bluuebunny/crossref_metadata_2025 huggingface dataset:
THE CONTRIBUTIONS OF E.M. TIFFANY AND THE FFA CREED TO LEADERSHIP DEVELOPMENT WITHIN THE FFA
Authors: Connors James J. , Velez Jonathan J.
Published: April 2010

The FFA Creed by E.M. Tiffany has influenced the lives of countless FFA members. However, the creed has received little attention in terms of its origin. A creed is a foundational component for many organizations. It serves to establish collective vision and goals with the intent of providing purpose and direction to the individual as well as the organization. This historical research study investigated the origins of the FFA Creed, the motivations of its author E.M. Tiffany, how it has been modified over its history, and its use as a leadership development tool through creed speaking events. The FFA Creed was written by E.M. Tiffany in 1928 and officially adopted by the National FFA Organization in 1930. The creed was revised twice to form the current version. A new FFA Creed was proposed in 1990 and overwhelmingly rejected by a committee of delegates to the national FFA convention. The impact of the creed on leadership development has been substantial. Local, state, and national career development events have been created to enhance this leadership development opportunity. The creed has evidenced a resilience through the last 80 years and continues to provide leadership, direction and value to current and former FFA members.
TEACHER BURNOUT AND JOB SATISFACTION AMONG AGRICULTURAL EDUCATION TEACHERS
Authors: Chenevey Jamie L. , Ewing John C. , Whittington M. Susie
Published: April 2010

The demands on teachers both in and out of classrooms combined with increased budget cuts have led many to question the levels of job satisfaction and burnout among agricultural education teachers. The purpose of this study was to describe the occurrence of burnout and the level at which burnout exists among agricultural education teachers in Ohio. The study was also designed to consider the relationships between job satisfaction, occupational stress, personal strain, personal coping resources, and burnout among agricultural education teachers. A random sample (n = 388) of the population (N = 628) received a mailed questionnaire (37% response, n = 145). Teachers were described predominantly as married, white males with one to two children and less than 10 years of experience in their present positions. The majority of agricultural education teachers in the study possessed high levels of job satisfaction, low levels of occupational stress and personal strain, and high levels of personal coping resources. However, teachers in the study indicated a moderate level of frequency of burnout and a moderate to high level of intensity of burnout. No significant relationships were found between demographic characteristics and burnout, or between organizational factors and burnout.
INVESTIGATING COMMUNITY FACTORS AS PREDICTORS OF RURAL 11THGRADE AGRICULTURAL SCIENCE STUDENTS’ CHOICE OF CAREERS IN AGRICULTURE
Authors: Adedokun Omolola A. , Balschweid Mark A.
Published: April 2010

This study investigates the links between community contexts/factors and rural 11th-grade agricultural science students’ choice of careers in agriculture. A logistic regression model was developed and tested to examine the extent to which nine measures of community contexts (i.e., membership in FFA, membership in 4-H, community attachment, community satisfaction, length of residency in the community, positive perception of local community, preference for residing close to nature, and participation in volunteer activities) influence the odds of a student choosing a career in agriculture. The results show that the major community factors influencing the choice of agriculture related careers are membership in 4-H club, participation in FFA, preference for living close to natural environment, opportunity to achieve dream career in the rural community, and participation in volunteer activities within the community.
AN EVALUATION OF INNER-CITY YOUTH GARDEN PROGRAM PARTICIPANTS’ DIETARY BEHAVIOR AND GARDEN AND NUTRITION KNOWLEDGE
Authors: Lautenschlager Beckman Lauren , Smith Chery
Published: April 2010

Unhealthful eating patterns established early in life tend to be maintained into adulthood, and as a result, chronic diseases such as heart disease, cancer, and obesity may develop. These nutrition-related problems could be reduced through dietary changes; and to facilitate these changes, nutrition education for youth that is delivered experientially may be an effective beginning. Garden curricula, which have a strong experiential learning basis, have been proposed as a method to reinforce nutrition education. Therefore, the purpose of this study was to evaluate dietary behaviors as well as nutrition/gardening knowledge among multiethnic innercity youth garden program participants using the expanded theory of planned behavior. Youth attending a 10-week garden program completed a pre- and post-survey. Results indicated that gender and age differences were present in both dietary behavior and nutrition/gardening knowledge. Boys significantly increased their fruit and vegetable intake from the pre- to postsurvey, whereas girls significantly increased meat and cholesterol consumption. Garden programs have the potential to positively affect inner-city youths’ dietary behaviors and nutrition/gardening knowledge; but because results suggest that learning style differences were present in terms of gender and age, , further evaluation is needed for the development of appropriate programs.
IT’S IN THE GENES: EXPLORING RELATIONSHIPS BETWEEN CRITICAL THINKING AND PROBLEM SOLVING IN UNDERGRADUATE AGRISCIENCE STUDENTS’ SOLUTIONS TO PROBLEMS IN MENDELIAN GENETICS
Authors: Friedel Curtis R. , Irani Tracy A. , Rhoades Emily B. , Fuhrman Nicholas E. , Gallo Maria
Published: April 2010

