Central Position Research Articles

Digital Pupillometry and Centroid Shift Changes in Dominant and Nondominant Eyes.

To investigate the differences between dominant and nondominant eyes in a predominantly young patient population by analyzing the angle kappa, pupil size, and center position in dominant and nondominant eyes. A total of 126 young college students (252 eyes) with myopia who underwent femtosecond laser-combined LASIK were randomly selected. Ocular dominance was determined using the hole-in-card test. The WaveLight Allegro Topolyzer (WaveLight Laser Technologies AG, Erlangen, Germany) was used to measure the pupil size and center position. The offset between the pupil center and the coaxially sighted corneal light reflex (P-Dist) of the patients was recorded by the x- and y-axis eyeball tracking adjustment program of the WaveLight Eagle Vision EX500 excimer laser system (Wavelight GmbH). The patient's vision (uncorrected distance visual acuity [UDVA], best-corrected visual acuity (BCVA), and refractive power (spherical equivalent, SE) were observed preoperatively, 1 week, 4 weeks, and 12 weeks postoperatively, and a quality of vision (QoV) questionnaire was completed. Ocular dominance occurred predominantly in the right eye [right vs. left: (178) 70.63% vs. (74) 29.37%; p < 0.001]. The P-Dist was 0.202 ± 0.095 mm in the dominant eye and 0.215 ± 0.103 mm in the nondominant eye (p = 0.021). The horizontal pupil shift was - 0.07 ± 0.14 mm in dominant eyes and 0.01 ± 0.13 mm in nondominant eyes (p = 0.001) (the temporal displacement of the dominant eye under mesopic conditions). The SE was negatively correlated with the P-Dist (r = - 0.223, p = 0.012 for the dominant eye and r = - 0.199, p = 0.025 for the nondominant eye). At 12weeks postoperatively, the safety index (postoperative BDVA/preoperative BDVA) of the dominant and nondominant eyes was 1.20 (1.00, 1.22) and 1.20 (1.00, 1.20), respectively, and the efficacy index (postoperative UDVA/preoperative BDVA) was 1.00 (1.00, 1.20) and 1.00 (1.00, 1.20), respectively; the proportion of residual SE within ± 0.50 D was 98 and 100%, respectively. This study found that ocular dominance occurred predominantly in the right eye. The pupil size change was larger in the dominant eye. The angle kappa of the dominant eye was smaller than that of the nondominant eye and the pupil center of the dominant eye was slightly shifted to the temporal side under mesopic conditions. The correction of myopia in the dominant and nondominant eyes exhibits good safety, efficacy, and predictability in the short term after surgery, and has good subjective visual quality performance after correction. We suggest adjusting the angle kappa percentage in the dominant eye to be lower than that of the nondominant eye in individualized corneal refractive surgery in order to find the ablation center closest to the visual axis.

Governance Concepts, Frameworks and Lake Governance’s Conceptualisation

This academic paper embraces a politically theoretical discourse to examine the research gap from Governance concepts to the water and lake frameworks. It explains and understands the idea of Lake Governance and its central constituents: the collective people, development, conservation, and the Government. Governance’s concept is entrenched, and the water and lake frameworks are complicated, making the lake’s conceptualisation challenging to grasp and comprehend fully. This article asserts that: (i) Lake Governance is more suitable as this concept is simplicity, parsimony, and essential to understand and utilise. (ii) Lake Governance’s conceptualisation should be centered on contributing the scholarly literature and more so recognised and established in the lakes’ discourse. (iii) Government is crucial, the utmost consequential in Lake Governance, where this central position interlocks the collective people in development and the lake in conservation.

