Maximum Distance Research Articles

"Honey pot"-like lesion formation: impact of catheter contact angle on lesion formation by novel temperature controlled ablation catheter in a porcine experimental model

Abstract Background The DiamondTemp(DT) catheter enables precise temperature-controlled ablation. However, the effects of the DT catheter's contact angle on lesion formation are poorly understood. Purpose This study evaluated lesion formation using the DT catheter at different angles in a porcine experimental model. Methods We used freshly sacrificed porcine hearts, and radiofrequency catheter ablation with DT was performed at 50 watts for 15 seconds at an upper-temperature setting of 60°C. The contact force (5, 10, and 30 grams) and catheter contact angles (30°, 45°, and 90°) were changed in each set (n = 13 each). The surface width (SW), maximum lesion width (MW), lesion depth (LD), surface area (SA), and distance from the distal edge to the widest area (DW) were evaluated. In addition, the generator impedance drop during radiofrequency application was analyzed. Results Figure 1 shows the summarized data in this study. SW and MW were longer at 30° than at 90° (SW 5 g: 6.34 ± 0.91 vs. 5.07 ± 0.87 mm; SW 10 g: 7.46 ± 0.55. vs. 5.60 ± 0.84 mm; SW 30 g: 7.42 ± 0.74. vs. 6.14 ± 0.77 mm; MW 10 g: 8.81 ± 0.55. vs. 7.89 ± 0.84 mm; MW 30 g: 9.24 ± 0.67. vs. 8.03 ± 1.04 mm, p <0.05, respectively). There were no significant differences in LD by catheter angle except at 30 g. SA was larger at 30° than at 90° (SA 5 g: 30.03 ± 0.91. vs. 23.61 ± 0.87; SA 10 g: 29.24 ± 0.55. vs. 21.27 ± 0.84; SA 30 g: 35.86 ± 0.74. vs. 31.74 ± 0.77, p <0.05, respectively). Besides, DW was longer at 30° than at 90° (DW 5 g: 4.28 ± 1.17. vs. 2.50 ± 0.32 mm; DW 10 g: 4.94 ± 0.52. vs. 2.47 ± 0.38 mm; DW 30 g: 5.34 ± 0.26. vs. 2.96 ± 0.40 mm, p <0.05, respectively). There were no significant differences in the impedance drop according to the catheter angle. Conclusion With the DT catheters, the lesion width increased at a shallower contact angle, whereas the LD did not. SA also increased at a shallower contact angle. The DT catheter created a large ablation lesion on the proximal side of the catheter, which looked like a "honey pot." (Figure 2)summarized dataImage of honey pot-like lesion formation

Baseline patient reported outcomes in patients with peripheral artery disease and type 2 diabetes from STRIDE: a phase 3, 52-week, randomised, double-blind, placebo-controlled trial

Abstract Introduction Lower extremity peripheral artery disease (PAD) is caused by atherosclerotic steno-occlusive arterial lesions in the lower extremities and can lead to intermittent claudication, severe functional impairment and reduced health-related quality of life (HRQoL). People living with type 2 diabetes (T2D) are at higher risk of developing PAD than those without T2D. The most common clinical manifestation of PAD, functional impairment, can be stratified based on severity using Fontaine classification (stages I-IV). There are a limited number of therapies approved for the management of PAD related functional impairment and no glucose-lowering medication has been shown to improve functional capacity in people with PAD and T2D. STRIDE is a phase 3 clinical trial investigating once-weekly subcutaneous (s.c.) semaglutide treatment in people with PAD (Fontaine IIa claudication) and T2D. Purpose To report the patient-reported outcomes (PROs) at baseline from STRIDE and elucidate the impact that PAD has on the functional capacity and HRQoL in this early-stage symptomatic PAD population with T2D. Methods STRIDE enrolled 792 participants with PAD (Fontaine IIa claudication) and T2D who were randomised to receive either 1 mg once-weekly s.c. semaglutide or placebo for 52 weeks. The primary outcome of STRIDE is the change in maximum walking distance at week 52 on a constant load treadmill. Baseline PRO assessments included two Patient Global Impression of Severity (PGI-S) questions and three patient-reported questionnaires: the six items version of the Vascular Quality of Life questionnaire (VascuQoL-6), the Walking Impairment Questionnaire (WIQ) and the Medical Outcomes Short Form 36 (SF-36). Results Baseline responses to both PGI-S questions showed that two thirds of patients reported a moderate-to-severe limitation in their ability to walk (64.9%) and reported that the impact of poor blood circulation in their legs on their HRQoL was also moderate-to-severe (62.5%) (Figure 1A and B). The baseline VascuQoL-6 median score was 15 (score range: 6-24, with a low score indicating more severe impact) and details of impact on the six domains are presented in Table 1. Baseline responses to the WIQ indicated that 20.1% of participants found the degree of difficulty to walk 200 meters either ‘much difficulty’ or were ‘unable to do so’ and 21.8% reported the same when climbing 2 flights of stairs. The secondary supportive outcome assessed in the SF-36 questionnaire was the domain physical functioning where a median baseline value of 38.09 was observed (score range: 19.03-57.60, with a low score indicating more impact). Conclusion Participants in STRIDE, characterized as having early-stage symptomatic PAD, have reported moderate-to-high impact on their physical functioning and HRQoL at baseline. These findings highlight the need for better therapies that improve the functional capacity and HRQoL in people with PAD and T2D.

