Transit Time Research Articles

Jerk (d(acceleration)/dt) as an operative variable in pneumatic tube transport (PTT).

Jerk, the rate of change of acceleration (d(acceleration)/dt), is a known operative variable in public transportation safety, but this term has never appeared in the literature regarding pneumatic tube transport (PTT) and specimen integrity. We investigated profiles of acceleration and jerk for 2 PTT routes within our hospital system. Acceleration data were collected for PTT for 2 routes (A, B) using an accelerometer. Acceleration vectors (a) were analyzed in terms of distributions of jerk (da/dt), and distributions of θ, the angle between successive acceleration vectors. Routes A and B had transit times of approximately 300s. Acceleration vectors (a) ranged in magnitude from 0 to 8 g. For B, a > 1.2 g comprised 29.0% of results, compared to 13.5% of results for A (ratio = 2.1). Jerk ranged from 0 to 94 g/s. For B, jerk > 0.5 g/s comprised 71.9% of results, compared to 32.5% of results for A (ratio = 2.2). θ ranged from 0 to 180 degrees. For B, θ > 5 degrees comprised 59.3% of results, compared to 26.6% of results for A (ratio = 2.2). Differences in distribution in acceleration, jerk, and θ ran in parallel as variables for comparison between 2 PTT routes. Jerk and θ are likely to be operative variables in effects of PTT.

Identification of prognostic imaging biomarkers in H3 K27-altered diffuse midline gliomas in adults: impact of tumor oxygenation imaging biomarkers on survival.

To investigate prognostic markers for H3 K27-altered diffuse midline gliomas (DMGs) in adults with clinical, qualitative and quantitative imaging phenotypes, including tumor oxygenation characteristics. Retrospective chart and imaging reviews were conducted on 32 adults with H3 K27-altered DMGs between 2017 and 2023. Clinical and qualitative imaging characteristics were analyzed. Quantitative imaging assessment was performed from the tumor mask via automatic segmentation to calculate normalized cerebral blood volume (nCBV), capillary transit time heterogeneity (CTH), oxygen extraction fraction (OEF), relative cerebral metabolic rate of oxygen (rCMRO2), and mean ADC values. Leptomeningeal metastases (LM) was diagnosed with imaging. Cox analyses were conducted to determine predictors of overall survival (OS) in entire patients and a subgroup of patients with contrast-enhancing (CE) tumor. The median patient age was 40.5 years (range 19.9-75.7), with an OS of 30.3 months (interquartile range 11.3-32.3). In entire patients, the presence of LM was the only independent predictor of OS (hazard ratio [HR] = 6.01, P = 0.009). In the subgroup of 23 (71.9%) patients with CE tumors, rCMRO2 of CE tumor (HR = 1.08, P = 0.019) and the presence of LM (HR = 5.92, P = 0.043) were independent predictors of OS. The presence of LM was independently associated with poor prognosis in adult patients with H3 K27-altered DMG. In patients with CE tumors, higher rCMRO2 of CE tumor, which may reflect higher metabolic activity in the tumor oxygenation microenvironment, may be a useful imaging biomarker to predict poor prognosis.

Clinical and demographic features of patients undergoing video-capsule endoscopy management: A descriptive study

