bluuebunny/crossref_metadata_2025 huggingface dataset:
INTEGRATING SCIENCE IN AGRICULTURAL EDUCATION: ATTITUDES OF INDIANA AGRICULTURAL SCIENCE AND BUSINESS TEACHERS
Authors: Balschweid Mark A. , Thompson Gregory W.
Published: December 2010

The purpose of this study was to determine how Indiana Agricultural Science and Business (ASB) teachers perceived the impact of integrating science on agricultural education programs. The population consisted of all Indiana ASB teachers employed during the fall 1999 semester (N = 243). The Integrating Science Survey Instrument developed by Thompson (1996) was used to identify the perceptions of the ASB instructors. From the data it was concluded that many of Indiana’s Agricultural Science and Business instructors have responded positively to the call for the integration of science into the agricultural education curriculum. As a result of their efforts, over half of the teachers reported their students receive science credit toward high school graduation after successfully completing one or more of the approved Agricultural Science and Business courses. Indiana Agricultural Science and Business teachers agreed they felt prepared to teach integrated biological science concepts but that it required more preparation time than before they integrated scientific concepts into their agricultural education curriculum. Teachers identified specific barriers to integrating scientific concepts into their programs as a lack of appropriate equipment, and a lack of adequate funding to support their integration efforts.
CAN SELECTED LEARNING STRATEGIES INFLUENCE THE SUCCESS OF ADULT DISTANCE LEARNERS IN AGRICULTURE?
Authors: Miller Greg , Pilcher Carol L.
Published: December 2010

The purpose of this study was to determine whether providing information about learning strategies to agricultural distance learners through a professionally developed videotape would result in their achieving intended learning outcomes to a greater degree and result in increased satisfaction with the distance learning experience. At the beginning of fall and spring semesters of the 1999-2000 academic year, 110 of the 218 students enrolled in 25 off-campus courses offered by 14 different departments in the Iowa State University College of Agriculture were randomly selected to receive the videotape and a book mark outlining six learning strategies that were recommended in the literature. At the end of each semester, all off-campus students were asked to complete a learning survey. Students who viewed the tape rated it very favorably in terms of its value to off-campus learners. Even so, students who watched the videotape did not earn higher grades for the semester in which they were involved in the study nor did they express a more positive attitude toward the distance-learning environment than students in the control group. Further analysis revealed that students who chose to participate in the study achieved a semester GPA 32% higher than students who did not participate. Those who may have been able to benefit most chose not to participate.
A COMPARISON OF THE INSERVICE EDUCATION NEEDS OF TWO COHORTS OF BEGINNING MINNESOTA AGRICULTURAL EDUCATION TEACHERS
Authors: Joerger Richard M.
Published: December 2010

This study sought to identify the common and unique in-service education needs of year 2000 and 2001 cohorts of beginning agricultural education teachers who had completed one semester of teaching. The study assessed the perceptions of beginning teachers regarding the importance of, and their competence with 59 professional competencies using a revised instrument originally designed by Garton and Chung (1996). The in-service education needs for each cohort were determined using the mean weighted discrepancy scores for each competency and categories of competencies. The results revealed the beginning teachers from both cohorts viewed the listed competencies as important for their survival and success, although they believed they were only somewhat competent in implementing the competencies. The program design and management and teaching and classroom management categories of professional competencies were the categories with the highest need for in-service education for both cohorts. Further analysis revealed that except for the program and design category of competencies, the two cohorts had differing in-service education needs for the professional teaching competencies within the teaching and classroom management, leadership and SAEP development, and technical agriculture categories. Therefore, it was recommended that assessments of teacher in-service needs continue to be conducted with each new cohort of beginning agricultural education teachers.
AGRICULTURAL EDUCATION AT A DISTANCE: LET’S HEAR FROM THE STUDENTS
Authors: Kelsey Kathleen D. , Lindner James R. , Dooley Kim E.
Published: December 2010

The purpose of this study was to describe student satisfaction with Texas A&M and Texas Tech University’s joint Doc-at-a-Distance program. Using qualitative methods, it was found that all 18 students were satisfied with the program for various reasons. The convenience of the program allowed students to maintain their lifestyle while earning an advanced degree. The instructional design, faculty, and cohort group were all very satisfying to the students. Students were dissatisfied with isolation, inaccessible resources and educational materials, lack of an agricultural communications curriculum, registration and technology problems, and amount of time required to complete course requirements. Five students specifically mentioned that technical difficulties were problematic and called for improvements. Students reported they received excellent support from their employers and families. Community support was less important or measurable. Students’ recommendations to improve the program included making the technology more user friendly and increased training for managing the technology. It was concluded that student-identified variables for satisfaction and dissatisfaction were consistent with the literature. Although not mentioned in the literature as a variable for satisfaction, convenience of the program was especially important to this cohort.
A FOLLOW-UP STUDY OF AGRICULTURAL EDUCATION PROGRAM GRADUATES ON TEACHING COMPETENCIES
Authors: Dormody Thomas J. , Torres Robert M.
Published: December 2010

