bluuebunny/crossref_metadata_2025 huggingface dataset:
Roles of stromal cell RANKL, OPG, and M‐CSF expression in biphasic TGF‐β regulation of osteoclast differentiation
Authors: Karst Mary , Gorny Genevieve , Galvin Rachelle J. Sells , Oursler Merry Jo
Published: April 2004

To better understand the complex roles of transforming growth factor‐beta (TGF‐β) in bone metabolism, we examined the impact of a range of TGF‐β concentrations on osteoclast differentiation. In co‐cultures of support cells and spleen or marrow osteoclast precursors, low TGF‐β concentrations stimulated while high concentrations inhibited differentiation. We investigated the influences of TGF‐β on macrophage colony stimulating factor (M‐CSF), receptor activator of NF‐κB ligand (RANKL), and osteoprotegerin (OPG) expression and found a dose dependent inhibition of M‐CSF expression. RANKL expression was elevated at low TGF‐β concentrations with a less dramatic increase in OPG. Addition of OPG blocked differentiation at the stimulatory TGF‐β dose. Thus, low TGF‐β concentrations elevated the RANKL/OPG ratio while high concentrations did not, supporting that, at low TGF‐β concentrations, there is sufficient M‐CSF and a high RANKL/OPG ratio to stimulate differentiation. At high TGF‐β concentrations, the RANKL/OPG ratio and M‐CSF expression were both repressed and there was no differentiation. We examined whether TGF‐β‐mediated repression of osteoclasts differentiation is due to these changes by adding M‐CSF and/or RANKL and did not observe any impact on differentiation repression. We studied direct TGF‐β impacts on osteoclast precursors by culturing spleen or marrow cells with M‐CSF and RANKL. TGF‐β treatment dose‐dependently stimulated osteoclast differentiation. These data indicate that low TGF‐β levels stimulate osteoclast differentiation by impacting the RANKL/OPG ratio while high TGF‐β levels repress osteoclast differentiation by multiple avenues including mechanisms independent of the RANKL/OPG ratio or M‐CSF expression regulation. © 2004 Wiley‐Liss, Inc.
SPR for molecular interaction analysis: a review of emerging application areas
Authors: Karlsson Robert
Published: April 2004

PubMed searches identified four emerging application areas for surface plasmon resonance systems. Food analysis, proteomics, immunogenicity and drug discovery. These application areas are reviewed. In connection with the review of drug discovery applications a case study is presented. This study demonstrates the value of combining results from drug–target and ADME predictive assays for compound selection. Copyright © 2004 John Wiley & Sons, Ltd.
Artificial metallo‐DNA towards discrete metal arrays
Authors: Shionoya Mitsuhiko
Published: April 2004

DNA shows promise as a provider of a structural basis for the “bottom‐up” fabrication of functionalized molecular building blocks. In particular, the replacement of hydrogen‐bonded DNA base pairing for alternative one could possibly provide a novel tool for re‐engineering DNA as well as for biological applications. This review describes our recent approaches to metal‐based strategy directed towards self‐assembled metal arrays within DNAs. Recently, we reported the synthesis of a series of artificial oligonucleotides, d(5′‐GHnC‐3′) (n = 1‐5), using hydroxypyridone nucleobases (H) as flat bidentate ligands. Right‐handed double helices of the oligonucleotides, nCu2+·d(5′‐GHnC‐3′)2 (n = 1‐5), are quantitatively formed through Cu2+‐mediated alternative base pairing (H‐Cu2+‐H), where the Cu2+ ions are aligned along the helix axes inside the duplexes with the Cu2+‐Cu2+ distance of 3.7 ± 0.1 Å. The Cu2+ ions are coupled in a ferromagnetic manner with one another through unpaired d electrons to form magnetic chains. This strategy represents a new method for self‐assembled metal arrays in a predesigned fashion, leading to the possibility of metal‐based molecular devices such as molecular magnets and wires.
Synthesis of iron‐containing polymers with azo dyes in the backbones or side chains
Authors: Abd‐El‐Aziz Alaa S. , Okasha Rawda M. , Todd Erin K. , Afifi Tarek H. , Shipman Patrick O. , Copping K. Michelle D.
Published: April 2004

The synthesis of cationic cyclopentadienyliron‐containing polymers with pendent azobenzene chromophores was accomplished via metal‐mediated nucleophilic aromatic substitution reactions. All of the desired polymers were isolated as vibrantly coloured materials and displayed excellent solubility in polar aprotic solvents. Cationic and neutral cyclopentadienyliron polymers incorporating azo dyes in the backbone were also prepared. Reactions of azo dyes with dichlorobenzene complexes allowed for the isolation of cationic cyclopentdienyliron (CpFe+) complexes with azo dye chromophores. These complexes were then reacted with 1,1′‐ferrocenedicarbonyl chloride to produce the trimetallic monomers with terminal chloro groups. These monomers contained two pendent CpFe+ cations and a neutral iron moiety in the backbone. Nucleophilic substitution reactions of these monomers with oxygen and sulfur containing dinucleophiles gave rise to a new class of polymeric materials. The pendent CpFe+ moieties could also be cleaved from the polymer backbones using photolysis to afford novel ferrocene based polymers. The UV‐vis spectra of the organoiron monomers and polymers display similar wavelength maxima however incorporating azobenzene chromophores with electron‐withdrawing substituent into the polymer chains resulted in bathochromic shifts of the λmax values.
Parkinson's disease sleep scale: Validation study of a Spanish version
Authors: Martínez‐Martín Pablo , Salvador Carlos , Menéndez‐Guisasola Luis , González Sonia , Tobías Aurelio , Almazán Javier , Chaudhuri K. Ray
Published: April 2004