This study was conducted to examine the statistical relationship between problem solving and critical thinking to guide future teaching and research for agricultural educators using the problem-solving approach. Students enrolled in an undergraduate genetics course in the College of Agricultural and Life Sciences at the University of Florida were prompted to use their criticalthinking skills while answering a problem in the context of biotechnology. Students’ criticalthinking skills were assessed through content analysis of a think-aloud protocol. Other cognitive factors assessed included problem-solving style, problem-solving level, and critical-thinking disposition. A path analysis was used to examine how these trait-based variables and use of critical-thinking skills contribute to solving a problem. Of these cognitive factors, only problem-solving level, critical-thinking disposition, and use of critical-thinking skills were included in the revised model. The authors argue that although correlations were significant, they were low and indicated that critical thinking and problem-solving may be more independent than previously thought. Limitations of this study require more research to better understand how these cognitive factors are employed by the learner to solve problems.
TOTAL PROGRAM EFFICACY: A COMPARISON OF TRADITIONALLY AND ALTERNATIVELY CERTIFIED AGRICULTURE TEACHERS
Authors: Duncan Dennis W. , Ricketts John C.
Published: April 2010

The purpose of this study was to determine agriculture teachers’ perceived levels of efficacy as they relate to managing the total program of agricultural education, both for traditionally and alternatively certified teachers. The constructs used in this study were technical content, FFA/leadership development/SAE, teaching and learning, and program management. Respondents consisted of 136 traditionally certified teachers and 76 alternatively certified teachers at either the middle and/or high school level. Traditionally certified teachers were predominately male (81%); alternatively certified teachers were 63% male. Traditionally certified teachers had either earned a bachelor’s and/or master’s degree, alternatively certified teachers indicated having obtained a least a master’s degree. Ninety-six percent of traditionally certified teachers have an advisory committee versus 88% of alternatively certified teachers. Traditionally certified teachers were most efficacious in their program management abilities and least efficacious in the technical agriculture content knowledge. Alternatively certified agriculture teachers were most efficacious in their pedagogical strategies and least efficacious in their technical agriculture content knowledge. Technical content was the lowest teacher efficacy variable for both groups. Traditionally certified agriculture teachers exhibit more selfefficacy than alternatively certified teachers in technical content knowledge, in conducting FFA, leadership development, and SAE activities, and in managing the total program.
EXAMINING THE INSTRUCTIONAL PLANNING PROCESS TAUGHT IN AGRICULTURAL EDUCATION TEACHER PREPARATION PROGRAMS: PERSPECTIVES OF UNIVERSITY FACULTY
Authors: Greiman Bradley C. , Bedtke Mary Anne
Published: April 2010

Instructional planning is a curricular topic in teacher preparation programs, but limited research in agricultural education has been conducted in this area. The purpose of this study was to examine aspects of the instructional planning process that are taught to agricultural education preservice teachers. Survey research and content analysis of course materials was utilized to collect and analyze data. The population for the study was a census of agricultural education teacher educators who taught instructional planning to preservice teachers at land grant institutions during 2006-2007. This study found that the two most frequent instructional planning models being taught were the Allen 4-step and the Madeline Hunter direct instructional model. A majority of the instructional plan components being utilized were aligned with Searcy and Maroney’s (1996) literature review; however, notable exceptions pertained to estimated time required and reflection. Teacher educators were most frequently requiring Methods of Teaching Agriculture (Newcomb, McCracken, Warmbrod, & Whittington, 2004) as a required text and a course Web site as a required student reading resource. This study concluded that while instructional plan requirements did not change at a number of institutions during student teaching compared with when taught during coursework, there were changes whereby a more succinct or more expanded instructional plan was required.
Examining Differences in Middle School Student Achievement on a Criterion-Referenced Competency Test (CRCT) in Science
Authors: Rich Jamie , Duncan Dennis W. , Navarro Maria , Ricketts John C.
Published: April 2010

Many authors have posited that agricultural education curriculum in middle schools may enhance student performance in science. To determine the effect that agricultural education curriculum has upon Georgia middle schools’ student performance in science, this descriptive study compared science knowledge among middle school students in Georgia who were enrolled in schools with and without agricultural education programs. To quantify the science knowledge and skills of students, the researchers used the state’s annual Criterion-Referenced Competency Test (CRCT) (science), mandatory for all students in middle schools. The scores of students in the 51 middle schools in the state with agricultural education programs were compared to the scores of students in 51 similar schools that did not have an agricultural education program. The percentage of students meeting or exceeding the standards in the CRCT test were consistently higher (and sometimes significantly higher) in schools with agricultural education programs over two consecutive school years. Although the researchers cannot conclude that the difference is due solely to the agricultural education programs, the results of this study open a myriad of opportunities for further research.
Evaluation of Agricultural Professionals' Perceptions and Knowledge on Sustainable Agriculture: A Useful Step in the Development of an Online Extension Program
Authors: Menalled Fabian D. , Grimberg Bruna I. , Jones Clain A.
Published: April 2010

This study assessed needs, knowledge, and interests of agricultural professionals who were likely to enroll in an online extension course in sustainable agriculture. The objectives of the study were: to (1) describe their demographic characteristics, (2) identify their concerns and interests related to farming, (3) evaluate participants’ knowledge and adoption of sustainable farming practices, and (4) use the evidence to implement a distance education program in sustainable agriculture. A questionnaire was distributed electronically through mailing lists and Web sites. Responses were analyzed using a text analysis and a Chi-square test to evaluate the existence of associations between interests and knowledge in sustainable agriculture. Despite the study participants’ diverse professions and backgrounds, they identified similar constraints impeding the adoption of sustainable farming practices. They further proposed solutions, many of which are supported by current agroecological research, indicating a vast knowledge base regarding sustainable farming. The findings were used to develop and deliver an online extension program in sustainable agriculture. This study highlights the importance of understanding the levels of knowledge, concerns, and interests of the targeted audience. Incorporating this understanding into an extension program through peer-to-peer collaboration in discussion forums and electronic mail could facilitate the dissemination of innovate education approaches to teach sustainable agriculture.
Toward an Intellectual Common for Agricultural Education
Authors: Camp William G.
Published: April 2010

