An integrated approach to coupled nutrient and microbial source tracking in an agricultural watershed.

Estuaries often experience multiple water quality impairments including nitrogen enrichment and elevated fecal pollution. These pollutant sources are often linked and difficult to characterize, especially in multiple use watersheds, hindering the identification of effective mitigation steps. Tillamook Bay (Oregon, USA) has a mixed-use watershed including many potential nutrient and fecal bacteria sources due to agricultural activities, human development, and local wildlife populations.

Feedbacks Between Estuarine Metabolism and Anthropogenic CO Accelerate Local Rates of Ocean Acidification and Hasten Threshold Exceedances.

Attribution of the ocean acidification (OA) signal in estuarine carbonate system observations is necessary for quantifying the impacts of global anthropogenic emissions on water quality, and informing managers of the efficacy of potential mitigation options. We present an analysis of observational data to characterize dynamics and drivers of seasonal carbonate system variability in two seagrass habitats of Puget Sound, WA, USA, and estimate how carbon accumulations due to anthropogenic emissions interact with these drivers of carbonate chemistry to determine seasonally resolved rates of acidification in these habitats. Three independent simulations of accumulation from 1765 to 2100 were run using two previously published methods and one novel method for estimation.

Brain Activation Imaging in Emotional Decision Making and Mental Health: A Review-Part 1.

In part 1 of this article, we describe an approach and methodology that bridges 2 worlds: the internal, subjective experience of emotions and thoughts, and the external world of brain electrical activity. Using a novel event-related brain activation imaging method, we demonstrate that within single trials, short-term mental processes, on the order of 100 ms, can be clearly related to observed brain activation in controlled experiments. We use an ipsative assessment validation process that combines self-report with real-time EEG recordings to provide a combined picture of both the mental and the brain activity, during short-term reactions, emotions, and decisions regarding controlled information.

Brain Activation Imaging in Emotional Decision Making and Mental Health: A Review-Part 2.

In this report, we integrate the principles described in part 1 and describe an operational model for emotional decision making that incorporates brain activation data along with subjective experience correlates. This model takes the form of a state machine that carries out transitions between a finite set of 16 possible states of emotional and decision-making response. By considering a 4 × 4 grid of possible states based on left and right activation, in primary (sensation) and secondary (perception/comprehension) response, the range of responses is completely specified.

Toward an operational model of decision making, emotional regulation, and mental health impact.

Current brain research increasingly reveals the underlying mechanisms and processes of human behavior, cognition, and emotion. In addition to being of interest to a wide range of scientists, educators, and professionals, as well as laypeople, brain-based models are of particular value in a clinical setting. Psychiatrists, psychologists, counselors, and other mental health professionals are in need of operational models that integrate recent findings in the physical, cognitive, and emotional domains, and offer a common language for interdisciplinary understanding and communication.

The cortical generators of the contingent negative variation in humans: a study with subdural electrodes.

Contingent negative variations (CNVs) and Bereitschaftspotentials (BPs) were recorded from subdural electrodes implanted in 14 patients with intractable epilepsy. For recording CNVs, a Go/NoGo S2 choice reaction-time paradigm was employed. Two seconds after presentation of a low tone burst (S1), either a medium (S2m) or a high tone burst (S2h) was delivered at random.

Subdural potentials at orbitofrontal and mesial prefrontal areas accompanying anticipation and decision making in humans: a comparison with Bereitschaftspotential.

Field potentials associated with the execution of a warned choice Go/No-Go reaction task were recorded from prefrontal supplementary (SMA) and primary motor cortex (MI) by using subdural electrodes in 5 epileptic patients during presurgical evaluation. The choice was between a Go and a No-Go imperative stimulus (S2) in the S1-S2 paradigm. Orbitofrontal and mesial prefrontal areas generated a slow preceding potential before S2 (most likely late CNV), and bilateral mesial prefrontal areas generated a transient potential, most likely related to decision making, upon S2 in both Go and No-Go conditions.

Movement-related potentials associated with bilateral simultaneous and unilateral movements recorded from human supplementary motor area.

To clarify the differences of movement-related potentials (MRPs) among ipsilateral, contralateral and simultaneous bilateral movements, MRPs with finger, thumb or foot movements were recorded from subdural electrodes chronically implanted on the supplementary motor area (SMA) in 3 patients, and also from the primary sensorimotor area in two of them being evaluated for epilepsy surgery. As a result: (1) SMA generated clear pre-movement potentials regardless of the type of movement. Its amplitude was almost identical between contralateral and bilateral movements except for the motor potential (MP).

EView--a workstation-based viewer for intensive clinical electroencephalography.

We describe a workstation-based EEG viewer that satisfies the requirements for high-volume clinical EEG review. It currently supports two 24-h four-bed epilepsy monitoring units and a network of routine, intraoperative, and intensive care monitors, providing paperless review of over 5000 pages/day by a staff of clinical neurophysiologists. The design takes advantage of the development environment, processing and graphics resources, and networking capabilities of high-performance UNIX workstations.

A data interchange standard for clinical neurophysiology.

A Standard Specification for Transferring Digital Neurophysiological Data Between Independent Computer Systems (Designation E 1467-92) has been developed. The specification defines a common representation of all of the data associated with a complete clinical study, including digitized neurophysiological waveforms, textual annotations and interpretive reports. Patterned after existing, related healthcare data interchange standards, it will facilitate data interchange between neurophysiological instruments, computer systems within the neurophysiology laboratory, other information systems in the hospital, and outside healthcare facilities or research laboratories.

Data interchange for clinical neurophysiology.

Clinical Neurophysiology is rapidly moving towards complete dependence on digital instrumentation and computer-based systems. ASTM E 1467-92 "Standard Specification for Transferring Digital Neurophysiological Data Between Independent Computer Systems" was developed to allow exchange of multichannel electrophysiological waveforms, embedded textual annotations, results of mathematical processing, and clinical interpretive reports between various instruments and systems. This will permit integration of the neurophysiology laboratory interaction with hospital and clinic informations systems, and sharing of data between institutions for clinical or research purposes.

Real-time filtering for the estimation of steady-state visual evoked brain potentials.

It is shown that EEG visual evoked potentials elicited by repetitive stimuli in the range of 2 to 20 per second can be readily estimated in real time using a simple filtering approach. This measurement takes advantage of the fact that a comb filter will pass the important Fourier harmonics of the signal to provide an estimate of the evoked activity, plus track time-variations in the signal. Results on human subjects demonstrate the effectiveness of the approach.

EEG mapping for surgery of epilepsy.

This report describes the objectives, problems, and current techniques associated with using EEG maps in the management of surgery of epilepsy. The purpose of EEG mapping in epilepsy is to precisely identify and characterize epileptogenic zones of the brain. Such zones may be single or multiple, pointlike or diffuse, and may be near or distant from the recording electrodes.