189 research outputs found
Explaining social learning of food preferences without aversions: an evolutionary simulation model of Norway rats
No full textNorway rats (Rattus norvegicus) transmit preferences for novel foods socially by smelling each other's breath. However, rats fail to learn aversions, acquiring a preference even if the rat whose breath they smell has been poisoned. Rats can distinguish between sick and healthy conspecifics and social learning of both preferences and aversions is present in other species - hence it is unclear why rats cannot learn aversions socially. We constructed an evolutionary simulation in which a population of rats foraged from a central location, exploiting food sites that could contain edible or toxic foodstuffs. We examined the relationship between toxin lethality and selection for individual versus social learning and discrimination between sick and healthy conspecifics in order to allow learning of both preferences and aversions. At low lethality levels individual learning was selected for and at intermediate levels we found social learning of both preferences and aversions. Finally, given high lethality levels the simulated rats would employ social learning but failed to learn aversions, matching the behaviour of real rats. We argue that Norway rats do not learn aversions socially because their environment may contain only highly lethal toxins which make interaction with a sick conspecific an extremely rare event
Autonomous Traffic Management:Integrating Vissim Traffic Model with a Swarm of Drones
No full textIn this research, we propose a system for monitoring and efficiently managing traffic congestion at the intersection of Park Avenue and E 72nd Street, New York, USA. This methodology is applied to a realistic traffic scenario where all intersections are controlled by fixed traffic signals. The method is based on a data-driven approach deploying a swarm of drones to measure the number of vehicles on roads. The collected information by the drones is sent to traffic lights and simultaneous perturbation stochastic approximation (SPSA) method is used to minimize traffic congestion by adapting the green traffic light durations. More precisely, we simulate the scenario thanks to the Vissim traffic software and Python. The simulation results highlight the effects of traffic light optimization to reduce traffic jams in contrast to the baseline case, where the duration of green lights is fixed.</p
Costs of Information Gathering Strategies and Their Impact on Animal Dispersal
No full textAnimal dispersal is among the most impacted behaviours from habitat loss and fragmentation. Animals disperse in search of better conditions to ultimately increase their fitness. However, the dispersal process induces costs that can be translated as a loss in fecundity or as an increase in predation risks. In this study, we use an evolutionary multi-agent model to quantify how costs related to information acquisition shape information gathering strategies used in animal dispersal. We separate costs of private information, i.e., related to the direct acquisition of information sensed in the physical environment, from costs related to social information, i.e., derived from the observation of conspecifics behaviour. We find that a low mortality risk associated with dispersal movements selects non-informed dispersal in low-variability environments. However, high-variability environments select an information gathering strategy based on the exploration of multiple patches of habitat. A higher mortality risk causes drastic drops in population abundance and agents gather information from only one patch to limit their movements. Overall, private information is predominantly used in high-variability environments while social and private information are used equally in low-variability environments.</p
Implementation of the response to synchronization in e-puck2 robots
No full textThe response to synchronization is a phenomenon observed in several firefly species, where male ensembles synchronize their rhythmic flashes by triggering a response from females which ends the courtship process. In this work, we present a robotic implementation of this phenomenon by using a team of static e-puck2 robots that integrate oscillatory dynamics to mimic the flashing rhythm of the fireflies. To this end, robots communicate with each other via infrared (IR) and follow a distributed control law. They are divided into two groups: one representing the male population with bursting dynamics and the other representing females with non-bursting behavior. Our experimental results demonstrate that response to synchronization is robust with respect to the presence of realistic features such as obstacles and information loss. These factors play a significant role in refining the original model and enhancing its applicability in real-world scenarios
Clidemo naturalista (FGrHist 323 F 31-36)
No full textThis paper focuses on six fragments dealing with naturalistic
topics, that Aristotle and Theophrastus assign to Clidemus, without specifying
whether he is the attidographer or a namesake of him. After a brief
introduction (§ 1), the fragments are presented (§ 2): the first couple
concerns thunderbolts and sense perception, the others deal with the
botanical world. Afterwards, some clues about the issue of attribution are
investigated (§ 3), and it is concluded that we should not exclude that the
author can actually be the attidographer Clidemus, rather than someone
with his same name (§ 4)
Evolution of neuro-controllers for robots' alignment using local communication
No full textSCOPUS: ar.jinfo:eu-repo/semantics/publishe
La storia greca di età classica in Valerio Massimo (490-362)
No full textThe present
paper
aims at studying Valerius Maximus
’
presentation of Greek history between 490
and 362
an
d it is divided into three paragraphs. The first deals with the period from the Persian to the
Peloponnesian war, while the second with the ages of Spartan and Theban hegemony.
