Nature 428, 783 (2004). doi:10.1038/428783a

Some oceanographers were hoping that a commission chaired by James Watkins would propose more radical reform of ocean research, education and exploration.

Nature 428, 783 (2004). doi:10.1038/428783b

Conventional agriculture needs to plough furrows of knowledge that were dismissed until recently as marginal and esoteric.

Nature 428, 785 (2004). doi:10.1038/428785a

Author: Rex Dalton

Plans to build a $178-million infectious diseases laboratory at Boston University have triggered strong objections from local scientists and residents, threatening the US government's plans to shore up its defences against biological agents.Around 150 scientists from the Boston area released a letter on 13

Nature 428, 785 (2004). doi:10.1038/428785b

Author: Alison Abbott

MunichOver a fifth of the expenses claimed by researchers funded under the European Commission's Fifth Framework Programme of Research (FP5) should not have been paid, according to the European Court of Auditors.The court studied 28 representative projects from the [euro]13.7-billion (US$16.3-billion), five-year programme,

Nature 428, 786 (2004). doi:10.1038/428786a

Author: Meredith Wadman

WashingtonThe US health department has issued comprehensive rules for handling scientific misconduct cases. And instead of kicking up a stink, most research organizations say that they find the regulations to their liking.On 19 April, the Department of Health and Human Services issued a

Nature 428, 786 (2004). doi:10.1038/428786b

Author: Erika Check

WashingtonBiotechnology firm Genentech is pinning its hopes on a mouse model, in a bid to broaden the use of a billion-dollar cancer drug.The company, based in South San Francisco, makes the drug Rituxan, which is used to treat non-Hodgkin's lymphoma. But clinical trials

Nature 428, 787 (2004). doi:10.1038/428787a

Author: Virginia Gewin

Ocean scientists in the United States have been waiting three years for a study, commissioned by President Bush, that they fervently hoped would revitalize the institutions that support their work. This week they got their report — but it remains unclear whether the revitalization will

Nature 428, 787 (2004). doi:10.1038/428787b

Author: David Cyranoski

TokyoFour Nobel prizes and various initiatives to popularize science don't seem to be making much difference: a survey just released by Japan's science ministry says that the public is losing interest in science and technology.Just 51% of the 2,084 adults polled earlier this

Nature 428, 788 (2004). doi:10.1038/428788a

Author: Laura Nelson

LondonEurope this week introduced stringent rules for the labelling of food that contains genetically modified organisms. But in most countries the labels will take months to appear — and questions remain about how they will be implemented.The rules, which are imposed by the

Nature 428, 788 (2004). doi:10.1038/428788b

Author: Quirin Schiermeier

MunichDumping iron sulphate in the ocean to cause plankton blooms might not seem an eco-friendly way to tackle global warming. But, according to the most extended trial of the technique so far, it could prove an effective one.The outcome of the trial in

Nature 428, 789 (2004). doi:10.1038/428789a

Author: Jim Giles

The Advanced Photon Source in Argonne, Illinois, occupies an area the size of a sports stadium. But if Ronald Ruth is right, this tool, widely used in materials and biomedical science, can be shrunk down to fit on a desk.Ruth's idea, which he outlined

Nature 428, 789 (2004). doi:10.1038/428789b

Author: Erika Check

WashingtonTrials of a new version of the smallpox vaccine have been halted because of a rare side effect, raising concerns about the vaccine's suitability for widespread use.On 13 April, Acambis in Cambridge, UK, said that it had stopped recruiting patients into a large

Nature 428, 790 (2004). doi:10.1038/428790a

Foxes and shrews identified as potential carriers of SARS virusTokyoFoxes and hedge-shrews have been added to the list of animals that harbour the virus that causes severe acute respiratory syndrome (SARS) in humans. The list also includes cats and ferrets, although the masked

Nature 428, 792 (2004). doi:10.1038/428792a

Author: Colin Macilwain

In its pure form, maybe not. But elements of the organic philosophy are starting to be deployed in mainstream agriculture. Nature's reporters analyse this trend, assess the extent of organic farming worldwide, and frame the questions on which its wider adoption will depend.

