bluuebunny/crossref_metadata_2025 huggingface dataset:
Free energy calculation of water addition coupled to reduction of aqueous RuO4−
Authors: Tateyama Yoshitaka , Blumberger Jochen , Ohno Takahisa , Sprik Michiel
Published: May 2007

Free energy calculations were carried out for water addition coupled reduction of aqueous ruthenate, RuO4−+H2O+e−→[RuO3(OH)2]2−, using Car-Parrinello molecular dynamics simulations. The full reaction is divided into the reduction of the tetrahedral monoanion, RuO4−+e−→RuO42−, followed by water addition, RuO42−+H2O→[RuO3(OH)2]2−. The free energy of reduction is computed from the fluctuations of the vertical energy gap using the MnO4−+e−→MnO42− reaction as reference. The free energy for water addition is estimated using constrained molecular dynamics methods. While the description of this complex reaction, in principle, involves multiple reaction coordinates, we found that reversible transformation of the reactant into the product can be achieved by control of a single reaction coordinate consisting of a suitable linear combination of atomic distances. The free energy difference of the full reaction is computed to be −0.62eV relative to the normal hydrogen electrode. This is in good agreement with the experimental value of −0.59eV, lending further support to the hypothesis that, contrary to the ruthenate monoanion, the dianion is not tetrahedral but forms a trigonal-bipyramidal dihydroxo complex in aqueous solution. We construct an approximate two-dimensional free energy surface using the coupling parameter for reduction and the mechanical constraint for water addition as variables. Analyzing this surface we find that in the most favorable reaction pathway the reduction reaction precedes water addition. The latter takes place via the protonated complex [RuO3(OH)]− and subsequent transport of the created hydroxide ion to the fifth coordination site of Ru.
Simple synchronic detection at audio frequencies through a PC sound card
Authors: González Martín G. , Santiago Guillermo D. , Slezak Verónica B. , Peuriot Alejandro L.
Published: May 2007

We present a simple personal computer based, synchronic detection system that emulates a lock-in amplifier at audio frequencies. The inputs of the sound card are used to acquire two sets of samples: the one to be measured, previously preamplified, and the reference. From the last one, two “quasiorthogonal” signals are derived to perform dual-phase detection. The procedure is fast and compares favorably with a benchtop lock-in amplifier. In the band from 100Hzto20kHz we obtained average amplitude and phase errors below 1% and 0.1°, respectively.
Experimental and simulational study of the operation conditions for a high transmission mass filter
Authors: Ayesh A. I. , Lassesson A. , Brown S. A. , Dunbar A. D. F. , Kaufmann M. , Partridge J. G. , Reichel R. , van Lith J.
Published: May 2007

The operation conditions of a double pulsed field mass filter were studied using both experiment and simulation. The mass filter consists of two pairs of parallel plates and operates on the time-of-flight principle. The study showed that the ions’ beam deflection angle is a critical factor in optimizing the mass filter transmission efficiency. This angle is dependent on the accelerating voltage, ion mass, and horizontal velocity of the ions. The optimum operating conditions for the mass filter were found and used to study the mass distribution of palladium ions produced by a magnetron sputtering source. The study shows that this mass filter is suitable for technological applications because of its high transmission and wide mass range.
Phase-locked 10MHz reference signal for frequency domain time-resolved fluorescence measurements
Authors: Smith Trevor A. , Bird Damian K. , Nuske John W.
Published: May 2007

A complete electronic system that is suitable for use in megahertz frequency domain time-resolved fluorescence instruments based on mode-locked lasers is described. The circuit produces a 10MHz signal, phase locked to the mode-locked laser pulse frequency, which is required by many commercial frequency synthesizers as the external reference signal. This device is particularly useful in conjunction with ultrafast gated intensified charge coupled device cameras capable of being frequency modulated for time-resolved fluorescence imaging.
Strain and in-plane orientation effects on the ferroelectricity of (111)-oriented tetragonal Pb(Zr0.35Ti0.65)O3 thin films prepared by metal organic chemical vapor deposition
Authors: Kuwabara Hiroki , Menou Nicolas , Funakubo Hiroshi
Published: May 2007

The growth and characterization of epitaxial (111)-oriented Pb(Zr0.35Ti0.65)O3 films deposited by metal organic chemical vapor deposition on (100)-oriented silicon substrates [(111)SrRuO3‖(111)Pt‖(100)yttria-stabilizedzirconia‖(100)Si] are reported. The orientation, microstructure, and electric properties of these films are compared to those of fiber-textured highly (111)-oriented lead zirconate titanate (PZT) films deposited on (111)SrRuO3∕(111)Pt∕TiOx∕SiO2∕(100)Si substrates and epitaxial (111)-oriented PZT films deposited on (111)SrRuO3‖(111)SrTiO3 substrates. The ferroelectric properties of these films are not drastically influenced by the in-plane orientation of the film and by the strain state imposed by the underlying substrate. These results support the use of fiber-textured highly (111)-oriented films in highly stable ferroelectric capacitors.
Segregation and precipitation of Er in Ge
Authors: Kucheyev S. O. , Bradby J. E. , Ruffell S. , Li C. P. , Felter T. E. , Hamza A. V.
Published: May 2007

