3,077 research outputs found
Descriptions, Biology, and Notes on the Identification of Some Trogoderma Larvae
For several years members of the dermestid beetle genus Trogoderma have attracted widespread attention, particularly since T. granariurn Everts, the khapra beetle, became established as an introduced pest in Arizona, California, Mexico, and New Mexico. This species has been the object of a control program to remove it as a hazard to stored grain and to prevent its spread to parts of the country where it is not known to occur. Species of Trogoderma other than the khapra beetle may also build up to damaging numbers in stored products. Information has been obtained on these species, as well as on granariurn, during the course of these studies
Performance Characteristics of a Cluster of 5-kW Laboratory Hall Thrusters
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76117/1/AIAA-19752-159.pd
Human larynx motor cortices coordinate respiration for vocal-motor control.
Vocal flexibility is a hallmark of the human species, most particularly the capacity to speak and sing. This ability is supported in part by the evolution of a direct neural pathway linking the motor cortex to the brainstem nucleus that controls the larynx the primary sound source for communication. Early brain imaging studies demonstrated that larynx motor cortex at the dorsal end of the orofacial division of motor cortex (dLMC) integrated laryngeal and respiratory control, thereby coordinating two major muscular systems that are necessary for vocalization. Neurosurgical studies have since demonstrated the existence of a second larynx motor area at the ventral extent of the orofacial motor division (vLMC) of motor cortex. The vLMC has been presumed to be less relevant to speech motor control, but its functional role remains unknown. We employed a novel ultra-high field (7T) magnetic resonance imaging paradigm that combined singing and whistling simple melodies to localise the larynx motor cortices and test their involvement in respiratory motor control. Surprisingly, whistling activated both 'larynx areas' more strongly than singing despite the reduced involvement of the larynx during whistling. We provide further evidence for the existence of two larynx motor areas in the human brain, and the first evidence that laryngeal-respiratory integration is a shared property of both larynx motor areas. We outline explicit predictions about the descending motor pathways that give these cortical areas access to both the laryngeal and respiratory systems and discuss the implications for the evolution of speech
Nonmonotonic d_{x^2-y^2} Superconducting Order Parameter in Nd_{2-x}Ce_xCuO_4
Low energy polarized electronic Raman scattering of the electron doped
superconductor Nd_1.85Ce_0.15CuO_4 (T_c=22 K) has revealed a nonmonotonic
d_{x^2-y^2} superconducting order parameter. It has a maximum gap of 4.4 k_BT_c
at Fermi surface intersections with antiferromagnetic Brillouin zone (the ``hot
spots'') and a smaller gap of 3.3 k_BT_c at fermionic Brillouin zone
boundaries. The gap enhancement in the vicinity of the ``hot spots'' emphasizes
role of antiferromagnetic fluctuations and similarity in the origin of
superconductivity for electron- and hole-doped cuprates.Comment: 4 pages, 4 figure
Resilient distributed collection through information speed thresholds
Part 6: Large-Scale Decentralised SystemsInternational audienceOne of the key coordination problems in physically-deployed distributed systems, such as mobile robots, wireless sensor networks, and IoT systems in general, is to provide notions of âdistributed sensingâ achieved by the strict, continuous cooperation and interaction among individual devices. An archetypal operation of distributed sensing is data summarisation over a region of space, by which several higher-level problems can be addressed: counting items, measuring space, averaging environmental values, and so on. A typical coordination strategy to perform data summarisation in a peer-to-peer scenario, where devices can communicate only with a neighbourhood, is to progressively accumulate information towards one or more collector devices, though this typically exhibits problems of reactivity and fragility, especially in scenarios featuring high mobility. In this paper, we propose coordination strategies for data summarisation involving both idempotent and arithmetic aggregation operators, with the idea of controlling the minimum information propagation speed, so as to improve the reactivity to input changes. Given suitable assumptions on the network model, and under the restriction of no data loss, these algorithms achieve optimal reactivity. By empirical evaluation via simulation, accounting for various sources of volatility, and comparing to other existing implementations of data summarisation algorithms, we show that our algorithms are able to retain adequate accuracy even in high-variability scenarios where all other algorithms are significantly diverging from correct estimations
