March 2003

 Click for larger version (22K) We surveyed 261 readers to find out if they regularly check citations to the papers they have written and whether they think that citations are important. More than 70% of respondents check citations to their papers in ISI's Science Citation Index or Web of Science, with 40% checking more than once per year, and over 20% checking more than once per quarter. The average interval between checks is about nine months. Over 65% of respondents consider it import

Frontlines | Porcine Parts on the Horizon? Courtesy of Scott Bauer Infigen of DeForest, Wis., and BioTransplant of Charlestown, Mass., recently announced the birth of three pigs that mark the next stop on road toward xenotransplantation. The minipigs are clones derived from previous research (J. Betthauser et al., "Production of cloned pigs from in vitro systems," Nat Biotech, 18:1055-9, 2000) as well as knockouts for alpha-1,3-galactosyltransferase (GGTA1), which normally places a particu

Frontlines | See-through Mummies Thanks to a new take on an old technology, scientists now can unravel secrets of Egypt's mummies without undoing any bandages. Using multidetector computerized tomography (MDCT), a group of Italian researchers took a noninvasive, yet highly accurate virtual tour of the mummies' bodies (F. Cesarani et al., "Whole-body three-dimensional multidetector CT of 13 Egyptian human mummies," Am J Roentgenol, 180:597-606, March 2003). The instrument scanned along the

Foundations | Discovery of the First Angiogenic Factor Courtesy of Judah Folkman During the mid-1970s to early 1980s, my laboratory was trying to isolate an angiogenic stimulator from tumors, the factor we called TAF [tumor angiogenic factor] in our notebooks. This was at a time when no angiogenic stimulators were known to exist, nor had any angiogenesis inhibitors been discovered. In fact, few, if any, colleagues believed that angiogenic proteins would ever be found. "We used tumors grow

First Person | Elizabeth Blackburn Photo: © UCSF News Office One day, when Elizabeth Blackburn was about 15, mischief filled her mind. She and a friend mixed ammonia and iodine, then watched as their fellow French-language classmates reacted to the bang. "I was a bad girl," recounts Blackburn, known worldwide for her work on telomeres, the structures that stabilize the ends of eukaryotic chromosomes. What's on her mind today is deciphering how the enzyme telomerase works, as it is cr

So They Say "Working and living in someplace this remote, this bizarre, it's only fitting that your habitat should resemble the set of some 1970s sci-fi thriller." --Shayne Claussen, explaining why he'll stay in the South Pole's existing geodesic dome, rather than move into the NSF-funded, $130 million research station. From The New York Times. "I told him all you need is New York steak to make a good meal. He looked at that big one, shook his head, and said, 'I no need steak.'" --An

Science Seen | Tight Squeeze  TIGHT SQUEEZE: Many cancer biologists believe that tumor metastases could be prevented by inhibiting the proteolytic enzymes that chew through the extracellular matrix. When Peter Friedl's team at the University of Wuerzburg, Germany blocked all proteolytic activity of the cancer cells (blue) they found that the cells took a surprising alternate route, squeezing their way through small gaps in the matrix. Friedl speculates that mammalian cells can revert to

5-Prime | Nonribosomal Peptide Synthesis What is it? As the name suggests, nonribosomal peptide synthesis (NRPS) generates polypeptides sans ribosome. The resultant peptides, generally short oligomers of two to perhaps 48 residues, are not genome-encoded. Where ribosomal translation is limited to the standard complement of 20 L-amino acids, nonribosomal peptides may contain unusual building blocks, including D-amino acids, methylated variants of the standard amino acids, and nonproteinogen

Why is it that smoking--so expensive, personally injurious, and detrimental to the public purse--is still an essential part of daily life for so many of us? The primary answer is craving: Smoking is more reinforcing than crack cocaine. Teasing out the factors--psychological, neurological, and genetic--that contribute to nicotine dependence is a complex process, as we report on page 21. But the potential payoffs from new treatments in terms of health benefits (and developer profits) guarantees

Just as cataloging the human genome provides a jumping-off point to develop genetic testing and molecular-based therapies, a similar effort is necessary on the cellular level. A detailed understanding of how human cells develop into specialized tissues will open the door to regenerative medicine, the therapeutic replacement of cells, tissues, and organs lost to disease. But a significant barrier to fulfilling the promise of regenerative medicine is the absence of a fully characterized, human

