bluuebunny/crossref_metadata_2025 huggingface dataset:
Ventilation rates and activity levels of juvenile jumbo squids under metabolic suppression in the oxygen minimum zones
Authors: Trübenbach Katja , Pegado Maria R. , Seibel Brad A. , Rosa Rui
Published: September 2012

The Humboldt (jumbo) squid, Dosidicus gigas, is a part-time resident of the permanent oxygen minimum zone (OMZ) in the Eastern Tropical Pacific and, thereby, it encounters oxygen levels below its critical oxygen partial pressure. To better understand the ventilatory mechanisms that accompany the process of metabolic suppression in these top oceanic predators, we exposed juvenile D. gigas to the oxygen levels found in the OMZ (1% O2, 1kPa, 10ºC) and measured metabolic rates, activity cycling patterns, swimming mode, escape-jet (burst) frequency, mantle contraction frequency and strength, stroke volume and oxygen extraction efficiency. In normoxia, the metabolic rates varied between 14 to 29 µmol O2 g (ww)-1 h-1, depending on the level of activity. The mantle contraction frequency and strength was linearly correlated and increased significantly with activity level. Additionally, an increased stroke volume and ventilatory volume per minute were observed, followed by a mantle hyperinflation process during high activity periods. Squid metabolic rates dropped more than 75% during exposure to hypoxia. Maximum metabolic rates were not achieved under such conditions and the metabolic scope was significantly decreased. Hypoxia changed the relationship between mantle contraction strength and frequency from linear to polynomial with increasing activity indicating that, under hypoxic conditions, the jumbo squid primarily increases the strength of mantle contraction and does not regulate its frequency. Under hypoxia, jumbo squids also showed a larger inflation period (reduced contraction frequency) and decreased relaxed mantle diameters (shortened diffusion pathways), which optimize oxygen extraction efficiency (up to 82%/34%, without/with consideration of 60% potential skin respiration). Additionally, they breathe “deeply”, with more powerful contractions and enhanced stroke volume. This deep-breathing behavior allows them to display a stable ventilatory volume per min, and explains the maintenance of the squid’s cycling activity under such O2 conditions. During hypoxia, the respiratory cycles were shorter in length but increased in frequency. This was accompanied by an increase in the number of escape-jets during active periods and a faster switch between swimming modes. In late hypoxia (onset ~170±10 min), all the ventilatory processes were significantly reduced and followed by a lethargic state, a behavior that seems closely associated with the process of metabolic suppression and enables the squid to extend its residence time in the OMZ.
Associative learning in the dengue vector mosquito,Aedes aegypti: avoidance of a previously attractive odor or surface color that is paired with an aversive stimulus
Authors: Menda Gil , Uhr Joshua H. , Wyttenbach Robert A. , Vermeylen Françoise M. , Smith David M. , Harrington Laura C. , Hoy Ronald R.
Published: September 2012

Associative learning has been shown in a variety of insects, including the mosquitoes Culex quinquefasciatus and Anopheles gambiae. This study demonstrates associative learning for the first time in Aedes aegypti, an important vector of dengue, yellow fever, and chikungunya viruses. This species prefers to rest on dark surfaces and is attracted to the odor of 1-octen-3-ol. After training in which a dark surface alone or a dark surface with odor was paired with electric shock, mosquitoes avoided the previously attractive area. The association was stronger when odor was included in training, was retained for at least 60 min but not for 24 hours, and was equal for males and females. These results demonstrate the utility of a bulk-training paradigm for mosquitoes similar to that used with Drosophila melanogaster.
Tracking bed bugs (Cimex lectularius): a study of the effect of physiological and extrinsic factors on the response to bed bug-derived volatiles
Authors: Weeks Emma N.I. , Logan James G. , Birkett Michael A. , Pickett John A. , Cameron Mary M.
Published: September 2012

The common bed bug, Cimex lectularius, feeds on the blood of mammal and bird hosts, and is a pest of global importance. Semiochemicals are chemicals involved in animal communication that may affect behaviour and/or physiology. Attractive semiochemicals that play a role in mediating bed bug behaviour could be exploited for the development of a highly effective novel monitoring device. Tracking software, was used to record the response of bed bugs to volatiles from paper previously exposed to conspecific bugs in a still-air olfactometer illuminated by infrared lights, through a variety of activity variables. The effect of time of day as an extrinsic factor, and sex, stage, mating status and nutritional status as physiological factors on the response of bed bugs to the volatiles was examined. Bed bugs of both sexes and all stages responded to the volatiles from bed bug-exposed papers, showing significant attraction and orientation towards the volatile source whether they were starved or engorged. Confirmation that the physiological factors examined do not affect the response of bed bugs to the volatiles from bed bug-exposed papers provides evidence that these bed bug derived volatiles contain aggregation cues, as semiochemicals that promote aggregation should by definition be detected by both sexes and all life stages. A device baited with such semiochemicals could play a major role in limiting the impact of the current bed bug resurgence by enabling timely detection of infestations, along with quantitative evaluation of control and effective surveillance of the geographical distribution of the pest species.
Analysis of the transitional flow field over a fixed hummingbird wing
Authors: Elimelech Yossef , Ellington Charles P.
Published: September 2012

