Framework for integrated planning of bus and paratransit services in Indian cities

Public transport services in India and many other developing countries are provided by a combination of formal-Government led public transport systems and informal paratransit or Intermediate Public Transport (IPT) systems, which offer shuttle services along high demand corridors with passengers boarding and alighting at multiple points. Despite limited Government support, paratransit systems continue to thrive in many cities serving a crucial shared mobility need of users, without which cities would have more private vehicle usage. Due to their informal nature and the perceived competition to formal public transport systems, they have traditionally been either excluded from the public transport planning processes or designed as a feeder service to the formal transit system. The current thesis recognises paratransit’s role in serving end to end travel demand needs, particularly in developing economies with limited public transport supply and not just being a feeder to the formal public transport system. Hence, we develop an integrated planning framework that enables formal and informal public transport systems to operate as complementary systems towards meeting the mobility needs of the city. We proved an integrated planning framework based on comprehensive understanding of the demand and supply characteristics of both formal and informal systems which currently operate independently to realign services and complement each other. The tactical planning stage of public transport planning i.e. frequency setting was identified as the ideal stage of planning for integration of the two types of services. This will ensure continuity of their existing route networks and at the same time allow for paratransit services’ flexibility to switch operations between routes. Visakhapatnam, a representative medium sized Indian city with a significant presence of formal public transport in the form of city bus services and paratransit services provided by three-wheeler auto-rickshaws with a seating capacity of three to six passengers, was selected as the case city to demonstrate the methodology. A household survey based data collection and analysis methodology was adopted to analyse the socio-economic and travel demand characteristics of city bus and paratransit users. The variables impacting users’ choice between these two systems were derived through binary logistic regression. The high frequency and low occupancy paratransit systems were more popular among shorter trips, while longer trips preferred the fixed table bus systems. The operational characteristics of bus and paratransit systems were derived through a combination of primary surveys with paratransit operators and secondary data on the city bus operations. Data regarding their network of operation, services offered, passenger demand and revenue generated were collected for analysis. Buses perform a service function in the city by operating throughout the day and on a wider network, while paratransit operates with a profit motive only on high demand corridors and during peak hours. A Data Envelopment Analysis (DEA) based methodology was adopted to compare the performance efficiency of the two systems using a set of input and output indicators that define the performance of the two systems. Paratransit operations were identified to be more efficient compared to buses, due to their demand responsive operations. The lower efficiency of buses was also due to their service obligation to the city to provide affordable services throughout the day, even in areas with low demand. A bi-level transit assignment and frequency optimisation framework is developed to integrate formal bus and paratransit services. The lower-level of the model solves for the multi- modal transit assignment problem while the upper level solves for the integrated frequency optimisation problem. The transit assignment problem was solved from the users perspective i.e. to minimise their travel time through the user-equilibrium method. The frequency optimisation problem was solved using an integer programming formulation with the objective of minimising operational cost of bus and paratransit systems while meeting constraints like the travel demand on any link. The outputs from the optimisation exercise were used to quantify the impact of the public transport system at various levels i.e. users total travel time spent in the system, operators cost of providing the services and the overall impact on the society by estimating its road space requirement and emissions. Alternative user demand and transit supply scenarios were tested to assess their impacts on the society. The results show significant operational cost benefits of an integrated transit assignment and frequency planning approach where paratransit provides demand responsive services for short distance trips while formal public transport provides fixed schedule services on with broader network coverage. The analysis established the complimentary role played by bus and paratransit systems in meeting users travel demands. Therefore, it is recommended that cities harness both the systems towards meeting increasing travel needs of developing economies. Formal transit will continue to be the core of the public transport system, providing fixed route services, while paratransit can augment its capacity on high demand corridors and during peak hours. The planning and frequency optimisation framework developed in this thesis can help cities in identifying the modal-mix of fixed route public transport and on-demand services

