Absence of placeholders abolishes exogenous attention effect in a peripheral cueing procedure

Most studies of exogenous visuospatial attention use placeholders indicating the regions where the stimuli appear on the screen. Preliminary results from our laboratory provided evidence that the attentional effect is more frequently observed when placeholders are used in these experimental procedures. Four experiments were carried out. Experiment 1 aimed at confirming the finding that the attentional effect of a spatially non-informative cue (S1) observed in the presence of placeholders disappears in their absence. The results confirmed this finding. Experiments 2, 3, and 4 examined several possible processes that could explain this finding. Experiment 2 investigated if the contribution of a faster disengagement of attention from the cued location or a stronger forward masking could explain the absence of attentional effect when no placeholders were used. Experiment 3 investigated if increased difficulty in discrimination of the target (S2) from S1 would favor the appearance of the attentional effect in the absence of placeholders. Experiment 4 investigated if an insufficient focusing of attention towards the cued location could explain the absence of attentional effect when no placeholders were used. The results of the three experiments indicated that placeholders act by reducing the discriminability of the S2. This would presumably lead to the adoption of an attentional set that favors the mobilization of attention by the S1

Microfluidic wound-healing assay to assess the regenerative effect of HGF on wounded alveolar epithelium

We present a microfluidic epithelial wound-healing assay that allows characterization of the effect of hepatocyte growth factor (HGF) on the regeneration of alveolar epithelium using a flow-focusing technique to create a regular wound in the epithelial monolayer. The phenotype of the epithelial cell was characterized using immunostaining for tight junction (TJ) proteins and transmission electron micrographs (TEMs) of cells cultured in the microfluidic system, a technique that is reported here for the first time. We demonstrate that alveolar epithelial cells cultured in a microfluidic environment preserve their phenotype before and after wounding. In addition, we report a wound-healing benefit induced by addition of HGF to the cell culture medium (19.2 vs. 13.5 μm h(-1) healing rate).

Experimental and theoretical study of microstructure effect on piezoelectric property of one dimensional ZnO nanostructures

Emerging nanogenerators have attracted the attention of the research community, focusing on energy generation using piezoelectric nanomaterials. Nanogenerators can be utilized for powering NEMS/MEMS devices. Understanding the piezoelectric properties of ZnO one-dimensional materials such as ZnO nanobelts (NBs) and Nanowires (NWs) can have a significant impact on the design of new devices. The goal of this dissertation is to study the piezoelectric properties of one-dimensional ZnO nanostructures both experimentally and theoretically. First, the experimental procedure for producing the ZnO nanostructures is discussed. The produced ZnO nanostructures were characterized using an in-situ atomic force microscope and a piezoelectric force microscope. It is shown that the electrical conductivity of ZnO NBs is a function of applied mechanical force and its crystalline structure. This phenomenon was described in the context of formation of an electric field due to the piezoelectric property of ZnO NBs. In the PFM studies, it was shown that the piezoelectric response of the ZnO NBs depends on their production method and presence of defects in the NB. Second, a model was proposed for making nanocomposite electrical generators based on ZnO nanowires. The proposed model has advantages over the original configuration of nanogenerators which uses an AFM tip for bending the ZnO NWs. Higher stability of the electric source, capability for producing larger electric fields, and lower production costs are advantages of this configuration. Finally, piezoelectric properties of ZnO NBs were simulated using the molecular dynamics (MD) technique. The size-scale effect on piezoelectric properties of ZnO NBs was captured, and it is shown that the piezoelectric coefficient of ZnO NBs decreases by increasing their lateral dimensions. This phenomenon is attributed to the surface charge redistribution and compression of unit cells that are placed on the outer shell of ZnO NBs.

Retrospective evaluation of all recorded horse race starts in Switzerland during a four-year period focusing on discipline specific risk factors for clinical events

