bluuebunny/crossref_metadata_2025 huggingface dataset:
Relay communications for Mars exploration
Authors: D. Edwards Charles
Published: February 2007

Telecommunication is an essential and challenging aspect of planetary exploration. For Mars landers, the constraints of mass, volume, power and energy typically limit their communications capabilities on the long‐distance link back to Earth. By deploying relay spacecraft in Martian orbit, these landers can achieve much greater data return and can obtain contact opportunities at times when Earth is not in view. Currently, both NASA and European Space Agency (ESA) have pursued this strategy, deploying relay payloads on their Mars science orbiters. This relay infrastructure has significantly benefited the science return from the 2003 Mars Exploration Rovers and is poised to support the Phoenix Lander and Mars Science Laboratory missions later this decade. Longer‐term plans call for continued growth in relay capability, greatly increasing data return from the Martian surface to enable exciting new Mars exploration concepts and advance our understanding of our planetary neighbour. Copyright © 2007 John Wiley & Sons, Ltd.
Software process improvement—A personal view: How it started and where it is going
Authors: Humphrey Watts S.
Published: February 2007

While the software process improvement movement is relatively recent, the need for improvement is not new. In this paper, the author reviews his personal experiences with software process improvement and describes some of the key events that led to such current widely‐used methods as the CMMI, the PSP, and the TSP. He summarizes the principles behind these methods and explains the principal reasons that these highly effective development methods have not been adopted more rapidly. In closing, he notes that their ultimate adoption is inevitable. Copyright © 2007 John Wiley & Sons, Ltd.
Delivering effective diversity management through effective structures
Authors: Bassett‐Jones Nigel , Brown Reva Berman , Cornelius Nelarine
Published: February 2007

The premise of this paper is that for effective diversity management, it is essential that an organization has in place factors that create effective structure, including workplace equality processes and programmes. In order to demonstrate this viewpoint, research was undertaken in a communications‐intensive firm by means of the extensive examination of documents and corroborative interviews. The findings were obtained by means of Beer's Viable Systems Model (1985). The research assumption was shown to be the case—the major finding indicates that effective diversity management is dependent on appropriate structures and systems to support the communication and implementation of arrangements to create and sustain workplace equality. Copyright © 2007 John Wiley & Sons, Ltd.
Adsorption of Novel Alkylaminoamide Sugar Surfactants at Tailor‐made Surfaces
Authors: Oskarsson Hans , Frankenberg Maud , Annerling Annika , Holmberg Krister
Published: February 2007

N,N‐di(3‐aminopropyl)dodecylamine (C12‐Y‐amine), N‐dodecyl‐N,N‐di[(3‐d‐gluconylamido)propyl]amine (C12‐DGA), N‐dodecyl‐N,N‐bis[(3‐lactobionylamido)propyl]amine (C12‐DLA), N‐dodecyl‐N‐[(3‐lactobionylamido)propyl]amine (C12‐LA), and ethoxylated N,N‐di(3‐aminopropyl)dodecylamine [C12‐Y‐amine with 4 and 8 ethylene oxide (EO)] have been synthesized, and their physical‐chemical properties have been studied. Adsorption was measured at the air–water interface by the du Noüy ring method and at solid surfaces consisting of self‐assembled monolayers (SAMs) of alkanethiols on gold using surface plasmon resonance. Results from surface tension measurements showed that adsorption at the air–water interface is pH dependent. At low pH, reduction in surface tension is less pronounced as a result of protonation of the amino groups of the surfactants. At the SAM model surfaces, generated by adsorption of alkanethiols or mixtures of alkanethiols on gold presenting methyl, hydroxyl, and carboxyl groups, the highest amount of adsorbed surfactant was obtained on a surface composed of a mixture of methyl and carboxyl groups. In general, the sugar‐derived surfactants, DGA, DLA, and LA, adsorbed less than the ethoxylates. Surfactant biodegradation was investigated by the closed bottle test. Only C12‐Y‐amine was found to be readily biodegradable. However, the polyol surfactants were more biodegradable than the ethoxylates.
A critical review of predefined diet quality scores
Authors: Waijers Patricia M. C. M. , Feskens Edith J. M. , Ocké Marga C.
Published: February 2007

The literature on predefined indexes of overall diet quality is reviewed. Their association with nutrient adequacy and health outcome is considered, but our primary interest is in the make-up of the scores. In total, twenty different indexes have been reviewed, four of which have gained most attention, and many others were based on those four. The various scores differ in many respects, such as the items included, the cut-off values used, and the exact method of scoring, indicating that many arbitrary choices have been made. Correlations in intake between dietary components may not be adequately addressed. In general, diet quality scores show an association with mortality or disease risk, but these relations are generally modest. Existing indexes do not predict morbidity or mortality significantly better than individual dietary factors. Although conclusions from the review may provide guidance in the construction of a diet quality score, it is questionable whether a dietary score can be obtained that is a much better predictor of health outcome.
Mononuclear cell metallothionein mRNA levels in human subjects with poor zinc nutrition
Authors: Kwon Chong-Suk , Kountouri Aggeliki M. , Mayer Claus , Gordon Margaret-Jane , Kwun In-Sook , Beattie John H.
Published: February 2007

