bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of Small Concentrations of Gadolinium in Ceria (CeO2) and Magnesia (MgO) Using Electron Magnetic Resonance
Authors: De Biasi Ronaldo S. , Grillo Maria L. N.
Published: September 2008

Electron magnetic resonance linewidths of Gd3+in ceria and magnesia were measured in samples doped with small concentrations (up to 1.0 mol%) of Gd. The linewidth was found to change in a predictable way with Gd concentration. The experimental results show that the technique can be used to measure, rapidly and nondestructively, small concentrations of Gd in commercial CeO2and MgO.
Dielectric Constant of Barium Titanate Powders Near Curie Temperature
Authors: Petrovsky Vladimir , Petrovsky Tatiana , Kamlapurkar Swetha , Dogan Fatih
Published: September 2008

Impedance spectroscopy is an effective method to investigate the dielectric properties of powders by dispersing particles in proper liquids. It allows reliable calculation of the dielectric constant by analysis of impedance spectra for a variety of particulate materials. The temperature dependence of the dielectric constant near the Curie temperature was investigated for hydrothermal barium titanate powders suspended in ethylene glycol or butoxyethanol. Room‐temperature measurements revealed that the dielectric constant of hydrothermal BaTiO3 powders was ɛ∼500. After annealing of powders at 1250°C for 1 h, the dielectric constant increased to ɛ∼3000. The temperature dependence of the impedance spectra was determined by conducting measurements within the temperature range from 20° to 150°C. It was shown that hydrothermal BaTiO3 powders with a primarily cubic crystal structure had a suppressed temperature dependence of the dielectric constant near the Curie temperature. The dielectric constant of annealed powders with a tetragonal crystal structure was significantly higher at the Curie temperature similar to the values obtained for sintered bulk barium titanate.
Room‐Temperature Synthesis of BaTiO3 Nanoparticles in Large Batches
Authors: Wei Xiao , Xu Gang , Ren Zhaohui , Shen Ge , Han Gaorong
Published: September 2008

A new method has been developed to synthesize barium titanate (BaTiO3) nanoparticles with a narrow size distribution under ambient conditions at room temperature. The as‐prepared BaTiO3 nanoparticles were characterized by X‐ray diffraction, transmission electron microscopy, high‐resolution TEM, and selected area electron diffraction. On the basis of the characterizations, it was found that the particle size could be easily tuned by adjusting the experimental parameters, such as the solvent component and reaction time. The basicity of the organic solvent was considered to play an important role in the room‐temperature synthesis and the solvent molecules had a strong influence on the crystal growth of BaTiO3 nanoparticles. The BaTiO3 nanoparticles obtained were well dispersed and possessed a cubic perovskite structure at room temperature.
Phase Transition and Electrical Properties of Li‐and Ta‐Substituted (Na0.52K0.48)(Nb0.96Sb0.04)O3Piezoelectric Ceramics
Authors: Fu Jian , Zuo Ruzhong , Wu Yuping , Xu Zhengkui , Li Longtu
Published: September 2008

Lead‐free (Na0.52K0.48−x)(Nb0.96−xSb0.04)O3–xLiTaO3ceramics (x=0.0375–0.0575) have been manufactured by a conventional solid‐state method. All compositions form solid solutions with a pure perovskite structure. A morphotropic phase boundary (MPB) between orthorhombic (x≤0.04) and tetragonal (x≥0.045) ferroelectric phases was identified in the composition range of the 0.04<x<0.045. The composition near the MPB (x=0.0425) exhibits the best electrical properties with a dielectric constant of 1644, a piezoelectric constant of 310 pC/N, a planar‐mode electromechanical coupling factor of 0.48, and a Curie temperature of 340°C. The results indicate that the materials studied could be a promising lead‐free piezoelectric candidate for device applications.
Preliminary Insights into the Constitution of a Tibetan Buddhist Monastery through Autoethnographic Reflections on the Dual/Nondual Mind Duality
Authors: BRUMMANS BORIS H. J. M.
Published: September 2008

In this autoethnographic essay, I reflect on my brief personal experiences of conducting field research on ways in which way a small group of Tibetan Buddhist monks enact a monastic total institution in Ladakh, India. More specifically, I analyze my experiences in view of the relationship between dual and nondual mind, as discussed byHenry Vyner (2002)in Anthropology of Consciousness, and use this analysis to develop preliminary insights into the ways in which a Tibetan Buddhist monastery is constituted.
Thin Layer Chromatography/Fluorescence Detection of 3,4‐Methylenedioxy‐Methamphetamine and Related Compounds
Authors: Kato Noriyuki , Fujita Susumu , Ohta Hikoto , Fukuba Makoto , Toriba Akira , Hayakawa Kazuichi
Published: September 2008

Abstract:  A rapid and sensitive method for the detection of six methylenedioxylatedphenethylamines, 3,4‐methylenedioxymethamphetamine (MDMA); 3,4‐methylenedioxyamphetamine; 3,4‐methylenedioxyethylamphetamine; N‐methyl‐1‐(3,4‐methylenedioxyphenyl)‐2‐butamine; N‐methyl‐1‐(3,4‐methylenedioxyphenyl)‐3‐butamine; and 3,4‐methylenedioxydimethylamphetamine, by thin‐layer chromatography with fluorescence detection is proposed. These compounds form fluorophores on the developing plate following spraying with a reagent consisting of sodium hypochlorite, potassium hexacyanoferrate (III), and sodium hydroxide, and heating for 3 min at 100°C. Blue fluorescent spots were observed under ultraviolet light in a wavelength range of 250–400 nm. The detection limits for MDMA and the above related compounds were 50 ng. The proposed method was effectively applied to the detection of MDMA in urine samples.
Toward a Quantitative Typology of Burglars: A Latent Profile Analysis of Career Offenders
Authors: Vaughn Michael G. , DeLisi Matt , Beaver Kevin M. , Howard Matthew O.
Published: September 2008