Although Er-doped Ge nanomaterials are attractive for photonic applications, very little is known about the basic properties of Er in Ge. Here, the authors study the annealing behavior of Ge implanted with keV Er ions to doses resulting in ≲1at.% of Er. Large redistribution of Er, with segregation at the amorphous/crystalline interface, starts at ≳500°C, while lower temperatures are required for material recrystallization. However, even at 400°C, Er forms precipitates. The concentration of Er trapped in the bulk after recrystallization decreases with increasing temperature but is independent of the initial bulk Er concentration for the range of ion doses studied here.
Dynamics of bound excitons versus thickness in freestanding GaN wafers grown by halide vapor phase epitaxy
Authors: Pozina G. , Hemmingsson C. , Bergman J. P. , Trinh D. , Hultman L. , Monemar B.
Published: May 2007

The bound exciton recombination properties in freestanding GaN layers of various thicknesses grown by halide vapor phase epitaxy have been characterized by time-resolved spectroscopy. Improvement of the donor bound exciton (D0X) lifetime was observed with increasing GaN layer thickness up to ∼400μm, while for thicker layers the recombination time of D0X shows a tendency to saturate. The thickness-dependent behavior of the D0X decay can be understood in terms of competition between two nonradiative mechanisms: one of which is connected to structural defects, and consequently more important for thinner layers, while for layers with thickness above 400μm with low structural defect density the recombination time is limited by point defects such as impurities and vacancies.
Domain ordering of strained 5 ML SrTiO3 films on Si(001)
Authors: Ryan P. , Wermeille D. , Kim J. W. , Woicik J. C. , Hellberg C. S. , Li H.
Published: May 2007

High resolution x-ray diffraction data indicate ordered square shaped coherent domains, ∼1200Å in length, coexisting with longer, ∼9500Å correlated regions in highly strained 5 ML SrTiO3 films grown on Si(001). These long range film structures are due to the Si substrate terraces defined by the surface step morphology. The silicon surface “step pattern” is comprised of an “intrinsic” terrace length from strain relaxation and a longer “extrinsic” interstep distance due to the surface miscut.
In vitro
high-resolution structural dynamics of single germinating bacterial spores
Authors: Plomp Marco , Leighton Terrance J. , Wheeler Katherine E. , Hill Haley D. , Malkin Alexander J.
Published: May 2007

Although significant progress has been achieved in understanding the genetic and biochemical bases of the spore germination process, the structural basis for breaking the dormant spore state remains poorly understood. We have used atomic force microscopy (AFM) to probe the high-resolution structural dynamics of single
Bacillus atrophaeus
spores germinating under native conditions. Here, we show that AFM can reveal previously unrecognized germination-induced alterations in spore coat architecture and topology as well as the disassembly of outer spore coat rodlet structures. These results and previous studies in other microorganisms suggest that the spore coat rodlets are structurally similar to amyloid fibrils. AFM analysis of the nascent surface of the emerging germ cell revealed a porous network of peptidoglycan fibers. The results are consistent with a honeycomb model structure for synthetic peptidoglycan oligomers determined by NMR. AFM is a promising experimental tool for investigating the morphogenesis of spore germination and cell wall peptidoglycan structure.
Transcription factor Sp4 regulates dendritic patterning during cerebellar maturation
Authors: Ramos Belén , Gaudillière Brice , Bonni Azad , Gill Grace
Published: May 2007

Integration of inputs by a neuron depends on dendritic arborization patterns. In mammals, the genetic programs that regulate dynamic remodeling of dendrites during development and in response to activity are incompletely understood. Here we report that knockdown of the transcription factor Sp4 led to an increased number of highly branched dendrites during maturation of cerebellar granule neurons in dissociated cultures and in cerebellar cortex. Time-course analysis revealed that depletion of Sp4 led to persistent generation of dendritic branches and a failure in resorption of transient dendrites. Depolarization induced a reduction in the number of dendrites, and knockdown of Sp4 blocked depolarization-induced remodeling. Furthermore, overexpression of Sp4 wild type, but not a mutant lacking the DNA-binding domain, was sufficient to promote dendritic pruning in nondepolarizing conditions. These findings indicate that the transcription factor Sp4 controls dendritic patterning during cerebellar development by limiting branch formation and promoting activity-dependent pruning.
A specific
c
-type cytochrome maturation system is required for oxygenic photosynthesis
Authors: Kuras Richard , Saint-Marcoux Denis , Wollman Francis-André , de Vitry Catherine
Published: May 2007

Oxygenic photosynthesis is an important bioenergetic process that maintains the Earth's atmosphere and allows carbon fixation. A critical enzyme in this process, the cytochrome
b
6
f
complex, differs from other protein complexes of the same family by an unusual covalently attached cofactor chemically defined as a
c′
heme. We have identified a set of pioneer proteins that carry the biogenesis of this
c′
heme and started their characterization. They are encoded by the genomes of all organisms performing oxygenic photosynthesis, whatever their phylogenetic distances. These proteins are thus among the few that distinguish photosynthetic cells evolving oxygen from other types of living cells.
p38 MAPK-dependent shaping of the keratin cytoskeleton in cultured cells
Authors: Wöll Stefan , Windoffer Reinhard , Leube Rudolf E.
Published: May 2007