Getting It Wrong Good to see some light-hearted history in the latest edition of The Scientist, but some of it appears incorrect.1 Karl Wilhelm Scheele did not discover arsenic. Arsenic compounds were known to the ancients, and the element's discovery is attributed to Albertus Magnus (1193-1280). Neither did Scheele discover nitrogen, let alone by 'sniffing it' (since nitrogen is an odorless gas). The discovery of nitrogen (in 1772) is attributed to Daniel Rutherford (1749-1819). And 'Hump

On the Postdoc Plantation Scientists should set up some system of assurances that funded scientists must behave as ethical employers. The practice that a 60- to 100-hour work week is required or an employee will be fired while being paid for 40 hours a week is an unfair labor practice. If an employer in the private sector paid 40 hours of wages to someone forced to work 80 hours, s/he would be considered a criminal. Yet this practice goes unnoticed in science every day. Ethical scientists

Reviewing Peer Review In response to the Closing Bell article in Jan. 27, 2003,1 I often think that the peer review system being blinded only one way (i.e., against the submitter but not the reviewer) is flawed and should be made transparent. Unblinding peer review may make the scientific process more adversarial, since rejections can be taken personally against a reviewer. Another potential disadvantage would be that collaborations between related labs might become harder to come by. Howev

Necessary Ambassadors At Oklahoma State we have a lot of grad students from the Arab countries, and this year the Biosystems and Agricultural Engineering Departments were unable to get two very good candidates because they couldn't get visas.1 These students are some of our best ambassadors of the US way of life when they return to the Arab world. We have little to fear from educated people. It is the uneducated zealot that will die for his cause that is the threat. The current INS polici

Null or Nil Steve Bunk's 5-PRIME on the null hypothesis was a good, brief piece.1 However, he made the common error of confusing the null hypothesis (the hypothesis against which the research result is tested) with the nil hypothesis (definition: if samples come from populations with identical parameters, the hypothesized difference is zero). The null hypothesis--that is, the one "sought to be nullified"--may be nil. But it also may be a population parameter, or a specified difference betwe

Front Page | Smoking Out Skin Cancer; Evolution in Action; Colon Cancer Resistance Found in Traveler's Diarrhea Anne Macnamara Ah, the Irony: Colon Cancer Resistance Found in Traveler's Diarrhea Put the Imodium away, fly to an exotic location, and please drink the water. A new study--prompted by a manuscript outline on a dinner napkin--links resistance to colon cancer with "travelers' diarrhea" (G.M. Pitari et al., "Bacterial enterotoxins are associated with resistance to colon cancer,"

Reprinted with permission, J Natl Cancer Inst, 94:1704-11, 2002 OF MICE AND DUCTS: Ductal branching (arrows), part of normal mammary-gland development, is absent in tissues from leptin-deficient (panel B) and leptin-receptor-deficient (D) mice, but is present in tissues from wild-type controls (A and C). By fostering mammary development, the leptin pathway might contribute to tumorigenesis. An estimated 30.5% of American adults--nearly 59 million people--were obese in 2000, after their r

Courtesy of Vincent A. Fischetti  ENIGMATIC ENZYME: Computer-generated ribbon model of the C-terminal end of the M protein sequence containing the conserved LPXTG motif (red). This region is also found in all C-terminal-anchored surface proteins from gram-positive bacteria. Imagine an enzyme assembled from multiple peptides, each the product of a different gene. Imagine that of the 60 amino acids in the sequence, only 40 are identifiable in the standard repertoire; the others are novel i

Courtesy of Upstate Cell Signaling Solutions  CONNECT THE DOTS: Apoptosis is a highly complex cellular process with many discrete and interacting signaling pathways. Apoptosis is about as complex a cellular choreography as one can imagine. Death signals impinge, chromatin cleaves, mitochondria release cell-destroying contents, and membranes undulate and form blebs, eventually shrink-wrapping the shattered cell into neat packages destined for the innards of a phagocyte. Many research grou

Front Page | DNA Detection Without PCR; Sequence-Analysis Beerware; Shuffling the Genome Deck Courtesy of AcaClone Software SOFTWARE WATCH | Sequence-Analysis Beerware DNA sequence analysis software needn't be expensive. For a decade, molecular biologist Kjeld Olesen has spent much of his spare time developing pDRAW32, a free sequence-analysis software package for Windows PCs. Researchers can perform restriction enzyme analyses, edit sequences, create plasmid maps, cut and ligate "in silico

Images courtesy of G. Méhes, University of Pécs, Hungary "As is our pathology, so is our practice... what the pathologist thinks today, the physician does tomorrow." --Sir William Osler (1849-1919)1 A woman visits her gynecologist for her annual Pap smear. The doctor takes a cervical swab and tells the patient that the results will be back in a few days. Now the woman waits and wonders, "Could I be sick, and not even know it?" The answer will come from the doctor by way of a p