Human zinc deficiency is thought to be prevalent worldwide, particularly in populations with diets low in zinc and animal protein and high in inhibitors of zinc absorption, such as phytic acid. Confirmation of zinc deficiency is, however, difficult in the absence of a reliable and sensitive marker of zinc status. Under controlled conditions, T-lymphocyte metallothionein-2A (MT-2A) mRNA levels change in relation to zinc status and the objective of the present study was to investigate whether these transcript levels could be related to dietary zinc intake, plasma zinc or other biochemical parameters influenced by, or influencing, zinc metabolism in human subjects likely to be zinc deficient. Rural Koreans (n110, age 50–80 years) with a range of zinc and phytic acid dietary intake were recruited for the study and blood samples were analysed for plasma zinc, HDL, LDL, α-tocopherol and thiobarbituric acid reactive substances, mononuclear cell (MNC) MT-2A mRNA, serum protein and albumin, and blood haematocrit, Hb and glucose. Multiple correlation and principal component analysis showed a significant negative correlation between plasma zinc and MNC MT-2A mRNA levels. Female subjects had higher MT-2A transcript levels than males and MT-2A mRNA levels tended to increase with age. There was no significant association between dietary zinc intake or any index of zinc intake relating to dietary inhibitors of zinc absorption. It is concluded that MNC MT-2A mRNA levels cannot be used to predict poor zinc nutrition.
Influence of prebiotics and antioxidants in bread on the immune system, antioxidative status and antioxidative capacity in male smokers and non-smokers
Authors: Seidel Christiane , Boehm Volker , Vogelsang Heinz , Wagner Andreas , Persin Christoph , Glei Michael , Pool-Zobel Beatrice L. , Jahreis Gerhard
Published: February 2007

Interest in functional foods is increasing. The aim of the present study was to investigate breads supplemented with functional components. One was bread supplemented with inulin, linseed and soya fibre (prebiotic bread). The other was a prebiotic antioxidant bread (pre-aox-bread), which additionally contained green tea powder, herbs and tomato paste. The effects of these two breads on immunological and antioxidative parameters were compared with control bread (placebo). Twenty smokers and eighteen non-smokers were enrolled in the randomised parallel study, which consisted of a control period and an intervention period, each lasting for 5 weeks. Daily intake of bread and nutrients did not differ between the intervention and the control period. Most of the twenty-three investigated immunological parameters measured in peripheral blood were unaffected. However, the percentage of CD19 increased after intervention with prebiotic bread, whereas intercellular adhesion molecule-1 (ICAM-1) and CD3+NK+ (P < 0·05) decreased in both intervention arms. The ferric reducing ability of plasma (FRAP) was increased after consumption of the pre-aox-bread for non-smokers (1256v.1147 μmol/l;P = 0·019) and remained unchanged for smokers consuming the pre-aox-bread. All analysed carotenoids (P ≤ 0·001) in plasma were increased after the consumption of pre-aox-bread. The concentrations of uric acid and α-tocopherol rose after intervention with both breads. ICAM-1 as a marker of stress decreased after consuming the prebiotic bread. In conclusion, increased plasma concentrations of carotenoids and the responses observed with the FRAP assay after intervention with the pre-aox-bread indicate a unique response in terms of antioxidative potentials for this type of functional food.
Efficacy of the entomopathogenic nematode, Steinernema feltiae, against sweetpotato whitefly Bemisia tabaci (Homoptera: Aleyrodidae) under laboratory and glasshouse conditions
Authors: Cuthbertson A.G.S. , Walters K.F.A. , Northing P. , Luo W.
Published: February 2007

The potential of using the entomopathogenic nematode Steinernema feltiae to control the sweetpotato whitefly Bemisia tabaci (Gennadius) has been established in previous laboratory studies. However, laboratory studies can overestimate the level of control achieved by biocontrol agents in the glasshouse. Glasshouse trials are therefore required to confirm laboratory results before full-scale commercial development is considered. Under both controlled laboratory and glasshouse conditions high mortality of second instar B. tabaci (>90% and >80%, respectively) was recorded after application of S. feltiae. The efficacy of the biocontrol agent at various application rates was also investigated, where halving the rate of S. feltiae application caused no significant reduction in B. tabaci mortality on tomato foliage. Steinernema feltiae has shown much potential for incorporation into integrated pest management strategies for the control of B. tabaci.
Dichroplus vittatus(Orthoptera: Acrididae) follows the converse to Bergmann's rule although male morphological variability increases with latitude
Authors: Bidau C.J. , Martí D.A.
Published: February 2007

Geographic body size variation was analysed in males and females of 19 populations of the South American grasshopperDichroplus vittatusBruner spanning 20 degrees of latitude and 2700 m of altitude. Using mean and maximum body length of each sex and factors obtained from principal components analyses of six morphometric linear characters it was shown thatD. vittatusfollowed the converse to Bergmann's rule latitudinally but not altitudinally where no significant trends were observed. For males, variability of body size increased with latitude but not with altitude. Both types of trends were significantly correlated with mean annual temperature and minimum annual temperature (positive correlations), and two estimators of seasonality, the coefficients of variation of mean annual temperature (negative) and mean annual precipitation (positive). Some allometric relationships also showed geographic variation. It is suggested that the observed decrease in size with latitude together with the increase in morphological variability is a consequence of a number of factors: the shortening of the growing season southwards; the increasing seasonality and climatic unpredictability; and the fact that the species exhibits protandry which contributes to smaller and more variable size in males and smaller but more constant body size in females.
Characterization of resistance to multiple aphid species (Hemiptera: Aphididae) inMedicago truncatula
Authors: Gao L.-L. , Horbury R. , Nair R.M. , Singh K.B. , Edwards O.R.
Published: February 2007