Plasticity of the resilient keratin intermediate filament cytoskeleton is an important prerequisite for epithelial tissue homeostasis. Here, the contribution of stress-activated p38 MAPK to keratin network organization was examined in cultured cells. It was observed that phosphorylated p38 colocalized with keratin granules that were rapidly formed in response to orthovanadate. The same p38p recruitment was noted during mitosis, in various stress situations and in cells producing mutant keratins. In all these situations keratin 8 became phosphorylated on S73, a well-known p38 target site. To demonstrate that p38-dependent keratin phosphorylation determines keratin organization, p38 activity was pharmacologically and genetically modulated: up-regulation induced keratin granule formation, whereas down-regulation prevented keratin filament network disassembly. Furthermore, transient p38 inhibition also inhibited keratin filament precursor formation and mutant keratin granule dissolution. Collectively, the rapid and reversible effects of p38 activity on keratin phosphorylation and organization in diverse physiological, stress, and pathological situations identify p38-dependent signalling as a major intermediate filament–regulating pathway.
Negotiating Innovation in a Market Economy: Foodstuffs and Beverages Adulteration in Nineteenth-Century France
Authors: Stanziani Alessandro
Published: May 2007

In France, between 1870 and 1914, the business world was very concerned with the increase in “fraud” and “counterfeiting” in beverages and foodstuffs. This paper explores the origin and significance of this phenomenon. Three main products and markets are analyzed: wine, butter, and milk. On the basis of primary research, the paper contests the traditional interpretation according to which adulteration was linked to an increasing demand for food by low-income classes in highly imperfect markets. The paper adopts a radically different approach by questioning the way innovation is defined and perceived in a market economy: why is it common to speak of “innovation” for manufactures while evoking the term “adulteration” when food and drinks are concerned? The argument is that food and drink adulteration had its origins in technical progress (the introduction of chemistry into the food industry), urbanization, and the internationalization of the economy. As such, adulteration was a juridical category that was mobilized on occasions by economic lobbies in order to benefit from rents in the market, while continuously regulating innovation by agreement and compromise.One clear implication is that quality is not an objective, ahistorical category but that at different times different definitions of an item's quality compete with one another. It was only after the institutional and legal framework had been defined that social conventions and consumers' choices could take effect.
The Role of Pollution Regulation and Litigation in the Development of the U.S. Meatpacking Industry, 1865–1880
Authors: Rosen Christine Meisner
Published: May 2007

Business historians have treated the emergence of large, modern, vertically integrated meatpacking firms in the second half of the nineteenth century as the economically rational and inevitable product of the industry's search for ways to maximize profits through technological innovation, vertical integration, and the achievement of economies of scale and scope. This is only part of the story, however. Society's efforts to force the industry to abate its environmental pollution through government regulation and private lawsuits also stimulated and shaped these processes of modernization.
Evaluation of Compass as a comparative mapping tool for ESTs using horse radiation hybrid maps
Authors: Coleman S. J. , Gong G. , Gaile D. P. , Chowdhary B. P. , Bailey E. , Liu L. , MacLeod J. N.
Published: May 2007

Loci for 9322 equine expressed sequence tags (ESTs) were predicted using the Comparative Mapping by Annotation and Sequence Similarity (Compass) strategy in order to evaluate the programme's ability to make accurate locus predictions in species with comparative gene maps. Using human genome sequence information from Build 35 (May 2004) and published marker information from the radiation hybrid (RH) maps for equine chromosomes (ECA) 17 and X, 162 ESTs were predicted to locations on ECA17 and 328 ESTs to locations on ECAX by selection of the ‘top blast hit’. The locations of 30 ESTs were assessed experimentally by RH mapping analysis to evaluate the accuracy of the Compass predictions. The data revealed that 53% (16 of 30) of the ESTs predicted on ECA17 and ECAX mapped to those chromosomes. Analysis of the results suggested the need to identify expressed orthologous sequences in order to generate more accurate predictions for ESTs. Locus predictions were reassessed with three modifications to the Compass strategy's orthologue selection parameters. Selection of the ‘top gene hit’ improved accuracy to 72% (21 of 29), while selection of the ‘top expressed gene hit’ improved accuracy to 86% (24 of 28). Using the default Compass parameters with the UniGene database improved prediction accuracy to 96% (22 of 23); however, this level of accuracy came with a substantial decrease in the total number of predictions. When used with optimized prediction parameters, the Compass strategy can be a practical in silico map location prediction tool for large EST sample sets from unsequenced animal genomes.
AVO study of a gas‐hydrate deposit, offshore Costa Rica
Authors: Müller Christian , Bönnemann Christian , Neben Sönke
Published: May 2007

Amplitude variation with offset (AVO) analysis and waveform inversion are techniques used to determine qualitative or quantitative information on gas hydrates and free gas in sediments. However, the quantitative contribution of gas hydrates to the acoustic impedance contrast observed at the bottom‐simulating reflector and the reliability of quantitative AVO analyses are still topics of discussion. In this study, common‐midpoint gathers from multichannel wide‐angle reflection seismic data, acquired offshore Costa Rica, have been processed to preserve true amplitude information at the bottom‐simulating reflector for a quantitative AVO analysis incorporating angles of incidence of up to 60°. Corrections were applied for effects that significantly alter the observed amplitudes, such as the source directivity. AVO and rock‐physics modelling indicate that free gas immediately beneath the gas‐hydrate stability zone can be detected and low concentrations can be quantified from AVO analysis, whereas the offset‐dependent reflectivity is not sensitive to gas‐hydrate concentrations of less than about 10% at the base of the gas‐hydrate stability zone. Bulk free‐gas saturations up to 5% have been determined from the reflection seismic data assuming a homogeneous distribution of free gas in the sediment. Assuming a patchy distribution of free gas increases the estimated concentrations up to 14%.

