852 research outputs found
Low-Intensity Conflict in the Peaceable Kingdom: The Attributes of International Terrorism in Canada, 1960-90
An Events Data Base on Political Terrorism in Canada: Some Conceptual and Methodological Problems
How States Facilitate Small Arms Trafficking in Africa: A Theoretical and Juristic Interpretation
Small arms’ trafficking is complex and involves a host of actors. As numerous court documents, transcripts, United Nations and NGO reports have revealed, many state institutions play a prominent role in the facilitation of, complicity in, and implicit involvement in black and grey arms trafficking. We suggest that if we are to consider the vast number of actors involved in the trafficking of small arms, the issue of controls is highly problematic, given the extent of limited applicable international legal doctrines, such as joint criminal enterprise, criminal organization, or collective criminality. Furthermore, there are broader political issues that hinder efforts of control as highlighted by the state crime literature, including issues of enforcement, political will and states’ positions to hinder the advancement of levels of accountability for their own behaviors. Consequentially, our focus here is not to empirically test the etiological factors of states complicit or implicit involvement in arms trafficking, but instead to move the discussion forward to broader theoretical and juristic issues associated with efforts to control arms trafficking. If the goal is to reduce illegal arms trafficking (and subsequent numbers of civilian deaths) policies and controls must be based, not only on the immediate or apparent actors, the role of states in the facilitation of this type of crime
Prison Research from the Inside: The Role of Convict Autoethnography
A perspective that has often been absent in criminal justice research is that of former prisoners. This article discusses the establishment, in 1997, of “convict criminology,” a group of scholars producing research informed by their experiences of crime and the criminal justice process; that is, either those who have served time themselves or who have operated alongside prisoners as professionals in custodial settings. It is argued that such scholars face similar dilemmas to others in terms of emotionalism, but suggests that their emotions are of a different nature. While an “insider” perspective cannot lay claim to scientific “objectivity,” the article argues that the existence of emotion does not invalidate an “insider” criminologist’s views. Rather, the passion engendered by the experience of incarceration can add color, context, and contour to data collection, findings, and analysis and may therefore be regarded as an essential thread in the tapestry of criminological inquiry
Single-Neuron Correlates of Error Monitoring and Post-Error Adjustments in Human Medial Frontal Cortex
Humans can self-monitor errors without explicit feedback, resulting in behavioral adjustments on subsequent trials such as post-error slowing (PES). The error-related negativity (ERN) is a well-established macroscopic scalp EEG correlate of error self-monitoring, but its neural origins and relationship to PES remain unknown. We recorded in the frontal cortex of patients performing a Stroop task and found neurons that track self-monitored errors and error history in dorsal anterior cingulate cortex (dACC) and pre-supplementary motor area (pre-SMA). Both the intracranial ERN (iERN) and error neuron responses appeared first in pre-SMA, and ∼50 ms later in dACC. Error neuron responses were correlated with iERN amplitude on individual trials. In dACC, such error neuron-iERN synchrony and responses of error-history neurons predicted the magnitude of PES. These data reveal a human single-neuron correlate of the ERN and suggest that dACC synthesizes error information to recruit behavioral control through coordinated neural activity
Comparative Analysis of Tandem Repeats from Hundreds of Species Reveals Unique Insights into Centromere Evolution
Centromeres are essential for chromosome segregation, yet their DNA sequences
evolve rapidly. In most animals and plants that have been studied, centromeres
contain megabase-scale arrays of tandem repeats. Despite their importance, very
little is known about the degree to which centromere tandem repeats share
common properties between different species across different phyla. We used
bioinformatic methods to identify high-copy tandem repeats from 282 species
using publicly available genomic sequence and our own data. The assumption that
the most abundant tandem repeat is the centromere DNA was true for most species
whose centromeres have been previously characterized, suggesting this is a
general property of genomes. Our methods are compatible with all current
sequencing technologies. Long Pacific Biosciences sequence reads allowed us to
find tandem repeat monomers up to 1,419 bp. High-copy centromere tandem repeats
were found in almost all animal and plant genomes, but repeat monomers were
highly variable in sequence composition and in length. Furthermore,
phylogenetic analysis of sequence homology showed little evidence of sequence
conservation beyond ~50 million years of divergence. We find that despite an
overall lack of sequence conservation, centromere tandem repeats from diverse
species showed similar modes of evolution, including the appearance of higher
order repeat structures in which several polymorphic monomers make up a larger
repeating unit. While centromere position in most eukaryotes is epigenetically
determined, our results indicate that tandem repeats are highly prevalent at
centromeres of both animals and plants. This suggests a functional role for
such repeats, perhaps in promoting concerted evolution of centromere DNA across
chromosomes
Persistently active neurons in human medial frontal and medial temporal lobe support working memory
Persistent neural activity is a putative mechanism for the maintenance of working memories. Persistent activity relies on the activity of a distributed network of areas, but the differential contribution of each area remains unclear. We recorded single neurons in the human medial frontal cortex and medial temporal lobe while subjects held up to three items in memory. We found persistently active neurons in both areas. Persistent activity of hippocampal and amygdala neurons was stimulus-specific, formed stable attractors and was predictive of memory content. Medial frontal cortex persistent activity, on the other hand, was modulated by memory load and task set but was not stimulus-specific. Trial-by-trial variability in persistent activity in both areas was related to memory strength, because it predicted the speed and accuracy by which stimuli were remembered. This work reveals, in humans, direct evidence for a distributed network of persistently active neurons supporting working memory maintenance
The human amygdala parametrically encodes the intensity of specific facial emotions and their categorical ambiguity
The human amygdala is a key structure for processing emotional facial expressions, but it remains unclear what aspects of emotion are processed. We investigated this question with three different approaches: behavioural analysis of 3 amygdala lesion patients, neuroimaging of 19 healthy adults, and single-neuron recordings in 9 neurosurgical patients. The lesion patients showed a shift in behavioural sensitivity to fear, and amygdala BOLD responses were modulated by both fear and emotion ambiguity (the uncertainty that a facial expression is categorized as fearful or happy). We found two populations of neurons, one whose response correlated with increasing degree of fear, or happiness, and a second whose response primarily decreased as a linear function of emotion ambiguity. Together, our results indicate that the human amygdala processes both the degree of emotion in facial expressions and the categorical ambiguity of the emotion shown and that these two aspects of amygdala processing can be most clearly distinguished at the level of single neurons
- …