REASONS FOR PERFORMING THE STUDY: Racetrack injuries are of welfare concern and prevention of injuries is an important goal in many racing jurisdictions. Over the years this has led to more detailed recording of clinical events on racecourses. However, risk factor analyses of clinical events at race meetings have never been reported for Switzerland OBJECTIVE: To identify discipline-specific factors that influence the occurrence of clinical events during race meetings with the ultimate aim to improve the monitoring and safety on racetracks in Switzerland and optimise racehorse welfare. STUDY DESIGN: Retrospective study of horse race data collected by the Swiss horse racing association. METHODS: All race starts (n = 17,670, including 6,198 flat, 1,257 obstacle and 10,215 trot race starts) recorded over a period of four years (2009-2012) were analysed in multivariable mixed effect logistic regression models including horse and racecourse related data. The models were designed to identify discipline specific factors influencing the occurrence of clinical events on racecourses in Switzerland. RESULTS: Factors influencing the risk of clinical events during races were different for each discipline. The risk of a clinical event in trot racing was lower for racing on a Porphyre-sand track than on grass tracks. Horses whose driver was also their trainer had an approximately two times higher risk for clinical events. In obstacle races, longer distances (2401-3300 m and 3301-5400 m respectively) had a protective effect compared to racing over shorter distances. In flat racing, five racecourses reported significantly less clinical events. In all three disciplines, finishing 8th place or later was associated with clinical events. CONCLUSIONS: Changes in management that aim to improve the safety and welfare of racehorses, such as racetrack adaptations, need to be individualised for each discipline.

The effect of the shift from HMO to PPO plans on the prevalence of hospital bad debt in the insured population: A case study in two Houston-area hospitals

In spite of the dramatic increase and general concern with U.S. hospital bad debt expense (AMNews, January 12, 2004; Philadelphia Business Journal, April 30, 2004; WSJ, July 23, 2004), there appears to be little available analysis of the precise sources and causes of its growth. This is particularly true in terms of the potential contribution of insured patients to bad debt expense in light of the recent shift in managed care from health maintenance organization (HMO) plans to preferred provider organization (PPO) plans (Kaiser Annual Survey Report, 2003). This study examines and attempts to explain the recent dramatic growth in bad debt expense by focusing on and analyzing data from two Houston-area hospital providers within one healthcare system. In contrast to prior studies in which self-pay was found to be the primary source of hospital bad debt expense (Saywell, R. M., et al., 1989; Zollinger, T. W., 1991; Weissman, Joel S., et al., 1999), this study hypothesizes that the growing hospital bad debt expense is mainly due to the shifting trend away from HMOs to PPOs as a conscious decision by employers to share costs with employees. Compared to HMO plans, the structure of PPOs includes higher co-pays, coinsurance, and deductibles for the patient-pay portion of medical bills, creating the potential for an increase in bad debt for hospital providers (from a case study). This bad debt expense has a greater impact in the community hospital than in the Texas Medical Center hospital. ^

The Effect of Exchange Rate Volatility on International Trade: The Implication for Production Networks in East Asia

This paper is an empirical investigation of the relationship between exchange rate volatility and international trade, focusing on East Asia. It finds that intra-East Asian trade is discouraged by exchange rate volatility more seriously than trade in other regions because intermediate goods trade in production networks, which is quite sensitive to exchange rate volatility compared with other types of trade, occupies a significant fraction of trade. In addition, this negative effect of volatility is mainly induced by the unanticipated volatility and has an even greater impact than that of tariffs.

Latent hardening size effect in small-scale plasticity

We aim at understanding the multislip behaviour of metals subject to irreversible deformations at small-scales. By focusing on the simple shear of a constrained single-crystal strip, we show that discrete Dislocation Dynamics (DD) simulations predict a strong latent hardening size effect, with smaller being stronger in the range [1.5 µm, 6 µm] for the strip height. We attempt to represent the DD pseudo-experimental results by developing a flow theory of Strain Gradient Crystal Plasticity (SGCP), involving both energetic and dissipative higher-order terms and, as a main novelty, a strain gradient extension of the conventional latent hardening. In order to discuss the capability of the SGCP theory proposed, we implement it into a Finite Element (FE) code and set its material parameters on the basis of the DD results. The SGCP FE code is specifically developed for the boundary value problem under study so that we can implement a fully implicit (Backward Euler) consistent algorithm. Special emphasis is placed on the discussion of the role of the material length scales involved in the SGCP model, from both the mechanical and numerical points of view.

Latent hardening size effect in small-scale plasticity

We aim at understanding the multislip behaviour of metals subject to irreversible deformations at small-scales. By focusing on the simple shear of a constrained single-crystal strip, we show that discrete Dislocation Dynamics (DD) simulations predict a strong latent hardening size effect, with smaller being stronger in the range [1.5 µm, 6 µm] for the strip height. We attempt to represent the DD pseudo-experimental results by developing a flow theory of Strain Gradient Crystal Plasticity (SGCP), involving both energetic and dissipative higher-order terms and, as a main novelty, a strain gradient extension of the conventional latent hardening. In order to discuss the capability of the SGCP theory proposed, we implement it into a Finite Element (FE) code and set its material parameters on the basis of the DD results. The SGCP FE code is specifically developed for the boundary value problem under study so that we can implement a fully implicit (Backward Euler) consistent algorithm. Special emphasis is placed on the discussion of the role of the material length scales involved in the SGCP model, from both the mechanical and numerical points of view.

