Showing papers by "Ford Motor Company published in 2013"

Sofosbuvir for hepatitis C genotype 2 or 3 in patients without treatment options

Abstract: A B S T R AC T BACKGROUND Patients chronically infected with hepatitis C virus (HCV) genotype 2 or 3 for whom treatment with peginterferon is not an option, or who have not had a response to prior interferon treatment, currently have no approved treatment options. In phase 2 trials, regimens including the oral nucleotide polymerase inhibitor sofosbuvir have shown efficacy in patients with HCV genotype 2 or 3 infection. METHODS We conducted two randomized, phase 3 studies involving patients with chronic HCV genotype 2 or 3 infection. In one trial, patients for whom treatment with peg­ interferon was not an option received oral sofosbuvir and ribavirin (207 patients) or matching placebo (71) for 12 weeks. In a second trial, patients who had not had a response to prior interferon therapy received sofosbuvir and ribavirin for 12 weeks (103 patients) or 16 weeks (98). The primary end point was a sustained virologic response at 12 weeks after therapy. RESULTS Among patients for whom treatment with peginterferon was not an option, the rate of a sustained virologic response was 78% (95% confidence interval [CI], 72 to 83) with sofosbuvir and ribavirin, as compared with 0% with placebo (P<0.001). Among previously treated patients, the rate of response was 50% with 12 weeks of treat­ ment, as compared with 73% with 16 weeks of treatment (difference, −23 percent ­ age points; 95% CI, −35 to −11; P<0.001). In both studies, response rates were lower among patients with genotype 3 infection than among those with genotype 2 infection and, among patients with genotype 3 infection, lower among those with cirrhosis than among those without cirrhosis. The most common adverse events were headache, fatigue, nausea, and insomnia; the overall rate of discontinuation of sofosbuvir was low (1 to 2%). CONCLUSIONS In patients with HCV genotype 2 or 3 infection for whom treatment with peginter­ feron and ribavirin was not an option, 12 or 16 weeks of treatment with sofosbu­ vir and ribavirin was effective. Efficacy was increased among patients with HCV genotype 2 infection and those without cirrhosis. In previously treated patients with genotype 3 infection, 16 weeks of therapy was significantly more effective than 12 weeks. (Funded by Gilead Sciences; POSITRON and FUSION ClinicalTrials.gov numbers, NCT01542788 and NCT01604850, respectively.)

Global warming potentials and radiative efficiencies of halocarbons and related compounds: a comprehensive review

Abstract: [1] In the mid-1970s, it was recognized that chlorofluorocarbons (CFCs) were strong greenhouse gases that could have substantial impacts on radiative forcing of climate change, as well as being substances that deplete stratospheric ozone. Around a decade later, this group of radiatively active compounds was expanded to include a large number of replacements for ozone-depleting substances such as chlorocarbons, hydrochlorocarbons, hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), bromofluorocarbons, and bromochlorofluorocarbons. This paper systematically reviews the published literature concerning the radiative efficiencies (REs) of CFCs, bromofluorocarbons and bromochlorofluorocarbons (halons), HCFCs, HFCs, PFCs, sulfur hexafluoride, nitrogen trifluoride, and related halogen containing compounds. In addition, we provide a comprehensive and self-consistent set of new calculations of REs and global warming potentials (GWPs) for these compounds, mostly employing atmospheric lifetimes taken from the available literature. We also present global temperature change potentials for selected gases. Infrared absorption spectra used in the RE calculations were taken from databases and individual studies and from experimental and ab initio computational studies. Evaluations of REs and GWPs are presented for more than 200 compounds. Our calculations yield REs significantly (> 5%) different from those in the Intergovernmental Panel on Climate Change Fourth Assessment Report (AR4) for 49 compounds. We present new RE values for more than 100 gases which were not included in AR4. A widely used simple method to calculate REs and GWPs from absorption spectra and atmospheric lifetimes is assessed and updated. This is the most comprehensive review of the radiative efficiencies and global warming potentials of halogenated compounds performed to date.

