bluuebunny/crossref_metadata_2025 huggingface dataset:
Ecomorphological trends in the Artedidraconidae (Pisces: Perciformes: Notothenioidei) of the Weddell Sea
Authors: LOMBARTE ANTONI , OLASO IGNACIO , BOZZANO ANNA
Published: May 2003

An ecomorphological study was performed on ten species of the family Artedidraconidae, the most benthic of the suborder Notothenioidei. These species are sympatric on the shelf of the Weddell Sea. The results show that the four genera comprising the family (Artedidraco, Dolloidraco, Histiodraco and Pogonophryne) can be differentiated by just a few morphometric features of their sensory organs and mouth. The genera were also clearly defined by the composition of their diet (benthic and epibenthic), the size of their prey, and their bathymetric distribution. Comparison of the morphological and ecological data shows a very close connection between sensory organs development, the mouth and bathymetric distribution. The morphological and ecological divergence observed can be explained as the result of the rapid adaptive radiation of the artedidraconids. The results confirm that characteristics of the sensory organs and alimentary structures are very suitable for the ecomorphological study of fishes.
Trends in bird and seal populations as indicators of a system shift in the Southern Ocean
Authors: WEIMERSKIRCH HENRI , INCHAUSTI PABLO , GUINET CHRISTOPHE , BARBRAUD CHRISTOPHE
Published: May 2003

Although world oceans have been warming over the past 50 years, the impact on biotic components is poorly understood because of the difficulty of obtaining long-term datasets on marine organisms. The Southern Ocean plays a critical role in global climate and there is growing evidence of climate warming. We show that air temperatures measured by meteorological stations have steadily increased over the past 50 years in the southern Indian Ocean, the increase starting in mid 1960s and stabilizing in mid 1980s, being particularly important in the sub-Antarctic sector. At the same time, with a time lag of 2–9 years with temperatures, the population size of most seabirds and seals monitored on several breeding sites have decreased severely, whilst two species have increased at the same time. These changes, together with indications of a simultaneous decrease in secondary production in sub-Antarctic waters and the reduction of sea-ice extent further south, indicate that a major system shift has occurred in the Indian Ocean part of the Southern Ocean. This shift illustrates the high sensitivity of marine ecosystems, and especially upper trophic level predators, to climatic changes.
The vertical flux of particulate matter in the polynya of Terra Nova Bay. Part II. Biological components
Authors: ACCORNERO A. , MANNO C. , ESPOSITO F. , GAMBI M.C.
Published: May 2003

Downward fluxes of particulate matter were investigated in the polynya of Terra Nova Bay (western Ross Sea) from February 1995 to December 1997. The main biological components were siliceous phytoplankton (diatoms, silicoflagellates and parmales), abundant faecal pellets of several types and zooplankton (mainly shelled pteropods). Vertical fluxes of particles occurred mainly through diatoms and faecal pellets in the first and second part of the summer, respectively. The highest fluxes were recurrently observed in late summer, when faeces contributed up to 100% of organic carbon. Unusually high fluxes were recorded in winter 1995, when faecal pellets accounted for 84.6% of the organic carbon. Peak fluxes were always driven by the sinking of faecal pellets, that hence appear to be the most efficient vector of export in the polynya of Terra Nova Bay. A major flux component was the pteropod Limacina helicina, which repeatedly sank in high amounts after the growing season. In April–June, L. helicina probably transported biogenic carbon to deep layers as a passive sinker. The inclusion of pteropods in flux estimates resulted in values that were up to 20 (for total mass), 25 (for organic matter) and 48 (for carbonate) times higher than the previously measured fluxes. Fluxes are known to be biased by swimmers, but ultimately attention must be paid to a possible erroneous categorization of some zooplankton as swimmers to avoid severe underestimation of fluxes of total mass (up to 95% in our study), organic matter (up to 96%) and carbonate (up to 100%).
Ecology of periphyton in a meltwater stream ecosystem in the maritime Antarctic
Authors: ELSTER JOSEF , KOMAREK ONDREJ
Published: May 2003

The ecology of two meltwater streams on King George Island, Ornithologists Creek (with penguin rookeries close to its lower reaches) and Petrified Forest Creek (a highly oligotrophic system), was studied during the 1996–97 summer season. To estimate seasonal productivity of the periphyton and to establish which environmental parameters influenced periphyton growth most strongly, two types of artificial substrata (fibreglass nets – ash-free dry weight (AFDW), and microscope slides – Chlorophyll a (Chl a)) were tested in situ. Thus relative periphyton productivity (RPP) reflects algal colonization and growth as well as losses due to cell mortality and abrasive action of moving sediments. The Petrified Forest Creek was more productive (AFDW = 108.63 μg cm−2 d−1, Chl a = 0.35 μg g cm−2 d−1) than the Ornithologists Creek (AFDW = 69.90 μg cm−2 d−-1, Chl a = 0.26 μg cm−2 d−1). RPP differed both along the streams, and during the season. Significant positive or negative relationships (generalized linear models) were found between RPP and streamwater ‘physico-chemical parameters’ and ‘geomorphological-geographical characteristics’ of the streams' catchments. In addition, in the lower reaches of both streams almost no active colonization or growth was recorded. In the Petrified Forest Creek, the periphyton biomass was so high that mainly passive organic matter deposition occurred. By contrast, in the lower reach of Ornithologists Creek, periphyton colonization and growth was around zero, being negatively influenced by penguin excrement. Ornithologists Creek was richer in nutrients (DIN, DRP), which also fluctuated more widely along its length and throughout the season, than in the Petrified Forest Creek. Parameters associated with the inorganic carbon cycle of the streamwater reflect higher RPP in Petrified Forest Creek. Moreover, RPP was higher in stream reaches with higher amounts of gravel boulders on the bottom.
Two new species of Myriochele (Polychaeta: Oweniidae) from the Bransfield Strait, Antarctica
Authors: PARAPAR JULIO
Published: May 2003

