Large-scale text processing pipeline with Apache Spark

In this paper, we evaluate Apache Spark for a data-intensive machine learning problem. Our use case focuses on policy diffusion detection across the state legislatures in the United States over time. Previous work on policy diffusion has been unable to make an all-pairs comparison between bills due to computational intensity. As a substitute, scholars have studied single topic areas. We provide an implementation of this analysis workflow as a distributed text processing pipeline with Spark dataframes and Scala application programming interface. We discuss the challenges and strategies of unstructured data processing, data formats for storage and efficient access, and graph processing at scale

Perceptions of door-to-door HIV counselling and testing in Botswana

Prevalence of HIV infection in Botswana is among the highest in the world, at 23.9% of 15 - 49-year-olds. Most HIV testing is conducted in voluntary counselling and testing centres or medical settings. Improved access to testing is urgently needed. This qualitative study assessed and documented community perceptions about the concept of door-to-door HIV counselling and rapid testing in two of the highest-prevalence districts of Botswana. Community members associated many positive benefits with home-based, door-to-door HIV testing, including convenience, confidentiality, capacity to increase the number of people tested, and opportunities to increase knowledge of HIV transmission, prevention and care through provision of correct information to households. Community members also saw the intervention as increasing opportunities to engage and influence family members and to role model positive behaviours. Participants also perceived social risks and dangers associated with home-based testing including the potential for conflict, coercion, stigma, and psychological distress within households. Community members emphasised the need for individual and community preparation, including procedures to protect confidentiality, provisions for psychological and social support, and links to appropriate services for HIV-positive persons

HMGB1 Mediates Endogenous TLR2 Activation and Brain Tumor Regression

Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor that carries a 5-y survival rate of 5%. Attempts at eliciting a clinically relevant anti-GBM immune response in brain tumor patients have met with limited success, which is due to brain immune privilege, tumor immune evasion, and a paucity of dendritic cells (DCs) within the central nervous system. Herein we uncovered a novel pathway for the activation of an effective anti-GBM immune response mediated by high-mobility-group box 1 (HMGB1), an alarmin protein released from dying tumor cells, which acts as an endogenous ligand for Toll-like receptor 2 (TLR2) signaling on bone marrow-derived GBM-infiltrating DCs. Using a combined immunotherapy/conditional cytotoxic approach that utilizes adenoviral vectors (Ad) expressing Fms-like tyrosine kinase 3 ligand (Flt3L) and thymidine kinase (TK) delivered into the tumor mass, we demonstrated that CD4(+) and CD8(+) T cells were required for tumor regression and immunological memory. Increased numbers of bone marrow-derived, tumor-infiltrating myeloid DCs (mDCs) were observed in response to the therapy. Infiltration of mDCs into the GBM, clonal expansion of antitumor T cells, and induction of an effective anti-GBM immune response were TLR2 dependent. We then proceeded to identify the endogenous ligand responsible for TLR2 signaling on tumor-infiltrating mDCs. We demonstrated that HMGB1 was released from dying tumor cells, in response to Ad-TK (+ gancyclovir [GCV]) treatment. Increased levels of HMGB1 were also detected in the serum of tumor-bearing Ad-Flt3L/Ad-TK (+GCV)-treated mice. Specific activation of TLR2 signaling was induced by supernatants from Ad-TK (+GCV)-treated GBM cells; this activation was blocked by glycyrrhizin (a specific HMGB1 inhibitor) or with antibodies to HMGB1. HMGB1 was also released from melanoma, small cell lung carcinoma, and glioma cells treated with radiation or temozolomide. Administration of either glycyrrhizin or anti-HMGB1 immunoglobulins to tumor-bearing Ad-Flt3L and Ad-TK treated mice, abolished therapeutic efficacy, highlighting the critical role played by HMGB1-mediated TLR2 signaling to elicit tumor regression. Therapeutic efficacy of Ad-Flt3L and Ad-TK (+GCV) treatment was demonstrated in a second glioma model and in an intracranial melanoma model with concomitant increases in the levels of circulating HMGB1. Our data provide evidence for the molecular and cellular mechanisms that support the rationale for the clinical implementation of antibrain cancer immunotherapies in combination with tumor killing approaches in order to elicit effective antitumor immune responses, and thus, will impact clinical neuro-oncology practice

