bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel use of nanostructured alumina as an insecticide
Authors: Stadler Teodoro , Buteler Micaela , Weaver David K
Published: February 2010

BACKGROUND: The worldwide need to produce an inexpensive and abundant food supply for a growing population is a great challenge that is further complicated by concerns about risks to environmental stability and human health triggered by the use of pesticides. The result is the ongoing development of alternative pest control strategies, and new, lower‐risk insecticidal molecules. Among the recent technological advances in agricultural science, nanotechnology shows considerable promise, although its development for use in crop protection is in its initial stages.

RESULTS: This study reports for the first time the insecticidal effect of nanostructured alumina. Two species were used as model organisms, Sitophilus oryzae L. and Rhyzopertha dominica (F.), which are major insect pests in stored food supplies throughout the world. Both species experienced significant mortality after 3 days of continuous exposure to treated wheat. Nine days after treatment, the median lethal doses (LD50) observed ranged from 127 to 235 mg kg−1.

CONCLUSION: Comparison of these results with recommended rates for commercial insecticidal dusts suggests that inorganic nanostructured alumina may provide a cheap and reliable alternative for control of insect pests. This study expands the frontiers for nanoparticle‐based technologies in pest management. Further research is needed to identify its mode of action and its non‐target toxicity, and to determine the potential of other nanostructured materials as pest control options for insects. Copyright © 2010 Society of Chemical Industry
Residues of the herbicide fenoxaprop‐P‐ethyl, its agronomic safener isoxadifen‐ethyl and their metabolites in rice after field application
Authors: Lucini Luigi , Pietro Molinari Gian
Published: February 2010

BACKGROUND: Fenoxaprop‐P‐ethyl is a herbicide used on cereals and in particular on rice, the degradation of which leads to several relevant metabolites. The herbicide is used together with an agronomic safener such as isoxadifen‐ethyl, which also generates some metabolites. The present work was aimed at developing and validating an analytical method for the determination of the above parent compounds and their main metabolites in the edible fractions of rice. Parent compounds were extracted in acetonitrile and determined by gas chromatography with a mass spectrometer detector, while metabolites were extracted in acetonitrile and analysed by liquid chromatography tandem mass spectrometry.

RESULTS: The method was validated through recovery tests in rice straw, grain and plant: accuracy was in the range 76–86% and 90–103% for parent compounds and metabolites respectively. Precision, as relative standard deviation, was in the range 3–11% and 6–17% for parent compounds and metabolites respectively. The limit of detection was 0.01 mg kg−1 for each analyte, while the limit of quantification was set at 0.05 mg kg−1.

CONCLUSION: The analytical method is suitable for quantitative determination of each analyte considered in rice commodities. Copyright © 2010 Society of Chemical Industry
The relationship between $I_{{\rm H}_{\rm \alpha } } /(I_{{\rm SiH}}^* )^2$ and crystalline volume fraction in microcrystalline silicon growth
Authors: Chantana Jakapan , Higuchi Takuya , Nagai Tomoyuki , Sasaki Shota , Sobajima Yasushi , Toyama Toshihiko , Sada Chitose , Matsuda Akihisa , Okamoto Hiroaki
Published: February 2010

Optical‐emission‐intensity ratio of $I_{{\rm H}_{\rm \alpha } } /(I_{{\rm SiH}}^* )$ during film growth has been used as a simple indicator to predict crystallinity (crystal‐volume fraction: XC) in the resulting microcrystalline silicon (µc‐Si:H) thin films. The relationship between $I_{{\rm H}_{\rm \alpha } } /(I_{{\rm SiH}}^* )$ and XC has been checked under a wide variety of film‐preparation conditions including low‐deposition‐rate (<0.1 nm/s) and high‐deposition‐rate (>5 nm/s) cases. On the basis of theoretical consideration, we have proposed optical‐emission‐intensity ratio of $I_{{\rm H}_{\rm \alpha } } /(I_{{\rm SiH}}^* )^2 $ as a new indicator of XC during film growth of µc‐Si:H.
Field‐induced nematic phase in the spin ladder system with easy‐axis anisotropy
Authors: Sakai Tôru , Tonegawa Takashi , Okamoto Kiyomi
Published: February 2010

The spin ladder system with the easy‐axis anisotropy in magnetic field is theoretically investigated using the numerically exact diagonalization, the density matrix renormalization group (DMRG) and the finite‐size scaling analysis. It is found that the field‐induced nematic phase appears above the critical field. In addition, there exists another critical field at which the quantum phase transition from the nematic phase to the conventional field‐induced Tomonaga–Luttinger liquid (TLL) phase occurs. The phase diagram on the coupling anisotropy versus magnetization plane is given by the numerical diagonalization. Furthermore, a typical magnetization curve calculated by the DMRG is presented.
Observing the anisotropic optical response of the heavy‐fermion compound UNi2Al3
Authors: Ostertag Julia P. , Scheffler Marc , Dressel Martin , Jourdan Martin
Published: February 2010