There is a patchy occurrence of bottom‐simulating reflectors south‐east of the Nicoya Peninsula on the continental margin, offshore Costa Rica. AVO analysis indicates that this phenomenon is related to the local presence of free gas beneath the gas‐hydrate stability zone, probably related to a focused vertical fluid flow. In areas without bottom‐simulating reflectors, the results indicate that no free gas is present.
Phytogeographical data and modern pollen rain of the puna belt in southern Peru (Nevado Coropuna, Western Cordillera)
Authors: Kuentz Adèle , De Mera Antonio Galán , Ledru Marie‐Pierre , Thouret Jean‐Claude
Published: May 2007

Aim To improve knowledge of the distribution of species and modern pollen dispersal in the puna vegetation belt (central Andes) for palaeoenvironmental analysis and reconstructions.

Location Puna belt, Nevado Coropuna, Western Cordillera, Peru.

Methods The vegetation facies and belts of the area were mapped by remote sensing using a March 1998 SPOT4 image. This was complemented by the interpretation of aerial photographs, by field sampling, and by the identification of plants. Data from 1940 to 1994 from the Peruvian meteorological station network were modelled to characterize the relationship between climate and vegetation. Twenty‐four soil‐surface samples were collected in the various vegetation facies identified on the map, and standard palynological techniques were applied to analyse these samples. A principal components analysis was performed on the pollen data set.

Results The map shows three bioclimatic belts and seven facies in the punasensu lato, and identifies the main plants that are characteristic of each bioclimatic area. The pollen results fit the vegetation facies and belts, including the plant species of the distinct facies that are well represented in the pollen assemblages. The mesotropical belt is characterized by the predominance of Asteraceae‐typeAmbrosia; the supratropical belt shows significant frequencies of Asteraceae‐typeSenecio; the orotropical belt is characterized by high frequencies of Apiaceae and includesPolylepiswoodland and peat bogs; and the cryorotropical belt shows significant frequencies of Asteraceae‐typeSenecioand Apiaceae.

Main conclusions The pollen grains of the plants that grow on the punasensu latoare generally entomophilous and are therefore not transported far from their plant source. The distinct bioclimatic facies and belts identified by the cartography can thus be well distinguished by their pollen production and deposition. We were therefore able to characterize the relationship between pollen, vegetation and climate that can be used for palaeoenvironmental reconstructions. An altitudinal pollen gradient on the western slopes of the central Andes was revealed by the pollen study, with the succession of Asteraceae‐typeAmbrosia(1800–2200 m), Malvaceae (2700–3300 m), Asteraceae‐typeSenecio(3500–4100 m) and Apiaceae (above 4600 m).
Lymphoid cell proliferation in renal transplants: biologic and diagnostic implications
Authors: Akgun Hulya , Ozcan Ayhan , Chirala Mini , Zhai Jim , Shen Steven S. , Suki Wadi N. , Truong Luan D.
Published: May 2007

Abstract:  It is unclear whether alloreaction develops in peripheral lymphoid organs and effector cells being recruited to the target organs, or the entire process of alloreaction can happen within the transplanted kidneys. Interstitial inflammatory cell (IIC) proliferation was evaluated by MIB‐1 antigen immunostain and the rate expressed as positive cells/1000 cells. This rate was higher in acute cell‐mediated rejection (ACR) (25.7, n = 14) compared with normal kidney (0.4, n = 8), acute tubular necrosis (1.2, n = 8), chronic allograft nephropathy (CAN, 2.4, n = 20), and native kidneys with diverse diseases (9.2, n = 63); but was comparable to that in CAN with significant IIC (20.6, n = 16). 10.1% and 8.3% of T lymphocytes underwent proliferation in ACR with or without CAN, whereas only rare B lymphocytes or macrophages showed this change (<1.2%), regardless of diagnostic categories. All biopsies diagnosed as ACR in conjunction with a high rate of MIB‐1 + IIC and 9/12 biopsies with CAN and significant IIC in which ACR was diagnosed due to a high rate of MIB‐1 + IIC, responded to anti‐rejection therapy. Proliferation of IIC involves predominantly T lymphocytes. These observations provide support for the concept of in situ alloimmunization, and facilitate the diagnosis of ACR.
Early steroid withdrawal in solitary pancreas transplantation results in equivalent graft and patient survival compared with maintenance steroid therapy
Authors: Vessal Ghazal , Wiland Anne M. , Philosophe Benjamin , Fink Jeffrey C. , Weir Matthew R. , Klassen David K.
Published: May 2007

Abstract:  Although steroid withdrawal in simultaneous kidney pancreas transplantation has been shown to be feasible, the results of early steroid withdrawal in immunologically solitary pancreas transplantation are not well known. This study evaluated an early steroid withdrawal protocol in this group. The results of steroid withdrawal at 21 d post‐transplant in solitary pancreas transplant recipients was compared with a control group consisting of solitary pancreas transplant recipients maintained on steroids (MG). Additional immunosuppression consisted of rabbit anti‐thymocyte globulin induction followed by tacrolimus and mycophenolate mofetil in both groups. The withdrawal group (WG, n = 22) consisted of 11 pancreas transplant alone (PTA), six pancreas after kidney (PAK), and five simultaneous cadaveric pancreas living kidney (SPLK) recipients. The steroid maintenance group (MG, n = 32) consisted of 8 PTA, 11 PAK, and 13 SPLK recipients. Recipient and donor demographic characteristics were similar. Seventy eight percent of MG patients had infection‐related complications in the first year compared with 50% of the WG patients (p = 0.04). The one‐yr rejection, pancreas graft, and patient survival rates were 27.3% 95.5%, and 100% in the WG, and 37.5%, 81.3%, and 93.8% in the MG respectively and not significantly different. We conclude that early corticosteroid withdrawal in isolated pancreas transplantation results in fewer infections and can be achieved without an increased risk of rejection or graft loss over the first year.
Successful pediatric living donor liver transplantation from carrier to carrier of hereditary butyrylcholinesterase variant
Authors: Kawano Youichi , Mizuta Koichi , Hisikawa Shuji , Saito Takeshi , Egami Satoshi , Takatsuka Yuka , Sanada Yukihiro , Fujiwara Takehito , Yasuda Yoshikazu , Ohmori Masami , Sakamoto Koichi , Liu Weidong , Nishiguchi Shuhei , Hada Toshikazu , Kawarasaki Hideo
Published: May 2007

