Terminal Point Research Articles

Metformin promotes Schwann cell remyelination, preserves neural tissue and improves functional recovery after spinal cord injury

Patients with a spinal cord injury (SCI) usually suffer lifelong disability as a result. Considering this, SCI treatment and pathology study are urgently needed. Metformin, a widely used hypoglycemic drug, has been indicated for its important role in central nervous system diseases. This study aimed to investigate the potential effect of metformin on remyelination after SCI. In the present study, we established a cervical contusion SCI model and metformin treatment was applied after SCI. Biomechanical parameters and behavioral assessment were used to evaluate the severity of injury and the improvement of functional recovery after SCI, respectively. The immunofluorescence and western blot were performed at the terminal time point. Our results showed that treating with metformin after SCI improved functional recovery by reducing the white matter loss and promoting Schwann cell remyelination, and the Nrg1/ErbB signaling pathway may be involved in promoting remyelination mediated by oligodendrocytes and Schwann cells. In addition, the area of spared tissues was significantly increased in the metformin group. However, metformin had no significant effects on the glial scar and inflammation after SCI. In summary, these findings indicated that the role of metformin in Schwann cell remyelination after SCI was probably related to the regulation of the Nrg1/ErbB pathway. It is, therefore, possible to suggest that metformin may be a potential therapy for SCI.

면적속도 기반 DTW를 이용한 이탈 항적 탐지

In the field of aviation safety, data analysis research is being conducted to detect the precursors of aviation accidents. A deviation trajectory, which means the trajectory of an aircraft deviating from its normal trajectory, is one of the precursor signs of an aviation accident that occurs in an en-route section. The en-route section means segment of flight from the termination point of a departure procedure to the origination point of an arrival procedure. trajectory data is track data meaning positional information according to time. A general method for calculating the dissimilarity of trajectory data having different numbers of sample points constituting the trajectory is dynamic time wrapping (DTW). However, area-based dissimilarity from normal tracks is more useful than distance-based dissimilarity for deviation trajectory detection. Therefore, in this study, ‘area velocity-based DTW (hereafter referred to as ADTW)' was developed to calculate the value corresponding to the area. Dissimilarity was calculated by DTW and ADTW methods using ADS-B (automatic dependent surveillance-broadcast) trajectory data, and then deviation tracks were determined using clustering-based outlier detection technology. For clustering, the k-medoids method, PAM (partitioning around medoids), was used. As a result of calculating the average silhouette, it was classified into two clusters, and the deviation track was detected using the dissimilarity from the representative track of each cluster. Detection criteria were constructed using quantiles. When evaluated using the average silhouette width of clusters, ADTW performed better than DTW.

A Three-Dimensional (3D) Evaluation Unveiling if the Anterior Mandible Is Truly a Safe Zone for Implant Placement.

Background Dental implants are increasingly being used in the rehabilitation of the edentulous areas in the maxilla and mandible. The anterior mandible is considered a safe zone for implant placement, but clinicians often find it challenging to control bleeding in this area. This is due to the presence of the sublingual artery, which can be of varying dimensions and can cause severe bleeding. This can be of higher significance in patients with high or uncontrolled blood pressure and in patients on blood thinners like Aspirin or Coumadin where establishing a clot can be difficult. With newer guidelines recommending that medication be discontinued only a few hours before surgery and that bleeding be managed locally, this issue has become even more challenging. With three-dimensional (3D) imaging using cone beam computed tomography (CBCT) becoming more common for implant planning, the presence of the sublingual artery can be evaluated and incorporated into the treatment plan. The objective of this study is to evaluate the 3D location of the sublingual artery in the edentulous anterior mandible of CBCT scans of patients referred for dental implant therapy. Methodology A total of 50 de-identified CBCT scans with an edentulous anterior mandible referred for dental implant therapy were evaluated for this study. Cross-sectional images were generated using a CBCT reconstruction program INVIVO-5 (Anatomage, San Jose, CA, USA). After the sublingual artery was localized, measurement was conducted from a standardized point on the alveolar crest to the artery's entry point on the lingual aspect. Measurements were also obtained from the terminal point of the artery's course to the buccal cortical plate. Alveolar crest can either resorb or be subjected to alveoloplasty during implant placement, similar measurements were also done from a standardized point on the inferior cortical border of the mandible to the artery's entry points on the lingual aspect. Two oral and maxillofacial radiologists conducted all measurements. Results It was found that the median value of the sublingual artery from the alveolar crest to the level of entry (V1) was 6.78, the vertical measurement of the artery coursing into the alveolar bone was ~4.03 mm (V2), the vertical measurement of the artery's position within the alveolar bone at the terminal point form the crest was ~11.71 (V3), and the inferior vertical measurement from the course of the artery to the inferior border of the mandible was 9.60 mm. The artery extended about ~8.3 mm within the alveolar bone from the lingual cortex (H1), and the artery was located about 4.97 mm away from the buccal cortex (H2).Cronbach's Alpha test showed high interoperator reliability. Conclusions In this retrospective study, the sublingual artery was noted to be at a critical location in the potential implant site. A site-specific evaluation using CBCT can help in localizing and avoiding perforation of the sublingual artery.

