bluuebunny/crossref_metadata_2025 huggingface dataset:
Glycerol formation during wine fermentation is mainly linked to Gpd1p and is only partially controlled by the HOG pathway
Authors: Remize F. , Cambon B. , Barnavon L. , Dequin S.
Published: November 2003

Glycerol 3‐phosphate dehydrogenase, a key enzyme in the production of glycerol, is encoded by GPD1 and GPD2. The isoforms encoded by these genes have different functions, in osmoregulation and redox balance, respectively. We investigated the roles of GPD1, GPD2 and HOG1—the kinase involved in the response to osmotic stress—in glycerol production during wine fermentation. We found that the deletion of GPD2 in a wine yeast‐derived strain did not affect growth or fermentation performance and reduced glycerol production by only 20%. In contrast, a gpd1Δ mutant displayed a prolonged lag phase, and produced 40% less glycerol than the wild‐type strain. The deletion of HOG1 resulted in a slight decrease in growth rate and a 20% decrease in glycerol production, indicating that the HOG pathway operates under wine fermentation conditions. However, the hog1Δ mutant was not as severely affected as the gpd1Δ mutant during the first few hours of fermentation, and continued to express GPD1 strongly. The hog1Δ mutant was able to increase glycerol production in response to high sugar concentration (15–28% glucose), to almost the same extent as the wild‐type, whereas this response was totally abolished in the gpd1Δ mutant. These data show that Gpd1p plays a major role in glycerol formation, particularly during the first few hours of exposure to high sugar concentration, and that GPD2 is only of little significance in anaerobic fermentation by wine yeast. The results also demonstrate that the HOG pathway exerts only limited control over GPD1 expression and glycerol production during wine fermentation. Copyright © 2003 John Wiley & Sons, Ltd.
The level of glucose‐6‐phosphate dehydrogenase activity strongly influences xylose fermentation and inhibitor sensitivity in recombinant Saccharomyces cerevisiae strains
Authors: Jeppsson Marie , Johansson Björn , Jensen Peter Ruhdal , Hahn‐Hägerdal Bärbel , Gorwa‐Grauslund Marie F.
Published: November 2003

Disruption of the ZWF1 gene encoding glucose‐6‐phosphate dehydrogenase (G6PDH) has been shown to reduce the xylitol yield and the xylose consumption in the xylose‐utilizing recombinant Saccharomyces cerevisiae strain TMB3255. In the present investigation we have studied the influence of different production levels of G6PDH on xylose fermentation. We used a synthetic promoter library and the copper‐regulated CUP1 promoter to generate G6PDH‐activities between 0% and 179% of the wild‐type level. G6PDH‐activities of 1% and 6% of the wild‐type level resulted in 2.8‐ and 5.1‐fold increase in specific xylose consumption, respectively, compared with the ZWF1‐disrupted strain. Both strains exhibited decreased xylitol yields (0.13 and 0.19 g/g xylose) and enhanced ethanol yields (0.36 and 0.34 g/g xylose) compared with the control strain TMB3001 (0.29 g xylitol/g xylose, 0.31 g ethanol/g xylose). Cytoplasmic transhydrogenase (TH) from Azotobacter vinelandii has previously been shown to transfer NADPH and NAD+ into NADP+ and NADH, and TH‐overproduction resulted in lower xylitol yield and enhanced glycerol yield during xylose utilization. Strains with low G6PDH‐activity grew slower in a lignocellulose hydrolysate than the strain with wild‐type G6PDH‐activity, which suggested that the availability of intracellular NADPH correlated with tolerance towards lignocellulose‐derived inhibitors. Low G6PDH‐activity strains were also more sensitive to H2O2 than the control strain TMB3001. Copyright © 2003 John Wiley & Sons, Ltd.
GIMS: an integrated data storage and analysis environment for genomic and functional data
Authors: Cornell Michael , Paton Norman W. , Hedeler Cornelia , Kirby Paul , Delneri Daniela , Hayes Andrew , Oliver Stephen G.
Published: November 2003

Effective analyses in functional genomics require access to many kinds of biological data. For example, the analysis of upregulated genes in a microarray experiment might be aided by information concerning protein interactions or proteins' cellular locations. However, such information is often stored in different formats at different sites, in ways that may not be amenable to integrated analysis. The Genome Information Management System (GIMS) is an object database that integrates genomic data with data on the transcriptome, protein–protein interactions, metabolic pathways and annotations, such as gene ontology terms and identifiers. The resulting system supports the running of analyses over this integrated data resource, and provides comprehensive facilities for handling and interrelating the results of these analyses. GIMS has been used to store Saccharomyces cerevisiae data, and we demonstrate how the integrated storage of diverse types of data can be beneficial for analysis, using combinations of complex queries. As an example, we describe how GIMS has been used to analyse a collection of aryl alcohol dehydrogenase gene deletion mutants. The GIMS database can be accessed remotely using a Java application that can be downloaded from http://img.cs.man.ac.uk/gims. Copyright © 2003 John Wiley & Sons, Ltd.
High rates of pregnancy among vocational school students: results of audio computer‐assisted self‐interview survey in Chiang Rai, Thailand
Authors: Manopaiboon Chomnad , Kilmarx Peter H. , van Griensven Frits , Chaikummao Supaporn , Jeeyapant Supaporn , Limpakarnjanarat Khanchit , Uthaiworavit Wat
Published: November 2003

