بایگانی برچسب برای: PARADIGMS

Changing Paradigms[taliem.ir]

Changing Paradigms in the Management of Breast Cancer

Breast imaging plays a critical role in the detection, diagnosis, and management of women diagnosed with breast cancer. Although there are a multitude of risk factors associated with breast cancer, such as female gender, increasing age, and family history, the density of breast tissue as evident on mammography has more recently been identifed as an independent risk factor . Although some studies suggest that the lifetime risk increases by four to six times for women with dense breast tissue, this is misleading as this compares women with extremely dense tissue to women with predominantly fatty breasts, both of which represent a minority of the population . More realistically, the lifetime risk is only increased by 1.2–2.1 times in a woman with heterogeneously dense or extremely dense breasts, respectively, when compared to the average woman who has scattered fbroglandular tissue. However, as breast density is known to lower the sensitivity of mammography due to “masking” of cancers, the integration of newer modalities for the management of newly diagnosed breast cancer, such as digital breast tomosynthesis, ultrasound, and magnetic resonance imaging (MRI), continues to evolve. In addition, recent legislative efforts that mandate direct patient otifcation of breast density exist in nearly 50% of states in the USA. Consequently, there is a growing research on developing more sensitive and specifc tools to “see through” the dense tissue and therefore permit earlier cancer detection, which should translate into improved outcomes.
DISTRIBUTED SYSTEMS[taliem.ir]

DISTRIBUTED SYSTEMS PRINCIPLES AND PARADIGMS

Q: An alternative definition for a distributed system is that of a collection of independent computers providing the view of being a single system, that is, it is completely hidden from users that there even multiple computers. Give an example where this view would come in very handy. A: What immediately comes to mind is parallel computing. If one could design programs that run without any serious modifications on distributed systems that appear to be the same as nondistributed systems, life would be so much easier. Achieving a single-system view is by now considered virtually impossible when performance is in play. Q: What is the role of middleware in a distributed system? A: To enhance the distribution transparency that is missing in network operating systems. In other words, middleware aims at improving the single-system view that a distributed system should have. Q: Many networked systems are organized in terms of a back office and a front office. How does organizations match with the coherent view we demand for a distributed system? A: A mistake easily made is to assume that a distributed system as operating in an organization, should be spread across the entire organization. In practice, we see distributed systems being installed along the way that an organization is split up. In this sense, we could have a distributed system supporting backoffice procedures and processes, as well as a separate front-office system. Of course, the two may be coupled, but there is no reason for letting this coupling be fully transparent.
DISTRIBUTED SYSTEMS[taliem.ir]

DISTRIBUTED SYSTEMS PRINCIPLES AND PARADIGMS

Q: An alternative definition for a distributed system is that of a collection of independent computers providing the view of being a single system, that is, it is completely hidden from users that there even multiple computers. Give an example where this view would come in very handy. A: What immediately comes to mind is parallel computing. If one could design programs that run without any serious modifications on distributed systems that appear to be the same as nondistributed systems, life would be so much easier. Achieving a single-system view is by now considered virtually impossible when performance is in play. Q: What is the role of middleware in a distributed system? A: To enhance the distribution transparency that is missing in network operating systems. In other words, middleware aims at improving the single-system view that a distributed system should have. 3. Q: Many networked systems are organized in terms of a back office and a front office. How does organizations match with the coherent view we demand for a distributed system? A: A mistake easily made is to assume that a distributed system as operating in an organization, should be spread across the entire organization. In practice, we see distributed systems being installed along the way that an organization is split up. In this sense, we could have a distributed system supporting backoffice procedures and processes, as well as a separate front-office system. Of course, the two may be coupled, but there is no reason for letting this coupling be fully transparent.