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The virtual environment for radiotherapy training (VERT) helps students to gain technical skills and understanding of 3D anatomy and dosimetry. It has potential as a tool for treatment plan evaluation, although little formal evidence currently supports this.
This paper reports findings from a plan evaluation workshop that facilitated comparison of VERT plan evaluation tools with those provided by conventional treatment planning software (TPS).
Students on a pre-registration Post-Graduate Diploma in Radiotherapy worked in small groups evaluating lung plans using both VERT and Eclipse TPS tools. All students were invited to provide ratings concerning how helpful each modality was for a range of evaluation parameters and preferences for use.
Most students (11 out of 14) found the session useful and expressed a desire to use VERT in future plan evaluation. The TPS was perceived to be more helpful with constraint-based evaluation while VERT was more helpful with evaluating plans for clinical set-up and delivery (p < 0·001).
Student therapeutic radiographers found VERT to be helpful as a plan evaluation tool alongside standard TPS tools, in particular for clinical set-up and delivery aspects of planning. Future work is ongoing to identify the specific impact of VERT as a plan evaluation tool for both students and qualified planners.
Using multilevel models, we examined mother-, father-, and child-reported (N = 1,336 families) externalizing behavior problem trajectories from age 7 to 14 in nine countries (China, Colombia, Italy, Jordan, Kenya, the Philippines, Sweden, Thailand, and the United States). The intercept and slope of children's externalizing behavior trajectories varied both across individuals within culture and across cultures, and the variance was larger at the individual level than at the culture level. Mothers’ and children's endorsement of aggression as well as mothers’ authoritarian attitudes predicted higher age 8 intercepts of child externalizing behaviors. Furthermore, prediction from individual-level endorsement of aggression and authoritarian attitudes to more child externalizing behaviors was augmented by prediction from cultural-level endorsement of aggression and authoritarian attitudes, respectively. Cultures in which father-reported endorsement of aggression was higher and both mother- and father-reported authoritarian attitudes were higher also reported more child externalizing behavior problems at age 8. Among fathers, greater attributions regarding uncontrollable success in caregiving situations were associated with steeper declines in externalizing over time. Understanding cultural-level as well as individual-level correlates of children's externalizing behavior offers potential insights into prevention and intervention efforts that can be more effectively targeted at individual children and parents as well as targeted at changing cultural norms that increase the risk of children's and adolescents’ externalizing behavior.
Using data from 1,177 families in eight countries (Colombia, Italy, Jordan, Kenya, the Philippines, Sweden, Thailand, and the United States), we tested a conceptual model of direct effects of childhood family adversity on subsequent externalizing behaviors as well as indirect effects through psychological mediators. When children were 9 years old, mothers and fathers reported on financial difficulties and their use of corporal punishment, and children reported perceptions of their parents’ rejection. When children were 10 years old, they completed a computerized battery of tasks assessing reward sensitivity and impulse control and responded to questions about hypothetical social provocations to assess their hostile attributions and proclivity for aggressive responding. When children were 12 years old, they reported on their externalizing behavior. Multigroup structural equation models revealed that across all eight countries, childhood family adversity had direct effects on externalizing behaviors 3 years later, and childhood family adversity had indirect effects on externalizing behavior through psychological mediators. The findings suggest ways in which family-level adversity poses risk for children's subsequent development of problems at psychological and behavioral levels, situated within diverse cultural contexts.
The Virtual Environment for Radiotherapy Training (VERT) is a high-fidelity simulation hardware and software resource that replicates the expensive and high-pressure clinical environment of a radiotherapy treatment machine. The simulation allows students to gain confidence with clinical techniques in a safe and unpressured academic environment before clinical placement. The aim of this study was to establish the current and future role of VERT and explore the potential for collaborative resource development and research.
An anonymous online survey was made available to all users of the software internationally (n=52). A mixture of fixed and open response questions gathered usage data and user feedback.