The Parkinson's Disease Sleep Scale (PDSS) is the first published bedside clinical tool to specifically measure sleep disturbances in Parkinson's disease (PD). The objective of the present study was to carry out a metric analysis of a Spanish version (PDSS‐SV) using a cross‐sectional study of 100 PD patients who participated in the study. Usual measures for PD and mental status were applied by neurologists. Patients completed the Epworth Sleepiness Scale, Parkinson's Disease Questionnaire‐39 Items (PDQ‐39), and PDSS‐SV. PDSS internal consistency (Cronbach's α, 0.77; significant item‐total correlation for 11 items) was satisfactory. PDSS showed high test–retest reliability (intraclass correlation coefficient for items, 0.79–0.99; for total score, 0.94). Standard error of measurement was 9.80 (crossover) and 5.01 (longitudinal). Scores were distributed uniformly, with low floor and ceiling effect (1%). PDSS scores were correlated significantly with depression (Hamilton Depression Rating Scale, rS = −0.55; P < 0.0001) and quality of life (PDQ‐39 Summary Index, rS = −0.26; P = 0.007), but not with clinical variables. Self‐perception of mood disorder, pain, or hallucinations correlated individually with PDSS scores, and a factor explaining 65% of the variance was found. The assessment of PD sleep disorders with the PDSS met some basic standards required for health status measures. © 2004 Movement Disorder Society
Complete binary trees in folded and enhanced cubes
Authors: Choudum S.A. , Nandini R. Usha
Published: April 2004

It is well known that the complete binary treeBn(n≥ 3) on 2n− 1 vertices is not embeddable into then‐dimensional hypercube. In this article, we describe a recursive technique to embedBninto then‐dimensional folded and enhanced cubes, ifnsatisfies certain necessary parity conditions. © 2004 Wiley Periodicals, Inc.
Cytotoxicity in cytokine stimulated astrocyte cultures: role of IL‐6 and nitric oxide
Authors: Yilmaz Ozlem , Taskiran Dilek , Aydar Sevgen
Published: April 2004

The cytokines interleukin 1 (IL‐1) and tumor necrosis factor alpha (TNF‐α), produced by glial cells within the brain, appear to contribute to the neuropathogenesis of several inflammatory neurodegenerative diseases. However, little is known about the mechanism underlying cytokine‐induced neurotoxicity. Using astroglial cultures obtained from fetal rat brain, we investigated the effects of lipopolysaccharides (LPS) and cytokines (IL‐1β and TNF‐α). Primary cell cultures treated with LPS, IL‐1β plus TNF‐α generated substantial amounts of nitric oxide (NO), elevated interleukin 6 (IL‐6) levels and caused astroglial injury measured by lactate dehydrogenase (LDH) activity. However, blockade of NO production with nitric oxide synthase (NOS) inhibitors did not affect cell death, suggesting that NO is not responsible for cytokine‐induced astroglial cell death under the experimental conditions employed.
BK virus‐associated nephropathy in kidney transplant recipients
Authors: de Bruyn Guy , Limaye Ajit P.
Published: April 2004

Polyomavirus BK has emerged as an important cause of renal allograft infection leading to allograft dysfunction and loss in kidney transplant recipients. Significant progress has been made, particularly in the area of diagnostic methods for BK virus, thereby facilitating diagnosis, screening and monitoring of infection. This review outlines current concepts on the epidemiology, pathogenesis, diagnosis and therapy of BK virus nephropathy. The precise risk factors that are important for induction and progression of infection to invasive disease, the most effective diagnostic strategies, and the efficacy of current therapeutic approaches, all remain to be defined fully. It is to be hoped that these deficiencies will stimulate research to address these important questions. Copyright © 2004 John Wiley & Sons, Ltd.
Presentation of multivariate data for clinical use: The Framingham Study risk score functions
Authors: Sullivan Lisa M. , Massaro Joseph M. , D'Agostino Ralph B.
Published: April 2004

The Framingham Heart Study has been a leader in the development and dissemination of multivariable statistical models to estimate the risk of coronary heart disease. These models quantify the impact of measurable and modifiable risk factors on the development of coronary heart disease and can be used to generate estimates of risk of coronary heart disease over a predetermined period, for example the next 10 years. We developed a system, which we call a points system, for making these complex statistical models useful to practitioners. The system is easy to use, it does not require a calculator or computer and it simplifies the estimation of risk based on complex statistical models. This system represents an effort to make available a tool for clinicians to aid in their decision‐making process regarding treatment and to assist them in motivating patients toward healthy behaviours. The system is also readily available to patients who can easily estimate their own coronary heart disease risk and monitor this risk over time. Copyright © 2004 John Wiley & Sons, Ltd.
A risk‐adjusted Sets method for monitoring adverse medical outcomes
Authors: Grigg O. A. , Farewell V. T.
Published: April 2004

The Sets method has been advocated in previous work as a method for monitoring adverse medical outcomes where the adverse event rate is low. Here, a risk‐adjusted version of the refined Sets method is presented and an example is given to demonstrate its advantage over the unadjusted method. The method is suitable for any risk distribution and does not assume that changes in risk will be small. A graphical representation, referred to as the Grass plot, of the original and risk‐adjusted methods is also given. Copyright © 2004 John Wiley & Sons, Ltd.
Physicochemical Properties of Casein‐Starch Interaction Obtained by Extrusion Process
Authors: Fernández‐Gutiérrez Jaime Antonio , San Martín‐Martínez Eduardo , Martínez‐Bustos Fernando , Cruz‐Orea Alfredo
Published: April 2004

