Search Results (27)

Background/Objectives: Pseudohypoparathyroidism (PHP) is a group of genetic disorders characterized by end-organ resistance to multiple hormones, short stature, brachydactyly, subcutaneous ossifications, obesity, and developmental delays. The tissue specific imprinting of GNAS in the hypothalamus may lead to different eating behavior phenotypes in maternally inherited (PHP1A, PHP1B) vs. paternally inherited (PPHP) variants. In this exploratory study, we aimed to evaluate differences in eating behaviors in a cohort of patients with PHP1A, PPHP and PHP1B. Methods: Assessments included caregiver-reported measures (hyperphagia questionnaire, children’s eating behavior questionnaire, child feeding questionnaire) and self-reported measures (three factor eating behavior questionnaire). Results: A total of 58 patients with PHP1A, 13 patients with PPHP and 10 patients with PHP1B contributed data, along with 124 obese pediatric controls. An increased risk of obesity was found in PHP1A vs. PPHP (adult body mass index (BMI) 39.8 ± 8.7 vs. 30.2 ± 7.4 kg/m², p = 0.03). Parents reported significantly earlier onset of interest in food in children with PHP1A (2.0 ± 2.3 years) and PHP1B (1.1 ± 1.3 years) compared with controls (5.2 ± 3.2 years, p < 0.001). Measures of hyperphagia, satiety and other feeding behaviors were all similar to controls. The highest hyperphagia questionnaire scores were seen prior to adolescence. In a multi-year, longitudinal assessment of 11 pediatric patients with PHP1A, hyperphagia scores were stable and 25% showed an improvement in symptoms. Conclusion: Patients with PHP1A/1B may have hyperphagia symptoms from a young age but they do not worsen over time. Patients may overeat when allowed access to food, but do not usually have disruptive food seeking behaviors. Early diagnosis can give clinicians the opportunity to provide anticipatory diagnosis on the increased risk of obesity in PHP1A/1B and need for scheduled meals and controlled portions. Further studies with larger cohorts are needed to confirm these findings. Full article

Rapidly expanding power demand in economically developing regions significantly amplifies the operational risks associated with the delayed commissioning of planned substations. This study proposes a data–physics fusion framework integrating analytic hierarchy process-based quantitative assessment with multi-voltage level grid evolution simulation. First, a novel set of evaluation indicators for assessing planned substation criticality, with weights determined through the analytic hierarchy process (AHP), was established, enabling rapid assessment of delay impacts on investments and identification of crucial substations. This approach addresses the fundamental limitation of traditional planning methodologies, which inadequately quantify the compound effects of substation commissioning delays on multi-voltage grid evolution and associated investment inefficiencies. Subsequently, a multi-voltage level grid evolution model was developed, which quantitatively measures the cascading effects of substation commissioning delays on both low-voltage grid development and multi-level grid construction investments. Case study validation demonstrated a strong linear correlation between the proposed substation importance scores and the incremental construction costs induced by delays. The simulation-driven impact assessment model exhibits superior accuracy in evaluating commissioning delay consequences on multi-voltage grid construction compared to conventional approaches. This research provides power grid planners with a robust decision support framework for optimizing substation construction scheduling and minimizing delay-related cost escalations in complex grid development scenarios. Full article

