bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatially implicit approaches to understand the manipulation of mating success for insect invasion management
Authors: Yamanaka Takehiko , Liebhold Andrew M.
Published: May 2009

Recent work indicates that Allee effects (the positive relationship between population size and per capita growth rate) are critical in determining the successful establishment of invading species. Allee effects may create population thresholds, and failure to establish is likely if invading populations fall below these thresholds. There are many mechanisms that may contribute to Allee effects, but mate‐location failure is a common cause in sexually reproducing insects. Consequently, mate‐location failure represents a type of “weak link” that may be enhanced in order to achieve eradication of insect populations during the early stages of invasion. In this paper, spatially implicit models that account for mating behavior of both sexes are used to explore the enhancement of mate‐location failure in pest eradication programs. Distinct from the previous studies, the Allee effect emerges from a mechanistic representation of mate‐location failure in our model. Three specific eradication strategies, sterile insect release, mass‐trapping, and mating disruption, are incorporated into the model and tested for their ability to depress population growth during the early stages of invasions. We conducted simulations with the model parameterized to represent two types of insects: Coleopteran‐like insects which are long‐lived and capable of multiple matings, but have low daily reproductive rates, and Lepidopteran‐like insects which are capable of mating only once per generation, have an ephemeral reproductive stage, and have high reproductive rates. Simulations indicated that: (1) many insect pests are more likely to be eradicated than had been previously predicted by classic models which do not account for mate‐finding difficulties, (2) for Lepidopteran‐like insects, mass‐trapping has the greatest potential for eradication among the three methods when a large number of traps can be installed, although mating‐disruption will be the most effective if we can anticipate confusion or trail‐masking mechanisms of disruption, and (3) populations of Coleopteran‐like insects may be most effectively eradicated using the sterile male release method. Though more detailed models should be tailored for individual species, we expect that the spatially implicit approaches outlined in this paper can be widely adapted to study the efficiency of various eradication approaches in sparse conditions.
Effects of Dietary Coconut Oil on the Biochemical and Anthropometric Profiles of Women Presenting Abdominal Obesity
Authors: Assunção Monica L. , Ferreira Haroldo S. , dos Santos Aldenir F. , Cabral Cyro R. , Florêncio Telma M. M. T.
Published: May 2009

The effects of dietary supplementation with coconut oil on the biochemical and anthropometric profiles of women presenting waist circumferences (WC) >88 cm (abdominal obesity) were investigated. The randomised, double‐blind, clinical trial involved 40 women aged 20–40 years. Groups received daily dietary supplements comprising 30 mL of either soy bean oil (group S; n = 20) or coconut oil (group C; n = 20) over a 12‐week period, during which all subjects were instructed to follow a balanced hypocaloric diet and to walk for 50 min per day. Data were collected 1 week before (T1) and 1 week after (T2) dietary intervention. Energy intake and amount of carbohydrate ingested by both groups diminished over the trial, whereas the consumption of protein and fibre increased and lipid ingestion remained unchanged. At T1 there were no differences in biochemical or anthropometric characteristics between the groups, whereas at T2 group C presented a higher level of HDL (48.7 ± 2.4 vs. 45.00 ± 5.6; P = 0.01) and a lower LDL:HDL ratio (2.41 ± 0.8 vs. 3.1 ± 0.8; P = 0.04). Reductions in BMI were observed in both groups at T2 (P < 0.05), but only group C exhibited a reduction in WC (P = 0.005). Group S presented an increase (P < 0.05) in total cholesterol, LDL and LDL:HDL ratio, whilst HDL diminished (P = 0.03). Such alterations were not observed in group C. It appears that dietetic supplementation with coconut oil does not cause dyslipidemia and seems to promote a reduction in abdominal obesity.
Formulation of zero‐trans acid shortenings and margarines and other food fats with products of the oil palm
Authors: Berger K. G. , Idris Nor Aini
Published: May 2009

The fruit of the oil palm yields two types of oil. The flesh yields 20–22% of palm oil (C16∶0 44%, C18∶1 39%, C18∶2 10%). This represents about 90% of the total oil yield. The other 10%, obtained from the kernel, is a lauric acid oil similar to coconut oil. Palm oil is semisolid, and a large part of the annual Malaysian production of about 14 million tonnes is fractionated to give palm olein, which is widely used for industrial frying, and palm stearin, a valuable hard stock. Various grades of the latter are available. Formulae have been developed by straight blending and by interesterification of palm oil and palm kernel oil to produce shortenings and margarines using hydrogenated fats to give the consistency required. Products that include these formulations are cake shortenings, vanaspati (for the Indian subcontinent), soft and brick margarines, pastry margarines, and reduced fat spreads. Other food uses of palm products in vegetable‐fat ice cream and cheese, salad oils, as a peanut butter stabilizer, and in confectioners fats are discussed briefly here.
Production of cocoa butter substitutes via two‐stage static fractionation of palm kernel oil
Authors: Calliauw G. , Foubert I. , De Greyt W. , Dijckmans P. , Kellens M. , Dewettinck K.
Published: May 2009

