bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of polyelectrolyte coating conditions on capillary coating stability and separation efficiency in capillary electrophoresis
Authors: Nehmé Reine , Perrin Catherine , Cottet Hervé , Blanchin Marie D. , Fabre Huguette
Published: June 2008

Polyelectrolytes are widely used in capillary electrophoresis as coating agents of silica capillaries to prevent adsorption phenomena and improve the repeatability of peptide and protein analysis. A systematic study of the coating experimental conditions has been carried out to optimize coating stability and performance. The main experimental parameters studied were the type and concentration of polyelectrolytes used in several monolayer and multilayer coatings, the ionic strength of coating and stabilizing solutions, and the procedures used for coating and capillary storage. Electroosmotic flow magnitude, direction and repeatability were used to monitor coating stability. Coating ability to limit adsorption was investigated by monitoring variations of migration times, time‐corrected peak areas and separation efficiency of test peptides. Capillary‐to‐capillary and batch‐to‐batch reproducibility was also studied. In addition, the separation performance of polyelectrolyte coatings were compared to those obtained with bare silica capillaries.
Single‐cell gel electrophoresis (the comet assay): Loops or fragments?
Authors: Shaposhnikov Sergey A. , Salenko Veniamin B. , Brunborg Gunnar , Nygren Jonas , Collins Andrew R.
Published: June 2008

Single‐cell gel electrophoresis, or the comet assay, is widely used to measure DNA damage and repair. Upon electrophoresis, the DNA of lysed, agarose‐embedded cells known as nucleoids, extends towards the anode in a structure resembling a comet, the relative intensity of the tail reflecting the frequency of DNA breaks. The structural organization of the DNA within comet preparations is not fully understood. We have used fluorescent in situ hybridization with large‐insert genomic probes and human Cot‐I DNA to investigate whether the production of the comet tail is simply explained by the relaxation of supercoiled DNA loops. We find that, under neutral electrophoresis conditions, when the tail and head DNA are double‐stranded, the probed sequence of DNA is seen as a linear array, consistent with extension from a fixed point on the nuclear core or matrix. After alkaline electrophoresis, the appearance of the fluorescent probes suggests that linear DNA has coalesced into a granular form.
Carbon nanotube disposable detectors in microchip capillary electrophoresis for water‐soluble vitamin determination: Analytical possibilities in pharmaceutical quality control
Authors: Crevillén Agustín G. , Pumera Martin , González María Cristina , Escarpa Alberto
Published: June 2008

In this work, the synergy of one mature example from “lab‐on‐chip” domain, such as CE microchips with emerging miniaturized carbon nanotube detectors in analytical science, is presented. Two different carbon electrodes (glassy carbon electrode (GCE) 3 mm diameter, and screen‐printed electrode (SPE) 0.3 mm×2.5 mm) were modified with multiwalled carbon nanotubes (MWCNTs) and their electrochemical behavior was evaluated as detectors in CE microchip using water‐soluble vitamins (pyridoxine, ascorbic acid, and folic acid) in pharmaceutical preparations as representative examples. The SPE modified with MWCNT was the best electrode for the vitamin analysis in terms of analytical performance. In addition, accurate determination of the three vitamins in four different pharmaceuticals was obtained (systematic error less than 9%) in only 400 s using a protocol that combined the sample analysis and the methodological calibration.
Rapid characterization of fatty alcohol ethoxylates by non‐aqueous capillary electrophoresis
Authors: Arias Mónica , Bauza Roberto , Rodríguez Juana , Castañeda Gregorio , Ríos Ángel
Published: June 2008

Fatty alcohol ethoxylates (FAE) (a mixture of nonionic surfactants) have been characterized using NACE with UV detection. Phenyl polyurethane derivatives of these compounds were previously obtained by reaction with phenyl isocyanate. The derivatization reaction only requires microwave irradiation for 30 s (600 W). Phenyl polyurethanes were separated and characterized using a BGE containing a mixture of ammonium nitrate (15 mM), acetic acid (1.5%) and 9:1 v/v methanol/ACN. After optimization of the instrumental conditions for the separation, phenyl polyurethane compounds (formed from the corresponding FAE) with ethylene oxide numbers (EON) of 6 (certified standard and industrial samples), 7 and 10 (both as industrial samples), and 5.5 (microemulsion phase) were successfully separated and characterized. The properties of these FAE nonionic surfactants are very important in the petroleum industry, which requires characterization of the quality of the purchased materials as well as the final products in the microemulsion‐oil‐water stream process. This analytical objective has been achieved by the proposed NACE methods, allowing FAE to be distinguished from 5.5 to 10 EON with errors below 4%, and shows advantages against to HPLC methods.
A high‐throughput multicomponent screening method for diuretics, masking agents, central nervous system (CNS) stimulants and opiates in human urine by UPLC–MS/MS
Authors: Thörngren John‐Olof , Östervall Fredrik , Garle Mats
Published: June 2008

