319 research outputs found

    Legislation Review and Recommendations to Reduce Evasion of Kentucky Road Fund Revenues

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    Kentucky, like other states, is facing fiscal challenges in providing expanding public services demanded by citizens. One danger of constrained fiscal resources and shortsighted political horizons is the tendency to neglect the investment and maintenance of long-term infrastructures like highways. The Kentucky road fund protects against these dangers by providing earmarked resources for the state\u27s roadways, insuring that basic infrastructure needs are met. However, evasion of road fund revenues decreases the funds available to meet the needs of Kentucky\u27s transportation infrastructure. For these reasons, the Kentucky Transportation Cabinet is interested in developing policy recommendations intended to mitigate evasion of road fund revenues. This report compliments the final report The Motor Fuel Tax Evasion Issue in Kentucky, 1996 (KYSPR 93-153) which identifies potential concerns in the nature and causes of road fund tax evasion. This current study constitutes an informal report that is complimentary to research report KTC-96-16. Moreover, it provides additional detail regarding the legislative action that addresses fuel tax evasion in the southern region. This report also develops estimates of the revenues lost through evasion in vehicle registration and licensing in the Commonwealth. The Federal Highway Trust and the Kentucky road fund were established to provide earmarked resources for maintaining and building federal and state roadways. Two major sources of the revenues for the Kentucky road fund are the motor fuels tax and vehicle licensing and registration fees/taxes. Evasion of these revenues diminishes the resources available to maintaining and building state roadways. There are three studies that have estimated the fuel tax revenue lost through evasion. The U.S. Department of Transportation estimated that evasion of the gasoline tax is between three and seven percent of the gallons consumed nationally, while diesel fuel tax evasion is 15 to 25 percent of gallons consumed nationally. Evidence of fuel tax evasion is provided in the Council of State Governments (CSG) study that estimated nearly 1.2 billion dollars of aggregate state fuel tax revenue was evaded in fiscal year 1993. Estimates of the fuel tax evasion occurring in Kentucky are provided in the KTC final report The Motor Fuel Tax Evasion Issue in Kentucky (1996). This study estimates that up to 20 million dollars of Kentucky fuel tax revenue was potentially evaded in fiscal year 1993. Estimates of revenue lost through evasion of vehicle registration and licensing are less common. The CSG report estimated that between 421 to 654 million dollars of aggregate state revenue from licensing and registration were evaded in fiscal year 1993. Similar analysis is applied to obtain the evasion losses of Kentucky vehicle registration and the associated ad valorem taxes as reported in Appendix B. The estimation predicts that over 239 thousand vehicles were unregistered in Kentucky in 1994, resulting in a road fund revenue loss that approach 50 million dollars

    Validating soil denitrification models based on laboratory N2 and N2O fluxes and underlying processes derived by stable isotope approaches: concept, methods and regulation of measured fluxes

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    Robust denitrification data suitable to validate soil N2 fluxes in denitrification models are scarce due to methodical limitations and the extreme spatio-temporal heterogeneity of denitrification in soils. Numerical models have become essential tools to predict denitrification at different scales. Model performance could either be tested for total gaseous flux (NO + N2O + N2), individual denitrification products (e.g. N2O and/or NO) or for the effect of denitrification factors (e.g. C-availability, respiration, diffusivity, anaerobic volume, etc.). While there are numerous examples for validating N2O fluxes, there are neither robust field data of N2 fluxes nor sufficiently resolved measurements of control factors used as state variables in the models. Here we present the concept, methods and first results of collecting model validation data. This is part of the coordinated research unit “Denitrification in Agricultural Soils: Integrated Control and Modelling at Various Scales” (DASIM). Novel approaches are used including analysis of stable isotopes, microbial communities, pore structure and organic matter fractions to provide denitrification data sets comprising as much detail on activity and regulation as possible. This will be the basis to validate existing and calibrate new denitrification models that are applied and/or developed by DASIM subprojects. To allow model testing in a wide range of conditions, denitrification control factors are varied in the initial settings (pore volume, plant residues, mineral N, pH) but also over time, where moisture, temperature, and mineral N are manipulated according to typical time patterns in the field. This is realized by including precipitation events, fertilization (via irrigation), drainage (via water potential) and temperature in the course of incubations. Moreover, oxygen concentration is varied to simulate anaerobic events. The 15N gas flux method is employed to quantify N2 and N2O emissions from various pools and processes

    Fast MAP Search for Compact Additive Tree Ensembles (CATE)

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    Cervicothoracic Intradural Arachnoid Cyst Misdiagnosed as Motor Neuron Disease