As are traditional fractionation technologies, static dry fractionation is a highly reliable technology for the consistent production of good‐quality palm kernel stearin (PKS) for use as cocoa butter substitute (CBS) after total hydrogenation. A new process route now permits the production of unhardened yet high‐quality CBS. Also an increase in total stearin yield can be achieved, via a successful refractionation of palm kernel olein. DSC analysis together with pilot static fractionation trials on the palm kernel olein indicates that a cooling water temperature that is too low (e.g., 17°C) may result in the quick formation of unstable crystals that are possibly later converted to a more stable form. The resulting mixture of crystals with a possibly different polymorphic structure is easily squeezed through the filter cloth during filtration, whereas a slower, but more homogeneous co‐crystallization occurs at higher temperature (18°C or higher) and results in a much more stress‐resistant slurry. Polarized light microscopy analysis confirmed that crystal size is not the only determining factor for a successful filtration. The total two‐stage static fractionation of palm kernel oil (PKO) [iodine value (IV) 18] on a pilot scale results in the following three end products: PKS IV 5 (yield: 29%, for direct use as CBS), PK olein IV 27 (yield: 58%), and PKS IV 7 (yield: 13% for use as CBS after full hydrogenation). The unhardened PKS IV 5 has outstanding melting and crystallization properties, comparable to traditional hydrogenated stearin fractions. Therefore, rather than the higher stearin yield, the reduced hydrogenation capacity is most probably the most important benefit of the two‐stage static fractionation process.
Rapid synthesis of palm‐based monoacylglycerols
Authors: Cheng Sit‐Foon , Choo Yuen‐May , Ma Ah‐Ngan , Chuah Cheng‐Hock
Published: May 2009

Rapid synthesis of high‐purity MAG from refined, bleached, and deodorized palm stearin (RBDPS) via chemical glycerolysis in the presence of pyridine was developed to obviate the conventional molecular distillation in the production of pure MAG. The optimal reaction for the sodium methoxide‐catalyzed glycerolyis of RBDPS was recorded at 110°C using a 3 wt% catalyst concentration based on the weight of RBDPS, with an RBDPS/glycerol ratio of 1∶2 and an RBDPS/pyridine ratio of 1∶4. High yields of over 99% were achieved rapidly in 15 min, and increases in DAG and FFA were observed after a prolonged reaction time.
The composition of corn oil obtained by the alcohol extraction of ground corn
Authors: Moreau Robert A. , Hicks Kevin B.
Published: May 2009

All commercial corn oil is obtained by the hexane extraction of corn germ. The chemical composition of commercial corn oil has been well characterized. This study was under‐taken to quantitatively evaluate the lipid composition of corn oil obtained by the ethanol extraction of ground, whole corn kernels. When corn oil was obtained by extracting ground corn kernels (ground corn) with polar or nonpolar solvents, the resulting corn oil contained much higher levels of hydroxycinnamate steryl esters (≈0.3%) than those found in commercial hexane‐extracted corn (germ) oil (≈0.02%). The levels of valuable tocopherols and tocotrienols were also significantly higher in kernel oil than in traditional corn germ oil. We previously reported that when corn oil was obtained by extracting corn kernels with polar solvents, the oil contained two polyamine conjugates, diferuloylputrescine and p‐coumaroyl feruloylputrescine. In the current study, when ground corn was extracted with ethanol, the resulting corn oil contained about 0.5% diferuloylputrescine and about 0.2% p‐coumaroyl feruloylputrescine. This is the first study to quantify these unique compounds in corn oil extracted by new techniques. This compositional information is important because this new oil is being considered for human food use.
Purification of Arachidonic acid from Mortierella single‐cell oil by selective esterification with Burkholderia cepacia lipase
Authors: Yamauchi Asao , Nagao Toshihiro , Watanabe Yomi , Sumida Motoo , Kobayashi Takashi , Shimada Yuji
Published: May 2009

Purification of arachidonic acid (AA) from Mortierella alpina single‐cell oil was attempted. The process comprised three steps: (i) preparation of FFA by nonselective hydrolysis of the oil with Alcaligenes sp. lipase; (ii) elimination of long‐chain saturated FA from the resulting FFA by urea adduct fractionation; and (iii) enrichment of AA through lipase‐catalyzed selective esterification with lauryl alcohol (LauOH). In the third step, screening of industrially available lipases indicated that Burkholderia cepacia lipase (Lipase‐PS, Amano Enzyme Inc., Aichi, Japan) acted on AA more weakly than on other FA and was the most effective for enrichment of AA in the FFA fraction. When the FFA obtained by urea adduct fractionation were esterified with 2 molar equivalents of LauOH at 30°C for 16 h in a mixture with 20% water and 20 units (U)/g‐mixture of Lipase‐PS, the esterification reached 39% and the content of AA in the FFA fraction was raised from 61 to 86 wt%. To further increase the content of AA, unesterified FFA were allowed to react again under the same conditions as those in the first selective esterification except for the use of 50 U/g Lipase‐PS. A series of procedures raised the content of AA to 97 wt% with a 49% recovery based on the initial content in the single‐cell oil. These results indicated that the three‐step process for selective esterification with Lipase‐PS was effective for purifying AA from the single‐cell oil.
The production of fatty acid isopropyl esters and their use as a diesel engine fuel
Authors: Wang Paul S. , Tat Mustafa E. , Van Gerpen Jon
Published: May 2009

