bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation ofAnguillicola crassus(Nematoda) infrapopulations in their definitive host, the European eel,Anguilla anguilla
Authors: FAZIO G. , SASAL P. , DA SILVA C. , FUMET B. , BOISSIER J. , LECOMTE-FINIGER R. , MONÉ H.
Published: October 2008

The parasitic nematodeAnguillicola crassuswas recently introduced into populations of the European eel,Anguilla anguilla. We investigated, under experimental conditions, the regulation ofA. crassusinfrapopulations. We tested the effects of (1) the resource-limited habitat of the parasite and (2) the coexistence of several developmental stages in its niche (the swim-bladder) on the composition of the infrapopulations. The results revealed that the respective effects of these factors differed substantially during the course of the infection. Third-stage larvae (L3s) establishment would not be constrained by the size of the swim-bladder. Their moult to fourth-stage larvae (L4s) would be accelerated as the number of L3s increased. The moulting time of L4s to adults would be reduced by males and would be constrained by the size of the swim-bladder. However, the moult of L4s to adults and their further development would be synchronized with those of the opposite sex. At the time of mating, the number of males and the body weight of adults would depend on the size of the swim-bladder. Soon after the laying of eggs, the developmental constraint on the late L3s would decrease. When adults die, constraints would cease and late larval stages would moult to become adults.
Efficacy of different chemotherapeutic schemes for hookworm-infected villagers in China
Authors: YANG W. P. , YANG L. J. , SHEN Y. P. , SHAO J. O. , ZHANG T.
Published: October 2008

A comparative analysis has been made of the efficacy of different chemotherapeutic schemes against hookworm infections in China. Hookworm eggs were detected by the improved Kato's thick smear method. Benzimidazole was offered to residents in the tested villages, while NaHCO3 was used as placebo in control villages. Data were analysed by negative binomial distribution with statistic software R2.2.1. In the tested village as a result of the application of selective chemotherapy, hookworm infection rate decreased from 58·79% to 1·08%, while the average of eggs per gram (EPG) reduced from 526·29 to 56·91. The infection rates in the target chemotherapy village and in the mass chemotherapy village declined from 6·90% to 1·92% and 10·10% to 0·65% respectively. It was concluded that the consecutive selective chemotherapy could rapidly decrease the infection rate and EPG of hookworm and maintain the infection rate at low level. The curative effect of the target chemotherapy was similar to that of the mass chemotherapy in the low hookworm endemic area.
Calendar calculating in savants with autism and healthy calendar calculators
Authors: Dubischar-Krivec A. M. , Neumann N. , Poustka F. , Braun C. , Birbaumer N. , Bölte S.
Published: October 2008

Background

Calendar calculation is the ability to quickly name the day that a given date falls on. Previous research has suggested that savant calendar calculation is based on rote memory and the use of rule-based arithmetic skills. The objective of this study was to identify the cognitive processes that distinguish calendar calculation in savant individuals from healthy calendar calculators.

Method

Savant calendar calculators with autism (ACC, n=3), healthy calendar calculators (HCC, n=3), non-savant subjects with autism (n=6) and healthy calendar calculator laymen (n=18) were included in the study. All participants calculated dates of the present (current month). In addition, ACC and HCC also calculated dates of the past and future 50 years.

Results

ACC showed shorter reaction times and fewer errors than HCC and non-savant subjects with autism, and significantly fewer errors than healthy calendar calculator laymen when calculating dates of the present. Moreover, ACC performed faster and more accurate than HCC regarding past dates. However, no differences between ACC and HCC were detected for future date calculation.

Conclusions

The findings may imply distinct calendar calculation strategies in ACC and HCC, with HCC relying on calendar regularities for all types of dates and an involvement of (rote) memory in ACC when processing dates of the past and the present.
Specialist cardiac services: what do young people want?
Authors: Wray Jo , Maynard Linda
Published: October 2008

Purpose

With improvements in the surgical and medical management of children with congenital heart disease, the majority are now expected to transition into adult services. Whilst the importance of successful transition is increasingly acknowledged, previous research has identified a number of areas of concern. We therefore wished to elicit the views of young people themselves concerning their requirements from a specialist cardiac service.

Methods

Using an exploratory approach our aims were to increase awareness of the service needs and expectations of young people, identify good practice and areas where communication processes and facilities could be improved, and enhance understanding of transition between paediatric and adult services. Postal questionnaires were sent to 63 young people with congenital cardiac disease aged 17 to 20 years. Open ended questions asked for views and experiences about facilities in the paediatric and adult areas, perceptions of transition between services and suggestions for improvements. Qualitative data were transferred verbatim into electronic format to facilitate coding and theming.

Results

Thirty-eight (60.3 percent) completed questionnaires were received. A number of themes, including communication, care processes/caring interactions and environment, emerged regarding areas of satisfaction and dissatisfaction within the paediatric and adult services, together with areas for improvement and important aspects of transition.

