bluuebunny/crossref_metadata_2025 huggingface dataset:
A preliminary investigation of the lipids and fatty acids composition of Gammarus aequicauda (Crustacea: Amphipoda) and its main food source
Authors: Biandolino Francesca , Prato Ermelinda
Published: March 2006

Lipid and fatty acid composition in Gammarus aequicauda from Mar Piccolo (Ionian Sea, southern Italy) were studied during the spring months. Simultaneously, samples of the macroalgae Chaetomorpha linum were also collected from the same area. During these months Chaetomorpha linum was the main food source of Gammarus aequicauda. The main lipid classes were phospholipids (PL) and triacylglycerols (TG) both in Gammarus aequicauda and in Chaetomorpha linum with similar concentrations. But PL was the main lipid class in Gammarus aequicauda and TG in Chaetomorpha linum. On average unsaturated fatty acids represent the preponderant part in both G. aequicauda and C. linum. Gammarus aequicauda had a higher level in monounsaturated fatty acids (MUFA), on the contrary polyunsaturated fatty acids (PUFA) were the dominant unsaturated fatty acids in C. linum. Both were characterized by high levels of 18:0, 18:1(n-9), 20:5(n-3) and 20:4(n-6), in particular C. linum had a high proportion of 14:0 and the ratio of 18:1n 9/18:1n 7 was high.
Development of external sexual characters of deep sea Bythocaris shrimps (Crustacea: Decapoda: Hippolytidae)
Authors: Sokolov Vassily I. , Spiridonov Vassily A.
Published: March 2006

The development of sex-specific characters is described for the deep sea North Atlantic/Arctic shrimp genus Bythocaris. A number of species were examined in the collections of Russian institutions including B. biruli, B. curvirostris, B. irene, B. leucopis and B. payeri. The pattern of size-specific variation in the masculine characters, i.e. the development of the modified appendix interna on the endopodite of the first pleopod and the appendix masculina do not indicate the presence of sex change (protandric hermaphroditism) in the life history.
A complex sexual cycle in sandy beaches: the reproductive strategy of Emerita brasiliensis (Decapoda: Anomura)
Authors: Delgado Estela , Defeo Omar
Published: March 2006

Reproductive tactics displayed by the mole crab Emerita brasiliensis that inhabits Atlantic beaches of South America are reported. The analysis of external sexual characters and reproductive organs disclosed seven developmental forms: megalopae, neotenic males, early females, juveniles, males, females (ovigerous or not) and intersex individuals. Precocious acquisition of gonopores in females, production of spermatophores in neotenic males and presence of juveniles and intersex individuals are reported for the first time for this species. Sex ratios were biased towards male forms in summer, whereas the opposite trend was observed in autumn. The occurrence of different forms within a single population, coupled with a marked temporal variability in its abundance, suggest a high complexity in the sexual life cycle of the mole crab. This involves two different pathways: (a) short, where megalopae moult into neotenic (mature) males or early females; and (b) long, following a sequence of moults involving several stages (zoeas, megalopae, juveniles and adults).
Opisthobranch molluscs from the subtidal trawling grounds off Blanes (Girona, north-east Spain)
Authors: Domènech Anna , Avila Conxita , Ballesteros Manuel
Published: March 2006

Studies on the opisthobranch molluscs inhabiting the continental platform in areas not accessible by SCUBA diving are rare in the subtidal bottoms of the Iberian Peninsula. Data obtained from trawls are not adequate for quantitative analysis, due to the indirect method used and the high number of variables which affect the capture of the samples. However, with the aim of obtaining qualitative information on the opisthobranch molluscs inhabiting the subtidal trawling grounds off Blanes, we took more than 500 samples over a two-year period, on the non-commercial fraction of the trawling fisheries, finding opisthobranchs in 306 samples. We analysed samples from 16 trawling sites, at depths between 50 and 300 m, by using ten fishing boats of the ‘Confraria de Pescadors del Port de Blanes’. We obtained 4.295 specimens of opisthobranchs belonging to 29 species. From these, 4 are Cephalaspidea s.s., 1 Anaspidea, 1 Umbraculacea, 3 Pleurobranchacea and 20 Nudibranchia (3 Arminina, 3 Dendronotina and 14 Doridina). The most abundant species were Gastropteron rubrum and Scaphander lignarius, both cephalaspideans present during all seasons, and the dendronotacean Tethys fimbria. For Scaphander lignarius it was possible to distinguish three size-groups, from which the smallest one was usually found in summer. Other interesting species found were, among others, Armina tigrina, Baptodoris cinnabarina, Thordisa filix and Kaloplocamus ramosus. The richest trawling grounds in species numbers and abundances were La Planassa and Els Capets. The total number of opisthobranch species reported for the trawling grounds off Blanes is now 48.
Some aspects of the reproductive biology of two Atlantic species of Polycera (Mollusca: Opisthobranchia)
Authors: Martínez-Pita Ines , Sánchez-España Ana I. , García Francisco J.
Published: March 2006

Spawn and the embryonic development of two species of the genus Polycera were studied. Both species, Polycera aurantiomarginata and Polycera quadrilineata, were collected in the intertidal zone of El Portil (Huelva) in south-western Spain. In the laboratory spawn were collected daily. Length and width of the spawn, number of eggs per mm2, egg size and capsule size were measured. The egg masses were controlled several times a day to provide a timetable for the main developmental events until hatching. Embryonic growth was measured between some characteristic stages (gastrula, preveliger, primordial velum and veliger prior to hatch).