Biodiesel is an alternative fuel for diesel engines that consists of the monoalkyl esters of vegetable oils or animal fats. Currently, most biodiesel consists of methyl esters, which have poor cold‐flow properties. Methyl esters of soybean oil will crystallize and plug fuel filters and lines at about 0°C. However, isopropyl esters have better cold‐flow properties than methyl esters. This paper describes the production of isopropyl esters and their evaluation in a diesel engine. The effects of the alcohol amount, the catalyst amount, and two different catalysts on producing quality biodiesel were studied. Both sodium isopropoxide and potassium isopropoxide were found to be suitable for use in the transesterification process. A 20∶1 alcohol/TG molar ratio and a catalyst amount equal to 1% by weight (based on the TG amount) of sodium metal was the most cost‐effective way to produce biodiesel fuel. The emissions from a diesel engine running on isopropyl esters made from soybean oil and yellow grease were investigated by comparing them with No. 2 diesel fuel and methyl esters. For nitrogen oxide emission, the difference between the biodiesel produced from soybean oil and yellow grease was greater than the difference between the methyl and isopropyl esters of both feedstocks. The other emissions from using isopropyl esters were about 50% lower in hydrocarbons, 10–20% lower in carbon monoxide, and 40% lower in smoke number when compared with No. 2 diesel fuel.
Early reduction versus skin traction in the orthopaedic treatment of femoral shaft fractures in children under 6 years old
Authors: d'Ollonne Thomas , Rubio Amandine , Leroux Julien , Lusakisimo Simon , Hayek Toni , Griffet Jacques
Published: May 2009

Background

Femoral shaft fractures occur very frequently in children, and their prognosis usually is good. Nonoperative treatment is the gold standard for children under 6 years because of the excellent bony union and the remodelling qualities.

Purpose

The aim of this study was to compare two orthopaedic therapeutic methods: skin traction versus immediate reduction.

Materials and methods

The study involved 35 children, divided into two groups: in group 1, treatment consisted of skin traction for 21 days followed by hip spica casting; in group 2, an immediate reduction with early hip spica casting was performed. The ranges of motion, the delay before weight bearing, the hospitalisation duration and the required amount of painkillers were recorded. We compared initial shortening, axial, sagittal and rotational alignment, and femoral length discrepancy. We calculated the injured femoral diaphysal overgrowth and correlated it to the fracture type and location and to the initial shortening. Economical variables were also studied.

Results

The mean overgrowth was 8.9 mm in group 1 and 8.5 mm in group 2. Three years after the trauma, length discrepancy was 4 mm in group 1 and 1 mm in group 2. Hip spica casting leads to significant reductions in weight-bearing delay, hospitalisation duration and pain. The cost of treatment with skin traction was four times higher (24,472 euros) than that of immediate reduction (6,384 euros).

Discussion

Our results are in accordance with the literature. The femoral overgrowth was proportional to the initial shortening. Masculine gender, an oblique fracture and injury of the lower third of the femur were associated with the greatest femoral overgrowth. During the first year of follow-up, the femoral length discrepancy hardly varied after immediate reduction (4 mm), whereas the overgrowth reached 6 mm after skin traction. Overall, immediate hip spica casting leads to significant reductions in weight-bearing delay, hospitalisation duration, complications and costs, while having similar clinical results as traction.
Driver-vehicle interfaces and interaction: where are they going?
Authors: Damiani Sergio , Deregibus Enrica , Andreone Luisa
Published: May 2009

Car evolution

The car was born around a century ago and its evolution has been incredibly fast, both in technology and in style. We have to move through different social and cultural evolutions to arrive to the present state of the art. The technical and social acceleration of the 20th century is well visible looking at the different worldwide research programs. Nowadays digital content and ubiquitous computing are changing us and our life style. New concepts involving the full society are emerging and the term “personal mobility” becomes more and more used together with “co-operative driving” and “environmental compatibility”.

HMI evolution

Human Machine Interaction (HMI), initially limited only to the primary in-vehicle commands, has been a major issue since the beginning. In which direction is it moving? Which technological efforts will be key factors to face the challenges of the future? We are in the middle of a transition phase where the world has to cope with and to solve big problems as energy and climate change that can strongly influence the future of the automotive industry and not only.
PREVALENCE OF CONSANGUINEOUS MARRIAGES IN SYRIA
Authors: OTHMAN HASAN , SAADAT MOSTAFA
Published: May 2009