Conclusions

Young people’s views need to be taken into account at all stages of the patient journey. They want an individualised approach to their care which recognises that they have specific emotional and practical needs. Such findings need to be incorporated into an ongoing model of care.
Does this list contain what you were searching for? Learning adaptive dialogue strategies for interactive question answering
Authors: RIESER V. , LEMON O.
Published: October 2008

Policy learning is an active topic in dialogue systems research, but it has not been explored in relation to interactive question answering (IQA). We take a first step in learning adaptive interaction policies for question answering : we address the question of how to acquire enough reliable query constraints, how many database results to present to the user and when to present them, given the competing trade-offs between the length of the answer list, the length of the interaction, the type of database and the noise in the communication channel. The operating conditions are reflected in an objective function which we use to derive a hand-coded threshold-based policy and rewards to train a reinforcement learning policy. The same objective function is used for evaluation. We show that we can learn strategies for this complex trade-off problem which perform significantly better than a variety of hand-coded policies, for a wide range of noise conditions, user types, types of DB and turn-penalties. Our policy learning framework thus covers a wide spectrum of operating conditions. The learned policies produce an averagerelativeincrease in reward of 86.78% over the hand-coded policies. In 93% of the cases the learned policies perform significantly better than the hand-coded ones (p< .001). Furthermore we show that the type of database has a significant effect on learning and we give qualitative descriptions of the learned IQA policies.
Recovering Transitions From Repeated Cross-Sectional Samples
Authors: Eisinga Rob
Published: October 2008

This paper proposes a dynamic Markov model for the estimation of binary state-to-state transition probabilities from a sequence of independent cross-sectional samples. It discusses parameter estimation and inference using maximum likelihood (ML) methodology. The model is illustrated by the application of a three-wave panel study on pupils’ interest in learning physics. These data encompass more information than what is used to estimate the model, but this surplus information allows us to assess the accuracy and the precision of the transition estimates. Bootstrap and Bayesian simulations are used to evaluate the accuracy and the precision of the ML estimates. To mimic genuine cross-sectional data, samples of independent observations randomly drawn from the panel are also analyzed.
Solar wind drivers of large geomagnetically induced currents during the solar cycle 23
Authors: Huttunen K. E. J. , Kilpua S. P. , Pulkkinen A. , Viljanen A. , Tanskanen E.
Published: October 2008

In this paper we investigate the interplanetary drivers of the largest geomagnetically induced currents (GIC) during the solar cycle 23. Interplanetary coronal mass ejections (ICMEs) are the major causes of intense geomagnetic storms and large GIC. In particular, in this work we examine the effectiveness of different structures embedded in an ICME (namely sheath regions, ejecta, and boundary layers) in causing large GIC. It was found that when an ICME interacts with the Earth's magnetosphere the most intense GIC activity is likely to take place during the passage of the turbulent sheath region. The effectiveness of sheath regions in driving large GIC is possibly due to their capability to trigger substorms and to drive intense directly driven ionospheric activity. We also investigated the relationships between different solar wind parameters and the GIC amplitudes. The best correlation with the GIC amplitudes was found with the solar wind electric field and the epsilon parameter. Ejecta‐associated GIC seem to require an on‐going magnetospheric Dst storm while sheath regions and boundary layers can cause large GIC even when no activity is taking place in terms of Dst. Interestingly, four of the nine ejecta‐associated GIC took place during the recovery phases of a intense magnetic storm (but when Dst still was having storm time values below −50 nT).
Distributional impacts of water markets on small farmers: Is there a safety net?
Authors: Hadjigeorgalis Ereney
Published: October 2008

The United Nations 2006 human development report states that water markets have not been shown to protect the interests of the poor, while other research has found that water markets have benefited smaller, resource‐constrained farmers. This article provides insight into this international development debate by analyzing the impact of water markets on small farmers in the Limarí River Basin of Chile. The analysis is based on data collected from an extensive in‐person survey of 316 farmers in the basin. Results show that water markets in the basin have been successful in moving water and water rights from low‐ to high‐valued uses and that resource‐constrained farmers use temporary water sales as a safety net. The long‐term beneficial effects of water market trades for the most resource‐constrained farmers, however, remain unclear. These results are relevant to both Chile and a host of developing countries where agriculture is a predominant activity and water resources are scarce. They are also applicable to the western United States, where water market trades often originate in the agricultural sector.
Hunting a New Ocean Tracer
Authors: Umlauf Lars , Tanhua Toste , Waniek Joanna J. , Schmale Oliver , Holtermann Peter , Rehder Gregor
Published: October 2008

A useful method to obtain integrated estimates of vertical mixing in the ocean over a long period of time and a large area is the release of a tracer. Recent large‐scale tracer release experiments conducted in the Southern Ocean, such as the Diapycnal and Isopycnal Mixing Experiment (DIMES [see Gille et al., 2007]), and in the equatorial Atlantic will rely on a new tracer chemical called trifluoromethyl sulfur pentafluoride (SF5CF3), which is likely to become a standard for future experiments. Here we report results from the first injection of pure SF5CF3 into the ocean, which was carried out in a deep basin of the Baltic Sea.

Using the Baltic Sea as a natural laboratory for the investigation of physical mixing processes, this pilot study aims at improving our understanding of one of the most puzzling mixing properties in stratified ocean basins: Almost independent of the basin's size, the basin‐scale vertical mixing rates exceed the rates inferred from local turbulence measurements in the basin center by approximately 1 order of magnitude [see, e.g., Ledwell and Bratkovich, 1995].
Global Environmental Solutions Require Global Funding
Authors: Fry Juliane
Published: October 2008

As members of the next generation of environmental scientists, we are committed to conducting solutions‐oriented research on global environmental problems. In addition to the highly visible problem of climate change, we face global environmental threats such as biodiversity loss, worsening air quality, and limited food security and water availability. These threats do not stop at national borders. Research in these areas requires global coordination and collaboration, and it would be best served by an equally global funding infrastructure.

