A Linear Poisson Autoregressive Model: The Poisson AR(p) Model

Time series of event counts are common in political scienceand other social science applications. Presently, there arefew satisfactory methods for identifying the dynamics in suchdata and accounting for the dynamic processes in event countsregression. We address this issue by building on earlier workfor persistent event counts in the Poisson exponentially weightedmoving-average model (PEWMA) of Brandt et al. (American Journalof Political Science 44(4):823–843, 2000). We developan alternative model for stationary mean reverting data, thePoisson autoregressive model of order p, or PAR(p) model. Issuesof identification and model selection are also considered. Wethen evaluate the properties of this model and present bothMonte Carlo evidence and applications to illustrate.     

Artifactual injuries of the larynx produced by resuscitative intubation

Over a period of 9 months we examined a series of 50 deaths due to natural and unnatural causes in which there had been endotracheal intubation and chest compression during resuscitation at the scene or in the emergency department shortly before death. In 37 of 50 cases (74%) there were airway injuries directly resulting from the intubation procedure which we documented using a standardized protocol and photography. Specific airway injuries, ranging from petechiae to contusions, included oral injury (28%), posterior pharyngeal injury (16%), epiglottic injury (22%), piriform recess injury (12%), laryngeal and tracheal mucosa injury (64%), strap muscle hemorrhage (14%), and cutaneous injury of the neck (4%). In addition, we recorded the presence of facial (6%) and conjunctival petechiae (21%) and attributed these changes to resuscitative chest compression. No cases had associated fractures of the hyoid or thyroid cartilage. Based on our findings, we conclude that resuscitative intubation can cause artifactual injury that may mimic inflicted injuries caused by neck compression, including strangulation and neck holds.     

Late-form hemorrhagic disease of the newborn: a fatal case report with illustration of investigations that may assist in avoiding the mistaken diagnosis of child abuse

Hemorrhagic disease of the newborn (HDN) is usually a self-limiting hemorrhagic disorder of childhood that occurs as a result of vitamin K deficiency. It may be defined as early or late form depending on the time of onset related to birth. HDN is recognized as one of several bleeding disorders that can mimic the findings of nonaccidental head injury and may lead to a mistaken diagnosis of child abuse. We present a single fatal case of late-onset HDN with illustration of hematologic assays that can be performed to assist the pathologist in making the correct diagnosis of HDN.     

Evaluating the Dimensionality and Invariance of ”Low Self-Control”

According to Gottfredson and Hirschi's (1990) A General Theory ofCrime, all illegal activity is the manifestation of a single underlyingcause. The authors argue that inadequate child-rearing causes individualsto develop a similar type of propensity for criminal and analogousbehavior. Gottfredson and Hirschi label this characteristiclow self-control. Six dimensions, which can be identified intheir theory, are suggested to comprise a final low self-controltrait. Further, low self-control is proposed to be an invariantcharacteristic (i.e., its form does not change with the age of theindividual or context in which the person resides). In this research, weevaluate these two propositions. First, the six dimensions are measured andused to determine if a multidimensional model can explain another commonfactor—low self-control—in two samples of individuals (fromdifferent locales) with dissimilar mean ages. Second, low self-control inboth samples is tested for invariance. We test the proposed invariance oflow self-control by examining if the parameter values in a model, which isreflective of Gottfredson and Hirschi's conceptualization of thecharacteristic, differ across the two samples of individuals. The resultssupport both of Gottfredson and Hirschi's propositions. Lowself-control does appear to be a multidimensional characteristic whosedimensions represent another common factor. Low self-control also appears tobe an invariant latent trait that members of these two samplespossess. These tests help to clarify Gottfredson and Hirschi'sconceptualization of low self-control.     

The Service Sector's Acquisition and Development of Information Technology: Infrastructure and Productivity

The paper explains why the productivity of information technology (IT) in the service sector of the U.S. economy is increased by the provision of infratechnology. The size and growth of the service sector and its investment in IT are discussed, and a key fact and a key inference are developed. The fact: The absorption costs of IT are the vast majority of the IT investment costs to the service sector. The inference: Infratechnology investments are an efficient way to increase both private and social benefits of incurring the cost of implementing IT.