Extruded samples of starch‐casein blends were processed by using a single‐screw extruder. The independent variables in the process were temperature (126–194°C), moisture content (18–29%) and starch‐casein blend (5–95%). These independent variables affected significantly the physicochemical and textural properties of the biopolymers. The highest values for expansion (EXP) and water absorption index (WAI) were found when a higher starch proportion was present in the blends, at 126°C barrel temperature and moisture content higher than 25%. By increasing the barrel temperature, from 126°C to 194°C, the water solubility index (WSI) and color parameter were increased. Initial viscosity (IV) and viscosity at 90°C (V90) were mainly affected by the barrel temperature at 194°C. However, the viscosity at 50°C (V50) was affected neither by the different extrusion variables nor by the biopolymer proportion in the blends. Compression force (CF) was strongly dependent on moisture content and casein proportion in the blend. The higher CF values were found at starch concentrations around 50% and 25% moisture content, for higher or lower values than these the obtained extruded products were softer and consequently had lower CF values.
Starch Phosphates Produced by Extrusion: Physical Properties and Influence on Yogurt Stability
Authors: San Martín‐Martínez Eduardo , Aguilar‐Méndez Miguel A. , Espinosa‐Solares T. , Pless Reynaldo C. , Quintana Z. Delia
Published: April 2004

Starch phosphorylation with sodium tripolyphosphate (STP) was performed using a single‐screw extrusion process. The extrusion variables studied were temperature (from 99.5°C to 200.4°C), water content (16.3% to 19.7%, w/w), and STP content (0.82% to 4.18%, w/w). The resulting phosphorylated starch was evaluated with respect to expansion, water solubility index (WSI), water absorption index (WAI), degree of substitution (DS), and viscosity. The phosphorylated starch was tested as a stabilizing additive in yogurt formulations, with respect to the syneresis index (SI) and the syneresis susceptibility coefficient (SSC). The results show that the expansion increases with increasing STP content, and decreases with increasing temperature and water content employed in the process. Increasing extrusion temperatures and decreasing water content resulted in increasing WSI and decreasing WAI. The DS was dependent on STP content, increasing as STP content increased, but appeared to be insensitive to changes in water content (between 16% and 20%, w/w). The highest level of yogurt stability, as measured by the syneresis index (SI) and the syneresis susceptibility coefficient (SSC), were obtained when the yogurt was formulated with the starch of the highest DS (0.018), which had been obtained at 150°C, 18% water content, and 4.12% (w/w) of STP.
Introduction to faculty learning communities
Authors: Cox Milton D.
Published: April 2004

Faculty learning communities create connections for isolated teachers, establish networks for those pursuing pedagogical issues, meet early‐career faculty expectations for community, foster multidisciplinary curricula, and begin to bring community to higher education.
Institutional considerations in developing a faculty learning community program
Authors: Shulman Gary M. , Cox Milton D. , Richlin Laurie
Published: April 2004

For successful implementation of FLCs, consider leadership recommendations for institutional change, reasons for choosing the FLC model, and institutional conditions that may facilitate or hinder FLC development.
Developing facilitators for faculty learning communities
Authors: Sandell Karin L. , Wigley Katy , Kovalchick Ann
Published: April 2004

The processes for choosing, preparing, and supporting facilitators for faculty learning communities are as unique as the campuses housing them. This chapter reports on a range of activities and highlights three preparation programs.
Supporting diversity with faculty learning communities: Teaching and learning across boundaries
Authors: Petrone Martha C.
Published: April 2004

Both in structure and focus, FLCs create a necessary construct for a cultural transformation of teaching and learning that invites all to achieve their intellectual and social potential.
Modern methods for the iterative computation of eigenpairs of matrices of high dimension
Authors: van der Vorst H.A.
Published: April 2004

We give an overview of computational methods for the eigenproblem Ax = λx and related eigenproblems, in particular those for large matrices. Subspace methods, including the Lanczos and Arnoldi methods, have become increasingly popular. We will highlight a quite recent subspace method for the iterative computation of a few eigenvalues and eigenvectors of high‐dimensional eigenproblems: The so‐called Jacobi‐Davidson method. The application of this method for standard, generalized, and quadratic eigenproblems will be discussed.
The Puzzle of Regulatory Competition
Authors: RADAELLI CLAUDIO M.
Published: April 2004

Our understanding of international competition in regulatory policies has not progressed much because conventional theories lead to a bewildering range of conclusions. Empirical evidence has shown the limitations of simplistic models. Fresh work should overcome the obsession with ‘races’ and ‘final outcomes’ of conventional theoretical approaches and start modelling real-world mechanisms of regulatory competition. The first part of the article shows the limitations of conventional theories. The second introduces eight problems that explanations of international regulatory competition should address. It also discusses how the articles presented here contribute to the solution to problematic aspects of the puzzle. The conclusion reports results achieved in terms of key concepts of regulatory competition, sequences of cooperation and competition, the role of non-unitary actors in networked regulatory action, and why regulatory competition is still limited, both in the EU and in transatlantic relations.
Habitat preferences in freshwater diatom communities from sub-Antarctic Îles Kerguelen
Authors: Vijver Bart Van De , Ledeganck Pieter , Beyens Louis
Published: April 2004