A simple and rapid multicomponent screening method of 130 substances for direct injections of urine samples has been developed. The fully automated method based on ultra‐performance liquid chromatography (UPLC) and tandem mass spectrometry (MS/MS) is used for three different classes of doping agents: diuretics, central nervous system stimulants (CNS stimulants) and opiates. The samples are diluted with buffer containing internal standards (IS) by a pipetting robot system into 96‐well plates. Samples are injected on a reversed phase sub 2‐µm particle column connected to a fast polarity switching and rapid scanning tandem mass spectrometer with an electrospray interface. The software used to evaluate the results produced reports containing a small‐sized window for each component and a data table list with flags to indicate any adverse analytical findings in the sample. The report can also be processed automatically using an application software, which interpret the data and indicate if there is a suspicious sample. One 96‐well plate can be analyzed within 16 h. Copyright © 2008 John Wiley & Sons, Ltd.
Identification of zinc‐alpha‐2‐glycoprotein binding to clone AE7A5 antihuman EPO antibody by means of nano‐HPLC and high‐resolution high‐mass accuracy ESI‐MS/MS
Authors: Reichel Christian
Published: June 2008

The detection of doping with recombinant erythropoietins (Epo) by isoelectric focusing (IEF) and Western double blotting strongly relies on the specificity of the detection antibody used. Currently a monoclonal mouse antibody (clone AE7A5) is used for that purpose. Despite its excellent sensitivity (amol range) the antibody shows some nonspecific binding behavior. However, the binding occurs outside the currently used pH range for evaluating erythropoietin IEF profiles. A shotgun proteomics approach is described consisting of preparative IEF on large‐sized carrier ampholyte gels (pH 3–5), SDS‐PAGE, Western single and double blotting, on‐membrane elution of intact proteins, on‐membrane and in‐solution tryptic digestions, as well as nano‐HPLC peptide separation and high‐resolution high‐mass accuracy ESI‐MS/MS peptide sequencing. The nonspecifically interacting protein could be identified as zinc‐alpha‐2‐glycoprotein (ZAG). Confirmation analyses were performed using recombinant ZAG (rhZAG) and a monoclonal anti‐ZAG antibody. It could be demonstrated that the binding of the monoclonal antihuman EPO antibody (clone AE7A5) to ZAG occurs in a highly concentration‐dependant manner and that only samples containing increased amounts of urinary ZAG lead to a detectable interaction of the AE7A5 antibody on Epo‐IEF gels. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and identification of hydroxylated metabolites of the anti‐estrogenic agent cyclofenil
Authors: Gärtner Peter , Hofbauer Karin , Reichel Christian , Geisendorfer Thomas , Gmeiner Günter
Published: June 2008

The detection of metabolites of the anti‐estrogenic substance cyclofenil, listed on the World Anti‐Doping Agency (WADA) Prohibited List since 2004 is described. Target substances are hydroxylated metabolites, bearing an aliphatic hydroxyl group either in the 2‐, 3‐ or 4‐position of the aliphatic ring, in addition to the phenolic functions on the aromatic rings. Structural identification used NMR as well as high‐resolution mass spectrometry after nano‐electrospray ionisation (ESI). Unambiguous detection of all three synthesised cyclofenil metabolites M1M3 was done using gas chromatography for separation and electron ionisation mass spectrometry for detection of the per‐silylated compounds in comparison with a reference urine deriving from an excretion study within the WADA 2007 Educational Programme. Copyright © 2008 John Wiley & Sons, Ltd.
Hydrogels for Potential Colon Drug Release by Thiol‐ene Conjugate Addition of a New Inulin Derivative
Authors: Pitarresi Giovanna , Tripodo Giuseppe , Calabrese Rossella , Craparo Emanuela Fabiola , Licciardi Mariano , Giammona Gaetano
Published: June 2008

Inulin was chosen as a starting polymer for biocompatible, pH‐sensitive and biodegradable hydrogels. Three INUDVSA‐TT hydrogels were obtained by crosslinking inulin derivatives with trimethylolpropane tris(3‐mercaptopropionate) under varying conditions. The resulting hydrogels were cell compatible, as demonstrated by MTS and trypan blue exclusion assays acting on Caco‐2 cells, and were biodegraded by inulinase and esterase, thus suggesting their use as colonic drug delivery systems. 2‐Methoxyestradiol, an anti‐cancer drug, was soaked in INUDVSA‐TT hydrogels and its in vitro release and apoptotic effect on Caco‐2 cells were evaluated.

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Generalized Reconstruction by Inversion of Coupled Systems (GRICS) applied to free‐breathing MRI
Authors: Odille Freddy , Vuissoz Pierre‐André , Marie Pierre‐Yves , Felblinger Jacques
Published: June 2008

A reconstruction strategy is proposed for physiological motion correction, which overcomes many limitations of existing techniques. The method is based on a general framework allowing correction for arbitrary motion–nonrigid or affine, making it suitable for cardiac or abdominal imaging, in the context of multiple coil, arbitrarily sampled acquisition. A model is required to predict motion in the field of view at each sample time point, based on prior knowledge provided by external sensors. A theoretical study is carried out to analyze the influence of motion prediction errors. Small errors are shown to propagate linearly in that reconstruction algorithm, and thus induce a reconstruction residue that is bounded (stability). Furthermore, optimization of the motion model is proposed in order to minimize this residue. This leads to reformulating reconstruction as two inverse problems which are coupled: motion‐compensated reconstruction (known motion) and model optimization (known image). A fixed‐point multiresolution scheme is described for inverting these two coupled systems. This framework is shown to allow fully autocalibrated reconstructions, as coil sensitivities and motion model coefficients are determined directly from the corrupted raw data. The theory is validated with real cardiac and abdominal data from healthy volunteers, acquired in free‐breathing. Magn Reson Med 60:146–157, 2008. © 2008 Wiley‐Liss, Inc.
Multiscale roughness analysis in injection‐molding process
Authors: Bigerelle Maxence , Van Gorp Adrien , Iost Alain
Published: June 2008

