bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid evolution of mammalian X-linked testis microRNAs
Authors: Guo Xuejiang , Su Bing , Zhou Zuomin , Sha Jiahao 
Published: March 2009

Abstract

Background
MicroRNAs (miRNAs), which are small, non-coding RNAs approximately 21-nucleotides in length, have become a major focus of research in molecular biology. Mammalian miRNAs are proposed to regulate approximately 30% of all protein-coding genes. Previous studies have focused on highly conserved miRNAs, but nonconserved miRNAs represent a potentially important source of novel functionalities during evolution.

Results
An analysis of the chromosome distribution of miRNAs showed higher densities of miRNAs on the X chromosome compared to the average densities on autosomes in all eight mammalian species analyzed. The distribution pattern did not, however, apply well to species beyond mammals. In addition, by comparing orthologous human and mouse miRNAs, we found that X-linked miRNAs had higher substitution rates than autosomal miRNAs. Since the highest proportion of X-linked miRNAs were found in mouse testis, we tested the hypothesis that testis miRNAs are evolving faster on the X chromosome than on autosomes. Mature X-linked testis miRNAs had an average substitution rate between mouse and human that was almost 25-fold higher than mature testis miRNAs on autosomes. In contrast, for mature miRNAs with precursors not expressed in testis, no significant difference in the substitution rate between the X chromosome and autosomes was found. Among mammals, the rapid evolution of X-linked testis miRNAs was also observed in rodents and primates.

Conclusion
The rapid evolution of X-linked testis miRNAs implies possible important male reproductive functions and may contribute to speciation in mammals.
Improvement in right ventricular function during reversibility testing in pulmonary arterial hypertension: a case report
Authors: Huez Sandrine , Vachiéry Jean-Luc , Naeije Robert 
Published: March 2009

Abstract
A right heart catheterization with reversibility testing is recommended for the diagnosis and treatment of pulmonary arterial hypertension. In this 24 years-old woman, the inhalation of 5 μg iloprost transiently decreased mean pulmonary artery pressure from 62 to 36 mmHg and pulmonary vascular resistance from 11.0 to 4.9 Wood units, meeting the criteria of a "positive response". The echocardiographic examination showed normalization of right heart chamber dimensions and of the right ventricular performance (Tei) index. Pulsed tissue Doppler imaging of the right ventricle showed a decrease in the isovolumic relaxation time from 102 to 73 ms, and an increase of the E/A ratio from 0.72 to 1.38, together with marked improvements in mid-apical free wall systolic strain and strain rate. A positive response to reversibility testing of pulmonary arterial hypertension may be associated with quasi normalization of right ventricular function, in spite of still elevated pulmonary artery pressure.
Transgenic up-regulation of alpha-CaMKII in forebrain leads to increased anxiety-like behaviors and aggression
Authors: Hasegawa Shunsuke , Furuichi Takahiro , Yoshida Taro , Endoh Kengo , Kato Kenichi , Sado Megumi , Maeda Ryouta , Kitamoto Aya , Miyao Takahisa , Suzuki Ryosuke , Homma Seiichi , Masushige Shoichi , Kajii Yasushi , Kida Satoshi 
Published: March 2009

Abstract

Background
Previous studies have demonstrated essential roles for alpha-calcium/calmodulin-dependent protein kinase II (alpha-CaMKII) in learning, memory and long-term potentiation (LTP). However, previous studies have also shown that alpha-CaMKII (+/-) heterozygous knockout mice display a dramatic decrease in anxiety-like and fearful behaviors, and an increase in defensive aggression. These findings indicated that alpha-CaMKII is important not only for learning and memory but also for emotional behaviors. In this study, to understand the roles of alpha-CaMKII in emotional behavior, we generated transgenic mice overexpressing alpha-CaMKII in the forebrain and analyzed their behavioral phenotypes.