Aphids are phloem-feeding insects that damage many important crops throughout the world yet, compared to plant–pathogen interactions, little is known about the mechanisms by which plants become resistant to aphids.Medicago truncatula(barrel medic) is widely considered as the pre-eminent model legume for genetic and biological research and in Australia is an important pasture species. Six cultivars ofM. truncatulawith varying levels of resistance to two pests of pasture and forage legumes, the bluegreen aphidAcyrthosiphon kondoiShinji and the spotted alfalfa aphidTherioaphis trifoliif.maculata. (Buckton) are investigated. Two resistance phenotypes againstT. trifoliif.maculataare described, one of which is particularly effective, killing most aphids within 24 h of infestation. Each resistance phenotype provided a similar but somewhat less effective degree of resistance to the closely-related spotted clover aphidTherioaphis trifolii(Monell). In the case ofA. kondoionly one resistance phenotype was observed, which did not vary among different genetic backgrounds. None of the observed resistance againstA. kondoiorT. trifoliif.maculatasignificantly affected the performance of green peach aphidMyzus persicae(Sulzer) or cowpea aphidAphis craccivoraKoch. The existence of multiple aphid resistance mechanisms in similar genetic backgrounds of this model plant provides a unique opportunity to characterize the fundamental basis of plant defence to these serious agricultural pests.
(De-)Mobilising the Marginalised: A Comparison of the Argentine Piqueteros and Ecuador's Indigenous Movement
Authors: WOLFF JONAS
Published: February 2007

In recent years, socio-political crises have challenged democracy across South America. Social movements that succeeded in mobilising marginalised sectors are at the forefront of this turbulence, Ecuador's indigenous movement and the organisations of unemployed workers in Argentina being paradigmatic cases. Recent developments point to an intrinsic weakness of both indigenous and unemployed movements, in that democratic regimes have proved highly successful at ‘taming’ them. By comparing the two movements, in terms of their internal dynamics and interactions with the political system, this article argues that common characteristics that were crucial for successful mobilisation in the first place, at the same time, help explain their vulnerability to division and clientelist integration.
Growth with Inequality: Living Standards in Mexico, 1850–1950
Authors: LÓPEZ-ALONSO MORAMAY
Published: February 2007

This article focuses on trends in the adult heights of various sectors of Mexican society between 1850 and 1950 as a proxy for their biological and material standards of living. The evolution of biological standards of living is an alternative way to assess whether or not economic development after 1850 was beneficial to the population, using a proxy that relies on a basic natural characteristic, adult height. The recruitment records of the Mexican rural and federal militia provide us with information on the secular trends of heights of the Mexican labouring classes, while a database of passport applications allows us to compare the evolution of living standards across social classes. It is argued that the benefits of industrialisation and improved economic performance fostered by the Díaz regime (1876–1910) did not have a favourable impact on the biological wellbeing of the labouring population. There are, however, signs of improvement in living standards with the launching of welfare programmes at the end of the Cárdenas administration. In contrast, the average height of the elites increased throughout the period, suggesting that there was a growing disparity in the evolution of living standards between social classes.
Chirurgische Therapie der Divertikulitis
Authors: Bittner  , Ulrich
Published: February 2007

Die Sigmadivertikulitis ist eine in den westlichen Industrienationen zunehmend häufiger zu beobachtende Erkrankung. Nach allgemeiner Übereinstimmung besteht eine Operationsindikation bei Vorliegen einer Komplikation sowie nach dem zweiten Schub bei chronisch-rezidivierendem Verlauf. Bei jüngeren Patienten sollte bereits nach einem ersten behandlungswürdigen Schub die Operation in Erwägung gezogen werden. Die Therapie der Wahl ist die Sigmaresektion mit primärer Anastomosierung. Sollte die Divertikulitis auch das untere Colon descendens betreffen, muss auch dieser Darmabschnitt mit reseziert werden. In der Notfallsituation mit schwerer lokaler oder generalisierter Peritonitis oder ausgedehnter lokaler Abszessbildung ist ein zweizeitiges Vorgehen, im Besonderen in einer nicht spezialisierten Klinik zu empfehlen, d.h. in einer ersten Operation erfolgt die Resektion mit Schaffung einer Hartmann-Situation (Blindverschluss des Rektums, endständiges Kolonstoma) und nach frühestens drei Monaten die Rückverlagerung des Stomas mit Reanatomosierung. Die Operationstechnik der Wahl ist – sofern die notwendige Expertise besteht – die Laparoskopie. Wenngleich in einer Vielzahl von Studien signifikante Vorteile für die neue Technik belegt werden konnten, so handelt es sich doch um ein vollkommen neues Verfahren, das eine signifikante Lernkurve hat, die 50-60 Operationen umfasst. Die Konversion zur konventionellen Technik ist daher nicht als ein persönliches Versagen, sondern als verantwortungsbewusstes Handeln zum Wohle des Patienten anzusehen.
Centennial‐scale variability of the British Ice Sheet: Implications for climate forcing and Atlantic meridional overturning circulation during the last deglaciation
Authors: Knutz Paul C. , Zahn Rainer , Hall Ian R.
Published: February 2007

