Specific Orientation Research Articles

The hare and the tortoise: A comparative study of Vietnam's and Kenya's pathways to local enterprise development through foreign direct investment

ABSTRACT Almost simultaneously, two developing countries – Kenya and Vietnam – set out to promote industrial development through FDI. Vietnam embarked on a targeted strategy aimed at selecting FDI that could specifically aid the country’s strategic export sectors through linkages to local industry. In contrast, Kenya embarked on a cross-the-board FDI attraction policy with no specific sector orientation and with few specific linkage policies. This paper asks how FDI has contributed to local industry development in the two countries. Based on an analysis of firm level data from the World Bank Enterprise Survey, the paper compares the two countries’ ability to generate spillovers from FDI spillovers and discusses what explains differences and similarities. The paper finds that in spite of the obvious differences between the two countries in terms of local industrial development and policy, firm and industry factors appeared to be better predictors of variations in spillovers than country level factors. Among the policy implications drawn are that developing countries should focus their FDI policies on firms and industries that have high linkage and hence spillover potential rather than adopting cross-the-board policies.

On the possibility of the existence of orienting hydrodynamic steering effects in the kinetics of receptor-ligand association.

In the vast majority of biologically relevant cases of receptor-ligand complex formation, the binding site of the receptor is a small part of its surface, and moreover, formation of a biologically active complex often requires a specific orientation of the ligand relative to the binding site. Before the formation of the initial form of the complex, only long-range, electrostatic and hydrodynamic interactions can act between the ligand approaching the binding site and the receptor. In this context, the question arises whether as a result of these interactions, there is a pre-orientation of the ligand towards the binding site, which to some extent would accelerate the formation of the complex. The role of electrostatic interactions in the orientation of the ligand relative to the binding site of the receptor is well documented. The analogous role of hydrodynamic interactions, although assessed as very significant by Brune and Kim (PNAS 91, 2930-2934, (1994)), is still debatable. In this article, I present the current state of knowledge on this subject and consider the possibilities of demonstrating the orienting effect of hydrodynamic interactions in the processes of receptor-ligand association, in an experimental way supported by computer simulations.

X-ray-to-visible light-field detection through pixelated colour conversion

Light-field detection measures both the intensity of light rays and their precise direction in free space. However, current light-field detection techniques either require complex microlens arrays or are limited to the ultraviolet–visible light wavelength ranges1–4. Here we present a robust, scalable method based on lithographically patterned perovskite nanocrystal arrays that can be used to determine radiation vectors from X-rays to visible light (0.002–550 nm). With these multicolour nanocrystal arrays, light rays from specific directions can be converted into pixelated colour outputs with an angular resolution of 0.0018°. We find that three-dimensional light-field detection and spatial positioning of light sources are possible by modifying nanocrystal arrays with specific orientations. We also demonstrate three-dimensional object imaging and visible light and X-ray phase-contrast imaging by combining pixelated nanocrystal arrays with a colour charge-coupled device. The ability to detect light direction beyond optical wavelengths through colour-contrast encoding could enable new applications, for example, in three-dimensional phase-contrast imaging, robotics, virtual reality, tomographic biological imaging and satellite autonomous navigation.

Anisotropy factors in small-angle scattering for dilute rigid-rod suspensions

Alignment of anisotropic particles along specific orientations influences the mechanical and rheological properties of a material. Small-angle scattering techniques are widely used to probe this alignment through analysis of anisotropic two-dimensional scattering intensity patterns. The anisotropy factor is the simplest and most common quantitative parameter for describing scattering anisotropy, especially in systems containing rod-like particles, and there are several methods for calculating this factor. However, there has been no systematic study comparing these methods while also evaluating the limitations imposed by non-idealities from instrumentation or polydisperse morphology. Three of the most common methods for calculating an anisotropy factor are examined here and their effectiveness for describing the orientation of a theoretical cylinder is evaluated. It is found that the maximum theoretical value of 1 for the anisotropy factor is only accessible at certain values of scattering vectorq. The analysis details recommendations forq-range selection and data binning, as these influence the calculations. The theoretical results are supported by experimental small-angle neutron scattering data for a wormlike micelle solution undergoing shear, where different calculation methods yield distinct quantifications of anisotropy.