Abstract:  Burglary is a serious, costly, and prevalent crime but prior typologies of burglars are mostly speculative and based on qualitative data. Using a sample of 456 adult career criminals, the current study used latent profile analysis to construct a methodologically rigorous quantitative typology. Four classes of burglars emerged: young versatile, vagrant, drug‐oriented, and sexual predators. All groups demonstrated significant involvement in varied forms of crime, but the sexual predator group was the most violent and had the most serious criminal careers. Connections to the criminal career literature are offered and suggestions for further empirical study of offender typologies are discussed.
Variability of Bodily Measures of Normally Dressed People Using PhotoModeler® Pro 5*
Authors: Larsen Peter K. , Hansen Lone , Simonsen Erik B. , Lynnerup Niels
Published: September 2008

Abstract:  Photogrammetry is used in forensic science to help identify perpetrators from crime scenes by way of surveillance video, but the reproducibility of manually locating hidden body‐points such as the joints remains to be established. In this study, we quantified the inter‐ and intra‐observer variability of bodily measures of clothed individuals in two different poses and examined whether body segment lengths could be used to distinguish between people of similar stature. Stature was reproduced within ±1.5 cm in both the intra‐ and inter‐observer study. Segment lengths were best reproduced when flexion in the joints was present in the intra‐observer study, but only the length of the trunk could be used to distinguish between people of similar height. The reproducibility between the two poses was low. Other measures than stature should be used with caution and with the perpetrator and suspect in the same pose. Consistent guidelines for locating body‐points should be developed.
Structural Analysis of Human Rib Fracture and Implications for Forensic Interpretation*
Authors: Daegling David J. , Warren Michael W. , Hotzman Jennifer L. , Self Casey J.
Published: September 2008

Abstract:  Patterns of rib fractures are of significant clinical and forensic interest. Linking patterns of rib fracture with specific physical events provides a foundation for understanding the nature of traumatic events that are associated with rib fracture in forensic contexts. In this study, isolated human ribs (n = 8) were end‐loaded to failure to investigate: (i) local deformations (bone strain) prior to and during structural failure, (ii) location of ultimate failure, and (iii) fracture mode. Structural properties of ribs were used to calculate theoretical stresses to determine whether such calculations could be used to predict site of fracture. Ribs fractured on the sternal side of midshaft in all experiments, but mode of failure varied with transverse, buckle, spiral, and “butterfly” fractures observed. Comparison of calculated stress with observed strain values suggest that experimental, rather than theoretical, approaches will be most productive in furthering understanding rib fracture in forensic contexts.
The ubiquitin C‐terminal hydrolase UCH‐L1 regulates B‐cell proliferation and integrin activation
Authors: Rolén Ulrika , Freda Elio , Xie Jianjun , Pfirrmann Thorsten , Frisan Teresa , Masucci Maria G.
Published: September 2008

The ubiquitin C‐terminal hydrolase‐L1 (UCH‐L1) is a deubiquitinating enzyme that catalyses the hydrolysis of polyubiquitin precursors and small ubiquitin adducts. UCH‐L1 has been detected in a variety of malignant and metastatic tumours but its biological function in these cells is unknown. We have previously shown that UCH‐L1 is highly expressed in Burkitt’s lymphoma (BL) and is up‐regulated upon infection of B lymphocytes with Epstein–Barr virus (EBV). Here we show that knockdown of UCH‐L1 by RNAi inhibits the proliferation of BL cells in suspension and semisolid agar and activates strong LFA‐1‐dependent homotypic adhesion. Induction of cell adhesion correlated with cation‐induced binding to ICAM‐1, clustering of LFA‐1 into lipid rafts and constitutive activation of the Rap1 and Rac1 GTPases. Expression of a catalytically active UCH‐L1 promoted the proliferation of a UCH‐L1‐negative EBV transformed lymphoblastoid cell line (LCL) and inhibited cell adhesion, whereas a catalytic mutant had no effect, confirming the requirement of UCH‐L1 enzymatic activity for the regulation of these phenotypes. Our results identify UCH‐L1 as a new player in the signalling pathways that promote the proliferation and invasive capacity of malignant B cells.
Functional and histopathological improvement of the post‐infarcted rat heart upon myoblast cell grafting and relaxin therapy
Authors: Bonacchi Massimo , Nistri Silvia , Nanni Cristina , Gelsomino Sandro , Pini Alessandro , Cinci Lorenzo , Maiani Massimo , Zecchi‐Orlandini Sandra , Lorusso Roberto , Fanti Stefano , Silvertown Josh , Bani Daniele
Published: September 2008