The optical conductivity of heavy fermions can reveal fundamental properties of the charge carrier dynamics in these strongly correlated electron systems. Here we extend the conventional techniques of infrared optics on heavy fermions by measuring the transmission and phase shift of THz radiation that passes through a thin film of UNi2Al3, a material with hexagonal crystal structure. We deduce the optical conductivity in a previously not accessible frequency range, and furthermore we resolve the anisotropy of the optical response (parallel and perpendicular to the hexagonal planes). At frequencies around 7 cm−1, we find a strongly temperature‐dependent and anisotropic optical conductivity that – surprisingly – roughly follows the dc behavior.
Anisotropy of the low‐temperature magnetostriction of Sr3Ru2O7
Authors: Stingl C. , Perry R. S. , Maeno Y. , Gegenwart P.
Published: February 2010

We use high‐resolution capacitive dilatometry to study the low‐temperature linear magnetostriction of the bilayer ruthenate Sr3Ru2O7 as a function of magnetic field applied perpendicular to the ruthenium‐oxide planes ($B\parallel c$). The relative length change ${\rm \Delta }L(B)/L$ is detected either parallel or perpendicular to the c‐axis close to the metamagnetic region near B = 8 T. In both cases, clear peaks in the coefficient $\lambda (B) = {\rm d}({\rm \Delta }L/L)/{\rm d}B$ at three subsequent metamagnetic transitions are observed. For ${\rm \Delta }L \bot c$, the third transition at 8.1 T bifurcates at temperatures below 0.5 K. This is ascribed to the effect of an in‐plane uniaxial pressure of about 15 bar, unavoidable in the dilatometer, which breaks the original fourfold in‐plane symmetry.
Magnetotransport in the magnetic superconductor HoNi2B2C
Authors: Ohashi M. , Oomi G. , Cho B. K. , Canfield P. C.
Published: February 2010

The electrical resistivity and the magnetization of single crystalline HoNi2B2C have been measured at several magnetic fields. In the paramagnetic region, the magnetization is nicely reproduced by calculations that take the crystal electric field (CEF) into consideration. The magnetoresistance is negative at a wide temperature range, and is strongly dependent on the magnetization. It is interpreted by the reduction of spin‐disorder scattering as the moments are polarized.
Performance improvement in bucky gel actuators by chemical modifications of carbon nanotubes
Authors: Biso Maurizio , Ansaldo Alberto , Ricci Davide
Published: February 2010

Single walled carbon nanotubes functionalized with an aromatic diamine have been successfully used to prepare bucky gel layers by mixing with an imidazolium based ionic liquid, allowing to build bimorph actuators that significantly outperform those prepared by using the pristine or oxidized carbon nanotubes. The carbon nanotube gravimetric specific capacitance doubles, the actuator maximum operating frequency becomes five times higher and for same injected charge the strain reaches a fourfold increase. The origin of such dramatic effects is most probably due to an enhanced binding between the carbon nanotubes induced by their chemical modification. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Antiplasmodial and cytotoxic activity of phloroglucinol derivatives from Hypericum erectum thunb
Authors: Moon Hyung‐In
Published: February 2010

The chloroform extracts of whole plants of Hypericum erectum were investigated for antiplasmodial activity against chloroquine‐sensitive strains of Plasmodium falciparum. Five phloroglucinol derivatives, otogirin (1), otogirone (2), erectquione A (3), erectquione B (4), and erectquione C (5) were isolated from the whole plants of H. erectum. Also, five compounds were evaluated for in vitro antiplasmodial activities as well as their cytotoxic potential on SK‐OV‐3 cancer cell line cells. Compounds 2, 4 showed notable growth inhibitory activity against chloroquine‐sensitive strains of Plasmodium falciparum with IC50 values from 5.6 and 7.2 μM. This compound showed no significant cytotoxicity (IC50 > 150 μM) evaluated using SK‐OV‐3 cancer cell line cells. Copyright © 2010 John Wiley & Sons, Ltd.
The tocotrienol‐rich fraction from rice bran enhances cisplatin‐induced cytotoxicity in human mesothelioma H28 cells
Authors: Nakashima Keisuke , Virgona Nantiga , Miyazawa Mio , Watanabe Takashi , Yano Tomohiro
Published: February 2010

Resistance to chemotherapy (chemoresistance) is a serious problem in malignant mesothelioma, a highly aggressive neoplasm. Gamma‐tocotrienol (γ‐T3) can sensitize various cancerous cells to chemotherapeutic agents by inhibiting pathways that lead to treatment resistance. In this study, we investigated the modulating effect of tocotrienol‐rich fraction (TRF) from rice bran, which is abundant in γ‐T3, on chemoresistance in human MM H28 cells. TRF treatment caused a marked reduction in the viability of H28 cells in a dose‐dependent manner, while cisplatin treatment had no effect on the cells, indicating that H28 cells are resistant to cisplatin. A significant increase in cytotoxicity was observed in H28 cells treated with TRF, and this effect was enhanced by the combination treatment with cisplatin. The cytotoxic effect was closely related to the inhibition of phosphatidylinositol 3‐kinase (PI3K)‐AKT signaling. Inactivation of Akt signaling by TRF or the combination with cisplatin mitigated cisplatin‐induced activation of Akt, resulting in reducing the chemoresistance H28 cells to cisplatin. Reduced cell viability and attenuated chemoresistance of the H28 cells against cisplatin were also observed following the use of a PI3K inhibitor, LY294002. These results suggest that the combination therapy of cisplatin with TRF is a plausible strategy for achieving tolerance for the chemotherapeutic agent in MM therapy. Copyright © 2010 John Wiley & Sons, Ltd.
Four‐dimensional variational assimilation in the unstable subspace and the optimal subspace dimension
Authors: Trevisan Anna , D'Isidoro Massimo , Talagrand Olivier
Published: February 2010