Strategic Positioning and Organizational Performance of Center for International Forestry Research and World Agro-Forestry in Nairobi City County, Kenya

The vision of the CIFOR-ICRAF is to ensure the sustainable availability of food and nutritional benefits in the world using lands, trees, and other renewable resources. CIFOR- ICRAF works in partnership with private companies, civil society, academia, and governments in delivering solutions to five major global challenges: extreme inequality, unsustainable supply and value chains, unsustainable food systems, the climate crisis, and biodiversity loss and deforestation. However, various factors have hindered this vision thereby limiting their performance. The study sought to ascertain how strategic positioning affects organizational performance of CIFOR-ICRAF in Nairobi, Kenya and specifically determine the influence of strategic leadership, mergers, and market positioning strategy on their organizational performance. The study was hinged on positioning theory, stakeholder’s theory, and resource- based theory. Descriptive research study was utilized by the study and the target population was 300 staff of CIFOR-ICRAF. The target population was sampled using stratified sampling technique whereby the CIFOR-ICRAF six main themes formed the strata and a sample of 5 staff from each stratum formed the sample size of 30 respondents. The study mainly utilized primary data gathered through structured questionnaire to collect qualitative data and secondary data mainly from the CIFOR-ICRAF reports to establish growth rate. The questionnaire was subject to pilot study, content and construct validity test and Cronbach-Alpha internal consistency reliability test. Descriptive statistics and inferential analysis (multiple regression analysis) evaluated the data. Tables and graphs displayed the study results. The study found that strategic leadership, mergers, and market positioning had a positive significant effect on the organizational performance of CIFOR-ICRAF in Kenya. The study concludes that that in strategic leadership, the leader expresses a vision for a business or organization, or its branches, and encourages more people to join them to bring the vision to light. Mergers enable organizations to secure more resources and increase their scale of operations and organizations undergo a merger to benefit their shareholders. Positioning in marketing allows organizations to influence how others view the product or services. The study recommends that the organization strategic leadership should be a forward-thinking, an effective communicator, and have the will to challenge the status quo. For successful merger, organizations should create an integration plan early in the process. Ensure that both sides are on the same page about how the combined entity will work going forward. The organization should establish its current position in the market by looking into who forms its current customer base and identifying the target market the organization wish to address.

Analysis of the scattering of chiral layered particle by dual beams

The present study investigates the interaction between a chiral multilayer dielectric sphere and dual laser beams. Using the generalized Lorenz-Mie theory (GLMT), we extend the theory of single laser beam expansion to dual laser beam expansion. Analytical solutions of the scattering on chiral layered particles by dual laser beams are derived based on the boundary continuum condition. To validate the efficiency of our theory and methodologies proposed in this paper, we conduct a comparative analysis between our findings and the simulation results reported in existing literature. The numerical outcomes presented on the scattering pattern of far region and near-surface fields are analyzed in detail with the impact of various parameters, such as the incident angle, polarization angle, waist width, beam center position, inner and outer chiral parameters. The investigations are of significant importance for the analytical understanding of the optical scattering properties of multilayered biological cells with complex shapes and possess important application values in micro-manipulation of multilayered biological structures.

Innovation-facilitating networks create inequality.

Theories of innovation often balance contrasting views that either smart people create smart things or smartly constructed institutions create smart things. While population models have shown factors including population size, connectivity and agent behaviour as crucial for innovation, few have taken the individual-central approach seriously by examining the role individuals play within their groups. To explore how network structures influence not only population-level innovation but also performance among individuals, we studied an agent-based model of the Potions Task, a paradigm developed to test how structure affects a group's ability to solve a difficult exploration task. We explore how size, connectivity and rates of information sharing in a network influence innovation and how these have an impact on the emergence of inequality in terms of agent contributions. We find, in line with prior work, that population size has a positive effect on innovation, but also find that large and small populations perform similarly per capita; that many small groups outperform fewer large groups; that random changes to structure have few effects on innovation in the task; and that the highest performing agents tend to occupy more central positions in the network. Moreover, we show that every network factor which improves innovation leads to a proportional increase in inequality of performance in the network, creating 'genius effects' among otherwise 'dumb' agents in both idealized and real-world networks.

