2,275 research outputs found
Spitzer/MIPS Imaging of NGC 650: Probing the History of Mass Loss on the Asymptotic Giant Branch
We present the far-infrared (IR) maps of a bipolar planetary nebula (PN), NGC
650, at 24, 70, and 160 micron taken with the Multiband Imaging Photometer for
Spitzer (MIPS) on-board the Spitzer Space Telescope. While the two-peak
emission structure seen in all MIPS bands suggests the presence of a near
edge-on dusty torus, the distinct emission structure between the 24 micron map
and the 70/160 micron maps indicates the presence of two distinct emission
components in the central torus. Based on the spatial correlation of these two
far-IR emission components with respect to various optical line emission, we
conclude that the 24 micron emission is largely due to the [O IV] line at 25.9
micron arising from highly ionized regions behind the ionization front, whereas
the 70 and 160 micron emission is due to dust continuum arising from
low-temperature dust in the remnant asymptotic giant branch (AGB) wind shell.
The far-IR nebula structure also suggests that the enhancement of mass loss at
the end of the AGB phase has occurred isotropically, but has ensued only in the
equatorial directions while ceasing in the polar directions. The present data
also show evidence for the prolate spheroidal distribution of matter in this
bipolar PN. The AGB mass loss history reconstructed in this PN is thus
consistent with what has been previously proposed based on the past optical and
mid-IR imaging surveys of the post-AGB shells.Comment: 9 pages in the emulated ApJ format with 6 figures, to appear in Ap
Barriers to career advancement for female engineers in Australia’s civil construction industry and recommended solutions
© 2019, © 2019 Engineers Australia. This study explores the challenges that have emerged from the outdated and inflexible workplace culture of the civil construction industry, and how it is affecting female engineers and women in other functional site roles. The study primarily explores issues such as the strong culture of long work hours, the perception of staff who pursue work-life balance, and the perception of part time and flexible working options within the industry. The study was conducted over three phases where members of the industry answered questionnaires on the workplace issues listed above. The first phase aimed to document a female perspective on the construction workplace culture while the second phase focused on the perceptions of the same respondents regarding the industry’s attitude to work-life balance and whether any of the aspects of workplace culture has discouraged them from staying in the industry. The final phase included men and women in management and employer roles to determine their views on part time and flexible working options within the industry. The results of the study are presented and discussed before recommendations are offered for contractor organisations, their employers and staff. The recommendations have been addressed in a way that a gradual culture change can be accepted and acted on throughout the entire workplace
DIFFERENCES IN TEMPORAL VARIABLES AND THEIR EFFECT ON KINETICS IN HIGH SCHOOL PITCHERS WITH HIGH AND LOW PITCH VELOCITIES
The purpose of this study was to compare temporal parameters between high and low velocity high school (HS) pitchers and investigate the influence these parameters have on both pitch speed and upper extremity kinetics. 30 healthy right-handed HS male pitchers with no recent injuries, and clearance to play were included. A 3D motion analysis system was used. Analysis included 15 kinetic and 35 temporal variables. Statistical tests conducted in SPSS. Correlation strength was interpreted as weak, moderate, or strong. High velocity and low velocity throwers showed differences in the timing to progress through the pitching cycle and these temporal variables showed separate relations to pitch speed and kinetics
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Detailed Visual Cortical Responses Generated by Retinal Sheet Transplants in Rats with Severe Retinal Degeneration.