Consanguineous marriage is the union of individuals having at least one common ancestor. The present cross-sectional study was done in order to illustrate the prevalence and types of consanguineous marriages in the Syrian Arab Republic. Data on consanguineous marriages were collected using a simple questionnaire. The total number of couples in this study was 67,958 (urban areas: 36,574 couples; rural areas: 31,384 couples) from the following provinces: Damascus, Hamah, Tartous, Latakia, Al Raqa, Homs, Edlep and Aleppo. In each province urban and rural areas were surveyed. Consanguineous marriage was classified by the degree of relationship between couples: double first cousins (F=1/8), first cousins (F=1/16), second cousins (F=1/64) and beyond second cousins (F<1/64). The coefficient of inbreeding (F) was calculated for each couple and the mean coefficient of inbreeding (α) estimated for the population of each province, stratified by rural and urban areas. The results showed that the overall frequency of consanguinity was 30.3% in urban and 39.8% in rural areas. Total rate of consanguinity was found to be 35.4%. The equivalent mean inbreeding coefficient (α) was 0.0203 and 0.0265 in urban and rural areas, respectively. The mean proportion of consanguineous marriages ranged from 67.5% in Al Raqa province to 22.1% in Latakia province. The α-value ranged from 0.0358 to 0.0127 in these two provinces, respectively. The western and north-western provinces (including Tartous, Lattakia and Edlep) recorded lower levels of inbreeding than the central, northern and southern provinces. The overall α-value was estimated to be about 0.0236 for the studied populations. First cousin marriages (with 20.9%) were the most common type of consanguineous marriages, followed by double first cousin (with 7.8%) and second cousin marriages (with 3.3%), and beyond second cousin was the least common type.
Interaction of finite-amplitude waves with vertically sheared current fields
Authors: NWOGU OKEY G.
Published: May 2009

A computationally efficient numerical method is developed to investigate nonlinear interactions between steep surface gravity waves and depth-varying ocean currents. The free-surface boundary conditions are used to derive a coupled set of equations that are integrated in time for the evolution of the free-surface elevation and tangential component of the fluid velocity at the free surface. The vector form of Green's second identity is used to close the system of equations. The closure relationship is consistent with Helmholtz's decomposition of the velocity field into rotational and irrotational components. The rotational component of the flow field is given by the Biot–Savart integral, while the irrotational component is obtained from an integral of a mixed distribution of sources and vortices over the free surface. Wave-induced changes to the vorticity field are modelled using the vorticity transport equation. For weak currents, an explicit expression is derived for the wave-induced vorticity field in Fourier space that negates the need to numerically solve the vorticity transport equation. The computational efficiency of the numerical scheme is further improved by expanding the kernels of the boundary and volume integrals in the closure relationship as a power series in a wave steepness parameter and using the fast Fourier transform method to evaluate the leading-order contribution to the convolution integrals. This reduces the number of operations at each time step from O(N2) to O(NlogN) for the boundary integrals and O[(NM)2] to O(NlogN) for the volume integrals, where N is the number of horizontal grid points and M is the number of vertical layers, making the model an order of magnitude faster than traditional boundary/volume integral methods. The numerical model is used to investigate nonlinear wave–current interaction in depth-uniform current fields and the modulational instability of gravity waves in an exponentially sheared current in deep water. The numerical results demonstrate that the mean flow vorticity can significantly affect the growth rate of extreme waves in narrowband sea states.
An exact Riemann-solver-based solution for regular shock refraction
Authors: DELMONT P. , KEPPENS R. , VAN DER HOLST B.
Published: May 2009

We study the classical problem of planar shock refraction at an oblique density discontinuity, separating two gases at rest. When the shock impinges on the density discontinuity, it refracts, and in the hydrodynamical case three signals arise. Regular refraction means that these signals meet at a single point, called the triple point. After reflection from the top wall, the contact discontinuity becomes unstable due to local Kelvin–Helmholtz instability, causing the contact surface to roll up and develop the Richtmyer–Meshkov instability (RMI). We present an exact Riemann-solver-based solution strategy to describe the initial self-similar refraction phase, by which we can quantify the vorticity deposited on the contact interface. We investigate the effect of a perpendicular magnetic field and quantify how its addition increases the deposition of vorticity on the contact interface slightly under constant Atwood number. We predict wave-pattern transitions, in agreement with experiments, von Neumann shock refraction theory and numerical simulations performed with the grid-adaptive code AMRVAC. These simulations also describe the later phase of the RMI.
Passive separation control using a self-adaptive hairy coating
Authors: FAVIER JULIEN , DAUPTAIN ANTOINE , BASSO DAVIDE , BOTTARO ALESSANDRO
Published: May 2009

A model of hairy medium is developed using a homogenized approach, and the fluid flow around a circular cylinder partially coated with hair is analysed by means of numerical simulations. The capability of this coating to adapt to the surrounding flow is investigated, and its benefits are discussed in the context of separation control. This fluid–structure interaction problem is solved with a partitioned approach, based on the direct resolution of the Navier–Stokes equations together with a nonlinear set of equations describing the dynamics of the coating. A volume force, arising from the presence of a cluster of hair, provides the link between the fluid and the structure problems. For the structure part, a subset of reference elements approximates the whole layer. The dynamics of these elements is governed by a set of equations based on the inertia, elasticity, interaction and losses effects of articulated rods. The configuration chosen is that of the two-dimensional flow past a circular cylinder atRe= 200, a simple and well-documented test case. Aerodynamics performances quantified by the Strouhal number, the drag and the maximum lift in the laminar unsteady regime are modified by the presence of the coating. A set of parameters corresponding to a realistic coating (length of elements, porosity, rigidity) is found, yielding an average drag reduction of 15% and a decrease of lift fluctuations by about 40%, associated to a stabilization of the wake.
Ageostrophic instabilities of fronts in a channel in a stratified rotating fluid
Authors: GULA J. , PLOUGONVEN R. , ZEITLIN V.
Published: May 2009

