Coherent control of nanomagnet dynamics via ultrafast spin torque pulses

The magnetization orientation of a nanoscale ferromagnet can be manipulated using an electric current via the spin transfer effect. Time domain measurements of nanopillar devices at low temperatures have directly shown that magnetization dynamics and reversal occur coherently over a timescale of nanoseconds. By adjusting the shape of a spin torque waveform over a timescale comparable to the free precession period (100-400 ps), control of the magnetization dynamics in nanopillar devices should be possible. Here we report coherent control of the free layer magnetization in nanopillar devices using a pair of current pulses as narrow as 30 ps with adjustable amplitudes and delay. We show that the switching probability can be tuned over a broad range by timing the current pulses with the underlying free-precession orbits, and that the magnetization evolution remains coherent for more than 1 ns even at room temperature. Furthermore, we can selectively induce transitions along free-precession orbits and thereby manipulate the free magnetic moment motion. We expect this technique will be adopted for further elucidating the dynamics and dissipation processes in nanomagnets, and will provide an alternative for spin torque driven spintronic devices, such as resonantly pumping microwave oscillators, and ultimately, for efficient reversal of memory bits in magnetic random access memory (MRAM).Comment: 4 pages, 3 figures, submitted to Nature Physic

Rival bishops, rival cathedrals : the election of Cormac, archdeacon of Sodor, as bishop in 1331

Peer reviewedPublisher PD

Bioresorbable Polylactide Interbody Implants in an Ovine Anterior Cervical Discectomy and Fusion Model: Three-Year Results

Study Design. In vivo study of anterior discectomy and fusion using a bioresorbable 70:30 poly(l-lactide-co-d,l-lactide) interbody implant in an ovine model. Objective. To evaluate the efficacy of the polylactide implant to function as an interbody fusion device, and to assess the tissue reaction to the material during the resorption process. Summary of Background Data. The use of polylactide as a cervical interbody implant has several potential advantages when compared with traditional materials. Having an elastic modulus very similar to bone minimizes the potential for stress shielding, and as the material resorbs additional loading is transferred to the developing fusion mass. Although preclinical and clinical studies have demonstrated the suitability of polylactide implants for lumbar interbody fusion, detailed information on cervical anterior cervical discectomy and fusion (ACDF) with polylactide devices is desirable. Methods. Single level ACDF was performed in 8 skeletally mature ewes. Bioresorbable 70:30 poly (l-lactide-co-d,l-lactide) interbody implants packed with autograft were used with single-level metallic plates. Radiographs were made every 3 months up to 1 year, and yearly thereafter. The animals were killed at 6 months (3 animals), 12 months (3 animals), and 36 months (2 animals). In addition to the serial plain radiographs, the specimens were evaluated by nondestructive biomechanical testing and undecalcified histologic analysis. Results. The bioresorbable polylactide implants were effective in achieving interbody fusion. The 6-month animals appeared fused radiographically and biomechanically, whereas histologic sections demonstrated partial fusion (in 3 of 3 animals). Radiographic fusion was confirmed histologically and biomechanically at 12 months (3 of 3 animals) and 36 months (2 of 2 animals). A mild chronic inflammatory response to the resorbing polylactide implant was observed at both 6 months and 12 months. At 36 months, the operative levels were solidly fused and the implants were completely resorbed. No adverse tissue response was observed in any animal at any time period. Conclusion. Interbody fusion was achieved using bioresorbable polylactide implants, with no evidence of implant collapse, extrusion, or adverse tissue response to the material. The use of polylactide as a cervical interbody device appears both safe and effective based on these ACDF animal model results

INTSORMIL 2004 ANNUAL REPORT

The 2004 INTSORMIL Annual Report presents the progress and notable achievements by the SorghumlMillet CRSP during the period of July 1, 2003 - June 30, 2004. These results are an outcome of partnerships between scientists at six U.S. Land Grant Universities (Kansas State University, Mississippi State University, University of Nebraska, Purdue University, Texas A&M University and West Texas A&M University) and scientists of the Agricultural Research Service of the U.S. Department of Agriculture at Tifton, Georgia and National Agricultural Research Systems (NARS) and National Universities in nineteen countries in Central America, West Africa, East Africa and Southern Africa. Agricultural research provides benefits not only to producers of agricultural products but also to processors and consumers of agricultural products. Agricultural research has proven itself continuously as providing improvements which yield products of greater quantity and quality, as well as improved health to consumers and broad-based economic growth which goes beyond producers and consumers

