the reduced volume of these brain regions in depressed patients. Conversely, the actions of antidepressant treatment could be mediated in part by blocking or reversing the atrophy caused by stress and depression. Recent studies have identified a novel, rapid-acting antidepressant, ketamine, in treatment-resistant depressed patients that addresses the limitations of currently available agents (i.e. delayed onset of action and low response rates). We have found that ketamine, an
N
-methyl-
d
-aspartate (NMDA) receptor antagonist, causes a rapid induction of synaptogenesis and spine formation in the PFC via stimulation of the mammalian target of the rapamycin signalling pathway and increased synthesis of synaptic proteins. These effects of ketamine rapidly reverse the atrophy of PFC neurons caused by chronic stress and correspond to rapid behavioural actions of ketamine in models of depression. Characterization of a novel signalling pathway also identifies new cellular targets that could result in rapid and efficacious antidepressant actions without the side effects of ketamine.
Transcriptional regulation of the 5-HT1Areceptor: implications for mental illness
Authors: Albert Paul R.
Published: July 2012

The serotonin-1A (5-HT1A) receptor is an abundant post-synaptic 5-HT receptor (heteroreceptor) implicated in regulation of mood, emotion and stress responses and is the major somatodendritic autoreceptor that negatively regulates 5-HT neuronal activity. Based on animal models, an integrated model for opposing roles of pre- and post-synaptic 5-HT1Areceptors in anxiety and depression phenotypes and response to antidepressants is proposed. Understanding differential transcriptional regulation of pre- versus post-synaptic 5-HT1Areceptors could provide better tools for their selective regulation. This review examines the transcription factors that regulate brain region-specific basal and stress-induced expression of the 5-HT1Areceptor gene (Htr1a). A functional polymorphism, rs6295 in theHtr1apromoter region, blocks the function of specific repressors Hes1, Hes5 and Deaf1, resulting in increased 5-HT1Aautoreceptor expression in animal models and humans. Its association with altered 5-HT1Aexpression, depression, anxiety and antidepressant response are related to genotype frequency in different populations, sample homogeneity, disease outcome measures and severity. Preliminary evidence from gene × environment studies suggests the potential for synergistic interaction of stress-mediated repression of 5-HT1Aheteroreceptors, and rs6295-induced upregulation of 5-HT1Aautoreceptors. Targeted therapeutics to inhibit 5-HT1Aautoreceptor expression and induce 5-HT1Aheteroreceptor expression may ameliorate treatment of anxiety and major depression.
Probing the diversity of serotonin neurons
Authors: Gaspar Patricia , Lillesaar Christina
Published: July 2012

The serotonin (5-HT) system is generally considered as a single modulatory system, with broad and diffuse projections. However, accumulating evidence points to the existence of distinct cell groups in the raphe. Here, we review prior evidence for raphe cell heterogeneity, considering different properties of 5-HT neurons, from metabolism to anatomy, and neurochemistry to physiology. We then summarize more recent data in mice and zebrafish that support a genetic diversity of 5-HT neurons, based on differential transcription factor requirements for the acquisition of the 5-HT identity. In both species, PET1 plays a major role in the acquisition and maintenance of 5-HT identity in the hindbrain, although some 5-HT neurons do not require PET1 for their differentiation, indicating the existence of several transcriptional routes to become serotoninergic. In mice, both PET1-dependent and -independent 5-HT neurons are located in the raphe, but have distinct anatomical features, such as the morphology of axon terminals and projection patterns. In zebrafish, all raphe neurons express
pet1
, but Pet1-independent 5-HT cell groups are present in the forebrain. Overall, these observations support the view that there are a number of distinct 5-HT subsystems, including within the raphe nuclei, with unique genetic programming and functions.
Targeting brain serotonin synthesis: insights into neurodevelopmental disorders with long-term outcomes related to negative emotionality, aggression and antisocial behaviour
Authors: Lesch Klaus-Peter , Araragi Naozumi , Waider Jonas , van den Hove Daniel , Gutknecht Lise
Published: July 2012

