Analyticity and the NcN_c counting rule of SS matrix poles

By studying $\pi\pi$ scattering amplitudes in the large $N_c$ limit, we clarify the $N_c$ dependence of the $S$ matrix pole position. It is demonstrated that analyticity and the $N_c$ counting rule exclude the existence of $S$ matrix poles with ${\cal M}, \Gamma\sim O(1)$. Especially the properties of $\sigma$ and $f_0(980)$ with respect to the $1/N_c$ expansion are discussed. We point out that in general tetra-quark resonances do not exist.Comment: This paper replaces hep-ph/0412175. The latter is withdraw

Anisotropic Generalized Bayesian Coherent Point Drift for Point Set Registration

Registration is highly demanded in many real-world scenarios such as robotics and automation. Registration is challenging partly due to the fact that the acquired data is usually noisy and has many outliers. In addition, in many practical applications, one point set (PS) usually only covers a partial region of the other PS. Thus, most existing registration algorithms cannot guarantee theoretical convergence. This article presents a novel, robust, and accurate three-dimensional (3D) rigid point set registration (PSR) method, which is achieved by generalizing the state-of-the-art (SOTA) Bayesian coherent point drift (BCPD) theory to the scenario that high-dimensional point sets (PSs) are aligned and the anisotropic positional noise is considered. The high-dimensional point sets typically consist of the positional vectors and normal vectors. On one hand, with the normal vectors, the proposed method is more robust to noise and outliers, and the point correspondences can be found more accurately. On the other hand, incorporating the registration into the BCPD framework will guarantee the algorithm's theoretical convergence. Our contributions in this article are three folds. First, the problem of rigidly aligning two general PSs with normal vectors is incorporated into a variational Bayesian inference framework, which is solved by generalizing the BCPD approach while the anisotropic positional noise is considered. Second, the updated parameters during the algorithm's iterations are given in closed-form or with iterative solutions. Third, extensive experiments have been done to validate the proposed approach and its significant improvements over the BCPD

Closed-Loop Magnetic Manipulation for Robotic Transesophageal Echocardiography

This paper presents a closed-loop magnetic manipulation framework for robotic transesophageal echocardiography (TEE) acquisitions. Different from previous work on intracorporeal robotic ultrasound acquisitions that focus on continuum robot control, we first investigate the use of magnetic control methods for more direct, intuitive, and accurate manipulation of the distal tip of the probe. We modify a standard TEE probe by attaching a permanent magnet and an inertial measurement unit sensor to the probe tip and replacing the flexible gastroscope with a soft tether containing only wires for transmitting ultrasound signals, and show that 6-DOF localization and 5-DOF closed-loop control of the probe can be achieved with an external permanent magnet based on the fusion of internal inertial measurement and external magnetic field sensing data. The proposed method does not require complex structures or motions of the actuator and the probe compared with existing magnetic manipulation methods. We have conducted extensive experiments to validate the effectiveness of the framework in terms of localization accuracy, update rate, workspace size, and tracking accuracy. In addition, our results obtained on a realistic cardiac tissue-mimicking phantom show that the proposed framework is applicable in real conditions and can generally meet the requirements for tele-operated TEE acquisitions.Comment: Accepted by IEEE Transactions on Robotics. Copyright may be transferred without notice, after which this version may no longer be accessibl

The role of early childhood development and education (ECDE) in supporting learning and well-being in rural early childhood and primary schools in South Africa

This paper examines how early childhood and primary schools can be constructed as enabling spaces to improve the learning and well-being of children aged six to nine who live in multidimensionally poor, low-resourced rural communities in South Africa. Quality early childhood development and education (ECDE) can be the catalyst to break the cycle of poverty for many young children in rural areas. A systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses flowchart. A comprehensive search strategy using electronic databases and hand searches systematically whittled down an initial database of 30,080 articles to 16 articles for this study. A thematic analysis identified enablers and constraints for supporting children’s learning and well-being across three themes: (1) infrastructure, educational resources and child agency (2) initial teacher education (ITE) and (3) socioeconomic status. The findings and discussion highlight child agency as an enabler to learning and well-being and the structural and pedagogical challenges of implementing ITE curricula specific to rural educational contexts

Reliable Hybrid Mixture Model for Generalized Point Set Registration

Point set registration (PSR) is an essential problem in the field of surgical navigation and augmented reality (AR). In surgical navigation, the aim of registration is mapping the pre-operative space to the intra-operative space. This article introduces a reliable hybrid mixture model, in which the reliability of the normal vectors in the generalized point set (GPS) is examined and exploited. The motivation of considering the reliability of orientation information is that normal vectors cannot be estimated or measured accurately in the clinic. The point set (PS) is divided into two subsets according to the reliability of normal vectors. PSR is cast into the maximum likelihood estimation (MLE) problem. The expectation maximization (EM) framework is used to solve the MLE problem. In the E-step, the posterior probabilities between points in two PSs are computed. In the M-step, the transformation matrix and model components are updated by optimizing the objective function. We have demonstrated through extensive experiments on the human femur bone PS that the proposed algorithm outperforms the state-of-the-art ones in terms of accuracy, robustness, and convergence speed

