63 research outputs found
Recovery of mycorrhizal fungi from wild collected protocorms of Madagascan endemic orchidAerangis ellisii(BS Williams) Schltr. and their use in seed germination in vitro
Orchid mycorrhizal fungi (OMF) are critical for seed germination and maintaining natural populations of orchids, yet the degree of specificity of most orchids to their mycorrhizal associates remains unknown. Many orchids are at risk of extinction, whether generalists or specialists, but orchid species of narrow fungal specificity are arguably under increased threat due to their requirement for specific fungal symbionts. This study characterises the fungi associated with Aerangis ellisii, a lithophytic orchid from a site in the Central Highlands of Madagascar. Culturable OMF isolated from spontaneous protocorms of this species from the wild were used for seed germination. In vitro germination and seedling development of A. ellisii were achieved with fungi derived from A. ellisii and an isolate from a different Aerangis species 30 km away. The significance of these findings and their importance to conservation strategies for this species and other Aerangis spp. is discussed. These results have important implications for the conservation of A. ellisii populations in Madagascar
Do You See What I Mean? Corticospinal Excitability During Observation of Culture-Specific Gestures
People all over the world use their hands to communicate expressively. Autonomous gestures, also known as emblems, are highly social in nature, and convey conventionalized meaning without accompanying speech. To study the neural bases of cross-cultural social communication, we used single pulse transcranial magnetic stimulation (TMS) to measure corticospinal excitability (CSE) during observation of culture-specific emblems. Foreign Nicaraguan and familiar American emblems as well as meaningless control gestures were performed by both a Euro-American and a Nicaraguan actor. Euro-American participants demonstrated higher CSE during observation of the American compared to the Nicaraguan actor. This motor resonance phenomenon may reflect ethnic and cultural ingroup familiarity effects. However, participants also demonstrated a nearly significant (p = 0.053) actor by emblem interaction whereby both Nicaraguan and American emblems performed by the American actor elicited similar CSE, whereas Nicaraguan emblems performed by the Nicaraguan actor yielded higher CSE than American emblems. The latter result cannot be interpreted simply as an effect of ethnic ingroup familiarity. Thus, a likely explanation of these findings is that motor resonance is modulated by interacting biological and cultural factors
Soil surface temperatures reveal moderation of the urban heat island effect by trees and shrubs
Urban areas are major contributors to air pollution and climate change, causing impacts on human health that are amplified by the microclimatological effects of buildings and grey infrastructure through the urban heat island (UHI) effect. Urban greenspaces may be important in reducing surface temperature extremes, but their effects have not been investigated at a city-wide scale. Across a midsized UK city we buried temperature loggers at the surface of greenspace soils at 100 sites, stratified by proximity to city centre, vegetation cover and land-use. Mean daily soil surface temperature over 11 months increased by 0.6 °C over the 5 km from the city outskirts to the centre. Trees and shrubs in non-domestic greenspace reduced mean maximum daily soil surface temperatures in the summer by 5.7 °C compared to herbaceous vegetation, but tended to maintain slightly higher temperatures in winter. Trees in domestic gardens, which tend to be smaller, were less effective at reducing summer soil surface temperatures. Our findings reveal that the UHI effects soil temperatures at a city-wide scale, and that in their moderating urban soil surface temperature extremes, trees and shrubs may help to reduce the adverse impacts of urbanization on microclimate, soil processes and human health
Tales of future weather
Society is vulnerable to extreme weather events and, by extension, to human impacts on future events. As climate changes weather patterns will change. The search is on for more effective methodologies to aid decision-makers both in mitigation to avoid climate change and in adaptation to changes. The traditional approach uses ensembles of climate model simulations, statistical bias correction, downscaling to the spatial and temporal scales relevant to decision-makers, and then translation into quantities of interest. The veracity of this approach cannot be tested, and it faces in-principle challenges. Alternatively, numerical weather prediction models in a hypothetical climate setting can provide tailored narratives for high-resolution simulations of high-impact weather in a future climate. This 'tales of future weather' approach will aid in the interpretation of lower-resolution simulations. Arguably, it potentially provides complementary, more realistic and more physically consistent pictures of what future weather might look like
Telerobotic Pointing Gestures Shape Human Spatial Cognition
This paper aimed to explore whether human beings can understand gestures
produced by telepresence robots. If it were the case, they can derive meaning
conveyed in telerobotic gestures when processing spatial information. We
conducted two experiments over Skype in the present study. Participants were
presented with a robotic interface that had arms, which were teleoperated by an
experimenter. The robot could point to virtual locations that represented
certain entities. In Experiment 1, the experimenter described spatial locations
of fictitious objects sequentially in two conditions: speech condition (SO,
verbal descriptions clearly indicated the spatial layout) and speech and