Lower rate of ischemic events with PCSK9 inhibition in patients with atherosclerotic cardiovascular disease but without prior ischemic events

Abstract Background Individuals with atherosclerotic cardiovascular disease (ASCVD) without prior ischemic events, such as myocardial infarction (MI), ischemic stroke (IS), or unstable angina (UA) hospitalization, are at very high risk for having an event. Purpose To estimate the impact of PCSK9 inhibitor (PCSK9i) therapy on ischemic events in this population. Methods Patients with ASCVD were initially selected from the Optum Research Database during Jan 2016 to Dec 2022. For selected patients the index (time zero for follow-up) was required to be in a period of ASCVD without prior ischemic events, however patients may have ischemic events after index. Determination of ASCVD and ischemic events was based on diagnosis and procedure codes. For the PCSK9i group, index was initiation of PCSK9i and information before index was examined to ascertain ASCVD and rule out prior ischemic events. For each patient in the PCSK9i group, up to 5 matching patients in the no-PCSK9i group were chosen based on propensity score (PS) distance, with maximum allowable PS distance of 0.1. Among all possible choices for index for the no-PCSK9i patient, the selected one minimized the PS-distance. The primary endpoint was defined as the composite of nonfatal MI, nonfatal IS, and all-cause death. In order to further reduce bias and ensure causally interpretable estimation, the G-computation methodology was employed by marginalizing the conditional treatment effect (as estimated by a Cox model) over the baseline characteristics. Two effects were estimated: intention-to-treat (ITT) where only the treatment assignment at index was considered as the intervention, and per-protocol (PP) where the effect of sustained treatment with PCSK9i over time was estimated. Results A total of 15,067 and 66,470 patients met the selection criteria for the PCSK9i and no-PCSK9i groups, respectively. Baseline characteristics were well-balanced at index. G-computation analysis resulted in estimated survival curves over time in the two groups for the ITT and PP scenarios (Figures 1 and 2). For the ITT scenario, the estimated 5-year event rate was 18.7% (95% confidence interval [CI]: 17.1%–20.1%) in the PCSK9i group and 28.4% (95% CI: 27.7%–29.1%) in the no-PCSK9i group. The implied relative risk reduction (RRR) and absolute risk reduction (ARR) were 34.3% (p<0.001) and 9.7% (p<0.001), respectively, in favor of the PCSK9i group. For the PP scenario, the estimated 5-year event rate was 10.7% (95% CI: 9.7%–11.7%) in the PCSK9i group and 28.8% (95% CI: 28.3%–29.5%) in the no-PCSK9i group. The implied RRR and ARR were 62.7% (p<0.001) and 18.1% (p<0.001), respectively, in favor of the PCSK9i group. Conclusions Initiation of PCSK9i in patients with ASCVD but without prior ischemic events is associated with significantly and substantially lower risk for ischemic events.Event Rates Intention-to-Treat ScenarioEvent Rates Per-Protocol Scenario

