2,955 research outputs found
GreenCare for Children -- Measuring Environmental Hazards in the Childcare Industry
Presents findings from a two-year survey administered to a random sampling of childcare providers. Developed and interpreted by a diverse team of industry, technical, and educational experts
Suppression of spin-torque in current perpendicular to the plane spin-valves by addition of Dy cap layers
We demonstrate that the addition of Dy capping layers in current
perpendicular to the plane giant magneto-resistive spin-valves can increase the
critical current density beyond which spin-torque induced instabilities are
observed by about a factor of three. Current densities as high as 5e7 A/cm2 are
measured provided that the electron current flows from the free to the
reference layer. While Dy capped samples exhibit nonmagnetic 1/f noise, it is
sufficiently small to be unimportant for read head operation at practical data
rates.Comment: 13 pages (manuscript form), with 5 figures. Submitted for publicatio
Thermal Effects on the Magnetic Field Dependence of Spin Transfer Induced Magnetization Reversal
We have developed a self-aligned, high-yield process to fabricate CPP
(current perpendicular to the plane) magnetic sensors of sub 100 nm dimensions.
A pinned synthetic antiferromagnet (SAF) is used as the reference layer which
minimizes dipole coupling to the free layer and field induced rotation of the
reference layer. We find that the critical currents for spin transfer induced
magnetization reversal of the free layer vary dramatically with relatively
small changes the in-plane magnetic field, in contrast to theoretical
predictions based on stability analysis of the Gilbert equations of
magnetization dynamics including Slonczewski-type spin-torque terms. The
discrepancy is believed due to thermal fluctuations over the time scale of the
measurements. Once thermal fluctuations are taken into account, we find good
quantitative agreement between our experimental results and numerical
simulations.Comment: 14 pages, 4 figures, Submitted to Appl. Phys. Lett., Comparison of
some of these results with a model described by N. Smith in cond-mat/040648
Body representation difficulties in children and adolescents with autism may be due to delayed development of visuo-tactile temporal binding
Recent research suggests visuo-tactile binding is temporally extended in autism spectrum disorders (ASD), although it is not clear whether this specifically underlies altered body representation in this population. In the current study children and adolescents with ASD, and typically developing controls, placed their hand into mediated reality system (MIRAGE) and saw two identical live video images of their own right hand. One image was in the proprioceptively correct location (veridical hand) and the other was displaced to either side. While visuotactile feedback was applied via brushstroke to the participant’s (unseen) right finger, they viewed one hand image receiving synchronous brushstrokes and the other receiving brushstrokes with a temporal delay (60, 180 and 300ms). After brushing, both images disappeared from view and participants pointed to a target, with direction of movement indicating which hand was embodied. ASD participants, like younger mental aged-matched controls, showed reduced embodiment of the spatially incongruent, but temporally incongruent, hand compared to chronologically age-matched controls at shorter temporal delays. This suggests development of visuo-tactile integration may be delayed in ASD. Findings are discussed in relation to atypical body representation in ASD and how this may contribute to social and sensory difficulties within this population
Bacterial defences: mechanisms, evolution and antimicrobial resistance
Throughout their evolutionary history, bacteria have faced diverse threats from other microorganisms, including competing bacteria, bacteriophages and predators. In response to these threats, they have evolved sophisticated defence mechanisms that today also protect bacteria against antibiotics and other therapies. In this Review, we explore the protective strategies of bacteria, including the mechanisms, evolution and clinical implications of these ancient defences. We also review the countermeasures that attackers have evolved to overcome bacterial defences. We argue that understanding how bacteria defend themselves in nature is important for the development of new therapies and for minimizing resistance evolution
Measurement of Gilbert damping parameters in nanoscale CPP-GMR spin-valves
In-situ, device level measurement of thermal mag-noise spectral linewidths in
60nm diameter CPP-GMR spin-valve stacks of IrMn/ref/Cu/free, with reference and
free layer of similar CoFe/CoFeGe alloy, are used to simultaneously determine
the intrinsic Gilbert damping for both magnetic layers. It is shown that
careful alignment at a "magic-angle" between free and reference layer static
equilibrium magnetization can allow direct measurement of the broadband
intrinsic thermal spectra in the virtual absence of spin-torque effects which
otherwise grossly distort the spectral line shapes and require linewidth
extrapolations to zero current (which are nonetheless also shown to agree well
with the direct method). The experimental magic-angle spectra are shown to be
in good qualitative and quantitative agreement with both macrospin calculations
and micromagnetic eigenmode analysis. Despite similar composition and
thickness, it is repeatedly found that the IrMn exchange pinned reference layer
has ten times larger intrinsic Gilbert damping (alpha ~ 0.1) than that of the
free-layer (alpha ~ 0.01). It is argued that the large reference layer damping
results from strong, off -resonant coupling to to lossy modes of an IrMn/ref
couple, rather than commonly invoked two-magnon processes.Comment: 11 pages (2-column format), 12 figures. This work was presented at
the 2010 Joint MMM-Intermag Conference (Washington, DC) as paper AB-01
(invited
Treatment and outcomes for synovial sarcoma patients in Western Australia: the role of neoadjuvant chemoradiotherapy
Background
This is a retrospective review of synovial sarcoma (SS) patients treated over the last 12 years in Western Australia (WA). SS is both chemo and radiotherapy sensitive. Results of trials in adjuvant chemotherapy are conflicting and there is limited support for neoadjuvant chemotherapy. The use of combined chemoradiotherapy is based on institutional preferences.
Aim
We reviewed the outcomes for SS patients treated in WA over a 12 year period focusing on patients who received neoadjuvant chemoradiotherapy (NACRT).
Methods
Patient details including demographics, histopathology, treatment details, were obtained from the WA sarcoma database (2006-2018). Progression free survival (PFS) and overall survival (OS) were derived for whole cohort.
Results
Twenty seven patients were identified with SS with equal gender incidence. Median age of the cohort was 36 (14-76) years. The most common primary site of disease was extremity (81.5%). 22/27 patients presented with only localized disease and 59.2% of these received neo-adjuvant treatment. Of those who received neoadjuvant treatment, 56.2% had NACRT, while 25.0% and 18.7% of patients had chemotherapy and radiotherapy respectively. Mesna, doxorubicin, ifosfamide, dacarbazine (MAID) was the most commonly used chemotherapy regimen as neoadjuvant or adjuvant treatment while ifosfamide (93.7%) was the most commonly used chemotherapy drug in any setting. There was no reported case of disease progression in group of patients who received NACRT apart from one patient who had oligometastatic disease at diagnosis. Median OS of the whole cohort was 38 months while median PFS was 24 months. Bone marrow toxicity was the most commonly reported high grade toxicity in NACRT group (55.5%) but there were no treatment related deaths.
Conclusion
NACRT is not widely adopted and treatment is based on institutional preferences, however our data shows that NACRT is a feasible therapy option. NACRT should be evaluated prospectively in a randomized trial
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