Although the myocardium contains progenitor cells potentially capable of regenerating tissue upon lethal ischaemic injury, their actual role in post‐infarction heart healing is negligible. Therefore, transplantation of extra‐cardiac stem cells is a promising therapeutic approach for post‐infarction heart dysfunction. Paracrine cardiotropic factors released by the grafted cells, such as the cardiotropic hormone relaxin (RLX), may beneficially influence remodelling of recipient hearts. The current study was designed to address whether grafting of mouse C2C12 myoblasts, genetically engineered to express green fluorescent protein (C2C12/GFP) or GFP and RLX (C2C12/RLX), are capable of improving long‐term heart remodelling in a rat model of surgically induced chronic myocardial infarction. One month after myocardial infarction, rats were treated with either culture medium (controls), or C2C12/GFP cells, or C2C12/RLX cells plus exogenous RLX, or exogenous RLX alone. The therapeutic effects were monitored for 2 further months. Cell transplantation and exogenous RLX improved the main echocardiographic parameters of cardiac function, increased myocardial viability (assessed by positron emission tomography), decreased cardiac sclerosis and myocardial cell apoptosis and increased microvascular density in the post‐infarction scar tissue. These effects were maximal upon treatment with C2C12/RLX plus exogenous RLX. These functional and histopathological findings provide further experimental evidence that myoblast cell grafting can improve myocardial performance and survival during post‐infarction heart remodelling and dysfunction. Further, this study provides a proof‐of‐principle to the novel concept that genetically engineered grafted cells can be effectively employed as cell‐based vehicles for the local delivery of therapeutic cardiotropic substances, such as RLX, capable of improving adverse heart remodelling.
Complexity of complement activation in sepsis
Authors: Markiewski Maciej M. , DeAngelis Robert A. , Lambris John D.
Published: September 2008

Introduction

Sepsis – terminology and basic facts

The pathways of complement activation

The role of the complement system in the pathogenesis of sepsis

Aetiology‐dependent mechanisms of complement activation in sepsis

Sepsis‐associated coagulopathy and complement activation

Concluding remarks

The complement system is one of the key players in the defence against infections. Its activation during the innate immune response leads to the generation of several proteins that contribute to the lysis and opsonization of microorganisms, regulate inflammatory reactions and bridge innate immunity with the subsequent adaptive immune response. Complement is also activated in overwhelming bacterial infections that lead to sepsis, and its protective functions play a role in this frequently lethal disorder. However, despite its role in protection, complement can also contribute to the development of severe complications that significantly worsen the prognosis of septic patients. Therefore, an understanding of the mechanisms involved in the activation of complement during sepsis is essential to our efforts to introduce rational therapies targeting complement to the treatment of patients suffering from this condition. This review presents a current view of the mechanisms involved in the activation of complement in sepsis, in the context of the multiple interactions between complement and other biological systems that are involved in the pathogenesis of this disorder.
Isolation of a novel basic FGF‐binding peptide with potent antiangiogenetic activity
Authors: Wu Xiaoping , Yan Qiuxia , Huang Yadong , Huang Huixian , Su Zhijian , Xiao Jian , Zeng Yaoying , Wang Yi , Nie Changjun , Yang Yongguang , Li Xiaokun
Published: September 2008

Basic fibroblast growth factor (bFGF), which plays an important role in tumour angiogenesis and progression, provides a potential target for cancer therapy. Here we screened a phage display heptapeptide library with bFGF and identified 11 specific bFGF‐binding phage clones. Two of these clones had identical sequence and the corresponding peptide (referred to as P7) showed high homology to the immunoglobulin‐like (Ig‐like) domain III (D3) of high‐affinity bFGF receptors, FGFR1 (IIIc) and FGFR2 (IIIc). The P7 peptide and its corresponding motif in D3 of FGFRs both carried negative charges and shared similar hydrophobic profiles. Functional analysis demonstrated that synthetic P7 peptides mediate strong inhibition of bFGF‐induced cell proliferation and neovascularization. Our results demonstrate that the P7 peptide is a potent bFGF antagonist with strong antiangiogenetic activity, and might have therapeutic potential in cancer therapy.
Does cannabis use lead to depression and suicidal behaviours? A population‐based longitudinal study
Authors: Pedersen W.
Published: September 2008

Objective: This study investigates the relationship between cannabis use and later depression, suicidal ideation and suicide attempts in a cohort of young Norwegians.

Method: Data were gathered through theYoung in Norway longitudinal study, in which a population‐based sample of 2033 Norwegians were followed up over a 13‐year period, from their early teens to their late twenties. Data were gathered on: (a) exposure to cannabis use; and (b) depression, suicide ideation and suicide attempts. In addition, information about possible confounding factors was included.

Results: In early adolescence, no associations with later depression or suicidal behaviours were observed. In the sample’s twenties, we observed highly significant associations with suicide ideation and suicide attempts. When adjusting for confounders, the OR was 2.9 (95% CI 1.3–6.1) for later suicide attempts in the group who had used cannabis 11+ times during the past 12 months.

Conclusion: The findings suggest that exposure to cannabis by itself does not lead to depression but that it may be associated with later suicidal thoughts and attempts.
The melatonin receptor MT1 is required for the differential regulatory actions of melatonin on neuronal ‘clock’ gene expression in striatal neurons in vitro
Authors: Imbesi Marta , Arslan Ahmet Dirim , Yildiz Sevim , Sharma Rajiv , Gavin David , Tun Nguwah , Manev Hari , Uz Tolga
Published: September 2008