The United Nations Framework Convention on Climate Change Conference of the Parties will convene in 2009 in Copenhagen, Denmark, to negotiate post—Kyoto Protocol climate policy. One criterion for the success of these negotiations is their basis in the best available scientific understanding of the climate system at local, regional, and global scales. While the organizational infrastructure for global research coordination exists, funding is managed by national and regional agencies individually, with increasing emphasis on local concerns.
Understanding Great Earthquakes in Japan's Kanto Region: Third International Workshop on the Kanto Asperity Project; Chiba, Japan, 16–19 February 2008
Authors: Kobayashi Reiji , Curewitz Daniel
Published: October 2008

The 1703 (Genroku) and 1923 (Taisho) earthquakes in Japan's Kanto region (M 8.2 and M 7.9, respectively) caused severe damage in the Tokyo metropolitan area. These great earthquakes occurred along the Sagami Trough, where the Philippine Sea slab is subducting beneath Japan. Historical records, paleoseismological research, and geophysical/geodetic monitoring in the region indicate that such great earthquakes will repeat in the future.

A dense regional array of geodetic monitoring stations recorded several slow‐slip events (or “silent earthquakes”) off the Boso Peninsula in 1996, 2002, and 2007. These are thought to have occurred in the zone between coupled and stable‐sliding areas. The shape and extent of these great earthquake asperities (regions of maximum slip along fault planes during earthquakes) and source areas of slow‐slip events are still unclear. Geophysical monitoring and understanding the distribution of seismicity in areas exhibiting distinctly different seismotectonic characteristics will help to define regions along these plate boundaries characterized by slow‐slip events, repeating events, locked plate interfaces, and regions of maximum coseismic slip.
Exploring Venus as a Terrestrial Planet
Authors: Showstack Randy
Published: October 2008

AGU's book, Exploring Venus as a Terrestrial Planet, edited by Larry W. Esposito, Ellen R. Stofan, and Thomas E. Cravens, focuses on how the study of Venus will aid in understanding the evolution of terrestrial and extrasolar planets. The book's 12 chapters include discussions on Venus's surface and interior processes, atmospheric circulation, chemistry, and aeronomy as well as on astrobiology and technological challenges.

In this interview, Eos talks with Esposito, professor of astrophysical and planetary sciences at the University of Colorado's Laboratory for Atmospheric and Space Physics, in Boulder. Esposito has had a long interest in Venus, serving as coinvestigator for the NASA Pioneer Venus Orbiter's ultraviolet spectrograph from 1978 to 1993 and for the European Space Agency's Venus Express Venus Monitoring Camera since 2003, and as principal investigator for a NASA Venus Discovery mission study from 1993 to 1998.
Sunglint observations over land from ground and airborne L‐band radiometer data
Authors: Escorihuela M. J. , Saleh K. , Richaume P. , Merlin O. , Walker J. P. , Kerr Y. H.
Published: October 2008

This study quantifies the effects of Sun reflection over land surfaces on radiometric measurements at L‐band. The impact of the reflected Sun on radiometric measurements over a grass field and over an agricultural area reached 25 K and 17 K respectively. A model that predicts the impact of Sun reflection over land is developed and tested for two different radiometer configurations and spatial resolutions.
Comparison of total column ozone data from ground‐based MFRSR measurements taken in the southern U.S. region with OMI satellite retrievals
Authors: Williams Quinton L. , Reddy Remata S. , Liu Heping , Benjamin Markeitta S. , Lu Duanjun , Greene Kantave M.
Published: October 2008

A study of total column ozone (TCO) measurement data taken with a network of ground‐based MultiFilter Rotating Shadowband Radiometers (MFRSR) compared with data retrieved from the satellite‐based Ozone Monitoring Instrument (OMI) shows an average positive bias of 3.04% ± 1.7% under all sky days. The MFRSR station‐to‐station standard deviation was ±2.1%. In contrast, a recent 2‐year comparison of ground‐based Dobson and Brewer stations shows that OMI‐TOMS TCO averages only 0.4% higher than the station average, with station‐to‐station standard deviation of ±0.6%. Annual seasonal variability in the TCO is manifested through an increase beginning in December and going through May before the levels decrease over the northern summer until reaching the lowest levels around October. In this study, positive biases were found for the 11 southern U.S. MFRSR monitoring sites after an analysis of 2 years of data from January 2006–December 2007. Overall, our comparisons show that there is good agreement between OMI‐TOMS and MFRSR readings over the southern U.S.
Inversion of polar motion data: Chandler wobble, phase jumps, and geomagnetic jerks
Authors: Gibert Dominique , Le Mouël Jean‐Louis
Published: October 2008