Broad environmental adaptation of abundant microbial taxa in Robinia pseudoacacia forests during long-term vegetation restoration

Vegetation restoration has significant impacts on ecosystems, and a comprehensive understanding of microbial environmental adaptability could facilitate coping with ecological challenges such as environmental change and biodiversity loss. Here, abundant and rare soil bacterial and fungal communities were characterized along a 15−45-year chronosequence of forest vegetation restoration in the Loess Plateau region. Phylogenetic-bin-based null model analysis (iCAMP), niche breadth index, and co-occurrence network analysis were used to assess microbial community assembly and environmental adaptation of a Robinia pseudoacacia plantation under long-term vegetation restoration. The drift process governed community assembly of abundant and rare soil fungi and bacteria. With increasing soil total phosphorus content, the relative importance of drift increased, while dispersal limitation and heterogeneous selection exhibited opposite trends for abundant and rare fungi. Rare soil fungal composition dissimilarities were dominated by species replacement processes. Abundant microbial taxa had higher ecological niche width and contribution to ecosystem multifunctionality than rare taxa. Node property values (e.g., degree and betweenness) of abundant microbial taxa were substantially higher than those of rare microbial taxa, indicating abundant species occupied a central position in the network. This study provides insights into the diversity and stability of microbial communities during vegetation restoration in Loess Plateau. The findings highlight that abundant soil fungi and bacteria have broad environmental adaptation and major implications for soil multifunctionality under long-term vegetation restoration.

Diagnostic significance of endotoxin and antitoxic opsonin – fibronectin in the blood flow in purulent-necrotic inflammatory of the lower limb in patients with diabetes mellitus

Introduction. In the cascade of pathogenetic mechanisms of diabetes mellitus, one of the central positions is occupied by systemic vascular lesions, including the lower extremities with the formation of diabetic foot syndrome. Aim. To investigate and evaluate the diagnostic significance of endotoxin concentration and plasma fibronectin parameters in indicating the severity of purulent-necrotic inflammation of the feet in patients with diabetes mellitus. Materials and methods. The study included 112 patients with purulent-necrotic inflammation of the feet aged 61.4 ± 12.5 years. By types of surgical intervention, patients were divided into groups: the main group (21 patients with transmetadarsal ammutation of the foot and 27 with amputation at the level of the lower leg), the comparison group – 64 patients with necrectomy and plastic closure of wounds on the foot. The concentration of endotoxin in the bloodstream was determined by the micro-LAL test (EU/ml), the content of plasma fibronectin was assessed by enzyme immunoassay (µg/ml). Results. With the progressive development of purulent inflammation of the feet in patients of the main group, the concentration of endotoxin reached 9.32 (0.91) EU/ml, in the comparison group – 5.73 (0.36) EU/ml, in which purulent-necrotic the process was limited. In the main group of examined patients, hypofibronectinemia also had a more significant character. At the same time, the lowest fibronectin in patients was observed with an extensive purulent-necrotic process, in whom an amputation was performed at the level of the lower leg – 124.7 (6.2) µg/ml, the concentration of endotoxin in them reached the maximum figures – 10.51 (0.5) EU/ml. Discussion.The main factor determining the depth of endotoxin aggression and destructive lesions of the extremities can be the enhanced utilization of fibronectin. Conclusion. The progression of endotoxin aggression is a predictor of an increase in the severity of destructive tissue damage in patients with diabetes mellitus.

Structural Design and Optimization of the Milling Force Measurement Tool System Embedded with Thin-Film Strain Sensors.

