Spectral classification of the brightest objects in the galactic star forming region W40

We present high S/N, moderate resolution near-infrared spectra, as well as 10 micron imaging, for the brightest members of the central stellar cluster in the W40 HII region, obtained using the SpeX and MIRSI instruments at NASA's Infrared Telescope Facility. Using these observations combined with archival Spitzer Space Telescope data, we have determined the spectral classifications, extinction, distances, and spectral energy distributions for the brightest members of the cluster. Of the eight objects observed, we identify four main sequence (MS) OB stars, two Herbig Ae/Be stars, and two low-mass young stellar objects. Strong HeI absorption at 1.083 micron in the MS star spectra strongly suggests that at least some of these sources are in fact close binaries. Two out of the four MS stars also show significant infrared excesses typical of circumstellar disks. Extinctions and distances were determined for each MS star by fitting model stellar atmospheres to the SEDs. We estimate a distance to the cluster of between 455 and 535 pc, which agrees well with earlier (but far less precise) distance estimates. We conclude that the late-O star we identify is the dominant source of LyC luminosity needed to power the W40 HII region and is the likely source of the stellar wind that has blown a large (~4 pc) pinched-waist bubble observed in wide field mid-IR images. We also suggest that 3.6 cm radio emission observed from some of the sources in the cluster is likely not due to emission from ultra-compact HII regions, as suggested in other work, due to size constraints based on our derived distance to the cluster. Finally, we also present a discussion of the curious source IRS 3A, which has a very strong mid-IR excess (despite its B3 MS classification) and appears to be embedded in a dusty envelope roughly 2700 AU in size.Comment: Accepted for publication in The Astronomical Journal. 29 pages, 10 figure

A new approach to generalized chaos synchronization based on the stability of the error system

summary:With a chaotic system being divided into linear and nonlinear parts, a new approach is presented to realize generalized chaos synchronization by using feedback control and parameter commutation. Based on a linear transformation, the problem of generalized synchronization (GS) is transformed into the stability problem of the synchronous error system, and an existence condition for GS is derived. Furthermore, the performance of GS can be improved according to the configuration of the GS velocity. Further generalization and appropriation can be acquired without a stability requirement for the chaotic system’s linear part. The Lorenz system and a hyperchaotic system are taken for illustration and verification and the results of the simulation indicate that the method is effective

A STUDY ON THE REPRESENTATIVE POINT OF HORSE’S CENTER OF GRAVITY

The purpose of this study was to explore are there bony landmarks on the horse body’s surface matching the motion of center of gravity. The relationship between the bony landmarks and the center of gravity during actual race under Buchner and Kubo horse inertial models were analyzed. Results showed Buchner and Kubo models had high consistency on the kinematic parameters of the center of gravity. Comparing the relationship of the middle of mesoscapula and tail root with the center of gravity in displacement, velocity and the absolute difference, it was found that the middle of mesoscapula under Kubo model is a suitable represent point of the center of gravity among the characteristic points of two models in the motion of observed race horses

Predictive factors for lymph node metastasis in papillary thyroid cancer patients undergoing neck dissection: insights from a large cohort study

BackgroundThis study aimed to investigate the risk factors and metastatic patterns in papillary thyroid cancer (PTC) patients undergoing lymph node dissection, offering guidance for clinical practice.MethodsA total of 924 PTC patients who underwent thyroidectomy with central neck dissection (CND) or lateral neck dissection (LND) between January 2021 and November 2022 were included in the analysis. The study investigated the relationships between clinicopathological characteristics, lymph node metastasis, and various risk factor.ResultsAmong the 924 PTC patients, the cervical lymph node metastasis rate was 59.1% (546 patients). Of these patients, 381 had central neck metastasis (CNM, 41.2%), while the remaining 165 patients had lateral neck metastasis (LNM, 17.9%). Factors associated with increased risk of CNM and LNM included larger tumor diameter, presence of multiple tumors, and capsular invasion (p<0.05). Male sex, age <55 years, larger tumor diameter (>0.85 cm), multiple tumors, capsular invasion, and absence of Hashimoto’s disease were identified as independent risk factors for CNM (p<0.05), with an AUC value of 0.722. CNM, maximum diameter >1.15 cm, and multiple tumors were independent risk factors for LNM (p<0.05), with an AUC of 0.699.ConclusionThese findings suggest that tailored neck dissection based on individual risk factors is crucial, particularly in cases of suspected LNM with larger tumors, CNM, multiple tumors, and capsular invasion