We reconsider the analysis of the polar motion with a method totally different from the wavelet analysis used in previous papers. The total polar motion is represented as the sum of oscillating annual and Chandler terms whose amplitude and phase perturbations are inverted with a nonlinear simulated annealing method. The phase variations found in previous papers are confirmed with the huge phase change (≈3π/2) occurring in the 1926–1942 period and another less important one (≈π/3) in the 1970–1980 epoch. The best Chandler period, Tc, is found to be 434 ± 0.5 mean solar days. The epochs of significant phase changes found in the Chandler wobble are also those where important geomagnetic jerks occur in the secular variation of the geomagnetic field. Turbulent viscous friction produced by small‐scale topography at the core‐mantle boundary might be responsible for the observed phase jumps.
Increased Apparent Diffusion Coefficients on MRI Linked with Matrix Metalloproteinases and Edema in White Matter after Bilateral Carotid Artery Occlusion in Rats
Authors: Sood Rohit , Yang Yi , Taheri Saeid , Candelario-Jalil Eduardo , Estrada Eduardo Y , Walker Espen J , Thompson Jeffrey , Rosenberg Gary A
Published: October 2008

White matter (WM) injury after bilateral common carotid artery occlusion (BCAO) in rat is associated with disruption of the blood—brain barrier (BBB) by matrix metalloproteinases (MMPs). We hypothesized that WM injury as seen on magnetic resonance imaging (MRI) would correlate with regions of increased MMP activity. MRI was performed 3 days after BCAO surgery in rats. Apparent diffusion coefficients (ADC) were calculated and vascular permeability was quantified by the multiple-time graphical analysis (MTGA) method, using gadolinium-diethylenetriamine pentaacid (Gd-DTPA). After MRI, one group of animals had BBB permeability measured in the WM with 14C-sucrose, and another had Evans blue (EB) injected for fluorescent microscopy for MMP-2, MMP-9, tight junction proteins (TJPs), and in situ zymography. We found that ADC values were increased in WM in BCAO rats compared with controls ( P< 0.05). WM with increased ADC had leakage of EB. MMP-2 and MMP-9 activity on in situ zymograms corresponded with leakage of EB. Although increased permeability to EB could be visualized, permeability quantification with 14C-sucrose and Gd-DTPA failed to show increases and TJPs were intact. We propose that increased ADC, which is a marker of vasogenic edema, is related to activity of MMP-2 and MMP-9. MRI provides unique information that can be used to guide tissue studies of WM injury.
Expression of Cadherin Superfamily Genes in Brain Vascular Development
Authors: Krishna K , Redies Christoph
Published: October 2008

Cadherins are Ca2+-dependent cell adhesion molecules that are important in vertebrate nervous system development. We identified seven members of the cadherin superfamily (cadherin-4, cadherin-5, cadherin-6, cadherin-6, cadherin-11, protocadherin-1, and protocadherin-17) and an intracellular binding partner of δ-protocadherins, protein phosphatase 1α, as novel markers for developing blood vessels in the ferret brain. Some of the cadherin molecules are restricted to specific brain regions or a subset of blood vessels. The expression levels show a peak during perinatal vascular development. Our results suggest that multiple cadherins, which are also involved in neurogenesis, are regulators of angiogenesis in developing vertebrate brain.
Psychological antecedents to socially responsible behavior
Authors: Crilly Donal , Schneider Susan C. , Zollo Maurizio
Published: October 2008

To date, the discussion regarding corporate social responsibility (CSR) has primarily addressed organizational rationale and activities. Little has been said about the individual characteristics and behaviors that promote the development of CSR within organizations. In this paper, we propose and test a model to explain individual differences in the propensity to engage in socially responsible behavior (SRB). By linking values, affect and reasoning to managers' propensity to ‘do good’ and ‘do no harm,’ we provide a more complete picture of how SRB arises in organizations. A survey of 643 middle managers in five multinational corporations supports our contention that values, affect and reasoning matter for SRB. In particular, self‐transcendence values (universalism and benevolence) and positive affect increase the propensity to engage in SRB, as do moral and reputation‐based reasoning styles. Moreover, we find that values and affect shape more controlled processes such as moral reasoning. We develop implications for the interaction between the individual and the organization in promoting SRB.
The plasma transistor: A microcavity plasma device coupled with a low voltage, controllable electron emitter
Authors: Chen K.-F. , Eden J. G.
Published: October 2008

A microplasma transistor has been realized by injecting electrons into the sheath of a rare gas plasma with a low voltage (|Vb|<25 V), controllable electron emitter. Integrating a solid state emitter with a 500 μm diam. cylindrical microcavity plasma yields a three terminal current-controlled device capable of modulating the conduction current and light intensity generated by the microplasma. For an emitter voltage of Vb=−10 V, the rms charge carried by the conduction current of a Ne microplasma is tripled relative to the value measured for no current injection. Similarly, the wavelength-integrated visible emission is increased by 2.7 and 4 dB for Vb=−5 and −25 V, respectively. From the continuity equation for charged particle flux in the sheath, the electron density at the edge of the sheath is determined to be ns=(3±1)×1012 cm−3 for an electron temperature in the 1–5 eV range. Energizing the electron emitter is estimated to reduce the ratio of the ion to electron number densities at the cathode surface from 25 to 14. A parameter βp, defined as the microplasma transistor conductance normalized to that for the conventional plasma device (i.e., Vb=0), is introduced and found to be ∼40 for this unoptimized device when |Vb|=5 V.
Hydration free energy difference of acetone, acetamide, and urea
Authors: Jedlovszky Pál , Idrissi Abdenacer
Published: October 2008