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    Recognizing syndromes which mimic ALS is crucial both to avoid giving this diagnosis erroneously and since there may be appropriate treatments. We report a 63-year-old woman diagnosed with possible ALS five years ago based on upper and lower motor neuron signs with typical electrophysiology and normal cranial MRI. At reassessment, spinal MRI revealed a cervicothoracic cyst with cord compression that was successfully treated neurosurgically. Histopathology confirmed an arachnoid origin as suspected from MRI. Spinal cysts may mimic ALS and need to be thoroughly excluded by appropriate imaging

    Comparative studies on the structure of an upland African stream ecosystem

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    Upland stream systems have been extensively investigated in Europe, North America and Australasia and many of the central ideas concerning their function are based on these systems. One central paradigm, the river continuum concept is ultimately derived from those North American streams whose catchments remain forested with native vegetation. Streams of the tropics may or may not fit the model. They have been little studied. The Amani Nature Reserve in the East Usambara Mountains of north-eastern Tanzania offers an opportunity to bring these naturally forested systems to the attention of the ecological community. This article describes a comparison made between two lengths of the River Dodwe in this area. The work was carried out by a group of postgraduate students from eighteen European and African countries with advice from five staff members, as part of a course organised by the Tropical Biology Association. Rigorous efforts were made to standardise techniques, in a situation where equipment and laboratory facilities were very basic, through a management structure and deliberate allocation of work to specialists in each area.The article offers a summary of invertebrate communities found in the stream and its biomass. Crabs seem to be the key organism in both sections of the streams

    Statistical methods to correct for verification bias in diagnostic studies are inadequate when there are few false negatives: a simulation study

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    <p>Abstract</p> <p>Background</p> <p>A common feature of diagnostic research is that results for a diagnostic gold standard are available primarily for patients who are positive for the test under investigation. Data from such studies are subject to what has been termed "verification bias". We evaluated statistical methods for verification bias correction when there are few false negatives.</p> <p>Methods</p> <p>A simulation study was conducted of a screening study subject to verification bias. We compared estimates of the area-under-the-curve (AUC) corrected for verification bias varying both the rate and mechanism of verification.</p> <p>Results</p> <p>In a single simulated data set, varying false negatives from 0 to 4 led to verification bias corrected AUCs ranging from 0.550 to 0.852. Excess variation associated with low numbers of false negatives was confirmed in simulation studies and by analyses of published studies that incorporated verification bias correction. The 2.5<sup>th </sup>– 97.5<sup>th </sup>centile range constituted as much as 60% of the possible range of AUCs for some simulations.</p> <p>Conclusion</p> <p>Screening programs are designed such that there are few false negatives. Standard statistical methods for verification bias correction are inadequate in this circumstance.</p

    Collagen VI regulates motor circuit plasticity and motor performance by cannabinoid modulation

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    Collagen VI is a key component of muscle basement membranes, and genetic variants can cause monogenic muscular dystrophies. Conversely, human genetic studies recently implicated collagen VI in central nervous system function, with variants causing the movement disorder dystonia. To elucidate the neurophysiological role of collagen VI, we generated mice with a truncation of the dystonia-related collagen alpha 3 (VI) (COL6A3) C-terminal domain (CTD). These Col6a3(CTT) mice showed a recessive dystonia-like phenotype in both sexes. We found that COL6A3 interacts with the cannabinoid receptor 1 (CB1R) complex in a CTD-dependent manner. Col6a3(CTT) mice of both sexes have impaired homeostasis of excitatory input to the basal pontine nuclei (BPN), a motor control hub with dense COL6A3 expression, consistent with deficient endocannabinoid signaling. Aberrant synaptic input in the BPN was normalized by a CB1R agonist, and motor performance in Col6a3(CTT) mice of both sexes was improved by CB1R agonist treatment. Our findings identify a readily therapeutically addressable synaptic mechanism for motor control

    Gigahertz (GHz) hard x-ray imaging using fast scintillators

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    Gigahertz (GHz) imaging technology will be needed at high-luminosity X-ray and charged particle sources. It is plausible to combine fast scintillators with the latest picosecond detectors and GHz electronics for multi-frame hard Xray imaging and achieve an inter-frame time of less than 10 ns. The time responses and light yield of LYSO, LaBr_3, BaF_2 and ZnO are measured using an MCP-PMT detector. Zinc Oxide (ZnO) is an attractive material for fast hard X-ray imaging based on GEANT4 simulations and previous studies, but the measured light yield from the samples is much lower than expected
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