BACKGROUND Video-capsule endoscopy (VCE) is an efficient tool that has proven to be highly useful in approaching several gastrointestinal diseases. VCE was implemented in Colombia in 2003, however current characterization of patients undergoing VCE in Colombia is limited, and mainly comes from two investigations conducted before the SARS-CoV-2 pandemic period. AIM To describe the characteristics of patients undergoing VCEs and establish the main indications, findings, technical limitations, and other outstanding features. METHODS A descriptive study was carried out using data from reports of VCE (PillCam SB3 system) use in a Gastroenterology Unit in Bogotá, Colombia between September 2019 and January 2023. Demographic and clinical variables such as indication for the VCE, gastric and small bowel transit times (GTT, SBTT), endoscopic preparation quality, and limitations were described [n (%), median (IQR)]. RESULTS A total of 133 VCE reports were analyzed. Most were in men with a median age of 70 years. The majority had good preparation (96.2%), and there were technical limitations in 15.8% of cases. The main indications were unexplained anemia (91%) or occult bleeding (23.3%). The median GTT and SBTT were 14 and 30 minutes, respectively. The frequencies of bleeding stigma (3.79%) and active bleeding (9.09%) were low, and the most frequent abnormal findings were red spots (28.3%), erosions (17.6%), and vascular ectasias (12.5%) CONCLUSION VCE showed high-level safety. The main indication was unexplained anemia. Active bleeding was the most frequent finding. Combined with artificial intelligence, VCE can improve diagnostic precision and targeted therapeutic interventions.

Evaluation of cerebral microcirculation in a mouse model of systemic inflammation.

Perturbations in the microcirculatory system have been observed in neurological conditions, such as Alzheimer's disease or systemic inflammation. However, changes occurring at the level of the capillary are difficult to translate to biomarkers that could be measured macroscopically. We aim to evaluate whether transit time changes reflect capillary stalling and to what degree. We employ a combined spectral optical coherence tomography (OCT) and fluorescence optical imaging (FOI) system to investigate the relation between capillary stalling and transit time in a mouse model of systemic inflammation induced by intraperitoneal injection of lipopolysaccharide. Angiograms are obtained using OCT, and fluorescence signal images are acquired by the FOI system upon intravenous injection of fluorescein isothiocyanate via a catheter inserted into the tail vein. Our findings reveal that lipopolysaccharide (LPS) administration significantly increases both the percentage and duration of capillary stalling compared to mice receiving a 0.9% saline injection. Moreover, LPS-induced mice exhibit significantly prolonged arteriovenous transit time compared to control mice. These observations suggest that capillary stalling, induced by inflammation, modulates cerebral mean transit time, a measure that has translational potential.

Use of wastewater from passenger ships to assess the movement of COVID-19 and other pathogenic viruses across maritime international boundaries

Objective:The worldwide spread of SARS-CoV-2 and the resulting COVID-19 pandemic has been driven by international travel. This has led to the desire to develop surveillance approaches which can estimate the rate of import of pathogenic organisms across international borders. The aim of this study was to investigate the use of wastewater-based approaches for the surveillance of viral pathogens on commercial short-haul (3.5 h transit time) roll-on/roll-off passenger/freight ferries operating between the UK and the Republic of Ireland.MethodsSamples of toilet-derived wastewater (blackwater) were collected from two commercial ships over a 4-week period and analysed for SARS-CoV-2, influenza, enterovirus, norovirus, the faecal-marker virus crAssphage and a range of physical and chemical indicators of wastewater quality.ResultsA small proportion of the wastewater samples were positive for SARS-CoV-2 (8% of the total), consistent with theoretical predictions of detection frequency (4%–15% of the total) based on the national COVID-19 Infection Survey and defecation behaviour. In addition, norovirus was detected in wastewater at low frequency. No influenza A/B viruses, enterovirus or enterovirus D68 were detected throughout the study period.ConclusionWe conclude that testing of wastewater from ships that cross international maritime boundaries may provide a cost-effective and relatively unbiased method to estimate the flow of infected individuals between countries. The approach is also readily applicable for the surveillance of other disease-causing agents.

