bluuebunny/crossref_metadata_2025 huggingface dataset:
Speed effects in gliding motility assays due to surface passivation, water isotope, and osmotic stress.
Authors: Maloney Andy , Herskowitz Lawrence , Koch Steven
Published: May 2010

The molecular motor kinesin-1, an ATPase, and the substrate it walks along, microtubules, are vital components of eukaryotic cells. Kinesin converts chemical energy to linear motion as its two motor domains step along microtubules in a process similar to how we walk. Cells create systems of microtubules that direct the motion of kinesin. This directed motion allows kinesin to transport various cargos inside cells.During the stepping process, the kinesin motor domains bind and unbind from their binding sites on the microtubules. Binding and unbinding rates of biomolecules are highly dependent on hydration and exclusion of water from the binding interface. Osmotic stress will likely strongly affect the binding and unbinding rates for kinesin and thus offers a tool to specifically probe those steps. We will report the effects of different osmolytes on microtubule speed and other observables in the gliding motility assay.Kinesin’s kinetic core cycle hydrolyzes ATP with the help of a water molecule. Any modification to the water molecules the kinesin is in will change how ATP hydrolyzes and will ultimately affect how kinesin moves along microtubules. We will report preliminary results showing how kinesin is affected when the solvent it is in is changed from light water to heavy water. When used in a surface assay or in devices, the kinesin and microtubule system is also dependent on substrate passivation. Kinesin motor domains do not transport microtubules in the gliding motility assay if kinesin is added to a glass microscope slide that has not been functionalized. Functionalization of the glass slides and slips is typically performed with bovine milk proteins called caseins. Bovine casein is a globular protein that can be broken up into four constituents: αs1, αs2, β, and κ. Each casein constituent affects how kinesin adheres to the glass and ultimately the speed at which microtubules are observed to glide at. Building on the work of Verma et.al., we have found that each constituent individually produces different outcomes in gliding assays. We will present these findings and discuss implications they have for use of gliding assays to study kinesin and use of kinesin-microtubule system in microdevices. [1] Chaen, S, N Yamamoto, I Shirakawa, and H Sugi. 2001. Effect of deuterium oxide on actomyosin motility in vitro. Biochimica et biophysica acta 1506, no. 3: 218-23. [2] Vivek Verma, William O Hancock, Jeffrey M Catchmark, "The role of casein in supporting the operation of surface bound kinesin," J. Biol. Eng. 2008; 2: 14.

Acknowledgements:

This work was supported by the DTRA CB Basic Research Program under Grant No. HDTRA1-09-1-008.
Development and validation of an analysis method for the detection of altered resistance in transgenic plants to herbivore-pathogen-complexes
Authors: Hühnlein Anja , Schubert Jörg , Thieme Thomas
Published: May 2010

Genetically modified plants (GMPs) have to pass several safety evaluations before they can be approved but identification of undesired changes in metabolism is hard to achieve due to its complexity. Such unexpected changes could be reflected by changes in virus resistance and feeding behaviour of herbivores such as aphids. Altered behaviour can be determined by so- called life table statistics where e. g. the lifetime and the reproduction rate are analysed. Such experiments are time consuming and costly. The behaviour alterations should also be detectable by changes in virus uptake und transmission. Thus, quantitative detection methods are needed in order to measure the absolute virus content in plants and in aphids. Potato leafroll virus (PLRV) and Potato virus Y (PVY) are efficiently transmitted by the green peach aphid Myzus persicae. PVY is transmitted non-persistently whereas PLRV is transmitted in a persistent and circulative manner. Consequently, PLRV is especially suited for experiments determining changes in the feeding behaviour.In recent years, several quantitative PCR-assays have been developed for the detection of PLRV in plants. Published assay conditions were not useful for the virus detection in aphids, since primers often bound non-specifically. Furthermore, particular extraction methods had to be developed, since reagents used for plant material were not suitable for aphids with their high content of inhibitory substances.However, RNA extraction is very costly and not suitable for high-throughput screening. Therefore, highly specific assays based on immunocapture-RT-qPCR were developed for the quantitative detection of both PLRV and PVY in aphids and plants. The efficiency of the assays is comparable for the detection of viruses in plants as well as in vectors.In the future, these methods will be applied to investigate the influence of differentgenetic modifications on virus content and feeding behaviour.
Frequency-dependent stability of parallel-plate electrostatic actuators in conductive fluids
Authors: Sounart T. L. , Panchawagh H. V. , Mahajan R. L.
Published: May 2010

We present an electromechanical stability analysis of passivated parallel-plate electrostatic actuators in conductive dielectric media and show that the pull-in instability can be eliminated by tuning the applied frequency below a design-dependent stability limit. A partial instability region is also obtained, where the actuator jumps from the pull-in displacement to another stable position within the gap. The results predict that the stability limit is always greater than the critical actuation frequency, and therefore any device that is feasible to actuate in a conductive fluid can be operated with stability over the full range of motion.
Acoustic driven flow and lattice Boltzmann simulations to study cell adhesion in biofunctionalized μ-fluidic channels with complex geometry
Authors: Fallah M. A. , Myles V. M. , Krüger T. , Sritharan K. , Wixforth A. , Varnik F. , Schneider S. W. , Schneider M. F.
Published: May 2010

