bluuebunny/crossref_metadata_2025 huggingface dataset:
Energetic and Fitness Costs of Mismatching Resource Supply and Demand in Seasonally Breeding Birds
Authors: Thomas Donald W. , Blondel Jacques , Perret Philippe , Lambrechts Marcel M. , Speakman John R.
Published: July 2002

By advancing spring leaf flush and ensuing food availability, climatic warming results in a mismatch between the timing of peak food supply and nestling demand, shifting the optimal time for reproduction in birds. Two populations of blue tits (
Parus caeruleus
) that breed at different dates in similar, but spatially distinct, habitat types in Corsica and southern France provide a unique opportunity to quantify the energetic and fitness consequences when breeding is mismatched with local productivity. As food supply and demand become progressively mismatched, the increased cost of rearing young pushes the metabolic effort of adults beyond their apparent sustainable limit, drastically reducing the persistence of adults in the breeding population. We provide evidence that the economics of parental foraging and limits to sustainable metabolic effort are key selective forces underlying synchronized seasonal breeding and long-term shifts in breeding date in response to climatic change.
Culturing American Life
Authors: Wolfe Audra J.
Published: July 2002

Biologists and the Promise of American Life
From Meriwether Lewis to Alfred Kinsey. Philip J. Pauly. Princeton University Press, Princeton, NJ, 2000. 329 pp. $29.95, £18.95. ISBN 0-691-04977-7.

Examining the social history of biology in the United States, Pauly argues that scientists coupled their researches to their desires to improve plants, animals, and human life and thus build a nation of "prosperous, liberal, secular, and humane" people.
Modern Molecular Vision
Authors: Baker Shenda M.
Published: July 2002

The New Chemistry
. Nina Hall, Ed. Cambridge University Press, New York, 2001. 505 pp. $49.95, £30. ISBN 0-521-45224-4.

Highlighting links between chemistry and other disciplines, the contributors cover advances in such areas as molecular technology, materials, computers, environmental chemistry, biochemistry, and biomedicine.
More Than a Mass of Incandescent Gas
Authors: Jokipii J. R.
Published: July 2002

The Sun from Space
. Kenneth R. Lang. Springer, New York, 2000. 373 pp. $64.95, DM129. ISBN 3-540-66944-2.

Lang's lucid overview highlights importance of spacecraft-based observations to the last decade's advances in our understanding of the Sun and its effects on Earth.
Grappling with Qubits
Authors: Mahler Günter
Published: July 2002

Quantum Computation and Quantum Information
. Michael A. Nielsen and Isaac L. Chuang. Cambridge University Press, New York, 2000. 702 pp. $130, £80. ISBN 0-521-63235-8. Paper, $47.95, £29.95. ISBN 0-521-63503-9.

Targeting their text at beginning graduate students and researchers with interests in quantum information and quantum computation, the authors offer a comprehensive overview of the most important techniques and results in this rapidly developing field.
Waiting for Vaccine
Authors: Weiss Robin A.
Published: July 2002

Shots in the Dark
The Wayward Search for an AIDS Vaccine. Jon Cohen. Norton, New York, 2001. 458 pp. $27.95, C$39.99, £21.95. ISBN 0-393-05027-0.

One of Science's writers, Cohen explores why we do not yet have a safe, efficacious vaccine to protect humans from HIV infection.
The Meaning of Make-Believe
Authors: Gopnik Alison
Published: July 2002

The Work of the Imagination
. Paul L. Harris. Blackwell, Oxford, 2000. 234 pp. $59.95, £50. ISBN 0-631-21885-8. Paper, $26.95, £14.99. ISBN 0-631-21886-6.

Refuting long-held views that the fantasies of children reflect primitive and irrational thought, Harris explores how imagination contributes to cognitive and emotional development.
The Shadow of Droughts' Deaths
Authors: Smil Vaclav
Published: July 2002

Late Victorian Holocausts
El Niño Famines and the Making of the Third World. Mike Davis. Verso, London, 2001. 474 pp. $27, C$38, £20. ISBN 1-85984-739-0.

In this passionate discussion of interactions among climate, economics, and politics, Davis argues that the widespread catastrophic crop failures of the late 19th-century led not only to tens of millions of deaths but also to the deepened division of humanity into haves and have-nots.
Ingredients for Tropical Renewal
Authors: Kapos Valerie
Published: July 2002

Green Phoenix
Restoring the Tropical Forests of Guanacaste, Costa Rica. William Allen. Oxford University Press, New York, 2001. 332 pp. $35, £22.95. ISBN 0-19-510893-0.

Allen's chronicle of the efforts to restore tropical forest lands in northwestern Costa Rica highlights the importance of political, social, and economic factors in conservation biology.
Dealing with Superabundant Diversity
Authors: Schulenberg Thomas S.
Published: July 2002

The Birds of Ecuador
Volume I: Status, Distribution, and Taxonomy. Volume II: Field Guide. by Robert S. Ridgely and Paul J. Greenfield. Cornell University Press, Ithaca, NY, 2001. Vol. I, 868 pp. Paper, $70. ISBN 0-8014-8720-X. Vol. II, 956 pp. Paper, $50. ISBN 0-8014-8721-8. Slipcased set. Paper, $110. ISBN 0-8014-8722-6.

Authors of field guides to the birds of tropical countries face the major challenge of addressing very diverse avifaunas within books that one could reasonably expect can be carried about in the field. Ridgely and Greenfield have opted to divide their coverage of Ecuador's more than 1500 species into an excellent identification guide and a companion volume that provides additional information on the occurrence and systematics of the birds.
Explaining Time's Arrow
Authors: Bricmont Jean
Published: July 2002

Time and Chance
. David Z. Albert. Harvard University Press, Cambridge, MA, 2001. 186 pp. $29.95, £20.50. ISBN 0-674-00317-9.

