bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustainability and urban food supply in Africa
Authors: Lynch Kenneth
Published: February 2007

Agenda 21 has made a major contribution to a range of aspects of development initiatives, of which one chapter, Chapter Seven, focuses on sustainable human settlements. There are a growing number of publications on issues relating to food supply to urban areas in the less developed world. These publications have several focuses, particularly fruit and vegetables, urban agriculture and food marketing. The main aspects of the chapter of Agenda 21 relating to sustainable human settlements are discussed and also the role that the emerging research on urban food systems suggests can be played in establishing sustainable development in cities in less developed countries. Particular attention is paid to Dar es Salaam in Tanzania.
‘A burger and a coke’ and other environmental problems: Reflections on diet and the environmental crisis
Authors: Sager Gene
Published: February 2007

Most environmental organizations do not focus attention on the impact of diet on the environment. However, my findings as spelled out in this article indicate that dietary changes, especially reduction of beef consumption, could have dramatic and heretofore unforeseen environmental implications ranging from local issues of fertilizer and pesticide use to global sustainability. Using illustrations from American and Australian practices, I trace a wide variety of environmental and nutritional impacts of beef consumption and conclude that a burger and a coke is an outmoded lunch for a humanoid on Planet Earth today.
Combining information from multiple surveys to enhance estimation of measures of health
Authors: Schenker Nathaniel , Raghunathan Trivellore E.
Published: February 2007

Survey estimates are often affected by non‐sampling errors due to missing data, coverage error, and measurement or response error. Such non‐sampling errors can be difficult to assess, and possibly correct for, using information from a single survey. Thus, combining information from multiple surveys can be beneficial. In addition, combining information from multiple surveys can help to reduce sampling error. This article describes four examples of projects undertaken by researchers within and outside the National Center for Health Statistics of the Centers for Disease Control and Prevention, in which information from multiple surveys was combined to adjust for non‐sampling errors and thereby enhance estimation of various measures of health. The four projects can be described briefly as follows: (1) combining estimates from a survey of households and a survey of nursing homes to extend coverage; (2) using information from an interview survey to bridge the transition in race reporting in the United States census; (3) combining information from an examination survey and an interview survey to improve on analyses of self‐reported data; and (4) combining information from two interview surveys to enhance small‐area estimation. The article highlights the goals, techniques, and results from the four projects and discusses issues that can arise when information is combined from multiple surveys. Published in 2007 by John Wiley & Sons, Ltd.
Influences on strategic decision effectiveness: Development and test of an integrative model
Authors: Elbanna Said , Child John
Published: February 2007

This paper draws upon three broad perspectives on the strategic decision‐making process in order to develop a more completely specified model of strategic decision effectiveness in a different context, namely Egypt. The key variables in this model consist of three strategic decision‐making process dimensions (rationality, intuition, and political behavior); seven moderating variables concerning decision‐specific, environmental, and organizational factors; and strategic decision effectiveness as an outcome variable. A two‐stage study was conducted in which the first stage provided exploratory insights and the second stage investigated hypotheses on the impact of strategic decision‐making process dimensions on strategic decision effectiveness and the moderating role of broader contextual variables. The second‐stage study produced three major findings: (1) both rational and political processes appear to have more influence on strategic decision effectiveness than does intuition; (2) strategic decision effectiveness is both process‐ and context‐specific; and (3) certain results support the ‘culture‐free’ argument, while others support the ‘culture‐specific’ argument. Copyright © 2007 John Wiley & Sons, Ltd.
Batchwise Growth of Silica Cone Patterns via Self‐Assembly of Aligned Nanowires
Authors: Luo Shudong , Zhou Weiya , Chu Weiguo , Shen Jun , Zhang Zengxing , Liu Lifeng , Liu Dongfang , Xiang Yanjuan , Ma Wenjun , Xie Sishen
Published: February 2007

Silica‐cone patterns self‐assembled from well‐aligned nanowires are synthesized using gallium droplets as the catalyst and silicon wafers as the silicon source. The cones form a triangular pattern array radially on almost the whole surface of the molten Ga ball. Detailed field‐emission scanning electron microscopy (SEM) analysis shows that the cone‐pattern pieces frequently slide off and are detached from the molten Ga ball surface, which leads to the exposure of the catalyst surface and the growth of a new batch of silicon oxide nanowires as well as the cone patterns. The processes of growth and detachment alternate, giving rise to the formation of a volcano‐like or a flower‐like structure with bulk‐quantity pieces of cone patterns piled up around the Ga ball. Consequently, the cone‐patterned layer grows batch by batch until the reaction is terminated. Different to the conventional metal‐catalyzed growth model, the batch‐by‐batch growth of the triangular cone patterns proceeds on the molten Ga balls via alternate growth on and detachment from the catalyst surface of the patterns; the Ga droplet can be used continuously and circularly as an effective catalyst for the growth of amorphous SiOx nanowires during the whole growth period. The intriguing batchwise growth phenomena may enrich our understanding of the vapour–liquid–solid (VLS) growth mechanism for the catalyst growth of nanowires or other nanostructures and may offer a different way of self‐assembling novel silica nanostructures.
Periodic homogenization in viscoelasticity. Influence of micro mechanical parameters on the homogenized memory law: numerical tests
Authors: Cherraf‐Schweyer C. , Maurice G. , Taghite M. , Taous K.
Published: February 2007