Accurately mimicking the complexity of microvascular systems calls for a technology which can accommodate particularly small sample volumes while retaining a large degree of freedom in channel geometry and keeping the price considerably low to allow for high throughput experiments. Here, we demonstrate that the use of surface acoustic wave driven microfluidics systems successfully allows the study of the interrelation between melanoma cell adhesion, the matrix protein collagen type I, the blood clotting factor von Willebrand factor (vWF), and microfluidic channel geometry. The versatility of the tool presented enables us to examine cell adhesion under flow in straight and bifurcated microfluidic channels in the presence of different protein coatings. We show that the addition of vWF tremendously increases (up to tenfold) the adhesion of melanoma cells even under fairly low shear flow conditions. This effect is altered in the presence of bifurcated channels demonstrating the importance of an elaborate hydrodynamic analysis to differentiate between physical and biological effects. Therefore, computer simulations have been performed along with the experiments to reveal the entire flow profile in the channel. We conclude that a combination of theory and experiment will lead to a consistent explanation of cell adhesion, and will optimize the potential of microfluidic experiments to further unravel the relation between blood clotting factors, cell adhesion molecules, cancer cell spreading, and the hydrodynamic conditions in our microcirculatory system.
Dynamic light scattering investigations of nanoparticle aggregation following a light-induced pH jump
Authors: Murphy Ryan J. , Pristinski Denis , Migler Kalman , Douglas Jack F. , Prabhu Vivek M.
Published: May 2010

There are many important processes where the stability of nanoparticles can change due to changes in solution environment. These processes are often difficult to study under controlled changes to the solution conditions. Dynamic light scattering was used to measure the initial kinetics of aggregation of carboxylated polystyrene nanoparticles after well-defined pH jumps using aqueous solutions of photoacid generator (PAG). With this approach, the pH of the solution was controlled by exposure to ultraviolet (UV) light without the delays from mixing or stirring. The aggregation kinetics of the nanoparticles was extremely sensitive to the solution pH. The UV exposure dose is inversely correlated with the resulting surface charge of the nanoparticles. Decreasing pH decreases the electrostatic repulsion force between particles and leads to aggregation. The reaction-limited or diffusion-limited aggregation kinetics was sensitive to the pH quench depth, relative to the acid-equilibrium constant (pKa) of the surface carboxylic acid groups on the nanoparticles. Since numerous PAGs are commercially available, this approach provides a flexible method to study the aggregation of a variety of solvent-dispersed nanoparticle systems.
Control of orbital ordered state in strained Nd0.25Sr1.75MnO4 films
Authors: Takahashi K. S. , Fujioka J. , Ida Y. , Kawasaki M. , Tokura Y.
Published: May 2010

Epitaxial strain effect has been studied for Nd0.25Sr1.75MnO4 thin films on (100) surfaces of two different isostructural (single-layered perovskite) substrates, LaSrAlO4 and LaSrGaO4. Due to the anisotropic strain in the MnO2 plane, the orientation-controlled films were stabilized with the structure consistent with that of C-type antiferromagnetic and d3x2−r2 ferro-orbital-ordered state. Measurements of highly anisotropic optical spectra show that the tensile strain in the MnO2 plane aligns ferroically the direction of d3x2−r2 orbitals parallel to the film plane, whereas compressive strain does those vertical to the film plane. These results indicate that the direction of the ferroic ordering of d3x2−r2 orbitals can be controlled by external uniaxial pressure, implying a potential for a switching device.
Strain induced suppression of silver agglomeration of indium-containing silver contact
Authors: Jung Gwan Ho , Son Jun Ho , Song Yang Hee , Lee Jong-Lam
Published: May 2010

The mechanism for thermally stable indium-containing silver [Ag(In)] Ohmic contact on p-type GaN has been investigated. The specific contact resistivity as low as 3.8×10−5 Ω cm2 and a high reflectance of 88.4% at a 460 nm wavelength were obtained by annealing Ag(0.5 wt % In) alloy contact at 450 °C in air ambient. The In atoms in Ag matrix made In–O chemical bonds, producing a tensile stress in the film. This compensated thermal compressive stress built in the Ag film. As a result, In atoms in Ag film play a role in preventing Ag contact from agglomeration, leading to high reflectance and good thermal stability.
Modified ion sensitive field effect transistor sensors having an extended gate on a thick dielectric
Authors: Ahn Chang-Geun , Kim Ansoon , Park Chan Woo , Ah Chil Seong , Yang Jong-Heon , Kim Tae-Youb , Jang Moongyu , Sung Gun Yong
Published: May 2010

Modified ion sensitive field effect transistors having an extended gate (EG) on a thick dielectric have been developed to obtain extremely high sensitivity. The capacitance of the EG is controlled to be very small via the thickness of the dielectric layer so that it may be ignored when compared with the gate capacitance of the transistor. As a result, the gate voltage can be fully dependent on the surface charge of the EG. When microalbumin protein of concentration 1 μg/ml on a monoclonal antibody of a microalbumin surface of the EG is injected, an extremely high sensitivity of 1800% is observed.
Enhanced microwave performance of cobalt nanoflakes with strong shape anisotropy
Authors: Ma Fei , Qin Yong , Li Yun-Ze
Published: May 2010