Temporal self-imaging effect for periodically modulated trains of pulses

In this paper, the mathematical description of the temporal selfimaging effect is studied, focusing on the situation in which the train of pulses to be dispersed has been previously periodically modulated in phase and amplitude. It is demonstrated that, for each input pulse and for some specific values of the chromatic dispersion, a subtrain of optical pulses is generated whose envelope is determined by the Discrete Fourier Transform of the modulating coefficients. The mathematical results are confirmed by simulations of various examples and some limits on the realization of the theory are commented.

New non-reorientational optical nonlinear effect in MBBA

A new effect producing self-focusing of light in a nematic MBBA film is reported. This effect produces a static diffraction pattern composed of circular rings which is different from the ones arising from self-focusing previously reported. The influence of the cell thickness, the optical intensity, and the wavelength is studied. Once the nematic is distorted by a láser beam, the effect produced in other light beam passing through the modified región is independent of its polarization. This isotropic behavior shows that a molecular reorientation has not been produced. The origin of this effect seems to be the same of that of the effect which produces a randomly oscillating diffraction pattern previously reported by our group. Some possible causes such as thermal indexing, convective instabilities and self-induced transparency are discussed.

Self-standing curved crystals for X and Gamma rays focusing

The efficiency of a Laue lens for X and Gamma ray focusing in the energy range 60 ÷ 600 keV is closely linked to the diffraction efficiency of the single crystals composing the lens. A powerful focusing system is crucial for applications like medical imaging and X ray astronomy where wide beams must be focused. Mosaic crystals with a high density, such as Cu or Au, and bent crystals with curved diffracting planes (CDP) are considered for the realization of a focusing system for X rays, owing to their high diffraction efficiency. In this work, a comparison of the efficiency of CDP crystals and mosaic crystals was performed on the basis of the theory of X-ray diffraction. Si, GaAs and Ge CDP crystals with optimized thicknesses and moderate radii of curvature of several tens of metres demonstrate comparable or superior performance with respect to the higher atomic number mosaic crystals generally used. A simplified approach for calculating the integrated reflectivity of the crystals is applied. A bending technique used during this work to realize CDP crystals consists in a controlled surface damaging induced by a mechanical lapping process. A compressive strained layer of few micrometres in thickness is generated and causes the convex curvature of the damaged side of the crystal. Another new bending technique is developed and the main results are shown. The process consists on a film deposition of a selected bi-component epoxy resin on one side of crystal, made uniform in thickness by mean of a spin-coater. Choosing the speed of spin-coating, so changing the thickness of the film, a control of radius of curvature can be obtained. Moreover the possibility to combine the two bending technique to obtain CDP crystal with a stronger curvature in rather thick crystals was demonstrated. Detailed characterization of Si, and GaAs CDP crystals at low and high x-ray energies are performed on flat and bent crystals obtained with the damaging and the resin deposition technique. As expected an increase of diffraction efficiency in asymmetrical diffraction geometry in CDP crystals with respect to the flat ones is observed. On the other hand an unexpected increase of the integrated intensity in symmetrical geometry, not predicted by the theory, is observed in all the measurements performed with different set up. The experimental trend of the integrated reflectivity as a function of the radius of curvature is in a good agreement with that predicted by the theory of bent perfect crystals, so it is possible to conclude that the surface damage has a limited effect on the crystal reflectivity. A study of the integrated reflectivity in the energy range of interest (100÷350 keV) in CDP crystals realized with damaging and resin deposition technique at symmetrical and asymmetrical geometries was performed at ILL Institute. Also at these energies the diffraction efficiency of bent crystals was much larger (a 12 time increase is observed for bent crystals in asymmetrical 111 geometry) than that measured in flat crystals. The diffraction efficiency of CDP crystals realized with both techniques tends to coincide with that of flat crystals at very high energies (> 200 keV). This suggesting that also real flat perfect crystals can be considered as strongly bent or mosaic crystals at very high X ray energies.