The roughness of polymer surfaces is often investigated to guarantee both the surface integrity and the surface functionality. One of the major problems in roughness measurement analyses consists in determining both the evaluation length and the reference line (i.e., the degree of the polynomial equation) from which roughness parameters are computed. This article outlines an original generic method based on the generalized analysis of variance and experimental design methodology for estimating the most relevant roughness parameter p, the most pertinent scale, s, and finally, the degree of the polynomial fitting, d. This methodology is then applied to characterize the influence of four process parameters on the final roughness of poly(polypropylene) samples obtained by injection molding. This method allows us to determine the most efficient triplet (p, s, d) that best discriminates the effect of a process parameter q. It is shown that different (p, s, d) values are affected to each process parameter giving finally the scale on which each process parameter modifies the roughness of a polymeric surface obtained by injection molding. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Supercritical carbon dioxide‐induced melting temperature depression and crystallization of syndiotactic polypropylene
Authors: Li Bin , Zhu Xinyuan , Hu Guo‐Hua , Liu Tao , Cao Guiping , Zhao Ling , Yuan Weikang
Published: June 2008

This work was aimed at studying supercritical carbon dioxide (scCO2)‐induced melting temperature depression and crystallization of a syndiotactic polypropylene (sPP). Under scCO2, the melting temperature of the sPP could be significantly reduced depending on the CO2 pressure. The scCO2‐induced crystallization of sPP was investigated using differential scanning calorimeter (DSC) and Fourier transform infrared spectroscopy. Two melting peaks were observed in DSC. The one at lower melting temperature referred to the melting of the sPP crystals induced by scCO2 in its amorphous phase. Its location was shifted to higher temperature, and its area increased with increasing scCO2 treatment time, temperature, and pressure. The melting peak at higher temperature corresponded to the melting of the sPP crystals that already existed before scCO2 treatment. Its location and area remained almost unaffected by the scCO2 treatment. The scCO2‐induced crystallization was related to scCO2‐promoted transformation of the mesophase form III of the sPP to the stable form I. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Precipitation fronts and the reflection and transmission of tropical disturbances
Authors: Pauluis Olivier , Frierson Dargan M. W. , Majda Andrew J.
Published: June 2008

This paper investigates the interactions between precipitation and the circulation in an idealized model for the tropical atmosphere where convection is represented by a quasi‐equilibrium closure. When studying large‐scale circulation in the Tropics, the governing equations can be further simplified by making the strict quasi‐equilibrium assumption which considers that convection acts to instantaneously adjust the atmospheric temperature profile to a moist adiabatic lapse rate. It is shown here that, under this assumption, the interface between the precipitating and non‐precipitating regions exhibits a discontinuity in the precipitation rate and vertical velocity. Furthermore, this interface, referred to as a precipitation front, moves at a velocity distinct from the propagation speed of dry and moist disturbances. The theory predicts the existence of three types of precipitation fronts: drying fronts, slow moistening fronts and fast moistening fronts. In previous studies, numerical simulations have demonstrated the existence of the three types of front, and have also confirmed that the precipitation front theory offers a good approximation for the behaviour of the interface between dry and moist regions for finite value of the convective adjustment time.

A new framework is proposed here in which the encounter of an atmospheric disturbance and the edge of a precipitation region is recast as a Riemann problem. It is shown that, for any precipitation fronts, there are three incident characteristics but only two outgoing characteristics. This makes it possible to solve simultaneously for the intensity of the outgoing invariants and the propagation speed of the front. This also implies that atmospheric disturbances will be partially transmitted and partially reflected when encountering a precipitation front. For small perturbations, linear reflection and transmission coefficients can be computed analytically. These results also indicate that that disturbances can be amplified through over‐transmission or over‐reflection. These theoretical results are confirmed in numerical simulations of an idealized Walker circulation. A solution that includes a stationary precipitation front is perturbed by adding a small‐amplitude gravity wave, convectively coupled gravity wave, or moisture disturbance. All numerical simulations exhibit reflection and transmission of the incoming signal, and one simulation shows a case of over‐transmission of the incoming disturbance. Copyright © 2008 Royal Meteorological Society
In situ Synthesis of Lipopeptides as Versatile Receptors for the Specific Binding of Nanoparticles and Liposomes to Solid‐Supported Membranes
Authors: Schuy Steffen , Treutlein Barbara , Pietuch Anna , Janshoff Andreas
Published: June 2008