Co nanoflakes are synthesized through a low temperature hydrothermal method. The single-phased hexagonal close-packed Co nanoflakes have a diameter of several micrometers and a thickness about 80 nm. Magnetic hysteresis loops are quite different along different directions deviating from the nanoflakes plane, which shows Co nanoflakes have strong magnetic anisotropy. Flakelike morphology influence the performance of complex permeability in gigahertz frequency. Natural resonance peak happens at 5.74 GHz with the contribution of shape anisotropy. Multiple resonance phenomenon appears due to the exchange resonance effect, which makes Co nanoflakes a broadband candidate for microwave absorbing material.
Effect of three-body interactions on Ar adsorption on graphitized carbon black
Authors: Ustinov Eugene A.
Published: May 2010

The Axilrod–Teller equation is incorporated into nonlocal density functional theory (NLDFT) to improve the description of low-temperature argon adsorption isotherm on graphitized carbon black. Using the NLDFT based on the Tarazona smoothed density approximation and the test-particle method, the pair and triplet distribution functions for liquid argon were analyzed. The latter allowed us to quantitatively account for the three-body Axilrod–Teller nonadditive term. An analogous scheme to that of Weeks, Chandler, and Andersen is proposed to incorporate the Axilrod–Teller equation into the NLDFT in the framework of mean field approximation. The three-body nonadditive term appeared to decrease the internal energy of liquid argon by about 5%, which is in agreement with molecular simulation results. The new approach has been applied to the vapor-liquid coexistence and to argon adsorption on graphitized carbon black at 87.3 K. The approach has been shown to fit the experimental adsorption isotherm within the relative error of about 4% as opposed to 37% in the case of the standard NLDFT. This is due to weakening of the intermolecular interaction potential by about 20% in the molecular layer nearest to the graphite surface resulted mainly from the positive Axilrod–Teller contribution of triplets comprising one carbon atom.
Obsessive compulsive disorder: integration of cognitive-behaviour therapy and clinical psychology care into the primary care context
Authors: Kyrios Michael , Moulding Richard , Jones Barbara
Published: May 2010

In primary care, evidence-based psychological treatments for obsessive compulsive disorder (OCD), such as cognitive behaviour therapy (CBT), have not been readily available. We aimed to develop models of care for OCD that account for barriers to access and can be integrated into general practice settings. Multiple methodologies and sources were utilised, including literature reviews, a reference group, focus groups, interviews and questionnaire responses from consumers, psychologists and/or GPs. It was found that there were similarities and some differences among stakeholders in attitudes and knowledge about OCD, and views about treatment and assessment in primary care. Three models of care for patients with OCD were developed and integrated into a treatment program operating through a division of general practice. Participating GPs preferred referral to a specialist clinic, irrespective of participation in an educational program about OCD. Based on these findings, it is suggested that effective integration of specialist CBT treatments for OCD into primary care is possible if the needs and views of all stakeholders are accounted for.
Termination of pregnancy and the over 30s: what are trends in contraception use 1996 - 2006?
Authors: Abigail Wendy F. , Power Charmaine , Belan Ingrid
Published: May 2010

There is a shift in fertility patterns with more women commencing childbearing over 30 years of age. Little is known about trends in contraception use by women in this age group seeking a termination of pregnancy. This research presents a trend analysis to determine if there were significant changes in trends in contraception use pre- and post-termination of pregnancy for women over 30 years of age from 1996 to 2006 in South Australia. Data were collected from 1996 to 2006 from a service in South Australia. Data were examined using simple linear regression. At the time of conception, 53% of women reported using some form of contraception. Additionally, there was a significant decline in women using natural family planning methods at conception. Post-operatively, there was a significant decline in hormone methods being chosen, and a significant increase in women not using any contraception. Women over 30 years of age used contraception at the time of conception pre- and post-operatively of having a pregnancy terminated over the 10 year period of the study. Health promotion activities need to be further developed to cater for this age group and to take into consideration changing fertility patterns.
Theorising stigma and the experiences of injecting drug users in Australia
Authors: Tindal Christine , Cook Kay , Foster Nena
Published: May 2010

This paper examines the stigma of injecting drug use as an underlying factor in the poor health status of Australian injecting drug users. Drawing on various models of stigma described in the literature, we examine injecting drug users’ experiences. As a case study, examples from Victorian (specifically Melbourne) policy and practice are included to exemplify community and societal attitudes towards injecting drug users and the implications of these for injecting drug user health. We conclude that redressing the negative effects of stigma requires political will, financial support, increased community commitment and a better understanding of the links between the social determinant of health and the poor health status of injecting drug users. Without reducing the stigma of injecting drug use the health of this marginalised population is likely to get worse, which will have broader negative population health effects.
Indigenous men's support groups and social and emotional wellbeing: a meta-synthesis of the evidence
Authors: McCalman Janya , Tsey Komla , Wenitong Mark , Wilson Andrew , McEwan Alexandra , James Yvonne Cadet , Whiteside Mary
Published: May 2010

