Ambiguity and uncertainty in Ellsberg and Shackle

This paper argues that Ellsberg’s and Shackle’s frameworks for discussing the limits of the (subjective) probabilistic approach to decision theory are not as different as they may appear. To stress the common elements in their theories Keynes’s Treatise on Probability provides an essential starting point. Keynes’s rejection of well-defined probability functions, and of maximisation as a guide to human conduct, is shown to imply a reconsideration of what probability theory can encompass, that is in the same vein of Ellsberg’s and Shackle’s concern in the years of the consolidation of Savage’s new probabilistic mainstream. The parallel between Keynes and the two decision theorists is drawn by means of a particular assessment of Shackle’s theory of decision, namely, it is interpreted in the light of Ellsberg’s doctoral dissertation. In this thesis, published only as late as 2001, Ellsberg developed the details and devised the philosophical background of his criticism of Savage as first put forward in the famed 1961 QJE article. The paper discusses the grounds on which the ambiguity surrounding the decision maker in Ellsberg’s urn experiment can be deemed analogous to the uncertainty faced by Shackle’s entrepreneur taking “unique decisions.” The paper argues also that the insights at the basis of the work of both Shackle and Ellsberg, as well as the criteria for decision under uncertainty they put forward, are relevant to understand the development of modern decision theory.uncertainty, weight of argument, non-additive probability

Shackle versus Savage: non-probabilistic alternatives to subjective probability theory in the 1950s

G.L.S Shackle’s rejection of the probability tradition stemming from Knight's definition of uncertainty was a crucial episode in the development of modern decision theory. A set of methodological statements characterizing Shackle’s stance, abandoned for long, especially after Savage’s Foundations, have been re-discovered and are at the basis of current non-expected utility theories, in particular of the non-additive probability approach to decision making. This paper examines the discussion between Shackle and his critics in the 1950s. Drawing on Shackle’s papers housed at Cambridge University Library as well as on printed matter, we show that some critics correctly understood two aspects of Shackle’s theory which are of the utmost importance in our view: the non-additive character of the theory and the possibility of interpreting Shackle’s ascendancy functions as a specific distortion of the weighting function of the decision maker. It is argued that Shackle neither completely understood criticisms nor appropriately developed suggestions put forward by scholars like Kenneth Arrow, Ward Edwards, Nicholas Georgescu- Roegen. Had he succeeded in doing so, we contend, his theory might have been a more satisfactory alternative to Savage’s theory than it actually was.uncertainty, decision theory, non-additive measures

Production of a New Drug: A Sequential Investment ProcessUnder Uncertainty

On the basis of a database of more than 80 thousand records on total retails and production costs of the pharmaceutical industry worldwide we consider four classes of drugs. We evaluate the expected profits of an investment in a new drug in the four classes of pharmaceutical products by considering the standard NPV evaluation. We compare these outcomes with the evaluation of the expected profits of the four new drugs obtained by the real option approach. Interestingly enough quite different outcomes are obtained. These results loom on the capacity of standard methods to give a reliable evaluation of real investment projects that are analogous to compound optionscompound option, real option valuation, net present value, drugs

The effect of foot position on Power Doppler Ultrasound grading of Achilles enthesitis

The aim of this study was to determine whether foot position could modify power Doppler grading in evaluation of the Achilles enthesis. Eighteen patients with clinical Achilles enthesitis were studied with power Doppler ultrasound (PDUS) in five different positions of the foot: active and passive dorsiflexion, neutral position, active and passive plantar flexion. The Doppler signal was graded in any position and compared with the others. The Doppler signal was higher with the foot in plantar flexion and decreased gradually, sometimes till to disappear, while increasing dorsiflexion. The Doppler signal was always less during the active keeping of the position of the joint, than during the passive. The PDUS examination of the Achilles enthesis should be performed also with the foot in passive plantar flexion, in order not to underestimate the degree of vascularization

CT-guided radiofrequency ablation of spinal osteoblastoma: treatment and long-term follow-up.

Osteoblastoma (OB) is a painful, rare, benign bone tumour usually observed in young populations, and this condition involves the spine in up to one-third of cases. We sought to focus on the minimally invasive treatment of spinal OB with radiofrequency ablation (RFA) under computed tomography (CT) guidance. When performed near the spinal cord, surgery can lead to instability of the spine, sometimes requiring additional interventions to stabilise the segments involved, and can cause the precocious onset of arthrosis or other degenerative diseases. The results were evaluated both clinically and with the aid of diagnostic imaging techniques during a 5-year follow-up study.Eleven patients affected by spinal OB were treated in a single session with biopsy and CT-guided RFA. Pre- and post-evaluations of the patients were performed both clinically and with CT and magnetic resonance imaging (MRI).Complete success in terms of pain relief was achieved in all patients. Additional treatments were not required in any patients. There were no complications. During follow-up, neither complications nor pathological findings related to the treatment were observed.Our experience demonstrates that RFA for spinal OB is safe and effective. One of the main advantages of this technique is represented by its lower grade of invasiveness compared with that for potentially hazardous surgical manoeuvres

Musculocutaneous nerve variations. Meta-analysis of proportions and proposal for categorization

