Are We Sims? How Computer Simulations Represent and What this Means for the Simulation Argument

N. Bostrom’s simulation argument and two additional assumptions imply that we are likely to live in a computer simulation. The argument is based upon the following assumption about the workings of realistic brain simulations: The hardware of a computer on which a brain simulation is run bears a close analogy to the brain itself. To inquire whether this is so, I analyze how computer simulations trace processes in their targets. I describe simulations as fictional, mathematical, pictorial, and material models. Even though the computer hardware does provide a material model of the target, this does not suffice to underwrite the simulation argument because the ways in which parts of the computer hardware interact during simulations do not resemble the ways in which neurons interact in the brain. Further, there are computer simulations of all kinds of systems, and it would be unreasonable to infer that some computers display consciousness just because they simulate brains rather than, say, galaxies.

Computer assisted planning and navigation of periacetabular osteotomy with range of motion optimization

Femoroacetabular impingement (FAI) before or after Periacetabular Osteotomy (PAO) is surprisingly frequent and surgeons need to be aware of the risk preoperatively and be able to avoid it intraoperatively. In this paper we present a novel computer assisted planning and navigation system for PAO with impingement analysis and range of motion (ROM) optimization. Our system starts with a fully automatic detection of the acetabular rim, which allows for quantifying the acetabular morphology with parameters such as acetabular version, inclination and femoral head coverage ratio for a computer assisted diagnosis and planning. The planned situation was optimized with impingement simulation by balancing acetabuar coverage with ROM. Intra-operatively navigation was conducted until the optimized planning situation was achieved. Our experimental results demonstrated: 1) The fully automated acetabular rim detection was validated with accuracy 1.1 ± 0.7mm; 2) The optimized PAO planning improved ROM significantly compared to that without ROM optimization; 3) By comparing the pre-operatively planned situation and the intra-operatively achieved situation, sub-degree accuracy was achieved for all directions.

Virtue, Law and Mercy

The attribution of responsibility in world society is increasingly a field of contestation. On the one hand, the perception of causal and moral links reaching far in space and time are ever more explicitly pronounced; on the other hand, the very complexity of these links often engenders a fragmentation of responsibility both in law (Veitch 2007) as well as in moral commitment. Moreover, those institutions of legal responsibility attempting to reflect some of these interrelations are often criticised as insufficient by those who follow alternative narratives of causation and moral community. Current institutions of responsibility in law appear to abstract from what could be called enabling contexts; they perform their cuts in the chains of enabling interactions at very brief intervals (Strathern 2001). The result is often “organised irresponsibility” (Veitch 2007; Beck 1996), producing appeals to a global community of concern in time and space without corresponding obligatory commitments. This talk explores alternative conceptualisations of responsibility, and enquires into their notion of the person, their temporal and socio-spatial dimensions, and their notion of liability.

Law and science: risk assessment and risk management in the WTO agreement on the application of sanitary and phytosanitary measures

Assessing and managing risks relating to the consumption of food stuffs for humans and to the environment has been one of the most complex legal issues in WTO law, ever since the Agreement on Sanitary and Phytosanitary Measures was adopted at the end of the Uruguay Round and entered into force in 1995. The problem was expounded in a number of cases. Panels and the Appellate Body adopted different philosophies in interpreting the agreement and the basic concept of risk assessment as defined in Annex A para. 4 of the Agreement. Risk assessment entails fundamental question on law and science. Different interpretations reflect different underlying perceptions of science and its relationship to the law. The present thesis supported by the Swiss National Research Foundation undertakes an in-depth analysis of these underlying perceptions. The author expounds the essence and differences of positivism and relativism in philosophy and natural sciences. He clarifies the relationship of fundamental concepts such as risk, hazards and probability. This investigation is a remarkable effort on the part of lawyer keen to learn more about the fundamentals based upon which the law – often unconsciously – is operated by the legal profession and the trade community. Based upon these insights, he turns to a critical assessment of jurisprudence both of panels and the Appellate Body. Extensively referring and discussing the literature, he deconstructs findings and decisions in light of implied and assumed underlying philosophies and perceptions as to the relationship of law and science, in particular in the field of food standards. Finding that both positivism and relativism does not provide adequate answers, the author turns critical rationalism and applies the methodologies of falsification developed by Karl R. Popper. Critical rationalism allows combining discourse in science and law and helps preparing the ground for a new approach to risk assessment and risk management. Linking the problem to the doctrine of multilevel governance the author develops a theory allocating risk assessment to international for a while leaving the matter of risk management to national and democratically accountable government. While the author throughout the thesis questions the possibility of separating risk assessment and risk management, the thesis offers new avenues which may assist in structuring a complex and difficult problem

Computer Assisted Diagnosis and Treatment Planning of Femoroacetabular Impingement (FAI)

Femoroacetabular impingement (FAI) is a dynamic conflict of the hip defined by a pathological, early abutment of the proximal femur onto the acetabulum or pelvis. In the past two decades, FAI has received increasing focus in both research and clinical practice as a cause of hip pain and prearthrotic deformity. Anatomical abnormalities such as an aspherical femoral head (cam-type FAI), a focal or general overgrowth of the acetabulum (pincer-type FAI), a high riding greater or lesser trochanter (extra-articular FAI), or abnormal torsion of the femur have been identified as underlying pathomorphologies. Open and arthroscopic treatment options are available to correct the deformity and to allow impingement-free range of motion. In routine practice, diagnosis and treatment planning of FAI is based on clinical examination and conventional imaging modalities such as standard radiography, magnetic resonance arthrography (MRA), and computed tomography (CT). Modern software tools allow three-dimensional analysis of the hip joint by extracting pelvic landmarks from two-dimensional antero-posterior pelvic radiographs. An object-oriented cross-platform program (Hip2Norm) has been developed and validated to standardize pelvic rotation and tilt on conventional AP pelvis radiographs. It has been shown that Hip2Norm is an accurate, consistent, reliable and reproducible tool for the correction of selected hip parameters on conventional radiographs. In contrast to conventional imaging modalities, which provide only static visualization, novel computer assisted tools have been developed to allow the dynamic analysis of FAI pathomechanics. In this context, a validated, CT-based software package (HipMotion) has been introduced. HipMotion is based on polygonal three-dimensional models of the patient’s pelvis and femur. The software includes simulation methods for range of motion, collision detection and accurate mapping of impingement areas. A preoperative treatment plan can be created by performing a virtual resection of any mapped impingement zones both on the femoral head-neck junction, as well as the acetabular rim using the same three-dimensional models. The following book chapter provides a summarized description of current computer-assisted tools for the diagnosis and treatment planning of FAI highlighting the possibility for both static and dynamic evaluation, reliability and reproducibility, and its applicability to routine clinical use.