Nature 428, 796 (2004). doi:10.1038/428796a

In the developed world, sales of organic produce are growing rapidly. But how far can this trend extend? That depends on how strictly you define organic farming ... and the answers to three other pivotal questions.

Nature 428, 799 (2004). doi:10.1038/428799a

Author: Hermann Bondi

Misunderstanding of statistics is widespread and has led to miscarriages of justice.

Nature 428, 799 (2004). doi:10.1038/428799b

Authors: Richard J. Ladle, Paul Jepson, Miguel B. Araújo & Robert J. Whittaker

SirMedia coverage of conservation research is usually welcomed by the scientists involved, but there are pitfalls to heed. Damaging simplifications of research findings may expose conservationists to accusations of crying wolf, and play directly into the hands of anti-environmentalists. For example, in January 2004

Nature 428, 799 (2004). doi:10.1038/428799c

Author: David L. Vaux

SirIn the 19 February 2004 issue of Nature, there were ten items (one Brief Communication, one Article and eight Letters to Nature) containing figures with error bars, but only three had figure legends describing what the error bars were: in one case,

Nature 428, 801 (2004). doi:10.1038/428801a

Author: William Shaw

Howard Florey and colleagues overcame great obstacles to isolate penicillin.

Nature 428, 802 (2004). doi:10.1038/428802a

Authors: John Harris & Tuija Takala

For members of the general public confused by the heated debate generated by human cloning, A Clone of Your Own? does an admirable job in explaining many of the complicated ethical and scientific issues without giving way to academic jargon. Drawing from literature, the

Nature 428, 803 (2004). doi:10.1038/428803a

Author: Martin Kemp

Attila Csörgö's kinetic sculptures bring regular polyhedra to life.

Nature 428, 804 (2004). doi:10.1038/428804a

Author: David B. Wilson

Recovering unfamiliar ideas from the past can be difficult, but David Lindley accepts the challenge, providing for the most part a fine survey of Lord Kelvin's life for a general audience. His narrative takes us from the child prodigy William Thomson to his later years

Nature 428, 804 (2004). doi:10.1038/428804b

Strange Matters: Undiscovered Ideas at the Frontiers of Space and Timeby Tom SiegfriedBerkley, $15“Not just a tour of current theoretical speculation on time, space and matter, but rather a cogent argument as to why we should take these exotic ideas seriously.” Marc

Nature 428, 805 (2004). doi:10.1038/428805a

Authors: Horst-Werner Korf & Helmut Wicht

Anatomy: displays of bodies are no longer sufficient to explain the richness of modern anatomy to students or to the public.

Nature 428, 807 (2004). doi:10.1038/428807a

Author: Ian Woodward

The tallest living organisms are trees, but how tall could they be and what stops them growing any taller? Measurements at the tops of the world's tallest trees now provide quantitative answers to these questions.

Nature 428, 808 (2004). doi:10.1038/428808a

Authors: C. H. Back & D. Pescia

Are there any limits to what science and technology can achieve? When it comes to recording data in magnetic media, the answer is yes: there is a natural limit to the speed at which data can be encoded.

Nature 428, 809 (2004). doi:10.1038/428809a

Authors: David A. F. Loebel & Patrick P. L. Tam

In mammals, genomes from both parents are generally needed to make viable offspring. But changing the expression of ‘imprinted’ genes can render the father's contribution dispensable.

Nature 428, 809 (2004). doi:10.1038/428809b

100 YEARS AGOA Study of British Genius. Mr. Havelock Ellis recognises three great foci of intellectual ability in England:— (1) the East Anglian focus; (2) the south-western focus; and (3) the focus of the Welsh Border. The first of these is the most

Nature 428, 812 (2004). doi:10.1038/428812a

Author: Sébastien Merkel

What happens to minerals under the conditions characteristic of the Earth at great depths? Experiments performed under such conditions illustrate how the main constituent of the lower mantle may behave.