Unequilibrated Charge Carrier Mobility in Organic Semiconductors Measured Using Injection Metal–Insulator–Semiconductor Charge Extraction by Linearly Increasing Voltage

The charge carrier mobility in tris(4‐carbazoyl‐9‐ylphenyl)amine (TCTA), a host and hole transport material typically used in organic light‐emitting diodes (OLEDs), is measured using charge carrier electrical injection metal–insulator–semiconductor charge extraction by linearly increasing voltage (i‐MIS‐CELIV). By employing the injection current i‐MIS‐CELIV method, charge transport at time scales shorter than the transit times typically observed in standard MIS‐CELIV is measured. The i‐MIS‐CELIV technique enables the experimental measurement of unequilibrated and pretrapped charge carriers. Through a comparison of injection and extraction current transients obtained from i‐MIS‐CELIV and MIS‐CELIV, it is concluded that hole trapping is negligible in evaporated neat films of TCTA within the time‐scales relevant to the operational conditions of optoelectronic devices, such as OLEDs. Furthermore, photocarrier generation in conjunction with i‐MIS‐CELIV (photo‐i‐MIS‐CELIV) to quantify the properties of charge injection from the electrode to the semiconductor of the MIS devices is utilized. Based on the photo‐i‐MIS‐CELIV measurements, it is observed that the contact resistance does not limit the injection current at the TCTA/molybdenum oxide/silver interface. Therefore, when TCTA is employed as the hole transport/electron‐blocking layer in OLEDs, it does not significantly reduce the injection current and remains compatible with the high injection current densities required for efficient OLED operation.

Integrated optimization of truck appointment quotas and container relocations for multiple blocks considering transshipment containers handling

The container terminal is a crucial transshipment node in the sea and land cargo transport supply chain, and the efficiency of container collection and distribution has always been a research hotspot. In this paper, we consider the impact of transshipment containers resulting from various uncertainties and integrate the operations of external truck pickups with the handling of transshipment containers in the import yard of the container terminal. In light of the varying number of transshipment containers and transit times for different blocks, coupled with the unpredictable arrival order of external trucks leading to the unknown number of relocations, it is proposed to dynamically adjust the upper limit of the appointed quota for each block. We establish a two stage mixed integer programming model for the truck appointment quota and the block relocation problem. The objective functions aim to minimize the number of relocations and minimize the number of yard crane moves under the maximal appointment quota, respectively. This model is utilized for dynamically regulating the upper limit of the appointed quota for each block and determining the time intervals for picking up the appointed and transshipment containers, along with the yard crane scheduling scheme. The problem is solved using CPLEX and the improved variable neighborhood search algorithm (IVNS). The IVNS incorporates the correction strategy, decoding strategy, and scheduling rules designed to align closely with the characteristics of the problem. Through scheme comparison and sensitivity analysis, five management insights are proposed for terminals. Experimental results demonstrate that the approach presented in this paper effectively enhances the utilization efficiency of yard cranes, reduces yard congestion, and yields benefits for both terminals and trucking companies.

In vivo turnover and biodistribution of soluble AXL: implications for biomarker development

Soluble biomarkers are paramount to personalized medicine. However, the in vivo turnover and biodistribution of soluble proteins is seldom characterized. The cleaved extracellular domain of the AXL receptor (sAXL) is a prognostic biomarker in several diseases and a predictive marker of AXL targeting agents. Plasma sAXL reflects a balance between production in tissues with lymphatic transport into the circulation and removal from blood by degradation or excretion. It is unclear how this transport cycle affects plasma sAXL levels that are the metric for biomarker development. Radiolabeled mouse sAxl was monitored after intravenous injection to measure degradation and urinary excretion of sAxl, and after intradermal injection to mimic tissue or tumor production. sAxl was rapidly taken-up and degraded by the liver and kidney cortex. Surprisingly, intact sAxl was detectable in urine, indicating passage through the glomerular filter and a unique sampling opportunity. The structure of sAxl showed an elongated, flexible molecule with a length of 18 nm and a thickness of only 3 nm, allowing passage through the glomerulus and excretion into the urine. Intradermally injected sAxl passed through local and distant lymph nodes, followed by uptake in liver and kidney cortex. Low levels of sAxl were seen in the plasma, consistent with an extended transit time from local tissue to circulation. The rapid plasma clearance of sAxl suggests that steady-state levels in blood will sensitively and dynamically reflect the rate of production of sAxl in the tissues but will be influenced by perturbations of liver and kidney function.

