Horizontal Stability Research Articles

Wall-modeled large eddy simulation of a tandem wing configuration in transonic flow

In this study, the interaction between a turbulent wake and the boundary layer of a horizontal tail plane (HTP) in the transonic flow regime is investigated. The setup considered corresponds to a generic tandem wing configuration with an OAT15A airfoil as the main wing and a National Advisory Committee for Aeronautics (NACA) 64A-110 as an HTP. Due to the transonic flow, the suction side of the OAT15A exhibits buffet. The numerical approach consists of a two-stage procedure in which a detached eddy simulation (DES) provides unsteady inflow conditions for a subsequent zonal high-fidelity large eddy simulation (LES) performed for the HTP region only; the turbulent boundary layer is modeled using scale-resolved wall-modeled LES (WMLES). The study mainly pursues two objectives: first, to discuss the influence of wake turbulence on the flow characteristics of the NACA airfoil; and second, to evaluate the capability of WMLES as a low-cost but high-resolution numerical approach in challenging flow conditions. Essentially, the study confirms the expected result that the outer part of the HTP's boundary layer is dominated by the wake of the main wing. Mainly based on a discussion of turbulence spectra, the study further demonstrates the advantage of WMLES over DES, proving that WMLES is able to capture the effects of wake turbulence on boundary layer dynamics, and thus validates the WMLES approach as a cost-effective, high-resolution turbulence modeling approach. On a superordinate level, the study further sketches a possible way on how a flow problem with such a strongly unsteady behavior could be systematically evaluated.

Influence of structural elasticity on the aerodynamic characteristics of the common research model with deflected control surfaces

Numerical aerodynamic and aeroelastic investigations are conducted for the Common Research Model (CRM) configuration with deployable aileron control surfaces and a trimmable horizontal stabilizer at cruise and off-cruise conditions. The numerical methodology which is implemented in the multi-disciplinary simulation environment SimServer is based on CFD and coupled CFD-CSM simulations. The DLR Tau Code is applied in order to solve the Reynolds-Averaged-Navier-Stokes (RANS) equations. The Spalart-Allmaras turbulence model with Edwards modification is used for the closure modeling of the three-dimensional RANS equations. A linear modal solver is utilized to calculate structural displacements and rotations of control surfaces are modeled by a Chimera approach. A grid independence study is conducted by using the rigid aerodynamic model of the CRM. The main focus of the analysis lies on the evaluation of the stationary CFD-CSM simulations addressing the influence of structural deformation on aileron effectiveness. Influences of various flow conditions and different fuel tank filling levels on the resulting local and global aerodynamic properties of the CRM are investigated. The reduction of aileron effectiveness as well as the difference in horizontal trim deflection angle if structural elastic effects are considered is investigated for the considered Mach number range and aircraft mass configurations.

Customized and high-performing acoustic levitators for contact-free experiments

Acoustic levitators are becoming increasingly common research instrumentation for contact-free, lab-in-a-droplet studies. Recently, levitators that employ multiple, small, ultrasonic transducers have gained popularity, given their low price, temperature and spatial stability, low voltage, and accessibility. Yet, the current state-of-the-art device, TinyLev, presents limitations for certain applications in terms of stability, strength, and compactness. Herein, we developed three new levitators and evaluated the effect of the construction parameters (e.g., distance of opposing arrays, number and arrangement of transducers, etc.) on their performance. The best performing levitator from this work had half the number of transducers, compared to TinyLev, though presented 1.7 and 3.5 times higher levitation capacity along the horizontal and vertical configurations, respectively, and 4.7 and 2.0 times higher horizontal and vertical stability of a levitated object, respectively. Additionally, we present a direct means to evaluate the acoustic radiation net force acting on a deformable object for uniaxial levitators, without the use of a microphone or a schlieren deflectometer for this type of levitators. The theoretical and experimental observations provide insights for adapting the acoustic levitator design for specific applications. Finally, we developed an open-source software which allows the evaluation of the acoustic pressure field generated by customized designs and provides the necessary files for 3D printing the scaffold of the levitator. This study aims to increase accessibility and promote further developments in contact-free experiments.