Abstract:  Through inhibitory G protein‐coupled melatonin receptors, melatonin regulates intracellular signaling systems and also the transcriptional activity of certain genes. Clock genes are proposed as regulatory factors in forming dopamine‐related behaviors and mood and melatonin has the ability to regulate these processes. Melatonin‐mediated changes in clock gene expression have been reported in brain regions, including the striatum, that are crucial for the development of dopaminergic behaviors and mood. However, it is not known whether melatonin receptors present in striatum mediate these effects. Therefore, we investigated the role of the melatonin/melatonin receptor system on clock gene expression using a model of primary neuronal cultures prepared from striatum. We found that melatonin at the receptor affinity range (i.e., nm) affects the expression of the clock genes mPer1, mClock, mBmal1 and mNPAS2 (neuronal PAS domain protein 2) differentially in a pertussis toxin‐sensitive manner: a decrease in Per1 and Clock, an increase in NPAS2 and no change in Bmal1 expression. Furthermore, mutating MT1 melatonin receptor (i.e., MT1 knockouts, MT1−/−) reversed melatonin‐induced changes, indicating the involvement of MT1 receptor in the regulatory action of melatonin on neuronal clock gene expression. Therefore, by controlling clock gene expression we propose melatonin receptors (i.e., MT1) as novel therapeutic targets for the pathobiologies of dopamine‐related behaviors and mood.
Stress‐Induced Analgesia and Morphine Responses Are Changed in Catechol‐O‐methyltransferase‐Deficient Male Mice
Authors: Kambur Oleg , Männistö Pekka T. , Viljakka Kaarin , Reenilä Ilkka , Lemberg Kim , Kontinen Vesa K. , Karayiorgou Maria , Gogos Joseph A. , Kalso Eija
Published: September 2008

Abstract: Catechol‐O‐methyltransferase (COMT) polymorphisms modulate pain and opioid analgesia in human beings. It is not clear how the effects of COMT are mediated and only few relevant animal studies have been performed. Here, we used old maleComtgene knock‐out mice as an animal model to study the effects of COMT deficiency on nociception that was assessed by the hot plate and tail flick tests. Stress‐induced analgesia was achieved by forced swim. Morphine antinociception was measured after 10 mg/kg of morphine subcutaneously. Morphine tolerance was produced with subcutaneous morphine pellets and withdrawal provoked with subcutaneous naloxone. In the hot plate test, morphine‐induced antinociception was significantly greater in the COMT knock‐out mice, compared to the wild‐type mice. This may be due to increased availability of opioid receptors as suggested by previous human studies. In the tail flick test, opioid‐mediated stress‐induced analgesia was absent and morphine‐induced analgesia was decreased in COMT knock‐out mice. In the hot plate test, stress‐induced analgesia developed to all mice regardless of the COMT genotype. There were no differences between the genotypes in the baseline nociceptive thresholds, morphine tolerance and withdrawal. Our findings show, for the first time, the importance of COMT activity in stress‐ and morphine‐induced analgesia in mice. COMT activity seems to take part in the modulation of nociception not only in the brain, as suggested earlier, but also at the spinal/peripheral level.
In vivo Reversal of P‐Glycoprotein‐Mediated Multidrug Resistance by Efficient Delivery of StealthTM RNAi
Authors: Xiao Hong , Wu Zhuo , Shen Hong , Luo Ai‐Lan , Yang Yu‐Fei , Li Xiao‐Bo , Zhu Dong‐Ya
Published: September 2008

Abstract:  P‐Glycoprotein‐mediated multidrug resistance (MDR) is a major hurdle in cancer therapy. P‐Glycoprotein is a 170 KD protein encoded by the MDR1 gene. Over‐expression of P‐glycoprotein is considered one of the characteristics of the MDR phenotype, thus down‐regulation of the MDR1 gene expression will circumvent MDR partly. RNA interference (RNAi) is a process that can result in sequence‐specific gene silencing by cleavage target mRNA. Electroporation has been demonstrated to be a promising and efficient method for gene delivery and has been successfully applied in gene therapy. In our study, by using electric pulse to delivery StealthTM RNAi into nude mice NCI‐H460 tumour xenografts, we successfully inhibited MDR1 both at the mRNA level as determined by reverse transcription–polymerase chain reaction and at the protein level as determined by immunohistochemistry. Furthermore, by administration of navelbine after transfection with StealthTM RNAi targeted on the MDR1 gene, its depression to tumour xenografts dramatically improved by nine times. These studies demonstrate that through electrotransfection of StealthTM RNAi, P‐glycoprotein‐mediated MDR can be reversed.
Cross‐species tests of 45 microsatellite loci isolated from different species of ungulates in the Iberian red deer (Cervus elaphus hispanicus) to generate a multiplex panel
Authors: SANCHEZ‐FERNANDEZ B. , SORIGUER R. , RICO C.
Published: September 2008

The Iberian red deer (Cervus elaphus hispanicus) is an emblematic game species in Spain. To generate a battery of polymorphic markers for multiplex polymerase chain reactions for the Spanish red deer, 45 loci isolated in different species of ungulates were tested. Of the primers tested, 27 amplified but only 21 were polymorphic. Eleven of these markers were subsequently optimized for multiplex in four polymerase chain reactions. This allows analysing several molecular markers jointly to substantially reduce costs. Finally, we report descriptive summary statistics such as number of alleles for the former and also test of disequilibria and heterozygosity for the latter.
Characterization of eight microsatellite markers in the white sea bream, Diplodus sargus (Teleostei, Sparidae)
Authors: PÉREZ L. , INFANTE C. , PONCE M. , CRESPO A. , ZUASTI E. , FUNES V. , CATANESE G. , MANCHADO M.
Published: September 2008

The white sea bream, Diplodus sargus (Teleostei, Sparidae), is a species with a high commercial importance in Mediterranean aquaculture. There is currently little information available about the genetic characteristics of cultured populations. In this survey, we have developed eight polymorphic microsatellites for the white sea bream using an enriched genome library protocol. All of them were polymorphic in the 67 individuals tested, 32 of which were wild specimens, and 35 were individuals from a captive F1 broodstock. These markers can potentially be useful tools for use in population genetic studies.
Isolation and characterization of nine microsatellite markers for Brachypodium sylvaticum (Huds.) Beauv., a recently invasive grass species in Oregon
Authors: RAMAKRISHNAN ALISA P. , ROSENTHAL DAVID M. , MUSIAL TRIESTE , CRUZAN MITCHELL B.
Published: September 2008