Nature 428, 813 (2004). doi:10.1038/428813a

Author: Deborah K. Morrison

The B-RAF protein is often mutated in human cancers, contributing to their development. Although most known mutations stimulate its catalytic activity, others, surprisingly, impair it — yet still cause cancer.

Nature 428, 813 (2004). doi:10.1038/428813b

Author: Günter Theißen

Structures that occur in closely related organisms and that look the same are usually considered to be homologous — their similarity is taken to arise from their common ancestry. Common sense suggests that the more complex such structures are, the less likely they are to

Nature 428, 816 (2004). doi:10.1038/428816a

Author: Leo Radom

Sir John Pople died on 15 March 2004 at the age of 78. He was a giant in his chosen field, computational quantum chemistry, for which he was awarded the Nobel Prize in Chemistry in 1998. Pople revolutionized the way chemistry is practised today by

Nature 428, 817 (2004). doi:10.1038/428817a

Surface chemistry: The molecules have landedAngew. Chem. Int. Edn43, 2092–2095 (2004)The ‘Lander’ molecules got their name from their resemblance to the Mars Lander craft. They have a conducting ‘board’ and four insulating legs, which act as tiny pylons that support the

Nature 428, 819 (2004). doi:10.1038/428819a

Authors: S. N. Patek, W. L. Korff & R. L. Caldwell

This shrimp packs a punch powerful enough to smash its prey's shell underwater.Stomatopods (mantis shrimp) are well known for the feeding appendages they use to smash shells and impale fish. Here we show that the peacock mantis shrimp (Odontodactylus scyllarus) generates an extremely fast strike that requires major energy storage and release, which we explain in terms of a saddle-shaped exoskeletal spring mechanism. High-speed images reveal the formation and collapse of vapour bubbles next to the prey due to swift movement of the appendage towards it, indicating that O. scyllarus may use destructive cavitation forces to damage its prey.

Nature 428, 820 (2004). doi:10.1038/428820a

Authors: Michael Worobey, Mario L. Santiago, Brandon F. Keele, Jean-Bosco N. Ndjango, Jeffrey B. Joy, Bernard L. Labama, Benoît D. Dhed'a, Andrew Rambaut, Paul M. Sharp, George M. Shaw & Beatrice H. Hahn

Despite strong evidence to the contrary, speculation continues that the AIDS virus, human immunodeficiency virus type 1 (HIV-1), may have crossed into humans as a result of contamination of the oral polio vaccine (OPV). This ‘OPV/AIDS theory’ claims that chimpanzees from the vicinity of Stanleyville — now Kisangani in the Democratic Republic of Congo — were the source of a simian immunodeficiency virus (SIVcpz) that was transmitted to humans when chimpanzee tissues were allegedly used in the preparation of OPV. Here we show that SIVcpz is indeed endemic in wild chimpanzees of this region but that the circulating virus is phylogenetically distinct from all strains of HIV-1, providing direct evidence that these chimpanzees were not the source of the human AIDS pandemic.

Nature 428, 821 (2004). doi:10.1038/nature02403

Authors: Ian J. Wright, Peter B. Reich, Mark Westoby, David D. Ackerly, Zdravko Baruch, Frans Bongers, Jeannine Cavender-Bares, Terry Chapin, Johannes H. C. Cornelissen, Matthias Diemer, Jaume Flexas, Eric Garnier, Philip K. Groom, Javier Gulias, Kouki Hikosaka, Byron B. Lamont, Tali Lee, William Lee, Christopher Lusk, Jeremy J. Midgley, Marie-Laure Navas, Ülo Niinemets, Jacek Oleksyn, Noriyuki Osada, Hendrik Poorter, Pieter Poot, Lynda Prior, Vladimir I. Pyankov, Catherine Roumet, Sean C. Thomas, Mark G. Tjoelker, Erik J. Veneklaas & Rafael Villar

Bringing together leaf trait data spanning 2,548 species and 175 sites we describe, for the first time at global scale, a universal spectrum of leaf economics consisting of key chemical, structural and physiological properties. The spectrum runs from quick to slow return on investments of