This manuscript provides the expanded text that formed the basis for the 2009 Distinguished Lecture presented at the annual conference of the American Association for Agricultural Education. Commons have existed in various forms as long as humankind has struggled for survival. In a very real sense, our hunter–gather ancestors stepped into a common every time they went forth so seek sustenance. As civilization developed, governments established more formal commons for public gatherings and for trading. Adam Smith’s vision of a free market economy is effectively that of an economic common unfettered by excessive regulation. In the past few decades, the Internet has developed into a massive and pervasive cyber–common. In the past few years the concept of the academic or intellectual common has started to develop. The author examines the concept of the common from historical and modern perspectives and proposes an intellectual common for university–level agricultural education under the management of AAAE.
Usability Evaluation of an Online Media Resource Guide
Authors: Cooper-Jennett Kim , Akers Cindy , Doerfert David , Chambers Todd
Published: April 2010

This study used a survey research design to evaluate the effectiveness, efficiency, satisfaction, credibility, and therefore, the overall usability of CottonLink, an online media resource guide as determined by members of the Texas Plains region associated press medium. Using a modified version of Dillman’s (2000) Tailored Design Method, the response rate reached 54.2%, with a total of 39 completed online surveys. The researcher designed instrument achieved acceptable reliability scores for each portion of usability: effectiveness ,0.95; efficiency,0 .98; satisfaction, 0.92; credibility, 0.92; and overall usability, 0.97. Respondent’s found the Web site to be effective, efficient, satisfying, credible, and usable. Findings were relevant for both researchers and practitioners. Future research should evaluate terminology related to usability test actual agriculture knowledge and experience, analyze usability qualitatively, and replicate this study with a larger population. Recommended practices for practitioners include continually develop usable educational resources for media members, extend media resource guides for additional commodities and states, and hold training workshops for both media and industry representatives.
Is Extension Still Reaching Stakeholders? An Assessment of Minor Crop Producers’ Educational Needs and Use of Cooperative Extension Services
Authors: Franke-Dvorak Tanya C. , Kelsey Kathleen D. , Royer Tom A.
Published: April 2010

Stakeholder engagement is critical for extension education to fulfill the land–grant mission of extending the university to the public. A survey of a stratified random sample of minor crop producers in Oklahoma determined how and from whom producers obtained crop production information. Findings indicated the land–grant university remains relevant and is accomplishing its mission of extending research–based knowledge to its intended audience. Field days were the most frequently attended event and a majority of the producers worked with university personnel to learn about new production practices. Most producers (67%) used Cooperative Extension Service (CES) to obtain crop production information; however, many other sources were also used, including crop consultants. Extension specialists were contacted; however, extension educators had not sufficiently engaged stakeholders to assess their preferences of receiving educational programs and materials, indicating producers seek deeper knowledge than what is provided by county educators. It is recommended that the university continue to host field days and workshops for producers and CES educators continuously strive to engage minor crop producers and devise relevant workshops, programs, and publications which address their preferred method of receiving information from the land–grant university.
Mixing and Blending
Authors: Dickey David S.
Published: April 2010

Mixing and blending are processes by which fluids, powders, and gases are made more homogeneous or more uniformly dispersed. Mixing is difficult to categorize, because of the many possible combinations and applications. Often the phases present: liquids, solids, gases, or combinations, will describe the mixing characteristics or suggest intensity requirements. In the process industries, a mixing step may be the critical one that converts raw materials into products. Most chemical reactions, many biological processes, nearly all formulations, and many physical conversions involve some type of mixing operation. Besides being called mixing, terms like agitation, blending, and stirring are used as both general and specific descriptions of related operations. Mixing and agitation are most often used in the context of fluid or powder motion. Mixing or blending may refer more specifically to the combination of different materials. The broad use of mixing processes and equipment can be found in many chemical applications.
Resins, Natural
Authors: Class Jay B.
Published: April 2010

Natural resins are solid, amorphous, usually transparent or translucent organic substances that originate from plant secretions. They may be obtained directly as tree or plant extrudates. Shellac is refined from insect secretions. These resins may be altered by methods of isolation or modified in production to increase their industrial utility. Rosin and rosin derivatives are commercially the most important commercial resins. The isolation of rosin from natural resources is discussed as well as properties, composition, chemical reactions, and derivatives. China is the largest producer of rosin and derivatives. Rosin and modified rosins are used in the paper‐making industry as a sizing agent, in ink, adhesives, as a glazing agent, in soap,and in soldering. Traditional natural resins, such as dammar resins, copal, and amber are also discussed. The history, cultivation, production, and composition of shellac are detailed. Shellac is used as a protective coating in the food and pharmaceutical industries. Synthetic resins have replaced shellac in some markets.
Tungsten Compounds
Authors: Penrice Thomas W.
Published: April 2010