The patterns of genetic diversity caused by rapid range expansions following recent colonizations are best observed using highly polymorphic genetic markers. We characterized nine microsatellite markers for Brachypodium sylvaticum, a bunchgrass invasive in the Northwestern United States and native to Eurasia. Loci exhibited from two to 10 alleles, and generally had high FIS values. These loci will help identify sources of new populations in the region, and they will be useful for studying patterns of genetic diversity during rapid range expansions.
Polymerase chain reaction‐based detection of Fusarium circinatum, the causal agent of pitch canker disease
Authors: RAMSFIELD T. D. , DOBBIE K. , DICK M. A. , BALL R. D.
Published: September 2008

Pitch canker is a highly damaging disease of Pinus radiata and the New Zealand forest industry is concerned by the potential impact of the disease, should it arrive, in New Zealand. To provide a rapid identification technique for this pathogen, a polymerase chain reaction‐based diagnostic method has been developed. The method is able to detect the presence of the pathogen within infected host tissue, as well as infested soil and the reliability of the test has been estimated using Bayesian statistics.
Eight polymorphic microsatellite markers developed in the Chinese scorpion, Mesobuthus martensii (Scorpiones: Buthidae)
Authors: JI YA‐JIE , LENG LIANG , SHI CHENG‐MIN , HUA YUE‐PING , ZHANG DE‐XING
Published: September 2008

Eight polymorphic di‐ and trinucleotide microsatellite loci were developed in the Chinese scorpion, Mesobuthus martensii. The expected heterozygosity at these loci ranges from 0.019 to 0.860, with the observed allele numbers varying from two to 25. Overall, there were no deviations from Hardy–Weinberg equilibrium and no observed linkage disequilibrium after Bonferroni correction. Cross‐species amplification of these loci in Mesobuthus eupeus revealed that five loci can amplify successfully in this species. The polymorphic microsatellite DNA markers reported here should provide helpful means to address questions concerning phylogeographical patterns and evolutionary history of M. martensii and closely related species.
The D4 set: primers that target highly variable intron loops in plant chloroplast genomes
Authors: WATTS CHAD D. , FISHER AMANDA E. , SHRUM CELENA D. , NEWBOLD WENDY L. , HANSEN SHANNALEE , LIU CHANG , KELCHNER SCOT A.
Published: September 2008

Chloroplast group II introns offer high‐quality, rapidly evolving single‐copy loci for comparative sequence analysis. These introns feature diagnostic secondary structures with loops that are among the least evolutionarily constrained sequence in plastomes. We exploited these structures to develop universal primers that amplify and sequence the large Domain IV (D4) loop in several angiosperm introns. With a single sequence read, we recover 300–600 nucleotides of highly variable sequence across angiosperms, with rates of change that are equal to or higher than many of the best known intergenic spacers in plant chloroplast genomes.
Characterization of microsatellite loci for the littorine snail Bembicium vittatum
Authors: KENNINGTON W. J. , LUKEHURST S. S. , JOHNSON M. S.
Published: September 2008

We describe the isolation and development of 17 polymorphic microsatellite loci for the intertidal snail Bembicium vittatum (Gastropoda: Littorinidae). The loci were tested in 46 individuals from a single population situated near the centre of the species distribution. No evidence of linkage disequilibrium was detected between any pair of loci. However, two loci showed significant departures from Hardy–Weinberg expectations. The number of alleles per locus ranged from two to 15.
Exclusive contracts foster relationship‐specific investment
Authors: de Meza David , Selvaggi Mariano
Published: September 2008

Exclusive contracts prohibit one or both parties from trading with anyone else. Contrary to earlier findings, we show that investments that are specific to the contracting parties may be encouraged by exclusivity. Results depend on the nature of investments and the bargaining solution. The major part of the analysis shows that exclusivity deals designed to “assure” the supply of essential inputs promote investment. Infinite penalties for breach, even if ex post renegotiable, may result in excessive investment, in which case a positive but finite damage payment yields the first‐best outcome.
Buy or wait, that is the option: the buyer's option in sequential laboratory auctions
Authors: Février Philippe , Linnemer Laurent , Visser Michael
Published: September 2008

We report results from an experiment on two‐unit sequential auctions with and without a buyer's option (which allows the winner of the first auction to buy the second unit). The four main auction institutions are studied. Observed bidding behavior is close to Nash equilibrium bidding in the auctions for the second unit, but not in the auctions for the first unit. Despite these deviations, the buyer's option is correctly used in most cases. The revenue ranking of the four auctions is the same as in single‐unit experiments. Successive prices are declining when the buyer's option is available.
Seasonality in the U.S. motion picture industry
Authors: Einav Liran
Published: September 2008

The observed seasonality of box‐office revenues reflects both seasonality in underlying demand for movies and seasonality in the number and quality of available movies. I separately identify these aspects by estimating weekly demand for movies, using movie fixed effects, a long panel of movies' weekly revenues, and restrictions on their decay pattern. I find that the estimated seasonality in underlying demand is much smaller and slightly different from the observed seasonality of sales. The biggest movies are released at times when demand is highest, amplifying the underlying seasonality. Price rigidities in the industry may facilitate this amplification effect.
Merger waves: a model of endogenous mergers
Authors: Qiu Larry D. , Zhou Wen
Published: September 2008

