3,460 research outputs found
A model for the screen printing of Newtonian fluids
A preliminary investigation into aspects of the off-contact screen-printing process is presented. A mathematical model for the printing of a thin film of Newtonian fluid is proposed, in which the screen is modelled as a permeable membrane, and the entire region above and below the screen is flooded. By drawing upon widely used industrial circuit printing practices, the distinguished limit of greatest interest to this industry is identified. Numerical and asymptotic solutions of this distinguished limit are presented that reproduce many of the features observed in industrial screen-printing
Measurement of the transverse spatial quantum state of light at the single-photon level
We present an experimental method to measure the transverse spatial quantum
state of an optical field in coordinate space at the single-photon level. The
continuous-variable measurements are made with a photon-counting,
parity-inverting Sagnac interferometer based on all-reflecting optics. The
technique provides a large numerical aperture without distorting the shape of
the wave front, does not introduce astigmatism, and allows for characterization
of fully or partially coherent optical fields at the single-photon level.
Measurements of the transverse spatial Wigner functions for highly attenuated
coherent beams are presented and compared to theoretical predictions.Comment: 3 pages, 2 figure
Probing Spectral Line Gradients Beyond One Effective Radius in NGC 3610
The outer region (0.75--1.25 r_e in the B-band) of the merger-remnant
elliptical NGC 3610 is studied using extremely high signal to noise Keck
spectra, with a supplementary spectrum of the galaxy center. Stellar population
parameters -- age, [Z/H], [/Fe] -- are measured in several apertures
along the slit. Using the multi-index simultaneous fitting method of Proctor et
al. (2004), no significant stellar population gradients are detected in the
outer parts of the galaxy. The overall gradients relative to the galaxy center
are consistent with those found in many other early-type galaxies, though the
metallicity gradient is much steeper than would be expected if NGC 3610 formed
in a major merger event. Standard analysis methods using the H index are
found to produce spurious radially variable gradients.Comment: 15 pages, 9 figures, accepted by A
Interactions of substrate and non-substrate effectors with p-hydroxybenzoate hydroxylase from
3,4-Dihydroxybenzoate (3,4-DOHB), 2,4-dihydroxybenzoate (2,4-DOHB), and benzoate facilitate the interaction of p-hydroxybenzoate hydroxylase with TPNH. The two dihydroxybenzoate effectors form 1:1 complexes with the enzyme, inducing large spectral perturbations and fluorescence quenching. The dissociation constants for 2,4-DOHB and 3,4-DOHB are 0.15 and 0.50 mM respectively. During the reaction of enzyme with TPNH and oxygen, all the 2,4-DOHB, <5% of the benzoate, and none of the 3,4-DOHB is hydroxylated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33509/1/0000006.pd
Validation of the Exoplanet Kepler-21b using PAVO/CHARA Long-Baseline Interferometry
We present long-baseline interferometry of the Kepler exoplanet host star
HD179070 (Kepler-21) using the PAVO beam combiner at the CHARA Array. The
visibility data are consistent with a single star and exclude stellar
companions at separations ~1-1000 mas (~ 0.1-113 AU) and contrasts < 3.5
magnitudes. This result supports the validation of the 1.6 R_{earth} exoplanet
Kepler-21b by Howell et al. (2012) and complements the constraints set by
adaptive optics imaging, speckle interferometry, and radial velocity
observations to rule out false-positives due to stellar companions. We conclude
that long-baseline interferometry has strong potential to validate transiting
extrasolar planets, particularly for future projects aimed at brighter stars
and for host stars where radial velocity follow-up is not available.Comment: 5 pages, 3 figures, accepted for publication in MNRAS Letters; v2:
minor changes added in proo
Design of a Transradial Myoelectric Prosthesis
Due to the rapid growth of children and the high cost of myoelectric technology, children are not given the same opportunities to use myoelectric prosthetics as adults. The Muscle Activated Prosthesis (MAP) team is developing an affordable, transradial, myoelectric prosthetic for a thirteen-year-old girl. The MAP team is designing a myoelectric prosthetic that will cost under $1,000, over 90% less than custom myoelectric devices on the market. This device has an EMG sensor, a microprocessor, a printed circuit board (PCB), linear actuator motors, and a battery organized within a 3D-printed transradial prosthesis to open and close the hand grip when the EMG detects electrical signals via muscle contractions in the clientâs flexor carpi radialis. Currently, the team has fully assembled a prosthetic prototype and will obtain feedback from the partner, Ability Prosthetics, and the client to deliver a final prototype. This poster details the recent mechanical and electrical design optimizations, grip strength testing, and integration of mechanical and electrical components to build the current functioning prosthesis.https://mosaic.messiah.edu/engr2021/1009/thumbnail.jp
Discerning the clinical relevance of biomarkers in early stage breast cancer
Purpose
Prior data suggest that breast cancer patients accept significant toxicity for small benefit. It is unclear whether personalized estimations of risk or benefit likelihood that could be provided by biomarkers alter treatment decisions in the curative setting.