Active fixation as an efficient coding strategy for neuromorphic vision

Contrary to a photographer, who puts a great effort in keeping the lens still, eyes insistently move even during fixation. This benefits signal decorrelation, which underlies an efficient encoding of visual information. Yet, camera motion is not sufficient alone; it must be coupled with a sensor specifically selective to temporal changes. Indeed, motion induced on standard imagers only results in burring effects. Neuromorphic sensors represent a valuable solution. Here we characterize the response of an event-based camera equipped with fixational eye movements (FEMs) on both synthetic and natural images. Our analyses prove that the system starts an early stage of redundancy suppression, as a precursor of subsequent whitening processes on the amplitude spectrum. This does not come at the price of corrupting structural information contained in local spatial phase across oriented axes. Isotropy of FEMs ensures proper representations of image features without introducing biases towards specific contrast orientations.

Orientation of capture antibodies on gold nanoparticles to improve the sensitivity of ELISA-based medical devices

The sensitivity of ELISA-based devices strongly depends on the right orientation of antibodies on the sensor surface. The aim of this work was to increase the analytical performance of a commercial ELISA-based medical device (VIDAS®), thanks to the specific orientation of antibodies on gold nanostructured disposables. For this purpose, fPSA VIDAS® assay was used as model and the disposable providing the antigen binding surface (SPR®) was functionalized with gold nanostructures coated with monovalent half-fragment antibodies (reduced IgG, rIgG). The functionalization of polystyrene SPRs® with gold nanostructures was achieved through a one-step incubation of gold dispersions in a mixture of non-toxic solvents. Five different concentrations of gold nanoparticles (NPs) were tested with a maximum fluorescence enhancement for NPs density around 3–8 *103 NPs/μm2 (752 ± 11 RFV vs 316 ± 5 RFV of bare SPRs®). The comparison of the dose-response curve obtained with commercial and gold coated-SPRs® revealed a significant improvement (p < 0.0001) of the analytical sensitivity of the VIDAS® system using nanostructured disposables. This improved version of SPRs® allows to distinguish small variations of fPSA concentrations opening the way to the application of this biomarker to other kinds of cancer as recently described in the literature.

In Silico Activation of CO2, NO2, and SO2 with Light Atom Molecules and Stepwise Conversion of CO2 into Methanol and Water

AbstractCO2, NO2, and SO2 can be activated in silico with tailor‐made light atom tripodal ligand systems carrying particular numbers of Lewis acidic and basic sites in specific relative orientations. In the calculated EO2‐adducts (E=C, N, S), considerable E−O bond elongations of 0.1–0.3 Å, decreasing the E=O double bond character, and O−E−O angle alterations, approaching tetrahedral geometry, activate the donor acceptor complexes towards reduction with BH4−. The lone pairs of the P atoms thereby serve as donors towards the central element, C, N, or S, whereas the electron deficient B atoms serve as acceptors. The charge redistribution within the EO2 complex was monitored by a variety of DFT‐derived real‐space bonding indicators (RSBIs) including bond topologies, non‐covalent contact patches, and electron pair basins. For one CO2‐complex, the reduction towards methanol and water was conducted via stepwise addition of H− and H+. The most critical steps are the initial CO2 uptake due to potential quenching of the ligand systems in their active state, increasing the kinetic barrier, and the release of methanol and water from the ligand system due to potential ligand poisoning. Unbeneficial side reactions in the stepwise reduction and protonation have to be considered.

Permanently Polarized Materials: An Approach for Designing Materials with Customized Electrical Properties

The development of experimental procedures to transform conventional materials into new materials with unique properties has become a necessity in many fields, as for example catalysis, electronics, electrochemistry and biomedicine, among others. In recent years, the thermal stimulated polarization (TSP) treatment, which consists of applying a constant voltage at a high temperature, has been applied to hydroxyapatite, Ca5(PO4)3OH (HAp), leading to permanently polarized HAp (p-HAp). The enhanced electrical properties of p-HAp, which are the consequence of the controlled generation of vacancies, the specific orientation of the remaining OH– groups and the surface charge accumulation have been used for the catalytic fixation of CO2, CH4 and/or N2 under very mild conditions (<120 °C) and with accurate selectivity toward different reaction products (up to 95%). In this Perspective, we stablish the fundamentals of permanently polarized materials, providing the generalized concepts of the permanent polarized state and some representative examples of applying the TSP approach to a wide variety of materials. More specifically, we provide empirical evidence of the polarized state after applying the TSP treatment to quartz nanopowder, binary metal oxides (TiO2 and ZrO2) and different synthetic polymers, confirming the obtaining of enhanced electrical properties and the associated structural changes. Finally, the implications, challenges and perspectives of the polarized state are discussed considering different fields, such as catalysis, biomedicine, optics and electronics, sensors and energy storage devices.