We develop a model of endogenous mergers to study their dynamic process. Firms choose whether, when, and with whom to merge. Two necessary conditions are identified for mergers to occur: firm heterogeneity and negative demand shocks. We show that mergers are strategic complements and therefore tend to occur in waves. Moreover, some mergers occur for strategic reasons in order to precipitate further mergers.
Long‐run price competition
Authors: Dutta Prajit , Matros Alexander , Weibull Jörgen W.
Published: September 2008

We generalize the standard repeated‐games model of dynamic oligopolistic competition to allow for consumers who are long‐lived and forward looking. Each period leaves some residual demand to future periods and pricing in one period affects consumers' expectations about future prices. We analyze this setting for an indivisible durable good with price‐setting firms and overlapping cohorts of consumers. The model nests the repeated‐game model and the Coasian durable‐goods model as its two extreme cases. The analysis is mostly focused on constant‐price collusion but conditions for collusive recurrent sales are also identified.
Auctions and information acquisition: sealed bid or dynamic formats?
Authors: Compte Olivier , Jehiel Philippe
Published: September 2008

The value of an asset is generally not known a priori, and it requires costly investments to be discovered. In such contexts with endogenous information acquisition, which selling procedure generates more revenues? We show that dynamic formats, such as ascending‐price or multistage auctions, perform better than their static counterpart. This is because dynamic formats allow bidders to observe the number of competitors left throughout the selling procedure. Thus, even if competition appears strong ex ante, it may turn out to be weak along the dynamic format, thereby making the option to acquire information valuable. This very possibility also induces the bidders to stay longer in the auction, just to learn about the state of competition. Both effects boost revenues, and our analysis provides a rationale for using dynamic formats rather than sealed‐bid ones.
Optimal information revelation in procurement schemes
Authors: Gal‐Or Esther , Gal‐Or Mordechai , Dukes Anthony
Published: September 2008

A buyer procuring a single input possesses private information about each potential supplier's degree of fit with the buyer's needs. She can search among suppliers either sequentially or simultaneously. As long as the distribution of the fit parameter is not overly skewed to the left, sharing information with suppliers yields intensified price competition under simultaneous search. Moreover, the buyer cannot benefit by providing suppliers additional information beyond their own fitness parameter. Information revelation is never optimal with sequential search.
Tacit collusion under interest rate fluctuations
Authors: Bó Pedro Dal
Published: September 2008

Previous literature has shown that demand fluctuations affect the scope for tacit collusion. I study whether discount factor fluctuations can have similar effects. I find that collusion depends not only on the level of the discount factor but also, and more surprisingly, on its volatility. Collusive prices and profits increase with a higher discount factor level, but decrease with its volatility. These results have important implications for empirical studies of collusive pricing, the role that collusive pricing may play in economic cycles and the study of cooperation in repeated games.
Academic freedom, private‐sector focus, and the process of innovation
Authors: Aghion Philippe , Dewatripont Mathias , Stein Jeremy C.
Published: September 2008

We develop a model that clarifies the respective advantages and disadvantages of academic and private‐sector research. Rather than relying on lack of appropriability or spillovers to generate a rationale for academic research, we emphasize control‐rights considerations, and argue that the fundamental tradeoff between academia and the private sector is one of creative control versus focus. By serving as a precommitment mechanism that allows scientists to freely pursue their own interests, academia can be indispensable for early‐stage research. At the same time, the private sector's ability to direct scientists toward higher‐payoff activities makes it more attractive for later‐stage research.
Buy‐out prices in auctions: seller competition and multi‐unit demands
Authors: Kirkegaard René , Overgaard Per Baltzer
Published: September 2008

Online auction sites often enable sellers to add a buy‐out price. In one‐shot auctions, this has been motivated by appeal to impatience or risk aversion. We offer additional justification in a dynamic model, by showing that an early seller has an incentive to use a buy‐out price, if a similar product is offered later by another seller, and bidders desire multiple objects. Revenue in the first auction increases, but revenue in the second auction decreases, as does the sum of revenues. The buy‐out price causes the auction sequence to become inefficient, because the first item may be awarded to a bidder who should have received none.
Do report cards tell consumers anything they don't already know? The case of Medicare HMOs
Authors: Dafny Leemore , Dranove David
Published: September 2008

Estimated responses to report cards may reflect learning about quality that would have occurred in their absence (“market‐based learning”). Using panel data on Medicare HMOs, we examine the relationship between enrollment and quality before and after report cards were mailed to 40 million Medicare beneficiaries in 1999 and 2000. We find consumers learn from both public report cards and market‐based sources, with the latter having a larger impact. Consumers are especially sensitive to both sources of information when the variance in HMO quality is greater. The effect of report cards is driven by beneficiaries' responses to consumer satisfaction scores.
Comparison of a semiquantitative point‐of‐care assay for the detection of canine microalbuminuria with routine semiquantitative methods for proteinuria
Authors: Garner, Bridget C. , Wiedmeyer Charles E.
Published: September 2008