Aggression, which comprises multi-faceted traits ranging from negative emotionality to antisocial behaviour, is influenced by an interaction of biological, psychological and social variables. Failure in social adjustment, aggressiveness and violence represent the most detrimental long-term outcome of neurodevelopmental disorders. With the exception of brain-specific tryptophan hydroxylase-2 (Tph2), which generates serotonin (5-HT) in raphe neurons, the contribution of gene variation to aggression-related behaviour in genetically modified mouse models has been previously appraised (Lesch 2005Novartis Found Symp.268, 111–140; Lesch & Merschdorf 2000Behav. Sci. Law18, 581–604). Genetic inactivation of Tph2 function in mice led to the identification of phenotypic changes, ranging from growth retardation and late-onset obesity, to enhanced conditioned fear response, increased aggression and depression-like behaviour. This spectrum of consequences, which are amplified by stress-related epigenetic interactions, are attributable to deficient brain 5-HT synthesis during development and adulthood. Human data relating altered TPH2 function to personality traits of negative emotionality and neurodevelopmental disorders characterized by deficits in cognitive control and emotion regulation are based on genetic association and are therefore not as robust as the experimental mouse results. Mouse models in conjunction with approaches focusing onTPH2variants in humans provide unexpected views of 5-HT's role in brain development and in disorders related to negative emotionality, aggression and antisocial behaviour.
The CCM model: a stock valuation tool for a student managed investment fund
Authors: Bowers Jared H. , Lavin Angeline M.
Published: July 2012

Purpose

The purpose of this paper is to develop and test a model that can be used to help students learn the investment analysis process and accurately identify good and bad investment opportunities.

Design/methodology/approach

The model tested in this research was developed by a former member of the student managed investment fund Coyote Capital Management at the University of South Dakota. The goal of this project was to refine that original model and test it using historical data from a sample of companies during both bull and bear market periods.

Findings

During the bull market period (2004‐2006), 81 per cent of the model's recommendations were correct, and during the 2007‐2009 bear market period, approximately 66 per cent of the model's recommends were correct.

Originality/value

While following the model's recommendations could potentially produce returns well above those of the market in the best case scenario and returns in line with the market in the worst case scenario, there are many factors that should go into making an investment decision. This model can be useful as an item in the investor's tool kit, and it has the potential to help students better understand the process of evaluating an investment opportunity.
Evidence of managerial opportunism in Australia
Authors: Trumble Andrew , Pinder Sean
Published: July 2012

Purpose

The purpose of this paper is to test for managerial opportunism, specifically the backdating of executive options, in Australia.

Design/methodology/approach

The paper analyses the return behaviour associated with a sample of 161 unscheduled options granted by Australian firms. Specifically, the authors test for differences between a subsample of grants that had late‐filed notices (and hence may be subject to backdating) versus those that had notices filed on‐time.

Findings

Consistent with backdating, it is found that these abnormal post‐grant returns persist for a sub‐sample of late‐filed grants but not for a sub‐sample of grants with same‐day filing. Furthermore – the authors find even stronger results for option grants made by firms with a history of late‐filing but for which no notice was filed with the Australian Securities Exchange. This paper is the first to demonstrate these effects in a setting subject to the IFRS requirement that the fair value (rather than the intrinsic value) of executive options be expensed.

Originality/value

This paper is the first to demonstrate these effects in Australia and further in a setting subject to the IFRS requirement that the fair value (rather than the intrinsic value) of executive options be expensed.
Developing a psychological approach: learning from a housing association pilot
Authors: Edwards Aileen
Published: July 2012

Purpose

This paper seeks to offer a commentary on Psychologically Informed Services: A Good Practice Guide, a recently published operational guidance document on developing psychologically informed environments (PIEs) in services for homeless people.

Design/methodology/approach

The paper is an invited opinion piece and comment, based on the specialist experience and viewpoint of the author as Chief Executive of Second Step, a housing association providing support to a range of vulnerable people.

Findings

The new operational guidance is welcomed. The author outlines the use of the concept of a psychologically informed environment, as developed in practice through an initial pilot service run by Second Step. This practice learning was then spread and developed more broadly through other Second Step services.

Originality/value

On the basis of their experience, the author makes observations on what was found most useful, to “inform” their service. The agency has now agreed a Psychological Therapies Strategy, which focuses on developing training for staff on interventions that can be effectively used within the staff role. Reflective practice is promoted throughout the service.
Intellectual capital disclosure trends: some Malaysian evidence
Authors: Ahmed Haji Abdifatah , Mohd Ghazali Nazli A.
Published: July 2012

Purpose

The purpose of this paper is to examine the trend of intellectual capital disclosures (ICD) over a three‐year period (2008‐2010), when the Malaysian business environment was characterized by a number of major events such as the recent 2008/2009 global financial crisis and corporate governance restructuring.

