The non-parametric, or re-sampling, bootstrap for a single unstructured sample corresponds to the algebraic operation of monoid composition, with a uniform distribution on the monoid. With this interpretation, the notion of re-sampling can be extended to designs having a certain group-invariance property. Two types of exchangeable array structures are considered in some detail, namely the one-w...

1. Exchangeable potassium, sulphate space and intracellular fluid have been determined in eight normal males and in seven uraemic male patients on a regime of twice weekly 8 h dialysis. 2. Intracellular water was more closely correlated with exchangeable potassium than were body weight or lean body mass. 3. There was no correlation between exchangeable potassium and plasma or erythrocyte potass...

Wavelength-selective infrared multiple-photon photodissociation (WS-IRMPD) was used to study isotopically-labeled ions generated by McLafferty rearrangement of nicotinyl-glycine-tert-butyl ester and betaine-glycine-tert-butyl ester. The tert-butyl esters were incubated in a mixture of D(2)O and CH(3)OD to induce solution-phase hydrogen-deuterium exchange and then converted to gas-phase ions usi...

The amount of readily exchangeable Ca2+ in mitochondria of an isolated working rat heart is less than 10 ng-ions/g heart. We therefore conclude that either no Ca2+ enters mitochondria or that the Ca+ which does enter is removed continuously. Using Sr2+ and Mn2+, we obtained evidence that the mitochondrial Na+-Ca2+ exchanger was indeed operational in releasing metal from mitochondria of the hear...

The conformations of cytochrome c ions (+8 through +18) in the gas phase are examined by simultaneous ion-mobility and hydrogen-deuterium exchange measurements. By varying the voltage used to inject ions into the drift tube it is possible to study H/D exchange of specific conformers observed in the ion-mobility spectra: either very diffuse structures that are favored for all charge states at hi...

To avoid increasing costs of landfill disposal, it has become increasingly important for U.S. foundries to identify beneficial reuses for the 8 to 12 million tons of waste foundry sand (WFS) generated annually. A major drawback to the reuse of some WFSs as a soil amendment is their high soil strength, under dry conditions, where root growth may be limited. Fifteen WFSs were analyzed for strengt...

the low bioavailability of zinc (zn) is in calcareous and saline soil, therefore the study of chemical forms and bioavailability of zn in these soils is necessary to estimate the potential availability. the objective of this study was to evaluate the effect of plant growth promoting rhizobacteria and mycorrhizae fungi inoculation on the chemical forms of zn in a calcareous soil at different sal...

Previous studies have suggested that angiotensin II and sodium can act as alternative mechanisms in maintaining high blood pressure in chronic renovascular hypertension, In the present study, exchangeable sodium was measured in rats in which angiotensin II has been confirmed or excluded as the main cause of the hypertension. To determine the degree of participation of angiotensin II in the main...