The hydration free energy and hydration entropy difference of urea and acetone, and of acetamide and acetone have been calculated both by free energy perturbation and by the method of thermodynamic integration. The obtained results show a striking asymmetry between the thermodynamic changes accompanying the replacement of the first and second CH3 group of acetone by NH2. Thus, the first CH3∕NH2 exchange is found to lead to an about 10kJ∕mol decrease in the energy, 8kJ∕mol decrease in the Helmholtz free energy, and 5–10J∕molK decrease in the entropy of hydration, while similar values accompanying the second CH3∕NH2 exchange are found to be about −65kJ∕mol, −35kJ∕mol and −100J∕molK, respectively. These results indicate that the two NH2 groups of the urea molecule have a strong synergetic effect on the thermodynamics of the hydration of urea. The fact that the replacement of the two CH3 groups of acetone by NH2 leads to a strong decrease in the hydration entropy indicates that urea clearly has an ordering effect on nearby water.
Anisotropic in-plane strains in nonpolar AlN and AlGaN (112¯) films grown on SiC (112¯) substrates
Authors: Akasaka Tetsuya , Kobayashi Yasuyuki , Kasu Makoto
Published: October 2008

Nonpolar Al1−xGaxN (0≤x≤0.196) (112¯0) films were grown on 4H-SiC (112¯0) substrates by metal organic vapor phase epitaxy. Al1−xGaxN (0≤x≤0.057) films grew almost pseudomorphically on the substrates due to balanced in-plane stresses along [0001] and [11¯00], while Al1−xGaxN (0.057<x) films were strained along [0001] but partially relaxed along [11¯00] due to the absence of the balance. The crystal tilts of the films toward [0001] decreased monotonically with increasing Ga composition due to the correspondence between the (0001) plane distances of the films and the (0002) plane distance of substrates and due to a decrease in the in-plane strain along [0001].
Convection in deep vertically shaken particle beds. I. General features
Authors: Klongboonjit Sakon , Campbell Charles S.
Published: October 2008

It has long been known that shaking a granular bed can produce circulating convection. This is the first in a series of papers that explores convection in beds a hundred particles or more deep. In such deep beds, the pressures are high enough that the particles remain in contact with their neighbors throughout much of the vibrational period. As such, they interact elastically and convection becomes dependent on the elastic properties of the bed. Changing the particle stiffness can dramatically alter the convection, and for very soft or very hard particles, eliminate it completely. In this paper, the effect of stiffness, bed geometry, and frictional properties on the global convection properties are assessed.
Convection in deep vertically shaken particle beds. II. The relationship between convection and internal wave propagation
Authors: Klongboonjit Sakon , Campbell Charles S.
Published: October 2008

The convective motion in deep vertically shaken beds is not continuous but occurs only during a brief portion of a cycle that roughly repeats over three periods of vibration. The convection is coordinated by a series of waves that propagate through the bed, a compression wave formed as the flask’s bottom pushes upward against the bottom of the bed, and two expansion waves: a Type 1 expansion wave that is the reflection of the compression wave and a Type 2 expansion wave that forms as the flask’s bottom moves away from the bottom of the bed. Convection only is observed after Type 1 expansion wave has passed the convective zone, relaxing the stresses in the bed and leaving the particles free to move. However the convective motion is confined to the region above Type 2 wave and convection disappears as a Type 2 wave passes.
Dynamics of Alfvén solitons in inhomogeneous plasmas
Authors: Xu Tao , Tian Bo , Li Li-Li , Lü Xing , Zhang Cheng
Published: October 2008

To provide an analytical scheme for the dynamical behavior of nonlinear Alfvén waves in inhomogeneous plasmas, this paper investigates a generalized variable-coefficient derivative nonlinear Schrödinger equation. In the sense of admitting the Lax pair and infinitely many conservation laws, the integrability of this equation is established under certain coefficient constraint which suggests which inhomogeneities support stable Alfvén solitons. The Hirota method is adopted to construct the one- and multi-Alfvén-soliton solutions. The inhomogeneous soliton features are also discussed through analyzing some important physical quantities. A sample model is treated with our results, and graphical illustration presents two energy-radiating Alfvén soliton structures.
A comparative investigation of H2 adsorption strength in Cd- and Zn-based metal organic framework-5
Authors: Srepusharawoot Pornjuk , Araújo C. Moysés , Blomqvist Andreas , Scheicher Ralph H. , Ahuja Rajeev
Published: October 2008

Hydrogen binding energies for the primary and secondary adsorption sites in the Cd- and Zn-based metal organic framework-5 (MOF-5) were studied using density functional theory. Out of the three exchange-correlation functionals employed in our study, we find that the local density approximation yields a qualitatively correct description of the interaction strengths of H2 in MOF-5 systems. The H2 adsorption energies for all trapping sites in Zn- and Cd-based MOF-5 are seen to be of the same order of magnitude but with a generally stronger binding in Cd-based MOF-5 as compared to Zn-based MOF-5. In particular, the H2 binding energy at the secondary adsorption sites in Cd-based MOF-5 is increased by around 25% compared to Zn-based MOF-5. This result suggests that Cd-based MOF-5 would be better suited to store hydrogen at higher temperatures than Zn-based MOF-5.
All-optical human cell fusion by a fiber femtosecond laser
Authors: He Hao , Chan Kam Tai , Kong Siu Kai , Lee Rebecca Kit Ying
Published: October 2008