Among the benthic lithological samples collected during the Spanish Antarctic survey GEBRAP 1996–97 in the Bransfield Strait, two new oweniid (Annelida, Polychaeta, Oweniidae) species were collected: Myriochele riojai n. sp. and Myriochele robusta n. sp. Myriochele riojai is closely related to M. heeri Malmgren, 1867 but differs in body size, number and distribution of the notosetae and in the position of elongated abdominal body segments. Myriochele robusta differs from all known species of the genus owing to its possession of a biramous setiger between two uniramous setigers in the anterior (thoracic) body region. A key to oweniid species recorded in Antarctic waters is provided.
Haul-out behaviour of two Ross seals off eastern Antarctica
Authors: SOUTHWELL COLIN
Published: May 2003

Accurate assessment of the abundance of pinnipeds from
visual surveys requires estimation of both the available
(hauled-out) and unavailable (in-water) components of the
population (Eberhardt et al. 1979). Continental estimates of
the abundance of the four Antarctic seals are based on
limited information on haul-out behaviour. In developing
continental estimates, Erickson & Hanson (1990) corrected
visual surveys of the hauled-out component of the species'
populations using data from observational studies of haulout
behaviour by Erickson et al. (1989). Erickson & Hanson
(1990) point out that, because the observational studies did
not account for an unknown fraction of seals that remained
in the water during the peak haul-out period, their
abundance estimates are minimum values. Further,
Erickson & Hanson (1990) corrected the visual surveys for
all four species using haul-out data for the crabeater seal
only, as observational data for the other species were not
available. This assumes that haul-out patterns are constant
across species, which is largely untested. Consequently,
there is potential for bias, in both a relative and absolute
sense, in the estimated abundance of Antarctic seals.
Glacial sediment provenance, dispersal and deposition, Vestfold Hills, East Antarctica
Authors: GORE DAMIAN B. , SNAPE I. , LEISHMAN M.R.
Published: May 2003

Field observations involving landform evaluation and the physical characterization of sediments, combined with a detailed analysis of the spatial distribution of bedrock and sediment geochemical patterns, suggests a limit to the glacial transport half-distance of c. 3 km in Vestfold Hills. Four morphologically distinct glacial deposits were sampled (small debris ridges, large debris ridges, debris drapes and valley fills) on the basis of field geometry. These landforms were subsequently distinguished by grain size, mineralogy and geochemistry. Since there are no nunataks south of Vestfold Hills, all debris is derived subglacially and sedimentological differences are attributed to the physical weathering of preglacial surfaces in Vestfold Hills and fluvial winnowing during deposition. Given that thrust geometries may occur in large debris ridges, glacial transport distances were short, and fluvial sorting of sediments was an important mechanism, reconstructions of glacial histories based on the stratigraphy of deposits in Vestfold Hills should be made with caution.
Gas hydrate volume estimations on the South Shetland continental margin, Antarctic Peninsula
Authors: JIN Y.K. , LEE M.W. , KIM Y. , NAM S.H. , KIM K.J.
Published: May 2003

Multi-channel seismic data acquired on the South Shetland margin, northern Antarctic Peninsula, show that Bottom Simulating Reflectors (BSRs) are widespread in the area, implying large volumes of gas hydrates. In order to estimate the volume of gas hydrate in the area, interval velocities were determined using a 1-D velocity inversion method and porosities were deduced from their relationship with sub-bottom depth for terrigenous sediments. Because data such as well logs are not available, we made two baseline models for the velocities and porosities of non-gas hydrate-bearing sediments in the area, considering the velocity jump observed at the shallow sub-bottom depth due to joint contributions of gas hydrate and a shallow unconformity. The difference between the results of the two models is not significant. The parameters used to estimate the total volume of gas hydrate in the study area were 145 km of total length of BSRs identified on seismic profiles, 350 m thickness and 15 km width of gas hydrate-bearing sediments, and 6.3% of the average volume gas hydrate concentration (based on the second baseline model). Assuming that gas hydrates exist only where BSRs are observed, the total volume of gas hydrates along the seismic profiles in the area is about 4.8 × 1010 m3 (7.7 × 1012 m3 volume of methane at standard temperature and pressure).
Recent iceberg calving events in the Ninnis Glacier region, East Antarctica
Authors: MASSOM ROBERT A.
Published: May 2003