The two species differ in a number of aspects: spawn are longer, eggs and capsules are bigger in P. aurantiomarginata than in P. quadrilineata. The number of eggs per mm2, however, is greater in P. quadrilineata than in its congener. Furthermore, spawn of P. quadrilineata are semicircular whereas those of P. aurantiomarginata are spiral and wavy. Both species show planktotrophic development but embryonic development of P. quadrilineata is faster than that of P. aurantiomarginata. The dynamic of embryonic growth is very similar in the two species, although embryos of P. aurantiomarginata are larger at any measured stage than those of P. quadrilineata.
Description of two new phanerobranch nembrothid species (Nudibranchia: Polyceridae: Doridacea)
Authors: Pola M. , Cervera J.L. , Gosliner T.M.
Published: March 2006

Two new species of dorid nudibranchs of the genus Tambja are described from the Indo-Pacific and the temperate waters of the western Atlantic. Tambja haidari sp. nov. is only known from the type locality in Senegal. This species has dark blue ground colour with yellow bands and sky-blue spots, which become real tubercles along the tail. The internal features are typical of species of the genus, with rachidian teeth that lack denticles and with a prostate slightly differentiated from the rest of the vas deferens. Tambja blacki sp. nov., from Papua New Guinea and eastern Australia, has yellow-green or green colour with black blotches. There are two large blotches on the head continuing from the inner side of the base of the rhinophores towards the rear. The notal margin is elevated and joins behind the gill in a well-developed hump. The reproductive system of this species is very characteristic because it has some features more typical of species of Nembrotha than of Tambja (i.e. vaginal gland absent, prostate spread over the bursa copulatrix and wide and elongate vagina). These descriptions bring the number of species of Tambja found around the world to 31.
A new species of the family Thyasiridae (Mollusca: Bivalvia) from the oxygen minimum zone of the Pakistan margin
Authors: Oliver P. Graham , Levin Lisa
Published: March 2006

A new species of Thyasiridae, ‘Leptaxinus’ indusarium sp. nov. is described from the Indus margin, off Pakistan. The generic affinity is tentative and possible alternatives are discussed. It occurs between 800 m and 1000 m water depth in a low oxygen environment, where it is relatively abundant. The ecological setting is described and data suggest that this species is not chemosymbiotic.
The bioengineer Perumytilus purpuratus (Mollusca: Bivalvia) in central Chile: biodiversity, habitat structural complexity and environmental heterogeneity
Authors: Prado Luis , Castilla Juan Carlos
Published: March 2006

The mussel Perumytilus purpuratus is distributed from Ecuador to the Strait of Magellan on the Pacific coast; and also extends along the Atlantic coast up to La Lobería, Argentina. The species forms dense three-dimensional matrices which constitute a microhabitat for a wide variety of organisms. Here we test the hypothesis that factors determining habitat structural complexity and environmental heterogeneity of Perumytilus matrices have significant effects on the associated macrofaunal community. In total we found 92 invertebrate taxa in P. purpuratus matrices. The number of layers (stratification) in the matrix had a significant effect on evenness: the greater the stratification, the lower the evenness index. Sediment retention by matrices in sheltered sectors had a significant effect on evenness: greater sediment retention resulted in lower evenness. Sediment retention also determined significant differences in macrofaunal assemblages. In matrices without sediment retention, mussel layering and the presence of algae on the shells of P. purpuratus determined significant macrofaunal differences. As a dominant competitor, P. purpuratus plays a major role in intertidal rocky shores where it is present, structuring communities and determining local biodiversity.
Spermatozoa and phylogenesis of the pectinid bivalve Flexopecten glaber
Authors: Pennec Gaël Le , Aloui-Bejaoui Nejla , Pennec Marcel Le
Published: March 2006

Gonad of the Mediterranean pectinid Flexopecten glaber was studied in order to describe the morphology and the ultrastructural characteristics of the mature spermatozoa. The spermatozoon has a 2.5 μm pyriform head and a 40–45 μm flagellum. The four mitochondria of the mid-piece are 0.6 μm in diameter. The nucleus contains dense chromatin fibres and possesses two depressions: a wide (0.19 μm) and deep (0.58 μm) sub-acrosomal one, and the other at the base of the head, less deep (0.36 μm) and less wide (0.12 μm). The objective was to situate this scallop in the phylogenetic diagrams found in the literature concerning the commercial pectinid species.
Diet of the cuttlefish Sepia officinalis (Cephalopoda: Sepiidae) off the south coast of Portugal (eastern Algarve)
Authors: Alves Dário Mendes , Cristo Margarida , Sendão João , Borges Teresa Cerveira
Published: March 2006

