Interruption Of Flow Research Articles

Reliable container supply chain under disruption.

In this study, we develop a reliable formulation based on a container network flow problem, along with the full implementation of an empty container management strategy in the context of an integer linear programming model. The proposed approach can play a key role in coping with disruption in the network and can offer a proactive measure for effective disruption management to maintain a stable level of reliability in supply capability. To formulate a reliable container network problem, we design the pattern of disruption, a rare and irregular uncertainty, based on binomial coefficients in the objective function. In this way, flow interruption due to disruption can be expressed in node- and arc-failures and can be properly managed. Furthermore, we provide a non-disruptive model based on a deterministic formulation derived from a bast-case scenario. Through numerical illustrations and sensitivity analyses, we conduct in-depth analyses on the impact of disruption in the container supply chain, and a benchmark model based on a bast-case scenario is used to determine disruption costs, for comparative study. In particular, the numerical experiments show that if both maritime and hinterland disruptions are not managed in advance, disruption costs derived from a benchmark model result in a significant surge according to increasing potential disruption risk. Throughout computational experiments, we also found that maritime disruption is more destructive to container supply capability than hinterland disruption is. In particular, critical findings show that when a certain level of threshold is violated, the proposed strategies are completely interrupted in a container supply chain. Therefore, proactive measures to keep up a reliability of container supply in a high-risk region are highly recommended for management side.

System dynamics modeling and robustness analysis for capital-constrained supply chain under disruption

PurposeThe purpose of this study is to explore mitigation measures for cash flow interruption during the epidemic and provide decision support to ensure the regular operation and robustness of the supply chain (SC).Design/methodology/approachConsidering the scenarios of production capacity and demand disruption during the epidemic, the authors adopt system dynamics (SD) to construct a three-echelon SC financial system consisting of a core manufacturer, a capital-constrained retailer and the customer. In different interruption scenarios, through the decision adjustments of stakeholders, the differences in performance are compared to explore solutions for SC robust optimization.FindingsThe results show that partial credit guarantee (PCG) could solve cash flow interruption and maintain the regular operation of the SC. During epidemic, with the product price increases, the revenue of stakeholders and the robustness are generally negatively correlated. But when the manufacturer's production capacity is fully interrupted, increasing product price is the right decision for the retailer and could simultaneously promote performance and robustness.Originality/valueThis paper primarily focuses on the PCG under the cash flow interruption caused by epidemics. The authors adopt the supply chain finance (SCF) theory and SD method to supplement and expand existing research on interruption management of SC. It is a pioneering study to explore the robustness of the SC financial system under disruptions.

Gene flow and introgression are pervasive forces shaping the evolution of bacterial species

BackgroundAlthough originally thought to evolve clonally, studies have revealed that most bacteria exchange DNA. However, it remains unclear to what extent gene flow shapes the evolution of bacterial genomes and maintains the cohesion of species.ResultsHere, we analyze the patterns of gene flow within and between >2600 bacterial species. Our results show that fewer than 10% of bacterial species are truly clonal, indicating that purely asexual species are rare in nature. We further demonstrate that the taxonomic criterion of ~95% genome sequence identity routinely used to define bacterial species does not accurately represent a level of divergence that imposes an effective barrier to gene flow across bacterial species. Interruption of gene flow can occur at various sequence identities across lineages, generally from 90 to 98% genome identity. This likely explains why a ~95% genome sequence identity threshold has empirically been judged as a good approximation to define bacterial species. Our results support a universal mechanism where the availability of identical genomic DNA segments required to initiate homologous recombination is the primary determinant of gene flow and species boundaries in bacteria. We show that these barriers of gene flow remain porous since many distinct species maintain some level of gene flow, similar to introgression in sexual organisms.ConclusionsOverall, bacterial evolution and speciation are likely shaped by similar forces driving the evolution of sexual organisms. Our findings support a model where the interruption of gene flow—although not necessarily the initial cause of speciation—leads to the establishment of permanent and irreversible species borders.

