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Abstract: This book describes how bioprinting emerged from 3D printing and details the accomplishments and challenges in bioprinting tissues of cartilage, skin, bone, muscle, neuromuscular junctions, liver, heart, lung, and kidney. It explains how scientists are attempting to provide these bioprinted tissues with a blood supply and the ability to carry nerve signals so that the tissues might be used for transplantation into persons with diseased or damaged organs. The book presents all the common terms in the bioprinting field and clarifies their meaning using plain language. Readers will learn about bioink—a bioprinting material containing living cells and supportive biomaterials. In addition, readers will become at ease with concepts such as fugitive inks (sacrificial inks used to make channels for blood flow), extracellular matrices (the biological environment surrounding cells), decellularization (the process of isolating cells from their native environment), hydrogels (water-based substances that can substitute for the extracellular matrix), rheology (the flow properties of a bioink), and bioreactors (containers to provide the environment cells need to thrive and multiply). Further vocabulary that will become familiar includes diffusion (passive movement of oxygen and nutrients from regions of high concentration to regions of low concentration), stem cells (cells with the potential to develop into different bodily cell types), progenitor cells (early descendants of stem cells), gene expression (the process by which proteins develop from instructions in our DNA), and growth factors (substances—often proteins—that stimulate cell growth, proliferation, and differentiation). The book contains an extensive glossary for quick reference.

From years prior to the release of the first commercial transgenic crop in 1995 to the present, many concerned activists, regulators, and scientists have questioned how genetic engineering might impact the environment. No measurable negative environmental impacts have been observed for commercial genetically modified crops to date, even though several risks have been identified in experimental releases. Even so, none have approached doomsday scenarios posed by activists. The risks that have been extensively studied are gene flow from crops to weeds or crop landraces; side-effects of insecticidal transgenic proteins, such as accidental killing of monarch butterflies or beneficial insects; viral recombination; and transgene combinations. Close examination has uncovered no negative effects, but plenty of positive environmental impacts from growing crops engineered for insect resistance and herbicide resistance. Insect resistant cotton and corn kill only the insects that attempt to eat the crops and have saved several million gallons of chemical insecticide applications. Herbicide resistant soybean and corn have helped in soil conservation efforts since farmers do not have to use as much tillage to control weeds. In addition to these benefits, scientists are conducting research to produce genetically engineered plants to clean up toxins, produce plastics and biofuels, and perform other ecological services. The responsible use of genetic engineering is part of sustainable agriculture now and in the future.

The measurement of metabolic rates is important in many areas of science. Examples range from ecology through a broad spectrum of physiological disciplines to biomedical fields such as genetic screening, obesity, and trauma research. The organisms being measured range in size from bacteria through insects to whales, and many different measurement methodologies have developed over the years, most of which are famously difficult for the novice to master. This book covers a wide range of metabolic measurement techniques, giving background and applications information for each, with enough practical detail to allow for accurate and informed measurements with minimal trial-and-error. Much tribal wisdom, passed down from professors to students and between scientific peers, is included. A broad range of techniques is covered, including Gilson and Warburg respirometry and their modern derivatives; direct calorimetry; stable isotope work; coulometric respirometry; aquatic respirometry; and practically every variation of field and laboratory flow-through respirometry, including complex, computer-driven multi-animal systems. Characteristics of the different varieties of gas analyzers, flow measurement systems, and so on are evaluated in detail. The book brings to the task over two decades of experience in practically every type of respirometry, from laboratory settings to the jungles of Panama and the deserts of Namibia.