In vivo impedance of the aerial organs of some mono- and dicotyledonous plants

In vivo impedance of the aerial organs of some mono- and dicotyledonous plants. We measure in this paper the electrical capacitance and resistance of aerial organs of some plants, grown in the laboratory (sunflower, pumpkin, and maize, of different ages) or bought at the market (sorrel), in a range of 34 frequencies, from 40 Hz to 100 kHz. The electrospectrometric curves of the leaves aged 14 days of the dicotyledoneous studied are close to each other.     

First report on the emergency dance of Apis cerana japonica,which induces odorous plant material collection in response to Vespa mandarinia japonica scouting

Previously, we observed several instances in which Apis cerana japonica performed dancing around the hive entrance and smeared plant materials there immediately after scouting of Vespa mandarinia japonica. In this study, we conducted a series of attack simulation experiments with three hornet species to investigate whether the hive entrance dance is a specific response to V. m. japonica scouting. We also tracked dancing bees and dance‐follower bees to observe whether they perform hive entrance smearing. Only V. m. japonica scouting induced dancing, and we confirmed that dancing and dance‐follower bees performed smearing behavior at the hive entrance. These results suggest that the hive entrance dance informs nestmates of a specific emergency and of the urgent need to collect odorous plant materials as a counter‐attack strategy.     

Dance Education Matters: Rebuilding Postsecondary Dance Education for Twenty-First Century Relevance and Resonance

Postsecondary dance education is at a crucial juncture in its history in academe. Emerging from women's physical education programs in the 1930s, the profession's realignment with the arts broadly and arts-based education specifically has been characterized by ambitious goals and steady growth through the 1990s. However, a number of critical developments over the past decade have displaced many previous gains and undermined the overall stability and integrity of the field. Four primary challenges are investigated in this article: curricular equity, expansive dance education programs, graduate study opportunities, and national leadership. I urge dance educators and administrators to re-envision and expand P–12 dance education in the liberal arts tradition to include private studio, commercial-sector dance in community and related teaching professions. This article provides recommendations and strategies for developing relevant and resonant twenty-first-century dance education programs beyond current confines.     

Doodle-Do Board

The field of dance arts education in the United States is in an entirely different place today than it was at the turn of the century. Much of this change is due to a convergence of events that involved: federal and state legislation, policy, and funding that supported dance in arts education; a forty-year transition of dance out of departments of physical education into the colleges of fine and performing arts; and the establishment of the National Dance Education Organization, which provided infrastructure (standards, assessments, research, certification, teacher training, professional development, and programs and services) that was needed to support dance taught as an art form. This infrastructure has become an integral component to building, nurturing, and sustaining strong arts-based programs over the years at local, state, or national levels.     

西藏准驼舞虻属二新种（双翅目：舞虻科）

首次报道西藏准驼舞虻属Parahybos,并记述2新种:短突准驼舞虻Parahybos breviprocerus sp.nov.和长突准驼舞虻P.longiprocerus sp.nov.。     

Row crop fields provide mid‐summer forage for honey bees

Honey bees provide invaluable economic and ecological services while simultaneously facing stressors that may compromise their health. For example, agricultural landscapes, such as a row crop system, are necessary for our food production, but they may cause poor nutrition in bees from a lack of available nectar and pollen. Here, we investigated the foraging dynamics of honey bees in a row crop environment. We decoded, mapped, and analyzed 3459 waggle dances, which communicate the location of where bees collected food, for two full foraging seasons (April–October, 2018–2019). We found that bees recruited nestmates mostly locally (<2 km) throughout the season. The shortest communicated median distances (0.474 and 0.310 km), indicating abundant food availability, occurred in July in both years, which was when our row crops were in full bloom. We determined, by plotting and analyzing the communicated locations, that almost half of the mid‐summer recruitment was to row crops, with 37% (2018) and 50% (2019) of honey bee dances indicating these fields. Peanut was the most attractive in July, followed by corn and cotton but not soybean. Overall, row crop fields are indicated by a surprisingly large proportion of recruitment dances, suggesting that similar agricultural landscapes may also provide mid‐summer foraging opportunities for honey bees.     