Active cell divisions generate fourfold orientationally ordered phase in living tissue

Morphogenesis, the process through which genes generate form, establishes tissue-scale order as a template for constructing the complex shapes of the body plan. The extensive growth required to build these ordered substrates is fuelled by cell proliferation, which, naively, should destroy order. Understanding how active morphogenetic mechanisms couple cellular and mechanical processes to generate order—rather than annihilate it—remains an outstanding question in animal development. We show that cell divisions are the primary drivers of tissue flow, leading to a fourfold orientationally ordered phase. Waves of anisotropic cell proliferation propagate across the embryo with precise patterning. Defects introduced into the nascent lattice by cell divisions are moved out of the tissue bulk towards the boundary by subsequent divisions. Specific cell proliferation rates and orientations enable cell divisions to organize rather than fluidize the tissue. We observe this using live imaging and tissue cartography to analyse the dynamics of fourfold tissue ordering in the trunk segmental ectoderm of the crustacean Parhyale hawaiensis beginning 72 h after egg lay. The result is a robust, active mechanism for generating global orientational order in a non-equilibrium system that sets the stage for the subsequent development of shape and form.

Epitaxial growth, optical and electrical conductivity of the metallic pyrochlore Bi2Ru2O7 on Y-stabilized ZrO2 substrate

Epitaxial heterostructures composed of complex correlated metal oxides, grown along specific crystallographic orientations, offer a route to investigating emergent phenomena such as topological states and spin liquids through geometrical lattice engineering. A2Ru2O7 pyrochlore ruthenates, in particular, exhibit a metal–insulator transition with varying A cation, whose mechanism is not fully understood. We report on the epitaxial growth, and structural and electrical properties of metallic pyrochlore bismuth ruthenate heterostructures, grown along both the [001] and [111] directions. Ordered pyrochlore thin films were obtained with a highly oriented texture along the [001] and [111] crystallographic directions. Density functional theory calculations of the electronic band structure and density of states indicated that Bi2Ru2O7 is semimetallic and that hybridization of the Ru 4d and Bi 6p orbitals via the anion network at the Fermi energy was responsible for the metallicity. Electrical conductivity measurements confirmed that the compound is weakly metallic, in agreement with the reported conductivity for the stoichiometric bulk compound. The carrier concentration and mobility of the electrons compared favorably with previous reports on bulk material and indicate strong electron–electron interactions. The measured and computed optical conductivities were found to share coincident spectral features and confirm the electronic correlation. Comparison of the electrical and optical properties of the two distinct orientations indicates differences that cannot be attributed to differences in crystalline quality or dislocations and may indicate anisotropy in the electronic structure of Bi2Ru2O7. This study will enable access to the kagome lattice arising naturally in the 111 planes of the pyrochlore B cation sublattice, which may be used to uncover emergent topological properties.

Inverse Kinematic Algorithm with Newton-Raphson Method iteration to Control Robot Position and Orientation based on R programming language

The homogeneous transform program is a function used to calculate the homogeneous transformation matrix at a specific position and orientation of a three-link manipulator. The homogeneous transformation matrix is a 4x4 matrix used to represent the position and orientation of an object in three-dimensional space. In the program, the rotation matrix R is calculated using the Euler formula and stored in a 4x4 matrix along with the position coordinates. The Jacobian matrix function calculates the Jacobian matrix at a specific position and orientation of a three-link manipulator using the homogeneous transformation matrix. The Euler formula used in the program is based on the rotation matrices for rotations around the x, y, and z-axes. The output of these functions can be useful for future research in developing advanced manipulators with improved accuracy and flexibility. Research gaps in exploring the limitations of these functions in real-world applications, particularly in scenarios involving complex manipulator configurations and environmental factors.