A theoretical and numerical approach based on the finite element method highlights the existing bond between the periodic structure and the micro viscoelastic behavior and on the other hand the macro behavior. The homogenized law, contrary to the micro laws, presents a long memory which is conditioned by the elastic and visco parameters of the micro materials. We focus our attention on the influence of the variation of the micro mechanical parameters on the homogenized long memory function.
Axially poled solid cylinder under tension with a flat annular crack
Authors: Narita F. , Shindo Y. , Lin S.
Published: February 2007

We investigate the electroelastic response of a flat annular crack in a solid piezoelectric cylinder of finite radius under mode I loading. By the use of Fourier and Hankel transforms, the mixed boundary value problem is reduced to a singular integral equation. Numerical values on the stress intensity factor, energy release rate, and energy density factor for piezoelectric cylinders are obtained to show the influence of applied electric fields, and the results are presented in graphical form. Special cases of a penny‐shaped crack and a circumferential edge crack are also discussed.
Incremental friction problems for continuous elastic bodies with discretized contact
Authors: Rietz A.
Published: February 2007

We examine the existence of solutions to incremental friction problems for a continuous elastic object in contact with obstacles. The contact is modelled by a modified Signorini impenetrability contact condition. In particular, we consider the case when the boundary conditions of the object permit the object to perform rigid body motions. This means that the friction forces have to balance the applied forces if the object is to remain stationary. The main result is friction dependent conditions on the applied force that is sufficient for the existence of solutions to the incremental friction problem.
Markedly raised intake of saturated and monounsaturated fatty acids in rats on a high‐fat ketogenic diet does not inhibit carbon recycling of13C‐α‐linolenate
Authors: Taha Ameer Y. , Ryan Mary Ann , Cunnane Stephen C.
Published: February 2007

Under various dietary and physiological conditions, carbon from α‐linolenic acid (ALA) is extensively recycled into saturated and monounsaturated fatty acids. In this study we investigated whether carbon is still recycled from ALA when a dietary source of saturated and monounsaturated fatty acids is provided in excess.13C‐labeled ALA was given to rats consuming a high‐fat ketogenic diet and to rats consuming a low‐fat control diet. In rats on the ketogenic diet,13C recycling from α‐linolenate into several, but not all, saturated and monounsaturated fatty acids matched or exceeded that in the controls (P<0.05). We conclude that carbon recycling into saturated and monounsaturated fatty acids persists when the main end products of ALA recycling are provided in excess, using a ketogenic diet.
Inward Translocation of the Phospholipid Analogue Miltefosine across Caco‐2 Cell Membranes Exhibits Characteristics of a Carrier‐mediated Process
Authors: Ménez Cécile , Buyse Marion , Farinotti Robert , Barratt Gillian
Published: February 2007

Miltefosine (hexadecylphosphocholine, HePC) is the first effective oral agent for the treatment of visceral leishmaniasis. The characteristics of HePC incorporation into the human intestinal epithelial cell line Caco‐2 were investigated in order to understand its oral absorption mechanism. The results provide evidence for the involvement of a carrier‐mediated mechanism, since the association of HePC at the apical pole of Caco‐2 cells was (1) saturable as a function of time with a rapid initial incorporation over 5 min followed by a more gradual increase; (2) saturable as a function of concentration over the range studied (2–200 μM) with a saturable component which followed Michaelis–Menten kinetics (apparent Km 15.7 μmol/L, Vmax 39.2 nmol/mg protein/h) and a nonspecific diffusion component; (3) partially inhibited by low temperature and ATP depletion, indicating the temperature and energy‐dependence of the uptake process. Moreover, we demonstrated, by an albumin back‐extraction method, that HePC is internalized via translocation from the outer to the inner leaflet of the plasma membrane and that HePC may preferentially diffuse through intact raft microdomains. In conclusion, our results suggest that incorporation of HePC at the apical membrane of Caco‐2 cells may occur through a passive diffusion followed by a translocation in the inner membrane leaflet through an active carrier‐mediated mechanism.
Interesterification of tea seed oil and its application in margarine production
Authors: Fattahi‐far Elham , Sahari Mohammad Ali , Barzegar Mohsen
Published: February 2007