Results
We generated transgenic mice overexpressing alpha-CaMKII in the forebrain under the control of the alpha-CaMKII promoter. In contrast to alpha-CaMKII (+/-) heterozygous knockout mice, alpha-CaMKII overexpressing mice display an increase in anxiety-like behaviors in open field, elevated zero maze, light-dark transition and social interaction tests, and a decrease in locomotor activity in their home cages and novel environments; these phenotypes were the opposite to those observed in alpha-CaMKII (+/-) heterozygous knockout mice. In addition, similarly with alpha-CaMKII (+/-) heterozygous knockout mice, alpha-CaMKII overexpressing mice display an increase in aggression. However, in contrast to the increase in defensive aggression observed in alpha-CaMKII (+/-) heterozygous knockout mice, alpha-CaMKII overexpressing mice display an increase in offensive aggression.

Conclusion
Up-regulation of alpha-CaMKII expression in the forebrain leads to an increase in anxiety-like behaviors and offensive aggression. From the comparisons with previous findings, we suggest that the expression levels of alpha-CaMKII are associated with the state of emotion; the expression level of alpha-CaMKII positively correlates with the anxiety state and strongly affects aggressive behavior.
Crevice Corrosion Testing of Austenitic, Superaustenitic, Superferritic, and Superduplex Stainless Type Alloys in Seawater
Authors: Zeuthen AW , Kain RM 
Published: March 2009

In industry, many problems from corrosion occurring in crevices have been experienced and reported. These include the refining industry, offshore drilling platforms, fossil and nuclear power plants, chemical plants and the public utilities. The services are highly variable. Corrosion mechanisms and the results experienced are influenced by severe environments which cannot always be avoided.
Corrosion testing is considered useful not only in comparing materials, but also in selecting materials from the design standpoint. The ultimate goal is to use materials which are superior to those currently in use. This will result in fewer outages, reduce repairs and significantly lower costs.
This paper provides the results from four seawater test programs addressing crevice corrosion resistance of a number of “superferritic,” “superaustenitic,” and “superduplex” alloys, along with conventional “300 Series” stainless steel. These programs included exposure to natural fouling organisms which can produce crevices, and testing which comprised several different manmade crevice configurations. Alloys found to be resistant under some test conditions were prone to attack under others. All of the “super stainless” steels were found to be more resistant to crevice corrosion than conventional austenitic grades, but some were susceptible to some degree.
Statistical Analysis of Pitting Corrosion in Condenser Tubes
Authors: Ault JP , Gehring GA 
Published: March 2009

Condenser tube failure via wall penetration allows cooling water to contaminate the working fluid (steam). Contamination, especially from brackish or saltwater, will lower steam quality and thus lower overall plant efficiency. Because of the importance of minimizing leakages, power plant engineers are primarily concerned with the maximum localized corrosion in a unit rather than average corrosion values or rates. Extreme value analysis is a useful tool for evaluating the condition of condenser tubing. Extreme value statistical techniques allow the prediction of the most probable deepest pit in a given surface area based upon data acquired from a smaller surface area. Data is gathered from a physical examination of actual tubes (either in-service or from a sidestream unit) rather than small sample coupons. Three distinct applications of extreme value statistics to condenser tube evaluation are presented in this paper: (1) condition assessment of an operating condenser, (2) design data for material selection, and (3) research tool for assessing impact of various factors on condenser tube corrosion.
The projections for operating units based on extreme value analysis are shown to be more useful than those made on the basis of other techniques such as eddy current or electrochemical measurements. Extreme value analysis would benefit from advances in two key areas: (1) development of an accurate and economical method for the measurement of maximum pit depths of condenser tubes in-situ would enhance the application of extreme value statistical analysis to the assessment of condenser tubing corrosion pitting and (2) development of methodologies to predict pit depth-time relationship in addition to pit depth-area relationship would be useful for modeling purposes.
Corrosion Coupon Testing in Natural Waters: A Case History Dealing With Reverse Osmosis Desalination of Seawater
Authors: Kain RM , Adamson WL , Weber B 
Published: March 2009

