The Social Environment of an Aggregating, Ant-Attended Treehopper (Hemiptera: Membracidae: Vanduzea arquata)

Many membracid treehoppers are attended by honeydew-harvesting ants. Ant mutualism often favors group living, which will in turn influence social interactios and communication. I investigated aspects of life history that underlie the social behavior of an aggregating, ant-attended treehopper. The number of adults, and their patterns of distribution, changes dramatically over the course of a season. Despite the relatively low vagility and high persistence in the same clump of host plants, individuals encounter a wide range of social environments. This aggregating species differs from solitary species in the clumped distribution of females, and possibly in the intensity of acoustic competition among males, but both aggregating and solitary species exhibit large temporal changes in density. A high degree of temporal and spatial variation in the social environment is probably characteristic of many insects and may be an important source of selection on insect communication.     

Drivers of Vaginal Drug Delivery System Acceptability from Internet-Based Conjoint Analysis

Vaginal microbicides potentially empower women to protect themselves from HIV and other sexually transmitted infections (STIs), especially when culture, religion, or social status may prevent them from negotiating condom use. The open literature contains minimal information on factors that drive user acceptability of women’s health products or vaginal drug delivery systems. By understanding what women find to be most important with regard to sensory properties and product functionality, developers can iteratively formulate a more desirable product. Conjoint analysis is a technique widely used in market research to determine what combination of elements influence a consumer’s willingness to try or use a product. We applied conjoint analysis here to better understand what sexually-active woman want in a microbicide, toward our goal of formulating a product that is highly acceptable to women. Both sensory and non-sensory attributes were tested, including shape, color, wait time, partner awareness, messiness/leakage, duration of protection, and functionality. Heterosexually active women between 18 and 35 years of age in the United States (n = 302) completed an anonymous online conjoint survey using IdeaMap software. Attributes (product elements) were systematically presented in various combinations; women rated these combinations of a 9-point willingness-to-try scale. By coupling systematic combinations and regression modeling, we can estimate the unique appeal of each element. In this population, a multifunctional product (i.e., broad spectrum STI protection, coupled with conception) is far more desirable than a microbicide targeted solely for HIV protection; we also found partner awareness and leakage are potentially strong barriers to use.     

Ribosomal subunits and ribosomal proteins of Tetrahymena thermophila. Effect of the presence of iodoacetamide during ribosome extraction on the properties of the subunits

Proteolytic degradation of ribosomal proteins occurs during the preparation of subunits of the cytoplasmic ribosomes of the protozoa Tetrahymena thermophila and the isolated subunits are inactive. Addition of 5 mM iodoacetamide to cell suspensions before extraction inhibits proteolytic activity and permits isolation of active subunits. The protein complements of these subunits have been characterized in two different two-dimensional electrophoretic systems, and their molecular weights have been determined.     

Determination of a particle's radius by two-dimensional agarose gel electrophoresis

Electrophoresis in an agarose gel dilute enough to be almost nonretarding, followed by electrophoresis in an orthogonal direction into a more concentrated agarose gel, has been developed as a procedure to determine the radius of spherical particles. Unlike procedures of unidirectional electrophoresis in a single gel, the above procedure can be used to compare the radii of particles that differ in solid-support-free electrophoretic mobility. Accuracy of 0.3 nm has been achieved with particles 30 nm in radius. It was found that the apparent radius of the spherical capsid of bacteriophage P22 decreased by 3% during elevated temperature-induced ejection of DNA from the capsid. Though originally designed for use with multimolecular particles, the procedure described here should also be useful with monomolecular particles.