bluuebunny/crossref_metadata_2025_split huggingface dataset:
Allee threshold and extinction threshold for spatially explicit metapopulation dynamics with Allee effects
Authors: Sato Kazunori 
Published: May 2009

AbstractIn this paper, we investigate a spatially explicit metapopulation model with Allee effects. We refer to the patch occupancy model introduced by Levins (Bull Entomol Soc Am 15:237–240, 1969) as a spatially implicit metapopulation model, i.e., each local patch is either occupied or vacant and a vacant patch can be recolonized by a randomly chosen occupied patch from anywhere in the metapopulation. When we transform the model into a spatially explicit one by using a lattice model, the obtained model becomes theoretically equivalent to a “lattice logistic model” or a “basic contact process”. One of the most popular or standard metapopulation models with Allee effects, developed by Amarasekare (Am Nat 152:298–302, 1998), supposes that those effects are introduced formally by means of a logistic equation. However, it is easier to understand the ecological meaning of associating Allee effects with this model if we suppose that only the logistic colonization term directly suffers from Allee effects. The resulting model is also well defined, and therefore we can naturally examine it by Monte Carlo simulation and by doublet and triplet decoupling approximation. We then obtain the following specific features of one‐dimensional lattice space: (1) the metapopulation as a whole does not have an Allee threshold for initial population size even when each local population follows the Allee effects; and (2) a metapopulation goes extinct when the extinction rate of a local population is lower than that in the spatially implicit model. The real ecological metapopulation lies between two extremes: completely mixing interactions between patches on the one hand and, on the other, nearest neighboring interactions with only two nearest neighbors. Thus, it is important to identify the metapopulation structure when we consider the problems of invasion species such as establishment or the speed of expansion.
Synthesis and Characterization of Lauryl Trimethyl Ammonium Surfactants with New Counteranion Types
Authors: Xu Bao‐cai , Han Fu , Shui Jin‐huan , Zhou Ya‐wen 
Published: May 2009

AbstractA new family of lauryl trimethyl ammonium surfactants of the general formula CH3(CH2)11 N+(CH3)3X− (X = CH3OCOO, HCOO, CH3COO, CH3CHOHCOO) were prepared and characterized both structurally and as aqueous surfactants. Lauryl trimethyl ammonium mono‐methyl carbonate was synthesized by using dimethyl carbonate (DMC) as the alkylating agent and lauryl dimethyl amine as the starting material. The latter compound was reacted with formic acid, acetic acid, and lactic acid, respectively, to give the corresponding quaternary ammonium salts with other counteranions. They were structurally characterized by IR, 1H NMR, MS. Members of this family reduced the surface tension of water to 32–38 mN/m at concentration levels of 10−2 mol/L.
Characterization of fish oil‐in‐water emulsions using light‐scattering, nuclear magnetic resonance, and gas chromatography‐headspace analyses
Authors: Shen Zhiping , Udabage Punsandani , Burgar Iko , Augustin Mary Ann 
Published: May 2009

AbstractThe effect of the molecular environment on the physical and oxidative properties of homogenized or microfluidized fish oil‐in‐water emulsions (5% w/w tuna oil in pH 7 phosphate buffer) stabilized by whey protein isolate (WPI, 1 or 5% w/w) or lecithin (2.5% w/w) was examined. Laser light‐scattering measurements showed that WPI‐stabilized emulsions had smaller particle sizes than lecithin‐stabilized emulsions, and that higher pressures reduced the particle size. WPI afforded more protection against oil oxidation than did lecithin, as evidenced by the lower headspace propanal of emulsions as measured by GC‐headspace analysis, despite the larger interface in WPI‐stabilized emulsions. Reducing the concentration of WPI in emulsions from 5 to 1% decreased the oxidative stability of WPI‐stabilized emulsions. The 1H NMR transverse relaxation times (T2) of FA chains in emulsion droplets stabilized by the same surfactants made by homogenization or microfluidization were different and not always related to particle size. The higher mobility (i.e., longer T2) of the unsaturated parts of the FA chains within an oil droplet, compared with the saturated parts, suggests that the unsaturated components tended to stay in the core of the oil droplets. This experimental result supports the hypothesis reported in other literature that the more unsaturated FA are buried in the oil core of oil‐in‐water emulsions. The lack of a universal correlation between particle size and oxidation suggests that the mobility of particles in an emulsion has an influence on the rate of oxidation.
Deacidification of soybean oil using supercritical fluid and membrane technology
Authors: Artz W. E. , Kinyanjui T. , Cheryan M. 
Published: May 2009

