The public oyster grounds of the Rappahannock River

The Rappahannock River includes some of tho best oyster grounds in the state. The public grounds comprise a poorly used natural resource of great potential value to the state. At present oystermen gather the wild crop which, unf\u27ortunately, represents only a small portion of the oysters which could be raised by intensive management. In a single phrase, the Rappahannock can be described as a river where oysters grow fast but set poorly . The chief factor limiting production is the lack of adequate set of young oysters each year. It is not likely that biologists will learn in the near future how to improve setting by controlling natural conditions in a river. The alternative is to plant seed oysters. (...

Supplement to The public oyster grounds of the Rappahannock River

In the spring of 1952 a summary was made of conditions on the Rappahannock River oyster grounds.for the previous five yea.rs. Five more years have passed but little change is noted in this river. The exceptionally heavy set above Towles Point in 1954 and an apparent decline in setting below the Point are the chief deviations from the patterns described in 1952. A severe loss of oysters in the Rappahannock from hurricanes in August 1955 accentuated a scarcity which appears to be general on the Atlantic Coast. A period of unfavorable weather in the form of hurricanes and high temperatures has caused or intensified this scarcity. Prices have continued to rise, consequently, and probably effort to catch oysters has been increased

High efficiency GaAs-Ge tandem solar cells grown by MOCVD

High conversion efficiency and low weight are obviously desirable for solar cells intended for space applications. One promising structure is GaAs on Ge. The advantages of using Ge wafers as substrates include the following: they offer high efficiency by forming a two-junction tandem cell; low weight combined with superior strength allows usage of thin (3 mil) wafers; and they are a good substrate for GaAs, being lattice matched, thermal expansion matched, and available as large-area wafers

Modeling Concept Combinations in a Quantum-theoretic Framework

We present modeling for conceptual combinations which uses the mathematical formalism of quantum theory. Our model faithfully describes a large amount of experimental data collected by different scholars on concept conjunctions and disjunctions. Furthermore, our approach sheds a new light on long standing drawbacks connected with vagueness, or fuzziness, of concepts, and puts forward a completely novel possible solution to the 'combination problem' in concept theory. Additionally, we introduce an explanation for the occurrence of quantum structures in the mechanisms and dynamics of concepts and, more generally, in cognitive and decision processes, according to which human thought is a well structured superposition of a 'logical thought' and a 'conceptual thought', and the latter usually prevails over the former, at variance with some widespread beliefsComment: 5 pages. arXiv admin note: substantial text overlap with arXiv:1311.605

The use of sonic gear to chart locations of natural bars in lower Chesapeake Bay.

An underwater microphone has been developed to detect shell material on the bottom. The system is simple to use and easily constructed. It consists of a microphone encased in a PVC tube and suspended from an A-frame which is towed over the bottom. It is being used along with other methods to chart oyster bottoms in Virginia

Comparative attachment, growth and mortalities of oyster (Crassostrea virginica) spat on slate and oyster shell in the James River, Virginia

Slate was investigated as a substitute for oyster shells which are used as a substrate for oyster spat (Crassostrea virginica) settlement in James River, Virginia oyster repletion programs. Oyster shells and slate fragments were planted on adjacent plots in two submerged locations about 825 m apart in July 1984. Quantitative .093 m2 (one ft2) samples were collected by a diver on seven occasions through July 1985, with additional samples collected from teh natural oyster bottoms adjacent to the two areas. Percent mortality, growth and numbers of live spat and spat scars (dead spat) per unit area of bottom were determined. As the end of the study, the number of spat on shell was 4-5 times higher than on slate; however, slate had 5-6 times more spat per unit area of bottom than the shell on the natural bottom. During the July to October setting season mortalities were much higher on slate than on shell; during the remaining period they were high but about equal on both substances

The Effect of Tropical Storm Agnes on Oysters, Hard Clams, Soft Clams, and Oyster Drills in VIrginia

Tropical Storm Agnes had a major effect on the molluscan fisheries of Virginia. One effect was the direct mortality of oysters, Crassostrea virginiaa, in the upper parts of many estuaries. Typical losses on leased bottoms were: the James River, 10%; the York River, 2%; the Rappahannock River, 50%; and the Potomac River tributaries (Virginia) 70%. Economic loss was in excess of 7.9 million dollars. There was a nearly complete absence of oyster larvae attachment (setting) in 1972. Other effects of Agnes included a nearly complete loss of soft clams, Mya arenaria, in the Rappahannock River. Hard clams, Meraenaria meraenaria, were killed in the upper part of the York River. Oyster drills, Urosalpinx ainerea, were eliminated from the Rappahannock and reduced greatly in numbers in the York and James Rivers.https://scholarworks.wm.edu/vimsbooks/1074/thumbnail.jp

What is Quantum? Unifying Its Micro-Physical and Structural Appearance

We can recognize two modes in which 'quantum appears' in macro domains: (i) a 'micro-physical appearance', where quantum laws are assumed to be universal and they are transferred from the micro to the macro level if suitable 'quantum coherence' conditions (e.g., very low temperatures) are realized, (ii) a 'structural appearance', where no hypothesis is made on the validity of quantum laws at a micro level, while genuine quantum aspects are detected at a structural-modeling level. In this paper, we inquire into the connections between the two appearances. We put forward the explanatory hypothesis that, 'the appearance of quantum in both cases' is due to 'the existence of a specific form of organisation, which has the capacity to cope with random perturbations that would destroy this organisation when not coped with'. We analyse how 'organisation of matter', 'organisation of life', and 'organisation of culture', play this role each in their specific domain of application, point out the importance of evolution in this respect, and put forward how our analysis sheds new light on 'what quantum is'.Comment: 10 page

Quantum Experimental Data in Psychology and Economics

We prove a theorem which shows that a collection of experimental data of probabilistic weights related to decisions with respect to situations and their disjunction cannot be modeled within a classical probabilistic weight structure in case the experimental data contain the effect referred to as the 'disjunction effect' in psychology. We identify different experimental situations in psychology, more specifically in concept theory and in decision theory, and in economics (namely situations where Savage's Sure-Thing Principle is violated) where the disjunction effect appears and we point out the common nature of the effect. We analyze how our theorem constitutes a no-go theorem for classical probabilistic weight structures for common experimental data when the disjunction effect is affecting the values of these data. We put forward a simple geometric criterion that reveals the non classicality of the considered probabilistic weights and we illustrate our geometrical criterion by means of experimentally measured membership weights of items with respect to pairs of concepts and their disjunctions. The violation of the classical probabilistic weight structure is very analogous to the violation of the well-known Bell inequalities studied in quantum mechanics. The no-go theorem we prove in the present article with respect to the collection of experimental data we consider has a status analogous to the well known no-go theorems for hidden variable theories in quantum mechanics with respect to experimental data obtained in quantum laboratories. For this reason our analysis puts forward a strong argument in favor of the validity of using a quantum formalism for modeling the considered psychological experimental data as considered in this paper.Comment: 15 pages, 4 figure