Vehicle Yaw Stability Control by Coordinated Active Front Steering and Differential Braking in the Tire Sideslip Angles Domain

Abstract: Vehicle active safety receives ever increasing attention in the attempt to achieve zero accidents on the road. In this paper, we investigate a control architecture that has the potential of improving yaw stability control by achieving faster convergence and reduced impact on the longitudinal dynamics. We consider a system where active front steering and differential braking are available and propose a model predictive control (MPC) strategy to coordinate the actuators. We formulate the vehicle dynamics with respect to the tire slip angles and use a piecewise affine (PWA) approximation of the tire force characteristics. The resulting PWA system is used as prediction model in a hybrid MPC strategy. After assessing the benefits of the proposed approach, we synthesize the controller by using a switched MPC strategy, where the tire conditions (linear/saturated) are assumed not to change during the prediction horizon. The assessment of the controller computational load and memory requirements indicates that it is capable of real-time execution in automotive-grade electronic control units. Experimental tests in different maneuvers executed on low-friction surfaces demonstrate the high performance of the controller.

Online Parameterization of Lumped Thermal Dynamics in Cylindrical Lithium Ion Batteries for Core Temperature Estimation and Health Monitoring

Abstract: Lithium ion batteries should always be prevented from overheating and, hence, thermal monitoring is indispensable. Since only the surface temperature of the battery can be measured, a thermal model is needed to estimate the core temperature of the battery, which can be higher and more critical. In this paper, an online parameter identification scheme is designed for a cylindrical lithium ion battery. An adaptive observer of the core temperature is then designed based on the online parameterization methodology and the surface temperature measurement. A battery thermal model with constant internal resistance is explored first. The identification algorithm and the adaptive observer is validated with experiments on a 2.3Ah 26650 lithium iron phosphate/graphite battery. The methodology is later extended to address temperature-dependent internal resistance with nonuniform forgetting factors. The ability of the methodology to track the long-term variation of the internal resistance is beneficial for battery health monitoring.

Autonomous vehicle with driver presence and physiological monitoring

Abstract: A transportation vehicle with an autonomous driving control has a set-up mode, an active drive mode, a safe shutdown mode, and an emergency response mode. The active drive mode autonomously navigates along a driving route specified in the set-up mode. A driver sensing system senses a driver presence in the driver seat and a driver's physiological state. Active drive mode is not entered from set-up mode unless the driver is present in the driver seat and the physiological state matches a normal condition. While in active driving mode, an elapsed time period is measured whenever the driver presence is not detected. If the time period increases above a first threshold then a notice is given to the driver that the active drive mode may be interrupted. If the time period increases above a second threshold then the active drive mode is terminated and the safe shutdown mode is initiated. A sensed physiological state is compared to a predetermined emergency condition and if a match is found then the autonomous driving control terminates the active drive mode and the emergency response mode is initiated.

Life-cycle energy and greenhouse gas emission benefits of lightweighting in automobiles: review and harmonization.

Abstract: Replacing conventional materials (steel and iron) with lighter alternatives (e.g., aluminum, magnesium, and composites) decreases energy consumption and greenhouse gas (GHG) emissions during vehicl...

Evaluated kinetic and photochemical data for atmospheric chemistry: Volume VI - heterogeneous reactions with liquid substrates

Abstract: . This article, the sixth in the ACP journal series, presents data evaluated by the IUPAC Task Group on Atmospheric Chemical Kinetic Data Evaluation. It covers the heterogeneous processes involving liquid particles present in the atmosphere with an emphasis on those relevant for the upper troposphere/lower stratosphere and the marine boundary layer, for which uptake coefficients and adsorption parameters have been presented on the IUPAC website since 2009. The article consists of an introduction and guide to the evaluation, giving a unifying framework for parameterisation of atmospheric heterogeneous processes. We provide summary sheets containing the recommended uptake parameters for the evaluated processes. The experimental data on which the recommendations are based are provided in data sheets in separate appendices for the four surfaces considered: liquid water, deliquesced halide salts, other aqueous electrolytes and sulfuric acid.

