533 research outputs found
Habituation to Auditory Stimuli by Captive African Elephants (Loxodonta africana)
Habituation is a major concern for the development of effective, long-term human-wildlife conflict mitigation and zoo enrichment programs. Elephants are cognitive species that exhibit many types of learning, such as associative, social, and insight learning. However, no study has examined the habituation process in elephants. Elephants possess a well-developed sensory system and may habituate to stimuli that could be used for enrichment and/or management. The aim of this study was to examine their habituation process in response to repeated presentations of two auditory stimuli: buzzing by a disturbed beehive and the sound created by banging on pots and pans, and in comparison to no sound trials. The selected sounds often invoke alert behaviors and movements in wild elephants as part of human-elephant conflict mitigation. We predicted that elephants would initially exhibit strong reactions to both sounds, but these responses would diminish over repeated trials. This study was conducted with four female African elephants (Loxodonta africana) at the Nashville Zoo in Tennessee. During the first sound presentation, the elephants reacted by showing distress, avoidance, and vigilance behaviors. Over repeated presentations, their reactions to the sounds diminished to levels observed during the no-sound trials, suggesting habituation had occurred. The elephants also reduced their response to the second sound more rapidly than to the first sound, suggesting that generalization of their habituation had occurred. The results support our hypothesis that elephants use habituation to learn which stimuli are non-threatening and subsequently stop responding to them. Habituation is an important learning process that should be considered during the implementation of captive and wildlife management, especially for highly intelligent species, such as elephants
A pachyderm perfume: odour encodes identity and group membership in African elephants
Group-living animals that live in complex social systems require effective modes of communication to maintain social cohesion, and several acoustic, olfactory and visual signaling systems have been described. Individuals need to discriminate between in- and out-group odour to both avoid inbreeding and to identify recipients for reciprocal behaviour. The presence of a unique group odour, identified in several social mammals, is a proposed mechanism whereby conspecifics can distinguish group from non-group members. African elephants (Loxodonta africana) live in stable, socially complex, multi-female, fissionâfusion groups, characterized by female philopatry, male dispersal and linear dominance hierarchies. Elephant social behaviour suggests that individuals use odour to monitor the sex, reproductive status, location, health, identity and social status of conspecifics. To date, it is not clear what fixed or variable information is contained in African elephant secretions, and whether odour encodes kinship or group membership information. Here we use SPME GCâMS generated semiochemical profiles for temporal, buccal and genital secretions for 113 wild African elephants and test their relationship with measures of genetic relatedness. Our results reveal the existence of individual identity odour profiles in African elephants as well as a signature for age encoded in temporal gland and buccal secretions. Olfactory signatures for genetic relatedness were found in labial secretions of adult sisters. While group odour was not correlated with group genetic relatedness, our analysis identified âgroup membershipâ as a significant factor explaining chemical differences between social groups. Saturated and short-chain fatty acids (SCFAs), derived from key volatile compounds from bacterial fermentation, were identified in temporal, buccal and genital secretions suggesting that group odour in African elephants may be the result of bacterial elements of the gut microbiome. The frequent affiliative behavior of African elephants is posited as a likely mechanism for bacterial transmission. Our findings favour flexible group-specific bacterial odours, which have already been proposed for other social mammals and present a useful form of olfactory communication that promotes bond group cohesion among non-relatives in fissionâfusion mammals
Recommended from our members
Ionization detail parameters and cluster dose: a mathematical model for selection of nanodosimetric quantities for use in treatment planning in charged particle radiotherapy
Objective. To propose a mathematical model for applying ionization detail (ID), the detailed spatial distribution of ionization along a particle track, to proton and ion beam radiotherapy treatment planning (RTP).Approach. Our model provides for selection of preferred ID parameters (Ip) for RTP, that associate closest to biological effects. Cluster dose is proposed to bridge the large gap between nanoscopicIpand macroscopic RTP. Selection ofIpis demonstrated using published cell survival measurements for protons through argon, comparing results for nineteenIp:Nk,k= 2, 3, âŠ, 10, the number of ionizations in clusters ofkor more per particle, andFk,k= 1, 2, âŠ, 10, the number of clusters ofkor more per particle. We then describe application of the model to ID-based RTP and propose a path to clinical translation.Main results. The preferredIpwereN4andF5for aerobic cells,N5andF7for hypoxic cells. Significant differences were found in cell survival for beams having the same LET or the preferredNk. Conversely, there was no significant difference forF5for aerobic cells andF7for hypoxic cells, regardless of ion beam atomic number or energy. Further, cells irradiated with the same cluster dose for theseIphad the same cell survival. Based on these preliminary results and other compelling results in nanodosimetry, it is reasonable to assert thatIpexist that are more closely associated with biological effects than current LET-based approaches and microdosimetric RBE-based models used in particle RTP. However, more biological variables such as cell line and cycle phase, as well as ion beam pulse structure and rate still need investigation.Significance. Our model provides a practical means to select preferredIpfrom radiobiological data, and to convertIpto the macroscopic cluster dose for particle RTP
Perception of soundscapes : an interdisciplinary approach