Design/methodology/approach

A checklist was constructed to measure the extent and quality of ICD in Malaysian corporate annual reports. The extent of ICD was measured on a dichotomous basis (0, 1) while the quality of ICD was measured using a four‐point scale (0‐3).

Findings

The results showed an increasing trend of the ICD and a significant overall increase by the sample Malaysian companies. The results also revealed that there are significant differences between the categories of the IC disclosures, with external capital related information accounting for the largest portion. However, only human capital disclosures significantly increased over time.

Practical implications

The time series analysis carried out in this study observed that, despite the general ICD increasing trend, item‐specific analysis showed inconsistent results. Hence, the regulators may want to devise reporting guidelines for IC for Malaysian public listed companies.

Originality/value

This paper is one of the few which investigate trends in ICD following significant changes in the business environment in an attempt to determine if those changes have some impact on ICD practices.
A call for collaborative academic and practitioner efforts to address remote‐access voting methods
Authors: Rosacker Robert E. , Rosacker Kirsten
Published: July 2012

Purpose

The purpose of this paper is to provide a timely discussion of the important topic of remote‐access voting technology.

Design/methodology/approach

First, an introduction to the topic is offered; second the existing state of the art is considered; third, a brief history of electronic and internet voting methods is presented; and fourth, a short list of critical success factors for remote‐access voting is presented. Finally, a conclusion is offered surrounding how academics and practitioners can collaboratively proceed to address the salient issues and barriers that currently prohibit the advancement of remote‐access voting.

Findings

There is a brief and largely successful history involving applications of information communication technologies (ICTs) and computer technology to assist in data capture and tabulation of democratic elections. While several critical issues have been identified, none has been so significant that an end‐game strategy should be invoked rather than continued innovation. Concurrently, the business world has witnessed an expanding use of computer‐based infrastructures and enhanced ICTs to facilitate the processing of remote‐access commercial transactions. These advancements have provided a rich opportunity to seek out, identify, and address the substantive operational issues permitting the successful expansion of a variety of business methods, models, and processes. While these successes have provided a solid foundation upon which e‐government voting systems can be attempted, such a process improvement has been elusive to this date with many of the real issues and concerns seeming to be too large to resolve.

Originality/value

The paper considers the important issue of remote‐access voting as a means for supporting the expansion and refinement of democratic processes across the world through increased citizen participation.
Factors influencing e‐government adoption in Pakistan
Authors: Rehman Mariam , Esichaikul Vatcharaporn , Kamal Muhammad
Published: July 2012

Purpose

The purpose of this paper is to identify critical factors that enable citizens to adopt e‐Government services in a society which is at a rudimentary stage of e‐Government adoption. To achieve the objective of the research study, an integrated conceptual model has been proposed and validated which is based on sound theoretical conditions, keeping in view the local context of Pakistani society.

Design/methodology/approach

An integrated conceptual model is proposed highlighting a comprehensive set of potential factors influencing the adoption of e‐Government services. The conceptual model was developed using related literature review and also by conducting expert reviews with government officials, academic researchers and software engineers in Pakistan.

Findings

From expert reviews, the results indicate that awareness, trust in the internet and trust in the government are the significant variables specific to the context of Pakistani society. The results of this study prove that awareness is a significant variable having influence on the citizens' intention to use e‐Government services, either to get information or to perform a transaction using the government web site. Information quality is found to be a significant variable when getting information from the government website. Perceived ease of use, service quality and transaction security are significant variables which influence the citizens' intention to perform transactions with the government.

Research limitations/implications

An integrated conceptual model is a robust way to explore the key factors that have great influence on e‐Government adoption. The target respondents for this study are internet users. In future, the research work will be extended by including technology divide citizens called offline respondents, i.e. less frequent internet users. The results of online and offline respondents are compared so that the perception of technology divide citizens may also be included to identify the factors influencing the adoption of e‐Government services.

Practical implications

The key findings are useful for policy makers and decision makers, for a real understanding of the needs of the citizens. The proposed model can be used as a guideline for e‐Government strategy formulation and implementation for the Government of Pakistan.