Efficacy of shock wave therapy and ultrasound therapy in non-insertional Achilles tendinopathy: a randomised clinical trial

ObjectivePhysiotherapists and physicians continue to seek effective conservative treatments for Achilles tendinopathy. This study aimed to subjectively and objectively determine the therapeutic efficacy of radial shock wave therapy (RSWT) and ultrasound therapy in non-insertional Achilles tendinopathy.Materials and methodsThirty-nine patients with non-insertional Achilles tendinopathy were randomly assigned to three experimental groups, i.e., RSWT (group A), ultrasound therapy (group B), and placebo ultrasound (group C) groups. Before the intervention and at weeks 1 and 6 after the treatment, the patients were assessed using the Victorian Institute of Sport Assessment–Achilles (VISA-A) questionnaire and posturographic measurements of step initiation performed on the force platforms under two different conditions (non-perturbed transit and perturbed transit).ResultsSix weeks after therapy, all groups exhibited significantly increased VISA-A scores against the measurement at week 1 after therapy. The post-therapy percentage changes in VISA-A scores were significantly greater in group A compared to group B. The three-way ANOVA demonstrated that treatment type affected sway range in the frontal plane and mean velocity of the centre of foot pressure displacements in the sagittal and frontal planes during quiet standing before step initiation. The Bonferroni post-hoc test showed that the means of all those variables were significantly smaller for group A than for group B patients. The three-way ANOVA revealed an effect of the platform arrangement on transit time and double-support period. The Bonferroni post-hoc test revealed statistically longer transit time for the perturbed vs. non-perturbed trials; a reverse relationship was observed for the double-support period.ConclusionThe VISA-A showed that RSWT was significantly more effective than sonotherapy for alleviation of pain intensity as well as function and activity improvement in patients with non-insertional Achilles tendinopathy. Therefore, RSWT therapy can be used in clinical practice by physiotherapists to alleviate the symptoms of non-insertional Achilles tendinopathy. Objective data registered by force platforms during quiet standing before and after step initiation did not prove useful for monitoring the progress of treatment applied to patients with non-insertional Achilles tendinopathy between consecutive therapy interventions.Clinical trial registration:https://anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12617000860369, identifier (ACTRN12617000860369).

Dynamic Flow Algorithm with Intermediate Storage for Emergency Evacuation Allowing Lane Reversal based on Incomplete Intuitionistic Fuzzy Preference Relation

Background Evacuation in case of disasters is of the greatest importance because of significant occurrences of natural and artificial disasters worldwide, which is why a reliable evacuation plan is always needed. However, evacuation models are difficult to develop due to various uncertain aspects that need to be considered, multiple and often conflicting criteria for evaluation and as lack of expertise regarding a specific preference of alternatives. Objective This study aims to transport the maximum number of evacuees in a dynamic network with lane reversal by a safe pattern of transportation, i.e., allowing storage at intermediate nodes. The optimal order of shelters and intermediate nodes for a reliable evacuation plan will be defined by incomplete intuitionistic fuzzy preference relation. Methods The illustrated method incorporates multiple and often conflicting criteria into a process of emergency decision-making. When evaluating evacuation alternatives, a decision-maker may hesitate and be unsure which alternative is better or not have sufficient expertise to evaluate a pair of alternatives. To model uncertainty and hesitation, intuitionistic fuzzy values are used to describe alternatives in more detail. This study relies on flow models and graph theory to simulate the movement of evacuees to safe destinations. Furthermore, fuzzy methods and their recent modifications are applied to determine the effective priority order of shelters. A case study which simulates the evacuation of aggrieved to safe destinations is presented. Results A method of evaluating the shelters and intermediate nodes for evacuation based on incomplete intuitionistic fuzzy preference relation is proposed. The method allows the missed values of experts’ assessments to be filled in regarding the evacuation alternatives and deals with intuitionistic fuzzy values, which describe experts’ hesitation. The dynamic character of flow distribution enables transit arc capacities and time factors to be processed. The contraflow technique, which is a powerful tool to decrease traffic jams and congestion on roads by reversing the movement along the unused segments, is applied to maximize the number of survivors. Conclusion The results of the method were compared to those of existing methods, and their consistency was proved. In the future, we intend to apply interval-valued intuitionistic preference relations and iterative algorithms to improve the consistency of intuitionistic preference relations to the tasks of transporting the maximum possible number of aggrieved to safe locations.