The diet of Sepia officinalis was studied by examining the stomach contents of 522 specimens caught off the coast of the Algarve, Portugal. A total of 49 different prey items, belonging to six taxa (Polychaeta, Cephalopoda, Teleostei, Bivalvia, Crustacea and Gastropoda) was found, indicating opportunistic feeding behaviour. The diet was examined in relation to season, sex and size. The diet of males and females were similar. For small S. officinalis, crustaceans were more important in weight, whereas for larger specimens, fish were dominant. Seasonal differences in the diet were apparent but were shown to be possibly influenced by the cuttlefish size.
Stable isotopes in jumbo squid (Dosidicus gigas) beaks to estimate its trophic position: comparison between stomach contents and stable isotopes
Authors: Ruiz-Cooley R.I. , Markaida Unai , Gendron D. , Aguíñiga S.
Published: March 2006

Stomach contents and carbon (C) and nitrogen (N) stable isotope analysis were used to evaluate trophic relationships of jumbo squid, Dosidicus gigas. Buccal masses, beaks and stomach contents of large and medium maturing-sized jumbo squid and muscle from its main prey, the myctophid Benthosema panamense, were collected in the Gulf of California, Mexico during 1996, 1997 and 1999. Both the quantified C and N-isotope ratios in muscle, and stomach content analysis revealed that larger-sized maturing squid showed a higher trophic position than medium-sized individuals. However, a discrepancy between stomach contents versus stable isotope analyses was found in evaluating trophic relationships. Simple dilution models as a function of growth were used to estimate the C and N renewal dietary shift for jumbo squid. Estimates of the initial C and N pools in D. gigas with an initial age of 70 days and 210 days indicated isotopic shifts of 32% after a threefold biomass increase and 25% after a fourfold biomass increase, respectively. Additionally, beak samples of jumbo squid were evaluated as an alternative tissue to estimate squid trophic position using stable isotopes. The results showed a significant correlation between stable isotope ratios from muscle and beak samples. Muscle isotope values were higher than beak by 1% and 4% for δ13C and δ15N respectively. A test with jumbo squid beaks collected from a stomach of a stranded sperm whale confirmed the viability of this method.
Ampullary pore distribution of Galeus melastomus and Etmopterus spinax: possible relations with predatory lifestyle and habitat
Authors: Atkinson Carla Jayne Louise , Bottaro Massimiliano
Published: March 2006

The number and distribution of ampullary pores present on the blackmouth catshark, Galeus melastomus and the velvet belly dogfish, Etmopterus spinax do not differ with the size/maturity or gender of the specimen and were found to be related to prey preference.
‘It's one of those scary areas’: Leadership and management of music in primary schools
Authors: Beauchamp Gary , Harvey Janet
Published: March 2006

The role of the subject leader, or co-ordinator, in the primary school has evolved considerably over recent years. Ultimately, responsibility for individual subjects remains with the headteacher and governors, but much work has been increasingly devolved, at least theoretically, to subject leaders. In this role they need to demonstrate the ability to be both leaders and managers. Whilst some aspects of leadership and management are generic, others may be specific to the subject and type of school. Through interviews with three subject leaders in schools where music is judged to be successful, this article examines their roles from a leadership and management perspective within the context of the existing primary school (3–11 years) structure. The tentative conclusion is that music is different and may need special considerations in equipping subject leaders to work effectively within this type of school.
The teaching of music in the primary school by the non-music specialist
Authors: Holden Hilary , Button Stuart
Published: March 2006

This article reports on an investigation of the teaching of music by non-music specialists in the primary school. In particular, it examines attitudes to teaching music, factors affecting teachers' confidence, the relationship between confidence and training, support for music teaching, teaching experience and musical background. The non-specialist teachers taking part in this survey were chosen from twelve schools across one Local Education Authority (LEA). The attitudes and views on teaching music of 71 teachers were obtained through a questionnaire survey and follow-up interviews. The findings of this survey show that there is much work still to be done in providing non-specialists with effective long-term training and support to increase their music skills, subject knowledge, and confidence, to enable them to make a more marked difference to children's musical education.
Life histories of music service teachers: The past in inductees' present
Authors: Baker David
Published: March 2006

This article discusses inductee music service teachers (to 25 years of age). It explores how their lives, as perceived, shape current identities in teaching and result in several career problems. Respondents were drawn from a comprehensive life history study of 28 Local Education Authority employees. Of this larger cohort, four were age 25 years and below, and the remaining 24 teachers made retrospective comments. Data were collected and analysed between October 2002 and March 2004. Principal findings suggest that schooling failed to address these educators' needs as musical learners; key childhood experiences were external of schools. This often resulted in an idealistic trajectory, in teenage years, towards an occupation as a performer. An occupation in music education was entirely disregarded. Consequently, inductees now consider training experiences an inappropriate platform for their professional lives. Managing group teaching and children's behaviour engenders considerable anxiety. Music service work is also deemed a transient state of affairs. There are implications for training, retention and professional development.
Taking the plunge: The hopes and fears of students as they begin music college
Authors: Burt Rosie , Mills Janet
Published: March 2006