AbstractMembrane processing has been used for oil purification, but low flux and membrane instability are major impediments. A technique that combines membrane processing and supercritical CO2 was investigated. A specialized, high‐pressure, dead‐end membrane cell was designed, fabricated, and connected to two ISCO (Lincoln, NE) supercritical fluid extraction (SFE) systems. The cell has a base with a grooved bottom for permeate removal, plus a porous metal disc for membrane support; a cell body with threaded connections; and a cap with an inlet assembly. One SFE pump provided the appropriate pressure on the feed stream, the second maintained pressure on the permeate at a slightly lower pressure. The sample consisted of 50% TAG and 50% FFA. For example, for separations at 45°C and a transmembrane pressure of 7‐atm, the β (selectivity factor) values (TAG, FFA) for the SE and BW membranes were 0.56, 3.63 and 0.60, 2.63, respectively, whereas the β values (TAG, FFA) for the DK and NF90 membranes were 0.58, 1.37 and 0.70, 1.28, respectively.
Optimization of enzymatic assay for the measurement of lipoxygenase activity in organic solvent media
Authors: Vega Mireille , Karboune Salwa , Husson Florence , Kermasha Selim 
Published: May 2009

AbstractLipoxygenases (LOX; EC 1.13.11.12) are an important class of non‐heme iron enzymes that catalyze the di‐oxidation of PUFA to hydroperoxy FA, which can be measured by the xylenol orange method (FOX). To determine the enzymatic production of these FA in organic solvent media, the FOX assay was optimized using the standard cumene hydroperoxide. An increase in the proportion of methanol from 0 to 75% in the FOX reagent resulted in a 93% increase in the molar absorption coefficients at 560 nm. In addition, the presence of linoleic acid in the cumene hydroperoxide sample enhanced the formation of the FOX complex, resulting in a 50% increase in the sensitivity of the method. Moreover, when perchloric acid was used, the source of ferrous ions and presence of denatured LOX had little effect on the sensitivity of the FOX assay whereas sensitivity decreased by 40–46% with sulfuric acid. The overall results demonstrated that the modified FOX assay may be used for the precise and accurate measurement of hydroperoxy FA obtained by LOX activity in organic solvent media.
The effects of travel information presentation through nomadic systems on driver behaviour
Authors: Brookhuis K. A. , Dicke M. 
Published: May 2009

Abstract

Introduction
The aim of this study was to investigate the effects of providing travel information to drivers about a traffic jam ahead and a potential detour or short-cut. Two groups of participants, native and non-native Dutch speakers were requested to drive in a driving simulator under both calm and dense traffic conditions.

Method
Travel-information was presented by means of three nomadic systems; in visual mode on a PDA and on a mobile phone via SMS, and through a mobile phone in auditory mode via the (simulator mock-up) vehicle’s audio system.

Results
The results showed that with regard to usability the SMS message was evaluated worse than the other two systems, while with respect to cognitive processing, SMS caused more subjective (i.e. experienced) workload than the other two systems. Native participants believed any information-providing system to be less useful than non-native participants did. All participants remembered more of the information when traffic was dense whereas natives remembered more than non-natives. With regard to performance and safety, driving performance was better when traffic was calm, as compared to dense traffic; however, compensation was shown by lowering driving speed in the latter condition. After participants were provided with travel information, their driving performance with respect to the consequences of distraction differed between systems.