Mobility heterogeneity of urban freight areas: Geospatial evidence from shared logistics dynamics

Amid rising mobility services in cities, the logistics sector plays a crucial role in envisioning daily services for local neighborhoods. Previous research has primarily identified key freight areas (KFAs) in small-scale regions using traditional census and travel survey data. However, differing from KFAs, other areas with distinct freight patterns remain largely unexamined, and there is a lack of comprehensive indicators to evaluate the travel behaviors of large-scale freight vehicles. This study introduces a data-driven geospatial framework to characterize and understand the patterns exhibited by different freight areas through freight dynamics data collected in cities. To analyze key aspects of freight mobility within spatial units, a set of areal indicators is developed using GPS trajectories of shared freight vehicles in Hong Kong. Descriptive statistics illustrate the inherent differences across various areas and their spatial distributions. A hierarchical clustering approach groups all areas based on proposed indicators, providing a quantitative evaluation of collective spatial patterns. The analysis also explores the non-linear relationships between different categories of freight activities and the local built environments and socioeconomic conditions. The results suggest a strong spatial heterogeneity in the areal mobility profile of Hong Kong. Loading and unloading behaviors are frequently observed in districts such as Eastern Kowloon, Kwai Chung, and the Airport, highlighting prevalent freight trip origins and destinations. In contrast, areas with high transit times are mostly found in suburban regions, particularly on the periphery. This study provides essential insights for area-based planning and management of urban freight activities, with relevant practical implications.

The Impact of Vocal Tremor on Deglutition: A Pilot Study.

Vocal tremor (VT) poses treatment challenges due to uncertain pathophysiology. VT is typically classified into two phenotypes: isolated vocal tremor (iVT) and essential tremor-related voice tremor (ETvt). The impact of phenotypes on upper aerodigestive tract physiology during swallowing remains unclear. Qualitative and quantitative measures were employed to characterize tremor phenotypes and investigate the effects on swallowing physiology. Eleven ETvt participants (1 Male, 10 Female; x̄ age = 74) and 8 iVT participants (1 Male, 7 Female; x̄ age = 71) swallowed 20 mL boluses in cued and uncued conditions under standardized fluoroscopic visualization. Sustained/a/productions were captured to assess the rate and extent of fundamental frequency (F0) modulation. Penetration and Aspiration Scale (PAS) scores were obtained and swallowing biomechanics were captured using Swallowtail™ software. Participants also completed the Swallowing Quality of Life (SWAL-QOL) questionnaire. Hypopharyngeal transit was faster in both VT phenotypes compared with Swallowtail™ normative reference data. Total pharyngeal transit times, however, were only faster in patients with iVT, relative to reference data. No significant differences were observed on the SWAL-QOL or PAS between tremor phenotypes. SWAL-QOL scores revealed that these patients rarely reported dysphagia symptoms. Subtle differences in swallowing patterns were observed across VT phenotypes, possibly related to adaptive mechanisms resulting in quicker pharyngeal bolus transit. Most patients did not report swallowing issues or dysphagia symptoms. This study is foundational for larger studies on this challenging population. 4 Laryngoscope, 2024.