Examining the distinction between the past and the future, Albert combines an elementary introduction and an original contribution to the topic. He focuses on the tension between our understanding of the fundamental physical structure of the world and our everyday experience of it.
Anomalous Weak Magnetism in Superconducting YBa
2
Cu
3
O

6+
x
Authors: Sonier J. E. , Brewer J. H. , Kiefl R. F. , Miller R. I. , Morris G. D. , Stronach C. E. , Gardner J. S. , Dunsiger S. R. , Bonn D. A. , Hardy W. N. , Liang R. , Heffner R. H.
Published: July 2002

For some time now, there has been considerable experimental and theoretical effort to understand the role of the normal-state “pseudogap” phase in underdoped high-temperature cuprate superconductors. Recent debate has centered on the question of whether the pseudogap is independent of superconductivity. We provide evidence from zero-field muon spin relaxation measurements in YBa
2
Cu
3
O

6+
x

for the presence of small spontaneous static magnetic fields of electronic origin intimately related to the pseudogap transition. Our most significant finding is that, for optimal doping, these weak static magnetic fields appear well below the superconducting transition temperature. The two compositions measured suggest the existence of a quantum critical point somewhat above optimal doping.
Cenozoic Dramas
Authors: Pimm Stuart
Published: July 2002

The Eternal Frontier
An Ecological History of North America and Its Peoples. Tim Flannery. Atlantic Monthly Press, New York, 2001. 420 pp. $27.50. ISBN 0-87113-789-5.

In this engaging narrative covering the past 65 million years, Flannery emphasizes the underlying forces and common themes that have shaped the fauna and flora of North America.
The Model Science Adviser
Authors: O'Nions Keith
Published: July 2002

Solly Zuckerman
A Scientist out of the Ordinary. John Peyton. John Murray, London, 2001. 286 pp. £22.50. ISBN 0-7195-6283-X.

Peyton offers readers an account of the life of the anatomist and physiologist whose influential advice helped shape UK (and US) policies on matters ranging from bombing strategy during the Normany invasion to nuclear weapons policies during the 1960s.
Raising the Bar for Bird Guides
Authors: Dingle Hugh
Published: July 2002

Birds of North America
. by Kenn Kaufman. Houghton Mifflin, New York, 2000. 384 pp. Paper, $20. ISBN 0-395-96464-4.

The Sibley Guide to Birds
. by David Allen Sibley. Knopf, New York, 2000. 544 pp. Paper, $35, C$53. ISBN 0-679-45122-6.

North American Bird Guide
. Pica (Helm Information), East Sussex, UK, 2000. 544 pp. Paper, £25. ISBN 1-873403-98-4.

Collins Bird Guide
. by Lars Svensson, Killian Mullarney, Dan Zetterström, and Peter J. Grant. Harper Collins, London, 1999. 399 pp. £24.99. ISBN 0-00-219728-6. Large format, 2000. £29.99. ISBN 0-00-710082-5. Paper, 2001. £16.99. ISBN 0-00-711332-3.

Birds of Europe
. Princeton University Press, Princeton, NJ, 2000. 400 pp. Paper, $29.95. ISBN 0-691-05054-6.

These three books advance the state-of-the-art in bird guides. Those new to birdwatching will find Kaufman's digitally edited photographs and concise text an efficient introduction to North American birds. Sibley's annotated, detailed paintings of flying and perched birds cover sexual, age, and geographic variation, and his book has been enthusiastically received by birders. Svensson
et al
. combine a comprehensive text on the field identification of European birds and superb artwork in what is the finest field guide to date for any regional avifauna.
Old Insects, New Treatment
Authors: Paulson Dennis R.
Published: July 2002

Dragonflies Through Binoculars
A Field Guide to Dragonflies of North America. by Sidney W. Dunkle. Oxford University Press, New York, 2000. 274 pp. Paper, $29.95, £18.99. ISBN 0-19-511268-7.

To aid those interested in dragonfly-watching, Dunkle offers color photographs and informative text on the field identification and biology of the 307 species found in North America.
Mutated into Oblivion
Authors: Delph Lynda F.
Published: July 2002

Mendel's Demon
Gene Justice and the Complexity of Life.
By Mark Ridley
. Weidenfeld and Nicolson, London, 2000. 351 pp. 20 pounds. ISBN 0-297-64634-6.
released in the US as
.
The Cooperative Gene
How Mendel's Demon Explains the Evolution of Complex Beings. Free Press, New York, 2001. 336 pp. $26, C$39.50. ISBN 0-7432-0161-2.

Ridley offers an intriguing consideration of the origins, persistence, and future prospects of complex life. He discusses how organisms adapted to deal with mutational mistakes in the copying of DNA, and he interprets the complicated process of meiosis as a mechanism that evolved to check selfish genes.
Comparative Genomics of
Listeria
Species
Authors: Glaser P. , Frangeul L. , Buchrieser C. , Rusniok C. , Amend A. , Baquero F. , Berche P. , Bloecker H. , Brandt P. , Chakraborty T. , Charbit A. , Chetouani F. , Couvé E. , de Daruvar A. , Dehoux P. , Domann E. , Domı́nguez-Bernal G. , Duchaud E. , Durant L. , Dussurget O. , Entian K.-D. , Fsihi H. , Portillo F. Garcia-Del , Garrido P. , Gautier L. , Goebel W. , Gómez-López N. , Hain T. , Hauf J. , Jackson D. , Jones L.-M. , Kaerst U. , Kreft J. , Kuhn M. , Kunst F. , Kurapkat G. , Madueño E. , Maitournam A. , Vicente J. Mata , Ng E. , Nedjari H. , Nordsiek G. , Novella S. , de Pablos B. , Pérez-Diaz J.-C. , Purcell R. , Remmel B. , Rose M. , Schlueter T. , Simoes N. , Tierrez A. , Vázquez-Boland J.-A. , Voss H. , Wehland J. , Cossart P.
Published: July 2002