Comparison of engagement and emotional responses of older and younger adults interacting with 3D cultural heritage artefacts on personal devices

The availability of advanced software and less expensive hardware allows museums to preserve and share artefacts digitally. As a result, museums are frequently making their collections accessible online as interactive, 3D models. This could lead to the unique situation of viewing the digital artefact before the physical artefact. Experiencing artefacts digitally outside of the museum on personal devices may affect the user's ability to emotionally connect to the artefacts. This study examines how two target populations of young adults (18–21 years) and the elderly (65 years and older) responded to seeing cultural heritage artefacts in three different modalities: augmented reality on a tablet, 3D models on a laptop, and then physical artefacts. Specifically, the time spent, enjoyment, and emotional responses were analysed. Results revealed that regardless of age, the digital modalities were enjoyable and encouraged emotional responses. Seeing the physical artefacts after the digital ones did not lessen their enjoyment or emotions felt. These findings aim to provide an insight into the effectiveness of 3D artefacts viewed on personal devices and artefacts shown outside of the museum for encouraging emotional responses from older and younger people

Removal of phenol using sulphate radicals activated by natural zeolite-supported cobalt catalysts

Two Co oxide catalysts supported on natural zeolites from Indonesia (INZ) and Australia (ANZ) were prepared and used to activate peroxymonosulphate for degradation of aqueous phenol. The two catalysts were characterized by several techniques such as X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy (EDS) and N2 adsorption. It was found that Co/INZ and Co/ANZ are effective in activation of peroxymonosulphate to produce sulphate radicals for phenol degradation. Co/INZ and Co/ANZ could remove phenol up to 100 and 70 %, respectively, at the conditions of 25 ppm phenol (500 mL), 0.2 g catalyst, 1 g oxone and 25 °C. Several parameters such as amount of catalyst loading, phenol concentration, oxidant concentration and temperature were found to be the key factors influencing phenol degradation. A pseudo first order would fit to phenol degradation kinetics, and the activation energies on Co/INZ and Co/ANZ were obtained as 52.4 and 61.3 kJ/mol,respectively

Inflation Risk Premia in the US and the Euro Area

We use a joint model of macroeconomic and term structure dynamics to estimate inflation risk premia in the United States and the euro area. To sharpen our estimation, we include in the information set macro data and survey data on inflation and interest rate expectations at various future horizons, as well as term structure data from both nominal and index-linked bonds. Our results show that, in both currency areas, inflation risk premia are relatively small, positive, and increasing in maturity. The cyclical dynamics of long-term inflation risk premia are mostly associated with changes in output gaps, while their high-frequency fluctuations seem to be aligned with variations in inflation. However, the cyclicality of inflation premia differs between the US and the euro area. Long term inflation premia are countercyclical in the euro area, while they are procyclical in the US

Spontaneous versus mechanical ventilation during video-assisted thoracoscopic surgery for spontaneous pneumothorax: a randomized trial

Objective: Spontaneous ventilation video-assisted thoracic surgery (SV-VATS) is reported to have superior or equal efficacy on postoperative recovery to mechanical ventilation VATS (MV-VATS). However, perioperative safety of the SV-VATS blebectomy is not entirely demonstrated. Methods: We performed a noninferiority, randomized controlled trial (No. NCT03016858) for primary spontaneous pneumothorax patients aged 16 to 50 years undergoing a SV-VATS and the MV-VATS procedure. The trial was conducted at 10 centers in China from April 2017 to January 2019. The primary outcome was the comparison of intra- and postoperative complications between SV-VATS and MV-VATS procedures. Secondary outcomes included total analgesia dose, change of vital sign during surgery, procedural duration, recovery time, postoperative visual analog pain scores, and hospitalization length. Results: In this study, 335 patients were included. There was no significant difference between the SV-VATS group and the MV-VATS group in the intra- and postoperative complication rates (17.90% vs 22.09%; relative risk, 0.81; 95% confidence interval, 0.52-1.26; P = .346). The SV-VATS group was associated with significantly decreased total dose of intraoperative opioid agents; that is, sufentanil (11.37 μg vs 20.92 μg; P < .001) and remifentanil (269.78 μg vs 404.96 μg; P < .001). The SV-VATS procedure was also associated with shorter extubation time (12.28 minutes vs 17.30 minutes; P < .001), postanesthesia care unit recovery time (25.43 minutes vs 30.67 minutes; P = .02) and food intake time (346.07 minute vs 404.02 minutes; P = .002). Moreover, the SV-VATS procedure deceased the anesthesia cost compared with the MV-VATS ($297.81 vs$399.81; P < .001). Conclusions: SV-VATS was shown to be noninferior to MV-VATS in term of complication rate and in selected patients undergoing blebectomy for primary spontaneous pneumothorax