The Basic Surgical Skills course in sub-Saharan Africa: an observational study of effectiveness

Background: The Basic Surgical Skills (BSS) course is a common component of postgraduate surgical training programmes in sub-Saharan Africa, but was originally designed in a UK context, and its efficacy and relevance have not been formally assessed in Africa. Methods: An observational study was carried out during a BSS course delivered to early-stage surgical trainees from Rwanda and the Democratic Republic of the Congo. Technical skill in a basic wound closure task was assessed in a formal Objective Structured Assessment of Technical Skills (OSAT) before and after course completion. Participants completed a pre-course questionnaire documenting existing surgical experience and self-perceived confidence levels in surgical skills which were to be taught during the course. Participants repeated confidence ratings and completed course evaluation following course delivery. Results: A cohort of 17 participants had completed a pre-course median of 150 Caesarean sections as primary operator. Performance on the OSAT improved from a mean of 10.5/17 pre-course to 14.2/17 post-course (mean of paired differences 3.7, p < 0.001). Improvements were seen in 15/17 components of wound closure. Pre-course, only 47% of candidates were forming hand-tied knots correctly and 38% were appropriately crossing hands with each throw, improving to 88 and 76%, respectively, following the course (p = 0.01 for both components). Confidence levels improved significantly in all technical skills taught, and the course was assessed as highly relevant by trainees. Conclusion: The Basic Surgical Skills course is effective in improving the basic surgical technique of surgical trainees from sub-Saharan Africa and their confidence in key technical skills

Global integration of the Schr\"odinger equation within the wave operator formalism: The role of the effective Hamiltonian in multidimensional active spaces

A global solution of the Schr\"odinger equation, obtained recently within the wave operator formalism for explicitly time-dependent Hamiltonians [J. Phys. A: Math. Theor. 48, 225205 (2015)], is generalized to take into account the case of multidimensional active spaces. An iterative algorithm is derived to obtain the Fourier series of the evolution operator issuing from a given multidimensional active subspace and then the effective Hamiltonian corresponding to the model space is computed and analysed as a measure of the cyclic character of the dynamics. Studies of the laser controlled dynamics of diatomic models clearly show that a multidimensional active space is required if the wavefunction escapes too far from the initial subspace. A suitable choice of the multidimensional active space, including the initial and target states, increases the cyclic character and avoids divergences occuring when one-dimensional active spaces are used. The method is also proven to be efficient in describing dissipative processes such as photodissociation.Comment: 33 pages, 11 figure

Constrained Adiabatic Trajectory Method (CATM): a global integrator for explicitly time-dependent Hamiltonians

The Constrained Adiabatic Trajectory Method (CATM) is reexamined as an integrator for the Schr\"odinger equation. An initial discussion places the CATM in the context of the different integrators used in the literature for time-independent or explicitly time-dependent Hamiltonians. The emphasis is put on adiabatic processes and within this adiabatic framework the interdependence between the CATM, the wave operator, the Floquet and the (t,t') theories is presented in detail. Two points are then more particularly analysed and illustrated by a numerical calculation describing the $H_2^+$ ion submitted to a laser pulse. The first point is the ability of the CATM to dilate the Hamiltonian spectrum and thus to make the perturbative treatment of the equations defining the wave function possible, possibly by using a Krylov subspace approach as a complement. The second point is the ability of the CATM to handle extremely complex time-dependencies, such as those which appear when interaction representations are used to integrate the system.Comment: 15 pages, 14 figure

Controlling vibrational cooling with Zero-Width Resonances: An adiabatic Floquet approach