Methods
A choice-based conjoint (CBC) survey was conducted in 417 HER2-negative breast cancer patients who received chemotherapy in the curative setting. The survey presented pairs of treatment choices derived from common taxane- and anthracycline-based regimens, varying in degree of benefit by risk of recurrence and in toxicity profile, including peripheral neuropathy (PN) and congestive heart failure (CHF). Hypothetical biomarkers shifting benefit and toxicity risk were modeled to determine whether this knowledge alters choice. Previously identified biomarkers were evaluated using this model.
Results
Based on CBC analysis, a non-anthracycline regimen was the most preferred. Patients with prior PN had a similar preference for a taxane regimen as those who were PN naĂŻve, but more dramatically shifted preference away from taxanes when PN was described as severe/irreversible. When modeled after hypothetical biomarkers, as the likelihood of PN increased, the preference for taxane-containing regimens decreased; similarly, as the likelihood of CHF increased, the preference for anthracycline regimens decreased. When evaluating validated biomarkers for PN and CHF, this knowledge did alter regimen preference.
Conclusions
Patients faced with multi-faceted decisions consider personal experience and perceived risk of recurrent disease. Biomarkers providing information on likelihood of toxicity risk do influence treatment choices, and patients may accept reduced benefit when faced with higher risk of toxicity in the curative setting
A Qualitative Analysis of Women's Short Accounts of Labour and Birth in a Western Australian Public Tertiary Hospital
This paper reports the findings of the postnatal qualitative arm of a larger study,which investigated women's prenatal and postnatal levels of childbirth fear. Women's expectations and experiences of labour and birth in a Western Australian public tertiary hospital were identified following thematic analysis of short written accounts from 141 participants who had given birth in the previous 6 to 14 weeks. Four major categories emerged to describe features and mediating factors in the trajectory of childbirth and the early puerperium "Anticipating Labour and Birth", "Labour and birth Depicted", "Mediating Factors and their consequences" and "Evaluating, Resolving, and Looking Ahead" portray women's comparative reflections on expectations and realities of birth, on mediating influences, and on moving on from their experience. These findings will provide maternity care professionals with insight into the personal and environmental features of the childbirth setting which colours women's recollections. Being aware of what women value during labour and birth will reinforce the need for professionals to provide care using a mindful approach that considers the potential psychological, emotional and behavioural implications of events
Revisiting with Chandra the Scaling Relations of the X-ray Emission Components (Binaries, Nuclei and Hot Gas) of Early Type Galaxies
We have selected a sample of 30 normal (non-cD) early type galaxies, for all
of which optical spectroscopy is available, and which have been observed with
Chandra to a depth such to insure the detection of bright low-mass X-ray
binaries (LMXBs) with Lx>1e38 erg/s. This sample includes a larger fraction of
gas-poor galaxies than previously studied samples, and covers a wide range of
stellar luminosity, velocity dispersion, GC specific frequency, and stellar
age. We derive X-ray luminosities (or upper limits) from the different
significant X-ray components of these galaxies: nuclei, detected and undetected
LMXBs, coronally active binaries (ABs), cataclysmic variables (CVs), and hot
gas. The ABs and CVs contribution is estimated from the Lx-LK scaling relation
of M31 and M32. The contribution of undetected LMXBs is estimated both by
fitting the spectra of the unresolved X-ray emission and by extrapolating the
LMXB X-ray luminosity function. The results for the nuclei are consistent with
those discussed by Pellegrini (2010). We derive a revised scaling relation
between the integrated X-ray luminosity of LMXBs in a galaxy and the LK
luminosity of the host galaxy: Lx(LMXB)/LK ~ 1e29 erg s-1 LK-1 with 50% 1sigma
rms; moreover, we also obtain a tighter LX(LMXB)/LK - SN relation than
previously published. We revisit the relations between hot gas content and
other galaxy parameters. finding a steeper LX(gas)-LK relation with larger
scatter than reported in the literature. We find a positive correlation between
the luminosity and temperature of the hot ISM, significantly tighter than
reported by earlier studies.[abridged
- âŠ