A Scalable Digital Light Processing 3D Printing Method

The 3D printing method based on digital light processing (DLP) technology can transform liquid resin materials into complex 3D models. However, due to the limitations of digital micromirror device (DMD) specifications, the normal DLP 3D printing method (NDPM) cannot simultaneously process large-size and small-feature parts. Therefore, a scalable DLP 3D printing method (SDPM) was proposed. Different printing resolutions for a part were designed by changing the distance between the projector and the molding liquid level. A scalable DLP printer was built to realize the printing resolution requirements at different sizes. A series of experiments were performed. Firstly, the orthogonal experimental method was used, and the minimum and maximum projection distances were obtained as 20.5 cm and 30.5 cm, respectively. Accordingly, the layer thickness, exposure time, and waiting leveling time were 0.08 mm, 3 s, and 6 s and 0.08 mm, 7 s, and 10 s. Secondly, single-layer column feature printing was finished, which was shown to have two minimum printing resolutions of 101 μm and 157 μm at a projection distance of 20.5 cm and 30.5 cm. Thirdly, a shape accuracy test was conducted by using the SDPM. Compared with the NDPM, the shape accuracy of the small-feature round, diamond, and square parts was improved by 49%, 42%, and 2%, respectively. This study verified that the SDPM can build models with features demonstrating high local shape accuracy.

Contrasting effects of shooting disturbance on the movement and behavior of sympatric wildfowl species.

Human-wildlife conflict is a global conservation issue, necessitating effective mitigation strategies. Hunting is a common management approach to reduce conflict, but the indirect consequences are often overlooked. Chronic hunting-related disturbance can reduce fitness and redistribute species. In recent decades, goose-agricultural conflict has intensified due to increasing abundance and shifts towards agricultural foraging. On Islay, Scotland, escalating conflict culminated in shooting Greenland barnacle geese Branta leucopsis to reduce damage to agricultural grassland. In this study, we contrast the impact of shooting disturbance on the movement, behavior, energy expenditure and habitat selection of the target species (Greenland barnacle goose) and a vulnerable nontarget species (Greenland white-fronted goose, Anser albifrons flavirostris) using biologging devices (target species: n = 33; nontarget species: n = 94). Both species were displaced by shooting, and greater distances were subsequently traveled by the target species (1.71 km when directly targeted). When disturbed at any distance, total daily movement increased significantly by 1.18 km for the target species but not for the nontarget species. The target species exhibited no accompanying change in diurnal energy expenditure (measured via accelerometery) but foraged in improved grasslands further from roads after shooting disturbance, where disturbance from all sources was likely lower. The significant increases in movement and changes in foraging site selection of the target species could reduce fitness but given the infrequency of shooting disturbances (0.09 per day) there is likely capacity for compensatory feeding to recoup energetic losses. The nontarget species expectedly showed no significant change in energy expenditure, behavior or habitat selection following shooting disturbance, suggesting mitigation strategies have been effective at minimizing fitness impacts. Refuge areas with a 3.5 km diameter (three times the maximum distance from shooting that displacement was detectable) could provide undisturbed foraging for the target species, minimizing compensatory feeding and further agricultural damage. Wildlife managers should, where possible, consider the fitness implications of shooting disturbance, and whether compensatory feeding and redistribution could hamper conflict mitigation. Management strategies should also include species-specific monitoring and mitigation as we have demonstrated differing responses potentially due to imposed mitigation but also differing species ecology and "landscapes of fear."

