Helium tables.

These tables are intended to provide a standard method and to facilitate the calculation of the quantity of "Standard Helium" in high pressure containers. The research data and the formulas used in the preparation of the tables were furnished by the Research Laboratory of Physical Chemistry, of the Massachusetts Institute of Technology

Three-Year Creel Census of Lake Catherine, Lake Hamilton, and Lake Ouachita, Arkansas

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201

Ephedrine-Epinephrine Antagonism

2 p. Reprinted from: Proceedings of the Society for Experimental Biology and Medicine, vol. 26, pp. 500-50

Brief Note Distribution of Polygonum amphibium L. (Polygonaceae) in Ohio

Author Institution: Department of Biological Sciences, Kent State UniversityThe water smartweeds are now considered one species, Polygonum amphibium sensu lato, represented in the Ohio flora by two varieties. One, var. stipulaceum, occurs mainly in the glaciated portion of Ohio; the other, var. emersum and also the intermediates between these two varieties, have an apparent random distribution in the state

Origin and geological significance of mylonitic shear zones, northern Lucy Gray Range, Clark County, Nevada

The Beer Bottle Pass pluton, at the northern end of the Lucy Gray Range, Nevada, is part of a continent-scale belt of 1.4 Ga intrusive rocks that extend from California to Labrador. These granites are conventionally interpreted as anorogenic; however, recent work has documented that some of these plutons may have been deformed during or after emplacement. In the Lucy Gray Range, a series of mylonite zones is spatially associated with the Beer Bottle Pass pluton. An integrated study involving field and laboratory work, was used to distinguish between three possible scenarios for the origin of the mylonites: (1) intrusion into an active shear zone, (2) post-emplacement ductile deformation, and (3) mylonitization during and as a consequence of forcible pluton emplacement. Observations made during this study indicate that forcible intrusion is unlikely and the mylonites are a result of late synkinematic or post emplacement deformation

Results of Millikan Library Forced Vibration Testing

This report documents an investigation into the dynamic properties of Millikan Library under forced excitation. On July 10, 2002, we performed frequency sweeps from 1 Hz to 9.7 Hz in both the East-West (E-W) and North-South (N-S) directions using a roof level vibration generator. Natural frequencies were identified at 1.14 Hz (E-W fundamental mode), 1.67 Hz (N-S fundamental mode), 2.38 Hz (Torsional fundamental mode), 4.93 Hz (1st E-Wovertone), 6.57 Hz (1st Torsional overtone), 7.22 Hz (1st N-S overtone), and at 7.83 Hz (2nd E-Wovertone). The damping was estimated at 2.28% for the fundamental E-W mode and 2.39% for the N-S fundamental mode. On August 28, 2002, a modal analysis of each natural frequency was performed using the dense instrumentation network located in the building. For both the E-W and N-S fundamental modes, we observe a nearly linear increase in displacement with height, except at the ground floor which appears to act as a hinge. We observed little basement movement for the E-W mode, while in the N-S mode 30% of the roof displacement was due to basement rocking and translation. Both the E-W and N-S fundamental modes are best modeled by the first mode of a theoretical bending beam. The higher modes are more complex and not well represented by a simple structural system

Dosage compensation in birds

AbstractThe Z and W sex chromosomes of birds have evolved independently from the mammalian X and Y chromosomes [1]. Unlike mammals, female birds are heterogametic (ZW), while males are homogametic (ZZ). Therefore male birds, like female mammals, carry a double dose of sex-linked genes relative to the other sex. Other animals with nonhomologous sex chromosomes possess “dosage compensation” systems to equalize the expression of sex-linked genes. Dosage compensation occurs in animals as diverse as mammals, insects, and nematodes, although the mechanisms involved differ profoundly [2]. In birds, however, it is widely accepted that dosage compensation does not occur [3–5], and the differential expression of Z-linked genes has been suggested to underlie the avian sex-determination mechanism [6]. Here we show equivalent expression of at least six of nine Z chromosome genes in male and female chick embryos by using real-time quantitative PCR [7]. Only the Z-linked ScII gene, whose ortholog in Caenorhabditis elegans plays a crucial role in dosage compensation [8], escapes compensation by this assay. Our results imply that the majority of Z-linked genes in the chicken are dosage compensated

The Drag of Airships : Drag of Bare Hulls II

The extension of wind tunnel tests of models of airship hulls to full scale requires an extension from a VL of the order of less than 500 sq.ft./sec., to that of 80000 sq.ft./sec., where V = air speed, feet per second, L = length in feel of the particular form of hull. The reason for this research was to furnish the airship designer with a method for finding the VL curve of any conventional type of hull, using data obtained from actual performance of airships flown prior to 1926