Optimal team composition for tool‐based problem solving

In this paper, we construct a framework for modeling teams of agents who apply techniques or procedures (tools) to solve problems. In our framework, tools differ in their likelihood of solving the problem at hand; agents, who may be of different types, vary in their skill at using tools. We establish baseline hiring rules when a manager can dictate tool choice and then derive results for strategic tool choice by team members. We highlight three main findings: First, that cognitively diverse teams are more likely to solve problems in both settings. Second, that teams consisting of types that master diverse tools have an indirect strategic advantage because tool diversity facilitates coordination. Third, that strategic tool choice creates counterintuitive optimal hiring practices. For example, optimal teams may exclude the highest ability types and can include dominated types. In addition, optimal groups need not increase setwise. Our framework extends to cover teamwork on decomposable problems, to cases where individuals apply multiple tools, and to teams facing a flow or set of problems.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152035/1/jems12295.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152035/2/jems12295_am.pd

A mouse model of autism implicates endosome pH in the regulation of presynaptic calcium entry.

Psychoactive compounds such as chloroquine and amphetamine act by dissipating the pH gradient across intracellular membranes, but the physiological mechanisms that normally regulate organelle pH remain poorly understood. Interestingly, recent human genetic studies have implicated the endosomal Na+/H+ exchanger NHE9 in both autism spectrum disorders (ASD) and attention deficit hyperactivity disorder (ADHD). Plasma membrane NHEs regulate cytosolic pH, but the role of intracellular isoforms has remained unclear. We now find that inactivation of NHE9 in mice reproduces behavioral features of ASD including impaired social interaction, repetitive behaviors, and altered sensory processing. Physiological characterization reveals hyperacidic endosomes, a cell-autonomous defect in glutamate receptor expression and impaired neurotransmitter release due to a defect in presynaptic Ca2+ entry. Acute inhibition of synaptic vesicle acidification rescues release but without affecting the primary defect due to loss of NHE9

Redundancy in Public Transit - Vol. IV: Structure, Competition, and Reliability in Planning and Operations

In contrast to the private sector, public services in the United States are organized monopolistically. the structure of public sector monopoly has been bolstered by the conventional wisdom in public administration, which has traditionally maintained that functional duplication is wasteful. This position has recently been challenged by a small group of political scientists and economists who suggest that a redundant organizational structure can make the execution of a given program more reliable and make the design of new programs more innovative.This study examines urban transit planning and operations, subjecting these two opposing perspectives to empirical scrutiny. It was hypothesized that, during transit planning, redundant planning would increase the intensity of search for transit alternatives, and that during operations, redundant modes would increase service reliability in the face of a variety of disturbances. These propositions were examined in three case studies: (1) a study of interorganizational, redundant, transit operations in the San Francisco Bay Area; (2) a study of modally integrated, monopolistic transit operations in Washington, D.C.; and (3) a study of interorganizational competitive transit planning in Minneapolis-St. Paul. The findings follow below.The redundant transit system composed of overlapping operators proved more reliable than either of its parts. The bus agency was plagued by two long strikes; the rapid rail district, by mechanical difficulties and labor disputes. Because the two organizations are (nearly) completely independent, failures in one agency did not impair the other's functioning.The nonredundant, monopolistic system in Washington, D.C. performed more reliably than expected, largely because of the system's conservative technical design. However, there were internal management difficulties associated with efforts at modal integration. The old and ailing bus system received insufficient managerial support and attention for several years, as top management apparently perceived the organizational mission to be the completion of the rail system. This orientation resulted in a neglect of transit patrons who rode buses. There was no clear evidence that organizational merger per se saved money, although eliminating bus routes paralleling rail has saved several million dollars annually.In the case of competitive planning, in Minneapolis-St. Paul rivalry between two regional agencies presenting alternative transit designs focused public attention on fundamental choices and gave the state Legislature time for reflection and studied consideration of the issues. The competition also reduced the danger that the conclusion of system planning would be predetermined from the beginning of the process. The arguments between advocates made planning genuinely iterative; the final system design had not been envisaged by any participant. However, the competition did have certain negative effects, most importantly an excessive personalizing of transit planning. Institutionalizing rules of due process in competitive planning would decrease this problem.In sum, it seems that far more subjective confidence has been placed in the conventional wisdom of nonredundant, monopolistic public organizations than evidence warrants. the study concludes by extrapolating the findings from urban transit to evaluate the general desirability and feasibility of redundancy in government