Blends of hydrogenated and nonhydrogenated tea seed oil (Lahijan variety) (30:70, w/w) were chemically interesterified at 60, 90, and 120°C for 30, 60, and 90 min in the presence of 1% (w/w) NaOH. Physicochemical properties of the products were compared with those of the noninteresterified mixture. Statistical comparison of m.p., iodine values (IV), and solid fat contents (SFC) showed that the sample having the highest ranking was interesterified at 120°C for 30 min. The sample was used as a hardstock (40%), with liquid tea seed oil and sunflower oil (ratios of 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100) as, a softstock (60%) for production of table magarine, and the properties of these margarines were compared with those of commercial ones. Samples E and D (ratio of 80:20 and 60:40 liquid tea seed oil/sunflower oil, respectively) had the lowest significant differences with commercial table margarine for physicochemical (m.p., IV, and SFC) and organoleptic characteristics, respectively. Generally, based on m.p. and SFC, margarines E and D were classified as soft margarine. ThetransFA content of E, D, and commercial margarines were 1.8, 1.8, and 2.2%, respectively.
Oxidative stability of flax and hemp oils
Authors: Abuzaytoun Reem , Shahidi Fereidoon
Published: February 2007

Oxidative stability of flax and hemp oils, and of flax and hemp oils stripped of their minor components, was evaluated in the dark at 60°C and under fluorescent light at 27°C. Several analytical methods were used to assess the oxidative stability of oils. Oil extracts were also investigated for their scavenging of 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical and for their total phenolic contents. The results indicate that bioactive constituents of these edible oils play a major role in their oxidative stability. However, the FA composition of the oils and their total content of tocopherols as well as the type of pigments present contribute to their stability. Nonstripped flax and hemp oils were more stable than their corresponding stripped counterparts. Furthermore, nonstripped hemp oil had a higher oxidative stability than nonstripped flax oil as evidenced by scavenging of DPPH radical and consideration of total phenolic contents.
Hydroxyl content and refractive index determinations on transesterified soybean oil
Authors: Xie Wenlei , Li Haitao
Published: February 2007

Biodiesel, a promising alternative diesel fuel, is produced by transesterification of vegetable oils or animal fats with methanol. One of the main problems in the industrial application of the transesterification process is how to determine the conversion of oils to methyl esters. In this work, a quick analytical method was developed for monitoring the transesterification reaction of soybean oil with methanol. The conversion of oils to methyl esters could be determined by applying a simple linear correlation with hydroxyl content of the transesterified mixture or refractive index of the product. The results were in agreement with the values measured by 1H NMR spectroscopy. Compared with existing chromatographic and other methods, this method for monitoring the transesterification of vegetable oils with methanol is simple, rapid, and inexpensive and is especially suitable for process control purposes.
Kinetics of base‐catalyzed transesterification of triglycerides from Pongamia oil
Authors: Karmee S. K. , Chandna D. , Ravi R. , Chadha A.
Published: February 2007

The kinetics of transesterification of Pongamia oil using methanol at 60°C were studied. The forward as well as the reverse rate constants of all three steps involved in the transesterification of Pongamia oil are reported for the first time. Among the forward rate constants, the one governing the conversion of TG to DG was the highest and the one for DG to MG was the lowest. A distinct feature of the present work is the direct estimation of the equilibrium constants of all three steps by measuring the concentrations of TG, DG, and MG at very long reaction times. This reduced the number of parameters to be, determined from the kinetic data by one‐half, thereby leading to more accurate estimation of the rate constants. The equilibrium constant of the final step involving the conversion of MG to methyl ester and glycerol was at least an order of magnitude greater than that of the first two reaction steps. A detailed comparison was made with kinetic parameters reported in literature. The trend in the relative magnitudes of the rate constants appears to be unique to Pongamia oil.
Effects of neutralization with lime on the quality of acid olive oil
Authors: Essid K. , Trabelsi M. , Frikha M. H.
Published: February 2007

The technique described in this study makes it possible to neutralize olive oils having very high acidities. The neutralization is carried out in a solid‐liquid biphasic medium, which is slightly hydrated, by substituting lime (calcium hydroxide, an inexpensive and locally manufactured product) for soda (sodium hydroxide) as the neutralizing agent. Neutralization by lime limits TAG hydrolysis. The use of lime as a neutralizing agent makes it possible to preserve almost 80% of the α‐tocopherol. Oils neutralized with lime have higher temperatures of thermal decomposition than oils neutralized with soda. Oils neutralized with lime had better oxidative stability because natural antioxidants were preserved. Oils neutralized by lime conformed with international olive oil standards.
Predicting temperature‐dependence viscosity of vegetable oils from fatty acid composition
Authors: Fasina O. O. , Hallman H. , Craig‐Schmidt M. , Clements C.
Published: February 2007

The viscosities of 12 vegetable oils were experimentally determined as a function of temperature (5 to 95°C) by means of a temperature‐controlled rheometer. Viscosities of the oil samples decreased exponentially with temperature. Of the three models [modified Williams‐Landel‐Ferry (WLF), power law and Arrhenius] that were used to describe the effects of temperature on viscosity, the modified WLF model gave the best fit. The amounts of monounsaturated FA or polyunsaturated fatty acids (PUFA) highly correlated (R2>0.82) with the viscosities of the oil samples whereas and the amounts of saturated or unsaturated FA. An exponential equation was therefore used to relate the viscosity of these vegetable oil samples to the amounts of monounsaturated FA or PUFA. The models developed are valuable for designing or evaluating systems and equipment that are involved in the storage, handling, and processing of vegetable oils.
Apoptosis repressor with caspase recruitment domain (ARC) inhibits myogenic differentiation
Authors: Hunter Arwen L. , Zhang Jingchun , Chen Shirley C. , Si Xiaoning , Wong Brian , Ekhterae Daryoush , Luo Honglin , Granville David J.
Published: February 2007