The attitudes and experiences of 13 music students entering a conservatoire were tracked before their entry and throughout their first term at college. Aspirations and apprehensions towards the musical, academic and social aspects of college life were collected in addition to career aims, and the data analysed qualitatively to produce emergent themes. Three pivot points were drawn from the analysis, describing events or factors that appear to shape the development of the students as musicians. The first highlights the importance of the students' first performance at college, and the second focuses on overcoming possible feelings of inadequacy generated from being one of many outstanding musicians. Thirdly, the role of feedback is highlighted as an important part of the students becoming confident in all aspects of their musical work.
Assessing collaborative learning
Authors: Hunter Desmond
Published: March 2006

This paper is informed by one clear guiding principle: collaborative learning provides the platform on which independent learning is nurtured. The nature of collaborative learning in musicology as well as performance is considered. The focus is on learning rather than achievement, on process rather than presentation, on how students are encouraged to develop good learning habits. It will be argued that the assessment of a group endeavour needs to be integral to rather than detached from the learning. The centrality of the group endeavour in the learning environment does not diminish the role of the individual. The integrity of an individual's contribution to a group endeavour is validated by the group.
Design spaces: The explicit representation of spaces of
alternatives
Authors: STOUFFS RUDI
Published: March 2006

This Special Issue is in an exceptional format. Starting with an
invited Keynote by Rob Woodbury and Andrew Burrow, the rest of the issue
is taken up by invited papers that are responses to Woodbury and
Burrow's paper, written by selected authorities on design. A final
short section is devoted to Woodbury and Burrow's reactions to the
responses.
Whither design space?
Authors: WOODBURY ROBERT F. , BURROW ANDREW L.
Published: March 2006

Design space exploration is a long-standing focus in computational design research. Its three main threads are accounts of designer action, development of strategies for amplification of designer action in exploration, and discovery of computational structures to support exploration. Chief among such structures is the design space, which is the network structure of related designs that are visited in an exploration process. There is relatively little research on design spaces to date. This paper sketches a partial account of the structure of both design spaces and research to develop them. It focuses largely on the implications of designers acting as explorers.
The whittled design space
Authors: AKIN ÖMER
Published: March 2006

The paper by Woodbury and Burrow is examined using four criteria: completeness, discrimination, alternative approaches, and combining exploration in different problem domains. Although the paper covers significant aspects of the search space literature it leaves out some relevant aspects of the cognitive approach. It fares much better in terms of discriminating important concepts and alternative approaches to the modeling of the design search space. Thestructure–function–behaviormodel is suggested as an analogy for the central parameters of the search space paradigm. The Woodbury and Burrow paper reveals more than what has been accomplished up to now in the design search space area, but its task still remains incomplete.
Yes, and by the way … thoughts on “Whither design
space?”
Authors: FLEMMING ULRICH
Published: March 2006

Having no fundamental difficulties with Woodbury and Burrow's
article, I explore some implications of their work based on my experience,
and that of PhD students advised by me, with developing design support
systems. I suggest that such systems need a distinct task layer
on top of the computational layer, where the power of a system
rests. I also express unease with some details of the article under
review, in the hope of contributing to a wider discussion.
Explicit design space?
Authors: KRISHNAMURTI RAMESH
Published: March 2006

This paper examines the need for explicit representations of the design space, in response to Woodbury and Burrow. Specifically, their proposal for a particular search strategy, by means of which one can reuse past experiences explicitly represented by previously traversed paths, is examined. This is done by exploring issues with respect to design search and representation in general, while relating these to specific issues raised by Woodbury and Burrow. The paper concludes by suggesting that their arguments essentiallypointto devising an appropriate “programming language” for design.
Modeling dialogue with mixed initiative in design space exploration
Authors: DATTA SAMBIT
Published: March 2006

Exploration with a generative formalism must necessarily account for the nature of interaction between humans and the design space explorer. Established accounts of design interaction are made complicated by two propositions in Woodbury and Burrow's Keynote on design space exploration. First, the emphasis on the primacy of the design space as an ordered collection of partial designs (version, alternatives, extensions). Few studies exist in the design interaction literature on working with multiple threads simultaneously. Second, the need to situate, aid, and amplify human design intentions using computational tools. Although specific research and practice tools on amplification (sketching, generation, variation) have had success, there is a lack of generic, flexible, interoperable, and extensible representation to support amplification. This paper addresses the above, working with design threads and computer-assisted design amplification through a theoretical model of dialogue based on Grice's model of rational conversation. Using the concept of mixed initiative, the paper presents a visual notation for representing dialogue between designer and design space formalism through abstract examples of exploration tasks and dialogue integration.
A typology of design space explorers
Authors: WOODBURY ROBERT F. , BURROW ANDREW L.
Published: March 2006

The act of design is a complex of actions and abilities that is evolving and often highly individual. Given the context of human–computer interaction, and a commitment to the model of design space exploration, we identify two axes that help position efforts to realize this model: the spectrum of strengths and needs that stretches from the machine to the human, and the time scale of events in design. Considering a section of each reveals a landscape that prefers certain activities and gives rise to particular emphases. This paper places the other authors in this Special Issue upon this map, and argues the value of typed feature structures and information orderings to the endeavor of realizing design space explorers.
Editorial
Authors: Clarence-Smith William Gervase , Pomeranz Kenneth , Vries Peer
Published: March 2006

