Carbonic Anhydrase in Certain Species of Plants

Author Institution: Charles F. Kettering Foundation, Yellow Springs, Ohi

The Photosynthetic Function of Manganese and Chloride

Author Institution: Charles F. Kettering Foundation, Yellow Springs, Ohi

The Effectiveness of Grade 5 Mobilizations vs. Grade 1-4 Mobilizations on Mechanical Neck Pain: A Clinically Appraised Topic

• From 2000 to 2010, mechanical neck pain (MNP) prevalence ranged from 30% to 50% in adults. Other data suggests that 46% to 54% of every adult will experience some form of neck pain during their lives. • Non-thrust mobilizations (NTM) and Thrust mobilizations (TM) are among the common interventions used in manual therapy in treatment of MNP. • The evidence accumulated for this clinically appraised topic (CAT) suggests high clinical variability among the effectiveness in NTM and TM among adults with mechanical neck pain

The Vibrational Energy Levels and Specific Heat of Ethylene

In a recent review of the experimental infra-red and Raman spectra of ethylene and tetradeuteroethylene [1], Conn and Sutherland have succeeded in giving very reasonable estimates of the positions of the four fundamental lelvels associated with the "rocking frequencies" of the methylene groups in C2H4. They have at the same time revised the previous estimate of the position of the "torisional" lelvel [2] to 700 cm^-1, for reasons which are in our opinion inadequate, and with results which prove to be unsatisfactory. In particular, as they themselves remark, the calculated heat capacities then become too large. We wish to point out that a return to the Bonner assignment of this level not only yields a more reasonable explanation of the weak combination and harmonic lines in the Raman spectra, but also leads to a theoretical heat capacity which is in good agreement with the existing measured values [3] and with new experimental values recently obtained in these Laboratories

Possible Eoarchean records of the geomagnetic field preserved in the Isua supracrustal belt, southern West Greenland

Recovering ancient records of Earth's magnetic field is essential for determining the role of the magnetosphere in protecting early Earth from cosmic radiation and atmospheric escape. We present paleomagnetic field tests hinting that a record of Earth's 3.7-billion-year (Ga) old magnetic field may be preserved in the northeastern Isua Supracrustal Belt as a chemical remanent magnetization acquired during amphibolite-grade metamorphism in the banded iron formation. Multiple petrological and geochronological lines of evidence indicate that the northernmost part of Isua has not experienced metamorphic temperatures exceeding 380°C since the Eoarchean, suggesting the rocks have not been significantly heated since magnetization was acquired. We use “pseudo” baked contact tests (intrusions emplaced 3.26–3.5 Ga ago) and a fold test (folding 3.6 Ga ago) to demonstrate that some samples preserve a ca. 3.7 Ga record of the magnetic field. We recover a field strength of >15 µT. This suggests that Earth's magnetic field may have been weak enough to enhance atmospheric escape during the Archean

Evaluating the Shinumo-Sespe drainage connection: Arguments against the “old” (70–17 Ma) Grand Canyon models for Colorado Plateau drainage evolution

The provocative hypothesis that the Shinumo Sandstone in the depths of Grand Canyon was the source for clasts of orthoquartzite in conglomerate of the Sespe Formation of coastal California, if verified, would indicate that a major river system flowed southwest from the Colorado Plateau to the Pacific Ocean prior to opening of the Gulf of California, and would imply that Grand Canyon had been carved to within a few hundred meters of its modern depth at the time of this drainage connection. The proposed Eocene Shinumo-Sespe connection, however, is not supported by detrital zircon nor paleomagnetic-inclination data and is refuted by thermochronology that shows that the Shinumo Sandstone of eastern Grand Canyon was \u3e60 °C (∼1.8 km deep) and hence not incised at this time. A proposed 20 Ma (Miocene) Shinumo-Sespe drainage connection based on clasts in the Sespe Formation is also refuted. We point out numerous caveats and non-unique interpretations of paleomagnetic data from clasts. Further, our detrital zircon analysis requires diverse sources for Sespe clasts, with better statistical matches for the four “most-Shinumo-like” Sespe clasts with quartzites of the Big Bear Group and Ontario Ridge metasedimentary succession of the Transverse Ranges, Horse Thief Springs Formation from Death Valley, and Troy Quartzite of central Arizona. Diverse thermochronologic and geologic data also refute a Miocene river pathway through western Grand Canyon and Grand Wash trough. Thus, Sespe clasts do not require a drainage connection from Grand Canyon or the Colorado Plateau and provide no constraints for the history of carving of Grand Canyon. Instead, abundant evidence refutes the “old” (70–17 Ma) Grand Canyon models and supports a \u3c6 Ma Grand Canyon