Flow fields characterized by chord-based Reynolds numbers of 5000 to 15000 over a stationary model of a hummingbird wing (Calypte anna) are analyzed below. Utilizing two experimental techniques, constant-temperature anemometry and particle image velocimetry, the high fidelity results depict a laminar-to-turbulent transition process that develops over the wing. At both zero and non-zero angles of attack the spectrum of the velocity signals is wide. At non-zero angle of attack the flow separates from the wing surface and a shear layer forms. As a result, unsteady flow disturbances amplify at a chord-based Reynolds number which is as low as 5000. Nevertheless, only at a Reynolds number of 15000 is the flow disturbance growth rate sufficient to bring enough momentum to reattach the flow to the wing surface. For a Reynolds number of 5000, a comparison between the observed growth rates to a theoretical approximation concludes that flow disturbances of a Strouhal number of unity (and above) are no longer two-dimensional. In view of these conclusions, this study could serve as the first step toward better understanding of the flow mechanisms over steady revolving and periodically flapping wings at this Reynolds number regime.
Rapid decline of cold tolerance at young age is associated with expression of stress genes in Drosophila melanogaster
Authors: Colinet Hervé , Sciaussat David , Bozzolan Francoise , Bowler Kenneth
Published: September 2012

Many endogenous factors influence thermal tolerance of insects. Among these, age contributes an important source of variation. Heat tolerance is typically high in newly-enclosed insects, before declining dramatically. It is not known whether this phenomenon relates to cold tolerance also. In addition, the underlying mechanisms of this variation are unresolved. In this study we tested whether cold tolerance declines in Drosophila melanogaster females aged from 0 to 5 days. We also assessed whether expression (basal and induced) of eight stress genes (hsp22, hsp23, hsp40, hsp68, hsp70Aa, hsp83, Starvin and Frost) varied post-eclosion in correspondence with changes found cold tolerance. We report that cold tolerance was very high at eclosion and then it rapidly declined in young flies. hsp23 and hsp68 showed a dramatic age-related variation of basal expression that was associated with cold tolerance proxies. Significant age-related plasticity of cold-induced expression was also found for hsp22, hsp23, hsp68, hsp70Aa, Frost and Starvin. hsp22 and hsp70Aa induced expression was high in newly-enclosed phenotypes before declining dramatically, whilst opposite age-related patterns were found for hsp23, hsp68, Starvin and Frost. This study shows a marked within-stage variation in cold tolerance. The involvement of the stress genes in setting basal thermal tolerance is discussed.
Intrinsic expression of transcortin in neural cells of the mouse brain: a histochemical and molecular study
Authors: Sivukhina Elena , Helbling Jean-Christophe , Minni Amandine M. , Schäfer Hendrick H. , Pallet Veronique , Jirikowski Gustav F. , Moisan Marie-Pierre
Published: September 2012

Corticosteroid binding globulin (CBG, transcortin) has been shown to be expressed in the brain of rat and human species. In this study we examined the CBG brain expression and cDNA structure in mice, comparing wild-type (Cbg+/+) and Cbg knockout mice (Cbg-/-, obtained by genetic disruption of the SerpinA6 alias Cbg gene). We used double immunofluorescence labelling with specific neuronal and glial markers to analyze the cellular localization of CBG in various regions of the mouse brain. In wild-type (Cbg+/+) mice we found CBG immunoreactivity in neuronal perikarya of the magnocellular hypothalamic nuclei, amygdala, hippocampus, cerebral cortex, cerebellum and pituitary. A portion of glial cells (astrocytes, oligodendrocytes) contained CBG immunoreactivity, including some of the ependymal cells and choroid plexus cells. No CBG immunoreactivity was detected in Cbg-/- brain tissues. We showed by RT-PCR that the full-length Cbg mRNA is present in those regions, indicating an intrinsic expression of the steroid-binding globulin. Furthermore, we found by sequencing analysis that Cbg cDNA obtained from the mouse hypothalamus was homologous to Cbg cDNA obtained from the liver. Finally, we have evaluated the relative levels of CBG expression by quantitative PCR in various brain regions and in the liver. We found that brain levels of Cbg mRNA are low compared to the liver but significantly higher than in CBG-deficient mice. Although derived from the same gene than liver CBG, brain CBG protein may play a specific or complementary role that requires the production and analysis of brain-specific Cbg knockout models.
Direct Measurement of Interaction Forces between Adsorbed Polymer Layers
Authors: Tadros Tharwat
Published: September 2012

