601 research outputs found
Relationship quality affects fission decisions in wild spider monkeys (Ateles geoffroyi)
Fission-fusion dynamics are thought to be mainly a response to differential availability of food resources. However, social factors may also play a role. Here, we examined whether the quality of social relationships between group members affects fission decisions. During 21 months, we collected data on social interactions and fission events of 22 spider monkeys (Ateles geoffroyi) living in a community in the protected area of Otoch Ma'ax Yetel Kooh, Yucatan, Mexico. By entering seven indexes of social interactions into a principal component analysis, we obtained three components of relationship quality, which we labelled "compatibility," "value" and "insecurity" given the relative loadings of the indexes. Our results showed that individuals were more likely to fission into the same subgroup with community members with whom they shared higher levels of compatibility and value and lower levels of insecurity. In addition, individuals preferred to fission into the same subgroup with same-sex group members, as expected based on what is known for the species. Our findings highlight the role of social factors in fission decisions. Adjustments in subgroup size are based on multifaceted social preferences, incorporating previously unexamined aspects of relationship quality, which are independent from overall levels of affiliative interactions. © 2017 Blackwell Verlag GmbH
Watch out or relax: conspecifics affect vigilance in wild spider monkeys (Ateles geoffroyi)
In most animal species, predation risk is considered the main factor affecting vigilance, and an individual is expected to spend less time vigilant in larger than in smaller groups. However, vigilance patterns in primates appear to differ, with no consistency in group-size effects. As individuals in highly gregarious species such as diurnal primates face frequent threats from group members, there may be increased vigilance in larger groups to monitor conspecifics rather than or in addition to predators. We tested this hypothesis in wild spider monkeys, which live in communities but fission and fuse in subgroups of variable size and membership throughout the same day. We found no overall effect of subgroup size, as traditionally measured, on vigilance. However, a possible explanation is that vigilance may be effectively shared only with individuals in close proximity, rather than with all subgroup members. We found that a larger number of neighbours (i.e., subgroup members within 5 m) was associated with a lower proportion of time individuals spent vigilant, which is similar to findings in other studies. Another social factor that may affect individuals’ vigilance is the possibility of between-community encounters. Higher levels of vigilance can be expected in areas closer to the boundary of the home range, where between-community encounters are more likely to occur compared with non-boundary areas. We found that location in terms of boundary vs. non-boundary areas had a significant effect on the time individuals spent vigilant in the expected direction. We also found that location modulated the effect of subgroup size on vigilance: only in the boundary areas did larger subgroup sizes result in less individual vigilance time. We concluded that conspecifics affect vigilance of wild spider monkeys in multiple ways
Scientific basis of nanotechnology, implications for the food sector and future trends
Nanotechnologies are opening up new horizons in almost all
scientific and technological fields. Among these, applications
of nanotechnologies are expected to bring large benefits and
add value to the food and food-related industries through the current regulatory framework
whole food chain, from production to processing, safety, packaging,
transportation, storage and delivery. Nanotechnology
consists in the realization and manipulation of nano-sized
matter, the unique properties of which with respect to their
bulk counterparts are illustrated and discussed. Then, the
main tools and techniques routinely used in nanotechnology
for the nanoscale characterization of food matrices as well
as for the analytical determination of nanomaterials in food
samples are reviewed. Finally, safety and risk assessment issues
are discussed and an overview of applications of nanotechnology
to the food sector is provided along with a description of th
Seasonal effects on reconciliation in Macaca Fuscata Yakui
Dietary composition may have profound effects on the activity budgets, levelof food competition, and social behavior of a species. Similarly, in seasonally breeding species, the mating season is a period in which competition for mating partners increases, affecting amicable social interactions among group members. We analyzed the importance of the mating season and of seasonal variations in dietary composition and food competition on econciliation
in wild female Japanese macaques (Macaca fuscata yakui) on Yakushima Island, Japan. Yakushima macaques are appropriate subjects because they are seasonal breeders and their dietary composition significantly changes among the seasons. Though large differences occurred between the summer months and the winter and early spring months in activity budgets and the consumption of the main food sources, i.e., fruits, seeds, and leaves, the level
of food competition and conciliatory tendency remained unaffected. Conversely,conciliatory tendency is significantly lower during the mating season than in the nonmating season. Moreover, conciliatory tendency is lower when 1 or both female opponents is in estrous than when they are not. Thus the mating season has profound effects on reconciliation, whereas seasonal changes in activity budgets and dietary composition do not. The detrimental effects of the mating season on female social relationships and reconciliation may be due to the importance of female competition for access to male partners in multimale, multifemale societies
Structural bases for substrate and inhibitor recognition by matrix metaloproteinases
Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases which are involved in the proteolytic processing of several components of the extracellular matrix. As a consequence, MMPs are implicated in several physiological and pathological processes, like skeletal growth and remodelling, wound healing, cancer, arthritis, and multiple sclerosis, raising a very widespread interest toward this class of enzymes as potential therapeutic targets. Here, structure-function relationships are discussed to highlight the role of different MMP domains on substrate/inhibitor recognition and processing and to attempt the formulation of advanced guidelines, based on natural substrates, for the design of inhibitors more efficient in vivo. © 2008 Bentham Science Publishers Ltd
You are Not Welcome: Social Exchanges between Female Spider Monkeys (Ateles geoffroyi)
