bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficient vectors for expression cloning of large numbers of PCR fragments in P. pastoris
Authors: Rao Ben , Zhong Xing , Wang Yaping , Wu Qiong , Jiang Zhengbing , Ma Lixin 
Published: February 2010

AbstractThe yeast vectors described, pYEV and pYEVB, were designed for parallel polymerase chain reaction (PCR) cloning of open reading frames (ORFs) and immediate protein expression in Pichia pastoris. The pYEV vector was used to clone PCR fragments obtained by using Taq or similar polymerase mixes, which leave an A‐base overhang. The other vector pYEVB, with the same features for blunt‐end ligation of PCR products, was developed to be complementary to pYEV. These two plasmids were linearized using the restriction enzymes BfuI and SchI, respectively. The purified PCR products, without any other treatments, were cloned into the linearized vectors, followed by selection on plates supplemented with X‐gal. Only desired recombinants carrying the target gene in the correct orientation can give typical blue colonies. This screening technique is based on a lacO reconstruction strategy that can produce a full‐length lacO to exhaust endogenous LacI and switch on the transcription of lacZ in the host. The recombinant plasmids extracted from the blue colonies can be linearized by SalI and transformed into P. pastoris for immediate expression. By using these two vectors, researchers could be saved from the tedious and time‐consuming conventional cloning procedures. Copyright © 2010 John Wiley & Sons, Ltd.
A functional analysis of Kluyveromyces lactis glutathione reductase
Authors: García‐Leiro A. , Cerdán M. E. , González‐Siso M. I. 
Published: February 2010

AbstractGlutathione reductase (GLR) null mutants of the yeast Kluyveromyces lactis, a model eukaryotic respiratory cell, were created and phenotypically analysed. We found that cells lacking GLR show decreased resistance to oxidative stress and higher levels of reactive oxygen species and catalase activity than the wild‐type strain. However, glutathione redox levels (GSH : GSSG ratio) were similar in the ΔKlglr1 mutant and wild‐type strains. The thioredoxin–thioredoxin reductase system is proposed as an alternative system for maintaining the GSH : GSSG ratio in the ΔKlglr1 mutant. The involvement of GLR in glucose metabolism in K. lactis is suggested by the improved growth on glucose caused by the ΔKlglr1 mutation and by the increased GLR activity in the ΔKlgcr1 strain, KlGcr1 being a transcriptional activator of glycolytic genes. We also studied the subcellular location of GLR in K. lactis, showing that it is present in mitochondria; however, the ΔKlglr1 mutation does not affect mitochondrial morphology. Genomic DNA integrity and life span are also unaffected by the ΔKlglr1 mutation, at least under the conditions tested in this study. Copyright © 2010 John Wiley & Sons, Ltd.
The role of PaAAC1 encoding a mitochondrial ADP/ATP carrier in the biosynthesis of extracellular glycolipids, mannosylerythritol lipids, in the basidiomycetous yeast Pseudozyma antarctica
Authors: Morita Tomotake , Ito Emi , Fukuoka Tokuma , Imura Tomohiro , Kitamoto Dai 
Published: February 2010

AbstractPseudozyma antarctica produces large amounts of the glycolipid biosurfactants known as mannosylerythritol lipids (MEL), which show not only excellent surface‐active properties but also versatile biochemical actions. A gene homologous with a mitochondrial ADP/ATP carrier was dominantly expressed in P. antarctica under MEL‐producing conditions on the basis of previous gene expression analysis. The gene encoding the mitochondrial ADP/ATP carrier of P. antarctica (PaAAC1) contained a putative open reading frame of 954 bp and encodes a polypeptide of 317 amino acids. The deduced translation product shared high identity of 66%, 70%, 69%, 74%, 75% and 52% with the mitochondrial ADP/ATP carrier of Saccharomyces cerevisiae (AAC1), S. cerevisiae (AAC2), S. cerevisiae (AAC3), Kluyveromyces lactis (KlAAC), Neurospora crassa (NcAAC) and human (ANT1), respectively, and conserved the consensus sequences of all ADP/ATP carrier proteins. The gene expression by introducing a plasmid pUXV1‐PaAAC1 into the yeast cells increased the MEL production. In addition, the expression of PaAAC1 in which the conserved arginine and leucine required for ATP transport activity were replaced with isoleucine and serine, respectively, failed to increase MEL production. Accordingly, these results suggest that PaAAC1 encoding a mitochondrial ADP/ATP carrier should be involved in MEL biosynthesis in the yeast. Copyright © 2010 John Wiley & Sons, Ltd.
Trans Fatty Acids in Human Milk are an Indicator of Different Maternal Dietary Sources Containing Trans Fatty Acids
Authors: Mueller A. , Thijs C. , Rist L. , Simões‐Wüst A. P. , Huber M. , Steinhart H. 
Published: February 2010