The causal associations of circulating lipids with Barrett’s Esophagus and Esophageal Cancer: a bi-directional, two sample mendelian randomization analysis

ObjectiveThe causal associations of circulating lipids with Barrett’s Esophagus (BE) and Esophageal Cancer (EC) has been a topic of debate. This study sought to elucidate the causality between circulating lipids and the risk of BE and EC.MethodsWe conducted two-sample Mendelian randomization (MR) analyses using single nucleotide polymorphisms (SNPs) of circulating lipids (n = 94,595 − 431,167 individuals), BE (218,792 individuals), and EC (190,190 individuals) obtained from the publicly available IEU OpenGWAS database. The robustness and reliability of the results were ensured by employing inverse-variance weighted (IVW), weighted median, MR-Egger, and MR-PRESSO methods. The presence of horizontal pleiotropy, heterogeneities, and stability of instrumental variables were assessed through MR-Egger intercept test, Cochran’s Q test, and leave-one-out sensitivity analysis. Additionally, bidirectional MR and multivariable MR (MVMR) were performed to explore reverse causality and adjust for known confounders, respectively.ResultsNone of the testing methods revealed statistically significant horizontal pleiotropy, directional pleiotropy, or heterogeneity. Univariate MR analyses using IVW indicated a robust causal relationship between increased triglycerides and BE (odds ratio [OR] = 1.79, p-value = 0.009), while no significant association with EC was observed. Inverse MR analysis indicated no evidence of reverse causality in the aforementioned outcomes. In MVMR analyses, elevated triglycerides (TRG) were significantly and positively associated with BE risk (OR = 1.79, p-value = 0.041).ConclusionThis MR study suggested that genetically increased triglycerides were closely related to an elevated risk of BE, potentially serving as a biomarker for the diagnosis of BE in the future.

Causal Role of Immune Cells in Chronic Obstructive Pulmonary Disease: A Two-Sample Mendelian Randomization Study

Accumulating evidence has highlighted the importance of immune cells in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the understanding of the causal association between immunity and COPD remains incomplete due to the existence of confounding variables. In this study, we employed a two-sample Mendelian randomization (MR) analysis, utilizing the genome-wide association study database, to investigate the causal association between 731 immune-cell signatures and the susceptibility to COPD from a host genetics perspective. To validate the consistency of our findings, we utilized MR analysis results of lung function data to assess directional concordance. Furthermore, we employed MR-Egger intercept tests, Cochrane’s Q test, MR-PRESSO global test, and "leave-one-out" sensitivity analyses to evaluate the presence of horizontal pleiotropy, heterogeneity, and stability, respectively. Inverse variance weighting results showed that seven immune phenotypes were associated with the risk of COPD. Analyses of heterogeneity and pleiotropy analysis confirmed the reliability of MR results. These results highlight the interactions between the immune system and the lungs. Further investigations into their mechanisms are necessary and will contribute to inform targeted prevention strategies for COPD.

Is it inevitable to have dynamic horizontal acromioclavicular joint instability with a single tightrope?