Tungsten combines with many other elements to form simple stable compounds. It readily polymerizes, but the chemistry of aqueous solutions is very complex. The chemical uses of tungsten have increased. The compounds discussed fall into the following categories: hexacarbonyl; halides and oxyhalides; sulfides; and interstitial compounds. Properties and uses of these compounds are discussed. Some important compounds,eg, are the halides, which are useful as starting materials in the chemical vapor deposition of tungsten; the oxides are intermediates in the stepwise reduction in hydrogen to metal; ammonium paratungstate (APT) is of commercial significance because it is the precursor of high purity tungsten oxides, tungsten, and tungsten carbide powders. APT is the most widely traded primary tungsten material. More than half of tungsten production is for the preparation of tungsten carbide. The carbides are widely used in the manufacture of hard carbides for high speed machining tools, drill bits, turning tools, etc. Soluble tungsten compounds show varying degrees of toxicity, exposures in the workplace are regulated. In general, tungsten compounds are used to make catalysts, corrosion‐resistant coatings, dyes and pigments, fire‐resistant compounds, lubricants, phosphor, and semiconductors.
The Organic Thermochemistry of Hydroxylamines, Oximes, Hydroxamic Acids and their Derivatives
Authors: Slayden Suzanne W. , Liebman Joel F.
Published: April 2010

Introduction: Scope of the Chapter, Definitions of Key Terms and Sources of Data

Hydroxylamines andN‐Substituted Derivatives

O‐Substituted Hydroxylamine Derivatives (Alkoxylamines)

Monooximes

Glyoxime and Other Dioximes

Quinone Oximes and Nitrosoarenols

Oxime Ethers

Hydroxamic Acids and their Derivatives
NMRSpectra of Hydroxylamines, Oximes and Hydroxamic Acids
Authors: Rudolf Seidl Peter , Fernandes Dias Jacques
Published: April 2010

Introduction

Structural and Conformational Effects

Spectral Parameters

Solvent Effects
Synthesis of Hydroxylamines
Authors: Melman Artem
Published: April 2010

Introduction

Hydroxylamines through Hydrolysis of Hydroxamic Acids, Oximes and Nitrones

Synthesis of Hydroxylamines through Alkylation and Arylation of other Hydroxylamines

Hydroxylamines through Reduction Reactions

Hydroxylamines through Addition to the
C

N
Double Bond of Oximes, Oxime Ethers and Nitrones

Hydroxylamines through Addition to the
N

O
Double Bond of Nitroso and Nitro Compounds

Hydroxylamines through Oxidation of Amines

Hydroxylamines through Cycloaddition Reactions
Synthesis of Oximes and Hydroxamic Acids
Authors: Porcheddu Andrea , Giacomelli Giampaolo
Published: April 2010

Synthesis of Oximes

Synthesis of Hydroxamic Acids
Synthesis of Heterocycles from Oximes
Authors: Abele Edgars , Lukevics Edmunds
Published: April 2010

Introduction

Synthesis of Heterocyclic Compounds from Oximes

Conclusions
Structural Effects on Reactivity and Properties of Oximes and Hydroxamic Acids
Authors: Charton Marvin
Published: April 2010

The Nature of Structural Effects

Electrical Effects

Steric Effects

Intermolecular Forces

Application Methods

Applications of Correlation Analysis to Acidity

Further Applications to Reactivities and Properties
N‐Heteroatom‐Substituted Hydroxamic Esters
Authors: Glover Stephen A.
Published: April 2010

Introduction

Unusual Characteristics ofN‐Heteroatom‐Substituted Hydroxamic Esters

N‐Alkoxy‐N‐Haloamides

N‐Acyloxy‐N‐Alkoxyamides

N,N‐Dialkoxyamides

N‐Alkoxy‐N‐Aminoamides

N‐Alkoxy‐N‐Thioalkylamides

Acknowledgement
Toxic Territories
Authors: Gissen David
Published: April 2010

As half of the world's population has become urbanised, toxic or at least previously built‐up land has become more like the norm. Guest‐editor David Gissen considers the reality for architecture of toxic territories, in which the relationship of architecture with pollution needs to shift from one in which architecture is wholly regarded as a means of separation from a noxious external environment to one of interaction. Copyright © 2010 John Wiley & Sons, Ltd.
The Aurora Project
Authors: Johnson Jason Kelly , Gattegno Nataly
Published: April 2010

The new opportunities for simulation and representation that computer modelling affords designers has been well charted. Jason Kelly Johnson and Nataly Gattegno of Future Cities Lab, however, are combining these new potentials with dynamic mapping and modelling methods derived from modern cartography. The most familiar of these tools is Google Earth, which provides a unique new bird's‐eye view of the earth's surface. Other geographical softwares also combine to enable the manipulation of real‐time, open‐source, user‐generated data as never before. Copyright © 2010 John Wiley & Sons, Ltd.
Mass transfer and separation criteria for high‐speed countercurrent chromatography
Authors: Zhao Chun‐Xia , He Chao‐Hong
Published: April 2010

