245 research outputs found
Zeroth and Second Laws of Thermodynamics Simultaneously Questioned in the Quantum Microworld
Several models of quantum open systems are known at present to violate,
according to principles of the standard quantum theory of open systems, the
second law of thermodynamics. Here, a new and rather trivial model of another
type is suggested describing mechanism that violates, according to the same
principles, the zeroth and the second laws of thermodynamics simultaneously. Up
to a technically minor modification, the model resembles some models already
known, solved by standard means, and properly understood. Universal validity of
two basic principles of thermodynamics in strictly quantum situations is thus
simultaneously called in question.Comment: Extended reference list and acknowledgement
Neural Networks Supporting Phoneme Monitoring Are Modulated by Phonology but Not Lexicality or Iconicity: Evidence From British and Swedish Sign Language
Sign languages are natural languages in the visual domain. Because they lack a written
form, they provide a sharper tool than spoken languages for investigating lexicality effects
which may be confounded by orthographic processing. In a previous study, we showed
that the neural networks supporting phoneme monitoring in deaf British Sign Language
(BSL) users are modulated by phonology but not lexicality or iconicity. In the present
study, we investigated whether this pattern generalizes to deaf Swedish Sign Language
(SSL) users. British and SSLs have a largely overlapping phoneme inventory but are
mutually unintelligible because lexical overlap is small. This is important because it means
that even when signs lexicalized in BSL are unintelligible to users of SSL they are usually
still phonologically acceptable. During fMRI scanning, deaf users of the two different sign
languages monitored signs that were lexicalized in either one or both of those languages
for phonologically contrastive elements. Neural activation patterns relating to different
linguistic levels of processing were similar across SLs; in particular, we found no effect of
lexicality, supporting the notion that apparent lexicality effects on sublexical processing
of speech may be driven by orthographic strategies. As expected, we found an effect of
phonology but not iconicity. Further, there was a difference in neural activation between
the two groups in a motion-processing region of the left occipital cortex, possibly driven
by cultural differences, such as education. Importantly, this difference was not modulated
by the linguistic characteristics of the material, underscoring the robustness of the neural
activation patterns relating to different linguistic levels of processing
Mimicry cannot explain rejection type in a host–brood parasite system
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordOne of the most effective defensive strategies of hosts against brood parasites is rejection, commonly achieved by ejection of the parasitic egg or desertion of the parasitized nest. Nest desertion should be a costlier strategy than egg ejection, because birds must thesn spend additional time and energy renesting, and therefore we still cannot explain why some individuals desert their nests rather than eject parasitic eggs and continue a given breeding attempt. The great reed warbler, Acrocephalus arundinaceus, is a frequent host of the common cuckoo, Cuculus canorus, and is known to use both types of rejection response. By measuring cuckoo egg mimicry, we investigated the hypothesis that the hosts desert if they cannot reliably recognize the cuckoo egg in their nest. We predicted that we would find better mimicry when hosts deserted rather than ejected. However, we did not find a difference in mimicry between these two groups of nests, implying that host females do not desert because they cannot reliably recognize the parasitic egg. We also showed that neither the date in the season nor the age of the host females influenced the type of rejection. Other factors potentially eliciting nest desertion, including host personality, host, inability to eject, excessive clutch reduction and visibility of the cuckoo female at the host nest, are discussed. Finally, we suggest that desertion may persist as a host defensive strategy against brood parasitism because it is not as costly as previously assumed and/or it is beneficial for host females in good physical condition.Czech Science FoundationCzech Academy of SciencesNatural Environment Research Council (NERC
Impact of the tip radius on the lateral resolution in piezoresponse force microscopy
We present a quantitative investigation of the impact of tip radius as well
as sample type and thickness on the lateral resolution in piezoresponse force