Originality/value

To address the originality, an integrated conceptual model is proposed to overcome the shortcomings of the previous models by adding factors and their respective variables to make the model more comprehensive. Later, the proposed conceptual model is customized and also validated according to the local context of Pakistani society.
Middle managers in elderly care under demands and expectations
Authors: Ekholm Bodil
Published: July 2012

Purpose

The purpose of this project was to study how middle managers look on and shape their work and leadership with regard to the demands and expectations that exist from different participants within the home help service operation. The participants are politicians, officials at central level, nursing staff, persons receiving care and their relatives.

Design/methodology/approach

The participants are eight managers in eight different home‐help service units. The units are spread out in four districts with high socioeconomic status and four districts with low. Four managers are at public units and four are at units with private executor. The majority of the managers had worked as leaders between three and eight years. The study is based on individual interviews and observations of the managers and of staff meetings. The data were subjected to content analysis. Two main categories and five subcategories were generated.

Findings

There were large similarities in how the managers perceived the demands and expectations, but there were differences when it came to how they handled them. Three of the managers experienced that they could handle the demands and expectations through organizing and structuring the operation and prioritizing the assignments, while five of the managers experienced difficulties to handle them and they conveyed that they suffered from stress. The managers who could handle the demands combine a professional and an organizational perspective in their leadership.

Originality/value

The knowledge from the study may be of great value in recruiting new managers in elderly care but also in creating programs of competence development for managers.
Finding, training, and keeping best service workers
Authors: Dandira Martin
Published: July 2012

Subject area

Organisational behaviour, business reengineering and management of change, human resources management.

Study level/applicability

This case study is intended for undergraduate and post-graduate management degrees. It includes courses on organizational behaviour, human resources management, marketing, business management, travel and tourism and strategic management.

Case overview

Zim-Zum Welcome Hotel is a hotel in Zimbabwe in the travel and tourism sector. It was facing high turnover of employees and this was affecting the business through continuous hiring and training. The organization decided to introduce changes completely changing the way it does things, focusing on satisfying employees as well as customers. The new approach yielded favourable results, labour turnover dropped significantly and business improved greatly. In an effort to improve service, and increase profit, Zim-Zum has begun radically changing the way it hires, trains and deploys frontline workers. Management also examined how waiters and waitress do their job and concluded that there was supposed to be a division of labour between them and culinary staff. Management of Zim-Zum believe that companies that excel at managing frontline workers understand that excellent service is more than just a transaction.

Expected learning outcomes

Students can focus on: the importance of redesigning work so that superior service satisfies both the employee and the customer; human resources management is an important factor in improving employee performance and business performance; the importance of external and internal customers in improving company performance.
Mesenteric phlebosclerosis associated with long‐term oral intake of geniposide, an ingredient of herbal medicine
Authors: Hiramatsu K. , Sakata H. , Horita Y. , Orita N. , Kida A. , Mizukami A. , Miyazawa M. , Hirai S. , Shimatani A. , Matsuda K. , Matsuda M. , Ogino H. , Fujinaga H. , Terada I. , Shimizu K. , Uchiyama A. , Ishizawa S. , Abo H. , Demachi H. , Noda Y.
Published: July 2012

Background

Idiopathic mesenteric phlebosclerosis (IMP) is a rare disease, characterised by thickening of the wall of the right hemicolon with calcification of mesenteric veins. However, the aetiology remains unknown.

Aim

To investigate the possible association of herbal medicines with IMP.

Method

The clinical data of four of our own patients were collected. Furthermore, we searched for previous reports about similar patients with detailed descriptions of herbal prescriptions that they had taken. We compared herbal ingredients to identify the toxic agent as a possible aetiological factor.

Results

Clinical data on a total of 25 patients were summarised. Mean age was 61.8 years and there was female predominance (6 men and 19 women). The used Kampo prescription, the number of cases, and the mean duration of use were as follows: kamisyoyosan in 12 cases for 12.8 years, inshin‐iseihaito in 5 cases for 13.4 years, orengedokuto in 4 cases for 14.3 years, inchinkoto in 1 case for 20 years, kamikihitou in 1 case for 19 years, seijobofuto in 1 case for 10 years and gorinsan in 1 case for an unknown duration. Only one ingredient, sansisi, was common to the herbal medicines of all 25 patients. This crude drug called geniposide in English is a major constituent of the Gardenia fruits.

Conclusion

The long‐term use of geniposide in herbal medicines appears to be associated with mesenteric phlebosclerosis.