Effects of Rotationally-Induced Mixing in Compact Binary Systems with Low-Mass Secondaries and in Single Solar-Type Stars

Many population synthesis and stellar evolution studies have addressed the evolution of close binary systems in which the primary is a compact remnant and the secondary is filling its Roche lobe, thus triggering mass transfer. Although tidal locking is expected in such systems, most studies have neglected the rotationally-induced mixing that may occur. Here we study the possible effects of mixing in the mass-losing stars for a range in secondary star masses and metallicities. We find that tidal locking can induce rotational mixing prior to contact and thus affect the evolution of the secondary star if the effects of the Spruit-Tayler dynamo are included both for angular momentum and chemical transport. Once contact is made, the effect of mass transfer tends to be more rapid than the evolutionary time scale, so the effects of mixing are no longer directly important, but the mass transfer strips matter to inner layers that may have been affected by the mixing. These effects are enhanced for secondaries of 1-1.2 Msun and for lower metallicities. We discuss the possible implications for the paucity of carbon in the secondaries of the cataclysmic variable SS Cyg and the black hole candidate XTE J1118+480 and for the progenitor evolution of Type Ia supernovae. We also address the issue of the origin of blue straggler stars in globular and open clusters. We find that for models that include rotation consistent with that observed for some blue straggler stars, evolution is chemically homogeneous. This leads to tracks in the HR diagram that are brighter and bluer than the non-rotating main-sequence turn-off point. Rotational mixing could thus be one of the factors that contribute to the formation of blue stragglers.Comment: 46 pages, 18 figure

Natural Enemies of Alfalfa Weevil, \u3ci\u3eHypera Postica\u3c/i\u3e (Coleoptera: Curculionidae), in Minnesota

Alfalfa weevil, Hypera postica, is present throughout Minnesota. How- ever, economically damaging populations seldom occur, due to a combination of natural enemies and adverse climatic conditions. Five natural enemies of alfalfa weevil were found in Minnesota. Microctonus aethiopoides (Hymenoptera: Braconidae), a parasitoid of adults, was recovered from 43 of 65 counties surveyed during 1984 and 1985. Tetrastichus incertus (Hymenoptera: Eulophidae) and Bathyplectes curculionis (Hymenoptera: Ichneumonidae), para­sitoids of larvae, were each recovered from 13 of 15 counties surveyed during 1991-1993. Bathyplectes anurus, another parasitoid of larvae, was recovered from one county In 1991, four counties in 1992, and six counties in 1993. Zoophthora phytonomi (Entomophthora: Entomophthoraceae), a pathogen of larvae, was recovered from 14 of 15 counties surveyed in 1991-1993. Winters with low minimum temperatures and little snow cover were detrimental to the weevil. Usually, southeastern Minnesota has milder winters and higher alfalfa weevil populations than other areas of the State. However, even here, because of natural enemies, weevil populations seldom reach economically damaging levels

Understanding the effects of high-pressure, high-temperature processing on the key quality parameters of green beans (Phaseolus vulgaris) with a view to assessing the potential quality benefits of the approach relative to conventional thermal processing.

Studies were conducted to explore whether high pressure (up to 700 MPa) could be used in combination with elevated temperatures (up to 90°C initial temperature) to produce ambient stable green beans (Phaseolus vulgaris) with improved quality compared with conventionally heat processed samples. Colour changes, texture change and chlorophyll retention were explored at a range of pressures, temperatures and times using a surface response methodology. Texture changes were essentially related to temperature effects; higher temperatures resulted in a greater loss in texture. Significant improvements in texture retention were possible using High Pressure Sterilisation (HPS) but sample colour was negatively affected. Colour parameters were predicted primarily by time and pressure so deterioration in green vegetable quality for a commercially sterile products appears inevitable when using HPS. The use of ohmic heating as a pre-heating method greatly reduced cook values (T$_{ref}$ = 100°C, z = 39C°) for colour degradation (down to 0.24, 0.12, 0.35 from 3.02, 2.50, 3.70 minutes for ohmically heating and water bath heated samples respectively) which yielded significant benefits in terms of colour retention of raw materials at the start of the HPS cycle; values of a* and b* for ohmically pre-heated samples were close to that of blanched beans

