Production of Specific Fragments of {varphi}X174 Replicative Form DNA by a Restriction Enzyme from Haemophilus parainfluenzae, Endonuclease HP

A restriction endonuclease from Haemophilus parainfluenzae degrades {varphi}X174 replicative form DNA into eight specific fragments, ranging from 1,700 to 150 base pairs and terminated specifically by deoxycytidylic acid

Factors Affecting U.S. Trade and Shipments of Information Technology Products: Computer Equipment, Telecommunications Equipment, and Semiconductors

Despite a recent downturn, the information technology (IT) products sector experienced a tremendous expansion in trade and shipments during the last decade and became an increasingly important component of the U.S. economy. This expansion was driven by a variety of factors such as the globalization of IT production, constant technological innovation, rapid growth in worldwide consumption, and global trade liberalization. This working paper will examine these factors, providing particular attention to the computer equipment, telecommunications equipment, and semiconductor industries.International Development,

An electronics curriculum based on industry standards

Thesis (M.A.)--Boston Universit

Robert H. Johnson Collection

Written histories, notes, and clippings, chiefly related to buffalo and buffalo bones

Quantification of Pulmonary Arterial Wall Distensibility Using Parameters Extracted from Volumetric Micro-CT Images

Stiffening, or loss of distensibility, of arterial vessel walls is among the manifestations of a number of vascular diseases including pulmonary arterial hypertension. We are attempting to quantify the mechanical properties of vessel walls of the pulmonary arterial tree using parameters derived from high-resolution volumetric x-ray CT images of rat lungs. The pulmonary arterial trees of the excised lungs are filled with a contrast agent. The lungs are imaged with arterial pressures spanning the physiological range. Vessel segment diameters are measured from the inlet to the periphery, and distensibilities calculated from diameters as a function of pressure. The method shows promise as an adjunct to other morphometric techniques such as histology and corrosion casting. It possesses the advantages of being nondestructive, characterizing the vascular structures while the lungs are imaged rapidly and in a near-physiological state, and providing the ability to associate mechanical properties with vessel location in the intact tree hierarchy

Deformation and crystallization of Zr-based amorphous alloys in homogeneous flow regime

The purpose of this study is to experimentally investigate the interaction of inelastic deformation and microstructural changes of two Zr-based bulk metallic glasses (BMGs): Zr_(41.25)Ti_(13.75)Cu_(12.5)Ni_(10)Be_(22.5) (commercially designated as Vitreloy 1 or Vit1) and Zr_(46.75)Ti_(8.25)Cu_(7.5)Ni_(10)Be_(27.5) (Vitreloy 4, Vit4). High-temperature uniaxial compression tests were performed on the two Zr alloys at various strain rates, followed by structural characterization using differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). Two distinct modes of mechanically induced atomic disordering in the two alloys were observed, with Vit1 featuring clear phase separation and crystallization after deformation as observed with TEM, while Vit4 showing only structural relaxation with no crystallization. The influence of the structural changes on the mechanical behaviors of the two materials was further investigated by jump-in-strain-rate tests, and flow softening was observed in Vit4. A free volume theory was applied to explain the deformation behaviors, and the activation volumes were calculated for both alloys