12 Access to paediatric maltreatment services through a northern community hospital

Abstract Background Few studies have evaluated how paediatric maltreatment services based in community hospitals can provide access to care for populations who live far away from tertiary centres. The Violence Intervention Prevention Program (VIPP) and the Paediatric Abuse and Referral Evaluation (PARE) clinic based in a northern community hospital in Canada offer assessment for sexual and physical maltreatment. Objectives The aim of the study was to describe demographic and clinical characteristics of patients accessing VIPP and PARE services and to characterize the length of time required to access care. Design/Methods We conducted a retrospective chart review of patients, under 16 years of age, who attended PARE clinic for initial consultation between 2017-2019. Analyses were descriptive. This work was approved by the research ethics board at our hospital. There are no funding disclosures. Results Of 164 patients, 62.2% were female; 37.8% male. The mean age was 6.6 years, ranging from 1 month to 15.9 years. 54.3% of referrals were for suspected physical maltreatment, 44.4% for suspected sexual maltreatment and 1.2% for both. 87.5% of patients listed home addresses within the hospital’s city limits. The maximum distance travelled from home to access care was 171 km. 87.2% of patients presented through the emergency department; a minority presented through direct referral to outpatient services (11.5%) or through inpatient (1.2%). When called from the emergency department, on-call VIPP nurses responded within a mean of 32 minutes for initial assessment. These patients received a maltreatment assessment by a paediatrician through the PARE clinic a mean of 14.3 days later. If patients did not present through the emergency department, the mean wait time for a maltreatment assessment by a paediatrician was 16 days. 13.4% (22/164) required referral to other medical or multidisciplinary services. General paediatrics (11/22) was the most frequent referral, followed by community speech programs (5/22). A minority (3.0%) of cases required consultation with external maltreatment teams, where two cases were peer-reviewed with a tertiary care team, one with a paediatric maltreatment physician at another community hospital and two cases were reviewed with a paediatric tertiary care radiologist. Conclusion Our results suggest that community-based paediatric maltreatment services provide care for our regional northern population. There is timely on-call access to allied-health providers through the emergency department. All patients were able to be assessed locally and none were required to travel to a tertiary care hospital. Further study is needed to assess how our data compares to other community maltreatment programs.

A repeated jumping solution based on the bistable film structure for film-structured miniature soft robots

Abstract Miniature film-structured robots achieved remarkable locomotion performance and various applications. The integration of a jumping function could empower existing film-structured terrestrial robots to conquer complex terrains. However, current repeated jumping mechanisms for miniature soft robots are often constrained to specific materials and mechanical configurations, rendering them incompatible with film-structured robots. A solution that effectively addresses these limitations remains absent in the field. This work introduces an electrically actuated solution for repeated jumping in miniature soft robots, utilizing a bistable film structure coupled with a numerical two-rod model. The bistable film structure integrates a flexible film, polydimethylsiloxane (PDMS) linear spring, and a shape memory alloy spring to achieve repeated jumping motion through snap-through buckling. The numerical model is employed to optimize the spring parameters, tailoring the structure to the specific properties of the target robot. To demonstrate the practicality of this solution, the bistable film structure is seamlessly integrated into an existing fast-steering insect robot, which previously lacks jumping capabilities. By customizing PDMS spring design based on the robot body’s dimensions and stiffness, the prototype robot, measuring 23 × 16 × 8 mm3 in size and 120 mg in weight, demonstrates repeated jumping ability with a maximum horizontal jumping distance of 11.8 cm (5.1 body lengths), a jumping height of 3.8 cm (4.7 body heights) and a jumping frequency of 0.1 Hz. The robot traverses a 43 cm-long road with half walls and trench obstacles in 41 s. This work presents the bistable film structure’s potential as a repeated jumping solution for film-structured robots, enhancing their obstacle-crossing abilities and expanding their applicability in complex environments.

Genetic variability, character association and path analyses effects on fiber yield and yield attributing morpho-agronomic traits of tossa jute (Corchorus olitorius L.)

Jute (Corchorus spp.) is a natural fiber crop having a lower extent of genetic variability due to its self-pollinating nature. The success of any breeding program for variety development primarily depends on the presence of genetic variation in the parental genotypes. A field experiment was conducted in a randomized complete block design at ManikganjStation of Bangladesh Jute Research Institute (BJRI) during 2019-2020. The genetic divergence of 58 tossa jute (C. olitorius) genotypes including two pre-released standard varieties (O-9897, BJRI Tossa pat 4) and 56 accessions were studied to select genotypes having the most divergence in natural rainy condition. The jute genotypes were categorized into five clusters based on Mahalanobis D2 analysis. Cluster I and IV showed maximum inter-cluster distance (181.44) while the maximum intra-cluster distance (16.15) was recorded in cluster I. Cluster V revealed the highest values for number of nodes, stem mid-diameter, core diameter, green weight with leaves, dry stick weight and dry fiber weight per plant while cluster IV showed higher means for plant height, green bark thickness and leaf area. The highest contribution (47.14%) was wielded by plant height of total deviations. The results recommended that hybridization between genotypes of cluster V, IV and III could provide a wide range of discrepancies in the segregating generation which could offer chance for isolation of good genotypes with high fibre yielding lines.