With the rapid development of the low-altitude economy, the intensive take-offs and landings of Unmanned Aerial Vehicles (UAVs) performing logistics transport tasks in urban areas have introduced significant safety risks. To reduce the likelihood of collisions, logistics operators—such as Meituan, Antwork, and Fengyi—have established fixed departure and arrival air routes above vertiports and designed fixed flight air routes between vertiports to guide UAVs to fly along predefined paths. In the complex and constrained low-altitude urban environment, the design of safe and efficient air routes has undoubtedly become a key enabler for successful operations. This research, grounded in both current theoretical research and real-world logistics UAV operations, defines the concept of UAV logistics air routes and presents a comprehensive description of their structure. A parametric model for one-way round-trip logistics air routes is proposed, along with an air route evaluation model and optimization method. Based on this framework, the research identifies four basic configurations that are commonly adopted for one-way round-trip operations. These configurations can be further improved into two optimized configurations with more balanced performance across multiple metrics. Simulation results reveal that Configuration 1 is only suitable for small-scale transport; as the number of delivery tasks increases, delays grow linearly. When the task volume exceeds 100 operations per 30 min, Configurations 2, 3, and 4 reduce average delay by 88.9%, 89.2%, and 93.3%, respectively, compared with Configuration 1. The research also finds that flight speed along segments and the cruise segment capacity have the most significant influence on delays. Properly increasing these two parameters can lead to a 28.4% reduction in the average delay. The two optimized configurations, derived through further refinement, show better trade-offs between average delay and flight time than any of the fundamental configurations. This research not only provides practical guidance for the planning and design of UAV logistics air routes but also lays a methodological foundation for future developments in UAV scheduling and air route network design. Full article

Significant weather-induced delays often plague construction projects in India’s extremely cold regions, yet comprehensive studies addressing this issue remain scarce. This study aims to fill this gap by identifying key delay factors and proposing mitigation strategies for the construction industry. Through an extensive literature review, 42 delay factors were identified and categorized into four groups. A survey of 83 experts from cold regions was conducted to evaluate these factors’ significance to contractors and subcontractors. Employing exploratory factor analysis (EFA), structural equation modeling (SEM), and artificial neural networks (ANN), the study analyzed the relationships between these factors and ranked their impact. The findings reveal that snowfall, rainfall, and low temperatures are the most significant contributors to delays, with snowfall being the most influential (significance: 1.000), followed by rainfall (0.890) and low temperatures (0.790). This research establishes a risk hierarchy and develops a predictive model to facilitate the proactive scheduling of challenging tasks during favorable seasons. This study advances the understanding of weather-induced delays in India’s cold regions and offers valuable insights for project management in such climates. However, it underscores the importance of clearly articulating its novel contributions to differentiate it within the existing literature on weather-related construction delays. Full article

We study the use of a homogeneous fleet of drones to design an unattended persistent drone-based patrolling system for vast circular areas. The drones follow flight missions supported by auxiliary on-ground charging stations, whose location and number must be determined. To this end, we first present a mixed integer non-linear programming model for defining cyclic schedules of drone flights considering the selection of the drone model from a set of candidate drone platforms. By imposing a minimum acceptable time between consecutive visits to any perimeter point, the objective consists of minimizing the total surveillance system deployment cost. The solution provides the best platform, the location of base stations, and the number of drones needed to monitor the perimeter, as well as the flight mission for each drone. We test five commercial platforms in six different scenarios whose radios vary between 1196 and 1696 m. In five of them, the MD4-100 Microdrones model achieves the lower cost solution, with values of EUR 66,800 and 83,500 for Scenarios 1 and 2 and EUR 116,900 for Scenarios 3, 4 and 5, improving its rivals in average percentages that vary between 8.46% and 70.40%. In Scenario number 6, the lower cost solution is provided by the TARTOT-500 model, with a total cost of EUR 168,000, improving by 20% the solution provided by the MD4-100. After obtaining the optimal solution, to evaluate the system robustness, we propose a discrete event simulation model incorporating uncertain flight times taking into account the possibility of accelerated depletion of drones’ Lithium-Ion polymer (Li-Po) batteries. Overall, our research investigates how various factors—such as the number of drones in the fleet and the division of the perimeter into sectors—impact the reliability of the system. Using Scenario number 3, our tests demonstrate that under a risk of battery failures of 2.5% and three UAVs per station, the surveillance system reaches a global percentage of punctually patrolled sectors of 92.6% and limits the number of delayed sectors (the relay UAV reaches the perimeter slightly above the required time, but it positively re-establishes the cyclic pattern for patrolling) to only a 5.6%. Our findings provide valuable insights for designing more robust and cost-effective drone patrol systems capable of operating autonomously over large planning horizons. Full article