A limited sampling campaign on the main island of Îles Kerguelen revealed 170 freshwater diatom taxa, belonging to 29 genera. Four different communities were distinguished in two major groups, being determined principally by habitat type. The Fragilaria vaucheriae–Fragilaria germainii assemblage occurs exclusively in running waters. The three other communities, observed in standing waterbodies, are separated by their geographical position on the island with the Fragilaria exigua–Aulacoseira alpigena and the Fragilaria exigua–Fragilaria vaucheriae assemblages, mainly found in the Lac Studer area and the Fragilaria pinnata var. pinnata assemblage, recorded near the coastal line and the research station. Analysis of different waterbody types revealed the habitat preference of the various diatom taxa and identified a diatom flora for running waters and one preferring stagnant waterbodies.
Weaning mass variation of southern elephant seals at King George Island and its possible relationship with “El Niño” and “La Niña” Events
Authors: Vergani D.F. , Stanganelli Z.B. , Bilenca D.
Published: April 2004

Possible effects of “El Niño” Southern Oscillation (ENSO) components “El Niño”and “La Niña“ on populations of southern elephant seals, Mirounga leonina L., are considered in this study. Information on pup weaning mass, collected at King George Island, South Shetland Islands, over a ten-year period (1985–94) was analysed with respect to the occurrence of ENSO and recent research in feeding ecology of this population in the Bellinghausen Sea. Weaning mass of elephant seals was found to be higher during “La Niña” and a lower during “El Niño”. Differences in weaning mass between sexes varied in different proportions during El Niño and La Niña. The teleconnection between tropical Pacific anomalies and the Bellinghausen Sea deserves further research, and our results suggest a way to study this phenomenon using data of elephant seal pups weaning mass as indicators of changes in food availability.
Invertebrate body sizes from Marion Island
Authors: Mercer Richard D. , Gabriel A.G.A. , Barendse J. , Marshall D.J. , Chown S.L.
Published: April 2004

Body size was measured for 67 of the approximately 120 invertebrate species on Marion Island. These include more than 60% of the 29 acarine families, and more than 80% of the remaining terrestrial invertebrate species. Thus the data are regarded as representative of the entire invertebrate fauna of sub-Antarctic, Marion Island. Length–mass and fresh–dry mass relationships were calculated for orders, families and species to provide a means of estimating body size parameters for species in collections and those which are known from only a few specimens. A comparison of the regression slopes for the different taxonomic ranks indicates that it is better to use regressions from the lowest possible taxonomic level for prediction of body mass. Differences between length–mass relationships for Marion Island insects and continental assemblages raises the question as to the applicability of continental regressions to sub-Antarctic species. This study provides a useful means for estimating body size parameters for Antarctic and sub-Antarctic invertebrates and provides baseline data on an important species trait that seems to be changing with local and global environmental changes.
Ice record of a 13th century explosive volcanic eruption in northern Victoria Land, East Antarctica
Authors: Narcisi Biancamaria , Proposito Marco , Frezzotti Massimo
Published: April 2004

A volcanic event, represented by both coarse ash and a prominent sulphate peak, has been detected at a depth of 85.82 m in a 90 m ice core drilled at Talos Dome, northern Victoria Land. Accurate dating of the core, based on counting annual sulphate and nitrate fluctuations and on comparison with records of major known volcanic eruptions, indicates that the event occurred in 1254 ± 2 AD. The source volcano is most likely to be located within the Ross Sea region. In particular, the glass shards have a trachytic composition similar to rocks from The Pleiades and Mount Rittmann (Melbourne volcanic province), about 200 km from Talos Dome. Sulphate concentration is comparable with that of violent extra-Antarctic explosive events recorded in the same core, but atmospheric perturbation was short-lived and localized, suggesting a negligible impact on regional climate. It is suggested that this eruption may represent the most important volcanic explosion in the Melbourne province during the last eight centuries; thus this event may also represent a valuable chrono-stratigraphical marker on the East Antarctic plateau and in adjoining areas.
Moisture source of precipitation in Western Dronning Maud Land, Antarctica
Authors: Reijmer C. H. , Broeke M.R. Van Den
Published: April 2004

Moisture sources for snow falling in Dronning Maud Land (DML), Antarctica, are calculated for 1998 using three dimensional 5-days backward air parcel trajectories. The drilling site of the European Project on Ice Coring in Antarctica (EPICA) in DML is chosen as the main arrival point (75.0°S, 0.01°E). A distinction is made between trajectories with and without snowfall at arrival. Of the snowfall trajectories, 40–80% are located in the Atlantic Ocean within four days before arrival. Evaporation along these trajectories is largest three to four days before arrival. The air parcels are then located between 40° and 60°S in the Atlantic Ocean where surface temperatures range between 0° and 20°C. A case study for May 1998 shows that when snow falls exceptionally high temperatures and wind speeds prevail in the atmospheric boundary layer. The position of the trajectories in the boundary layer suggests a source region for this event between 40° and 50°S and 20° and 60°W in the Atlantic Ocean, where sea surface temperatures vary between 5° and 15°C.
Dispersal of the moss Campylopus pyriformis on geothermal ground near the summits of Mount Erebus and Mount Melbourne, Victoria Land, Antarctica
Authors: Skotnicki M.L. , Selkirk P.M. , Broady P. , Adam K.D. , Ninham J.A.
Published: April 2004