It is known that for finite Rossby numbers geostrophically balanced flows develop specific ageostrophic instabilities. We undertake a detailed study of the Rossby–Kelvin (RK) instability, previously studied by Sakai (J. Fluid Mech., vol. 202, 1989, pp. 149–176) in a two-layer rotating shallow-water model. First, we benchmark our method by reproducing the linear stability results obtained by Sakai (1989) and extend them to more general configurations. Second, in order to determine the relevance of RK instability in more realistic flows, simulations of the evolution of a front in a continuously stratified fluid are carried out. They confirm the presence of RK instability with characteristics comparable to those found in the two-layer case. Finally, these simulations are used to study the nonlinear saturation of the RK modes. It is shown that saturation is achieved through the development of small-scale instabilities along the front which modify the mean flow so as to stabilize the RK mode. Remarkably, the developing instability leads to conversion of kinetic energy of the basic flow to potential energy, contrary to classical baroclinic instability.
Complex political perpetrators: reflections on Dominic Ongwen
Authors: Baines Erin K.
Published: May 2009

Dominic Ongwen is an indicted war criminal and former child soldier in one of the world's most brutal rebel organisations, the Lord's Resistance Army (LRA). Ongwen is at once victim and perpetrator: what justice strategy is relevant? I introduce the concept of complex political perpetrators to describe youth who occupy extremely marginal spaces in settings of chronic crisis, and who use violence as an expression of political agency. Ongwen represents a troupe of young rebels who were ‘bred’ in the shadows of illiberal war economies. Excluded from the polity, or rather never having been socialised within it, such complex political perpetrators must be recognised in the debate on transitional justice after mass atrocity, lest cycles of exclusion and violence as politics by another means continue.
Women and the 2005 election in Liberia
Authors: Bauer Jacqui
Published: May 2009

In 2005, Ellen Johnson Sirleaf defeated George Weah to become President of Liberia and the first woman elected to head an African country. Women voters were widely credited with her victory. This paper quantifies this claim by analysing newspaper content during the election period to gauge civil society group activity. It finds thatconsistencyin their activities may have allowed women's groups to surpass other civil society groups in impacting the election. Activity levels of women's groups remained stable between the election and run-off periods, unlike other major group types whose activity level dropped by between 37% and 70%. It concludes that the environment surrounding the 2005 election was conducive to participation by women because of their existing, latent power in many spheres; their long experience as peacebuilders; the decimation of conventional social and political structures; Liberian women's experience in leadership positions; the failure of multiple male-dominated efforts; and the presence of a well-qualified female candidate.
The Post-Larval Stages of Ammodytes Species Captured during the Cruises of s.s. “Oithona” in Plymouth Waters in the Year 1919
Authors: Ford E.
Published: May 2009

The post-larval stages of Ammodytes species captured in the young fish trawl and small-meshed nets during the cruises of s.s. Oithona in the year 1919 were separable into two well-defined series, A and B respectively. Details of the hauls of the trawl and nets with dates and localities are to be found on pages 210–212 of Mr. R. S. Clark's account of the cruises in the present volume.

Considering the adult forms of Ammodytes known to occur in Plymouth waters, it is observed that Ammodytes lanceolatus, Lesauvage, and Ammodytes tobianus, L. are frequently met with, but no record is to hand at present of the occurrence of Ammodytes cicerellus, Rafin., although the latter has been taken frequently in the Atlantic. In regard to the larvæ and post-larvæ, none comparable to those assigned to A. cicerellus by Louis Fage (1, p. 17) have been described previously as occurring in this district, nor have such forms revealed themselves in the material under present consideration.

In endeavouring to identify the post-larvæ of any species, a study of the characters of the adults is often of great help, but in the case of Ammodytes species the only features of the adult which seem to be of value in this respect are the number of vertebræ and the relative length of the head to the total length of the body, and even so these characters, on account of the difficulty of determining them, are not so helpful as they would appear to be. Other characters have therefore to be sought for, and the following are those by which Series A and B have been distinguished:—
The Eggs of Gobius Minutus, Pictus and Microps
Authors: Lebour Marie V.
Published: May 2009

The eggs of Gobius minutus and Gobius microps are already known, Petersen (1892, 1917) having distinguished between them and figured them. Apparently the only mention of those of Gobius pictus is by Holt and Byrne (1901) who give the size of the eggs as about 0.80 mm. high by 0.65 mm. broad. Gobius minutus and pictus often occur together in the Sound and at the mouth of the Cattewater, but pictus is chiefly to be found near coarse sandy bottoms such as one gets near Duke Rock and New Grounds. Gobius microps occurs usually higher up the rivers, but the eggs and young are to be found occasionally in the Sound in the same localities as minutus and pictus.

Shells with eggs on them are commonly dredged in the Sound, those between Plymouth and the Breakwater are usually minutus, but pictus eggs are dredged from New Grounds and microps sometimes in the Catte-water.

