4,357 research outputs found
Internesting Movements of Loggerhead (Caretta caretta) Sea Turtles in Virginia, USA
Virginia is the northern most nesting region regularly utilized by loggerhead sea turtles (Caretta caretta) along the eastern coast of the United States. Along the southern shoreline of Virginia, between two and ten nests have been recorded annually since 1989 within Back Bay National Wildlife Refuge and False Cape State Park. Since 1992, the Virginia Institute of Marine Science (VIMS) has attached eight satellite transmitters to nesting loggerhead sea turtles in order to monitor their interesting movements and falVwinter migrations. VIMS has tracked the same nesting loggerhead three separate times during the 1993, 1995 and 1997 nesting seasons. This turtle has been observed to migrate into the Delaware Bay and Chesapeake Bay between nesting events and prior to her fall migrations. This project has demonstrated that nesting loggerhead sea turtles return to Virginia over subsequent seasons to nest, and utilize the Chesapeake and Delaware Bays as internesting and post-nesting habitat. Late season nesters tracked by VIMS have migrated south after their last recorded Virginia nesting event and have traveled along the coasts of North and South Carolina, in two cases establishing fall residency off the Carolinas. Three turtles have been tracked as far south as eastern Florida, with two entering the Gulf of Mexico before satellite transmissions ceased. The tracking data generated by this project suggest that the adult turtles utilizing Virginia as nesting habitat preferentially utilize either the orth Atlantic region or South Atlantic region as over-wintering habitat. Temperature ranges within which tagged turtles have remained range between 13° and 31 ° C. Three tagged turtles have remained in Virginia\u27s waters until sea surface temperatures dropped to between 13° and 16° C before migrating south
Quantum entanglement between a nonlinear nanomechanical resonator and a microwave field
We consider a theoretical model for a nonlinear nanomechanical resonator
coupled to a superconducting microwave resonator. The nanomechanical resonator
is driven parametrically at twice its resonance frequency, while the
superconducting microwave resonator is driven with two tones that differ in
frequency by an amount equal to the parametric driving frequency. We show that
the semi-classical approximation of this system has an interesting fixed point
bifurcation structure. In the semi-classical dynamics a transition from stable
fixed points to limit cycles is observed as one moves from positive to negative
detuning. We show that signatures of this bifurcation structure are also
present in the full dissipative quantum system and further show that it leads
to mixed state entanglement between the nanomechanical resonator and the
microwave cavity in the dissipative quantum system that is a maximum close to
the semi-classical bifurcation. Quantum signatures of the semi-classical
limit-cycles are presented.Comment: 36 pages, 18 figure
A systematic review of evidence for the potential of live sites to generate community and public health outcomes
Optimal strategies for a game on amenable semigroups
The semigroup game is a two-person zero-sum game defined on a semigroup S as
follows: Players 1 and 2 choose elements x and y in S, respectively, and player
1 receives a payoff f(xy) defined by a function f from S to [-1,1]. If the
semigroup is amenable in the sense of Day and von Neumann, one can extend the
set of classical strategies, namely countably additive probability measures on
S, to include some finitely additive measures in a natural way. This extended
game has a value and the players have optimal strategies. This theorem extends
previous results for the multiplication game on a compact group or on the
positive integers with a specific payoff. We also prove that the procedure of
extending the set of allowed strategies preserves classical solutions: if a
semigroup game has a classical solution, this solution solves also the extended
game.Comment: 17 pages. To appear in International Journal of Game Theor
Light-Cone Quantization of the Liouville Model
We present the quantization of the Liouville model defined in light-cone
coordinates in (1,1) signature space. We take advantage of the representation
of the Liouville field by the free field of the Backl\"{u}nd transformation and
adapt the approch by Braaten, Curtright and Thorn.
Quantum operators of the Liouville field ,
, , are constructed consistently in
terms of the free field. The Liouville model field theory space is found to be
restricted to the sector with field momentum , , which
is a closed subspace for the Liouville theory operator algebra.Comment: 16 p, EFI-92-6
Curvature condensation and bifurcation in an elastic shell
We study the formation and evolution of localized geometrical defects in an
indented cylindrical elastic shell using a combination of experiment and
numerical simulation. We find that as a symmetric localized indentation on a
semi-cylindrical shell increases, there is a transition from a global mode of
deformation to a localized one which leads to the condensation of curvature
along a symmetric parabolic crease. This process introduces a soft mode in the
system, converting a load-bearing structure into a hinged, kinematic mechanism.
Further indentation leads to twinning wherein the parabolic crease bifurcates
into two creases that move apart on either side of the line of symmetry. A
qualitative theory captures the main features of the phenomena and leads to
sharper questions about the nucleation of these defects.Comment: 4 pages, 5 figures, submitted to Physical Review Letter
A novel, aerosol-nanocrystal floating-gate device for non-volatile memory applications
This paper describes the fabrication, and structural and electrical characterization of a new, aerosol-nanocrystal floating-gate FET, aimed at non-volatile memory (NVM) applications. This aerosol-nanocrystal NVM device features program/erase characteristics comparable to conventional stacked gate NVM devices, excellent endurance (>l0^5 P/E cycles), and long-term non-volatility in spite of a thin bottom oxide (55-60Å). In addition, a very simple fabrication process makes this aerosol-nanocrystal NVM device a potential candidate for low cost NVM applications
Strong extinction of a far-field laser beam by a single quantum dot
Through the utilization of index-matched GaAs immersion lens techniques we
demonstrate a record extinction (12%) of a far-field focused laser by a single
InAs/GaAs quantum dot. This contrast level enables us to report for the first
time resonant laser transmission spectroscopy on a single InAs/GaAs quantum dot
without the need for phase-sensitive lock-in detection
Severe mental illness and chronic kidney disease: a cross-sectional study in the United Kingdom
OBJECTIVE: We investigated the burden of chronic kidney disease (CKD) among patients with
severe mental illness (SMI).
METHODS: We identified patients with SMI among all those aged 25–74 registered in the UK
Clinical Practice Research Datalink as on March 31, 2014. We compared the prevalence of CKD
(two measurements of estimated glomerular filtration rate <60 mL/min/1.73 m2
for ≥3 months)
and renal replacement therapy between patients with and without SMI. For patients with and
without a history of lithium prescription separately, we used logistic regression to examine the
association between SMI and CKD, adjusting for demographics, lifestyle characteristics, and
known CKD risk factors.
RESULTS: The CKD prevalence was 14.6% among patients with SMI and a history of lithium
prescription (n = 4,295), 3.3% among patients with SMI and no history of lithium prescription
(n = 24,101), and 2.1% among patients without SMI (n = 2,387,988; P < 0.001). The prevalence
of renal replacement therapy was 0.23%, 0.15%, and 0.11%, respectively (P = 0.012). Compared
to patients without SMI, the fully adjusted odds ratio for CKD was 6.49 (95% CI 5.84–7.21) for
patients with SMI and a history of lithium prescription and 1.45 (95% CI 1.34–1.58) for patients
with SMI and no history of lithium prescription. The higher prevalence of CKD in patients with SMI
may, in part, be explained by more frequent blood testing as compared to the general population.
CONCLUSION: CKD is identified more commonly among patients with SMI than in the general
population
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