Indigenous men’s support groups are designed to empower men to take greater control and responsibility for their health and wellbeing. They provide health education sessions, counselling, men’s health clinics, diversionary programs for men facing criminal charges, cultural activities, drug- and alcohol-free social events, and advocacy for resources. Despite there being ~100 such groups across Australia, there is a dearth of literature on their strategies and outcomes. This paper is based on participatory action research involving two north Queensland groups which were the subject of a series of five ‘phased’ evaluative reports between 2002 and 2007. By applying ‘meta-ethnography’ to the five studies, we identified four themes which provide new interpretations of the data. Self-reported benefits included improved social and emotional wellbeing, modest lifestyle modifications and willingness to change current notions of ‘gendered’ roles within the home, such as sharing housework. Our qualitative research to date suggests that through promoting empowerment, wellbeing and social cohesion for men and their families, men’s support groups may be saving costs through reduced expenditure on health care, welfare, and criminal justice costs, and higher earnings. Future research needs to demonstrate this empirically.
Use of SMS to support parents who experience violence from their adolescents
Authors: Howard Jo , Friend Denise , Parker Trish , Streker Garry
Published: May 2010

This study explores the use of the short messaging service (SMS) to support parents who experience violence from their adolescent. The parents participated in the Inner South Community Health Service (ISCHS) Who’s the Boss program, an 8-week parent psycho-educational program for parents abused by their adolescents. An ISCHS counsellor, Andrew Compton, was interested in exploring the benefits of SMS technology and how text messages could be used to support women who had experienced family violence. We decided to pilot the use of SMS with group participants of Who’s the Boss who were interested in this ‘value-added’ strategy. This pilot used SMS technology to reinforce behavioural strategies that had been learnt in the groups to support parents in self-care. The project involved 19 consumers (through focus groups) to design the SMS messages that would most benefit them, decide how often and when they would be sent and evaluate their usefulness in supporting them to take a stand against their adolescent’s abuse and violence in the home. Safety concerns were also explored with all participants before the commencement of the project. The project findings demonstrated that SMS messages were useful and supported parents to make changes and address their adolescent’s abuse and violence. The use of SMS has applicability to a range of therapeutic programs including parenting programs, anxiety and depression programs and family violence programs. An extensive risk assessment must be undertaken if the use of SMS is to be considered to support women who have left violent partners to ascertain the safety of women and the likelihood that their partners may have access to their mobile phones. Women with violent partners are most at risk at the point of, or immediately following, separation and the use of SMS may in fact severely compromise the safety of these women. For this reason, SMS may not be appropriate in the support of women who have experienced family violence where there is still contact with the perpetrator.
Leaf fossils of Proteaceae tribe Persoonieae from the Late Oligocene - Early Miocene of New Zealand
Authors: Carpenter Raymond J. , Bannister Jennifer M. , Jordan Gregory J. , Lee Daphne E.
Published: May 2010

Fossils from the Newvale lignite mine, Southland, are the first substantiated foliar records of Proteaceae subfamily Persoonioideae. The fossils possess very large stomata, a probable synapomorphy for Persoonioideae, and within Proteaceae the combination of this feature and more or less parallel-aligned, brachyparacytic stomatal complexes and undulate anticlinal epidermal cell walls is uniquely found in this subfamily. The new genus Persoonieaephyllum is described to recognise affinity of the fossil leaves and cuticles with tribe Persoonieae of Persoonioideae and their distinction from its only other extant representative, Placospermum. Two new species are described. P. ornatum is represented by linear leaves less than 20 mm wide and possessing more or less parallel-aligned major veins. These leaves closely match those of extant hypostomatic, broad-leaved species of tribe Persoonieae and are distinct from Placospermum in venation and several cuticular details. P. villosum has so far been recovered only as cuticular material in disaggregated lignite. It is distinct from P. ornatum in having abundant trichome bases, an absence of surface tubercules, and even larger stomata (guard cells often >70 μm long). The fossils extend the known record of Persoonioideae in the New Zealand–New Caledonia region by ~20 million years.
Vaccination with peptide mimetics of the gp41 prehairpin fusion intermediate yields neutralizing antisera against HIV-1 isolates
Authors: Bianchi Elisabetta , Joyce Joseph G. , Miller Michael D. , Finnefrock Adam C. , Liang Xiaoping , Finotto Marco , Ingallinella Paolo , McKenna Philip , Citron Michael , Ottinger Elizabeth , Hepler Robert W. , Hrin Renee , Nahas Deborah , Wu Chengwei , Montefiori David , Shiver John W. , Pessi Antonello , Kim Peter S.
Published: May 2010