Abstract 11318: A Rare Case of Stretch Syncope of Adolescence Masquerading as Carotid Artery Dissection and Carotid Sinus Syndrome

Introduction: Syncope describes a brief, sudden loss of consciousness and tone, with spontaneous return to baseline. Although episodes arise from a transient interruption of cerebral blood flow, work-up identifying an underlying is critical, as it can determine the proper treatment for cessation of these episodes. In this case, we describe a patient who was later diagnosed with stretch syncope of adolescence (SSA), a rarely reported cause of syncope. Case Presentation A 16-year-old male presented to the E.R. after experiencing a syncopal event immediately after looking up. He endorsed a similar episode one week earlier, after standing and looking up. The patient also revealed that he commonly would crack his neck and would often sleep with his head extended over the arm of his couch. In the E.R., the patient was hypotensive to 107/62 mmHg, but physical exam and lab work-up did not reveal any significant pathology. EKG and a CT head without IV Contrast showed no acute intracranial abnormality. Soon after admission, he became bradycardic, hypotensive, and lightheaded. Due to concern for carotid artery dissection, bilateral carotid duplex scan and CT of the head and neck were completed, and given the reproducibility of the patient’s symptoms with neck dorsiflexion, an MRI to evaluate for carotid sinus syndrome was completed. All imaging, however, returned unremarkable. Given the patient’s age, symptom onset with movement, and exclusion of other etiologies, a diagnosis of SSA was made. The patient was discharged with strict instructions to avoid stretching, especially when standing. Discussion SSA is characterized by episodic loss of consciousness triggered by a combination of stretching and neck hyperextension. It is a rarely reported phenomenon, with only 14 case reports published on SSA as of 2014, and is often confused with more common syndromes, most commonly epileptic seizures. Our case is especially unique because the patient’s presentation was initially most consistent with carotid artery dissection and coronary sinus syndrome, a previously unreported presentation. By continuing to recognize and report cases such as ours, patients with SSA may receive more prompt diagnosis, avoid extraneous work-up, and ultimately, prevent future syncopal events.

Fragmentation by major dams and implications for the future viability of platypus populations

The evolutionarily unique platypus (Ornithorhynchus anatinus) has experienced major declines and extinctions from a range of historical and recent interacting human-mediated threats. Although spending most of their time in the water, platypuses can move over land. Nevertheless, uncertainties remain whether dams are barriers to movement, thus limiting gene flow and dispersal, essential to evolution and ecology. Here we examined disruption of gene flow between platypus groups below and above five major dams, matched to four adjacent rivers without major dams. Genetic differentiation (FST) across dams was 4- to 20-fold higher than along similar stretches of adjacent undammed rivers; FST across dams was similar to differentiation between adjacent river systems. This indicates that major dams represent major barriers for platypus movements. Furthermore, FST between groups was correlated with the year in which the dam was built, increasing by 0.011 every generation, reflecting the effects of these barriers on platypus genetics. This study provides evidence of gene flow restriction, which jeopardises the long-term viability of platypus populations when groups are fragmented by major dams. Mitigation strategies, such as building of by-pass structures and translocation between upstream and downstream of the dam, should be considered in conservation and management planning.

Construction Cost and Schedule Impacts Due to COVID-19

Construction companies are facing unprecedented challenges in terms of coping with the new circumstances as well as understanding their legal and contractual impacts. Because the COVID-19 pandemic affected all businesses across the globe, identifying and analyzing the impact of COVID-19 on construction projects in terms of material supply disruption, labor shortage, construction delay, and disruption in cash flow is vital. The purpose of this study is to enhance construction companies’ ability to better tackle such situations in the future by identifying and addressing the impact of COVID-19 on the material supply disruptions and construction schedule. This research used a quantitative methodology using an online questionnaire as the instrument to collect data. The study analyzed responses from 32 construction company executive members across the United States. The survey collected cost and schedule impact due to material supply disruption in building construction divisions. The analysis shows that COVID-19 pandemic impacted project schedule, increased cost, and disrupted the supply chain of building materials. The findings can provide a better understanding and solution to reduce the pandemic’s impact on the construction industry in the future and understand the legal implications that can arise due to this pandemic disruption.