The third
paragraph
presents the conclusions of the
survey
,
focusing in
particular on
the chronological
distribution of the episodes treated (1),
on
Valerius Maximus
’
interests (2),
on his
evaluations about
the reported deeds and sayings
(3) and
on
the
much debated
problem of his sources (4).
The analysis of the
considered
pas
sages
is
grouped around some thematic
cores
, mostly concerning
characters con
sidered emblematic; more rarely
the attention is specifically focused on episodes that
do not have a reference to single personalities. Moreover, it is evident that Valerius Maxim
us chooses
to present facts and
protagonists not
much with the aim of illustrating fundamental events in Greek
history, but rather
on account
of their exemplarity, or rather their function of providing an example
(positi
ve or negative) related to the chapt
er
in which they are inserted. This is
the reason
why the
same historical figure not infrequently appears under different
chapters
and is sometimes presented
in a different light, with a favourable or
unfavourable bias
, depending on the context in which it
is set
(and, of course, on the source from which
Valerius Maximus
draws
the
exemplum
). The author, in
fact, seems to
produce
stand
-
alone
“
pills
” of history
and his work seems to acquire sense not so mu
ch
in the horizon of an overall
comparison be
tween the
Greek and Roman world
, but rather
in the
message that each of the
chapters
and each of the
exempla
wants to communicate
La fortuna di Milziade fra IV secolo a.C. e I d.C. Frammenti di una tradizione
No full textIl presente lavoro studia il ritratto di Milziade nelle fonti tra il IV sec. a.C. e il I sec. d.C.,
cioè dopo Erodoto e prima di Plutarco e della Seconda sofisitica. Dopo una breve introduzione
contenuta nel primo paragrafo, il secondo si sofferma sulle fonti di IV secolo: gli
oratori generalmente forniscono una presentazione elogiativa di Milziade, riabilitandone
l’immagine dopo la sua morte in disgrazia (par. 2.1); successivamente, viene analizzata la
sua presentazione in autori come Platone, Aristotele (par. 2.2) e Teopompo ed Eforo (par.
2.3). Il terzo paragrafo affronta le fonti relative al periodo tra il I sec. a.C. e il I d.C.: l’unica
fonte greca è Diodoro (par. 3.1), mentre abbiamo un buon numero di fonti latine, tra cui
Nepote, Cicerone, Seneca il Vecchio e Valerio Massimo (par. 3.2). Nel quarto paragrafo
sono analizzate alcune notizie isolate su Milziade, relative alla battaglia di Maratona (par.