Unplanned pregnancy among young people can lead to adverse social, psychological, and health outcomes, particularly when it results in abortion. In 1999, we examined the prevalence of and factors associated with pregnancy and abortion among 1725 consenting vocational school students in northern Thailand. Results from an audio computer‐assisted self‐interview showed that 48% of the male and 43% of the female students reported ever having had sexual intercourse. Among those who had had intercourse, 27% of the women and 17% of the men said they or their partner had ever been pregnant. Among the last reported pregnancies that resulted in delivery or abortion, 95% were aborted. Age, current contraceptive use, early initiation of sexual intercourse (⩽16 years), alcohol and drug use, and sexual coercion were associated with self or partner pregnancy. The high rates of pregnancy and abortion in this population indicate the need for better sexual health education and access to effective contraceptive methods.
Stress, coping, and behavioural problems among rural and urban adolescents
Authors: Elgar Frank J , Arlett Christine , Groves Renee
Published: November 2003

Rural/urban differences were studied in self‐reported stress (life events, daily hassles and conflict), coping and behavioural problems in a community sample of adolescents. Despite challenging socioeconomic conditions in rural areas, levels of stress and ways of coping were similar in rural and urban adolescents. However, urban males reported more conflict and externalizing behaviours than females and rural males. Stress, coping, and behavioural problems were interrelated but approach coping did not moderate the influence of stress on psychological functioning. Results suggest that adolescents may utilize many coping strategies that serve little benefit in terms of behavioural outcomes.
The genetics of mating recognition between Drosophila simulans and D. sechellia
Authors: CIVETTA ALBERTO , CANTOR ELLIOTT J. F.
Published: November 2003

During courtship, visual and chemical signals are often exchanged between the sexes. The proper exchange of such signals ensures intraspecific recognition. We have examined the genetic basis of interspecific differences in male mating behaviour and pheromone concentration between Drosophila simulans and D. sechellia by using Drosophila simulans/D. sechellia introgression lines. Our results show a majority of quantitative trait loci (QTLs) explaining variation in both male mating behaviour and pheromone concentration to be located on the third chromosome. One QTL found on the third chromosome explains variation in time needed to start courtship and copulation as well as time spent courting. The position of such QTL (approximately 84A–88B) with effects on courtship and copulation aspects of mating includes the candidate sex determination gene doublesex (84E5–6) and Voila (86E1–2), a gene that affects male courtship in D. melanogaster. One additional third chromosome QTL explained variation in 7-tricosene pheromone concentrations among males. The interval mapping position of this QTL (approximately 68E–76E) did not overlap with the position detected for differences in mating behaviour and the intervals did not include candidate genes previously identified as having an effect on D. melanogaster cuticular hydrocarbon production. We did not detect any directionality of the effect of Drosophila sechellia allele introgressions in male mating recognition.
Sex determination in crayfish: are intersex Cherax quadricarinatus
(Decapoda, Parastacidae) genetically females?
Authors: PARNES S. , KHALAILA I. , HULATA G. , SAGI A.
Published: November 2003

In the Australian red-claw crayfish Cherax quadricarinatus (von
Martens) (Decapoda, Parastacidae), a gonochoristic species, seven different
combinations of intersex individuals (with both male and female genital openings)
have been described. However, to date, the genetic basis for this phenomenon has
not been investigated. This study was designed to test a simple chromosome-based
sex-determination model for C. quadricarinatus that assumes the male to
be the homogametic (ZZ) sex. According to our model, intersex individuals that
are functionally males are genetically females (WZ). Individual crosses were
performed between intersex and female crayfish, with control crosses being
performed between normal males and females. The control crosses yielded, in most
cases, the expected 1[ratio ]1 sex ratio in the F1 progeny. Crosses
between intersex individuals and females yielded a 1[ratio ]3 (male[ratio ]female)
sex ratio in most crosses. According to our hypothesis, one-third of the females
produced in a cross of a female with an intersex animal should be WW females. The
hypothesis was tested by crossing normal males with F1 females, which
were progeny of intersex fathers. These crosses yielded almost 100% females, a
finding that conforms to the above-suggested sex determination model for C.
quadricarinatus and the female WZ genotype of intersex individuals.
Inferences regarding the numbers and locations of QTLs under multiple-QTL models using interval mapping and composite interval mapping
Authors: CORNFORTH THEODORE W. , LONG ANTHONY D.
Published: November 2003