Conclusion
The auditory information provision system allowed the best driving performance; the other two systems required the participants to look away from the road (too) long compromising safety, while reading an SMS took longer than scanning a PDA.
The vehicle approach for freight road transport energy and environmental analysis in Spain
Authors: Pérez-Martínez P. J. 
Published: May 2009

Abstract

Purpose and methodology
This paper summarizes the results of a permanent road freight sample survey carried out in 1997-2003 on heavy duty vehicles in Spain. In particular, this work reviews some of the key indicators that are measuring the efficiency and the operational performance of the freight road transport. The indicators of transport are coming directly and indirectly from the survey. The survey is based on a stratified random sampling, and represents an audit of the performance of 41,600 vehicles in a yearly basis.

Main results
Although the study shows wide variation in absolute values between 1997 and 2003, energy and environment efficiencies improve by 0.2%.

Conclusions
Nevertheless, assumptions and analyses of freight road transport in Spain find significant new points of view to the problems in order to assess vehicle utilization, fuel efficiency and CO2 emissions.
CONSANGUINEOUS MARRIAGES IN MOROCCO AND THE CONSEQUENCE FOR THE INCIDENCE OF AUTOSOMAL RECESSIVE DISORDERS
Authors: JAOUAD I. CHERKAOUI , ELALAOUI S. CHAFAÏ , SBITI A. , ELKERH F. , BELMAHI L. , SEFIANI A. 
Published: May 2009

SummaryConsanguineous marriage is traditionally common throughout Arab countries. This leads to an increased birth prevalence of infants with recessive disorders, congenital malformations, morbidity and mortality. The aim of this study was to evaluate the rate of consanguineous marriage in families with autosomal recessive diseases, and to compare it with the average rate of consanguinity in the Moroccan population. The study was conducted in the Department of Medical Genetics in Rabat on 176 families with autosomal recessive diseases diagnosed and confirmed by clinical, radiological, enzymatic or molecular investigations. The rate of consanguinity was also studied in 852 families who had infants with trisomy 21 confirmed by karyotyping. These families were chosen because: (i) there is no association between trisomy 21 and consanguinity, (ii) these cases are referred from different regions of Morocco and (iii) they concern all social statuses. Among 176 families with autosomal recessive disorders, consanguineous marriages comprised 59.09% of all marriages. The prevalence of consanguinity in Morocco was found to be 15.25% with a mean inbreeding coefficient of 0.0065. The differences in the rates of consanguineous marriages were highly significant when comparing the general population and couples with offspring affected by autosomal recessive conditions. These results place Morocco among the countries in the world with high rates of consanguinity. Autosomal recessive disorders are strongly associated with consanguinity. This study better defines the health risks associated with consanguinity for the development of genetic educational guidelines targeted at the public and the health sector.
Numerical investigation of the oscillatory flow around a circular cylinder close to a wall at moderate Keulegan–Carpenter and low Reynolds numbers
Authors: SCANDURA PIETRO , ARMENIO VINCENZO , FOTI ENRICO 
Published: May 2009

The oscillatory flow around a circular cylinder close to a plane wall is investigated numerically, by direct numerical simulation of the Navier–Stokes equations. The main aim of the research is to gain insight into the effect of the wall on the vorticity dynamics and the forces induced by the flow over the cylinder. First, two-dimensional simulations are performed for nine values of the gap-to-diameter ratio e. Successively, three-dimensional simulations are carried out for selected cases to analyse the influence of the gap on the three-dimensional organization of the flow. An attempt to explain the pressure distribution around the cylinder in terms of vorticity time development is presented. Generally, the time development of the hydrodynamic forces is aperiodic (i.e. changes from cycle to cycle). In one case (Re = 200), when the distance of the cylinder from the wall is reduced, the behaviour of the flow changes from aperiodic to periodic. When the cylinder approaches the wall the drag coefficient of the in-line force increases in a qualitative agreement with the results reported in literature. The transverse force is not monotonic with the reduction of the gap: it first decreases down to a minimum, and then increases with a further reduction of the gap. For intermediate values of the gap the decrease of the transverse force is due to the reduction of the angle of ejection of the shedding vortices caused by the closeness of the wall; for small gaps the increase of the transverse force is due to the strong interaction between the vortex system ejected from the cylinder and the shear layer generated on the wall.Three-dimensional simulations show that the flow is unstable with respect to spanwise perturbations which cause the development of three-dimensional vortices and the distortion of the two-dimensional ones generated by flow separation.In all the analysed cases, the three-dimensional effects on the hydrodynamic forces are clearly attenuated when the cylinder is placed close to the wall.The spanwise modulation of the vortex structures induces oscillations of the sectional forces along the axis of the cylinder which in general are larger for the transverse sectional force. In the high-Reynolds-number case (Re = 500), the reduction of the gap produces a large number of three-dimensional vortex structures developing over a wide range of spatial scales. This produces homogenization of the flow field along the spanwise direction and a consequent reduction of the amplitudes of oscillation of the sectional forces.
Remarkable returns: the influence of a labour-led socio-economic rights movement on legislative reasoning, process and action in Nigeria, 1999–2007
Authors: Okafor Obiora Chinedu 
Published: May 2009