4.1) o ad eventi ad essa successivi (par. 4.2) o ancora ad altri fatti (par. 4.3), allo scopo non
tanto di accertarne l’attendibilità storica, di solito piuttosto bassa, bensì di trarne deduzioni
sull’immagine di Milziade che l’autore voleva veicolare attraverso di esse. Il quinto e ultimo
paragrafo propone alcune considerazioni conclusive e osserva da un lato che è innegabile
una significativa riabilitazione di Milziade, dovuta sia alla propaganda cimoniana,
sia soprattutto alla nuova situazione internazionale che Atene si trovava a vivere nel IV
secolo, ma, dall’altro, che la sua immagine rimane almeno in parte controversa: sono attestate
posizioni critiche, come quella di Platone, e anche giudizi chiaroscurali, come quello
di Nepote, autore dell’unica biografia nota di Milziade.This paper focuses on the portrait of Miltiades in the sources between 4th cent. B.C. and
1st A.D., thus after Herodotus and before Plutarch and the Second sophistic. After the first
paragraph, devoted to an introduction to the issue, the second one considers sources of the
4th century: the orators usually praise Miltiades and therefore they rehabilitate his reputation
after he died in disgrace (par. 2.1); then his figure is analysed in authors like Plato,
Aristotle (par. 2.2) and Theopompus and Ephorus (par. 2.3). The third paragraph focuses
on the sources between 1st cent. B.C. and 1st A.D.: the only Greek-writing author is Diodorus
(par. 3.1), but we have a number of Latin sources, like Nepos, Cicero, Seneca the
Elder, Valerius Maximus and others (par. 3.2). In the fourth paragraph it is provided a list
of rare pieces of information preserved by the sources, concerning the battle of Marathon
(par. 4.1), the events after the battle (par. 4.2) and other episodes (par. 4.3): the aim of this
section is not to ascertain the reliability of these pieces of news, that is usually very low,
but to use them in order to understand which portrait of Miltiades these sources intended
to provide. The fifth paragraph offers final remarks and suggests that, notwithstanding
Miltiades’ rehabilitation, due both to Cimon’s propaganda and to the new conditions of
4th century Athens, his imagine remains at least partly controversial: criticisms are attested
(e.g. by Plato), but also ambivalent judgments, such as that of Nepos, who wrote the only
biography of Miltiades
Tucidide di Melesia e il partito di opposizione a Pericle
No full text1. The main source on the opposition of Thucydides the son of Melesias to Pericles is Plut. Per. XI 1-2, the reliability of which has often been doubted by scholars because of the distance between the author and the events: thus, a preliminary examination of this text, both in historiographical (§ 2) and historical (§ 3) terms, is required.
2. In the passages of his Lives in which refers about Thucydides, Plutarch uses fourth century sources (above all Theopompus, but perhaps Ephorus and philosophers too) and, directly or indirectly, fifth century ones (like Stesimbrotus, Ion, the comedy). Besides, as can be inferred from Per. XIII 16, Plutarch carefully analyzes his sources and their historical reliability. Therefore, the author seems well documented and there is no need to reject his report.
3. Many sources (Thuc. VI 13, 1; Aristoph. Eccl., 296-298; FGrHist 328 F 140; Demosth. XVIII 143) suggest that it wasn’t unusual for the Athenians to gather in groups of similar political orientation in the assembly: therefore, what Plutarch tells about Thucydides of Melesias is confirmed by analogous situations and cannot be easily rejected.
4. Political groups could variously influence an assembly meeting: by interruptions and heckling; swinging the votes of the uncertain; trying to manipulate the assessment of the outcome of a cheirotonia.
5. Thucydides’ opposition of to Pericles, between 451/50 or 450/49 (Kimon’s death) and 444 or 443 (Thucydides’s ostracism), can be reconstructed from a few allusions in the sources, such as Plut. Per. XI-XIV, especially about the building program of the Acropolis; evidence can be also be inferred from Per. XXIII 1 and from Anaxagoras’ trial after Thucydides’ return from his exile.
6. (1) Can Thucydides’ group be termed “party”? In effect, despite what most scholars sustain, the careful examination of the requisites of the use of the term “party” and their unbiased application to the direct democracy of classical Athens provide no cogent reason for rejecting the term. (2) Why Thucydides’ opposition to Pericles failed? Although Thucydides’ debacle can be explained through various reasons, the most significant is perhaps that his opposition wasn’t secret and clandestine as that of 411 and 404 conspirators: since the demos was strongly attached to democracy, the nature of Thucydides’ opposition was destined to lead to failure
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