Design and Implementation of Wind Speed-Based Radar Antenna Safety System Prototype

Air defense radar is a system that detects the presence of one or more air objects at a certain distance, altitude, and direction. One type of air defense radar used by the Indonesian National Armed Forces (TNI) is the Thomson TRS 2215D. An essential part of the radar is the rotating part of the radar antenna support called the antenna pivot. The rotation of the radar antenna must constantly be monitored and controlled for rotational stability at a speed of 6 Rotations per Minute (RPM) with a maximum wind speed of 120 km/h to prevent damage to the driving gear. Stormy weather with high wind speeds can cause the rotation speed of the radar antenna to be uncontrollable, which can cause damage. The solution offered in this study is to build a safety system that will lock the radar antenna automatically when the wind speed is detected to exceed tolerances and maintain the security of the radar antenna and its support system. The safety system was designed using an ESP32 Wi-Fi device equipped with an anemometer wind speed sensor, a Liquid Crystal Display (LCD) monitor, a Direct Current (DC) motor, and a Blynk Internet of Things (IoT) application. The test was conducted in a simulation using a multi-meter and oscilloscope measuring instrument. Testing the radar antenna's safety system prototype on a laboratory scale shows that the safety system can work as designed. The system can lock the radar antenna when the airflow is set at a speed of 54 km/h or 15 m/s, communication with the Blynk server works well, and the ESP32 device can transmit data at a maximum distance of 14 meters.

Single-Use Aircraft Launch System with Small Helium Balloon for 1 kPa Flight Testing

A single-use aircraft launch system using a small helium balloon concept was proposed to elevate the likelihood of successful high-altitude flight tests above 30 km. The system, capable of carrying a payload of 0.5 kg, has been developed and reported. Completing the flight within a range of 92 km, which represents the maximum communication distance between the airborne flight system and the ground station for operational phase control, is imperative. Therefore, a straightforward method for simulating flight trajectories was outlined to determine launch windows and suitable locations to ensure flight completion within uninhabited areas. Simulation studies revealed that the shortest landing distance was obtained during summer at the selected launch site. Additionally, a parameter study was conducted to assess the influence of varying ascent velocities on the targeted flight test altitude, which depends on the payload weight and helium gas volume. Consequently, the parameter study results established the constraints for flight model design. A demonstration flight was conducted in 2023 to validate the feasibility of the system for high-altitude flight experiments. This flight successfully released the flight model at 31 km and recovered flight data before landing on the sea surface. The proposed system concept offers an expedited approach to aircraft design for operating in thin air. It enables component function tests and scaled model flights as an alternative to employing large high-altitude balloons for high-altitude experiments.

Design and Baseline Characteristics of the STRIDE Trial: evaluating Semaglutide in People with Symptomatic Peripheral Artery Disease and Type 2 Diabetes.

People with lower extremity peripheral artery disease (PAD) suffer from a high burden of symptoms and significant functional impairment. There are few therapies that improve function and reduce symptoms in this population. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have been shown to improve glycemic control, reduce body weight and reduce the risk of major adverse cardiovascular events, in people with atherosclerotic cardiovascular disease and type 2 diabetes (T2D). STRIDE (NCT04560998) is a randomized, placebo-controlled, double-blind phase 3b trial evaluating 1mg once-weekly subcutaneous semaglutide (GLP-1 RA) vs. placebo, in people with symptomatic PAD (Fontaine IIa claudication) and T2D. Eligible participants were≥18 years, had hemodynamically stable PAD, had no planned intervention, and were not receiving a GLP-1 RA. The primary endpoint is change in maximum walking distance on a constant-load treadmill (CLT). Secondary endpoints include quality of life and cardiometabolic assessments. A total of 792 participants were randomized in 20 countries. Participants' median age was 68 and they had T2D for a median of 12 years. Risk factors included 25.6% current smokers, 87.9% with hypertension, and 42.7% with coronary heart disease. The mean BMI was 29.6kg/m2 and mean HbA1C was 7.3%. Participants exhibited baseline functional impairment with a median maximum walking distance of 186 meters on a CLT. STRIDE has enrolled participants with symptomatic PAD and T2D, frequent risk factors and comorbidities, and functional impairment. The trial will provide evidence for the functional outcomes with semaglutide in people with PAD and T2D.