Historians have expressed increasing concern about the segmentation of their discipline’s scholarly expertise into discrete compartments, whether defined by place, period, theme, or sub-discipline. A deluge of monographs is obscuring the landscapes of historical knowledge, even in relatively neglected parts of the globe. The Journal of Global History has the ambition of helping to overcome this fragmentation in historiography, while avoiding pitfalls that have emerged in earlier attempts to achieve this goal.
Historiographical traditions and modern imperatives for the restoration of global history
Authors: O’Brien Patrick
Published: March 2006

This essay has been written to serve as a prolegomenon for a new journal in Global History. It opens with a brief depiction of the two major approaches to the field (through connexions and comparisons) and moves on to survey first European and then other historiographical traditions in writing ‘centric’ histories up to the times of the Imperial Meridian 1783–1825, when Europe’s geopolitical power over all other parts of the world became hegemonic. Thereafter, and for the past two centuries, all historiographical traditions converged either to celebrate or react to the rise of the ‘West’. The case for the restoration of Global History rests upon its potential to construct negotiable meta-narratives, based upon serious scholarship that will become cosmopolitan in outlook and meet the needs of our globalizing world.
Merchants, migrants, missionaries, and globalization in the early-modern Pacific
Authors: Clossey Luke
Published: March 2006

In 1571 the founding of Manila made possible regular transpacific trade and thus forged the missing link in the global trade network. American interest in China and Japan soared to new heights. In the next two centuries this attraction fuelled other globalizing exchanges—parallel to the commercial ties—across the Pacific. Thousands crossed the ocean to create the America’s first Asian diaspora communities, and Mexico became Europe’s clearinghouse for information about Asia. The most intense connection was missionary, for churchmen in America worked with one eye relentlessly turned to East Asia and dreamed of the possibility of evangelization, and of its alluring dangers. These exchanges, and the attendant expanding mental horizons, evince enough similarities with modern globalization to warrant incorporation into that concept.
The rapid growth of Egypt’s agricultural output, 1890–1914, as an early example of the green revolutions of modern South Asia: some implications for the writing of global history
Authors: Owen Roger
Published: March 2006

The article uses comparative Indian material from British India and later, the Pakistani Punjab to ask new questions of the standard accounts of Egypt’s post-1890 cotton boom. It also argues for the particular relevance of the rich Punjabi green revolution data to the Egyptian case, and more generally, for the rewards to be obtained from an academic dialog between selected aspects of late nineteenth and of late twentieth century globalization. Topics analyzed include the impact of the various agricultural revolutions on social and regional inequalities, the issue of sustainability, the role of experts and the impact on health of long-term environmental degradation.
Streamline‐based simulation of carbon dioxide storage in a North Sea aquifer
Authors: Obi Eguono‐Oghene I. , Blunt Martin J.
Published: March 2006

We model carbon dioxide (CO2) storage into a deep North Sea aquifer using streamline‐based simulation. We assume incompressible flow of liquid‐like CO2 and aqueous phases. We simulate dissolution of CO2 and a rate‐limited precipitation reaction. Advective transport and reactions are solved along streamlines, while dispersion and flow due to gravity segregation of the phases are solved on the underlying grid. Geological storage is modeled on a one million cell model. The distribution of CO2 after injection is dominated by advective transport due to multiphase flow, and CO2 moves preferentially through high‐permeability channels. Without reaction the regional groundwater flow causes the CO2 to continue to migrate until it reaches residual saturation, where it continues, slowly, to dissolve. Precipitation leads to a decrease in porosity and permeability, while CO2 is stored in the solid phase. The storage efficiency is low, around 2%, because of aquifer heterogeneity.
Dimensions of standing waves at steps in mountain rivers
Authors: Comiti Francesco , Lenzi Mario A.
Published: March 2006

Oscillations of the water surface are common features of flows around critical conditions (Fr ∼ 1) and of both natural and structure‐induced undular hydraulic jumps. The paper describes experimental tests and field data on the dimensions of standing waves created by artificial drops in steep gravel bed rivers. The purpose of the research is to analyze what parameters affect the phenomenon, to provide semiempirical formulations for wave dimensions, and to assess whether previous models for undular hydraulic jumps and antidunes are reasonably predictive. The dimensionless wavelength and wave amplitude were correlated to the Froude number at the sill. The first wavelength appears linearly related to the Froude parameter, whereas the amplitude of the first wave shows a less defined behavior, possibly indicating that a maximum value occurs for sill Froude numbers around 1.6–1.7. The corresponding wave steepness (i.e., wave amplitude/length) results between 0.15–0.16, and this range also characterizes the point at which the dimensionless trough depth below the sill achieves a local maximum, probably related to hydrodynamic conditions just before wave breaking. The transition between roller and undular jumps at drops is then argued to likely represent a critical stage in step pool streams, and the hydraulic and morphological implications of this finding are also discussed, with particular emphasis on step stability and step wavelength.
Probing structural elements of small buried craters using ground‐penetrating radar in the southwestern Egyptian desert: Implications for Mars shallow sounding
Authors: Heggy Essam , Paillou Philippe
Published: March 2006

