Common Systemic Factors Research Articles

Lifecycle of Accident Pathogens: Common Systemic Factors in Construction System Accidents

AbstractConstruction system accidents are accidents due to defects embedded in the constructed systems (e.g., buildings, bridges, and other infrastructures) originating from failures in construction systems, which we can consider as organic and ephemeral temporary multi‐organizations (TMOs). Understanding the mechanisms of such accidents in transient and multi‐organizational systems requires a system‐wide perspective and consideration of the temporary aspect. This paper examines six accident cases using the framed‐and‐layered accident pathogen propagation (FLAPP) model—‐an accident model we specifically developed to capture system‐wide factors and the time dimension—‐and identifies five types of pathogen threads and eight types of thread elements that contribute to the propagation of latent failures and defects, i.e., accident pathogens. With concrete reference to the processes and products found in accident cases, the concept of pathogen thread provides an explicit structure to the classic metaphor of pathogens that the safety literature has been using to describe latent failures. This paper further proposes the concepts of pathogen susceptibility and transmissibility to explain the mechanisms and dynamics that drive the generation and propagation of accident pathogens. Acknowledging the limitations of the modeling framework, this paper concludes with a discussion of lessons for systems engineering practices and directions for future work to ensure system safety in the construction of systems in various domains.

Obesity and Hunger Threaten the Foundations of Child Health

Obesity and Hunger Threaten the Foundations of Child Health

Retinal vascular occlusive disease and tilt-table inversion

PK is a 58-year-old female with an unremarkable past medical history other than hanging inverted 180 degrees in a tilt-table for 1-3 minutes several times in the two weeks before her examination who presented for a routine follow-up eye examination with no visual complaints. On dilated fundoscopic examination, she was found to have a central retinal vein occlusion in her right eye. A retinal consultation determined her vein occlusion was non-ischemic without macular edema and no further treatment was required. While most cases of central retinal vein occlusion can be attributed to common systemic factors, in cases where no risk factors are present it is important to ask patients whether they are regularly performing activities where they are inverting themselves 180 degrees or any activities causing rapid fluctuations in intraocular pressure and blood pressure within the central retinal artery.

Role of Software in Spacecraft Accidents

The first and most important step in solving any problem is understanding the problem well enough to create effective solutions. To this end, several software-related spacecraft accidents were studied to determine common systemic factors. Although the details in each accident were different, very similar factors related to flaws in the safety culture, the management and organization, and technical deficiencies were identified. These factors include complacency and discounting of software risk, diffusion of responsibility and authority, limited communication channels and poor information flow, inadequate system and software engineering (poor or missing specifications, unnecessary complexity and software functionality, software reuse without appropriate safety analysis, violation of basic safety engineering practices in the digital components), inadequate review activities, ineffective system safety engineering, flawed test and simulation environments, and inadequate human factors engineering. Each of these factors is discussed along with some recommendations on how to eliminate them in future projects.

Equity Transmission Mechanisms from Asia to Australia: Interdependence or Contagion?

The linkages between daily Asian and Australian equity market returns over the period 1995–2001 are investigated within the framework of a latent factor model. Transmission mechanisms arising from both market interdependence and contagion are studied. The empirical results reveal that co-movements in Asian and Australian equity markets are largely determined by interdependent linkages arising from common systemic factors. There is little significant evidence of contagion, although negative shocks have more effect than positive ones.

The Management of Myofascial Pain Syndromes

Objective: To present an approach to the management of the Myofascial Pain Syndrome [MPS] based on clinical experience, addressing the problems posed by the specific nature of primary myofascial trigger point pain, and the problem of chronic myofascial pain. Results: Specific trigger point therapy is designed to inactivate the myofascial trigger point by means of manual techniques, intermittent cold and stretch, and invasive trigger point needling or injection with a local anesthetic. Management of recurrent MPS requires addressing the perpetuating factors of mechanical imbalances [structural, postural, compressive] and systemic abnormalities which interfere with the ability of muscle to recover or which continuously stress muscle reactivating the trigger point. The common systemic factors associated with MPS are hypothyroidism, folic acid insufficiency and iron insufficiency. The relationship of many of the perpetuating factors to MPS is clinically apparent, but has yet to be established firmly by statis...