Project Managers face many difficulties when scheduling the development and production of multiple, largely independent systems required for a new capability, especially when there are multiple stakeholders, uncertainties in the expected development time, and developmental dependencies among the systems. The Systems Developmental Dependency Analysis methodology provides a systemic approach to address these challenges by offering decision support for such a ‘System-of-Systems’. The method, based on a parametric piece-wise linear model of dependencies between elements in the developmental domain, propagates the interactions between systems to estimate delays in the development of individual systems and to evaluate the impact of such delays on the expected schedule of completion for the establishment of the whole desired capability. The schedule can be automatically re-generated based on new system information, changed dependencies, and/or modified risk levels. As demonstrated in this paper using a complex space mission case, the method enhances decision-support by identifying criticalities, computing possible delay absorption strategies, and comparing different development strategies in terms of robustness to delays. Full article

Scheduling is essential in managing projects. ‘Schedula Anima’ is a new software designed to provide a comprehensive view of schedules between early and late dates for construction project managers. Capturing the dynamic nature of projects, it offers improved visualization through an animation process that creates incremental frames of bar charts and the corresponding resource graphs. As activity delays are simulated, it is observed that delays earlier in the schedule have more significant effects on project completion. A new prioritization method is introduced to evaluate the ease of rescheduling activities. A metric for monitoring resource usage float is presented, and the search space for resource utilization is delineated. As resource smoothing is studied in the resource usage graph and the time domain, a correlation is discovered between resource smoothness and the float consumption rate. It is shown that the schedule and resource usage graph comprises five sub-areas representing different risk exposures. Animation also improves communication in project teams and is beneficial in education. Finally, it is discovered that the permutations of activities in the simulation form a group. Enhancing our perception of resource utilization and the management of delays, ‘Schedula Anima’ brings a renewed perspective to project scheduling. Full article

People living with HIV (PLHIV) are at greater risk of illness and death from vaccine-preventable diseases. This study aimed to identify the predictors associated with the recommended vaccination schedule for this group. This was a single-center cross-sectional study conducted in a large Brazilian municipality, evaluating the vaccination statuses of 645 PLHIV for nine immunizers. The primary outcome was the adequacy of the vaccination schedule. The vaccination status was assessed for the diphtheria/tetanus, hepatitis B, hepatitis A, measles/mumps/rubella, yellow fever, 13- and 23-valent pneumococcal, meningococcal C, and HPV vaccines. Those who had received all of the recommended vaccinations in accordance with the schedule established by the government at the time of the assessment, without any delays, were classified as having received an “adequate schedule”. The independent variables included sociodemographic, clinical–epidemiological, and social vulnerability factors, analyzed by multiple logistic regression with adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs). Only 47 individuals (7.3%) had an adequate vaccination schedule for all vaccines. The vaccines with the highest adequacy rate were diphtheria and tetanus (533; 82.6%), and the one with the lowest rate was measles/mumps/rubella (MMR) (243; 37.7%). The main predictors of a complete vaccination schedule were the age group, place of clinical follow-up, and where they received their last doses of vaccines. Educational interventions for PLHIV and health professionals are needed to improve the vaccination coverage in this group. Full article

Load balancing to alleviate network congestion remains a critical challenge in Vehicular Ad Hoc Networks (VANETs). During route and response scheduling, road side units (RSUs) risk being overloaded beyond their calculated capacity. Despite recent advancements like RSU-based load transfer, NP-Hard hierarchical geography routing, RSU-based medium access control (MAC) schemes, simplified clustering, and network activity control, a significant gap persists in employing a load-balancing server for effective traffic management. We propose a server-based network congestion handling mechanism (SBNC) in VANETs to bridge this gap. Our approach clusters RSUs within specified ranges and incorporates dedicated load balancing and network scheduler RSUs to manage route selection and request–response scheduling, thereby balancing RSU loads. We introduce three key algorithms: optimal placement of dedicated RSUs, a scheduling policy for packets/data/requests/responses, and a congestion control algorithm for load balancing. Using the VanetMobiSim library of Network Simulator-2 (NS-2), we evaluate our approach based on residual energy consumption, end-to-end delay, packet delivery ratio (PDR), and control packet overhead. Results indicate substantial improvements in load balancing through our proposed server-based approach. Full article

