Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.
--------
Question: Abstract: Optical imaging of cortical activity offers several advantages over conventional electrophysiological and anatomical techniques. One can map a relatively large region, obtain successive maps to different stimuli in the same cortical area and follow variations in response over time. In the intact mammalian brain this imaging has been accomplished with the aid of voltage sensitive dyes. However, it has been known for many years that some intrinsic changes in the optical properties of the tissue are dependent on electrical or metabolic activity. Here we show that these changes can be used to study the functional architecture of cortex. Optical maps of whisker barrels in the rat and the orientation columns in the cat visual cortex, obtained by reflection measurements of the intrinsic signal, were confirmed with voltage sensitive dyes or by electrophysiological recordings. In addition, we describe an intrinsic signal originating from small arteries which can be used to investigate the communication between local neuronal activity and the microvasculature. One advantage of the method is that it is non-invasive and does not require dyes, a clear benefit for clinical applications.

Answer: Animal

Question: Abstract: This prospective study evaluated the use of basic vital signs, two mechanisms of injury, and time-distance factors as field triage criteria for on-scene helicopter transport of 130 patients to a trauma center serving a rural area. The vital signs criteria included any one or more of the following: level of consciousness (LOC) less than or equal to unresponsive to verbal stimulation; respiration rate (RR) less than or equal to 10 or greater than or equal to 30; systolic blood pressure (BP) less than or equal to 90; pulse (P) less than or equal to 60 or greater than or equal to 120. The flight crew recorded vital signs taken by the first responder capable of basic assessment. Entrapment and associated fatalities in motor vehicular accidents were recorded and flight logistics were examined. The presence of one or more abnormal signs identified a group of seriously injured trauma patients (mean Injury Severity Score = 29.1) with 24% mortality compared to a predicted mortality of 32% (p less than 0.02). Unresponsiveness to verbal stimulation in the field was the single most predictive criterion, yielding sensitivity of 93% and specificity of 85%. Time-distance criteria were helpful to determine helicopter use.

Answer: Adolescence

Question: Abstract: Beading of a retinal vein draining a choroidal melanoma is reported, showing that the endothelial proliferation producing the beading is a response to some blood borne factor(s) traversing the vein and that retinal capillary non-perfusion adjacent to the beaded vein is not a necessary part of the process.

Answer:
Capillaries