61 research outputs found
Sentencing Guidelines and Judicial Discretion: Quasi-experimental Evidence from Human Calculation Errors
There is a debate about whether advisory non-binding sentencing guidelines affect the sentences outcomes of individuals convicted in jurisdictions with this sentencing framework. Identifying the impact of sentencing guidelines is a difficult empirical problem because court actors may have preferences for sentencing severity that are correlated with the preferences that are outlined in the guidelines. But, in Maryland, ten percent of the recommended sentences computed in the guideline worksheets contain calculation errors. We use this unique source of quasi-experimental variation to quantify the extent to which sentencing guidelines influence policy outcomes. Among drug offenses, we find that the direct impact of the guidelines is roughly œ the size of the overall correlation between recommendations and outcomes. For violent offenses, we find the same œ discount for sentence recommendations that are higher than they should have been, but more responsiveness to recommendations that are too low. We find no evidence that the guidelines themselves directly affect discretion for property offenders, perhaps because judges generally have substantial experience with property cases and therefore do not rely on the errant information. Sentences are more sensitive to both accurate and inaccurate recommendations for crimes that occur less frequently and have more complicated sentencing. This suggests that when the court has more experience, the recommendations have less influence. More tentative findings suggest that, further down the decision chain, parole boards counteract the remaining influence of the guidelines.
Law vs. War: Competing Approaches to Fighting Terrorism
The authors address one of the fundamental assumptions underlying the conduct of the War on Terrorism - the nature of our enemy, whether perpetrators of terrorist activities are criminals or soldiers (combatants). Although the United States recognizes that terrorist acts are certainly illegal, it has chosen to treat perpetrators as combatants; but much of the world, including many of our traditional allies, have opted for a purely legalistic approach. Disagreement about assumptions is not the only basis for divergent policies for confronting terrorism, but certainly explains much of our inability to agree on strategies to overcome what we recognize as a serious common and persistent international problem. Their insights into how our respective cultures and histories influence our definitions, assumptions, and subsequent policy decisions can assist us to respect and learn from competing strategies. They correctly surmise that our current international struggle is too important for us to ignore assumptions underlying our own and competing ideas.https://press.armywarcollege.edu/monographs/1740/thumbnail.jp
Identifying High-Risk Intersections for Walking and Bicycling Using Multiple Data Sources in the City of San Diego
Over the last decade, demand for active transportation modes such as walking and bicycling has increased. While it is desirable to provide high levels of safety for these eco-friendly modes of travel, unfortunately, the overall percentage of pedestrian and bicycle fatalities increased from 13% to 18% of total road-related fatalities in the last decade. In San Diego County, although the total number of pedestrian and bicyclist fatalities decreased over the same period of time, a similar trend with a more drastic change is observed; the overall percentage of pedestrian and bicycle fatalities increased from 19.5% to 31.8%. This study aims to estimate pedestrian and bicyclist exposure and identify signalized intersections with highest risk for walking and bicycling within the city of San Diego, California, USA. Multiple data sources such as automated pedestrian and bicycle counters, video cameras, and crash data were utilized. Data mining techniques, a new sampling strategy, and automated video processing methods were adopted to demonstrate a holistic approach that can be applied to identify facilities with highest need of improvement. Cluster analysis coupled with stratification was employed to select a representative sample of intersections for data collection. Automated pedestrian and bicycle counting models utilized in this study reached a high accuracy, provided certain conditions exist in video data. Results from exposure modeling showed that pedestrian and bicyclist volume was characterized by transportation network, population, traffic generators, and land use variables. There were both similarities and differences between pedestrian and bicycle models, including different spatial scales of influence by mode. Additionally, the study quantified risk incorporating injury severity levels, frequency of victims, distance crossed, and exposure into a single equation. It was found that not all intersections with the highest number of pedestrian and bicyclist victims were identified as high-risk after exposure and other factors such as crash severity were taken into account.
Document type: Articl
Application of Laser Mass Spectrometry to Art and Archaeology
REMPI laser mass spectrometry is a combination of resonance enhanced multiphoton ionization spectroscopy and time of flight mass spectrometry, This technique enables the collection of mass specific optical spectra as well as of optically selected mass spectra. Analytes are jet-cooled by entrainment in a molecular beam, and this low temperature gas phase analysis has the benefit of excellent vibronic resolution. Utilizing this method, mass spectrometric analysis of historically relevant samples can be simplified and improved; Optical selection of targets eliminates the need for chromatography while knowledge of a target's gas phase spectroscopy allows for facile differentiation of molecules that are in the aqueous phase considered spectroscopically indistinguishable. These two factors allow smaller sample sizes than commercial MS instruments, which in turn will require less damage to objects of antiquity. We have explored methods to optimize REMPI laser mass spectrometry as an analytical tool to archaeology using theobromine and caffeine as molecular markers in Mesoamerican pottery, and are expanding this approach to the field of art to examine laccaic acid in shellacs
Mars Tumbleweed: FY2003 Conceptual Design Assessment
NASA LaRC is studying concepts for a new type of Mars exploration vehicle that would be propelled by the wind. Known as the Mars Tumbleweed, it would derive mobility through use of the Martian surface winds. Tumbleweeds could conceivably travel greater distances, cover larger areas of the surface, and provide access to areas inaccessible by conventional vehicles. They would be lightweight and relatively inexpensive, allowing a multiple vehicle network to be deployed on a single mission. Tumbleweeds would be equipped with sensors for conducting science and serve as scouts searching broad areas to identify specific locations for follow-on investigation by other explorers. An extensive assessment of LaRC Tumbleweed concepts was conducted in FY03, including refinement of science mission scenarios, definition of supporting subsystems (structures, power, communications), testing in wind tunnels, and development of a dynamic simulation capability
Sub-micron proximal probe thermal desorption and laser mass spectrometry on painting cross-sections
Cross-sections containing organic dyes are used to demonstrate sub-micron atomic force microscopy thermal desorption (AFM-TD), followed by laser mass spectrometry
Phoenix Is Required for Mechanosensory Hair Cell Regeneration in the Zebrafish Lateral Line
In humans, the absence or irreversible loss of hair cells, the sensory mechanoreceptors in the cochlea, accounts for a large majority of acquired and congenital hearing disorders. In the auditory and vestibular neuroepithelia of the inner ear, hair cells are accompanied by another cell type called supporting cells. This second cell population has been described as having stem cell-like properties, allowing efficient hair cell replacement during embryonic and larval/fetal development of all vertebrates. However, mammals lose their regenerative capacity in most inner ear neuroepithelia in postnatal life. Remarkably, reptiles, birds, amphibians, and fish are different in that they can regenerate hair cells throughout their lifespan. The lateral line in amphibians and in fish is an additional sensory organ, which is used to detect water movements and is comprised of neuroepithelial patches, called neuromasts. These are similar in ultra-structure to the inner ear's neuroepithelia and they share the expression of various molecular markers. We examined the regeneration process in hair cells of the lateral line of zebrafish larvae carrying a retroviral integration in a previously uncharacterized gene, phoenix (pho). Phoenix mutant larvae develop normally and display a morphologically intact lateral line. However, after ablation of hair cells with copper or neomycin, their regeneration in pho mutants is severely impaired. We show that proliferation in the supporting cells is strongly decreased after damage to hair cells and correlates with the reduction of newly formed hair cells in the regenerating phoenix mutant neuromasts. The retroviral integration linked to the phenotype is in a novel gene with no known homologs showing high expression in neuromast supporting cells. Whereas its role during early development of the lateral line remains to be addressed, in later larval stages phoenix defines a new class of proteins implicated in hair cell regeneration
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
- âŠ