Incorporating Domain Knowledge in Deep Neural Networks for Discrete Choice Models

Discrete choice models (DCM) are widely employed in travel demand analysis as a powerful theoretical econometric framework for understanding and predicting choice behaviors. DCMs are formed as random utility models (RUM), with their key advantage of interpretability. However, a core requirement for the estimation of these models is a priori specification of the associated utility functions, making them sensitive to modelers' subjective beliefs. Recently, machine learning (ML) approaches have emerged as a promising avenue for learning unobserved non-linear relationships in DCMs. However, ML models are considered "black box" and may not correspond with expected relationships. This paper proposes a framework that expands the potential of data-driven approaches for DCM by supporting the development of interpretable models that incorporate domain knowledge and prior beliefs through constraints. The proposed framework includes pseudo data samples that represent required relationships and a loss function that measures their fulfillment, along with observed data, for model training. The developed framework aims to improve model interpretability by combining ML's specification flexibility with econometrics and interpretable behavioral analysis. A case study demonstrates the potential of this framework for discrete choice analysis

How small is too small? A systematic review of center volume and outcome after cardiac transplantation

Background—The aim of this study was to assess the relationship between the volume of cardiac transplantation procedures performed in a center and the outcome after cardiac transplantation. Methods and Results—PubMed, Embase, and the Cochrane library were searched for articles on the volume–outcome relationship in cardiac transplantation. Ten studies were identified, and all adopted a different approach to data analysis and varied in adjustment for baseline characteristics. The number of patients in each study ranged from 798 to 14401, and observed 1-year mortality ranged from 12.6% to 34%. There was no association between the continuous variables of center volume and observed mortality. There was a weak association between the continuous variables of center volume and adjusted mortality up to 1 year and a stronger association at 5 years. When centers were grouped in volume categories, low-volume centers had the highest adjusted mortality, intermediate-volume centers had lower adjusted mortality, and high-volume centers had the lowest adjusted mortality but were not significantly better than intermediate-volume centers. Category limits were arbitrary and varied between studies. Conclusions—There is a relationship between center volume and mortality in heart transplantation. The existence of a minimum acceptable center volume or threshold is unproven. However, a level of 10 to 12 heart transplants per year corresponds to the upper limit of low-volume categories that may have relatively higher mortality. It is not known whether outcomes for patients treated in low-volume transplant centers would be improved by reorganizing centers to ensure volumes in excess of 10 to 12 heart transplants per year

Individual and Collective Dimensions of Resilience within Political Violence

Research has documented a link between political violence and the functioning of individuals and communities. Yet, despite the hardships that political violence creates, evidence suggests remarkable fortitude and resilience within both individuals and communities. Individual characteristics that appear to build resilience against political violence include demographic factors such as gender and age, and internal resources such as hope, optimism, determination and religious convictions. Research has also documented the protective influence of individuals’ connection to community and their involvement in work, school or political action. Additionally, research on political violence and resilience has increasingly focused on communities themselves as a unit of analysis. Community resilience, like individual resilience, is a process supported by various traits, capacities, and emotional orientations towards hardship. This review addresses various findings related to both individual and community resilience within political violence and offers recommendations for research, practice, and policy

Individual and Collective Dimensions of Resilience within Political Violence

Research has documented a link between political violence and the functioning of individuals and communities. Yet, despite the hardships that political violence creates, evidence suggests remarkable fortitude and resilience within both individuals and communities. Individual characteristics that appear to build resilience against political violence include demographic factors such as gender and age, and internal resources such as hope, optimism, determination and religious convictions. Research has also documented the protective influence of individuals’ connection to community and their involvement in work, school or political action. Additionally, research on political violence and resilience has increasingly focused on communities themselves as a unit of analysis. Community resilience, like individual resilience, is a process supported by various traits, capacities, and emotional orientations towards hardship. This review addresses various findings related to both individual and community resilience within political violence and offers recommendations for research, practice, and policy