Generalized quadrature spatial modulation for STAR-RIS aided NOMA networks

The simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) is regarded as a promising paradigm for enhancing the connectivity and reliability of non-orthogonal multiple access (NOMA) networks. However, the transmission of STAR-RIS enhanced NOMA networks performance is severely limited due to the inter-user interference (IUI) on multi-user detections. To mitigate this drawback, we propose a generalized quadrature spatial modulation (GQSM) aided STAR-RIS in conjunction with the NOMA scheme, termed STAR-RIS-NOMA-GQSM, to improve the performance of the corresponding NGMA network. By STAR-RIS-NOMA-GQSM, the information bits for all users in transmission and reflection zones are transmitted via orthogonal signal domains to eliminate the IUI so as to greatly improve the system performance. The low-complexity detection and upper-bounded bit error rate (BER) of STAR-RIS-NOMA-GQSM are both studied to evaluate its feasibility and performance. Moreover, by further utilizing index modulation (IM), we propose an enhanced STAR-RIS-NOMA-GQSM scheme, termed E-STAR-RIS-NOMA-GQSM, to enhance the transmission rate by dynamically adjusting reflection patterns in both transmission and reflection zones. Simulation results show that the proposed original and enhanced scheme significantly outperform the conventional STAR-RIS-NOMA and also confirm the precision of the theoretical analysis of the upper-bounded BER

Covert Communications by Encoding UAV Motion States:Joint Design of Codebook and Controller

In this paper, we investigate the information piggyback capability of the unmanned aerial vehicle (UAV) by encoding observed motion states. Specifically, at specific moments throughout the holistic navigation process, the distance between the UAV and the starting point, the position expressed by the three-dimensional (3D) Cartesian coordinates, the linear velocities, and the attitude angles are encoded into 16-bit digital symbols through a proposed codebook. In this way, covert data communications can be enabled, complementing conventional radio frequency (RF) communications in harsh electromagnetic environments. To achieve a well-designed flight controller that is necessary to enable fluent movement against external disturbances and accurate motion state encoding, we introduce the whole flight control structure and perform system dynamic analysis. The proposed motion control mechanism can mitigate the jitter and oscillation during the journey while ensuring the required motion status for information encoding purposes

Quality Improvement to Increase Breastfeeding in Preterm Infants: Systematic Review and Meta-Analysis

Background and Objective: Due to its numerous health benefits, breast milk (BM) is recommended for preterm infants. Despite such recommendations, the rates of breastfeeding in preterm infants are lower than that in term infants. Quality improvement (QI) bundles increase breastfeeding in preterm infants, but their replication in neonatal intensive care units has had inconsistent outcomes.Methods: We used the Population or Problem, Intervention, Comparison, and Outcomes (PICO) framework to develop our search strategy, and searched MEDLINE, Embase, and the Cochrane Library from inception through January 15, 2021. Studies describing any active QI intervention to increase BM use in preterm infants were included. The primary outcome measure was the rate of any breastfeeding or exclusive mother's own milk (MOM) at discharge or during hospitalization.Results: Sixteen studies were eligible for inclusion and showed an acceptable risk of bias, and included 1 interrupted time series, study 3 controlled before-and-after studies, and 12 uncontrolled before-and-after studies; of these, 3 studies were excluded due to insufficient dichotomous data, 13 were included in the meta-analysis. In the meta-analysis, the rate of any breastfeeding was significantly improved at discharge and during hospitalization after QI [risk ratio (RR) = 1.23, 95% confidence interval (CI): 1.14–1.32, P < 0.00001 and RR = 1.89, 95% CI: 1.09–3.29, P = 0.02, respectively]. The rate of exclusive MOM after QI was also significantly increased at discharge (RR = 1.51, 95% CI: 1.04–2.18, P = 0.03), but not during hospitalization (RR = 1.53, 95% CI: 0.78–2.98, P = 0.22). However, after sensitivity analysis, the comprehensive results still suggested that QI could significantly improve the rate of exclusive MOM during hospitalization (RR = 1.21, 95% CI: 1.08–1.35, P = 0.001). Funnel plots and Egger's test indicated publication bias in the rate of any BF at discharge. We corrected publication bias by trim and fill analysis, and corrected RR to 1.272, 95% CI: (1.175, 1.369), which was consistent with the results of the initial model.Conclusions: A QI bundle appears to be effective for promoting BM use in preterm infants at discharge or during hospitalization

Generalized Pre-Coded Quadrature Spatial Modulation-Aided STAR-RIS-NOMA

This paper incorporates the concept of generalized pre-coded quadrature spatial modulation (GPQSM) into non-orthogonal multiple access (NOMA) systems aided by simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) to boost spectral efficiency. The proposed GPQSM-STAR-RIS-NOMA scheme allows for the conveyance of additional information bits to different users according to a pre-coding scheme for adapting the subsurface allocation patterns. Furthermore, we derive an approximate expression for the bit error rate. Simulation results demonstrate that our proposed scheme achieves a better transmission rate than the conventional STAR-RIS-NOMA scheme