4,076 research outputs found
Connectivity of the bay scallop (Argopecten irradians) in Buzzards Bay, Massachusetts, U.S.A.
Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Fisheries Oceanography 24 (2015): 364-382, doi:10.1111/fog.12114.The harvest of bay scallops (Argopecten irradians) from Buzzards Bay, Massachusetts,
USA undergoes large interannual fluctuations, varying by more than an order of magnitude
in successive years. To investigate the extent to which these fluctuations may be due to
yearly variations in the transport of scallop larvae from spawning areas to suitable juvenile
habitat (settlement zones), a high-resolution hydrodynamic model was used to drive an
individual-based model of scallop larval transport. Model results revealed that scallop
spawning in Buzzards Bay occurs during a time when nearshore bay currents were
principally directed up-bay in response to a persistent southwesterly sea breeze. This
nearshore flow results in substantial transport of larvae from lower-bay spawning areas to
settlement zones further up-bay. Averaged over the entire bay, the spawning-to-settlement
zone connectivity exhibits little interannual variation. However, connectivities between
individual spawning and settlement zones vary by up to an order of magnitude. The model
results identified spawning areas that have the greatest probability of transporting larvae to
juvenile habitat. Because managers may aim to increase scallop populations either locally
or broadly, the high-connectivity spawning areas were divided into: 1) high larval retention
and relatively little larval transport to adjoining settlement areas, 2) both significant larval
retention and transport to more distant settlement areas, and 3) little larval retention but
significant transport to distant settlement areas.This project was supported
by the Woods Hole Sea Grant through award NA10OAR4170083. All modeling
computations were made on the University of Massachusetts at Dartmouth’s (UMD’s)
GPGPU cluster, which was acquired with support from NSF award CNS-0959382 and
AFOSR DURIP award FA9550-10-1-0354.2016-07-1
Recreation reduces tick density through fine-scale risk effects on deer space-use
Altered interactions between pathogens, their hosts and vectors have potential consequences for human disease risk. Notably, tick-borne pathogens, many of which are associated with growing deer abundance, show global increasing prevalence and pose increasing challenges for disease prevention. Human activities can largely affect the patterns of deer space-use and can therefore be potential management tools to alleviate human-wildlife conflicts. Here, we tested how deer space-use patterns are influenced by human recreational activities, and how this in turn affects the spatial distribution of the sheep tick (Ixodes ricinus), a relevant disease vector of zoonoses such as Lyme borrelioses. We compared deer dropping and questing tick density on transects near (20 m) and further away from(100 m) forest trails that were either frequently used (open for recreation) or infrequently used (closed for recreation, but used by park managers). In contrast to infrequently used trails, deer dropping density was 31% lower near (20 m) than further away from (100 m) frequently used trails. Similarly, ticks were 62% less abundant near (20 m) frequently used trails compared to further away from (100 m) these trails, while this decline in tick numbers was only 14% near infrequently used trails. The avoidance by deer of areas close to human-used trails was thus associated with a similar reduction in questing tick density near these trails. As tick abundance generally correlates to pathogen prevalence, the use of trails for recreation may reduce tick-borne disease risk for humans on and near these trails. Our study reveals an unexplored effect of human activities on ecosystems and how this knowledge could be potentially used to mitigate zoonotic disease risk
Demonstration of Entanglement of Electrostatically Coupled Singlet-Triplet Qubits
Quantum computers have the potential to solve certain interesting problems
significantly faster than classical computers. To exploit the power of a
quantum computation it is necessary to perform inter-qubit operations and
generate entangled states. Spin qubits are a promising candidate for
implementing a quantum processor due to their potential for scalability and
miniaturization. However, their weak interactions with the environment, which
leads to their long coherence times, makes inter-qubit operations challenging.