Apoptosis repressor with caspase recruitment domain (ARC), an anti‐apoptotic protein, is highly expressed in differentiated heart and skeletal muscle. Apoptosis and differentiation share numerous common pathways; therefore, we examined the impact of ARC on H9c2‐myoblast differentiation. We demonstrate that ARC expression levels increase and stabilize upon differentiation. ARC‐overexpression in pre‐differentiated H9c2‐cells suppresses differentiation; indicated by increased myotube formation, nuclear fusion and expression of the differentiation markers myogenin and troponin‐T. ARC‐overexpression inhibited myoblast differentiation associated caspase‐3 activation, suggesting ARC inhibits myogenic differentiation through caspase inhibition. In summary, we show a novel role for ARC in the regulation of muscle differentiation.
VPMCD: Variable interaction modeling approach for class discrimination in biological systems
Authors: Raghuraj Rao , Lakshminarayanan Samavedham
Published: February 2007

Data classification algorithms applied for class prediction in computational biology literature are data specific and have shown varying degrees of performance. Different classes cannot be distinguished solely based on interclass distances or decision boundaries. We propose that inter‐relations among the features be exploited for separating observations into specific classes. A new variable predictive model based class discrimination (VPMCD) method is described here. Three well established and proven data sets of varying statistical and biological significance are utilized as benchmark. The performance of the new method is compared with advanced classification algorithms. The new method performs better during different tests and shows higher stability and robustness. The VPMCD is observed to be a potentially strong classification approach and can be effectively extended to other data mining applications involving biological systems.
Transformation of the proteasome with age‐related macular degeneration
Authors: Ethen Cheryl M. , Hussong Stacy A. , Reilly Cavan , Feng Xiao , Olsen Timothy W. , Ferrington Deborah A.
Published: February 2007

The proteasome mediates pathways associated with oxidative stress and inflammation, two pathogenic events correlated with age‐related macular degeneration (AMD). In human donor eyes corresponding to four stages of AMD, we found the proteasomal chymotrypsin‐like activity increased in neurosensory retina with disease progression. Increased activity correlated with a dramatic increase in the inducible subunits of the immunoproteasome, which was not due to an increase in CD45 positive immune cells in the retina. The novel observation of proteasome transformation may reflect retinal response to local inflammation or oxidative stress with AMD.
Asymmetry of syringomycin E channel studied by polymer partitioning
Authors: Ostroumova Olga S. , Gurnev Philip A. , Schagina Ludmila V. , Bezrukov Sergey M.
Published: February 2007

To probe the size of the ion channel formed by Pseudomonas syringae lipodepsipeptide syringomycin E, we use the partial blockage of ion current by penetrating poly(ethylene glycol)s. Earlier experiments with symmetric application of these polymers yielded a radius estimate of ∼1 nm. Now, motivated by the asymmetric non‐ohmic current–voltage curves reported for this channel, we explore its structural asymmetry. We gauge this asymmetry by studying the channel conductance after one‐sided addition of differently sized poly(ethylene glycol)s. We find that small polymers added to the cis‐side of the membrane (the side of lipodepsipeptide addition) reduce channel conductance much less than do the same polymers added to the trans‐side. We interpret our results to suggest that the water‐filled pore of the channel is conical with cis‐ and trans‐radii differing by a factor of 2–3 and that the smaller cis‐radius is in the 0.25–0.35 nm range. In symmetric, two‐sided addition, polymers entering the pore from the larger opening dominate blockage.
Prevalence of Rickettsia felis DNA in the blood of cats and their fleas in the United States
Authors: Hawley Jennifer R. , Shaw Susan E. , Lappin Michael R.
Published: February 2007

Rickettsia felis is associated with fever, headache, myalgia, and macular rash in some infected humans and has been detected in the cat flea ( Ctenocephalides felis) in many countries around the world. While some naturally exposed cats have been assessed for antibodies against R felis, to our knowledge, no one has reported use of polymerase chain reaction (PCR) to attempt to amplify R felis DNA from client-owned cats and the fleas collected from them. In this study, we assayed 92 pairs of cat blood and flea extracts from Alabama, Maryland and Texas, using PCR assays that amplify a region of the citrate synthase gene (gltA) and the outer membrane protein B gene (ompB). Of the 92 pairs, 62 of 92 (67.4%) flea extracts and none of the cat blood samples were positive for R felis DNA.
Fatal attraction: Using distance to measure contagion in good times as well as bad
Authors: Bayoumi Tamim , Fazio Giorgio , Kumar Manmohan , MacDonald Ronald
Published: February 2007