The study had a 90% response rate (n=47). Most participants (78·5%) used the resource 1 day/week or less; around 8,000 hours worldwide. It was clear that most participants used the simulation resource to help student to either gain understanding of concepts and techniques or to gain practice with techniques and practical skills. There was good support for collaborative resource development, deployment and evaluation to help VERT users to fully exploit its range of pedagogical uses.
This audit demonstrated high levels of engagement and enthusiasm for collaborative resource development and ongoing research among the radiotherapy simulation community. Adoption of an international Academic Community of Practice for collaborative simulation resource deployment and support may be of significant value and is worthy of further discussion and consideration.
Background: A diagnosis of SCD in childhood confers a 200-fold increase in the risk of arterial ischemic stroke. Blood flow velocity measures provide better identification of ischemic risk compared to angiography. This indicates that steno-occlusive arteriopathy is not the singular causative factor. Cerebrovascular reactivity allows for augmentation of cerebral blood flow when needed. Kosinski et al in 2016 demonstrated a direct correlation between CVR and hematocrit levels in SCD. We report a case where CVR persistently normalized in an SCD patient following bone marrow transplant therapy (BMT). Methods: A nine-month-old SCD patient presented with right AIS. Angiography revealed a bilateral Moya-Moya like arteriopathy. A TCD study was normal while a CVR-MRI study revealed markedly impaired reactivity in the entire anterior circulation. Haemaglobin-S at that time was 20.2 %. BMT was performed at age four due to frequent sickle cell crises. Results: One year post-transplant, CVR had dramatically improved in areas previously shown to have impairment (haemoglobin-S 0%). Neuroimaging five years post-transplant showed no further arteriopathy and persistently normalized CVR. Conclusions: BMT therapy resulted in the arrest of progressive intracranial arteriopathy and persistently restored vascular reserve. SCD might not only produce global hematological effects but also triggers local processes such as endothelial dysfunction and vascular inflammation that impair cerebrovascular function.
This study advances understanding of predictors of child abuse and neglect at multiple levels of influence. Mothers, fathers, and children (N = 1,418 families, M age of children = 8.29 years) were interviewed annually in three waves in 13 cultural groups in nine countries (China, Colombia, Italy, Jordan, Kenya, Philippines, Sweden, Thailand, and the United States). Multilevel models were estimated to examine predictors of (a) within-family differences across the three time points, (b) between-family within-culture differences, and (c) between-cultural group differences in mothers' and fathers' reports of corporal punishment and children's reports of their parents' neglect. These analyses addressed to what extent mothers' and fathers' use of corporal punishment and children's perceptions of their parents' neglect were predicted by parents' belief in the necessity of using corporal punishment, parents' perception of the normativeness of corporal punishment in their community, parents' progressive parenting attitudes, parents' endorsement of aggression, parents' education, children's externalizing problems, and children's internalizing problems at each of the three levels. Individual-level predictors (especially child externalizing behaviors) as well as cultural-level predictors (especially normativeness of corporal punishment in the community) predicted corporal punishment and neglect. Findings are framed in an international context that considers how abuse and neglect are defined by the global community and how countries have attempted to prevent abuse and neglect.
The structure of La2LiTaO6 has been derived from the powder X-ray powder diffraction (XRD) data. La2LiTaO6 is monoclinic with unit-cell parameters a = 5.621(1) Å, b = 5.776(1) Å, c = 7.954(2) Å, β = 90.34(2)°, space group P21/n (14), and Z = 2. The structure of La2LiTaO6 is an ordered perovskite with alternating Li and Ta octahedra. A new set of powder XRD data (d-spacing and intensity listing) has been generated to replace entry 00-039-0897 within the Powder Diffraction File. The newly elucidated structural data for La2LiTaO6 shall facilitate quantitative analysis of this impurity phase which is often observed during synthesis of the fast-ion conductor phase Li5La3Ta2O12.