This paper examines the properties of likelihood maps generated by interval mapping (IM) and composite interval mapping (CIM), two widely used methods for detecting quantitative trait loci (QTLs). We evaluate the usefulness of interpretations of entire maps, rather than only evaluating summary statistics that consider isolated features of maps. A simulation study was performed in which traits with varying genetic architectures, including 20–40 QTLs per chromosome, were examined with both IM and CIM under different marker densities and sample sizes. IM was found to be an unreliable tool for precise estimation of the number and locations of individual QTLs, although it has greater power for simply detecting the presence of QTLs than CIM. The ability of CIM to resolve the correct number of QTLs and to estimate their locations correctly is good if there are three or fewer QTLs per 100 centiMorgans, but can lead to erroneous inferences for more complex architectures. When the underlying genetic architecture of a trait consists of several QTLs with randomly distributed effects and locations likelihood profiles were often indicative of a few underlying genes of large effect. Studies that have detected more than a few QTLs per chromosome should be interpreted with caution.
An EM algorithm for mapping binary disease loci: application to fibrosarcoma in a four-way cross mouse family
Authors: XU SHIZHONG , YI NENGJUN , BURKE DAVID , GALECKI ANDRZEJ , MILLER RICHARD A.
Published: November 2003

Many diseases show dichotomous phenotypic variation but do not follow a simple Mendelian pattern of inheritance. Variances of these binary diseases are presumably controlled by multiple loci and environmental variants. A least-squares method has been developed for mapping such complex disease loci by treating the binary phenotypes (0 and 1) as if they were continuous. However, the least-squares method is not recommended because of its ad hoc nature. Maximum Likelihood (ML) and Bayesian methods have also been developed for binary disease mapping by incorporating the discrete nature of the phenotypic distribution. In the ML analysis, the likelihood function is usually maximized using some complicated maximization algorithms (e.g. the Newton–Raphson or the simplex algorithm). Under the threshold model of binary disease, we develop an Expectation Maximization (EM) algorithm to solve for the maximum likelihood estimates (MLEs). The new EM algorithm is developed by treating both the unobserved genotype and the disease liability as missing values. As a result, the EM iteration equations have the same form as the normal equation system in linear regression. The EM algorithm is further modified to take into account sexual dimorphism in the linkage maps. Applying the EM-implemented ML method to a four-way-cross mouse family, we detected two regions on the fourth chromosome that have evidence of QTLs controlling the segregation of fibrosarcoma, a form of connective tissue cancer. The two QTLs explain 50–60% of the variance in the disease liability. We also applied a Bayesian method previously developed (modified to take into account sex-specific maps) to this data set and detected one additional QTL on chromosome 13 that explains another 26% of the variance of the disease liability. All the QTLs detected primarily show dominance effects.
Parasite communities as indicators of recovery from pollution: parasites of roach (Rutilus rutilus) and perch (Perca fluviatilis) in Central Finland
Authors: VALTONEN E. T. , HOLMES J. C. , ARONEN J. , RAUTALAHTI I.
Published: November 2003

We compared parasite communities in fish taken from a polluted lake (L. Vatia) and two control lakes before (1986) and after (1995) nine years of markedly reduced chemical and nutrient loading from a pulpmill in central Finland. Discriminant analyses of the 1995 data, using a function based on the 1986 data, showed that the parasite communities in the fish from the two control lakes had changed relatively little, whereas those from L. Vatia had converged on those from the mesotrophic control lake, indicating substantial recovery from the effects of pollution. Only a few species of parasites provided evidence for recovery. These were anodontid glochidia, which had increased markedly in perch, Rhipidocotyle fennica in roach and R. campanula in both fish species. This suggests that the recovery of the polluted lake involved increased populations of anadontid clams in shallow waters. On the other side decrease of Dermocystidium percae on perch fins and Ichthyophthirius multifiliis on roach indicate increased immune responses in the fish, reflecting better water quality. Other parts of the system have apparently not yet recovered.
Accumulation of heavy metals by intestinal helminths in fish: an overview and perspective
Authors: SURES B.
Published: November 2003

Intestinal helminths of fish are of increasing interest as potential bioindicators for heavy metal contamination in aquatic habitats. Among these parasites cestodes and acanthocephalans in particular have an enormous heavy metal accumulation capacity exceeding that of established free living sentinels. Metal concentrations several thousand times higher in acanthocephalans than in host tissues were described from field and laboratory studies. Whereas larval stages inside their intermediate hosts are not able to take up high quantities of metals, young worms begin to take up metals immediately after infection of the final host. After four to five weeks of exposure, the parasites reach a steady-state concentration orders of magnitude higher than the ambient water level. Thus, acanthocephalans are not only very effective in taking up metals, but they can also respond very rapidly to changes in environmental exposure. The mechanism which enable acanthocephalans to take up metals from the intestinal lumen of the host appears to be based on the presence of bile acids, which form organo-metallic complexes that are easily absorbed by the worms due to their lipophilicity. Investigations of the environmental conditions affecting metal uptake have shown that the parasites are more consistent and reliable indicators for metal pollution than the host tissues as metal levels of the latter are much more dependent on the water chemistry. Thus, after some years of research on the uptake of metals by acanthocephalans and on the factors affecting metal accumulation in intestinal parasites it should be asked if acanthocephalans meet the criteria commonly accepted for sentinels. If parasites can be considered as promising sentinels, we need reasons for the establishment of ‘new’ indicators. Therefore, this review summarises the present knowledge about parasites as bioindicators and compares the accumulation properties of parasites and established free living indicators. Finally, this review presents possible answers to the question why it could be advantageous to have new and even more sensitive indicators for environmental monitoring purposes.
Living together, working together: concentrations amongst German immigrants in the Netherlands in the nineteenth century
Authors: SCHROVER MARLOU
Published: November 2003