Design System of Solar-Powered Safety Lamp Integrated Proximity Sensor as a Solution for Accident Prevention at Blind Spot Areas

The curved contour of the road creates blind spots which increase the risk of traffic accidents. Throughout 2019, there were 107,500 accident cases recorded in Indonesia. Therefore, efforts are needed to provide road infrastructure that supports driving safety, such as traffic signs to reduce the risk of accidents in blind spot areas. This research aims to design a smart safety light warning system that is integrated with solar-based street lighting. The design uses a design-based research approach referring to several established standards including Indonesia National Standard (SNI) 7931: 2008, SNI IEC 60529:2014, Regulation of the Minister of Transportation of the Republic of Indonesia Number PM 13 of 2014, Manual on Uniform Traffic Control Devices (MUTCD) issued by the Federal Highway Administration (FHWA) of the United States Department of Transportation (USDOT), and Article 115 of Minister of Transportation Republic of Indonesia Regulation PM 27 of 2018. This study used Design-Based Research (DBR) as a research methodology. The result of this study is a prototype design and development of smart safety light warning system which can be optimized. Validation of the design and circuit is conducted using prototyping modeling 1:20 from the original dimensions to measure the function and performance of the circuit. The prototype is capable of turning on warning lights and siren notifications when detecting objects with a maximum distance of 350 cm as measured by the HC – SR04 sensor. Charging the stored solar panels via the accumulator allows the technology to continue working for 45 hours without charging. For power efficiency purposes, the technology is equipped with an LDR (Light Dependent Resistor) sensor with a minimum limit of 341-lux which regulates the lighting. The development of these safety lights will increase driver awareness when passing through blind spot areas and have positive implications for reducing the number of accidents in Indonesia.

Design of unmanned aerial vehicle formation keeping controller based on improved consistency algorithm design

This article conducts in-depth research on the problems of large gain convergence oscillation and simultaneous application of translational rotation in traditional consistency algorithms. First, based on the traditional consistent formation algorithm, a virtual long machine is introduced, and a new norm is defined to extend the original consistent algorithm to solve the problem of large gain convergence oscillation in the Linearizability algorithm. Secondly, in response to the issue of the inability to maintain the formation caused by the application of translational rotation in traditional consistent formation processes, the maximum distance is introduced as feedback to the reference controller to modify the reference input trajectory to ensure good tracking of the formation during translational rotation. Finally, a joint semi physical simulation was conducted using the open-source flight control Ardupilot and the open-source simulation platform Airsim to further validate the feasibility of the improved algorithm. The results of this study indicate that the proposed algorithm has significant improvements in solving the problems existing in traditional consistency protocols and has good feasibility in practical applications.

Application of a GIS-Based Multi-Criteria Decision-Making Approach to the Siting of Ocean Thermal Energy Conversion Power Plants: A Case Study of the Xisha Sea Area, China

In order to achieve the goals of carbon neutrality and reduced carbon emissions, China is increasingly focusing on the development and utilization of renewable energy sources. Among these, ocean thermal energy conversion (OTEC) has the advantages of small periodic fluctuations and large potential reserves, making it an important research field. With the development of the “Maritime Silk Road”, the Xisha Islands in the South China Sea will see a growing demand for electricity, providing the potential for OTEC development in this region. Optimal site selection of OTEC power plants is a prerequisite for developing thermal energy provision, affecting both the construction costs and future benefits of the power plants. This study establishes a scientific evaluation model based on the decision-making frameworks of geographic information systems (GISs) and multi-criteria decision-making (MCDM) methods, specifically the analytic hierarchy process (AHP) for assigning weights, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) to reclassify the factors, and weighted linear combination (WLC) to compute the suitability index. In addition to commonly considered factors such as temperature difference and marine usage status, this study innovatively incorporates geological conditions and maximum offshore distances of cold seawater based on cost control. The final evaluation identifies three suitable areas for OTEC development near the Xuande Atoll and the Yongle Atoll in the Xisha Sea Area, providing valuable insights for energy developers and policymakers.

