1,785 research outputs found
Restorative Federal Criminal Procedure
A Review of Until We Reckon: Violence, Mass Incarceration, and a Road to Repair. by Danielle Sered
Impulsive Choice, Alcohol Self-administration, and Pre-exposure to Reward Delay
Impulsive choice (i.e., preference for smaller, sooner over larger, later rewards) is cross-sectionally and longitudinally associated with drug dependence in humans. Similarly, impulsive choice is associated with greater drug self-administration in rodents. These findings suggest that impulsive choice plays a causal role in drug use. However, little research has been designed to experimentally test this hypothesis or the boundary conditions under which it may operate.
The research reported in this document examined the relation between impulsive choice and alcohol consumption in rats. We developed and refined an experimental method, in which rats were pre-exposed to delayed rewards, to produce trait-like reductions in impulsive choice. We then examined the effects of this manipulation on subsequent alcohol consumption. If impulsive choice is causally related to alcohol consumption in this rodent model, then reduction of impulsive choice should be accompanied by a reduction in alcohol consumption. However, in the experiment presented in Chapter 2, reductions in impulsive choice for food rewards were accompanied by unexpected increases in alcohol consumption. Accordingly, the goals of the experiments in Chapters 3 and 4 were to help determine the conditions that produced this unexpected finding.
Results reported in Chapters 3 and 4 suggest that the unexpected results reported in Chapter 2 were dependent on the way in which alcohol was introduced in that experiment and perhaps other variables specific to orally consumed alcohol (e.g., taste, slow onset of pharmacological effects). Moreover, in Chapter 3, examination of our own and newly reported data suggests that the naturally occurring relation between impulsive choice and alcohol consumption in rodents is not as robust as it is for other drugs of abuse (e.g., psychostimulants, such as cocaine or nicotine). Nonetheless, the work reported in these experiments developed a method of reducing impulsive choice which may be used in future research to examine its related effects on consumption of other drugs of abuse
Effects of the Novel NMDA Receptor Antagonist Gacyclidine on Recovery From Medial Frontal Cortex Contusion Injury in Rats
Gacyclidine, a novel, noncompetitive NMDA receptor antagonist, was injected (i.v.) into rats at three different doses to determine if the drug could promote behavioral recovery and reduce the behavioral and anatomical impairments that occur after bilateral contusions of the medial frontal cortex (MFC). In the Morris water maze,contused rats treated with gacyciidine at a dosage of 0.1 mg/kg performed better than their vehicle-treated conspecifics. Rats given gacyclidine at either 0,3 or 0.03 mg/kg performed better than brain-injured controls, but not as well as those treated with 0.1 mg/kg. Counts of surviving neurons in the nucleus basalis magnoceilularis (NBM) and the medial dorsal nucleus (MDN) of the thalamus were used to determine whether gacyclidine treatment attenuated secondary cell death. In both the NBM and the MDN, the counts revealed fewer surviving neurons in untreated contused rats than in gacyclidine-treated rats. Increases in the size and number of microglia and astrocytes were observed in the striatum of gacyclidinetreated contused brains. Although most consequences of MFC contusions were attenuated, we still observed increases in ventricle dilation and thinning of the cortex. In fact, the ventricles of rats treated with 0.1 mg/kg of gacyclidine were larger than those of their vehicle treated counterparts, although we observed no behavioral impairment
What does it take to learn in next generation learning spaces?
