June 2003

5-Prime | Stem Cell Fusion Confusion 1. How did the idea of transdifferentiation arise? In the late 1990s, sex-mismatched transplants and experiments with rodents revealed apparent transgressions of embryonic cell fates. Bone marrow cells could yield liver, muscle, neuron, and endothelium, while neurons could give rise to blood, and hepatocytes to pancreatic beta cells. Stem cells seemed to home in on injury sites, producing daughters that dedifferentiate and redifferentiate into exactly

So They Say "The procedure is just too simple. There's no complicated cocktail of growth factors." --Hans Scholer, University of Pennsylvania, on how he got mouse embryonic stem cells to transform into ovaries by increasing their density in cell culture. From New Scientist "[Aging] is so often viewed as a process of decline--your hair falls out, your teeth fall out--but we're seeing aging as a process of development. All the biggest changes were for the better." --Stanford University's

Science Seen | Chocolate Pinwheels? Courtesy of The Natural History Museum, London  CHOCOLATE PINWHEELS? Plankton are Earth's primary defense against global warming, as they consume more carbon dioxide than any other organism. But who knew that these microscopic algae-like organisms, which pervade the world's oceans, could be so beautiful? This electron micrograph captures a Calcidiscus leptoporus shedding its exoskeleton and building a new one. function sendData() { document.frm.p

The voices of patient advocates can be electrifying. Consider the following examples: "I am one of the many millions of Americans who will benefit from biomedical research, made possible by the dollars that you appropriate. I view this invitation to testify as my opportunity to change the world. If I choose the right words, paint the right picture, I hope to give you not only a glimpse of what it's like to have a neurodegenerative disease, but also a sense of the staggering utter despair, fru

Ned Shaw That guy is 20 years ahead of his time. He could be a flake or a genius, who knows?" Spoken by a neuroscientist about his colleague at an annual convention, these words set me thinking. What does he mean? Can anyone be 20 years ahead of time? The better explanation must be that academic science may live 20 years in the past. This explanation rings true when we realize the pace of contemporary science: It is incremental, consensual, and expensive. Progress is slow in the mainstream. A

Rich with Meaning Language shapes the way we think. For this reason the precise choice of words is as important in science as in any other field of scholarly endeavor. The use of "enrichment" to describe more complex housing environments for laboratory animals1 is misleading. A better term might be "naturalized". The continued use of enrichment in describing environments that provide some improved attempt to offer artificial equivalents of the range of stimuli and experiences an animal mi

Advice and Dissent As a relatively young member of the scientific community (I am 22 years old and in my first year of graduate studies, working towards my PhD), the Office of Technology Assessment was an entirely novel topic to me.1 For someone so young, it would be presumptuous of me to make an objective judgment call on whether or not the OTA was a good or bad thing. I can, however, speak from my own experience when I say that at least a small cross-section of the American public is gros

The Two R's Jim Jarvis1 feels that undergraduates in science should take "a rigorous course in composition." Readers of The Scientist might be interested in what the research says about writing: For those writing in both their first and second languages, the best predictor of writing quality is the amount of reading done. There is no evidence linking writing ability to the formal study of grammar or to the study of the structure of expository prose, topics generally emphasized in compositio

Under the Sun The article by Stacie Zoe Berg1 raises the interesting possibility that exposure to solar UV-B radiation could induce autoimmune diseases. This certainly sounds plausible. We know that prolonged exposure to UV-B causes basal-cell and squamous-cell cancers in susceptible individuals, particularly fair-skinned people. [Melanoma appears to be caused by both UV-B and the much stronger UV-A radiation.] But the report states that autoimmune incidence decreases towards lower latitu

Making Copies I've long been under the impression that "xerox" derives from "xerography," which in turn comes from the Greek for "dry writing." Now, in the May 19 issue, I read twice, in articles by different authors, that xerox is actually arbitrary and meaningless.1,2 Perhaps you would be willing to clarify this issue for your readers. Pedro J.N. Silva Departamento de Biologia Vegetal Faculdade de Ciencias da Universidade de Lisboa Lisboa, Portugal Pedro.Silva@fc.ul.pt References 1

Roots of the Problem I am writing this letter in response to Mr. Jaffe's article in the last issue of The Scientist.1 I recognize the difficulty of conducting science under conditions such as those that exist in the West Bank, and I salute Dr. Kanaan for his endurance and achievements, surely not an easy task. However, I find the article to be extremely biased in its reporting. Yes, Dr. Kanaan must endure lengthy checkpoints on his way to work, but Mr. Jaffe never questions the reason for

Talent or Greediness? The letter entitled "The Misery,"1 signed by a retired lawyer, has called forth conflicting emotions and thoughts, and a certain amount of dissatisfaction and discomfort in the undersigned, both devoted scientists. Although it is undeniably true that the author did succeed in bringing out some interesting arguments, in our opinion, and with all due respect, we reckon that he entirely missed the point. We won't discuss here his surely arguable statement that "getting ri