This paper proposes a new measure of contagion that is good at anticipating future vulnerabilities. Building on previous work, it uses correlations of equity markets across countries to measure contagion, but in a departure from previous practice measures contagion using the relationship of these correlations with distance. Also in contrast to previous work, our test is good at identifying periods of “positive contagion,” in which capital flows to emerging markets in a herd‐like manner largely unrelated to fundamentals. Identifying such periods of “fatal attraction” is important as they provide the essential ingredients for subsequent crises and rapid outflows of capital.
Rapid response of forested vegetation to multiple climatic oscillations during the last deglaciation in the northeastern United States
Authors: Yu Zicheng
Published: February 2007

Isotopic and pollen results from a marl lake (White Lake) in the Mid-Atlantic region of USA indicate the coupling of climate and vegetation changes. Oxygen isotopes of calcite from this site show multiple oscillations at millennial and centennial scales, including the Younger Dryas with 3‰ negative shifts inδ18O at 12.4–11.4 ka (1 ka = 1000 cal yr BP) and three cold events of magnitude 1–2‰ shifts during the Bølling–Allerød warm period (BOA) at 14.3–12.4 ka. Pollen data from the same core show nearly synchronous, close correspondence with isotope-inferred climate shifts, indicating rapid forest response to deglacial climate oscillations in southern New England. A plateau-like BOA is similar to other records around the North Atlantic Ocean.
Mass transport in water waves over a thin layer of soft viscoelastic mud
Authors: NG CHIU-ON , ZHANG XUEYAN
Published: February 2007

A theory is presented for the mass transport induced by a small-amplitude progressive wave propagating in water over a thin layer of viscoelastic mud modelled as a Voigt medium. Based on a sharp contrast in length scales near the bed, the boundary-layer approximation is applied to the Navier–Stokes equations in Lagrangian form, which are then solved for the first-order oscillatory motions in the mud and the near-bed water layers. On extending the analysis to second order for the mass transport, it is pointed out that it is inappropriate, as was done in previous studies, to apply the complex viscoelastic parameter to a higher-order analysis, and also to suppose that a Voigt body can undergo continuous steady motion. In fact, the time-mean motion of a Voigt body is only transient, and will stop after a time scale given by the ratio of the viscosity to the shear modulus. Once the mud has attained its steady deformation, the mass transport in the overlying water column can be found as if it were a single-layer system. It is found that the near-bed mass transport has non-trivial dependence on the mud depth and elasticity, which control the occurrence of resonance. Even when the resonance is considerably damped by viscosity, the mass transport in water over a viscoelastic layer can be dramatically different, in terms of magnitude and direction, from that over a rigid bed.
Laboratory observations of mean flows under surface gravity waves
Authors: MONISMITH S. G. , COWEN E. A. , NEPF H. M. , MAGNAUDET J. , THAIS L.
Published: February 2007

In this paper we present mean velocity distributions measured in several different wave flumes. The flows shown involve different types of mechanical wavemakers, channels of differing sizes, and two different end conditions. In all cases, when surface waves, nominally deep-water Stokes waves, are generated, counterflowing Eulerian flows appear that act to cancel locally, i.e. not in an integral sense, the mass transport associated with the Stokes drift. No existing theory of wave–current interactions explains this behaviour, although it is symptomatic of Gerstner waves, rotational waves that are exact solutions to the Euler equations. In shallow water (kH≈ 1), this cancellation of the Stokes drift does not hold, suggesting that interactions between wave motions and the bottom boundary layer may also come into play.
Oscillatory motion and wake instability of freely rising axisymmetric bodies
Authors: FERNANDES PEDRO C. , RISSO FRÉDÉRIC , ERN PATRICIA , MAGNAUDET JACQUES
Published: February 2007

This paper reports on an experimental study of the motion of freely rising axisym- metric rigid bodies in a low-viscosity fluid. We consider flat cylinders with height h smaller than the diameter d and density ρb close to the density ρf of the fluid. We have investigated the role of the Reynolds number based on the mean rise velocity um in the range 80 ≤ Re = umd/ν ≤ 330 and that of the aspect ratio in the range 1.5 ≤ χ = d/h ≤ 20. Beyond a critical Reynolds number, Rec, which depends on the aspect ratio, both the body velocity and the orientation start to oscillate periodically. The body motion is observed to be essentially two-dimensional. Its description is particularly simple in the coordinate system rotating with the body and having its origin fixed in the laboratory; the axial velocity is then found to be constant whereas the rotation and the lateral velocity are described well by two harmonic functions of time having the same angular frequency, ω. In parallel, direct numerical simulations of the flow around fixed bodies were carried out. They allowed us to determine (i) the threshold, Recf1(χ), of the primary regular bifurcation that causes the breaking of the axial symmetry of the wake as well as (ii) the threshold, Recf2(χ), and frequency, ωf, of the secondary Hopf bifurcation leading to wake oscillations. As χ increases, i.e. the body becomes thinner, the critical Reynolds numbers, Recf1 and Recf2, decrease. Introducing a Reynolds number Re* based on the velocity in the recirculating wake makes it possible to obtain thresholds $\hbox{\it Re}^*_{cf1}$ and $\hbox{\it Re}^*_{cf2}$ that are independent of χ. Comparison with fixed bodies allowed us to clarify the role of the body shape. The oscillations of thick moving bodies (χ < 6) are essentially triggered by the wake instability observed for a fixed body: Rec(χ) is equal to Recf1(χ) and ω is close to ωf. However, in the range 6 ≤ χ ≤ 10 the flow corrections induced by the translation and rotation of freely moving bodies are found to be able to delay the onset of wake oscillations, causing Rec to increase strongly with χ. An analysis of the evolution of the parameters characterizing the motion in the rotating frame reveals that the constant axial velocity scales with the gravitational velocity based on the body thickness, $\sqrt{((\rho_f-\rho_b)/\rho_f)\,gh}$, while the relevant length and velocity scales for the oscillations are the body diameter d and the gravitational velocity based on d, $\sqrt{((\rho_f-\rho_b)/\rho_f)\,gd}$, respectively. Using this scaling, the dimensionless amplitudes and frequency of the body's oscillations are found to depend only on the modified Reynolds number, Re*; they no longer depend on the body shape.
Impulsive fluid forcing and water strider locomotion
Authors: BÜHLER OLIVER
Published: February 2007