Eliciting a broadly neutralizing polyclonal antibody response against HIV-1 remains a major challenge. One approach to vaccine development is prevention of HIV-1 entry into cells by blocking the fusion of viral and cell membranes. More specifically, our goal is to elicit neutralizing antibodies that target a transient viral entry intermediate (the prehairpin intermediate) formed by the HIV-1 gp41 protein. Because this intermediate is transient, a stable mimetic is required to elicit an immune response. Previously, a series of engineered peptides was used to select a mAb (denoted D5) that binds to the surface of the gp41 prehairpin intermediate, as demonstrated by x-ray crystallographic studies. D5 inhibits the replication of HIV-1 clinical isolates, providing proof-of-principle for this vaccine approach. Here, we describe a series of peptide mimetics of the gp41 prehairpin intermediate designed to permit a systematic analysis of the immune response generated in animals. To improve the chances of detecting weak neutralizing polyclonal responses, two strategies were employed in the initial screening: use of a neutralization-hypersensitive virus and concentration of the IgG fraction from immunized animal sera. This allowed incremental improvements through iterative cycles of design, which led to vaccine candidates capable of generating a polyclonal antibody response, detectable in unfractionated sera, that neutralize tier 1 HIV-1 and simian HIV primary isolates in vitro. Our findings serve as a starting point for the design of more potent immunogens to elicit a broadly neutralizing response against the gp41 prehairpin intermediate.
Charting the Course for the Future of Science in Healthcare Epidemiology: Results of a Survey of the Membership of the Society of Healthcare Epidemiology of America
Authors: Sinaii Ninet ,   Research Committee of the Society of Healthcare Epidemiology of America_p1
Published: May 2010

Objective.

To describe the results of a survey of members of the Society for Healthcare Epidemiology of America (SHEA) that (1) measured members' perceptions of gaps in the healthcare epidemiology knowledge base and members' priorities for SHEA research goals, (2) assessed whether members would be willing to participate in consortia to address identified gaps in knowledge, and (3) evaluated the need for training for the next generation of investigators in the field of healthcare epidemiology.

Design.

Electronic and paper survey of members of SHEA, a professional society formed to advance the science of healthcare epidemiology through research and education.

Participants.

All society members were invited to participate.

Results.

Of 1,289 SHEA members, 593 (46.0%) responded. Respondents identified the following issues as important for the Research Committee of SHEA: setting the scientific agenda for healthcare epidemiology, developing collaborative infrastructure to conduct research, and developing funding mechanisms for research. Respondents ranked multidrug-resistant gram-negative organisms, antimicrobial stewardship, methicillin-resistant Staphylococcus aureus, adherence to effective hand hygiene guidelines, and Clostridium difficile infections as the most important scientific issues facing the field. Respondents ranked inadequate project funding, lack of protected time for research, and inability to obtain a grant, contract, and/or outside funding as the most significant barriers to conducting research. More than 92% of respondents support creating a SHEA research consortium; more than 40% would participate even if no additional funding were available; nearly 90% identified developing research training as a key function for SHEA.

Conclusions.

These data provide a road map for the SHEA Research Committee for the next decade.
Nanoscale transport properties at silicon carbide interfaces
Authors: Roccaforte F , Giannazzo F , Raineri V
Published: May 2010

Wide bandgap semiconductors promise devices with performances not achievable using silicon technology. Among them, silicon carbide (SiC) is considered the top-notch material for a new generation of power electronic devices, ensuring the improved energy efficiency required in modern society. In spite of the significant progress achieved in the last decade in the material quality, there are still several scientific open issues related to the basic transport properties at SiC interfaces and ion-doped regions that can affect the devices' performances, keeping them still far from their theoretical limits. Hence, significant efforts in fundamental research at the nanoscale have become mandatory to better understand the carrier transport phenomena, both at surfaces and interfaces. In this paper, the most recent experiences on nanoscale transport properties will be addressed, reviewing the relevant key points for the basic devices' building blocks. The selected topics include the major concerns related to the electronic transport at metal/SiC interfaces, to the carrier concentration and mobility in ion-doped regions and to channel mobility in metal/oxide/SiC systems. Some aspects related to interfaces between different SiC polytypes are also presented. All these issues will be discussed considering the current status and the drawbacks of SiC devices.
Investigation of the physical properties of ion assisted ZrN thin films deposited by RF magnetron sputtering
Authors: Signore M A , Valerini D , Rizzo A , Tapfer L , Capodieci L , Cappello A
Published: May 2010

Ion bombardment during thin film growth is known to cause structural and morphological changes in the deposited films, thus affecting their physical properties. In this work zirconium nitride films have been deposited by the ion assisted magnetron sputtering technique. The ion energy is controlled by varying the voltage applied to the substrate in the range 0–25 V. The deposited ZrN films are characterized for their structure, surface roughness, oxygen contamination, optical reflectance and electrical resistivity. With increasing substrate voltage crystallinity of the films is enhanced with a preferential orientation of the ZrN grains having the (1 1 1) axis perpendicular to the substrate surface. At the same time, a decrease in electrical resistivity and oxygen contamination content is observed up to 20 V. A higher substrate voltage (25 V) causes an inversion in the observed experimental trends. The role of oxygen contamination decrease and generation of nitrogen vacancies due to ionic assistance have been considered as a possible explanation for the experimental results.
Electropyroelectric technique for measurement of the thermal effusivity of liquids
Authors: Ivanov R , Marin E , Moreno I , Araujo C
Published: May 2010