ABSTRACTDuring 1999–2007, a labour-led but broad-based socio-economic rights movement, which focused on a pro-poor (and therefore highly popular) anti-fuel price hike message, persuaded and/or pressured Nigeria's federal legislature, the National Assembly, to: mediate between it and the Executive Branch of Government; take it seriously enough to lobby it repeatedly; re-orient its legislative processes; explicitly oppose virtually all of the Executive Branch's fuel price hikes; and reject key anti-labour provisions in a government bill. Yet the movement did not always succeed in its efforts to influence the National Assembly. This article maps, discusses, contextualises and analyses these generally remarkable developments. It also argues that while many factors combined to facilitate or militate against the movement's impact on legislative reasoning, process and action during the relevant period, this movement's ‘mass social movement’ character was the pivotal factor that afforded it the necessary leverage to exert considerable, if limited, influence on the National Assembly.
The story of a tragedy: how people in Haut-Katanga interpret the post-colonial history of Congo
Authors: Rubbers Benjamin 
Published: May 2009

ABSTRACTIn order to give an account of the Congolese tragedy since independence, the inhabitants of Haut-Katanga often resort to four different narratives: the abandonment by Belgium; the biblical curse on Africans; the conspiracy of Western capitalism; or the alienation of life powers by Whites. Though these four stories offer different scenarios, they are all constructed with two types of actors – Whites and Congolese people. This article suggests that this racial/national frame finds its origins in colonial and national ideologies, which have left their mark on Haut-Katanga, and that it continues today to structure the narratives through which people remember their post-colonial history. Collective memory and racial/national identity are reciprocally constituted in these stories, but in different terms. They offer, accordingly, different ways of influencing the present.
The Pelagic Young and Early Bottom Stages of Teleosteans
Authors: Clark Robert S. 
Published: May 2009

The present report deals with the young fish which were collected in the neighbourhood of Plymouth during the summer and autumn of 1919, from the beginning of July to the end of September, by small meshed nets operated from the Association's steamer Oithona. It is a supplement to Dr. Allen's report on the “Post-larval Teleosteans collected near Plymouth during the Summer of 1914,” published in Vol. XI, No. 2 (May, 1917), of this Journal, and to the writer's “General Report on the Larval and Post-larval Teleosteans in Plymouth Waters” in Vol. X, No. 2 (June, 1914).The total number of fish examined amounts to 16,400, which are referable to 24 families, 39 genera and 71 species. All the forms are stages in the life histories of fishes, which are well known as adults.The pelagic young of the species of Gadus and Pleuronectes are poorly represented in the catches, but this is not surprising when one considers the lateness in the year when the hauls were made. Similarly the young of early spawners like the Herring are absent.The pelagic young of the Hake (Merluccius merluccius) appear for the first time since investigations with small meshed nets have been undertaken in the Plymouth area, the only other records of their occurrence in the western area of the English Channel being those which were taken by the Danish research steamer Thor, vide Schmidt (1909).
Clavella iadda, N.Sp. A Parasitic Copepod of Gadus Morrhua. Including some further remarks upon C. sciatherica, with a detailed account of the renal excretory system.
Authors: Leigh-Sharpe W. Harold 
Published: May 2009

