Signals from radio pulsars show a wavelength-dependent delay due to dispersion in the interstellar plasma. At a typical observing wavelength, this delay can vary by tens of microseconds on 5-yr ...time-scales, far in excess of signals of interest to pulsar timing arrays, such as that induced by a gravitational wave background. Measurement of these delay variations is not only crucial for the detection of such signals, but also provides an unparalleled measurement of the turbulent interstellar plasma at astronomical unit (au) scales.
In this paper we demonstrate that without consideration of wavelength-independent red noise, 'simple' algorithms to correct for interstellar dispersion can attenuate signals of interest to pulsar timing arrays. We present a robust method for this correction, which we validate through simulations, and apply it to observations from the Parkes Pulsar Timing Array. Correction for dispersion variations comes at a cost of increased band-limited white noise. We discuss scheduling to minimize this additional noise, and factors, such as scintillation, that can exacerbate the problem.
Comparison with scintillation measurements confirms previous results that the spectral exponent of electron density variations in the interstellar medium often appears steeper than expected. We also find a discrete change in dispersion measure of PSR J1603−7202 of ∼2 × 10−3 cm−3 pc for about 250 d. We speculate that this has a similar origin to the 'extreme scattering events' seen in other sources. In addition, we find that four pulsars show a wavelength-dependent annual variation, indicating a persistent gradient of electron density on an au spatial scale, which has not been reported previously.
Orthodontic patients have an increased risk of white-spot lesion formation. A clinical trial was conducted to test whether, in a post-orthodontic population using fluoride toothpastes and receiving ...supervised fluoride mouthrinses, more lesions would regress in participants using a remineralizing cream containing casein phosphopeptide- amorphous calcium phosphate compared with a placebo. Forty-five participants (aged 12–18 yrs) with 408 white-spot lesions were recruited, with 23 participants randomized to the remineralizing cream and 22 to the placebo. Product was applied twice daily after fluoride toothpaste use for 12 weeks. Clinical assessments were performed according to ICDAS II criteria. Transitions between examinations were coded as progressing, regressing, or stable. Ninety-two percent of lesions were assessed as code 2 or 3. For these lesions, 31% more had regressed with the remineralizing cream than with the placebo (OR = 2.3, P = 0.04) at 12 weeks. Significantly more post-orthodontic white-spot lesions regressed with the remineralizing cream compared with a placebo over 12 weeks.
In the past few decades, the placenta became a very controversial topic that has had many researchers and pharmacists discussing the significance of the effects of pharmaceutical drug intake and how ...it is a possible leading cause towards birth defects. The creation of an
microengineered model of the placenta can be used to replicate the interactions between the mother and fetus, specifically pharmaceutical drug intake reactions. As the field of nanotechnology significantly continues growing, nanotechnology will become more apparent in the study of medicine and other scientific disciplines, specifically microengineering applications. This review is based on past and current research that compares the feasibility and testing of the placenta-on-a-chip microengineered model to the previous and underdeveloped
and
approaches. The testing of the practicality and effectiveness of the
,
and
models requires the experimentation of prominent pharmaceutical drugs that most mothers consume during pregnancy. In this case, these drugs need to be studied and tested more often. However, there are challenges associated with the
,
and
processes when developing a practical placental model, which are discussed in further detail.
PCM‐101 is a phosphine coordination material comprised of tris(p‐carboxylato)triphenylphosphine and secondary pillaring groups coordinated to M3(OH)5+ nodes (M=Co, Ni). PCM‐101 has a unique topology ...in which R3P: sites are arranged directly trans to one another, with a P⋅⋅⋅P separation distance dictated by the pillars. Post‐synthetic coordination of soft metals to the P: sites proceeds at room temperature to provide X‐ray quality crystals that permit full structural resolution. Addition of AuCl groups forces a large distortion of the parent framework. In contrast, CuBr undergoes insertion directly between the trans‐P sites to form dimers that mimic solution‐phase complexes, but that are geometrically strained due to steric pressure exerted by the MOF scaffold. The metalated materials are active in heterogeneous hydroaddition catalysis under mild conditions, yielding different major products compared to their molecular counterparts.
Trans‐phosphines in a MOF: A phosphine‐containing coordination material, PCM‐101, is the first example of a trans‐phosphine binding pocket within a MOF. Single‐crystal‐to‐single‐crystal metal addition allows for incorporation of strained versions of analogous small‐molecule trans‐phosphine complexes.
