Data-Driven Optimization of Public Transit Schedule

Bus transit systems are the backbone of public transportation in the United States. An important indicator of the quality of service in such infrastructures is on-time performance at stops, with published transit schedules playing an integral role governing the level of success of the service. However there are relatively few optimization architectures leveraging stochastic search that focus on optimizing bus timetables with the objective of maximizing probability of bus arrivals at timepoints with delays within desired on-time ranges. In addition to this, there is a lack of substantial research considering monthly and seasonal variations of delay patterns integrated with such optimization strategies. To address these,this paper makes the following contributions to the corpus of studies on transit on-time performance optimization: (a) an unsupervised clustering mechanism is presented which groups months with similar seasonal delay patterns, (b) the problem is formulated as a single-objective optimization task and a greedy algorithm, a genetic algorithm (GA) as well as a particle swarm optimization (PSO) algorithm are employed to solve it, (c) a detailed discussion on empirical results comparing the algorithms are provided and sensitivity analysis on hyper-parameters of the heuristics are presented along with execution times, which will help practitioners looking at similar problems. The analyses conducted are insightful in the local context of improving public transit scheduling in the Nashville metro region as well as informative from a global perspective as an elaborate case study which builds upon the growing corpus of empirical studies using nature-inspired approaches to transit schedule optimization.Comment: 20 pages, 6 figures, 2 table

Understanding active school travel through the Behavioural Ecological Model

Active school travel (AST) is an important source of physical activity for children and a conceptual understanding of AST is necessary to inform promotion efforts. The aim of this article is to provide a conceptual analysis of AST. All currently identified AST formulations include intra-individual variables which are often recommended as intervention targets. However, existing literature lacks clarity on precisely how these intra-individual variables might shape specific AST interventions. Moreover, evaluative studies of AST interventions typically fail to specify an underpinning theory or model. To address this limitation, the Behavioural Ecological Model (BEM), not previously addressed in AST, is presented to guide this area of research. Based on specific examples, we draw attention to the role of potential antecedents and potential reinforcers of AST, as well as potential reinforcers of motorised travel. Antecedents and reinforcers may help to explain choices of school travel mode, and to inform and increase intervention options to promote AST. Consistent with the BEM, the provision of more immediate consequences, such as fun and material prizes, is an evidence-based strategy for increasing AST which is likely to be low-cost and easier to deliver than alternative interventions. This approach to the study of AST is expected to contribute to similar analyses in this and other areas of behaviour change research, and to a more useful discussion and treatment of theoretical and conceptual behavioural models

Indian community health insurance schemes provide partial protection against catastrophic health expenditure

BACKGROUND: More than 72% of health expenditure in India is financed by individual households at the time of illness through out-of-pocket payments. This is a highly regressive way of financing health care and sometimes leads to impoverishment. Health insurance is recommended as a measure to protect households from such catastrophic health expenditure (CHE). We studied two Indian community health insurance (CHI) schemes, ACCORD and SEWA, to determine whether insured households are protected from CHE. METHODS: ACCORD provides health insurance cover for the indigenous population, living in Gudalur, Tamil Nadu. SEWA provides insurance cover for self employed women in the state of Gujarat. Both cover hospitalisation expenses, but only upto a maximum limit of US$23 and US$45, respectively. We reviewed the insurance claims registers in both schemes and identified patients who were hospitalised during the period 01/04/2003 to 31/03/2004. Details of their diagnoses, places and costs of treatment and self-reported annual incomes were obtained. There is no single definition of CHE and none of these have been validated. For this research, we used the following definition; "annual hospital expenditure greater than 10% of annual income," to identify those who experienced CHE. RESULTS: There were a total of 683 and 3152 hospital admissions at ACCORD and SEWA, respectively. In the absence of the CHI scheme, all of the patients at ACCORD and SEWA would have had to pay OOP for their hospitalisation. With the CHI scheme, 67% and 34% of patients did not have to make any out-of-pocket (OOP) payment for their hospital expenses at ACCORD and SEWA, respectively. Both CHI schemes halved the number of households that would have experienced CHE by covering hospital costs. However, despite this, 4% and 23% of households with admissions still experienced CHE at ACCORD and SEWA, respectively. This was related to the following conditions: low annual income, benefit packages with low maximum limits, exclusion of some conditions from the benefit package, and use of the private sector for admissions. CONCLUSION: CHI appears to be effective at halving the incidence of CHE among hospitalised patients. This protection could be further enhanced by improving the design of the CHI schemes, especially by increasing the upper limits of benefit packages, minimising exclusions and controlling costs