Evidence from paleoclimatic archives suggests that Earth's climate experienced rapid temperature changes associated with pronounced interhemispheric asymmetry during the last glacial period. Explanations for these climate excursions have converged on nonlinear interactions between ice sheets and the ocean's thermohaline circulation, but the driving mechanism remains to be identified. Here we use multidecadal marine records of faunal, oxygen isotope, and sediment proxies from the northeast Atlantic proximal to the western margins of the last glacial British Ice Sheet (BIS) to document the coupling between ice sheet dynamics, ocean circulation, and insolation changes. The core data reveal successions of short‐lived (80–100 years), high‐amplitude ice‐rafted debris (IRD) events that were initiated up to 2000 years before the deposition of detrital carbonate during Heinrich events (HE) 1 and 2. Progressive disintegration of the BIS 19–16 kyr before present (B.P.) occurred in response to abrupt ocean‐climate warmings that impinged on the northeast Atlantic during the early deglaciation. Peak IRD deposition recurs at 180–220 year intervals plausibly involving repeated breakup of glacial tidewater margins and fringing marine ice shelves. The early deglaciation culminated in a major meltwater pulse at ∼16.3 kyr B.P. followed by another discharge associated with HE1 some 300 years after. We conclude that temperature changes related to external forcing and marine heat transport caused a rapid response of the BIS and possibly other margins of the Eurasian Ice Sheet. Massive but short‐lived meltwater surges influenced the Atlantic meridional overturning circulation thereby contributing to North Atlantic climate variability and bipolar climatic asymmetry.
Controllable switching behavior of defect modes in one-dimensional heterostructure photonic crystals
Authors: Lu Y. H. , Huang M. D. , Park S. Y. , Kim P. J. , Nahm T.-U. , Lee Y. P. , Rhee J. Y.
Published: February 2007

A dimerlike-positional-correlation heterostructure is used in one-dimensional photonic crystals to introduce the defect mode with perfect transmittance. The switching behavior of the transmittance, at the defect mode, is demonstrated theoretically. When the normal incident beam is tilted at a negligibly small angle, the perfect transmittance peak vanishes. It is found that this condition causing this phenomenon can be easily met and controlled through elucidation on the mechanism. This finding is significant for potential applications in high-precision filters and optical switches.
Variable capacitance mechanisms in carbon nanotubes
Authors: Dragoman D. , Dragoman M.
Published: February 2007

This paper demonstrates that semiconducting carbon nanotubes can be used to implement a room temperature capacitance tunable via an external bias, i.e., a varactor, which is a key element in any communication system working up to a few terahertz. The paper describes the implementation of two types of varactors based, respectively, on a single gated nanotube and on a biased array of carbon nanotubes. In the former case, the varactor is the density-of-states dependent quantum capacitance that can be tuned via a gate voltage due to the shift of the Fermi level. In the latter case, the varactor consists of a selectively biased brushlike carbon nanotube array with a capacitance tuned via attractive and repulsive electrostatic forces between different nanotubes of the array.
Variation of quantum-yield curves for GaAs photocathodes under illumination
Authors: Zou Jijun , Chang Benkang , Chen Huailin , Liu Lei
Published: February 2007

The variation of the quantum-yield curves of reflection-mode and transmission-mode GaAs photocathodes under illumination has been studied using an instrument for measuring quantum yields at room temperature. The two kinds of photocathodes have an identical doping concentration and active-layer thickness, 1×1019cm−3 and 1.6μm, respectively. These photocathodes were illuminated by white light with an intensity of 100lx, and the yield curves were measured simultaneously every other hour. The measured results show that the shape of the yield curves for the reflection-mode photocathodes changes rapidly with increasing illumination time, whereas the shape of the curves for the transmission-mode photocathodes is almost constant, we find that the reason is the average path lengths that photoelectrons have to travel are different for the two kinds of photocathodes. In the yields of the transmission-mode photocathodes, all types of photoemission except Γ may be neglected, whereas all of the Γ, L, and hot-electron photoemission must be included in the yields of the reflection-mode photocathodes. Based on the two-minima diffusion model and the fit of the escape probability, we have revised the quantum-efficiency equation for the reflection-mode photocathodes and used this revised equation to explain the variation of their yield curves.
Calculated optical properties of wurtzite InN
Authors: Jin H. , Zhao G. L. , Bagayoko D.
Published: February 2007