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Courtesy of Bonnie Bartel and David P. Bartel Reprinted from Plant Physiol, 132:1-9, June 2003.  CURRENT MODEL: (A) A microRNA (MIR) gene encodes a primary transcript with a stem-loop structure. A hairpin precursor (in brackets) has been found in animals but not in plants. The enzyme Dicer cleaves the transcript to form a microRNA (miRNA) which nestles in a ribonucleoprotein (RNP) complex that is similar, if not identical, to the RNA-induced silencing complex (RISC). (B) When an mRNA has n

Since 1948, military men and women have smeared on DEET, otherwise known as N,N-diethyl-3-methylbenzamide, to repel the itchy, the deadly, and the otherwise annoying. DEET is effective but unloved--it literally melts plastic--and the US military has been working for some time to find a replacement. The newcomer is called SS-220. At the army's Aberbeen Proving Ground in Maryland, SS-220 has passed toxicity tests for short-duration exposure. Lab tests with human volunteers and mosquitoes, Anop

Data derived from the Science Watch/Hot Papers database and the Web of Science (ISI, Philadelphia) show that Hot Papers are cited 50 to 100 times more often than the average paper of the same type and age. D.G. Burbee et al., "Epigenetic inactivation of RASSF1A in lung and breast cancer and malignant phenotype suppression," J Natl Cancer Inst, 93:691-9, May 2, 2001. (Cited in 105 papers) M. Esteller et al., "A gene hypermethylation profile of human cancer," Cancer Res, 61:3225-9, April 15, 200

GADGET WATCH | Fighting the Membrane Protein-Extraction Blues Courtesy of Geno Technology Efficient extraction of membrane proteins can be a dicey business: Add too little detergent, and you fail to extract the protein; add too much, and purification procedures and downstream applications may be compromised. Geno Technology (www.genotech.com) of St. Louis offers one solution: Optimizer-blueBALLS™, which are glass beads coated with a hydrophobic blue dye that behaves like membrane-bound

Photos courtesy of Sandia National Laboratories, Center for Integrated Nanotechnologies Everyone knows that all labs are not created equally. What differentiates the Cold Spring Harbors and Max Plancks of the world from less-illustrious facilities? Certainly money plays a part, but so, too, does some intangible quality--call it critical mass, if you like--a fusion of the right people, resources, architecture, and vision that combine and cooperate to make a whole that is greater by far than th

Courtesy of Ivan Rayment  CAUGHT IN MID HOP: Structure of the Tn5 transposase/DNA complex No one believed Barbara McClintock in 1951 when she first described DNA that "jumped" from site to site within maize chromosomes, altering the expression of genes near the sites of integration. In due course, these transposable elements, or transposons, were found to be ubiquitous in nature, and 30 years later McClintock won the Nobel Prize. Today transposons have gone from molecular oddity to molec

Courtesy of Tecan Group Knowledge of the tissues and cells that express particular genes is key to understanding gene function. In situ hybridization (ISH), a popular method for deciphering gene expression, is a slow, labor-intensive, error-prone operation that limits parallel investigation of multiple genes and tissues to what may be carried out quickly by hand. These attributes essentially preclude slide-staining efforts from the high-throughput analyses that are so critical to functional ge

Courtesy of Leica Microsystems Throughout the microscope's history, engineering enhancements have mainly addressed image quality, with little regard for the user's comfort. But poor body mechanics associated with operating traditional microscopes can cause discomfort and fatigue and ultimately lead to serious musculoskeletal and repetitive-motion injuries. In the 1980s, manufacturers began incorporating ergonomic features aimed at alleviating these problems. These upgrades first appeared in

Courtesy of Nanoprobes Yaphank, NY-based Nanoprobes has expanded its Nanogold® product line with the release of Alexa-Fluoronanogold™, a combination of Alexa Fluor® dyes (a product of Molecular Probes of Eugene, Ore.) with Nanogold particles. Scientists can thus study and easily correlate samples at the cellular level via fluorescence microscopy and at the macromolecular level via electron microscopy. Additionally, fluorescence microscopy can be performed prior to electron micros

Courtesy of Affymetrix Santa Clara, Calif.-based Affymetrix has released a new array designed for complete resequencing of the SARS coronavirus. The GeneChip® CustomSeq™ SARS pathogen detection and resequencing array encompasses the entire 30 kb genome of the virus, allowing full genome resequencing and permitting all mutations to be identified, says Greg Yap, senior director of marketing. Yap notes that although only a few SARS strains have been sequenced to date, this is only a f

TRAINING @ | Trundling for Money in Tucson WHAT: FASEB Grantsmanship Training Program WHERE: Omni Tucson National Golf Resort & Spa, Tucson, Ariz. WHY: To teach investigators grant-writing skills that will maximize their ability to generate their ideas ADVANTAGES: Strategies for what should and shouldn't be done in grant writing WHEN: July 31-Aug. 2, 2003 DEADLINE: July 1 COST: $500 URL: ns2.faseb.org/careerutilities/grant03.pdf   TIP TROVE | Unleash Researche