The photopyroelectric method has been recognized as a reliable and useful tool for the measurement of the thermal properties of condensed matter samples. Usually the photothermal signal is generated using intensity modulated light beams, whose amplitudes are difficult to maintain stable. In this paper we describe a variant of this technique that uses amplitude modulated electrical current as excitation source, via Joule heating of the metal contact on one side of the pyroelectric sensor. The possibilities of this method, called by us the electropyroelectric technique, for thermal effusivity measurements of liquid samples are shown using test samples of distilled water, ethanol and glycerine. The results obtained for this parameter agree well with the values reported in the literature. Our measurement uncertainties are about 3%, a fact that opens several possible applications.
A new data mining approach for profiling and categorizing kinetic patterns of metabolic biomarkers after myocardial injury
Authors: Baumgartner Christian , Lewis Gregory D. , Netzer Michael , Pfeifer Bernhard , Gerszten Robert E.
Published: May 2010

Motivation: The discovery of new and unexpected biomarkers in cardiovascular disease is a highly data-driven process that requires the complementary power of modern metabolite profiling technologies, bioinformatics and biostatistics. Clinical biomarkers of early myocardial injury are lacking. A prospective biomarker cohort study was carried out to identify, categorize and profile kinetic patterns of early metabolic biomarkers of planned myocardial infarction (PMI) and spontaneous (SMI) myocardial infarction. We applied a targeted mass spectrometry (MS)-based metabolite profiling platform to serial blood samples drawn from carefully phenotyped patients undergoing alcohol septal ablation for hypertrophic obstructive cardiomyopathy serving as a human model of PMI. Patients with SMI and patients undergoing catheterization without induction of myocardial infarction served as positive and negative controls to assess generalizability of markers identified in PMI.

Results: To identify metabolites of high predictive value in tandem mass spectrometry data, we introduced a new feature selection method for the categorization of metabolic signatures into three classes of weak, moderate and strong predictors, which can be easily applied to both paired and unpaired samples. Our paradigm outperformed standard null-hypothesis significance testing and other popular methods for feature selection in terms of the area under the receiver operating curve and the product of sensitivity and specificity. Our results emphasize that this new method was able to identify, classify and validate alterations of levels in multiple metabolites participating in pathways associated with myocardial injury as early as 10 min after PMI.

Availability: The algorithm as well as supplementary material is available for download at: www.umit.at/page.cfm?vpath=departments/technik/iebe/tools/bi

Contact:  christian.baumgartner@umit.at

Supplementary information:  Supplementary data are available at Bioinformatics online.
Correction for King, Introduction: energy for a sustainable future
Authors: King David A.
Published: May 2010

Correction for ‘Introduction: energy for a sustainable future’ by David A. King (Phil. Trans. R. Soc. A
365
, 883–895.
(doi:
10.1098/rsta.2006.1954
)).

The author's affiliation in the print version of the paper is incorrect, and should read as follows.
Chief Scientific Advisor to HM Government, Head of the Office of Science and Innovation and Director of Research, Department of Chemistry, University of Cambridge
G-Box Binding Factor1 Reduces CATALASE2 Expression and Regulates the Onset of Leaf Senescence in Arabidopsis
Authors: Smykowski Anja , Zimmermann Petra , Zentgraf Ulrike
Published: May 2010

Hydrogen peroxide (H2O2) is discussed as being a signaling molecule in Arabidopsis (Arabidopsis thaliana) leaf senescence. Intracellular H2O2 levels are controlled by the H2O2-scavenging enzyme catalase in concert with other scavenging and producing systems. Catalases are encoded by a small gene family, and the expression of all three Arabidopsis catalase genes is regulated in a senescence-associated manner. CATALASE2 (CAT2) expression is down-regulated during bolting time at the onset of leaf senescence and appears to be involved in the elevation of the H2O2 level at this time point. To understand the role of CAT2 in senescence regulation in more detail, we used CAT2 promoter fragments in a yeast one-hybrid screen to isolate upstream regulatory factors. Among others, we could identify G-Box Binding Factor1 (GBF1) as a DNA-binding protein of the CAT2 promoter. Transient overexpression of GBF1 together with a CAT2:β-glucuronidase construct in tobacco (Nicotiana benthamiana) plants and Arabidopsis protoplasts revealed a negative effect of GBF1 on CAT2 expression. In gbf1 mutant plants, the CAT2 decrease in expression and activity at bolting time and the increase in H2O2 could no longer be observed. Consequently, the onset of leaf senescence and the expression of senescence-associated genes were delayed in gbf1 plants, clearly indicating a regulatory function of GBF1 in leaf senescence, most likely via regulation of the intracellular H2O2 content.
Divinyl Chlorophyll(ide)aCan Be Converted to Monovinyl Chlorophyll(ide)aby a Divinyl Reductase in Rice
Authors: Wang Pingrong , Gao Jiaxu , Wan Chunmei , Zhang Fantao , Xu Zhengjun , Huang Xiaoqun , Sun Xiaoqiu , Deng Xiaojian
Published: May 2010

