scholarly journals Behavioural variability among captive African elephants in the use of the trunk while feeding

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9678
Author(s):  
Maëlle Lefeuvre ◽  
Patrick Gouat ◽  
Baptiste Mulot ◽  
Raphaël Cornette ◽  
Emmanuelle Pouydebat
Keyword(s):  
African Elephants ◽  
Individual Level ◽  
Captive Group ◽  
Trunk Movements ◽  
Sensitive Organ ◽  
Highly Sensitive ◽  
Probable Consequence ◽  
Feeding Activities ◽  
Complete Catalogue ◽  
Individual Strategies

The Proboscideans, an order of mammals including elephants, are the largest of the Earth lands animals. One probable consequence of the rapid increase of their body size is the development of the trunk, a multitask highly sensitive organ used in a large repertoire of behaviours. The absence of bones in the trunk allows a substantial degree of freedom for movement in all directions, and this ability could underlie individual-level strategies. We hypothesised a stronger behavioural variability in simple tasks, and a correlation between the employed behaviours and the shape and size of the food. The observations of a captive group of African elephants allowed us to create a complete catalogue of trunk movements in feeding activities. We noted manipulative strategies and impact of food item properties on the performed behaviours. The results show that a given item is manipulated with a small panel of behaviours, and some behaviours are specific to a single shape of items. The study of the five main feeding behaviours emphasises a significant variability between the elephants. Each individual differed from every other individual in the proportion of at least one behaviour, and every behaviour was performed in different proportions by the elephants. Our findings suggest that during their lives elephants develop individual strategies adapted to the manipulated items, which increases their feeding efficiency.

Individual strategies for successful ageing

2021 ◽  
pp. 37-42
Author(s):  
Clemens Tesch-Römer ◽  
Hans-Werner Wahl ◽  
Suresh I. S. Rattan ◽  
Liat Ayalon
Keyword(s):  
External Factors ◽  
Successful Ageing ◽  
Individual Level ◽  
Ageing Research ◽  
Primary Responsibility ◽  
The Individual ◽  
Individual Strategies

Individual strategies are necessary for successful ageing. Three of the models discussed in the previous chapter—the pragmatic, hedonic, and eudaimonic models—put particular emphasis on individuals’ striving to reach their desired endpoints: to be fit, autonomous and engaged; to be happy; or to be wise, respectively. Nevertheless, the primary responsibility for successful ageing lies mainly in the hands of the individual, although external factors may be in place to support the individual’s effort to age successfully. At present, ageing research has focused to a large extent on individual strategies and resources for successful to the individual level. The main results from ageing research are discussed in this chapter.

Freeze-Etch Replicas of the Mouse Proximal Tubule Cell

1972 ◽  
Vol 30 ◽  
pp. 300-301
Author(s):  
Ben O. Spurlock
Keyword(s):  
Fine Structure ◽  
Phosphate Buffer ◽  
Present Report ◽  
Specimen Preparation ◽  
Proximal Tubule Cell ◽  
Vascular Perfusion ◽  
Sensitive Organ ◽  
Highly Sensitive ◽  
Insight Into ◽  
Conventional Electron Microscopy

The fine structure of the mouse kidney has been studied in detail. Attempts at preserving this metabolically highly sensitive organ in the “closest to living state” have prompted some rather elaborate and involved methods of specimen preparation. Acknowledging that these techniques probably represent the best methods of preserving the integrity of this organ, it was felt that freeze-etch techniques might provide insight into structures heretofore unappreciated by conventional electron microscopy of thin sectioned material. The present report deals with the fine structure of the mouse renal proximal tubules as visualized in replicas of freeze-fractured and freeze-etched preparations.The left kidneys of lightly anesthesized mice were surgically exposed and fixed with 2% glutaraldehyde/0.1M phosphate buffer (pH 7. 2) by either the drip method (2) or by vascular perfusion (3). The kidneys were removed and stored in 0.1M phosphate buffer with 5% sucrose.

scholarly journals Evening home lighting adversely impacts the circadian system and sleep

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sean W. Cain ◽  
Elise M. McGlashan ◽  
Parisa Vidafar ◽  
Jona Mustafovska ◽  
Simon P. N. Curran ◽  
...  
Keyword(s):  
Energy Efficient ◽  
Light Sensitivity ◽  
Circadian System ◽  
Light Environment ◽  
The Sun ◽  
Individual Level ◽  
Highly Sensitive ◽  
Wide Range ◽  
Specific Individual ◽  
The Impact

