TEST OF THE ISLAND BIOGEOGRAPHY THEORY WITH BOULDERS IN A SEAGRASS BED

We used shore boulders that had been previously colonized, and were scattered in a seagrass bed as models for islands. We tested two predictions of Island Biogeography theory: (1) small boulders harbored fewer species than large boulders, and (2) small boulders had higher rates of extinction than large boulders, as reflected in higher faunal replacement variability. We detected a definite relation between species richness and boulder size although not for all statistical models. We did not confirm higher compositional variability in small boulders.

The Fluctuations of the Cosmic X-Ray Background as a Sensitive Tool to the Universal Source Distribution

Recent experimental results (Giacconi et al, 79, Tananbaum et al 79) ascribe an increasingly important role to the contribution of discrete sources to the low-energy (few Kev) cosmic X-ray background (CXB). While the astrophysical nature of the objects involved is not yet clear, distant and powerful emitters like QSO play probably an important role (e.g. Setti and Woltjer 1979, Field 1980). For them, often the number-flux curve (LogN-LogS) provides useful hints on such properties as space distribution and/or evolution. For the case of the X-ray sources, moreover, a definite relation exists between their LogN-LogS and the granularity of the sky emission as described by the fluctuations of the X-ray background.

Sweat sodium content and flow rate in cystic fibrosis of the pancreas

Sweat of healthy children and patients with cystic fibrosis was compared following stimulation with methacholine by iontophoresis and by intradermal injection. Sweat samples were collected at 10 min and subsequent 20-min intervals. With injection of methacholine higher initial secretory rates and sodium concentrations were obtained and a steeper decline of these parameters followed, while iontophoresis resulted in a more sustained sweating response. Sodium concentrations in sweat were from 3.45 to 6.75 times elevated in cystic fibrosis. A definite relation of Na content and secretory rate was established for normal children as well as for patients with cystic fibrosis. children; methacholine Submitted on November 16, 1962

A Criterion for Minimum Scatter in Fatigue Testing

When a number of fatigue tests are run on specimens with a longitudinal radius of curvature, there results a scatter in both the number of cycles to failure and the position of failure. A previous statistical analysis showed that if the variations in life are due solely to local inhomogeneities in the specimen, then there is a definite relation between the scatter in position of failure and the scatter in the number of cycles to failure. If the scatter in life significantly exceeds that corresponding to the scatter in position of failure, then there is some factor other than local inhomogeneities contributing to the scatter in life. Such other factors can be eliminated by improving the experimental technique. The usefulness of this criterion is illustrated by its application to crack detection tests on polycrystalline ingot iron.

523. A note on the electrical resistance and the keeping quality of butter

During the course of some earlier work (not yet published) on the physical properties and the quality of butter, the writer noticed that occasionally a sample was encountered which appeared to be very slightly rancid after only 3 weeks' storage in a cold store. These samples were observed to have a low electrical resistance, and to be of inferior texture, usually exhibiting some free moisture droplets when freshly cut. It appeared likely that there might be some definite relation between the resistance, the texture, and the keeping quality of butter. At the time of these experiments, however, the phenomenon only occurred with a few samples of one type of blended butter. The present note describes an experiment designed to explore the possibility that the relationship might be more general, and apply to other types of butter.

OBSERVATIONS ON INTERPHASE AND PROPHASE NUCLEI OF ROOT TIPS OF EINKORN WHEAT AND ONION

Studies of cells in interphase and prophase show that at all stages of the mitotic cycle in the nuclei of Einkorn wheat and onion root tips the arrangement of the chromosomes bears a definite relation to the axis of the nucleus. The establishment, by the centromeres, of the metaphase plate is described. The observations are compared with those of previous investigators and possible applications in other fields of investigation are suggested.