Ground failure and soil erosion caused by bursting of buried water pipeline: experimental and numerical investigations

Pressurized water pipelines buried in an urban environment are prone to bursting failures, threatening public safety and traffic convenience. The limited studies in literature just focused on soil fluidization while few studies considered ground failure, shear strain, soil erosion and the influence of leakage locations during pipe bursts. In this study, extensive experimental tests along with a finite difference method – discrete element method (FDM-DEM) solid–fluid coupling analysis were conducted to investigate these issues. It was disclosed that the failure development during pipe bursts can be divided into three stages, i.e., seepage diffusion, erosion cavity expansion, and soil fluidization. By digital image correlation (DIC) analysis of the experimental results, a wedge-shaped displacement zone in ground was identified, with peak shear strain near its boundaries. Moreover, it was revealed that leakage locations affected the expansion origin of erosion cavity; as the burial depths increased, the ground heave range increased linearly; the maximum water outflow distance was closely related to the internal pressures of buried pipeline, which could be modeled by a square root formula based on turbulent jet theory. Mesoscopic analyses revealed that finer particles were more susceptible to erosion during pipe bursts because of the low possibility of forming strong connections with surrounding particles. The findings yielded from this study can enhance the understanding of pipe bursts and help professionals mitigate potential damage.

Morphological and molecular diversity analysis vis-a-vis phylogenetic correlation among pomegranate (Punica granatum L.) varieties

Abstract Identification of different pomegranate (Punica granatum L.) genotypes using morphological descriptors and further substantiated through molecular means is essential for a breeding program. Characterization using molecular markers has an advantage over its morphological counterpart due to its low expense, quick and reliable results, and the requirement of less sophisticated equipment. In this study, eight different pomegranate cultivars were characterized based on their morphological and molecular characters in sub-tropical regions between 2018 and 2019. Morphological experiments were conducted in a randomized block design replicated thrice for each cultivar, whereas RAPD markers were employed for molecular studies. Principal component analysis revealed significant morphological variation (79.61%) among the cultivars. A high level of polymorphism, similar to PCA, was observed with RAPD analysis (80.49%). Some discrepancies between morphological and molecular results were noted in UPGMA cluster analysis. However, eight primers (total = 41) distinctively separated the Bhagwa variety from others, with the maximum similarity coefficient value (ca. 0.54) and superior fruit quality distinguished in PCA analysis with the maximum mean Euclidean distance (ca. 16). Hence, RAPD markers could be used along with morphological markers for a quick screening of germplasms in further crop improvement programs.

Numerical Study on the Influence of the Slope Composition of the Asymmetric V-Shaped Tunnel on Smoke Spread in Tunnel Fire

Asymmetrical V-shaped tunnels often appear in tunnels crossing the river or urban underground road tunnels. The smoke flow inside is affected by a lot of factors. A full understanding of the smoke flow in this kind of tunnel is the basis of the smoke control. In this study, the effects of slope composition and fire heat release rate (HRR) on the longitudinal induced airflow velocity, the smoke back-layering length at the small slope side, and the maximum ceiling temperature were studied by the numerical method. The results show that when the fire occurs at the slope change point of the V-shaped tunnel, the maximum ceiling temperature decreases with the increase in the slope of the large-slope side tunnel. The longitudinally induced velocity is primarily related to the slope of the large-slope side tunnel and the fire HRR. When the slope difference between the side tunnels or the slope of the large-slope side tunnel is large, the smoke in the small-slope side tunnel flows back toward the fire source after reaching its maximum dispersion distance and then reaches a quasi-steady state. The smoke back-layering length is mainly affected by the slope and length of the large-slope side tunnel. When the slope of the large-slope side tunnel is 9%, the induced airflow velocity from the small-slope side can prevent the spread of smoke. The empirical models of the smoke back-layering length and the longitudinal induced airflow velocity in the small-slope side tunnel are drawn, respectively, by the theoretical analysis and the numerical results. This study can provide technical support for the design and operation of smoke control systems in V-shaped tunnels.