We report ab initio, self-consistent calculations of the dielectric function of wurtzite indium nitride (w-InN). Our calculations employed a local density approximation (LDA) potential, a linear combination of atomic orbital basis set, and the Bagayoko-Zhao-Williams (BZW) method. Our findings agree very well with recent measurements up to photon energies of 6eV. This excellent agreement shows the correct description, by the LDA-BZW method, of the relative separations between upper valence bands and low-lying conduction bands, in general, and corroborates our previous result of 0.88eV for the intrinsic, fundamental band gap of w-InN, in particular. We also report results of simulations of the effect of high electron doping on the optical properties of InN.
Permanent-magnet longitudinal fields for magnetostrictive devices
Authors: Zhang Tianli , Jiang Chengbao , Xu Huibin , Mao Jianqin
Published: February 2007

This paper discusses a technique for improving the homogeneity of the magnetic field of tube-like permanent magnets designed for magnetostrictive devices. The high homogeneity of the magnetic field along the tube is achieved by gradually changing shape or remanence of combined short rings. The analysis of the field in the magnet is performed using the magnetic charge principle and axial magnetic field equations are deduced. An example of design of a longitudinal uniform field for a magnetostrictive rod with large length to diameter ratio is presented.
Social and Environmental Accounting, Auditing, and Reporting: A Potential Source of Organisational Risk Governance?
Authors: Bebbington Jan , Thomson Ian
Published: February 2007

The authors examine the extent to which the practices of social and environmental accounting, auditing, and reporting (SEAAR) provide opportunities for the identification, communication, and management of social and environmental risks. In introducing and exploring accounting practices, the theoretical allegiances of accounting are also outlined in order to situate accounting as a social science discipline which experiences similar debates to other areas of scholarship. The authors also extend discussion of risk governance and accounting by reference to the ‘new’ literature on risk from writers such as Adams, Beck, and Lash. It is suggested that the insights from these broader theorists on risk apply equally to conventional accounting and attempts via SEAAR to create an expanded governance framework. In particular, Beck identifies a number of critical aspects of risk governance that are also central to an understanding of accounting, including: the danger of seeking verifiable and neutral truth; the causal denial of harm; the contestation of expert and lay knowledge of risks; social construction of risk; and the radicalisation of rationality. Paraphrasing Beck, it is argued that accounting and accountants are incapable of managing the risks of industrialisation as they are implicated in the creation and multiplication of these risks, yet accounting and accountants, in particular those engaged in SEAAR, can play an essential role in identifying these risks. It is further argued that the contribution of SEAAR to risk governance will largely depend upon a radicalisation of accounting rationality in practice.
Hydrocarbon degradation at high salinity by a novel extremely halophilic actinomycete
Authors: Al-Mueini Ratiba , Al-Dalali Muna , Al-Amri Issa S. , Patzelt Heiko
Published: February 2007

Environmental context. Large areas of arid countries, such as those of the Arabian Peninsula, Central Asia and Australia, are covered by saline sand and gravel deserts, which until recently were considered to be devoid of microbial life. Although in recent times a large number of salt-tolerant and drought-resistant microbes have been described, their metabolism – especially their potential to degrade xenobiotics – is still poorly understood. The ability to degrade xenobiotics is a prerequisite for the use of such organisms for pollution control and environmental field biotechnology. This study describes a potentially to biotechnologically useful actinomycete that is able to degrade some xenobiotics under saline conditions. Abstract. A new, extremely halophilic, species of Actinopolyspora (Family Pseudonocardiacaea, Order Actinomycetales) was isolated from the saline and arid surroundings of an oil field in the Sultanate of Oman. The strain grows well at salt concentrations up to 250 g L–1 and is tolerant of the presence of high concentrations of aromatic and aliphatic hydrocarbons. It efficiently degrades alkanes up to C15 and at a slower rate up to C25. Most notable, however, is its fluorene metabolism, which proceeds through several novel metabolites and most likely follows a previously undescribed pathway.
Partitioning and stability of engineered ZnO nanoparticles in soil suspensions using flow field-flow fractionation
Authors: Gimbert Laura J. , Hamon Rebecca E. , Casey Phil S. , Worsfold Paul J.
Published: February 2007

Environmental context. Nanoparticulate materials are increasingly being used as catalysts and lubricants, for pollution control and drug delivery, and in electronics, fabrics, cosmetics and sunscreens. In spite of this growth, information about the fate and toxicity of nanoparticles in the environment is limited, partly due to the lack of techniques capable of measuring nanoparticles in complex environmental matrices. One emerging tool, flow field-flow fractionation, can be used to determine the presence and particle size distribution of engineered nanoparticles, for example in soil pore waters, thereby enhancing our understanding of their environmental fate and impacts.
Abstract. This paper reports preliminary results for the determination of engineered ZnO nanoparticles using flow field-flow fractionation (FlFFF). This separation technique was used to determine the particle size distributions (PSDs) of ZnO nanoparticles spiked in soil suspensions. Before FlFFF analysis, the soil was prepared in suspension form, shaken overnight and gravitationally settled to extract the <1-µm fraction. The effect of aging was also investigated using soil samples incubated with known concentrations of ZnO nanoparticles for 7 and 14 days. The results show that FlFFF can be used to determine the PSD of engineered nanoparticles and monitor their partitioning and stability in soil suspensions.
Characterization of a marine gammaproteobacterium capable of aerobic anoxygenic photosynthesis
Authors: Fuchs Bernhard M. , Spring Stefan , Teeling Hanno , Quast Christian , Wulf Jörg , Schattenhofer Martha , Yan Shi , Ferriera Steve , Johnson Justin , Glöckner Frank Oliver , Amann Rudolf
Published: February 2007