Background and purpose Literature showed that single Tightrope fixation in acromioclavicular joint (ACJ) dislocation cases does not secure horizontal joint stability. A positive clinical cross-body adduction test is a usual outcome finding. We hypothesized that some cases might have some degree of horizontal stability, which might be confirmed with ultrasound examination. Methods This clinical study was performed on 27 patients who underwent single Tightrope application in acute ACJ dislocation. Patients were divided into group A which had an arthroscopic technique, and group B which had an open technique augmented with trans-ACJ fixation using two k-wires for 6 weeks. A clinical examination of the operated shoulders was done, and the results were compared with the sound shoulder examination in the same patient at the last 24 months postoperative follow-up visit. Besides, the results of the cross-body adduction test were correlated with ultrasound findings at the same visit. Records, operative details, and postoperative radiography were reviewed to assess if any factors would diminish the dynamic horizontal stability of the ACJ. Body mass index (BMI) was calculated per case. Results Group A had 17 patients (three patients had grade III dislocations, and 14 patients had grade V dislocations). Group B had 10 patients (four patients had grade III dislocations, and six patients had grade V dislocations). The clinical cross-body adduction test gave gross positive results in 14 patients out of group A patients while it gave gross positive results in six patients out of group B patients. Group A patients with negative results were 3, while group B patients with negative results were 4. By ultrasound, differences in horizontal translation of the clavicle within the ACJ in resting and cross-arm positions were more obvious in all operated shoulders than in all sound shoulders. Conclusion The less the Rockwood grading, the more potential to secure more horizontal stability. An open approach also gives more horizontal stability. With increased BMI, horizontal instability is usually masked. So, some factors may diminish, or mask clinical dynamic horizontal instability, which can be confirmed or rolled out with ultrasound usage.

An In Vitro Study Demonstrating the Significance of Acromioclavicular Ligament Repair in Restoring Horizontal and Rotational Acromioclavicular Joint Stability.

The principle of joint reconstruction surgery is to try to recreate the native joint biomechanics and stability. With respect to acromioclavicular joint (ACJ) surgery, much focus to date has been on restoring the superoinferior stability. There is concern that persistent horizontal instability following ACJ reconstruction could lead to poorer patient outcomes; therefore, we evaluated whether acromioclavicular (AC) ligament repair offers improved horizontal stability in conjunction with ACJ reconstruction. A whole-body human cadaver was used. The ACJ was exposed and subjected to a constant 70N load on the lateral end of the clavicle to test the anteroposterior (AP), superoinferior (SI), and horizontal pivot angle (HPA) around the ACJ. The AC and coracoclavicular (CC) ligaments were subsequently divided, and the above three parameters were re-tested. Ligament augmentation and reconstruction system (Corin Group, Cirencester, UK), LockDown (LockDown Medical Limited, Redditch, UK), Endobutton (Smith and Nephew Inc.,London, UK), and Neoligament implant (Xiros Ltd., Leeds, UK) were used to reconstruct the CC ligaments and tested with and without AC repair. The native ACJ allowed an average 2.48 mm AP and 3.88 mm SI translation with a 27° HPA. All synthetic implants significantly improved the vertical stability of the ACJ but allowed up to a four-fold increase in AP translation. Coupled with ACJ repair, all the reconstructions were far superior, especially in restoring horizontal stability. The implants varied in their approach to fixation and concentrated primarily on the reconstruction of CC ligaments. Our study was able to demonstrate that AC repair significantly improves the stability of the construct and significantly reduces vertical and horizontal instability.

Evaporator with horizontal water plane stabilization

Evaporation plays an important role in maintaining water balance and managing water resources in reservoirs. This problem is relevant in hot regions with a lack of fresh water. In addition, reliable operation of evaporators plays an important role in preventing overheating and ensuring safe cooling of reactors which is critical to maintaining nuclear safety. The complete control and accurate measurement of the evaporation process provided by the developed device enables efficient water management ensuring the stability of nuclear power plants and minimising environmental risks. Evaporators are used to control the evaporation process in reservoirs. Based on the analysis of existing evaporators and their shortcomings, an evaporator with horizontal plane stabilization in the pan is developed. Due to this function the developed device allows to control the evaporation process with higher accuracy by reducing fluctuations in the water level in the evaporator. The developed device contains an autonomous power supply that uses energy-saving technology based on a solar battery which ensures operation without additional sources. The use of such a power supply increases the evaporator reliability. One of the important advantages of this device is the use of a cellular-based information transmission channel to the control center which allows to transmit the results of evaporation quickly monitoring and make water management decisions accordingly. In addition, the use of a GPS navigation system allows to set or determine the coordinates of the evaporator installation in the reservoir accurately. The developed device can be included in an intelligent energy resource management system; its use will significantly improve the safety and sustainability of nuclear power plants by improving evaporation process control. It will also optimize the nuclear power plants operation, promote efficient management of water resources and ensure safety in the nuclear energy field.