Abstract The regular rise and fall of the sun resulted in the development of 24-h rhythms in virtually all organisms. In an evolutionary heartbeat, humans have taken control of their light environment with electric light. Humans are highly sensitive to light, yet most people now use light until bedtime. We evaluated the impact of modern home lighting environments in relation to sleep and individual-level light sensitivity using a new wearable spectrophotometer. We found that nearly half of homes had bright enough light to suppress melatonin by 50%, but with a wide range of individual responses (0–87% suppression for the average home). Greater evening light relative to an individual’s average was associated with increased wakefulness after bedtime. Homes with energy-efficient lights had nearly double the melanopic illuminance of homes with incandescent lighting. These findings demonstrate that home lighting significantly affects sleep and the circadian system, but the impact of lighting for a specific individual in their home is highly unpredictable.

Oestrous Behaviour and Female Choice in the African Elephant

Behaviour ◽  
1983 ◽  
Vol 86 (3-4) ◽  
pp. 167-195 ◽  
Author(s):  
Cynthia J. Moss
Keyword(s):  
Female Choice ◽  
National Park ◽  
Size Class ◽  
African Elephants ◽  
Age Classes ◽  
Short Term ◽  
Individual Level ◽  
Female Behaviour ◽  
The Individual

Abstract1. During the course of an eight year field study of African elephants in Amboseli National Park, Kenya, from September, 1972 to December, 1980, females were seen exhibiting oestrous behaviour on 154 occasions, during which 43 copulations were witnessed. 2. Five categories of oestrous behaviour are described: a) wariness, b) the oestrous walk, c) the chase, d) mounting, and e) consort behaviour. 3. The oestrous behaviour as described was found to be temporally associated with ovulation, as judged by conceptions, in 70.7% of 58 cases. 4. The duration of oestrous periods is estimated at 2-6 days. 5. On average Amboseli females conceived once every 5 years and for each of these conceptions the female may only have been in oestrus once. 6. Evidence from the Amboseli study suggests that some females may exercise choice in mating partners. For example, females were able to elude their pursuers in 69.4% of all chases (n = 134). Observation of female behaviour during oestrus suggested that some females preferred to mate with males in the largest size class, particularly those in musth. 7. Two possible short-term advantages to females exercising choice in mating partners are suggested: a) avoidance of harassment from other bulls; and b) Large males in musth may be more likely to impregnate a female. 8. A possible long-term advantage to mating with a Large, and therefore older, male could be his ability to pass on a trait for longevity. 9. Although females may be exercising choice among the size/age classes, male-male competition among the Large males may override female choice on the individual level.

scholarly journals Analogous laterality in trunk movements in captive African elephants: A pilot study

2021 ◽  
pp. 1-26
Author(s):  
Maëlle Lefeuvre ◽  
Patrick Gouat ◽  
Baptiste Mulot ◽  
Raphaël Cornette ◽  
Emmanuelle Pouydebat
Keyword(s):  
Pilot Study ◽  
African Elephants ◽  
Trunk Movements

scholarly journals Evolution viewed from physics, physiology and medicine

2017 ◽  
Vol 7 (5) ◽  
pp. 20160159 ◽  
Author(s):  
Denis Noble
Keyword(s):  
Dna Sequences ◽  
Molecular Level ◽  
Medical Science ◽  
Functional Variation ◽  
Evolution And Development ◽  
Functional Development ◽  
Sensitive Organ ◽  
Highly Sensitive ◽  
Level Order ◽  
Development And Evolution

Stochasticity is harnessed by organisms to generate functionality. Randomness does not, therefore, necessarily imply lack of function or ‘blind chance’ at higher levels. In this respect, biology must resemble physics in generating order from disorder. This fact is contrary to Schrödinger's idea of biology generating phenotypic order from molecular- level order, which inspired the central dogma of molecular biology. The order originates at higher levels, which constrain the components at lower levels. We now know that this includes the genome, which is controlled by patterns of transcription factors and various epigenetic and reorganization mechanisms. These processes can occur in response to environmental stress, so that the genome becomes ‘a highly sensitive organ of the cell’ (McClintock). Organisms have evolved to be able to cope with many variations at the molecular level. Organisms also make use of physical processes in evolution and development when it is possible to arrive at functional development without the necessity to store all information in DNA sequences. This view of development and evolution differs radically from that of neo-Darwinism with its emphasis on blind chance as the origin of variation. Blind chance is necessary, but the origin of functional variation is not at the molecular level. These observations derive from and reinforce the principle of biological relativity, which holds that there is no privileged level of causation. They also have important implications for medical science.