Key apriori information used in 4D‐Var is the knowledge of the system's evolution equations. In this article we propose a method for taking full advantage of the knowledge of the system's dynamical instabilities in order to improve the quality of the analysis. We present an algorithm for four‐dimensional variational assimilation in the unstable subspace (4D‐Var – AUS), which consists of confining in this subspace the increment of the control variable. The existence of an optimal subspace dimension for this confinement is hypothesized. Theoretical arguments in favour of the present approach are supported by numerical experiments in a simple perfect nonlinear model scenario. It is found that the RMS analysis error is a function of the dimension N of the subspace where the analysis is confined and is a minimum for N approximately equal to the dimension of the unstable and neutral manifold. For all assimilation windows, from 1 to 5 d, 4D‐Var – AUS performs better than standard 4D‐Var. In the presence of observational noise, the 4D‐Var solution, while being closer to the observations, is farther away from the truth. The implementation of 4D‐Var – AUS does not require the adjoint integration. Copyright © 2010 Royal Meteorological Society
The accuracy of linear theory for predicting mountain‐wave drag: Implications for parametrization schemes
Authors: Wells H. , Vosper S. B.
Published: February 2010

This study focuses on the accuracy of simple methods used in parametrization schemes for predicting the drag due to orographically excited gravity waves (mountain waves). Linear and nonlinear model simulations of flow over a long, low two‐dimensional ridge are used to evaluate the importance of internal wave reflection and nonlinearity. A long ridge with a small non‐dimensional mountain height and a gentle slope is used so that, in the absence of vertical variations in the background profile of wind and stability, the mountain‐wave drag is accurately predicted by linear theory. Simulations conducted for simple idealised profiles in which the background stability has a two‐layer (troposphere–stratosphere) structure show that whilst the drag is accurately predicted by linear solutions, interference effects due to partial wave reflection can alter the drag significantly. Estimates of the drag which are based solely on low‐level measurements of wind and stability, such as those in current operational mountain‐wave parametrizations, cannot account for this effect. Results from simulations based on more complex realistic profiles, obtained from both radiosondes and a forecast model, show that the linear and nonlinear drag predictions can differ significantly. This implies that linear solutions can be inaccurate even when they are calculated for the full atmospheric profile (rather than being based on low‐level average quantities). It is hypothesised that, in this case, the nonlinearity is due to resonant triad interactions which occur when there are oscillations in the Scorer parameter with a wavelength half that of the dominant vertically propagating mountain wave. The implications of the results for mountain‐wave drag parametrization are discussed. © Crown Copyright 2010. Published by John Wiley & Sons, Ltd.
Shrinking‐horizon dynamic programming
Authors: Skaf Joëlle , Boyd Stephen , Zeevi Assaf
Published: February 2010

We describe a heuristic control policy for a general finite‐horizon stochastic control problem, which can be used when the current process disturbance is not conditionally independent of the previous disturbances, given the current state. At each time step, we approximate the distribution of future disturbances (conditioned on what has been observed) by a product distribution with the same marginals. We then carry out dynamic programming (DP), using this modified future disturbance distribution, to find an optimal policy, and in particular, the optimal current action. We then execute only the optimal current action. At the next step, we update the conditional distribution, and repeat the process, this time with a horizon reduced by one step. (This explains the name ‘shrinking‐horizon dynamic programming’). We explain how the method can be thought of as an extension of model predictive control, and illustrate our method on two variations on a revenue management problem. Copyright © 2010 John Wiley & Sons, Ltd.
River regulation influences the composition and distribution of inland frog communities
Authors: Wassens S. , Maher M.
Published: February 2010

Frogs are widespread through inland rivers and floodplains and are an important component of floodplain food chains. Despite this, studies of frog communities in inland river systems are limited and the impacts of river regulation on frog communities have received very little attention. Surveys for frogs, tadpoles and egg masses along with assessment of vegetation, hydrology and water chemistry were conducted along 10 km reaches of three creek systems in the Lachlan River catchment, a major regulated river in Australia's Murray–Darling Basin. A total of 23 sample sites were surveyed at locations above and below in‐stream weirs as well as adjacent floodplain depressions. The hydrological regimes of sample sites were classified according to the length of time that they were known to hold water (water permanence). The sample sites fell into two distinct categories, 14 were classified as permanent and occurred upstream of weirs while nine were classified as temporary and were located downstream of weirs and in depressions adjacent to the weir pool. Permanent sample sites had a significantly higher percentage of dead standing timber and were deeper with less aquatic vegetation cover than temporary sample sites. Seven frog species were identified; there were no significant differences in species richness between permanent and the temporary waterbodies but the composition of frog assemblages differed significantly between them. This suggests that alteration to the hydrology of inland creek systems can lead to changes in the distribution frog species, with some becoming more common due to increases in the availably of permanent waterbodies while others decline due to reductions in the availability of seasonally flooded waterbodies. Copyright © 2010 John Wiley & Sons, Ltd.
The effects of short‐term inundation on carbon dynamics, microbial community structure and microbial activity in floodplain soil
Authors: Wilson J. S. , Baldwin D. S. , Rees G. N. , Wilson B. P.
Published: February 2010