A detailed study of the in situ coupling of small peptides such as CGGH6 (H6) and CGWK8 (K8) to maleimide functionalized phospholipid bilayers is presented. Individually addressable microstructured membranes are employed to unequivocally probe the conjugation. The in situ coupling of peptides via a terminal cysteine moiety to maleimide functionalized phospholipids is shown to be a convenient and versatile way to selectively fabricate peptide‐modified phospholipid bilayers serving as specific receptor platforms for functionalized vesicles and nanoparticles. Specific binding of functional vesicles to the peptide‐modified bilayers is achieved by either histidine complexation with Ni‐NTA‐DOGS containing vesicles or electrostatic interaction between positively charged oligolysine bearing lipopeptides and negatively charged POPC/POPG vesicles. Peptide receptors are also found to be easily accessible from the aqueous phase and not buried within the membrane interior.
Circadian and ultradian rhythms in the crayfish caudal photoreceptor
Authors: Rodríguez‐Sosa Leonardo , Calderón‐Rosete Gabina , Flores Gonzalo
Published: June 2008

The study of circadian clocks in crustaceans has led to the hypothesis of a distributed circadian system of pacemakers. In this review, we investigate the role of the crayfish caudal photoreceptor (CPR) as a candidate to form part of this pacemaking circadian system. Two circadian rhythms are documented for CPR electrical activity. These rhythms correspond to the spontaneous and light‐induced discharge of action potentials. The intrinsic characterization of the rhythms is made through the analysis of the firing rate of the corresponding action potentials. The discharges were extracellularly recorded in the isolated 6th abdominal ganglion (AG) in an organ culture kept at constant temperature for up to 5 days. For preparations kept in the dark, spontaneous activity varies in a circadian manner, with a period of 24.7 h and the acrophase at subjective nighttime (2140). For light‐induced activity, pulses of constant intensity applied regularly throughout the 24‐h cycle show that the firing rate at peak and latency vary rhythmically. The period for this rhythm is 24.24 h and the acrophase is at subjective dawn (0326). Additionally, an ultradian rhythm of a ∼12‐h period was observed for both rhythms. When tested with light pulses of different intensities, the CPR responsiveness at night is almost one log unit greater than in daytime. The effect of temperature on both activities is also described. The phase‐shift caused by temperature for these circadian rhythms depends on the application time. These results show that the 6th AG is capable of generating a circadian rhythm of electrical activity in the CPR, which in turn is likely to be part of the crayfish circadian system. A possible interaction of different pacemakers forming the distributed circadian system is also discussed. The role of serotonin as a possible modulator of the CPR electrical activity is documented. In addition, the level of the 5‐HT1Areceptors displays a diurnal rhythm in the 6th AG, with the acrophase at twilight (1849). We suggest that the 5‐HT1Areceptor does participate in this modulation. Finally, the hypothesis of the expression of two circadian oscillators in a single identified neuron is presented. Synapse 62:643–652, 2008. © 2008 Wiley‐Liss, Inc.
Serpins show structural basis for oligomer toxicity and amyloid ubiquity
Authors: Carrell Robin W. , Mushunje Alec , Zhou Aiwu
Published: June 2008

Many disorders, including Alzheimer's, the prion encephalopathies and other neurodegenerative diseases, result from aberrant protein aggregation. Surprisingly, cellular toxicity is often due not to the highly‐ordered aggregates but to the oligomers that precede their formation. Using serpins as a paradigm, we show how the active and infective interface of oligomers is inherently toxic and can promiscuously bind to unrelated peptides, including neurotransmitters. Extension of the oligomer and its eventual sequestration as amyloid can thus be seen as a protective response to block the toxic interface. We illustrate how the preferential self‐association that gives this protection has been selectively favoured.
Cdx2 initiates histodifferentiation of the midgut endoderm
Authors: Stringer Emma J. , Pritchard Catrin A. , Beck Felix
Published: June 2008

Null mutation or haploinsufficiency of Cdx2 results in the development of heterotopic lesions with a gastric phenotype in the midgut endoderm. Conversely transgenic expression of Cdx2 in the stomach causes the endoderm to differentiate into intestinal‐type mucosa. We demonstrate that the mesoderm adjacent to intestinal heterotopic areas expresses stomach specific Barx1 while the surrounding mesoderm is Barx1 negative. We conclude that the initiation of gut histodifferentiation lies in the endodermal expression of Cdx2 and that endodermal/mesodermal cross‐talk involving Barx1 with appropriate feedback loops results in the development of the postnatal gut phenotype.
Mantle sources of Permian-Triassic Siberian traps (West Siberian Plate and Siberian craton)
Authors: Sharapov V.N. , Perepechko Yu.V. , Perepechko L.N. , Rakhmenkulova I.F.
Published: June 2008

We investigate the dynamics of multilevel subcontinental melting beneath a lithosphere of variable thickness as a model simulating generation of melts that produced flood basalt in the Siberian Trap province. The inferred sequence of volcanic events correlates with upper mantle decompression melting above hotspots and related conductive melting of metasomatized depleted lithosphere. Numerical experiments show that complex mafic magmatic systems of this kind are at least two-stage with a zone of decompression melting in upwelling mantle flow and a sub-Moho lithospheric melting region; the shallower lithospheric melting region can be disconnected from the mantle zone of decompression melting along the edges of the magmatic system; the lithospheric melting region has a particular layered structure with its top at a depth of 60–70 km and a maximum size exceeding the length of the erupted lava field; mafic melts produced at different levels of the system have different compositions.
Dating impact craters: palaeogeographic versus isotopic and stratigraphic methods – a brief case study
Authors: SCHMIEDER MARTIN , BUCHNER ELMAR
Published: June 2008

