476 research outputs found

    Everything\u27s Relative: The Theory of Relativity\u27s Influence on Early Twentieth-Century Thought

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    In the early twentieth century Albert Einstein revolutionized humankind\u27s understanding of the universe. Few scientific innovations have had as pervasive an impact as Einstein\u27s Theory of Relativity. His conjectures accounted for scientific phenomena which were otherwise unexplained. With a set of abstract equations, he created unity and consistency among otherwise disconnected entities. He redefined the universe and transformed previous notions about space and time. For the scientific community the Theory of Relativity established a foundation for subsequent developments in physics. It is important to note, however, that the nonscientific community was also profoundly affected by Einstein\u27s theory. Lay people did not comprehend the true scientific importance of the Theory of Relativity. Nevertheless, the popular conception of relativity reintroduced subjectivism and uncertainty into the world of philosophy. Religion, art, and other creative fields were likewise transformed by relativity. The impacts of Einstein\u27s theory are not limited to the early twentieth century nor to the scientific community. Rather, the effects of this breakthrough in science are ubiquitous

    Temperature dependence of piezoelectric properties of high- TC Bi (Mg1/2Ti1/2) O3 - PbTiO3

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    The temperature dependence of both polarization and electric-field induced strain was investigated for (1-x)Bi(Mg1/2Ti1/2)O-3-xPbTiO(3) (x=0.36, 0.37, and 0.38), with the morphotropic phase boundary located at x=0.37. Remanent polarization (P-r) and maximum polarization (P-max) of all compositions are enhanced with increasing temperature up to 175 degrees C, which is rationalized as improved domain switching due to reduced tetragonality (c/a). The hysteresis during unipolar electric cycling tends to decrease with increase in the fraction of tetragonal phase. Temperature dependent x-ray diffraction demonstrates that switched non-180 degrees domains are stable against thermal depoling above 200 degrees C, which indicates that the currently investigated materials are suitable for high temperature applications. This promising high-T-C piezoelectric is further discussed with reference to oxygen octahedron of the tilted R3c and untilted R3m space groups and the tolerance factor (t).open371

    Anticoagulation in Atrial Fibrillation Patients

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    Atrial fibrillation (AF) is the most common arrhythmia and may cause thromboembolic events, typically stroke. Advances in pharmacological approaches to anticoagulation and groundbreaking large randomized controlled trials of non-vitamin K antagonist oral anticoagulants (NOACs) have changed the paradigm of anticoagulation therapy. Furthermore, observational studies support the efficacy and safety of NOAC. Few studies address the differences among NOACs, but prescriptions should be based on a thorough understanding of their pharmacological differences, including interactions, side effects, reversibility, and practical approach. In a subset of patients with AF, warfarin may still be the preferable option. Consequently, an individualized approach to oral anticoagulation is crucial

    An Analysis of Event Managers\u27 Problem-Solving Propensity: Applying the Problem-Solving Inventory (PSI) to the Field of Event Management

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    The field of event management encompasses the conceptualization of a festival or event, a determination of the intended target market, coordination of systems, policies, and procedures needed to plan and support the event, and the eventual administration of a proposed event. This broad scope of functional duties surrounding event planning requires that an event manger have at his or her disposal a diverse repertoire of problem-solving abilities. Using Heppner\u27s Problem-Solving Inventory (PSI) the researchers determined that the sampled group of event professionals from the International Special Events Society (ISEP) exhibited high levels of problem-solving self-confidence, high approach behavior, and high levels of personal control in their role as event managers

    Lead-free high-temperature dielectrics with wide operational range

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    The dielectric, electrical and structural properties of (1-x) (0.94Bi(1/2)Na(1/2)TiO(3)-0.06BaTiO(3))-xK(0.5)Na(0.5)NbO(3) (BNT-BT-xKNN) with x=0.09, 0.12, 0.15, and 0.18 were investigated as potential candidates for high-temperature capacitors with a working temperature far beyond 200 degrees C. Temperature dependent dielectric permittivity (epsilon) showed two local broad maxima that at the optimal composition of KNN (x=0.18) are combined to form a plateau. This then results in a highly temperature-insensitive permittivity up to similar to 300 degrees C at the expense of a small reduction in absolute permittivity values. High-temperature in situ x-ray diffraction study showed pseudocubic symmetry without obvious structural changes, which implies that the dielectric anomalies observed could only be a consequence of a slight change in space group. BNT-BT-0.18KNN showed a permittivity of similar to 2150 at the frequency of 1 kHz at 150 degrees C with a normalized permittivity epsilon/epsilon(150 degrees C) varying no more than +/- 10% from 43 to 319 degrees C. With very good electrical properties persisting up to 300 degrees C, i.e., a resistivity on the order of magnitude of 10(8) Omega m and the RC constant of about 1 s, the examined BNT-BT-xKNN compositions present a good starting point for the development of high-temperature capacitor materials.open343

    Speed and sensitivity of phototransduction in Drosophila depend on degree of saturation of membrane phospholipids.