microscopy (PFM) investigating bulk single crystals. The observed linear
dependence of the width of the domain wall on the tip radius as well as the
independence of the lateral resolution on the specific crystal-type are
validated by a simple theoretical model. Using a Ti-Pt-coated tip with a
nominal radius of 15 nm the so far highest lateral resolution in bulk crystals
of only 17 nm was obtained
PRIMEROS REGISTROS DE ACAROS DEL GENERO NEHARPYRHYNCHUS (ACARIFORMES: HARPIRHYNCHIDAE) EN AVES DEL PERU
Two mite species of the genus Neharpyrhynchus (Acariformes: Harpirhynchidae) were recorded on wild birds in Peru: Neharpyrhynchus trochilinus from Amazilia lacteal, and A. chionogaster (both Apodiformes: Trochilidae) and Neharpyrhynchus tangara from Thraupis episcopus (Passeriformers: Thraupidae). Records from A. chionogaster and T. episcopus represent new hostparasite associations. Mites of this genus were found in Peru for the first time.Dos especies de ácaros del género Neharpyrhynchus (Acariformes: Harpirhynchidae) fueron registrados en aves silvestres del Perú: Neharpyrhynchus trochilinus ex Amazilia lactea y A. chionogaster (ambos Apodiformes: Trochilidae) y Neharpyrhynchus tangara ex Thraupis episcopus (Passeriformes: Thraupidae). Los registros en A. chionogaster y T. episcopus representan nuevas asociaciones huesped - parásito. Los ácaros de este género fueron reportados por primera vez para el Perú
On the V-type asteroids outside the Vesta family. I. Interplay of nonlinear secular resonances and the Yarkovsky effect: the cases of 956 Elisa and 809 Lundia
Among the largest objects in the main belt, asteroid 4 Vesta is unique in
showing a basaltic crust. It is also the biggest member of the Vesta family,
which is supposed to originate from a large cratering event about 1 Gyr ago
(Marzari et al. 1996). Most of the members of the Vesta family for which a
spectral classification is available show a V-type spectra. Before the
discovery of 1459 Magnya (Lazzaro et al. 2000) and of several V-type NEA (Xu
1995), all the known V-type asteroids were members of the Vesta family.
Recently two V-type asteroids, 809 Lundia and 956 Elisa, (Florczak et al. 2002)
have been discovered well outside the limits of the family, near the Flora
family. We currently know 22 V-type asteroids outside the family, in the inner
asteroid belt. In this work we investigate the possibility that these objects
are former family members that migrated to their current positions via the
interplay of Yarkovsky effect and nonlinear secular resonances. The main
dynamical feature of 956 Elisa and 809 Lundia is that they are currently inside
the 2(g-g6)+s-s6 (z2 by Milani and Knezevic, 1993) secular resonance. Our
investigations show that members of the Vesta dynamical family may drift in
three-body and weak secular resonances until they are captured in the strong z2
secular resonance. Only asteroids with diameters larger than 16 km can remain
in one of the three-body or secular resonances long enough to reach the region
of the z2 resonance. This two-step mechanism of capture into the z2 resonance
could explain: i) the current resonant orbits of 956 Elisa and 809 Lundia, ii)
why their size is significantly larger than that of the typical member of the
Vesta family, and iii) provide a lower limit on the Vesta family age.Comment: 14 pages, 10 figures, 3 tables. Accepted for publication in A&
How does visual language affect crossmodal plasticity and cochlear implant success?
Cochlear implants (CI) are the most successful intervention for ameliorating hearing loss in severely or profoundly deaf children. Despite this, educational performance in children with CI continues to lag behind their hearing peers. From animal models and human neuroimaging studies it has been proposed the integrative functions of auditory cortex are compromised by crossmodal plasticity. This has been argued to result partly from the use of a visual language. Here we argue that 'cochlear implant sensitive periods' comprise both auditory and language sensitive periods, and thus cannot be fully described with animal models. Despite prevailing assumptions, there is no evidence to link the use of a visual language to poorer CI outcome. Crossmodal reorganisation of auditory cortex occurs regardless of compensatory strategies, such as sign language, used by the deaf person. In contrast, language deprivation during early sensitive periods has been repeatedly linked to poor language outcomes. Language sensitive periods have largely been ignored when considering variation in CI outcome, leading to ill-founded recommendations concerning visual language in CI habilitation
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