Isotopic and stratigraphic ages of the ~ 80 km diameter Puchezh-Katunki (Russia; 220 ± 10 to 167 ± 3 Ma) and the ~ 20 km diameter Obolon (Ukraine; 215 ± 25 to 169 ± 7 Ma) impact structures are associated with significant age uncertainties. As a case study, reconstructions of the palaeogeography at the time of crater formation (Late Triassic to Middle Jurassic) based on recent palaeogeographic maps help further to constrain impact ages. Palaeogeographic studies suggest that Puchezh-Katunki is older than 170 Ma and that Obolon is younger than 185 Ma. This also rules out that Obolon formed during a ~ 214 Ma Late Triassic multiple impact event as recently discussed.
Thermal properties of operative endoscopes used in otorhinolaryngology
Authors: MacKeith S A C , Frampton S , Pothier D D
Published: June 2008

Objectives:

To measure the thermal properties of operative endoscopes used in otorhinolaryngological practice.

Methods:

A series of endoscopes of varying diameters and angulations were attached to a light source and temperature measurements taken of their shaft and tip; a measurement was also taken 5 mm in front of the endoscope tip.

Results:

Temperature changes took place rapidly. The amount of heat produced by the endoscopes was maximal at the tip, with larger diameter endoscopes attaining a higher temperature. Temperatures on the shaft and in front of the tip reached relatively constant temperatures independent of the type of endoscope. The maximum temperature achieved was 104.6°C for the 4 mm, 0° endoscope. Cooling occurred rapidly after the light source was switched off.

Conclusion:

The heat produced by some endoscopes is sufficiently great to cause thermal injury to tissues. Awareness of the temperatures produced by these endoscopes should prompt clinicians to actively cool their endoscopes during a procedure, before any thermal injury is caused.
Variations in Posidonia oceanica meadow structure along the coast of the Dugi Otok Island (eastern Adriatic Sea)
Authors: Kru΂ić Petar
Published: June 2008

Although the anthropogenic impact on Posidonia oceanica meadows in the Mediterranean Sea has been studied over the last few decades, the data about the status of this endemic magnoliophyte are scarcer from the Adriatic Sea. Samples of P. oceanica meadows were collected in June and July 2004 using SCUBA diving at 8 sites in the area of the Dugi Otok Island, all at depths of 10 m. The meadow's shoot density was measured, and shoots were collected to be examined and compared through number of leaves per shoot, leaf surface per shoot, leaf area index, number and biomass of taxa of epiphytic flora. Significant differences in P. oceanica meadow structure were found among investigated sites, especially between sites in the vicinity of the fish farm and the other sites. Meadow density decreased at sites in the Dugi Otok channel and the main impact factors seem to be the input of organic matter, originating from the fish cages and sewage input. These human activities are a source of nutrient pollution and stimulate blooms of phytoplankton and higher algae. The sea grass meadow vitality seems to be more negatively affected in the channel. The highest values of shoot density were recorded at investigated sites VR and ME at the outer part of the Dugi Otok Island. The shoot density was very low at site FU, situated in the channel. Biomass of the epiphytic algae exhibited the highest values at the site FU, while at the other investigated sites the values were significantly lower. Concerning the epiphytic macroflora, a total of 55 taxa of epiphytic macroalgae were identified and the class Rhodophyta dominated in all samples. The present study shows the high differences in morphological and structural characteristics of Posidonia oceanica meadows among various sites with and without anthropogenic influence.
Geographical variation of barricade-building behaviour in the intertidal brachyuran crab Ilyoplax pusilla
Authors: Furukawa Fumiko , Yamada Arisa , Ohata Mari , Wada Keiji
Published: June 2008

The small dotillid crab Ilyoplax pusilla builds an earthen structure, termed barricade, close to its neighbour's burrow. Barricades function for territorial defence by deterring invasion by neighbours. Comparison of the frequency of barricade building in the breeding season among 5 localities across the geographical range of I. pusilla, showed higher values at more northern localities. In two localities differing in the frequency of barricade building, the response of crabs to artificial barricades placed near their burrows was examined. The artificial barricade was less often broken and more often avoided in the locality with the higher frequency of barricades. These results suggest that the local difference in frequency of barricade building is correlated with a difference in how crabs respond to this earthen barrier.
Spatial patterns of meiofauna and diversity of nematode species assemblages in the Uvea lagoon (Loyalty Islands, South Pacific)
Authors: Guo Y. , Helleouet M.-N. , Boucher G.
Published: June 2008