D.F. Dowd Joel Hirsch, an Israeli biochemist at Tel Aviv University, has one more thing to worry about when he submits a scientific paper for publication: the possibility that scientists who disagree with his country's policies will shun his work. "My nightmare scenario is that the paper gets sent to a reviewer who might have an axe to grind about Israeli scientists," Hirsch says. In the year since some British researchers called for a boycott of Israeli scientists, funding agencies have larg

Great Lakes Fishery Commission Just in from the Hammond Bay Biological Station on Lake Huron, Jared Fine heads to his St. Paul laboratory to perform bioassays on sea lampreys. He's looking for chemicals that may be sexually alluring to this parasitic fish. Electro-olfactograms (EOGs), which Fine uses to track the lamprey's responses to odors, "require a pretty elaborate setup," says the fisheries graduate student from the University of Minnesota. It's easier and cheaper for his advisor, Peter

Ned Shaw Omar Ahmed, a Sussex, UK-based researcher, describes a labmate who possesses a greater flair for ending Ahmed's sanity than for eradicating disease. "He hoards solvents and glassware, walks around like he owns the place, and often wanders around the lab singing," Ahmed says. "The singing really bothers me. He seriously thinks he's Frank Sinatra." The absence of suits and dearth of cubicles as hiding places can create an informal work environment in the lab. With collaboration often n

How I Got This Job | Toward a Pleasurable Postdoc Courtesy of Andrew Pemberton Early Indications: I saw a flyer for marine biology degrees on a school bulletin board when I was either 16 or 17 years old and just thought, "This is for me." How I got here: After earning my Bachelor's degree at Liverpool University, I spent a year at Leicester University learning basic molecular biology techniques before starting my PhD at Aberdeen University. During the third year of my PhD studies, I began

Courtesy of Moffa Photography Work continues on a method for setting priorities for big research projects at the National Science Foundation, an effort that started in 1991 when Congress asked for help in weighing competing proposals. Lawmakers say they simply cannot understand the big-ticket requests for funding of major research equipment and new facilities that turn up in NSF's budget. Because of the large expense, proposals to build a string of ocean observatories, for one example, or to i

In 1909, the Danish biologist Wilhelm Johannsen coined the terms gene, to describe the unit of heredity, and genotype as the entire genetic profile of an organism. Seven years later, the term biome appeared, used to describe an ecological community of organisms and environments. As technology progressed, it became possible to do high-throughput molecular biology, and we began exploring the genomes of various microbes. This essentially entailed sequencing and annotating the entire genetic com

 Click for larger version (35K) We asked our readers with postgraduate degrees how long they spent in postgraduate education and in postdoc positions; 215 responded. The average time spent in postgraduate study, which varies by country, was 4.9 years. Students in both the UK and Germany devote an average of 3.5 years; in the United States and Canada, the average is 5.5 years. The vast majority, 83%, went on to nontenured or nonpermanent positions--mostly postdocs--after completing their

Frontlines | Waiting Out Addiction Erica P. Johnson Recent research shows that for smokers who are trying to quit, the day seems to pass slowly. Pennsylvania State University researchers found that time perception was impaired for these people, suggesting both a decrease in performance and an increase in discomfort for abstainers.1 Nonpuffers and daily smokers, who went 24 hours without inhaling, were asked to estimate how much time had elapsed during a 45-second span. To the abstaining s

Frontlines | Shopping on the Wing Diana Lynn Boyle It's a marketing ploy that routinely traps shoppers. Faced with only two choices, say microwave A, small and cheap, and microwave B, large and pricey, a buyer is apt to pick either one. But throw in choice C, which is slightly more expensive but also slightly smaller than B, and shoppers flock to microwave B. "Item C," says behavioral economist Dan Ariely, Massachusetts Institute of Technology, "is used as a decoy to draw attention to targe

Foundations | The Death of a Cell  Click for larger version (21K) In the autumn of 1974, more out of curiosity than of any particular plan, I sat down to watch newly hatched nematodes. The idea was to see where certain, late-developing neurons came from. At first the details were hard to follow, because the larvae jittered around. But I learned to keep them well fed, contented, and growing normally. The first time that I saw a cell division from beginning to end was a wonderful revelat

First Person | Carl Woese Courtesy of Bill Wiegand He speaks with the wisdom of someone approaching 75 years of age, with a knowledge of biology acquired from studying cellular evolution for the past 40, and with the assurance of a scientist who has proven himself right, a time or two. Carl Woese, a MacArthur Foundation "genius" award recipient who will accept the $500,000 Crafoord Prize in Sweden this fall, is initially reticent about speaking about his life, and himself. But tug at the s