This paper takes an overall view of findings from the Positive Soundscape Project, a large inter-disciplinary soundscapes study. Qualitative fieldwork (soundwalks and focus groups) have found that soundscape perception is influenced by cognitive effects such as the meaning of a soundscape and its components, and how information is conveyed by a soundscape, for example on the behaviour of people within the soundscape. Three significant clusters were found in the language people use to describe soundscapes: sound sources, sound descriptors and soundscape descriptors. Results from listening tests and soundwalks have been integrated to show that the two principal dimensions of soundscape emotional response seem to be calmness and vibrancy. Further, vibrancy seems to have two aspects: organisation of sounds and changes over time. The possible application of the results to soundscape assessment and design are briefly discussed
Landlabs: An Integrated Approach to Creating Agricultural Enterprises That Meet the Triple Bottom Line
Global demand is increasing for food, feed, and fiber; for additional agricultural outputs, such as biofuels; and for ecosystem services, such as clean water and outdoor recreation. In response, new agricultural enterprises are needed that produce more outputs from existing lands while meeting the triple bottom line of high performance in economic, environmental, and social terms. Establishing such enterprises requires coordination and development within three critical domains: landscape configurations (i.e., types and arrangements of land uses), supply/value chains (i.e., processing and utilization), and policy and governance. In this essay, we describe our efforts, as land-grant university scientists, to support coordinated innovation and enterprise development in integrated place-based institutions, which we term landlabs. We describe our experiences in three prototyping efforts and outline key features of landlabs that are emerging from these efforts. Land-grant universities have a central and crucial role to play in organizing and operating landlabs
Patch - Occupancy Survey of Elephant (Loxodonta africana) Surrounding Livingstone, Zambia
Wild elephants represent the biggest humanâwildlife conflict issue in Livingstone, Zambia. However, little is known about their movements. This survey investigated elephantsâ habitat use outside a core protected and fenced zone that forms part of Mosi-oa-Tunya National Park, Zambia. Using âpatch-occupancyâ methodology, indications of elephant presence (feeding behaviour, dung and tracks) were surveyed. The survey aimed to assist proposed future monitoring exercises by defining the geographical extent that should be considered to improve accuracy in species abundance estimates. Results were supplemented using collected indications of elephant presence from prior monitoring exercises, and during this survey. Elephant presence was confirmed up to 8 km from the boundary of the protected core habitat, focussed in: (1) an unfenced zone of the national park, (2) along a road leading from the national park to the Dambwa Forest to the north and (3) along two rivers located to the west (Sinde River) and east (Maramba River) of the core area. Detection probability of elephant presence was high using these methods, and we recommend regular sampling to determine changes in habitat use by elephants, as humans continue to modify land-use patterns.
Conservation implications: Identification of elephant ranging behaviour up to 8 km outside of the Mosi-oa-Tunya National Park in southern Zambia will assist in managing humanâ elephant conflict in the area, as well as in assessing this seasonal populationâs abundance
In-spiraling Clumps in Blue Compact Dwarf Galaxies
Giant star-formation clumps in dwarf irregular galaxies can have masses
exceeding a few percent of the galaxy mass enclosed inside their orbital radii.
They can produce sufficient torques on dark matter halo particles, halo stars,
and the surrounding disk to lose their angular momentum and spiral into the
central region in 1 Gyr. Pairs of giant clumps with similarly large relative
masses can interact and exchange angular momentum to the same degree. The
result of this angular momentum loss is a growing central concentration of old
stars, gas, and star formation that can produce a long-lived starburst in the
inner region, identified with the BCD phase. This central concentration is
proposed to be analogous to the bulge in a young spiral galaxy. Observations of
star complexes in five local BCDs confirm the relatively large clump masses
that are expected for this process. The observed clumps also seem to contain
old field stars, even after background light subtraction, in which case the
clumps may be long-lived. The two examples with clumps closest to the center
have the largest relative clump masses and the greatest contributions from old
stars. An additional indication that the dense central regions of BCDs are like
bulges is the high ratio of the inner disk scale height to the scale length,
which is comparable to 1 for four of the galaxies.Comment: 15 pages, 2 figures, accepted by ApJ 1/5/201
Thermodynamic Description of the Relaxation of Two-Dimensional Euler Turbulence Using Tsallis Statistics
Euler turbulence has been experimentally observed to relax to a
metaequilibrium state that does not maximize the Boltzmann entropy, but rather
seems to minimize enstrophy. We show that a recent generalization of
thermodynamics and statistics due to Tsallis is capable of explaining this
phenomenon in a natural way. The maximization of the generalized entropy
for this system leads to precisely the same profiles predicted by the
Restricted Minimum Enstrophy theory of Huang and Driscoll. This makes possible
the construction of a comprehensive thermodynamic description of Euler
turbulence.Comment: 15 pages, RevTe
Little Things
We present LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes,
The HI Nearby Galaxy Survey) that is aimed at determining what drives star
formation in dwarf galaxies. This is a multi-wavelength survey of 37 Dwarf
Irregular and 4 Blue Compact Dwarf galaxies that is centered around HI-line
data obtained with the National Radio Astronomy Observatory (NRAO) Very Large
Array (VLA). The HI-line data are characterized by high sensitivity (less than
1.1 mJy/beam per channel), high spectral resolution (less than or equal to 2.6
km/s), and high angular resolution (~6 arcseconds. The LITTLE THINGS sample
contains dwarf galaxies that are relatively nearby (less than or equal to 10.3
Mpc; 6 arcseconds is less than or equal to 300 pc), that were known to contain
atomic hydrogen, the fuel for star formation, and that cover a large range in
dwarf galactic properties. We describe our VLA data acquisition, calibration,
and mapping procedures, as well as HI map characteristics, and show channel
maps, moment maps, velocity-flux profiles, and surface gas density profiles. In
addition to the HI data we have GALEX UV and ground-based UBV and Halpha images
for most of the galaxies, and JHK images for some. Spitzer mid-IR images are
available for many of the galaxies as well. These data sets are available
on-line.Comment: In press in A
- âŠ