Emerging evidence suggests that cancer cell metabolism can be regulated by cancer-associated fibroblasts (CAFs), but the mechanisms are poorly defined. Here we show that CAFs regulate malignant cell ...metabolism through pathways under the control of FAK. In breast and pancreatic cancer patients we find that low FAK expression, specifically in the stromal compartment, predicts reduced overall survival. In mice, depletion of FAK in a subpopulation of CAFs regulates paracrine signals that increase malignant cell glycolysis and tumour growth. Proteomic and phosphoproteomic analysis in our mouse model identifies metabolic alterations which are reflected at the transcriptomic level in patients with low stromal FAK. Mechanistically we demonstrate that FAK-depletion in CAFs increases chemokine production, which via CCR1/CCR2 on cancer cells, activate protein kinase A, leading to enhanced malignant cell glycolysis. Our data uncover mechanisms whereby stromal fibroblasts regulate cancer cell metabolism independent of genetic mutations in cancer cells.
e-Stores and online shopping have become important aspects of a retailer's strategy. Previous research suggests that online shoppers are fundamentally different from traditional offline shoppers. ...However, based on the Big Middle Theory (
Levy et al. 2005), the authors believe that there are segments of online shoppers that are very similar to regular shopper groups. To determine this, online shopping motivations and e-store attribute importance measures are separately used as the basis to develop online shopper typologies. Results reveal that there are more similarities than differences among traditional and online store shoppers. However, there are a few unique shopper types present at online stores, attracted by the distinctive characteristics and attributes of the online retail environment. The findings offer interesting implications for online retail strategy.
Abstract
Background
Healthcare work is known to be stressful and challenging, and there are recognised links between the psychological health of staff and high-quality patient care. Schwartz Center ...Rounds® (Rounds) were developed to support healthcare staff to re-connect with their values through peer reflection, and to promote more compassionate patient care. Research to date has focussed on self-report surveys that measure satisfaction with Rounds but provide little analysis of how Rounds ‘work’ to produce their reported outcomes, how differing contexts may impact on this, nor make explicit the underlying theories in the conceptualisation and implementation of Rounds.
Methods
Realist evaluation methods aimed to identify how Rounds work, for whom and in what contexts to deliver outcomes. We interviewed 97 key informants: mentors, facilitators, panellists and steering group members, using framework analysis to organise and analyse our data using realist logic. We identified mechanisms by which Rounds lead to outcomes, and contextual factors that impacted on this relationship, using formal theory to explain these findings.
Results
Four stages of Rounds were identified. We describe how, why and for whom Schwartz Rounds work through the relationships between nine partial programme theories. These include: trust safety and containment; group interaction; counter-cultural/3rd space for staff; self-disclosure; story-telling; role modelling vulnerability; contextualising patients and staff; shining a spotlight on hidden stories and roles; and reflection and resonance. There was variability in the way Rounds were run across organisations. Attendance for some staff was difficult. Rounds is likely to be a ‘slow intervention’ the impact of which develops over time. We identified the conditions needed for Rounds to work optimally. These contextual factors influence the intensity and therefore degree to which the key ingredients of Rounds (mechanisms) are activated along a continuum, to produce outcomes. Outcomes included: greater tolerance, empathy and compassion for self and others; increased honesty, openness, and resilience; improved teamwork and organisational change.
Conclusions
Where optimally implemented, Rounds provide staff with a safe, reflective and confidential space to talk and support one another, the consequences of which include increased empathy and compassion for colleagues and patients, and positive changes to practice.
Porphyromonas, Tannerella, and Prevotella species found in severe periodontitis use the Type IX Secretion System (T9SS) to load their outer membrane surface with an array of virulence factors. These ...virulence factors are then released on outer membrane vesicles (OMVs), which penetrate the host to dysregulate the immune response to establish a positive feedback loop of chronic, inflammatory destruction of the tooth’s supporting tissues. In this review, we present the latest information on the molecular architecture of the T9SS and provide mechanistic insight into its role in secretion and attachment of cargo proteins to produce a virulence coat on cells and OMVs. The recent molecular structures of the T9SS motor comprising PorL and PorM as well as the secretion pore Sov, together with advances in the overall interactome, have provided insight into the possible mechanisms of secretion. We propose the presence of PorL/M motors arranged in a circle at the inner membrane with bent periplasmic rotors interacting with the PorN protein. At the outer membrane, we envisage a slide carousel model where the PorN protein is driven around a circular track composed of PorK. Cargo proteins are transported by PorN to PorW and the Sov translocon just as slides are rotated to the projection window. Secreted proteins are proposed to then be shuttled along highways consisting of the PorV shuttle protein to an array of attachment complexes distributed around the cell. The cell surface attachment of cargo is a hallmark of the T9SS, and in Porphyromonas gingivalis and Tannerella forsythia, this attachment is achieved via covalent bonding to a linking sugar synthesized by the Wbp/Vim pathway. The cell-surface attached cargo are enriched on OMVs, which are then released from the cell.
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