ANALYSIS OF MERCURY AND LEAD IN BIRDS OF PREY FROM GOLD-MINING AREAS OF THE PERUVIAN AMAZON

This study was conducted to determine levels of lead and mercury in the raptors of the South-eastern Peruvian Amazon. The study took place within the Los Amigos Conservation Concession in Madre de Dios, Peru. Eighty-six raptors from among sixteen species were captured with Bal-Chatri traps. From each individual, feather samples were obtained for mercury analysis and blood was taken for lead analysis. Each raptor was then released without incident or injury. Mercury amalgamation for gold extraction is widely used by small-scale, transient mining operations, which are numerous along the rivers and creeks in the tropical forests and other locations in Latin America. These mining operations have a high waste output of mercury into the water and the air. Mercury which is not bound to gold is dumped into the waste water which returns to the river; and mercury which is bound to gold is later burned off to purify the gold. Once elemental mercury is released into the environment, it cannot be cleaned up. It persists for decades, even centuries after the mining has ceased. Predatory birds are useful for representing the contamination of the ecosystem at levels higher than mammalian bioindicators. The use of feathers to evaluate exposure of birds to heavy metals like mercury is a common method of analysis. During this investigation, a combination of tail and breast feathers were analyzed from each individual sampled. It was determined that 81 of the raptors sampled had elevated mercury levels, with many at or above the level known to cause reproductive symptoms in other species. No toxic reference values exist for any of the species sampled. Further study is required to determine if these levels represent a significant threat to raptors. Blood samples were analyzed for lead concentrations. Lead levels were consistant with or slightly above background levels, with the exception of one individual. This individual appeared healthy and normal upon capture, although his lead levels were consistant with those known to cause symptoms in other species. Probable causes for this individual\u27s elevated blood lead level include having survived being shot with lead shot, ot having consumed a prey item which had been shot with lead shot. The results of this study will provide insight as to the threat to raptors from mercury and lead from gold mining activity. The results will be reviewed by Peruvian agencies responsible for ecosystem monitoring. This study, among others, may lead to the control of mercury use for gold mining in the Amazon

Terrorist Attacks On Public Bus Transportation: A Preliminary Empirical Analysis, MTI Report WP 09-01

This report provides data on terrorist attacks against public bus transportation targets and serious crimes committed against such targets throughout the world. The data are drawn from the MTI database of attacks on public surface transportation, which is expanded and updated as information becomes available. This analysis is based on the database as of December 17, 2009. Data include the frequency and lethality with which buses, bus stations, and bus stops are attacked; the relationship between fatalities and attacks against bus targets and the relationship between injuries and attacks against those targets; how often, relative to other surface transportation targets, buses are attacked, first with all weapons and then with only explosive and incendiary devices; the relative lethality of attacks; and the distribution of attacks. It then presents some preliminary observations drawn from those data that can help stakeholders governments, transit managers, and employees to focus on the ways the most frequent and/or most lethal attacks are carried out as they consider measures to prevent or mitigate attacks that may be considered likely to happen in the United States

Calibration and Validation of the Checkpoint Model to the Air Force Electronic Systems Center Software Database

This research effort focused on the calibration and validation of CHECKPOINT Version 2.3.1, a computerized software cost estimating tool, to the USAF Electronic Systems Center (ESC) software database. This thesis is a direct follow-on to a 1996 CHECKPOINT study at the Air Force Institute of Technology, which successfully calibrated and validated CHECKPOINT to the SMC software database. While this research generally parallels the methodology in the aforementioned study, it offers advancements in the CHECKPOINT calibration and validation procedure, and it refines the data stratification process and the statistical analyses employed. After stratifying the ESC software database into ten usable data sets, the author calibrated and validated the CHECKPOINT model on each data set. Although the results of this study exhibited occasional improvements in estimating accuracy for both the calibration and validation subsets, the model generally failed to satisfy the accuracy criteria used to assess overall calibration success and estimating accuracy (MMRE0.75). Thus, the CHECKPOINT model was not successfully calibrated or validated to the 1997 version of the ESC database. The results of this study illuminate the need for complete, accurate and homogeneous data as a requirement for a successful calibration and validation effort

Evaluation of Moisture Damage in Warm Mix Asphalt Containing Recycled Asphalt Pavement