We report results from a field survey performed on a recently discovered impact field in the southwestern Egyptian desert, using a 270 MHz Ground‐Penetrating Radar (GPR). This hyperarid region has significant similarities to the Martian heavily eroded mid‐latitude cratered terrains in terms of crater density, size, and geomorphology. Profiles across small‐buried craters revealed a coherent sequence of tilted layers constituting the cratonic infill resulting from aeolian deposits. In the intercrater areas the radargram revealed a poorly‐defined subsurface stratigraphy and the presence of shallow structural elements associated with potential evidences of the consequences of the shock effects, i.e., faulting, fractures, and chaotic bedrock. The radar‐penetration depth varied from 2 to 15 m, depending mainly on the amplitude of the volume and multiple scattering in the subsurface, caused by fractures and debris created by the impacts. We conclude that mid‐frequency GPR onboard future Martian rovers can successfully perform similar structural mapping.
Nature and characteristics of the flows that carved the Simud and Tiu outflow channels, Mars
Authors: Rodriguez J. A. P. , Tanaka Kenneth L. , Miyamoto Hideaki , Sasaki Sho
Published: March 2006

Geomorphic and topographic relations of higher and lower levels of dissection within the Simud and Tiu Valles outflow channels on Mars reveal new insights into their formational histories. We find that the water floods that carved the higher channel floors were primarily sourced from Hydaspis Chaos. The floods apparently branched into distributaries downstream that promoted rapid freezing and sublimation of water and limited discharge into the lowlands. In contrast, we suggest that the lower outflow channels were carved by debris flows from Hydraotes Chaos. Surges within individual debris flows possessed variable volatile contents and led to the deposition of smooth deposits marked by low relief longitudinal ridges. Lower outflow channel discharges resulted in widespread deposition within the Simud/Tiu Valles as well as within the northern plains of Mars.
Incorporating model uncertainty into attribution of observed temperature change
Authors: Huntingford Chris , Stott Peter A. , Allen Myles R. , Lambert F. Hugo
Published: March 2006

Optimal detection analyses have been used to determine the causes of past global warming, leading to the conclusion by the Third Assessment Report of the IPCC that “most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations”. To date however, these analyses have not taken full account of uncertainty in the modelled patterns of climate response due to differences in basic model formulation. To address this current “perfect model” assumption, we extend the optimal detection method to include, simultaneously, output from more than one GCM by introducing inter‐model variance as an extra uncertainty. Applying the new analysis to three climate models we find that the effects of both anthropogenic and natural factors are detected. We find that greenhouse gas forcing would very likely have resulted in greater warming than observed during the past half century if there had not been an offsetting cooling from aerosols and other forcings.
Quantifying the amount of impact ejecta at the MER landing sites and potential paleolakes in the southern Martian highlands
Authors: Cohen Barbara A.
Published: March 2006

Applying previous equations for estimating ejecta thickness to Mars, tens of meters of ballistically‐emplaced impact ejecta might be expected over the heavily‐cratered southern Martian hemisphere. The calculated thickness of ejecta material, even accounting for large uncertainties in methods of estimation, is not enough to fully explain observed depth discrepancies in Gusev Crater or in other potential Martian paleolakes. Ejecta contributed to the Spirit landing site in Gusev Crater is largely derived from local craters while distal ejecta from large, faraway craters dominates the contribution to the Opportunity landing site in Meridiani Planum. However, emplacement of this type of ejecta probably predates the present surfaces. Thira crater may have excavated impact‐melt products created by Gusev, samples of which would provide a unique insight into the composition of the bulk Martian crust. Though ballistically‐emplaced crater ejecta contribute a relatively small amount of material to any given site, this type of material provides important lithologic diversity.
Sensitivity of inverse estimation of annual mean CO2 sources and sinks to ocean‐only sites versus all‐sites observational networks
Authors: Patra Prabir K. , Gurney Kevin R. , Denning A. Scott , Maksyutov Shamil , Nakazawa Takakiyo , Baker David , Bousquet Philippe , Bruhwiler Lori , Chen Yu‐Han , Ciais Philippe , Fan Songmiao , Fung Inez , Gloor Manuel , Heimann Martin , Higuchi Kaz , John Jasmin , Law Rachel M. , Maki Takashi , Pak Bernard C. , Peylin Philippe , Prather Michael , Rayner Peter J. , Sarmiento Jorge , Taguchi Shoichi , Takahashi Taro , Yuen Chiu‐Wai
Published: March 2006

Inverse estimation of carbon dioxide (CO2) sources and sinks uses atmospheric CO2 observations, mostly made near the Earth's surface. However, transport models used in such studies lack perfect representation of atmospheric dynamics and thus often fail to produce unbiased forward simulations. The error is generally larger for observations over the land than those over the remote/marine locations. The range of this error is estimated by using multiple transport models (16 are used here). We have estimated the remaining differences in CO2 fluxes due to the use of ocean‐only versus all‐sites (i.e., over ocean and land) observations of CO2 in a time‐independent inverse modeling framework. The fluxes estimated using the ocean‐only networks are more robust compared to those obtained using all‐sites networks. This makes the global, hemispheric, and regional flux determination less dependent on the selection of transport model and observation network.
Relationships among air‐water interfacial area, capillary pressure, and water saturation for a sandy porous medium
Authors: Brusseau Mark L. , Peng Sheng , Schnaar Gregory , Costanza‐Robinson Molly S.
Published: March 2006