A mesocosm study was carried out to determine whether flooding affected soil microbial structure and function. Over a 24 day period soils were either flooded or remained dry and changes in the microbial community structure, microbial metabolic activity (determined by looking at soil respiration rates and exo‐enzyme activity), community level physiological profiles and soil carbon speciation were examined. Flooding induced significant changes in the microbial community structure and increased soil respiration and enzymatic degradation rates. Shifts occurred in carbon speciation after flooding and increases in ‘labile’ carbon fractions were observed. The duration of flooding was also important for carbon dynamics and microbial community structure. Based on the results of the mesocosm experiment a conceptual model of floodplain soils response to flooding over time was formulated. The findings of this mesocosm study illustrate the importance of flooding to floodplain soil functioning. Copyright © 2010 John Wiley & Sons, Ltd.
A high‐resolution hydrodynamic investigation of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) redds
Authors: Marchildon M. A. , Annable W. K. , Imhof J. G. , Power M.
Published: February 2010

High‐resolution velocity measurements were taken over a series of redds on a gravel‐bed stream using a Pulse Coherent Acoustic Doppler Profiler (PCADP) to quantify the hydrodynamics of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) redds. On redds studied, over 4500 velocity measurements per redd were acquired per day to quantify the flow velocity, flow depth and related fluid mechanics metrics of Reynolds numbers, Froude numbers and turbulent kinetic energy per unit area. Results showed that velocity and Froude numbers varied widely at the redd scale, but consistently showed higher velocities and Froude numbers over the tailspill regions relative to the surrounding study limits. Results of Reynolds numbers calculations showed no apparent correlations to spawning location preference and redd structure. Turbulent kinetic energy per unit area consistently demonstrated a strong correlation with redd locations. The metric maintained low values (i.e. unidirectional flow with little turbulence) where all redds and attempted redds were observed. The study also demonstrates that a number of hydraulic metrics and several spatial scales will likely be necessary to understand any inherent relationship between river hydraulics and redd placement. Copyright © 2010 John Wiley & Sons, Ltd.
A boundary corrected expansion of the moments of nearest neighbor distributions
Authors: Liitiäinen Elia , Lendasse Amaury , Corona Francesco
Published: February 2010

In this article, the moments of nearest neighbor distance distributions are examined. While the asymptotic form of such moments is well‐known, the boundary effect has this far resisted a rigorous analysis. Our goal is to develop a new technique that allows a closed‐form high order expansion, where the boundaries are taken into account up to the first order. The resulting theoretical predictions are tested via simulations and found to be much more accurate than the first order approximation obtained by neglecting the boundaries.

While our results are of theoretical interest, they definitely also have important applications in statistics and physics. As a concrete example, we mention estimating Rényi entropies of probability distributions. Moreover, the algebraic technique developed may turn out to be useful in other, related problems including estimation of the Shannon differential entropy.© 2010 Wiley Periodicals, Inc. Random Struct. Alg., 2010
Securing business operations in an SOA
Authors: de Leusse Pierre , Brossard David , Georgalas Nektarios
Published: February 2010

In order to achieve agility and shorter concept‐to‐market timescales for new products and services, ICT service providers and their corporate customers alike increasingly adopt a collection of technologies, concepts and capabilities which come under the banner of the Service Oriented Architecture (SOA). The Service Oriented Infrastructure (SOI) approach complements SOA by enabling the optimal use of virtualised infrastructure services and resources via the network, and their integration in tailored solutions that meet customer needs and adapt to their growth pattern.

In this paper we focus on the business and technological challenges relating to security and service dependability for SOI. In particular the paper studies challenges in the security areas of (i) identity federation, (ii) distributed usage and access management, (iii) context‐aware secure messaging, routing and transformation and (iv) SOA security governance. It gathers requirements and it proposes an architecture comprising design patterns and a governance framework that address these challenges. An example case‐study presents an implementation of the proposed architecture's SOI security capabilities aiming at the practical validation of the proposed architectural concepts. Copyright © 2010 John Wiley & Sons, Ltd.
Building advanced applications with the Belgian eID
Authors: Lapon Jorn , Naessens Vincent , Verdegem Bram , Verhaeghe Pieter , De Decker Bart
Published: February 2010

The Belgian Electronic Identity Card (eID) was introduced in 2002. The card enables Belgian citizens to digitally prove their identity and to sign electronic documents. Today, only a limited number of citizens really use the card in electronic applications. An important reason is the lack of killer functionality and killer applications.

This paper presents two reusable extensions to the Belgian eID technology that opens up new opportunities for application developers. First, a secure and ubiquitously accessible remote storage service is presented. Second, it is shown how the eID card can be used to issue new certificates. The feasibility and reusability of both extensions are validated through the development of several applications in different domains. Copyright © 2010 John Wiley & Sons, Ltd.
Defending Sybil attacks based on neighboring relations in wireless sensor networks
Authors: Wang Wei‐Tong , Ssu Kuo‐Feng , Chang Wen‐Chung
Published: February 2010

As the prevalence of Wireless Sensor Networks (WSNs) grows in the military and civil domains, network security becomes an evermore critical concern. In Sybil attack, malicious nodes forge a lot of fake identities to disrupt the network's protocols. Previous work used either authentication‐based mechanisms which use shared encryption keys, or location information to verify the identities of the nodes. By contrast, this paper uses only neighboring node relation to verify the node identities. The evaluation results show that the detection rate was around 95% when the network was not very sparse. Copyright © 2010 John Wiley & Sons, Ltd.
Negative workplace behaviour: temporal associations with cardiovascular outcomes and psychological health problems in Australian police
Authors: Tuckey Michelle R. , Dollard Maureen F. , Saebel Judith , Berry Narelle M.
Published: February 2010