The interaction forces between adsorbed layers of two graft copolymers were directly measured using surface force apparatus and atomic force microscopy. Two types of graft copolymers that were adsorbed on hydrophobic surfaces were used: (i) a graft copolymer consisting of poly(methyl methacrylate)/poly(methacrylic acid) backbone (the B chain) on which several poly(ethylene oxide) chains are grafted (to be referred to as PMMA/PEOn) and (ii) a graft copolymer consisting of inulin (linear polyfructose with degree of polymerization greater than 23) (the A chain) on which several C12 chains are grafted (INUTEC SP1). In the first case, adsorbed layers of the graft copolymer were obtained on mica sheets and the interaction forces were measured using the surface force apparatus. In the second case, the interaction forces were measured using atomic force microscopy (AFM). For this purpose, a hydrophobically modified glass sphere was attached to the tip of the cantilever of the AFM and the glass plate was also made hydrophobic. Both the sphere and the glass plate contained an adsorbed layer of INUTEC SP1. The curves of energy E(D) versus distance D for the graft copolymer of PMMA/PEOn between mica surfaces bearing the graft copolymer could be used to estimate the interaction energy between flat surfaces, by using Derjaguin approximation for cross cylinders. The results were compared with the theoretical calculations using de Gennes scaling theory. The agreement between experimental results and theoretical calculations was satisfactory. The same graft copolymer was used in latex dispersions, and the high frequency modulus G′∝ was measured as a function of the volume fraction φ of the dispersion. This high-frequency modulus could be related to the potential of mean force. In this way, one could compare the results obtained from rheology and those obtained from direct measurement of interaction forces. In the AFM method, the interaction forces are measured in the contact area between two surfaces, i.e., the surfaces of a spherical glass particle and a glass plate. The glass spheres and plates were hydrophobized using dichlorodimethylsilane. Results were obtained for adsorbed layers of INUTEC SP1 in water and in the presence of various concentrations of Na2SO4 (0.3, 0.8, 1.0, and 1.5 mol dm−3). All results showed a rapid increase in force with a decrease in the separation distance, and the forces were repulsive up to the highest Na2SO4 concentration. This explains the high stability of dispersions when using INUTEC SP1 as the stabilizer.
Synthesis of ZnO and ZnO2 Nanoparticles by the Oil-in-water Microemulsion Reaction Method
Authors: Pemartin Kelly , Solans Conxita , Vidal-Lopez German , Sanchez-Dominguez Margarita
Published: September 2012

Crystalline ZnO and ZnO2 nanoparticles (NPs) were prepared in one-pot oil-in-water (O/W) microemulsion media at room temperature by adding an aqueous solution of sodium hydroxide (followed by H2O2 in the case of synthesis of ZnO2) to the O/W microemulsion containing a Zn(II) organometallic precursor dissolved in the oil phase. After calcination of ZnO2 NPs, ZnO NPs were also obtained, and their characteristics were compared with those of ZnO NPs prepared directly in O/W microemulsion. The materials were characterized by X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy.
A New Device for Simultaneous Measurements of Dynamic Interfacial Tension and Electrical Potential Difference
Authors: Wojciechowski Kamil
Published: September 2012

A new device for simultaneous time-resolved measurements of electromotive force (EMF) and interfacial tension (IT) at liquid–liquid interfaces is described. Two examples of applications are presented: 1) measurement of the variations in IT during simulated EMF measurements in model membrane-based ion-selective electrodes, and 2) measurements of transient changes in EMF in a system displaying IT oscillations without any chemical reaction.
Encapsulation of Water-soluble Vitamins by Gold Nanoparticles in Hydrophobic Media
Authors: Zhao Pengxiang , Ruiz Jaime , Salmon Lionel , Astruc Didier
Published: September 2012

Thiolate-mPEG ligand-protected gold nanoparticles (AuNPs) are shown to encapsulate the water-soluble vitamins C (ascorbic acid), B3 (nicotinic acid), B6 (pyridoxine), and B9 (folic acid) in a hydrophobic medium, i.e., between 1000 and 3000 vitamin molecules per 6-nm-core AuNP (overall size: 19.2 ± 2 nm) in dichloromethane solution.
Peer Effects in the Diffusion of Solar Photovoltaic Panels
Authors: Bollinger Bryan , Gillingham Kenneth
Published: September 2012

Social interaction (peer) effects are recognized as a potentially important factor in the diffusion of new products. In the case of environmentally friendly goods or technologies, both marketers and policy makers are interested in the presence of causal peer effects as social spillovers can be used to expedite adoption. We provide a methodology for the simple, straightforward identification of peer effects with sufficiently rich data, avoiding the biases that occur with traditional fixed effects estimation when using the past installed base of consumers in the reference group. We study the diffusion of solar photovoltaic panels in California and find that at the average number of owner-occupied homes in a zip code, an additional installation increases the probability of an adoption in the zip code by 0.78 percentage points. Our results provide valuable guidance to marketers designing strategies to increase referrals and reduce customer acquisition costs. They also provide insights into the diffusion process of environmentally friendly technologies.
Competition in Consumer Shopping Experience
Authors: Iyer Ganesh , Kuksov Dmitri
Published: September 2012

This paper analyzes the competitive role of retail shopping experience in markets with consumer search costs. We examine how a retailer's advantage in providing consumer shopping experience affects its equilibrium pricing and price advertising strategies. We find that if the consumer valuation of a shopping experience is sufficiently low, its effect on retailer strategy is similar to that of quality, and the retailer with the advantage in shopping experience then deploys higher levels of price advertising. On the other hand, when the shopping experience is valuable enough for consumers, it acts akin to price advertising in that it makes it optimal for the retailer with the advantage in shopping experience to eschew price advertising. The optimal competitive investments in consumer shopping experience can be higher than that of a monopoly. The profit impact of shopping experience for a retailer depends on the level of shopping experience: for low levels, the profit impact depends on the difference in the levels between the retailers, but for high enough levels, it depends only on whether the retailer's shopping experience level is higher than that of its competitor. In this case, even small differences in shopping experience levels can result in large differences in equilibrium profits.
Practice Prize Paper—PROSAD: A Bidding Decision Support System for Profit Optimizing Search Engine Advertising
Authors: Skiera Bernd , Abou Nabout Nadia
Published: September 2012