Members of the gammaproteobacterial clade NOR5/OM60 regularly form an abundant part, up to 11%, of the bacterioplankton community in coastal systems during the summer months. Here, we report the nearly complete genome sequence of one cultured representative,
Congregibacter litoralis
strain KT71, isolated from North Sea surface water. Unexpectedly, a complete photosynthesis superoperon, including genes for accessory pigments, was discovered. It has a high sequence similarity to BAC clones from Monterey Bay [Beja O, Suzuki MT, Heidelberg JF, Nelson WC, Preston CM,
et al
. (2002)
Nature
415:630–633], which also share a nearly identical gene arrangement. Although cultures of KT71 show no obvious pigmentation, bacteriochlorophyll
a
and spirilloxanthin-like carotenoids could be detected by HPLC analysis in cell extracts. The presence of two potential BLUF (blue light using flavin adenine dinucleotide sensors), one of which was found adjacent to the photosynthesis operon in the genome, indicates a light- and redox-dependent regulation of gene expression. Like other aerobic anoxygenic phototrophs (AAnPs), KT71 is able to grow neither anaerobically nor photoautotrophically. Cultivation experiments and genomic evidence show that KT71 needs organic substrates like carboxylic acids, oligopeptides, or fatty acids for growth. The strain grows optimally under microaerobic conditions and actively places itself in a zone of ≈10% oxygen saturation. The genome analysis of
C. litoralis
strain KT71 identifies the gammaproteobacterial marine AAnPs, postulated based on BAC sequences, as members of the NOR5/OM60 clade. KT71 enables future experiments investigating the importance of this group of gammaproteobacterial AAnPs in coastal environments.
Hydrophobic interaction and hydrogen-bond network for a methane pair in liquid water
Authors: Li Je-Luen , Car Roberto , Tang Chao , Wingreen Ned S.
Published: February 2007

We employ fully quantum-mechanical molecular dynamics simulations to evaluate the force between two methanes dissolved in water, as a model for hydrophobic association. A stable configuration is found near the methane–methane contact separation, while a shallow second potential minimum occurs for the solvent-separated configuration. The strength and shape of the potential of mean force are in conflict with earlier classical force-field simulations but agree well with a simple hydrophobic burial model which is based on solubility experiments. Examination of solvent dynamics reveals stable water cages at several specific methane–methane separations.
EQUILIBRIUM AND THE CORE IN ALONSO'S DISCRETE POPULATION MODEL OF LAND USE*
Authors: Berliant Marcus , Raa Thijs ten
Published: February 2007

Conventional wisdom tells us that with no market failure and local nonsatiation of preferences, the core is at least as large as the collection of competitive equilibrium allocations. We confirm this for a standard model featuring private ownership of land. Next we consider the public land ownership version of the model. If the role of land ownership and rent distribution is assumed by a government that ploughs back rent (at least in excess of its agricultural value) to its citizens, the equilibrium allocation remains efficient, but no longer need be in the core.
Reversible Cerebral Vasoconstriction in Spontaneous Intracranial Hypotension
Authors: Schievink Wouter I. , Maya M. Marcel , Chow William , Louy Charles
Published: February 2007

Myelography showed an opening pressure of 0 cm H2O and multiple thoracic meningeal diverticula in a 52‐year‐old woman suffering from orthostatic headaches of instantaneous onset. MR‐angiography showed severe segmental arterial stenosis of the anterior and posterior circulation, which resolved over a 4‐day period following an epidural blood patch. Spontaneous intracranial hypotension should be considered in the differential diagnosis of reversible cerebral vasoconstriction.
Cysticercosis Headache: An Important Differential of Childhood Headache Disorder in Endemic Countries
Authors: Mishra Devendra
Published: February 2007

Neurocysticercosis is a common pediatric central nervous system (CNS) disease in endemic areas, presenting usually with seizures but has pleomorphic manifestations, including migraine‐like secondary headache. We herein report a pediatric patient with tension‐type headache as the sole presenting feature of single cysticercus granuloma.
Hormonal Management of Migraine Associated With Menses and the Menopause: A Clinical Review
Authors: Loder Elizabeth , Rizzoli Paul , Golub Joan
Published: February 2007

Objective.—This article reviews hormonal strategies used to treat headaches attributed to the menstrual cycle or to peri‐ or postmenopausal estrogen fluctuations. These may occur as a result of natural ovarian cycles, or in response to the withdrawal of exogenously administered estrogen.

Background.—A wide variety of evidence indicates that cyclic ovarian sex steroid production affects the clinical expression of migraine. This has led to interest in the use of hormonal treatments for migraine.

Methods.—A PubMed search of the literature was conducted using the terms “migraine,”“treatment,”“estrogen,”“hormones,”“menopause,“ and “menstrual migraine.” Articles were selected on the basis of relevance.