This paper describes a major calving of the Ninnis Glacier tongue in January 2000. This event, which took 10 years to complete, produced a major change in the George V Land coastline and a large iceberg (∼800 km2). By grounding or becoming “locked in” by fast ice, bergs produced locally and drifting in from afar reside for long periods (10–20 years) in the region ∼146 to 154°E to have a profound impact on sea ice distribution, both locally and 100s of kilometres up- and downstream. They are responsible for the formation of a lens of thick perennial ice to the east (∼14 000 km2 in area), and polynyas. Iceberg movement is sporadic, with intermittent ungroundings of large bergs occurring every 5–13 years. “Escaping” bergs have a temporary impact on the Mertz Glacier polynya to the west. Although public attention focuses on vast bergs, assemblages of small bergs appear to be equally important in terms of their impact on regional fast and pack ice distribution. Possible global change scenarios are discussed. The need for field observations and improved bathymetric and oceanographic data is emphasized.
The impact of human interference on Hill Mynahs Gracula religiosa breeding in Thailand
Authors: Archawaranon Manee
Published: May 2003

The breeding biology of Hill Mynah Gracula religiosa was studied in eight provinces of Thailand from 1991 to 1998 to evaluate how breeding behaviour has evolved to enhance reproductive success in the face of human interference. The northern race G. r. intermedia bred mostly during February to April whereas the southern race G. r. religiosa bred mostly later during April to June. Both races were cavity-nesting, non-excavating, monogamous and similar in breeding activities except for differences in body size. They nested at the bottom of deep cavities with a long entrance (mean 45 cm), in tall trees. Average nest height was 23 m. Nests were sometimes abandoned (10% of nests) during nest-building or incubation. Most Hill Mynahs (70%) had clutches of three eggs. Both parents shared incubation and feeding of young. The most detrimental factor to the reproductive success of this species was human theft of the young, rather than any natural factors. During 1991 to 1998, 80% of eggs laid were hatched, but 88% of all eggs hatched were lost before fledgling. Those illegally stolen by humans amounted to 61% of eggs hatched. Only 37 of 308 nestlings or 12% of eggs hatched survived to independence. In 1999, nests were experimentally guarded to prevent human interference, and fledgling success increased to 75% of eggs hatched. The remaining 25% of nestlings were lost to predators and unknown causes, close to the 27% lost to these causes in unguarded nests during 1991 to 1998. Although the breeding pattern of this species has evolved to promote survival of young, it does not seem to have evolved adaptations to human predation. The continuing decrease of wild Hill Mynah populations has prompted attempts at captive breeding. Data on breeding biology from this study should enhance its success.
The breeding avifauna of Cosmoledo Atoll (Seychelles) with special reference to seabirds: conservation status and international importance
Authors: Rocamora Gérard , Feare Chris J. , Skerrett Adrian , Athanase Majella , Greig Edwina
Published: May 2003

Cosmoledo Atoll, in the Aldabra Group, western Indian Ocean, has rarely been visited by scientists. This paper reports the first visit by ornithologists during the south-east monsoon when many seabirds breed. The breeding populations of three species of booby (Sula spp.) and of Sooty Tern Sterna fuscata were censused and all other species of bird seen were recorded. The atoll proved to have globally significant populations of Masked Booby Sula dactylatra of the subspecies melanops, Red-footed Booby S. sula of the subspecies rubripes, and Sooty Tern of the subspecies nubilosa. Cosmoledo also supports populations of landbirds that have forms endemic to the Aldabra group, but whose taxonomy requires examination using molecular techniques. The atoll, although currently uninhabited, suffers the impacts of exotic fauna and flora, including cats and rats, introduced by previous inhabitants. The isolation of Cosmoledo confers some protection, but its value as a centre of biodiversity, and designation as an Important Bird Area by BirdLife International, indicate that formal protection is needed. Political mechanisms for this are suggested, the implementation of which would help to procure funding to enable practical conservation of the atoll's biota.
A categorical framework for finite state machines
Authors: HINES PETER
Published: May 2003

We provide a consistent way of looking at a range of finite state machines and their algebraic models. Our claim is that the natural representation of transitions of finite state machines is in terms of monoid homomorphisms, and distinct generalisation processes that can be applied to finite state machines correspond to distinct categorical generalisation processes at the level of the algebraic models.

The generalisations we consider are those from deterministic to non-deterministic machines, from one-way to two-way machines, and from read-only machines to read/write machines. Hence the finite state machines we consider, and provide algebraic models for, are (deterministic and non-deterministic) finite state automata, two-way automata, Mealy machines, and bounded Turing machines.

The categorical constructions corresponding to these generalisation processes are, respectively: altering the base category from functions to relations, applying the Geometry of Interaction, or Int construction, and a categorical process, which we refer to as the Comp construction, that uses the tensor on monoidal categories to construct graded categories.
SAFETY ASPECTS OF THE USE OF ULTRASOUND IN PREGNANCY
Authors: DUCK FRANCIS A
Published: May 2003

Diagnostic ultrasound has an enviable reputation for safety, and the lack of evidence for risk has been one of the key factors which has established it as the pre-eminent imaging method in obstetrics. Ultrasound remains one of very few common diagnostic procedures which may be carried out with little regard to safety. By comparison, all radiographic examinations carry known genetic and somatic risks associated with ionising radiation. Magnetic resonance imaging (MRI) investigations have resulted in several hundred cases of superficial burns, trauma from projectiles, and deaths from malfunctioning pacemakers or displaced metallic inserts. Furthermore, these other modes give rise to biological effects in organs other than those being imaged. For example, a radioisotope lung scan exposes the uterus due to radioactive urine, and scattered x-radiation exposes the ovaries during a chest computed tomography (CT) examination. By comparison, all bio-effects from ultrasound are restricted to the scanned region of tissue.
FETAL THORACIC LESIONS
Authors: CAMERON HELEN M
Published: May 2003