Negative workplace behaviour, such as workplace bullying, is emerging as an important work‐related psychosocial hazard with the potential to contribute to employee ill health. We examined the risk of two major health issues (poor mental and cardiovascular health) associated with current and past exposure to negative behaviour in the workplace. Data from 251 police officers, who completed an anonymous mail survey at two time‐points spaced 12 months apart, support the potential role of exposure to negative workplace behaviour in the development of physical disease and psychological illness. Specifically, we saw significant effects associated with past exposure to such behaviour on indicators of poor cardiovascular health, and a significant effect of current exposure on the indicator of mental health problems. Our findings reinforce the need to continue to study links between employee health and both negative workplace behaviour and more severe cases of bullying, particularly the mechanisms involved to strengthen theory in this area, and to protect against employee ill health (specifically cardiovascular outcomes and psychological problems) by preventing negative behaviour at work. Copyright © 2010 John Wiley & Sons, Ltd.
Conjugated‐Polyelectrolyte‐Functionalized Reduced Graphene Oxide with Excellent Solubility and Stability in Polar Solvents
Authors: Qi Xiaoying , Pu Kan‐Yi , Zhou Xiaozhu , Li Hai , Liu Bin , Boey Freddy , Huang Wei , Zhang Hua
Published: February 2010

Conjugated‐polyelectrolyte (CPE)‐functionalized reduced graphene oxide (rGO) sheets are synthesized for the first time by taking advantage of a specially designed CPE, PFVSO3, with a planar backbone and charged sulfonate and oligo(ethylene glycol) side chains to assist the hydrazine‐mediated reduction of graphene oxide (GO) in aqueous solution. The resulting CPE‐functionalized rGO (PFVSO3‐rGO) shows excellent solubility and stability in a variety of polar solvents, including water, ethanol, methanol, dimethyl sulfoxide, and dimethyl formamide. The morphology of PFVSO3‐rGO is studied by atomic force microscopy, X‐ray diffraction, and transmission electron microscopy, which reveal a sandwich‐like nanostructure. Within this nanostructure, the backbones of PFVSO3 stack onto the basal plane of rGO sheets via strong π–π interactions, while the charged hydrophilic side chains of PFVSO3 prevent the rGO sheets from aggregating via electrostatic and steric repulsions, thus leading to the solubility and stability of PFVSO3‐rGO in polar solvents. Optoelectronic studies show that the presence of PFVSO3 within rGO induces photoinduced charge transfer and p‐doping of rGO. As a result, the electrical conductivity of PFVSO3‐rGO is not only much better than that of GO, but also than that of the unmodified rGO.
Software project effort assessment
Authors: Haapio Topi , Eerola Anne
Published: February 2010

Software project assessments and postmortem analyses can increase the success of future projects and forthcoming project phases. However, although assessments and analyses are well‐presented in the software engineering literature, they are short of descriptions to assess effort. This paper proposes a stepwise effort assessment method that strives to facilitate learning from past experiences and to increase effort estimation accuracy by exploring realized project effort. The proposed method can be used either to assess the realized project effort of a time span from project's lifecycle or as a part of the whole project postmortem analysis in producing effort information for the project iteration assessment, final report, and annual project portfolio report. In addition, the effort information increases the project team's knowledge on realized activity sets and their relationships, and the information can be utilized in estimation method and model calibration for both re‐estimations and future estimations. The method was evaluated with case projects, a sample supplied by Tieto Finland Oy. Copyright© 2010 John Wiley & Sons, Ltd.
Functional Properties and Retrogradation of Heat‐Moisture Treated Wheat and Potato Starches in the Presence of Hydroxypropyl β‐cyclodextrin
Authors: Gunaratne Anil , Kong Xiangli , Corke Harold
Published: February 2010

Some functional and retrogradation properties of native and heat‐moisture treated potato and wheat starches were examined in the presence of hydroxypropyl β‐cyclodextrin (HPβ‐CD). HPβ‐CD increased swelling factor, amylose leaching, and solubility of both native and heat‐moisture treated wheat starches but it had less impact on corresponding potato starches. Gelatinization enthalpy of native wheat starch was decreased in the presence of HPβ‐CD but was increased in potato starch with increasing concentration. Reduction of amylose‐lipid complex endotherm in both native and heat‐moisture treated wheat starch was observed in the presence of HPβ‐CD. Heat‐moisture treatment did not change the transition parameters of amylose‐lipid complex showing its resistance to hydrothermal treatment. HPβ‐CD greatly decreased the pasting temperature of wheat starch. Cold paste viscosity of both native and heat‐moisture treated wheat starch was increased by HPβ‐CD to a greater extent than corresponding potato starch. Amylopectin retrogradation of all the starches was unaffected in the presence of HPβ‐CD but heat‐moisture treatment slightly decreased retrogradation of potato starch. These results suggest that HPβ‐CD can disrupt the amylose‐lipid complex within the starch granule in both native and heat‐moisture treated wheat starch but has no influence on amylopectin retrogradation. However, greatly increased wheat starch setback with HPβ‐CD indicates its greater effect on wheat starch amylose retrogradation.
Ductus venosus blood flow velocity waveform in diabetic pregnancies
Authors: Stuart A. , Amer‐Wåhlin I. , Gudmundsson S. , Maršál K. , Thuring A. , Källen K.
Published: February 2010

Objective

Maternal diabetes during pregnancy is associated with congenital cardiac malformations and hypertrophic cardiomyopathy. Blood flow in the ductus venosus (DV) has been postulated to reflect cardiac function. The aim of our study was to investigate if diabetic pregnancies exhibit abnormal DV hemodynamics, hence indicating changes in fetal cardiac function.