Vehicle dome lighting system with photoluminescent structure

Abstract: A vehicle lighting system is provided and includes a vehicle fixture, an excitation source for emitting at least one inputted electromagnetic radiation, and a photoluminescent structure coupled to the vehicle fixture. The photoluminescent structure includes an energy conversion layer having at least one photoluminescent material formulated to convert the at least one inputted electromagnetic radiation into at least one outputted electromagnetic radiation.

Autonomous vehicle control for impaired driver

Abstract: A condition of an operator of a vehicle is detected. It is determined that the condition is an impaired condition. At least one autonomous operation is performed based on the impaired condition.

Intelligent Hybrid Vehicle Power Control—Part II: Online Intelligent Energy Management

Abstract: This is the second paper in a series of two that describe our research in intelligent energy management in a hybrid electric vehicle (HEV). In the first paper, we presented the machine-learning framework ML_EMO_HEV, which was developed for learning the knowledge about energy optimization in an HEV. The framework consists of machine-learning algorithms for predicting driving environments and generating the optimal power split of the HEV system for a given driving environment. In this paper, we present the following three online intelligent energy controllers: 1) IEC_HEV_SISE; 2) IEC_HEV_MISE ; and 3) IEC_HEV_MIME. All three online intelligent energy controllers were trained within the machine-learning framework ML_EMO_HEV to generate the best combination of engine power and battery power in real time such that the total fuel consumption over the whole driving cycle is minimized while still meeting the driver's demand and the system constraints, including engine, motor, battery, and generator operation limits. The three online controllers were integrated into the Ford Escape hybrid vehicle model for online performance evaluation. Based on their performances on ten test drive cycles provided by the Powertrain Systems Analysis Toolkit library, we can conclude that the roadway type and traffic congestion level specific machine learning of optimal energy management is effective for in-vehicle energy control. The best controller, IEC_HEV_MISE, trained with the optimal power split generated by the DP optimization algorithm with multiple initial SOC points and single ending point, can provide fuel savings ranging from 5% to 19%. Together, these two papers cover the innovative technologies for modeling power flow, mathematical background of optimization in energy management, and machine-learning algorithms for generating intelligent energy controllers for quasioptimal energy flow in a power-split HEV.

Commissioning of the Varian TrueBeam linear accelerator: a multi-institutional study.

Abstract: Purpose: Latest generation linear accelerators (linacs), i.e., TrueBeam (Varian Medical Systems, Palo Alto, CA) and its stereotactic counterpart, TrueBeam STx, have several unique features, including high-dose-rate flattening-filter-free (FFF) photon modes, reengineered electron modes with new scattering foil geometries, updated imaging hardware/software, and a novel control system. An evaluation of five TrueBeam linacs at three different institutions has been performed and this work reports on the commissioning experience. Methods: Acceptance and commissioning data were analyzed for five TrueBeam linacs equipped with 120 leaf (5 mm width) MLCs at three different institutions. Dosimetric data and mechanical parameters were compared. These included measurements of photon beam profiles (6X, 6XFFF, 10X, 10XFFF, 15X), photon and electron percent depth dose (PDD) curves (6, 9, 12 MeV), relative photon output factors (Scp), electron cone factors, mechanical isocenter accuracy, MLC transmission, and dosimetric leaf gap (DLG). End-to-end testing and IMRT commissioning were also conducted. Results: Gantry/collimator isocentricity measurements were similar (0.27–0.28 mm), with overall couch/gantry/collimator values of 0.46–0.68 mm across the three institutions. Dosimetric data showed good agreement between machines. The average MLC DLGs for 6, 10, and 15 MV photons were 1.33 ± 0.23, 1.57 ± 0.24, and 1.61 ± 0.26 mm, respectively. 6XFFF and 10XFFF modes had average DLGs of 1.16 ± 0.22 and 1.44 ± 0.30 mm, respectively. MLC transmission showed minimal variation across the three institutions, with the standard deviation <0.2% for all linacs. Photon and electron PDDs were comparable for all energies. 6, 10, and 15 MV photon beam quality, %dd(10)x varied less than 0.3% for all linacs. Output factors (Scp) and electron cone factors agreed within 0.27%, on average; largest variations were observed for small field sizes (1.2% coefficient of variation, 10 MV, 2 × 2 cm2) and small cone sizes (<1% coefficient of variation, 6 × 6 cm2 cone), respectively. Conclusions: Overall, excellent agreement was observed in TrueBeam commissioning data. This set of multi-institutional data can provide comparison data to others embarking on TrueBeam commissioning, ultimately improving the safety and quality of beam commissioning.