Group living leads to competition for food between group members. Two types of intragroup food competition may occur: scramble competition, in which all group members use the same resource, such that feeding opportunities are equal for everyone; and contest competition, in which some group members monopolize resources through aggression and dominance. In species in which females disperse from the natal group and immigrate into other groups, immigrant females increase group size and thus possibly food competition. Under these circumstances, other females may use aggression to discourage new females from joining the group. We assessed the distribution of aggression, embraces, and kisses among female spider monkeys (Ateles geoffroyi) in relation to group tenure. We recorded social interactions during 1688 10-min focal animal samples on 11 females in Santa Rosa, Costa Rica. We found that aggression was rare between long-term resident females and aggression rates were not higher during feeding than in other contexts, suggesting there was little contest competition. Long-term residents and less recently immigrant females showed higher aggression rates toward the most recent immigrants than toward other females, especially during the first months after a female immigrated, which coincided with the dry season. We did not find similar patterns for embrace and kiss. These results suggest that other females target aggression toward the most recent immigrants to reduce scramble competition. This finding suggests that group tenure should be included in socioecological models for species with female dispersal. © 2017 Springer Science+Business Media, LL
EquiFACS: the Equine Facial Action Coding System
Although previous studies of horses have investigated their facial expressions in specific contexts, e.g. pain, until now there has been no methodology available that documents all the possible facial movements of the horse and provides a way to record all potential facial configurations. This is essential for an objective description of horse facial expressions across a range of contexts that reflect different emotional states. Facial Action Coding Systems (FACS) provide a systematic methodology of identifying and coding facial expressions on the basis of underlying facial musculature and muscle movement. FACS are anatomically based and document all possible facial movements rather than a configuration of movements associated with a particular situation. Consequently, FACS can be applied as a tool for a wide range of research questions. We developed FACS for the domestic horse (Equus caballus) through anatomical investigation of the underlying musculature and subsequent analysis of naturally occurring behaviour captured on high quality video. Discrete facial movements were identified and described in terms of the underlying muscle contractions, in correspondence with previous FACS systems. The reliability of others to be able to learn this system (EquiFACS) and consistently code behavioural sequences was high—and this included people with no previous experience of horses. A wide range of facial movements were identified, including many that are also seen in primates and other domestic animals (dogs and cats). EquiFACS provides a method that can now be used to document the facial movements associated with different social contexts and thus to address questions relevant to understanding social cognition and comparative psychology, as well as informing current veterinary and animal welfare practices
Design and analysis of vibration energy harvesters based on peak response statistics
Energy harvesting using cantilever piezoelectric vibration energy harvesters excited by Gaussian broadband random base excitation is considered. The optimal design and analysis of energy harvesters under random excitation is normally performed using the mean and standard deviation of a response quantity of interest, such as the voltage. An alternative approach based on the statistics of the peak voltage is developed in this paper. Three extreme response characteristics, namely (a) level crossing, (b) response peaks above certain level, and (c) fractional time spend above a certain level, have been employed. Two cases, namely the harvesting circuit with and without an inductor, have been considered. Exact closed-form expressions have been derived for number of level crossings, statistics of response peaks and fractional time spend above a certain level for the output voltage. It is shown that these quantities can be related to the standard deviation of the voltage and its derivative with respect to time. Direct numerical simulation has been used to validate the analytical expressions. Based on the analytical results, closed-form expressions for optimal system parameters have been proposed. Numerical examples are given to illustrate the applicability of the analytical results
Matrilineal behavioral and physiological changes following the death of a non-alpha matriarch in rhesus macaque
In many species, the loss of alpha matriarchs is associated with a number of negative outcomes such as troop fission, eviction, wounding, and reduced vitality. However, whether
the dramatic consequences of their loss are due to their role as an old experienced figure or
to their alpha status remains unclear. In a retrospective study, we tested that in a semi-free
ranging colony of rhesus macaques (Macaca mulatta), the removal of a non-alpha matriarch, who had a large set of kin, led to changes in behavior and physiological stress within
her matriline. Following her removal, her matriline increased in aggression, vigilance, and
social grooming. Additionally, hierarchical stability, measured by levels of rank changes,
decreased within her matriline, and levels of intense aggression by high-ranking animals
were more frequent, as well as matrilineal wounding. Although ordinal rank was positively
associated with higher chronic hair cortisol concentrations (HCCs) in the months before the
matriarch’s removal, following her removal, only those who experienced large increases in
rank within her matriline displayed higher HCCs. Changes in matrilineal stability, aggression, behavior, and HCCs within the other two matrilines in the troop were not evident,
although caution is needed due to the small sample sizes. We conclude that the removal of
the non-alpha matriarch led to matrilineal instability, characterized by higher levels of
aggression and subsequent vigilance, rank changes, physiological stress, and grooming.
We suggest that non-alpha matriarchs with a large number of kin and social support can be
integral to the stability of matrilines.Division of Intramural Research, National Institute of Child Health and Human Development, 1ZIAHD001107- 3
A megbocsátás pszichológiája: kialakulása, hatásai és fejlesztése
A megbocsátás az interperszonális sérelmekre adott egyik lehetséges válasznak tekinthető, melynek fókuszában a sérelmet elszenvedő személy kognitív, érzelmi és viselkedéses válaszaiban bekövetkező proszociális változás áll. A megbocsátás mentális és fizikai egészségre kifejtett pozitív hatása jól dokumentált. Magas szintje alacsony szorongás- és depressziószinttel társul, illetve sikeresen csökkenti a stresszre adott fizikai választ (kortizol és kardiovaszkuláris reaktivitás). A megbocsátást - hatásai alapján - olyan emóció fókuszú megküzdési módként definiálhatjuk, mely sikeresen csökkenti az interperszonális sérelem nyomán kialakult stresszreakciót. Az utóbbi években számos intervenciós technikát dolgoztak ki, melyek a megbocsátás támogatását, illetve fejlesztését tűzték ki célként. Ezek a módszerek általában sikeresen növelik a megbocsátásra való hajlandóságot.</o:p
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