Listeria monocytogenes
is a food-borne pathogen with a high mortality rate that has also emerged as a paradigm for intracellular parasitism. We present and compare the genome sequences of
L. monocytogenes
(2,944,528 base pairs) and a nonpathogenic species,
L. innocua
(3,011,209 base pairs). We found a large number of predicted genes encoding surface and secreted proteins, transporters, and transcriptional regulators, consistent with the ability of both species to adapt to diverse environments. The presence of 270
L. monocytogenes
and 149
L. innocua
strain-specific genes (clustered in 100 and 63 islets, respectively) suggests that virulence in
Listeria
results from multiple gene acquisition and deletion events.
Human Appropriation of Photosynthesis Products
Authors: Rojstaczer Stuart , Sterling Shannon M. , Moore Nathan J.
Published: July 2002

Previous global estimates of the human impact on terrestrial photosynthesis products depended heavily on extrapolation from plot-scale measurements. Here, we estimated this impact with the use of recent data, many of which were collected at global and continental scales. Monte Carlo techniques that incorporate known and estimated error in our parameters provided estimates of uncertainty. We estimate that humans appropriate 10 to 55% of terrestrial photosynthesis products. This broad range reflects uncertainty in key parameters and makes it difficult to ascertain whether we are approaching crisis levels in our use of the planet's resources. Improved estimates will require high-resolution global measures within agricultural lands and tropical forests.
Nota Bene: For the Curious
Authors: Lavine Marc
Published: July 2002

How Things Work
The Physics of Everyday Life. 2nd ed. Louis A. Bloomfield . Wiley, New York, 2001. 536 pp. Paper, $74.95. ISBN 0-471-38151-9.

Scientific American
How Things Work Today

. Michael Wright and Mukul Patel, Eds. Crown, New York, 2000. 288 pp. $29.95, C$49.95. ISBN 0-375-41023-6.

These two books with nearly identical titles offer readers complementary approaches to understanding the hows and whys of ordinary and no-so-ordinary objects.
Systems Analysis of Ran Transport
Authors: Smith Alicia E. , Slepchenko Boris M. , Schaff James C. , Loew Leslie M. , Macara Ian G.
Published: July 2002

The separate components of nucleocytoplasmic transport have been well characterized, including the key regulatory role of Ran, a guanine nucleotide triphosphatase. However, the overall system behavior in intact cells is difficult to analyze because the dynamics of these components are interdependent. We used a combined experimental and computational approach to study Ran transport in vivo. The resulting model provides the first quantitative picture of Ran flux between the nuclear and cytoplasmic compartments in eukaryotic cells. The model predicts that the Ran exchange factor RCC1, and not the flux capacity of the nuclear pore complex (NPC), is the crucial regulator of steady-state flux across the NPC. Moreover, it provides the first estimate of the total in vivo flux (520 molecules per NPC per second and predicts that the transport system is robust.
Structure, Function, and Activator-Induced Conformations of the CRSP Coactivator
Authors: Taatjes Dylan J. , Näär Anders M. , Andel Frank , Nogales Eva , Tjian Robert
Published: July 2002

The human cofactor complexes ARC (activator-recruited cofactor) and CRSP (cofactor required for Sp1 activation) mediate activator-dependent transcription in vitro. Although these complexes share several common subunits, their structural and functional relationships remain unknown. Here, we report that affinity-purified ARC consists of two distinct multisubunit complexes: a larger complex, denoted ARC-L, and a smaller coactivator, CRSP. Reconstituted in vitro transcription with biochemically separated ARC-L and CRSP reveals differential cofactor functions. The ARC-L complex is transcriptionally inactive, whereas the CRSP complex is highly active. Structural determination by electron microscopy (EM) and three-dimensional reconstruction indicate substantial differences in size and shape between ARC-L and CRSP. Moreover, EM analysis of independently derived CRSP complexes reveals distinct conformations induced by different activators. These results suggest that CRSP may potentiate transcription via specific activator-induced conformational changes.
McClintock at 100--Reason to Celebrate
Authors: Wessler Susan R.
Published: July 2002

The Tangled Field
Barbara McClintock's Search for the Patterns of Genetic Control. Nathaniel C. Comfort. Harvard University Press, Cambridge, MA, 2001. 357 pp. $37.50, £25.95. ISBN 0-674-00456-6.

Comfort focuses on the development and context of McClintock's research. He argues that, contrary to current opinion, her work on transposition was both understood and appreciated, although her ideas on "controlling elements" failed to convince her colleagues.
A Highly Personal Perspective
Authors: Ptashne Mark
Published: July 2002

Operators and Promoters
The Story of Molecular Biology and Its Creators. Harrison Echols. Edited by Carol A. Gross. University of California Press, Berkeley, 2001. 486 pp. $65, £43. ISBN 0-520-21331-9.

Combining observations and experiences from his own career with results from interviews of many of the important participants, the late "Hatch" Echols offers a interesting personal perspective on the development of modern molecular biology.
High-Density Intro to Information Devices
Authors: Goodwin David G.
Published: July 2002

The Physics of Information Technology
. Neil Gershenfeld. Cambridge University Press, Cambridge, 2000. 384 pp. $39.95, £24.95. ISBN 0-521-58044-7.