Mr. Kerry goes to Washington: Lord Lothian and the genesis of the Anglo-American alliance, 1939-1940

The purpose of this dissertation is to examine and assess the role of Philip Henry Kerr, eleventh Marquis of Lothian, the British ambassador to the United States from August 1939 to December 1940. While much of the historiography of Anglo-American relations during the Second World War focuses on the Roosevelt-Churchill axis, this dissertation contends that Lord Lothian played a vital, if not the principal, role in creating that axis and in forging closer relations during the vital months before Pearl Harbor. More generally, this dissertation contends that Lothian is a vital, if not the principal, architect of the “Special Relationship.” Anglo-American relations during the interwar years were characterized by an underlying discord, caused by economic disparity, naval rivalry, and divergent approaches to international security. By December 1940, however, relations were stronger and closer, as many Americans came to appreciate that Britain’s survival was critical to keeping the United States out of the war. Although not exclusively responsible, Lothian played a significant role in affecting this transformation in public opinion. First, he established a British public relations apparatus and initiated a vigorous publicity campaign in the United States, which generated greater awareness of Britain’s increasingly dire military predicament and more widespread popular support for Britain. Second, Lothian helped to broker the celebrated Destroyers-for-Bases deal, by which the United States agreed to provide Britain with fifty destroyers in return for land rights in various British possessions in the Western Hemisphere. Third, Lothian helped to lay the foundations for the Lend-Lease program. Following a brief autumn visit to Britain, he intimated to the American press that London was running out of cash with which to purchase American military supplies. He also urged Churchill to outline the realities of Britain’s position in a long, detailed letter to Roosevelt. These two initiatives presented the Roosevelt administration with a comprehensive view of Britain’s desperate situation that compelled the president to take action. The result was the Lend-Lease Act, which provided Britain with a program of American assistance, hardly compatible with neutrality, and ultimately became the foundation of the Anglo-American alliance during the Second World War

The acute effects of combining resistive and endurance exercise regimens

The present study investigated the acute interactions of performing concurrent strength and endurance exercises. [This is an excerpt from the abstract. For the complete abstract, please see the document.

Enumeration and Low Temperature Storage of Obligately Anaerobic Bacteria in Convenience Foods

The present study was undertaken to determine the kinds and numbers of obligate anaerobes possibly present in various frozen and refrigerated commercial convenience foods. Also, known numbers of pathogenic species of obligate anaerobes were added to various convenience foods and stored at refrigeration and freezing temperatures to determine their die-off or loss in viability. The conditions investigated included the effects of different organisms, different foods, different temperatures, and various storage time periods. The results of this investigation demonstrate to food producers as well as consumers that the possibility does exist for the presence of non-sporeforming obligate anaerobes in frozen or refrigerate convenience foods

The Paleomagnetism of a Thick Middle Tertiary Volcanic Sequence in Northern California

The mean direction of remanent magnetism for 44 sampling sites from Oligo-Miocene lava flows in northern California points about 12° east of the expected Oligo-Miocene geomagnetic field direction for the area. Our paleomagnetic data and other data indicate that the Cascade Range has rotated clockwise since the middle Tertiary. Similar, but larger, clockwise rotations have been documented in previous studies throughout the Coast Ranges. Two mechanisms are suggested to account for the differential rotation that has occurred within the Coast and Cascade Ranges. First, the Coast Ranges are rotated and then accreted to a curved continental margin during the Eocene, leaving the Washington Coast Range relatively unrotated at the end of the Eocene. Secondly, during post- Eocene rotation, the thick crystalline crust of the Klamath Mountains prohibited the southern end of the Cascade Range from rotating as rapidly as the northern end, producing an oroclinal bend in the range