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    Drosophila phototransduction is mediated via a G-protein-coupled PLC cascade. Recent evidence, including the demonstration that light evokes rapid contractions of the photoreceptors, suggested that the light-sensitive channels (TRP and TRPL) may be mechanically gated, together with protons released by PLC-mediated PIP2 hydrolysis. If mechanical gating is involved we predicted that the response to light should be influenced by altering the physical properties of the membrane. To achieve this, we used diet to manipulate the degree of saturation of membrane phospholipids. In flies reared on a yeast diet, lacking polyunsaturated fatty acids (PUFAs), mass spectrometry showed that the proportion of polyunsaturated phospholipids was sevenfold reduced (from 38 to ∼5%) but rescued by adding a single species of PUFA (linolenic or linoleic acid) to the diet. Photoreceptors from yeast-reared flies showed a 2- to 3-fold increase in latency and time to peak of the light response, without affecting quantum bump waveform. In the absence of Ca(2+) influx or in trp mutants expressing only TRPL channels, sensitivity to light was reduced up to ∼10-fold by the yeast diet, and essentially abolished in hypomorphic G-protein mutants (Gαq). PLC activity appeared little affected by the yeast diet; however, light-induced contractions measured by atomic force microscopy or the activation of ectopic mechanosensitive gramicidin channels were also slowed ∼2-fold. The results are consistent with mechanosensitive gating and provide a striking example of how dietary fatty acids can profoundly influence sensory performance in a classical G-protein-coupled signaling cascade.This research was supported by the Biotechnology and Biological Sciences Research Council (BBSRC; to M.J.O.W. and Q.Z., BBSRC Grant BB/G006865/1 to R.C.H., BB/H013849/1 to M.J., and BBSRC doctoral awards to A.S.R. and S.A.D.), the State Key Laboratory of Cognitive Neuroscience and Learning Open Research Fund (to M.J.), Jane and Aatos Erkko Foundation Fellowship (to M.J.), the Leverhulme Trust Grant (RPG-2012-567 to M.J.), and the UK Medical Research Council (Career Development Award to K.F.).This is the final published version of the article, originally published in the Journal of Neuroscience, February 11, 2015, 35(6): 2731–2746, DOI: 10.1523/JNEUROSCI.1150-14.201

    Fixing the broken image of care homes, could a 'care home innovation centre' be the answer?

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    The UK has many excellent care homes that provide high-quality care for their residents; however, across the care home sector, there is a significant need for improvement. Even though the majority of care homes receive a rating of ‘good’ from regulators, still significant numbers are identified as requiring ‘improvement’ or are ‘inadequate’. Such findings resonate with the public perceptions of long-term care as a negative choice, to be avoided wherever possible—as well as impacting on the career choices of health and social care students. Projections of current demographics highlight that, within 10 years, the part of our population that will be growing the fastest will be those people older than 80 years old with the suggestion that spending on long-term care provision needs to rise from 0.6% of our Gross Domestic Product in 2002 to 0.96% by 2031. Teaching/research-based care homes have been developed in the USA, Canada, Norway, the Netherlands and Australia in response to scandals about care, and the shortage of trained geriatric healthcare staff. There is increasing evidence that such facilities help to reduce inappropriate hospital admissions, increase staff competency and bring increased enthusiasm about working in care homes and improve the quality of care. Is this something that the UK should think of developing? This commentary details the core goals of a Care Home Innovation Centre for training and research as a radical vision to change the culture and image of care homes, and help address this huge public health issue we face

    ERK1/2-Akt1 Crosstalk Regulates Arteriogenesis in Mice and Zebrafish

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    Arterial morphogenesis is an important and poorly understood process. In particular, the signaling events controlling arterial formation have not been established. We evaluated whether alterations in the balance between ERK1/2 and PI3K signaling pathways could stimulate arterial formation in the setting of defective arterial morphogenesis in mice and zebrafish. Increased ERK1/2 activity in mouse ECs with reduced VEGF responsiveness was achieved in vitro and in vivo by downregulating PI3K activity, suppressing Akt1 but not Akt2 expression, or introducing a constitutively active ERK1/2 construct. Such restoration of ERK1/2 activation was sufficient to restore impaired arterial development and branching morphogenesis in synectin-deficient mice and synectin-knockdown zebrafish. The same approach effectively stimulated arterial growth in adult mice, restoring arteriogenesis in mice lacking synectin and in atherosclerotic mice lacking both LDL-R and ApoB48. We therefore conclude that PI3K-ERK1/2 crosstalk plays a key role in the regulation of arterial growth and that the augmentation of ERK signaling via suppression of the PI3K signaling pathway can effectively stimulate arteriogenesis
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