In molecular photodissociation, some specific combinations of laser parameters (wavelength and intensity) lead to unexpected Zero-Width Resonances (ZWR), with in principle infinite lifetimes. Their interest in inducing basic quenching mechanisms have recently been devised in the laser control of vibrational cooling through filtration strategies [O. Atabek et al., Phys. Rev. A87, 031403(R) (2013)]. A full quantum adiabatic control theory based on the adiabatic Floquet Hamiltonian is developed to show how a laser pulse could be envelop-shaped and frequency-chirped so as to protect a given initial vibrational state against dissociation, taking advantage from its continuous transport on the corresponding ZWR, all along the pulse duration. As compared with previous control scenarios actually suffering from non-adiabatic contamination, drastically different and much more efficient filtration goals are achieved. A semiclassical analysis helps in finding and interpreting a complete map of ZWRs in the laser parameter plane. In addition, the choice of a given ZWR path, among the complete series identified by the semiclassical approach, amounts to be crucial for the cooling scheme, targeting a single vibrational state population left at the end of the pulse, while all others have almost completely decayed. The illustrative example, offering the potentiality to be transposed to other diatomics, is Na2 prepared by photoassociation in vibrationally hot but translationally and rotationally cold states.Comment: 15 pages, 14 figure

Water (management) as a decisive factor in the land use planning of agriculture in an urbanising context

The Centre for Mobility and Physical Planning of the Ghent University coordinates a two-year research project about the preconditions for sustainable land use by agriculture in (the Flemish) urbanising network society. The project questions the traditional legitimacy of agriculture in planning to claim the majority of the surface, merely because of economical reasons. If agriculture wants to have a raison d’être in urbanised and urbanising society, it will have to meet the quality demands of network society which are more than economical demands. The degree in which agriculture is capable in fulfilling these needs, will be decisive for the spatial development perspectives for agriculture. Questioning the traditional legitimacy of agriculture in planning is also questioning the actual planning discourse that has been dominating policy for the last three decades, not only in Belgium but in the most of North-Western Europe. This dominant discourse considers city and countryside as antipoles and is still translated in current planning initiatives that strengthen compact cities and restrict new developments in the countryside. This discourse is no longer tenable within the concept of network society, especially in the densely populated and fragmentarily urbanised Flemish region in Belgium where numerous urban activities and functions are silently and autonomously taking over the countryside. The research tries to evaluate the spatial development perspectives for agriculture of three alternative planning discourses about the spatial relation between city and countryside through design-oriented research. These alternative discourses try to meet the characteristics of network society in a different way than the dominant discourse: the first one considers city and countryside as networks of activities, the second one sees them as systems of places with an identity and the last one defines the ecosystem as the common layer of city and countryside. As the design-oriented research is evolving in a study area around Kortrijk and Roeselare in the Western part of Flanders, it becomes clear that each of these three alternative discourses is confronted with water (management) as a decisive factor in the planning of the land use of agriculture in relation to urban activities in the countryside. This is of course obvious for the ecosystem discourse as water is one of the driving forces in the ecosystem. But also in the network of activities discourse the exhaustion of the ground water supply seems to be one of the main frustrations, to be solved through planning, between the international network of activities of the farming industry and the local/regional network of villages and agriculture. Finally, water seems to be an important factor in defining and planning the identity of places in the system of places discourse. The paper will primarily focus on the theoretical background of dominant and alternative planning discourses about city and countryside. Consequently it will summarise the results of the water related design-oriented planning research on and the spatial development perspectives for agriculture of the three alternative planning discourses in the study area.

Efficiency of Insurance Firms with Endogenous Risk Management and Financial Intermediation Activities

Risk management is now present in many economic sectors. This paper investigates the role of risk management in creating value for financial institutions by analyzing U.S. property-liability insurers. Property-liability insurers are financial intermediaries whose primary roles in the economy are risk pooling and risk bearing. The risk pooling and risk bearing functions performed by insurers are the primary determinants of the need for risk management. The main goal of this paper is to test how risk management and financial intermediation activities create value for insurers by enhancing economic efficiency. Insurer cost efficiency is measured relative to an econometric cost function. Since the prices of risk management and financial intermediation services are not observable, we consider these two activities as intermediate outputs and estimate their shadow prices. The shadow prices isolate the contributions of risk management and financial intermediation to insurer cost efficiency. The econometric results show that both activities significantly increase the efficiency of the property-liability insurance industry.Risk management, US property-liability insurer, risk pooling, financial intermediation, economic efficiency, intermediate output, shadow price, cost function, translog approximation