Derivation of weighting rules for developing a class of A-stable numerical integration scheme: αI-(2 + 3)P method

ABSTRACT The main concern of this paper is to develop a new class of A-stable fourth-order numerical scheme for solving initial value problems. The idea is an evolutionary and heuristic approach; using the Grasshopper optimization, along with the Hermite interpolation for stages, we obtain a class of A-stable methods. Four types of weighting rules are introduced for the current formulation. The fundamental weighting rule (FWR) is the most important rule, which emphasizes on the symmetric and central structure of the method. A systematic strategy is proposed to obtain the FWR based on swarm intelligence and regression. The new techniques are called -(e + i)P, where e and i are the number of terminal and internal points, respectively. The numerical experiments demonstrate the reasonable behaviour of the algorithms on several test problems from different applications. Finally, we find that the new formulas are well suited for long time behaviour of the time-history analysis in earthquake engineering.

Parametric stability of Timoshenko taper sandwich beam on Pasternak foundation

The goal of the present study is to analyze the parametric stability of a Timoshenko non-uniform sandwich beam using computational method which is stayed on Pasternak foundation having inconstant spring stiffness parameter. Axial load is applied at terminal points. The governing equation of motion and associated end conditions are defined using extended Hamilton’s principle. The equation of motion and the associated boundary conditions are non-dimensionalized by the application of the main principle of Galerkin method. A set of Hills equations are found from the non-dimensional equation of motion. The regions of parametric instability are analyzed considering the effect of numerous system parameters and geometric parameters and displayed through a series of plots. The computational analysis is done by using MATLAB programming.

Radiological study of variations in intersphenoidal septum in a south Indian population- a retrospective cross-sectional study

Introduction and Aim: The anatomical variations in intersphenoidal septum (ISS) will affect the ease of surgery and risk of intraoperative injury to neurovascular structures. It is very important to assess the same in different populations using preoperative imaging. Hence the objective of this study is to determine the prevalence of anatomical variations of intersphenoidal septum and its pattern of attachment among Southern Indian population for better planning of surgery and avoid complications.
 
 Materials and Methods: A retrospective cross-sectional analysis of patients who underwent computed tomography paranasal sinus at a tertiary care hospital was done. Data from 186 cases in total were used in this study. The proportion of cases with intersphenoidal septa was the primary outcome evaluated, and the number, location, development, and point of termination of intersphenoidal septa were the secondary outcomes. Statistical software for social studies was used to analyse the data.
 
 Results: Absence of intersphenoidal septum was noted in 0.5% of cases with predominant sellar type of pneumatization. Also, single intersphenoidal septum (81.6%), right sided deviation of septum (48.1%), complete formation of intersphenoidal septum (92.4%) and protrusion of septum towards optic nerve canal (45.9%) were the common findings noted in this study.
 
 Conclusion: Anatomical variations of the intersphenoidal septum clearly signify that the surgeons should keenly note the variations before planning the surgery.

Modeling of curves by a design-control approximating refinement scheme

This paper introduces a modified method for construction of a new design-control 6-point approximating refinement scheme. The construction of the new scheme is based on translation of the points of 4-point approximating refinement scheme to the new position according to the linear combination of certain displacement vectors. The initial and terminal points of these vectors are the refinement points of two 4-point approximating binary schemes. The new scheme contains three design-control parameters. These parameters increase the efficiency and flexibility of the new scheme. The mathematical and graphical analysis of the refinement scheme show that this scheme is good choice for curve modeling.