Gershenfeld offers a concise but wide-ranging account of the physical processes that underlie and constrain information technology.
Certain Diseases, Uncertain Explanations
Authors: Morens David
Published: July 2002

Human Frontiers, Environments and Disease
Past Patterns, Uncertain Futures. Tony McMichael. Cambridge University Press, Cambridge, 2001. 413 pp. $59.95. ISBN 0-521-80311-X. Paper, $24.95. ISBN 0-521-00494-2.

McMichael uses ecology to meld a wide range of perspectives on understanding human health and disease.
A Synthesis that Failed
Authors: Dixon Thomas
Published: July 2002

Reconciling Science and Religion
The Debate in Early-Twentieth-Century Britain. Peter J. Bowler. University of Chicago Press, Chicago, 2001. 493 pp. $40, £24. ISBN 0-226-06858-7.

In contrast to the clash between evolution and fundamentalism in the United States, Bowler finds conservative scientists and liberal theologians in Britain made a concerted effort to promote a unified perspective on humans' place in the world.
Working Towards a Sustainable Future
Authors: Patterson Walt
Published: July 2002

World Energy Assessment
Energy and the Challenge of Sustainability. José Goldemberg, Ed. United Nations Development Programme, United Nations Department of Economic and Social Affairs, and World Energy Council, New York, 2001. 528 pp. Paper, $65. ISBN 92-1-126126-0.

In this comprehensive global perspective on energy, the authors conclude that achieving sustainable development will require changes in the kinds of energy we produce and the ways we use them.
Role of Diacylglycerol in PKD Recruitment to the TGN and Protein Transport to the Plasma Membrane
Authors: Baron Carole L. , Malhotra Vivek
Published: July 2002

Protein kinase D (PKD) is a cytosolic serine-threonine kinase that binds to the trans-Golgi network (TGN) and regulates the fission of transport carriers specifically destined to the cell surface. PKD was found to bind diacylglycerol (DAG), and this binding was necessary for its recruitment to the TGN. Reducing cellular levels of DAG inhibited PKD recruitment and blocked protein transport from the TGN to the cell surface. Thus, a DAG-dependent, PKD-mediated signaling regulates the formation of transport carriers from the TGN in mammalian cells.
A Martian's Chronicles
Authors: Herken Gregg
Published: July 2002

Memoirs
A Twentieth-Century Journey in Science and Politics. Edward Teller with Judy Shoolery. Perseus, Cambridge, MA, 2001. 640 pp. $35, C$52.95. ISBN 0-7382-0532-X.

One of the most influential and most controversial scientists of the just-concluded century offers a personal perspective on his life, his causes, and their context.
Wider Than the Sky
Authors: Smith Orla
Published: July 2002

The Secret Life of the Brain
. David Grubin Productions and Thirteen/WNET, New York. On PBS, beginning 22 January 2002.

The Secret Life of the Brain
. by Richard Restak. Joseph Henry (National Academy Press), Washington, DC, and the Dana Press, 2001. 224 pp. $35, £21.95. ISBN 0-309-07435-5.

Drawing heavily on research from the past decade, this five-part series on PBS (and Restak's accompanying book) detail the brain's development from gestation through old age.
Stability in Real Food Webs: Weak Links in Long Loops
Authors: Neutel Anje-Margriet , Heesterbeek Johan A. P. , de Ruiter Peter C.
Published: July 2002

Increasing evidence that the strengths of interactions among populations in biological communities form patterns that are crucial for system stability requires clarification of the precise form of these patterns, how they come about, and why they influence stability. We show that in real food webs, interaction strengths are organized in trophic loops in such a way that long loops contain relatively many weak links. We show and explain mathematically that this patterning enhances stability, because it reduces maximum “loop weight” and thus reduces the amount of intraspecific interaction needed for matrix stability. The patterns are brought about by biomass pyramids, a feature common to most ecosystems. Incorporation of biomass pyramids in 104 food-web descriptions reveals that the low weight of the long loops stabilizes complex food webs. Loop-weight analysis could be a useful tool for exploring the structure and organization of complex communities.
Control of Stomatal Distribution on the
Arabidopsis
Leaf Surface
Authors: Nadeau Jeanette A. , Sack Fred D.
Published: July 2002

Stomata regulate gas exchange and are distributed across the leaf epidermis with characteristic spacing.
Arabidopsis
stomata are produced by asymmetric cell divisions. Mutations in the gene
TOO MANY MOUTHS
(
TMM
) disrupt patterning by randomizing the plane of formative asymmetric divisions and by permitting ectopic divisions.
TMM
encodes a leucine-rich repeat–containing receptor-like protein expressed in proliferative postprotodermal cells. TMM appears to function in a position-dependent signaling pathway that controls the plane of patterning divisions as well as the balance between stem cell renewal and differentiation in stomatal and epidermal development.
Optical Control of Photogenerated Ion Pair Lifetimes: An Approach to a Molecular Switch
Authors: Debreczeny Martin P. , Svec Walter A. , Wasielewski Michael R.
Published: July 2002

A prototype molecular switch is demonstrated that works on the principle that the local electric field produced by one photogenerated ion pair (D
1
+
-A
1
−
) can influence the rate constants for photoinduced electron transfer and recombination in a second donor-acceptor pair (A
2
-D
2
). Two ultrafast laser pulses were used to control the rate of a photoinduced electron transfer reaction within a molecule that consists of two covalently linked electron donor-acceptor pairs fixed in a linear structure, D
1
-A
1
-A
2
-D
2
. This type of molecular architecture may lead to the development of electronic devices that function on the molecular length scale.
Travel Grants to Boost Sagging Labs
Authors: Stone Richard
Published: July 2002