German immigrants who came to the Netherlands in the nineteenth century did not concentrate in ‘Little Germanys’ within Dutch towns, as they did in some other countries. Some concentrations amongst German immigrants can, however, be pointed out. Contrary to what perhaps might be expected, it was not a common religion or a shared regional background that explains these concentrations. A shared profession does explain some, but only if the nature of a particular profession allowed or encouraged concentration.
Reciprocal exchange, credit and cash: agricultural labour markets and local economies in the southern Low Countries during the eighteenth century
Authors: LAMBRECHT THIJS
Published: November 2003

This article examines the labour market for day labourers in the Southern Low Countries during the eighteenth century from the perspective of reciprocal exchange. In particular I will look at wage payment structures and their economic and social foundations. In contrast with other agricultural regions, wage payments in proto-industrialized inland Flanders were highly diversified. Large farmers and day labourers engaged in a system of reciprocal exchange of labour, goods and services in which monetary payments played only a secondary role. I find that both employers and employees had strong reasons for maintaining this exchange relationship and that they both, in their own ways, benefited from this mutual dependency.
The emergence of grammar: early verbs and beyond
Authors: ARMON-LOTEM SHARON , BERMAN RUTH A.
Published: November 2003

The paper examines the first twenty verb-forms recorded for six Hebrew-speaking children aged between 1;2 and 2;1, and how they evolve into fully inflected verbs for three of these children. Discussion focuses first on what word-forms children initially select for the verbs they produce, what role these forms play in children's emergent grammar, and how emergent grammar is reflected in the acquisition of fully inflected forms of verbs. Children's early verb repertoire indicates that they possess a strong basis for moving into the expression of a variety of semantic roles and the syntax of a range of different verb–argument structures. On the other hand, children's initial use of verbs demonstrates that they still need to acquire considerable language-particular grammatical knowledge in order to encode such relations explicitly. This language-particular knowledge demonstrates a clear pattern of acquisition, in which aspect precedes inflectional marking for gender, followed by tense, and then by person.
Possible explanations for children's literal interpretations of homonyms
Authors: MAZZOCCO MICHÈLE M. M. , MYERS GWEN F. , THOMPSON LAURIE A. , DESAI SNEHA S.
Published: November 2003

This study was designed to examine factors associated with literal interpretations of homonyms. Participants were 212 second graders, ages 7;0–8;11, who listened to a story containing 16 key words. The key words were homonymous words (‘pseudo-homonyms’), nonsense words, or familiar words used accurately. While listening to the story, children selected an illustration of each key word. Later, they were asked to recall the key words and to justify their picture selections. There was no association between interpretation and recall accuracy for nonsense words or familiar words used accurately; however, children who accurately recalled a homonymous key word were more likely to interpret the homonym ‘literally,’ relative to children who failed to recall the key word. Yet most of the children who correctly interpreted the pseudo-homonyms also correctly interpreted these key words. Most children correctly recalled the story context regardless of key word type, but whereas correct recall of context predicted accurate interpretation of nonsense words and familiar words used accurately, it did not do so for homonyms. Children made equivalent numbers of literal and accurate interpretations of homonyms, even when correctly recalling context. Children's justifications for their word interpretations implicated the role of metacognitive skills, particularly in terms of selective attention, as a factor influencing homonym interpretation.
The sources of young children's name innovations for novel artifacts
Authors: KEMLER NELSON DEBORAH G. , HERRON LINDSAY , HOLT MORGHAN B.
Published: November 2003

Two studies investigated whether four-year-old children (12 in Experiment 1 with a mean age of 4;8 and 36 in Experiment 2 with a mean age of 4;7) invent names for new artifacts based on the objects' functions as opposed to their perceptual properties. Children informed about the intended functions of novel objects provided more name innovations that were clearly function-based than perception-based. This tendency was observed when children were shown the objects' functions, even if they were also given verbal descriptions of the objects' perceptual properties and parts. Only when ignorant of the objects' intended functions did children tend to use perceptual features to create substantial numbers of names. Accordingly, results from this name-innovation methodology converge with findings from some recent studies of lexical categorization suggesting that functional information is critical to how preschoolers extend artifact names. Children appear to appreciate an intimate relation between the functions of artifacts and how they are named.
Do word learners ignore ignorant speakers?
Authors: SABBAGH MARK A. , WDOWIAK SYLWIA D. , OTTAWAY JENNIFER M.
Published: November 2003

Thirty-six three- to four-year-old children were tested to assess whether hearing a word-referent link from an ignorant speaker affected children's abilities to subsequently link the same word with an alternative referent offered by another speaker. In the principal experimental conditions, children first heard either an ignorant or a knowledgeable speaker link a novel word with one of three toys. The first speaker's labelling episode was followed by a second in which a different speaker used the same novel label but for a different toy. There was also a Base-line condition which was the same as the experimental condition involving the ignorant speaker except that she did not associate the novel label with a referent. When tested for comprehension of the novel label, children selected the FIRST speaker's toy at high levels when the first speaker was knowledgeable, but selected the SECOND speaker's toy when the first speaker was ignorant. These findings suggest that children's experience with the ignorant speaker did not affect their abilities to learn a subsequently presented alternative word-referent link. These findings are discussed in terms of understanding the mechanisms by which children adapt their word-learning in line with speakers' knowledge states.
At the feet of the dinosaurs: the early history and radiation of lizards
Authors: EVANS SUSAN E.
Published: November 2003