3,8-Divinyl (proto)chlorophyll(ide) a 8-vinyl reductase (DVR) catalyzes the reduction of 8-vinyl group on the tetrapyrrole to an ethyl group, which is indispensable for monovinyl chlorophyll (Chl) synthesis. So far, three 8-vinyl reductase genes (DVR, bciA, and slr1923) have been characterized from Arabidopsis (Arabidopsis thaliana), Chlorobium tepidum, and Synechocystis sp. PCC6803. However, no 8-vinyl reductase gene has yet been identified in monocotyledonous plants. In this study, we isolated a spontaneous mutant, 824ys, in rice (Oryza sativa). The mutant exhibited a yellow-green leaf phenotype, reduced Chl level, arrested chloroplast development, and retarded growth rate. The phenotype of the 824ys mutant was caused by a recessive mutation in a nuclear gene on the short arm of rice chromosome 3. Map-based cloning of this mutant resulted in the identification of a gene (Os03g22780) showing sequence similarity with the Arabidopsis DVR gene (AT5G18660). In the 824ys mutant, nine nucleotides were deleted at residues 952 to 960 in the open reading frame, resulting in a deletion of three amino acid residues in the encoded product. High-performance liquid chromatography analysis of Chls indicated the mutant accumulates only divinyl Chl a and b. A recombinant protein encoded by Os03g22780 was expressed in Escherichia coli and found to catalyze the conversion of divinyl chlorophyll(ide) a to monovinyl chlorophyll(ide) a. Therefore, it has been confirmed that Os03g22780, renamed as OsDVR, encodes a functional DVR in rice. Based upon these results, we succeeded to identify an 8-vinyl reductase gene in monocotyledonous plants and, more importantly, confirmed the DVR activity to convert divinyl Chl a to monovinyl Chl a.
Stromal Hsp70 Is Important for Protein Translocation into Pea and Arabidopsis Chloroplasts
Authors: Su Pai-Hsiang , Li Hsou-min
Published: May 2010

Hsp70 family proteins function as motors driving protein translocation into mitochondria and the endoplasmic reticulum. Whether Hsp70 is involved in protein import into chloroplasts has not been resolved. We show here Arabidopsis thaliana knockout mutants of either of the two stromal cpHsc70s, cpHsc70-1 and cpHsc70-2, are defective in protein import into chloroplasts during early developmental stages. Protein import was found to be affected at the step of precursor translocation across the envelope membranes. From solubilized envelope membranes, stromal cpHsc70 was specifically coimmunoprecipitated with importing precursors and stoichiometric amounts of Tic110 and Hsp93. Moreover, in contrast with receptors at the outer envelope membrane, cpHsp70 is important for the import of both photosynthetic and nonphotosynthetic proteins. These data indicate that cpHsc70 is part of the chloroplast translocon for general import and is important for driving translocation into the stroma. We further analyzed the relationship of cpHsc70 with the other suggested motor system, Hsp93/Tic40. Chloroplasts from the cphsc70-1 hsp93-V double mutant had a more severe import defect than did the single mutants, suggesting that the two proteins function in parallel. The cphsc70-1 tic40 double knockout was lethal, further indicating that cpHsc70-1 and Tic40 have an overlapping essential function. In conclusion, our data indicate that chloroplasts have two chaperone systems facilitating protein translocation into the stroma: the cpHsc70 system and the Hsp93/Tic40 system.
Females of Cotesia vestalis, a parasitoid of diamondback moth larvae, learn to recognise cues from aphid‐infested plants to exploit honeydew
Authors: KUGIMIYA SOICHI , SHIMODA TAKESHI , MCNEIL JEREMY N. , TAKABAYASHI JUNJI
Published: May 2010

1. To maximise their reproductive success, the females of most parasitoids must not only forage for hosts but must also find suitable food sources. These may be nectar and pollen from plants, heamolymph from hosts and/or honeydew from homopterous insects such as aphids.

2. Under laboratory conditions, females of Cotesia vestalis, a larval parasitoid of the diamondback moth (Plutella xylostella) which does not feed on host blood, survived significantly longer when held with cruciferous plants infested with non‐host green peach aphids (Myzus persicae) than when held with only uninfested plants.

3. Naïve parasitoids exhibited no preference between aphid‐infested and uninfested plants in a dual‐choice test, but those that had been previously fed aphid honeydew significantly preferred aphid‐infested plants to uninfested ones.