Methods

The pulsatility index of the DV (DV‐PI) was analyzed retrospectively in 142 diabetic patients and compared to previously published DV‐PI reference values from a non‐diabetic low‐risk population. DV values were then correlated with maternal glycosylated hemoglobin (HbA1c).

Results

DV‐PI was significantly higher in pregnancies complicated by either pre‐existing insulin‐dependent (DM) or gestational diabetes when compared with normal reference values. Increased DV‐PI values were still evident in both diabetic groups when neonates that were small‐for‐gestational age and neonates with pathological umbilical blood flow pattern were excluded from the analysis. In DM pregnancies a statistically significant correlation was found between DV‐PI and maternal HbA1c.

Conclusion

Diabetic pregnancies exhibit increased DV‐PI values when compared to a normal low‐risk pregnant population, possibly indicating a fetal cardiac effect. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Learning curve in measurement of fetal frontomaxillary facial angle at 11–13 weeks of gestation
Authors: Yang X. , Chen M. , Wang H. F. , Leung T. Y. , Borenstein M. , Nicolaides K. , Sahota D. S. , Lau T. K.
Published: February 2010

Objective

To determine the number of ultrasound examinations required to train sonographers to accurately measure the fetal frontomaxillary facial (FMF) angle at 11–13 weeks of gestation.

Methods

Eight sonographers accredited for nuchal translucency thickness (NT) measurement (and with different levels of experience) were trained to measure the fetal FMF angle using specially acquired three‐dimensional (3D) volumes. Training was provided in cycles, and each cycle consisted of a training period on 20 randomly selected cases followed by an examination using 10 randomly selected cases. During training, the sonographer was informed of the true FMF angle value after each FMF angle measurement on a case‐by‐case basis. During examination, the difference between the measured and the true values of the FMF angle (i.e. the delta angle) was calculated. A measurement was considered accurate if the delta angle was less than 5°. The sonographer was considered to be competent and the training finished if all 10 examination cases satisfied this criterion. Otherwise, the sonographer would undergo further cycles of training–examination, until he/she became competent.

Results

The number of training cases required for a sonographer to become competent was 40 for two sonographers, 60 for one, 80 for one, 100 for two, 120 for one and 140 for one, with a median of 90. The median number of failed cases reduced from 2.5 (out of 10) at the first cycle to 0 by the 7th cycle. As training cycles increased, the mean angle deviation and measurement time required both reduced significantly. The average delta angle of the passing examination cycle was 2.06 ± 1.40°. The number of training cases required to become competent in FMF angle measurement was 40 for the two most experienced trainees and 80, 120 and 140 for the three least experienced ones.

Conclusions

We have demonstrated that competence in FMF angle measurement was achieved after a median number of 90 cases, with a range of up to 140. The number required was substantially lower, at 40 cases, among those with extensive experience of NT measurement. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
A practical authentication protocol with anonymity for wireless access networks
Authors: Chen Yen‐Cheng , Chuang Shu‐Chuan , Yeh Lo‐Yao , Huang Jiun‐Long
Published: February 2010

The use of anonymous channel tickets was proposed for authentication in wireless environments to provide user anonymity and to probably reduce the overhead of re‐authentications. Recently, Yanget al.proposed a secure and efficient authentication protocol for anonymous channel in wireless systems without employing asymmetric cryptosystems. In this paper, we will show that Yanget al.'s scheme is vulnerable to guessing attacks performed by malicious visited networks, which can easily obtain the secret keys of the users. We propose a new practical authentication scheme not only reserving the merits of Yanget al.'s scheme, but also extending some additional merits including: no verification table in the home network, free of time synchronization between mobile stations and visited networks, and without obsolete anonymous tickets left in visited networks. The proposed scheme is developed based on a secure one‐way hash function and simple operations, a feature which is extremely fit for mobile devices. We provide the soundness of the authentication protocol by using VO logic. Copyright © 2010 John Wiley & Sons, Ltd.
A secure and efficient RSU‐aided bundle forwarding protocol for vehicular delay tolerant networks
Authors: Lin Xiaodong , Chen Hsiao‐Hwa
Published: February 2010

Recently, vehicularad hocnetwork (VANET) has emerged as a promising approach for road safety and traffic efficiency improvement through a variety of vehicle applications enabled by communications between vehicles such as emergency braking warning, etc. However, due to its unique characteristics, such as intermittent connectivity due to high‐speed mobility of the network nodes (or vehicles), also known as vehicular delay tolerant network, it poses a major challenge to the realization of those applications. In this paper, we propose a new roadside unit (RSU) aided bundle forwarding protocol for vehicular delay tolerant networks. Furthermore, with the assistance from those RSUs deployed at some critical points on the road, for example, intersections, the proposed protocol can increase the network performance in terms of delivery ratio. At the same time, since vehicle‐to‐vehicle (V2V) and vehicle‐to‐RSU (V2R) privacy‐preserving authentications are guaranteed, the black (gray) hole attacks can be avoided. Extensive simulations demonstrate the effectiveness of the proposed protocol. Copyright © 2010 John Wiley & Sons, Ltd.
Hierarchical queue‐length‐aware power control for real‐time applications over wireless networks
Authors: Li Xiaochen , Dong Xihua , Wu Dapeng
Published: February 2010