Courtesy of UVItec  UVItec's UVIscan system Most life scientists own lab notebooks bursting with Polaroid film, each frame capturing a piece of agarose-embedded information. Whether those images are priceless or mundane, crystal-clear or blurry, all are one-of-a-kind: Spill a cup of coffee on the notebook, and a piece of data could be lost forever. But thanks to digital gel documentation systems, such worries are receding. "Basic documentation systems have become commodities in the labor

Courtesy of PerkinElmer  PerkinElmer's prOTOF 2000 MALDI-TOF mass spectrometer. Boston-based PerkinElmer Life and Analytical Sciences has released the prOTOF™ 2000, the first commercially available matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometer to feature orthogonal geometry and collisional cooling. The technology, originally developed at the University of Manitoba and sublicensed from instrumentation manufacturer MDS Sciex, offers improved

Complementary DNA (cDNA) libraries are standard tools for gene expression studies. In theory, the library contains full-length DNA copies of every mRNA in the starting sample, in abundances representative of the original sample. In reality, however, the libraries are often missing rare clones and contain partial gene fragments, complicating subsequent analyses. Further, transferring specific cDNA clones from one vector to another--to express the protein in mammalian cells instead of in bacteri

Courtesy of Applied Biosystems Single nucleotide polymorphisms--variations at specific nucleotide positions in the genome sequences of two individuals--are perhaps the most common form of genetic diversity; it is estimated that 3-10 million SNPs are present in the human genome. Researchers use these markers to map disease genes, and in the burgeoning field of pharmacogenomics (personalized medicine). Such research necessarily requires the ability to genotype on a grand scale, but until recent

Front Page | Defining the Dance of Molecules; How to Stem Seduction; The Prince, the Professors, and the Pea TIP TROVE | How to Stem Seduction Courtesy of Virginia Ashby Sharpe The allure of money and status has become a distraction that can divert even a "good" scientist from seeking the truth. Just the appearance of conflict of interest can damage the credibility of your research. Preserve intellectual freedom by not signing research contracts that give control of research or its public

Jennifer Strange In September 2000, the National Academy of Sciences released a report on the state of postdoctoral fellowships. Among other findings, the NAS determined that postdoctoral fellows were poorly paid. They believed that the system exploited them, and many had little hope for the future.1 Much has happened since then. The National Institutes of Health raised future postdoc salary targets by as much as 10% a year over the next five years. Offices for postdoctoral affairs have crop

D.F. Dowd When terrorists unleashed a new kind of fear in the United States on Sept. 11, 2001, few Americans may have guessed their attacks would also have significant repercussions for scientists and scientific research. Frustration over visa delays, discouragement over visa denials, and fears that US students, researchers, and employers might now be reluctant to work with them have led some foreign scholars to look elsewhere to advance their careers. As a result, concerns are growing that ne

Digitalvision Whether you're a penurious postdoc or a highly paid pharmaceutical executive, stress may be an unknown by-product of your daily lab work. Stress is our great common denominator. We are stressed, feel stressed, are stressed out, or are overstressed. Anyway you say it, grad students, professors, bench scientists, and their department supervisors live with some amount of stress everyday. "I guess it's demands, it's time lines," says Patrick Edwards, associate director in regulatory

Courtesy of Utpal Banerjee Utpal BanerjeeChair of the Department of Molecular, Cell, and Developmental Biology (MCDB) Professor of MCDB and the Biological Chemistry Department, University of California, Los Angeles Early indications: As far as I can remember, I have always wanted to become a scientist. In elementary school I saw a transparent liquid turn pink upon touching it; perhaps it was not quite as profound as wondering about the origin of life or anything, but it had the same effe

File Photo When I sought my first staff position in science writing, the Web didn't exist. Now I rely on it daily. Online resources provide limitless options in your job search, whether you're a writer like me, or a scientist seeking a research position. From start to finish, the Web can mostly help--but sometimes hinder--the job hunt. Judy Brobst and Erin Fendrich, both career counselors at Colorado State University, advise job hunters not to rely entirely on the Web or on E-mail to apply fo

Does the United States face a shortage of scientists and engineers? Are drooping science enrollments undermining America's strength? You might conclude so from the anxious warnings that perennially occupy a prominent place in scientific establishment pronouncements. An American Scientist editorial, in its July-August 2001 issue, asserts, "We are not training enough American scientists and engineers to retain our prosperity ...." Former NASA head Dan Goldin wrote in the September 2001 Atlantic