8,493 research outputs found
Change in Working Length at Different Stages of Instrumentation as a Function of Canal Curvature
The aim of this study was to determine the change in working length (âWL) before and after coronal flaring and after complete rotary instrumentation as a function of canal curvature. One mesiobuccal or mesiolingual canal from each of 43 extracted molars had coronal standardization and access performed. Once the access was completed, canal preparation was accomplished using Gates Glidden drills for coronal flaring and EndoSequence files for rotary instrumentation. WLs were obtained at 3 time points: pre-instrumentation (unflared), mid-instrumentation (flared) and post-instrumentation (concluded). Measurements were made via direct visualization (DV) and the CanalPro apex locator (EM) in triplicate by a single operator with blinding within the time points. Root curvature was measured using Schneiderâs technique. The change in working length was assessed using repeated-measures ANCOVA. The direct visualization measurements were statistically larger than the electronic measurements (paired t-test difference = 0.20 mm, SE = 0.037, P \u3c .0001), although a difference this large may not be clinically important. Overall, a greater change in working length was observed in straight canals than in curved canals, and this trend was more pronounced when measured electronically than via direct visualization, especially in the unflared-concluded time points compared with unflared-flared time points. A greater change in working length was also observed in longer canals than in shorter canals.https://scholarscompass.vcu.edu/gradposters/1032/thumbnail.jp
Geriatric screening in first opinion practice: results from 45 dogs
Objectives
To evaluate and report the results of screening geriatric dogs in a first opinion practice.
Methods
A prospective health screen of dogs over nine-years-old involving history taking, physical examination and urinalysis.
Results
At least one previously unrecognised problem was identified in 80% of 45 dogs and 353 findings (mean 7·8 per dog) were recorded. Owners often failed to recognise and report serious signs of age-related disease. However, they most often reported increased sleeping (31%), loss of hearing (29%) or sight (20%), stiffness or lameness (22%) and âslowing downâ (20%). Increased lens opacity (64%), increased thirst (58%), pain (24%), increased frequency of urination (24%), signs of osteoarthritis (24%) and dental disease (22%) were most frequently identified at the time of consultation. Potentially, life-threatening findings included respiratory distress, palpable abdominal masses and metastatic lung disease. Screening resulted in 29 further diagnostic procedures, including 10 dental procedures, seven medical treatments, two surgical procedures and euthanasia of two dogs.
Clinical Significance
Screening elderly dogs identified unrecognised and unreported health risk factors resulting in lifestyle modification and ongoing monitoring, as well as signs of age-related diseases resulting in diagnostic investigations, early diagnoses and surgical and medical interventions to improve quality of life
Morphogenetic Theory and the Constructivist Institutionalist Challenge
This article engages with two meta-theoretical approaches to social analysis, âmorphogenetic theoryâ and âconstructivist institutionalismâ, and specifically explores how the former fares under the critical scrutiny of the latter. The key proponent of constructivist institutionalism, Colin Hay, has offered two detailed critiques of morphogenesis that criticise its position on the foundational sociological issues of structure-agency and material-ideational. Although Hayâs critiques are largely rejected in an overall defence of the morphogenetic approach, the process of engagement is seen to be particularly useful for morphogenetic theory because it allows a number of important clarifications to be made and it also opens up space for theoretical development. In the course of this debate, accessible introductions are given to both theories, and the similarities and differences between them are outlined, providing clarity to both. Therefore, although this article ultimately operates as a defence of morphogenetic theory, especially in the form proposed by Margaret Archer and Douglas Porpora, it finds a great deal of fruitful discussion in the constructivist institutionalist challenge
Patient safety and quality of care in mental health: a world of its own?