This paper presents a study of the global response of a fluid to impulsive and localized forcing; it has been motivated by the recent laboratory experiments on the locomotion of water-walking insects reported in Hu, Chan & Bush (Nature, vol. 424, 2003, p. 663). These insects create both waves and vortices by their rapid leg strokes and it has been a matter of some debate whether either form of motion predominates in the momentum budget. The main result of this paper is to argue that generically both waves and vortices are significant, and that in linear theory they take up the horizontal momentum with share 1/3 and 2/3, respectively.

This generic result, which depends only on the impulsive and localized nature of the forcing, is established using the classical linear impulse theory, with adaptations to weakly compressible flows and flows with a free surface. Additional general comments on experimental techniques for momentum measurement and on the wave emission are given and then the theory is applied in detail to water-walking insects.

Owing to its generality, this kind of result and the methods used to derive it should be applicable to a wider range of wave–vortex problems in the biolocomotion of water-walking animals and elsewhere.
A jet-like structure revealed by a numerical simulation of rotating spherical-shell magnetoconvection
Authors: SAKURABA ATARU
Published: February 2007

Numerical results on thermally driven nonlinear magnetoconvection in a rapidly rotating fluid spherical shell are reported. A uniform magnetic field that is parallel to the rotation axis is imposed externally. The Ekman number is 2 × 10−6, representing a state of negligible viscosity, as in the Earth's core. The convection pattern is characterized by a few large-scale vortex columns superimposed on a fast westward (retrograde) zonal flow. In the equatorial region, an anticyclonic vortex is intensified, in which an induced axial magnetic field is stored. Interaction between the magnetized vortex and the zonal flow leads to a thin jet at the western side of the vortex. The jet is also characterized by a thin electric current sheet caused by a steep gradient of the axial magnetic field. Because of this structure, the jet region can be designated as a magnetic front by analogy with fronts in mid-latitude atmospheric cyclones. It can be estimated from an order-of-magnitude analysis that the jet width decreases in inverse proportion to the zonal flow speed, and that the jet speed and the sheet-like electric current are proportional to the square of the zonal flow speed.
On scaling the mean momentum balance and its solutions in turbulent Couette–Poiseuille flow
Authors: WEI TIE , FIFE PAUL , KLEWICKI JOSEPH
Published: February 2007

The statistical properties of fully developed planar turbulent Couette–Poiseuille flow result from the simultaneous imposition of a mean wall shear force together with a mean pressure force. Despite the fact that pure Poiseuille flow and pure Couette flow are the two extremes of Couette–Poiseuille flow, the statistical properties of the latter have proved resistant to scaling approaches that coherently extend traditional wall flow theory. For this reason, Couette–Poiseuille flow constitutes an interesting test case by which to explore the efficacy of alternative theoretical approaches, along with their physical/mathematical ramifications. Within this context, the present effort extends the recently developed scaling framework of Weiet al. (2005a) and associated multiscaling ideas of Fifeet al. (2005a,b) to fully developed planar turbulent Couette–Poiseuille flow. Like Poiseuille flow, and contrary to the structure hypothesized by the traditional inner/outer/overlap-based framework, with increasing distance from the wall, the present flow is shown in some cases to undergo abalance breakingandbalance exchangeprocess as the mean dynamics transition from a layer characterized by a balance between the Reynolds stress gradient and viscous stress gradient, to a layer characterized by a balance between the Reynolds stress gradient (more precisely, the sum of Reynolds and viscous stress gradients) and mean pressure gradient. Multiscale analyses of the mean momentum equation are used to predict (in order of magnitude) the wall-normal positions of the maxima of the Reynolds shear stress, as well as to provide an explicit mesoscaling for the profiles near those positions. The analysis reveals a close relationship between the mean flow structure of Couette–Poiseuille flow and two internal scale hierarchies admitted by the mean flow equations. The averaged profiles of interest have, at essentially each point in the channel, a characteristic length that increases as a well-defined ‘outer region’ is approached from either the bottom or the top of the channel. The continuous deformation of this scaling structure as the relevant parameter varies from the Poiseuille case to the Couette case is studied and clarified.
Slow rupture of viscous films between parallel needles
Authors: CHEPUSHTANOVA SOFYA V. , KLIAKHANDLER IGOR L.
Published: February 2007