This chapter identifies the attributes that learners need in order to learn effectively in new technology rich educational environments. There are a number of different ways of synthesising the findings from this emerging literature which relies heavily on qualitative research. This chapter reports on a literature review which adopted a deliberately interpretative qualitative meta-analysis, synthesising the findings from 15 key studies. As such, the chapter demonstrates a way of reviewing and compiling current research. The synthesis resulted in the identification of six attributes that learners need to do well in next generation learning spaces. These are: engaged, connected, confident, adaptable, intentional and self-aware. Although some of these attributes are applicable to all learning contexts, those of being connected, confident, adaptable and intentional seem to be particularly important in learning in next generation learning spaces. The challenge is to design learning activities that encourage and reward the development of these attributes. The hope is that through both its findings and its method, this chapter provokes debate on what it now means to be a successful learner in today’s technology rich world
Size-dependent rheology of type-I collagen networks
We investigate the system size dependent rheological response of branched
type I collagen gels. When subjected to a shear strain, the highly
interconnected mesh dynamically reorients, resulting in overall stiffening of
the network. When a continuous shear strain is applied to a collagen network,
we observe that the local apparent modulus, in the strain-stiffening regime, is
strongly dependent on the gel thickness. In addition, we demonstrate that the
overall network failure is determined by the ratio of the gel thickness to the
mesh size. These findings have broad implications for cell-matrix interactions,
the interpretation of rheological tissue data, and the engineering of
biomimetic scaffolds.Comment: 3 pages, 4 figures, to appear in Biophysical Journal Letters,
September 201
The Long-Term Impact of Physical and Emotional Trauma: The Station Nightclub Fire
Background: Survivors of physical and emotional trauma experience enduring occupational, psychological and quality of life impairments. Examining survivors from a large fire provides a unique opportunity to distinguish the impact of physical and emotional trauma on long-term outcomes. The objective is to detail the multi-dimensional long-term effects of a large fire on its survivor population and assess differences in outcomes between survivors with and without physical injury. Methods and Findings: This is a survey-based cross-sectional study of survivors of The Station fire on February 20, 2003. The relationships between functional outcomes and physical injury were evaluated with multivariate regression models adjusted for pre-injury characteristics and post-injury outcomes. Outcome measures include quality of life (Burn Specific Health Scale–Brief), employment (time off work), post-traumatic stress symptoms (Impact of Event Scale–Revised) and depression symptoms (Beck Depression Inventory). 104 fire survivors completed the survey; 47% experienced a burn injury. There was a 42% to 72% response rate range. Although depression and quality of life were associated with burn injury in univariate analyses (p<0.05), adjusted analyses showed no significant relationship between burn injury and these outcomes (p = 0.91; p = .51). Post-traumatic stress symptoms were not associated with burn injury in the univariate (p = 0.13) or adjusted analyses (p = 0.79). Time off work was the only outcome in which physical injury remained significant in the multivariate analysis (p = 0.03). Conclusions: Survivors of this large fire experienced significant life disruption, including occupational, psychological and quality of life sequelae. The findings suggest that quality of life, depression and post-traumatic stress outcomes are related to emotional trauma, not physical injury. However, physical injury is correlated with employment outcomes. The long-term impact of this traumatic event underscores the importance of longitudinal and mental health care for trauma survivors, with attention to those with and without physical injuries
Choice Bundling Increases Valuation of Delayed Losses More Than Gains in Cigarette Smokers
Choice bundling, in which a single choice produces a series of repeating consequences over time, increases valuation of delayed monetary and non-monetary gains. Interventions derived from this manipulation may be an effective method for mitigating the elevated delay discounting rates observed in cigarette smokers. No prior work, however, has investigated whether the effects of choice bundling generalize to reward losses. In the present study, an online panel of cigarette smokers (N = 302), recruited using survey firms Ipsos and InnovateMR, completed assessments for either monetary gains or losses (randomly assigned). In Step 1, participants completed a delay-discounting task to establish Effective Delay 50 (ED50), or the delay required for an outcome to lose half of its value. In Step 2, participants completed three conditions of an adjusting-amount task, choosing between a smaller, sooner (SS) adjusting amount and a larger, later (LL) fixed amount. The bundle size (i.e., number of consequences) was manipulated across conditions, where a single choice produced either 1 (control), 3, or 9 consequences over time (ascending/descending order counterbalanced). The delay to the first LL amount in each condition, as well as the intervals between all additional SS and LL amounts (where applicable), were set to individual participants’ ED50 values from Step 1 to control for differences in discounting of gains and losses. Results from Step 1 showed significantly higher ED50 values (i.e., less discounting) for losses compared to gains (p \u3c 0.001). Results from Step 2 showed that choice bundling significantly increased valuation of both LL gains and losses (p \u3c 0.001), although effects were significantly greater for losses (p \u3c 0.01). Sensitivity analyses replicated these conclusions. Future research should examine the potential clinical utility of choice bundling, such as development of motivational interventions that emphasize both the bundled health gains associated with smoking cessation and the health losses associated with continued smoking
Alkaline-stable nickel manganese oxides with ideal band gap for solar fuel photoanodes
Combinatorial (photo)electrochemical studies of the (Ni–Mn)O_x system reveal a range of promising materials for oxygen evolution photoanodes. X-ray diffraction, quantum efficiency, and optical spectroscopy mapping reveal stable photoactivity of NiMnO_3 in alkaline conditions with photocurrent onset commensurate with its 1.9 eV direct band gap. The photoactivity increases upon mixture with 10–60% Ni_6MnO_8 providing an example of enhanced charge separation via heterojunction formation in mixed-phase thin film photoelectrodes. Density functional theory-based hybrid functional calculations of the band edge energies in this oxide reveal that a somewhat smaller than typical fraction of exact exchange is required to explain the favorable valence band alignment for water oxidation
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