Lizards, snakes and amphisbaenians together constitute the Squamata, the largest and most diverse group of living reptiles. Despite their current success, the early squamate fossil record is extremely patchy. The last major survey of squamate palaeontology and evolution was published 20 years ago. Since then, there have been changes in systematic theory and methodology, as well as a steady trickle of new fossil finds. This review examines our current understanding of the first 150 million years of squamate evolution in the light of the new data and changing ideas. Contrary to previous reports, no squamate fossils are currently documented before the Jurasis. Nonetheless, indirect evidence predicts that squamates had evolved by at least the middle Triassic, and diversified into existing major lineages before the end of this period. There is thus a major gap in the squamate record at a time when key morphological features were evolving. With the exception of fragmentary remains from Africa and India, Jurassic squamates are known only from localities in northern continents (Laurasia). The situation improves in the Early Cretaceous, but the southern (Gondwanan) record remains extremely poor. This constrains palaeobiogeographic discussion and makes it difficult to predict centres of origin for major squamate clades on the basis of fossil evidence alone. Preliminary mapping of morphological characters onto a consensus tree demonstrates stages in the sequence of acquisition for some characters of the skull and postcranial skeleton, but many crucial stages – most notably those relating to the acquisition of squamate skull kinesis – remain unclear.
Parasitic exploitation as an engine of diversity
Authors: SUMMERS KYLE , McKEON SEA , SELLARS JON , KEUSENKOTHEN MARK , MORRIS JAMES , GLOECKNER DAVID , PRESSLEY COREY , PRICE BLAKE , SNOW HOLLY
Published: November 2003

Parasitic exploitation occurs within and between a wide variety of taxa in a plethora of diverse contexts. Theoretical and empirical analyses indicate that parasitic exploitation can generate substantial genetic and phenotypic polymorphism within species. Under some circumstances, parasitic exploitation may also be an important factor causing reproductive isolation and promoting speciation. Here we review research relevant to the relationship between parasitic exploitation, within species‐polymorphism, and speciation in some of the major arenas in which such exploitation has been studied. This includes research on the vertebrate major histocompatibility loci, plant –pathogen interactions, the evolution of sexual reproduction, intragenomic conflict, sexual conflict, kin mimicry and social parasitism, tropical forest diversity and the evolution of language. We conclude by discussing some of the issues raised by comparing the effect of parasitic exploitation on polymorphism and speciation in different contexts.
The radiation of the Cape flora, southern Africa
Authors: LINDER H. P.
Published: November 2003

The flora of the south‐western tip of southern Africa, the Cape flora, with some 9000 species in an area of 90 000 km2 is much more speciose than can be expected from its area or latitude, and is comparable to that expected from the most diverse equatorial areas. The endemism of almost 70%, on the other hand, is comparable to that found on islands. This high endemism is accounted for by the ecological and geographical isolation of the Cape Floristic Region, but explanations for the high species richness are not so easily found. The high species richness is accentuated when its taxonomic distribution is investigated: almost half of the total species richness of the area is accounted for by 33‘Cape floral clades'. These are clades which may have initially diversified in the region, and of which at least half the species are still found in the Cape Floristic Region. Such a high contribution by a very small number of clades is typical of island floras, not of mainland floras. The start of the radiation of these clades has been dated by molecular clock techniques to between 18 million years ago (Mya)(Pelargonium) and 8 Mya (Phylica), but only six radiations have been dated to date. The fossil evidence for the dating of the radiation is shown to be largely speculative. The Cenozoic environmental history of southern Africa is reviewed in search of possible triggers for the radiations, climatic changes emerge as the most likely candidate. Due to a very poor fossil record, the climatic history has to be inferred from larger scale patterns, these suggest large‐scale fluctuations between summer wet (Palaeocene, Early Miocene)and summer dry climates (Oligocene, Middle Miocene to present). The massive speciation in the Cape flora might be accounted for by the diverse limitations to gene flow (dissected landscapes, pollinator specialisation, long flowering times allowing much phenological specialisation), as well as a richly complex environment providing a diversity of selective forces (geographically variable climate, much altitude variation, different soil types, rocky terrain providing many micro‐niches, and regular fires providing both intermediate disturbances, as well as different ways of surviving the fires). However, much of this is based on correlation, and there is a great need for (a)experimental testing of the proposed speciation mechanisms, (b)more molecular clock estimates of the age and pattern of the radiations, and (c)more fossil evidence bearing on the past climates.
Fine-Tuning in Living Systems
Authors: Carr B.J. , Rees M.J.
Published: November 2003

We give an overview of an interdisciplinary meeting held last year in Windsor to discuss the evidence for fine-tuning in living systems. Many of the papers presented there appear in this volume, so this serves as an introduction to them. We also briefly review a meeting held the previous year in Cambridge to assess the evidence for fine-tuning in physics and cosmology.
A unifying concept for astrobiology
Authors: Chaisson E.J.
Published: November 2003