Results.—The overarching goal of hormonal treatment regimens for migraine is minimization of estrogen fluctuations. For migraine associated with the menstrual cycle, supplemental estrogen may be administered in the late luteal phase of the natural menstrual cycle or during the pill‐free week of traditional combination oral contraceptives. Modified contraceptive regimens may be used that extend the duration of active hormone use, minimize the duration or extent of hormone withdrawal, or both. In menopause, hormonally associated migraine is most likely to be due to estrogen‐replacement regimens, and treatment generally involves manipulating these regimens. Evidence regarding the safety and efficacy of these regimens is limited.

Conclusions.—Hormonal treatment of migraine is not a first‐line treatment strategy for most women with migraine. Evidence is lacking regarding its long term harms and migraine is a contraindication to the use of exogenous estrogen in all women with aura and those aged 35 or older. The harm to benefit balances of several traditional nonhormonal therapies are better established.
Sensitizing potential of acetaldehyde and formaldehyde using a modified cumulative contact enhancement test (CCET)
Authors: Bergh Margareta , Karlberg Ann‐Therese
Published: February 2007

The contact allergenic activity of acetaldehyde was investigated with a modified cumulative contact enhancement test (CCET) method in guinea pigs. Possible cross‐reactivity between acetaldehyde and formaldehyde was also studied. In contrast to the original CCET protocol, we used shamtreated controls and the chemicals were tested with closed epicutaneous application at 1st challenge. The suitability of the method was verified with formaldehyde and the results were comparable with those previously found with the guinea pig maximization test (GPMT). For the 1st time, acetaldehyde was shown to be a contact allergen in predictive tests. No cross‐reactivity was observed between acetaldehyde and formaldehyde. Acetaldehyde seems to be a rare sensitizer in man. However, its allergenic activity should be considered, since it might be present as an impurity in ethoxylated surfactants. As the CCET protocol involves topical induction and challenge, we regard the modified version as well suited to evaluation of the contact allergenic potential of chemicals.
Comparison of the composition of oral mucosal residual saliva with whole saliva
Authors: Lee J‐Y , Chung J‐W , Kim Y‐K , Chung S‐C , Kho H‐S
Published: February 2007

Objective:  Compared with whole saliva, residual saliva comprising the oral mucosal film shows a high protein concentration. The purpose of this study was to compare the composition of residual saliva with unstimulated and stimulated whole saliva in normosalivators.

Materials and methods:  The composition of oral mucosal residual saliva in 30 healthy individuals was investigated and compared with that of whole saliva. The concentrations of total protein, secretory immunoglobin A (sIgA), lactoferrin, total carbohydrate, and sialic acid were examined. The activities of peroxidase, lysozyme and α‐amylase were determined.

Results:  Residual saliva had higher levels of total protein and carbohydrate than whole saliva, with a higher carbohydrate to protein ratio in the residual saliva suggesting that salivary glycoproteins are concentrated on the oral mucosal surface. sIgA, lactoferrin and sialic acid were present as highly concentrated forms in residual saliva. The enzymatic activity of peroxidase in residual saliva was higher than that of whole saliva.

Conclusions:  These concentrated carbohydrate and antimicrobials on the oral mucosal surface work for mucosal defence and could be used for targeting sites for the delivery of therapeutic agents.
A Practical Formulation for Evaluating Combined Fatigue Damage From High- and Low-Frequency Loads
Authors: Huang Wenbo , Moan Torgeir
Published: February 2007

Based on Gaussian load processes, a new formula suitable for evaluating the combined fatigue damage due to high- and low-frequency loads is derived. Then, by using of the Winterstein’s transformation, the developed formula is extended for the combination of non-Gaussian loads. The numerical simulation shows that the predicted damage by the derived formula is very simple to use and close to the rain-flow prediction.
The Simultaneous Assessment of Constitutional, Behavioral, and Environmental Factors in the Development of Large Nevi
Authors: Cockburn Myles , Hamilton Ann , Mack Thomas
Published: February 2007

Background: The presence of large nevi (>4 mm diameter) is the most important predictor of melanoma risk. We report on the simultaneous assessment of behavioral, constitutional, and environmental risk factors for the prevalence of large nevi in a population-based study of 33,305 individuals and compare those to risk factors for melanoma.

Methods: We used self-reported data from a population-based study of twins in California, assessing the prevalence of large nevi, lifetime usual sun exposure behavior and sunburn experience, skin type and color, and birthplace and recent domicile, for which we obtained estimates of potential sun exposure.

Results: Among constitutional variables, skin type (burn rather than tan) and having blond (but not red) hair color were associated with having more than three large nevi, as was Celtic ancestry. Spending more time in the sun in adulthood was inversely associated with number of large nevi, whereas spending time in the sun during weekends in childhood increased the risk of having large nevi. We observed no latitude gradient in nevi prevalence, except among those of Mediterranean ancestry (those in the South were more likely than those in the North to report large nevi).