Study of the Influence of Factors on Passenger Service Quality and Efficiency of Rolling Stock Use

The tasks of transport planning are relevant for most countries and comprise implemenation of solutions at regional and local level. The development of transport planning documents in the constituent entities of the Russian Federation is an acute problem and implies the achievement of such goals as improving the quality of passenger transportation and reducing transportation costs. Each of the transport planning documents includes a list of measures, the implementation of which improves the quality of passenger service and the efficiency of the use of rolling stock. The objective of the article is to determine the significance of the influence of technical and operational factors on the resulting indicators of passenger service quality and efficiency of rolling stock use. The research applied experiment planning method described in the work of Yu. P. Adler. The experiment planning method used makes it possible to obtain quantitative estimates of the influence of factors with the same reliability as with other methods. The evaluation was carried out for independent or conditionally independent factors. In the researched case, such factors comprise the number of buses on the route, the length of the route, the turnaround time, the downtime at the terminal points, the allowable deviation from the schedule, the work hours of the drivers, the zero mileage of all buses. Constants in the calculations are independent factors related to the characteristics of the demand for transportation, since when carrying out measures to improve the organisation of the work of buses on routes, they cannot be influenced. These factors comprise the walking distance on the route, the average travel distance of a passenger on the route and the passenger flow on the most loaded haul. The method is implemented in the article on the example of an operating bus on the route. For all basic factors, the upper, lower, and main levels are set. Based on the analysis of the actual values of technical and operational indicators on the existing routes of Moscow region, the numerical values of the above levels were determined. Next, the variation intervals for each factor were selected. An experiment in which all possible combinations of factor levels are implemented is known as a full factorial experiment. The coefficients calculated from the results of the experiment indicate the strength of the influence of a factor. The value of the coefficient corresponds to the contribution of this factor to the value of the optimisation parameter when the factor moves from the zero level to the upper or lower one. As a result of the research, it was found that five basic factors influence the time spent by a passenger, travel comfort, and the completeness of revenue collection, and ten factors affect the daily costs of servicing the route for a carrier. The specificity of the problem is that for all four optimisation parameters, one and the same matrix can be constructed. To conduct a full factorial experiment with varying ten factors at two levels, it is necessary to carry out more than a thousand calculation options. However, in accordance with the methodology, in this case, we can limit ourselves to the minimum number of calculations. On this basis, an experiment planning matrix was built, then, based on the results of calculations, the coefficients in the regression equations for each of the optimisation parameters can be determined. The regression coefficients obtained when calculating the experiment design matrix are similar to those that could be obtained as a result of calculations using the least squares method. Based on this, it is possible to calculate all the statistical characteristics of the basic factors necessary to determine the closeness of the relationship between the factors and optimisation parameters, as well as between the factors themselves. The experiment planning method used in the study made it possible to identify the factors influencing each of the four optimisation parameters. Therefore, the explicit dependence of the optimisation parameters on such a factor as the number of buses on the route was confirmed, but at the same time, the factors were ranked according to the degree of their influence on the result. The correspondence of the obtained results to real and obvious dependencies has allowed to conclude that the chosen method and its implementation are correct.

Asymptotically efficient estimation for diffusion processes with nonsynchronous observations

We study maximum-likelihood-type estimation for diffusion processes when the coefficients are nonrandom and observations occur in nonsynchronous manner. The problem of nonsynchronous observations is important when we consider the analysis of high-frequency data in a financial market. Constructing a quasi-likelihood function to define the estimator, we adaptively estimate the parameter for the diffusion part and the drift part. We consider the asymptotic theory when the terminal time point T_n and the observation frequency goes to infinity, and show the consistency and the asymptotic normality of the estimator. Moreover, we show local asymptotic normality for the statistical model, and asymptotic efficiency of the estimator as a consequence. To show the asymptotic properties of the maximum-likelihood-type estimator, we need to control the asymptotic behaviors of some functionals of the sampling scheme. Though it is difficult to directly control those in general, we study tractable sufficient conditions when the sampling scheme is generated by mixing processes.