Nature 428, 828 (2004). doi:10.1038/nature02470

Author: Philip S. Marcus

Jupiter's atmosphere, as observed in the 1979 Voyager space craft images, is characterized by 12 zonal jet streams and about 80 vortices, the largest of which are the Great Red Spot and three White Ovals that had formed in the 1930s. The Great Red Spot has been observed continuously since 1665 and, given the dynamical similarities between the Great Red Spot and the White Ovals, the disappearance of two White Ovals in 1997–2000 was unexpected. Their longevity and sudden demise has been explained however, by the trapping of anticyclonic vortices in the troughs of Rossby waves, forcing them to merge. Here I propose that the disappearance of the White Ovals was not an isolated event, but part of a recurring climate cycle which will cause most of Jupiter's vortices to disappear within the next decade. In my numerical simulations, the loss of the vortices results in a global temperature change of about 10 K, which destabilizes the atmosphere and thereby leads to the formation of new vortices. After formation, the large vortices are eroded by turbulence over a time of ∼60 years—consistent with observations of the White Ovals—until they disappear and the cycle begins again.

Nature 428, 831 (2004). doi:10.1038/nature02438

Authors: I. Tudosa, C. Stamm, A. B. Kashuba, F. King, H. C. Siegmann, J. Stöhr, G. Ju, B. Lu & D. Weller

In magnetic memory devices, logical bits are recorded by selectively setting the magnetization vector of individual magnetic domains either ‘up’ or ‘down’. In such devices, the fastest and most efficient recording method involves precessional switching: when a magnetic field Bp is applied as a write pulse over a period τ, the magnetization vector precesses about the field until Bpτ reaches the threshold value at which switching occurs. Increasing the amplitude of the write pulse Bp might therefore substantially shorten the required switching time τ and allow for faster magnetic recording. Here we use very short pulses of a very high magnetic field to show that under these extreme conditions, precessional switching in magnetic media supporting high bit densities no longer takes place at well-defined field strengths; instead, switching occurs randomly within a wide range of magnetic fields. We attribute this behaviour to a momentary collapse of the ferromagnetic order of the spins under the load of the short and high-field pulse, thus establishing an ultimate limit to the speed of deterministic switching and magnetic recording.

Nature 428, 834 (2004). doi:10.1038/nature02494

Authors: J. F. McManus, R. Francois, J.-M. Gherardi, L. D. Keigwin & S. Brown-Leger

The Atlantic meridional overturning circulation is widely believed to affect climate. Changes in ocean circulation have been inferred from records of the deep water chemical composition derived from sedimentary nutrient proxies, but their impact on climate is difficult to assess because such reconstructions provide insufficient constraints on the rate of overturning. Here we report measurements of 231Pa/230Th, a kinematic proxy for the meridional overturning circulation, in a sediment core from the subtropical North Atlantic Ocean. We find that the meridional overturning was nearly, or completely, eliminated during the coldest deglacial interval in the North Atlantic region, beginning with the catastrophic iceberg discharge Heinrich event H1, 17,500 yr ago, and declined sharply but briefly into the Younger Dryas cold event, about 12,700 yr ago. Following these cold events, the 231Pa/230Th record indicates that rapid accelerations of the meridional overturning circulation were concurrent with the two strongest regional warming events during deglaciation. These results confirm the significance of variations in the rate of the Atlantic meridional overturning circulation for abrupt climate changes.

Nature 428, 837 (2004). doi:10.1038/nature02472

Authors: Patrick Cordier, Tamás Ungár, Lehel Zsoldos & Géza Tichy

Seismic anisotropy provides an important observational constraint on flow in the Earth's deep interior. The quantitative interpretation of anisotropy, however, requires knowledge of the slip geometry of the constitutive minerals that are responsible for producing rock fabrics. The Earth's lower mantle is mostly composed of (Mg, Fe)SiO3 perovskite, but as MgSiO3 perovskite is not stable at high temperature under ambient pressure, it has not been possible to investigate its mechanical behaviour with conventional laboratory deformation experiments. To overcome this limitation, several attempts were made to infer the mechanical properties of MgSiO3 perovskite on the basis of analogue materials. But perovskites do not constitute an analogue series for plastic deformation, and therefore the direct investigation of MgSiO3 perovskite is necessary. Here we have taken advantage of recent advances in experimental high-pressure rheology to perform deformation experiments on coarse-grained MgSiO3 polycrystals under pressure and temperature conditions of the uppermost lower mantle. We show that X-ray peak broadening measurements developed in metallurgy can be adapted to low-symmetry minerals to identify the elementary deformation mechanisms activated under these conditions. We conclude that, under uppermost lower-mantle conditions, MgSiO3 perovskite deforms by dislocation creep and may therefore contribute to producing seismic anisotropy in rocks at such depths.

