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Antisocial personality disorder (ASPD) and psychopathy are related but distinguishable conditions with long histories in the mental health field. Recent years have seen a shift toward viewing these diagnostic conditions as dimensional and multifaceted, as opposed to discrete and unitary. This chapter covers historic and contemporary conceptualizations of these conditions and current approaches to assessing each. The authors describe the new dimensional system for personality disorders in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders. In addition, they discuss the triarchic model, an integrative framework for clarifying similarities and differences between ASPD and psychopathy, and guiding etiological research on these conditions. In particular, they consider how the three constructs of the triarchic model – boldness, meanness, and disinhibition – relate to distinct biobehavioral systems and measures. The chapter concludes with suggestions for future research that can help to advance our understanding of ASPD and psychopathy, with a focus on multi-method assessments and targeted treatments.
In addressing questions posed by Marcus and Nagel, the authors call attention to the variegated nature of psychopathy, highlighting its symptom subdimensions and differing manifest expressions (variants/subtypes). They discuss how the constructs of the triarchic model can be viewed both as phenotypic characteristics and as biobehavioral dispositions, and consider how these alternative perspectives can be helpful for clarifying what psychopathy “is” and “how” it develops. In responding to Lynam, they consider the sources of his criticisms as well as their content – focusing in particular on his preference for the five-factor trait model (FFM) as a descriptive framework, and the priority he places on psychopathy in its aggressive-criminal form. The authors discuss how the triarchic model complements the FFM descriptive approach through its emphasis on biobehavioral systems/processes and its ability to account for other variants of psychopathy.
There is currently tension in the field of psychopathology regarding recent scientific initiatives that seek to incorporate neurobiological concepts and measures into models of psychopathology, particularly with regard to significant methodological challenges facing such endeavors. In order to establish multimodal models of psychopathology that include brain and behavioral indicators along with report-based measures, a methodological strategy is needed for addressing basic psychometric issues common to lab-task measures. This chapter describes an iterative psychoneurometric research strategy to addressing such issues. This approach focuses on neurobehavioral traits – i.e., latent dispositions that manifest in brain and behavioral responses within lab tasks as well as in self-reported proclivities. The chapter provides an overview of this approach and illustrates its use in developing a multimodal model for inhibitory control capacity (inhibition-disinhibition), a neurobehavioral trait that confers liability for externalizing forms of psychopathology (substance problems, delinquency, and aggression) as well as internalizing disorders marked by pervasive and unregulated distress. It discusses how the psychoneurometric approach can be extended to other neurobehavioral traits (e.g., threat sensitivity) that operate as liabilities for psychopathology, and how multimodal models of core trait liabilities can serve as anchors for an integrative, measurement-based framework for understanding, assessing, and treating mental health problems.
We present a sediment-mixing process model of till genesis based on data from surface tills of the Saginaw lobe terrain in lower Michigan. Our research uses a spatial approach to understanding glacial landsystems and till genesis. We sampled calcareous till at 336 upland sites and at 17 sites in lacustrine sediment of the Saginaw Lake plain. The loamy tills have bimodal grain-size curves, with a fine-texture mode near the silt–clay boundary and a sand mode. Spatial grouping analysis suggests that tills can be divided into six groups, each with different textures and clay mineral compositions that vary systematically down-ice. The similarity among groups with respect to the silt–clay mode and clay mineralogy argues for a common origin for the fines—illite-rich lacustrine sediment of the Saginaw Lake plain. Fine-textured sediments were probably entrained, transported, and deposited down-ice as till, which also becomes sandier and enriched in kaolinite, reflecting increasing mixing with shallow sandstone bedrock with distance from the lacustrine clay source. Clayey tills on the flanks of the Saginaw terrain may reflect proglacial ponding against nearby uplands. A process model of progressive down-ice mixing of preexisting fine lake sediments with crushed/abraded sandstone bedrock helps to better explain till textures compared with a purely crushing/abrasion process model.
Restriction of access to suicide methods has been shown to effectively reduce suicide mortality rates.
To examine how the global economic crisis of 2008 and the firearm legislation reform of 1997 affected suicide and homicide mortality rate within Austria.
Official data for the years 1985–2016 for firearm certificates, suicide, homicide, unemployment rates and alcohol consumption were examined using auto regressive error and Poisson regression models.
Firearm certificates, total suicide mortality rate, suicide and homicides by firearms, and the fraction of firearm suicides/homicides among all suicides/homicides decreased after the firearm legislation reform in 1997. However, significant trend changes can be observed after 2008. The availability of firearm certificates significantly increased and was accompanied by significant changes in trends of firearm suicide and homicide rates. Concurrently, the total suicide mortality rate in 2008, for the first time since 1985, stopped its decreasing trend. While the total homicide rate further decreased, the fraction of firearm homicides among all homicides significantly increased.