A milling force measurement tool system is designed with an elastic beam structure, which is divided into a two-end ring hoop compression sensor mode and a two-end square hoop compression sensor mode to improve the strain sensitivity. A simplified mechanical model of the elastic beam is established, and the relationship between the strain and force of the elastic beam under the action of three cutting force components is investigated, which can act a guide for subsequent milling force measurement tool system calibration tests. Thin-film strain sensors occupy a central position in the milling force measurement tool system, which consists of a substrate, transition layer, insulating layer and resistance grid layer. The resistance grid layer has a particularly significant effect on the thin-film strain sensor's performance. In order to further improve the sensitivity of thin-film strain sensors, the shapes of the substrate, the transition layer, the insulating layer and the resistance grid layer are optimized and studied. A new thin-film strain sensor is designed with a resistance grid beam constructed from an insulating layer and a resistive grid layer double-end-supported on the transition layer. The flow of the wet-etching process of thin-film strain sensors is studied and samples are obtained. The surface microforms of the sensor samples are observed by extended depth-of-field microscopy, confocal microscopy and atomic force microscopy. It can be seen that the boundary of the resistance grid layer pattern is tidy and has high dimensional accuracy, thus enabling the basic achievement of the expected effect of the design. The electrical performance of the samples is tested on an experimental platform that we built, and the results show that the resistive sensitivity coefficient of the samples is increased by about 20%, to 51.2%, compared with that of the flat thin-film strain sensor, which fulfils the design's requirements.

Research on Demonstration Curriculum-Based Political and Virtuous Awareness Construction of Introduction of International Chinese Language Education Course

The course Introduction to International Chinese Language Education occupies a central position in the undergraduate curriculum in the major of Chinese International Education, significantly influencing the cultivation of talent in this domain. This research paper systematically examines the present condition of course delivery, discerns the multifaceted factors that contribute to suboptimal teaching outcomes, and utilizes a case study approach, focusing on our university’s exemplary ideological and political education course. The case study provides a comprehensive overview of the course’s role in promoting ideological and political education. It elucidates the strategies and initiatives implemented in the context of ideological and political education development. Drawing on the empirical results derived from curriculum reforms, this study synthesizes a coherent model and a well-defined pathway for curriculum enhancement (365 Model).

Modeling Synaptic Integration of Bursty and β Oscillatory Inputs in Ventromedial Motor Thalamic Neurons in Normal and Parkinsonian States.

The ventromedial motor thalamus (VM) is implicated in multiple motor functions and occupies a central position in the cortico-basal ganglia-thalamocortical loop. It integrates glutamatergic inputs from motor cortex (MC) and motor-related subcortical areas, and it is a major recipient of inhibition from basal ganglia. Previous in vitro experiments performed in mice showed that dopamine depletion enhances the excitability of thalamocortical (TC) neurons in VM due to reduced M-type potassium currents. To understand how these excitability changes impact synaptic integration in vivo, we constructed biophysically detailed mouse VM TC model neurons fit to normal and dopamine-depleted conditions, using the NEURON simulator. These models allowed us to assess the influence of excitability changes with dopamine depletion on the integration of synaptic inputs expected in vivo We found that VM neuron models in the dopamine-depleted state showed increased firing rates with the same synaptic inputs. Synchronous bursting in inhibitory input from the substantia nigra pars reticulata (SNR), as observed in parkinsonian conditions, evoked a postinhibitory firing rate increase with a longer duration in dopamine-depleted than control conditions, due to different M-type potassium channel densities. With β oscillations in the inhibitory inputs from SNR and the excitatory inputs from cortex, we observed spike-phase locking in the activity of the models in normal and dopamine-depleted states, which relayed and amplified the oscillations of the inputs, suggesting that the increased β oscillations observed in VM of parkinsonian animals are predominantly a consequence of changes in the presynaptic activity rather than changes in intrinsic properties.