Cell-cell fusion by physical methods has progressed slowly until the advent of femtosecond lasers in the near infrared range, which have an ultrahigh photon density and few side effects. Here we demonstrated using a fiber femtosecond laser at 1550 nm with an average power of 1.6×104 W per pulse to fuse human HepG2 and HeLa cells homotypically with an efficiency of 35%–37% in the absence of chemical fusogen. Heterohybrid HepG2-HeLa cells were also prepared. Our site-directed cell-cell fusion technique offers a precise tool for biotechnology and fundamental research in biomedical fields.
Influences of multiple low-n modes on n=1 resistive wall mode identification and feedback control
Authors: In Y. , Kim J. , Kim J. S. , Garofalo A. M. , Jackson G. L. , La Haye R. J. , Strait E. J. , Okabayashi M. , Reimerdes H.
Published: October 2008

It is well known in theory that even after the n=1 resistive wall mode (RWM) is suppressed, the other low-n modes, such as n=2 or 3, can appear sequentially, as β increases. In recent DIII-D experiments [J. L. Luxon, Nucl. Fusion 42, 614 (2002)], we found such an example that supports the theoretical prediction: while the n=1 mode was suppressed, an n=3 mode grew dominant, leading to a β collapse. The n=1 RWM suppression was likely due to a combination of rotational stabilization and n=1 RWM feedback. The multiple RWM identification was performed using an expanded matched filter, where n=1 and n=3 RWM basis vectors are simultaneously considered. Taking advantage of the expanded matched filter, we found that an n=3 mode following an edge-localized-mode burst grew almost linearly for several milliseconds without being hindered. This n=3 mode appeared responsible for the β collapse (down to the n=3 no-wall limit), as well as for a drop in toroidal rotation. A preliminary analysis suggests that the identity of the n=3 mode could be related to the n=3 RWM (possibly the first observation in tokamak experiments), while the impact of the n=3 mode was not as destructive as that of n=1 RWM. A numerical postprocessing of Mirnov probes showed that the n=2 mode was also unstable, consistent with the theoretical prediction. In practice, since the presence of an n=3 mode can interfere with the existing n=1 RWM identification, multiple low-n mode identification is deemed essential not only to detect n>1 mode, but also to provide accurate n=1 RWM identification and feedback control.
Non-ohmic contact resistance and field-effect mobility in nanocrystalline silicon thin film transistors
Authors: Ahnood Arman , Ghaffarzadeh Khashayar , Nathan Arokia , Servati Peyman , Li Flora , Esmaeili-Rad Mohammad R. , Sazonov Andrei
Published: October 2008

Contact resistance has a significant impact on the electrical characteristics of thin film transistors. It limits their maximum on-current and affects their subsequent behavior with bias. This distorts the extracted device parameters, in particular, the field-effect mobility. This letter presents a method capable of accounting for both the non-ohmic (nonlinear) and ohmic (linear) contact resistance effects solely based upon terminal I-V measurements. Applying our analysis to a nanocrystalline silicon thin film transistor, we demonstrate that contact resistance effects can lead to a twofold underestimation of the field-effect mobility.
Growth and characterization of high-density mats of single-walled carbon nanotubes for interconnects
Authors: Robertson J. , Zhong G. , Telg H. , Thomsen C. , Warner J. H. , Briggs G. A. D. , Dettlaff-Weglikowska U. , Roth S.
Published: October 2008

We grow high-density, aligned single wall carbon nanotube mats for use as interconnects in integrated circuits by remote plasma chemical vapor deposition from a Fe–Al2O3 thin film catalyst. We carry out extensive Raman characterization of the resulting mats, and find that this catalyst system gives rise to a broad range of nanotube diameters, with no preferential selectivity of semiconducting tubes, but with at least 1∕3 of metallic tubes.
Experimental investigation of the variation of the absorption coefficient with nitrogen content in GaAsN and GaInAsN grown on GaAs (001)
Authors: Turcotte S. , Beaudry J.-N. , Masut R. A. , Desjardins P. , Bentoumi G. , Leonelli R.
Published: October 2008

We have measured the absorption coefficient at the fundamental band edge in Ga1−yInyAs1−xNx and GaAs1−xNx alloys. In contrast to what is observed in most III-V semiconductors, the absorption coefficient of Ga(In)AsN increases when the band gap energy decreases. In the Ga1−yInyAs1−xNx alloys, the absorption coefficient at threshold saturates near x=0.009, whereas the absorption coefficient of the GaAs1−xNx layers shows no sign of saturation for 0<x<0.016. Furthermore, the value of the absorption coefficient at threshold is higher for Ga1−yInyAs1−xNx layers than for indium-free GaAs1−xN films with the same nitrogen content, a result opposite to what is observed for the nitrogen-free GaInAs alloy. The comparison of our results with calculations performed using the k⋅p formalism suggests that the proper description of the optical properties of Ga(In)AsN alloys must go beyond the effective mass approximation.
Superdiffusivity of asymmetric energy model in dimensions 1 and 2
Authors: Bernardin Cédric
Published: October 2008