A hundred U.S. scientists will travel next year to Russia's two main nuclear weapons institutes in a program that will spur collaborative research but is not likely to be the tonic that Russian scientists need to regain the productivity and comfortable way of life they once enjoyed.
Design of Nonionic Surfactants for Supercritical Carbon Dioxide
Authors: McClain J. B. , Betts D. E. , Canelas D. A. , Samulski E. T. , DeSimone J. M. , Londono J. D. , Cochran H. D. , Wignall G. D. , Chillura-Martino D. , Triolo R.
Published: July 2002

Interfacially active block copolymer amphiphiles have been synthesized and their self-assembly into micelles in supercritical carbon dioxide (CO
2
) has been demonstrated with small-angle neutron scattering (SANS). These materials establish the design criteria for molecularly engineered surfactants that can stabilize and disperse otherwise insoluble matter into a CO
2
continuous phase. Polystyrene-
b
-poly(1,1-dihydroperfluorooctyl acrylate) copolymers self-assembled into polydisperse core-shell-type micelles as a result of the disparate solubility characteristics of the different block segments in CO
2
. These nonionic surfactants for CO
2
were shown by SANS to be capable of emulsifying up to 20 percent by weight of a CO
2
-insoluble hydrocarbon into CO
2
. This result demonstrates the efficacy of surfactant-modified CO
2
in reducing the large volumes of organic and halogenated solvent waste streams released into our environment by solvent-intensive manufacturing and process industries.
Center Seeks Synthesis to Make Ecology More Useful
Authors: Baskin Yvonne
Published: July 2002

Ecology is supposed to be the most synthetic of the biological disciplines, but in the past few decades, many ecological studies have drifted toward a short-term, small-scale focus. How can the field get back to its roots as a synthetic science, and so answer broad environmental questions? Officials at a new center in Santa Barbara, California, think they can help by examining ecology's big questions—without collecting any new data.
Heterogeneous and Multiphase Chemistry in the Troposphere
Authors: Ravishankara A. R.
Published: July 2002

Heterogeneous and multiphase reactions on solids and in liquids, respectively, have the potential to play a major role in determining the composition of the gaseous troposphere and should be included in models for understanding this region and assessing the effects of anthropogenic emissions. Making a distinction between reactions on solids (heterogeneous reactions) and those occurring in liquid droplets (multiphase reactions) is convenient for understanding, describing, and including them in models of the troposphere. Frameworks are available for including multiphase reactions in numerical models, but they do not yet exist for heterogeneous reactions. For most of these reactions, water not only provides the medium but it is also a reactant. Other substrates such as sulfate and organic and sea-salt aerosols may also be important, but their effects cannot currently be accurately assessed because of a lack of information on their abundance, nature, and reactivities. Our ability to accurately predict the composition of the troposphere will depend on advances in understanding the microphysics of particle formation, laboratory investigations of heterogeneous and multiphase reactions, and collection of field data on tropospheric particles.
Midwinter Start to Antarctic Ozone Depletion: Evidence from Observations and Models
Authors: Roscoe H. K. , Jones A. E. , Lee A. M.
Published: July 2002

Measurements of total ozone at Faraday, Antarctica (65°S), by a visible spectrometer show a winter maximum. This new observation is consistent with the descent of air within the polar vortex during early winter, together with ozone depletion starting in midwinter. Chemical depletion at these latitudes in midwinter is suggested by existing satellite observations of enhanced chlorine monoxide and reduced ozone above 100 hectapascals and by reduced ozone in sonde profiles. New three-dimensional model calculations for 1994 confirm that chemical ozone depletion started in June at the sunlit vortex edge and became substantial by late July. This would not have been observed by most previous techniques, which either could not operate in winter or were closer to the Pole.
A Laser Ablation Method for the Synthesis of Crystalline Semiconductor Nanowires
Authors: Morales Alfredo M. , Lieber Charles M.
Published: July 2002

A method combining laser ablation cluster formation and vapor-liquid-solid (VLS) growth was developed for the synthesis of semiconductor nanowires. In this process, laser ablation was used to prepare nanometer-diameter catalyst clusters that define the size of wires produced by VLS growth. This approach was used to prepare bulk quantities of uniform single-crystal silicon and germanium nanowires with diameters of 6 to 20 and 3 to 9 nanometers, respectively, and lengths ranging from 1 to 30 micrometers. Studies carried out with different conditions and catalyst materials confirmed the central details of the growth mechanism and suggest that well-established phase diagrams can be used to predict rationally catalyst materials and growth conditions for the preparation of nanowires.
The Life and Death of "Bare" Viscous Bubbles
Authors: Debrégeas G. , de Gennes P.-G. , Brochard-Wyart F.
Published: July 2002

Air bubbles collect and explode at the surface of many viscous liquids, as observed with polymer foams, in glass furnaces, and during volcanic eruptions. The liquid film separating the bubble from bulk air can have a long lifetime (if it is viscous) even if it is not protected by a surfactant. These “bare” films display unusual dynamic behaviors in drainage and rupture. Two different model systems were studied: a polymer melt (silicone oil) and a molten (borosilicate) glass of comparable viscosity. Although the two systems differ greatly in their relaxation time, they are described by the same set of laws, which can be understood from a relatively simple hydrodynamic model.
Chaos, Persistence, and Evolution of Strain Structure in Antigenically Diverse Infectious Agents
Authors: Gupta Sunetra , Ferguson Neil , Anderson Roy
Published: July 2002