gesture condition (SR, verbal descriptions were ambiguous but accompanied by
robotic pointing gestures). Participants were then asked to recall the objects'
spatial locations. We found that the number of spatial locations recalled in
the SR condition was on par with that in the SO condition, suggesting that
telerobotic pointing gestures compensated ambiguous speech during the process
of spatial information. In Experiment 2, the experimenter described spatial
locations non-sequentially in the SR and SO conditions. Surprisingly, the
number of spatial locations recalled in the SR condition was even higher than
that in the SO condition, suggesting that telerobotic pointing gestures were
more powerful than speech in conveying spatial information when information was
presented in an unpredictable order. The findings provide evidence that human
beings are able to comprehend telerobotic gestures, and importantly, integrate
these gestures with co-occurring speech. This work promotes engaging remote
collaboration among humans through a robot intermediary.Comment: 27 pages, 7 figure
Intentional communication between wild bonnet macaques and humans
Comparative studies of nonhuman communication systems could provide insights into the origins and
evolution of a distinct dimension of human language: intentionality. Recent studies have provided
evidence for intentional communication in diferent species but generally in captive settings. We report
here a novel behaviour of food requesting from humans displayed by wild bonnet macaques Macaca
radiata, an Old World cercopithecine primate, in the Bandipur National Park of southern India. Using
both natural observations and feld experiments, we examined four diferent behavioural components—
coo-calls, hand-extension gesture, orientation, and monitoring behaviour—of food requesting for their
conformity with the established criteria of intentional communication. Our results suggest that food
requesting by bonnet macaques is potentially an intentionally produced behavioural strategy as all
the food requesting behaviours except coo-calls qualify the criteria for intentionality. We comment on
plausible hypotheses for the origin and spread of this novel behavioural strategy in the study macaque
population and speculate that the cognitive precursors for language production may be manifest in the
usage of combination of signals of diferent modalities in communication, which could have emerged in
simians earlier than in the anthropoid ape
How What We See and What We Know Influence Iconic Gesture Production
In face-to-face communication, speakers typically integrate information acquired through different sources, including what they see and what they know, into their communicative messages. In this study, we asked how these different input sources influence the frequency and type of iconic gestures produced by speakers during a communication task, under two degrees of task complexity. Specifically, we investigated whether speakers gestured differently when they had to describe an object presented to them as an image or as a written word (input modality) and, additionally, when they were allowed to explicitly name the object or not (task complexity). Our results show that speakers produced more gestures when they attended to a picture. Further, speakers more often gesturally depicted shape information when attended to an image, and they demonstrated the function of an object more often when they attended to a word. However, when we increased the complexity of the task by forbidding speakers to name the target objects, these patterns disappeared, suggesting that speakers may have strategically adapted their use of iconic strategies to better meet the task’s goals. Our study also revealed (independent) effects of object manipulability on the type of gestures produced by speakers and, in general, it highlighted a predominance of molding and handling gestures. These gestures may reflect stronger motoric and haptic simulations, lending support to activation-based gesture production accounts
Preliminary findings on identification of mycorrhizal fungi from diverse orchids in the Central Highlands of Madagascar
The Orchid flora of Madagascar is one of the most diverse with nearly 1000 orchid taxa, of which about 90 % are endemic to this biodiversity hotspot. The Itremo Massif in the Central Highlands of Madagascar with a Highland Subtropical climate range encompasses montane grassland, igneous and metamorphic rock outcrops, and gallery and tapia forests. Our study focused on identifying culturable mycorrhizae from epiphytic, lithophytic, and terrestrial orchid taxa to understand their diversity and density in a spatial matrix that is within the protected areas. We have collected both juvenile and mature roots from 41 orchid taxa for isolating their orchid mycorrhizal fungi (OMF), and to culture, identify, and store in liquid nitrogen for future studies. Twelve operational taxonomic units (OTUs), of three known orchid mycorrhizal genera, were recognized by analysis of internal transcribed spacer (ITS) sequences of 85 isolates, and, by comparing with GenBank database entries, each OTU was shown to have closely related fungi that were also found as orchid associates. Orchid and fungal diversity were greater in gallery forests and open grasslands, which is very significant for future studies and orchid conservation. As far as we know, this is the first ever report of detailed identification of mycorrhizal fungi from Madagascar. This study will help start to develop a programme for identifying fungal symbionts from this unique biodiversity hotspot, which is undergoing rapid ecosystem damage and species loss. The diversity of culturable fungal associates, their density, and distribution within the Itremo orchid hotspot areas will be discussed
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