Nature 428, 840 (2004). doi:10.1038/nature02490

Authors: Joanne Lello, Brian Boag, Andrew Fenton, Ian R. Stevenson & Peter J. Hudson

Most animal species are infected with multiple parasite species; however, the role of interspecific parasite interactions in influencing parasite dynamics and shaping parasite communities has been unclear. Although laboratory studies have found evidence of cross-immunity, immunosuppression and competition, analyses of hosts in the field have generally concluded that parasite communities are little more than random assemblages. Here we present evidence of consistent interspecific interactions in a natural mammalian system, revealed through the analysis of parasite intensity data collected from a free-ranging rabbit (Oryctolagus cuniculus) population, sampled monthly for a period of 23 yr. The wild rabbit plays host to a diverse gut helminth community that reflects the communities seen in other economically important domestic herbivores. These findings suggest that parasite interactions could have profound implications for the dynamics of parasite communities. The efficacy of parasite control programmes could be jeopardized if such interactions are not taken into account. In contrast, a clear understanding of such interactions may provide the basis for the development of more environmentally acceptable methods of parasite control.

Nature 428, 844 (2004). doi:10.1038/nature02431

Authors: Philipp Langer, Katja Hogendoorn & Laurent Keller

One of the main transitions in evolution is the shift from solitary organisms to societies with reproductive division of labour. Understanding social evolution requires us to determine how ecological, social and genetic factors jointly influence group stability and partitioning of reproduction between group members. Here we test the role of the three key factors predicted to influence social evolution by experimentally manipulating them in a social allodapine bee. We show that increased relatedness between nestmates results in more even reproduction among group members and a greater productivity per individual. By contrast, the degree of reproductive skew is not influenced by the opportunity for solitary breeding or by the potential benefits of cooperation. Relatedness also has a positive effect on group stability and overall productivity. These findings are in line with predictions of the tug-of-war models, in which the degree of reproductive division of labour is determined primarily by selfish competition between group members. The alternative view, where the degree of reproductive skew is the outcome of a social contract between potential breeders, was not supported by the data.

Nature 428, 847 (2004). doi:10.1038/nature02489

Authors: Rebecca A. Zufall & Mark D. Rausher

A commonly accepted evolutionary principle is that adaptive change constrains the potential directions of future evolutionary change. One manifestation of this is Dollo's law, which states that character elimination is irreversible. Although the common occurrence of irreversibility has been documented by phylogenetic analyses of phenotypic transitions, little is known about the underlying causes of this phenomenon. One explanation for evolutionary irreversibility relies on the fact that many characteristics result from interactions between multiple gene products. Such characteristics may often be eliminated by inactivation of just one gene in the network. If they serve no other functions, other genes of the network are then free to accumulate mutations or evolve new functions. Evolutionary change after character loss results in the accumulation of redundant loss-of-function mutations. Such pathway degeneration makes it very unlikely that the characteristic will re-evolve, because multiple simultaneous mutations would be required. Here we describe what appear to be the initial stages of such degeneration in the anthyocyanin pigment pathway associated with an adaptive change from blue to red flowers in the morning glory Ipomoea quamoclit.