Numerical Study of Porous Cylindrical Containment for the Fuel Element of a Centrifugal Nuclear Thermal Rocket

For deep-space propulsion and interplanetary exploration, the centrifugal nuclear thermal rocket (CNTR) has the ability to achieve a very high specific impulse (Isp) metric beyond that of conventional chemical rockets or solid-core nuclear thermal propulsion systems. The high Isp allows the rocket to use less propellant or achieve a higher velocity for shorter transit times. However, the cylindrical containment structure of a CNTR fuel element encounters extreme conditions, as it houses molten uranium at temperatures exceeding 1408 K, leading to challenges such as dissolution, chemical reactions, and thermal stresses that conventional materials struggle to withstand. This study aims to address this issue by analyzing appropriate materials for constructing the cylindrical containment component. The operating conditions of the annular porous medium that confines the liquid uranium in the centrifugal fuel element are simulated by conducting a comprehensive one-dimensional numerical analysis using a range of candidate porous materials, including Mo, W, zirconium carbide, and silicon carbide. The porous structure facilitates the flow of the hydrogen propellant into the internal molten uranium section, where it gains significant thermal energy while simultaneously cooling the cylinder. The containment cylinder has an internal temperature of 1478.1 K, exceeding the melting point of uranium, while the external gas temperature of the hydrogen propellant is much lower. This temperature difference induces significant thermal stresses in the cylinder. The porous containment cylinder made from molybdenum was able to maintain elastic deformation throughout the thickness of the cylinder, showcasing its ability to handle these extreme thermal stress conditions. Tungsten, on the other hand, experienced plastic deformation at the cylinder’s edges and elastic deformation through the middle radial locations. In contrast, the stresses experienced by the ceramic materials far exceeded their failure stress values, leading to brittle failure. These findings will help with the refinement of the CNTR design, edging it closer to practical implementation.

Butyrate promotes visceral hypersensitivity in IBS model via mast cell-derived DRG neuron lincRNA-01028-PKC-TRPV1 pathway.

Emerging evidence indicates that gut dysbiosis is involved in the pathogenesis of visceral hypersensitivity (VH). However, how gut microbiota contributes to the development of VH is unknown. Here, we sought to examine the signal transduction pathways from gut to dorsal root ganglion (DRG) responsible for this. Therefore, abdominal withdrawal reflex (AWR) scores, fecal output, fecal water content, and total gastrointestinal transit time (TGITT) were assessed in Con rats, VH rats, rats treated with NaB, and VH rats treated with VSL#3. Fecal microbiota and its metabolite (short-chain fatty acids, SCFAs), mast cell degranulation in colon, lincRNA-01028, miR-143, and protease kinase C (PKC) and TRPV1 expression in DRGs were further detected. VH rats showed an increased fecal water content, a shortened TGITT, an increased abundance of Clostridium sensu stricto 1 and increased butyrate in fecal samples, an increased mast cell degranulation, an increased expression of lincRNA-01028, PKC, and TRPV1, and a decreased expression of miR-143 in DRGs compared with control rats, which could be restored by the application of probiotic VSL#3. The above-mentioned detection in rats treated with butyrate was similar to that of VH rats. We further confirm whether butyrate sensitized DRG neurons by a lincRNA-01028, miR-143, and PKC-dependent mechanism via mast cell in vitro. In co-cultures, MCs treated with butyrate elicited a higher TRPV1 current, a higher expression of lincRNA-01028, PKC, and a lower expression of miR-143 in DRG neurons, which could be inhibited by a lincRNA-01028 inhibitor. These findings indicate that butyrate promotes visceral hypersensitivity via mast cell-derived DRG neuron lincRNA-01028-PKC-TRPV1 pathway.IMPORTANCEIrritable bowel syndrome (IBS), characterized by visceral hypersensitivity, is a common gastrointestinal dysfunction syndrome. Although the gut microbiota plays a role in the pathogenesis and treatment of irritable bowel syndrome (IBS), the possible underlying mechanisms are unclear. Therefore, it is of critical importance to determine the signal transduction pathways from gut to DRG responsible for this in vitro and in vivo assay. This study demonstrated that butyrate sensitized TRPV1 in DRG neurons via mast cells in vivo and in vitro by a lincRNA-01028, miR-143, and PKC-dependent mechanism. VH rats similarly showed an increased abundance of Clostridium sensu stricto 1, an increased fecal butyrate, an increased mast cell degranulation, and increased expression of TRPV1 compared with control rats, which could be restored by the application of VSL#3. In conclusion, butyrate produced by the altered intestinal microbiota is associated with increased VH.