Prospects for the application of GaN power devices in hybrid electric vehicle drive systems

Abstract: GaN, a wide bandgap semiconductor successfully implemented in optical and high-speed electronic devices, has gained momentum in recent years for power electronics applications. Along with rapid progress in material and device processing technologies, high-voltage transistors over 600?V have been reported by a number of teams worldwide. These advances make GaN highly attractive for the growing market of electrified vehicles, which currently employ bipolar silicon devices in the 600?1200?V class for the traction inverter. However, to capture this billion-dollar power market, GaN has to compete with existing IGBT products and deliver higher performance at comparable or lower cost. This paper reviews key achievements made by the GaN semiconductor industry, requirements of the automotive electric drive system and remaining challenges for GaN power devices to fit in the inverter application of hybrid vehicles.

Nocturnal Rapid Eye Movement Sleep Latency for Identifying Patients With Narcolepsy/Hypocretin Deficiency

Abstract: Importance Narcolepsy, a disorder associated with HLA-DQB1*06:02 and caused by hypocretin (orexin) deficiency, is diagnosed using the Multiple Sleep Latency Test (MSLT) following nocturnal polysomnography (NPSG). In many patients, a short rapid eye movement sleep latency (REML) during the NPSG is also observed but not used diagnostically. Objective To determine diagnostic accuracy and clinical utility of nocturnal REML measures in narcolepsy/hypocretin deficiency. Design, Setting, and Participants Observational study using receiver operating characteristic curves for NPSG REML and MSLT findings (sleep studies performed between May 1976 and September 2011 at university medical centers in the United States, China, Korea, and Europe) to determine optimal diagnostic cutoffs for narcolepsy/hypocretin deficiency compared with different samples: controls, patients with other sleep disorders, patients with other hypersomnias, and patients with narcolepsy with normal hypocretin levels. Increasingly stringent comparisons were made. In a first comparison, 516 age- and sex-matched patients with narcolepsy/hypocretin deficiency were selected from 1749 patients and compared with 516 controls. In a second comparison, 749 successive patients undergoing sleep evaluation for any sleep disorders (low pretest probability for narcolepsy) were compared within groups by final diagnosis of narcolepsy/hypocretin deficiency. In the third comparison, 254 patients with a high pretest probability of having narcolepsy were compared within group by their final diagnosis. Finally, 118 patients with narcolepsy/hypocretin deficiency were compared with 118 age- and sex-matched patients with a diagnosis of narcolepsy but with normal hypocretin levels. Main Outcome and Measures Sensitivity and specificity of NPSG REML and MSLT as diagnostic tests for narcolepsy/hypocretin deficiency. This diagnosis was defined as narcolepsy associated with cataplexy plus HLA-DQB1*06:02 positivity (no cerebrospinal fluid hypocretin-1 results available) or narcolepsy with documented low (≤ 110 pg/mL) cerebrospinal fluid hypocretin-1 level. Results Short REML (≤15 minutes) during NPSG was highly specific (99.2% [95% CI, 98.5%-100.0%] of 516 and 99.6% [95% CI, 99.1%-100.0%] of 735) but not sensitive (50.6% [95% CI, 46.3%-54.9%] of 516 and 35.7% [95% CI, 10.6%-60.8%] of 14) for patients with narcolepsy/hypocretin deficiency vs population-based controls or all patients with sleep disorders undergoing a nocturnal sleep study (area under the curve, 0.799 [95% CI, 0.771-0.826] and 0.704 [95% CI, 0.524-0.907], respectively). In patients with central hypersomnia and thus a high pretest probability for narcolepsy, short REML remained highly specific (95.4% [95% CI, 90.4%-98.3%] of 132) and similarly sensitive (57.4% [95% CI, 48.1%-66.3%] of 122) for narcolepsy/hypocretin deficiency (area under the curve, 0.765 [95% CI, 0.707-0.831]). Positive predictive value in this high pretest probability sample was 92.1% (95% CI, 83.6%-97.0%). Conclusions and Relevance Among patients being evaluated for possible narcolepsy, short REML (≤15 minutes) at NPSG had high specificity and positive predictive value and may be considered diagnostic without the use of an MSLT; absence of short REML, however, requires a subsequent MSLT.