Groups as Lawmakers: Group Bills in a US State Legislature

AbstractScholars posit that groups play an important role in the legislative process and legislator decision making, but find these questions difficult to empirically study due to the private information exchanges. This article exploits a legislative reporting institution to explore group involvement in policy making. In the California state legislature, extra-legislative individuals or organizations that write legislation and secure a legislator to author the bill may be listed as sponsors. Data come from California bill analyses and extend from 1993 to 2014. This group tactic is frequently used: 40% of bills introduced and over 60% of bills that become law list an extra-legislative sponsor. Group sponsorship is significantly related to passage, even after matching on a number of covariates. Legislators use fewer group bills and substitute out of group bills as they gain experience. Group input serves as an integral part of a legislative portfolio and the agenda-setting stage of legislative decision making.</jats:p

How Groups Write the Law: An Empirical Analysis of Group Influence in American State Legislatures

This dissertation empirically examines the role that organized groups play in drafting legislation in U.S. state legislatures. Using a large dataset, new data, and a variety of empirical tests, I measure the distribution of power across actors within and outside of legislatures. First, I examine the predictors of model legislation sponsorship within state legislatures. Using textual analysis to compare model bills with introduced and enacted state bills from 1995-2014, I detect the use of model bills in state legislatures. I test predictions derived from a model of strategic interaction between a group and legislature under varying legislative resources, ideological distance, and policy area complexity. Using variation across legislative bodies and across legislators, I test claims that legislators under greater resource constraints rely more heavily upon model legislation given the ease of introducing a prepackaged bill. Since the universe of model legislation is not well-defined, I use a unique reporting institution to examine the extent to which legislation originates from groups. In the California state legislature, extra-legislative groups that write legislation and secure a legislator to author the bill may be listed as sponsors. Data on group sponsorship come from bill analyses and extend from 1993-2014. This unstudied group tactic is frequently used: 37% of bills introduced and 59% of bills that become law list an extra-legislative sponsor. Group sponsorship is significantly related to passage, even after matching on a number of covariates. Also, legislators use fewer group bills and substitute out of group bills as they gain more experience. The final chapter of the dissertation explores the systematic changes that bills undergo as they pass through the legislature. I find that as the distance between a sponsor and median legislator increases, the original bill is altered more extensively. By examining how 199,200 bills change throughout the legislative process in various state legislatures, I study which actors' preferences are prioritized in legislative outcomes. In the first two chapters, I find that group input serves as an integral part of a legislative portfolio and the agenda-setting stage of legislative decision-making. The final chapter finds that legislators' bills change in systematic ways

Companion Bills and Cross-Chamber Collaboration in the U.S. Congress

The U.S. House and Senate were designed to have an adversarial relationship. Yet, House members and senators often collaborate on the introduction of “companion” bills. We develop a theory of these cross-chamber collaborations, which asserts that companion bill introductions are driven by legislators’ desire to increase the probability of bill passage and the relational difficulties in developing companion bill partnerships. To test the expectations emerging from our theory, we develop a novel data set of every companion bill introduction in the 111th and 112th U.S. Congress. Then, using social networking techniques, we develop an empirical model of partner selection in companion bill introduction. Our results are supportive of our expectations, and suggest that companion bills are more likely to survive chamber deliberation and are typically introduced by senior members with secure electoral margins.</jats:p

Replication Data for: Democracy by Deterrence: Norms, Constitutions, and Electoral Tilting

In contemporary democracies, backsliding typically occurs through legal machinations. Self-enforcing democracy requires that political parties refrain from exploiting legal opportunities to tilt electoral rules. Using a formal model, we argue that informal norms of mutual forbearance and formal constitutional rules are fundamentally intertwined via a logic of deterrence. By circumscribing how far each party can legally bend the rules, legal bounds create reversion points if mutual forbearance collapses. If legal bounds are symmetric between parties, they deter electoral tilting by making credible each party's threat to punish transgressions by the other. If legal bounds become sufficiently asymmetric, however, the foundations for forbearance crumble. Asymmetries emerge when some groups (a) are more vulnerable than others to legally permissible electoral distortions and (b) favored and disfavored groups sort heavily into parties. We apply this mechanism to explain gerrymandering and voting rights in the United States in the post-Civil Rights era

Replication Data for: Motivated Corporate Political Action: Evidence from an SEC Experiment

Do bureaucratic actions trigger political engagement by firms? From 2005 through 2007, the Securities and Exchange Commission (SEC) conducted a pilot study, for which they exempted a third of the stocks in the Russell 3000 Index from short-selling price restrictions. This case presents a unique opportunity to study the connection between governmental regulation and firms’ costly political engagement in an experimentally-manipulated setting. Using a difference-in-differences design, we find that firms exempted from price restrictions on short selling are more likely to lobby than the rest of the firms in the pilot study. In contrast, there is no discernible effect on treated firms' PAC contribution patterns. This study helps clarify the strategic motivations behind why firms differentially engage in political activity