3,268 research outputs found
Spin-Orbit Dimers and Non-Collinear Phases in Cubic Double Perovskites
We formulate and study a spin-orbital model for a family of cubic double
perovskites with ions occupying a frustrated fcc sublattice. A
variational approach and a complimentary analytical analysis reveal a rich
variety of phases emerging from the interplay of Hund's and spin-orbit
couplings (SOC). The phase digram includes non-collinear ordered states, with
or without net moment, and, remarkably, a large window of a non-magnetic
disordered spin-orbit dimer phase. The present theory uncovers the physical
origin of the unusual amorphous valence bond state experimentally suggested for
BaMoO (=Y,Lu), and predicts possible ordered patterns in
BaOsO (=Na,Li) compounds.Comment: 4 pages, 4 figures, supplement: 3 pages and 3 figures, to appear in
PR
Family and individual line selection for palmitate, saturates, linolenate and seed yield of soybean
Soybean [Glycine max (L.) Merr.] genotypes with reduced palmitate, stearate, and linolenate have been developed to improve the nutritional characteristics and oxidative stability of the seed oil. The reduction of palmitate and stearate in soybean is necessary to comply with U.S. Food and Drug Administration (FDA) regulations for vegetable oils that are labeled as being low in saturated fatty acids (U.S. FDA, 1994). The reduction of linolenate should improve the oxidative stability and reduce the formation of undesirable flavor compounds in the oil (Dutton et al., 1951; Smouse, 1979; Mounts et al., 1988; White and Miller, 1988);Plant-row-yield tests (PRYT) are used by soybean breeders for the initial yield evaluation of experimental lines. The highest yielding lines in the PRYT are advanced for evaluation in replicated tests. The objectives of this study were to compare the family and line methods of selection for reduced palmitate, palmitate + stearate (saturates), linolenate, and for increased seed yield, determine the influence of the combination of reduced palmitate and linolenate on agronomic and seed traits, and determine the effectiveness of selecting lines from unreplicated plots;Four random F3-derived lines from 21 F2 families from each of four populations were evaluated in a PRYT in 1995 and in replicated tests at four locations in 1996. For the family method, the mean palmitate, palmitate + stearate (saturates), linolenate, and seed yield of the four F3-derived lines of each F2 family was used to identify families from which to select individual lines. For the line method, lines were selected without regard to the family structure. The fatty ester contents or seed yield of the selected and unselected lines based on data from the PRYT were compared with their mean performance in the 1996 environments. Selection of lines based on data from one 1996 environment was compared with their mean performance in the other three environments. The total number of lines selected by the family method was less than for the line method for all traits in the four populations. The percentage of selected lines that were correctly classified for all traits was similar for both methods. There was a greater percentage of lines incorrectly rejected by the family method than by the line method for all traits. For development of cultivars with reduced palmitate, saturates, and linolenate, and with increased seed yield, breeding methods that rely on family performance would not be more effective or efficient than methods that ignore family structure. The evaluation of lines in unreplicated plots was useful for identifying lines to advance to replicated tests
Attitudes and perceptions of selected educators, administrators and legislators toward agriculture
The purpose of the investigation was to determine the attitudes and perceptions of selected Iowa educators, administrators and legislators. Specific objectives were to determine: (1) their perceptions toward agriculture, (2) their attitudes toward agriculture, (3) the demographic factors associated with their attitudes and perceptions expressed toward agriculture, and (4) differences between their attitudes and perceptions expressed when grouped by associated demographic characteristics;A survey instrument was mailed to teachers, school board presidents, school administrators, and state legislators. Simple random sampling and stratified random sampling were employed for the investigation;Cronbach\u27s alpha was calculated for the scaled items of the survey instrument and for the ten perception factors and six attitude factors identified through factor analysis;Respondents were most knowledgeable about the usage of agricultural chemicals and agricultural mechanization in Iowa. The respondents were observed to be less knowledgeable about agriculture as a way of life, current agricultural economic conditions and new agricultural technology. The only factor that the legislator group appeared more knowledgeable of was agricultural economic conditions;It was observed that the industry of agriculture was more important to the respondents than the other attitude factors and that if the respondent\u27s perception of an issue was higher, the respondent placed less importance on the corresponding issue;The researcher concluded that: (1) several events in the respondents\u27 lifetime influenced their perception and attitude toward agriculture; (2) respondents with past agricultural involvement, being raised or having lived in a region of the state more directly involved with agriculture, were more knowledgeable about agriculture; (3) respondents closest to agriculture were knowledgeable about agriculture and placed more importance on agriculture; and (4) legislators were least knowledgeable and placed less importance on agriculture than any of the other respondent groups
THE EFFECTS OF DIBUTYRYL CYCLIC 3\u27,5\u27-ADENOSINE-MONOPHOSPHATE AND RELATEDCOMPOUNDS ON (TRITIUM-LABELED)THYMIDINE AND (CARBON-14-LABELED)LEUCINE INCORPORATION BY NEWT LIMB REGENERATION BLASTEMAS IN VITRO
A MECHANISM TO ENABLE CREATION OF PER-STUDENT WORKSHEET COPIES THROUGH INTEROPERATION BETWEEN LEARNING MANAGEMENT SYSTEM AND CLOUD-BASED CONTENT SOFTWARE TOOLS
A method for enabling creation of per-student worksheet copies through interoperation between learning management systems (LMS) and cloud-based content software tools is disclosed. The LMS may receive, from an educator, a request to create copies of a specific third-party cloud-based content software tool worksheet for a class. The LMS may send the request to the third-party software tool along with a class roster, which may create a unique digital copy of the worksheet for each student in the class. The LMS may then send, to each student, a unique resource link to the worksheet. The LMS may, alternatively, create a unique identifier identifying the course assignment and the worksheet. When a student requests access to the worksheet, the LMS may add the unique identifier to the request. The third-party software tool may then intercept the request, create a unique digital copy of the worksheet for the student, and redirect the student to the newly created unique worksheet
Energy Sources in Starter Diets for Early Weaned Pigs
Cereal grains constitute the major percentage of swine diets. Although they are used mainly as energy sources, these grains also supply a considerable amount of protein to the diet. With increased feed prices, much interest has been expressed in alternate ingredient sources in swine diets and combinations of ingredients that will be palatable and furnish the nutrients required. Starter diets for young weaned pigs are the most expensive diets because of the higher nutrient requirement at this stage of the life cycle. Therefore, this experiment was conducted to evaluate the performance of young weaned pigs fed different grains, alone and in combination, as the energy source in starter diets and to study the effect of lysine and protein levels of these diets on pig performance
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