Advances in Drinking Water Treatment through Piloting with UF Membranes

This manuscript presents the advances of a pilot testing, located in Spain, using ultrafiltration (UF) membranes to supply drinking water. These results could be extended to the islands of the Macaronesia area, for instance, Azores, Madeira, Canaries, and Cape Verde. The UF project targeted by the pilot activity is a refurbishment of an existing installation. The existing installation is located at a higher altitude, thus drinking water could be supplied to most of the island without further pumping, reducing the carbon footprint, ecological footprint, and energy consumption. The raw water is soft surface water (mainly of rainwater origin) coming from a dam. On the islands of Macaronesia, water is a scarce resource in high demand. Therefore, this is a technically and economically viable business opportunity with a promising future for isolated water treatment systems to produce drinking water on islands. The Macaronesia area is formed by volcanic islands with a small surface in the Atlantic Ocean, so usually there is not enough space for conventional technology and only a compact UF can be used. The raw water quality is not satisfactory and the municipality receives many complaints from end users, thus a potable water plant with UF membranes is in high demand to supply drinking water of good quality. Membrane processes can be categorized into various, related methods, three of which include the following: pore size, molecular weight cut-off, and operating pressure. Regarding the obtained results, the UF system successfully produced excellent filtrate quality with turbidity readings on average less than 0.03 NTU; furthermore, membrane instantaneous flux of 90 Lmh at 14 °C is achievable with long-term stability under various feed water conditions, peak operations are available at 105 Lmh without a large impact on the filtration performance of the modules, and CIP is only to be performed if the TMP increase reaches the terminal point.

New mechanisms for forming multiple hotspots in radio jets

ABSTRACTHotspots of radio galaxies are regions of shock-driven particle acceleration. Multiple hotspots have long been identified as potential indicators of jet movement or precession. Two frequent explanations describe a secondary hotspot as either the location of a prior jet termination point or a deflected backflow-driven shock: the so-called dentist’s drill and splatter-spot models. We created high-resolution simulations of precessing jets with a range of parameters. In addition to the existing mechanisms, our results show three additional mechanisms for multiple hotspot formation: (1) the splitting of a large terminal hotspot into passive and active components; (2) jet stream splitting resulting in two active hotspots; and (3) dynamic multiple hotspot complexes that form as a result of jet termination in a turbulent cocoon, linked here to rapid precession. We show that these distinct types of multiple hotspots are difficult to differentiate in synthetic radio maps, particularly hotspot complexes that can easily be mistaken for the jet itself. We discuss the implication for hypothesized binary supermassive black hole systems where jet precession is a key component of the morphology, and show a selection of potential precession candidates found using the Low-Frequency Array Two-metre Sky Survey Data Release 2.

Stability of oblique liquid curtains with surface tension

Oblique (non-vertical) liquid curtains are examined under the assumption that the Froude number is large. As shown previously [E. S. Benilov, “Oblique liquid curtains with a large Froude number,” J. Fluid Mech. 861, 328 (2019)], their structure depends on the Weber number: if We < 1 (strong surface tension), the Navier–Stokes equations admit asymptotic solutions describing curtains bending upward, i.e., against gravity. In the present paper, it is shown that such curtains are unstable with respect to small perturbations of the flow parameters at the outlet: they give rise to a disturbance traveling downstream and becoming singular near the curtain's terminal point (where the liquid runs out of the initial supply of kinetic energy). It is argued that, since the instability is spatially localized, the curtain can be stabilized by a properly positioned collection nozzle. All curtains with We > 1 bend downward and are shown to be stable.

Offshore Fault-related Fold along the Eastern Marginal Zone of Ishikari Lowland, Hokkaido, Japan