We consider the problem of optimal power control for quality‐of‐service‐assured wireless communication. The quality of service (QoS) measures of our consideration are a triplet of data rate, delay, and delay bound violation probability (DBVP). Our target is to develop power control laws that can provide delay guarantees for real‐time applications over wireless networks. The power control laws that aim at optimizing certain physical‐layer performance measures, usually adapt the transmission power based on the channel gain; we call these “channel‐gain‐based” (CGB) power control (PC). In this paper, we show that CGB‐PC laws achieve poor link‐layer delay performance. To improve the performance, we propose a novel scheme called hierarchical queue‐length‐aware (HQLA) power control. The key idea is to combine the best features of the two PC laws, i.e., a given CGB‐PC law and the clear‐queue (CQ) PC law; here, the CQ‐PC is defined as a PC law that uses a transmission power just enough to empty the queue at the link layer. We analyze our proposed HQLA‐PC scheme by the matrix‐geometric method. The analysis agrees well with the simulation results. More importantly, our results show that the proposed HQLA power control scheme is superior to the corresponding CGB‐PC in both average power consumption and effective capacity. Copyright © 2010 John Wiley & Sons, Ltd.
Introspection
Authors: Engelbert Mark , Carruthers Peter
Published: February 2010

Two main questions about introspection are addressed: whether it exists, and whether it is a reliable source of self‐knowledge. Most philosophers have assumed that the answers to both questions are positive, whereas an increasing number of cognitive scientists take the view that introspection is either nonexistent (with self‐attributions of mental states being made on the same sort of interpretative basis as attributions of mental states to other people) or unreliable. A number of different models of self‐knowledge are discussed, and the evidence bearing on the existence and reliability of introspection is reviewed. New experiments are required to tease apart some of the alternatives. Copyright © 2010 John Wiley & Sons, Ltd.

This article is categorized under:

Psychology > Attention

Philosophy > Consciousness
Cognition and animal welfare
Authors: Rogers Lesley J.
Published: February 2010

Animals exhibit species‐typical adaptations of behavior and may suffer stress in captivity if they are prevented from performing these patterns of behavior. This article considers whether these particular ‘needs’ rely on cognitive processes or are performed without complex cognition despite their appearance of behavioral complexity. Emotion and cognition in animals are also discussed, particularly whether animals can feel emotions and, if so, what ranges of emotions they might feel. Cognitive capacities that would contribute to suffering include empathy with the suffering of others, memories of negative events and suffering in anticipation of future events. Cognitive bias of individual animals toward positive or negative feelings is related to dominance of the left or right hemisphere, respectively. These biases might be reflected in the animal's preferred limb to pick up food. Hence, limb preference could be a useful measure of cognitive bias. Post‐traumatic stress disorder is a cognitive condition that, it is suggested, might involve dominance of the right hemisphere. This debilitating condition is experience‐dependent and not infrequently seen in animals in captivity. In conclusion, it is argued that there is an obvious need for more research on cognition as it relates to animal welfare and as a basis for changing legislature to protect animals from suffering. Copyright © 2010 John Wiley & Sons, Ltd.

This article is categorized under:

Cognitive Biology > Evolutionary Roots of Cognition

Psychology > Comparative Psychology

Neuroscience > Behavior
Working memory
Authors: Ricker Timothy J. , AuBuchon Angela M. , Cowan Nelson
Published: February 2010

The working memory system maintains the limited information that can be kept in mind at one time. These memories are distinct from the vast amount of information stored in long‐term memory. Here we give a brief summary of findings over the past half‐century in the areas of working memory that we see as particularly important for understanding its nature. We discuss several current controversies, including whether there are different systems or brain modules for different kinds of working memory, why we lose items from working memory, and how individuals and age groups differ. We try to describe what is and is not known. Last, a discussion of findings from neuroimaging helps to constrain working memory theory. Copyright © 2010 John Wiley & Sons, Ltd.

This article is categorized under:

Psychology > Memory

Neuroscience > Cognition
Quinine‐Derived Imidazolidin‐2‐imine Ligands: Synthesis, Coordination Chemistry, and Application in Catalytic Transfer Hydrogenation
Authors: Filimon Sabina‐Alexandra , Hrib Cristian G. , Randoll Sören , Neda Ion , Jones Peter G. , Tamm Matthias
Published: February 2010