We perform a controlled two-qubit operation between singlet-triplet qubits
using a dynamically decoupled sequence that maintains the two-qubit coupling
while decoupling each qubit from its fluctuating environment. Using state
tomography we measure the full density matrix of the system and determine the
concurrence and the fidelity of the generated state, providing proof of
entanglement
Enantioselective NHC-catalysed redox [4+2]-hetero-Diels-Alder reactions using α-aroyloxyaldehydes and unsaturated ketoesters
The authors thank the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) ERC Grant Agreement No. 279850 (J.E.T. and A.T.D.) as well as the EPSRC, UK and AstraZeneca plc, UK (Case award to J.J.D.) for financial support. A.D.S. thanks the Royal Society, London, UK, for a Wolfson Merit Award.N-Heterocyclic carbene (NHC)-catalysed redox [4+2]-hetero-Diels-Alder reactions of α-aroyloxyaldehydes with either β,γ-unsaturated α-ketoesters or α,β-unsaturated γ-ketoesters generates substituted syn-dihydropyranones in good yield with excellent enantioselectivity (up to >99:1 er). The product diastereoselectivity is markedly dependent upon the nature of the unsaturated enone substituent. The presence of either electron-neutral or electron-rich aryl substituents gives excellent diastereoselectivity (up to >99:5 dr), while electron-deficient aryl substituents give reduced diastereoselectivity. In these cases, the syn-dihydropyranone products are more susceptible to base-promoted epimerisation at the C(4)-position under the reaction conditions, accounting for the lower diastereoselectivity obtained.PostprintPeer reviewe
Resoundings of the flesh: Caring for others by way of “second person” perspectivity
In bringing ourselves to the encounter with the experience of others, we bring our bodies with us—and, in doing so, we are able to resonate not only intellectually but also empathically with the other's experiences and expressions (which are given to us both verbally and nonverbally). In remaining faithful to our foundations in phenomenology (Husserl, Heidegger, Merleau-Ponty, and Levinas), we shall talk about taking notice of others from within the relational “exchange” and reflect upon what, precisely, are the experientially given “affairs” to which Husserl invited us to return. Our interest begins with the other's “first person” experience, but since we cannot access this directly, we must rely on the resonance we find within ourselves, within our own lived bodies, when we are addressed by the other, whether in word or in gesture. I am wondering what the other is experiencing and all my powers of perception are driven toward this other, whose first person experience remains just out of reach and accessible only insofar as I have this capacity for a deeper “bodily felt” awareness in which the other's experience takes possession of me. Merleau-Ponty's notion of bearing “witness” to behavior is useful in illuminating this “second person” perspective, which takes its point of departure from Husserl's (1910–1911) intersubjective reduction, by means of which we “participate in the other's positing” (1952/1989, emphasis added) and thereby grasp the meaning of the other's expression. Ultimately, the intuitive talent of the caring professional will be shown to reside in his or her being able to move beyond what the other is able to say to a more deeply felt attunement to what is being revealed to us in the other's presence. Applications to patient care are discussed
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Gender-Inclusive HCI Research and Design: A Conceptual Review
Previous research has investigated gender and its implications for HCI. We consider inclusive design of technology whatever the gender of its users of particular importance. This conceptual review provides an overview of the motivations that have driven research in gender and inclusive HCI design. We review the empirical evidence for the impact of gender in thinking and behavior which underlies HCI research and design. We then present how HCI design might inadvertently embed and perpetuate gender stereotypes. We then present current HCI design approaches to tackle gender stereotypes and to produce gender-inclusive designs. We conclude by discussing possible future directions in this area
Tunneling in Fractional Quantum Mechanics
We study the tunneling through delta and double delta potentials in
fractional quantum mechanics. After solving the fractional Schr\"odinger
equation for these potentials, we calculate the corresponding reflection and
transmission coefficients. These coefficients have a very interesting
behaviour. In particular, we can have zero energy tunneling when the order of
the Riesz fractional derivative is different from 2. For both potentials, the
zero energy limit of the transmission coefficient is given by , where is the order of the derivative ().Comment: 21 pages, 3 figures. Revised version; accepted for publication in
Journal of Physics A: Mathematical and Theoretica
Heat exchange mediated by a quantum system
We consider heat transfer between two thermal reservoirs mediated by a
quantum system using the generalized quantum Langevin equation. The thermal
reservoirs are treated as ensembles of oscillators within the framework of the
Drude-Ullersma model. General expressions for the heat current and thermal
conductance are obtained for arbitrary coupling strength between the reservoirs
and the mediator and for different temperature regimes. As an application of
these results we discuss the origin of Fourier's law in a chain of large, but
finite subsystems coupled to each other by the quantum mediators. We also
address a question of anomalously large heat current between the STM tip and
substrate found in a recent experiment. The question of minimum thermal
conductivity is revisited in the framework of scaling theory as a potential
application of the developed approach.Comment: 16 pages, 6 figure
Recreation reduces tick density through fine-scale risk effects on deer space-use
Altered interactions between pathogens, their hosts and vectors have potential consequences for human disease risk. Notably, tick-borne pathogens, many of which are associated with growing deer abundance, show global increasing prevalence and pose increasing challenges for disease prevention. Human activities can largely affect the patterns of deer space-use and can therefore be potential management tools to alleviate human-wildlife conflicts. Here, we tested how deer space-use patterns are influenced by human recreational activities, and how this in turn affects the spatial distribution of the sheep tick (Ixodes ricinus), a relevant disease vector of zoonoses such as Lyme borrelioses. We compared deer dropping and questing tick density on transects near (20 m) and further away from (100 m) forest trails that were either frequently used (open for recreation) or infrequently used (closed for recreation, but used by park managers). In contrast to infrequently used trails, deer dropping density was 31% lower near (20 m) than further away from (100 m) frequently used trails. Similarly, ticks were 62% less abundant near (20 m) frequently used trails compared to further away from (100 m) these trails, while this decline in tick numbers was only 14% near infrequently used trails. The avoidance by deer of areas close to human-used trails was thus associated with a similar reduction in questing tick density near these trails. As tick abundance generally correlates to pathogen prevalence, the use of trails for recreation may reduce tick-borne disease risk for humans on and near these trails. Our study reveals an unexplored effect of human activities on ecosystems and how this knowledge could be potentially used to mitigate zoonotic disease risk
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