Clinical case of Bow Hunter's Syndrome

Bow Hunter‘s Syndrome (BHS) is a mechanical compression of the vertebral artery during head rotation, leading to partial disruption or complete interruption of the blood flow of the affected artery, causing vertebrobasilar vascular insufficiency. There are no established precise diagnostic and therapeutic behavioral algorithms in patients with BHS. I present a case of an 80-year-old woman with syncopal symptoms, in which a dynamic stenosis of the dominant left vertebral artery was diagnosed, and the same artery originates from the aortic arch with a separate ostium.

Etiopathogenesis and pathophysiology of cholestasis

Normal hepatobiliary function depends on an adequate bile flow from the liver through the biliary tree to the gallbladder, where bile is stored and concentrated, and from the gallbladder to the duodenum when it is required for the digestive process. Interruption of this secretory function results in partial or complete cholestasis, which is accompanied by important repercussions due to the lack of bile acids in the intestine and their regurgitation from hepatocytes to blood together with potentially toxic compounds that are normally eliminated in bile. The presence of active and selective transporter proteins located at both poles of the plasma membrane of hepatocytes, cholangiocytes, and epithelial cells of the ileal mucosa, together with the ability of hepatocytes to synthesize bile acids from cholesterol, enables the so-called bile acid enterohepatic circulation, which is essential in liver and gastrointestinal tract physiology. The presence in the ducts of the biliary tree of agents reducing their luminal diameter by external compression or space-occupying obstacles, either in the duct wall or its lumen, can result in total or partial obstructive cholestasis. The clinical impact and management of cholestasis are different depending on the intrahepatic or extrahepatic location of the obstacle. Thus, surgical interventions can often be helpful in removing extrahepatic obstructions and restoring normal bile flow to the duodenum. In contrast, hepatocyte or cholangiocyte damage, either global, restricted to subcellular compartments, or more specifically affecting the elements of the canalicular secretory machinery, may result in hepatocellular cholestasis or cholangiopathies. In these cases, bile flow interruption is usually partial and, except for extremely severe cases when liver transplantation is required, these patients often treated with pharmacological agents, such as ursodeoxycholic acid (UDCA) and rifampicin. The present review gathers updated information on the etiopathogenesis and pathophysiological aspects of different types of cholestasis.

Extreme weather events threaten biodiversity and functions of river ecosystems: evidence from a meta-analysis.

Both gradual and extreme weather changes trigger complex ecological responses in river ecosystems. It is still unclear to what extent trend or event effects alter biodiversity and functioning in river ecosystems, adding considerable uncertainty to predictions of their future dynamics. Using a comprehensive database of 71 published studies, we show that event - but not trend - effects associated with extreme changes in water flow and temperature substantially reduce species richness. Furthermore, event effects - particularly those affecting hydrological dynamics - on biodiversity and primary productivity were twice as high as impacts due to gradual changes. The synthesis of the available evidence reveals that event effects induce regime shifts in river ecosystems, particularly affecting organisms such as invertebrates. Among extreme weather events, dryness associated with flow interruption caused the largest effects on biota and ecosystem functions in rivers. Effects on ecosystem functions (primary production, organic matter decomposition and respiration) were asymmetric, with only primary production exhibiting a negative response to extreme weather events. Our meta-analysis highlights the disproportionate impact of event effects on river biodiversity and ecosystem functions, with implications for the long-term conservation and management of river ecosystems. However, few studies were available from tropical areas, and our conclusions therefore remain largely limited to temperate river systems. Further efforts need to be directed to assemble evidence of extreme events on river biodiversity and functioning.

Potential mechanisms of acupuncture in enhancing cerebral perfusion of ischemic stroke.