Abstract:  Hypocholinesterasemia is often observed clinically, especially in various liver diseases. Not well known, however, is the fact that some patients have a hereditary BChE variant. Little has been reported on liver transplants associated with this hereditary BChE variant. Furthermore, no cases have been reported of a LDLT involving hereditary BChE variant that had been diagnosed preoperatively. A 23‐month‐old girl who had had a failed Kasai operation for biliary atresia underwent a liver transplant using as a graft her father’s lateral segment. Preoperatively, she had been diagnosed with hypocholinesterasemia. As the donor, her father had undergone a preoperative examination, during which he was found to also have hypocholinesterasemia. DNA sequencing revealed that both had the hereditary BChE variant. The unique mutation caused a frame‐shift mutation. Variant K was also detected. The patient was discharged 143 days after the operation and has had no problems with immunosuppression since. In conclusion, we report that the hereditary BChE variant is not a contraindication for either transplantation or living liver donation.
Role of peroxisomes in the swift increase in alcohol metabolism
Authors: Bradford Blair U
Published: May 2007

The Swift Increase in Alcohol Metabolism occurs within 2.5 h after an acute gavage of ethanol causing an increase in hepatic respiration, an increase in alcohol metabolism, and pericentral hypoxia in the perfused liver. Alcohol treatment causes a release of endotoxin, activation of Kupffer cells to produce PGE2, therefore, stimulating mitochondrial function resulting in an increase in cofactor supply for nicotinamide adenine dinucleotide (NAD)‐dependent alcohol metabolism and depletion of glycogen reserves. Additionally, liberation of peripheral fatty acids via activation of an adrenergic response to alcohol provides added substrate for peroxisomes. In this study, rats were treatedin vivowith ethanol, methanol or oleate and basal rates of oxygen uptake in perfused liver were significantly increased as compared to untreated controls. Methanol (25 mmol/L), a selective substrate for catalase in rodents, was infused into the liver and rates of methanol metabolism were increased 3–4‐fold as compared to controls. Gadolinium chloride blocked the increase in oxygen and alcohol metabolism and inhibited the increase in ketogenesis normally observed after ethanol treatment. Excess fatty acids from oleate treatmentin vivoprovided additional substrate for peroxisomal alcohol metabolism and an increase in alcohol metabolism occurred even when Kupffer cells were eliminated. These data demonstrate that fatty acid supply either via peripheral reserves or after fatty acid treatment to peroxisomes generate sufficient H2O2for activation of catalase‐dependent alcohol metabolism.
Redox regulation of hepatocyte apoptosis
Authors: Garcia‐Ruiz Carmen , Fernández‐Checa José C
Published: May 2007

Cell death can be regulated by the sensitivity of proteins with a functional role in death pathways to redox environment. The antioxidant glutathione (GSH) regulates cell death pathways by modulating the redox state of specific thiol residues of target proteins including transcription factors, stress kinases and caspases, which participate in tumor necrosis factor (TNF)‐induced apoptosis. The TNF signals, upon its binding to its type 1 receptor, two simultaneous pathways with opposing functions, promoting cell survival through NF‐κB activation or cell death through mitochondria. As a consequence, hepatocytes are resistant to TNF unless the survival arm is neutralized, therefore, rendering hepatocytes sensitive to TNF. Cytosol GSH regulates TNF hepatocyte apoptosis by modulating caspase 8 activation or NF‐κB‐dependent gene expression. However, mitochondrial GSH controls hepatocyte susceptibility to TNF through modulation of reactive oxygen species, without inactivation of NF‐κB‐dependent survival pathways. So, understanding the role of mitochondrial reactive oxygen species in TNF‐induced hepatocyte death may have broad implications in the pathogenesis of acute and chronic liver diseases.
Genetic manipulation of sinusoidal endothelial cells
Authors: Takei Yoshiyuki , Maruyama Atsushi , Ikejima Kenichi , Enomoto Nobuyuki , Yamashina Shunhei , Lemasters John J , Sato Nobuhiro
Published: May 2007