4. These results suggest that parasitoids that do not use aphids as hosts have the potential ability to learn cues from aphid‐infested plants when foraging for food. This flexible foraging behaviour could allow them to increase their lifetime reproductive success.
The role of oceanographic conditions and plankton availability in larval fish assemblages off the Catalan coast (NW Mediterranean)
Authors: OLIVAR M. PILAR , EMELIANOV MIKHAIL , VILLATE FERNANDO , URIARTE IBON , MAYNOU FRANCESC , ÁLVAREZ IGNACIO , MOROTE ELVIRA
Published: May 2010

In the northwestern Mediterranean, most fish species reproduce in early summer and fewer in the autumn mixing period. This study analyses and compares larval fish assemblages (LFA) in both seasons, and is the first attempt to characterize LFA structure for the autumn period. We analyze horizontal and vertical distribution of fish larvae and the micro‐ and mesozooplankton biomass and abundance of the main zooplankton groups. The oceanographic situation was analyzed through the study of data from CTD, Nν‐Shuttle and ADCP surveys. LFA were determined by ordination analyses based on larval abundance, and the relationships between larval assemblages and environmental variables were investigated through canonical correspondence analysis. The importance of some hydrographic variables (temperature, salinity and stability of the water column), current fields (along‐shelf and across‐shelf transport) and the abundance of zooplankton are discussed as important factors shaping the structure of larval assemblages. In early summer, LFA were mainly structured by a combination of bathymetry and trophic components, although sea surface temperature also played a role in shaping the horizontal larval distributions. In autumn, trophic variables were the main factors influencing the shelf‐dwelling species assemblage. Larvae of oceanic species, on the other hand, were not related to trophic variables but were more affected by current fields.
Dynamic spatial zoning to manage southern bluefin tuna (Thunnus maccoyii) capture in a multi‐species longline fishery
Authors: HOBDAY ALISTAIR J. , HARTOG JASON R. , TIMMISS TRENT , FIELDING JOSH
Published: May 2010

Reduction of bycatch through spatial management is one possible approach in fisheries management. One requirement is description of the habitat of the species in question, and this is now possible for a range of species using data collected from electronic tags. Here we report on a spatial management approach used to limit unwanted capture of southern bluefin tuna (SBT, Thunnus maccoyii) in the eastern Australia longline fishery. The approach combines a habitat model conditioned with temperature preference data from 56 pop‐up satellite archival tags deployed on SBT, and an ocean model to produce near real‐time habitat predictions utilized by fishery managers during the fishing season. Three habitat types based on probability of SBT occurrence are identified in the fishing region, and spatial zoning by managers is used to regulate fisher access to these zones. This management approach has been used since 2003, and despite dynamic spatial management often being resisted by fishers or managers because of perceived implementation complexity, there has been an increase in complexity of the management actions over the 6‐yr period. Managers now request more habitat predictions each season, update the spatial zoning more frequently, and apply more complicated management lines dividing the habitat types. This has resulted in an improved fit to the modeled habitat predictions, and as catch per unit effort (CPUE) of SBT is related to the habitat type, has contributed to the overall success of the management approach. This implemented management approach illustrates that managers and fishers can successfully implement complex dynamic spatial zoning.
Molecular analysis in two Tunisian families with combined factor V and factor VIII deficiency
Authors: ABDALLAH H. E. , GOUIDER E. , AMOR M. B. , JLIZI A. , MEDDEB B. , ELGAAIED A.
Published: May 2010

Summary.  Combined factor V (FV) and factor VIII (FVIII) deficiency (F5F8D) is a rare autosomal recessive disorder caused by mutations in LMAN1 or MCFD2 genes which encode proteins that form a complex involved in the transport of FV and FVIII from the endoplasmic reticulum to Golgi apparatus. We report two novel mutations in MCFD2 gene and one recurrent mutation in LMAN1 gene that caused combined FV and FVIII deficiency in two unrelated Tunisian Muslim families. For the first family two patients were homozygous for a new missense mutation Asp81His in exon 3 of MCFD2 and heterozygous for a second new missense mutation Val100Asp in the same exon. Replacement respectively of the hydrophilic Asp residue with hydrophobic positively charged His and of the hydrophobic neutral Val residue with the Asp residue most likely disrupts the MCFD2–LMAN1 interaction, thus leading to the disease phenotype. For the second family a reported Arg202X mutation in exon 5 in the LMAN1 gene was identified in the homozygous state.
Plasma BDNF and tPA are associated with late‐onset geriatric depression
Authors: Shi Yanyan , You Jiayong , Yuan Yonggui , Zhang Xiangrong , Li Hailin , Hou Gang
Published: May 2010

Aims:  Studies in the recent decade have shown that brain‐derived neurotrophic factor (BDNF) may play an important role in the pathogenesis of major depressive disorder (MDD). Tissue‐type plasminogen activator (tPA) has been implicated in the control of the direction of BDNF action. The aim of the study was therefore to investigate the changes of BDNF/tPA levels and their clinical meanings in geriatric depression.

Methods:  Plasma BDNF and tPA levels were measured in late‐onset geriatric depression (LGD) before treatment (n = 24) and after 6 weeks of antidepressant treatment (n = 24) compared with control subjects (n = 30) using enzyme‐linked immunosorbent assay. The severity of depression was assessed with the Hamilton Depression Rating Scale.

Results:  Baseline plasma BDNF and tPA levels were significantly lower in LGD patients compared to controls (P = 0.037 and P = 0.000, respectively). There was a heightening tendency of plasma BDNF level after treatment.

Conclusions:  Plasma BDNF and tPA levels are associated with LGD. The complex mechanism of BDNF and tPA in LGD should be further explored in future studies.