Atmospheric Carbon and Transport - America (ACT-America) Data Sets: Description, Management, and Delivery.

The ACT-America project is a NASA Earth Venture Suborbital-2 mission designed to study the transport and fluxes of greenhouse gases. The open and freely available ACT-America data sets provide airborne in situ measurements of atmospheric carbon dioxide, methane, trace gases, aerosols, clouds, and meteorological properties, airborne remote sensing measurements of aerosol backscatter, atmospheric boundary layer height and columnar content of atmospheric carbon dioxide, tower-based measurements, and modeled atmospheric mole fractions and regional carbon fluxes of greenhouse gases over the Central and Eastern United States. We conducted 121 research flights during five campaigns in four seasons during 2016-2019 over three regions of the US (Mid-Atlantic, Midwest and South) using two NASA research aircraft (B-200 and C-130). We performed three flight patterns (fair weather, frontal crossings, and OCO-2 underflights) and collected more than 1,140 h of airborne measurements via level-leg flights in the atmospheric boundary layer, lower, and upper free troposphere and vertical profiles spanning these altitudes. We also merged various airborne in situ measurements onto a common standard sampling interval, which brings coherence to the data, creates geolocated data products, and makes it much easier for the users to perform holistic analysis of the ACT-America data products. Here, we report on detailed information of data sets collected, the workflow for data sets including storage and processing of the quality controlled and quality assured harmonized observations, and their archival and formatting for users. Finally, we provide some important information on the dissemination of data products including metadata and highlights of applications of ACT-America data sets.

Safe lateral-mass screw lengths in the Roy-Camille and Magerl techniques. An anatomic study.

STUDY DESIGN: Investigation of the mean safe lateral-mass screw lengths in the Roy-Camille and Magerl screw techniques in cadaveric cervical specimens. OBJECTIVES: To report the mean screw path length and to evaluate the relation of the screw trajectory to the nerve root in the Roy-Camille and Magerl screw techniques. SUMMARY OF BACKGROUND DATA: Potential injury to the cervical nerve root caused by too long a screw remains a major concern. Few studies regarding proper screw length and its relation to the adjacent nerve root are available. METHODS: Fourteen cervical spines were used for this study. Each lateral mass from C3 to C7 was drilled according to the techniques described by Roy-Camille (right side) and Magerl (left side). The cervical spines were harvested from the cadavers, and the anterior aspect of the lateral mass and spinal nerve were exposed. The screw path length between the dorsal and ventral cortices of the lateral mass were measured. An additional measurement was taken from the ventral aspect of the lateral mass to the nerve root along the screw path. RESULTS: The mean screw path length in the Roy-Camille technique decreased consistently from C3 (15.7 +/- 1.7 mm) to C7 (11.3 +/- 0.8 mm). The mean distance from the ventral cortex to the nerve root ranged from 1.2 to 2.3 mm, and the smallest value was at C7. The mean screw path length in the Magerl technique also decreased from cephelad to caudal, with a range of 15-16 mm at C3-C6 and a mean value of 13.8 mm at C7. CONCLUSIONS: A safe screw length is 14-15 mm in the Roy-Camille technique and 15-16 mm in the Magerl technique at C3-C6. A short screw may be used at C7 if desired.

Modified Magerl technique of lateral mass screw placement in the lower cervical spine: an anatomic study.

Twelve adult embalmed cadaveric cervical spines were used to modify the traditional Magerl technique for screw placement in the lower cervical spine. The starting point for the drill bit was 2 mm inferior to the inferiormost edge of the superior facet and 1-2 mm medial to the posterior midline of the lateral mass. The orientation of the drill bit was parallel to the superior facet in the sagittal plane, and 25-30 degrees lateral in the transverse plane. After drilling, we made direct measurements of the screw path length between the dorsal and ventral cortexes of the lateral mass and screw-path angles in both the sagittal and transverse planes. The results showed the mean screw-path length for all levels ranged from 11 to 15 mm with the smallest value at C7. The mean sagittal and transverse angles of the screw path ranged from 41 to 43 degrees and from 26 to 28 degrees. Penetration of the superior facet was found in three (2.5%) cases. Possible spinal nerve violation was seen in 13 (10.8%) cases if the drill bit was excessively overpenetrated. This study suggested that our modified Magerl technique for lateral mass screw placement be as high as possible without impinging on the facet joint, and drilling be as cranial and lateral as possible to leave the superior articular process as high and lateral as possible. This may further decrease the incidence of spinal nerve injury. Careful drilling and tapping technique is recommended to avoid overpenetration.

Changes in cerebral blood flow velocity associated with biofeedback-assisted relaxation treatment of migraine headaches are specific for the middle cerebral artery.

Twenty-five patients with diagnosed migraine headaches were randomly assigned to a biofeedback-assisted relaxation therapy group or to a group who relaxed on their own. This study confirmed that the biofeedback trained group significantly decreased pain and medication more than the self-relax group. The best responders were those with the more elevated initial cerebral blood flow values and the changes in cerebral blood flow were specific for the middle cerebral artery.