The initially preventative effect of the firearm legislation reform in Austria in 1997 seems to have been counteracted by the global economic downturn of 2008. Increased firearm availability was associated with corresponding increases in both firearm suicide and firearm homicide mortality. Restrictive firearm legislation should be an imperative part of a country’s suicide prevention programme. Although firearm legislation reform may have long-lasting effects, societal changes may facilitate compensatory firearm acquisitions and thus counteract preventive efforts, calling in turn again for adapted counter-measures.
The Triarchic Psychopathy Measure (TriPM) provides Disinhibition, Boldness, and Meanness scales for assessing the three trait domains of the triarchic model. Here we examined the genetic and environmental etiology of these three domains, including evaluation of potential sex differences.
A total of 1016 men and women ages 19–20 years were drawn from the University of Southern California Risk Factors for Antisocial Behavior twin study.
Scores for the three TriPM scales were correlated to differing degrees, with the strongest phenotypic correlation between Disinhibition and Meanness. No sex differences were found in the genetic and environmental influences underlying these three domains, suggesting that the same genes and life experiences contribute to these traits in young men and women. For TriPM Disinhibition and Boldness, genetic factors explained about half or less of the variance, with the rest of the variance being explained by non-shared environmental factors. For TriPM Meanness, on the other hand, genetic, shared environmental, and non-shared environmental factors accounted for the variance. The phenotypic correlation between Disinhibition and Meanness was explained in part by common genes (26%), with the remainder attributable about equally to common shared (39%), and non-shared environmental influences (35%).
These findings contribute to our understanding of psychopathic personality traits by demonstrating the importance of heritable factors for disinhibition and boldness facets of psychopathy, and the importance of shared environmental influences for the meanness facet.
Objectives: Concussions cause diverse symptoms that are often measured through a single symptom severity score. Researchers have postulated distinct dimensions of concussion symptoms, raising the possibility that total scores may not accurately represent their multidimensional nature. This study examined to what degree concussion symptoms, assessed by the Sport Concussion Assessment Tool 3 (SCAT3), reflect a unidimensional versus multidimensional construct to inform how the SCAT3 should be scored and advance efforts to identify distinct phenotypes of concussion. Methods: Data were aggregated across two prospective studies of sport-related concussion, yielding 219 high school and college athletes in the acute (<48 hr) post-injury period. Item-level ratings on the SCAT3 checklist were analyzed through exploratory and confirmatory factor analyses. We specified higher-order and bifactor models and compared their fit, interpretability, and external correlates. Results: The best-fitting model was a five-factor bifactor model that included a general factor on which all items loaded and four specific factors reflecting emotional symptoms, torpor, sensory sensitivities, and headache symptoms. The bifactor model demonstrated better discriminant validity than the counterpart higher-order model, in which the factors were highly correlated (r=.55–.91). Conclusions: The SCAT3 contains items that appear unidimensional, suggesting that it is appropriate to quantify concussion symptoms with total scores. However, evidence of multidimensionality was revealed using bifactor modeling. Additional work is needed to clarify the nature of factors identified by this model, explicate their clinical and research utility, and determine to what degree the model applies to other stages of injury recovery and patient subgroups. (JINS, 2018, 24, 793–804)
Based on the data from the Next Generation Virgo cluster Survey (NGVS), we statistically study the photometric properties of globular clusters (GCs), ultra-compact dwarfs (UCDs) and dwarf nuclei in the Virgo core (M87) region. We found an obvious negative color (g - z) gradient in GC system associate with M87, i.e. GCs in the outer regions are bluer. However, such color gradient does not exist in UCD system, neither in dwarf nuclei system around M87. In addition, we found that many UCDs are surrounded by extended, low surface brightness envelopes. The dwarf nuclei and UCDs show different spatial distributions from GCs, with dwarf nuclei and UCDs (especially for the UCDs with visible envelopes) lying at larger distances to the Virgo center. These results support the view that UCDs (at least for a fraction of UCDs) are more tied to dwarf nuclei than to GCs.
We present the first data release of the SkyMapper Southern Survey, a hemispheric survey carried out with the SkyMapper Telescope at Siding Spring Observatory in Australia. Here, we present the survey strategy, data processing, catalogue construction, and database schema. The first data release dataset includes over 66 000 images from the Shallow Survey component, covering an area of 17 200 deg2 in all six SkyMapper passbands uvgriz, while the full area covered by any passband exceeds 20 000 deg2. The catalogues contain over 285 million unique astrophysical objects, complete to roughly 18 mag in all bands. We compare our griz point-source photometry with Pan-STARRS1 first data release and note an RMS scatter of 2%. The internal reproducibility of SkyMapper photometry is on the order of 1%. Astrometric precision is better than 0.2 arcsec based on comparison with Gaia first data release. We describe the end-user database, through which data are presented to the world community, and provide some illustrative science queries.