Meiofauna assemblages were investigated at 15 stations on triplicated samples in the Uvea Atoll (Loyalty Islands) in relation to 9 selected environmental parameters. Spatial patterns and variability of meiofauna density were quantified according to location, macrofauna and nematode species assemblages. Meiofauna was dominated by ciliates and nematodes. Densities of total meiofauna and of most of the meiofauna taxa were significantly higher in the back reef North Pléiades stations than the leeward side of the Island. The highest correlation between biotic patterns and environmental parameters that best explains the pattern was with sediment thickness and to a lesser extent organic matter, C/N ratio and depth. One hundred and thirty-four nematode species were identified with four dominant species Chromadora macrolaimoides, an undescribed species of Bolbonema, Daptonema svalbardense and Prochromadorella septempapillata. Three significantly different nematode species assemblages were detected in two of the previously described macrofauna assemblages by cluster analysis and multidimensional scaling methods suggesting that nematodes are more sensible ecological indicators than macrofauna. Diversity indices based on dominance were not significantly different among the three nematode species assemblages but indices based on species richness and rarefaction were significantly higher leeward of Uvea Island. Estimates of total species richness showed no sign of stabilizing with sample size. However, rare species stabilized very quickly, whereas abundant species were added with increasing sampling coverage, indicating a high spatial variability of the local composition of nematodes.
Copepod community structure over a marine outfall area in the north-eastern South China Sea
Authors: Tseng Li-Chun , Kumar Ram , Dahms Hans-Uwe , Chen Chun-Te , Souissi Sami , Chen Qing-Chao , Hwang Jiang-Shiou
Published: June 2008

This study focuses on the dynamics of copepod abundances and species composition in the upper water column of a marine outfall area Tso-Ying (T-Y) in the boundary waters of the north-eastern South China Sea and the Taiwan Strait as an example. Zooplankton samples were collected in March, June and September 2002. Mean copepod abundance at all stations ranged from a minimum of 9.4 (individuals m−3) in March to a maximum of 1685 (individuals m−3) in June. A total of 66 copepod species belonging to 31 genera and 19 families were identified during three cruises. Copepod assemblages were dominated byTemora turbinatawhich occurred in >97% samples with a relative abundance of 75.46% combining all three sampling cruises. The ordination diagram derived from non-metric multidimensional scaling separated samples on the basis of season and revealed that different sampling stations clustered differently during each cruise. The second and third most dominant species wereAcrocalanus gracilisandAcrocalanus gibber, representing 1.73% and 1.65% of the total copepod abundance respectively. The outfall area studied here correlates with lower copepod densities represented by a few species that show a higher relative abundance in comparison with non-affected areas. We provide here the first example where plankton assemblages indicate useful information about environmental changes in the course of sewage disposal at a stable outlet site.
Role of physico-chemical environment on gastropod assemblages at hydrothermal vents on the East Pacific Rise (13°N/EPR)
Authors: Matabos Marjolaine , Le Bris Nadine , Pendlebury Sophie , Thiébaut Eric
Published: June 2008

Deep-sea hydrothermal vents display extreme and highly variable environmental conditions that are expected to be among the most important factors structuring associated benthic populations and communities. We tested this assumption, focusing on the distribution of gastropods, as well as on the demographic population structure and reproductive biology of one dominant gastropod species in zones characterized by alvinellid polychaetes and vestimentiferan tubeworms. A total of 14 biological samples from both types of habitats were collected at three sites on the East Pacific Rise 13°N vent field in May 2002. At all vents except one, the physico-chemical environment was described in two steps: (1) pH, total sulphide and reduced iron concentrations have been measuredin situinAlvinellahabitats and correlations to temperature were assessed at the scale of each sampled vent; and (2) assuming the consistency of these relationships within a single edifice, ranges of physico-chemical factors were estimated for each biological sample from the corresponding fine scale temperature measurements. A total of 11 gastropod species were identified from all samples and 2 main faunal assemblages were distinguished: one dominated byLepetodrilus elevatusin the alvinellid zone as well as in the vestimentiferan zone, and one dominated by the peltospiridsNodopelta heminoda, N. subnodaandPeltospira operculataconfined to the alvinellid zone. Peltospirid gastropods were dominant over lepetodrilid gastropods in the more acidic, sulphide-richer, and hotter environments. Although this pattern could be related to specific physiological tolerances to temperature and sulphide toxicity, the weak correlation between community structure and physico-chemical variables suggests that additional factors are also involved. Particularly, the low species richness and the overwhelming dominance ofL. elevatusin one faunal assemblage suggest that this species may outcompete peltospirids and greatly affect community structure. This hypothesis is supported by large differences in the demographic structure and reproductive biology ofL. elevatusbetween the 2 faunal assemblages.
Acoustic communication in the Lusitanian toadfish, Halobatrachus didactylus: evidence for an unusual large vocal repertoire
Authors: Amorim M.C.P. , Simões J.M. , Fonseca P.J.
Published: June 2008

