Adolescenceâ€"beginning with the onset of puberty and ending in the mid-20sâ€"is a critical period of development during which key areas of the brain mature and develop. These changes in brain structure, function, and connectivity mark adolescence as a period of opportunity to discover new vistas, to form relationships with peers and adults, and to explore one's developing identity. It is also a period of resilience that can ameliorate childhood setbacks and set the stage for a thriving trajectory over the life course. Because adolescents comprise nearly one-fourth of the entire U.S. population, the nation needs policies and practices that will better leverage these developmental opportunities to harness the promise of adolescenceâ€"rather than focusing myopically on containing its risks. This report examines the neurobiological and socio-behavioral science of adolescent development and outlines how this knowledge can be applied, both to promote adolescent well-being, resilience, and development, and to rectify structural barriers and inequalities in opportunity, enabling all adolescents to flourish.

In the hierarchical river system, any deviation from the pristine state will be translated into disturbances that propagate and eventually reach its endpoints (i.e. the biologic community). Endpoints are indicative of the overall health or integrity of a water body. Integrity is usually measured with multi-metric indices that compare actual observations to reference scenarios. Despite strong agreement among experts about the importance of biological indicators, development of numeric biological standards similar to those used for water quality remains uncertain for several reasons: (1) the natural system is composed of highly intertwined and cross-correlated variables. Identification of simple stress-response relationships is not often possible; (2) the natural system is organized in a nested hierarchy of suitable habitats with very different geographic scales; (3) many environmental variables have a categorical evaluation, which introduces subjectivity and relativity into the system ; (4) true reference conditions may no longer exist; and (5) natural randomness. In order to address these issues, an attempt to predict or characterize biologic integrity was performed. In the first section, fish Indices of Biologic Integrity (IBI) were predicted using the K-nearest neighbor concept (KNN). This methodology was used because it allows a fast, step-wise approach easily implemented with highly dimensional environmental vectors. The KNN concept was tested with databases in Maryland, Ohio, and Minnesota. Subsequently, a slightly modified version of the algorithm was tested with a new database in Ohio which combined instream and offtstream features improving the results significantly. The second section consisted of a progressive, hierarchical separation of biological responses using Self-Organizing Maps (SOM) and subsequent clustering of sites using one environmental variable at a time in decreasing order of importance. This methodology attempted to replicate the nested hierarchy of habitats in nature. The biologic responses were characterized using a Gaussian probabilistic curve because it was assumed that IBI was a projection of the log-normal distribution of species onto an arithmetic scale. The best sites in each group were considered as truly reference conditions and compared to the remaining sites within the group. This was applied in Ohio (with only instream or only offstream data) and Maryland (instream and offstream data combined).

Not all stress is stressful; instead, it appears that stress in the environment, below the mutation threshold, is essential for many subtle manifestations of population structures and biodiversity, and has played a substantial role in the evolution of life. Intrigued by the behavior of laboratory animals that contradicted our current understanding of stress, the author and his group studied the beneficial effects of stress on animals and plants. The seemingly “crazy” animals demonstrated that several stress paradigms are outdated and have to be reconsidered. The book describes the general stress responses in microorganisms, plants, and animals to abiotic and biotic, to natural and anthropogenic stressors. These stress responses include the activation of oxygen, the biotransformation system, the stress proteins, and the metal-binding proteins. The potential of stress response lies in the transcription of genes, whereas the actual response is manifested by proteins and metabolites. Yet, not all stress responses are in the genes: micro-RNAs and epigenetics play central roles. Multiple stressors, such as environmental realism, do not always act additively; they may even diminish one another. Furthermore, one stressor often prepares the subject for the next one to come and may produce extended lifespans and increased offspring numbers, thus causing shifts in population structures. This book provides the first comprehensive analysis of the ecological and evolutionary effects of stress.

Pituitary Adenylate Cyclase-Activating Polypeptide is the first volume to be written on the neuropeptide PACAP. It covers all domains of PACAP from molecular and cellular aspects to physiological activities and promises for new therapeutic strategies. Pituitary Adenylate Cyclase-Activating Polypeptide is the twentieth volume published in the Endocrine Updates book series under the Series Editorship of Shlomo Melmed, MD.

Cell and Molecular Responses to Stress is a new multi-volume book series from Elsevier Science that focuses on how organisms respond at a molecular level to environmental stresses imposed upon them. All organisms deal with variations in multiple environmental factors including temperature, oxygen, salinity, and water availability. Many show amazing tolerances to extreme stress with remarkable biochemical adaptations that allow life to persist under very difficult circumstances. This series explores the molecular mechanisms by which cells and organisms respond to stress, focusing on the variations in metabolic response that allow some cells and organisms to deal with extreme stress, others to endure stress within strict limits, and others to have a very low tolerance for changes in environmental parameters.Articles from within the series highlight the elastic limits of molecular responses in Nature, with examples drawn from animal, plant and bacteria systems.Volume 1, begins by considering some of the roles of environmental stress in determining the geographic distribution of animals and in promoting species divergence and then explores gene expression and metabolic responses to environmental stress with examples of adaptation to high and low temperature, osmotic, anoxia/ischemia, desiccation, high pressure and heavy metal stresses.

A systematic 1982 on human reactions to five environmental stress factors.

Most organisms and populations have to cope with hostile environments, threatening their existence. Their ability to respond phenotypically and genetically to these challenges and to evolve adaptive mechanisms is, therefore, crucial. The contributions to this book aim at understanding, from a evolutionary perspective, the impact of stress on biological systems. Scientists, applying different approaches spanning from the molecular and the protein level to individuals, populations and ecosystems, explore how organisms adapt to extreme environments, how stress changes genetic structure and affects life histories, how organisms cope with thermal stress through acclimation, and how environmental and genetic stress induce fluctuating asymmetry, shape selection pressure and cause extinction of populations. Finally, it discusses the role of stress in evolutionary change, from stress induced mutations and selection to speciation and evolution at the geological time scale. The book contains reviews and novel scientific results on the subject. It will be of interest to both researchers and graduate students and may serve as a text for graduate courses.