Distributions, characteristics, and activities of offshore fault-related folds which comprise the southern part of the Eastern Boundary Fault Zone of Ishikari Lowland (EBFIL) are clarified by conducting a high-resolution multi-channel seismic reflection survey. To determine termination point of the fault zone, we placed seven survey lines perpendicular to the fault-related folds with a total line length of 107.5 km. We choose a compact water gun (15 cubic inch) as the seismic source to obtain high-resolution imagery of the Late Quaternary and investigate activity of the fault zone. Based on seismic facies, we distinguished packages of offshore sediment (unit 2, 3 and 4, in descending order), which separated by downlap surfaces and correlated to the Middle to the Late Pleistocene. They are progressively deformed by the active fault and compose series of fault-related folds (Fo1, Fo2 and Fo3). Traces of these folds are figured out from the seismic sections obtained by this study and existing surveys. Deformation related to these folds are clearly recognized in the topography of the unit 4 base. The reliefs of strata indicate that the Fo2 fold should have uplifted seafloor at a rate of 0.09-0.20 m/ky since 300 ka. The structures, spatial distributions and growth-rates of the folds suggest that Fo1 and Fo2 should compose series of anticline developing at the front of EBFIL. Besides, Fo2 fold would compose the southern termination of the fault zone. This study has successfully demonstrated that densely operated high-resolution seismic survey can figure out distribution and activity of offshore active faults in the Late Quaternary, even at the outside of shelf.

Electronic Apex Locators and their Implications in Contemporary Clinical Practice: A Review

Background:The apical extent of instrument termination and final root-filling procedures have been found to be key prognostic factors in relation to the outcome of root canal treatment. The precise location of this termination point has always been a challenge in clinical endodontics. Until the introduction of contemporary electronic apex locators (EALs), conventional radiography was traditionally used to determine the working length. Since their inception more than 50 years ago, EALs have drawn a great deal of attention.Objective:The literature pertaining to these devices is saturated yet inexhaustive and controversial. While most reviews try to summarize this topic entirely, the scope of the subject makes this close to impossible. Most systematic reviews report a lack of high-quality evidence, making it impossible to reach a meaningful conclusion. This review of literature focuses on electronic apex location and its accuracy, specifically in relation to variables in the clinical setting that a practitioner might encounter while using this device.Methods:Electronic database searches were undertaken using a combination of key search words to find relevant studies about EALs.Results:The PubMed (MEDLINE) search engine was used to find studies published in the English language with no restrictions for time. Articles that were found to be most pertinent were chosen and included in the review.Conclusion:EALs are indispensable to the practice of endodontics; however, the adjunct use of radiographs remains a reasonable practice.

Oral chronic toxicity and carcinogenicity study of alpha-glycosyl isoquercitrin (AGIQ) in Sprague Dawley rats

alpha-Glycosyl isoquercitrin (AGIQ) is a flavonoid that possesses antioxidant and tumor suppressive capabilities and is marketed as a food additive in Japan. The aim of this study was to assess the potential for oral chronic toxicity and carcinogenicity of AGIQ in male and female Sprague Dawley rats following up to 5.0% dietary exposure. In the chronic toxicity study, rats were exposed to AGIQ or vehicle for one year with a 6-month interim termination point; for the carcinogenicity study, rats were treated for 24 months. No signs of AGIQ-related toxicity clinically or histologically were observed for up to one year except for yellow discoloration of bone. In the carcinogenicity study, a statistically significant increase in the incidence of malignant glioma of the brain or spinal cord was observed in female rats exposed to 5.0% AGIQ compared to those exposed to control feed. A Scientific Advisory Panel of experienced neuropathologists reviewed the gliomas (routine stains and glial cell markers) and concluded that the gliomas were a rare, spontaneous, rat-specific neoplasm: malignant microglial tumor. The lesions could not definitively be attributed to AGIQ exposure and have limited implications with respect to predicting human cancer risk.

The Night Trains: Moving Mozambican Miners to and from South Africa, 1902–1955

The Night Trains: Moving Mozambican Miners to and from South Africa, 1902–1955

Accuracy and Reliability of 3D Imaging for Facial Movement Evaluation: Validation of the VECTRA H1.

The accuracy, intrarater, and interrater reliability of the VECTRA H1 were assessed when imaging four facial expressions: eyebrow lift, smile, snarl, and lip pucker. Fourteen healthy adult subjects had the distances between 13 fiducial facial landmarks measured at rest and the terminal point of each of the four movements by digital caliper and by the VECTRA H1. Intraclass correlation and Bland-Altman limits of agreement were used to determine agreement between measures. The agreement between measurements obtained by five different reviewers was evaluated by intraclass correlation to determine interrater reliability. Median correlation between digital caliper and VECTRA H1 measurements ranged from 0.907 (snarl) to 0.921 (smile). Median correlation was very good for both intrarater (0.960-0.975) and interrater reliability (0.997-0.999). The mean absolute error between modalities, and both within and between raters was less than 2 mm for all movements tested. The VECTRA H1 met acceptable standards for the assessment of facial morphology when imaging facial movements.