SOME ASPECTS OF ORE DEPOSITS IMPORTANT IN GEOPHYSICAL WORK

The application of geophysics to mining problems is much more difficult than is the case with the petroleum industry. The fundamental contrasts between the occurrence of petroleum and ores are outlined. Difficulties arise because of the great complexity and variation in occurrence and size of deposits of commercial metallic and non‐metallic minerals. These complexities are discussed and illustrations cited in terms of mineralogic, petrographic, structural, and genetic variations in ores. The relatively large horizontal extent of petroleum deposits, as compared with many mineral deposits is emphasized. One of the important problems in the application of geophysics to ore‐finding is determining the definite relation of ore to specific geologic features, so that the results of geophysical work can be interpreted in terms of the probable location of more ore. This is essentially a geologic problem, and one not easily solved in many districts. For the successful application of geophysics and interpretation of the results, a very detailed knowledge and understanding of the geology is fundamental. Also additional geophysical methods are required, particularly those which might locate ore directly rather than indirectly through the geology as is largely the case in petroleum. Because of the complexities involved, no one method should be considered a true test of an area but several methods should be utilized. Much more extensive and intensive application of geophysics to problems of ore‐finding, as well as new methods are demanded by the rapid depletion of present ore reserves.

The calculus of individuals and its uses

An individual or whole we understand to be whatever is represented in any given discourse by signs belonging to the lowest logical type of which that discourse makes use. What is conceived as an individual and what as a class is thus relative to the discourse within which the conception occurs. One task of applied logic is to determine which entities are to be construed as individuals and which as classes when the purpose is the development of a comprehensive systematic discourse.The concept of an individual and that of a class may be regarded as different devices for distinguishing one segment of the total universe from all that remains. In both cases, the differentiated segment is potentially divisible, and may even be physically discontinuous. The difference in the concepts lies in this: that to conceive a segment as a whole or individual offers no suggestion as to what these subdivisions, if any, must be, whereas to conceive a segment as a class imposes a definite scheme of subdivision—into subclasses and members.The relations of segments of the universe are treated in traditional logistic at two places, first in its theorems concerning the identity and diversity of individuals, and second in its calculus of membership and class-inclusion. But further relations of segments and of classes frequently demand consideration. For example, what is the relation of the class of windows to the class of buildings? No member of either class is a member of the other, nor are any of the segments isolated by the one concept identical with segments isolated by the other. Yet the classes themselves have a very definite relation in that each window is a part of some building. We cannot express this fact in the language of a logistic which lacks a part-whole relation between individuals unless, by making use of some special physical theory, we raise the logical type of each window and each building to the level of a class—say a class of atoms—such that any class of atoms that is a window will be included (class-inclusion) in some class that is a building. Such an unfortunate dependence of logical formulation upon the discovery and adoption of a special physical theory, or even upon the presumption that such a suitable theory could in every case be discovered in the course of time, indicates serious deficiencies in the ordinary logistic. Furthermore, a raising of type like that illustrated above is often precluded in a constructional system by other considerations governing the choice of primitive ideas.

PROTEIN CONSUMPTION AND THE RESTORATION OF LOST ORGAN TISSUE

1. At all levels of immediate protein consumption, from almost none to excessive amounts, the degree of growth of the single kidney, suprarenal, and ovary left after removal of one of each of these organs is the same up to 5 days after the operation. 2. On a 1 per cent protein diet there is no growth of the remaining organs after the first 5 days. 3. On diets containing from 10 per cent to 57 per cent of protein there is no definite relation between the level of protein consumption and the rate and degree of growth from 5 to 40 days after the operation. 4. When rats are given a 1 per cent protein diet for 10 days before the operation a continuation of this diet reduces the initial growth of the remaining organs and leads to a cessation of growth after the first 2 days.

CONTRIBUTIONS TO THE BIOCHEMISTRY OF BROMINE: II. THE BROMINE CONTENT OF HUMAN TISSUES

A study of the bromine content in human tissues was made by the method outlined in Part I of this series. In many cases, total halogen determinations were made on the same material. The results suggest the following conclusions:Bromine is a constituent of all human tissues. The amounts found in the same tissue show definite variations.No evidence could be found to support the view that bromine is concerned with pituitary function. The thyroid contains amounts of bromine slightly greater than the amounts found in blood. While functional significance cannot be excluded, it has not been ascertained.No definite relation was found to exist between the distribution of bromine and chlorine in human tissues.