Understanding the Interplay Among Regulatory Self-Efficacy, Moral Disengagement, and Academic Cheating Behaviour During Vocational Education: A Three-Wave Study

The literature has suggested that to understand the diffusion of unethical conduct in the workplace, it is important to investigate the underlying processes sustaining engagement in misbehaviour and to study what occurs during vocational education. Drawing on social-cognitive theory, in this study, we longitudinally examined the role of two opposite dimensions of the self-regulatory moral system, regulatory self-efficacy and moral disengagement, in influencing academic cheating behaviour. In addition, in line with the theories highlighting the bidirectional relationship between cognitive processes and behaviour, we aimed to also examine the reciprocal influence of behaviour on these dimensions over time. Overall, no previous studies have examined the longitudinal interplay between these variables. The sample included 866 (62.8% female) nursing students who were assessed three times annually from the beginning of their vocational education. The findings from a cross-lagged model confirmed that regulatory self-efficacy and moral disengagement have opposite influences on cheating behaviour, that regulatory self-efficacy negatively influences not only the engagement in misconduct but also the justification mechanisms that allow the divorce between moral standards and action, and that moral disengagement and cheating behaviour reciprocally support each other over time. Specifically, not only did moral disengagement influence cheating behaviour even when controlling for its prior levels, but also cheating behaviour affected moral disengagement one year later, controlling for its prior levels. These findings suggest that recourse to wrongdoing could gradually lead to further normalising this kind of behaviour and morally desensitising individuals to misconduct

Incentivos y desincentivos de la industria farmacéutica privada para la I+D de nuevos medicamentos Incentives and disincentives for research and development of new drugs by the pharmaceutical industry

En el trabajo se desarrolló un modelo con los factores que influyen sobre la decisión de I+D de la industria farmacéutica. Los factores son el riesgo de contagio y la posibilidad de controlarlo; la letalidad y la presencia de curas o tratamientos; el ingreso; el número de personas que demandan y los costos de oportunidad de la empresa. Las empresas invertirán en mercados con demandas más inelásticas (enfermedades muy contagiosas sin posibilidad de controlar la transmisión y/o muy letales sin curas o tratamientos) y/o donde los demandantes tienen elevados ingresos y/o son numerosos. No invertirá en mercados donde sus costos marginales son superiores a sus ingresos marginales, particularmente cuando sus costos incrementan permanentemente como consecuencia del aumento del costo de oportunidad generado por lo que dejaría de ganar en otros mercados. Para estos casos, las políticas de subsidio de la I+D no son efectivas, por lo tanto, éstas deben orientarse al fortalecimiento de las investigaciones, tanto básica como aplicada, realizadas por las instituciones públicas o sin fines de lucro.<br>The authors present a model with factors that influence research and development decisions by the pharmaceutical industry: risk of disease transmission and possibility of control; case-fatality and the presence of cure or treatments; income; number of persons who demand the medicine; and opportunity costs for the company. Companies tend to invest in markets with inelastic demand (highly contagious diseases with no possibility of controlling transmission and/or very lethal diseases without treatment) and/or where there is a large population or high per capita income. Companies tend not to invest in markets where marginal costs exceed marginal income, particularly when costs increase permanently as a consequence of rising opportunity costs generated by foregoing profit in other markets. In such cases, policies to subsidize R&D are not effective, and policies must be orientated towards strengthening basic and applied research by public institutions

Porins of Haemophilus influenzae Type b mutated in loop 3 and in loop 4

Porin (341 amino acids; mass of 37,782 Da) in the outer membrane of Haemophilus influenzae type b (Hib) permits diffusion into the periplasm of small solutes up to a molecular mass of 1400 Da. Molecular modeling of Hib porin identified its structural similarities to OmpF of Escherichia coli and disclosed for Hib porin a shorter length of loop 3 and a longer length of loop 4. By sitedirected mutagenesis of the porin gene ompP2, mutant porins were constructed to contain 6 or 12 amino acid deletions either in loop 3 or in surface-exposed loop 4. Wild type Hib porin and mutant porins were expressed in a nontypeable H. influenzae strain deleted for the ompP2 gene. The mutant porins were purified and reconstituted into planar bilayers, tested for channel formation and compared with wild type Hib porin. Mutant Haemophilus porin possessing a 6-amino acid deletion in loop 3 displayed a broad distribution of single channel conductance values, while deletion of 12 amino acids from the same loop destabilized the porin channel. By comparison, deletion of 6 or of 12 amino acids from loop 4 of Hib porin resulted in an increased single channel conductance (1.15 and 1.05 nanosiemens, respectively) compared with wild type Hib porin (0.85 anosiemens). The C3 epitope of the poliovirus VP1 capsid protein was inserted either into loop 3 or into loop 4 of Hib porin. By flow cytometry, the C3 epitope was detected as surfaceexposed in strains expressing C3 insertion in loop 4; in strains expressing C3 insertion in loop 3, the epitope was inaccessible. We propose that loop 4 of Hib porin, although surface-accessible, is oriented toward the central axis of the pore and that deletions in this loop increase the single channel conductance by widening the pore entrance