A PREY-PREDATOR MODEL IN A MULTI-PATCH ENVIRONMENT WITH DIFFERENT TIME SCALES

1993 ◽  
Vol 01 (02) ◽  
pp. 187-197 ◽  
Author(s):  
P. AUGER ◽  
E. BENOÎT
Keyword(s):  
Perturbation Theory ◽  
Time Scales ◽  
Large Scale ◽  
Ecological Systems ◽  
System Of Differential Equations ◽  
Large Scale Systems ◽  
Individual Level ◽  
Predator Model ◽  
The Individual ◽  
Individual Strategies

Ecological systems are large scale systems involving a large number of variables. By aggregation, it is possible to obtain at each level of organization an approximate and simple system of differential equations which can be studied more easily than the whole system involving a very large number of variables. Important differences in the orders of magnitude of the time scales in ecological systems allow us to apply methods of perturbation theory in order to replace large scale systems by reduced systems described by a few number of global variables. Perturbation theory determines the conditions required for aggregation. As examples, we present prey-predator models taking into account the activity sequences of animals at the individual level. In this way, the predation pressure depends on the individual strategies selected by the animals. We compare numerical simulations for the whole system and for the reduced system. We show that as soon as the orders of magnitude for the slow and fast dynamics are sufficiently different, then the orbits obtained for the reduced system are very close to the orbits obtained for the whole system.

scholarly journals Alternatives to Social Science One

2020 ◽  
Vol 53 (4) ◽  
pp. 710-711
Author(s):  
Margaret Levi ◽  
Betsy Rajala
Keyword(s):  
Social Science ◽  
Administrative Data ◽  
Third Party ◽  
Social Scientists ◽  
Social Good ◽  
Individual Level ◽  
Level Data ◽  
Highly Sensitive ◽  
Research Facilities ◽  
Sensitive Individual

ABSTRACTThis article responds to King and Persily’s (2019) proposal for a new model of industry–academic partnership using an independent third party to mediate between firms and academics. We believe this is a reasonable proposal for highly sensitive individual-level data, but it may not be appropriate for all types of data. We explore alternative options to their proposal, including Administrative Data Research Facilities, Data Collaboratives at GovLab, and Tech Data for Social Good Initiative at the Center for Advanced Study in the Behavioral Sciences. We believe social scientists should continue to explore, evaluate, and scale a variety of industry–academic data-sharing models.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Fluorescence ratio imaging of dynamic intracellular ionic signals

1988 ◽  
Vol 46 ◽  
pp. 42-43
Author(s):  
R. Y. Tsien ◽  
A. Minta ◽  
M. Poenie ◽  
J.P.Y. Kao ◽  
A. Harootunian
Keyword(s):  
Binding Sites ◽  
Living Cells ◽  
Molecular Engineering ◽  
Ph Indicators ◽  
Highly Sensitive ◽  
Fluorescence Ratio Imaging ◽  
Ratio Imaging ◽  
Technical Advances ◽  
Indicator Dyes ◽  
Fluorescein Dyes

Recent technical advances now enable the continuous imaging of important ionic signals inside individual living cells with micron spatial resolution and subsecond time resolution. This methodology relies on the molecular engineering of indicator dyes whose fluorescence is strong and highly sensitive to ions such as Ca2+, H+, or Na+, or Mg2+. The Ca2+ indicators, exemplified by fura-2 and indo-1, derive their high affinity (Kd near 200 nM) and selectivity for Ca2+ to a versatile tetracarboxylate binding site3 modeled on and isosteric with the well known chelator EGTA. The most commonly used pH indicators are fluorescein dyes (such as BCECF) modified to adjust their pKa's and improve their retention inside cells. Na+ indicators are crown ethers with cavity sizes chosen to select Na+ over K+: Mg2+ indicators use tricarboxylate binding sites truncated from those of the Ca2+ chelators, resulting in a more compact arrangement of carboxylates to suit the smaller ion.

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