Acromioclavicular Joint Reconstruction with Modified Weaver–Dunn Operation Versus Hamstring Tendon Autograft Comparative Study

Abstract Background: The dislocation of the acromioclavicular joint (ACJ) is recognized as one of the most frequently occurring injuries most often after either direct or indirect force is applied to the affected shoulder. The best method of AC reconstruction is still controversial. Modified Weaver–Dunn operation (WD) is one of the popular operations. Recent ACJ reconstruction methods include the usage of the gracilis, semitendinosus auto grafts, synthetic grafts, end buttons, nonabsorbable sutures, suture anchors, and tight-rope system. Aim and Objectives: Clinical and radiological results of hamstring autograft versus modified WD operation for reconsrtuction of coracoclavicular and acromioclavicular ligaments. Patients and Methods: This prospective study was carried out at the orthopedic department of Benha University Hospital carried out on 30 cases with chronic ACJ dislocation. They divided into two groups. The modified WD technique was employed on 15 patients, whereas an autogenous semitendinosus tendon graft was used on the other 15. There was a comparison of radiographs taken before and after surgery. Results: Mean surgical time and coracoclavicular (CC) distance differed statistically between groups. Neither demographic data nor postoperative information (pain, range of motion, and postop) showed a difference of statistical significance between the groups. Constant score and post operative American Shoulder and Elbow Surgeons Score (ASES) and post operative complications show no statistically significant difference. Conclusion: Both AC and CC reconstruction by hamstring tendon autograft showed good-to-excellent outcomes with no implant-related complications as some other treatment methods, also more anatomical procedure more than WD operation with better biomechanical vertical and horizontal stability.

Biological soil crust elicits microbial community and extracellular polymeric substances restructuring to reduce the soil erosion on tropical island, South China Sea

Soil erosion stands as the preeminent environmental concern globally, attaining heightened significance, particularly within islands where land resources prove notably scarce. Biological soil crusts, referred to as biocrusts, assume a pivotal ecological role in soil conservation. Notably, they augment the horizontal stability of the substrate through the exudation of microbial extracellular polymeric substances (EPS), thereby shielding the soil against shear stress, exemplified in the form of water erosion. While extant research has delved into the anti-erosion mechanisms of biocrusts in arid landscapes, a conspicuous lacuna persists in the exploration of coral island environments. In this study, we collected and assessed 30 samples encompassing dark biocrusts, light biocrusts, and bare soil to scrutinize the potential anti-erosion efficacy of tropical coral island biocrusts within the South China Sea. Employing a cohesive strength meter, we quantified soil shear stress across various stages of biocrust development, revealing a discernible enhancement in soil erosion resistance during the formation of biocrusts. Relative to the exposed bare soil, the soil shear stress exhibited an escalation from 0.33 N m−2 to 0.61 N m−2 and 1.31 N m−2 in the light biocrusts and dark biocrusts, respectively. Mechanistically, we assayed microbial EPS contents, exposing a positive correlation between EPS and soil anti-erodibility, encompassing extracellular protein and polysaccharide. Concurrently, bacterial abundance displayed a significant augmentation commensurate with biocrust formation and development. In pursuit of elucidating the origin of EPS, high-throughput amplicon sequencing was executed to identify microorganisms contributing to biocrust development. Correlation analysis discerned Cyanobacteria, Chloroflexi, Deinococcota, and Patescibacteria as potential microbials fostering EPS production and fortifying erosion resistance. Collectively, our study presents the first evidence that biocrust from tropical coral reef island in the South China Sea promotes resistance to soil erosion, pinpointing key EPS-producing microbials against soil erosion. The findings would provide insights for island environment restoration.