Mount Melbourne in northern Victoria Land, Antarctica, is a glaciated 2733 m volcanic cone. The moss Compylopus pyriformis occurs on two small areas of steam-warmed snow-free ground near its summit. This moss species also occurs in temperate regions world-wide, but has not been recorded elsewhere in continental Antarctica. RAPD (Random Amplified Polymorphic DNA) studies of 26 samples of C. pyriformis from two areas of heated ground on Mount Melbourne showed there was genetic diversity within the population. Genetic evidence for dispersal between the two sites, together with some genetic variation within individual colonies, indicates a single colonisation event has probably occurred at this extremely isolated location followed by multiple mutations. A single sample of moss protonema was collected 25 years ago from steam-warmed ground near the summit of another volcano, Mount Erebus (3794 m), on Ross Island some 300 km south of Mount Melbourne. The moss could not be identified based on morphological and reproductive criteria, as all attempts to differentiate it to a recognisable gametophyte were unsuccessful. The RAPD technique has now shown it to be C. pyriformis, and closely related to the population on Mount Melbourne.
Bathymetry and acoustic facies beneath the former Larsen-A and Prince Gustav ice shelves, north-west Weddell Sea
Authors: Pudsey Carol J. , Evans Jeffrey , Domack Eugene W. , Morris Peter , Valle Rodolfo A. Del
Published: April 2004

We present preliminary results of the first detailied surveys of the former Larsen-A Ice Shelf, Larsen Inlet and southern Prince Gustav Channel, where disintegration of small ice shelves in the past ten years has exposed the seafloor. Glacial troughs in the Larsen-A area, Larsen Inlet and Prince Gustav Channel reach 900–1100 m depth and have hummocky floors. Farther south-east, the continental shelf is shallower (400–500 m) and its surface is fluted to smooth, with the density of iceberg furrowing increasing towards the shelf edge. Acoustic profiles show a drape of transparent sediment 4–8 m thick in Prince Gustav Channel, thinning southwards. In cores, this drape corresponds to diatom-bearing marine and glacial-marine mud. In the Larsen-A area and Larsen Inlet, acoustically opaque sediment includes proximal ice shelf glaciomarine gravelly and sandy muds, and firm to stiff diamicts probably deposited subglacilly. These are overlain by thin (up to 1.3 m) glaciomarine muds, locally with distinctive diatom ooze laminae.
Climate change as a unifying theme in Antarctic research
Authors: Howard-Williams Clive
Published: April 2004

How many times have you seen statements similar to the following: “Antarctica is a global barometer”, “Antarctica is a warning beacon for global change”, or “Antarctica is a warning beacon for global change”, or “Antarctica is the most sensitive continent to climate change”? The frequency of such statements in this, and other polar journals, is significant. We know that the polar regions are highly sensitive to natural and human induced changes that originate elsewhere on our planet, and the literature is extensive and growing. At the large scale there is increasing evidence of both direct and indirect linkages between climate patterns (e.g. ENSO) in the Pacific and Atlantic oceans and Antarctic climate. At a smaller scale are the follow-on linkages to glacier dynamics, including surface melt, glacier stream flows, lake levels, beaches, sea-ice dynamics and ice tongues. All of these have major repercussions on Antarctic ecosystems. The phase change from water (liquid) to ice (solid) occurs over avery small temperature range (depending on salinity, pressure etc). Thus, for a pond ecosystem, a change in temperature of less than one degree Celsius means the difference between a functioning aquatic ecosystem, and a frozen ecosystem. The recent IPCC report (Climate Change 2001 [3 vols], Cambridge University Press) leaves little doubt of the significant changes to world climate now taking place. As Antarctic scientists we surely must therefore consider that the principal issue to be addressed in Antarctica at present is that of “Responses to a changing climate”.
Foraging strategies of southern elephant seals (Mirounga leonina) in relation to frontal zones and water masses
Authors: Field Iain , Hindell Mark , Slip David , Michael Kelvin
Published: April 2004

Geolocating-time-depth-temperature-recorders (GLTDTR) provided a continuous record of diving behaviour in relation to water temperature for ten female southern elephant seals from Macquarie Island during their post-breeding trips to sea. Four water bodies were determined from depth/temperature profiles recorded by the GLTDTRs. These water bodies corresponded to Sub-Antarctic Mode Water (SAMW), Polar Front Zone Water (PFZW), Polar Front Water (PFW) and Antarctic Water Masses (AWM). Thermal structures within these water bodies did not influence seal diving behaviour. Overall mean dive depth, nocturnal dive depths, diurnal dive depths and dive duration were similar in all areas. However, individuals did change behaviour as they moved between different water bodies. Seals also used different water bodies in the two different years of the study. We suggest that variations in foraging behaviour among seals are a result of prey distribution associated with local oceanographic conditions, but also reflect important individual foraging strategies within thermal zones.
Seasonal relative abundance of fish larvae inshore at Îles Kerguelen, Southern Ocean
Authors: Koubbi P. , Duhamel G. , Hebert C.
Published: April 2004

Ichthyoplankton sampling was conducted seasonally with 36 surveys between spring 1989 and spring 1992 in four bays in the Kerguelen archipelago: Morbihan, Baleiniers, Choiseul and Audierne. Golfe des Baleiniers is open to the shelf whereas Choiseul and Audierne are long fjords. Golfe du Morbihan is a very large and protected area open to the shelf at its eastern end. Larvae of neritic species were abundant outside whereas larvae of inshore species were abundant inside the Golfe du Morbihan. Larval Lepidonotothen squamifrons were detected during summer every year whereas larvae of Champsocephalus gunnari were observed in only two years, mainly in the northern coastal zone. For both species, our results support coastal spawning grounds in addition to those on the shelf slope. Larvae of the mesopelagic fish Krefftichthys anderssoni were dominant primarily during winter; this was linked to homogenisation of the water column over the shelf and the coastal zone. Larvae of Notothenia cyanobrancha were present throughout the year everywhere, which is linked to the year long pelagic earlylife-history phase.
Population densities of pack ice seals in the Lazarev Sea, Antarctica
Authors: Bester M.N. , Ferguson J.W.H. , Jonker F.C.
Published: April 2004