Corrosion testing in natural waters has generally focused on assessing either resistance of materials to corrosion in a given environment or characterizing environmental corrosivity. Sometimes both can be accomplished simultaneously. For example, while the objective of another test program reported in this symposium was to determine the corrosivity of seawater world-wide, the corrosion resistance of three very diverse materials was also identified. In those tests, relatively large specimens (100 mm × 300 mm) were exposed in accordance with ASTM GS2: Standard Practice for Exposing and Evaluating Metals and Alloys in Surface Seawater.
This paper describes a series of corrosion tests performed to determine the general and localized corrosion behavior of two stainless alloys (UNS S31603 and UNS NO8367) and 70/30 CuNi (UNS C71500) in three aqueous environments associated with advanced reverse osmosis (RO) desalination of natural seawater. In addition to seawater (the RO feed stock), the other environments included a 2nd-pass RO brine with lower chloride content and total dissolved solids man raw seawater, and an ultrapure 3rd-pass permeate.
Two ASTM standards were reviewed for guidance in the design of the experiment Since testing could be conducted in an operating prototype RO system, the test program followed the general procedures for an in-plant corrosion tests described by ASTM G4-95: Standard Guide for Conducting Corrosion Coupon Tests in Field Applications. This standard, along with G78- 95: Standard Guide for Crevice Corrosion Testing of Iron-Base and Nickel-Base Alloys in Seawater and Other Chloride-Containing Environments, provided guidance in the selection of test specimens and mounting fixtures as well as crevice formers utilized. The G78-9S standard guide also provided considerations associated wim the interpretation of the crevice corrosion test results.
Quantification of Dna Adducts in Small Fish Exposed to Alkylating Agents
Authors: Law JM , McMillin DJ , Swenson DH , Means JC 
Published: March 2009

It is widely believed that most chemical carcinogens act by binding to cellular genetic material and causing somatic mutations. Chemical modification of DNA (e.g., the formation of DNA adducts) is the first in a series of stages that lead to mutation, cell transformation, and tumor development.
Sensitive methods for detection of DNA adducts are essential for mechanistic studies of mutagenesis and carcinogenesis and for biomonitoring of populations at risk for environmentally caused cancer. DNA adducts may be detected with such methods as 32Ppostlabeling, immunoassays, HPLC with fluorescence detection, and gas chromatography/mass spectrometry, with varying degrees of sensitivity and structural specificity. Alkylation at the N-7 position of guanine is a preferential site of attack for most alkylating agents, but may be of little biological consequence, while adduct formation at the O6 position of guanine (less common) is most highly correlated with carcinogenesis.
We have examined the suitability of western mosquitofish (Gambusia affinis) as a native sentinel species for monitoring environmental exposures to mutagens and carcinogens. Mosquitofish are a native species to the U.S. and are also widely distributed in warm waters throughout the world. These fish are ideal for monitoring local exposures because they are non-migratory and are found in a wide variety of habitats. In the laboratory, they are easily cultured using techniques developed for other small fish species and appear resistant to infectious diseases. Thus, methods may be directly assessed under controlled conditions before being applied to field situations.
In these studies, mosquitofish were exposed to a model alkylating agent, methylazoxymethanol acetate, at 10 ppm in the ambient water for 2 h. Fish were then transferred to clean water and held for up to 72 h. Livers were excised, pooled for 5 fish, and DNA was extracted and prepared for analysis. Liver DNA extracts were assessed for levels of N-7 and O6-methylguanine by isotope dilution GC/mass spectrometry, using deuterated analogs of methylguanine adducts as standards. Detection limits for the assay were approximately 1.6 femtomoles of adduct per mg DNA (about 1 adduct per 2 million bases). Approximately 55–185 pg (330–1100 femtomoles) O6 -methylguanine per mg DNA were measured in exposed fish in the first 72 h after exposure. These lesions were correlated with a 33% liver tumor incidence after 25 weeks in parallel experiments.
The Risk Implications of the Distribution of Chromium Forms in Environmental Media
Authors: Mahoney LA , Petroff DM , Batey JC 
Published: March 2009

