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Research has shown that some older people stay sharp into old age and retain the ability to recall personal experiences with just as much accuracy as their middle-aged peers. The brains of these so-called "super-agers" look distinct, too: Their gray-matter-rich outer layer, or cortex, is thicker.

The online textbook provides a background to understand and discuss the natural functioning of the different Earth systems; it introduces humans as part of the overall ecosystem and explores what is needed to sustain human life; and it looks at the effects that human actions have on different natural systems. The online textbook also includes full-color images of related figures, glossary terms, and a bibliography for further reading.

For researchers, understanding how cancer cells function differently from normal cells lays the foundation for developing treatments designed to rid the body of cancer cells without damaging normal cells.

About GeneCards®: GeneCards is a searchable, integrated database of human genes that provides comprehensive, updated, and user-friendly information on all known and predicted human genes. GeneCards extracts and integrates gene-related data, including genomic, transcriptomic, proteomic, genetic, clinical, and functional information. This is automatically mined from >100 carefully selected web sources, thereby allowing one-stop access to a very broad information base. GeneCards overcomes barriers of data format and heterogeneity, and uses standard nomenclature and approved gene symbols. It presents a rich subset of data for each gene, and provides deep links to the original sources for further scrutiny. GeneCards is widely used, and assists in the understanding of gene-related aspects of biology and medicine.

Possibly the most exciting use of stem cells rests on their ability to differentiate into an enormous range of healthy functioning adult cells, thereby providing a replacement source of cells to treat serious diseases. This ultimately means that virtually any disease that results in cellular and tissue destruction can potentially be treated by stem cells. Some of the conditions are particularly debilitating and these include diabetes, spinal cord injuries, retinal disease, Parkinson's disease, heart disease and cancer.

Scientists in Australia have grown the world's first kidney from stem cells - a tiny organ which could eventually help to reduce the wait for transplants. The breakthrough, published in the journal Nature Cell Biology, followed years of research and involved the transformation of human skin cells into an organoid - a functioning "mini-kidney" with a width of only a few millimetres.

When you look at yourself in the mirror you may ask, 'How, given that all the cells in my body carry the same DNA, can my organs look so unlike and function so differently?' With the recent progress in epigenetics, we are beginning to understand. We now know that cells use their genetic material in different ways: genes are switched on and off, resulting in the astonishing level of differentiation within our bodies.

Adverse life experiences, particularly those in childhood, contribute to disease morbidity and mortality [1, 2, 3, 4, 5, 6, 7]. There is considerable interest in understanding the mechanisms through which they do so, as it remains unclear how illness becomes apparent decades after the presumed initiating event. Long-standing hypotheses include chronic activation of the hypothalamic-pituitary-adrenal axis [8, 9, 10] and alterations of neuroimmune function [11]. Molecular signatures of stressful life experiences and their relation to disease are therefore of special interest to clarify the causal relationship between signature, disease, and stress.

3:45 video You might be under the impression that young blood is the fountain of youth. A number of studies conducted in older mice (and, once, humans) over the past 10 years have shown benefits from transfusions of young blood, or parabiosis, restoring cognitive function or regenerating muscles.

Many biology courses are designed to develop student understanding and application of the scientific method, but few seriously examine the various ethical questions associated with scientific research. This interdisciplinary case study presents three experiments and asks not only if they are scientifically valid but whether they were ethically performed.  The experiments examine the psychology of love, a cause of breast cancer, and how the immune system functions in the presence of cancer. Based on their opinions of the validity and ethics of each experiment, students are asked to conclude which of the experiments were actually conducted by scientists and which are fictional. Students should already be familiar with the scientific method, but information on the Georgetown Mantra and Nuremberg Code.is included. The case could be modified for use in non-majors and majors classes.  The format of the case challenges students of any background to use information from both science and ethics to see how the differing approaches of scientist and ethicist can complement and strengthen each other.

How are the stages of mitosis related to the creation of identical daughter cells? The primary function of the stages of mitosis is to make certain that each daughter cell is genetically identical to the mother cell. The mother cell's DNA is copied during interphase. During mitosis the chromosomes condense from long strands to highly coiled structures. The two copies of each DNA strand, called sister chromatids, are physically attached to one another. The chromosomes are moved to the center of the cell and split apart in a highly coordinated fashion. The condensation of the chromosomes, the physical connection of the sister chromatids, and the precise movement of the chromosomes are all important in making sure that each daughter cell has one copy of each chromosome and is genetically identical to the mother cell.

This case study examines the structure of hemoglobin and myoglobin and how the structure of these molecules dictates their function. The case is written as a play in which several candidates have responded to a help wanted ad seeking an employee with a strong work ethic, round-the-clock availability, and the capacity to carry oxygen in the human body and deliver it in a timely fashion when needed. The successful candidate also needs to carry a heavy load of carbon dioxide and dispose of it according to waste disposal regulations and be willing to work with human resources regarding salary and benefits.

Published today (17:00BST, 03/06/2015) in the journal Neuron, their work presents strong evidence that disruption of a delicate chemical balance in the brain is heavily implicated in the disorder. In the largest ever study of its kind, the team found that disease-linked mutations disrupt specific sets of genes contributing to excitatory and inhibitory signalling, the balance of which plays a crucial role in healthy brain development and function.

de Villena and his colleagues counted the RNA molecules produced and found that genes from the father produced on average more RNA than genes from the mother. (And remember, RNA directs the production of proteins, which are the workhorses of the body's development and function.) The implication? "It's not only what you inherit, but from whom you inherit," he said.

Huntington disease is caused by a mutation in the HTT gene. Understanding how the mutation causes neurodegeneration might help researchers develop treatments that protect brain function. This animation describes the genetic defect that underlies Huntington disease. Created by the editors at Nature Reviews Disease Primers.

Explore gene regulation with the Amoeba Sisters, including the fascinating Lac Operon found in bacteria! Learn how genes can be turned "on" and "off" and why this is essential for cellular function.

A package of papers investigates the functional regulatory elements in genomes that have been obtained from human tissue samples and cell lines. The implications of the project are presented here from three viewpoints. 

Dr. Richard Lifton, along with student volunteers, uses an aquarium and salt to illustrate the amount of work the kidney performs each day to maintain proper levels of ions in the body.

If thinking about the billions of bacteria taking up residence in and on your body gives you the willies, you probably won't find it comforting that humans are also full of viruses. These maligned microbes are actually intertwined in the very fibers of our being-about 8 percent of our genetic material is made up of absorbed forms of retroviruses, the viral family to which HIV, the pathogen that causes AIDS, belongs.

The researchers isolated different subpopulations of human brain stem cells and precisely identified, which genes are active in which cell type. In doing so, they noticed the gene ARHGAP11B: it is only found in humans and in our closest relatives, the Neanderthals and Denisova-Humans, but not in chimpanzees. This gene manages to trigger brain stem cells to form a bigger pool of stem cells. In that way, during brain development more neurons can arise and the cerebrum can expand. The cerebrum is responsible for cognitive functions like speaking and thinking.