Ischemic stroke is the predominant cause of long-term disability and death worldwide. It is attributable to the sudden interruption of regional cerebral blood flow, resulting in brain cell death and neurological impairment. Acupuncture is a widely used adjuvant treatment for ischemic stroke in China and shows promising efficacy in clinical practice. This review mainly focused on the evidence to illustrate several possible mechanisms of acupuncture therapy on cerebral perfusion in ischemic stroke. Studies have shown that acupuncture is probably effective in the enhancement of cerebral perfusion after ischemic stroke. It promotes the improvement of hemodynamics, the release of vasoactive substances, the formation of new blood vessels, as well as the restitution of microcirculation. Multiple factors may contribute to the variability in acupuncture's therapeutic effects, including the acupoint selection, stimulation frequency and intensity, and retaining needle time. Acupuncture has the potential to become a non-pharmacological adjuvant approach to enhance cerebral perfusion in ischemic stroke. Future studies are required to gain our insight into acupuncture as well as accelerate its clinical translation.

An Improved Detection Algorithm for Ischemic Stroke NCCT Based on YOLOv5.

Cerebral stroke (CS) is a heterogeneous syndrome caused by multiple disease mechanisms. Ischemic stroke (IS) is a subtype of CS that causes a disruption of cerebral blood flow with subsequent tissue damage. Noncontrast computer tomography (NCCT) is one of the most important IS detection methods. It is difficult to select the features of IS CT within computational image analysis. In this paper, we propose AC-YOLOv5, which is an improved detection algorithm for IS. The algorithm amplifies the features of IS via an NCCT image based on adaptive local region contrast enhancement, which then detects the region of interest via YOLOv5, which is one of the best detection algorithms at present. The proposed algorithm was tested on two datasets, and seven control group experiments were added, including popular detection algorithms at present and other detection algorithms based on image enhancement. The experimental results show that the proposed algorithm has a high accuracy (94.1% and 91.7%) and recall (85.3% and 88.6%) rate; the recall result is especially notable. This proves the excellent performance of the accuracy, robustness, and generalizability of the algorithm.

Colonoscopic Evaluation of Patients Treated Conservatively for Intestinal Obstruction: An Observational Study

Background: Acute intestinal obstruction occurs when there is an interruption in the forward flow of intestinal contents. This interruption can occur at any point along the length of the gastrointestinal tract, and clinical symptoms often vary based on the level of obstruction. Objectives: To evaluate the causes of obstruction of patients who were treated conservatively for acute intestinal obstruction. Materials & Method: A cross-sectional observational study. The study was carried out in the Surgery In-patient Department of Comilla Medical College Hospital, Comilla, from 01.07.2013 to 31.12.2013. A total of 246 patients got admitted to the surgery in-patient department and diagnosed as a case of intestinal obstruction. 101 patients of both sex, aged 23-79 responded to initial conservative treatment and were recruited for the study. The remaining 145 patients underwent emergency surgery for intestinal obstruction and were excluded from the study. All data gathered from the data collection sheet was compiled manually. After compilation, these data were shifted to statistical analysis software for further analysis. Results: Out of 246 intestinal obstruction patients, we recorded 101 patients who responded to conservative management. 59 (58.4%) patients were male, and the remaining were female. Peak Incidence (45.5%) was in 51-66 years age group. 54(53.4%) patients presented with large bowel obstruction, the remaining with small bowel obstruction. Most of the patients 68 (67.3%), presented with sub-acute obstruction, followed by acute 28 (27.7%) and chronic 5 (4.9%) obstruction, respectively. 12(11.8%) patients were diagnosed with colorectal carcinoma, 5(4.9%) patients with intestinal TB, and 1(0.9%) patient with diverticulosis. 10(83.3%) of the patients with Colorectal carcinoma were in the elderly age group (>50 years) whereas two patients were below 80 years of age. The cause of obstruction could not be detected in 83 (82.2%) patients by colonoscopy. ..............