The purpose of this follow-up study was to determine perceptions among New Mexico State University pre-service agricultural education program graduates (Bachelor of Science in Agriculture degree completers) from 1990 to 2001 who are currently teaching agriculture on their attainment of teacher competencies and professional development activities influencing their growth on these teacher competencies since graduation. Data were gathered using a researcher-developed questionnaire. Participants perceived their at-graduation teacher competency abilities as satisfactory on average. On average, participants perceived their current teacher competency abilities to be between satisfactory and very good. For each of the 28 teacher competency statements, participants perceived growth from the time of graduation to their current abilities. The biggest improvement was on participants’ ability to keep students on task. The least improvement was on their enthusiasm toward all facets of the educational program, however, this teacher competency statement was rated highest at graduation and maintained a high ranking as a current ability. Given a list of professional development activities, participants perceived on-the-job experience as having the highest level of influence on their teacher competency ability growth from the time of graduation to the present. Recommendations for program improvement and further research are offered.
INSERVICE NEEDS AND PERCEIVED COMPETENCIES OF SOUTH CAROLINA AGRICULTURAL EDUCATORS
Authors: Layfield K. Dale , Dobbins Thomas R.
Published: December 2010

This study focused on inservice needs of beginning and experienced agriculture teachers in South Carolina. Based on the Borich Needs Assessment Model, a modified list of 50 competencies from previous research was developed to assess needs of South Carolina teachers (N = 105) during the 1999-2000 academic year. Using a census of the population, the perceived level of importance and perceived level of competence of the 50 competencies of the teachers were measured. To determine specific needs, beginning teachers (
WHENCE WE CAME: THE LAND-GRANT TRADITION—ORIGIN, EVOLUTION, AND IMPLICATIONS FOR THE 21ST CENTURY
Authors: Herren Ray V. , Edwards M. Craig
Published: December 2010

Almost all aspects of our lives are continuously affected by the results of what has come to be known as the “Land-Grant Tradition” of teaching, research, and extension. However, in light of the current philosophical trends surfacing in many land-grant universities, it is essential that educational leaders address and define the role of these institutions in the 21st century. Using historical research methods, including the review of primary and secondary sources, this study described the contexts, circumstances, actors, and legislation that affected the genesis and evolution of land-grant institutions, and proposed selected questions about the future role and purpose of these institutions in the 21st Century.
Rural Elementary Students' Understanding Of Science And Agricultural Education Benchmarks Related To Meat And Livestock
Authors: Meischn Deanna L. , Trexler Cary J.
Published: December 2010

Agricultural educators and agricultural industry leaders have called for a basic level of agricultural literacy for Americans of all ages. Benchmarks have been developed by science and agricultural educators for students at all levels regarding an understanding of meat and livestock concepts. This qualitative study sought to ascertain rural fifth grade students' cognitive structures about these concepts. Through interviews and concept mapping, student understandings were unearthed. This study found that students were aware that food products come from animals, but they were not as aware of other products that animals produce for human use. The students did not understand the size and scope of modern agriculture, but most had a very basic understanding of the process that meat travels from farm to consumer. The language these students used to describe the benchmarks was not the language experts deemed necessary. Although the students could describe the steps of the process, their discourse did not include "scientifically" acceptable terminology educators prescribed in national benchmarks for science and agricultural education.
A Comparison Of Distance Education Competencies Delivered Synchronously And Asychronously
Authors: Dooley Kim E. , Lindner James R. , Richards Lance J.
Published: December 2010

Little research in the agricultural education field has focused on the competencies needed to be successful as a distance education professional. The research presented in this paper compares two types of instructional methods (synchronous and asynchronous) for delivering a graduate course. This study was grounded in the qualitative research paradigm. The natural setting for this study was a 15-week graduate course delivered synchronously (ITV) in the spring of 2001 and asynchronously (Web-developed) in the spring of 2002. The purposive sample included 20 graduate students in the spring of 2001 (ITV) and 22 graduate students in the spring of 2002 (Web-developed). Comparisons indicated that there was similar learning of core distance education competencies regardless of delivery method, gender, degree, and major. This study further contributes to the notion that it is not the media, but the methods, that make a difference in distance education. Questions of efficiency and quality are critical for furthering this line of inquiry.
Teacher Burnout In Agricultural Education
Authors: Croom D. Barry
Published: December 2010