Evolution, broadly construed, has become a powerful unifying concept in much of science – not only in the biological evolution of plants and animals, but also in the physical evolution of stars and planets, and the cultural evolution of society and its many varied products. This paper (1) explores the bulk structure and functioning of open, non-equilibrium, thermodynamic systems relevant to the interdisciplinary field of astrobiology, (2) places the astrobiological landscape into an even larger, cosmological context, (3) defines life, complexity and evolution writ large, (4) claims that life depends ultimately on the expansion of the Universe and the flow of energy derived therefrom and (5) proposes a quantitative metric to characterize the rise of complexity throughout all of natural history. That metric is neither information nor negentropy, for these inveterate yet qualitative terms cannot be quantified, nor even defined, to everyone's satisfaction in today's scientific community. Rather, the newly proposed metric is normalized energy flow, a revision of a long-cherished term – energy – that is physically intuitive, well defined and readily measurable. All ordered systems – from rocky planets and shining stars, to buzzing bees and redwood trees – can be best judged empirically and uniformly by gauging the amount of energy acquired, stored and expressed by those systems. Appeals to anthropism are unnecessary to appreciate the impressive hierarchy of the cosmic evolutionary narrative, including a technological civilization that now embraces an energetics agenda designed to better understand, and perhaps to unify, all the natural sciences.
Alien life: how would we know?
Authors: Boden Margaret A.
Published: November 2003

To recognize alien life, we would have to be clear about the defining criteria of ‘life’. Metabolism – in other words, biochemical fine-tuning – is one of these criteria. Three senses of metabolism are distinguished. The weakest allows strong artificial life (A-life): virtual creatures having physical existence in computer electronics, but not bodies, are classed as ‘alive’. The second excludes strong A-life but allows that some non-biochemical A-life robots could be classed as alive. The third, which stresses the body's self-production by energy budgeting and self-equilibrating energy exchanges of some (necessary) complexity, excludes both strong A-life and living non-biochemical robots.
How bio-friendly is the universe?
Authors: Davies P.C.W.
Published: November 2003

The oft-repeated claim that life is ‘written into’ the laws of nature is examined and criticised. Arguments are given in favour of life spreading between near-neighbour planets in rocky impact ejecta (transpermia), but against panspermia, leading to the conclusion that if life is indeed found to be widespread in the universe, some form of life principle or biological determinism must be at work in the process of biogenesis. Criteria for what would constitute a credible life principle are elucidated. I argue that the key property of life is its information content, and speculate that the emergence of the requisite information-processing machinery might require quantum information theory for a satisfactory explanation. Some clues about how decoherence might be evaded are discussed. The implications of some of these ideas for ‘fine-tuning’ are discussed.
Looking for life in unlikely places: reasons why planets may not be the best places to look for life
Authors: Dyson Freeman J.
Published: November 2003

A new method is proposed to search for extraterrestrial life adapted to cold environments far from the Sun. To keep warm, using the light from a distant sun, any life-form must grow a system of optical concentrators, lenses or mirrors, to focus sunlight on to its vital parts. Any light not absorbed, or any heat radiation emitted from the vital parts, will be focused by the optical concentrators into a narrow beam pointing back towards the sun. To search for such life-forms, we should scan the sky with optical and infrared telescopes pointing directly away from the Sun. Any living vegetation will be seen as a bright patch in strong contrast to its dark surroundings, like the eyes of a nocturnal animal caught in the headlights of a car. This method of search may be used either with space-based or with ground-based telescopes. Examples of places where the method would work well are the surfaces of Europa, Trojan asteroids or Kuiper Belt objects. Any life-form that adapted successfully to a vacuum environment would be likely to spread widely over objects with icy surfaces in the outer regions of the solar system.
Understanding genetic regulatory networks
Authors: Kauffman Stuart
Published: November 2003

Random Boolean networks (RBM) were introduced about 35 years ago as first crude models of genetic regulatory networks. RBNs are comprised of N on–off genes, connected by a randomly assigned regulatory wiring diagram where each gene has K inputs, and each gene is controlled by a randomly assigned Boolean function. This procedure samples at random from the ensemble of all possible NK Boolean networks. The central ideas are to study the typical, or generic properties of this ensemble, and see 1) whether characteristic differences appear as K and biases in Boolean functions are introducted, and 2) whether a subclass of this ensemble has properties matching real cells.

Such networks behave in an ordered or a chaotic regime, with a phase transition, ‘the edge
of chaos’ between the two regimes. Networks with continuous variables exhibit the same two regimes. Substantial evidence suggests that real cells are in the ordered regime. A key concept is that of an attractor. This is a reentrant trajectory of states of the network, called a state cycle. The central biological interpretation is that cell types are attractors. A number of properties differentiate the ordered and chaotic regimes. These include the size and number of attractors, the existence in the ordered regime of a percolating ‘sea’ of genes frozen in the on or off state, with a remainder of isolated twinkling islands of genes, a power law distribution of avalanches of gene activity changes following perturbation to a single gene in the ordered regime versus a similar power law distribution plus a spike of enormous avalanches of gene changes in the chaotic regime, and the existence of branching pathway of ‘differentiation’ between attractors induced by perturbations in the ordered regime.