RCPM_CFI: A regional core pattern mining method based on core feature influence

Regional co-location pattern mining is a branch of spatial co-location pattern mining, which is used to discover co-location patterns that prevalently co-occur in local regions. The regional co-location patterns can reveal the association relationships among spatial features in the local regions. However, in practice, the association relationship between certain features is asymmetrical, and some features play a key (core) role in the relationship, as central position. To explore the regional co-location patterns with core feature (called regional core patterns (RCPs)) as well as their prevalent regions, this paper presents a regional partition method based on the influence of core feature. Additionally, a regional core pattern mining (RCPM) algorithm is proposed to mine the RCPs and unveil their spatial distribution resulting from the arrangement of core feature. In the regional partition stage, we propose a partition criterion that takes into account the influence of core feature. This criterion aims to comprehensively address the spatial distribution relationship between core instances and their neighboring non-core instances, ensuring the partition process is rational and complete. In the RCPM stage, we propose a core-based nearest affiliation measure method to assess the neighbor relationship between core and non-core instances, which can consider the fact that there is competition between spatial instances of the same spatial feature. And, to effectively calculate pattern prevalence and quickly identify RCPs, we present a data structure called Core_Hash to store the influence relationship between core and non-core instances. Extensive experimental evaluations and analyses are conducted on synthetic and real-world datasets. Compared to the existing algorithms, our proposed algorithms yield more reasonable and comprehensive RCPs and demonstrate good efficiency and scalability.

Model Verification and Experimental Study of The Turbomachinery Wake Flow Field Reconstruction

Abstract A clear understanding of the turbomachinery wake flow field is one of the key problems in developing turbomachinery aerodynamics. The theoretical model of helical vortices is established in cylindrical coordinates (r,θ,z), and the model corresponds to the experimental scheme, which verifies the feasibility of reconstructing flow field by interpolation in r-z plane under different θ. This model shows that theta should not exceed 20 degrees in order to reconstruct the flow field more accurately. Taking rotors as the representative of the turbomachinery, Particle image velocimetry (PIV) is used to measure the velocity field in the rotor wake. Interpolating reconstruction of spacing between different measurement planes, the reconstruction results are relative to the theory, which plane spacing should be less than 20 deg. Using the vorticity weighted average method to calculate the central position of the vortex core, the wandering motion of the tip vortex is obtained. On this basis, a correct conditional average algorithm is proposed to eliminate this effect. Through the analysis method of the circulation, it is proved that the point where the second derivative of the circulation with respect to the radius is 0 corresponds to the radius of the vortex core, and the evolution law of the growth of the vortex core radius is proportional to the square root of the vortex ages. The results provide a reliable experimental method for the quantitative study of the spatio-temporal evolution of complex vortex structures in the three-dimensional flow of turbomachinery wakes.

Inkarnationsdeutung bei Johannes von Damaskus in Auseinandersetzung mit der „koranischen“ Bewegung

Abstract John of Damascus (ca. 650/660 – 754 AD) is one of the first contemporary witnesses to critically examine the emergence of Islam and its holy scripture, the Qur’an. John came from a distinguished Melkite family that held political offices in state finance for generations. Like his father, he was initially a civil servant under the Arab rule of Caliph ‘Abd al-Malik (685 – 705). The anti-Christian movement that began in that time forced him to withdraw from public life and enter the Mar Saba monastery near Jerusalem. While at the monastery, John grappled with the text of the “new” religion and defended the Christian position. In this milieu, the interpretation of the divine incarnation occupied a central position. By demonstrating the divine incarnation in Jesus Christ, John makes convergences with the Qur’anic movement of the new rulers. In doing so, he highlights the Qur’ans high esteem of the Virgin Mary as well as the birth and humanity of her Son, Jesus Christ. In this way, he seeks to bring Christianity into agreement with the Qur’an and to break down theological barriers.

Synthesis of peptide-siRNA conjugates via internal sulfonylphosphoramidate modifications and evaluation of their in vitro activity.

