1,720,978 research outputs found
Lateralization in the predatory behaviour of the lizard _Podarcis muralis_
No full textEctotherms have been demonstrated being lateralized as well as endotherms. This specialization is particularly evident in some species in a bias using the eyes, having a preference in using an eye to observe specific kinds of stimuli, processing them with the controlateral hemisphere. Several ectotherms are favorite in this from having a lateral position of the eyes, making them able to carry out more tasks simultaneously, controlled by different eyes and hemispheres. Predatory responses seem mediated by the right-eye/left-hemisphere. As there are no strong evidences of this in lizards, we analysed if males of Podarcis muralis in a laboratory predatory context are lateralized when looking at prey and if this task is right-eye/left-hemisphere mediated. Using a T-maze, we recorded what direction they chose to reach a familiar prey observed at the left or at the right side of the longitudinal body axis. With concern to this lizards were lateralized (P < 0.05). The preferential direction to reach the prey is the right for the majority (4 of 5) of lizards having a preference, indicating even a tendency (P < 0.07) of laterality at population level. In addition, lizards maintained the head longer to the same direction they later chose to catch the prey (P < 0.001). Our study demonstrates how males of Podarcis muralis are visually lateralized to capture prey. This is another support to the hypothesis of the common ancestral derivation of vertebrate lateralization
Lateralizzazione senso-motoria nel comportamento predatorio della lucertola muraiola (_Podarcis muralis_)
No full textL'utilizzo asimmetrico degli occhi sembra essere diffuso nei vertebrati. Questo è indicativo di una lateralizzazione visiva che potrebbe permettere l'esecuzione contemporanea di più comportamenti fondamentali per la sopravvivenza, ognuno elaborato da un emisfero differente. Tale capacità potrebbe essere favorita dal posizionamento laterale degli occhi.
Nonostante studi precedenti sembrino dimostrare come le risposte di tipo predatorio in pesci, anfibi ed alcuni sauropsidi siano mediate dall'occhio destro/emisfero sinistro, sulle lucertole esistono pochi dati
Complementary lateralisation in the exploratory and predatory behaviour of the common wall lizard (_Podarcis muralis_)
No full textLateralization in lizards: evidence of presence in several contexts
No full textRecent research has provided information about the right-eye mediation of predatory tasks in several taxa of
ectotherms, while antipredatory and exploratory behaviours are generally mediated by the left eye. This type
of visual specialisation allows individuals to hunt and to remain vigilant at the same time. However, very
little is known about such specialisation in sauropsids. In this study, we report on several different experiments
which have investigated the presence of lateralization in the lacertid Podarcis muralis lizard, for predatory,
antipredatory, and exploratory behaviours. We found right-eye control in prey detection in a T-maze and in
a detour test. In contrast, in escape behaviour from a simulated predator, we found that lizards significantly
preferred to escape to the right, and once at a safe distance, to turn their head back towards the left in order
to review the source of the threat, thereby supporting a left-eye mediated processing of antipredatory stimuli.
In experiments investigating the exploration of a new environment, a strong left-eye bias was found once
again. Finally, with individual lizards tested in experimental situations of both predation and exploration, we
confirmed once again a right-eye visual system for controlling predatory cues and a left-eye visual system
for controlling exploratory cues, supporting the hypothesis that cerebral specialisation of functions allows
the simultaneous performance of important tasks as part of the daily routine
Transiently triggered latch-up in CMOS twin-tub and epitaxial technologies
No full textWe present in this work an analysis of transiently triggered latch-up in test structures fabricate using a twin-tub process implemented on two different substrates: a p-type and a p/p+ epitaxial one. Steady-state electrical characterization confirmed the well-known increased latch-up resistance of epitaxial structures with respect to standard ones. In this paper it is shown that, depending on the chosen electrical configuration, when latch-up is transiently triggered, epitaxial structures may have dynamic triggering currents lower than twin-tub ones. The influence of some layout variables on turn-on threshold voltage has been investigated for all samples
Lateralization in the escape behaviour of the common wall lizard (_Podarcis muralis_)
No full textLateralization in ectotherms is now as well studied as in endotherms. Bias in eye use seems widespread, particularly in several ectotherms, most of them having lateral eyes. Several studies evidenced that the right eye/left hemisphere is involved in predatory behaviour and food searching while the left eye/right hemisphere seems to control predator monitoring, making lateralized individuals able to carry out both tasks simultaneously. Starting from previous observations that demonstrated a right-eye/left-hemisphere preference for observing a prey in common wall lizards, Podarcis muralis, we investigated whether a visual lateralization in antipredatory behaviour is present too. In a first experiment, we induced lizards in a terrarium to escape from a simulated predator attacking from behind, recording the direction of the escape path in relation to the starting point. We found that the preferred escape direction of most lateralized individuals was to the right and there was also a strong rightward preference in escape direction as a whole. In a second experiment the lizards, again stimulated from behind, had to choose to run down either the right or the left arm of a semi-circular tunnel ("ram-horn" maze). The rightward preference in escape behaviour was confirmed in this experiment too. We conclude that the constant rightward escape could be due to a left-eye early perception of the threatening cue and to the possibility it gives of better monitoring of most of the terrarium surface. Moreover, we found a left bias in turning the head for monitoring the predatory stimulus during escape, supporting the hypothesis that such a preference is likely due to visual lateralization rather than to motor lateralization
Detection and localization of gate oxide shorts in NMOS transistors by optical beam induced current
No full textPolysilicon gate high voltage MOS transistors have been submitted to electrical overstress and ESD. By mapping the optical beam induced current (OBIC) in a scanning laser system, shorts created under the device gate can be identified and correlated with electrical measurement
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