The teaching profession is one of the most visible professions in the world, and even though significant improvements have been made in student achievement, society continues to expect more from its teachers. As the gap widens between the public's expectations of education and the teachers ability to deliver that education, burnout will continue to be a concern. This study sought to determine the level of burnout experienced by agriculture teachers in three southeastern states using the Maslach Burnout Inventory – Educator's Survey. The study found that agricultural teachers experience moderate levels of emotional exhaustion, low levels of depersonalization in relationships with students, colleagues and others, and a high degree of personal accomplishment in their work. An agriculture teacher's gender, academic degree, field preparation method, and annual contract length do not seem to influence teachers' responses on each of the sub-scales of the Maslach Burnout Inventory nor do the size of the school, the type of community, and the size of the agricultural education department. The age and years of teaching experience of the agriculture teacher is related to depersonalization scores, but not to emotional exhaustion and personal accomplishment scores on the Maslach Burnout Inventory.
Student Misbehavior In Agricultural Education: A Comparative Study
Authors: Croom D. Barry , Moore Gary E.
Published: December 2010

This study examined the seriousness with which agriculture teachers view the misbehavior of students enrolled in their agriculture programs today and sought to determine if the level of seriousness of student misbehavior in agricultural education has changed over time. The participants in the study were 165 agricultural education teachers in North Carolina, South Carolina, and Virginia. These teachers rated 77 misbehaviors according to how serious a problem it created for them in their agriculture programs. No misbehaviors received a rating higher than 2.0 on a scale that had 4.0 as the critically disruptive behaviors, indicating that student misbehavior is not a serious problem in agricultural education. The most serious misbehavior manifested by students is a negative attitude toward school. However, there could be cause for concern when one realizes that the number one problem found in previous studies, "exhibiting an ambivalent attitude," slid to a 20th place ranking. In this study, teachers perceive that students have finally made up their minds about school - they don't like it. The "love-hate" relationship reported by Burnett and Moore (1988) has essentially developed into a "hate" relationship.
The Future Role Of Instructional Technology In Agricultural Education In North Carolina And Virgina
Authors: Alston Antoine J. , Miller W. Wade , Williams David L.
Published: December 2010

The purpose of this study was to assess teachers' perceptions regarding the future of instructional technology in secondary school agricultural education programs in North Carolina and Virginia. A stratified random sample was selected from the populations of agricultural education teachers in North Carolina and Virginia. Likert-type scales were used to measure the future role instructional technology will play in agricultural education programs, the potential benefits of instructional technology, and the potential barriers to the use of instructional technology. In general, teachers in both states were "undecided" about the future role of instructional technology in agricultural education programs. Accessing lesson plans via the Internet was the primary way teachers perceived themselves using instructional technology in the future. Teachers in both states perceived an array of benefits from future use of instructional technology in their programs, including teacher access to information resources as the primary benefit. To a large extent, teachers were undecided about barriers to future use of instructional technology in their programs. Teachers in both states identified the cost of equipment and the cost of software as the greatest barriers.
A Delphi Study Of Agricultural Teacher Perceptions Of Problems In Student Retention
Authors: Dyer James E. , Breja Lisa M. , Ball Anna L.
Published: December 2010

The objective of the study was to identify the major problems facing high school agriculture teachers in retaining students for secondary agricultural education programs as identified by agriculture teachers. To accomplish this objective the Delphi technique of obtaining group consensus was employed. The study used a series of four mailed questionnaires. The first round of the study used a questionnaire with an open-ended question. In the second questionnaire, respondents were asked to rate the items identified in round one on a five-point Likert-type scale. In the third round panel members were asked to indicate whether they agreed or disagreed with the statements from round two, and to provide comments if they could not agree with the summary findings. The fourth and final round produced concensus on ten of the statements from round three. The major problems identified by the Delphi technique in the successful retention of students in high school agricultural education programs were: scheduling difficulties, lack of guidance counselor support, the image of agriculture, increased graduation requirements, scheduling barriers created by college entrance requirements, competition from other school activities, block scheduling, the image of the local agriculture program, and the quality of the local agriculture instructor.
The Impact Of Raising And Exhibiting Selected 4-H Livestock Projects On The Development Of Life And Project Skills
Authors: Rusk Clinton P. , Summerlot-Early Jill M. , Machtmes Krisianna L. , Talbert B. Allen , Balschweid Mark A.
Published: December 2010

The purpose of the study was to identify perceptions of Indiana 4-H livestock members enrolled in beef, sheep and swine projects regarding their ability to perform project skills and develop life skills. A questionnaire was mailed to a sample of 420 4-H beef, sheep, and swine members, with a response rate of 41.9%. Members were able to accomplish project skills in the areas of sportsmanship, safety, animal grooming, and animal selection. Respondents are not as confident in their abilities related to animal health care. Members who exhibited at the state fair have higher skill levels in the areas of animal health care, animal grooming and animal selection, than 4-H members who exhibited only at the county fair. Members use the responsibility skills they developed from raising 4-H animal projects to complete homework assignments, be on time at work, and care for younger siblings. These skills are benefiting youth in school, at home, and on the job to be more dependable, confident, and qualified individuals.
Article has been redacted
Authors: Article has been redacted
Published: December 2010