The effects of selection by host immune responses on transmission dynamics was analyzed in a broad class of antigenically diverse pathogens. Strong selection can cause pathogen populations to stably segregate into discrete strains with nonoverlapping antigenic repertoires. However, over a wide range of intermediate levels of selection, strain structure is unstable, varying in a manner that is either cyclical or chaotic. These results have implications for the interpretation of longitudinal epidemiological data on strain or serotype abundance, design of surveillance strategies, and the assessment of multivalent vaccine trials.
Localization of Metastable Atom Beams with Optical Standing Waves: Nanolithography at the Heisenberg Limit
Authors: Johnson K. S. , Thywissen J. H. , Dekker N. H. , Berggren K. K. , Chu A. P. , Younkin R. , Prentiss M.
Published: July 2002

The spatially dependent de-excitation of a beam of metastable argon atoms, traveling through an optical standing wave, produced a periodic array of localized metastable atoms with position and momentum spreads approaching the limit stated by the Heisenberg uncertainty principle. Silicon and silicon dioxide substrates placed in the path of the atom beam were patterned by the metastable atoms. The de-excitation of metastable atoms upon collision with the surface promoted the deposition of a carbonaceous film from a vapor-phase hydrocarbon precursor. The resulting patterns were imaged both directly and after chemical etching. Thus, quantum-mechanical steady-state atom distributions can be used for sub-0.1-micrometer lithography.
Climate-Ocean Variability and Ecosystem Response in the Northeast Pacific
Authors: McGowan John A. , Cayan Daniel R. , Dorman LeRoy M.
Published: July 2002

The role of climatic variation in regulating marine populations and communities is not well understood. To improve our knowledge, the sign, amplitude, and frequency of climatic and biotic variations should be compared as a necessary first step. It is shown that there have been large interannual and interdecadal sea-surface temperature changes off the West Coast of North America during the past 80 years. Interannual anomalies appear and disappear rather suddenly and synchronously along the entire coastline. The frequency of warm events has increased since 1977. Although extensive, serial, biological observations are often incomplete, it is clear that climate-ocean variations have disturbed and changed our coastal ecosystems.
Lunar Surface Magnetic Fields and Their Interaction with the Solar Wind: Results from Lunar Prospector
Authors: Lin R. P. , Mitchell D. L. , Curtis D. W. , Anderson K. A. , Carlson C. W. , McFadden J. , Acuña M. H. , Hood L. L. , Binder A.
Published: July 2002

The magnetometer and electron reflectometer experiment on the Lunar Prospector spacecraft has obtained maps of lunar crustal magnetic fields and observed the interaction between the solar wind and regions of strong crustal magnetic fields at high selenographic latitude (30°S to 80°S) and low (∼100 kilometers) altitude. Electron reflection maps of the regions antipodal to the Imbrium and Serenitatis impact basins, extending to 80°S latitude, show that crustal magnetic fields fill most of the antipodal zones of those basins. This finding provides further evidence for the hypothesis that basin-forming impacts result in magnetization of the lunar crust at their antipodes. The crustal magnetic fields of the Imbrium antipode region are strong enough to deflect the solar wind and form a miniature (100 to several hundred kilometers across) magnetosphere, magnetosheath, and bow shock system.
Photorefractive Materials for Nonvolatile Volume Holographic Data Storage
Authors: Hesselink Lambertus , Orlov Sergei S. , Liu Alice , Akella Annapoorna , Lande David , Neurgaonkar Ratnakar R.
Published: July 2002

Optically gated recording and nonvolatile readout in a digital volume holographic data storage system that uses a pair of mutually incoherent light sources during recording and only one for readout were demonstrated recently. This approach used stoichiometric lithium niobate, which after post-growth processing gave rise to an at least two orders of magnitude improvement in sensitivity over the best materials reported previously. It is also shown that by adding certain dopants (iron and manganese) to near-stoichiometric lithium niobate, the dark storage time and gating efficiency can be increased compared with previous work. The underlying physical mechanisms of gated recording and the effectiveness of the gating process responsible for this manifold improved performance are discussed, and bipolarons and small polarons are identified as the responsible photorefractive species.
Regulation of the Proinflammatory Effects of Fas Ligand (CD95L)
Authors: Chen Jian-Jun , Sun Yongnian , Nabel Gary J.
Published: July 2002

Fas ligand (CD95L) inhibits T cell function in immune-privileged organs such as the eye and testis, yet in most tissues CD95L expression induces potent inflammatory responses. With a stably transfected colon carcinoma cell line, CT26-CD95L, the molecular basis for these divergent responses was defined. When injected subcutaneously, rejection of CT26-CD95L was caused by neutrophils activated by CD95L. CT26-CD95L survived in the intraocular space because of the presence of transforming growth factor–β (TGF-β), which inhibited neutrophil activation. Providing TGF-β to subcutaneous sites protected against tumor rejection. Thus, these cytokines together generate a microenvironment that promotes immunologic tolerance, which may aid in the amelioration of allograft rejection.
Electrochemical Principles for Active Control of Liquids on Submillimeter Scales
Authors: Gallardo Benedict S. , Gupta Vinay K. , Eagerton Franklin D. , Jong Lana I. , Craig Vincent S. , Shah Rahul R. , Abbott Nicholas L.
Published: July 2002

Electrochemical methods were combined with redox-active surfactants to actively control the motions and positions of aqueous and organic liquids on millimeter and smaller scales. Surfactant species generated at one electrode and consumed at another were used to manipulate the magnitude and direction of spatial gradients in surface tension and guide droplets of organic liquids through simple fluidic networks. Solid microparticles could be transported across unconfined surfaces. Electrochemical control of the position of surface-active species within aqueous films of liquid supported on homogeneous surfaces was used to direct these films into periodic arrays of droplets with deterministic shapes and sizes.
Giant Wormlike Rubber Micelles
Authors: Won You-Yeon , Davis H. Ted , Bates Frank S.
Published: July 2002