Selective liquid directional steering enabled by dual-scale reentrant ratchets

Achieving well-controlled directional steering of liquids is of great significance for both fundamental study and practical applications, such as microfluidics, biomedicine, and heat management. Recent advances allow liquids with different surface tensions to select their spreading directions on a same surface composed of macro ratchets with dual reentrant curvatures. Nevertheless, such intriguing directional steering function relies on 3D printed sophisticated structures and additional polishing process to eliminate the inevitable microgrooves-like surface deficiency generated from printing process, which increases the manufacturing complexity and severally hinders practical applications. Herein, we developed a simplified dual-scale structure that enables directional liquid steering via a straightforward 3D printing process without the need of any physical and chemical post-treatment. The dual-scale structure consists of macroscale tilt ratchet equipped with a reentrant tip and microscale grooves that decorated on the whole surface along a specific orientation. Distinct from conventional design requiring the elimination of microgrooves-like surface deficiency, we demonstrated that the microgrooves of dual-scale structure play a key role in delaying or promoting the local flow of liquids, tuning of which could even enable liquids select different spreading pathways. This study provides a new insight for developing surfaces with tunable multi-scale structures, and also advances our fundamental understanding of the interaction between liquid spreading dynamics and surface topography.

Optimization of Curvilinear Stiffener Beam Structures Simulated by Beam Finite Elements with Coupled Bending-Torsion Formulation.

This research presents the application of a beam finite element, specifically derived for simulating bending-torsion coupling in equivalent box-beam structures with curvilinear stiffeners. The stiffener path was simulated and optimized to obtain an expected coupling effect with respect to four typical static load cases, including geometric constraints related to the additive manufacturing production method. The selected load condition was applied to the centroid of the beam section, and the structure performance was consequently determined. A variation in load position up to one-fourth of the beam width was considered for investigating the stiffener path variation corresponding to a minimum bending-torsion coupling effect. The results demonstrated the capability of such a beam finite element to correctly represent the static behavior of beam structures with curvilinear stiffeners and show the possibility to uncouple its bending-torsion behavior using a specific stiffener orientation. The simulation of a laser powder bed fusion process showed new opportunities for the application of this technology to stiffened panel manufacturing.

Academic Second-Chance Education: Correction or Consolidation of Early Selection?

This article develops a theoretical approach by arguing that success in academic secondchance education leading to the eligibility to study is (besides academic achievement) influenced by normative orientations relevant to success acquired during compulsory secondary education. More precisely, we argue that in the highly stratified German school system at secondary level I (years 5 to 10), school-type specific socialization contexts lead to the development of school-type specific normative orientations relevant to success. This contributes to creating unequal starting points for academic second-chance education. Based on this assumption, we develop a theoretical grid using the contrastive analysis of ten interviews with students in their first semester of second-chance education. The results show that existing normative orientations are only partially related to the school type that was previously attended. This raises questions concerning the extent to which there is a normative school socialization effect. However, this study is a first step in using a classic approach of the sociology of education to empirically explore the effects of stratification, which has not been done before.

Transcatheter heart valve commissural alignment: an updated review.

Transcatheter aortic valve replacement (TAVR) indications recently extended to lower surgical risk patients with longer life expectancy. Commissural alignment (CA) is one of the emerging concepts and is becoming one of the cornerstones of the TAVR procedure in a patient with increased longevity. Indeed, CA may improve transcatheter heart valve (THV) hemodynamics, future coronary access, and repeatability. The definition of CA has been recently standardized by the ALIGN-TAVR consortium using a four-tier scale based on CT analysis. Progress has been made during the index TAVR procedure to optimize CA, especially with self-expandable platforms. Indeed, specific delivery catheter orientation, THV rotation, and computed-tomography-derived views have been proposed to achieve a reasonable degree of CA. Recent data demonstrate feasibility, safety, and a significant reduction in coronary overlap using these techniques, especially with self-expandable platforms. This review provides an overview of THV CA including assessment methods, alignment techniques during the index TAVR procedure with different THV platforms, the clinical impact of commissural misalignment, and challenging situations for CA.