Experiments and theory on the rupture of a free plane viscous film are reported. The relatively thick film, with a typical thickness of the order of 0.1–0.6 mm, rests between two long parallel needles. When the film is punctured, a hole is formed with the rim on the front. The hole expands, reaches the needles, and propagates along them with a constant velocity of the order of 2–50 cm s−1. The Reynolds numbers for the present experiments are relatively small, 0.002 ≤ Re ≤ 0.34. A crude theory for propagation velocity of the rim is proposed; the theory compares well with the experimental data. The rupture profile is visually similar to a U-shaped curve. Crude equations for the rupture profile are derived, and their solutions are consistent with the experimental observations. A theory for propagation velocity and profile of the rupture, applicable to all Reynolds numbers, is proposed.
Integral properties of the swash zone and averaging. Part 3. Longshore shoreline boundary conditions for wave-averaged nearshore circulation models
Authors: ANTUONO M. , BROCCHINI M. , GROSSO G.
Published: February 2007

The aim of the present work, final of a three-part series, is to analyse in detail flow motions within the swash zone and define suitable shoreline boundary conditions for the longshore flow for wave-averaged circulation models. The analyses of Parts 1 and 2 are extended to cover horizontally two-dimensional flows. An analytical solution for the longshore motion representing the drift velocity of the whole swash zone water mass is found. This is seen to be approximated well by the ratio between the time integral of the longshore momentum flux crossing the swash lower boundary and the swash zone net water volume. Further, a complete set of shoreline boundary conditions, taking into account wave–wave interactions, is obtained on the basis of fully numerical solutions of the nonlinear shallow-water equations. The main focus of the work is to clarify the structure of the shoreline boundary conditions for the longshore flow, but attention has also been paid to their derivation and assessment from the numerical solutions. The latter have been obtained on the basis of a fairly broad range of input wave conditions which, though biased towards those typical of reflective beaches, are believed to cover conditions also typical of moderate dissipative beaches. Two main terms are found to contribute to the longshore drift velocity: (i) a term, proportional to the shallow-water velocity, accounting for short-wave interactions, frictional swash zone forces and continuous forcing due to non-breaking wave nonlinearities and (ii) a drift-type term representing the momentum transfer due to wave breaking.
Vaginal symptoms and bacterial vaginosis (BV): how useful is self-report? Development of a screening tool for predicting BV status
Authors: NELSON D. B. , BELLAMY S. , ODIBO A. , NACHAMKIN I. , NESS R. B. , ALLEN-TAYLOR L.
Published: February 2007

Vaginal complaints compel an evaluation of bacterial vaginosis (BV), however, many cases of BV are asymptomatic. We evaluated the sensitivity and specificity of vaginal symptoms in the diagnosis of BV and examined the utility of creating a BV screening tool using clinical, behavioural and demographic characteristics. A total of 1916 pregnant women were included in this analysis. In total, 757 women screened positive for BV and over one third of BV-positive women presented without any lower genital tract symptoms (39·4%). African American race, abnormal vaginal odour, and smoking were independently related to BV positivity. A BV screening tool including these three factors was fairly predictive of BV status with the area under the ROC curve equal to 0·669. This three-item prediction rule may be useful in identifying high- risk pregnant women in need of BV screening and, given the high specificity, accurately identify the group of BV-negative pregnant women.
Multiple sites of exposure in an outbreak of ornithosis in workers at a poultry abattoir and farm
Authors: TIONG A. , VU T. , COUNAHAN M. , LEYDON J. , TALLIS G. , LAMBERT S.
Published: February 2007

Cases of ornithosis amongst workers on a rural duck abattoir and farm were notified from late 2003 to health authorities in Victoria, Australia. In May 2004 we conducted a serological survey to identify the extent of exposure toChlamydophila psittaciamongst workers and a case control study to identify high-risk work areas for ornithosis-related pneumonia. Some workers in all occupational groups showed serological evidence of exposure, while those with pneumonia were more likely to have worked in the slaughtering area of the abattoir (adjusted odds ratio 16·7, 95% confidence interval 1·3–207). High exposure to blood and feathers from recently killed birds is likely to represent an occupational hazard to workers, but pneumonia did occur in workers without these exposures. We recommended respiratory protection for all abattoir workers and improvements to airflow and reduction of environmental contamination in high-risk work areas to prevent further cases.
Experimental transmission of a ranavirus disease of common toads (Bufo bufo) to common frogs (Rana temporaria)
Authors: CUNNINGHAM A. A. , HYATT A. D. , RUSSELL P. , BENNETT P. M.
Published: February 2007