Simulation-Based Assessment of Hyperconnected Megacity Parcel Logistics

Background: The concept of Hyperconnected Megacity Parcel Logistics (HMPL) was introduced in 2018 and aims to enhance the efficiency, responsiveness, resilience, and sustainability of parcel movements in megacities. However, evaluating such fundamental solutions presents challenges and requires a comprehensive understanding of all stakeholders and decisions involved. Methods: This study introduces a discrete-event agent-based simulation platform that encompasses critical stakeholders and addresses various levels of decision-making. This platform provides an opportunity to evaluate key decisions within an HMPL structure. Results: To demonstrate the capability of the simulator, we assess the impact of package routing and consolidation strategies facilitated by HMPL compared to traditional practices. Preliminary findings suggest that increased interconnection among nodes in HMPL reduces transit times, thereby enabling tighter customer delivery services. However, examining different consolidation heuristics reveals potential trade-offs between handling and shipping costs under fixed shipment schedules, prompting further investigation into dynamic shipment services. Conclusions: The findings of this study suggest that the benefits of innovative approaches in a complex environment, such as parcel logistics, cannot be evaluated in isolation from other decisions. Accurate assessment of the ultimate outcomes and underlying trade-offs requires multi-faceted models that incorporate all key variables.

Integrating a Water Tracer Model Into WRF‐Hydro for Characterizing the Effect of Lateral Flow in Hydrologic Simulations

AbstractMost current land models approximate terrestrial hydrological processes as one‐dimensional vertical flow, neglecting lateral water movement from ridges to valleys. Such lateral flow is fundamental at catchment scales and becomes crucial for finer‐scale land models. To test the effect of incorporating lateral flow toward three‐dimensional representations of hydrological processes in the next generation land models, we integrate a water tracer model into the WRF‐Hydro framework to track water movement from precipitation to discharge and evapotranspiration. This hydrologic‐tracer integrated system allows us to identify the key mechanisms by which lateral flow affects the flow paths and transit times in WRF‐Hydro. By comparing modeling experiments with and without lateral routing in two contrasting catchments, we determine the impacts of lateral flow on the transit times of precipitation event‐water. Results show that with limited hydrologic connectivity, lateral flow extends the transit times by reducing (increasing) event‐water drainage loss (accumulation) in ridges (valleys) and allowing reinfiltration of infiltration‐excess flow, which is missing in most land models. On the contrary with high hydrologic connectivity, lateral flow can effectively accelerate the water release to streams and reduce the transit time. However, the transit times are substantially underestimated by the model compared with isotope‐derived estimates, indicating model limitations in representing flow paths and transit times. This study provides some insights on the fundamental differences in terrestrial hydrology simulated by land models with and without lateral flow representation.