High Vertical and Horizontal Stability at Short-Term Follow-Up After an All-Endoscopic Double Cerclage Endobutton Technique for Acute Acromioclavicular Joint Separations

PurposeThe aim of this study was to evaluate the clinical and radiological outcomes in the treatment of acute acromioclavicular joint (ACJ) separations using an all-endoscopic double cerclage endobutton technique compared to an arthroscopic-assisted single bundle endobutton technique. The secondary aim was to analyze the complication, failure and revision rate of both procedures. Material and methodsAll patients with acute ACJ separations Rockwood IIIB and V who were operated on using an all-endoscopic double-cerclage technique (2019-2022) or an arthroscopic-assisted single bundle technique (2017-2019) were included. The follow-up period was at least 12 months. Clinical and radiographic assessment was performed at follow-up. Complications, failures, and the revision rate were also investigated. ResultsTwenty-eight patients (14 double cerclage group, 14 single bundle group, all male) with an average age of 37 (IQR: 15) years were available for follow-up after 45 (IQR: 38) months. The median time between trauma and surgery was 7 (IQR: 8) days. Very good clinical results without significant differences were observed in both groups (Constant score: 94 (IQR: 12) vs. 95 (IQR: 15), p=0.427, ACJ Instability score: 95 (IQR: 11) vs 87 (IQR: 22), p=0.210). All patients returned to sport, with an average sports level of 95% compared to the preoperative status. The single bundle group showed significantly increased anteroposterior instability (6 vs. 0, p=0.006). A total of 5 complications occurred (2 vs. 3), leading to 1 revision surgery in each group. ConclusionExcellent clinical results and high vertical and horizontal stability can be achieved with the all-endoscopic double cerclage technique. Horizontal instability occurred significantly more frequently with the single bundle technique. The prolonged operation time in the double cerclage group had no negative impact on postoperative outcomes, including complication and failure rates, and a learning curve to reduce this prolonged operative time should be considered. Level of EvidenceIII, retrospective comparative clinical series

Associations between obesity and hyperuricemia combing mendelian randomization with network pharmacology

ObjectiveObesity has become a global health issue and a risk factor for hyperuricemia. However, the associations between obesity and hyperuricemia are sometimes confounding. In the present study, we performed mendelian randomization (MR) analysis to study their relationship and investigate the underlying mechanism by network pharmacology. MethodBody mass index (BMI) and uric acid related to single nucleotide polymorphism were selected as instrumental variables for MR analysis. Three robust analytical methods are used for bidirectional MR analysis such as inverse-variance weighting, weighted median and MR-Egger regression. Then, we further performed sensitivity analysis to evaluate the horizontal pleiotropy, heterogeneities, and stability. The targets related to obesity and hyperuricemia were collected, screened and further conducted for Kyoto Encyclopedia of Genes and Genomes pathway enrichment to explore the mechanism of obesity and hyperuricemia using network pharmacology. ResultsThe positive causality was indicated between BMI and hyperuricemia based on inverse variance-weighted analysis [odds ratio:1.23, 95% confidence interval: 1.11 to 1.30 for each standard deviation increase in BMI (4.6 kg/m2)]. Conversely, hyperuricemia did not influence BMI. 235 intersected targets from obesity and hyperuricemia were collected. Insulin resistance were the top 1 key target. The mechanism between obesity and hyperuricemia are associated with important pathways including adipocytokine signaling pathway, insulin resistance and cholesterol metabolism et al. ConclusionsOur MR analysis supported the causal association between obesity and hyperuricemia based on availablegenome-wide association analysis summary statistics. Obesity leads to hyperuricemia via insulin resistance, which is a key link in the huge network pathways using network pharmacology.