Chromium exhibits multiple oxidation (valence) states, ranging from (-II) to (+VI). Under natural conditions, however, chromium typically exists in the Cr(III) (trivalent) and/or Cr(VI) (hexavalent) form, with the hexavalent form exhibiting higher solubility and much greater toxicity than the trivalent form. Due to the large differences in toxicity, the distribution of chromium oxidation states (Cr(III) and Cr(VI)) in site media is potentially of great importance to the calculation of site risk levels, and thus ultimately to cleanup activities. Despite its importance, chromium oxidation states are often not available for media samples collected at waste sites.
Typical assumptions regarding the chromium distribution in site media are presented. Actual chromium distribution data from media from baseline investigations of several waste sites are also presented for groundwater, surface water, and soil and compared in terms of background chromium levels and the nature of site wastes. The differences in toxicity of Cr(III) and Cr(VI) are briefly discussed. Risk estimates and risk-based cleanup levels generated using different assumptions for the distribution of chromium in site media for a selected example site are then given. These risk-based cleanup levels are compared to various state regulatory limits, MCLs, and Practical Quantitation Limits (PQLs) for chromium.
Effects of Food Label Health and Nutrition Claims on Consumer Perceptions
Authors: Corney MJ , Issanchou S , Shepherd R , Griffin K , Nanayakkara C , Daillant B 
Published: March 2009

Two experiments are reported that examined consumers' perceptions of food package labels where health and nutrition claims were present and where they had been removed. Unlike previous studies examining the influence of information on perception, realistic materials were used. This was accomplished by presenting information on a computer as photo-realistic images of packages where claims had been removed by editing to give a without-claims condition. Automatic presentation of materials and data collection meant participants proceeded through the computer questionnaire without the presence of an experimenter. The experiment was conducted with both British and French consumers. No significant difference on purchase intention or attitude to purchase was found between conditions with either population sample.
The British group showed a significant trend to rate products as likely to be approved by those whose opinion they regarded as important in the claims condition. French participants showed a similar effect whereby packages without claims were always perceived as significantly beneficial with a low subjective norm effect and a mixture of both factors with claims present. In both population samples, label information provision was evaluated more highly than a collection of single sensory and nutritional attributes. Multiple regressions against attitude to purchase showed that sensory attributes were given higher weighting than nutritional or direct label attitude measures with both groups. Argument that health and nutrition claims are likely to have very large effects on consumers' buying patterns thus may be treated with caution. These results suggest that from a marketing perspective where claims are relevant they should be given a subsidiary position to claims about sensory qualities.
Choosing the Best Package: Sensory Scaling Provides Better Guidance
Authors: Gunn C , Cooper H 
Published: March 2009

Product packs and packages protect the contents but also contribute significantly to consumer perceptions of the brand and product through color and design. If advertising budgets are low, the pack plays a major sales role at the point-of-sale by communicating its product contents and brand image to consumers.
A theory of consumer interaction with packaging is proposed that consists of four stages: 1. Impact (noticeability at point-of-sale). 2. Imprint (message or image communicated). 3. Ident (communication fit with consumer needs). 4. Intent (sum of the first three in terms of intention to buy).
This theory forms the basis of an integrated approach for assessing packaging—combining qualitative research, perceptual mapping, and sensory scaling techniques. Sensory techniques are used to diagnose specific pack design elements and their contribution to the overall message or image. Direction can be given for optimization of the pack design, even in situations where there is a need to harmonize designs across more than one geographical market.
Dislocation Amplitude-Dependent Damping in Crystals
Authors: Kustov SB , Golyandin SN 
Published: March 2009

Experimental investigations of the amplitude-frequency dependences of the dislocation amplitude-dependent damping (ADD), amplitude-dependent Young's modulus defect, and reversible nonlinear anelastic strain in a number of crystals served as a basis for the phenomenological description of the dislocation amplitude-dependent damping and quantitative analysis of its components. A rheological model with a corresponding differential equation has been constructed to describe the amplitude-frequency spectra of the dislocation anelasticity. Calculations according to the proposed model revealed a good correspondence with the experimental data. Some parameters of the model, accounting, for example, for the effective stress component and its dependence on the anelastic strain rate, are found in some cases to be the same for the macro — and reversible microplastic deformation.
It has been shown that there exist at least three contributions, which may form the amplitude-frequency spectra of ADD due to dislocation motion: (i) overcoming of the internai stress “ripples” or internal stress field hysteresis, (ii) thermally activated, and (iii) athermal overcoming of point obstacles. These three components appear to be linked, in general, to the different levels of the defect structure of the crystals: interaction of dislocations, and perhaps, dislocation groups, and interaction of isolated dislocations with point obstacles. Limitations of the proposed phenomenological description are also discussed. Finally a qualitative microscopic description of dislocation nonlinear anelasticity is proposed, based on the “nonlocalized friction” concept.
Magnetoplastic Effect: Relaxation of the Dislocation Structure and Microcreep of Nonmagnetic Crystals
Authors: Alshits VI , Darinskaya EV , Kazakova OL , Mikhina EY , Petrzhik EA 
Published: March 2009