Noise is serious issue, since noise disrupts attractors. But numerical evidence suggests that attractors can be made very stable to noise, and meanwhile, metaplasias may be a biological manifestation of noise. As we learn more about the wiring diagram and constraints on rules controlling real genes, we can build refined ensembles reflecting these properties, study the generic properties of the refined ensembles, and hope to gain insight into the dynamics of real cells.
Kinder mit Lese- und Rechtschreibstörungen: Selbstwertgefühl und Integrative Lerntherapie
Authors: Schulz Wolfgang , Dertmann Jutta , Jagla Andrea
Published: November 2003

Zusammenfassung. In dieser Studie wird zum einen untersucht, ob und in welchem Umfang Kinder mit einer Lese- und Rechtschreibstörung zusätzlich zu ihrer Lernproblematik ein defizitäres Selbstwertgefühl und Verhaltensstörungen aufweisen, zum anderen wird die Wirksamkeit der Integrativen Lerntherapie überprüft. An der Studie nahmen 69 Kinder teil, die zu drei Messzeitpunkten, am Beginn der Therapie, nach einem halben und nach einem Jahr untersucht wurden. Die “LRS-Kinder“ haben zu Beginn der Therapie neben ihrer Lernproblematik im Vergleich zu einer unauffälligen Gruppe von Kindern ein geringeres Selbstwertgefühl, allerdings nur in der kognitiven Komponente, und aus Elternsicht überdurchschnittlich häufig Verhaltenstörungen, insbesondere im internalisierenden Bereich. Im Verlauf der Therapie hat sich das Selbstwertgefühl der Kinder signifikant verbessert und das Ausmaß der Verhaltensstörungen signifikant verringert. Bei jeweils einem Drittel der Kinder hat sich die kognitive Komponente des Selbstwertgefühls signifikant verbessert (33 %) und die Verhaltensstörungen signifikant verringert (37 %). Im Rechtschreibtest haben sich 47 % der Kinder um mindestens eine Schulnote verbessert, nach Einschätzung der Therapeuten war die Therapie bei 58 % der Kinder erfolgreich.
Lösungsalgorithmen und Selbstinstruktionen in der Rechtschreibförderung
Authors: Faber Günter
Published: November 2003

Zusammenfassung. Es wird ein Ansatz zur Rechtschreibförderung vorgestellt, der die Anwendung visualisierter Lösungsalgorithmen systematisch mit verbalen Selbstinstruktionen kombiniert und dadurch die Aneignung orthographischen Regelwissens mit der Modellierung geeigneter Handlungsstrategien verknüpft. Erste praxisbegleitende Effektkontrollen an drei Kohorten rechtschreibschwacher Schüler haben nach Abschluss einer längerfristigen Einzel- bzw. Kleingruppenförderung durchweg signifikante Leistungsfortschritte nachweisen können.
Entwicklungsdiagnostik in der Klinischen Kinderpsychologie - der ET 6-6
Authors: Pohl Peter
Published: November 2003

Zusammenfassung. Der vorliegende Beitrag befasst sich mit dem Einsatz von Entwicklungsdiagnostik in der Klinischen Kinderpsychologie und stellt in diesem Zusammenhang erste klinische Erfahrungen mit dem neuen Entwicklungstest 6 Monate - 6 Jahre (ET 6-6) von Petermann und Stein (2000) vor. Zwei Fallbeispiele demonstrieren die diagnostische Sensitivität des ET 6-6 und zahlreiche Anwendungen aus der kinderpsychologischen Praxis des Verfassers veranschaulichen die klinischen Einsatzmöglichkeiten. Nach der Darstellung der Grenzen des ET 6-6 werden Anwendungen des Verfahrens auf dem Gebiet der Prävention von psychischen Störungen im frühen Kindesalter erörtert.
Intermediate water circulation in the North Pacific subarctic and northern subtropical regions
Authors: Ueno Hiromichi , Yasuda Ichiro
Published: November 2003

The intermediate water circulation in the North Pacific subarctic and northern subtropical regions is investigated through inverse analysis, focusing on the volume and heat transports from the subtropical to the subarctic regions. The inverse method we adopted is a hybrid method of β‐spiral and box inverse methods which permits diapycnal flux. The isopycnal velocities estimated through the inverse analysis are mostly consistent with the oxygen distribution and support the hypothesis that warm and saline intermediate water is transported from the transition domain east of Japan to the northern Gulf of Alaska. The northward volume transport across 46°N between 158°E and 130°W is estimated to be −0.2 to 5.3 Sv in the density range of 26.7–27.2σθ. The upward diapycnal transports in the open subarctic North Pacific (region N) across 26.7 and 27.2σθ isopycnal surfaces are estimated to be 0.2 to 1.5 Sv and −0.2 to 0.9 Sv, respectively. Part of the water transported upward across 26.7σθ might outcrop and be carried to the subtropical region by the southward Ekman drift. Through the examination of heat balance of the intermediate layer in the subarctic region, it is suggested quantitatively that the intermediate heat transport from the south plays an essential role in maintaining the heat of the mesothermal waters in the subarctic region.
Electromagnetic bias estimates based on TOPEX, buoy, and wave model data
Authors: Kumar Raj , Stammer Detlef , Melville W. Kendall , Janssen Peter
Published: November 2003