Marketing Mix to Increase Sales of Wedding Package Resort Buyout at Alila Villas Uluwatu

Purpose: The purpose of this research is to determine strengths, weaknesses, opportunities and threats of an effort to increase sales of wedding package resort buyout, to find out marketing mix strategy that should be used by Sales & Marketing Department to increase sales of wedding package resort buyout. Research methods: Data collection methods that used were participation observation, interview, documentation, and questionnaire. The analysis technique that used are qualitative descriptive analysis, quantitative descriptive analysis, Internal Factor Analysis Summary (IFAS) matrix, External Factor Analysis Summary (EFAS) matrix, Internal-External (IE) matrix, and SWOT analysis. Results and discussion: The result of the research show that there are internal and external factors that influence the increase in upselling which carried out by Sales & Marketing Department at Alila Villas Uluwatu. Based on SWOT analysis score of IFAS was 2.88 and score EFAS was 2.86 that made the position of Alila Villas Uluwatu in current condition in cell 5, named the strategy of concentration through horizontal integration or stability (no change in profit). It means that this company is in a moderate attractive industry, the strategy that used has the goal relatively more defensive, namely to avoid losing sales and losing profits. Based on the SWOT analysis, alternative strategies that can be used to increase the sales of wedding package resort buyout is obtained by finding new markets, adding wedding inclusion on the wedding package, improving the payment regulation, making new building for attendees and equipment store, and making competitor list that shows if hotel is competed to the competitors. Implication: The advice given to the management of Alila Villas Uluwatu is to add new markets that are potential guests who hold wedding resort buyout such as India and Singapore, add more inclusions to the wedding package in order to make the guests interested, and improve the payment regulations to make the wedding operational runs better. Keywords: Marketing mix, IFAS matrix, EFAS matrix.

Current Concepts in Management of Acromioclavicular Joint Injury.

Background: The management of acromioclavicular joint injuries requires a thorough understanding of the anatomy and biomechanics of the joint, as well as knowledge of the pertinent physical exam findings and classification to determine an appropriate treatment approach, whether operative or nonoperative. In this article, we present a narrative review of the current state of understanding surrounding these issues. Although there are a large number of options for operative intervention, we additionally present our experience with anatomic coracoclavicular ligament reconstruction (ACCR) with imbrication of the deltoid fascia. Methods: A retrospective review of prospectively collected data on a total of 45 patients who had undergone ACCR between 2003 and 2016 were collected. Results: We found that improvements were seen in American Shoulder and Elbow Surgeons Score (ASES) (53 ± 19 to 81 ± 23), Simple Shoulder Test (SST) (6 ± 3 to 12 ± 13), Constant-Murley (CM) (60 ± 18 to 92 ± 8), and Rowe (67 ± 14 to 89 ± 11) and the mean post-operative SANE score was 86 ± 17. Conclusions: ACCR has the advantage of addressing both horizontal and vertical stability with good outcomes.

Functional reconstruction of chronic acromioclavicular joint separation using a double suture technique combined with semitendinosus autograft.

We present the functional and clinical results of a combined surgical technique that functionally restores chronic Acromioclavicular Joint Instability (AJI). The method combines a double-looped suture fixation augmented with a semitendinosus autograft. Between 2017 and 2021, 15 patients were treated using the surgical technique. All patients suffered an Acromioclavicular Joint Separation that remained untreated for at least 6 (6-16) weeks after the initial injury. Four Ethibond sutures were passed below the coracoid process and through a 4.5 drill hole in the clavicle. The sutures provided adequate horizontal and vertical reduction and stabilization of the clavicle. A semitendinosus autograft was passed below the coracoid process and looped around the clavicle. The remaining graft limbs were used to reconstruct the acromioclavicular capsule. Patients were radiologically evaluated with bilateral anteroposterior (AP), Zanca, and Alexander views. The clinical evaluation was based on the Acromioclavicular Joint Instability Score and the Constant-Murley Score. The mean follow-up period was 31.2months (17-61). The mean last ACJIS and CMS scores were 96 (90-100) and 97.67 (87-100), respectively. Reduction of the clavicle was radiologically confirmed in all cases throughout the follow-up period. AC arthritis was reported in 1 case without associated clinical symptoms. No significant complications were reported, and all patients returned to the pre-injury activity level. The presented functional reconstruction of the AC joint disruption in chronic cases is an effective and secure method with low complication rates and good clinical results. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Causal associations between gastroesophageal reflux disease and essential hypertension: A bidirectional Mendelian randomization study.