The relationships among air‐water interfacial area, capillary pressure, and water saturation were investigated for a sandy, natural porous medium. Air‐water interfacial areas as a function of water saturation were measured using two methods, gas phase partitioning tracer tests and synchrotron X‐ray microtomography. The tracer test method provides a measure of effective total (capillary and film) interfacial area, whereas microtomography can be used to determine both capillary‐associated and total areas (the latter is the focus of this study). Air‐water interfacial areas determined with both methods increased continuously with decreasing water saturation. The areas measured with the tracer test method were significantly larger than those obtained from microtomography. The maximum values measured with the tracer test method approached the N2/BET‐measured specific solid surface area, whereas the maximum values measured by microtomography approached the smooth‐sphere‐calculated specific solid surface area. The interfacial area‐saturation data were combined with capillary pressure‐saturation data obtained from water drainage experiments to examine the relationship between total air‐water interfacial area and capillary pressure. Air‐water interfacial area was observed to increase monotonically with increasing capillary pressure and then to plateau at values that correspond to areas associated with residual water saturation. These results are consistent with previously reported theoretically and computationally based analyses of functional relationships between total nonwetting‐wetting interfacial area and capillary pressure.
Switching the pooling similarity distances: Mahalanobis for Euclidean
Authors: Cunderlik Juraj M. , Burn Donald H.
Published: March 2006

In recent years, catchment similarity measures based on flood seasonality have become popular alternatives for identifying hydrologically homogeneous pooling groups used in regional flood frequency analysis. Generally, flood seasonality pooling measures are less prone to errors and are more robust than measures based on flood magnitude data. However, they are also subject to estimation uncertainty resulting from sampling variability. Because of sampling variability, catchment similarity in flood seasonality can significantly deviate from the true similarity. Therefore sampling variability should be directly incorporated in the pooling algorithm to decrease the level of pooling uncertainty. This paper develops a new pooling approach that takes into consideration the sampling variability of flood seasonality measures used as pooling variables. A nonparametric resampling technique is used to estimate the sampling variability for the target site, as well as for every site that is a potential member of the pooling group for the target site. The variability is quantified by Mahalanobis distance ellipses. The similarity between the target site and the potential site is then assessed by finding the minimum confidence interval at which their Mahalanobis ellipses intersect. The confidence intervals can be related to regional homogeneity, which allows the target degree of regional homogeneity to be set in advance. The approach is applied to a large set of catchments from Great Britain, and its performance is compared with the performance of a previously used pooling technique based on the Euclidean distance. The results demonstrate that the proposed approach outperforms the previously used approach in terms of the overall homogeneity of delineated pooling groups in the study area.
Motivation of synthesis, with an example on groundwater quality sustainability
Authors: Fogg Graham E. , LaBolle Eric M.
Published: March 2006

Synthesis of ideas and theories from disparate disciplines is necessary for addressing the major problems faced by society. The best motivation for broad, effective synthesis is the “big idea” that is sufficiently important and inspiring to marshal the appropriate collaborative efforts. Groundwater quality sustainability is posed as an example of one such idea that would potentially unify research efforts in both the sciences and social sciences toward a common, pressing objective.
Storage and transit time of chemicals in thick unsaturated zones under rangeland and irrigated cropland, High Plains, United States
Authors: McMahon P. B. , Dennehy K. F. , Bruce B. W. , Böhlke J. K. , Michel R. L. , Gurdak J. J. , Hurlbut D. B.
Published: March 2006

In 2000–2002, three rangeland and six irrigated sites were instrumented to assess the storage and transit time of chemicals in thick (15 to 50 m) unsaturated zones (UZ) in the High Plains. These processes are likely to influence relations between land use and groundwater quality, yet they have not been documented systematically in the High Plains. Land use and climate were important controls on the size of subsoil chloride, nitrate, and pesticide compound reservoirs. The reservoirs under irrigated cropland generally were larger than those under rangeland because more chemicals were applied to cropland than to rangeland. In some cases, chloride and nitrate reservoirs under rangeland were larger than those under cropland, presumably because of long‐term evaporative concentration near the base of the root zone. Natural salts mobilized by irrigation return flow accounted for as much as 60 and 80% of the nitrate and chloride reservoirs, respectively, under some cropland, as indicated by detailed chemical profiles and isotopic tracers (15N,18O in nitrate and2H,3H,18O in water). Advective chemical transit times in the UZ under cropland ranged from about 50 to 375 years, longer than any of the instrumented fields had been irrigated, yet agrichemicals were detected at the water table at four of the six sites. The data provide evidence for the existence of slow and fast paths for water movement in the UZ, with larger subsoil chemical reservoirs occurring in areas dominated by slow paths. Implications of these findings with respect to water quality in the aquifer are significant because they indicate that the amount of chemical mass reaching the aquifer could increase with time as chemicals that still reside under irrigated fields reach the water table.
Regulation of IL‐1‐induced selective IL‐6 release from human mast cells and inhibition by quercetin
Authors: Kandere‐Grzybowska Kristiana , Kempuraj Duraisamy , Cao Jing , Cetrulo Curtis L , Theoharides Theoharis C
Published: March 2006

Mast cells are involved in allergic reactions, but also in innate immunity and inflammation. Crosslinkage of mast cell Fc immunoglobulin E receptors (FcɛRI) by multivalent antigen triggers secretion of granule‐stored mediators, as well asde novosynthesis of cytokines, including interleukin (IL)‐6.