In order to distinguish the eggs of these three species, and especially to obtain the eggs of G. pictus, adults of all three species were isolated in separate tanks with shells on the bottom on which the fish laid their eggs. The adults of minutus were from the Cattewater, those of pictus from New Grounds, and microps from Chelson Meadow, which opens into the Laira and where the water varies much in salinity, from almost fresh to ordinary sea-water strength. G. minutus and pictus were put into the tanks into ordinary running sea-water, straight from the vessel in which they were brought in from the dredge.
The Food of Young Fish No. III (1919)
Authors: Lebour Marie V.
Published: May 2009

The investigation of the food of larval and post-larval fish from Plymouth Sound and beyond for three years has brought out some interesting facts. For the first two years fresh material from the tow-nets was examined together with old material from the Young Fish Trawl (Lebour, 1918, 1919). During the present year, in addition to the tow-nettings, fresh material from the Young Fish Trawl was also available from July to the end of September, and several fish from outside the Sound examined which had not been obtainable for the last two years. We thus have a fair number of young Mackerel, Ling, Hake and Gurnard and several others.
Studies of the Reproduction and Development of Teleostean Fishes Occurring in the neighbourhood of Plymouth
Authors: Cunningham J. T.
Published: May 2009

The following is a detailed account of the results of my investigations concerning the breeding and the development, under natural and artificial conditions, of some of the fishes met with at Plymouth. These researches extended over the period from the beginning of August, 1887, to the end of August, 1888. I have given brief preliminary accounts of some of the results in No. II of the ‘Journal,’ issued in August, 1888. As I mentioned there, the laboratory work was carried on from August to November in a small room hired for the purpose near the fish quay; from November to June, 1888, in a single room in the Laboratory without a constant supply of sea-water; after that time the Laboratory being finished all its appliances were available.
The Mackerel Fishery in the West of England
Authors: Ridge R. J.
Published: May 2009

The mackerel fishery began off Plymouth in January, and boats from Yarmouth, Lowestoft, Newhaven, Brighton, Eastbourne, Hastings, Plymouth, together with a considerable number of Mount's Bay boats (Porthleven, Newlyn, and Mousehole) were engaged in the above fishery. Fish were found about the 13th January fifteen to twenty-five miles south-west of the Start Point, of a very fine quality, and were caught in considerable quantities for some few nights, catches from two lasts (20,000) down to few hundreds per boat. Westerly and south-west winds prevailing (strong breezes), very stormy weather set in, and fishing operations were interrupted for three weeks, when the boats got to work again, meeting only with light catches for some weeks, February and March were not very successful months, easterly winds set in and continued throughout above months, and practically nothing was done till latter part of March and beginning of April, when boats fell in with fish south-west of Eddystone fifteen to twenty-five miles. There fish were not so fine in quality as those of January, and appeared to be quite distinct from the latter. Some good hauls were secured, one last (being about the largest catch) to few hundreds per boat. The fishing continued up to May, and boats did fairly well, a good average earnings was obtained, prices kept up, especially during Lent.
Further Investigations on the Function of the Electrical Organ of the Skate
Authors: Sanderson Burdon , Gotch F.
Published: May 2009

During the month of September, 1888, we availed ourselves of the facilities afforded by the Laboratory for the purpose of continuing the investigations began by us the year before, of the function of the electrical organ of the skate. In the record of the work done by us in 1887 at St. Andrews, published in the Journal of Physiology, vol. ix, p. 137, we indicated several new lines of investigation which we hoped to pursue if the opportunity offered. Two of these indications we have now been able to fulfil satisfactorily, namely, those relating to the electromotive force of the shock, and to the way in which the function of the electric organ is controlled and influenced by the central nervous system. In the first of these inquiries, we used apparatus which was brought from the Oxford Physiological Laboratory, and temporarily fitted up in the room at Plymouth, which is set apart for physiological researches, and which we found well adapted for this purpose. For the second, a large number of experiments and consequently a considerable number of fish were requisite. Forty skates of various species (Raia Batis, R. clavata, R. microcellata, and R. maculata) were supplied to us and used in our researches, of which the result will shortly be ready for publication.

We desire to express in the strongest terms our appreciation of the advantages afforded by the Laboratory for physiological researches. We would also record our personal obligation to the Director for his uniform courtesy and untiring zeal in obtaining for us, in spite of considerable difficulties, the material required for our work.
The Plymouth Laboratory of the Marine Biological Association of the United Kingdom, 1963
Authors: Russell F. S.
Published: May 2009

No general description of the Plymouth Laboratory of the Marine Biological Association of the United Kingdom has been published since that of Allen & Harvey (1928). Some information was, however, given by Russell (1947, 1948) in a survey of the work of the Association, and detailed accounts of the old and new aquarium and sea-water circulations were written by Wilson (1952, 1960).