Clinical studies have reported that patients with gastroesophageal reflux disease (GERD) have a higher prevalence of hypertension. To performed a bidirectional Mendelian randomization (MR) analysis to investigate the causal link between GERD and essential hypertension. Eligible single nucleotide polymorphisms (SNPs) were selected, and weighted median, inverse variance weighted (IVW) as well as MR egger (MR-Egger) regression were used to examine the potential causal association between GERD and hypertension. The MR-Pleiotropy RESidual Sum and Outlier analysis was used to detect and attempt to reduce horizontal pleiotropy by removing outliers SNPs. The MR-Egger intercept test, Cochran's Q test and "leave-one-out" sensitivity analysis were performed to evaluate the horizontal pleiotropy, heterogeneities, and stability of single instrumental variable. IVW analysis exhibited an increased risk of hypertension (OR = 1.46, 95%CI: 1.33-1.59, P = 2.14E-16) in GERD patients. And the same result was obtained in replication practice (OR = 1.002, 95%CI: 1.0008-1.003, P = 0.000498). Meanwhile, the IVW analysis showed an increased risk of systolic blood pressure (β = 0.78, 95%CI: 0.11-1.44, P = 0.021) and hypertensive heart disease (OR = 1.68, 95%CI: 1.36-2.08, P = 0.0000016) in GERD patients. Moreover, we found an decreased risk of Barrett's esophagus (OR = 0.91, 95%CI: 0.83-0.99, P = 0.043) in essential hypertension patients. We found that GERD would increase the risk of essential hypertension, which provided a novel prevent and therapeutic perspectives of essential hypertension.

The Relationship Between Systemic Lupus Erythematosus and Osteoporosis Based on Different Ethnic Groups: a Two-Sample Mendelian Randomization Analysis.

The previous observational studies could not overcome the effects of confounding variables and reverse causality. We aimed to determine whether there is a causal relationship between systemic lupus erythematosus and osteoporosis in East Asian and European populations, respectively, by two-sample Mendelian Randomization analysis. We obtained and downloaded data from publicly available genome-wide association study databases and analyses for East Asian and European populations, including systemic lupus erythematosus (SLE), osteoporosis (OP), multisite bone mineral density (BMD), and OP with fracture. After screening for instrumental single-nucleotide polymorphisms (SNPs) significantly correlated to SLE, the inverse-variance weighted (IVW) method was used for calculating the ratio and 95% confidence interval, besides utilizing MR-Egger, weighted median, and weighted mode to assess the robustness of the primary outcome. Moreover, multiple analyses, including MR-PRESSO, MR-Egger intercept, Cochran's Q test, as well as "leave-one-out" sensitivity, were used for evaluating horizontal pleiotropy, heterogeneity, and stability. Finally, we exchanged exposure and outcome and performed a reverse MR analysis. IVW (OR = 1.05, 95% CI = 1.01-1.09, P = 0.009) indicated a significant positive correlation between genetically predicted SLE and OP in East Asians. Furthermore, neither heterogeneity nor horizontal pleiotropy was observed. In Europe, there was no significant genetically predicted causal relation between SLE and OP. Bi-directional MR analysis showed no reverse causality between SLE and OP. In the East Asian population, genetically predicted SLE may have had a positive causal relationship with OP. In Europe, there is insufficient evidence for a potential causal relation between SLE and OP or BMD and fracture, and the correlations currently observed may be attributed to a variety of confounder variables.