From 15 December 1992–4 January 1993 aerial surveys of ice seals were undertaken by Puma helicopter across the pack ice off Dronning Maud Land. The 31 transects of 1/2 nautical mile (n.m.) width were flown at an elevation of 200 ft and a ground speed of 60 knots and covered 805.6 n.m.2 of pack ice. The overall species composition of the seals was 97.8% crabeater seals, 1.67% Ross seals, 0.34% leopard seals and 0.15% Weddell seals. The density abundance of seals was 2.47 n.m.−2 for crabeater, 0.01 n.m.−2 for leopard, 0.004 n.m.−2 for Weddell and 0.04 n.m.−2 for Ross seals. Leopard seals were largely found near the outer edge of the pack, Ross seals were absent only in the outer pack, whilst Weddell seals were virtually absent in the pack ice. Present throughout, crabeater seals and Ross seals showed a statistically significant preference for the inner pack, the reasons for this being unclear.
Seabird mortality in the Patagonian toothfish longline fishery around the Prince Edward Islands, 1996–2000
Authors: Nel Deon C. , Ryan Peter G. , Watkins Barry P.
Published: April 2004

Sanctioned longline fishing for Patagonian toothfish around the Prince Edward Islands (a globally important seabird breeding site) commenced in 1996 following high levels of Illegal, Unregulated and Unreported (IUU) fishing. Independent fishery observers accompanied all but two sanctioned trips between 1996 and 2000, allowing a thorough understanding of the impact of this fishery on seabirds. Overall, white-chinned petrels Procellaria aequinoctialis were by far the most frequently killed species. However, during the first year, when lines were set during the day and night, a significant number of albatrosses (particularly grey-headed albatrosses Thalassarche chrysostoma) were also killed. Birds were caught almost exclusively during their breeding seasons and most birds killed were breeding adult males from the Prince Edward Islands. Albatrosses and giant petrels were caught almost exclusively during day sets, whereas catch rates of white-chinned petrels did not differ between day and night sets. Albatrosses were caught closer to the islands than white-chinned petrels. Most white-chinned petrel carcasses were hooked in their wings and bodies, whereas albatrosses were caught most frequently in their bills and contained large numbers of baits. Rates of seabird bycatch in the sanctioned fishery decreased from 0.19 birds per 1000 hooks to 0.034 birds per 1000 hooks during the time of this study. This was probably mainly due to stricter implementation of mitigation measures and a progressive movement farther away from the islands over the years. We estimate that the combined impact of legal and IUU longline fishing around the Prince Edward Islands over the past four years could have resulted in between 7000 and 17 000 seabird mortalities and could have had significant impacts on the breeding populations of several seabird species breeding on the Prince Edward Islands. This was mainly due to high levels of IUU fishing during 1996/97.
Ammothea tibialis, a new pycnogonid from Drake Passage, Antarctica
Authors: León Tomás Munilla
Published: April 2004

The most recent reports about the family Ammotheidae of pycnogonids from Southern Ocean waters are those of Munilla (2000, 2001, Scotia Sea), Pushkin (1993, various zones), Bamber (1995, Falkland Islands and South Shetland Islands) and Child (1994, various zones) who also provide historical background. Some species from Livingston Island and surrounding waters (South Shetland Islands, Drake Passage, Bransfield Strait) have been documented previously, mainly by Gordon (1932), Fry & Hedgpeth (1969), Pushkin (1993) and the papers of Child and Bamber mentioned above. Keys to this genus are given in Clark (1977) and Child (1994).
Reduction of [NBu4][AuCl4] to [NBu4][AuCl2] with Sodium Acetylacetonate
Authors: Buckley Robbie W. , Healy Peter C. , Loughlin Wendy A.
Published: April 2004

The preparation of crystalline [NBu4]
[AuCl2] in 85-90% yield by the
reduction of [NBu4]
[AuCl4] with sodium acetylacetonate is
reported together with procedures for the quantitative synthesis of
crystalline [NBu4]
[AuX4] (X = Cl, Br) through direct
oxidation of metallic gold in
X2/[NBu4]
X/ethanol, and the determination of the crystal structure of
[NBu4]
[AuCl4].
The Stereochemical Structures of the Furanosesquiterpenoidal β-Hydroxy Ketones from the Myoporaceae
Authors: Kadirvelraj Renuka , Handley Paul N. , Robinson Ward T. , Carman Raymond M. , Sutherland Maurice D.
Published: April 2004

Four furanosesquiterpene β-hydroxy ketones
previously isolated from Myoporum spp., and given
tentative names, are now assigned complete stereostructures from n.m.r. and
X-ray data. The compounds are
(5R,7R,9S)-9-hydroxy-5,9-dihydromyomontanone
(Woogaroo) (1a),
(5S,7R,9R)-9-hydroxy-5,9-dihydro-
myomontanone (Redbank) (1b),
(5R,7R,9R)-9-hydroxy-5,9-dihydromyomontanone
(Perillup) (1c) and
(4S,7S,8R)-4-hydroxy-10,11-didehydro-4,8-dihydromyodesmone
(Carney's ketol) (2a). The stereo- structures of two other previously
reported compounds, Kindon ketol
((4S,7S,8R)-4-hydroxy-4,8-
dihydromyodesmone) (2b), and Carr's ketol
((4S,7S,8S)-4-hydroxy-4,8-dihydromyodesmone)
(2c), follow from the above results.
Space weathering on airless planetary bodies: Clues from the lunar mineral hapkeite
Authors: Anand Mahesh , Taylor Lawrence A. , Nazarov Mikhail A. , Shu J. , Mao H.-K. , Hemley Russell J.
Published: April 2004