Background: It has been speculated that renal disease can be identified through the detection and quantification of microalbuminuria, however, reliable measurement of albuminuria in any quantity can be challenging. Recently, a new point‐of‐care immunoassay was validated for the specific detection of microalbuminuria and early renal disease in dogs. Objectives:The goal of this study was to determine if measurement of microalbuminuria by the point‐of‐care immunoassay correlated with results from routine semiquantitative methods for detecting proteinuria in dogs. Methods: One hundred and thirty‐eight urine samples, from 133 different dogs, submitted for urinalysis to the Clinical Pathology Laboratory at the University of Missouri‐Columbia Veterinary Medical Teaching Hospital were eligible for the study. Samples that contained >20 RBC/high power field (hpf) or >20 WBC/hpf were excluded, as were samples with insufficient volume to complete all tests. All samples were evaluated with a urinary dipstick with or without a sulfosalicylic acid turbidimetric test, a urine protein:creatinine (UPC) ratio, and the immunoassay for microalbuminuria. Data were analyzed by the Spearman rank order correlation. Results: Microalbuminuria results correlated significantly with those of the dipstick (r= 0.715), sulfosalicylic acid test (r= 0.742), and UPC ratio (r= 0.830). Correlation between the immunoassay and UPC ratio was the same (r= 0.830) when only samples with trace or 1+ proteinuria by dipstick were analyzed (n = 51). Conclusions: The point‐of‐care immunoassay results for microalbuminuria correlated with the results of semiquantitative methods for detecting total proteinuria in dogs. Routine methods for canine proteinuria appear to be adequate for determining whether further testing for renal disease is warranted.
What is your diagnosis? Preputial mass in a ferret
Authors: Pinches Mark D.G. , Liebenberg Guy , Stidworthy Mark F
Published: September 2008

Abstract: A 7‐year‐old neutered male polecat‐type ferret (Mustela putorius furo) was presented for evaluation of a cutaneous mass close to the preputial orifice. Cytologic examination of a fine‐needle aspirate revealed numerous large clumps of amorphous pink mucinous material and numerous large clumps of slightly pleomorphic epithelial cells. The cells were arranged in papillary structures, palisades, and loosely cohesive sheets with a vaguely honeycomb appearance. Occasional acinar formations were also seen. The cells had moderate to large amounts of finely granular gray to gray–blue cytoplasm. The cells were round to wispy and elongated, with indistinct borders. Often, anuclear cytoplasmic clumps were seen free in the background or adjacent to intact cells. Nuclei were round to oval and usually off‐center. Chromatin was finely stippled and contained 1–3 indistinct nucleoli. Anisokaryosis and anisocytosis were moderate. Binucleated cells were noted occasionally. The cytologic features were consistent with a carcinoma of probable apocrine origin. Histopathologic examination supported a diagnosis of secretory apocrine adenocarcinoma of the preputial skin. Secretory apocrine adenocarcinomas of the prepuce are seen relatively frequently in ferrets, although their cytologic appearance has not been described widely. These neoplasms carry a poor prognosis although prompt surgical removal with wide and deep surgical margins and adjunctive radiotherapy may improve survival.
In Vitro Activities at pH 5.0 and pH 7.0 and In Vivo Efficacy of Flucytosine against
Aspergillus fumigatus
Authors: Verweij Paul E. , Te Dorsthorst Debbie T. A. , Janssen Willem H. P. , Meis Jacques F. G. M. , Mouton Johan W.
Published: September 2008

The antifungal agent flucytosine was found to be active in vitro against
Aspergillus fumigatus
isolates when the MIC was determined at pH 5.0 instead of pH 7.0. The in vitro MIC at pH 5.0 corresponded to the in vivo efficacy of flucytosine monotherapy in a murine model of invasive aspergillosis.
Caspofungin-Resistant
Candida tropicalis
Strains Causing Breakthrough Fungemia in Patients at High Risk for Hematologic Malignancies
Authors: Garcia-Effron Guillermo , Kontoyiannis Dimitrios P. , Lewis Russell E. , Perlin David S.
Published: September 2008

We identified three cases of
C. tropicalis
strains causing breakthrough fungemia in allogeneic stem cell recipients receiving caspofungin prophylaxis and treatment. Three genetically unrelated isolates with high echinocandin MICs were identified. Each strain carried a characteristic mutation conferring an amino acid substitution within Fks1p hot spot 1.
Sitamaquine Sensitivity inLeishmaniaSpecies Is Not Mediated by Drug Accumulation in Acidocalcisomes
Authors: López-Martín Carmen , Pérez-Victoria José María , Carvalho Luis , Castanys Santiago , Gamarro Francisco
Published: September 2008

Sitamaquine (WR6026), an 8-aminoquinoline derivative, is a new antileishmanial oral drug. As a lipophilic weak base, it rapidly accumulates in acidic compartments, represented mainly by acidocalcisomes. In this work, we show that the antileishmanial action of sitamaquine is unrelated to its level of accumulation in these acidic vesicles. We have observed significant differences in sitamaquine sensitivity and accumulation betweenLeishmaniaspecies and strains, and interestingly, there is no correlation between them. However, there is a relationship between the levels of accumulation of sitamaquine and acidotropic probes, acidocalcisomes size, and polyphosphate levels. TheLeishmania majorAP3δ-null mutant line, in which acidocalcisomes are devoid of their usual polyphosphate and proton content, is unable to accumulate sitamaquine; however, both the parental strain and the AP3δ-null mutants showed similar sensitivities to sitamaquine. Our findings provide clear evidence that the antileishmanial action of sitamaquine is unrelated to its accumulation in acidocalcisomes.
More than One Tandem Repeat Domain of the Extracellular Adherence Protein ofStaphylococcus aureusIs Required for Aggregation, Adherence, and Host Cell Invasion but Not for Leukocyte Activation
Authors: Hussain Muzaffar , Haggar Axana , Peters Georg , Chhatwal Gursharan S. , Herrmann Mathias , Flock Jan-Ingmar , Sinha Bhanu
Published: September 2008