This paper reports on a large-scale implementation of marketing science models to solve the bidding problem in search engine advertising. In cooperation with the online marketing agency SoQuero, we developed a fully automated bidding decision support system, PROSAD (PRofit Optimizing Search engine ADvertising; see http://www.prosad.de), and implemented it through the agency's bid management software. The PROSAD system maximizes an advertiser's profit per keyword without the need for human intervention. A closed-form solution for the optimized bid and a newly developed “costs-per-profit” heuristic enable advertisers to submit good bids even when there is significant noise in the data. A field experiment demonstrates that PROSAD can increase the return on investment by 21 percentage points and improve the yearly profit potential for SoQuero and its clients by €2.7 million.
Perseveration in the Connected Speech of Boys with Fragile X Syndrome with and Without Autism Spectrum Disorder
Authors: Martin Gary E. , Roberts Joanne E. , Helm-Estabrooks Nancy , Sideris John , Vanderbilt Jacqueline , Moskowitz Lauren
Published: September 2012

Verbal perseveration is a frequently reported language characteristic of males with Fragile X syndrome and may be a defining feature or hallmark of the syndrome. We compared the verbal perseveration of boys with Fragile X syndrome with (n  =  29) and without (n  =  30) autism spectrum disorder, boys with Down syndrome (n  =  27), and typically developing boys (n  =  25) at similar nonverbal mental ages. During a social interaction, boys with both Fragile X syndrome and autism spectrum disorder produced significantly more topic perseveration than all other groups. In social interaction as compared to narration, boys with Fragile X syndrome (regardless of autism status) produced significantly more topic perseveration. These findings suggest that autism status, as well as language sampling context, affect perseveration in boys with Fragile X syndrome.
Financial Well-being of Single, Working-age Mothers of Children with Developmental Disabilities
Authors: Parish Susan L. , Rose Roderick A. , Swaine Jamie G. , Dababnah Sarah , Mayra Ellen Tracy
Published: September 2012

Understanding the financial well-being of single mothers who care for children with developmental disabilities is important to ensure that public policies can be effectively targeted to support these vulnerable families. The authors analyze data from the Survey of Income and Program Participation to describe income poverty, asset poverty, income, net worth, and liquid assets of U.S. single, working-age mothers (n  =  242) of children and adult children with developmental disabilities. The well-being of these mothers was compared to the situation of married mothers of children with developmental disabilities (n  =  345) and of single mothers who did not have children with developmental disabilities (n  =  6,547). Compared with both married mothers of children with developmental disabilities and single mothers without children with developmental disabilities, single mothers of children with developmental disabilities had markedly worse financial well-being across a range of income- and asset-based measures. Single mothers caring for children with developmental disabilities face adverse financial well-being as compared with other mothers. Policy makers should consider targeted measures to improve the financial well-being of these parents.
Gas Chromatography–Tandem Mass Spectrometry Method for the Simultaneous Determination of Oxysterols, Plant Sterols, and Cholesterol Precursors
Authors: Matysik S , Klünemann HH , Schmitz G
Published: September 2012

BACKGROUND

Cholesterol precursors and plant sterols have considerable potential as plasma biomarkers in several disorders of sterol metabolism and intestinal sterol absorption. Oxysterols are associated with atherogenesis, neurodegeneration, and inflammation. We developed a GC-MS method for the simultaneous analysis of these species in human plasma, including 24-, 25-, 27-hydroxycholesterol; 7-ketocholesterol; lanosterol; lathosterol; 7-dehydrocholesterol; desmosterol; stigmasterol; sitosterol; and campesterol.

METHODS

Sterols were hydrolyzed with ethanolic potassium hydroxide solution, extracted by liquid/liquid extraction with n-hexane, and derivatized with N-methyl-N-trimethylsilyl-trifluoracetamide. Positive chemical ionization with ammonia, as reagent gas, was applied to generate high abundant precursor ions.

RESULTS

The definition of highly sensitive precursor/product ion transitions, especially for coeluting substances, allowed fast gas chromatography run times of under 8.5 min. Using the multiple reaction monitoring mode, detection limits in the picogram per milliliter range could be achieved for most compounds. The method was validated for precision and recovery. Intraassay and interassay CVs were mostly <15% for serum and plasma samples. The recoveries of supplemented plasma samples in different concentrations were 88%–117%. The method was applied to stratification of patients with disorders in cholesterol biosynthesis and/or cholesterol absorption in hypercholesterolemia. The method revealed associations of sterol species with thyroid dysfunction and type 2 diabetes.