Nature 428, 851 (2004). doi:10.1038/nature02417

Authors: George W. Koch, Stephen C. Sillett, Gregory M. Jennings & Stephen D. Davis

Trees grow tall where resources are abundant, stresses are minor, and competition for light places a premium on height growth. The height to which trees can grow and the biophysical determinants of maximum height are poorly understood. Some models predict heights of up to 120 m in the absence of mechanical damage, but there are historical accounts of taller trees. Current hypotheses of height limitation focus on increasing water transport constraints in taller trees and the resulting reductions in leaf photosynthesis. We studied redwoods (Sequoia sempervirens), including the tallest known tree on Earth (112.7 m), in wet temperate forests of northern California. Our regression analyses of height gradients in leaf functional characteristics estimate a maximum tree height of 122–130 m barring mechanical damage, similar to the tallest recorded trees of the past. As trees grow taller, increasing leaf water stress due to gravity and path length resistance may ultimately limit leaf expansion and photosynthesis for further height growth, even with ample soil moisture.

Nature 428, 854 (2004). doi:10.1038/nature02467

Authors: David M. Eagleman, John E. Jacobson & Terrence J. Sejnowski

Brightness—the perception of an object's luminance—arises from complex and poorly understood interactions at several levels of processing. It is well known that the brightness of an object depends on its spatial context, which can include perceptual organization, scene interpretation, three-dimensional interpretation, shadows, and other high-level percepts. Here we present a new class of illusion in which temporal relations with spatially neighbouring objects can modulate a target object's brightness. When compared with a nearby patch of constant luminance, a brief flash appears brighter with increasing onset asynchrony. Simultaneous contrast, retinal effects, masking, apparent motion and attentional effects cannot account for this illusory enhancement of brightness. This temporal context effect indicates that two parallel streams—one adapting and one non-adapting—encode brightness in the visual cortex.

Nature 428, 856 (2004). doi:10.1038/nature02442

Authors: Paul Chadderton, Troy W. Margrie & Michael Häusser

To understand the computations performed by the input layers of cortical structures, it is essential to determine the relationship between sensory-evoked synaptic input and the resulting pattern of output spikes. In the cerebellum, granule cells constitute the input layer, translating mossy fibre signals into parallel fibre input to Purkinje cells. Until now, their small size and dense packing have precluded recordings from individual granule cells in vivo. Here we use whole-cell patch-clamp recordings to show the relationship between mossy fibre synaptic currents evoked by somatosensory stimulation and the resulting granule cell output patterns. Granule cells exhibited a low ongoing firing rate, due in part to dampening of excitability by a tonic inhibitory conductance mediated by GABAA (γ-aminobutyric acid type A) receptors. Sensory stimulation produced bursts of mossy fibre excitatory postsynaptic currents (EPSCs) that summate to trigger bursts of spikes. Notably, these spike bursts were evoked by only a few quantal EPSCs, and yet spontaneous mossy fibre inputs triggered spikes only when inhibition was reduced. Our results reveal that the input layer of the cerebellum balances exquisite sensitivity with a high signal-to-noise ratio. Granule cell bursts are optimally suited to trigger glutamate receptor activation and plasticity at parallel fibre synapses, providing a link between input representation and memory storage in the cerebellum.

Nature 428, 860 (2004). doi:10.1038/nature02402

Authors: Tomohiro Kono, Yayoi Obata, Quiong Wu, Katsutoshi Niwa, Yukiko Ono, Yuji Yamamoto, Eun Sung Park, Jeong-Sun Seo & Hidehiko Ogawa

Only mammals have relinquished parthenogenesis, a means of producing descendants solely from maternal germ cells. Mouse parthenogenetic embryos die by day 10 of gestation. Bi-parental reproduction is necessary because of parent-specific epigenetic modification of the genome during gametogenesis. This leads to unequal expression of imprinted genes from the maternal and paternal alleles. However, there is no direct evidence that genomic imprinting is the only barrier to parthenogenetic development. Here we show the development of a viable parthenogenetic mouse individual from a reconstructed oocyte containing two haploid sets of maternal genome, derived from non-growing and fully grown oocytes. This development was made possible by the appropriate expression of the Igf2 and H19 genes with other imprinted genes, using mutant mice with a 13-kilobase deletion in the H19 gene as non-growing oocytes donors. This full-term development is associated with a marked reduction in aberrantly expressed genes. The parthenote developed to adulthood with the ability to reproduce offspring. These results suggest that paternal imprinting prevents parthenogenesis, ensuring that the paternal contribution is obligatory for the descendant.