ISOLATION AND CHARACTERIZATION OF MULTIPOTENT LUNG STEM CELLS FROM p53 MUTANT MICE MODELS

Recent advances in understanding lung biology have shown evidence for the existence of resident lung stem cells. Independent studies in identifying and characterizing these somatic lung stem cells have shown the potential role of these cells in lung repair and regeneration. Understanding the functional characteristics of these tissue resident stem/progenitor cells has gained much importance with increasing evidence of cancer stem cells, cells in a tumor tissue with stem cell characteristics. Lung cancer is most commonly characterized by loss of p53 function which results in uncontrolled cell divisions. Incidence of p53 point mutations is highest in lung cancer, with a high percentage of missense mutations as a result of tobacco smoking. Certain point mutations in p53 gene results in its oncogenic gain of functions (GOF), with enhanced tumorigenic characteristics beyond the loss of p53 function. However, there are no available data on characterization of lung stem cells carrying GOF mutations and correlating them with those of normal stem cells, in this study, for the first time we show that percentage of Sca-1 expressing subpopulation is significantly higher in the lungs of mice carrying p53 GOF mutations than those in lungs isolated from p53+/+ wild type mice. Further, we successfully established lung cells differentially expressing two cell surface markers, Sca-1 and PDGFR-α, with results demonstrating existence of different subpopulations of cells in the lung. Results from our project demonstrate the importance of p53 GOF mutations as correlated with specific lung cell subpopulations

Does Knowledge from Home Markets Boost Outward Foreign Direct Investments of Emerging Economy Multinationals? Evidence from Indian Family EMNEs

Despite increasing research on multinationals from emerging economies (EMNEs), our understanding of the antecedents of their international expansion is still limited. In this study, we seek to examine whether knowledge gained from operating in their complex and diverse domestic markets deter or aid the outward foreign direct investments of EMNEs. As family firms are dominant in emerging economies, we further explore how heterogeneity within family firms moderate this relationship. We conduct our investigations using a proprietary longitudinal dataset comprising 213 EMNEs from India featuring in the S&P Bombay Stock Exchange (BSE) 500 index covering a six-year period from 2007-08 to 2012-13, of which 175 were family EMNEs and find supporting evidence for our theoretical predictions

A Study of Chance-Corrected Agreement Coefficients for the Measurement of Multi-Rater Consistency

Chance corrected agreement coefficients such as the Cohen and Fleiss Kappas are commonly used for the measurement of consistency in the decisions made by clinical observers or raters. However, the way that they estimate the probability of agreement (Pe) or cost of disagreement (De) 'by chance' has been strongly questioned, and alternatives have been proposed, such as the Aickin Alpha coefficient and the Gwet AC1 and AC2 coefficients. A well known paradox illustrates deficiencies of the Kappa coefficients which may be remedied by scaling Pe or De according to the uniformity of the scoring. The AC1 and AC2 coefficients result from the application of this scaling to the Brennan-Prediger coefficient which may be considered a simplified form of Kappa. This paper examines some commonly used multi-rater agreement coefficients including AC1 and AC2. It then proposes an alternative subject-by-subject scaling approach that may be applied to weighted and unweighted multi-rater Cohen and Fleiss Kappas and also Intra-Class Correlation (ICC) coefficients

Chemistry and DMPK Core Facility

Medicinal chemistry is one of the vital components of the iterative cycle of drug discovery. This component is embedded in hit-to-lead and lead optimization stages. Twelve years of collective experiences and services provided by this Chemistry DMPK Core support the view that a majority of investigators are faced with two significant hurdles in advancing their research programs: compound acquisition and early-stage compound evaluation. This Core has bridged the gap by providing investigators with consultation, training, and services in medicinal chemistry, drug metabolism, and analysis, helping alleviate the bottleneck associated with compound acquisition and evaluationhttps://egrove.olemiss.edu/pharm_annual_posters_2024/1011/thumbnail.jp

Reformulation and Generalisation of the Cohen and Fleiss Kappas

The assessment of consistency in the categorical or ordinal decisions made by observers or raters is an important problem especially in the medical field. The Fleiss Kappa, Cohen Kappa and Intra-class Correlation (ICC), as commonly used for this purpose, are compared and a generalised approach to these measurements is presented. Differences between the Fleiss Kappa and multi-rater versions of the Cohen Kappa are explained and it is shown how both may be applied to ordinal scoring with linear, quadratic or other weighting. The relationship between quadratically weighted Fleiss and Cohen Kappa and pair-wise ICC is clarified and generalised to multi-rater assessments. The AC1 coefficient is considered as an alternative measure of consistency and the relevance of the Kappas and AC1 to measuring content validity is explore

NIH COBRE-Natural Products Neuroscience Chemistry Services Under Chemistry and DM-PK CORE Facility