Questioning policy, youth participation and lifestyle sports
Young people have been identified as a key target group for whom participation in sport and physical activity could have important benefits to health and wellbeing and consequently have been the focus of several government policies to increase participation in the UK. Lifestyle sports represent one such strategy for encouraging and sustaining new engagements in sport and physical activity in youth groups, however, there is at present a lack of understanding of the use of these activities within policy contexts. This paper presents findings from a government initiative which sought to increase participation in sport for young people through provision of facilities for mountain biking in a forest in south-east England. Findings from qualitative research with 40 young people who participated in mountain biking at the case study location highlight the importance of non-traditional sports as a means to experience the natural environments through forms of consumption which are healthy, active and appeal to their identities. In addition, however, the paper raises questions over the accessibility of schemes for some individuals and social groups, and the ability to incorporate sports which are inherently participant-led into state-managed schemes. Lifestyle sports such as mountain biking involve distinct forms of participation which present a challenge for policy-makers who seek to create and maintain sustainable communities of youth participants
Green turtles highlight connectivity across a regional marine protected area network in west Africa
Networks of marine protected areas (MPAs) are invaluable for the protection of species
with high dispersal capacity, yet connectivity within networks is poorly understood. We
demonstrate the connectivity within the regional MPA network in West Africa (RAMPAO),
mediated by the largest green turtle population in the eastern Atlantic Ocean. We
equipped with satellite tags 45 female green turtles nesting in the BijagoÌ
s Archipelago,
Guinea-Bissau, and tracked them during internesting, migration, and foraging to quantify
the degree of coverage the RAMPAO network provides during each of these critical
periods. During the internesting period, turtles were largely concentrated around the
nesting islands, with a mean of 94.8% (SD 0.1%, range: 46% - 100%, n = 40 turtles) of
tracking positions falling within MPA limits. Among the 35 turtles successfully tracked into
the foraging period, we identified variable migratory strategies, with 12 turtles remaining
near-resident at distances of 40-90 km from breeding sites, 10 turtles migrating 300-400
km to The Gambia and Senegal, and 13 turtles traveling >1000 km to northern Mauritania.
Of the 35 foraging turtles, 26 used MPAs, with a mean of 78.0% (SD 34.8%, range: 3.7% -
100%) of their tracking positions falling within the limits of RAMPAO MPAs, across
Guinea-Bissau, Senegal and Mauritania. Migration corridors with high concentrations of
passing turtles were mostly located nearshore, and 21% of these high passage areas fell
within the MPA network. Overall, we found that this population connects five RAMPAO
MPAs, yet some foraging sites (e.g., in the BijagoÌ
s) and important migration areas (e.g.,
Cap-Vert peninsula) described here are currently unprotected. These results are relevant
to any considerations of MPA extension or establishment within the regional network,
which would contribute towards meeting the Convention on Biological Diversity targets for
national marine protected area estate coverage. By documenting biological connectivity
across RAMPAO, this study represents an important example of the relevance of
international protected area networks for green turtle conservation and for wider
conservation action at a regional scale.Fundação para a CiĂȘncia e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio
Phenomenological description of the microwave surface impedance and complex conductivity of high- single crystals
Measurements of the microwave surface impedance and
of the complex conductivity of high-quality, high- single
crystals of YBCO, BSCCO, TBCCO, and TBCO are analyzed. Experimental data of
and are compared with calculations based on a modified
two-fluid model which includes temperature-dependent quasiparticle scattering
and a unique temperature variation of the density of superconducting carriers.
We elucidate agreement as well as disagreement of our analysis with the salient
features of the experimental data. Existing microscopic models are reviewed
which are based on unconventional symmetry types of the order parameter and on
novel mechanisms of quasiparticle relaxation.Comment: 15 pages, 17 figures, 1 tabl
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