We discuss an asymmetric energy model introduced by Giardina et al. [J. Math. Phys. 48, 033301 (2007)]. This model is expected to belong to the Kardar–Parisi–Zhang (KPZ) class. We obtain lower bounds for the diffusion coefficient. In particular, the diffusion coefficient is diverging in dimensions one and two as it is expected in the KPZ picture.
Native-oxide-confined high-index-contrast λ=1.15 μm strain-compensated InGaAs single quantum well ridge waveguide lasers
Authors: Liang D. , Hall D. C. , Huang J. Y.-T. , Tsvid G. , Mawst L. J.
Published: October 2008

High performance native-oxide-confined high-index-contrast (HIC) ridge waveguide (RWG) diode lasers are fabricated in a strain-compensated In0.4Ga0.6As single quantum well structure by employing a deep dry etch plus nonselective O2-enhanced wet thermal oxidation process. The thermal native oxide grown on the etch-exposed RWG sidewalls of the Al0.74Ga0.26As waveguide cladding layers and GaAs core with GaAsP–InGaAs quantum well provides both strong optical and electrical confinements for the active region. Due to a smoothing of sidewall roughness by the O2-enhanced oxidation, the lasers exhibit a low internal loss in αi=7.2 cm−1 for a w=7.2 μm narrow stripe HIC RWG structure, only 53% larger than that of w=87.2 μm broad-area devices, enabling their room temperature operation at a low 300 A/cm2 threshold current density.
Edge chirality determination of graphene by Raman spectroscopy
Authors: You YuMeng , Ni ZhenHua , Yu Ting , Shen ZeXiang
Published: October 2008

Raman imaging of single layer micromechanical cleavage graphene was carried out. The intensity of disorder-induced Raman feature (D band at ∼1350cm−1) was found to be correlated to the edge chirality: it is stronger at the armchair edge and weaker at the zigzag edge. This shows that Raman spectroscopy is a reliable and practical method to identify the chirality of graphene edge and hence the crystal orientation. The determination of graphene chirality is critically important for fundamental study of graphene as well as applications of graphene-based devices.
Development and quality of bovine morulae cultured in serum-free medium with specific retinoid receptor agonists
Authors: Gómez Enrique , Rodríguez Aida , Muñoz Marta , Caamaño José Néstor , Carrocera Susana , Martín David , Facal Nieves , Díez Carmen
Published: October 2008

Retinoids regulate development and differentiation of the bovine blastocyst in vitro, although the underlying mechanisms remain to be clarified. A challenge in reproductive biotechnology is the identification of pathways that regulate early embryonic development and their influence on blastocyst differentiation, apoptosis and survival to cryopreservation as traits of embryo quality. The present paper analyses the effects of short-term exposure (24 h) to retinoids on in vitro-produced bovine morulae. Immature cumulus oocyte complexes were in vitro matured and fertilised. Presumptive zygotes were subsequently cultured in modified synthetic oviduct fluid up to Day 6, in which morulae were randomly allocated to the different experimental groups. The treatments consisted of 0.1 μm LG100268 (LG; a retinoid X receptor agonist), 0.7 μm all-trans retinoic acid (ATRA; a retinoic acid receptor agonist) or no additives. Day 8 blastocyst development was increased in the ATRA-treated group compared with the LG and untreated embryos. In Day 7 embryos, the number of total cells and cells allocated to the trophectoderm were higher in the ATRA-treated group compared with untreated embryos. Apoptosis in the inner cell mass increased after LG treatment, whereas ATRA had no effect. After vitrification and warming, survival and hatching rates of Day 7 blastocysts did not change with retinoid treatment. Within the LG-treated and untreated blastocyst groups, survival and hatching rates were higher for Day 7 than Day 8 embryos; however, Day 8 blastocysts treated with ATRA showed improved hatching rates. In conclusion, treatment of morulae with ATRA in serum-free medium improves embryo development and quality without increasing the incidence of apoptosis and necrosis.
Nuclear transfer using clonal lines of porcine fetal fibroblasts with different sizes and population doubling rates
Authors: Cheong H. T.
Published: October 2008

The aim of the present study was to examine the development of pig embryos produced by somatic cell nuclear transfer (NT) using the clonal lines of fetal fibroblasts with different population doublings (PD) per day and sizes. Clonal lines were established by plating fetal fibroblasts from a Day 35 pig fetus into 96-well clusters, one cell to each well. Four clonal lines (L1–L4) were selected for NT according to their PD per day (1.1 ± 0.2 to 0.8 ± 0.2) and mean cell size (15.1 ± 2.0 to 20.1 ± 2.9). Donor cells were transferred into enucleated oocytes, fused and activated simultaneously with electrical stimuli (two pulses of 125 V mm–1 for 30 μs) and cultured for 6 days. The proportion of embryos that developed to the blastocyst stage in the L3 (19.6%) and L4 (25.3%) lines, which had a lower PD per day and larger cell size, were significantly higher (P < 0.05) than that of the L2 line (10.6%), which had a higher PD per day and the smallest cell size. The proportion of embryos developing to the blastocyst stage in the L1 line (17.3%), which had the highest PD per day and smaller cell size, was significantly lower (P < 0.05) than that of the L4 line. These results suggest that clonal lines with larger sized cell populations in mean and lower PD per day have a greater in vitro developmental potential following NT.
Variation in Phebalium glandulosum subsp. glandulosum: morphometric and anatomical evidence (Rutaceae)
Authors: Giles Robyn L. , Drinnan Andrew N. , Walsh Neville G.
Published: October 2008