Article has been redacted.
Evaluation Of The Incubators In The Classroom Program: Does It Increase Fourth Grade Students' And Teachers' Knowledge About Agricultural Professions?
Authors: Meunier Ryan A. , Talbert B. Allen , Latour Mickey A.
Published: December 2010

The purpose of the study was to determine the effectiveness of agricultural literacy materials designed for the Incubators in the Classroom program used in Indiana fourth grade classrooms. This article reports on the study objectives: determine the impact of the educational materials on fourth grade students' and teachers' knowledge level of agricultural professions and identify fourth grade students' perceptions and opinions of agricultural careers and their possible career plans. Effectiveness of the educational materials was measured through a pretest-posttest research design on Indiana fourth grade school children (n=736) and their respective teachers (n=39). The sample of students and teachers was divided into treatment and control groups. Quantitative data were collected through questionnaires. The findings indicated the educational materials developed and assessed for this study were effective in increasing knowledge of agricultural professions among both the treatment group students and teachers. The treatment group students were significantly more likely to see agricultural careers as interesting and exciting.
Supervisory Practices Used By Teacher Educators in Agriculture
Authors: Fritz Carrie A. , Miller Greg
Published: December 2010

The purposes of this study were to determine the status of student teacher supervision in agricultural education, the extent to which teacher educators in agricultural education used select models of supervision, and the relationship between the level of supervision and selected indicators of supervisor maturity. Results of this census study provide benchmark data on supervisory practices followed by teacher educators in agriculture. The supervisors (N=145) who participated in the study devoted, on average, 20% of their academic appointment to supervision. The majority of the respondents had received formal training on supervision. On average, respondents had been a university supervisor for 13 years and had served as a cooperating teacher for two student teachers. Based on the proposed Escalation Model, respondents used components of the structured level to a higher extent than the moderately structured or relatively unstructured levels. In addition, there was a low to negligible correlation between selected indicators of supervisor maturity and the most frequently used level of the Escalation Model.
Certification Measures: Are They Predictive Of Secondary Agriculture Teacher Proficiency?
Authors: Graham James C. , Garton Bryan L.
Published: December 2010

The purpose of this study was to assess the ability of teacher preparation program certification requirements to predict classroom teaching performance. The accessible sample consisted of 12 Agricultural Education graduates from the University of Missouri. Teaching performance was assessed by the teacher's supervising administrator using the Performance Based Teaching Evaluation instrument, and by the researcher through classroom observations using the Formative Assessment of Teaching instrument. The first research objective sought to describe the teacher certification requirements that were predictive of teaching performance during the initial years of teaching as assessed by the teachers' administrative supervisors. Agricultural education coursework GPA accounted for 40% of the variance associated with teaching performance, as assessed by public school administrators. The second research objective sought to describe the teacher certification requirements that were predictive of observed classroom teaching performance. Upon regressing the dependent variable, teaching performance, on the seven certification measures, no certification measure, or combination of certification measures, were found that could explain a significant proportion of the variance in teaching performance. Research objective three sought to describe school administrators' perceptions of necessary teaching characteristics and the relationship between cognitive abilities and teaching performance. Administrators, in face-to-face interviews, emphasized the importance of affective characteristics to teaching. Administrators perceived that higher academic abilities did not necessarily equate to successful teaching performance.
Agricultural Education Research Capacity In NCA-24 Institutions
Authors: Greiman Bradley C. , Birkenholz Robert J.
Published: December 2010

This study was conducted to assess the research capacity of agricultural educators in NCA-24 institutions. Research capacity was defined as the collective capability of agricultural education faculty to conduct independent research or to contribute to interdisciplinary research. The purpose of this study was to identify factors that characterize research capacity in agricultural education. Agricultural education faculty from 12 land grant institutions represented on the NCA-24 Agricultural Education Research Committee provided data for this study. Respondents were asked to report information regarding their individual faculty appointment and their level of expertise in several research and disciplinary skill areas. Agricultural education faculty reported smaller research appointments than teaching appointments. Respondents also reported wide variations in grant funding, graduate degrees awarded, and research publications. Individual faculty responses varied widely for each of 12 research planning skill areas and 27 disciplinary skill areas. Research capacity should be assessed for the entire agricultural education profession. Increased emphasis should be placed on research activities through faculty appointments and graduate student preparation. Agricultural education faculty should identify and promote a core of research and disciplinary skills.
Technology Integration By Agriscience Teachers In The Teaching/Learning Process
Authors: Kotrlik Joe W. , Redmann Donna H. , Douglas Bruce B.
Published: December 2010