The extracellular adherence protein (Eap) is a multifunctionalStaphylococcus aureusprotein and broad-spectrum adhesin for several host matrix and plasma proteins. We investigated the interactions of full-length Eap and five recombinant tandem repeat domains with host proteins by use of surface plasmon resonance (BIAcore) and ligand overlay assays. In addition, agglutination and host cell interaction, namely, adherence, invasion, and stimulation of proliferation, were determined. With plasmon resonance, the interaction of full-length Eap isoforms (from strains Newman and Wood 46) with fibrinogen, fibronectin, vitronectin, and thrombospondin-1 was found to be specific but with different affinities for the ligands tested. In the ligand overlay assay, the interactions of five single tandem repeat domains (D1 to D5) of Eap-7 (from strain CI-7) with fibronectin, fibrinogen, vitronectin, thrombospondin-1, and collagen I differed substantially. Most prominently, D3 bound most strongly to fibronectin and fibrinogen. Full-length Eap, but none of the single tandem repeat domains, agglutinatedS. aureusand enhanced adherence to and invasion of host cells byS. aureus. Constructs D3-4 and D1-3 (incis) increased adherence and invasiveness compared to what was seen for single Eap tandem repeat domains. By contrast, single Eap tandem repeat domains and full-length Eap similarly modulated the proliferation of peripheral blood mononuclear cells (PBMCs): low concentrations stimulated, whereas high concentrations inhibited, proliferation. Taken together, the data indicate that Eap tandem repeat domains appear to have distinct characteristics for the binding of soluble ligands, despite a high degree of sequence similarity. In addition, more than one Eap tandem repeat domain is required forS. aureusagglutination, adherence, and cellular invasion but not for the stimulation of PBMC proliferation.
Effect of Phage on the Infectivity of
Vibrio cholerae
and Emergence of Genetic Variants
Authors: Zahid M. Shamim Hasan , Udden S. M. Nashir , Faruque A. S. G. , Calderwood Stephen B. , Mekalanos John J. , Faruque Shah M.
Published: September 2008

Seasonal epidemics of cholera in Bangladesh are self-limited in nature, presumably due to phage predation of the causative
Vibrio cholerae
during the late stage of an epidemic, when cholera patients excrete large quantities of phage in their stools. To further understand the mechanisms involved, we studied the effect of phage on the infectivity and survival of
V. cholerae
shed in stools. The 50% infectious dose of stool vibrios in infant mice was ∼10-fold higher when the stools contained a phage (1.8 × 10
3
to 5.7 × 10
6
PFU/ml) than when stools did not contain a detectable phage. In competition assays in mice using a reference strain and phage-negative cholera stools, the infectivity of biofilm-like clumped cells was 3.9- to 115.9-fold higher than that of the corresponding planktonic cells. However, the difference in infectivity of these two cell populations in phage-positive stools was significantly less than that in phage-negative stools (
P
= 0.0006). Coculture of a phage and
V. cholerae
or dilutions of phage-positive cholera stools in nutrient medium, but not in environmental water, caused rapid emergence of phage-resistant derivatives of the bacteria, and these derivatives lost their O1 antigen. In cholera stools and in intestinal contents of mice prechallenged with a mixture of
V. cholerae
and phage, the bacteria remained completely phage susceptible, suggesting that the intestinal environment did not favor the emergence of phage-resistant derivatives that lost the O1 antigen. Our results indicate that phages lead to the collapse of epidemics by modulating the required infectious dose of the bacteria. Furthermore, the dominance of phage-resistant variants due to the bactericidal selective mechanism occurs rarely in natural settings, and the emerging variants are thus unable to sustain the ongoing epidemic.
Diminished ICAM-1 Expression and Impaired Pulmonary Clearance of NontypeableHaemophilus influenzaein a Mouse Model of Chronic Obstructive Pulmonary Disease/Emphysema
Authors: Pang Bing , Hong Wenzhou , West-Barnette Shayla L. , Kock Nancy D. , Swords W. Edward
Published: September 2008

The airways of patients with chronic obstructive pulmonary disease (COPD) are continually colonized with bacterial opportunists like nontypeableHaemophilus influenzae(NTHi), and a wealth of evidence indicates that changes in bacterial populations within the lung can influence the severity of COPD. In this study, we used a murine model for COPD/emphysema to test the hypothesis that COPD affects pulmonary clearance. Mice were treated with a pulmonary bolus of elastase, and as reported previously, the lungs of these mice were pathologically similar to those with COPD/emphysema at ∼1 month posttreatment. Pulmonary clearance of NTHi was significantly impaired in elastase-treated versus mock-treated mice. While histopathologic analysis revealed minimal differences in localized lung inflammation between the two groups, lower levels of intercellular adhesion molecule 1 (ICAM-1) were observed for the airway epithelial surface of elastase-treated mice than for those of control mice. Following infection, elastase-treated mice had lung pathology consistent with pneumonia for as long as 72 h postinfection, whereas at the same time point, mock-treated mice had cleared NTHi and showed little apparent pathology. Large aggregates of bacteria were observed within damaged lung tissue of the elastase-treated mice, whereas sparse individual bacteria were observed in lungs of mock-treated mice at the same time point postinfection. Additional infection studies showed that NTHi mutants with biofilm defects were less persistent in the elastase-treated mice than the parent strain. These findings establish a model for COPD-related infections and support the hypotheses that ICAM-1 promotes clearance of NTHi. Furthermore, the data indicate that NTHi may form biofilms within the context of COPD-related infections.