Together with the specimens of C. sciatherica, Leigh-Sharpe, presented to me by Michael G. L. Perkins, and taken by him from various Gadus morrhua at Lowestoft, in August, 1918 (vide Parasitology, XI, 118, and footnote), was another tube containing about a dozen further specimens taken by him at the same date, from the identical hosts. He first called my attention to the fact that we had two distinct species of Clavella from the same fish, and to him I am primarily indebted for most of the following observations. The claims of the other specimens to be considered as members of a distinct and new species are:—(1) Body less globose, longer than wide.(2) Ovisacs tapering.
On a Tornaria found in British Seas
Authors: Bourne Gilbert C. 
Published: May 2009

Before 1888 no specimen of Tornaria, the well-known pelagic larva of Balanoglossus, had been taken off the English Coast. But on August 9th of the past year Mr. Weldon, using the surface net near the Eddystone Lighthouse, took several young specimens of Tornaria, and subsequently the same gentleman, during a cruise of a week's duration towards the end of August, captured many larger and more mature specimens of the same larva. Other specimens were taken by us up to September 21st, and in the month of August, Mr. Rupert Vallentin found several specimens in the vicinity of Falmouth.The specimens taken on these occasions form the subject of the present memoir, and their anatomy is detailed at some length, both because of the interest attached to a form bitherto unknown to England, and because it is in some respects of morphological importance.The specimens taken by us came from the offing, and were not taken within four miles of theshore; Mr. Vallentin's Tornaria were found close to the shore at Falmouth. As he was able to bring his back alive and preserve them at leisure in his laboratory, they are better preserved than those taken by us, since we were obliged to preserve our catch in a somewhatrough manner out at sea. An examination of Mr. Vallentin's specimens leaves me no doubt that the larva is Tornaria Kröohnii, aspecies found in the Mediterranean. The different forms of Tornariahave not been with certainty referred to their adult forms, but T. Kröohnii must belong to one of the Mediterranean species of Balanoglossus, that is to say, to B. Kowalevsltii, B. minutus, or B. claviger, species which have not hitherto been recorded from the English Channel, unless we suppose that the larva of B. salmoneus v. sarniensis, which occurs in the Channel Islands andat Roscoff, is identical with Tornaria Kröohnii.
On the anthomedusaeTiaranna rotundaandModeeria formosa
Authors: Edwards C. 
Published: May 2009

The history of the medusaTiaranna rotunda(Quoy & Gaimard) is reviewed. Little has been published on its young stages and its hydroid is unknown.Young specimens of the medusa, caught in the Firth of Clyde, are described and figured.The speciesModeeria formosaForbes is discussed and is shown to have been described from a young specimen ofTiaranna rotunda. By priority the specific name becomesModeeria rotunda(Quoy & Gaimard), andModeeriaForbes becomes a senior synonym ofTiarannaHaeckel. The family name Tiarannidae is unchanged. The type-genus isModeeria, of which the typespecies isM. rotunda.The seasonal occurrence of the medusa is discussed and evidence is adduced supporting the belief that the species is specialized for living in deeper water.
Amino acids and some other nitrogenous compounds inCalanus finmarchicus
Authors: Cowey C. B. , Corner E. D. S. 
Published: May 2009

Amino acids, both free and combined as protein, and some other nitrogenous constituents ofCalanus finmarchicushave been examined. Seventy-six per cent of the total nitrogen inC. finmarchicuswas present in protein amino acids, 14% in the free amino acid fraction, 6% in trimethylamine oxide, and 1·5% in betaine. These findings are discussed in relation to previous work on nitrogenous constituents ofCalanus.The free amino acid fraction ofCalanusis compared with that of higher Crustacea and it is suggested that this fraction may be important in the adaptation of the animal to dilute sea water.Amino acid nitrogen made up 40% of the total nitrogen of particulate material from Clyde sea water. This finding is compared with other recent analyses of the phytoplanktonic nitrogen and total particulate nitrogen of inshore waters.