Conclusion: The prevalence of large nevi was most readily explained by constitutional and then by behavioral variables in this study, rather than by independent variables describing an individual's opportunity for sun exposure. There seem to be independent relationships between nevi frequency and other melanoma risk factors, with the notable exceptions of skin color and red hair phenotype: implying that if these risk factors represent a genetic propensity to develop melanoma, that risk would seem to be unrelated to the development of nevi. (Cancer Epidemiol Biomarkers Prev 2007;16(2):200–07)
Evaluation of RNA Markers for Early Detection of Cervical Neoplasia in Exfoliated Cervical Cells
Authors: Steinau Martin , Rajeevan Mangalathu S. , Lee Daisy R. , Ruffin Mack T. , Horowitz Ira R. , Flowers Lisa C. , Tadros Talaat , Birdsong George , Husain Mujtaba , Kmak David C. , Longton Garry M. , Vernon Suzanne D. , Unger Elizabeth R.
Published: February 2007

Numerous molecular biomarkers have been suggested for early detection of cervical cancer, but their usefulness in routinely collected exfoliated cells remains uncertain. We used quantitative reverse transcription-PCR to evaluate expression of 40 candidate genes as markers for high-grade cervical intraepithelial neoplasia (CIN) in exfoliated cervical cells collected at the time of colposcopy. Samples from the 93 women with CIN3 or cancer were compared with those from 186 women without disease matched (1:2) for age, race, and high-risk human papillomavirus status. Normalized threshold cycles (Ct) for each gene were analyzed by receiver operating characteristics to determine their diagnostic performance in a split sample validation approach. Six markers were confirmed by an area under the curve >0.6 in both sample sets: claudin 1 (0.75), minichromosome maintenance deficient 5 (0.71) and 7 (0.64), cell division cycle 6 homologue (0.71), antigen identified by monoclonal antibody Ki-67 (0.66), and SHC SH2-domain binding protein 1 (0.61). The sensitivity for individual markers was relatively low and a combination of five genes to a panel resulted in 60% sensitivity with 76% specificity, not positively increasing this performance. Although the results did not indicate superiority of RNA markers for cervical cancer screening, their performance in detecting disease in women referred for colposcopy suggests that the genes and pathways they highlight could be useful in alternative detection formats or in combination with other screening indicators. (Cancer Epidemiol Biomarkers Prev 2007;16(2):295–301)
The RAD51 135 G>C Polymorphism Modifies Breast Cancer and Ovarian Cancer Risk in Polish BRCA1 Mutation Carriers
Authors: Jakubowska Anna , Gronwald Jacek , Menkiszak Janusz , Górski Bohdan , Huzarski Tomasz , Byrski Tomasz , Edler Lutz , Lubiñski Jan , Scott Rodney J. , Hamann Ute
Published: February 2007

Breast and ovarian cancer penetrance in BRCA1 mutation carriers is estimated to be between 15% and 80% by age 70 years. At present, it is not possible to predict with any certainty who is most likely to develop disease or which age it will develop. Previous studies have tried to correlate the sites of BRCA1 mutations with disease risk; however, the results have not yielded any definitive association. An alternative explanation that could account for differences in the penetrance of BRCA1 mutations is the action of modifier genes. In this study, we have investigated the role of the RAD51_135_G>C polymorphism in breast and ovarian cancer case-control populations of Polish women who have been matched for BRCA1 mutation and year of birth. The results reveal that women who harbor the C allele have almost twice the reduction in breast and ovarian cancer risk compared with women who harbor only the G allele. These findings suggest that the effect of the RAD51 C allele is an important risk modifier for malignancies occurring on a background of BRCA1 mutations. In addition, we were able to show that the site of the BRCA1 mutation does not influence the effect of the RAD51 C allele, indicating that this polymorphism contributes to prevention of disease in BRCA1 carriers. In conclusion, the RAD51 C allele seems to protect against both breast and ovarian cancer in women harboring BRCA1 mutations. (Cancer Epidemiol Biomarkers Prev 2007;16(2):270–5)
A Prospective Study of Blood Selenium Levels and the Risk of Arsenic-Related Premalignant Skin Lesions
Authors: Chen Yu , Hall Marni , Graziano Joseph H. , Slavkovich Vesna , van Geen Alexander , Parvez Faruque , Ahsan Habibul
Published: February 2007

Arsenic exposure from drinking water is considered to be a risk factor for skin and internal cancers. Animal studies suggest a potential antagonism between arsenic and selenium in the body. We did a case-cohort analysis to prospectively evaluate the association between arsenic-related premalignant skin lesions and prediagnostic blood selenium levels in 303 cases of skin lesions newly diagnosed from November 2002 to April 2004 and 849 subcohort members randomly selected from the 8,092 participants in the Health Effects of Arsenic Longitudinal Study with available baseline blood and urine samples collected in 2000. Incidence rate ratios for skin lesions in increasing blood selenium quintiles were 1.00 (reference), 0.68 [95% confidence interval (95% CI), 0.39-1.18], 0.51 (95% CI, 0.29-0.87), 0.52 (95% CI, 0.30-0.91), and 0.53 (95% CI, 0.31-0.90). Effect estimates remained similar with adjustments for age, sex, body mass index, smoking status, excessive sunlight exposure (in men), well water arsenic concentration at baseline, and nutritional intakes of folate, iron, protein, vitamin E, and B vitamins. At any given arsenic exposure level, the risk of premalignant skin lesions was consistently greater among participants with blood selenium lower than the average level. The findings support the hypothesis that dietary selenium intake may reduce the incidence of arsenic-related premalignant skin lesions among populations exposed to arsenic exposure from drinking water. (Cancer Epidemiol Biomarkers Prev 2007;16(2):207–13)