AbstractThe trans fatty acid (TFA) patterns in the fats of ruminant meat and dairy products differ from those found in other (processed) fats. We have evaluated different TFA isomers in human breast milk as an indicator of dietary intake of ruminant and dairy fats of different origins. Breast milk samples were collected 1 month postpartum from 310 mothers participating in the KOALA Birth Cohort Study (The Netherlands). The study participants had different lifestyles and consumed different amounts of dairy products. Fatty acid methyl esters were determined by GC‐FID and the data were evaluated by principal component analysis (PCA), ANOVA/Post Hoc test and linear regression analysis. The two major principal components were (1) 18:1 trans‐isomers and (2) markers of dairy fat including 15:0, 17:0, 11(trans)18:1 and 9(cis),11(trans)18:2 (CLA). Despite similar total TFA values, the 9(trans)18:1/11(trans)18:1‐ratio and the 10(trans)18:1/11(trans)18:1‐ratio were significantly lower in milk from mothers with high dairy fat intake (40–76 g/day: 0.91 ± 0.48, P < 0.05) compared to low dairy fat intake (0–10 g/day: 1.59 ± 0.48), and lower with strict organic meat and dairy use (>90% organic: 0.92 ± 0.46, P < 0.05) compared to conventional origin of meat and dairy (1.40 ± 0.61). Similar results were obtained for the 10(trans)18:1/11(trans)18:1‐ratio. We conclude that both ratios are indicators of different intake of TFA from ruminant and dairy origin relative to other (including industrial) sources.
Brief report: Adolescents under missile attacks: Sense of coherence as a mediator between exposure and stress‐related reactions
Authors: Braun‐Lewensohn Orna , Sagy Shifra , Roth Guy 
Published: February 2010

ABSTRACTEmploying the salutogenic approach (Antonovsky, 1987), this pilot study aimed at exploring the mediation effect of Sense of Coherence (SOC) on the relationships between exposure to missile attacks and stress‐related reactions among adolescents. A strong SOC means a tendency to see the world as more comprehensible, manageable and meaningful. Data were gathered during August 2006 (Second Lebanon War) from 230 Israeli adolescents, 12–18 years old. Adolescents filled out self‐reported questionnaires, including demographics, level of physical exposure, SOC, Scale of Psychological Distress (SPD), State Anxiety and State Anger. Exposure to missile attacks was found to be significantly positively linked to stress reactions; exposure was negatively linked to SOC which was also negatively linked to stress reactions. The mediation hypothesis was supported, with SOC mediating the effect of exposure to missile attacks on stress reactions. It seems that SOC may have a protective effect against stress reactions among adolescents exposed to political violence. This should be further studied in a longitudinal research.
Eating Clean and Green? Investigating Consumer Motivations towards the Purchase of Organic Food
Authors: Smith Samantha , Paladino Angela 
Published: February 2010

Growing consumer concern for health and environment issues has resulted in increased attention towards the purchase and consumption of organic food. This has driven an increase in organic research, especially as marketers seek to understand the motivations behind consumer purchases of organic goods. This study explored the effects of health consciousness, environmental concern, organic knowledge, availability, quality, price consciousness, subjective norms, risk aversion, perceived control and familiarity on organic attitudes, organic purchase intentions and organic purchase behaviour. These variables formed the antecedents of the causal model which utilised Ajzen and Fishbein's (1980) Theory of Reasoned Action as the framework of analysis. Results showed strong support for the relationship between organic knowledge, subjective norms and environmental concern on organic attitudes. While health consciousness, quality, subjective norms and familiarity were found to influence purchase intentions, familiarity was the only variable found to exhibit a significant relationship with organic purchase behaviour. This paper will discuss the implications of these results for marketers. It will also consider the limitations of the study and areas for future research.
The significance of iron-stained foraminifera off SE Trinidad, West Indies, western central Atlantic Ocean
Authors: WILSON BRENT 
Published: February 2010