Since 1928 there have been very considerable alterations and additions to the laboratory and, now that the major building extension has been completed, the time is opportune for a new descriptive account of the buildings and research facilities.
Studies on a Calanus Patch I. The Identification of a Calanus patch
Authors: Cushing D. H. , Tungate D. S.
Published: May 2009

A series of nine plankton cruises was completed by the research ships ‘Sir Lancelot’ and ‘Platessa’ in the spring of 1954 to study the ecology of a patch of Calanus finmarchicus (Gunner.) off the north-east coast of England. This paper will deal with the problems encountered in identifying such a patch over the period from 19 March to 4 June 1954.
Studies on a Calanus Patch III. The quantity of food eaten by Calanus finmarchicus
Authors: Cushing D. H. , Vucetic T.
Published: May 2009

The purpose of this paper is to assess the grazing capacity of Calanus finmar-chicus (Gunner.) in terms of the quantity of food eaten in the sea. The part played in the growth of the animal by the quantity eaten will only be briefly discussed. The parts played by nutrient lack, sinking and diffusion on the algal productive rates will also be discussed, leading to the conclusion that grazing mortality is the most effective controlling agent on algal production.

A subsidiary purpose of this paper is to relate changes in the weight of Calanus finmarchicus to changes in food consumed and to changes in water temperature. Measurements of C. finmarchicus have been made by a number of workers (Adler & Jespersen, 1920; Russell, 1928; Marshall, 1933; Stormer, 1929; Bogorov, 1934; Jespersen, 1939; Clarke & Zinn, 1937). It will be shown that in the North Sea, in spring, the greatest changes in weight are most readily related to changes in quantities of food consumed.
Studies on a Calanus Patch IV. Nutrient salts off the north-east coast of england in the spring of 1954
Authors: Cushing D. H. , Nicholson H. F.
Published: May 2009

The part played by nutrient salts in the study of marine productivity is well known. When this series of production cruises was being planned, it was decided to take observations of the quantities of different nutrients in the sea. The cruises were closely spaced in time in order to provide an opportunity for examining the fairly rapid changes in nutrient content in relation to algal numbers. Nutrient observations were not made at such frequent intervals of time, because the spectrophotometer could not be used from R.V. ‘Platessa’. On ‘Sir Lancelot’ it was found that the spectrophotometer could be used adequately only when the ship was steaming before the wind and constituted a stable platform; this limit, however, reduced the opportunities for sampling nutrients in the desired positions.
Studies on a Calanus Patch V. The production cruises in 1954: summary and conclusions
Authors: Cushing D. H.
Published: May 2009

Thirteen cruises were made between mid-March and early June in 1954 off the coasts of southern Scotland and north-east England. It is likely that a Calanus patch was followed continuously during this period merely by observing the abundance of Calanus in and out the patch at very short time intervals (5–8 days between the mid-points of the cruises). Fig. 3 in Cushing & Tungate (1963) shows the distribution of Calanus copepoditestages during the period, which is the sort of picture expected if the same population were being sampled during the period. Application of the Joseph & Sendner (1958) equation suggested that the reduction of density due to diffusion was likely to be very low.
The fecundity of witches in the Firth of Clyde
Authors: Bagenal T. B.
Published: May 2009

The fecundity of Clyde witches was estimated from 1958 to 1962, and has been found to vary from over 49,000 eggs for a 26·8 cm fish to more than 599,000 in a 42 cm witch. Annual variations in the fecundity were found but there are not sufficient data to relate the changes to the population density as can be done with plaice. It appears that Clyde witches may grow faster, and they certainly attain a larger size than those in the Irish sea.
Antimetabolites as an aid to the study of phytoplankton nutrition
Authors: Johnston R.
Published: May 2009

Synthetic analogues of natural metabolites (antimetabolites) have been used to assess the sensitivity to inhibition of marine unicellular algae in laboratory cultures and also of more open-sea species grown in mixed culture in nutrient enriched sea waters. Different species show a different pattern of response to a range of antimetabolites. The presence of vitamins and metabolites in the medium influences inhibition of a species by an antimetabolite. The extent by which various sea waters influence inhibition is perhaps capable of development as a measure of the natural metabolites present. Species which are related or which occur together in the sea at the same time of year tend to show similar patterns of response. It is suggested that there may be a connexion between the susceptibility of species to antimetabolites and phytoplankton ‘succession’ in the sea.
On the Nutrition and Metabolism of Zooplankton II. The relationship between the marine copepodCalanus helgolandicusand particulate material in Plymouth sea water, in terms of amino acid composition
Authors: Cowey C. B. , Corner E. D. S.
Published: May 2009

The amino acid composition of adult femaleCalanus helgolandicusClaus and particulate material at station L4 has been analysed from March to December. The average concentration of amino acid nitrogen inCalanuswas 7·7% of the dry body weight and accounted for 83% of the total nitrogen. The average level of amino acid nitrogen in the particulate material was 11·9 μg/1. and accounted for 54% of the total nitrogen.

The relative quantities of amino acids inCalanusremained remarkably constant throughout the year. The relative quantities of amino acids in particulate material were more variable.

The rate of respiration ofCalanusmeasured at 8°C varied from 31 μl. O2/mg. dry body weight/day in winter (December–February) to 79 μl. O2/mg dry body weight/day in summer (April–August).

Starving winter Calanus lost 1·8% and starving summerCalanus2·1% of their dry body weight as amino acids each day. In order to replenish its daily losses of amino acids winterCalanusmust sustain a filtering rate of about 30 ml./animal/day: the corresponding value in summer is greater than 50 ml./animal/day.

