Planning complex engineer-to-order products

The design and manufacture of complex Engineer-to-Order products is characterised by uncertain operation durations, finite capacity resources and multilevel product structures. Two scheduling methods are presented to minimise expected costs for multiple products across multiple finite capacity resources. The first sub-optimises the operations sequence, using mean operation durations, then refines the schedule by perturbation. The second method generates a schedule of start times directly by random search with an embedded simulation of candidate schedules for evaluation. The methods are compared for industrial examples

The anatomy of the fibrous and osseous components of the first extensor compartment of the wrist: a cadaveric study

De Quervain disease is the stenosing tenosynovitis of the first extensor compartment of the wrist. It is diagnosed with a history of pain at the radial aspect of the wrist and a positive Finkelstein test. Although anatomic variations, such as a septum within the compartment, are considered as risk factors, bony anatomy of distal radius and its correlation with the septa are studied scarcely in the literature

The localization and morphology of pterion in adult west anatolian skulls

The pterion is an important skull landmark because it is located where the frontal, the great wing of sphenoid, parietal, and squamous parts of the temporal bone junction. The objectives of this study were to determine the localization and the shape of pterion on skulls and to find out the distances between the pterion and some certain anatomic landmarks on neighboring structures. The study was performed on the skulls of 128 (256 sides) adult West Anatolian people. All of the morphometric measurements of the distances between the pterion and the anatomic landmarks were performed using a Vernier caliper with an accuracy of 0.1 mm. The pterion was classified into 4 types: the sphenoparietal, frontotemporal, stellate, or epipteric types. The incidences of types of pterion in the skulls were also found as the sphenoparietal type (85.2%), the epipteric type (8.2%), the stellate type (5.5%), and the frontotemporal type (1.1%). The mean (SD) distances from the center of the pterion to the zygomatic arch were measured as 40.02 (4.06) mm and 39.88 (4.01) mm; to the frontozygomatic suture, 31.80 (4.51) mm and 31.44 (4.73) mm; to the zygomatic angle, 41.54 (4.95) mm and 41.35 (5.14) mm; to the mastoid process, 82.48 (5.45) mm and 81.81 (5.50) mm; and to the external acoustic meatus, 53.29 (4.55) mm and 56.22 (4.60) mm, on the right and left sides, respectively. The mean (SD) distances between the foremost point of pterion and the anterior edge of the lateral wall of the orbit were 31.02 (5.78) mm and 32.31 (5.79) mm on the right and left sides, respectively. The localization and the shape of pterion are of importance because it is an anatomic landmark and should be of use in surgical approaches and interventions via the pterion. © 2014 Mutaz B. Habal, MD

Sciatic nerve localization relative to the position of the hip, an anatomical study.

The incidence of iatrogenic peripheral nerve injury during hip arthroplasty procedures has been reported to be between 0.6 and 1.3 percent. The relative risk of nerve palsy is higher in certain groups of patients such as women, patients with developmental dysplasia of the hip, and those who have undergone revision arthroplasty. In this study, the dynamic relationship between the acetabulum and the sciatic nerve, which is important for preventing sciatic nerve palsy during the hip surgery, was investigated. The sciatic nerve was exposed in 69 cadaveric hips. The relationship between the bony acetabulum and the sciatic nerve was examined in three different positions; as the ipsilateral hip was flexed; extended; or in neutral position. We found that the middle part of the posterior acetabular rim was closer to the sciatic nerve than its superior or inferior parts. The sciatic nerve was perilous when the ipsilateral hip was flexed and the middle part of the posterior acetabular rim was more risky than the superior or inferior parts, in terms of iatrogenic sciatic nerve injury