The purpose of this study was to determine how technology was being integrated in the teaching/learning process in secondary agriscience education programs for four distinct and independent phases: Exploration, Experimentation, Adoption, and Advanced Integration. The study was based on the Kotrlik-Redmann Technology Integration Model©. The phases in which agriscience teachers are most active are exploration of the potential of using technology in the teaching/learning process, and adopting technology for regular use in instruction; however, they are functioning at a moderate level in both phases. They are not very active in the experimentation phase or in the advanced integration phase. Moderate barriers exist that prevent teachers from integrating technology into the teaching/learning process. Generally, agriscience teachers perceive that they are good teachers, although some have doubts. Agriscience teachers are experiencing a moderate level of technology anxiety. Teachers continue to use traditional sources for their technology training. Teachers' perceptions of barriers to the integration of technology, their technology anxiety, and their perceptions of their own teaching effectiveness are strong predictors of the extent to which agriscience teachers integrate technology in the teaching/learning process.
Agricultural Communications Students' Awareness And Perceptions Of Biotechnology Issues
Authors: Wingenbach Gary J. , Rutherford Tracy A. , Dunsford Deborah W.
Published: December 2010

The purpose of this study was to determine college students' awareness of and perceptions toward biotechnology issues reported in the mass media. Agricultural communications students (N = 330) responded from 11 land-grant universities in 10 states; respondents were mostly seniors (46%), female (55%), and considered themselves "B" average students (60%). Respondents were most aware of biotechnology practices affecting their food, but only somewhat aware of their effects on health or the environment. They were somewhat accepting of biotechnology practices for genetically modified organisms involving plant life, but viewed these same practices as somewhat unacceptable for using on humans. Respondents ranked knowledge from science classes, experience in science labs, and university professors' biotechnology beliefs as the top three sources used most often to form their perceptions about biotechnology. Agricultural communications educators are encouraged to seek opportunities that engage students in the learning processes of biotechnology, especially for students who lack an agricultural background. Such opportunities may include establishing student internships; site visits to biotechnology firms, regulatory and communication agencies; and professional interactions with biotechnology scientists.
FEMALE LEADERSHIP IN RURAL FLORIDA FFA CHAPTERS
Authors: Ricketts John C. , Osborne Edward W. , Rudd Rick D.
Published: December 2010

The purpose of this investigation was to explain the factors supporting the emergence of females in leadership roles in rural Florida FFA chapters. Six schools, seventeen female leaders, six agriscience instructors, and nine parents participated in the qualitative portion of the study, and 51 additional students provided quantitative data. The findings suggested that females were more active in career development events, officer positions, and other leadership development activities. The emergent themes devised from the qualitative data indicated that female leaders in local FFA chapters were more willing workers, more achievement oriented, felt a greater need for power, were more mature, had a greater need for affiliation, and were more willing to work outside their comfort zone than male FFA members. In addition, participants believed that female FFA members are more active in FFA activities that are based upon the non-production content areas of today’s agriscience curriculum.
PERSEVERANCE OF AGRICULTURAL EDUCATORS BY ACADEMIC ATTAINMENT
Authors: Rogers James F. , Townsend Christine D. , Lindner James R.
Published: December 2010

This study was designed to examine perseverance levels of agricultural education educators. The study design was descriptive and correlational with data collected using a written questionnaire that was mailed to a stratified, systemic sample drawn from a nationwide population. T-tests and analysis of variance were conducted to examine mean cumulative perseverance score by educational attainment and personal characteristics. Overall, agricultural educators indicated high levels of perseverance. Mean cumulative perseverance scores of agricultural educators did not differ by attainment of degree. Mean cumulative perseverance scores of agricultural educators did not differ by gender, status of enrollment, hours worked per week while a student, dependents, single parent status, or method of payment for most recent degree. Perseverance was not found to be a personality trait that distinguished educational attainment of agricultural educators.
A TRI-STATE NEEDS ASSESSMENT OF EMOTIONAL INTELLIGENCE IN AGRICULTURAL EDUCATION
Authors: Akers Cindy , Miller Keri , Fraze Steven D. , Haygood Jacqui D.
Published: December 2010

This study explored the importance and inclusion of emotional intelligence in the existing curriculum by agricultural education instructors. Although much research has been conducted about the importance of emotional intelligence in the realm of education, research in the area of emotional intelligence in agricultural education programs is limited. The concept of incorporating emotional intelligence into the agriscience curriculum is not a new idea. The very philosophy of agricultural education lends itself to the development of emotional intelligence. Agricultural education instructors identified eight out of twenty emotional intelligence competency areas identified through the review of literature as high-level success abilities. This means agricultural education instructors believe these competency areas are important and they are actually including them in their current curriculum. Eleven of the twenty emotional intelligence competency areas were identified as low-level needs. This indicates that agricultural education instructors do not believe these competency areas are important, and therefore they do not believe that the competency areas need to be included in their programs. One competency area, conflict resolution, was identified as being a critical need. This indicates that teachers believe conflict resolution is important, but they are not including it in their program curriculum.
Comparison between simulated and observed chemical composition of fine aerosols in Paris (France) during springtime: contribution of regional versus continental emissions
Authors: Sciare J. , d'Argouges O. , Zhang Q. J. , Sarda-Estève R. , Gaimoz C. , Gros V. , Beekmann M. , Sanchez O.
Published: December 2010