A new physical phenomenon—the dislocation displacements as a result of exposing specimens to a static magnetic field (B = 0.1-27) in the absence of mechanical loading—is discovered and investigated for sodium chloride, cesium iodide, lithium fluoride, zinc, and aluminum (NaCl, Csl, LiF, Zn, and AI) single crystals. This effect is characterized by the following properties: The mean dislocation displacement or path ℓ is proportional to B2, inversely proportional to the square root of the concentration C of paramagnetic impurities, and increases linearly with time t of the magnetic treatment; there is no influence of the magnetic field on dislocation mobility in crystals with diamagnetic impurities; the effect is temperature independent in the range T = 4.2-77 K and grows only by 20% with a further increase of T up to room temperature; the saturation of ℓ(t) and ℓ(B) dependencies takes place at large values of t and B on the level corresponding to an average distance between the “forest” dislocations; an abrupt decrease of the effect is found when the frequency v of an alternating (over orientation) magnetic field exceeds some critical value vc ∝ B2, independent of T and C, but sensitive to a type of impurity, to X-ray irradiation, and different for edge and screw dislocations; a strong effect of a static electric field (E = 0.2-12 kV/m) on the mobility of charged dislocations in NaCl and LiF specimens simultaneously exposed to a static magnetic field is found (with no electric influence at B = 0); and the critical level Ec is found above which there is no saturation of dislocation displacements ℓ (B, t)—that is, the transition from a relaxation of dislocation structure to a microcreep is observed at E &gt; Ec.
phenomenon is interpreted as a result of unlocking of dislocations from paramagnetic centers because of spin-dependent electron transitions in a dislocation-impurity system under the action of external magnetic field with further motion of dislocations in the long-range internal stress field combined with an electric driving force when an electric field is applied.
Internal Friction Spectrum Analysis for Complex Alloyed Austenitic Steels
Authors: Golovin IS , Zharkov RV , Golovin SA 
Published: March 2009

At least two maxima have been defined in the relatively narrow domain (240 to 280°C, 1 Hz) on the temperature-dependent internal friction curves for the quenched and coldworked austenitic alloys with different chemical composition. The first peak is connected with reorientation of interstitial atoms couples in the applied stresses, the second with the dislocation motion. Analysis of the temperature-dependent internal friction spectrum for heat treated or mechanical treated alloys or both is considered to be difficult.
A new approach for the investigation of this complex spectrum has been developed. Computer simulation of internal friction (IF) peak splitting to a few partial peaks is suggested. The method applied for the splitting of complex IF peaks in the heat treated iron-nickel-molybdenum (Fe-Ni-Mo) alloys is based on different activation energies of diffusion for carbon and nitrogen atoms in face-centered-cubic solid solution. The optimization procedure has been carried out with the use of experiment planning and by searching for the function minimum by the method of steepest descent.
After plastic deformation the IF spectrum of the quenched specimens becomes more compli-cated. The superposition of three IF peaks Qc-1 (carbon), Qn-1 (nitrogen) and strain-induced IF peak Qp-1 takes place.
The results of computer simulation of the IF spectrum as well as the obtained data for activation energies for the heat treated and deformed iron-nickel, iron-nickel-molybdenum, iron-chromium-nickel, and iron-manganese-aluminum alloys are discussed. The influence of the degree of plastic deformation and chemical composition on the IF peak is analyzed on this basis.