INTSORMIL 2000 Annual Report

Presently, worldwide, more than 800 million people are hungry and over I billion are desperately poor, and food demand is increasing rapidly. The majority of poor live in rural areas in developing countries and agricultural and food systems development is vital to economic growth; improving environmental quality; strengthening nutrition, health and child survival; improving the status of women; and promoting democratization. It is estimated that by 2000, the number of people living in developing countries will grow from 4.9 billion to 6.8 billion people. More than 1.3 billion people today live on less than one dollar per day. It is estimated that the number of hungry people will exceed one billion by 2020. The global population of underweight children below age five is expected to increase from 193 million in year 2000 to over 200 million in year 2020. Increased production of cereals, which are crucial sources of food energy and other nutrients, is necessary to reduce world hunger. Sorghum and millet are two major cereal grains, particularly in semi-arid regions of the world. In 1999,65.8 million metric tons (MT) of sorghum were produced worldwide, of which 19.7 million MT were produced in Africa, mainly for direct consumption by humans, and 14.7 million MT were produced in the United States, mainlyfor livestock feed to produce meat for human consumption. In the crop year 1997-1998, the United States exported 5.3 million MT of grain sorghum mainly for livestock feed, and in 1998, U.S. grain sorghum exports were worth $531 million. Large areas are planted to sorghum each year. For example, in 1999 sorghum was produced on 44.8 million hectares (ha, or 173,036 square miles, [sq mi]) worldwide, 23 million ha (88,728 sq mi) in Africa, and 3.4 million ha (13,278 sq mi) in the United States. About 500 million people worldwide depend upon sorghum for food, and most of these people are in developing countries where droughts and famine are common occurrences. Clearly, sorghum production and utilization as food and feed are vitally important to developing countries and to the United States

INTSORMIL 2002 Annual Report

The global community confronts an enonnous task of stimulating economic growth in rural areas where 75% of the very poor (90% in Africa) currently live and ensuring the nutritional security of a world popUlation that is growing in size and evolving in consumption patterns without intensifying environmental degradation, social security, or adverse consequences for human health. This challenge is not only great but it is also urgent. Today, access to food, sufficient, safe, and nutritious food, is the primary problem for nearly 800 million chronically undernourished people. Unless we act now, the next few decades will almost certainly find us unable to produce agricultural products sufficient to meet the demands of growing populations and changing diets. The majority of poor live in rural areas in developing countries and agricultural and food systems development is vital to economic growth; improving environmental quality; strengthening nutrition, health and child survival; improving the status of women; and promoting democratization. Over the next 50 years, the global population will increase to 8-10 billion, requiring advances in scientific knowledge across a broad range of agricultural endeavors, i.e., developing more productive food and commodity cultivars, improving nutritional quality of crop and livestock products, reducing food and commodity yield losses due to pests and diseases, ensuring healthy livestock, developing sustainable and responsible fisheries and aquaculture practices, optimizing the use of forests, managing water more efficiently, protecting and improving land productivity, and conserving and managing genetic diversity