Currently it is estimated that about 1 billion people globally have non-alcoholic fatty liver disease (NAFLD), a condition in which liver fat exceeds 5 % of liver weight in the absence of significant alcohol intake. Due to the central role of the liver in metabolism, the prevalence of NAFLD is increasing in parallel with the prevalence of obesity, insulin resistance and other risk factors of metabolic diseases. However, the contribution of liver fat to the risk of type 2 diabetes mellitus and CVD, relative to other ectopic fat depots and to other risk markers, is unclear. Various studies have suggested that the accumulation of liver fat can be reduced or prevented via dietary changes. However, the amount of liver fat reduction that would be physiologically relevant, and the timeframes and dose–effect relationships for achieving this through different diet-based approaches, are unclear. Also, it is still uncertain whether the changes in liver fat per se or the associated metabolic changes are relevant. Furthermore, the methods available to measure liver fat, or even individual fatty acids, differ in sensitivity and reliability. The present report summarises key messages of presentations from different experts and related discussions from a workshop intended to capture current views and research gaps relating to the points above.
Background: Despite the critical role played by neurosurgeons in performing radiosurgery, neurosurgery residents in Canada have limited exposure to radiosurgery during their training. A survey of neurosurgery residents and faculty along with radiation oncology faculty was conducted to analyze perspectives regarding incorporating formal radiosurgery training into the neurosurgery residency curriculum Methods: An online survey platform was employed. Descriptive statistics were used to summarize center and respondent characteristics. Categorical variables were compared using odds ratios and corresponding 95% confidence intervals. The chi-squared test was utilized to assess statistical significance. A value of p<0.05 was considered significant Results: The response rate was 31% (119/381); 87% (102/119) of respondents were from the neurosurgical specialty and 13% (17/119) from radiation oncology. Some 46% of residents (18/40) were “very uncomfortable” with radiosurgery techniques, and 57% of faculty (42/73) believed that dedicated radiosurgery training would be beneficial though impractical. No respondents felt that “no training” would be beneficial. A total of 46% of residents (19/41) felt that this training would be beneficial and that time should be taken away from other rotations, if needed, while 58% of faculty (42/73) and 75% (28/41) of residents believed that either 1 or 1-3 months of time dedicated to training in radiosurgery would suffice Conclusions: Canadian neurosurgeons are actively involved in radiosurgery. Despite residents anticipating a greater role for radiosurgery in their future, they are uncomfortable with the practice. With the indications for radiosurgery expanding, this training gap can have serious adverse consequences for patients. Considerations regarding the incorporation and optimal duration of dedicated radiosurgery training into the Canadian neurosurgery residency curriculum are necessary.
Metsulfuron is used for POST control of spotted spurge in many warm-season
turfgrasses. A suspected resistant (R) biotype of spotted spurge was
collected from turfgrass in Georgia with a history of exclusive metsulfuron
use. Research was conducted to evaluate the resistance level of this biotype
to metsulfuron, efficacy of other mechanisms of action for control, and the
molecular basis for resistance. Compared with a susceptible (S) biotype, the
R biotype required >90 and >135 times greater metsulfuron rates to
reach 50% injury and reduce biomass 50% from the nontreated, respectively.
The R biotype was also resistant to trifloxysulfuron but was injured
equivalent to the S biotype from dicamba, glyphosate, and triclopyr. Gene
sequencing of the R biotype revealed a Trp574 to Leu substitution
that has conferred resistance to acetolactate synthase (ALS) inhibitors in
previous research. This is the first report of ALS resistance in spotted
spurge. More importantly, this is the first report of a herbicide-resistant
broadleaf weed from a turfgrass system in the United States.
A scientific community can be modeled as a collection of epistemic agents attempting to answer questions, in part by communicating about their hypotheses and results. We can treat the pathways of scientific communication as a network. When we do, it becomes clear that the interaction between the structure of the network and the nature of the question under investigation affects epistemic desiderata, including accuracy and speed to community consensus. Here we build on previous work, both our own and others’, in order to get a firmer grasp on precisely which features of scientific communities interact with which features of scientific questions in order to influence epistemic outcomes.
Here we introduce a measure on the landscape meant to capture some aspects of the difficulty of answering an empirical question. We then investigate both how different communication networks affect whether the community finds the best answer and the time it takes for the community to reach consensus on an answer. We measure these two epistemic desiderata on a continuum of networks sampled from the Watts–Strogatz spectrum. It turns out that finding the best answer and reaching consensus exhibit radically different patterns. The time it takes for a community to reach a consensus in these models roughly tracks mean path length in the network. Whether a scientific community finds the best answer, on the other hand, tracks neither mean path length nor clustering coefficient.