Conjugates of therapeutic oligonucleotides (ONs) including peptide conjugates, provide a potential solution to the major challenge of specific tissue delivery faced by this class of drugs. Conjugations are often positioned terminal at the ONs, although internal placement of other chemical modifications are known to be of critical importance. The introduction of internal conjugation handles in chemically modified ONs require highly specialized and expensive nucleoside phosphoramidites. Here, we present a method for synthesizing a library of peptide-siRNA conjugates by conjugation at internal phosphorous positions via sulfonylphosphoramidate modifications incorporated into the sense strand. The sulfonylphosphoramidate modification offers benefits as it can be directly incorporated into chemically modified ONs by simply changing the oxidation step during synthesis, and furthermore holds the potential to create multifunctionalized therapeutic ONs. We have developed a workflow using a novel pH-controlled amine-to-amine linker that yields peptide-siRNA conjugates linked via amide bonds, and we have synthesized conjugates between GLP1 peptides and a HPRT1 siRNA as a model system. The in vitro activity of the conjugates was tested by GLP1R activity and knockdown of the HPRT1 gene. We found that conjugation near the 3'-end is more favorable than certain central internal positions and different internal conjugation strategies were compared.

A system science perspective on burn-out: development of an expert-based causal loop diagram.

Burn-out leads to reduced worker well-being, long-term absenteeism, and high costs for employers and society. Determinants at different levels may affect burn-out in an interrelated and dynamic manner. The aim of the present study was to apply a broader systems perspective by exploring and visualizing the complex system of determinants at different levels (living conditions, working conditions, and societal developments) underlying the prevalence of burn-out in the Netherlands. During three group model building (GMB) sessions with in total eight experts on workers' mental health, a causal loop diagram (CLD) was developed and relevant feedback loops were identified. For the selection of determinants to be included in the CLD a recently published overview of determinants on burn-out at different levels was used. Experts could also add factors that were not listed in the overview. The final CLD consists of 20 factors and depicts a central position of working conditions. Societal developments (e.g., access to mental health care, size of the working population, rougher social climate, etc.) were mostly located at the outside of the CLD and barely integrated in feedback loops. Several reinforcing feedback loops resulting in an increase of the prevalence of burn-out were identified in which the factors (very) high workload, imbalance between work and private life, and insufficient recovery time play an important role. Also, several balancing loops were found that visualize the crucial role of functional support from supervisors to prevent burn-out among workers. Applying a broader systems perspective, including determinants at different levels, offers new insights into dynamic feedback loops that contribute to the prevalence of burn-out. Supervisors, amongst others, have a considerable impact on the system underlying the high prevalence of burn-out and may therefore contribute to its prevention. Even though societal developments were less integrated in feedback loops, they might be considered drivers of existing feedback loops. The results from this study confirm that determinants at various levels underly the prevalence of burn-out. To be able to address the diversity of determinants underlying a high prevalence of burn-out, a complex system approach can be helpful.

Human sperm rotate with a conserved direction during free swimming in four dimensions.

Head rotation in human spermatozoa is essential for different swimming modes and fertilisation, as it links the molecular workings of the flagellar beat with sperm motion in three-dimensional (3D) space over time. Determining the direction of head rotation has been hindered by the symmetry and translucent nature of the sperm head, and by the fast 3D motion driven by the helical flagellar beat. Analysis has been mostly restricted to two-dimensional (2D) single focal plane image analysis, which enables tracking of head centre position but not tracking of head rotation. Despite the conserved helical beating of the human sperm flagellum, human sperm head rotation has been reported to be uni- or bi-directional, and even to intermittently change direction in a given cell. Here, we directly measure the head rotation of freely swimming human sperm using multi-plane 4D (3D+t) microscopy and show that: (1) 2D microscopy is unable to distinguish head rotation direction in human spermatozoa; (2) head rotation direction in non-capacitating and capacitating solutions, for both aqueous and viscous media, is counterclockwise (CCW), as seen from head to tail, in all rotating spermatozoa, regardless of the experimental conditions; and (3) head rotation is suppressed in 36% of spermatozoa swimming in non-capacitating viscous medium, although CCW rotation is recovered after incubation in capacitating conditions within the same viscous medium, possibly unveiling an unexplored aspect of the essential need of capacitation for fertilisation. Our observations show that the CCW head rotation in human sperm is conserved. It constitutes a robust and persistent helical driving mechanism that influences sperm navigation in 3D space over time, and thus is of critical importance in cell motility, propulsion of flagellated microorganisms, sperm motility assessments, human reproduction research, and self-organisation of flagellar beating patterns and swimming in 3D space.

