Guns are a ubiquitous feature of contemporary US culture, driven, at least partly, by firearms' constitutional enshrinement. However, the majority of laws intended to restrict or expand firearm ...access and use are formulated and passed in the states, leading to 50 different firearm-related legal environments. To date, little is known about why some states pass more restrictive or permissive firearm laws than others. In this article, we identify patterns of firearm law adoption across states, by framing the problem as a bipartite network (states connected to laws and laws connected to states) that is the result of a complex, and interconnected system of unobserved forces. We employ Exponential-family Random Graph Models (ERGMs), a class of statistical network models that allow for the dispensing of the assumptions of statistical independence, to identify factors that increase or decrease the likelihood of states adopting permissive or restrictive firearms laws over the period 1979 to 2020. Results show that more progressive state governments are associated with a higher chance of enacting restrictive firearm laws, and a lower chance of enacting permissive ones. Conservative state governments are associated with the analogous reversed association. States are more likely to adopt laws if bordering states have also adopted that law. For both restrictive and permissive laws the presence of a law in a neighboring state increased the conditional likelihood of a state having that law, that is laws diffuse across state borders. High levels of homicides are associated with a state having adopted more permissive, but not more restrictive, firearm laws. In summary, these results point to a complex interplay of state internal and external factors that seem to drive different patterns of firearm law adoption Based on these results, future work using related classes of models that take into account the time evolution of the network structure may provide a means to predict the likelihood of future law adoption.
Policy Points
Promoting healthy public policies is a national priority, but state policy adoption is driven by a complex set of internal and external factors.
This study employs new social network ...methods to identify underlying connections among states and to predict the likelihood of new firearm‐related policy adoption given changes to this interstate network.
This approach could be used to assess the likelihood that a given state will adopt a specific new firearm‐related law and to identify points of influence that could either inhibit or promote wider diffusion of specific laws.
Context
US states are largely responsible for the regulation of firearms within their borders. Each state has developed a different legal environment with regard to firearms based on different values and beliefs of citizens, legislators, governors, and other stakeholders. Predicting the types of firearm laws that states may adopt is therefore challenging.
Methods
We propose a parsimonious model for this complex process and provide credible predictions of state firearm laws by estimating the likelihood they will be passed in the future. We employ a temporal exponential‐family random graph model to capture the bipartite state law–state network data over time, allowing for complex interdependencies and their temporal evolution. Using data on all state firearm laws over the period 1979–2020, we estimate these models’ parameters while controlling for factors associated with firearm law adoption, including internal and external state characteristics. Predictions of future firearm law passage are then calculated based on a number of scenarios to assess the effects of a given type of firearm law being passed in the future by a given state.
Findings
Results show that a set of internal state factors are important predictors of firearm law adoption, but the actions of neighboring states may be just as important. Analysis of scenarios provide insights into the mechanics of how adoption of laws by specific states (or groups of states) may perturb the rest of the network structure and alter the likelihood that new laws would become more (or less) likely to continue to diffuse to other states.
Conclusions
The methods used here outperform standard approaches for policy diffusion studies and afford predictions that are superior to those of an ensemble of machine learning tools. The proposed framework could have applications for the study of policy diffusion in other domains.
Clozapine N-oxide (CNO) is a ligand for a powerful chemogenetic system that can selectively inhibit or activate neurons; the so-called Designer Receptors Exclusively Activated by Designer Drugs ...(DREADD) system. This system consists of synthetic G-protein-coupled receptors, which are not believed to be activated by any endogenous ligand, but are activated by the otherwise inert CNO. However, it has previously been shown that the administration of CNO in humans and rats leads to detectable levels of the bioactive compounds clozapine and
-desmethylclozapine (
-Des). As a follow-up, experiments were conducted to investigate the effects of CNO in male Long-Evans rats. It was found that 1 mg/kg CNO reduced the acoustic startle reflex but had no effect on prepulse inhibition (PPI; a measure of sensorimotor gating). CNO (2 and 5 mg/kg) had no effect on the disruption to PPI induced by the NMDA antagonist phencyclidine or the muscarinic antagonist scopolamine. In locomotor studies, CNO alone (at 1, 2, and 5 mg/kg) had no effect on spontaneous locomotion, but 5 mg/kg CNO pretreatment significantly attenuated d-amphetamine-induced hyperlocomotion. In line with the behavioral results, fast-scan cyclic voltammetry found that 5 mg/kg CNO significantly attenuated the d-amphetamine-induced increase in evoked dopamine. However, the effects seen after CNO administration cannot be definitively ascribed to CNO because biologically relevant levels of clozapine and
-Des were found in plasma after CNO injection. Our results show that CNO has multiple dose-dependent effects
and is converted to clozapine and
-Des emphasizing the need for a CNO-only DREADD-free control group when designing DREADD-based experiments.