Using Remote Sensing Techniques and Hydrological Models in Analyzing Water Drainage Systems Affecting Al-Kharj Governorate

The research investigates water drainage systems and identifying the flooding area in Al-Kharj, which is the confluence of the valleys of Hanifa, Al-Sulay, Al-Hannaya, Nasah, Al-Haytham, Al-Aqimi, and then Al-Sahba, with a total area 111,491km2, which may cause risks on the natural and human environment in Al-Kharj, whether through water accumulation and stagnation in Low-lying areas and the resulting environmental hazards, or as a result of their inundation on urban areas, causing destructive effects on lives and property.The methodology is based on analyzing the drainage systems affecting the city of Al-Kharj, which is product by many steps and multiple inputs that include the elements of the stage before the surface runoff occurred and then the stage during the runoff, where collecting the largest number of elements affecting each stage and the Methods of evaluation it, then counted and analyzed them to create a topographical and hydrologic model of the drainage systems and analyzed the expected rain condition at different recurring times, especially 100 years. The morphological analysis of the basins, comparing the results of the outputs of the (DEM), tracking the paths of the valleys through topographic maps, satellite visuals, and the field study revealed that there is a mismatch between the outputs due to the interruption of the valleys flow, either for natural or human reasons, as it actually affects only 8 basins with an area 16266.7km2, Hanifa basin consider the most nourished with a water volume 124.6million m3 and a discharge rate of 756.4m3/s.

A comparative analysis of machine learning classifiers for stroke prediction: A predictive analytics approach

Stroke is the third leading cause of death in the world. It is a dangerous health disorder caused by the interruption of the blood flow to the brain, resulting in severe illness, disability, or death. An accurate prediction of stroke is necessary for the early stage of treatment and overcoming the mortality rate. This study proposes a machine learning approach to diagnose stroke with imbalanced data more accurately. Random Over Sampling (ROS) technique has been used in this work to balance the data. Eleven classifiers, including Support Vector Machine, Random Forest, K-nearest Neighbor, Decision Tree, Naïve Bayes, Voting Classifier, AdaBoost, Gradient Boosting, Multi-Layer Perception, and Nearest Centroid, are analyzed in this study. Ten classifiers show more than 90% accurate results before balancing the data and four classifiers display more than 96% accurate results after data-balancing using the oversampling method. The Hyperparameter tuning and cross-validation are performed in each model to enhance the results. Moreover, Accuracy, F1-Measure, Precision, and Recall are used to measure the performance of machine learning models. The results show the Support Vector Machine has the highest accuracy of 99.99%, with recall values of 99.99%, precision values of 99.99%, and F1-measure of 99.99%. Random Forest achieves the second-highest accuracy of 99.87%, with a 0.001% error. In addition, a user-friendly web app and a user-friendly mobile app are built based on the most accurate model.

Pedestrian bottleneck flow when keeping a prescribed physical distance

We present experimental results of pedestrian evacuations through a narrow door under a prescribed safety distancing of either 1.5 or 2 meters. In this situation, flow rate augments with pedestrian velocity due to a complete absence of flow interruptions or clogs. Accordingly, the evacuation improves when the prescribed physical distance is reduced, as this implies shortening the time lapses between the exit of consecutive pedestrians. In addition, the analysis of pedestrian trajectories reveals that the distance to the first neighbor in the evacuation process is rather similar to the one obtained when pedestrians were just roaming within the arena, hence suggesting that this magnitude depends more on the crowd state (desired speed, prescribed safety distance, etc.) than on the geometry where the pedestrian flow takes place. Also, an important difference in pedestrian behavior is observed when people are asked to walk at different speeds: whereas slow pedestrians evidence a clear preference for stop-and-go motion, fast walkers display detouring and stop-and-go behavior roughly in the same proportion.

Pericyte remodeling is deficient in the aged brain and contributes to impaired capillary flow and structure

Deterioration of brain capillary flow and architecture is a hallmark of aging and dementia. It remains unclear how loss of brain pericytes in these conditions contributes to capillary dysfunction. Here, we conduct cause-and-effect studies by optically ablating pericytes in adult and aged mice in vivo. Focal pericyte loss induces capillary dilation without blood-brain barrier disruption. These abnormal dilations are exacerbated in the aged brain, and result in increased flow heterogeneity in capillary networks. A subset of affected capillaries experience reduced perfusion due to flow steal. Some capillaries stall in flow and regress, leading to loss of capillary connectivity. Remodeling of neighboring pericytes restores endothelial coverage and vascular tone within days. Pericyte remodeling is slower in the aged brain, resulting in regions of persistent capillary dilation. These findings link pericyte loss to disruption of capillary flow and structure. They also identify pericyte remodeling as a therapeutic target to preserve capillary flow dynamics.