The amino acid composition ofSkeletonema costatumis so close to that of the particulate material in the sea, that, as far as amino acids are concerned,Calanuswould gain no nutritional advantage by selecting the diatom in preference to the amino acid containing fraction of particulate material as a whole.
On a new species of Siboglinum (Pogonophora), found on both sides of the North Atlantic
Authors: Southward Eve C.
Published: May 2009

A description is given of Siboglinum holmei sp.nov., a shallow-water Atlantic species. It is compared with S. caulleryi, a related species from the Pacific.
The accumulation of radioactive caesium by marine invertebrates
Authors: Bryan G. W.
Published: May 2009

The accumulation of radioactive Cs has been studied in species from the principal marine invertebrate phyla. In some species the accumulation of radioactive Cs has been compared with that of42K and equilibrium levels of both isotopes have been related to the distribution of inactive K.

Radioactive Cs is always absorbed more slowly than42K. Most of the inactive K is readily exchangeable with42K so that at equilibrium inactive and active concentration factors are nearly equal. Whole animal concentration factors for radioactive Cs at equilibrium varied between 1·2 and 14 in unfed animals. These factors usually exceed those for inactive K because, although body fluid concentration factors are similar for both ions, the tissue/body fluid ratios for radioactive Cs exceed those for inactive K. Radioactive Cs penetrates rapidly into body fluids, so that uptake by the tissues is the limiting factor in accumulation. Although Cs is absorbed much more slowly than K, the eventual distribution of Cs between the tissues and body fluid of a particular species appears to bear a relationship to the distribution of K.

No evidence has been found to suggest that Cs is a necessary element which is absorbed specifically.
The Larvae of Sabellaria Spinulosa and their Settlement Behaviour
Authors: Wilson Douglas P.
Published: May 2009

In the Plymouth area Sabellaria spinulosa Leuckart is common on stones and shells below low tide mark in the Sound and on outside dredging and trawling grounds. It is often found on living Pecten maximus, much more rarely on Chlamys opercularis, and it is frequent on shells of Buccinum undatum, especially those inhabited by hermit crabs. Several tubes may be found close together, sometimes in contact, but it does not form massive colonies as it does on some shores bordering the North Sea and in deeper water of that region (McIntosh, 1922, pp. 14, 20). It is a smaller species than S. alveolata (L.) and its tubes, built mostly of mineral grains, are harder and stronger than those of the latter. At Plymouth the tubes attached to Pecten shells are usually larger, stronger, and include bigger grains, and are cleaner than are those on stones dredged in the Sound. Empty tubes are common, especially on stones and loose shells, and such tubes are sometimes tennanted by other worms.
Growth and Development of Spirula Spirula
Authors: Clarke M. R.
Published: May 2009

Spirula spirula has stimulated considerable interest since it was first discovered.

It is a member of one of the two genera of sepioids to frequent oceanic water (the other being Heteroteuthis); it has a unique spiral shell which acts as a buoyancy mechanism and can withstand considerable pressure (Denton, Gilpin-Brown & Howarth, 1967); and, until the capture by the Danish Oceanographical expeditions it was considered very rare, only 12 specimens having been captured. The Dana expeditions caught 193 individuals from 1909 to 1931 and these were described by Kerr (1931) and Bruun (1943,1955). Most of these were caught in the waters around the Canary Islands of the North Atlantic. Bruun (1943) arranged the specimens according to month and size and claimed that two size groups could be distinguished. The specimens were taken over a wide geographical area, in several years and during the months of February (1 specimen), March (40), April (3), May (8), June (1), August (1) and October (23). His conclusion concerning growth depends entirely upon his decision to split the March sample into two year-groups; those above 1.9 cm in ventral mantle length he put in a separate year-class to those below 1.9 cm in ventral mantle length. This division was arbitrary and, one suspects, based on a belief that a one-year life-span was likely.

Clearly the growth of Spirula requires further study based on a larger collection and the present paper is an attempt to fulfil this need.

MATERIAL AND METHODS

This work is based upon 256 specimens collected to the south-east of Fuerteventura in the Canary Islands by R.R.S. ‘Discovery’ during 1965–68.
Iron, Chelation and the Growth of Marine Phytoplankton I. Growth Kinetics and Chlorophyll Production in Cultures of the Euryhaline Flagellate Dunalliela Tertiolecta under Iron-Limiting Conditions
Authors: Davies Anthony G.
Published: May 2009

One of the major advances made in the development of media for the culture of marine phytoplankton was the introduction of chelating agents as a means of controlling the concentrations of the trace metals necessary for plant growth; an excellent historical survey of this field has been provided by Provasoli, McLaughlin and Droop (1957). Much of the discussion concerning the role of the chelating agents has centred upon the maintenance of the iron in solution at concentrations adequate for plant nutrition (Droop, 1961; Provasoli, 1963; Johnston, 1964). In the absence of chelators, the pH of the culture media would result in almost complete precipitation of the iron.
Further Observations on Podocyst Formation
Authors: Chapman David M.
Published: May 2009

The podocyst is a cuticular patella-shaped stage in the life-cycle of certain scyphopolyps and has been described recently (Chapman, 1968) from the standpoint of anatomy, histochemistry and development. New material has come to hand necessitating a reassessment of the views concerning the formation of this deceptively simple structure.