This study examined whether parents’ social information processing was related to their subsequent reports of their harsh discipline. Interviews were conducted with mothers (n = 1,277) and fathers (n = 1,030) of children in 1,297 families in nine countries (China, Colombia, Italy, Jordan, Kenya, the Philippines, Sweden, Thailand, and the United States), initially when children were 7 to 9 years old and again 1 year later. Structural equation models showed that parents’ positive evaluations of aggressive responses to hypothetical childrearing vignettes at Time 1 predicted parents’ self-reported harsh physical and nonphysical discipline at Time 2. This link was consistent across mothers and fathers, and across the nine countries, providing support for the universality of the link between positive evaluations of harsh discipline and parents’ aggressive behavior toward children. The results suggest that international efforts to eliminate violence toward children could target parents’ beliefs about the acceptability and advisability of using harsh physical and nonphysical forms of discipline.
In this paper, we explore the interfacial effects appearing in highly strained La0.7Ca0.3MnO3 (LCMO) ultra-thin films (10-12nm) grown on BaTiO3 (BTO) ferroelectric substrates. The strong tendency to phase separation of this optimally doped manganite contributes to the exotic phenomena observed in magnetism and transport experiments: the so-called Matteucci magnetic loops, magnetic granularity and a second metal insulator transition are observed between 50K and the LCMO Curie temperature, 180K. All these properties define the multiferroic character of these heterostructures, which in LCMO//BTO system is strongly linked to magnetoelastic coupling.
Some roofs that are thatched with combed wheat reed develop patches of more rapid decay within an otherwise uniform matrix of less rapid decay. Changes in the length and weight of reed from patches and matrix were estimated for one roof by comparison with samples of unused, undecayed reed. The fungal communities associated with patches and matrix were analysed using a particle plating method and the distribution of patches between and within roofs was analysed for departures from randomness. Reed from a patch was shorter than from the surrounding matrix due to more rapid loss of length. Weight loss was greatest at the thatch surface but only extended into the thatch for 8.5 cm in both cases. It is therefore probable that the decomposer communities of patches and matrix respond similarly to an environmental variable, probably water potential, that varies with depth. Fungal community analysis indicated that distinct functional units, or associations, of four and two taxa were present in the matrix and patches respectively. An analysis of patch distribution on a sample of roofs indicated that certain roofs are predisposed to develop patches. However, on individual roofs patches are distributed randomly. Predisposition may be due to relatively high levels of endogenous nitrogen in the thatching reed.
This study describes phenotypic and genotypic variations in the planktonic copepod, Centropages typicus (Copepoda: Calanoida) that indicate differentiation between geographical samples. We found consistent differences in the morphology of the chela of the sexually modified fifth pereiopod (P5) of male C. typicus between samples from the Mediterranean, western North Atlantic and eastern North Atlantic. A 560 base pairs (bp) region of the C. typicus mitochondrial cytochrome c oxidase subunit I (COI) and a 462 bp fragment of the nuclear rDNA internal transcribed spacer (ITS) tandem array were analysed to determine whether these morphological variations reflect population genetic differentiation. Mitochondrial haplotype diversity was found to be high with 100 unique COI haplotypes among 116 individuals. Analysis of mtCOI variation suggested differentiation between the Mediterranean and Atlantic populations but no separation was detected within the Atlantic. Intragenomic variation in the ITS array suggested genetic differentiation between samples from the western North Atlantic and those from the eastern North Atlantic and Mediterranean. Breeding experiments would be required to elucidate the extent of genetic isolation between C. typicus from the different population centres.
The chemical compositions of the stars in Milky Way (MW) satellite galaxies reveals the history of gas flows and star formation (SF) intensity. This talk presented a Keck/DEIMOS spectroscopic survey of the Fe, Mg, Si, Ca, and Ti abundances of nearly 3000 red giants in eight MW dwarf satellites. The metallicity and alpha-to-iron ratio distributions obey the following trends: (1) The more luminous galaxies are more metal-rich, indicating that they retained gas more efficiently than the less luminous galaxies. (2) The shapes of the metallicity distributions of the more luminous galaxies require gas infall during their SF lifetimes. (3) At [Fe/H]< −1.5, [α/Fe] falls monotonically with increasing [Fe/H] in all MW satellites. One interpretation of these trends is that the SF timescale in any MW satellite is long enough that Type Ia supernovae exploded for nearly the entire SF lifetime.