CONCLUSIONS

This method allows high-throughput sterol profiling in various diseases.
Compelled Speech and the Case for Judicial Engagement
Authors: Sherman Paul M.
Published: September 2012

Laws that compel speech implicate the First Amendment to the U.S. Constitution, which protects not only the right to speak but also the right to choose the content of one's speech. The U.S. Supreme Court's jurisprudence regarding compelled speech, however, has been far from consistent. Although the Court has typically been hostile to laws that compel the expression of opinions, it has been quite tolerant of laws that compel the expression of facts, including mandatory disclaimer laws. This essay examines the Supreme Court's compelled-speech jurisprudence in light of recent findings by Green and Armstrong (2012) that mandatory disclaimers may be worse than useless, leading consumers to make inferior decisions. These findings suggest that a properly engaged judiciary should be more skeptical of the alleged benefits of mandatory disclaimers in both the commercial and political arenas.
Reference Dependence and Conjoint Analysis
Authors: Davis Brennan , Currim Imran S. , Sarin Rakesh K.
Published: September 2012

Although there is enormous evidence that reference levels influence preferences, conjoint models, one of the most successful marketing research tools, assume that preferences depend on the absolute levels of attributes. In this paper we investigate the relevance of reference effects in two settings, compositional or self-explicated models in experimental studies 1 and 2, and decompositional or choice-based models in experimental study 3. In particular, we introduce a simple modification of the traditional self-explicated conjoint model which permits dependence of preference on reference levels. By eliciting gains and losses from expectations the model is adaptable to changes in respondents' reference points, which the traditional model is incapable of. Reference options are found to clearly affect subject choices in studies 1 and 2. In addition, the reference dependent self-explicated model is found to offer useful predictions when reference points are manipulated in study 1, and improve on predictions of its traditional counterpart when reference points are measured in study 2. In contrast, in study 3, the choice-based model’s diagnostics and predictions are found to be robust to reference point manipulations. Taken together, these results suggest that the self-explicated model is more suited than the choice-based model to understanding and predicting how respondents make judgments relative to reference points because reference points and gains and losses from reference levels are more salient in the self-explicated model. We discuss implications for managers constructing conjoint models in product-market settings wherein reference points are changing due to new product introductions or marketing efforts.
I hear a song in my head. A memoir in stories of love, fear, doctoring and flight
Authors: Shaper A. Gerald
Published: September 2012

No abstract available.
Comparison of tribological performance of PEEK, UHMWPE, glass fiber reinforced PTFE and PTFE reinforced PEI composite materials under dry and lubricated conditions
Authors: Unal Huseyin , Mimaroglu Abdullah
Published: September 2012

In this study, the tribological performance of poly-ether-ketone (PEEK), ultrahigh molecular weight polyethylene (UHMWPE), glass fiber reinforced poly-tetra-fluoro-ethylene (PTFE) and PTFE reinforced poly-ether-imide (PEI) composite materials, under dry and lubricated conditions, were compared and evaluated. Wear tests were carried out on a pin-disc arrangement and under 50, 100 and 150 N applied loads and 0.5 m/s sliding speed conditions. The results show that the coefficient of friction and specific wear rates for these materials decreases with the increase in applied load values. Finally, the wear rates for PEEK, UHMWPE polymers, PTFE+20% glass fiber reinforced (GFR) and PEI+10% PTFE composites under dry and lubricated conditions are in the order of 10-14 and 10-15, respectively. The results suggested that it is convenient to use PTFE+20% GFR composites for machine components with low processing and product costs.
Preparation and characterization of antibacterial silver loaded montmorillonite under microwave irradiation
Authors: Li Tian , Zhang Yuanyuan , Song Zhiyong , Wu Hongtao , Li Shuhao
Published: September 2012

Silver loaded montmorillonite (Ag-MMT) was prepared by ion exchange reaction under microwave irradiation. The effects of microwave irradiation time, AgNO3 concentration, and microwave power on the silver content of Ag-MMT were investigated using the Volhard method. The time of ion exchange reaction was found to be greatly shortened under microwave irradiation. The most suitable reaction condition was in 0.2 m AgNO3 under 100% microwave power irradiation for 4 min, and the silver content was determined and was found to be 1.23 wt%. The results of the Fourier transform infrared spectrum (FT-IR) and Ag+ release tests confirmed the successful loading of silver and its good slow-release property. The X-ray diffraction (XRD) patterns and ultraviolet-visible (UV-vis) spectra proved the existence of metallic Ag nanoparticles. The Ag-MMT showing a large inhibition zone, high inhibition ratio, and low minimum inhibitory concentration (MIC) value against Staphylococcus aureus ATCC6535 presented a very good antibacterial property.
Determining Performance of Marble Finished Products on Their Usage Areas by a New Impact-Resistance Test Method
Authors: Sariisik Gencay
Published: September 2012

This study determined the performances of marble finished products, in accordance with their applications within the construction sector, using a new, experimental impact-resistance test. Eight different kinds of marbles, which were categorized according to their commonly used formations, were subjected to a range of characterization tests (mineralogical and petrographic characteristics, chemical properties, and physical and mechanical properties) and their impact-resistance characteristics were determined. The results were analyzed statistically to determine the relationship between physical and mechanical properties of the marbles and their impact-resistance characteristics. The breaking potential of the marbles were categorized according to the number of impacts and impact-resistance values. The performance of the marble types within their areas of application were determined by taking into consideration the Turkish Standards Institution (TS EN) guidance and statistical analysis results, and classifying the marbles based on their physical and mechanical properties and impact resistances.
Micro-eukaryote Diversity in Freshwater Ponds That Harbor the Amphibian Pathogen Batrachochytrium dendrobatidis (Bd)
Authors: Lauer Antje , McConnel Lonnie , Singh Navdeep
Published: September 2012

