Stereoselective synthesis of (Z)-13-hexadecen-11-yn-1-yl acetate,the major component of the sex pheromone of the pine processionary moth (Thaumetopoea pityocampa)

A short and stereoselective synthesis of (Z)-13-hexadecen-1 1-yn-1-yl acetate is described. The main feature is a low-temperature Wittig reaction of a triphenylpropylphosphonium bromide with a long-chain alkylated propargyl aldehyde.     

Triggering Creativity in Teams: An Exploratory Investigation

Triggering, developing and maintaining creativity in teams is critical to the economic performance of the firm. This article presents an exploratory action research effort in a health care organization that focused on interaction patterns amongst team members, creativity and performance. The results indicate that the teams’ inquiry and dialogue into their interaction patterns have the potential of influencing creativity. Team interaction patterns were found to influence team performance. Directions for future research are discussed.     

Structure-activity relationship in the ability of flavonols to inhibit chemiluminescence

Fourteen flavonoids were evaluated for their ability to inhibit chemiluminescence, either of neutrophils that had been briefly exposed to both luminol and phorbol-myristate acetate or to an enzymatic system with H2O2, luminol and horseradish peroxidase. Using chemiluminescence as the quantitative parameter, it can be concluded that the hydroxyl group in position 3 of the flavonols is vital for their inhibitory effect, and that two hydroxyl groups on the phenyl ring are optimal for such an effect. It was also noted that the C2-C3 double bond is essential for the flavonols' anti-oxidative effect. It is suggested that the ability of flavonols to suppress chemiluminescence is reciprocally correlated with their lipophilicity.     

Adverse reactions to radiopharmaceuticals

This review covers the side effects and adverse reactions to radiopharmaceuticals that were reported in the literature over the past 25 years. The information published prior to 1970 is sporadic, but due to the increased utilization of nuclear medicine procedures and the recognition that radiopharmaceuticals may have pharmacologic side effects, a registry has existed since 1971 to tabulate information on such effects. This survey is medical, rather than pharmaceutical in emphasis and so the adverse reactions are classified according to the target-organ systems involved rather than according to the specific radionuclides or to pharmaceuticals. If any of the radiopharmaceuticals of present or past use are not mentioned in this review, it is because no reports on their side effects were retrived by us. Hopefully, the organized registry system suggested by the Society of Nuclear Medicine (SNM) will enable a more complete recording of side effects from radiopharmaceuticals in the future.     

Functionalization at the double-bond region of jojoba oil. 8. Chemical binding of jojoba liquid wax to a polymer matrixvia an amine “spacer”

Jojoba wax was chemically bonded to a polymer matrixvia stable C-N covalent bonds. The polymer matrix was prepared by amination of several types of styrene-divinyl benzene or styrene-vinylbenzylchloride-divinylbenzene copolymers with diamines or polyethylene imines (polyamines). The jojoba wax was attached to the aminated polystyrene matrix by reacting an allyl-brominated derivative of jojoba with the matrix to form a C-N bond between the matrix and the jojoba wax. The amount of bound jojoba wax added to the polymer was in the range of 20–70% (w/w), depending on the type of polymer matrix and reaction conditions. The double-bond regions in the jojoba wax bonded to the matrix were preserved, and they were subsequently functionalized by phosphonation and sulfur-chlorination reactions.     

Chemical protection of pheromones containing an internal conjugated diene system from isomerization and oxidation

Conjugated diene systems are common in natural products, including pheromones. The systems are sensitive to heat, light, and oxygen, among other things. They can be protected by antioxidants and UV absorbers, which slow downcis-trans isomerization and oxidation. Three sex pheromones (one as an analog) containingZ,E, E,Z, andE,E units were studied: (Z,E)-9,11-C₁₄OAc, (E,Z)-7,9-C₁₂OAc, and (E,E)-10,12-C₁₆OAc. The UV absorber 2-hydroxy-4-methoxybenzophenone and the antioxidants BHT and BHA were found to be effective in solution. The protective effect of the UV absorber against photoisomerization on paper carriers was not as good as that in solution. Preliminary studies on the utilization of formulations containing these compounds and (Z,E)-9,11-C₁₄OAc in the mass trapping of Egyptian cotton leafworm male in cotton fields showed the new combinations to be as good as a previously used formulation with UOP 688, a compound which is unpleasant to handle.     

Compound Bragg reflection filters made by spatial frequencydoubling lithography

A report is presented on the fabrication of complex Bragg filters with resonant wavelengths near 1.55 μm, patterned by photolithography using a high-resolution deep ultraviolet stepper. The projection of gratings with quarter-micrometer features was made possible by the use of spatial frequency-doubling lithography. A single chip, processed entirely in the silicon facility, was used to demonstrate five Bragg reflectors of different wavelengths, a quarter-wave shifted resonator, broadband stacked filters with as many as 15 uniform Bragg reflector sections of different Bragg wavelengths, and broadband stacked filters containing a passband within the reflection band. The filters exhibited nearly ideal spectral behavior     

The privacy of dense symmetric functions

Ann argument function,f, is calledt-private if there exists a distributed protocol for computingf so that no coalition of at mostt processors can infer any additional information from the execution of the protocol. It is known that every function defined over a finite domain is [(n–1)/2]-private. The general question oft-privacy (fort[n/2]) is still unresolved.In this work, we relate the question of [n/2]-privacy for the class of symmetric functions of Boolean argumentsf: {0, 1} ⁿ {0, 1,...,n} to the structure of Hamming weights inf ^–1(b) (b{0, 1, ...,n}). We show that iff is [n/2]-private, then every set of Hamming weightsf ^–1(b) must be an arithmetic progression. For the class ofdense symmetric functions (defined in the sequel), we refine this to the following necessary and sufficient condition for [n/2]-privacy off: Every collection of such arithmetic progressions must yield non-identical remainders, when computed modulo the greatest common divisor of their differences. This condition is used to show that for dense symmetric functions, [n/2]-privacy impliesn-privacy.     

Measuring the impact of a blended learning model on early literacy growth

In the context of trying to improve reading proficiency in elementary school students, this study investigated the use of digital technology as part of a blended learning program, Core5, in kindergarten and first grade classes. A quasi-experimental design compared 283 treatment students instructed in schools using Core5 with 237 control students in schools using traditional instruction in an urban school district. At the beginning of the school year, all students were pretested with Dynamic Indicators of Basic Early Literacy Skills (DIBELS), a commonly used reading assessment. During the school year, the treatment schools implemented Core5, which includes the online component and offline teacher-led lessons. The English Language Arts curriculum was evaluated and found to be similar across treatment and control schools. At the end of the school year, all students were post-tested with DIBELS. Results from propensity score analyses showed that treatment students outperformed control students and that the discrepancy between treatment and control groups on post-test scores was more pronounced when students had lower pretest scores. These outcomes point to the value of using Core5 for reading instruction in early elementary grades.