We showed recently that the proinflammatory cytokine IL‐1 stimulates human leukemic mast cells (HMC‐1) and human umbilical cord blood‐derived cultured mast cells (hCBMCs) to release newly synthesized IL‐6 without tryptase in the absence of degranulation.

Here, we investigated several signal‐transduction pathways activated by IL‐1 leading to IL‐6 production by HMC‐1 and hCBMCs.

We also investigated the effect of the flavonol quercetin that was recently shown to strongly inhibit IL‐6 secretion in response to allergic stimulation from hCBMCs.

IL‐1 stimulated p38, but did not activate extracellular signal‐regulated kinase (ERK) or c‐jun N‐terminal kinase (JNK); it also did not activate protein kinase C (PKC) isozymesα,β,μandζ, except for PKC‐θ, which was phosphorylated.

The p38 inhibitor SB203580 and the PKC inhibitors Calphostin C and Gö6976 completely inhibited IL‐1‐induced IL‐6 production.

Quercetin 1–100 μMinhibited IL‐1‐induced IL‐6 secretion, p38 and PKC‐θphosphorylation in a dose‐dependent manner.

These results indicate that IL‐1‐stimulated IL‐6 production from human mast cells is regulated by biochemical pathways distinct from IgE‐induced degranulation and that quercetin can block both IL‐6 secretion and two key signal transduction steps involved.

British Journal of Pharmacology(2006)148, 208–215. doi:10.1038/sj.bjp.0706695
Initial tests of the Spallation Neutron Source H− ion source with an external antenna
Authors: Welton R. F. , Stockli M. P. , Murray S. N. , Kang Y. , Peters J.
Published: March 2006

The ion source for the Spallation Neutron Source (SNS) is a radio-frequency (rf) multicusp source designed to deliver H− beam pulses of 40mA to the SNS accelerator with a normalized root-mean-square emittance of less than 0.2πmmmrad, with a pulse length of 1ms and a repetition rate of 60Hz. In order to achieve this performance the source must operate with both high-pulse rf power, ∼50kW, and high average rf power, ∼3.5kW, over a continuous operational period of 3weeks. During operation at these power levels the plasma-immersed, porcelain-coated rf antenna is susceptible to damage, limiting source lifetime. We are therefore developing an ion source where the plasma is separated from the Cu antenna by an Al2O3 discharge chamber. This article describes the ion source, presents initial beam extraction measurements, and details our ongoing effort to develop this concept into a suitable ion source for the SNS.
Time-resolved investigation of ionization processes in the Dresden Electron Beam Ion Source
Authors: Zschornack G. , Heller R. , Kreller M. , Landgraf S. , Grossmann F. , Kentsch U. , Ovsyannikov V. P. , Schmidt M. , Ullmann F.
Published: March 2006

The emission of characteristic x-ray lines of iron and krypton ions was measured in dependence on the confinement time in an Electron Beam Ion Source, the DRESDEN EBIS. Primarily the measurement was focused on x-ray lines from dielectronic recombination (DR) processes. Due to the sharp resonant character of DR processes the formation of individual ion charge states can be observed at different electron energies (resonance energies) with time-resolved energy-dispersive x-ray spectroscopy. In the case of iron ions, experimentally observed resonance energies are compared to resonance energies calculated with the Flexible Atomic Code (FAC). Further, on outer-shell Kα x-ray satellites of krypton ions are time-resolve analyzed to construct the evolution of the ionization of krypton ions in the electron beam.
The Frankfurt MAXEBIS setup for advanced charge breeding experiments
Authors: Kester Oliver , Zimmermann Holger , Becker Reinard , Kleinod Michael
Published: March 2006

The demand of exotic ions of higher charge states for the injection into an accelerator has driven the development of the charge breeding method. Existing facilities such as REX-ISOLDE or ISAC (TRIUMF) are already using a charge-state booster for the post acceleration of radioactive ions. Planned facilities such as MAFF, SPES, SPIRAL II, and EURISOL have identified the need for a breeding system because of the demand for highly charged ions for low-energy experiments and because of the available budget. Therefore, the exploration and optimization of existing charge-state breeders is mandatory and is supported by the I3-EURONS project. Some tasks of the joint research activity “charge breeding” are experiments with the Frankfurt MAXEBIS setup, which has been modified within the past years toward high current electron beam and external injection of alkaline ions by a surface ionization source. The electron gun, the inner electrode structure, and the collector of the MAXEBIS have been modified. The full MAXEBIS setup has been moved from Frankfurt to GSI, where the charge breeding measurements will be done. In addition the MAXEBIS will deliver highly charged ions for tests of the cooler Penning trap of the GSI Heavy Ion Trap project HITRAP. The setup, tests, and the planned breeding experiments will be discussed.