Three neonicotinoids, imidacloprid, clothianidin and thiacloprid, agonists of the nicotinic acetylcholine receptor in the central brain of insects, were applied at non-lethal doses in order to test their effects on honeybee navigation. A catch-and-release experimental design was applied in which feeder trained bees were caught when arriving at the feeder, treated with one of the neonicotinoids, and released 1.5 hours later at a remote site. The flight paths of individual bees were tracked with harmonic radar. The initial flight phase controlled by the recently acquired navigation memory (vector memory) was less compromised than the second phase that leads the animal back to the hive (homing flight). The rate of successful return was significantly lower in treated bees, the probability of a correct turn at a salient landscape structure was reduced, and less directed flights during homing flights were performed. Since the homing phase in catch-and-release experiments documents the ability of a foraging honeybee to activate a remote memory acquired during its exploratory orientation flights, we conclude that non-lethal doses of the three neonicotinoids tested either block the retrieval of exploratory navigation memory or alter this form of navigation memory. These findings are discussed in the context of the application of neonicotinoids in plant protection.

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A slow ionic current carried by calcium, sodium, or both constitutes transmembrane ionic flow through the slow channel; such a current may be involved in normal action potentials of sinus and atrioventricular (AV) nodal cells. In this study, we investigated the effects of the slow-channel inhibiting agents verapamil, D600, manganous chloride, and lanthanum chloride on sinus node automaticity and AV nodal conduction in open-chest dogs treated with atropine (0.5 mg/kg) and propranolol (1.0 mg/kg). The arteries to the sinus node and the AV node were cannulated and perfused with agents that inhibit the slow current. These agents slowed sinus node discharge rate, depressed AV nodal conduction, and lengthened the effective and the functional AV nodal refractory period. Effects were dose related and reversed with time. His-Purkinje conduction remained normal. Isoproterenol and epinephrine reversed the effects of slow-channel inhibiting agents, but calcium, sodium, glucagon, and phenylephrine did not. Concentrations of propranolol which produced beta-receptor blockade prevented isoproterenol-induced reversal of the effects of slow-channel inhibitors. We concluded that (l) agents which inhibit the slow channel directly depress sinus node discharge rate and AV nodal conduction, (2) effects of slow-channel inhibiting agents are not mediated through the activation of cholinergic discharge or inhibition of adrenergic discharge, and (3) beta-receptor stimulation reverses these effects.

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In academia, authorship is considered a currency, and is important for career advancement. As the Journal of Bone and Mineral Research (JBMR®) is the highest-ranked journal in the field of bone, muscle, and mineral metabolism, and is the official publication of the American Society for Bone and Mineral Research, we sought to examine authorship changes over JBMR®’s 30-year history. Two bibliometric methods were used to collect the data. The “decade method” included all published manuscripts throughout one year in each decade over the past 30 years starting with the inaugural year, yielding 746 manuscripts for analysis. The “random method” examined 10% of published manuscripts from each of the 30 years, yielding 652 manuscripts for analysis. Using both methods, the average number of authors per manuscript, numerical location of the corresponding author, number of collaborating institutions, number of collaborating countries, number of printed manuscript pages, and the number of times each manuscript was cited all significantly increased between 1986 and 2015 (p < 10−4). Using the decade method, there was a significant increase in the percentage of female first authors over time from 35.8% in 1986 to 47.7% in 2015 (p = 0.02) and this trend was confirmed using the random method. The highest percentage of female first authors in 2015 was in Europe (60.0%), and Europe also had the most dramatic increase in female first authors over time (more than double in 2015 compared with 1986). However, the overall number of female corresponding authors did not significantly change during the past 30 years. With the increasing demands of publishing in academic medicine, understanding changes in publishing characteristics over time and by geographical region is important. These findings highlight JBMR®’s authorship trends over the past 30 years, demonstrate those countries having the most changes, and where challenges still exist.

Spaceflight results in reduced mechanical loading of the skeleton, which leads to dramatic bone loss. Low bone mass is associated with increased fracture risk, and this combination may compromise future, long-term, spaceflight missions. Here, we examined the systemic effects of spaceflight and fracture surgery/healing on several non-injured bones within the axial and appendicular skeleton. Forty C57BL/6, male mice were randomized into the following groups: (1) Sham surgery mice housed on the earth (Ground + Sham); (2) Femoral segmental bone defect surgery mice housed on the earth (Ground + Surgery); (3) Sham surgery mice housed in spaceflight (Flight + Sham); and (4) Femoral segmental bone defect surgery mice housed in spaceflight (Flight + Surgery). Mice were 9 weeks old at the time of launch and were euthanized approximately 4 weeks after launch. Micro-computed tomography (μCT) was used to evaluate standard bone parameters in the tibia, humerus, sternebra, vertebrae, ribs, calvarium, mandible, and incisor. One intriguing finding was that both spaceflight and surgery resulted in virtually identical losses in tibial trabecular bone volume fraction, BV/TV (24-28% reduction). Another important finding was that surgery markedly changed tibial cortical bone geometry. Understanding how spaceflight, surgery, and their combination impact non-injured bones will improve treatment strategies for astronauts and terrestrial humans alike.

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