The musculocutaneous nerve (MCN) is one of the main terminal branches of the brachial plexus. It provides motor innervation to coracobrachialis, biceps brachii and brachialis muscles and sensory innervation to the skin of lateral side of the forearm. In the normal anatomical description, the MCN arises from lateral cord and don’t have communication with other terminal branches of brachial plexus. All motor branches arises from MCN, directly.[1] Despite these considerations, several variations of MCN have been reported. The most common are anomalous communications between MCN and median nerve. These communications could be relevant in clinical practice and could have several practical considerations that should be evaluated in different medical area, such as orthopedic surgery, traumatology or neurophysiology. Several classifications have been proposed but none of these is able to cover all aspects of this variation. Therefore, the aim of the present study are a systematic review of the available literature about MCN variations and a meta-analytic approach to define their prevalence.[2] At the same time, a new model of categorization with practical effects on clinical reasoning has been proposed. Several electronic databases have been searched. Articles have been screened and papers with anatomical description of MCN variations have been included. 43 out of 661 articles fulfilled inclusion criteria, with a description of 4695 brachial plexuses dissections. The random pooled prevalence of MCN variations is 18% (95%CI: 15-21%). The new categorization proposal is based on a 3 areas model: Area 1 (1A: absence of musculocutaneous nerve, 1B: variations before the division of the musculocutaneous nerve from lateral cord); Area 2: variations between origin of MCN from lateral cord and point of in coracobrachialis muscle (or same level if MCN does not pierce the muscle); Area 3: variations distal to point of entry in coracobrachialis muscle; Mixed areas: variations reported in more than a single area described above. Applying this model, the random pooled prevalence of reported variations is: Area 1A: 19% (95%CI: 11-28%), Area 1B: 26% (95%CI: 14-39%), Area 2: 46% (95%CI: 33- 59%), Area 3: 55% (95%CI: 40-70%), Mixed areas: 16 (95%CI: 8-25%). Therefore, MCN variations have a high prevalence. Among them, the most frequent are localized distal to coracobrachialis muscle. These results could be useful in clinical practice to point the attention at this anatomical region where variations in MCN are very common

Minimally invasive anatomic reconstruction of the anterolateral ligament with ipsilateral gracilis tendon: a kinematic in-vitro study

Purpose The anterolateral ligament (ALL) has been defined as a key stabilizer of internal tibial rotation at 35 degrees or more of knee flexion, with a minimal primary or secondary stabilizing role in the AP direction. This study aimed to demonstrate that anatomical reconstruction of the ALL confers rotational stability equal to that of the uninjured knee. Hypothesis: anteroposterior (AP) and rotatory laxity will significantly vary after ALL tenotomy and ALL reconstruction with the author's previously described technique. Methods After ultrasound (US) ALL identification, different kinematic measurements were performed with an image-less Computer-Assisted Navigation System with dedicated software for Laxity Analysis in 5 knee specimens. Anteroposterior (AP) translations and varus/valgus (VV) and Internal-External (IE) rotations were evaluated by two trained orthopedic surgeons before ALL section, after ALL section, and after ALL anatomical reconstruction with doubled ipsilateral autologous gracilis tendon. Results ALL resection significantly increased laxity in IE rotations with knee 90 degrees flexed (IE90) and AP translation with tibia internally rotated and the knee 30 degrees flexed (APlat) (p < 0.05). ALL reconstruction significantly reduced laxity in IE90 and APlat (p < 0.05) and reduced VV rotations at 30 degrees of flexion (VV30) (p < 0.05). There were no statistically significant elongation differences between native ALL and reconstructed ALL (graft) during laxity tests. The inter-operator repeatability of the tests was excellent for each measurement. Conclusions ALL acted as an important internal tibial rotation restrain at 90 degrees and a significant (secondary) AP stabilizer at 30 degrees of knee flexion. The presented ALL reconstruction technique significantly restored the increase of knee laxity produced by the ALL section. Scientific level Case-Controlled Laboratory Study, Level III

Increasing differential diagnosis between lipoma and liposarcoma through radiomics: a narrative review

Soft tissue sarcomas (STSs) are rare, heterogeneous, and very often asymptomatic diseases. Their diagnosis is fundamental, as is the identification of the degree of malignancy, which may be high, medium, or low. The Italian Medical Oncology Association and European Society of Medical Oncology (ESMO) guidelines recommend magnetic resonance imaging (MRI) because the clinical examination is typically ineffective. The diagnosis of these rare diseases with artificial intelligence (AI) techniques presents reduced datasets and therefore less robust methods. However, the combination of AI techniques with radiomics may be a new angle in diagnosing rare diseases such as STSs. Results obtained are promising within the literature, not only for the performance but also for the explicability of the data. In fact, one can make tumor classification, site localization, and prediction of the risk of developing metastasis. Thanks to the synergy between computer scientists and radiologists, linking numerical features to radiological evidence with excellent performance could be a new step forward for the diagnosis of rare diseases

I.S.Mu.L.T. Achilles Tendon Ruptures Guidelines

This work provides easily accessible guidelines for the diagnosis, treatment and rehabilitation of Achilles tendon ruptures. These guidelines could be considered as recommendations for good clinical practice developed through a process of systematic review of the literature and expert opinion, to improve the quality of care for the individual patient and rationalize the use of resources. This work is divided into two sessions: 1) questions about hot topics; 2) answers to the questions following Evidence Based Medicine principles. Despite the frequency of the pathology andthe high level of satisfaction achieved in treatment of Achilles tendon ruptures, a global consensus is lacking. In fact, there is not a uniform treatment and rehabilitation protocol used for Achilles tendon ruptures