Altered gene expression in liver sinusoidal endothelial cells (SEC) is associated with a variety of aspects of liver pathophysiology. It is, therefore, possible to envision a new therapeutic strategy for treatment of intractable liver diseases and achievement of graft‐specific immunotolerance through modulation of SEC functions by genetic engineering. The SEC possesses unique hyaluronan receptors that recognize and internalize hyaluronic acid (HA). This characteristic was used in the development of a system for targeting foreign DNA to SEC. A gene carrier system was prepared by coupling HA oligomers to poly L‐lysine (PLL) in a 1:1 weight ratio by reductive amination reaction. The resulting copolymer (PLL‐g‐HA) was mixed with various amounts of DNA in 154 mM NaCl. Inter‐polyelectrolyte complex formation between PLL‐g‐HA and DNA exhibited minimal self‐aggregation, explaining the highly soluble nature of the complex. Complex formation between PLL‐g‐HA and DNA was further assessed with a gel retardation assay. The titration point representing the minimum proportion of PLL‐g‐HA required to retard the DNA completely occurred at a 1:1 copolymer (based on PLL) to DNA charge ratio. Following intravenous injection of 32P‐labeled pSV β‐Gal plasmid complexed to PLL‐g‐HA in Wistar rats, >90% of the injected counts were shown to be taken up by the liver. Further, it was shown that the PLL‐g‐HA/DNA complex was distributed exclusively in the SEC. At 72 h after injection of 90 μg of pSV β‐Gal in a PLL‐g‐HA‐complexed form, a large number of SEC expressing β‐galactosidase were detected. So, the PLL‐g‐HA/DNA system permits targeted delivery of exogenous nucleotide agents selectively to the liver SEC, providing a novel strategy for manipulation of SEC functions.
Blockade of renin–angiotensin system in antifibrotic therapy
Authors: Yoshiji Hitoshi , Kuriyama Shigeki , Fukui Hiroshi
Published: May 2007

Recent studies have shown that the renin–angiotensin system (RAS) plays a pivotal role in liver fibrosis. An intrahepatic RAS is expressed in chronically damaged livers, and angiotensin‐II (AT‐II) reportedly stimulates contraction and proliferation of the activated hepatic stellate cells (Ac‐HSC), and increases the transforming growth factor‐β (TGF‐β) expression through angiotensin type‐I receptors (AT1‐R). Some studies have demonstrated that the clinically used angiotensin‐converting enzyme (ACE) inhibitor (ACE‐I), and AT1‐R blockers (ARB) significantly attenuated experimental liver fibrosis along with suppression of the Ac‐HSC and hepatic TGF‐β expression. Angiotensin‐II also stimulates the tissue inhibitor of metalloproteinases‐1 (TIMP‐1) in a dose‐ and time‐dependent manner via protein kinase‐C as an intracellular signaling cascade in the Ac‐HSC, and these effects are completely suppressed by ARB. Combination treatment with low‐dose interferon (IFN) and ACE‐I exerts a stronger inhibitory effect than either single agent on its own. In humans it has been reported that ARB markedly improved the liver fibrosis score and TGF‐β expression in patients with chronic hepatitis C and non‐alcoholic steatohepatitis. Serum fibrosis markers also significantly improved by treatment with low‐dose IFN and ACE‐I in patients with chronic hepatitis C, refractory to IFN monotherapy. Collectively, these data suggest that the interaction between AT‐II and AT1‐R plays a pivotal role in liver fibrosis development. Because both ACE‐I and ARB are widely used in clinical practice without serious side‐effects, these drugs in combination with IFN may provide a new strategy for antifibrosis therapy.
Fatal Malonyl CoA Decarboxylase Deficiency Due to Maternal Uniparental Isodisomy of the Telomeric End of Chromosome 16
Authors: Malvagia S. , Papi L. , Morrone A. , Donati M. A. , Ciani F. , Pasquini E. , La Marca G. , Scholte H. R. , Genuardi M. , Zammarchi E.
Published: May 2007

Malonic aciduria is a rare autosomal recessive disorder caused by deficiency of malonyl‐CoA decarboxylase, encoded by the MLYCD gene.

We report on a patient with clinical presentation in the neonatal period. Metabolic investigations led to a diagnosis of malonyl‐CoA decarboxylase deficiency, confirmed by decreased activity in cultured fibroblasts. High doses of carnitine and a diet low in lipids led to a reduction in malonic acid excretion, and to an improvement in his clinical conditions, but at the age of 4 months he died suddenly and unexpectedly. No autopsy was performed.

Molecular analysis of the MLYCD gene performed on the proband's RNA and genomic DNA identified a previously undescribed mutation (c.772–775delACTG) which was homozygous. This mutation was present in his mother but not in his father; paternity was confirmed by microsatellite analysis. A hypothesis of maternal uniparental disomy (UPD) was investigated using fourteen microsatellite markers on chromosome 16, and the results confirmed maternal UPD. Maternal isodisomy of the 16q24 region led to homozygosity for the MLYCD mutant allele, causing the patient's disease. These findings are relevant for genetic counselling of couples with a previously affected child, since the recurrence risk in future pregnancies is dramatically reduced by the finding of UPD. In addition, since the patient had none of the clinical manifestations previously associated with maternal UPD 16, this case provides no support for the existence of maternally imprinted genes on chromosome 16 with a major effect on phenotype.
Isolation and characterization of microsatellites in lane snapper (Lutjanus synagris), mutton snapper (Lutjanus analis), and yellowtail snapper (Ocyurus chrysurus)
Authors: RENSHAW MARK A. , KARLSSON STEN , GOLD JOHN R.
Published: May 2007

Polymerase chain reaction primer pairs for a total of 25 nuclear‐encoded microsatellites (loci) were developed from genomic DNA libraries of lane snapper (Lutjanus synagris), mutton snapper (Lutjanus analis), and yellowtail snapper (Ocyurus chrysurus). The microsatellites include 24 perfect (21 dinucleotide and three trinucleotide) and one imperfect (combination tetranucleotide/tetranucleotide) repeat motifs. A total of 32 individuals of each species were assayed for allelic variation at all 25 microsatellites; reliable amplification products were generated for lane snapper (25 loci), mutton snapper (21 loci), and yellowtail snapper (24 loci). Significant deviations from Hardy–Weinberg expectations, following Bonferroni corrections, were found for one microsatellite in lane and yellowtail snappers, and for three microsatellites in mutton snapper. All pairwise comparisons of microsatellites (all three species) did not deviate significantly from genotypic equilibrium.
Isolation and characterization of 17 polymorphic microsatellites in grass carp
Authors: LI JIA LE , ZHU ZE YUAN , WANG GUI LING , BAI ZHI YI , YUE GEN HUA
Published: May 2007

