3,534 research outputs found
External liquid-spray cooling of turbine blades Patent
External device for liquid spray cooling of gas turbine blade
The Transition between Nonorthogonal Polarization Modes in PSR B2016+28 at 1404 MHz
Polarization observations of the radio emission from PSR B2016+28 at 1404 MHz
reveal properties that are consistent with two, very different, interpretations
of the pulsar's viewing geometry. The pulsar's average polarization properties
show a rapid change in position angle (PA) near the pulse center, suggesting
that the observer's sightline nearly intersects the star's magnetic pole. But
single pulse, polarization observations of the pulsar show nearly orthogonal
modes of polarization following relatively flat and parallel PA trajectories
across the pulse, suggesting that the sightline is far from the pole.
Additionally, PA histograms reveal a "modal connecting bridge", of unknown
origin, joining the modal PA trajectories over much of the pulse and following
the rapid PA change shown in the average data. The nonorthogonality of
polarization modes is incorporated in a statistical model of radio polarization
to account for the deviations from mode orthogonality that are observed in the
pulsar. The model is used to interpret the rapid PA change and modal connecting
bridge as a longitudinally-resolved transition between modes of nonorthogonal
polarization. Thus, the modal PA trajectories are argued to reflect the
pulsar's true viewing geometry. This interpretation is consistent with the
pulsar's morphological classification, preserves the Radhakrishnan & Cooke
model of pulsar radio emission, and avoids the complication that the modal
connecting bridge might be produced by some other emission mechanism. The
statistical model's ability to simulate the rich variety of polarization
properties observed in the emission lends additional support to the model's
applicability and its underlying assumption that the polarization modes occur
simultaneously.Comment: Accepted for publication in Ap
Social Support Seeking And Early Adolescent Depression And Anxiety Symptoms: The Moderating Role Of Rumination
This study examined how social support seeking and rumination interacted to predict depression and anxiety symptoms 6 months later in early adolescents (N = 118; 11-14 years at baseline). We expected social support seeking would be more helpful for adolescents engaging in low rather than high levels of rumination. Adolescents self-reported on all measures at baseline, and on depression and anxiety symptoms 6 months later. Social support seeking predicted fewer symptoms of depression and anxiety at low rumination levels but was not associated with benefits as rumination increased. For depression symptoms, social support seeking predicted more symptoms at high rumination levels. Results were stronger for emotion-focused than problem-focused support seeking and for depression compared with anxiety symptoms. These findings suggest that cognitive risk factors like rumination may explain some inconsistencies in previous social support literature, and highlight the importance of a nuanced approach to studying social support seeking
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Evaluation of an Australian nursing partnership to improve disaster response capacity
Purpose– The purpose of this paper is to evaluate a partnership with specialized nurses from geographically disparate hospitals to provide critical support in national disaster
Orientation Angles of a Pulsar's Polarization Vector
A statistical model of the polarization of pulsar radio emission is used to
derive the general statistics of a polarization vector's orientation angles.