High‐speed countercurrent chromatography (HSCCC) is a versatile technique for preparative separations of a wide variety of solutes. For optimization of operating conditions, prediction of separations, and scale‐up study, a model is needed to describe the effluent concentration profile, which determines the separation efficiency (mass transfer, mixing, and partitioning) and the resolution between peaks. A transfer‐dispersive model is proposed to describe the effluent profile based on the assumption that the retention of a peak is caused by partitioning over two phases, and peak broadening is caused by axial dispersion and mass transfer limitation. In this work, mass transfer was investigated by comparing model simulations to experimental data. One generalized correlation of overall mass transfer coefficients was derived. Based on the correlations of axial dispersion coefficients in our previous work and mass transfer coefficients in this study, the model predicts the elution concentration profile well. Furthermore, separation criteria were proposed to predict the separation of two adjacent solutes, and they were verified using literature data. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Synthesis and Antibacterial Activity of a Novel Series of 2,3‐Diaryl‐substituted‐imidazo(2,1‐b)‐benzothiazole Derivatives
Authors: Palkar Mahesh , Noolvi Malleshappa , Sankangoud Ramappa , Maddi Veeresh , Gadad Andanappa , Nargund Laxmi Venkat G.
Published: April 2010

Benzothiazole and imidazole compounds are extensively studied heterocyclics due to their wide spectrum of bioactivities. Among them, the imidazo(2,1‐b)‐benzothiazole derivatives are pharmacologically important because of their immunostimulant, anti‐inflammatory, antifungal, antimicrobial, antitumor, and other activities. In the present research work, a novel series of 2,3‐diaryl‐substituted imidazo(2,1‐b)‐benzothiazoles 13a–o have been synthesized by reaction of substituted 2‐aminobenzothiazoles 1–8 and an appropriately substituted α‐bromo‐1‐(4′′‐substituted)‐phenyl‐2‐(4′‐substituted)‐phenyl‐1‐ethanones 9–12 in the presence of anhydrous acetonitrile. They were characterized by physicochemical, elemental, and spectral (IR, 1H‐NMR, and Mass) data. All the synthesized compounds were screened for their in‐vitro antibacterial activity against Gram‐positive, Gram‐negative bacteria. The investigation of antibacterial screening data revealed that most of the compounds tested have demonstrated congruent activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa as compared with the standard ampicillin. Among the series, compounds 13d, 13h, and 13m exhibited excellent an antibacterial activity profile as compared with the standard. In summary, preliminary results indicate that some of the newly synthesized title compounds exhibited promising antibacterial activities and they warrant more consideration as prospective antimicrobials.
Hydrogen‐Bonding Induced Cooperative Effect on the Energy Transfer in Helical Polynorbornenes Appended with Porphyrin‐Containing Amidic Alanine Linkers
Authors: Liu Zhi‐Chang , Chen Chih‐Hsien , Wang Hsian‐Wen , Huang Yen‐Chin , Kao Ming‐Jui , Lim Tsong‐Shin , Luh Tien‐Yau
Published: April 2010

Polynorbornenes appended with porphyrins containing a range of different linkers are synthesized. The use of bisamidic chiral alanine linkers between the pending porphyrins and the polymeric backbone has been shown to bring the adjacent porphyrin chromophores to more suitable orientation for exciton coupling owing to hydrogen bonding between the adjacent linkers. The hydrogen bonding between the adjacent pendants in these polymers may induce a cooperative effect and therefore render single‐handed helical structures for these polymers. Such a cooperative effect is reflected in the enhancement of FRET efficiencies between zinc–porphyrin and free base porphyrin in random copolymers.
Dimeric Capsules Formed by Tetra‐CMPO Derivatives of (Thia)Calix[4]arenes
Authors: Rudzevich Valentyn , Kasyan Oleg , Drapailo Andriy , Bolte Michael , Schollmeyer Dieter , Böhmer Volker
Published: April 2010

Thiacalix[4]arene 2, calix[4]arene 3 a and its tetraether fixed in the cone conformation 3 b form homo‐ and heterodimeric capsules in apolar solvents, which are held together by a seam of NH⋅⋅⋅O=P hydrogen bonds between carbamoylmethyl phospine oxide functions attached to their wide rim. Their internal volume of ∼370 Å3 requires the inclusion of a suitable guest. Although neutral molecules such as adamantane (derivatives) or tetraethylammonium cations form kinetically stable complexes (1H‐ and 31P‐time scale), the included solvent is rapidly exchanged. The internal mobility of the included tetraethylammonium cation is distinctly higher (ΔG=42.5 and 49.7 kJ mol−1 for 3 a and 3 b) than that for similar capsules of tetraurea calix[4]arenes 1. Mixtures of 1 with 2, 3 a, or 3 b contain only the two homodimers but the heterodimerization occurs with the tetraloop tetraurea 6, which cannot form homodimers. Two dimers with cationic guests (2⋅(C5H5)2Co+⋅2 and 3 a⋅Et3NH+⋅H2O⋅3 a) were confirmed by single‐crystal X‐ray analysis.
Dendrimers: A Mimic Natural Light‐Harvesting System
Authors: Zeng Yi , Li Ying‐Ying , Chen Jinping , Yang Guoqiang , Li Yi
Published: April 2010

In natural photosynthetic systems, a large array of chlorophyll molecules surrounds a single reaction center and channels the absorbed solar energy to the reaction center, ultimately resulting in ATP production. Dendrimers are well‐defined tree‐like macromolecules having numerous chain ends all emanating from a single core, which makes them an attractive candidate for light‐harvesting applications. More importantly, their synthesis is controllable and the accurate positioning of chromophores can be achieved. Photoinduced electron transfer and energy transfer are main processes involved in photosynthesis. Studies on these processes in dendritic systems are important for the future application of dendrimers in optoelectronic devices. In this Focus Review we will discuss recent advances of light‐harvesting dendrimers and emphasize the energy transfer and electron transfer characteristics in these systems.
An HPLC assay for the lipophilic camptothecin analog AR‐67 carboxylate and lactone in human whole blood
Authors: Tsakalozou Eleftheria , Horn Jamie , Leggas Mark
Published: April 2010