Here we report the isolation and characterization of 17 polymorphic loci isolated from a partial genomic DNA library of grass carp (Ctenopharyngodon idellus) enriched for CA repeats. We tested variability of these microsatellites on 24 unrelated individuals collected in China. All microsatellites were polymorphic. The average allele number was 7.9 per locus, ranging from four to 13. The observed heterozygosity was from 0.46 to 0.88 with an average of 0.71, whereas the average expected heterozygosity was 0.78. Sixteen of the 17 microsatellites conformed to Hardy–Weinberg equilibrium, and inherited independently. These microsatellites can be used to study genetic diversity and population structure of wild populations, and facilitate selective breeding of cultured broodstocks.
Characterization of 11 microsatellite loci derived from genomic sequences of polychaete Capitella capitata complex
Authors: DU HONGWEI , HAN JIE , LIN KUIXUAN , QU XIAOMING , WANG WEI
Published: May 2007

Eleven microsatellite loci derived from the genomic sequence data of Capitella capitata were characterized using 30 samples. The observed number of alleles per locus ranged from four to 36. The levels of observed and expected heterozygosities for polymorphic loci were from 0.10 to 0.87 and from 0.37 to 0.98, averaging 0.52 and 0.77, respectively. Analyses of Hardy–Weinberg equilibrium and genotypic linkage disequilibrium suggest the possible presence of both null alleles and Wahlund effect. One of the 11 loci was difficult to amplify for genotyping. Therefore, the rest 10 loci are good molecular markers for population genetic analysis.
Ageing and environmental factors affect PCR success in wolf (Canis lupus) excremental DNA samples
Authors: SANTINI ALBERTO , LUCCHINI VITTORIO , FABBRI ELENA , RANDI ETTORE
Published: May 2007

Individual genotypes determined from noninvasive DNA samples (typically extracted from shed hairs or scats) are used to estimate population size in monitoring projects of elusive species. However, polymerase chain reaction (PCR) success rates usually are lower, and genotyping errors higher than in standard population genetic surveys, due to DNA degradation or contamination in aged field samples. In this study, we evaluate the results of common garden experiments showing that DNA degradation is significant in wolf (Canis lupus) scats older than 3 days, and it is enhanced in scats in direct contact with soil. A storage test showed that samples kept frozen in 95% ethanol performed better compared to other methods. However, variance of PCR success among samples was high, independent on sample age or storage condition. The detrimental consequences of DNA degradation can be avoided by collecting scat samples as fresh as possible, and implementing efficient multitube procedures and stringent quality control of the laboratory results. Efficient multitube procedures can produce reliable data, like in this study, which showed that the consensus genotypes obtained from excremental DNA exactly matched distinct reference genotypes obtained from wolf blood samples.
‘M GLOW BLUE’: ARCHAEOMETRIC RESEARCH AT MICHIGAN'S FORD NUCLEAR REACTOR
Authors: MINC L. D. , SHERMAN R. J. , ELSON C. , SPENCER C. S. , REDMOND E. M.
Published: May 2007

The Ford Nuclear Reactor operated from 1957 to 2003 on the University of Michigan's North Campus in Ann Arbor, Michigan. Over its 45‐year lifespan, the facility played a key role in archaeometric research, fostering early methodological studies using INAA and supporting archaeological materials science investigations of lithics, ceramics, metals and bone. One small part of the FNR's abundant legacy was the initiation of trace‐element studies of Oaxacan ceramics, which are now beginning to shed light on early exchange interactions and the origin of the Monte Albán state in the Valley of Oaxaca, Mexico, between 500 bce and 200 ce.
Thresholds in Songbird Occurrence in Relation to Landscape Structure
Authors: BETTS MATTHEW G. , FORBES GRAHAM J. , DIAMOND ANTONY W.
Published: May 2007

Abstract:  Theory predicts the occurrence of threshold levels of habitat in landscapes, below which ecological processes change abruptly. Simulation models indicate that below critical thresholds, fragmentation of habitat influences patch occupancy by decreasing colonization rates and increasing rates of local extinction. Uncovering such putative relationships is important for understanding the demography of species and in developing sound conservation strategies. Using segmented logistic regression, we tested for thresholds in occurrence of 15 bird species as a function of the amount of suitable habitat at multiple scales (150–2000‐m radii). Suitable habitat was defined quantitatively based on previously derived, spatially explicit distribution models for each species. The occurrence of 10 out of 15 species was influenced by the amount of habitat at a landscape scale (≥500‐m radius). Of these species all but one were best predicted by threshold models. Six out of nine species exhibited asymptotic thresholds; the effects of habitat loss intensified at low amounts of habitat in a landscape. Landscape thresholds ranged from 8.6% habitat to 28.7% (

= 18.5 ± 2.6%[95% CI]). For two species landscape thresholds coincided with sensitivity to fragmentation; both species were more likely to occur in large patches, but only when the amount of habitat in a landscape was low. This supports the fragmentation threshold hypothesis. Nevertheless, the occurrence of most species appeared to be unaffected by fragmentation, regardless of the amount of habitat present at landscape extents. The thresholds we identified may be useful to managers in establishing conservation targets. Our results indicate that findings of landscape‐scale studies conducted in regions with relatively high proportions of habitat and low fragmentation may not be applicable in regions with low habitat proportions and high fragmentation.
Taiwan’s High Rate of Cesarean Births: Impacts of National Health Insurance and Fetal Gender Preference
Authors: Liu Tsai‐Ching , Chen Chin‐Shyan , Tsai Yi‐Wen , Lin Herng‐Ching
Published: May 2007