Quality and safety in healthcare, as an academic discipline, has made significant progress over recent decades, and there is now an active and established community of researchers and practitioners. However, work has predominantly focused on physical health, despite broader controversy regarding the attention paid to, and significance attributed to, mental health. Work from both communities is required in order to ensure that quality and safety is actively embedded within mental health research and practice and that the academic discipline of quality and safety accurately represents the scientific knowledge that has been accumulated within the mental health community
Intralocus sexual conflict can resolve the male-female health-survival paradox
This is the final version. Available on open access from Springer Nature via the DOI in this recordAt any given age, men are more likely to die than women, but women have poorer health at
older ages. This is referred to as the âmale-female, health-survival paradoxâ, which is not
fully understood. Here, we provide a general solution to the paradox that relies on intralocus
sexual conflict, where alleles segregating in the population have late-acting positive effects
on male fitness, but negative effects on female health. Using an evolutionary modelling
framework we show that male-benefit, female-detriment alleles can spread if they are
expressed after female reproduction stops. We provide support for our conflict based
solution using experimental Drosophila data. Our results show that selecting for increased
late-life male reproductive effort can increase male fitness but have a detrimental effect on
female fitness. Furthermore, we show that late-life male fertility is negatively genetically
correlated with female health. Our study suggests that intralocus sexual conflict could
resolve the health-survival paradoxWe thank the National Science Center
(Poland: 2013/09/N/NZ/NZ8/03231) and the Leverhulme Trust (UK: RF-2015-01) for funding
which partially supported this work, and the University of Exeterâs Deanâs Fellowship for
additional support
How a realistic magnetosphere alters the polarizations of surface, fast magnetosonic, and Alfvén waves
System-scale magnetohydrodynamic (MHD) waves within Earth's magnetosphere are often understood theoretically using box models. While these have been highly instructive in understanding many fundamental features of the various wave modes present, they neglect the complexities of geospace such as the inhomogeneities and curvilinear geometries present. Here, we show global MHD simulations of resonant waves impulsively excited by a solar wind pressure pulse. Although many aspects of the surface, fast magnetosonic (cavity/waveguide), and Alfvén modes present agree with the box and axially symmetric dipole models, we find some predictions for large-scale waves are significantly altered in a realistic magnetosphere. The radial ordering of fast mode turning points and Alfvén resonant locations may be reversed even with monotonic wave speeds. Additional nodes along field lines that are not present in the displacement/velocity occur in both the perpendicular and compressional components of the magnetic field. Close to the magnetopause, the perpendicular oscillations of the magnetic field have the opposite handedness to the velocity. Finally, widely used detection techniques for standing waves, both across and along the field, can fail to identify their presence. We explain how all these features arise from the MHD equations when accounting for a non-uniform background field and propose modified methods that might be applied to spacecraft observations
Generation of defects and disorder from deeply quenching a liquid to form a solid
We show how deeply quenching a liquid to temperatures where it is linearly
unstable and the crystal is the equilibrium phase often produces crystalline
structures with defects and disorder. As the solid phase advances into the
liquid phase, the modulations in the density distribution created behind the
advancing solidification front do not necessarily have a wavelength that is the
same as the equilibrium crystal lattice spacing. This is because in a deep
enough quench the front propagation is governed by linear processes, but the
crystal lattice spacing is determined by nonlinear terms. The wavelength
mismatch can result in significant disorder behind the front that may or may
not persist in the latter stage dynamics. We support these observations by
presenting results from dynamical density functional theory calculations for
simple one- and two-component two-dimensional systems of soft core particles.Comment: 25 pages, 11 figure
Magnetosonic ULF waves with anomalous plasma - magnetic field correlations: standing waves and inhomogeneous plasmas
Ultra-low frequency (ULF) wave observations across the heliosphere often rely on the sign of correlations between plasma (density/pressure) and magnetic field perturbations to distinguish between fast and slow magnetosonic modes. However, the assumptions behind this magnetohydrodynamic result are not always valid, particularly within the magnetosphere which is inhomogeneous and supports standing waves along the geomagnetic field. Through theory and a global simulation, we find both effects can result in anomalous plasmaâmagnetic field correlations. The interference pattern in standing waves can lead both body and surface magnetosonic waves to have different cross-phases than their constituent propagating waves. Furthermore, if the scale of gradients in the background are shorter than the wavelength or the waves are near-incompressible, then advection by the wave of inhomogeneities can overcome the wave's inherent sense of compression. These effects need to be allowed for and taken into account when applying the typical diagnostic to observations
Intrinsic point defects and volume swelling in ZrSiO4 under irradiation
The effects of high concentration of point defects in crystalline ZrSiO4 as
originated by exposure to radiation, have been simulated using first principles
density functional calculations. Structural relaxation and vibrational studies
were performed for a catalogue of intrinsic point defects, with different
charge states and concentrations. The experimental evidence of a large
anisotropic volume swelling in natural and artificially irradiated samples is
used to select the subset of defects that give similar lattice swelling for the
concentrations studied, namely interstitials of O and Si, and the anti-site
Zr(Si), Calculated vibrational spectra for the interstitials show additional
evidence for the presence of high concentrations of some of these defects in
irradiated zircon.Comment: 9 pages, 7 (color) figure
Excellence in Extension: Two Products for Definition and Measurement
Two products of the Excellence in Extension effort of ECOP will be useful at every level of the Extension System. The first is a pocket card. One side describes what makes Extension unique and defines Excellence of Extension, and the other side lists the seven most important criteria to identify Excellence in Cooperative Extension. The second product is the Matrix of Criteria of Excellence in Cooperative Extension. This matrix will assist Extension: (1) To be accountable for invested resources; (2) To continually improve the organization\u27s effectiveness; and (3) To describe its strengths and differentiate itself from other agencies and organizations
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