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McGraw Hill Financial, Inc. is an American publicly traded corporation headquartered in Rockefeller Center in New York City. Its primary areas of business are financial, publishing, and business services.
Implantable health-care devices are being used in diverse applications, including patient identification, continuous monitoring of patient vital signs, and automatic delivery of medications.
Many implantable devices have the ability to communicate wirelessly with other devices. This capability can be very useful; for example, an implanted insulin pump might be reprogrammed to alter its dosage without its having to be removed from the patient. However, wireless communication has vulnerabilities: an attacker may be able to eavesdrop on patient information, track or spoof patients, or even cause direct physical harm to patients by maliciously sending commands that affect the operation of an implanted device. Security issues for implantable devices deserve particular attention because of the permanent nature of these devices.
Industry:Science
Important evidence for microbial mediation in rock–water interactions has been recognized since the mid-1980s. Bacterial activity has been shown to contribute not only to the weathering and leaching of rocks but also to the deposition of new minerals. One example is the concentration of large amounts of iron and silica in sediments, such as the Banded Iron Formations, which had been difficult to explain by abiogenic physicochemical means alone.
Since the discovery in 1954 of coccoid and filamentous microfossils in the Early Proterozoic Gunflint chert formation of Canada and the United States, it has been realized that microorganisms would likely have influenced the formation of such deposits. Today many of the reactions involved in the deposition of sediments under natural conditions are thought to be microbially mediated.
Industry:Science
Ever since it was postulated in 1939 that stars obtain their energy from fusion reactions, continuous attempts have been made to harness this fusion, the main source of energy in the universe, in a controlled manner. However, it was realized in 1957 that to use fusion to produce electricity on Earth, even with the most reasonable fuel, a mixture of 50% deuterium and 50% tritium, the material would have to be heated to temperatures equivalent to at least 10 keV (approximately 10<sup>8</sup> K). The problem is how to isolate enough fuel (approximately 1–2 × 10<sup>20</sup> particles/m<sup>3</sup>) at such extreme temperatures (1–2 × 10<sup>8</sup> K) from the surrounding environment for enough time (approximately 2–3 s) to allow a sufficient number of reactions to occur and make the overall energy production process efficient.
Industry:Science
Fragmental volcanic products from explosive eruptions that are consolidated, cemented, or otherwise hardened to form solid rock. In strict scientific usage, the term “tuff” refers to consolidated volcanic ash, which by definition consists of fragments smaller than 2 mm. However, the term is also used for many pyroclastic rocks composed of fragments coarser than ash and even for pyroclastic material that has undergone limited posteruption reworking. If the thickness, temperature, and gas content of a tuff-forming pyroclastic flow are sufficiently high, the constituent fragments can become compacted and fused to form welded tuff.
The term “tuff” is also used in the naming of several related types of small volcanic edifices formed by hydrovolcanic eruptions, triggered by the explosive interaction of hot magma or lava with water.
Industry:Science
Cells that have the ability to self-replicate and to give rise to mature cells. The concept of stem cells was originally based on renewing tissues. Many adult tissues, such as the skin, blood, and intestines, consist of mostly mature and short-lived cells that must be continuously replaced. Stem cells were postulated as the source of the self-renewal.
In the early 1960s, Canadian scientists Ernest A. McCulloch and James E. Till provided the first experimental proof of the existence of stem cells in the blood system. They revealed that a type of cell in bone marrow possesses the capacity to replicate itself and to differentiate to various lineages of mature blood cells. Self-renewal, together with the capacity for differentiation, defined the properties of stem cells. This definition is generally used in stem cell biology today.
Industry:Science
Documenting the large-scale surface temperature changes of the past millennium is necessary in order to place recent climate change in an appropriate long-term context. Because the fundamental boundary conditions on the climate (the parameters of the Earth's orbit in relation to the Sun, and global patterns of vegetation and continental ice cover) have not changed appreciably, the major variations in climate over this time frame are representative of the range of natural climate variability that might be expected in the absence of any human influence on climate.
Placing global warming of the twentieth and twenty-first centuries in this longer-term context can aid in our ability to determine the role of anthropogenic factors, such as increases in greenhouse gas concentration produced by humans, in past and future climate change.
Industry:Science
Evolutionary computation is a rapidly growing interdisciplinary science area that is concerned with modeling aspects of natural evolution in order to solve real-world problems. Living organisms, as well as those long extinct, demonstrate optimized complex behavior at all levels: cells, organs, individuals, and populations. Charles Darwin wrote of “organs of extreme perfection” when describing the ability of evolution to craft ingenious solutions to complex problems such as vision.
Evolution is the great unifying principle of biology, but it extends beyond biology and can be used as an engineering principle where individuals in a population of candidate solutions to some particular problem undergo random variation (mutation and recombination) and face competition and selection based on their appropriateness for the task at hand.
Industry:Science
Autoimmune illnesses are characterized by a loss of self-tolerance, whereby the body's own immune defense mechanisms are inappropriately directed against body components, resulting in organ damage or activation of a systemic immune response. Some organ-specific autoimmune illnesses are self-limited, since only one tissue is affected, but the ongoing inflammatory response may interfere with normal organ function. However, multisystem autoimmune illnesses, such as rheumatoid arthritis (characterized by chronic inflammation of the synovium, or the lining membrane, of joints, and surrounding tissue, as well as other body systems) have the propensity to involve multiple organs. If the immune response is not adequately suppressed during times of increased disease activity, then organ failure, death, or permanent disability may result.
Industry:Science
Electron transfer between the electronically excited state of a dye and a semiconductor was discovered in 1887 by James Moser at the University of Vienna. He observed that the photoelectric effect detected on silver plates treated with iodide or bromide was greatly enhanced in the presence of erythrosine. A few years later, H. Vogel in Berlin exploited this phenomenon to render silver halide microcrystals sensitive to visible light, a process which eventually found wide application in color photography. Apart from the fundamental importance for photography and xerography, current investigations are fueled by the recent discovery of dye-sensitized injection solar cells. These cells have already reached an impressive conversion efficiency of 11% under full sunlight, rendering them competitive with commercial silicon-based devices.
Industry:Science
Four parameters define the requirements for navigational aids that operate in civil airspace: accuracy, integrity, continuity, and availability. Accuracy refers to how well the system can provide correct position information in the absence of a failure. Integrity refers to the ability of the system to inform the user in a timely manner of a latent failure that may cause a hazardous condition. (A latent failure is an undetected degradation of the navigational aid operation.)
Continuity refers to the ability of the system to let the user navigate without interruption. For example, radio-frequency interference (jamming) and blockage of radionavigation signals are potential causes of a loss of continuity. Availability is the probability that the system will function and provide required levels of accuracy, integrity, and continuity.
Industry:Science
