Decisionmakers searching for options to stabilize or mitigate concentrations of greenhouse gases in the atmosphere are faced with two broad approaches for controlling atmospheric carbon concentrations: (1) reduction of carbon emissions at their source, such as through reducing fossil fuel use and cement production or changing land use and management (e.g., reducing deforestation); and/or (2) enhanced sequestration of carbon, either through enhancement of biospheric carbon storage or through engineering solutions to capture carbon and store it in repositories such as the deep ocean or geologic formations. Enhancing carbon sequestration is of current interest as a near-term policy option to slow the rise in atmospheric CO2 and provide more time to develop a wider range of viable mitigation and adaptation options. However, uncertainties remain about how much additional carbon storage can be achieved, the efficacy and longevity of carbon sequestration approaches, whether they will lead to unintended environmental consequences, and just how vulnerable or resilient the global carbon cycle is to such manipulations. Successful carbon management strategies will require solid scientific information about the basic processes of the carbon cycle and an understanding of its long-term interactions with other components of the Earth system such as climate and the water and nitrogen cycles. Such strategies also will require an ability to account for all carbon stocks, fluxes, and changes and to distinguish the effects of human actions from those of natural system variability. Because CO2 is an essential ingredient for plant growth, it will be essential to address the direct effects of increasing atmospheric concentrations of CO2 on terrestrial and marine ecosystem productivity.

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Clinical trials have become the primary method of establishing medical benefit. The randomized, placebo-controlled, double-blind clinical trial (DB/PC RCT) has come to dominate the field. Without data from an RCT showing a statistically significant effect, an intervention is considered unproved, which many take to mean "not beneficial." This has led to the attempt to find the "best" medicine from the "perfect" data: an evidence-based approach to medicine. Certainly, the testing of many approaches that were in common practice has made a strong and highly beneficial impact on medical practice. For example, estrogen replacement therapy (ERT) was considered a standard practice for decades. Maintaining estrogen levels in women over 50 at levels similar to those for younger women was thought to be beneficial, and early observational studies suggested that the benefit extended to the cardiovascular system. However, more recent investigations of ERT, utilizing the RCT, did not support the findings from those early observational studies, indicating instead that some women on ERT may be at increased risk for thrombotic events and stroke, especially within the first two years of beginning ERT. The trials that showed increased risk of ERT generally included post-menopausal women who were not exhibiting symptoms of the menopause transition, such as hot flushes, whereas the benefit of exogenous hormones was observed in studies with younger women. As noted by Rosano et al., "several biological reasons may have contributed to the divergent findings from observational studies and RCTs." Older women may have fewer estrogen receptors, or a different pattern of expression of these receptors, and also may be more susceptible to inflammation and thrombotic events, factors that could alter their response to exogenous hormones, when compared to younger women.

[문제3]

External systems are systems or components of systems that are outside of the accreditation boundary established by the organization and for which the organization typically has no control over the application of required security levels or the assessment of security effectiveness. External information systems include, but are not limited to, personally owned information systems (e.g., computers, cellular telephones, or personal digital assistants); privately owned computing and communications components resident in commercial or public facilities (e.g., hotels, convention centers, or airports); information systems owned or controlled by nonfederal governmental organizations; and federal information systems that are not owned by, operated by, or under the direct control of the organization. Authorized individuals include organizational personnel, contractors, or any other individuals with authorized access to the organizational information system. This control does not apply to the use of external information systems to access organizational information systems and information that are intended for public access (e.g., individuals accessing federal information through public interfaces to organizational information systems). The organization prohibits authorized individuals from using an external system to access the AMI system or to process, store, or transmit organization-controlled information except in situations where the organization: 1) can verify the employment of required security mechanisms on the external system as specified in the organization’s security policy and system security plan; or 2) has approved system connection or processing agreements with the organizational entity hosting the external system.