AbstractEleven samples of seafloor sediment were taken from water depths of 78–90 m within the Savonette Field, off SE Trinidad, western Atlantic Ocean. This surface sediment is relict, having been deposited during an early Holocene transgression. The samples yielded much iron-stained quartz and a rich assemblage of dead foraminifera, of which 75% of planktonic foraminifera were stained with iron, as was 66.5% of the calcareous benthonic foraminiferal assemblage. The fauna, both iron-stained and unstained, was dominated byCibicidoidesex. gr.pseudoungerianus, and is concluded, despite the proximity of the Orinoco Delta, to be equivalent to a relictCibicidoidesbiofacies in carbonate-rich areas of the Gulf of Mexico. Staining was by limonite and hematite. Differing percentages of calcareous benthonic species had been stained with iron, ANOVA revealing three groups of species within which the mean percentage of iron-stained specimens per sample did not differ: (a)Globocassidulina subglobosaandHanzawaia concentrica; (b)Amphistegina gibbosa, Cassidulina norcrossi australis Cibicioidesex. gr.pseudoungerianus,C. io,Elphidium translucensandQuinqueloculina lamarckiana; and (c)Eponides antillarumandE. repandus. It is concluded that species differ in their susceptibility to iron staining, and that planktonic foraminifera are more susceptible than most benthonic species. Although waters off northern South America are turbid and the photic zone only ~25 m deep, the relict assemblage contained 8.4% algal symbiont-bearing foraminifera (especiallyA. gibbosaandE. translucens) that would be limited to the photic zone. These are thought to have lived at a time early in the Holocene transgression when sequestration of sediment within the Orinoco delta rendered the water sufficiently clear for viable populations of symbiont-bearing foraminifera. Should iron-stained foraminifera prove to be restricted to transgressive systems tracts, this would make them a useful sequence stratigraphic tool.
Age of volcanism and its migration in the Samoa Islands
Authors: McDOUGALL IAN 
Published: February 2010

AbstractPotassium–argon (K–Ar) ages on whole rock samples have been measured on lavas from the subaerial Samoa Islands, which form a broadly linear volcanic chain that extends from the ESE to the WNW for about 360 km. The Manu'a Islands near the southeast limit of the chain exhibit youthful ages, with most <0.4 Ma, in keeping with the geological observations. Tutuila consists of several volcanoes, and previous work yielded a mean K–Ar age of 1.26 ± 0.15 Ma for the shield-building volcanism. Upolu, to the WNW of Tutuila, gives a mean age of 2.15 ± 0.35 Ma for the shield-building phase, represented by the Fagaloa Volcanics, with much of the island covered by significantly younger volcanic rocks. Savai'i, further to the WNW, is dominated by youthful volcanism, extending into historic times. In a restricted area, adjacent to the NE coast of Savai'i, previously thought to have volcanic rocks correlating with the Fagaloa Volcanics of Upolu, the ages are much younger than those on Upolu, lying between 0.32 and 0.42 Ma. Considering only the subaerial volcanism from Ta'u to Upolu, but also including Vailulu'u, the volcanism has migrated in a systematic ESE direction at 130 ± 8 mm a−1 over 300 km in the last 2.2 Ma. This rate is nearly twice that obtained from GPS measurements of Pacific Plate motion of 72 mm a−1 at N64°W in this area. However, if the much older age of shield-building volcanism from the submarine foundations of Savai'i is included, the regression yields a volcanic migration rate of 72 ± 14 mm a−1, in keeping with the measured GPS rate and consistent with a hotspot origin for the island chain. This suggests that the volcanic migration rates determined from the age of subaerial volcanism can be considerably overestimated, and this is now evident in other Pacific Ocean island chains. Clearly, the ages of the main shield-building volcanism from subaerial volcanism are minima, and if the older submarine lavas can be measured, these may yield a migration rate more in keeping with current plate motions.
Analysis of the interaction between particles in non-ideal quasi-equilibrium extended systems
Authors: VAULINA O. S. , LISIN E. A. , GAVRIKOV A. V. , PETROV O. F. , FORTOV V. E. 
Published: February 2010