We present the first systematic comparison of the detailed properties, including internal kinematics, chemical abundances, sizes, and dark matter masses, of Milky Way and M 31 dSphs as a part of the SPLASH Survey (Spectroscopic and Photometric Landscape of Andromeda’s Stellar Halo). Through Keck/DEIMOS spectroscopy of several hundred individual red giants in a half dozen M 31 galaxies, our results indicate both similarities and differences between the family of dSphs in the Milky Way and M 31. For example, we find that the luminosity-metallicity relation of dSphs in the two hosts is very similar between L = 105 and 107L⊙, the size distribution of M 31 dSphs extends to larger values at the same luminosity compared to Milky Way counterparts (especially at the bright end), and that the dark matter masses of M 31 dSphs are slightly smaller than similar luminosity Milky Way galaxies.
There is a growing interest in high-order finite and spectral/hp element
methods using continuous and discontinuous Galerkin formulations. In this paper we
investigate the effect of h- and p-type refinement on
the relationship between runtime performance and solution accuracy. The broad spectrum of
possible domain discretisations makes establishing a performance-optimal selection
non-trivial. Through comparing the runtime of different implementations for evaluating
operators over the space of discretisations with a desired solution tolerance, we
demonstrate how the optimal discretisation and operator implementation may be selected for
a specified problem. Furthermore, this demonstrates the need for codes to support both
low- and high-order discretisations.
A new approach to spectroscopy of laser induced proton beams using radiochromic film (RCF) is presented. This approach allows primary standards of absorbed dose-to-water as used in radiotherapy to be transferred to the calibration of GafChromic HD-810 and EBT in a 29 MeV proton beam from the Birmingham cyclotron. These films were then irradiated in a common stack configuration using the TARANIS Nd:Glass multi-terawatt laser at Queens University Belfast, which can accelerate protons to 10–12 MeV, and a depth-dose curve was measured from a collimated beam. Previous work characterizing the relative effectiveness (RE) of GafChromic film as a function of energy was implemented into Monte Carlo depth-dose curves using FLUKA. A Bragg peak (BP) “library” for proton energies 0–15 MeV was generated, both with and without the RE function. These depth-response curves were iteratively summed in a FORTRAN routine to solve for the measured RCF depth-dose using a simple direct search algorithm. By comparing resultant spectra with both BP libraries, it was found that the effect of including the RE function accounted for an increase in the total number of protons by about 50%. To account for the energy loss due to a 20 µm aluminum filter in front of the film stack, FLUKA was used to create a matrix containing the energy loss transformations for each individual energy bin. Multiplication by the pseudo-inverse of this matrix resulted in “up-shifting” protons to higher energies. Applying this correction to two laser shots gave further increases in the total number of protons, N of 31% and 56%. Failure to consider the relative response of RCF to lower proton energies and neglecting energy losses in a stack filter foil can potentially lead to significant underestimates of the total number of protons in RCF spectroscopy of the low energy protons produced by laser ablation of thin targets.
Both ZnO and PZT Thin Film Bulk Acoustic Resonator filters were fabricated, tested and modeled in this study. The development of an accurate Mason model allows the effect of particular parasitic components on the microwave s-parameters in the region of the series and parallel resonances to be identified. The parasitic components that limit the performance of our ZnO and PbZr0.3Ti0.7O3 Thin Film Bulk Acoustic Resonator filters are analysed. From an analysis of PbZr0.3Ti0.7O3 Thin Film Bulk Acoustic Resonator measurements values for the longitudinal acoustic velocity and electromechanical coupling coefficient can be derived. Measured PbZr0.3Ti0.7O3 Thin Film Bulk Acoustic Resonator filter responses confirm that the larger electromechanical coupling coefficients in this material compared to ZnO give wider filter band-widths.