Enhanced mixing quality of ring-type electroosmotic micromixer using baffles

In this study, an attempt has been taken to enhance the mixing efficiency in a micromixer of two different concentration fluids using electrokinetic effects such as electroosmotic flow. Four microelectrodes are located at specific locations on the outer surface of the one ring-shaped micromixer chamber. In addition, rigid baffles at the inlet side of the microchannel have been considered to enhance the mixing quality. The computation is performed using the finite element-based solver. The influences of different parameters such as average inlet fluid velocity (U0), frequency of the alternating current (f), the voltage amplitude of the alternating current (V), angle of inclination of the baffles (α), and the orientation fashion of the baffles at the inlet side have been investigated to achieve best mixing quality. This technique produces rapid mixing in the microchamber. Higher mixing quality can be achieved by considering the baffles in a specific orientation. The best mixing quality (99.67%) is obtained at the low inlet velocity of 0.05 mm/s. On the contrary, the lowest mixing quality (15.78%) is concerned with the higher inlet velocity with a high frequency of AC electric field.

Sexual life of Spanish women during the lockdown by COVID-19: Differences according to sexual orientation?

The COVID-19 pandemic may have exacerbated the sexual health differences that already existed among women based on their sexual orientation. Therefore, a total of 971 Spanish women aged 18–60 years (84 % heterosexual and 16 % with a minority sexual orientation) answered an ad hoc online questionnaire about sexual behavior during April 2020. Compared to heterosexual women, sexual minority women showed a greater increase in sexual frequency, masturbated more, had more sex with a housemate, and engaged in more online sexual activities during lockdown. The emotional impact of the pandemic, having privacy, and age showed a relationship with the quality of sexual life, but not sexual orientation. Based on these results, women's sexual lives are not as closely related to their sexual orientation as they are to other variables. Therefore, it seems more necessary to address issues affecting women in general during lockdown than to focus on their specific sexual orientation.

Lead zirconate titanate ceramics with aligned crystallite grains.

The piezoelectric properties of lead zirconate titanate [Pb(Zr,Ti)O3 or PZT] ceramics could be enhanced by fabricating textured ceramics that would align the crystal grains along specific orientations. We present a seed-passivated texturing process to fabricate textured PZT ceramics by using newly developed Ba(Zr,Ti)O3 microplatelet templates. This process not only ensures the template-induced grain growth in titanium-rich PZT layers but also facilitates desired composition through interlayer diffusion of zirconium and titanium. We successfully prepared textured PZT ceramics with outstanding properties, including Curie temperatures of 360°C, piezoelectric coefficients d33 of 760 picocoulombs per newton and g33 of 100 millivolt meters per newton, and electromechanical couplings k33 of 0.85. This study addresses the challenge of fabricating textured rhombohedral PZT ceramics by suppressing the otherwise severe chemical reaction between PZT powder and titanate templates.

Influence of the hierarchical architecture of multi-core iron oxide nanoflowers on their magnetic properties

Magnetic properties of superparamagnetic iron oxide nanoparticles are controlled mainly by their particle size and by their particle size distribution. Magnetic properties of multi-core iron oxide nanoparticles, often called iron oxide nanoflowers (IONFs), are additionally affected by the interaction of magnetic moments between neighboring cores. The knowledge about the hierarchical structure of IONFs is therefore essential for understanding the magnetic properties of IONFs. In this contribution, the architecture of multi-core IONFs was investigated using correlative multiscale transmission electron microscopy (TEM), X-ray diffraction and dynamic light scattering. The multiscale TEM measurements comprised low-resolution and high-resolution imaging as well as geometric phase analysis. The IONFs contained maghemite with the average chemical composition gamma-Fe_{2.72pm 0.02}O_4. The metallic vacancies located on the octahedral lattice sites of the spinel ferrite structure were partially ordered. Individual IONFs consisted of several cores showing frequently a specific crystallographic orientation relationship between direct neighbors. This oriented attachment may facilitate the magnetic alignment within the cores. Individual cores were composed of partially coherent nanocrystals having almost the same crystallographic orientation. The sizes of individual constituents revealed by the microstructure analysis were correlated with the magnetic particle sizes that were obtained from fitting the measured magnetization curve by the Langevin function.

A model rural rehabilitation service station in China– Evaluation after 5 years

A simple setup for rehabilitation training was established in 2007 in a rural area of Shanxi Province, China. It made use of an underused facility created for elderly people’s leisure time. Simple equipment for rehabilitation training was provided free for the users, and instructions were given by rehab experts, Traditional medical doctors, and social workers. This rural Service Station must be the first of its kind in rural China and deserves scrutinizes for its unique nature. After 5 years of service, a service evaluation of its service nature, service providers, users, and special orientations was completed. It is hoped that this Service Station could be taken as a model of similar rural development in China.