The theoretical distributions are compared with orientation angle histograms
computed from single-pulse, polarization observations of PSR B2020+28. The
favorable agreement between the theoretical and measured distributions lends
support to the underlying assumptions of the statistical model, and
demonstrates, like recent work on other pulsars, that the handedness of
circular polarization is associated with the radiation's orthogonally polarized
modes. Comprehensive directional statistics of the vector's orientation angles
are also derived, and are shown to follow the Watson bipolar and Fisher
distributions in its limiting forms.Comment: 14 pages, 4 figures, accepted for publication in Ap
Lymphocytes of BRCA1 and BRCA2 germ-line mutation carriers, with or without breast cancer, are not abnormally sensitive to the chromosome damaging effect of moderate folate deficiency
Mutations in BRCA1 and BRCA2 genes may cause defective DNA repair and increase risk for breast cancer. Folate deficiency is associated with increased breast cancer risk and induces chromosome abnormalities. We hypothesised that BRCA1 and BRCA2 germ-line mutation carriers are more sensitive to the genome damaging effect of folate deficiency compared to healthy non-carrier controls and that this sensitivity is further increased in those carriers who develop breast cancer. We tested these hypotheses in lymphocytes cultured in medium containing 12 nM or 120 nM folic acid (FA) for 9 days and measured proliferative capacity and chromosomal instability using the cytokinesis-block micronucleus (CBMN) assay. BRCA1 and BRCA2 mutation carriers with or without breast cancer were not abnormally sensitive to FA deficiency-induced chromosome instability however BRCA2 mutation carriers had significantly reduced cell proliferation. FA deficiency reduced cell proliferation and increased micronucleus formation significantly accounting for 45-59% and 70-75% of the variance in these parameters compared to 0.3-8.5% and 0.2-0.3% contributed by BRCA1 or BRCA2 mutation carrier status respectively. The results of this study suggest that moderate folate deficiency has a stronger effect on chromosomal instability than BRCA1 or BRCA2 mutations found in breast cancer families.Sasja Beetstra, Carolyn Salisbury, Julie Turner, Meryl Altree, Ross McKinnon, Graeme Suthers and Michael Fenec
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Enhancing disaster preparedness of specialty nurses on a national scale
Purpose – The number of disasters has increased by 30 per cent worldwide in the past 30 years. Nurses constitute the largest clinical group within a hospital and their ability to respond to disasters is crucial to the provision of quality patient care. The purpose of this paper is to evaluate a four-year disaster preparedness partnership between two tertiary hospitals from the perspective of executive staff, senior clinical managers and specialist nurses. The national disaster response centre was situated in one hospital and the other hospital was located 3,500 km away.
Design/methodology/approach – The intervention involved selected nurses working at the partner hospital to enable familiarisation with policies, procedures and layout in the event of a request for back-up in the event of a national disaster. A mixed-methods design was used to elicit the strengths and limitations of the partnership. Surveys, in-depth interviews and focus groups were used.
Findings – In total, 67 participants provided evaluations including ten executive staff, 17 clinical management nurses and 38 nurses from the disaster response team. Improvements in some aspects of communication were recommended. The successful recruitment of highly skilled and committed nurses was a strength. A disaster exercise resulted in 79 per cent of nurses, able and willing to go immediately to the partner hospital for up to 14 days.
Research limitations/implications – During the four year partnership, no actual disaster occurred that required support. This limited the ability to fully trial the partnership in an authentic manner. The disaster exercise, although helpful in trialling the processes and assessing nurse availability, it has some limitations.
Originality/value – This innovative partnership successfully prepared specialist nurses from geographically distant hospitals for a disaster response. This together with a willingness to be deployed enhanced Australia’s capacity in the event of a disaster
First-principles prediction of redox potentials in transition-metal compounds with LDA+U
First-principles calculations within the Local Density Approximation (LDA) or
Generalized Gradient Approximation (GGA), though very successful, are known to
underestimate redox potentials, such as those at which lithium intercalates in
transition metal compounds. We argue that this inaccuracy is related to the
lack of cancellation of electron self-interaction errors in LDA/GGA and can be
improved by using the DFT+ method with a self-consistent evaluation of the
parameter. We show that, using this approach, the experimental lithium
intercalation voltages of a number of transition metal compounds, including the
olivine LiMPO (M=Mn, Fe Co, Ni), layered LiMO (Co,
Ni) and spinel-like LiMO (M=Mn, Co), can be reproduced
accurately.Comment: 19 pages, 6 figures, Phys. Rev. B 70, 235121 (2004
Self-aligned fabrication process for silicon quantum computer devices
We describe a fabrication process for devices with few quantum bits (qubits),
which are suitable for proof-of-principle demonstrations of silicon-based
quantum computation. The devices follow the Kane proposal to use the nuclear
spins of 31P donors in 28Si as qubits, controlled by metal surface gates and
measured using single electron transistors (SETs). The accurate registration of
31P donors to control gates and read-out SETs is achieved through the use of a
self-aligned process which incorporates electron beam patterning, ion
implantation and triple-angle shadow-mask metal evaporation
Lipid domains in the ram sperm plasma membrane demonstrated by differential scanning calorimetry.
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