We designed a microbiology project that fully engaged undergraduate biology students, high school students, and their teachers in a summer research program as part of the Research Education Vitalizing Science University Program conducted at California State University Bakersfield. Modern molecular biological methods and microscopy were used to detect and identify microcrustacean species in ponds around Bakersfield, California, that harbor the amphibian pathogen Batrachochytrium dendrobatidis (Bd). The students learned about the amphibian decline in California and worldwide due to chytridiomycosis and how microcrustaceans as natural predators of Bd-zoospores can be used in mitigation strategies for amphibian conservation.
Glucocorticoid sensitivity in Behçet's disease
Authors: Quax R A M , Laar J A M van , Heerebeek R van , Greiner K , Ben-Chetrit E , Stanford M , Wallace G R , Fortune F , Ghabra M , Soylu M , Hazes J M W , Lamberts S W J , Kappen J H , Hagen P M van , Koper J W , Feelders R A
Published: September 2012

Objective

Glucocorticoid (GC) sensitivity is highly variable among individuals and has been associated with susceptibility to develop (auto-)inflammatory disorders. The purpose of the study was to assess GC sensitivity in Behçet's disease (BD) by studying the distribution of four GC receptor (GR) gene polymorphisms and by measuring in vitro cellular GC sensitivity.

Methods

Healthy controls and patients with BD in three independent cohorts were genotyped for four functional GR gene polymorphisms. To gain insight into functional differences in in vitro GC sensitivity, 19 patients with BD were studied using two bioassays and a whole-cell dexamethasone-binding assay. Finally, mRNA expression levels of GR splice variants (GR-α and GR-β) were measured.

Results

Healthy controls and BD patients in the three separate cohorts had similar distributions of the four GR polymorphisms. The Bcll and 9β minor alleles frequency differed significantly between Caucasians and Mideast and Turkish individuals.

At the functional level, a decreased in vitro cellular GC sensitivity was observed. GR number in peripheral blood mononuclear cells was higher in BD compared with controls. The ratio of GR-α/GR-β mRNA expression levels was significantly lower in BD.

Conclusions

Polymorphisms in the GR gene are not associated with susceptibility to BD. However, in vitro cellular GC sensitivity is decreased in BD, possibly mediated by a relative higher expression of the dominant negative GR-β splice variant. This decreased in vitro GC sensitivity might play an as yet unidentified role in the pathophysiology of BD.
Vasoregulatory peptides pro-endothelin-1 and pro-adrenomedullin are associated with metabolic syndrome in the population-based KORA F4 study
Authors: Seissler Jochen , Feghelm Nina , Then Cornelia , Meisinger Christa , Herder Christian , Koenig Wolfgang , Peters Annette , Roden Michael , Lechner Andreas , Kowall Bernd , Rathmann Wolfgang
Published: September 2012

Background

Metabolic alterations and endothelial dysfunction are interrelated processes in type 2 diabetes (T2D) and metabolic syndrome (MetS) that often develop in parallel. We assessed the association of vasoactive precursor peptides (VPPs) with MetS and T2D.

Design and methods

Plasma levels of C-terminal pro-endothelin-1 (CT-proET-1) and midregional pro-adrenomedullin (MR-proADM) were measured by novel sensitive assays in 1590 participants of the population-based KORA F4 study. The association of the VPPs with T2D, MetS defined by IDF criteria, the components of MetS, and insulin resistance (IR) was assessed in logistic regression models.

Results

Elevated levels of CT-proET-1 and MR-proADM were associated with T2D, MetS, and IR in age- and sex-adjusted models. After adjustment for age, sex, former vascular complications, lifestyle factors, high-sensitive C-reactive protein, and serum creatinine, significant associations with MetS were found for MR-proADM (OR=5.94, 95% CI 3.78–9.33) and CT-proET-1 (OR=5.18, 95% CI 3.48–7.71) (top quartile vs bottom quartile). CT-proET-1 and MR-proADM were strongly associated with all components of MetS as defined by IDF criteria. After multivariable adjustment, association of CT-proET-1 and MR-proADM with pathological glucose tolerance and T2D disappeared and a borderline association with IR was found only for CT-proET-1 (OR=1.34, 95% CI 0.96–1.87).

Conclusions

We here demonstrate for the first time that plasma levels of both MR-proADM and CT-proET-1 levels are related to MetS and its components, thus suggesting that they possibly have a role as a surrogate biomarker for the disease and its complications.
Utilization of a MAB for BRAFV600E detection in papillary thyroid carcinoma
Authors: Bullock M , O'Neill C , Chou A , Clarkson A , Dodds T , Toon C , Sywak M , Sidhu S B , Delbridge L W , Robinson B G , Learoyd D L , Capper D , von Deimling A , Clifton-Bligh R J , Gill A J
Published: September 2012