PTCY 50 mg/kg/day on days +3/+4 is an excellent strategy to prevent GVHD. However, its use is associated with adverse outcomes such as delayed engraftment, increased risk of infection, and cardiac complications. This pilot study evaluates the efficacy and toxicity of a reduced dose of PTCY (40 mg/kg/day) combined with tacrolimus in 22 peripheral blood HLA-matched alloHSCT patients. At day +100, the cumulative incidences of grade II–IV and III–IV acute GVHD were 18.2% and 4.5%, respectively. No grade IV acute GVHD or steroid-refractory disease was observed. The cumulative incidences of all-grade and moderate-severe chronic GVHD at 1-year were 11.4% and 6.4%, respectively. No patient died from transplant-related complications. Two-year OS and RFS were 77.1% and 58.3%, respectively. All patients engrafted, with neutrophil and platelet recovery occurring at a median of 15 (IQR 14–16) and 16 days (IQR 12–23), respectively. The cumulative incidences of bloodstream bacterial infections, polyomavirus BK hemorrhagic cystitis, HHV6 reactivation, CMV reactivation, and fungal infections were 13.6%, 9.1%, 9.1%, 4.6%, and 6%, respectively. Only one early cardiac event was observed. These results suggest that PTCY 40 mg/kg/day on a +3/+4 schedule provides adequate immunosuppression to allow for engraftment and prevent clinically significant GVHD with a low toxicity profile. Full article

Vehicle scheduling at shipyards can involve delays due to numerous risk factors encountered in the complicated shipyard road environment. This paper studies the problems of risk coupling in shipyard vehicle scheduling based on the risk matrix approach, considering the complicated road environment, assessing the degrees of coupling and disorder. Based on safety-engineering theory and comprehensive analysis of the road environment, four key criteria are identified, vehicles, the road environment, the working environment, and humans, including 12 factors and their specific contents. The degree of coupling between various combinations of risk criteria is quantitatively determined utilizing the N-K model. Additionally, the degree of disorder in the risk criteria is assessed based on information entropy theory. The model’s correction coefficients are determined through comparative analysis of experimental data. By integrating the degree of coupling and disorder, delays caused by different combinations of risk criteria in scheduling tasks are computed. The quantitative evaluation model enables accurate appraisal of risk events during shipyard vehicle scheduling. The model provides a valuable managerial tool to analyze delays caused when specific risk criteria are met and to compare these delays to the potential impact on time resulting from adjusting vehicle scheduling plans. This research has significant implications for enhancing vehicle distribution efficiency in shipyards. Full article

Background: The implications of delaying surgical intervention for patients with adolescent idiopathic scoliosis (AIS) wishing to undergo vertebral body tethering (VBT) have not yet been explored. It is important to understand how these delays can impact surgical planning and patient outcomes. Methods: This was a retrospective review that analyzed all AIS patients treated between 2015 and 2021 at a single tertiary center. Time to surgery from initial surgical consultation and ultimate surgical plan were assessed. Patient characteristics, potential risk factors associated with increased curve progression, and reasons for delay were also analyzed. Results: 174 patients were evaluated and 95 were scheduled for VBT. Four patients later required a change to posterior spinal fusion (PSF) due to excessive curve progression. Patients requiring PSF were shown to have significantly longer delays than those who received VBT. Additionally, longer delays, younger age, greater curve progression, and lower skeletal maturity were correlated with significant curve progression (≥5 degrees). Conclusions: Surgical delays for AIS patients awaiting VBT may lead to significant curve progression and necessitate more invasive procedures. Patients with longer delays experienced an increased risk of needing PSF instead of VBT. Of those requiring PSF, the majority were due to insurance denials. Optimizing surgical timing and shared decision-making among patients, families, and healthcare providers are essential for achieving the best outcomes. Full article