Traumatic Brain Injury (TBI) Detection: Past, Present, and Future.

Traumatic brain injury (TBI) can produce temporary biochemical imbalance due to leaks through cell membranes or disruption of the axoplasmic flow due to the misalignment of intracellular neurofilaments. If untreated, TBI can lead to Alzheimer’s, Parkinson’s, or total disability. Mild TBI (mTBI) accounts for about about 90 percent of all TBI cases. The detection of TBI as soon as it happens is crucial for successful treatment management. Neuroimaging-based tests provide only a structural and functional mapping of the brain with poor temporal resolution. Such tests may not detect mTBI. On the other hand, the electroencephalogram (EEG) provides good spatial resolution and excellent temporal resolution of the brain activities beside its portability and low cost. The objective of this paper is to provide clinicians and scientists with a one-stop source of information to quickly learn about the different technologies used for TBI detection, their advantages and limitations. Our research led us to conclude that even though EEG-based TBI detection is potentially a powerful technology, it is currently not able to detect the presence of a mTBI with high confidence. The focus of the paper is to review existing approaches and provide the reason for the unsuccessful state of EEG-based detection of mTBI.

DELAYED CEREBRAL VENOUS SINUS THROMBOSIS (CSVT) AFTER AN INVASIVE MENINGIOMA RESECTION: AN UNCOMMON PRESENTATION OF A COMMON COMPLICATION

DELAYED CEREBRAL VENOUS SINUS THROMBOSIS (CSVT) AFTER AN INVASIVE MENINGIOMA RESECTION: AN UNCOMMON PRESENTATION OF A COMMON COMPLICATION

SOCIO-ECONOMIC AND ENVIRONMENTAL IMPLICATIONS OF ROADSIDE AUTOMOBILE WORKSHOPS IN OTA CITY, NIGERIA

Roadside Automobile Workshop (RAW) activities remain principal components of the informal sector in many Nigerian cities. Its emergence is attributed to the advent of automobiles and their use in easing urban mobility. Expectedly, unlike the formal auto-workshops, the RAW are located across the available spatial places where, motorists find solace to immediate respond to maintenance and other mechanical faults/malfunctions of their vehicles. However, the spatial locations and operations of RAW, along with the accompanying adverse effects, are recurring issues of concern in many cities in Nigeria. In this regard, this study assessed the socio-economic and environmental implications of RAW in the city of Ota, Nigeria. A cross-section survey research is adopted in this study, while 400 residents were sampled using multistage sampling technique. Major findings show that most of the residents have spent over four years in study area. It also revealed that increase loss of green area, noise pollution, and land vibration are the top-ranked environmental implications, while increase road traffic congestion, untrained technicians, and disruption of traffic flow are top-ranked economic implications. However, improve access to maintenance workshop, reduce vehicular breakdown on roads are top-ranked social implications of RAWs. This study concludes that the indiscriminate location of RAWs in the study area is detrimental to socio-economic development of study area (F10 38923.851, p=0.000<0.05), and recommends policy implications and strategies to improve the activities of RAW in the study area.

FUNGAL ORIGIN OF IN SITU PULMONARY ARTERY THROMBOSIS: A CASE REPORT

When filling defects are found on CTA, they are almost universally assumed to be emboli from a peripheral deep vein thrombosis. However, new studies have led to the theory that localized inflammation, endothelial cell damage, and disruption of blood flow cause de novo formation of clots within the pulmonary artery or in situ thrombosis. Fungal origin of pulmonary embolism is rare. We report the case of a 31-year-old man previously treated for tuberculosis. He was admitted with haemoptysis and a chest CT scan revealed an obstruction of the right upper pulmonary artery. He was initially diagnosed as a pulmonary embolism of cruoric origin and anticoagulant treatment was given. But the patient had massive hemoptysis a few days later. Aspergillosis serology was positive and the diagnosis of pulmonary aspergillosis complicated by pulmonary embolism in situ was retained. Antifungal treatment was started with good improvement and cessation of the haemoptysis.