Department/Unit poster (BioMolecular Sciences). Corresponding author: Rama S. Gadepalli ([email protected])https://egrove.olemiss.edu/pharm_annual_posters_2022/1008/thumbnail.jp

EVALUATION OF CARDIOVASCULAR AND PHARMACODYNAMIC EFFECTS OF TERMINALIA ARJUNA SINGLE DOSE AND MULTIPLE DOSE IN HEALTHY HUMAN MALES

Context: Terminalia arjuna is a medicinal plant used as a cardiotonic in Ayurveda. The presence of potent antioxidant constituents results in improvement in endothelial dysfunction seen in coronary artery disease.Aim: To evaluate the cardiovascular and pharmacodynamic effects of single and multiple doses of Terminalia arjuna in healthy human male subjects.Settings and Design: Randomized, double blind, placebo-controlled dose ranging study.Methods and Material: After approval from the institutional ethics committee, written informed consent was taken from subjects. Eligible subjects were allocated to the single and multiple dose groups, with six subjects in each group. The active treatment (Terminalia arjuna crude powder capsules of 500 mg, 1000 mg, 1500 mg & 2000 mg single dose and 1500 mg multiple dose) and placebo capsules were administered in 2:1 ratio in all the study groups. Vital parameters and pharmacodynamic assessment of cardiac profiling were performed using cold pressor test (CPT), tilt table and platelet aggregation tests.Statistical analysis used: The data was presented as mean ±SD. No statistical tests were applied as the sample size was less (n=6 in each group).Results: During CPT, Terminalia arjuna attenuated the rise in SBP, DBP and pulse rate in all the treatment groups compared to baseline. The CPT induced arterial stiffness was counteracted by treatment with 1500 mg & 2000 mg single dose and 1500 mg multiple doses of Terminalia arjuna. Cardiac output was increased with 1500 mg multiple dose at 600 tilt (Day 1) and at 450 & 600 phases of the tilt (Day 11). Platelet aggregation was markedly inhibited in 1500 mg multiple doses at Day 11.Conclusions: Treatment with single (1500 mg & 2000 mg) and multiple doses (1500 mg for 10 days) of Terminalia arjuna produced remarkable changes in the cardiovascular profile. Further studies in larger number of subjects and in patients with cardiovascular diseases are needed to confirm these effects

Evaluation of biochemical parameters in acute myocardial infarction and angina patients

Background: Early and accurate detection of acute myocardial infarction (AMI) is an important unmet clinical requirement. The present study sought to evaluate the levels of N-terminal pro-brain natriuretic peptide (NTproBNP), cardiac troponin I (cTnI), fasting lipid profile, random blood sugar, and serum creatinine in AMI patients compared to angina patients. Methods: In a single-center, hospital-based, cross-sectional, observational, prospective study conducted at Gandhi Medical College, Secunderabad, from October-2018 to September-2019. A total of 150 patients aged above 40 years with acute chest pain (within 2-6 hours) and who were clinically susceptive of AMI and angina were investigated. The patients were divided into group I (50 AMI patients) and group II (100 angina patients). Levels of all biochemical parameters of blood were assessed. The statistical analyses were performed using the SPSS statistical software, version 15. A student t-test was used to compare the continuous variables between the two groups. Results: Out of 150 patients, higher male prevalence was found in both the groups (60% and 63%, respectively). Group I had higher levels of NTproBNP (2909±273pg/ml vs. 110±20.74pg/ml, P<0.01), cTnI (2.06±1.3ng/ml vs. 0.006±0.002ng/ml, P<0.01), and fasting lipid profile (total cholesterol:216±41.2mg/dl vs.201±32.5mg/dl, P<0.05, triglycerides:217.7±63.6 mg/dl vs. 175.3±48.8 mg/dl, P<0.01, low-density lipoprotein:141.7mg/dl±41.5 vs. 127.1±30.24 mg/dl, P<0.05, very low-density lipoprotein:43.4±12.8mg/dl vs. 35.1±9.8mg/dl, P<0.01) than group II, except low levels of high-density lipoprotein (31.2±3.83mg/dl vs. 38.9±4.32 mg/dl, P<0.01). Conclusion: Assessment of NTproBNP, cTnI, and fasting lipid profile may aid in the early diagnosis of AMI and its management