Algorithm for Appropriate Design of Hydroelectric Turbines as Replacements for Pressure Reduction Valves in Water Distribution Systems

Gravity flow water distribution systems (WDSs) are used to permit water flow from an input point of highest elevation (source) to the terminal points of a system (consumers). In such WDSs, typically, there is no need for external power to maintain the flow due to the typical high gradients that exist. However, those gradients cause high water velocity and pressure to some network areas that could potentially lead to pipes bursting. Currently, the only means to regulate pressure within allowable range are Pressure Reduction Valves (PRVs). They are installed at various locations, but they cannot utilize the existing hydropower potential in terms of electrical energy production. This paper provides a methodology for hydro-turbines dimensioning, so that they mimic PRV operation in terms of pressure regulation while producing power efficiently. This includes an algorithmic process within which the proper turbine design and performance prediction are initially determined, and then, via an interconnection between EPANET and MATLAB, the hydraulic behavior of their operation within the water network is modeled and simulated. The methodology has been tested with simulations of a typical urban WDS. The results indicate that the produced turbine geometries mimic PRV action at the respective locations with more than 1% accuracy during 70% of the time (2% maximum error), while producing electric energy with hydraulic efficiency over 60%.

DFSP: A fast and automatic distance field-based stem-leaf segmentation pipeline for point cloud of maize shoot.

The 3D point cloud data are used to analyze plant morphological structure. Organ segmentation of a single plant can be directly used to determine the accuracy and reliability of organ-level phenotypic estimation in a point-cloud study. However, it is difficult to achieve a high-precision, automatic, and fast plant point cloud segmentation. Besides, a few methods can easily integrate the global structural features and local morphological features of point clouds relatively at a reduced cost. In this paper, a distance field-based segmentation pipeline (DFSP) which could code the global spatial structure and local connection of a plant was developed to realize rapid organ location and segmentation. The terminal point clouds of different plant organs were first extracted via DFSP during the stem-leaf segmentation, followed by the identification of the low-end point cloud of maize stem based on the local geometric features. The regional growth was then combined to obtain a stem point cloud. Finally, the instance segmentation of the leaf point cloud was realized using DFSP. The segmentation method was tested on 420 maize and compared with the manually obtained ground truth. Notably, DFSP had an average processing time of 1.52 s for about 15,000 points of maize plant data. The mean precision, recall, and micro F1 score of the DFSP segmentation algorithm were 0.905, 0.899, and 0.902, respectively. These findings suggest that DFSP can accurately, rapidly, and automatically achieve maize stem-leaf segmentation tasks and could be effective in maize phenotype research. The source code can be found at https://github.com/syau-miao/DFSP.git.

Assessment of the levels of termination of the conus medullaris and thecal sac in the pediatric population

PurposeThis study assessed the position of the termination of the conus medullaris (the point where the spinal cord tapers to an end) and thecal sac (the sheath of dura mater that surrounds the spinal cord and caudal nerve roots) in a large pediatric population, to characterise the nature of the pediatric Gaussian distribution and assess whether age affected the distribution. The study further aimed to assess the effect of gender on termination positions.MethodsA total of 520 MRI spine studies of children aged between 1 month and 19 years old were collected from two pediatric tertiary referral centres in the UK and Italy. Studies with pathological findings were excluded, and normal scans were found using keyword search algorithms on a database of radiologists’ reports. The reported scans were individually assessed and reviewed by two experienced neuroradiologists. The termination points of the conus medullaris and thecal sac were determined for each study. Local IRB approvals were sought.ResultsThe results showcased a Gaussian distribution in both conus medullaris (r=0.8997) and thecal sac termination levels (r=0.9639). No statistically significant results were noted with increasing age for the termination positions of the conus medullaris or thecal sac (p = 0.154, 0.063). No statistical significance was observed with gender variation with either anatomical landmark. A weak positive correlation was observed between the termination levels of the conus medullaris and the thecal sac (r=0.2567)ConclusionTermination levels across all pediatric age range followed a Gaussian distribution. Knowledge of normal termination levels has relevant clinical implications, including the assessment of patients with suspected spinal dysraphism.