ABSTRACT:  Background:
Taiwan has a high rate of cesarean section, approximately 33 percent in the past decade. This study investigates and discusses 2 possible factors that may encourage the practice, one of which is fetal gender difference and the other is Taiwan’s recently implemented National Health Insurance (NHI).
Methods:
A logistic regression model was used with the 1989 and 1996 National Maternal and Infant Health Survey and with the 2001 to 2003 NHI Research Databases.
Results:
Using survey data, we found a statistically significant 0.3 percent gender difference in parental choice for cesarean section. However, no statistically significant difference was found in the rate of cesarean section before and after NHI implementation.
Conclusions:
Taiwan’s high cesarean section rate is not directly related to financial incentives under NHI, indicating that adjusting policy to lower financial incentives from NHI would have only limited effect. Likewise, focusing effort on the small gender difference is unlikely to have much impact. Effective campaigns by health authorities might be conducted to educate the general population about risks associated with cesarean section and the benefits of vaginal birth to the child, mother, and society. (BIRTH 34:2 June 2007)
Can Transesophageal Pulse‐Wave Tissue Doppler Imaging Be Used to Evaluate Left Ventricular Function?
Authors: Sevimli Serdar , Arslan Sakir , Gundogdu Fuat , Aksakal Enbiya , Buyukkaya Eyup , Tas Hakan , Islamoglu Yahya , Gurlertop H. Yekta , Erol Mustafa Kemal , Acikel Mahmut , Senocak Huseyin , Karakelleoglu Sule , Alp Necip
Published: May 2007

Background: This study aimed to evaluate the efficiency of transesophageal tissue Doppler echocardiography (TDE) in evaluation of the left ventricular functions. To this end, the data obtained by transoesophageal tissue Doppler echocardiography and by transthoracic tissue Doppler echocardiography were compared simultaneously. Methods: Nineteen consecutive patients (7 female and 12 male) underwent a clinically indicated study. In transthoracic (TTE) and transoesophageal (TEE) echocardiographic study, a Vingmed System Five Doppler echocardiographic unit (GE Vingmed) was used. For the assessment of the left ventricular function using transthoracic and transoesophageal TDE, the mitral annular peak systolic (S), early diastolic (E), late diastolic velocities (A), late to early velocity ratio (E/A), deceleration times (DT), left ventricular isovolumetric relaxation times (IVRT) were measured at the lateral, medial, anterior, and posterior corners at the mitral annulus by activating TDE mode in the transthoracic and transoesophageal apical four‐ and two‐chamber view. Bland–Altman plots were used to compare the two measurement techniques. The differences between the groups were assessed by Mann–Whitney U test. All the data were expressed as mean ± SD. A P‐value of <0.05 was considered significant. Results: There were no significant differences between two techniques in terms of blood pressure and heart rate. Two techniques were compared for the transthoracic and transoesophageal TDE parameters. Bland–Altman analysis showed comparable values for E, A, E/A, S, and mE/E, although the measurements of DT and IVRT were different. Conclusion: PW tissue Doppler echocardiographic approach during TEE may be suitable for assessment of the left ventricular function.
Left Ventricular Response to Exercise in Aortic Stenosis: An Exercise Echocardiographic Study
Authors: Maréchaux Sylvestre , Ennezat Pierre‐Vladimir , LeJemtel Thierry H. , Polge Anne‐Sophie , Groote Pascal de , Asseman Philippe , Nevière Rémi , Le Tourneau Thierry , Deklunder Ghislaine
Published: May 2007

Background: While normal at rest, left ventricular (LV) systolic function may become abnormal during exercise in patients with aortic stenosis. Once contraindicated in patients with aortic stenosis, exercise testing is now recommended in asymptomatic patients with aortic stenosis to elicit symptoms and thereby ascertain the need for aortic valve replacement. However, the clinical significance of an abnormal LV response to exercise in asymptomatic patients with aortic stenosis remains unknown.
Objective: The aim of this study was to evaluate the clinical implications of an abnormal LV response during exercise in the setting of aortic stenosis.
Methods: We monitored the LV response to exercise by 2D‐Doppler echocardiography during a symptom limited semirecumbent bicycle exercise in 50 patients with tight aortic stenosis (aortic valve area ≤ 1.0 cm2) and a normal LV systolic function (LV ejection fraction, EF ≥ 50%) and followed them for an average of 11 months.
Results: Twenty patients had an abnormal LV response to exercise with a mean decrease in LV EF from 64 ± 10 to 53 ± 12% while 30 patients had a normal LV response to exercise with a mean increase in LV EF from 62 ± 7 to 70 ± 8%. Patients with an abnormal LV response during exercise were more likely to develop symptoms during exercise than patients with a normal LV response: 80% versus 27% (P
< 0.0001). The survival free of cardiac events was significantly lower in patients with abnormal LV response to exercise than in patients with a normal response (P = 0.03).
Conclusion: Exercise echocardiography provides objective data that facilitate interpretation of exercise elicited symptoms in asymptomatic patients with severe aortic stenosis. In addition, an abnormal LV response to exercise may predict a poor outcome.