AR‐67 (7‐t‐butyldimethylsilyl‐10‐hydroxycamptothecin, DB‐67) is a camptothecin analog currently in early stage clinical trials. The lactone moiety of camptothecins hydrolyzes readily in blood to yield the pharmacologically inactive carboxylate form. However the lactone form of third‐generation lipophilic congeners, such as AR‐67, is more stable, possibly due to partitioning into red cell membranes. This prompted us to develop a reverse‐phase HPLC method with fluorescence detection (excitation 380 nm/emission 560 nm), which could quantitate the concentration of AR‐67 lactone and carboxylate in whole blood. Samples were prepared by red cell lysis, protein precipitation with methanol and centrifugation to remove denatured materials. Recovery was estimated to be >85%. Analytes were eluted isocratically with 0.15 m ammonium acetate buffer containing 10 mm TBAP (pH 6.5) and acetonitrile (65:35, v/v) on a Nova‐Pak C18 column (4 µm; 3.9 × 150 mm). The assay was linear in the ranges 0.5–300 and 2.5–300 ng/mL for carboxylate and lactone, respectively. Accuracy and precision were acceptable. AR‐67 forms were stable in whole blood and in methanolic supernatants. This assay has been successfully applied to measure AR‐67 concentrations in whole blood of patients enrolled in a phase I study. Copyright © 2010 John Wiley & Sons, Ltd.
Development and validation of a highly sensitive LC‐MS/MS method for simultaneous quantitation of nortriptyline and 10‐hydroxynortriptyline in human plasma: application to a human pharmacokinetic study
Authors: Hotha Kishore Kumar , Ravindranath L. K. , Veera K. N. Jaya , Kumar K. Kishore , Reddy Y. Ramachandra , Jagadeesh B. , Rao D. V. Narayana , Bharathi D. Vijaya , Mullangi Ramesh
Published: April 2010

A highly sensitive and specific LC‐MS/MS method has been developed for simultaneous estimation of nortriptyline (NTP) and 10‐hydroxynortriptyline (OH‐NTP) in human plasma (250 µL) using carbamazepine as an internal standard (IS). LC‐MS/MS was operated under the multiple reaction‐monitoring mode using the electrospray ionization technique. A simple liquid–liquid extraction process was used to extract NTP, OH‐NTP and IS from human plasma. The total run time was 2.5 min and the elution of NTP, OH‐NTP and IS occurred at 1.44, 1.28 and 1.39 min, respectively; this was achieved with a mobile phase consisting of 20 mm ammonium acetate : acetonitrile (20:80, v/v) at a flow rate of 0.50 mL/min on a HyPURITY C18 column. The developed method was validated in human plasma with a lower limit of quantitation of 1.09 ng/mL for both NTP and OH‐NTP. A linear response function was established for the range of concentrations 1.09–30.0 ng/mL (r > 0.998) for both NTP and OH‐NTP. The intra‐ and inter‐day precision values for NTP and OH‐NTP met the acceptance as per FDA guidelines. NTP and OH‐NTP were stable in a battery of stability studies, i.e. bench‐top, auto‐sampler and freeze–thaw cycles. The developed assay was applied to a pharmacokinetic study in humans. Copyright © 2010 John Wiley & Sons, Ltd.
Regeneration of total RNA purification silica‐based columns
Authors: Nicosia Aldo , Tagliavia Marcello , Costa Salvatore
Published: April 2010

Silica‐based columns are largely used in RNA purification, allowing fast extractions and good yields of high quality nucleic acid, but their major limitation is the high cost. The reuse of such columns, although desirable, is not recommended because of residual amounts of material from the previous sample trapped in the column matrix, which might be released during further purification. Thus, recycling does need previous complete removal of any detectable RNA trace, but to date no protocol which allows decontamination and reuse is available. We report a very rapid decontamination procedure, based on treatment with warm alkaline solution containing Triton X‐100, which ensures no RNA carry‐over, and allows the recycling of columns without impairment of their efficiency in high‐quality RNA purification even after several regeneration rounds. Copyright © 2010 John Wiley & Sons, Ltd.
Liquid chromatography tandem mass spectrometry pharmacokinetic study of dl‐praeruptorin A in rat plasma
Authors: Ruan Hang , Zhang Zhen , Zhu Xuan
Published: April 2010

dl‐Praeruptorin A is a novel drug with valuable apoptosis and inflammation inhibitory effects in cardiac muscle. Previous pharmacokinetic studies of dl‐praeruptorin A have had limited success due to its very low plasma concentrations. In this study, we developed and validated a new rapid, sensitive and specific high‐performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC/ESI–MS/MS) method for quantitative analysis of dl‐praeruptorin A in rat plasma. dl‐Praeruptorin A and diazepam (internal standard) extracted from rat plasma samples with chloroform and analyzed on an XTerra™ RP18 column (150 mm × 4.6 mm i.d., 5 µm) were chromatographically separated within 5.5 min using methanol–water (75:25, v/v; flow rate 1 mL/min) as the mobile phase. dl‐Praeruptorin A was detected in positive ion mode using multiple reaction monitoring. The method was validated and the specificity, linearity, lower limit of quantitation (LLOQ, 2.5 ng/mL), precision (intra‐ and inter‐day <11.0%), accuracy (90.2–96.3%), recovery (>79.2%) and stability were determined. The correlation coefficient (r2) for the linear range of 2.5–2500.0 ng/mL was >0.999. No matrix effects were observed. The validated method was successfully applied to pharmacokinetic studies of dl‐praeruptorin A after intravenous administration to rats. The LLOQ obtained with this method was lower than in previous studies and could be valuable for determination of dl‐praeruptorin A in therapeutic drug monitoring and preclinical studies to establish appropriate dose and frequency. Copyright © 2010 John Wiley & Sons, Ltd.
Essential‐Oil Composition, Antileishmanial, and Toxicity Study of Artemisia abyssinica and Satureja punctata ssp. punctata from Ethiopia
Authors: Tariku Yinebeb , Hymete Ariaya , Hailu Asrat , Rohloff Jens
Published: April 2010