To combat retinal degeneration, healthy fetal retinal sheets have been successfully transplanted into both rodent models and humans, with synaptic connectivity between transplant and degenerated host retina having been confirmed. In rodent studies, transplants have been shown to restore responses to flashes of light in a region of the superior colliculus corresponding to the location of the transplant in the host retina. To determine the quality and detail of visual information provided by the transplant, visual responsivity was studied here at the level of visual cortex where higher visual perception is processed. For our model, we used the transgenic Rho-S334ter line-3 rat (both sexes), which loses photoreceptors at an early age and is effectively blind at postnatal day 30. These rats received fetal retinal sheet transplants in one eye between 24 and 40 d of age. Three to 10 months following surgery, visually responsive neurons were found in regions of primary visual cortex matching the transplanted region of the retina that were as highly selective as normal rat to stimulus orientation, size, contrast, and spatial and temporal frequencies. Conversely, we found that selective response properties were largely absent in nontransplanted line-3 rats. Our data show that fetal retinal sheet transplants can result in remarkably normal visual function in visual cortex of rats with a degenerated host retina and represents a critical step toward developing an effective remedy for the visually impaired human population.SIGNIFICANCE STATEMENT Age-related macular degeneration and retinitis pigmentosa lead to profound vision loss in millions of people worldwide. Many patients lose both retinal pigment epithelium and photoreceptors. Hence, there is a great demand for the development of efficient techniques that allow for long-term vision restoration. In this study, we transplanted dissected fetal retinal sheets, which can differentiate into photoreceptors and integrate with the host retina of rats with severe retinal degeneration. Remarkably, we show that transplants generated visual responses in cortex similar in quality to normal rats. Furthermore, transplants preserved connectivity within visual cortex and the retinal relay from the lateral geniculate nucleus to visual cortex, supporting their potential application in curing vision loss associated with retinal degeneration
Response to comment on "solid recovered fuel: Materials flow analysis and fuel property development during the mechanical processing of biodried waste"
Laner and Cencic1 comment on Velis et al. (2013)2 clarifying certain points on the use of the material flow analysis (MFA) software STAN3. We welcome the correspondence and the opportunity this exchange provides to discuss optimal approaches to using STAN. In keeping with Velis et al.2 these physically impossible, and otherwise insignificant, negative flows have enabled improvements to STAN. Here, we elaborate on the practicalities of using STAN in our research and on the correctness and validation of our results, notwithstanding the inclusion of negative flows. We explain the contribution of our approach to solid waste management and resource recovery
Generation of a short fibre biocomposite representative volume element
One of the greatest challenge in working with natural fibre composites is the large variation in mechanical properties that result from the geometric inconsistency amongst fibres. Traditional design tools and models are unable to accurately incorporate this non-homogeneity to predict the resulting local behaviour of biocomposite materials. The following paper presents a methodology to generate a representative volume element (RVE) to simulate the material microstructure of short fibre composites, with the intent of modelling the popular class of short fibre biocomposites materials. The capabilities of a range of particle packing algorithms used in literature are compared in terms of the maximum volume fraction they have been able to achieve and for what fibre length to diameter aspect ratio. The methodology is able to account for the characteristics of fibre geometry samples, according to their probability density functions (PDFs). The RVE generation strategy imposes periodic boundary conditions and fibres are declared invalid if an intersection between fibres is detected. The effect of different PDFs on the resulting RVE are discussed. An RVE populated with data following a Weibull distribution is compared to that from normally distributed data with an equal mean but varied standard deviations. Using a Weibull distribution to simulate the characteristics of an RVE requires a significantly higher number of fibres than any comparable normal distribution, due to the skewness of the data towards large values at low probabilities. The highest volume fraction achieved was 40% for an RVE containing fibres with lengths distributed according to a Weibull distribution and aspect ratios of 15. The future intent of this work is to perform finite element analysis on RVE samples with a range of varied microstructure characteristics to determine the effect on overall composite properties, which will provide new insights on how best to formulate short fibre compounds
An Interim Analysis of an Advance Care Planning Intervention in the Nursing Home Setting
Objectives
To describe processes and preliminary outcomes from the implementation of a systematic advance care planning (ACP) intervention in the nursing home setting.
Design
Specially trained project nurses were embedded in 19 nursing homes and engaged in ACP as part of larger demonstration project to reduce potentially avoidable hospitalizations.
Setting
Nursing homes.
Participants
Residents enrolled in the demonstration project for a minimum of 30 days between August 2013 and December 2014 (n = 2,709) and residents currently enrolled in March 2015 (n = 1,591).
Measurements
ACP conversations were conducted with residents, families, and the legal representatives of incapacitated residents using a structured ACP interview guide with the goal of offering ACP to all residents. Project nurses reviewed their roster of currently enrolled residents in March 2015 to capture barriers to engaging in ACP.
Results
During the initial implementation phase, 27% (731/2,709) of residents had participated in one or more ACP conversations with a project nurse, resulting in a change in documented treatment preferences for 69% (504/731). The most common change (87%) was the generation of a Physician Orders for Scope of Treatment form. The most frequently reported barrier to ACP was lack of time.
Conclusion
The time- and resource-intensive nature of robust ACP must be anticipated when systematically implementing ACP in the nursing home setting. The fact that these conversations resulted in changes over 2/3 of the time reinforces the importance of deliberate, systematic ACP to ensure that current treatment preferences are known and documented so that these preferences can be honored
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