2,827 research outputs found
The Philosophy of Mathematics, Values and Keralese Mathematics
This paper explores the philosophical significance of the Keralese and Indian subcontinent contribution to history of mathematics. Identifying the most accurate genesis and trajectory of mathematical ideas in history that current knowledge allows should be the goal of every history of mathematics, and is consistent with any philosophy of mathematics. I argue for the need of a broader conceptualization of philosophy of than the traditional emphasis on scholastic enquiries into epistemology and ontology. For such an emphasis has been associated, though I add need not necessarily be so, with an ideological position that devalues non-European contributions to history of mathematics. The philosophy of mathematics needs to be broad enough to recognise the salient features of the discipline it reflects upon, namely mathematics
Relation between Charge-Dipole Interactions and the Sqrt(E)-Dependent Mobility in Molecularly Doped Polymers
Time-of-flight measurements on a wide variety of molecularly-doped polymers reveal carrier mobilities that exhibit an exponential dependence on the square root of the applied electric field. Recent attempts to explain the observed field dependence have focused on the role played by spatial and energetic disorder. It as also been conjectured that the charge-dipole interactions often identified as the source of energetic disorder could be of sufficient range to lead to correlations in the energies of neighboring hopping sites. We have analytically explored the effect of such correlations on high field carrier transport in random potentials, and discuss how particular features of the correlations associated with charge-dipole interactions might lead to behavior similar to that seen in experiment
Transcatheter closure of patent ductus arterious at Chris Hani Baragwanath hospital and the importance of the shape and size of the patent ductus
A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg in partial fulfilment of the requirements for the degree in Master of Medicine in Paediatrics
Johannesburg 2016Objectives
Review outcomes of transcatheter closure of patent ductus arteriosus (PDA), role of PDA shape and changes in practice over time.
Methods
Retrospective analysis of patient files and clinic database performed on children who had transcatheter PDA closure at Chris Hani Baragwanath Hospital between 01/01/1993 and 30/06/2008.
Results
Over 15 years, 1254 PDAs were diagnosed, of which 293 required closure (167 with surgery and 139 transcatheter). Median age at transcatheter closure was 1.8 years (IQR=1-4.5years); 66.2% were female (92/139). Mean PDA diameter was 3.2mm (sd=1.6mm), with an average 2:1 shunt. Transcatheter closure was performed using COOK® Flipper coils (n= 93; 18 required multiple coils) or Amplatzer™ devices (n=46: 37 with ADO1, 8 AVP and 1 ADO2). Repeat procedures were needed in 20 children: Early occlusion rates for coils were 52% (39/75); late occlusion occurred in 90.6% (68/75). Amplatzer™ devices, available since 2003, are now overwhelmingly used. For ADOs, early occlusion rates were 94.3% (33/35) with 100% late occlusion. Successful closures were associated with PDA shape, with 88% closed with type A and E, 50% type B, 28% type C and 0% type D. Surgical closure reduced over time: from 94 weeks (1993–1997), to 40 weeks (1998–2002) and 32 weeks(2003–2008).
Conclusion
Transcatheter PDA occlusion is safe and effective in this setting, with outcomes similar to reports elsewhere. Shape and size of PDAs are important determinants of device selection and procedure outcome. Transcatheter occlusion helps minimise surgical waiting lists. Overall findings support more widespread use of this procedure in similar settings.MT201
The fascist element in A.M. Ludovici's defence of conservatism
By the study of the writings of Anthony Mario Ludovici, his affiliates, and other fascists, it is demonstrated that it is the traditions of ideologies that are incommensurable, not ideologies pet se. That it is not logically impossible for fascism to be introduced into a party system, which it intends to succeed, through rendering the ideology of an established political party commensurable with fascism. That fascists have attempted to render established ideologies commensurable with fascism, and have succeeded. The study of the doctrine of Anthony Mario Ludovici demonstrates the latter in relation to conservatism. That the fascists who rendered established ideologies commensurable with fascism, like Anthony Mario Ludovici and his affiliates, contingently failed to get their innovations accepted by the adherents of established ideologies. They failed because ideologies are traditions, and the respective traditions of established ideologies are incommensurable visions of how men should be associated and authority and power distributed. Incommensurable ideologies are both cause and consequence of the political divisions of party systems whose political parties deploy them as the language of their adherence. The practical success of an innovation in any ideology is always and everywhere decided by its contingent acceptance or rejection by the custodians of the traditions of an ideology, political parties and their constitutents. Political ideologies tend to inertia because they are traditions that are incommensurable. It is this inertia that the fascists who rendered established ideologies commensurable with fascism, could not overcome. Ludovici and his affiliates never succeeded in getting themselves regarded as conservatives because the traditions of conservatism, and the consensus among conservatives about its meanings as its traditions, created sufficient inertia that the innovations which the former sought could not be effected in the contemporary party system. If they had succeeded conservatism would have become commensurable with fascism
Long-Range Hopping in Substitutionally Disordered Solids
A theoretical approach for studying charge-carrier and energy diffusion due to long-range hopping in substitutionally disordered solids is presented. Unlike some earlier theories, which invoke a pair approximation to treat back-transfer processes, the current theory makes use of the exact solution to an appropriate single-defect problemone in which long-range jumps into, out of, and between both the defect site and all other active sites in the lattice are explicitly included. From this exact solution a new long-range effective-medium theory is constructed to describe the configurationally averaged transport properties of the disordered system
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