Nature 428, 864 (2004). doi:10.1038/nature02468

Authors: Sarah M. Webster, Donato del Camino, John P. Dekker & Gary Yellen

Voltage-gated potassium channels such as Shaker help to control electrical signalling in neurons by regulating the passage of K+ across cell membranes. Ion flow is controlled by a voltage-dependent gate at the intracellular side of the pore, formed by the crossing of four α-helices—the inner-pore helices. The prevailing model of gating is based on a comparison of the crystal structures of two bacterial channels—KcsA in a closed state and MthK in an open state—and proposes a hinge motion at a conserved glycine that splays the inner-pore helices wide open. We show here that two types of intersubunit metal bridge, involving cysteines placed near the bundle crossing, can occur simultaneously in the open state. These bridges provide constraints on the open Shaker channel structure, and on the degree of movement upon opening. We conclude that, unlike predictions from the structure of MthK, the inner-pore helices of Shaker probably maintain the KcsA-like bundle-crossing motif in the open state, with a bend in this region at the conserved proline motif (Pro-X-Pro) not found in the bacterial channels. A narrower opening of the bundle crossing in Shaker K+ channels may help to explain why Shaker has an approximately tenfold lower conductance than its bacterial relatives.

Nature 428, 868 (2004). doi:10.1038/nature02491

Authors: Lingchong You, Robert Sidney Cox, Ron Weiss & Frances H. Arnold

De novo engineering of gene circuits inside cells is extremely difficult, and efforts to realize predictable and robust performance must deal with noise in gene expression and variation in phenotypes between cells. Here we demonstrate that by coupling gene expression to cell survival and death using cell–cell communication, we can programme the dynamics of a population despite variability in the behaviour of individual cells. Specifically, we have built and characterized a ‘population control’ circuit that autonomously regulates the density of an Escherichia coli population. The cell density is broadcasted and detected by elements from a bacterial quorum-sensing system, which in turn regulate the death rate. As predicted by a simple mathematical model, the circuit can set a stable steady state in terms of cell density and gene expression that is easily tunable by varying the stability of the cell–cell communication signal. This circuit incorporates a mechanism for programmed death in response to changes in the environment, and allows us to probe the design principles of its more complex natural counterparts.

Nature 428, 873 (2004). doi:10.1038/nj6985-873a

Author: Paul Smaglik

Big science means big opportunities — huge centres, multimillion-dollar contracts and, often, hundreds of funded positions for investigators, postdocs and students. But choosing to take part in such enterprises, at any level, also comes with big risks — or at least some pretty serious questions

Nature 428, 874 (2004). doi:10.1038/nj6985-874a

Author: Quirin Schiermeier

Whenever Marc Van Montagu looks out of his office window, the plant-science pioneer sees a reminder of a field he seeded in Belgium. Twenty years ago, he and the late Josef Schell founded Plant Genetic Systems (PGS), one of the first companies to exploit the

Nature 428, 876 (2004). doi:10.1038/nj6985-876a

Author: Sidney Omelon

When I decided to leave my industry job to earn a master's degree, I knew I would return. Consequently, I sniffed out opportunities, went to interviews and even got a few job offers before I handed over my lab keys. When I left industry for

Nature 428, 876 (2004). doi:10.1038/nj6985-876b

Author: Ronald Laporte

E-recruitingIn academia, researchers traditionally use osmosis to build multidisciplinary collaborations — scientists diffuse into a new field by reading research in an area, then picking their partners. But the splitting of science into smaller units and the explosion in the amount of published literature

Nature 428, 876 (2004). doi:10.1038/nj6985-876c

Matthew Sherman, senior vice-president, Synta Pharmaceuticals, Lexington, MassachusettsMatthew Sherman's career path seems almost cyclical. Emerging from an academic background in Boston and Cambridge, Massachusetts, he went to work for the Genetics Institute, a small biotechnology company in Cambridge. That was eventually acquired by the