AbstractTwo techniques for the analysis of the interaction between particles in non-ideal quasi-equilibrium extended systems are considered. The first technique is based on a solution of the inverse problem describing the movement of dust particles by a system of Langevin equations. The second technique proceeds from the basic integral approaches of statistical physics. The conditions for the correct use of these techniques are presented, together with the results of their experimental application for the analysis of inter-grain interactions in the dusty plasma of radio frequency discharge.
Design and kinematics analysis of a new 3CCC parallel mechanism
Authors: Gan Dongming , Liao Qizheng , Dai Jian S. , Wei Shimin 
Published: February 2010

SUMMARYA CCC limb and a new 3CCC parallel mechanism have been designed in this paper based on geometry analysis. Their mobility and geometrical constraints are discussed by using screw theory and geometrical equations separately. Following that both the inverse and forward kinematics of the 3CCC parallel mechanism are proposed, in which Dixon's resultant is used to get the forward solutions for the orientation and a eighth-order polynomial equation in one unknown is obtained, leading to the results for the position analysis, numerical examples confirm these theoretical results. A short comparison with the traditional Stewart platforms is presented in terms of kinematics, workspace and trajectory planning.
Tendon sheath analysis for estimation of distal end force and elongation for sensorless distal end
Authors: Phee S. J. , Low S. C. , Dario P. , Menciassi A. 
Published: February 2010

SUMMARYTendon sheath actuation is found in many applications, particularly in robotic hands and surgical robots. Due to the friction between the tendon and sheath, many undesirable characteristic such as backlash, hysteresis and non-linearity are present. It is desirable to know the end-effector force and elongation of the tendon to control the system effectively, but it is not always feasible to fix sensors at the end effector. A method to estimate the end-effector parameters using only a force and position sensor at the proximal site is given. An analytical study is presented and experiments are reported to support the result, showing a maximum full-scale error of approximately 7%. This result is achieved if the shape of the sheath remains the same and buckling is negligible. The results presented in this study could contribute towards haptic development in robotics surgery.
Overcoming trends in irregularly spaced locations by regional polish – exemplified by estimation of the range of influence between Salmonella Dublin-seropositive cattle herds
Authors: ERSBØLL A. K. , ERSBØLL B. K. 
Published: February 2010

SUMMARYThe aim of the study was to develop a procedure to remove spatial trends in irregularly spaced data, with trends partly due to regional differences. Median polish is often used on regularly spaced (lattice) data where column and row medians are removed. For irregularly spaced data a low-resolution map of the spatial locations is often used where data locations are assigned to the nearest lattice node followed by median polish. In this study regional polish was developed. The inverse distance weighted median was calculated based on observations from locations in the neighbourhood of the actual observation. The regional polish residual is obtained as the difference between the observed value and the weighted median. The regional polish procedure was applied to Salmonella Dublin data showing strong regional trends. Estimation of the range of influence between cattle herds with positive S. Dublin herd status was considerably improved with a stable parameter estimate and reduced standard error.
Emergence of MRSA clone ST22 in healthy young adults in the community in the absence of risk factors
Authors: MOLLAGHAN A. M. , LUCEY B. , COFFEY A. , COTTER L. 
Published: February 2010