Two new optically active bidentate N,N‐ligands, DMIQCI (3a) and DMIQCD (3b), containing a quinuclidine core and an imidazolidin‐2‐imine unit, were synthesized. The reaction of these ligands with [(η5‐C5Me5)RuCl]4 afforded the brick‐red ruthenium(II) complexes [(η5‐C5Me5)Ru(DMIQCI)Cl] (4) and [(η5‐C5Me5)Ru(DMIQCD)Cl] (5), which were used as catalysts in the transfer hydrogenation of acetophenone in boiling 2‐propanol. The reactions of 3a and 3b with [(COD)PdCl2] (COD = 1,5‐cycloocta‐diene) and with [(DME)NiBr2] (DME = 1,2‐dimethoxyethane) afforded the square‐planar palladium(II) complexes [(DMIQCI)PdCl2] (7) and [(DMIQCD)PdCl2] (8) or the tetrahedral nickel(II) complexes [(DMIQCI)NiBr2] (9) and [(DMIQCD)NiBr2] (10), respectively. The X‐ray crystal structures of 4, 7, 9·THF, and 10 are reported.
Thermal Decomposition of New Mononuclear NiII Complexes with ONNO Type Reduced Schiff Bases and Pseudo Halogens
Authors: Ateş B. Meltem , Zeybek Bülent , Aksu Mecit , Ergun Ümit , Ercan Filiz , Aksu M. Levent , Atakol Orhan
Published: February 2010

Mononuclear nickel(II) complexes were prepared by reaction of the three ONNO type reduced Schiff bases bis‐N,N′‐(2‐hydroxybenzyl)‐1,3‐propanediamine (LHH2), bis‐N,N′‐(2‐hydroxybenzyl)‐2,2′‐dimethyl‐1,3‐propanediamine (LDMHH2), and bis‐N,N′‐[1‐(2‐hydroxyphenyl)ethyl]‐1,3‐propanediamine (LACHH2) with NiII ions in the presence of pseudo halides (OCN–, SCN– and N3–). The complexes were characterized with the use of elemental analyses, IR spectroscopy, and thermal analyses. The molecular structure of one of the complexes was obtained by single‐crystal X‐ray diffraction. The obtained complexes are mononuclear, and a pseudo halide molecule is attached. One of the oxygen atoms of the ligand is in phenolate and the other was in phenol form. According to the thermogravimetry results, it was thought that the pseudo halide thermally detaches from the structure as hydropseudo halide. In azide‐containing complexes an endothermic reaction was observed although the azide group usually decomposes with an exothermic reaction.
Synthesis, Structure and Chemical Bonding of CaCo2Si2 and BaCo2Ge2 – Two New Compounds with ThCr2Si2 Structure Type
Authors: Siggelkow Lisa , Hlukhyy Viktor , Fässler Thomas F.
Published: February 2010

The intermetallic compounds CaCo2Si2 and BaCo2Ge2 were prepared by melting mixtures of the elements in an arc‐furnace under argon. Single crystals were obtained by special heat treatment in welded tantalum ampoules. The compounds were investigated by powder and single‐crystal X‐ray diffraction. Both title compounds crystallize in the ThCr2Si2 structure type with space group I4/mmm: a = 3.9161(3) Å, c = 9.9184(7) Å, wR2 = 0.032, 220 F2 values, 9 variable parameters for CaCo2Si2; a = 4.0859(3) Å, c = 11.779(2) Å, wR2 = 0.046, 106 F2 values, 9 variable parameters for BaCo2Ge2. The described intermetallic compounds demonstrate the tunable distance between the tetrel elements, which is often observed for compounds with ThCr2Si2 structure type. In CaCo2Si2 a covalent Si–Si bond is present, whereas no Ge–Ge bond occurs in BaCo2Ge2. The CaCo2Si2 and BaCo2Ge2 are isoelectronic to BaFe2As2, the parent compound of a new “122” family of high temperature superconductors. The crystal chemistry and chemical bonding in title compounds is discussed in terms of LMTO band structure calculations and a topological analysis using the Electron Localization Function (ELF).
Impairment of Cognitive Function Reported by Patients Suffering from Carcinoid Syndrome
Authors: Chambers Anthony J. , Longman R. Stewart , Pasieka Janice L. , Dixon Elijah , Rorstad Otto , Rach‐Longman Kathy , Jones Jean
Published: February 2010

Background

Carcinoid syndrome (CS) is characterized by symptoms of diarrhea, flushing, bronchospasm, and valvular heart disease. It has been our impression that patients with CS also exhibit features of cognitive impairment. The purpose of this pilot study was to evaluate if symptoms of cognitive impairment were reported by patients with CS.

Methods

Patients with proven CS completed a 38‐question multiple‐ability self‐report questionnaire (MASQ) to assess symptoms in five cognitive domains: language skills, attention/concentration (A/C), visual‐perceptual function, visual memory, and verbal memory. Patients subsequently underwent neurocognitive assessment using a battery of six standardized tests. Results of the MASQ and the cognitive test were compared to published results for healthy individuals.

Results

Twenty‐one patients with CS were studied. MASQ symptom scores were higher than published norms in all five cognitive domains. Patients reported greatest difficulty with verbal memory (mean ± SD = 2.74 ± 0.5), followed by A/C (2.41 ± 0.65), language (2.31 ± 0.55), visual memory (2.30 ± 0.65), and visual‐perceptual function (2.17 ± 0.59). In contrast, neurocognitive tests for verbal memory immediate recall, visual memory, language, and executive function were within the normal range. CS patients, however, scored lower than expected in tests of verbal memory delayed recall and visual‐perceptual function.

Conclusions

Patients with CS report high levels of symptoms of impairment in all cognitive domains; however, on formal neurocognitive testing, patients scored lower than expected only in tests of verbal memory delayed recall and visual‐perceptual function. These findings appear to confirm our clinical impression that cognitive impairment may be an additional feature of CS. Further studies are needed to confirm and elucidate the cause of this cognitive impairment.