Identification of BRAFV600E in thyroid neoplasia may be useful because it is specific for malignancy, connotes a worse prognosis, and is the target of novel therapies currently under investigation. Sanger sequencing is the ‘gold standard’ for mutation detection but is subject to sampling error and requires resources beyond many diagnostic pathology laboratories. In this study, we compared immunohistochemistry (IHC) using a BRAFV600E mutation-specific MAB to Sanger sequencing on DNA from formalin-fixed paraffin-embedded tissue, in a well-characterized cohort of 101 papillary thyroid carcinoma (PTC) patients. For all cases, an IHC result was available; however, five cases failed Sanger sequencing. Of the 96 cases with molecular data, 68 (71%) were BRAFV600E positive by IHC and 59 (61%) were BRAFV600E positive by sequencing. Eleven cases were discordant. One case was negative by IHC and initially positive by sequencing. Repeat sequencing of that sample and sequencing of a macrodissected sample were negative for BRAFV600E. Of ten cases positive by IHC but negative by sequencing on whole sections, repeat sequencing on macrodissected tissue confirmed the IHC result in seven cases (suggesting that these were false negatives of sequencing on whole sections). In three cases, repeat sequencing on recut tissue remained negative (including using massive parallel sequencing), but these cases demonstrated relatively low neoplastic cellularity. We conclude that IHC for BRAFV600E is more sensitive and specific than Sanger sequencing in the routine diagnostic setting and may represent the new gold standard for detection of BRAFV600E mutation in PTC.
Time matters: pathological effects of repeated psychosocial stress during the active, but not inactive, phase of male mice
Authors: Bartlang Manuela S , Neumann Inga D , Slattery David A , Uschold-Schmidt Nicole , Kraus Dominik , Helfrich-Förster Charlotte , Reber Stefan O
Published: September 2012

Recent findings in rats indicated that the physiological consequences of repeated restraint stress are dependent on the time of day of stressor exposure. To investigate whether this is also true for clinically more relevant psychosocial stressors and whether repeated stressor exposure during the light phase or dark phase is more detrimental for an organism, we exposed male C57BL/6 mice to social defeat (SD) across 19 days either in the light phase between Zeitgeber time (ZT)1 and ZT3 (SDL mice) or in the dark phase between ZT13 and ZT15 (SDD mice). While SDL mice showed a prolonged increase in adrenal weight and an attenuated adrenal responsiveness to ACTHin vitroafter stressor termination, SDD mice showed reduced dark phase home-cage activity on observation days 7, 14, and 20, flattening of the diurnal corticosterone rhythm, lack of social preference, and higherin vitroIFNγ secretion from mesenteric lymph node cells on day 20/21. Furthermore, the colitis-aggravating effect of SD was more pronounced in SDD than SDL mice following dextran sulfate sodium treatment. In conclusion, the present findings demonstrate that repeated SD effects on behavior, physiology, and immunology strongly depend on the time of day of stressor exposure. Whereas physiological parameters were more affected by SD during the light/inactive phase of mice, behavioral and immunological parameters were more affected by SD during the dark phase. Our results imply that repeated daily SD exposure has a more negative outcome when applied during the dark/active phase. By contrast, the minor physiological changes seen in SDL mice might represent beneficial adaptations preventing the formation of those maladaptive consequences.
Comparison of gene expression in fresh and frozen–thawed human preimplantation embryos
Authors: Shaw Lisa , Sneddon Sharon F , Brison Daniel R , Kimber Susan J
Published: September 2012

Identification and characterisation of differentially regulated genes in preimplantation human embryonic development are required to improve embryo quality and pregnancy rates in IVF. In this study, we examined expression of a number of genes known to be critical for early development and compared expression profiles in individual preimplantation human embryos to establish any differences in gene expression in fresh compared to frozen–thawed embryos used routinely in IVF. We analysed expression of 19 genes by cDNA amplification followed by quantitative real-time PCR in a panel of 44 fresh and frozen–thawed human preimplantation embryos. Fresh embryos were obtained from surplus early cleavage stage embryos and frozen–thawed embryos from cryopreserved 2PN embryos. Our aim was to determine differences in gene expression between fresh and frozen–thawed human embryos, but we also identified differences in developmental expression patterns for particular genes. We show that overall gene expression among embryos of the same stage is highly variable and our results indicate that expression levels between groups did differ and differences in expression of individual genes was detected. Our results show that gene expression from frozen–thawed embryos is more consistent when compared with fresh, suggesting that cryopreserved embryos may represent a reliable source for studying the molecular events underpinning early human embryo development.
Long-Term and Short-Term Evolutionary Impacts of Transposable Elements onDrosophila
Authors: Lee Yuh Chwen G , Langley Charles H
Published: September 2012

Transposable elements (TEs) are considered to be genomic parasites and their interactions with their hosts have been likened to the coevolution between host and other nongenomic, horizontally transferred pathogens. TE families, however, are vertically inherited as integral segments of the nuclear genome. This transmission strategy has been suggested to weaken the selective benefits of host alleles repressing the transposition of specific TE variants. On the other hand, the elevated rates of TE transposition and high incidences of deleterious mutations observed during the rare cases of horizontal transfers of TE families between species could create at least a transient process analogous to the influence of horizontally transmitted pathogens. Here, we formally address this analogy, using empirical and theoretical analysis to specify the mechanism of how host–TE interactions may drive the evolution of host genes. We found that host TE-interacting genes actually have more pervasive evidence of adaptive evolution than immunity genes that interact with nongenomic pathogens in Drosophila. Yet, both our theoretical modeling and empirical observations comparing Drosophila melanogaster populations before and after the horizontal transfer of P elements, which invaded D. melanogaster early last century, demonstrated that horizontally transferred TEs have only a limited influence on host TE-interacting genes. We propose that the more prevalent and constant interaction with multiple vertically transmitted TE families may instead be the main force driving the fast evolution of TE-interacting genes, which is fundamentally different from the gene-for-gene interaction of host–pathogen coevolution.
The myth on the “first national opera”: The cases of Serbia and Croatia
Authors: Marković Tatjana
Published: September 2012