There have been significant strides made over the last two decades in the understanding of the natural history and pathophysiology of fetal thoracic lesions. Largely as a result of advances in prenatal ultrasound we are not only able to offer a tentative diagnosis of these lesions and advise parents about the prognosis but in selected centres offer the possibility of intervention for the most severely affected fetuses. Large gaps do remain in the current state of knowledge, in particular in the inability to predict pulmonary hypoplasia. Fetal surgery for lesions such as congenital cystic adenomatous malformation (CCAM) and pulmonary sequestration sequence (PSS) is still restricted to a very few centres and is reserved for those fetuses with hydrops where there is an extremely poor prognosis. Selection criteria for intervention have been refined over the last decade. Postnatal imaging studies, particularly computed tomography (CT) are essential in the evaluation of these lesions prior to surgical resection.
FETAL VENOUS CIRCULATION
Authors: KISERUD TORVID
Published: May 2003

Ultrasound evaluation of the venous system is now a compulsory part of the haemodynamic assessment of the fetus. Once umbilical venous flow was introduced1,2 and its pulsatile pattern discovered in the compromised fetus,3 other sections of the venous system have been added or explored for possible diagnostic use: the inferior and superior vena cava,4,5 ductus venosus,6,7 hepatic veins,8 pulmonary veins,9,10 and intracranial veins.11-13 The following presentation is not intended to be a complete review of the fetal venous circulation, which is growing by the day, but rather to focus on some central issues with an emphasis on physiologic principles. The reason for this focus is that, as clinicians, we tend to work according to pattern recognition, which is a necessary principle in daily life. However, in the long run as the fetal patient increasingly demands a more dynamic approach to solve the diagnostic riddles, we find ourselves digging deeper into the physiological mechanisms behind ultrasound images and recordings.
Beyond representativeness? Trends in political representation
Authors: ANDEWEG RUDY B.
Published: May 2003

The ascendancy of proportional representation as the electoral system of choice, and pervasive concerns with the demographic representativeness of parliaments, both testify to the importance that is attached to ‘descriptive’ or ‘microcosmic’ representation in politics, despite persistent doubts about its desirability. This paper makes three points. First, representation as representativeness presupposes the existence of stable and meaningful social or political collectivities, which can be reflected in the composition of parliament, and this condition is undermined by the general trend towards individualization, which can be observed throughout Western Europe. Second, this trend necessitates a conceptualization of political representation not as a state, but as a dynamic relationship between the citizen and the representative. This relationship can be characterized both by its direction (from below or from above), and by the moment at which popular control is exercised (before or after the representative's period in office). Third, it is argued that both growing uncertainty about citizen preferences and the transformation of political parties into para-statal agencies push towards representation from above; and that both growing unpredictability of the political agenda and European integration push towards ex-post popular control. These developments call for greater attention to mechanisms of accountability in representative democracies.
A characterization of philosophical knowledge in ‘Chinese modernity’: philosophical studies in Chinese Universities and the Academy of Social Sciences
Authors: JUNREN WAN
Published: May 2003

The present state of the study of philosophy in China cannot be understood if the introduction of Western philosophy, including Marxism, in the early decades of the 20th century is ignored. During the first half of the past century, philosophy flourished at Peking University with a heavy emphasis on social and political theory, as well as at Tsinghua University, which focused more on professionalization of the discipline, logic, epistemology and the history

of philosophy. From 1957 to 1979, philosophical studies suffered severely under an increasingly unfavourable political climate. It is only recently that departments of philosophy have been reconstructed, not only in Beijing but also in all major universities. Like their colleagues in other disciplines, many philosophers are nowadays struggling with the dichotomy between the old and the new, the Chinese and the Western tradition, and resisting an uncritical absorption of Western ideas. Finally, some observations are made on the lectures that Jürgen Habermas gave in China in 2001.
Gender in post-Mao China
Authors: ZHANG JEANNE HONG
Published: May 2003

Post-Mao gender discourse readjusts a politicized vision of gender based on Maoist ethics. While rejecting revolutionary concepts of sex equality, contemporary Chinese women embrace a notion of femininity through the revision of a traditional conception of womanhood as well as the construction of new role models. Women poets participate in this construction process with a fresh, powerful voice to express their gender consciousness. In their efforts to (re-)define womanhood, they present by poetic means radically gendered perspectives.
The fundamental processes in ecology: a thought experiment on extraterrestrial biospheres
Authors: WILKINSON DAVID M.
Published: May 2003

Ecological science is often organised as a hierarchical series of entities: genes, individuals, populations, species, communities, ecosystems and biosphere. Here, I consider an alternative process‐based approach to ecology, and analyse the nature of the fundamental processes in ecology. These fundamental processes are discussed in the context of the following question:‘for any planet with carbon‐based life, which persists over geological time scales, what are the minimum set of ecological processes that must be present?‘I suggest that the following processes would be present on any such planet: energy flow, multiple guilds, ecological tradeo ffs leading to within‐guild biodiversity, ecological hypercycles, merging of organismal and ecological physiology, carbon sequestration and possibly photosynthesis. Nutrient cycling is described as an emergent property of these fundamental processes. I discuss reasons why a biosphere based on a single species with no nutrient cycling is very unlikely to exist. I also describe the concept of ‘Gaian effect’. This suggests that some processes will always tend to extend the lifespan of a biosphere in which they develop (positive Gaian effect) while others could either increase or decrease (negative Gaian effect) such a lifespan. These ideas are discussed in the context of astrobiology, ecosystem services, conservation biology and Gaia theory.
Formation of dermal skeletal and dental tissues in fish: a comparative and evolutionary approach
Authors: SIRE JEAN‐YVES , HUYSSEUNE ANN
Published: May 2003