A low molecular weight poly(ethyleneoxide)-poly(butadiene) (PEO-PB) diblock copolymer containing 50 weight percent PEO forms gigantic wormlike micelles at low concentrations (<5 percent by weight) in water. Subsequent generation of free radicals with a conventional water-based redox reaction leads to chemical cross-linking of the PB cores without disruption of the cylindrical morphology, as evidenced by cryotransmission electron microscopy and small-angle neutron scattering experiments. These wormlike rubber micelles exhibit unusual viscoelastic properties in water.
A Glial-Neuronal Signaling Pathway Revealed by Mutations in a Neurexin-Related Protein
Authors: Yuan Li-Lian , Ganetzky Barry
Published: July 2002

In the nervous system, glial cells greatly outnumber neurons but the full extent of their role in determining neural activity remains unknown. Here the axotactin (
axo
) gene of
Drosophila
was shown to encode a member of the neurexin protein superfamily secreted by glia and subsequently localized to axonal tracts. Null mutations of
axo
caused temperature-sensitive paralysis and a corresponding blockade of axonal conduction. Thus, the AXO protein appears to be a component of a glial-neuronal signaling mechanism that helps to determine the membrane electrical properties of target axons.
How Human Can They Get?
Authors: Proudfoot Diane
Published: July 2002

The Age of Spiritual Machines
When Computers Exceed Human Intelligence. Ray Kurzweil. Viking, New York, 1999. 400 pp. $25.95. ISBN 0-670-88217-8.

Kurzweil predicts that the next century will witness the fusion of humans and machines, but the reviewer finds such predictions for the future undercut by shortcomings in the book's account of the present and recent past.
Dissociating Pain from Its Anticipation in the Human Brain
Authors: Ploghaus Alexander , Tracey Irene , Gati Joseph S. , Clare Stuart , Menon Ravi S. , Matthews Paul M. , Rawlins J. Nicholas P.
Published: July 2002

The experience of pain is subjectively different from the fear and anxiety caused by threats of pain. Functional magnetic resonance imaging in healthy humans was applied to dissociate neural activation patterns associated with acute pain and its anticipation. Expectation of pain activated sites within the medial frontal lobe, insular cortex, and cerebellum distinct from, but close to, locations mediating pain experience itself. Anticipation of pain can in its own right cause mood changes and behavioral adaptations that exacerbate the suffering experienced by chronic pain patients. Selective manipulations of activity at these sites may offer therapeutic possibilities for treating chronic pain.
Rapid Improvement in the Acuity of Infants After Visual Input
Authors: Maurer Daphne , Lewis Terri L. , Brent Henry P. , Levin Alex V.
Published: July 2002

Visual acuity was assessed in 28 human infants who had been deprived of all patterned visual input by cataracts in one or both eyes until they were treated at 1 week to 9 months of age. Immediately after treatment, acuity was no better than that of normal newborns. Acuity improved significantly over the next month, with some improvement apparent after as little as 1 hour of visual input. Unlike findings at older ages, the pattern of results was the same for eyes treated for monocular and for binocular deprivation. The results indicate that patterned visual input is necessary for the postnatal improvement of human visual acuity and that the onset of such input initiates rapid functional development.
Into the Minds of Babes
Authors: Johnson Mark H.
Published: July 2002

The Myth of the First Three Years
A New Understanding of Early Brain Development and Lifelong Learning. John T. Bruer. Free Press, New York, 1999. 256 pp. $25, C$37. ISBN 0-684-85184-9.

The Scientist in the Crib
Minds, Brains, and How Children Learn. Alison Gopnik, Andrew N. Meltzoff, and Patricia K. Kuhl. Morrow, New York, 1999. 299 pp. $24, C$35. ISBN 0-688-15988-5.

Johnson reviews two recent books that offer different perspectives on what we understand about the development of infant minds. Bruer argues that the overstatement and distortion of research results has had undesired effects on educational policy. Gopnik and colleagues focus on young children learn from their normal and complex surroundings.
Functional Human Corneal Equivalents Constructed from Cell Lines
Authors: Griffith May , Osborne Rosemarie , Munger Rejean , Xiong Xiaojuan , Doillon Charles J. , Laycock Noelani L. C. , Hakim Malik , Song Ying , Watsky Mitchell A.
Published: July 2002

Human corneal equivalents comprising the three main layers of the cornea (epithelium, stroma, and endothelium) were constructed. Each cellular layer was fabricated from immortalized human corneal cells that were screened for use on the basis of morphological, biochemical, and electrophysiological similarity to their natural counterparts. The resulting corneal equivalents mimicked human corneas in key physical and physiological functions, including morphology, biochemical marker expression, transparency, ion and fluid transport, and gene expression. Morphological and functional equivalents to human corneas that can be produced in vitro have immediate applications in toxicity and drug efficacy testing, and form the basis for future development of implantable tissues.
Cathedrals as Astronomical Instruments
Authors: Van Helden Albert
Published: July 2002

The Sun in the Church
Cathedrals as Solar Observatories. J. L. Heilbron. Harvard University Press, Cambridge, MA, 1999. 376 pp. $35. ISBN 0-674-85433-0.