The effect of universal futures on opening and closing stock market prices

Purpose – In 2001, Euronext-Liffe introduced single security futures contracts for the first time. The purpose of this paper is to examine the impact that these single security futures had on the volatility of the underlying stocks. Design/methodology/approach – The Inclan and Tiao algorithm was used to show that the volatility of underlying securities did not change after universal futures were introduced. Findings – It was found that in the aftermath of the introduction of universal futures the volatility of the underlying securities increases. Increased volatility is not apparent in the control sample. This suggests that single security futures did have some impact on the volatility of the underlying securities. Originality/value – Despite the huge literature that has examined the effects of a futures listing on the volatility of underlying stock returns, little consensus has emerged. This paper adds to the dialogue by focusing on the effects of a single security futures contract rather than concentrating on the effects of index futures contracts.

Excess leverage and productivity growth in emerging economies:is there a threshold effect?

This paper studies the relationship between leverage and growth, focusing on a large sample of firms in emerging economies of central and eastern Europe (CEE). Contrary to the general wisdom, we find that deviation from optimal leverage, especially, excess leverage is common among firms in many CEE countries. Using firm-level panel data from a group of transition countries, the paper provides support to the hypothesis that leverage positively affects productivity growth but only below an endogenously determined threshold level.

Numerical investigation of the effect of the temporal pulse shape on modification of fused silica by femtosecond pulses

We report the results of numerical studies of the impact of asymmetric femtosecond pulses focused in the bulk of the material on the femtosecond modification of fused silica. It is shown that such pulses lead to localisation of absorption in the process of femtosecond modification and to a decrease in the threshold energy of modification. It is found that the optimal asymmetry parameters for reaching the maximum plasma density in the focusing region depend on the pulse energy: at an initial energy of about 100 nJ, it is preferable to use pulses with positive TOD; however, when the energy is increased, it is preferable to use pulses with negative TOD. This is explained by differences in the dynamics of the processes of absorption of energy of a pulse propagating in the material.

Az online fogyasztói elégedettségmérés hatása a vállalatok versenyképességére (Effect of the online-customer satisfaction’s measurement to the corporate’s competitiveness)

A versenyképes működés elengedhetetlen feltétele a fogyasztói elégedettség, melynek egyik meghatározó eleme az észlelt és elvárt minőség közti kapcsolat. A minőségi elvárások az internettel, mint napjaink egyik meghatározó csatornájával kapcsolatban is megfogalmazódtak már, így kapott jelentős szerepet az online szolgáltatás minőségének meghatározása, illetve ezzel összekapcsolódva az online fogyasztói elégedettségmérés. Jelen tanulmány első része szakirodalmi áttekintést nyújt az online szolgáltatás minőségének fogyasztói érzékelésével, értékelésével kapcsolatos elméletekről, melyek az online fogyasztók elégedettségmérésének alapját képezik. Ezután kerül sor a különböző mérési módszerek bemutatására, kiemelt szerepet szánva a szakirodalomban sokat tárgyalt E-S-QUAL és E-RecS-QUAL skálának. Az áttekintés középpontjában azok az elméletek állnak, melyek az online vásárlást is nyújtó honlapokra vonatkoznak. A cikk további része két empirikus kutatást tartalmaz. Az első az elégedettségmérés hazai helyzetét tárgyalja, a másik pedig a szakirodalomból ismert E-S-QUAL és E-RecS-QUAL skálákat felhasználva részletesen elemzi az elektronikus szolgáltatásminőség dimenziói és a fogyasztói elégedettség közötti fontosabb összefüggéseket, emellett röviden vizsgálja az alkalmazott skálák megbízhatóságát és érvényességét. A kutatás fő célja a gyakorlati szakemberek számára is releváns kapcsolatok feltárása és bemutatása. _______ A company’s competitiveness significantly depends on the satisfaction of its consumers, which is influenced by the relationship between the expected and perceived quality. As over the last decade internet has become a significant channel, in parallel its customers have built some expectation about the quality of different websites and online services. Therefore the marketing literature should focus on the dimensions of e-service quality (e-sq) and online-customer satisfaction. This study first resumes with different concepts of e-sq, which are the principles of the online-customer satisfaction’s measurement. Than the different e-sq measurement methods are reviewed and the dimensions of E-S-QUAL and ERecS- QUAL scales are deeply explained. The study is focusing on concepts relating to web shops. The next part of the article includes two empirical studies. The first is about the situation of satisfaction measurement at Hungarian companies. The other one analyzes the most relevant relationships between the dimension of e-sq and customer satisfaction based on the E-S-QUAL and E-RecS-QUAL scales for measuring e-sq and briefly outlines the reliability and validity of these scales. The main purpose of this empirical research is to summarise the managerial and practical implications.