INTSORMIL 2003 ANNUAL REPORT

From 1980 to 1999, according to the Food and Agriculture Organization of the United Nations (FAO), the number of food-insecure people in developing countries fell from 920 million to about 800 million, yet in 2003, the International Food Policy Research Institute declared that without significant changes in policies, public investments, and institutions, we simply will not achieve the 1996 World Food Summit goal-reaffirmed at the 2000 Millennium Summit and again last year at the World Food Summit: five years later of reducing the number of our fellow human beings who are food insecure by at least half by no later than 2015. FAO indicates that the number has been decreasing by barely 2.5 million per year over the last eight years. At that rate, we will reach these goals one hundred years late, in 2115. Increased production of cereals, which are crucial sources of food energy and other nutrients, is necessary to reduce world hunger. According to Entering the 21st Century-World Development Report 1999/2000, about 900 million people in almost 100 countries are affected by drought and desertification, and by 2025, that number will double. The population of the world has doubled since 1940, but fresh water use has increased fourfold. Water scarcity is becoming more widespread, with concomitant effects on regional peace and global food security. Nearly all of the 3 billion increase in global population which is expected by 2025 will be in developing countries where water is already scarce. To meet the increasing demand for food in those countries, there is an increasing demand for more efficient production and new ways of utilizing drought-tolerant crops which have a competitive advantage to produce food under conditions of unpredictable and scarce rainfall. As water becomes more precious in the United States, cereals which can produce energy for feed and fuel in drought-prone areas of the country are demonstrating increasingly competitive advantages

INTSORMIL 2001 Annual Report

Presently, worldwide, more than 800 million people are hungry and over one billion are desperately poor, and food demand is increasing rapidly. The majority of poor live in rural areas in developing countries and agricultural and food systems development is vital to economic growth; improving environmental quality; strengthening nutrition, health and child survival; improving the status of women; and promoting democratization. It is estimated that, between 1980 and 2030, the population ofow- and middle-income countries will more than double-to seven billion, compared with one billion for high-income countries. In the next 35 years, 2.5 billion people will be added to the current population of 6 billion. More than 1.3 billion people today live on less than one dollar per day, and it is estimated that the number of hungry people will exceed one billion by 2020. The global population of underweight children below age five is expected to increase from 193 million in Year 2000 to over 200 million in Year 2020. Increased production of cereals, which are crucial sources of food energy and other nutrients, is necessary to reduce world hunger. According to Entering the 21st Century-World Development Report 1999-2000, about 900 million people in almost 100 countries are affected by drought and desertification, and by 2025, that number will double. The population of the world has doubled since 1940, but fresh water use has increased fourfold. Water scarcity is becoming more widespread, with concomitant effects on regional peace and global food security. Nearly all of the three billion increase in global population which is expected by 2025 will be in developing countries where water is already scarce. To meet the increasing demand for food in those countries, there is an increasing demand for more efficient production and new ways of utilizing drought-tolerant crops which have a competitive advantage to produce food under conditions of unpredictable and scarce rainfall. As water becomes more precious in the United States, cereals which can produce energy for feed and fuel in drought-prone areas of the country are demonstrating increasingly competitive advantages

INTSORMIL 2000 Annual Report

Presently, worldwide, more than 800 million people are hungry and over I billion are desperately poor, and food demand is increasing rapidly. The majority of poor live in rural areas in developing countries and agricultural and food systems development is vital to economic growth; improving environmental quality; strengthening nutrition, health and child survival; improving the status of women; and promoting democratization. It is estimated that by 2000, the number of people living in developing countries will grow from 4.9 billion to 6.8 billion people. More than 1.3 billion people today live on less than one dollar per day. It is estimated that the number of hungry people will exceed one billion by 2020. The global population of underweight children below age five is expected to increase from 193 million in year 2000 to over 200 million in year 2020. Increased production of cereals, which are crucial sources of food energy and other nutrients, is necessary to reduce world hunger. Sorghum and millet are two major cereal grains, particularly in semi-arid regions of the world. In 1999,65.8 million metric tons (MT) of sorghum were produced worldwide, of which 19.7 million MT were produced in Africa, mainly for direct consumption by humans, and 14.7 million MT were produced in the United States, mainlyfor livestock feed to produce meat for human consumption. In the crop year 1997-1998, the United States exported 5.3 million MT of grain sorghum mainly for livestock feed, and in 1998, U.S. grain sorghum exports were worth $531 million. Large areas are planted to sorghum each year. For example, in 1999 sorghum was produced on 44.8 million hectares (ha, or 173,036 square miles, [sq mi]) worldwide, 23 million ha (88,728 sq mi) in Africa, and 3.4 million ha (13,278 sq mi) in the United States. About 500 million people worldwide depend upon sorghum for food, and most of these people are in developing countries where droughts and famine are common occurrences. Clearly, sorghum production and utilization as food and feed are vitally important to developing countries and to the United States