Physical and chemical reactions occurring as a result of the high-velocity impacts of meteorites and micrometeorites and of cosmic rays and solar-wind particles are major causes of space weathering on airless planetary bodies, such as the Moon, Mercury, and asteroids. These weathering processes are responsible for the formation of their regolith and soil. We report here the natural occurrence of the mineral hapkeite, a Fe
2
Si phase, and other associated Fe-Si phases (iron-silicides) in a regolith breccia clast of a lunar highland meteorite. These Fe-Si phases are considered to be a direct product of impact-induced, vapor-phase deposition in the lunar soil, all part of space weathering. We have used an
in situ
synchrotron energy-dispersive, single-crystal x-ray diffraction technique to confirm the crystal structure of hapkeite as similar to the structure of synthetic Fe
2
Si. This mineral, hapkeite, is named after Bruce Hapke of the University of Pittsburgh, who predicted the presence and importance of vapor-deposited coatings on lunar soil grains some 30 years ago. We propose that this mineral and other Fe-Si phases are probably more common in the lunar regolith than previously thought and are directly related to the formation of vapor-deposited, nanophase elemental iron in the lunar soils.
CD43 Regulation of T Cell Activation Is Not through Steric Inhibition of T Cell–APC Interactions but through an Intracellular Mechanism
Authors: Tong Jiankun , Allenspach Eric J. , Takahashi Stephenie M. , Mody Purvi D. , Park Chan , Burkhardt Janis K. , Sperling Anne I.
Published: April 2004

CD43 is a large heavily glycosylated protein highly expressed on T cells and actively excluded from the immunological synapse through interactions with ezrin-radixin-moesin proteins. Due to its size and charge, it has been proposed that the CD43 ectodomain acts as a physical barrier to T cell–APC interactions. We have addressed this hypothesis by studying the effect of reconstituting CD43 mutants into the hyperproliferative CD43−/− T cells. Reintroduction of full-length CD43 reversed the CD43−/− T cell hyperproliferation. Interestingly, despite the lack of exclusion from the interaction site, a mutant containing the CD43 ectodomain on a glycosylphosphatidylinositol linkage was ineffective. Additionally, T cell–APC conjugate formation was not affected by this ectodomain-only construct. In contrast, CD43−/− T cell hyperproliferation was reversed by an intracellular-only CD43 fused to the small ectodomain of hCD16. Mutation of this intracellular-only CD43 such that it could not move from the T cell–APC contact site had no further affect on proliferation than the moveable CD43 but did dramatically reduce interleukin-2 production. Thus, the exclusion of the CD43 intracellular region from the immunological synapse is required for CD43 regulation of interleukin-2 production, but the presence of the cytoplasmic tail, independent of its location, is sufficient to reverse CD43−/− T cell hyperproliferation.
Growth retardation and premature aging phenotypes in mice with disruption of the SNF2-like gene, PASG
Authors: Sun Lin-Quan , Lee David W. , Zhang Quangeng , Xiao Weihong , Raabe Eric H. , Meeker Alan , Miao Dengshun , Huso David L. , Arceci Robert J.
Published: April 2004

Imperfect maintenance of genome integrity has been postulated to be an important cause of aging. Here we provide support for this hypothesis by demonstrating that the disruption of PASG (lsh), a SNF2-like factor that facilitates DNA methylation, causes global hypomethylation, developmental growth retardation and a premature aging phenotype. PASG mutant mice display signs of growth retardation and premature aging, including low birth weight, failure to thrive, graying and loss of hair, reduced skin fat deposition, osteoporosis, kyphosis, cachexia, and premature death. Fibroblasts derived from PASG mutant embryos show a replicative senescence phenotype. Both PASG mutant mice and fibroblasts demonstrate a markedly increased expression of senescence-associated tumor suppressor genes, such as p16INK4a, that is independent of promoter methylation, but, instead, is associated with down-regulation of bmi-1, a negative regulator of p16INK4a. These studies show that PASG is essential for properly maintaining DNA methylation and gene expression patterns that are required for normal growth and longevity. PASG mutant mice provide a useful model for the study of aging as well as the mechanisms regulating epigenetic patterning during development and postnatal life.
Comparison of genetically based antipredator behaviour in hatchery and wild coho fry from a coastal Oregon river: interpreting a negative result
Authors: Ryer C.
Published: April 2004

Coho salmon Oncorhynchus kisutch fry derived from wild and hatchery stocks demonstrated no difference in responsiveness to an overhead fright stimulus in laboratory experiments.
Contrasting genetic patterns and population histories in three threatened redfin species (Cyprinidae) from the Olifants River system, western South Africa
Authors: Swartz E. R. , Flemming A. F. , Mouton P. le F. N.
Published: April 2004