SUMMARYOne thousand adults aged between 18 and 35 years were investigated for nasal colonization with community-acquired methicillin-resistantStaphylococcus aureus(CA-MRSA). Each volunteer completed a questionnaire to assess the presence or absence of risk factors for hospital-acquired MRSA (HA-MRSA) carriage. All MRSA isolated were characterized by microbiological and molecular methods. AS. aureuscarriage rate of 22% and a MRSA carriage rate of 0·7% were observed. Analysis of the questionnaires revealed 121 individuals with HA-MRSA risk factors. Subsequently two MRSA infections with associated risk factors were excluded from calculation of the true carriage rate and an adjusted rate of 0·57% (5/879) was established. All seven MRSA isolates expressed the genotypic profile ST22-MRSA-IV, were PVL negative,agrtype 1, and differed only by their antimicrobial susceptibility patterns. ST22-MRSA-IV (EMRSA-15) has shown worldwide spread in the hospital setting but has not been previously documented in isolation in the community.
A modelling study of atrial septostomy for pulmonary arterial hypertension, and its effect on the state of tissue oxygenation and systemic blood flow
Authors: Diller Gerhard-Paul , Lammers Astrid E. , Haworth Sheila G. , Dimopoulos Konstantinos , Derrick Graham , Bonhoeffer Philipp , Gatzoulis Michael A. , Francis Darrel P. 
Published: February 2010

AbstractAtrial septostomy is performed in patients with severe pulmonary arterial hypertension, and has been shown to improve symptoms, quality of life and survival. Despite recognized clinical benefits, the underlying pathophysiologic mechanisms are poorly understood. We aimed to assess the effects of right-to-left shunting on arterial delivery of oxygen, mixed venous content of oxygen, and systemic cardiac output in patients with pulmonary arterial hypertension and a fixed flow of blood to the lungs. We formulated equations defining the mandatory relationship between physiologic variables and delivery of oxygen in patients with right-to-left shunting. Using calculus and computer modelling, we considered the simultaneous effects of right-to-left shunting on physiologies with different pulmonary flows, total metabolic rates, and capacities for carrying oxygen. Our study indicates that, when the flow of blood to the lungs is fixed, increasing right-to-left shunting improves systemic cardiac output, arterial blood pressure, and arterial delivery of oxygen. In contrast, the mixed venous content of oxygen, which mirrors the average state of tissue oxygenation, remains unchanged. Our model suggests that increasing the volume of right-to-left shunting cannot compensate for right ventricular failure. Atrial septostomy in the setting of pulmonary arterial hypertension, therefore, increases the arterial delivery of oxygen, but the mixed systemic saturation of oxygen, arguably the most important index of tissue oxygenation, stays constant. Our data suggest that the clinically observed beneficial effects of atrial septostomy are the result of improved flow of blood rather than augmented tissue oxygenation, provided that right ventricular function is adequate.
Family meals and adolescents: what have we learned from Project EAT (Eating Among Teens)?
Authors: Neumark-Sztainer Dianne , Larson Nicole I , Fulkerson Jayne A , Eisenberg Marla E , Story Mary 
Published: February 2010

AbstractObjectiveThe purpose of the present paper is to provide an integrated overview of the research methodology and key findings from a decade of research on family meals as part of Project EAT (Eating Among Teens), a large, population-based study of adolescents.DesignFocus groups conducted with 141 middle-school and high-school adolescents suggested the importance of family meals in influencing adolescents’ food choices. These findings led to the inclusion of questions on family meals in the Project EAT-I survey, completed by 4746 middle-school and high-school students, and in the Project EAT-II longitudinal survey, completed by 2516 of the original participants five years later. A subset of 902 parents also participated in telephone interviews as part of Project EAT-I.ResultsFindings indicate that many adolescents and parents view family meals in a positive light, but there is great diversity in the context and frequency of family meal patterns in the homes of adolescents. Findings further suggest that family meals may have benefits in terms of dietary intake, disordered eating behaviours, substance use and psychosocial health.ConclusionsFindings from Project EAT, in conjunction with other research studies on family meals, suggest the importance of working with families to increase the frequency and improve the quality of family meals. Further research is needed in order to elucidate the pathways that underpin the relationships between family meals and health outcomes. Suggestions for a future research agenda based on what was learned from Project EAT are provided.
Diamonds in Torsion of Abelian Varieties
Authors: Jarden Moshe 
Published: February 2010

AbstractA theorem of Kuyk says that every Abelian extension of a Hilbertian field is Hilbertian. We conjecture that for an Abelian variety A defined over a Hilbertian field K every extension L of K in K(Ator) is Hilbertian. We prove our conjecture when K is a number field. The proof applies a result of Serre about l-torsion of Abelian varieties, information about l-adic analytic groups, and Haran's diamond theorem.