Osteichthyan and chondrichthyan fish present an astonishing diversity of skeletal and dental tissues that are often difficult to classify into the standard textbook categories of bone, cartilage, dentine and enamel. To address the question of how the tissues of the dermal skeleton evolved from the ancestral situation and gave rise to the diversity actually encountered, we review previous data on the development of a number of dermal skeletal elements (odontodes, teeth and dermal denticles, cranial dermal bones, postcranial dermal plates and scutes, elasmoid and ganoid scales, and fin rays). A comparison of developmental stages at the tissue level usually allows us to identify skeletogenic cell populations as either odontogenic or osteogenic on the basis of the place of formation of their dermal papillae and of the way of deposition of their tissues. Our studies support the evolutionary affinities (1) between odontodes, teeth and denticles, (2) between the ganoid scales of polypterids and the elasmoid scales of teleosts, and (3) to a lesser degree between the different bony elements. There is now ample evidence to ascertain that the tissues of the elasmoid scale are derived from dental and not from bony tissues. This review demonstrates the advantage that can be taken from developmental studies, at the tissue level, to infer evolutionary relationships within the dermal skeleton in chondrichthyans and osteichthyans.
Astrobiological instrumentation for Mars – the only way is down
Authors: Ellery A. , Kolb C. , Lammer H. , Parnell J. , Edwards H. , Richter L. , Patel M. , Romstedt J. , Dickensheets D. , Steele A. , Cockell C.
Published: May 2003

In this paper, in this edition of the Journal commemorating the life and work of David Wynn-Williams, we consider approaches to the astrobiological investigation of Mars. We provide a brief account of the scientific rationale behind the approach presented here. In particular, we outline the capabilities of the Raman spectrometer for the detection of biomarkers. David Wynn-Williams was an active champion of this instrument who was keen to field-qualify a version in Antarctica with a view to flying a Raman instrument onboard a Mars-bound space mission. We examine a scenario for the deployment of such an instrument in conjunction with other instrumentation and argue that subsurface deployment of scientific instruments is essential if we are to succeed in detecting any evidence that may exist for former life on Mars. We outline a mission scenario – Vanguard – which represents a novel but low-risk, low-cost approach to Mars exploration that was conceived and developed jointly by one of the authors (Ellery) and the late David Wynn-Williams.
The potential of the lichen symbiosis to cope with extreme conditions of outer space – I. Influence of UV radiation and space vacuum on the vitality of lichen symbiosis and germination capacity
Authors: de Vera J.-P. , Horneck G. , Rettberg P. , Ott S.
Published: May 2003

The lichen symbiotic organisms Fulgensia bracteata and Xanthoria elegans as well as their isolated photobionts and mycobionts were exposed to conditions simulating the extreme parameters of outer space in order to assess their limits of survival, e.g. during a potential interplanetary transfer or on the surface of an extraterrestrial body. Using the space simulation facilities at DLR, the test parameters under investigation were vacuum (10−3 Pa) and ultraviolet (UV) radiation at wavelength ranges from vacuum-UV to UV-A, applied separately or in combination. An analysis of vitality was made using confocal laser scanning microscopy and LIVE/DEAD staining using FUN I or SYTOX green. Intact lichens were extremely resistant to vacuum exposure as well as to UV radiation up to doses of about 160 kJ m−2 (200<λ<400 nm). Removal of the upper-cortex structure significantly increased the sensitivity of the lichens to the space parameters: already a relatively short treatment of about 5 h and a UV dose of about 50 kJ m−2 reduced the vitality rate to nearly 50%; however, the dose effect curves levelled off and continued treatment did not reduce the vitality further. Similar survival curves levelling off at higher UV doses were observed for the isolated photobionts; however, in the latter cases, the saturation occurred at five times lower doses (full UV spectrum). Also spores of the mycobionts showed a remarkable UV (254 nm) resistance up to doses of about 3 kJ m−2. The data suggest that the symbiotic features peculiar to lichens allow them to cope with the extreme conditions of outer space or even with Martian surface conditions provided suitable niche habitats are available to serve as refuges and complementary endogenous or exogenous protection mechanisms are established.
Guest Editorial
Authors: Edwards Howell , Cockell Charles
Published: May 2003

Project Leader, Antarctic Astrobiology, British Antarctic Survey, Cambridge 1946–2002

David Donaldson Wynn-Williams, born 16th July, 1946, in West Kirby, Cheshire, UK and
Founding Editor of the International Journal of Astrobiology, met an ‘untimely
and unjust death’ (W. Block, Independent, 4th April, 2002) on 24th March, 2002, which
left his colleagues and family deeply saddened.
Fourier-transform Raman spectroscopic studies of chronological change in stromatolitic cores from Antarctic lake sediments
Authors: Edwards H.G.M. , Wynn-Williams the late D.D. , Ellis-Evans J.C. , Newton E.M. , Little S.J. , de Oliveira L.F.C. , Hodgson D. , Doran P.T.
Published: May 2003