Differentiation occurred in different areas of the same river system in Pseudobarbus phlegethon and two sister species of the serrated redfin lineage (Barbus calidus and Barbus erubescens) of the Western Cape region of South Africa. In an analysis of 27 allozyme loci a deep divergence was found within P. phlegethon between the Olifants and Doring catchments (seven fixed allelic differences; 0·338 < D < 0·366; FST = 0·925). In contrast, speciation in the serrated redfin lineage occurred within the Doring catchment between B. calidus and B. erubescens(one fixed allelic difference; 0·008 < D < 0·052; FST = 0·760). Different niche preferences, behaviour and morphology probably played an important role in the formation of these contrasting patterns of genetic structure and suggest that B. calidus may have been better able to disperse between the Olifants and Doring catchments (no fixed allelic differences; 0 < D < 0·040; FST = 0·281) than P. phlegethon.
Male reproductive system in the South American catfish Conorhynchus conirostris
Authors: Lopes D. C. J. R. , Bazzoli N. , Brito M. F. G. , Maria T. A.
Published: April 2004

The testes of the catfish Conorhynchus conirostris(n = 67) from the São Francisco River, Minas Gerais, Brazil were of the fringed type, similar to those of some Pimelodidae. The germ, Sertoli and Leydig cells showed characteristics which are general for all vertebrates although the spermatozoa had a peculiar morphology, with an ovoid head without an acrosome, inverted U‐shaped nucleus, a short midpiece and a long tail, typical of teleosts showing external fertilization. The spermatic duct and genital papilla performed a secretory function.
Costly courtship or dishonest display? Intensely displaying sand goby males have lower lipid content
Authors: Svensson O. , Nyman A. , Kvarnemo C.
Published: April 2004

Intensely displaying sand goby Pomatoschistus minutus males had lower lipid content, indicating that signalling increased energy expenditure, or that low condition males increased their signalling effort. Display intensity correlated positively with nest‐defence and tended to correlate positively with filial cannibalism.
Individual variation in the rate of oxygen consumption by zebrafish embryos
Authors: Bang A. , Grønkjær P. , Malte H.
Published: April 2004

A sensitive microsensor‐based method was used to measure oxygen consumption of individual zebrafish Danio rerio embryos at 6 h intervals from 24 to 75 h post‐fertilization. An increase in oxygen consumption rates from 4·54 to 8·29 nmol O2 h−1 was found during this period. At the individual level the differences in oxygen consumption rates caused the total oxygen consumption from 24 to 75 h post‐fertilization to vary between 0·261 and 0·462 μmol O2 per individual with a mean of 0·379 μmol O2 per individual. A separate carbon mass balance study corroborated the mean total oxygen consumption obtained by yielding a respiratory quotient of 0·80 for this period. These results suggest that there is significant intraspecific variation in the metabolic rate of developing zebrafish embryos, which may influence other early life‐history traits such as growth and starvation resistance.
Low levels of mitochondrial DNA variation among central and southern European Esox lucius populations
Authors: Nicod J.‐C. , Wang Y. Z. , Excoffier L. , Largiadèr C. R.
Published: April 2004

Low levels of mitochondrial DNA variation were observed among pike Esox lucius populations from major drainage systems of Europe. Populations from the Italian peninsula including southern Switzerland were genetically distinct from other samples.
Divergence of two forms of Triphoturus in the eastern Pacific based on mtDNA cytochrome b gene sequences and larval morphology
Authors: Rodríguez‐Graña L. , Herrera G. , Herrera L. , Castro L. R.
Published: April 2004

Divergence between two eastern Pacific forms of Triphoturus, currently considered to belong to the same species was tested by DNA sequences of the cytochrome b gene (DNA obtained from larvae collected in northern Chile and from adults in the Southern California Bight) and examination of larval characters. The number of apparently fixed substitutions (12 among 31 variable sites, out of 1001 bases) was high and the pattern of mid‐lateral trunk pigmentation in larvae also differed consistently between the two forms. The results support the separate species status for T. mexicanus(North America) and T. oculeus(Central‐South America).
Effects of packaging type, gas atmosphere and storage temperature on survival and growth of Listeria spp. in shredded dry coleslaw and its components
Authors: Bourke Paula , O'Beirne David
Published: April 2004

The survival and growth of Listeria populations inoculated on to dry coleslaw mix and its components were investigated, focusing on effects of storage temperatures and gas atmospheres within packaging films or storage chambers. There were few significant effects of packaging film at 3 °C, but at 8 °C the elevated CO2/low O2 atmospheres generated within orientated polypropylene (OPP) packages and used in controlled atmosphere chambers were inhibitory. Although two strains of Listeria monocytogenes had survival characteristics comparable with Listeria innocua, L. monocytogenes ATCC 19114 survived better at 3 °C and also in the elevated CO2/low O2 atmospheres within OPP at 8 °C. The effects of product components on the survival of L. innocua were linked to storage temperature. Shredded carrot reduced initial counts and at 8 °C inhibited survival of L. innocua in comparison with shredded cabbage.
Optimization of microbiological assay of folic acid and determination of folate content in spinach
Authors: Pandrangi Srilatha , LaBorde Luke F.
Published: April 2004

The microbiological method for the determination of folate in plant foods uses the growth response of folate‐dependent Lactobacillus rhamnosus in extracts that have been enzymatically treated to release the bound vitamin. However, the use of cryoprotected cultures is hampered by low recovery of the microorganism after extended frozen storage times. In this study, growth of L. rhamnosus was enhanced using a microaerophilic enrichment procedure and optimal pH conditions and enzyme reaction times were determined for the release of bound folate in spinach. Optimum pH values for the release of bound folate in spinach samples treated with α‐amylase or protease were 3.0 and 4.0, respectively. Although treatment with α‐amylase had no significant (P > 0.05) effect on measured folate, addition of protease at pH 4.0 significantly (P  0.05) increased the release of folate at an optimum incubation time of 8 h. Therefore, a dual‐enzyme treatment (protease and conjugase) is sufficient to determine folate content in spinach.