Cross-Country Assessment of Socio-Ecological Drivers of COVID-19 Dynamics in Africa: A Spatial Modelling Approach

Understanding how countries’ socio-economic, environmental, health status, and climate factors have influenced the dynamics of COVID-19 is essential for public health, particularly in Africa. This study explored the relationships between African countries’ COVID-19 cases and deaths and their socio-economic, environmental, health, clinical, and climate variables. It compared the performance of Ordinary Least Square (OLS) regression, the spatial lag model (SLM), the spatial error model (SEM), and the conditional autoregressive model (CAR) using statistics such as the Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), Root Mean Square Error (RMSE), and coefficient of determination (R2). Results showed that the SEM with the 10-nearest neighbours matrix weights performed better for the number of cases, while the SEM with the maximum distance matrix weights performed better for the number of deaths. For the cases, the number of tests followed by the adjusted savings, Gross Domestic Product (GDP) per capita, dependence ratio, and annual temperature were the strongest covariates. For deaths, the number of tests followed by malaria prevalence, prevalence of communicable diseases, adjusted savings, GDP, dependence ratio, Human Immunodeficiency Virus (HIV) prevalence, and moisture index of the moistest quarter play a critical role in explaining disparities across countries. This study illustrates the importance of accounting for spatial autocorrelation in modelling the dynamics of the disease while highlighting the role of countries’ specific factors in driving its dynamics.

Comparison of Different Obturation Techniques in the Dentinal Tubule Penetration of EndoSequence® Bioceramic Sealer HiFlow™: An In-Vitro Study.

Background This study aimed to assess the dentinal tubule penetration of bioceramic sealer(DTPB) using EndoSequence® Bioceramic Sealer HiFlow™ (BCHF). Three obturation techniques were compared, namely, single cone (SC), cold lateral condensation (CLC), and warm vertical compaction (WVC) using scanning electron microscopy (SEM). Methodology A total of 45 intact mandibular premolars were decoronated, instrumented, and irrigated with uniform procedures. Subsequently, they were randomly assigned into the following three groups according to the gutta-percha and BCHF obturation technique: Group 1 (n = 15) with the SC technique, Group 2 (n = 15) with the CLC technique, and Group 3 (n = 15) with the WVC technique. Afterward, the roots were sectioned at three levels (coronal, middle, apical) from the apex and examined using SEM to determine the maximum distance of DTPB in µm. The collected data were analyzed using SPSS software (IBM Corp., Armonk, NY, USA) using the one-way analysis of variance test and Bonferroni tests. The level of significance was set at α of 0.05. Results Significant differences were observed in the maximum distances of DTPB values among the three levels across groups (p < 0.05). Both the WVC and CLC groups exhibited higher values compared to the SC group (p < 0.05). Specifically, the DTPB maximum distance at the apical third was significantly higher in the CLC group than in the WVC and SC groups (p < 0.05). Additionally, the coronal third in each group demonstrated significant DTPB maximum distance (p < 0.05) compared to the other groups. Conclusions BCHF with the WVC and CLC obturation technique showed the best performance in DTPB maximum distance values at the three levels.

An almost sure limit theorem for the maximum interpoint distance of random vectors in spaces of growing dimension

Let { p n ; n ≥ 1 } be a sequence of positive integers. Let X 1 , … , X p n be i.i.d. random vectors in ℝ n with i.i.d. components that are centered and have variance 1. Consider the maximum interpoint distance M n = max 1 ≤ i < j ≤ p n ‖ X i − X j ‖ 2 . This article presents the almost sure limit theorem for M n under the polynomial and the exponential growth regimes for the dimension. The proofs rely on the moderate deviation principle of the partial sum of i.i.d. random variables, the Chen–Stein Poisson approximation method, and Gaussian approximation techniques.