The Egyptian Cardiothoracic Surgeon (ECTS - E-Journal)
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Ethics of Decisionism: Carl Schmitt’s theological blind spot
No full textIn this essay Decisionism as political theory is analysed in terms of its legal background and its ethical and theological implications. The first part aims to demonstrate that Decisionism has been developed as a response to Hans Kelsen's theory of legal positivism. In the second part the ethical and theological grounds of legitimising a rightful deviation from the norm are explored by concentrating on the virtue of epikieia
Cortical resonance frequencies emerge from network size and connectivity
No full textNeural oscillations occur within a wide frequency range with different brain regions exhibiting resonance-like characteristics at specific points in the spectrum. At the microscopic scale, single neurons possess intrinsic oscillatory properties, such that is not yet known whether cortical resonance is consequential to neural oscillations or an emergent property of the networks that interconnect them. Using a network model of loosely-coupled Wilson-Cowan oscillators to simulate a patch of cortical sheet, we demonstrate that the size of the activated network is inversely related to its resonance frequency. Further analysis of the parameter space indicated that the number of excitatory and inhibitory connections, as well as the average transmission delay between units, determined the resonance frequency. The model predicted that if an activated network within the visual cortex increased in size, the resonance frequency of the network would decrease. We tested this prediction experimentally using the steady-state visual evoked potential where we stimulated the visual cortex with different size stimuli at a range of driving frequencies. We demonstrate that the frequency corresponding to peak steady-state response inversely correlated with the size of the network. We conclude that although individual neurons possess resonance properties, oscillatory activity at the macroscopic level is strongly influenced by network interactions, and that the steady-state response can be used to investigate functional networks
Computation of the Jk-integrals for bimaterial interface cracks using boundary element crack shape sensitivities
No full textThis paper presents a new algorithm for the efficient evaluation of Jk-integrals for cracks between bonded homogeneous and isotropic materials using the boundary element crack shape sensitivities (BECSS). The flexibility of this novel method allows for analysis of both curved and straight interface cracks. In contrast to the available algorithms, the present method does not require stress analysis at a series of internal points around the crack or employment of an auxiliary equation. For an interface crack, the J1-integral is the strain energy release rate (SERR) or the derivative of the total potential energy with respect to the crack length extension. Although the J2-integral shows an oscillatory type behaviour and is non-existent at the crack tip, it can also be evaluated by direct differentiation of the structural response. It is well-known that a bimaterial interface crack induces both opening and shearing behaviour even for a single mode loading. Here it is shown that the computed Jk can be used to decouple and estimate the stress intensity factors (SIFs). Here, three example problems are analysed and their Jk values are presented which are in excellent agreement with the corresponding analytical results. Each case includes the contribution to J2 by the jump of displacement derivatives across the interface and the strain energy density discontinuity on the crack surfaces and interface region
Role of estrogen response element in the human prolactin gene: transcriptional response and timing
No full textThe use of bacterial artificial chromosome (BAC) reporter constructs in molecular physiology enables the inclusion of large sections of flanking DNA, likely to contain regulatory elements and enhancers regions that contribute to the transcriptional output of a gene. Using BAC recombineering we have manipulated a 160kb human prolactin luciferase (hPRL-Luc) BAC construct and mutated the previously defined proximal estrogen response element (ERE) located -1189bp relative to the transcription start site, to assess its involvement in the estrogen responsiveness of the entire hPRL locus. We found that GH3 cell lines stably expressing luciferase under control of the ERE-mutated hPRL promoter (ERE-Mut) displayed a dramatically reduced transcriptional response to E2 treatment compared to cells expressing luciferase from the wild type (WT) ERE hPRL-Luc promoter (ERE- WT). The -1189 ERE controls not only the response to E2 treatment, but also the acute transcriptional response to TNFalpha, which was abolished in ERE-Mut cells. ERE-WT cells displayed a biphasic transcriptional response following TNFalpha treatment, the acute phase of which was blocked following treatment with the estrogen receptor antagonist 4-hydroxytamoxifen (4-OHT). Unexpectedly we show the oscillatory characteristics of hPRL promoter activity in individual living cells were unaffected by disruption of this crucial response element, as real-time bioluminescence imaging showed transcription cycles were maintained, with similar cycle lengths, in ERE-WT and ERE-Mut cells. These data suggest the -1189 ERE is the dominant response element involved in the hPRL transcriptional response to both E2 and TNFalpha and crucially, that cycles of hPRL promoter activity are independent of ER binding
Psychological factors predict adherence to methotrexate in rheumatoid arthritis; findings from a systematic review of rates, predictors and associations with patient-reported and clinical outcomes
No full textTreatment response to methotrexate (MTX) for rheumatoid arthritis (RA) is not universal and non-adherence may partially explain this. The aims of this systematic review were to: (1) summarise existing rates of adherence to MTX, (2) identify predictors of adherence to MTX, and (3) assess the association between non-adherence and patient outcomes. The authors conducted a systematic search of papers published from January 1980 to February 2015 in PubMed, PsycINFO, EMBASE and CINAHL databases. Studies were eligible for inclusion if: (1) MTX was used as monotherapy or in combination with other therapies, (2) MTX was used in an RA or inflammatory polyarthritis population, (3) adherence was defined and measured as the extent to which patients followed their MTX regimen during the period of prescription, and (4) it was an original piece of research. In total, 10 studies met the inclusion criteria and 8 were evaluated as high quality. Rates of adherence ranged from 59% to 107%, and exposed differences in definitions of adherence, study methodologies and sample heterogeneity. A number of potential predictors of MTX adherence were identified; the strongest being related to beliefs in the necessity and efficacy of MTX, absence of low mood, mild disease and MTX monotherapy. Furthermore, 3 studies tested the association of adherence with disease activity as an outcome measure; all 3 found non-adherence associated with poor treatment response. This systematic review shows the importance of adherence to MTX treatment and summarises the associated modifiable factors
The Asymptotic Behavior of Frobenius Direct Images of Rings of Invariants
No full textWe define the Frobenius limit of a module over a ring of prime characteristic to be the limit of the normalized Frobenius direct images in a certain Grothendieck group. When a finite group acts on a polynomial ring, we calculate this limit for all the modules over the twisted group algebra that are free over the polynomial ring; we also calculate the Frobenius limit for the restriction of these to the ring of invariants. As an application, we generalize the description of the generalized F-signature of a ring of invariants by the second author and Nakajima to the modular case