During investigations of epidemic frog mortality in Britain, a novel fatal systemic haemorrhagic disease of common toads was discovered. This disease resembles a systemic haemorrhagic disease of common frogs in Britain, which is one of a range of fatal disease syndromes, characterized by systemic haemorrhages, skin ulceration or a combination of these lesions, caused by ranavirus infection. Ranavirus previously isolated from diseased toads was inoculated into common frogs to evaluate if this virus could infect and cause disease in common frogs. All virus-inoculated frogs died with systemic haemorrhages between 6 and 8 days post-inoculation, giving similar results to those produced by the inoculation of frogs with ranavirus cultured from naturally diseased frogs. These results indicate that the same, or similar, viruses are affecting both frogs and toads in the field and confirm that ranavirus has emerged as an important cause of amphibian mortality in Britain.
Reconciliation or Irredentism? The Irish Government and the Sunningdale Communiqué of 1973
Authors: FARRINGTON CHRISTOPHER
Published: February 2007

This article uses recently released archival material to examine the role of the Irish government in the negotiation of the Sunningdale communiqué of 1973, which marked, among other things, an agreement to establish a Council of Ireland and was therefore a key part of the first attempt to establish a power-sharing devolved executive in Northern Ireland. The article will problematise the distinctions which have been made between various strains of political thought held by leading intellectuals and politicians on the national question and show how the discourse of ‘revisionist nationalism’ and reconciliation which sponsored the key institution of the Sunningdale communiqué, the Council of Ireland, was in contradiction to the meaning attached to the functions of the Council, which was in fact closer to traditional nationalist aims.
DEVELOPMENTAL PROGRAMMING OF OBESITY AND TYPE 2 DIABETES
Authors: VICKERS MARK HEDLEY , CUPIDO CINDA-LEE , GLUCKMAN PETER DAVID
Published: February 2007

Obesity and type 2 diabetes are serious health issues in the developed world and are becoming increasingly important on a global scale. Furthermore, the marked increases in both childhood obesity and type 2 diabetes will translate to further increases in adult obesity, diabetes and associated co-morbidities in the near future; as such it has been ranked as a critical public health threat. It is a widely held view that the primary cause of obesity is the development of an obesogenic environment, due to ease of access to highly calorific food and reduced energy expenditure in work and leisure activities. In addition there is strong evidence for a genetic component to human obesity with the identification of a number of genes associated with human obesity. However, on its own the genetic component of this condition cannot account for the dramatic increase in the prevalence of obesity in recent years. Of relevance and as highlighted by epidemiological and experimental studies, is the relationship between the periconceptual, fetal and early infant phases of life and the subsequent development of adult obesity. The terms “developmental programming” and the “Developmental Origins of Adult Health and Disease” are preferentially used to describe these relationships. Despite initial controversy when these relationships were first suggested, both prospective clinical and experimental studies have clearly shown that the propensity to develop abnormalities of cardiovascular, endocrine and metabolic homeostasis in adulthood are increased when fetal development has been adversely affected. This pathogenesis is not based on genetic defects but on altered gene expression seen as a result of fetal adaptation to an adverse intrauterine environment. The relative role of genetic versus environmental factors and the mechanisms underlying developmental programming remain speculative. It is generally argued that in response to an adverse intrauterine environment, the fetus adapts its physiological development to maximise its immediate chances for survival. Owing to the plasticity of the fetus, these adaptations may include resetting of metabolic homeostasis and endocrine systems and the down-regulation of growth, commonly reflected in an altered birth phenotype. It is thought that whilst these changes in fetal physiology (i.e. the prenatal environment) may be beneficial for short term survivalin uterothey may be maladaptive in postnatal life, contributing to poor health outcomes when offspring are exposed to catch-up growth, diet-induced obesity and other factors. The “predictive adaptive response” hypothesis proposes that the degree of mismatch between the pre- and postnatal environments is a major determinant of subsequent disease. This review will address recent work in animal models and observations in the clinical and epidemiological settings onin uteroadaptations and subsequent development of obesity and type 2 diabetes.
On the identification of model structure in hydrological and environmental systems
Authors: Lin Z. , Beck M. B.
Published: February 2007

The paper presents a new recursive estimation algorithm designed expressly for the purpose of model structure identification (not for state estimation or primarily for parameter estimation) and discusses two applications thereof, one to a motivating, hypothetical example and one to data from whole‐pond manipulations designed to explore sediment‐nutrient‐phytoplankton dynamics. The algorithm is the current culmination of a long‐term technical development from state estimation using a Kalman filter, through state parameter estimation using an extended Kalman filter, through a recursive prediction error (RPE) algorithm for parameter estimation cast in the state space and recently modified for estimating time‐varying model parameters, to an RPE algorithm for estimating time‐varying parameters but cast in a parameter space formulation. It is concluded that the algorithm performs well, in the sense of being robust and indeed in revealing specifically where (but less so exactly how) a prior candidate model's structure may be in error.