A Host-Based RT-PCR Gene Expression Signature to Identify Acute Respiratory Viral Infection

Abstract: Improved ways to diagnose acute respiratory viral infections could decrease inappropriate antibacterial use and serve as a vital triage mechanism in the event of a potential viral pandemic. Measurement of the host response to infection is an alternative to pathogen-based diagnostic testing and may improve diagnostic accuracy. We have developed a host-based assay with a reverse transcription polymerase chain reaction (RT-PCR) TaqMan low-density array (TLDA) platform for classifying respiratory viral infection. We developed the assay using two cohorts experimentally infected with influenza A H3N2/Wisconsin or influenza A H1N1/Brisbane, and validated the assay in a sample of adults presenting to the emergency department with fever (n = 102) and in healthy volunteers (n = 41). Peripheral blood RNA samples were obtained from individuals who underwent experimental viral challenge or who presented to the emergency department and had microbiologically proven viral respiratory infection or systemic bacterial infection. The selected gene set on the RT-PCR TLDA assay classified participants with experimentally induced influenza H3N2 and H1N1 infection with 100 and 87% accuracy, respectively. We validated this host gene expression signature in a cohort of 102 individuals arriving at the emergency department. The sensitivity of the RT-PCR test was 89% [95% confidence interval (CI), 72 to 98%], and the specificity was 94% (95% CI, 86 to 99%). These results show that RT-PCR–based detection of a host gene expression signature can classify individuals with respiratory viral infection and sets the stage for prospective evaluation of this diagnostic approach in a clinical setting.

System and method of determining occupant location using connected devices

Abstract: A vehicle computing system enabling one or more processors to establish a communication connection with at least one of a plurality of handheld computing devices within a vehicle while enabling and determining infotainment control based on the location of the handheld device in the vehicle. The system may determine if the at least one of a plurality of handheld computing devices is a driver or non-driver handheld computing device based on a detected location of the communication connection. The system may determine that the at least one of a plurality of handheld computing devices is a non-driver handheld computing device based on the detected location, therefore enabling infotainment control from the non-driver handheld device. The system may determine that the at least one of a plurality of handheld computing devices is a driver handheld computing device based on the detected location, therefore limiting infotainment control from the driver handheld device.