Warm mix asphalt (WMA) has been used worldwide for many years, primarily in Europe. The National Asphalt Pavement Association first brought WMA to the United States in 2002. By using warm mix technology, the temperature of an asphalt mixture during production, transportation, and compaction decreases dramatically. Several concerns about WMA arise due to the reduced mixing temperature. One of the primary concerns in asphalt pavement is the moisture damage. The lower mixing temperature may not be high enough to vaporize all the moisture absorbed in the aggregate, and part of the moisture may be entrapped in the pavements during compaction. This thesis presents a laboratory study to evaluate the moisture susceptibility of warm mix asphalt (WMA) produced through plant foaming procedure. Two types of mixtures were evaluated. A base mixture meeting the state of Tennessee “BM-2” mix criteria was evaluated at 0, 30, 40, and 50 percent fractionated recycled asphalt pavement (RAP), and a surface mixture meeting the state of Tennessee “411-D” mix criteria was evaluated at 15, 20, 30, 40 percent fractionated RAP. WMA mixture specimens were obtained and compacted at the asphalt plant. The WMA specimens were compared to hot-mix asphalt (HMA) specimens through a set of laboratory mixture performance tests. In addition to traditional AASHTO T283 freeze and thaw (F-T) tensile strength ratio (TSR), Superpave indirect tensile test (IDT) with F-T and MIST conditioning, and Asphalt Pavement Analyzer (APA) Hamburg wheel tracking tests were utilized to evaluate asphalt mixtures. Moisture tests indicated that with the higher inclusions of RAP, specimens exhibited lower rut depths and higher tensile strength retention. Tensile strength ratio tests indicated that HMA specimens had higher tensile strength retention when freeze thaw conditioned. Dynamic modulus conditioned specimens indicated that simple performance tests can show the difference between conditioned and unconditioned specimens. HMA specimens showed lower susceptibility to moisture compared to WMA specimens for both BM-2 and 411-D mixtures. The higher percentages of RAP in WMA and HMA in both BM-2 and 411-D mixtures showed a reduction to moisture susceptibility

Digital Video as Research Practice: Methodology for the Millennium

This essay has its origin in a project on the globalization of science that rediscovered the wisdom of past research practices through the technology of the future. The main argument of this essay is that a convergence of digital video technologies with practices of social surveillance portends a methodological shift towards a new variety of qualitative methodology. Digital video is changing the way that students of the social world practice their craft, offering not just new ways of presenting but new ways of practicing field research. We introduce concepts of the fluid wall and videoactive context to emphasize that (1) the camera is an actor in the research process, and (2) both behaviour and observation occur in both directions--in front of and behind the camera. While these practices and procedures are novel in some ways, they may also be viewed as old methods in the context of new instruments for recording as well as a new social understanding of these instruments. Since new technologies interact with the social context, the digital video methods we discuss in this essay are likely to become increasingly important for generations to come. We provide an overview of the use of digital video in research practice and present an account of the use of digital video methodology in Chile

Slower-than-Light Spin-1/2 Particles Endowed with Negative Mass Squared

Extending in a straightforward way the standard Dirac theory, we study a quantum mechanical wave-equation describing free spinning particles --which we propose to call "Pseudotachyons" (PT's)-- which behave like tachyons in the momentum space, but like subluminal particles (v<c) in the ordinary space. This is allowed since, as it happens in every quantum theory for spin-1/2 particles, the momentum operator (that is conserved) and the velocity operator (that is not) are independent operators, which refer to independent quantities. As a consequence, at variance with ordinary Dirac particles, for PT's the average velocity is not equal to the classical velocity, but actually to the velocity "dual" of the classical velocity. The speed of PT's is therefore smaller than the speed of light. Since a lot of experimental data seems to involve a negative mass squared for neutrinos, we suggest that these particles might be PT's, travelling, because of their very small mass, at subluminal speeds very close to c. The present theory is shown to be separately invariant under the C, P, T transformations; the covariance under Lorentz transformations is also proved. Furthermore, we derive the kinematical constraints linking 4-impulse, 4-velocity and 4-polarization of free PT'sComment: LaTeX; 20 page

Cholinergic suppression: A postsynaptic mechanism of long-term associative learning

Food avoidance learning in the mollusc Pleurobranchaea entails reduction in the responsiveness of key brain interneurons in the feeding neural circuitry, the paracerebral feeding command interneurons (PCNs), to the neurotransmitter acetylcholine (AcCho). Food stimuli applied to the oral veil of an untrained animal depolarize the PCNs and induce the feeding motor program (FMP). Atropine (a muscarinic cholinergic antagonist) reversibly blocks the food-induced depolarization of the PCNs, implicating AcCho as the neurotransmitter mediating food detection. AcCho applied directly to PCN somata depolarizes them, indicating that the PCN soma membrane contains AcCho receptors and induces the FMP in the isolated central nervous system preparation. The AcCho response of the PCNs is mediated by muscariniclike receptors, since comparable depolarization is induced by muscarinic agonists (acetyl-ß -methylcholine, oxotremorine, pilocarpine), but not nicotine, and blocked by muscarinic antagonists (atropine, trifluoperazine). The nicotinic antagonist hexamethonium, however, blocked the AcCho response in four of six cases. When specimens are trained to suppress feeding behavior using a conventional food-avoidance learning paradigm (conditionally paired food and shock), AcCho applied to PCNs in the same concentration as in untrained animals causes little or no depolarization and does not initiate the FMP. Increasing the concentration of AcCho 10-100 times, however, induces weak PCN depolarization in trained specimens, indicating that learning diminishes but does not fully abolish AcCho responsiveness of the PCNs. This study proposes a cellular mechanism of long-term associative learning -- namely, postsynaptic modulation of neurotransmitter responsiveness in central neurons that could apply also to mammalian species