Integrating a Water Tracer Model Into WRF‐Hydro for Characterizing the Effect of Lateral Flow in Hydrologic Simulations

AbstractMost current land models approximate terrestrial hydrological processes as one‐dimensional vertical flow, neglecting lateral water movement from ridges to valleys. Such lateral flow is fundamental at catchment scales and becomes crucial for finer‐scale land models. To test the effect of incorporating lateral flow toward three‐dimensional representations of hydrological processes in the next generation land models, we integrate a water tracer model into the WRF‐Hydro framework to track water movement from precipitation to discharge and evapotranspiration. This hydrologic‐tracer integrated system allows us to identify the key mechanisms by which lateral flow affects the flow paths and transit times in WRF‐Hydro. By comparing modeling experiments with and without lateral routing in two contrasting catchments, we determine the impacts of lateral flow on the transit times of precipitation event‐water. Results show that with limited hydrologic connectivity, lateral flow extends the transit times by reducing (increasing) event‐water drainage loss (accumulation) in ridges (valleys) and allowing reinfiltration of infiltration‐excess flow, which is missing in most land models. On the contrary with high hydrologic connectivity, lateral flow can effectively accelerate the water release to streams and reduce the transit time. However, the transit times are substantially underestimated by the model compared with isotope‐derived estimates, indicating model limitations in representing flow paths and transit times. This study provides some insights on the fundamental differences in terrestrial hydrology simulated by land models with and without lateral flow representation.

Incomplete small bowel capsule endoscopy: Risk factors and cost-effectiveness of real-time viewing.

Background and study aims International guidelines recommend real-time viewing (RTV) in capsule endoscopy for gastric emptying monitoring, yet it is often overlooked in clinical practice. We aimed to assess risk factors for incomplete small bowel capsule endoscopy (SBCE) and evaluate the clinical relevance and cost-effectiveness of RTV implementation. Methods We included consecutive SBCEs from 2013 to 2020. RTV was not applied per local protocol. We used multivariate logistic regression to identify risk factors for incomplete SBCE, including prolonged gastric transit time (GTT) and prolonged small bowel transit time (SBTT). Results Analyzing 858 SBCEs, we observed a completion rate of 94.6%. Prolonged GTT and SBTT were present in 4.9% and 18.2% of complete SBCEs, and in 13% ( P =0.03) and 10.8% ( P =0.24) of incomplete SBCEs, respectively. Only 0.7% (6 of 858) had incomplete SBCE with prolonged GTT. In both univariate and multivariate analysis, a modifiable (prolonged GTT odds ratio [OR] 2.9; 95% confidence interval [CI] 1.1-7.5) and two unmodifiable risk factors (inpatient status OR 2.3; 95% CI 1.1-4.5) and history of incomplete SBCE (OR 4.2; 95% CI 1.3-13.7) were independently linked to higher incomplete SBCE rates. The pretest completion probability was 90.5% and 95.8% in patients with and without unmodifiable risk factors, respectively ( P <0.01). The direct cost of systematic RTV adoption and prokinetics administration would be €5059, aiming to identify and treat each case of prolonged GTT associated with incomplete SBCE. Conclusions Modern devices make incomplete SBCE rare, usually not tied to prolonged GTT. In a low-incidence scenario, widespread RTV use brings high costs and uncertain effectiveness.

Multi-Period Ordering Decisions in the Presence of Retail Promotions

This paper investigates the impact of retail promotions on inventory decisions in a multi-period ordering setting. A laboratory experiment was designed to examine how awareness of promotional information could improve ordering decisions and reduce supply chain costs. Drawing on data from 140 participants in Australia and Sri Lanka, our study reveals several key findings and practical insights. (i) Awareness of upcoming promotions significantly improves ordering decisions by minimizing ordering costs while maintaining service levels. (ii) Access to detailed promotional information (e.g., the extent of price discounts) does not noticeably improve these decisions. (iii) Transit times serve as a moderating factor; longer transit times can lead to supply line underestimations, thereby escalating ordering costs. (iv) A lack of promotional awareness results in adverse behaviors, including bracing and demand chasing. These findings and practical insights underscore the critical role of timely and effective communication of promotional information in improving multi-period ordering decisions.

The effects of bit chewing on gastric emptying and orocecal transit times in clinically normal horses

The effects of bit chewing on gastric emptying and orocecal transit times in clinically normal horses