A statistical approach to estimating acceptance of electric vehicles and electrification of personal transportation

Abstract: The environmental and economic impact of electric vehicles (EVs) will depend on the fraction of users that can accept an EV of a given capability, and then in turn on how those EVs are actually used. Historically, estimates of the fraction of total travel that could be electrified as a function of EV range are based on vehicle usage data for large populations of vehicles, most often the National Household Travel Survey (NHTS). Two assumptions implicit in such estimates are subject to question: (1) that any user could accept an EV as a primary vehicle and would use it for all trips within its range, and (2) that the usage patterns of any individual EV user are the same as that exhibited by entire population. The first assumption is clearly unrealistic; willingness to accept an EV is dependent on the transportation needs and alternatives readily available to each individual user. As a surrogate for a priori knowledge of individual preferences, we use a crude metric of acceptance defined as a threshold frequency of need for alternative transportation above which all users would not accept the inconvenience. To test the validity of the second assumption and better estimate market and electrification potential, we analyze roughly 1 year of usage data for each of 133 instrumented vehicles in Minneapolis–St. Paul. We find a characteristic individual usage pattern that does not resemble the average over a large number of vehicles. Using the surrogate metric of EV acceptance and a simple payback model, we show that although the market acceptance and electrification potential of EVs are severely limited by battery cost, it is possible to determine an optimal EV range. Using the same usage data and payback model, we show that plug-in hybrid electric vehicles (PHEVs) can be much more effective than all-electric vehicles in electrifying personal transportation.

Trailer monitoring system and method

Abstract: A vehicle trailer backup assist system and method includes a hitch angle detection apparatus and a target monitor controller. The target monitor controller processes images acquired of the trailer towed by a towing vehicle to assist with placement of a target on the trailer. The target monitor controller also monitors the target and provides feedback to the user as to proper positioning of the target on the trailer. A target move detection routine detects movement of a target by processing the pixels of the image to determine if a new trailer has been connected. Further, a trailer connection monitoring routine monitors for a changed trailer based on loss of the hitch angle or target for a predetermined time period.

Transitioning from autonomous vehicle control to to driver control to responding to driver control

Abstract: Instructions are provided to at least one vehicle control for autonomous operation of a vehicle. A change in position is detected of at the least one vehicle control. A determination is made whether to modify operation of the vehicle at least in part according to the change in position of the at least one vehicle control. The autonomous operation of the vehicle is modified according to the change in position.

Robust Estimation of Road Frictional Coefficient

Abstract: Knowledge of tire force potential, i.e., tire-road frictional coefficient, is important for vehicle active safety systems because tire-road friction is an effective measure of the safety margin of vehicle dynamics. For vehicle handling dynamics, the frictional coefficient is highly coupled with tire slip angle, therefore, they need to be estimated simultaneously when the latter is not measured. This paper presents an estimation algorithm based on a robust adaptive observer methodology. Stability and robustness of this observer are analyzed numerically. The performance is analyzed using computer simulations and experiments under various road and steering conditions.

Predictive control of an autonomous ground vehicle using an iterative linearization approach

Abstract: This paper presents the design of a controller for an autonomous ground vehicle. The goal is to track the lane centerline while avoiding collisions with obstacles. A nonlinear model predictive control (MPC) framework is used where the control inputs are the front steering angle and the braking torques at the four wheels. The focus of this work is on the development of a tailored algorithm for solving the nonlinear MPC problem. Hardware-in-the-loop simulations with the proposed algorithm show a reduction in the computational time as compared to general purpose nonlinear solvers. Experimental tests on a passenger vehicle at high speeds on low friction road surfaces show the effectiveness of the proposed algorithm.