Heilbron blends discussions of astronomy, religious architecture, and Catholic history to demonstrate that the Church's efforts to establish an unquestionable date for Easter led to evidence on the geometry of the solar system that favored the ideas for which Galileo had been condemned.
The Dark Halo of the Milky Way
Authors: Alcock Charles
Published: July 2002

Most of the matter in the Milky Way is invisible to astronomers. Precise numbers are elusive, but it appears that the dark component is 20 times as massive as the visible disk of stars and gas. This dark matter is distributed in space differently than the stars, forming a vast, diffuse halo, more spherical than disklike, which occupies more than 1000 times the volume of the disk of stars. The composition of this dark halo is unknown, but it may comprise a mixture of ancient, degenerate dwarf stars and exotic, hypothetical elementary particles.
Molecules in a Bose-Einstein Condensate
Authors: Wynar Roahn , Freeland R. S. , Han D. J. , Ryu C. , Heinzen D. J.
Published: July 2002

State-selected rubidium-87 molecules were created at rest in a dilute Bose-Einstein condensate of rubidium-87 atoms with coherent free-bound stimulated Raman transitions. The transition rate exhibited a resonance line shape with an extremely narrow width as small as 1.5 kilohertz. The precise shape and position of the resonance are sensitive to the mean-field interactions between the molecules and the atomic condensate. As a result, we were able to measure the molecule-condensate interactions. This method allows molecular binding energies to be determined with unprecedented accuracy and is of interest as a mechanism for the generation of a molecular Bose-Einstein condensate.
Proliferation, But Not Growth, Blocked by Conditional Deletion of 40
S
Ribosomal Protein S6
Authors: Volarević Siniša , Stewart Mary J. , Ledermann Birgit , Zilberman Frederic , Terracciano Luigi , Montini Eugenio , Grompe Markus , Kozma Sara C. , Thomas George
Published: July 2002

Because ribosome biogenesis plays an essential role in cell proliferation, control mechanisms may have evolved to recognize lesions in this critical anabolic process. To test this possibility, we conditionally deleted the gene encoding 40
S
ribosomal protein S6 in the liver of adult mice. Unexpectedly, livers from fasted animals deficient in S6 grew in response to nutrients even though biogenesis of 40
S
ribosomes was abolished. However, liver cells failed to proliferate or induce cyclin E expression after partial hepatectomy, despite formation of active cyclin D–CDK4 complexes. These results imply that abrogation of 40
S
ribosome biogenesis may induce a checkpoint control that prevents cell cycle progression.
Accommodating Phylogenetic Uncertainty in Evolutionary Studies
Authors: Huelsenbeck John P. , Rannala Bruce , Masly John P.
Published: July 2002

Many evolutionary studies use comparisons across species to detect evidence of natural selection and to examine the rate of character evolution. Statistical analyses in these studies are usually performed by means of a species phylogeny to accommodate the effects of shared evolutionary history. The phylogeny is usually treated as known without error; this assumption is problematic because inferred phylogenies are subject to both stochastic and systematic errors. We describe methods for accommodating phylogenetic uncertainty in evolutionary studies by means of Bayesian inference. The methods are computationally intensive but general enough to be applied in most comparative evolutionary studies.
Acts of Living
Authors: Harré Rom
Published: July 2002

The Drama of Everyday Life
. Karl E. Scheibe. Harvard University Press, Cambridge, MA, 2000. 295 pp. $25.95, £15.50. ISBN 0-674-00231-8.

Scheibe blends drama and psychology in an attempt to illuminate the connections between our everyday lives and our psychological processes.
Loss of Insulator Activity by Paired Su(Hw) Chromatin Insulators
Authors: Muravyova Ekaterina , Golovnin Anton , Gracheva Elena , Parshikov Aleksander , Belenkaya Tatiana , Pirrotta Vincenzo , Georgiev Pavel
Published: July 2002

Chromatin insulators are regulatory elements that block the action of transcriptional enhancers when interposed between enhancer and promoter. The
Drosophila
Suppressor of Hairy wing [Su(Hw)] protein binds the Su(Hw) insulator and prevents enhancer-promoter interaction by a mechanism that is not understood. We show that when two copies of the Su(Hw) insulator element, instead of a single one, are inserted between enhancer and promoter, insulator activity is neutralized and the enhancer-promoter interaction may instead be facilitated. This paradoxical phenomenon could be explained by interactions between protein complexes bound at the insulators.
Functional Nanoscale Electronic Devices Assembled Using Silicon Nanowire Building Blocks
Authors: Cui Yi , Lieber Charles M.
Published: July 2002

Because semiconductor nanowires can transport electrons and holes, they could function as building blocks for nanoscale electronics assembled without the need for complex and costly fabrication facilities. Boron- and phosphorous-doped silicon nanowires were used as building blocks to assemble three types of semiconductor nanodevices. Passive diode structures consisting of crossed
p
- and
n
-type nanowires exhibit rectifying transport similar to planar
p
-
n
junctions. Active bipolar transistors, consisting of heavily and lightly
n
-doped nanowires crossing a common
p
-type wire base, exhibit common base and emitter current gains as large as 0.94 and 16, respectively. In addition,
p
- and
n
-type nanowires have been used to assemble complementary inverter-like structures. The facile assembly of key electronic device elements from well-defined nanoscale building blocks may represent a step toward a “bottom-up” paradigm for electronics manufacturing.
An Internet Tea Party
Authors: Licinio Julio
Published: July 2002

The Diagnosis
. Alan Lightman. Pantheon, New York, 2000. 381 pp. $25, C$36. ISBN 0-679-43615-4. Bloomsbury, London, £16.99. ISBN 0-7475-4932-X.

A professor of humanities at MIT, Lightman has created a fascinating novel from a mysterious neurological disease, the hyperreality of the internet, and the story of Socrates' death.