The Lusitanian toadfish Halobatrachus didactylus (Bloch & Schneider) (Batrachoididae) is a well-known sound producer that has an unusual large acoustic repertoire for fish. This repertoire consists so far of five distinct sound categories: boatwhistles, grunt trains, croaks, double croaks and a mixed grunt–croak call. Sixteen males that spontaneously occupied artificial concrete nests placed in the intertidal zone of the Tagus estuary (Portugal) were recorded over 8 days in June/July 2006. During the analysis of the recordings new sound emissions were found. Long grunt trains that sounded to the human ear like a running engine were heard. These sounds differ from the normal grunt trains by having a lower amplitude, a much longer duration (tens of seconds versus <1 second) and more grunts per call. Other new sound emissions (e.g. triple croaks) were also registered but were heard less frequently. The incidence of the various sound types is given.
Neurocognitive profile analysis in obsessive-compulsive disorder
Authors: BURDICK KATHERINE E. , ROBINSON DELBERT G. , MALHOTRA ANIL K. , SZESZKO PHILIP R.
Published: June 2008

Although neurocognitive deficits have been identified in obsessive-compulsive disorder (OCD), little research has focused on whether these deficits are generalized or specific to a given cognitive domain. We assessed the relative strengths and weaknesses of 26 adult patients with OCD compared to 38 age- and sex-matched healthy volunteers in domains of motor, verbal memory, visual memory, reasoning/problem solving, processing speed processing, and language. Profile analysis revealed an overall neurocognitive deficit of ½ standard deviation in OCD patients versus healthy volunteers, with relative weaknesses in motor and processing speed domains. In contrast, relative strengths were observed in language, verbal memory, and reasoning/problem solving. Our findings demonstrate neurocognitive impairment in OCD that may relate to functional outcome in this population. Findings of specific abnormalities on tasks of motor and processing speed are consistent with a hypothesized role of thalamocortical and basal ganglia regions in the pathogenesis of OCD. (JINS, 2008, 14, 640–645.)
Addressing legal and political barriers to global pharmaceutical access: Options for remedying the impact of the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) and the imposition of TRIPS-plus standards
Authors: COHEN-KOHLER JILLIAN CLARE , FORMAN LISA , LIPKUS NATHANIEL
Published: June 2008

Despite myriad programs aimed at increasing access to essential medicines in the developing world, the global drug gap persists. This paper focuses on the major legal and political constraints preventing implementation of coordinated global policy solutions – particularly, the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) and bilateral and regional free trade agreements. We argue that several policy and research routes should be taken to mitigate the restrictive impact of TRIPS and TRIPS-plus rules, including greater use of TRIPS flexibilities, advancement of human rights, and an ethical framework for essential medicines distribution, and a broader campaign that debates the legitimacy of TRIPS and TRIPS-plus standards themselves.
Willingness to pay for alternative policies for patients with Alzheimer’s Disease
Authors: NEGRÍN MIGUEL A. , PINILLA JAIME , LEÓN CARMELO J.
Published: June 2008

This paper focuses on eliciting the willingness to pay (WTP) for policy measures aimed at improving the health care offered to patients suffering from Alzheimer’s disease (AD). We utilize a discrete choice experiment (DCE) approach for the elicitation of the preferences of the general population for three alternative policies: home care, day care centres, and medium or long-stay centres. The results show that these policies are significantly valued across the surveyed population. The monthly WTP per hour of home care is estimated as €4 per individual, while the monthly WTP values for full population coverage in day centres and medium–long-stay centres are estimated as €0.43 and €0.42 respectively. We compare the results of classical and Bayesian estimation methods, and conclude that the latter provide a better representation of the heterogeneity in the sample. The results are significant for health care, as they enable policymakers to identify the social demand for such services, as well as the relative economic values placed on the alternative policy measures.
Consumer-directed health care: promise or puffery?
Authors: CALLAHAN DANIEL
Published: June 2008

Consumer-directed health care (CDHC) is one of the basic ideas that has emerged in recent years as a way of bringing greater efficiency and cost control into health care. Its principal aims are to give patients greater control over their care, economically as well as medically, and to improve competition among providers to increase the range of patient control. Its roots are American, bespeaking a cultural suspicion of government, a worry about rising costs, and an appeal to the popularity of choice in almost all matters, now including health care. CDHC also bespeaks the ideology of market ideology, drawing on both market concepts in economics and a push by American conservatives (particularly President George W. Bush) to privatize as much of American health care as possible). It draws particularly on the business community as a source of ideas and inspiration, assuming that if choice and competition work well in the commercial sector, it will work equally well in health care. A fundamental question, however, is not simply how well business models might work, but also whether thinking of the patient as a savvy consumer could ever make full sense in the face of complicated, emotionally charged illnesses and complex decision-making situations. Skepticism is in order.
Cluster observations of the Earth's quasi‐parallel bow shock
Authors: Lucek E. A. , Horbury T. S. , Dandouras I. , Rème H.
Published: June 2008

Cluster observations of the Earth's quasi‐parallel shock are used to investigate properties of the transition and the role of magnetic pulsations in the shock process. We use crossings at small spacecraft separations to show that pulsations grow in only a few seconds. We then use an example when the spacecraft were only a few thousand kilometers apart, and yet at times the shock was located within the tetrahedron formation, to demonstrate that for a period of 10 min the thickness of the shock transition was less than 2500 km and that during several shorter intervals the shock thickness was less than 1000 km. In the context of evidence for the extent of SLAMS exceeding 1000 km, this suggests that the thickness of the shock layer over which the bulk of plasma thermalization occurs can be narrow, containing one or at most a few SLAMS. The small‐scale spatial properties of structures within the shock are difficult to extract independently of their time evolution, but we present a crossing at which two pairs of spacecraft observed the same magnetic signatures simultaneously. We show that signatures of these pulsations are consistent with their refraction as they are convected antisunward, as predicted by simulation work, and that they are coherent over a distance of at least 1300 km parallel to the expected shock surface.
Healing microstructures of experimental and natural fault gouge
Authors: Keulen Nynke , Stünitz Holger , Heilbronner Renée
Published: June 2008