Etiology of viral meningitis in Aleppo-Syria: a retrospective study

Background: Viruses are the most common causative agents of aseptic meningitis syndrome. This study aimed to identify the most common causes of viral meningitis (VM) by polymerase chain reaction (PCR) and study its relationship with age and seasonal variations.Methods: During the study period, the records of 129 patients who had been discharged and diagnosed with VM were identified and reviewed. Cerebrospinal fluid (CSF) samples collected from these patients were tested by PCR using the Seeplex V1 AC meningitis detection kit that detects herpes simplex virus type 1 and type 2 (HSV1) and (HSV2), varicella-zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus type 6 (HHV6), and the Seeplex V2 AC meningitis detection kit that detects human enteroviruses (EV).Results: VM was confirmed by PCR in 79 cases (61.42%). Most of the VM cases were reported in children younger than 6 years (72.15%; 57/79). EV were detected at the highest incidence of 60 cases (75.9%), followed by HSV1and EBV in 6 cases for each (7.6%, each), CMV in 3 cases (3.9%), VZV and HHV6 were detected in 2 cases for each (2.5%, each). VM cases were found to be more frequent during the spring season (64.6%; 51/79) and the peak incidence of enteroviral meningitis cases was during the spring season (68.4%; 41/60).Conclusions: Our study showed that EV were the most common causative agent of VM in Aleppo-Syria. Genotype and serotype of identified viruses are recommended

Safe introduction of ventricular assist devices into national clinical practice

IntroductionWe report the first national Scottish experience with ventricularassist- devices (VADs) in a selected group of patients for whom short-term VADs (ST-VADs) were used as a salvage ‘bridge-to-decision’ (BTD) and long-term VADs (LT-VADs) as a ‘bridge-to-transplantation/recovery’ (BTT/BTR). Method: From January 2010–July 2012, 13 (mean-age 42.4(16–62) years) INTERMACS I patients required emergency ST-VAD support as BTD and 9 (meanage 35.4(16-53) years) INTERMACS I–IV required LT-VADs as BTT/BTR.ResultsOf BTD patients, 8(61.5%) received ST-BiVADs, 3(23.1%) ST-LVADs and 2(15.4%) peripheral CentriMag ECMO. Nine(69.2%) survived to last follow-up: 1(7.7%) is on ST-VAD support, 5(45.5%) bridged to myocardial-recovery and VADexplantation, 1(9.1%) to transplantation and 2(9.1%) to LT-support. Mean durations of ST-support, renal-support and postoperative ICU-stay were 31.3(2–110), 6.6(0–31) and 35.5(1–119) days, respectively. Four(36.4%) early deaths and one after discharge. One(7.7%) stroke, 2(15.4%) acute-limb-ischemia and 6(46.2%) re-explored. No driveline-infections or device-failures. Cumulative survival was 57.1% at 4, 12 and 24 months postoperatively. Of LT-LVAD patients, 6(66.7%) remain on LT-support, 1(11.1%) bridged to myocardial-recovery and VAD-explantation, and another to transplantation. Mean postoperative ICU-stay and LT-support were 19.9(6–56) and 251.3(21–751) days, respectively. One(1.11%) patient demised after 98 days of support, 2(22.2%) suffered LVAD-induced RV failure, 2(22.2%) required re-exploration for bleeding and only one(11.1%) minor superficial driveline-infection was encountered but no device/pump failure, infection or thrombosis. Cumulative survival was 85.7% at 4, 12 and 24 months of support.ConclusionWith undue vigilance, complex VAD-therapy can be integrated safely into a national program, treating the most deranged advanced-heart-failure patients, with low rates of complications and high rates of myocardial-recovery

Posttraumatic stress disorder predicts poor health-related quality of life in cardiac patients in Palestine

BACKGROUND: The longitudinal association of posttraumatic stress disorder (PTSD) with health-related quality of life (HRQL) in cardiac patients' remains poorly studied, particularly in conflict-affected settings. MATERIALS AND METHODS: For this cohort study, we used baseline and one-year follow-up data collected from patients 30 to 80 years old consecutively admitted with a cardiac diagnosis to four major hospitals in Nablus, Palestine. All subjects were screened for PTSD and HRQL using the PTSD Checklist Specific and the HeartQoL questionnaire. We used a generalized structural equation model (GSEM) to examine the independent predictive association of PTSD at baseline with HRQL at follow-up. We also examined the mediating roles of depression, anxiety, and stress at baseline. RESULTS: The prevalence of moderate-to-high PTSD symptoms among 1022 patients at baseline was 27∙0%. Patients with PTSD symptoms reported an approximate 20∙0% lower HRQL at follow-up. The PTSD and HRQL relationship was largely mediated by depressive and anxiety symptoms. It was not materially altered by adjustment for socio-demographic, clinical, and lifestyle factors. DISCUSSION: Our findings suggest that individuals with a combination of PTSD and depression, or anxiety are potentially faced with poor HRQL as a longer-term outcome of their cardiac disease. In Palestine, psychological disorders are often stigmatized; however, integration of mental health care with cardiac care may offer an entry door for addressing psychological problems in the population. Further studies need to assess the effective mental health interventions for improving quality of life in cardiac patients