Specimens of Phebalium glandulosum Hook. subsp. glandulosum representing the entire geographic range of the subspecies were examined for morphological and anatomical variation. Phenetic patterns were identified with the pattern analysis package PATN, and three distinct groups were identified. One group consists of plants from inland areas of New South Wales, north-western Victoria, and the Yorke and Eyre Peninsulas of South Australia; a second group consists of plants collected from alongside the Snowy River in eastern Victoria and south-eastern New South Wales; and a third group consists of plants from Queensland and northern New South Wales. The climate analysis program BIOCLIM was used to compare climate variables across the geographic range, and showed clear climatic separation in support of the phenetic analysis. The three groups are formally recognised here as distinct subspecies. Plants from Queensland and the Bourke region of northern New South Wales belong to the typical subspecies; plants from north-western Victoria, central New South Wales, and the Yorke and Eyre Peninsulas of South Australia form a cohesive assemblage and are recognised as a new subspecies P. glandulosum subsp. macrocalyx; and plants from the Snowy River in far eastern Victoria and the Southern Tablelands of New South Wales form a distinct and isolated group recognised as a new subspecies P. glandulosum subsp. riparium. These new subspecies are formally described, and an identification key and summaries distinguishing all six subspecies of P. glandulosum are presented.
In situ morphometric study of the Diuris punctata species complex (Orchidaceae), with implications for conservation
Authors: Smith Zoë F. , James Elizabeth A. , McLean Cassandra B.
Published: October 2008

Taxa within the Diuris punctata species complex exhibit high levels of variation at both species and population level. Morphometric data collected in situ were used to investigate species boundaries of four Victorian Diuris species within the Diuris punctata species complex. Morphological characters and taxonomic groups identified in the present study were compared to those described under the current taxonomic treatment. Sixty-five multistate and continuous characters, including seven vegetative and 58 floral characters, were measured in situ across the range of each species within Victoria. The importance of flower colour in distinguishing taxa was highlighted but characters used were generally indiscrete. Certain characters used in current taxonomic descriptions, e.g. floral fragrance, were found to be uninformative. D. fragrantissima was confirmed as a separate taxon within the D. punctata group, justifying its recognition as a unique entity for conservation. Clustering of D. daltonii within D. punctata suggests that the recent elevation of the D. punctata var. daltonii to species level is not justified. The in situ measurement of morphological characters made it possible to incorporate sufficient sampling to encompass intra-specific and intra-population variation and is a feasible method to overcome sampling limitations encountered when herbarium specimens and limited destructive sampling are used.
Revision of Spergularia (Caryophyllaceae) in Australia
Authors: Adams Laurie G. , West Judy G. , Cowley Kirsten J.
Published: October 2008

A revision of the Australian taxa of the genus Spergularia (Caryophyllaceae) on the basis of herbarium material, field studies and analysis of morphological characters necessitates realignment of some taxa and application of some neglected names, clarifying circumscription and understanding of the species of this genus. Eleven species are here recognised, with five considered indigenous, Spergularia nesophila and S. diandroides described as new and S. tasmanica transferred to Spergularia from Lepigonum. Fruits and seeds provide compelling diagnostic characters in this genus and are used in supplementary dichotomous and tabular diagnostic keys. Scanning electron micrographs (SEMs) illustrate key seed shape and surface features.
Fertility control of rodent pests
Authors: Jacob Jens , Singleton Grant R. , Hinds Lyn A.
Published: October 2008

Ricefield rats (Rattus argentiventer) in south-east Asian rice fields and house mice (Mus domesticus) in Australian grain fields are major pest species. They cause damage before and after harvest and carry zoonotic diseases. For both species, management techniques have been pursued using the approach of immunocontraceptive vaccination. We review results from a series of enclosure and field studies conducted with these species to assess the effects of fertility control in small rodents. In the experiments, fertility control was simulated by tubal ligation, ovariectomy or progesterone treatment. A once-off sterilisation of 50–75% of enclosed founder females considerably reduced reproductive output of ricefield rat populations until the end of the reproductive period. In house mice, similar success was achieved when a sterility level of 67% of female founders and offspring was maintained. Repeated antifertility treatments are required because of the much longer breeding period of house mice versus ricefield rats. Comparing the results of enclosure trials with the outcome of simulation models suggests that partial compensation of treatment effects can occur through enhanced reproduction of the remaining fertile females and improved survival of juveniles. However, such compensatory effects as well as behavioural consequences of sterility in field populations are not likely to prevent the management effect at the population level. The challenge for effective fertility control of small rodents in the field is the wide-scale delivery of an antifertility treatment to founders at the beginning of the breeding season and to fertile immigrants that are recruited into the population, which otherwise contribute to the reproductive output at the population level. Future research efforts should focus on species-specific techniques and on agents that can be effectively delivered via bait.