Abstract. Hourly concentrations of inorganic salts (ions) and carbonaceous material in fine aerosols (aerodynamic diameter, A.D. <2.5 μm) have been determined experimentally from fast measurements performed for a 3-week period in spring 2007 in Paris (France). The sum of these two chemical components (ions and carbonaceous aerosols) has shown to account for most of the fine aerosol mass (PM2.5). This time-resolved dataset allowed investigating the factors controlling the levels of PM2.5 in Paris and showed that polluted periods with PM2.5 > 15 μg m−3 were characterized by air masses of continental (North-Western Europe) origin and chemical composition made by 75% of ions. By contrast, periods with clean marine air masses have shown the lowest PM2.5 concentrations (typically of about 10 μg m−3); carbonaceous aerosols contributing for most of this mass (typically 75%). In order to better discriminate between local and continental contributions to the observed chemical composition and concentrations of PM2.5 over Paris, a comparative study was performed between this time-resolved dataset and the outputs of a chemistry transport model (CHIMERE), showing a relatively good capability of the model to reproduce the time-limited intense maxima observed in the field for PM2.5 and ion species. Different model scenarios were then investigated switching off local and European (North-Western and Central) emissions. Results of these scenarios have clearly shown that most of the ions observed over Paris during polluted periods, were either transported or formed in-situ from gas precursors transported from Northern Europe. On the opposite, long-range transport from Europe appeared to weakly contribute to the levels of carbonaceous aerosols observed over Paris. The model failed to properly account for the concentration levels and variability of secondary organic aerosols (SOA) determined experimentally by the EC-tracer method. The abundance of SOA (relatively to organic aerosol, OA) was as much as 75%, showing a weak dependence on air masses origin. Elevated SOA/OA ratios were also observed for air masses having residence time above ground of less than 10 h, suggesting intense emissions and/or photochemical processes leading to rapid formation of secondary organic aerosols.
Error characterisation of global active and passive microwave soil moisture datasets
Authors: Dorigo W. A. , Scipal K. , Parinussa R. M. , Liu Y. Y. , Wagner W. , de Jeu R. A. M. , Naeimi V.
Published: December 2010

Abstract. Understanding the error structures of remotely sensed soil moisture observations is essential for correctly interpreting observed variations and trends in the data or assimilating them in hydrological or numerical weather prediction models. Nevertheless, a spatially coherent assessment of the quality of the various globally available datasets is often hampered by the limited availability over space and time of reliable in-situ measurements. As an alternative, this study explores the triple collocation error estimation technique for assessing the relative quality of several globally available soil moisture products from active (ASCAT) and passive (AMSR-E and SSM/I) microwave sensors. The triple collocation is a powerful statistical tool to estimate the root mean square error while simultaneously solving for systematic differences in the climatologies of a set of three linearly related data sources with independent error structures. Prerequisite for this technique is the availability of a sufficiently large number of timely corresponding observations. In addition to the active and passive satellite-based datasets, we used the ERA-Interim and GLDAS-NOAH reanalysis soil moisture datasets as a third, independent reference. The prime objective is to reveal trends in uncertainty related to different observation principles (passive versus active), the use of different frequencies (C-, X-, and Ku-band) for passive microwave observations, and the choice of the independent reference dataset (ERA-Interim versus GLDAS-NOAH). The results suggest that the triple collocation method provides realistic error estimates. Observed spatial trends agree well with the existing theory and studies on the performance of different observation principles and frequencies with respect to land cover and vegetation density. In addition, if all theoretical prerequisites are fulfilled (e.g. a sufficiently large number of common observations is available and errors of the different datasets are uncorrelated) the errors estimated for the remote sensing products are hardly influenced by the choice of the third independent dataset. The results obtained in this study can help us in developing adequate strategies for the combined use of various scatterometer and radiometer-based soil moisture datasets, e.g. for improved flood forecast modelling or the generation of superior multi-mission long-term soil moisture datasets.
Ethylene
Authors: Sundaram K. M. , Shreehan M. M. , Olszewski E. F.
Published: December 2010

In this comprehensive discussion of the production and uses of ethylene, the topics covered include the properties of ethylene, industrial production, storage, shipping, handling, and economics. Extensive coverage of the commercial production via thermal cracking is detailed.This reaction is discussed as well as the methods employed to predict the feedstock conversion. Product distributions are given for a variety of feedstocks. A description of the industrial furnaces available is given as well as description and process flow diagrams. Information is provided on coke deposition during the cracking process, giving the methods used to inhibit coke production and methods used to remove coke deposited, Ethylene is the largest volume building block for many petrochemicals. Although ethylene is a colorless gas with a mild odor that is not irritating to the eyes or respiratory system, it is considered a mild asphyxiant.
Restorative Regeneration of Digital Tips in the African Clawed Frog (Xenopus laevis Daudin)
Authors: Russell Anthony P. , Maddin Hillary C. , Chrbet Tasha
Published: December 2010