Study on VIV performance of streamlined steel box girder of a sea-crossing cable-stayed bridge

The frequent occurrence of vortex-induced vibrations (VIVs) poses significant challenges for the operations of large-span sea-crossing bridges subjected to wind loads. A wind tunnel test device for large-scale section models is developed for a sea-crossing bridge to investigate the VIV performance of a streamlined box girder. A new type of aerodynamic countermeasure combining horizontal stabilizers and deflectors is proposed to address vertical and torsional VIV mitigation. To achieve optimal control effects, adjustments are made to the layout of deflectors and the width of horizontal stabilizers. The effects of varying structural damping ratios and low turbulence on vertical VIVs are also thoroughly examined. The VIV triggering mechanism of the girder by maintenance rails is revealed through numerical simulations using the Shear Stress Transport (SST) k−ω model. Finally, the suppression mechanism of the countermeasures is elucidated. The instantaneous vorticity distribution indicates that implementing the countermeasures effectively reduces the size of alternating shedding vortices on the trailing edge of the main girder. This research provides valuable insights into the VIV mitigation of streamlined box girders.

Analysis of Marketing Strategies to Increase Cricket Sales at Maja Farm Company in Pesawaran

Maja Farm in Pesawaran is an individual company that focuses on cricket farming, located in Taman Sari Village, Gedung Tataan District, Pesawaran Regency. The company is facing challenges in the form of a decrease in cricket sales by 64.9% in 2018 and 30.4% in 2019. This study aims to analyse marketing strategies that can increase sales value at Maja Farm Company in Pesawaran, using SWOT Analysis as an analytical tool. The calculation results show a total IFAS value of 2.80 and EFAS of 2.55. From these results, it is known that the company's position is in cell 5, which indicates that the company is in a stable phase and is not experiencing growth with a concentration strategy through horizontal integration or stability. Through the combination of SWOT Matrix, the most dominant strategy is SO (Strengths-Opportunities) with a value of 3.55, namely creating positive relationships with customers through maintaining product quality and maintaining product availability in order to meet consumer needs, followed by the ST (Strengths-Threats) strategy with a value of 2.80, namely conducting market research to understand product prices in the market and determining efficient promotion strategies. This strategy is expected to be the basis for increasing sales of Maja Farm Company in Pesawaran. Keywords: SWOT Analysis, Marketing Strategy, Sales

Wind Tunnel Balance Measurements of Bioinspired Tails for a Fixed Wing MAV

Bird tails play a significant role in aerodynamics and stability during flight. This paper investigates the use of bioinspired horizontal stabilizers for Micro Air Vehicles (MAVs) with Zimmerman wing-body geometry. Five configurations of bioinspired horizontal stabilizers are presented. Then, 3-component external balance force measurements of each horizontal stabilizer are performed in the wind tunnel. The Squared-Fan-Shaped Horizontal Stabilizer (HSF-tail) is selected as the optimal horizontal stabilizer that provides the highest aerodynamic efficiency during cruise flight while maintaining high longitudinal stability on the vehicle. The integration of the HSF-tail increases the aerodynamic efficiency by more than 6% up to a maximum of 17% compared to the other alternatives while maintaining the lowest aerodynamic drag value during the cruise phase. Furthermore, balance measurements to analyze the influence of the HSF-tail deflection on the aerodynamic coefficients are conducted, resulting in increased lift force and reduced aerodynamic drag with negative tail deflections. Lastly, the experimental data is validated with CFD-RANS steady simulations for low angles of attack, obtaining a relative difference on the measurement around 5% for the aerodynamic drag coefficient and around 10% for the lift coefficient during the cruise flight that demonstrates a high degree of accuracy in the aerodynamic coefficients obtained by external balance in the wind tunnel. This work represents a novel approach through the implementation of a horizontal stabilizer inspired by the structure of the tails of birds that is expected to yield significant advancements in both stability and aerodynamic efficiency, with the potential to revolutionize MAV technology.