Essential oils of Artemisia abyssinica and Satureja punctata ssp. punctata from Ethiopia were analyzed by GC and GC/MS, and screened for leishmanicidal activity against promastigote and axenic amastigotes of Leishmania donovani and L. aethiopica, including toxicity studies on human monocytic leukemia cells (THP‐1) and erythrocytes in vitro. GC/MS of A. abyssinica oil revealed 67 compounds (99.94%) with the major constituents yomogi alcohol (38.47%), artemisyl acetate (24.88%), and artemisia alcohol (6.70%), and oxygenated monoterpenes (84.00%) as the dominant group. The oil of S. punctata contained 67 compounds (99.49%) with the main constituents geranial (27.62%), neral (21.72%), α‐bisabolol (13.62%), and (E)‐nerolidol (4.82%), of which oxygenated mono‐ and sesquiterpenes (58.39 and 26.91%, resp.) showed highest abundance. Both oils showed effect on promastigotes (MIC 76.5 to 312.5 nl/ml) and amastigotes (EC50 4.06 to 131.00 nl/ml) of L. donovani and L. aethiopica, and varying toxicities on THP‐1 cells (CC50 0.013 to 350 nl/ml with selectivity index between 0.001 and 28) and erythrocytes (with LC50 0.35 to 1.52 μl/ml). S. punctata oil exerted highest activity against both Leishmania sp. and toxicity. The revealed antileishmanial activities support further isolation and investigation of oil constituents for in vitro/in vivo evaluation.
Improved Expression of His6‐Tagged Strictosidine Synthase cDNA for Chemo‐Enzymatic Alkaloid Diversification
Authors: Yang Liuqing , Zou Hongbin , Zhu Huajian , Ruppert Martin , Gong Jingxu , Stöckigt Joachim
Published: April 2010

Strictosidine synthase (STR1) catalyzes the stereoselective formation of 3α(S)‐strictosidine from tryptamine and secologanin. Strictosidine is the key intermediate in the biosynthesis of 2,000 plant monoterpenoid indole alkaloids, and it is a key precursor of enzyme‐mediated synthesis of alkaloids. An improved expression system is described which leads to optimized His6‐STR1 synthesis in Escherichia coli. Optimal production of STR1 was achieved by determining the impact of co‐expression of chaperones pG‐Tf2 and pG‐LJE8. The amount and activity of STR1 was doubled in the presence of chaperone pG‐Tf2 alone. His6‐STR1 immobilized on Ni‐NTA can be used for enzymatic synthesis of strictosidines on a preparative scale. With the newly co‐expressed His6‐STR1, novel 3α(S)‐12‐azastrictosidine was obtained by enzymatic catalysis of 7‐azatryptamine and secologanin. The results obtained are of significant importance for application to chemo‐enzymatic approaches leading to diversification of alkaloids with novel improved structures.
Cell‐Cycle Markers and Biosensors
Authors: Kurzawa Laetitia , Morris May C.
Published: April 2010

Since the first schematic illustrations of dividing cells, we have come a long way in characterising eukaryotic cells and defining their cell‐cycle status thanks to a number of complementary approaches. Although most of these approaches rely on cell‐fixation procedures to identify molecular components in cell lysates, cultured cells or tissues, the development of GFP technology has enabled visualisation of virtually any fusion protein in cellulo and in vivo, and the exploitation of functional elements with well‐defined spatiotemporal characteristics has enabled the development of genetically encoded fluorescent markers of cell‐cycle phases, thus providing novel means of characterising the status of living cells in real time with high resolution. Together with technological advances in fluorescence chemistry and imaging approaches, the more recent development of fluorescent biosensors has provided direct means of probing cell‐cycle regulators and of studying their dynamics with high spatial and temporal resolution. Here we review classical approaches that rely on cell fixation to characterise the cell‐cycle status and its regulatory enzymes, and we describe the more recent development of cell‐cycle markers based on genetically encoded fusions of fluorescent proteins with characteristic cell‐cycle features, and of fluorescent biosensor technology to probe cell‐cycle regulators in living cells. Biosensors not only provide a means of characterising the behaviour of cell‐cycle regulators in their natural environment, they are also very useful for comparative studies of biological processes in healthy and pathological conditions, and can be further applied to diagnostic approaches to assess the status of a specific target, and to monitor response to therapeutic intervention.
Endovascular stent placement is an acceptable alternative to reoperation in selected infants with residual or recurrent aortic arch obstruction
Authors: Bentham Jamie , Shettihalli Naveen , Orchard Elizabeth , Westaby Stephen , Wilson Neil
Published: April 2010