The Fourier transform-Raman spectra of two lacustrine sediment cores from Antarctic sites are reported. The Lake Hoare specimens were predominantly calcium carbonate, quartz and β-carotene, with chlorophyll and calcium sulphate being noted as minor components. No evidence was found for iron (III) oxide or oxy-hydroxide bands. The Lake Nella specimens, in contrast, contain chlorophyll and quartz predominantly, but the absence of β-carotene is noteworthy. Here, the presence of haematite and a haematite–goethite mixture have been identified, with weaker features such as those of scytonemin, characteristic of cyanobacterial mats. The Raman spectra indicate that two different types of lake chemistry have been operating and several reasons are proposed for this.
Paleolimnology in the High Arctic – implications for the exploration of Mars
Authors: Lim Darlene S.S. , Cockell Charles S.
Published: May 2003

Paleolimnology provides information on the past chemical, physical and biological nature of water bodies. In polar regions, where global climatic changes can be exacerbated compared with lower latitudes, the science has become important for reconstructing past changes and in so doing, predicting possible effects of future changes. Owing to the association of life with water bodies, particularly stable water bodies sustained over many millennia, paleolake regions on the surface of Mars are of exobiological importance. In this mini-review, we use experience gathered in the High Arctic to describe the importance of paleolimnology in the Earth's polar regions as it pertains to the future application of this science to robotic and human exploration missions to the planet Mars.
FT-Raman spectroscopic analysis of an Antarctic endolith
Authors: Jorge Villar Susana E. , Edwards Howell G.M. , Wynn-Williams David D. , Roger Worland M.
Published: May 2003

The FT-Raman spectra of an Antarctic endolith from the LTER site at Lake Hoare are reported. The specimen provides an unusual occurrence of endolithic colonization of an igneous rock substratum, which analyses as microcline feldspar. The presence of aragonite in the red biological stratum and calcite in a fissure of the rock which has not been subjected to colonization can be attributed to the penetration of calcareous deposits from shallow ground water in an earlier environment in the Dry Valleys. The green biological layer is composed of chlorophyll and β-carotene. Comparison with previous Raman spectroscopic work on endoliths in sedimentary Beacon sandstone is effected.
Astrobiology with haloarchaea from Permo-Triassic rock salt
Authors: Stan-Lotter H. , Radax C. , Gruber C. , Legat A. , Pfaffenhuemer M. , Wieland H. , Leuko S. , Weidler G. , Kömle N. , Kargl G.
Published: May 2003

Several viable halophilic archaebacteria were isolated previously from rock salt of Permo-Triassic age in an Austrian salt mine; one of these strains was the first to be recognized as a novel species from subterranean halite and was designated Halococcus salifodinae. The halophilic microorganisms have apparently survived in the salt sediments over extremely long periods of time. Halobacteria could therefore be suitable model organisms for exploring the possibility of long-term survival of microbes on other planets, in particular, since extraterrestrial halite has been detected in meteorites and is assumed to be present in the subsurface ocean on Europa. Our efforts are directed at the identification of the microbial content of ancient rock salt and the development of procedures for the investigation of the halobacterial response to extreme environmental conditions. Using modified culture media, further halophilic strains were isolated from freshly blasted rock salt and bore cores; in addition, growth of several haloarchaea was substantially improved. Molecular methods indicated the presence of at least 12 different 16S rRNA gene species in a sample of Alpine rock salt, but these strains have not been cultured yet. The exploration of Mars is a target of space missions in the 21st century; therefore, testing the survival of haloarchaea under conditions comparable to present-day Mars, using a simulation chamber, was begun. Preliminary results with Halococcus and Halobacterium species suggested at least tenfold higher survival rates when cells were kept in liquid brines than under dry conditions; staining of cells with the LIVE–DEAD kit, which discriminates between damaged and intact membranes, corroborated these data.
Raman spectroscopy and light microscopy of a modern and sub-fossil microstromatolite: Rivularia haematites (cyanobacteria, Nostocales)
Authors: Pentecost Allan , Edwards Howell G.M.
Published: May 2003

A study of Rivularia stromatolites demonstrated seasonal and non-seasonal banding patterns of calcification, ‘sun-screen’ scytonemin pigment and nitrogen-fixing heterocysts. Calcification was controlled by seasonal events with abiogenic ‘winter’ deposition and biogenic ‘summer’ deposition. Scytonemin was produced as a series of complex bands, probably as a response to summer Atlantic weather systems. Its production was also correlated in part with the appearance of heterocysts. The heterocysts were produced in bands, the pattern of which was probably controlled by an internal regulatory system. Raman spectra of modern and ancient (up to 4000 year old) Rivularia showed that scytonemin and carotenoid pigment can persist in dried material for >100 yr. The 4000 year old fossils did not reveal any useful biomarkers.
The biogeochemistry of Si in the McMurdo Dry Valley lakes, Antarctica
Authors: Pugh Heather E. , Welch Kathleen A. , Lyons W. Berry , Priscu John C. , McKnight Diane M.
Published: May 2003