Localized, specialized structures are carried on the tips of digits of many amniote and certain non‐amniote tetrapods. The pes of some members of Pipidae represents a rare example among tetrapods of differential expression of digital tip form (clawed vs. non‐clawed digits). As a step towards understanding how such localized forms are generated and maintained, we conducted a series of amputation experiments and observed, through the process of regeneration, the potential for reconstitution, at the tissue and organ level, of the different digit tip morphologies. Results of this study reveal that immediately following metamorphosis specialized digit tip structures are regenerated with a high degree of structural and spatial accuracy by a process that essentially replicates normal development in recently metamorphosed Xenopus laevis froglets. Furthermore, this regenerative capacity is maintained in juveniles 4 months beyond metamorphosis, and also in adults of 1 year or more in age, indicating that metamorphosis‐specific conditions do not exclusively facilitate regeneration of digit tips. In addition, regenerative capacity is maintained through repeated bouts of amputation and regeneration, indicating deep‐seated digit identity and retention of the distinct digit tip developmental programs within the digits. Together, these data suggest that the developmental programing responsible for the formation of the discrete digital tip morphologies is located regionally within each digit, and that it is retained through time. Our results suggest that Xenopus can serve as a model organism for exploring the molecular underpinnings of digit tip formation because regeneration leads to morphologically identical structures to those of the original digit tips. Anat Rec, 2011. © 2010 Wiley‐Liss, Inc.
Identification of N‐Acetylgalactosamine in Carbohydrates of Xenopus laevis Testis
Authors: Valbuena Galder , Alonso Edurne , Díaz‐Flores Lucio , Madrid Juan Francisco , Sáez Francisco José
Published: December 2010

Identification of glycans in amphibian testis has shown the existence of N‐acetylgalactosamine (GalNAc)‐containing carbohydrates. Labeling of the sperm acrosome with GalNAc‐binding lectins has allowed the identification of GalNAc‐containing glycans in this organelle. Futhermore, this specific labeling of the acrosome has allowed the study of acrosomal biogenesis by lectin histochemistry. However, the testis of Xenopus laevis has never been analyzed by lectin histochemistry to locate GalNAc‐containing glycoconjugates. The aim of this work was to elucidate the expression of GalNAc in glycoconjugates of Xenopus testis using five specific lectins. The results showed that most of the lectins labeled the interstitium with variable intensity. However, labeling of the different spermatogenetic germ cell types showed different labeling patterns. Some lectins produced weak or very weak staining in germ cells, for example, horse gram Dolichos biflorus agglutinin, which labeled most of the germ cell types, and lima bean Phaseolus lunatus agglutinin, which weakly labeled only spermatogonia, but did not stain other germ cells. By contrast, Maclura pomifera lectin (MPL) moderately labeled all germ cell types, except mature sperm. Labeling with other lectins was seen only at later stages, suggesting variations involved in the spermatogenetic development. Thus, snail Helix pomatia agglutinin labeled spermatids, but neither spermatogonia nor spermatocytes, while soybean Glycine max agglutinin (SBA) labeled from preleptotene spermatocytes to later stages. The periphery of the acrosome was labeled with MPL and SBA, but no specific labeling of the acrosomal content was seen with any lectin. Thus, the GalNAc‐binding lectins that have been used as acrosomal markers in some amphibians cannot be used in Xenopus testis, suggesting that acrosomal glycoconjugates in amphibians are species specific. Anat Rec, 2011. © 2010 Wiley‐Liss, Inc.
Proportional multiple‐integral observer design for continuous‐time descriptor linear systems
Authors: Wu Ai‐Guo , Duan Guang‐Ren , Liu Wanquan
Published: December 2010

In this paper, a new type of proportional multiple‐integral observer is proposed for continuous‐time descriptor linear systems. A parametric design approach for the proposed observers is presented. Based on a complete general parametric solution to the generalized Sylvester‐observer matrix equation, complete parameterizations for all the observer gains are established in terms of four parameter matrices. The proposed approach can offer full design freedom, and has great potential in applications. A numerical example is given to show the design procedure and the effectiveness of the proposed approach.

Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Pharmacokinetics of dietary cancer chemopreventive compound dibenzoylmethane in rats and the impact of nanoemulsion and genetic knockout of Nrf2 on its disposition
Authors: Lin Wen , Hong Jin‐Liern , Shen Guoxiang , Wu Rachel T. , Wang Yuwen , Huang Mou‐Tuan , Newmark Harold L. , Huang Qingrong , Khor Tin Oo , Heimbach Tycho , Kong Ah‐Ng
Published: December 2010

The pharmacokinetic disposition of a dietary cancer chemopreventive compound dibenzoylmethane (DBM) was studied in male Sprague‐Dawley rats after intravenous (i.v.) and oral (p.o.) administrations. Following a single i.v. bolus dose, the mean plasma clearance (CL) of DBM was low compared with the hepatic blood flow. DBM displayed a high volume of distribution (Vss). The elimination terminal t1/2 was long. The mean CL, Vss and AUC0−∞/dose were similar between the i.v. 10 and 10 mg/kg doses. After single oral doses (10, 50 and 250 mg/kg), the absolute oral bioavailability (F*) of DBM was 7.4%–13.6%. The increase in AUC was not proportional to the oral doses, suggesting non‐linearity. In silico prediction of oral absorption also demonstrated low DBM absorption in vivo. An oil‐in‐water nanoemulsion containing DBM was formulated to potentially overcome the low F* due to poor water solubility of DBM, with enhanced oral absorption. Finally, to examine the role of Nrf2 on the pharmacokinetics of DBM, since DBM activates the Nrf2‐dependent detoxification pathways, Nrf2 wild‐type (+/+) mice and Nrf2 knockout (−/−) mice were utilized. There was an increased systemic plasma exposure of DBM in Nrf2 (−/−) mice, suggesting that the Nrf2 genotype could also play a role in the pharmacokinetic disposition of DBM. Taken together, the results show that DBM has low oral bioavailability which could be due in part to poor water solubility and this could be overcome by a nanotechnology‐based drug delivery system and furthermore the Nrf2 genotype could also play a role in the pharmacokinetics of DBM. Copyright © 2010 John Wiley & Sons, Ltd.
Engineering of baculovirus vectors for the manufacture of virion‐free biopharmaceuticals
Authors: Marek Martin , van Oers Monique M. , Devaraj Feana Francis , Vlak Just M. , Merten Otto‐Wilhelm
Published: December 2010

A novel baculovirus‐based protein expression strategy was developed to produce recombinant proteins in insect cells without contaminating baculovirus virions. This novel strategy greatly simplifies the downstream processing of biopharmaceuticals produced in insect cells. The formation of these virions is prevented by deletion of a baculovirus gene essential for virion formation. The deletion is trans‐complemented in a transgenic insect cell line in which the baculovirus seed stock is produced. The Autographa californica multicapsid nucleopolyhedrovirus vp80 gene was selected for this purpose, as absence of VP80 prevented the formation of budded virus as well as occlusion‐derived virus, while foreign gene expression was not affected. Sf9 insect cells were engineered to functionally complement the vp80 deletion in the expression vector virus during seed stock production. The trans‐complemented vp80‐deletion baculovirus seed produced an amount of recombinant protein similar to that produced with conventional baculovirus vectors but without contaminating virions. This novel expression method obviates the need to purify the virions away from the biopharmaceuticals. Bioeng. 2011; 108:1056–1067. © 2010 Wiley Periodicals, Inc.
Three hours of perfusion culture prior to 28 days of static culture, enhances osteogenesis by human cells in a collagen GAG scaffold
Authors: Keogh Michael B. , Partap Sonia , Daly Jacqueline S. , O'Brien Fergal J.
Published: December 2010

In tissue engineering, bioreactors can be used to aid in the in vitro development of new tissue by providing biochemical and physical regulatory signals to cells and encouraging them to undergo differentiation and/or to produce extracellular matrix prior to in vivo implantation. This study examined the effect of short term flow perfusion bioreactor culture, prior to long‐term static culture, on human osteoblast cell distribution and osteogenesis within a collagen glycosaminoglycan (CG) scaffold for bone tissue engineering. Human fetal osteoblasts (hFOB 1.19) were seeded onto CG scaffolds and pre‐cultured for 6 days. Constructs were then placed into the bioreactor and exposed to 3 × 1 h bouts of steady flow (1 mL/min) separated by 7 h of no flow over a 24‐h period. The constructs were then cultured under static osteogenic conditions for up to 28 days. Results show that the bioreactor and static culture control groups displayed similar cell numbers and metabolic activity. Histologically, however, peripheral cell‐encapsulation was observed in the static controls, whereas, improved migration and homogenous cell distribution was seen in the bioreactor groups. Gene expression analysis showed that all osteogenic markers investigated displayed greater levels of expression in the bioreactor groups compared to static controls. While static groups showed increased mineral deposition; mechanical testing revealed that there was no difference in the compressive modulus between bioreactor and static groups. In conclusion, a flow perfusion bioreactor improved construct homogeneity by preventing peripheral encapsulation whilst also providing an enhanced osteogenic phenotype over static controls. Bioeng. 2011; 108:1203–1210. © 2010 Wiley Periodicals, Inc.