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The mating decisions made by social insect males and females profoundly affect the structure of colonies and populations. However, few studies have used experimental approaches to understand mating behavior and mate choice in social insect taxa. This study investigated mating success in the polyandrous social wasp Vespula maculifrons. Mating trials were designed to test predictions that characteristics of body size and colony-of-origin would affect mating success. We first investigated if size differences existed among individuals and found that males from different colonies differed significantly in the size of nine morphological traits. However, male trait size was not significantly associated with male mating success. In contrast, females from different colonies differed significantly in only six of the nine measured traits, and four of these traits were associated with successful mating behaviors. Specifically, the correlated traits of gaster length, third tergum length, antennal length, and total length were positively associated with female mating success. Thus, long females experience mating advantages over females that are short. We also found that males and females from one particular colony displayed significantly greater mating activity than individuals from other colonies. Thus, the colony from which individuals originate plays an important role in determining mating success. Finally, our experiments failed to detect any evidence of nestmate avoidance during the mating trials. Overall, our data suggest that social insect reproductives may experience differential mating success based on their phenotype or developmental environment.

The evolution of the complex societies displayed by social insects depended partly on high relatedness among interacting group members. Therefore, behaviors that depress group relatedness, such as multiple mating by reproductive females (polyandry), are unexpected in social insects. Nevertheless, the queens of several social insect species mate multiply, suggesting that polyandry provides some benefits that counteract the costs. However, few studies have obtained evidence for links between rates of polyandry and fitness in naturally occurring social insect populations. We investigated if polyandry was beneficial in the social wasp Vespula maculifrons. We used genetic markers to estimate queen mate number in V. maculifrons colonies and assessed colony fitness by counting the number of cells that colonies produced. Our results indicated that queen mate number was directly, strongly, and significantly correlated with the number of queen cells produced by colonies. Because V. maculifrons queens are necessarily reared in queen cells, our results demonstrate that high levels of polyandry are associated with colonies capable of producing many new queens. These data are consistent with the explanation that polyandry is adaptive in V. maculifrons because it provides a fitness advantage to queens. Our research may provide a rare example of an association between polyandry and fitness in a natural social insect population and help explain why queens in this taxon mate multiply.

1. Mutations in the gene encoding the alpha 1-subunit of the skeletal muscle dihydropyridine (DHP) receptor are responsible for familial hypokalaemic periodic paralysis (HypoPP), an autosomal dominant muscle disease. We investigated myotubes cultured from muscle of patients with arginine-to-histidine substitutions in putative voltage sensors, IIS4 (R528H) and IVS4 (R1239H), of the DHP receptor alpha 1-subunit. 2. Analysis of the messenger ribonucleic acid (mRNA) in the myotubes from such patients indicated transcription from both the normal and mutant genes. 3. In control myotubes, the existence of the slow L-type current and of two rapidly activating and inactivating calcium current components (T-type with a maximum at about -20 mV and 'third type' with a maximum at +10 to +20 mV) was confirmed. In the myotubes from patients with either mutation, the third-type current component was seen more frequently and, on average, with larger amplitude. 4. In myotubes with the IVS4 mutation (R1239H) the maximum L-type current density was smaller than control (-0.53 +/- 0.31 vs. -1.41 +/- 0.71 pA pF-1). The voltage dependence of activation was normal, and hyperpolarizing prepulses to -120 mV for 20 s did not increase the reduced current amplitude during test pulses. 5. In myotubes with the IIS4 mutation (R528H) the L-type current-voltage relation, determined at a holding potential of -90 mV, was normal. However, the voltage dependence of inactivation was shifted by about 40 mV to more negative potentials (voltage at half-maximum inactivation, V1/2 = -41.5 +/- 8.2 vs. -4.9 +/- 4.3 mV in normal controls).(ABSTRACT TRUNCATED AT 250 WORDS)

Both clinical and experimental studies suggest that platelets play a major role in the development of several cardiovascular disorders, particularly those related to ischemic heart disease. The results from numerous reports indicate that dimethyl sulfoxide (DMSO) inhibits platelet aggregation in vitro, but there are few studies on its action in vivo. Since an agent that inhibits platelet aggregation should not be used as a diluent in experiments that test antiaggregatory activity of other agents, DMSO was tested in dogs with partially constricted coronary arteries to evaluate its effect on platelet aggregation in vivo.

The thermostable hydrogenase from Thiocapsa roseopersicina was examined by low-temperature ESR spectroscopy. Two types of signals were detected, from an oxidized iron-sulphur cluster and a nickel centre (Ni-A). In the oxidized protein additional signals were observed due to spin-spin interaction between the two paramagnetic centres. This interaction could be reversibly abolished by reduction to a redox potential below 105 mV. This implies that an additional redox centre is involved in the interaction, for which an Fe3+ ion is suggested. Reduction with hydrogen induced a second type of nickel ESR signal (Ni-C), corresponding to an intermediate redox state seen in other nickel hydrogenases. The Ni-C species was light-sensitive at cryogenic temperatures. At temperatures near to 4.2 K the Ni-C signal showed evidence of interaction with another paramagnetic centre, presumably a second iron-sulphur cluster. On reoxidation a signal due to a third Ni(III) species, Ni-B, increased in amplitude. These results establish that metal centres in the hydrogenase from T. roseopersicina are closely similar to those of the well-studied hydrogenase from Chromatium vinosum.

A 1-J/cm2 dose of single laser-irradiation applied on primary human embryo fibroblast culture was not followed either by functional or micromorphological alterations of cell surfaces. This dose, however, applied four times with 24-hour intervals changed the functional conditions as well as surface charges of cell membranes. As detection methods, radioactive glucosamine uptake, lectin, and cationized ferritin-binding techniques were applied. At the same time, the scanning and transmission electron microscopy of laser-irradiated cells did not reveal any micromorphological or ultrastructural alterations. The effect of a 5-J/cm2 dose did not differ from that of 1 J/cm2. It is suggested that laser radiation-induced circumstances on cell surfaces can contribute to the strength of cell-to-cell contacts, i.e., to the stimulation of epithelization experienced in the clinical gynecologic practice.

Following treatment with cibenzoline, a new antiarrhythmic agent, 23 of 53 patients showed positive proteinuria reactions. In all cases, these results were obtained with bromphenol reagent strips. Subsequent exposure of serial dilutions of cibenzoline to these reagent strips showed positive protein reactions at concentrations as low as 1 mg/ml. Treatment of these same solutions with acetic acid-sodium acetate heat coagulation technique produced negative findings. Specimens from 14 of the above patients were then retested employing both techniques, and in all cases the reagent strips produced positive results while the heat coagulation technique (or sulfosalicylic acid) produced negative results. Therefore, it appears that cibenzoline produces false-positive proteinuria results when bromphenol reagent strips are employed for analysis.