Investigation on Hydrogenation of Metal–Organic Frameworks HKUST-1, MIL-53, and ZIF-8 by Hydrogen Spillover

Abstract: The stabilities of three moisture-stable MOFs containing different metal clusters, i.e., HKUST-1 (Cu), MIL-53(Al), and ZIF-8 (Zn), were investigated in dihydrogen and dissociated hydrogen (caused by doped Pt nanoparticles) environments. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray-excited Auger electron spectroscopy (XAES) results showed that all three MOFs were stable in dihydrogen environment. However, the structure of Pt-doped HKUST-1 collapsed in the presence of dissociated hydrogen due to the higher reduction potential of Cu compared with H, and the degree of reduction that occurred to the divalent copper in HKUST-1 increased with temperature. Unlike HKUST-1, MIL-53 and ZIF-8 maintained their structures in both dihydrogen and dissociated hydrogen environments at temperatures up to 150 °C. Moreover, comparison of Pt-doped HKUST-1 samples synthesized by chemical vapor deposition (CVD) and incipient wetness impregnation showed that the contact between the doped Pt particles...

TEG On-Vehicle Performance and Model Validation and What It Means for Further TEG Development

Abstract: A high-temperature thermoelectric generator (TEG) was recently integrated into two passenger vehicles: a BMW X6 and a Lincoln MKT. This effort was the culmination of a recently completed Department of Energy (DOE)-sponsored thermoelectric (TE) waste heat recovery program for vehicles (award #DE-FC26-04NT42279). During this 7-year program, several generations of thermoelectric generators were modeled, designed, built, and tested at the couple, engine, and full-device level, as well as being modeled and integrated at the vehicle level. In this paper, we summarize the history of the development efforts and results achieved during the project, which is a motivation for ongoing research in this field. Results are presented and discussed for bench, engine dynamometer, and on-vehicle tests conducted on the current-generation TEG. On the test bench, over 700 W of power was produced. Over 600 W was produced in on-vehicle tests. Both steady-state and transient models were validated against the measured performance of these TEGs. The success of this work has led to a follow-on DOE-sponsored TE waste heat recovery program for passenger vehicles focused on addressing key technical and business-related topics that are meant to enable TEGs to be considered as a viable automotive product in the future.

Autonomous vehicle modes

Abstract: A vehicle operator is identified. Based at least in part on the operator's identity, one or more parameters are determined specifying a mode for autonomously operating the vehicle. The vehicle is autonomously operated at least in part according to the one or more parameters.

3-hydroxykynurenine and other Parkinson's disease biomarkers discovered by metabolomic analysis.

Abstract: Parkinson's disease (PD) biomarkers are needed to enhance therapeutics research and to understand PD pathogenesis. Methods that simultaneously measure hundreds of small molecular-weight compounds—metabolomic analysis–“fingerprint” disease-specific alterations in individual compounds or metabolic pathways. Beyond a nontargeted search for PD biomarkers, we hypothesized that PD cerebrospinal fluid would show increased formation of the excitotoxin 3-hydroxykynurenine and diminished concentration of the antioxidant glutathione. Cerebrospinal fluid was collected at <4 hours postmortem from 48 pathologically-verified PD subjects and 57 comparably-aged controls. Assays involved ultra-high-performance liquid and gas chromatography linked to mass spectrometry. We used univariate techniques to determine fold-changes in concentrations of biochemicals; false-discovery rates were calculated to exclude spurious findings. Data was modeled using a Support Vector Machine for analyzing compounds selected by Welch's t test. Classification accuracy was determined by cross-validation. Of 243 structurally-identified biochemicals,19 compounds differentiated PD from controls at a 20% false-discovery level. In PD, mean 3-hydroxykynurenine concentration was increased by one-third, and mean oxidized glutathione was decreased by 40% (for each, P < .01). Four of the 19 compounds differentiating PD from controls were N-acetylated amino acids, suggesting a generalized alteration in N-acetylation activity. The Support Vector Machine classification model distinguished between groups at 83% sensitivity and 91% specificity for the learning data, and at 65% and 79% from cross-validation. In this study, the first for metabolomic profiling of PD cerebrospinal fluid, we found several novel biomarkers and offer new directions for recognizing disease-specific biochemical indicators. The findings support involvement of excitotoxicity and oxidative stress in the pathogenesis of PD. © 2013 International Parkinson and Movement Disorder Society