A prolonged preoperatory aPTT in children is often the cause of a delay of scheduled surgeries and the repetition of multiple blood tests, with the consequent wasting of resources and significant discomfort for children and parents. The aim of this review is to analyze the situations in which an isolated prolongation of aPTT is found during preoperative evaluation in children, especially when it is due to the presence of antiphospholipid antibodies, providing the readers with the keys to interpret this situation and the possibility to correctly evaluate the hemorrhagic risk of a patient. Full article

Due to the fact that risks can cause project delays and increase project implementation costs, successful construction project completion requires effective and holistic risk management. Identification and evaluation of critical risk factors (CRFs) associated with different types of projects are the most significant components of accurate risk management. This study aims to identify and evaluate the CRFs inherent with private–public partnership (PPP) projects specifically for the development of water and wastewater infrastructure (WWI) facilities in the developing country of Iran. In this line, a comprehensive literature analysis was undertaken to extract the CRFs in applying PPP projects for the development of infrastructure projects in developing countries in general. Then, four rounds of a Delphi survey were conducted to consolidate the major risks to the circumstances of Iran and WWI facilities. There were a total of 35 risks that were grouped into six categories. The main risks were then analyzed and ranked using the Measurement Alternatives and Ranking according to the Compromise Solution (MARCOS) technique. The overall ranking results of the various CRFs revealed that “lack of trust in government’s economic programs” risk was ranked first in terms of importance, followed by the risk of “delay in timely fund payment for project financing and credits,” and the risk of “delay in finalizing bank negotiations.” The overall ranking of the risks placed “economic changes, such as inflation, increase or decrease in prices, and exchange rate” risk in the bottom position. According to the risk ranking findings based on the opinions of private experts, “lack of commitment to the project schedule” was placed first. Conversely, experts from the public sector considered “choosing the wrong financing method” to be the most CRF. It is anticipated that the key research findings and effective recommendations of this study will considerably contribute to the smooth development and remarkable improvement of risk management in applying PPP for WWI facilities in developing countries while enhancing different stakeholders’ understanding of the CRFs for PPP projects, particularly towards WWI services in Iran. Full article

Hydropower as a renewable source can help many countries achieve their sustainable energy and climate goals, but large projects are challenging to finance because of their costs and risks. To fully realize the climate benefits of such projects, sponsors have recently fashioned complex financing arrangements that structure and allocate risks to reduce financing costs. This paper focuses on the blended financing approach adopted for the Nachtigal Hydropower Plant (NHP) in Cameroon. The purpose of the paper is to present a detailed systems analysis of Nachtigal’s financial arrangement to address the question of why the complex financing approach worked in practice. We accomplish this by creating a “financial simulator”—a computational model for evaluating risks and incentives embedded within the financing structure under different contract architectures and risk–event scenarios. Our simulator is a dynamic value–risk calculator that can be easily updated to study other climate-oriented projects that involve complex financial arrangements. We evaluated three aspects of the financing/contractual arrangements that made Nachtigal “bankable:” (i) guarantees that covered nonpayments, (ii) financial options on locally sourced loans; and (iii) an interest rate swap. We found: (i) the guarantees recovered project value threatened by four specific risks often associated with large hydropower investments (cost overruns, schedule delays, offtake risk, and low flow due to climate change); (ii) the mechanism significantly lowered interest rate charges; and (iii) private finance was mobilized—especially due to the options. The financial safeguards employed increased the likelihood of capturing the long-run sustainability benefits from NHP. Full article