The biogeochemical dynamics of Si in temperate lakes is well documented and the role of biological uptake and recycling is well known. In this paper we examine the Si dynamics of a series of ice-covered, closed-basin lakes in the McMurdo Dry Valley region (~78° S) of Antarctica. Our data and calculations indicate that biological uptake of Si is not a major process in these lakes. Mass balance considerations in Lake Hoare, the youngest and the freshest lake, suggest that annual stream input during relatively low-flow years is minor and that Si dynamics is greatly influenced by hydrological variation and hence climatic changes affecting stream flow and lake level. The data imply that the Si input during high-flow years must dominate the system. Subtle changes in climate have a major control on Si input into the lake, and Si dynamics are not controlled by biogeochemical processes as in temperate systems.
Polar endoliths – an anti-correlation of climatic extremes and microbial biodiversity
Authors: Cockell Charles S. , McKay Christopher P. , Omelon Christopher
Published: May 2003

We examined the environmental stresses experienced by cyanobacteria living in endolithic gneissic habitats in the Haughton impact structure, Devon Island, Canadian High Arctic (75° N) and compared them with the endolithic habitat at the opposite latitude in the Dry Valleys of Antarctica (76° S). In the Arctic during the summer, there is a period for growth of approximately 2.5 months when temperatures rise above freezing. During this period, freeze–thaw can occur during the diurnal cycle, but freeze–thaw excursions are rare within higher-frequency temperature changes on the scale of minutes, in contrast with the Antarctic Dry Valleys. In the Arctic location rainfall of approximately 3 mm can occur in a single day and provides moisture for endolithic organisms for several days afterwards. This rainfall is an order of magnitude higher than that received in the Dry Valleys over 1 year. In the Dry Valleys, endolithic communities may potentially receive higher levels of ultraviolet radiation than the Arctic location because ozone depletion is more extreme. The less extreme environmental stresses experienced in the Arctic are confirmed by the presence of substantial epilithic growth, in contrast to the Dry Valleys. Despite the more extreme conditions experienced in the Antarctic location, the diversity of organisms within the endolithic habitat, which includes lichen and eukaryotic algal components, is higher than observed at the Arctic location, where genera of cyanobacteria dominate. The lower biodiversity in the Arctic may reflect the higher water flow through the rocks caused by precipitation and the more heterogeneous physical structure of the substrate. The data illustrate an instance in which extreme climate is anti-correlated with microbial biological diversity.
The Welfare Mix in Hungary as a New Phenomenon
Authors: Széman Zsuzsa
Published: May 2003

This paper, the first of a new series of ‘Briefing’ papers, describes the challenges encountered by the transition from state-socialism to what may be broadly described as a capitalist social democracy in one Central and Easter European country, Hungary. It considers the policy responses to a variety of challenges in the social security, employment and social welfare fields faced with a wave of impoverishment that followed the disintegration of state socialism from the late 1980s.
The New Face of Welfare in the US: From Income Transfers to Social Assistance?
Authors: Corbett Thomas
Published: May 2003

This article describes the 1996 reform of US welfare and reviews its consequences, concluding that the evidence so far is encouraging, but that the full effects of reform are still unknown. It demonstrates how much the essential character of US welfare has altered: the emphasis on changing behaviour rather than making cash payments; the shift in responsibility from federal government to frontline administrators; the move to discretionary rather than rights based decision-making; and the stress on performance rather than on process. Finally, it notes that the language of political debate takes little account of what has already been achieved.
‘Ending Consensus as We Began to Know It’: Welfare Reform and the Republicans after 2002
Authors: Deacon Alan
Published: May 2003

R. Blank and R. Haskins (eds) (2001), The New World of Welfare, Brookings Institution Press, Washington, DC.

K. Weaver (2001), Ending Welfare as We Know It, Brookings Institution Press, Washington, DC.
Unwed Parents in the US: Myths, Realities, and Policy Making
Authors: Garfinkel Irwin , McLanahan Sara
Published: May 2003

The Fragile Families Study, a survey of 5,000 children representative of all non-marital births in US cities with populations of over 200,000, provides new evidence on the characteristics of unmarried parents and their children. Initial analyses reported in this article reveal that the typical unmarried mother is in her early twenties and cohabiting at the birth of her children. Almost one third are Hispanic and 51 per cent non-Hispanic black. The great majority of unwed parents are committed to each other and their children at the time of birth but most are poorly equipped to support themselves and their children.
Barriers to Employment and the ‘Hard to Serve’: Implications for Services, Sanctions,
and Time Limits
Authors: Danziger Sandra K. , Seefeldt Kristin S.
Published: May 2003

Falling welfare rolls in the US has focussed attention on those remaining on the caseload, variously termed the ‘hard to serve’ or ‘difficult to employ’. Using data from the first three years of the Women's Employment Study, a sample of TANF (Temporary Assistance for Needy Families) recipients drawn in an urban county in Michigan, this article examines the barriers that inhibit people moving off welfare. The analysis indicates that the kinds of skill deficits and other personal problems experienced by welfare recipients are not frequently and systematically addressed within the rapid-employment, welfare to work models widely implemented across the USA.
Psychometrische Effekte von Farbgebung
Authors: Gittler Georg , Arendasy Martin
Published: May 2003