The healing of fault gouge was studied by examining microstructures of naturally and experimentally produced granitoid fault rock. We performed deformation experiments on intact granitoid rock samples at T = 300–500°C, Pc = 500 MPa, and = 1.2 × 10−4 – 1.3 × 10−7 s−1 with 0.2 wt% H2O added. Healing experiments were carried out on deformed samples at T = 200–500°C, Pc = 500 MPa, for 4 h to 14 days under hydrostatic and nonhydrostatic conditions. The grain size distributions (GSD) of the deformed samples were quantified using the D> value (slope of log(frequency) ‐log(radius) of the GSD) for quartz and feldspar fault gouge. Healing causes a decrease in the D> value from >2.0 to ∼1.5. The time dependence of the D> decrease is described by a hydrostatic healing law of the form ΔD = D>(t) − Df = A · e(−λ·t). The results of the laboratory experiments were compared to three natural fault systems, (1) Nojima Fault Zone (Japan), (2) fault zones in the Black Forest (Germany), and (3) Orobic Thrust (Italian Alps). Natural and experimental gouges have similar D> values. Healing is only observed in monomineralic aggregates; polymineralic (i.e., mixed) fault gouges retain their high D> value after extended healing times because grain growth is inhibited. Healing under nonhydrostatic conditions is more rapid than hydrostatic healing. The low strain rates, which were measured during nonhydrostatic healing, are temperature‐dependent and suggest that diffusive mass transfer processes take place during deformation. Thus, fault rocks at upper to midcrustal depth may deform by combined cataclasis and diffusive mass transfer.
Hyperspectral and multispectral ocean color inversions to detectPhaeocystis globosablooms in coastal waters
Authors: Lubac Bertrand , Loisel Hubert , Guiselin Natacha , Astoreca Rosa , Felipe Artigas L. , Mériaux Xavier
Published: June 2008

Identification of phytoplankton groups from space is essential to map and monitor algal blooms in coastal waters, but remains a challenge due to the presence of suspended sediments and dissolved organic matter which interfere with phytoplankton signal. On the basis of field measurements of remote sensing reflectance (Rrs(λ)), bio‐optical parameters, and phytoplankton cells enumerations, we assess the feasibility of using multispectral and hyperspectral approaches for detecting spring blooms ofPhaeocystis globosa(P. globosa). The two reflectance ratios (Rrs(490)/Rrs(510) andRrs(442.5)/Rrs(490)), used in the multispectral inversion, suggest that detection ofP. globosablooms are possible from current ocean color sensors. The effects of chlorophyll concentration, colored dissolved organic matter (CDOM), and particulate matter composition on the performance of this multispectral approach are investigated via sensitivity analysis. This analysis indicates that the development of a remote sensing algorithm, based on the values of these two ratios, should include information aboutCDOMconcentration. The hyperspectral inversion is based on the analysis of the second derivative ofRrs(λ) (dλ2Rrs). Two criteria, based on the position of the maxima and minima ofdλ2Rrs, are established to discriminate theP. globosablooms from diatoms blooms. We show that the position of these extremes is related to the specific absorption spectrum ofP. globosaand is significantly correlated with the relative biomass ofP. globosa. This result confirms the advantage of a hyperspectral over multispectral inversion for species identification and enumeration from satellite observations of ocean color.
How biogenic terpenes govern the correlation between sulfuric acid concentrations and new particle formation
Authors: Bonn B. , Kulmala M. , Riipinen I. , Sihto S.‐L. , Ruuskanen T. M.
Published: June 2008

New particle formation has been observed to take place all around the world. However, because of the inability to determine the chemical composition of the smallest clusters or particles, indirect tools such as the correlation between nucleation rate and measured sulfuric acid concentrations have been used to infer the nucleation mechanism. In this study we describe the observed correlation with gaseous sulfuric acid concentrations by interactions of sesquiterpene oxidation products with sulfuric acid. Two formation pathways of nucleation initiating molecules are considered. The interaction of sulfuric acid with organic sulfates, which are formed from stabilized Criegee intermediates (sCIs, formed from sesquiterpenes), can be used to explain the observed squared relationship between particle formation rate and ambient sulfuric acid concentrations. The corresponding linear dependence is explained with the participation of secondary ozonides, which are formed from sCIs and aldehydes. Both pathways are negatively affected by increasing water vapor concentration as observed in recent studies. In order to check the assumptions made we apply the derived nucleation coefficients to measurements of the BACCI/QUEST IV campaign made during spring 2005 in Hyytiälä, Finland. A reasonable agreement between the measurement data and the predicted nucleation rates is found, giving support for the presented nucleation description.