Dance-communicated distances support nectar foraging as a supply-driven system

Much like human consumers, honeybees adjust their behaviours based on resources'' supply and demand. For both, interactions occur in fluctuating conditions. Honeybees weigh the cost of flight against the benefit of nectar and pollen, which are nutritionally distinct resources that serve different purposes: bees collect nectar continuously to build large honey stores for overwintering, but they collect pollen intermittently to build modest stores for brood production periods. Therefore, nectar foraging can be considered a supply-driven process, whereas pollen foraging is demand-driven. Here we compared the foraging distances, communicated by waggle dances and serving as a proxy for cost, for nectar and pollen in three ecologically distinct landscapes in Virginia. We found that honeybees foraged for nectar at distances 14% further than for pollen across all three sites (n = 6224 dances, p < 0.001). Specific temporal dynamics reveal that monthly nectar foraging occurs at greater distances compared with pollen foraging 85% of the time. Our results strongly suggest that honeybee foraging cost dynamics are consistent with nectar supply-driven and pollen demand-driven processes.     

Honeybee navigation: critically examining the role of the polarization compass

Although it is widely accepted that honeybees use the polarized-light pattern of the sky as a compass for navigation, there is little direct evidence that this information is actually sensed during flight. Here, we ask whether flying bees can obtain compass cues derived purely from polarized light, and communicate this information to their nest-mates through the ‘waggle dance’. Bees, from an observation hive with vertically oriented honeycombs, were trained to fly to a food source at the end of a tunnel, which provided overhead illumination that was polarized either parallel to the axis of the tunnel, or perpendicular to it. When the illumination was transversely polarized, bees danced in a predominantly vertical direction with waggles occurring equally frequently in the upward or the downward direction. They were thus using the polarized-light information to signal the two possible directions in which they could have flown in natural outdoor flight: either directly towards the sun, or directly away from it. When the illumination was axially polarized, the bees danced in a predominantly horizontal direction with waggles directed either to the left or the right, indicating that they could have flown in an azimuthal direction that was 90° to the right or to the left of the sun, respectively. When the first half of the tunnel provided axial illumination and the second half transverse illumination, bees danced along all of the four principal diagonal directions, which represent four equally likely locations of the food source based on the polarized-light information that they had acquired during their journey. We conclude that flying bees are capable of obtaining and signalling compass information that is derived purely from polarized light. Furthermore, they deal with the directional ambiguity that is inherent in polarized light by signalling all of the possible locations of the food source in their dances, thus maximizing the chances of recruitment to it.     

Guidepost neurons for the lateral olfactory tract: Expression of metabotropic glutamate receptor 1 and innervation by glutamatergic olfactory bulb axons

The guidepost neurons for the lateral olfactory tract, which are called lot cells, are the earliest‐generated neurons in the neocortex. They migrate tangentially and ventrally further down this tract, and provide scaffolding for the olfactory bulb axons projecting into this pathway. The molecular profiles of the lot cells are largely uncharacterized. We found that lot cells specifically express metabotropic glutamate receptor subtype‐1 at a very early stage of development. This receptor is functionally competent and responds to a metabotropic glutamate receptor agonist with a transient increase in the intracellular calcium ion concentration. When the glutamatergic olfactory bulb axons were electrically stimulated, lot cells responded to the stimulation with a calcium increase mainly via ionotropic glutamate receptors, suggesting potential neurotransmission between the axons and lot cells during early development. Together with the finding that lot cells themselves are glutamatergic excitatory neurons, our results provide another notable example of precocious interactions between the projecting axons and their intermediate targets. © 2012 Wiley Periodicals, Inc. Develop Neurobiol, 2012