For quantitative studies of the ocean using altimetric measurements, the sea surface height measurements must be corrected for the electromagnetic (EM) bias effect. Project‐provided EM bias correction algorithms were derived from the altimeter data as a function of wind speed and wave height through variance minimization techniques [Gaspar et al., 1994]. In this paper we characterize the impact of those corrections on the altimeter data and compare it with an empirical algorithm based on tower observations of wave slopes and wave age (W. K. Melville et al., Wave slope and wave age effects in measurements of EM bias, submitted to Journal of Geophysical Research, 2002) and with theoretical predictions of EM bias [Srokosz, 1986]. We find a significant correlation between high‐frequency ocean signals with the project‐provided EM bias correction. This suggests that an EM bias algorithm cannot be estimated from altimeter data alone through variance minimization techniques. Since the EM bias depends on parameters that cannot be measured by an altimeter (e.g., wave slope), improved theoretical corrections appear to be preferable to altimetry‐based empirical estimates. Using wave buoy and wave model (WAM) data, we find good agreement between existing theoretical correction and empirical corrections based on wave slope and wave age information over a significant range of parameters. Although further work is needed to extend our tests of algorithms to larger wave slopes, existing wave slope and wave age‐based algorithms appear comparable in goodness to project‐provided empirical algorithms and may be used for routine altimetry processing in combination with WAM output on a global basis.
Global morphology of infrasound propagation
Authors: Drob Douglas P. , Picone J. M. , Garcés M.
Published: November 2003

Atmospheric sound waves in the 0.02–10 Hz region, also known as infrasound, exhibit long‐range global propagation characteristics. Measurable infrasound is produced around the globe on a daily basis by a variety of natural and man‐made sources. As a result of weak classical attenuation (∼0.01 dB km−1 at 0.1 hz), these acoustic signals can propagate thousands of kilometers in tropospheric, stratospheric, and lower thermospheric ducts. To model this propagation accurately, detailed knowledge of the background atmospheric state variables, the global winds and temperature fields from the ground to ∼170 km, is required. For infrasound propagation calculations, we have developed a unique atmospheric specification system (G2S) that is capable of providing this information. Using acoustic ray tracing methods and detailed G2S atmospheric specifications, we investigate the major aspects of the spatiotemporal variability of infrasound propagation characteristics.
Deep‐slab fluids fuel extremophilic Archaea on a Mariana forearc serpentinite mud volcano: Ocean Drilling Program Leg 195
Authors: Mottl Michael J. , Komor Stephen C. , Fryer Patricia , Moyer Craig L.
Published: November 2003

As the Pacific plate subducts beneath the Mariana forearc it releases water that hydrates the overlying mantle wedge, converting it to serpentinite that protrudes to form mud volcanoes at the seafloor. Excess H2O ascends through these mud volcanoes and exits as cold springs at their summits. The composition of this deep‐slab derived water has been determined by drilling on two of these seamounts. It has a pH of 12.5 and, relative to seawater, is enriched in sulfate, alkalinity, Na/Cl, K, Rb, B, light hydrocarbons, ammonia, 18O, and deuterium, and depleted in chloride, Mg, Ca, Sr, Li, Si, phosphate, and 87Sr. Within the upper 20 m below seafloor at South Chamorro Seamount a microbial community operating at pH 12.5, made up overwhelmingly of Archaea, is oxidizing methane from the ascending fluid to carbonate ion and organic carbon, while reducing sulfate to bisulfide and probably dissolved nitrogen to ammonia.
Mesoscale eddies in the South China Sea observed with altimeter data
Authors: Wang Guihua , Su Jilan , Chu Peter C.
Published: November 2003

A composite time series (1993–2000) of sea surface height anomaly from several satellites is used to identify eddies in the South China Sea (SCS). The eddy lifetime, radius, strength, and straight‐line travel distance are estimated. Altogether 58 anticyclonic eddies and 28 cyclonic eddies are identified for this period. They are grouped into four geographical zones according to known eddy generation mechanisms, and their statistics are discussed accordingly. Our geographical classification is a useful first step in gaining an overview of their generation.
Satellite data analysis and numerical simulation of tropical cyclone formation
Authors: Li Tim , Fu Bing , Ge Xuyang , Wang Bin , Peng Melinda
Published: November 2003

Forecast of tropical cyclone (TC) formation has long been a great challenge owing to lack of reliable observations over vast open oceans. Recent satellite products provide a unique opportunity to reveal detailed atmospheric wave structures prior to TC formation. Using the QuikSCAT surface wind and the Tropical Rainfall Measurement Mission Microwave Image data, we document temporal and spatial structures of Rossby wave trains induced by energy dispersion from a pre‐existing TC and easterly wave propagation characteristics prior to cyclogenesis in the western North Pacific. Using a baroclinic model, we further simulate cyclogenesis processes associated with the TC energy dispersion and easterly waves.