Firearm violence is a public health crisis. Most states prohibit local firearm laws, but some states have laws that allow for lawsuits and other penalties against local governments and lawmakers who ...pass firearm laws deemed preempted. These punitive firearm preemptive laws may reduce firearm policy innovation, discussion, and adoption beyond preemption alone. Yet, it is unknown how these laws spread from state to state.
In 2022, using an event history analysis framework with state dyads, logistic regression models estimate the factors associated with adoption and diffusion of firearm punitive preemption laws, including state-level demographic, economic, legal, political, population, and state-neighbor factors.
As of 2021, 15 states had punitive firearm preemption laws. Higher numbers of background checks (AOR=1.50; 95% CI=1.15, 2.04), more conservative government ideology (AOR=7.79; 95% CI=2.05, 35.02), lower per capita income (AOR=0.16; 95% CI=0.05, 0.44), a higher number of permissive state firearm laws (AOR=2.75; 95% CI=1.57, 5.30), and neighboring state passage of the law (AOR=3.97; 95% CI=1.52, 11.51) were associated with law adoption.
Both internal and external state factors predict the adoption of punitive firearm preemption. This study may provide insight into which states are susceptible to adoption in the future. Advocates, especially in neighboring states without such laws, may want to focus their firearm safety policy efforts on opposing the passage of punitive firearm preemption.
We explore the molecular nature of doping in organic semiconductors (OSCs) by employing a liquid crystalline organic semiconductor based on phenyl naphthalene as a model. The mesophase nature of ...composites that include a charge transfer complex (
CTC
) between the OSC (
8-PNP-O12
) and an electron acceptor (
F
4
TCNQ
) has been investigated by means of differential scanning calorimetry, polarized optical microscopy and X-ray scattering. Optical and vibrational spectroscopies allow us to explore the characteristics and the amount of charge transfer in the
CTC
and expose some properties that appear only in the complexed state. We have found this system to exhibit partial charge transfer, which manifests itself in all the phase states of the host
8-PNP-O12
, as well as in solution. Due to the lowering of molecular symmetry as a result of the charge transfer, one of the previously IR-only vibrational bands of the nitrile group is found to be now active in the Raman spectrum. We have also made an attempt to further investigate the influence of dopant introduction on the bulk hole mobility of
8-PNP-O12
. It is found that the presence of the
CTC
promotes the hole transport in the Smectic B mesophase, however it seems to have a somewhat negative influence in the less ordered smectic A mesophase. This work aims to establish the link between the inevitable change of molecular geometry that occurs on charge transfer with the results obtained by spectroscopic techniques and electronic charge carrier mobility measurements.
Novel composites of mesogenic organic semiconductor and electron acceptor exhibit charge transport dynamics strongly correlated to the liquid crystal order.
Shortly after the discovery of human herpesvirus 6 (HHV-6), two distinct variants, HHV-6A and HHV-6B, were identified. In 2012, the International Committee on Taxonomy of Viruses (ICTV) classified ...HHV-6A and HHV-6B as separate viruses. This review outlines several of the documented epidemiological, biological, and immunological distinctions between HHV-6A and HHV-6B, which support the ICTV classification. The utilization of virus-specific clinical and laboratory assays for distinguishing HHV-6A and HHV-6B is now required for further classification. For clarity in biological and clinical distinctions between HHV-6A and HHV-6B, scientists and physicians are herein urged, where possible, to differentiate carefully between HHV-6A and HHV-6B in all future publications.
Background. An 18-month-old boy developed encephalopathy, for which extensive investigation failed to identify an etiology, 6 weeks after stem cell transplant. To exclude a potential infectious ...cause, we performed high-throughput RNA sequencing on brain biopsy. Methods. RNA-Seq was performed on an Illumina Miseq, generating 20 million paired-end reads. Nonhost data were checked for similarity to known organisms using BLASTx. The full viral genome was sequenced by primer walking. Results. We identified an astrovirus, HAstV-VA1/HMO-C-UK1(a), which was highly divergent from human astrovirus (HAstV 1–8) genotypes, but closely related to VA1/HMO-C astroviruses, including one recovered from a case of fatal encephalitis in an immunosuppressed child. The virus was detected in stool and serum, with highest levels in brain and cerebrospinal fluid (CSF). Immunohistochemistry of the brain biopsy showed positive neuronal staining. A survey of 680 stool and 349 CSF samples identified a related virus in the stool of another immunosuppressed child. Conclusions. The discovery of HAstV-VA1/HMO-C-UK1(a) as the cause of encephalitis in this case provides further evidence that VA1/HMO-C viruses, unlike HAstV 1–8, are neuropathic, particularly in immunocompromised patients, and should be considered in the differential diagnosis of encephalopathy. With a turnaround from sample receipt to result of <1 week, we confirm that RNA-Seq presents a valuable diagnostic tool in unexplained encephalitis.