Analysis of error propagation: from raw light-field data to depth estimation.

In micro-lens-array-based light-field imaging, the micro-lens centers serve as the origins of local micro-lens coordinate systems. Each micro-lens receives angular/depth information coded according to its center location. Therefore, the errors in positioning the micro-lens centers will lead to errors in depth estimation. This paper proposes a method that resolves error propagation from raw light-field data to depth estimation based on analyzing large amounts of simulated images with various aperture sizes, noise levels, and object distance values. The simulation employs backward ray tracing and Monte Carlo sampling to improve computational efficiency. The errors are counted and accumulated stepwise from center positioning and generation of sub-aperture images to depth estimation. The disparity errors calculated during depth estimation are shown to be more apparent either with more significant center positioning errors or with a greater defocusing distance. An experiment using an industrial light-field camera is conducted, confirming that disparity errors at considerable object distances can be reduced significantly when the micro-lens centers are positioned with higher accuracy.

Experimental evidence of nonreciprocal propagation in space-time modulated piezoelectric phononic crystals

A nonreciprocal system composed of a one-dimensional piezoelectric phononic crystal whose periodic electrical conditions are modulated in time is presented. One-way longitudinal wave propagation is studied experimentally and compared to finite element temporal simulations. The modulation is performed by prescribing grounded or floating potential conditions on a periodic set of electrodes through external circuits. This approach makes it possible to consider a wide range of modulation speeds, and the large number of unit cells of the phononic crystal allows us to characterize experimentally the full dispersion curves of the system. This permits to observe the presence of directional bandgaps and to follow the shift in frequencies of these bandgaps as a function of the modulation speed. The experiments show the linear evolution of the central position of the bandgaps with the increase in the modulation speed, as well as their progressive closure, over a wide range of frequencies. Experiments are also used to estimate the evolution of bandgaps in a dispersive system, a problem discussed in several theoretical works but never observed experimentally. This work may constitute the foundation for experimental analysis of Floquet acoustic metamaterials, accelerated-modulation space-time metamaterials, or acoustic analog of the event horizon.

Pengaruh Kepemimpinan Terhadap Keterlibatan Pegawai Dan Kinerja (Studi pada Sektor Publik)

Leadership in an organization is a central position in moving employees to achieve optimal performance. This research aims to analyze the influence of leadership on employee performance in the public service sector with employee involvement as a mediating variable. Data analysis uses path analysis. This research also describes the variables of leadership, involvement and employee performance using a questionnaire. This research tries to prove that employee involvement is a variable that influences employee performance so that employee involvement acts as a mediating variable.

Exceptional points for crack detection in non-Hermitian beams

We study exceptional points (EPs) in parity-time (PT) symmetric non-Hermitian beams and explore their applications in crack detection. The EPs are formed by coupling different beam modes under feedback-controlled forces. The variations of the required non-Hermitian coefficient for the achievement of EPs are studied as a function of the separations and center positions of the applied force pairs. Then, a 3D cuboid-shaped crack is introduced at the center of the top surface of the beam, and results in the square-root behaviors of the frequency splitting under different crack geometries and force polarizations. This supports the enhanced sensitivity based on EPs as compared to the usual linear sensing methods. Using several polarizations allows access to different types of waves propagating in the beam and their modifications in the presence of the crack, therefore providing combined means of testing. Furthermore, a practical and feasible feedback control design is realized via replacing the applied forces by piezoelectric patches on the beam surface, exhibiting highly sensitive responses of the EPs to minor cracks. The studied results provide a new platform for crack or perturbation detection in elastic media.