Laboratory-based nationwide surveillance of antimicrobial resistance in Ghana

Japheth A Opintan,1 Mercy J Newman,1 Reuben E Arhin,1 Eric S Donkor,1 Martha Gyansa-Lutterodt,2 William Mills-Pappoe3 1Department of Medical Microbiology, School of Biomedical and Allied Health Sciences, University of Ghana, 2Pharmaceutical Services, Ministry of Health, Ghana Health Services, 3Clinical Laboratory Unit, Institutional Care Division, Ghana Health Service, Accra, Ghana Abstract: Global efforts are underway to combat antimicrobial resistance (AMR). A key target in this intervention is surveillance for local and national action. Data on AMR in Ghana are limited, and monitoring of AMR is nonexistent. We sought to generate baseline data on AMR, and to assess the readiness of Ghana in laboratory-based surveillance. Biomedical scientists in laboratories across Ghana with capacity to perform bacteriological culture were selected and trained. In-house standard operating protocols were used to perform microbiological investigations on clinical specimens. Additional microbiological tests and data analyses were performed at a centralized laboratory. Surveillance data were stored and analyzed using WHONET program files. A total of 24 laboratories participated in the training, and 1,598 data sets were included in the final analysis. A majority of the bacterial species were isolated from outpatients (963 isolates; 60.3%). Urine (617 isolates; 38.6%) was the most common clinical specimen cultured, compared to blood (100 isolates; 6.3%). Ten of 18 laboratories performed blood culture. Bacteria isolated included Escherichia coli (27.5%), Pseudomonas spp. (14.0%), Staphylococcus aureus (11.5%), Streptococcus spp. (2.3%), and Salmonella enterica serovar Typhi (0.6%). Most of the isolates were multidrug-resistant, and over 80% of them were extended-spectrum beta-lactamases-producing. Minimum inhibitory concentration levels at 50% and at 90% for ciprofloxacin, ceftriaxone, and amikacin on selected multidrug-resistant bacteria species ranged between 2 &micro;g/mL and &gt;256 &micro;g/mL. A range of clinical bacterial isolates were resistant to important commonly used antimicrobials in the country, necessitating an effective surveillance to continuously monitor AMR in Ghana. With local and international support, Ghana can participate in global AMR surveillance. Keywords: antimicrobial resistance, ESBL-producing, quinolone, multiple drug resistanc

Regolith mapping of deeply weathered terrain in savannah regions of the Birimian Lawra Greenstone Belt, Ghana

A regolith map for the Lawra Belt has been developed by categorizing the regolith-landform units by processing and interpreting remote sensing data. Regolith landform units were extracted from Landsat band ratios 3/1 and 5/4 to map ferruginous saprolite and lags; band ratio 5/7 was used to identify residual regolith and band ratio 4/2 was employed to separate ferruginous units from non-ferruginous regolith. Additional regolith landform units’ discrimination was provided by compiling and interpolating radiometric data particularly for Landsat TM poorly defined areas. SRTM images were used to mark out the extent of the alluvial plains. High topographical terrains were marked from DEM image to represent the residual areas. Regolith landform unit (RLU) map that showed residual (relict and erosional), ferruginous, and depositional domains of the Lawra Belt was developed by superimposing the extractions made from the remote sensed data. Interpretive map generated from the remote sensed image analysis was validated by first creating a non-genetic regolith map through ground truth survey. The non-genetic map based on spatial distributions of the different regolith mapping units were classified on genetic classes or regimes based on regolith-landform similarities to develop a genetic map. The interpretive and the genetic map were superimposed to develop the regolith map for the Lawra Belt. The inliers and outliers presenting compositional overlaps within broad regolith classes were rectified from the field mapping information. The combined approach of image analysis and the ground truth mapping grouped the regolith of Lawra Belt into ferruginous (F), relict (R), erosional (E) and depositional (D) regimes