Anatomically and functionally located between basal ganglia and brainstem circuitry, the pedunculopontine tegmental nucleus (PPTg) is in a pivotal position to contribute to motor behavior. Studies in ...primates have reported akinesia and postural instability following destruction of the PPTg. In humans, the PPTg partially degenerates in Parkinson's disease and stimulation of this region is under investigation as a possible therapeutic. Studies in rats report no crude motor impairment following PPTg lesion, although a detailed assessment of the role of the PPTg in rat motor function has not been reported. Our studies applied motor tests generally used in rodent models of Parkinson's disease to rats bearing either excitotoxic damage to all neuronal populations within PPTg, or selective destruction of the cholinergic subpopulation created with the toxin Dtx‐UII. Neither lesion type altered baseline locomotion. On the rotarod, excitotoxic lesions produced a persistent impairment on the accelerating, but not fixed speed, conditions. In the vermicelli handling task (a quantitative measure of fine motor control and effective behavioral sequencing) excitotoxic lesions produced no single impairment, but globally increased the number of normal and abnormal behaviors. In contrast, depletion of cholinergic PPTg neurons produced impairment on the accelerating rotarod but no changes in vermicelli handling. Together, these results show that while PPTg lesions produce no impairment in the execution of individual motor actions, impairments emerge when the demands of the task increase. Results are discussed in terms of PPTg acting as part of a rapid action selection system, which integrates sensory information into motor output.
In motor tests typically used to assess Parkinson's disease models, rats with either damage to all neuronal types within pedunculopontine or selective depletion of the cholinergic neuronal subpopulation did not have deficits in baseline locomotion or on fixed speed rotarod. Both lesion groups were impaired in performance on the accelerating rotarod, however, only the non‐selective lesioned rats had impairment in behavioral sequencing. Results are considered in terms of sensorimotor integration.
Causal inference over stochastic networks Clark, Duncan A; Handcock, Mark S
Journal of the Royal Statistical Society. Series A, Statistics in society,
01/2024
Journal Article
Recenzirano
Odprti dostop
Abstract
Claiming causal inferences in network settings necessitates careful consideration of the often complex dependency between outcomes for actors. Of particular importance are treatment ...spillover or outcome interference effects. We consider causal inference when the actors are connected via an underlying network structure. Our key contribution is a model for causality when the underlying network is endogenous; where the ties between actors and the actor covariates are statistically dependent. We develop a joint model for the relational and covariate generating process that avoids restrictive separability and fixed network assumptions, as these rarely hold in realistic social settings. While our framework can be used with general models, we develop the highly expressive class of Exponential-family Random Network models (ERNM) of which Markov random fields and Exponential-family Random Graph models are special cases. We present potential outcome-based inference within a Bayesian framework and propose a modification to the exchange algorithm to allow for sampling from ERNM posteriors. We present results of a simulation study demonstrating the validity of the approach. Finally, we demonstrate the value of the framework in a case study of smoking in the context of adolescent friendship networks.
Sensorimotor gating is the state‐dependent transfer of sensory information into a motor system. When this occurs at an early stage of the processing stream it enables stimuli to be filtered out or ...partially ignored, thereby reducing the demands placed on advanced systems. Prepulse inhibition (PPI) of the acoustic startle reflex (ASR) is the standard measure of sensorimotor gating. A brainstem–midbrain circuitry is widely viewed as mediating both PPI and ASR. In this circuitry, the pedunculopontine tegmental nucleus (PPTg) integrates sensory input and cortico‐basal ganglia output and, via presumed cholinergic signaling, inhibits ASR‐generating neurons within the reticular formation. Non‐selective damage to all neuronal types within PPTg reduces PPI. We assessed whether this effect originates in the loss of cholinergic signaling by examining ASR and PPI in rats bearing non‐selective (excitotoxic) or selective cholinergic (Dtx‐UII) lesions of PPTg. Excitotoxic lesions had no effect on ASR but reduced PPI at all prepulse levels tested. In contrast, selective depletion of cholinergic neurons reduced ASR to the extent that PPI was not measurable with standard (10–20 s) inter‐trial intervals. Subsequent testing revealed appreciable ASRs could be generated when the inter‐trial interval was increased (180 s). Under these conditions, PPI was assessed and no deficits were found after lesions of cholinergic PPTg neurons. These results show that cholinergic output from PPTg is essential for rapidly regenerating the ASR, but has no influence on PPI. Results are discussed in terms of sensorimotor integration circuitry and psychiatric disorders that feature disrupted ASR and PPI.
Startle responses and prepulse inhibition (PPI) were assessed after lesions of the pedunculopontine (PPTg). Non‐selective (excitotoxic) PPTg lesions impaired PPI while having no effect on acoustic startle or prepulse facilitation. Selective depletion of cholinergic PPTg neurons (Dtx‐UII lesions) dramatically impaired the ability to generate rapid sequences of startle responses. However, under conditions where stable startle responses were achieved, there were no deficits in prepulse inhibition.
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