Zusammenfassung: Digitale Testmodifikationen und -adaptationen sind infolge fortschreitender Computertechnologie immer einfacher durchzuführen. Dies wirft unter dem Aspekt der Qualitätskontrolle psychologischer Tests die Frage nach “psychometrischer Äquivalenz” von Original und Modifikation auf. In der vorliegenden Studie wurde der Effekt musterspezifischer Farbgebung bei Würfelaufgaben des Typs 3DW im Rahmen der IRT untersucht. Dazu sind verschiedene Testversionen (Farbversion, Schwarz/Weiß-Version und eine Linkversion mit Farb- und Schwarz/Weiß-Aufgaben) insgesamt 446 Personen vorgelegt worden. Die hypothesengeleiteten Datenanalysen, die mittels Rasch-Modell und dem linearen logistischen Testmodell (LLTM) vorgenommen wurden, ergaben weder qualitative (dimensionale) noch quantitative Unterschiede (im Sinne eines Farbeffekts). IRT-basierte sowie klassisch-statistische Kontrollanalysen bestätigen die Resultate. Diese Ergebnisse decken sich nicht mit den ursprünglichen Erwartungen der Autoren und sprechen somit einerseits für die Bedeutung derartiger Qualitätskontrollen bei psychologischen Tests und andererseits für die Robustheit des im Raumvorstellungstest 3DW verwendeten Aufgabentyps. Die gewählte Vorgangsweise kann als paradigmatisch für die probabilistische Analyse der Messäquivalenz von Rasch-homogenen Skalen betrachtet werden.
Eine revidierte Fassung der deutschsprachigen Skala zum Selbstwertgefühl von Rosenberg
Authors: von Collani Gernot , Herzberg Philipp Yorck
Published: May 2003

Zusammenfassung: Für die deutschsprachige Fassung der Rosenberg-Skala zum Selbstwertgefühl von Ferring und Filipp (1996) wird eine Teilrevision vorgeschlagen. Ein Item der bisherigen Skalenversion stellte sich in eigenen Analysen als psychometrisch unzulänglich heraus und weist eine mangelnde inhaltliche Validität auf. Dadurch ist möglicherweise die Vergleichbarkeit mit der Originalversion und mit Adaptationen der Rosenberg-Skala in anderen Sprachen nicht gewährleistet. Die vorgeschlagene Teilrevision der Skala versucht, diese Mängel zu beheben und erweist sich in zwei unabhängigen Untersuchungen als Verbesserung der bisherigen Skala auf Itemebene. Außerdem werden hier erstmals vollständige Kennwerte für alle Skalenitems mitgeteilt.
Der Kindheitsfragebogen, ein Instrument zur Beschreibung der erlebten Kindheitsbeziehung zu den Eltern
Authors: Hardt J. , Egle U.T. , Engfer A.
Published: May 2003

Zusammenfassung: Mit dem Kindheitsfragebogen (KFB) wird die erlebte Beziehung von erwachsenen Personen zu ihren Eltern in der Kindheit und Jugendzeit beschrieben. Es werden acht verschiedene Bereiche der Beziehungen zur Mutter bzw. zum Vater erfasst: Wahrgenommene Liebe, Strafverhalten, Elternteil als Vorbild, Bagatellisierung des Strafverhaltens, Ehrgeiz, Rollenumkehr, Kontrolle und Geschwisterrivalität. In vier weiteren Skalen wird die Ehe der Eltern beurteilt, der sozioökonomische Status des Elternhauses eingeschätzt sowie die soziale Unterstützung von außerhalb des Elternhauses und das Lebensgefühl in der Kindheit angegeben. In einer Stichprobe von 700 Patienten weisen die Skalen überwiegend gute bis sehr gute Reliabilitäten auf.
Der Fragebogen zur Erfassung aggressiver Verhaltensweisen im Straßenverkehr (AViS)
Authors: Herzberg Philipp Yorck
Published: May 2003

Zusammenfassung: Ausgehend von der Bedeutung aggressiver Verhaltensweisen im Straßenverkehr und dem Mangel an geeigneten diagnostischen Verfahren zu ihrer Erfassung wird die Entwicklung eines Fragebogens zur Erfassung aggressiver Verhaltensweisen im Straßenverkehr (AViS) beschrieben. Die Itemkonstruktion führt über drei Stufen zur Extraktion der sechs Faktoren instrumentelle Aggression, Ärger, Spaß an Gewalt, Ausleben, Negativismus und soziale Erwünschtheit. In einer unabhängigen Replikationsstudie mit 841 Personen konnten die Faktorenstruktur und deren faktorielle Invarianz konfirmatorisch gesichert werden.
Zum Zeitverhalten beim computergestützten adaptiven Testen
Authors: Rammsayer Thomas , Brandler Susanne
Published: May 2003

Zusammenfassung: Die vorliegende Studie untersucht, inwieweit Falsch- bzw. Richtig-Antwortlatenzen beim computergestützten adaptiven Testen vom individuellen Niveau der fluiden Intelligenz abhängig sind. Das Zeitverhalten einer Stichprobe von 80 Testpersonen, deren fluide Intelligenz mittels des CFT3 bestimmt wurde, wurde an Hand einer perzeptiv-sensorischen und einer kognitiven Diskriminationsaufgabe erfasst. Die Ergebnisse belegen, dass Antwortlatenzen weder von der Leistungsgüte bei der Aufgabenlösung noch vom Niveau der fluiden Intelligenz beeinflusst werden. Weiterhin erwiesen sich das so genannte “Falsch > Richtig-Phänomen” sowie starke korrelative Zusammenhänge zwischen Falsch- und Richtig-Antwortlatenzen als unabhängig vom Intelligenzniveau.