Objective: To describe endovascular stent placement in infants as a technically feasible option in circumstances where surgery is considered less favorable. Background: Endovascular stent placement has become established as a first line therapy for native coarctation of the aorta or recoarctation in older children where stents capable of expansion to adult size can be placed safely. Surgery remains the therapy of choice in infants and young children. The management of aortic arch obstruction in infants is, however, frequently complicated by complex anatomy or clinical condition that may make surgery or further surgery an unattractive option. There is little reported data and the implications thereof of transcatheter stent placement in aortic arch obstruction in infants. Methods: Between August 2004 and November 2009, 11 patients had aortic arch obstruction treated with endovascular stent placement. The median age and weight at first stent placement was 46 days (range 3–399 days) and 4 kg (range 1.4–8 kg), respectively. In 10 patients, surgical intervention preceded transcatheter stent placement. Four had complex aortic arch obstruction and seven had recoarctation. Results: Reduction in peak systolic gradient to <10 mm Hg was achieved in seven of 10 patients with an improvement in aortic artery diameter to >90% of adjacent aorta in all. The diameter of the arch obstruction increased from a median of 1.60 to 4.90 mm (P = 0.001) and the peak systolic gradient from 45 mm Hg to 8 mm Hg (P < 0.0001). Adverse events occurred in two patients one who required further surgical revision and a second who required placement of a second stent. The median follow up was 3.60 years (range 0.4–5.5 years) with two patients having died at 1.34 and 1.42 years poststent placement. Of the nine patients alive, six have since undergone further angioplasty at a median time interval of 0.77 years (range 0.17–2.76 years). Long‐term complications occurred in none. Conclusions: Endovascular stent placement in infants is technically feasible with good results achievable even in small babies. It should be considered as a therapeutic option in complex cases when surgical alternatives are less favorable. © 2010 Wiley‐Liss, Inc.
Stenting of aortic coarctation: Acute, intermediate, and long‐term results of a prospective multi‐institutional registry—Congenital cardiovascular interventional study consortium (CCISC)
Authors: Holzer Ralf , Qureshi Shakeel , Ghasemi Abdolrahim , Vincent Julie , Sievert Horst , Gruenstein Daniel , Weber Howard , Alday Luis , Peirone Alejandro , Zellers Thomas , Cheatham John , Slack Michael , Rome Jonathan
Published: April 2010

Introduction: Since the 1980s, stent implantation has evolved as an important therapeutic strategy for coarctation of the aorta. However, available data is frequently flawed by short follow‐up, lack of adequate follow‐up imaging, and retrospective nature of data collection. Methods: Data was prospectively collected using a multicenter registry congenital cardiovascular interventional study consortium (CCISC). Between 2000 and 2009, 302 patients from 34 centers with a median weight of 58 kg underwent stent implantation for coarctation. Eligible patients (44%) completed intermediate follow‐up (3–18 months) with integrated imaging (cath, CT, MRI), whereas 21% completed long‐term follow‐up (>18–60 months). Procedural success was defined as UL/LL systolic gradient of less than 20 mm Hg, lack of significant recurrent obstruction, and freedom from unplanned repeat intervention. Results: Acute procedural success was 96%. Cumulative intermediate success was 86%, and cumulative long‐term success was 77%. Unplanned repeat interventions were required in 4%, and aortic wall complications were seen in 1% of patients (dissection n = 1 and aneurysm n = 3). Other adverse events (n = 15) occurred mainly acutely and included technical complications such as stent malposition (n = 9). At long‐term follow‐up, 23% of patients continued to have systolic blood pressure above the 95th centile, 9% had an upper‐to‐lower limb blood pressure gradient in excess of 20 mm Hg, and 32% were taking antihypertensive medication. Conclusions: This study documented acute, intermediate, and long‐term outcome data comparable or superior with other surgical or interventional series. However, even with successful initial stent therapy, patients continue to require long‐term follow‐up and have associated long‐term morbidity, relating to aortic wall complications, systemic hypertension, recurrent obstruction as well as need for repeat intervention. © 2010 Wiley‐Liss, Inc.
Chemical Synthesis, Structure Characterization, and Optical Properties of Hollow PbSx–Solid Au Heterodimer Nanostructures
Authors: Huang Shoushuang , Huang Jianmei , Yang Jian , Peng Jun‐Jun , Zhang Qingbo , Peng Feng , Wang Hongjuan , Yu Hao
Published: April 2010

Heterodimer nanostructures have attracted extensive attention, owing to an increasing degree of complexity, functionality, and then importance. So far, all the reported ones are built from solid nanoparticles. Herein, nearly monodisperse heterodimer nanostructures are constructed by hollow PbSx and solid Au domains simultaneously through a mild reaction between PbS nanocrystals and the gold species in the presence of dodecylamine. Control experiments clearly reveal the underlying formation mechanism of the hollow PbSx–solid Au heterodimers. The AuIII species in the solution, lead to the etching of PbS nanocrystals and the AuI species facilitate the control of the number of gold domains per nanoparticle. Dodecylamine molecules not only work as a stabilizer in the reaction, but also act as a reducing agent that could greatly affect the morphology of the product. The optical properties of the heterodimers are investigated based on UV/Vis absorption spectroscopy and Raman spectroscopy. This novel heterodimer nanostructure pushes the development of complex nanocrystal‐based architectures forward, and also provides many opportunities for potential applications.