The so-called first national operas were usually not the earliest national operas, but works arbitrarily chosen in accordance to the given political and cultural circumstances. In the majority of cases, they reached this status during Romanticism, when the ideology of nationalism and historicism was dominant. This fact determined the topic and the language of libretti, as well as the musical means themselves, leading to the “contradictory” result of “global” musical setting of “local” narrative. The understanding what is national and what is international, and for whom, opens the question if “national opera” exists at all. It seems that the key criterion in this respect is actual reception. This thesis will be considered through the cases of the first Croatian and Serbian operas, written between 1846 and 1904, in the framework of their social and political contexts.
Nationale ‚Zukunftsmusik‘? Bedřich Smetanas Dalibor und die Debatte um eine tschechische Oper
Authors: Rentsch Ivana
Published: September 2012

The article deals with the political and cultural situation in the 1860s in Prague and Bedřich Smetana’s role after his return from Göteborg in 1861. Smetana was well aware that he had to act in accordance with the practical circumstances, which he described as “awful.” He worked quite pragmatically on the improvement of the musical quality in the Bohemian capital, but at the same time, he professed his deep interest in the “neudeutsche Schule” of Franz Liszt and Richard Wagner. The consequences of the practical orientation and the compositional ideal will be discussed at the example of Smetanas opera Dalibor.
Leoš Janáček und die „slawische Katharsis“
Authors: Zvara Vladimír
Published: September 2012

The expression “Slavic catharsis” was coined by Vladimír Helfert. The characterology of Slavic operatic figures may be obsolete, but his thoughts remain an interesting contribution to the history of the use of the Greek concept. Helfert intended to grasp the musico-dramatical idiom of Janáček’s operas where the element of “catharsis” is omnipresent. The work of Janáček suggests a new definition of “catharsis” in operatic music: more than a mere purification, it is to be understood as an insight in hidden truth.
„Ricomincio a respirare l’aria di quei paesi“. Zu einem ‚russischen‘ Naturalismus und seiner ästhetischen Entgrenzung in Opern von Umberto Giordano und Franco Alfano (1898–1904)
Authors: Nikolaidis Matthias
Published: September 2012

The unexpected success of Pietro Mascagni’s Cavalleria rusticana (1890) gave the starting signal for a turn of Italian opera to naturalism. The problematic integration of naturalistic plots into the melodramma was approached in part by means of musical exoticism. The recently started reception of Lev Tolstoy’s and Fyodor Dostoyevsky’s novels could serve as basis for a re-evaluation of Russian subjects in fin de siècle Italian opera.Since the beginning of the 19th century, the Western image of Russia had been stamped by the contrast of tsarist glamour and the penal camps of Siberia. Umberto Giordano’s Fedora displays this dichotomy from a Parisian point of view. For Siberia, Luigi Illica contributed a libretto based on Dostoyevsky’s House of the Dead, in the composition of which Giordano sought to amalgamate the notions of naturalism, Russian exoticism and tragic love. With Risurrezione, Franco Alfano expanded in this direction by creating a powerful Russian atmosphere. His formal solution for the opera’s finale uses a juxtaposition of disparate material which evolves as a hallmark of musical realism.
Zwischen nationalem Anspruch und lokalpolitischen Zwängen: Entstehungs- und Rezeptionsbedingungen der Kasseler Opern Louis Spohrs
Authors: Boder Wolfram
Published: September 2012

In 1823 Louis Spohr published an article entitled “Aufruf an deutsche Komponisten” (Appeal to German Composers) in the Allgemeine Musikalische Zeitung (AMZ). He did so for the purpose of encouraging young German composers to contribute to the genre of German opera. But he probably had other intentions, too. He was determined to promote his latest opera Jessonda, which he mentioned as a model for his ideas of German opera. Thus one could say that the project of “German opera” was in some aspects merely a marketing strategy.A closer look at Jessonda reveals that Spohr did certainly not think along nationalist lines. In a way its dramaturgy depicts Kant’s definition of the Enlightenment and aims at a united and enlightened mankind. So did Spohr in his personal life. And by so doing he became very popular with the liberal citizens in Kassel, the city in which he worked as “Hofkapellmeister” from 1822 to 1857. This popularity in some cases misguided him. The liberal and enlightened ideas of Spohr are so prominent in his operas that they became increasingly neglected in the 1870s when chauvinistic tendencies became more prominent. This development culminated in the 1940s when the Nazis banned Jessonda from the German stage. They did however try to make it suitable for their ideas of German opera. As Spohr’s original did resist to this violation, the “Reichsstelle für Musikbearbeitungen” commissioned an amended version. Luckily the end of World War II terminated these efforts.