Understanding the concept and importance of the health research system in Palestine : a qualitative study

The importance of a health research system (HRS), namely an instrument for developing and enabling health systems, is increasing, particularly in developing countries. Assessing the perceptions of system performers is a necessary part of system analysis, which seeks to recognize a system's strengths and limitations aiming towards improvement. This study assesses the perceptions of policy-makers, academicians and experts regarding the HRS concept and its importance to generate insights for system strengthening. In Palestine, HRS is just emerging, helping to address the many public health-related challenges faced by the country.; The study was implemented from January until July 2016, targeting three sectors, namely relevant government institutions, schools of public health, and major local and international health agencies. Data was collected through 52 in-depth interviews and six focus group discussions (FGDs) with policy-makers, academics, directors and experts. Participants and institutions were selected based on stated criteria and peer review. Data were translated, transcribed, checked and then imported to a software program (MAXQDA 12) for thematic and content analysis.; A total of 104 experts participated, wherein 52 were interviewed and 52 participated in the six FGDs. The HRS concept, as defined by WHO, was conceptualized differently among participants with unclear delineations between various components. Inconsistencies appeared when participants attempted to conceptualize HRS in broader contexts, though HRS goals and functions were sufficiently delineated. The majority of participants agreed that HRS correlates with notions of 'improvement' and recognized HRS 'as a significant gain'. Neglect of HRS was perceived as a big loss.; The study revealed that the level of understanding of HRS among health experts in Palestine is inadequate and not sufficiently conceptualized for its application. Findings also underlined the need to establish a central governance coordination body that promotes HRS understanding, awareness and culture as an enabler for HRS strengthening

A vision to strengthen resources and capacity of the Palestinian health research system: a qualitative assessment

The World Health Organization has proposed a global strategy to build a robust Health Research System Resources and Infrastructural Capacity (HRSRIC). Despite the growing research productivity, HRSRIC in Palestine has rarely been investigated.; To analyse perceptions of health research system performers to understand the status of HRSRIC, identify its gaps, and propose policy solutions to strengthen HRSRIC.; This qualitative study targeted 3 health sectors: government, academia, and local and international organizations. Fifty-two in-depth interviews and 6 focus group discussions were conducted with key informants who were selected purposively. Data were analysed using MAXQDA 12.; Despite the availability of competent personnel, the overall HRSRIC, such as human and financial resources, and facilities, forms a central challenge. HR financing is limited, unsustainable, and flows from external and individual sources. The public and private funds are largely in shortage with resources misallocation and donors' conditionality. HR quality is moderate while knowledge transfer and translation are not well conceptualized and inappropriately performed. Lack of governance, coordination, HRSRIC strategy, resource allocation, systematic and reliable data, evidence-informed culture, and environmental impacts are the main common gaps.; The overall status of HRSRIC in Palestine is still lacking and major challenges persist where the pace of strengthening efforts is steady. There is an emphasis that strengthening HRSRIC is an imperative step and real investment opportunity for building a successful health research system. Political commitment, consolidated leadership structure, operational capacity building strengthening strategy, resources mobilization, and sovereignty are key requirements

Mapping stakeholders of the Palestinian Health Research System: a qualitative study

There is a growing international and regional interest in Health Research Systems (HRSs) in light of a global strategy for HRS stakeholders' (HRSSHs) active involvement. HRSSHs in Palestine have rarely been investigated with regard to uncertainties.; This study aimed to analyse perceptions of HRSSHs in order to understand their roles and involvement, identify gaps, and offer policy solutions for stakeholders' engagement in the Palestinian HRS.; This qualitative study targeted three local Palestinian health sectors, government, academia, and local and international agencies. Data were collected through 52 in-depth interviews (IDIs) and 6 focus group discussions (FGDs) and then analysed using MAXQDA 12 software. Participants and institutions were selected purposively based on a set of criteria and peer review.; The overall HRS stakeholders' roles were unsatisfactory, with low involvement from society, the private sector, local and international sectors. The role of academia and the Ministry of Health is vital but observed moderate in health research while that of international agencies is weak due to conflicting agendas and lack of a guiding body. Most universities have poor representation in public decision-making and scarcity in health research potential and capacity. Interest-power imbalance among stakeholders is reported where political, organizational, and technical shortfalls were indicative of weak roles and low involvement, along with a lack of health research culture, structure, resources, defined roles, and network.; Tackling the inadequate roles, interests' disparity, and poor involvement of HRSSHs is imperative for HRS strengthening. Redefining HRSSHs' roles and involving all stakeholders is key through strategic dialogue, consolidated leadership, and resource mobilization