1,760 research outputs found
A versatile high resolution objective for imaging quantum gases
We present a high resolution objective lens made entirely from catalog
singlets that has a numerical aperture of 0.36. It corrects for aberrations
introduced by a glass window and has a long working distance of 35mm, making it
suitable for imaging objects within a vacuum system. This offers simple high
resolution imaging for many in the quantum gas community. The objective
achieves a resolution of 1.3{\mu}m at the design wavelength of 780nm, and a
diffraction-limited field of view of 360{\mu}m when imaging through a 5mm
window. Images of a resolution target and a pinhole show quantitative agreement
with the simulated lens performance. The objective is suitable for
diffraction-limited imaging on the D2 line of all the alkalis by changing only
the aperture diameter, retaining numerical apertures above 0.32. The design
corrects for window thicknesses of up to 15mm if the singlet spacings are
modified
Molecular dynamics of flows in the Knudsen regime
Novel technological applications often involve fluid flows in the Knudsen
regime in which the mean free path is comparable to the system size. We use
molecular dynamics simulations to study the transition between the dilute gas
and the dense fluid regimes as the fluid density is increased.Comment: REVTeX, 15 pages, 4 EPS figures, to appear in Physica
Early Intervention, Documentation, and Service Delivery: A Review of IFSPs and Service Notes
This abstract will be available for download after an embargo perio
Experiences in the Integration of Design Across the Mechanical Engineering Curriculum
The Faculty of the School of Mechanical Engineering at Purdue University have effected a major change in the Purdue Mechanical Engineering program by integrating design throughout the curriculum. In doing so, a significant level of faculty interaction has been achieved as well. The goals of the curriculum revision are: (1) to improve student skills in how to solve open-ended design problems, (2) to reduce the core of the curriculum to allow flexibility in course selection, and allow time for solving design problems, (3) to improve student skills in team work and communications, and (4) to improve student skills in using computers as tools for solving engineering problems. Reduction of the core allowed the addition of a sophomore cornerstone design course. This cornerstone course teaches students how to solve open-ended problems, bridging the gap between solution strategies that are effective for the science and mathematics courses, and those needed to solve open-ended engineering problems. The design fundamentals taught in the cornerstone course are applied in the core courses, such as heat transfer, thermodynamics, instrumentation, and machine design. The senior design experience comes primarily from a design elective and the capstone design course. This paper presents an overview of the curriculum revision process, and the changes which resulted from it. It also discusses the issues associated with infusing design projects into core courses which have traditionally focused on teaching engineering science fundamentals. Plans for the future evolution of the curriculum are also discussed
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Group 2 Innate Lymphoid Cells Are Redundant in Experimental Renal Ischemia-Reperfusion Injury.
Acute kidney injury (AKI) can be fatal and is a well-defined risk factor for the development of chronic kidney disease. Group 2 innate lymphoid cells (ILC2s) are innate producers of type-2 cytokines and are critical regulators of homeostasis in peripheral organs. However, our knowledge of their function in the kidney is relatively limited. Recent evidence suggests that increasing ILC2 numbers by systemic administration of recombinant interleukin (IL)-25 or IL-33 protects against renal injury. Whilst ILC2s can be induced to protect against ischemic- or chemical-induced AKI, the impact of ILC2 deficiency or depletion on the severity of renal injury is unknown. Firstly, the phenotype and location of ILC2s in the kidney was assessed under homeostatic conditions. Kidney ILC2s constitutively expressed high levels of IL-5 and were located in close proximity to the renal vasculature. To test the functional role of ILC2s in the kidney, an experimental model of renal ischemia-reperfusion injury (IRI) was used and the severity of injury was assessed in wild-type, ILC2-reduced, ILC2-deficient, and ILC2-depleted mice. Surprisingly, there were no differences in histopathology, collagen deposition or mRNA expression of injury-associated (Lcn2), inflammatory (Cxcl1, Cxcl2, and Tnf) or extracellular matrix (Col1a1, Fn1) factors following IRI in the absence of ILC2s. These data suggest the absence of ILC2s does not alter the severity of renal injury, suggesting possible redundancy. Therefore, other mechanisms of type 2-mediated immune cell activation likely compensate in the absence of ILC2s. Hence, a loss of ILC2s is unlikely to increase susceptibility to, or severity of AKI
Mast cell tumours in less than 12 months of age: a multi-institutional retrospective study
Objectives: To describe the clinicopathological and genetic characteristics of mast cell tumours in dogs less than 12 months old.
Materials and methods: Retrospective review of dogs aged less than 12 months when diagnosed with mast cell tumours at three referral hospitals in the UK.
Results: Sixteen pure-bred dogs were included, of which 11 were female. The median age at first presentation and diagnosis were 7.6 and 9 months, respectively. In 13 dogs the mast cell tumours were cutaneous and in three they were subcutaneous. Four cutaneous mast cell tumours were described as high-grade (Patnaik or Kiupel) and nine were Patnaik grade II; three had mitotic index of >5 in 10 high-power fields. Of the three subcutaneous tumours, two had an infiltrative growth pattern and one had mitotic index of 10 per 10 high-power fields. Of 10 tested dogs, seven had c-kit mutations in exon 11 and Ki-67 score was above the cut-off value in nine. Four of 12 cases showed evidence of metastasis in the regional lymph nodes. After varying treatment protocols, all patients were alive and disease free at a median of 1115 days after diagnosis.
Clinical significance: The prognosis of mast cell tumours in dogs less than a year old appears better than the adult counterparts, even without extensive treatment
Precise wavefunction engineering with magnetic resonance
Controlling quantum fluids at their fundamental length scale will yield
superlative quantum simulators, precision sensors, and spintronic devices. This
scale is typically below the optical diffraction limit, precluding precise
wavefunction engineering using optical potentials alone. We present a protocol
to rapidly control the phase and density of a quantum fluid down to the healing
length scale using strong time-dependent coupling between internal states of
the fluid in a magnetic field gradient. We demonstrate this protocol by
simulating the creation of a single stationary soliton and double soliton
states in a Bose-Einstein condensate with control over the individual soliton
positions and trajectories, using experimentally feasible parameters. Such
states are yet to be realized experimentally, and are a path towards
engineering soliton gases and exotic topological excitations.Comment: 8+ pages, 3 figures; revised parameters and added section about
optimisation of adiabatic, finite-duration pulses and analytic resolution
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