Feeding, a vital behavior in animals, is modulated depending on internal and external factors. In the nematode Caenorhabditis elegans, the feeding organ called the pharynx ingests food by pumping driven by the pharyngeal muscles. Here we report that optical silencing of the body wall muscles, which drive the locomotory movement of worms, affects pumping. In worms expressing the Arch proton pump...

Oscillatory pumping tests-in which flow is varied in a periodic fashion-provide a method for understanding aquifer heterogeneity that is complementary to strategies such as slug testing and constant-rate pumping tests. During oscillatory testing, pressure data collected at non-pumping wells can be processed to extract metrics, such as signal amplitude and phase lag, from a time series. These me...

Sodium-rich myometrium, obtained from the uteri of pregnant rats, rapidly hyperpolarized when 4.6-120 mM potassium was added to the bathing medium at 37 degrees C. Hyperpolarization was due to sodium pumping since the process was markedly temperature dependent, was abolished by ouabain, and required both intracellular sodium and extracellular potassium. The observed membrane potential exceeded ...

The stimulation by K+ of the initial rate of Hf-pumping by ATPase was studied in native plasmalemma (Zea mays L. var Mona) vesicles and in reconstituted vesicles with enzyme purified on a glycerol gradient. In reconstituted vesicles, a very high H+pumping rate (200,000% quenching per minute per milligram protein) was obtained with 9-amino-6-chloro-2-methoxyacridine provided that the pump was sh...

We consider the coherent population trapping phenomenon in a thermal sodium atomic beam. We compare the different coherent population trapping schemes that can be established on the D 1 line using the Zeeman sublevels of a given ground hyperfine state. The coherent population trapping preparation is examined by means of a Hanle effect configuration. The efficiency of the coherent population tra...

We consider the coherent population trapping phenomenon in a thermal sodium atomic beam. We compare the different coherent population trapping schemes that can be established on the D1 line using the Zeeman sublevels of a given ground hyperfine state. The coherent population trapping preparation is examined by means of a Hanle effect configuration. The efficiency of the coherent population trap...

We consider optical pumping with a quasi monochromatic tunable light beam, in the low intensity limit where a rate equation regime is obtained The velocity selective optical pumping (V.S.O.P.) introduces a correlation between atomic velocity and internal variables in the ground (or metastable) state. The aim of this article is to evaluate these atomic observables (orientation, alignment, popula...

We examine the hydrodynamic performance of two cilia beating patterns reconstructed from experimental data. In their respective natural systems, the two beating patterns correspond to: (A) pumping-specialized cilia, and (B) swimming-specialized cilia. We compare the performance of these two cilia beating patterns as a function of the metachronal coordination in the context of two model systems:...

Determinations were made for corn (Zea mays L., WF9-Tms x M14) mitochondria of the stoichiometric relationship between K(+) transport and bond energy produced in respiration (K(+)/ approximately ratio). With inward pumping of potassium acetate activated by NADH oxidation, the initial rate of K(+) transported into the sucrose inaccessible space varied between 0.58 and 0.97 K(+)/ approximately , ...