bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Identity of Physaloptera caucasica v. Linstow, 1902, and Physaloptera mordens Leiper, 1908
Authors: Ortlepp R. J.
Published: November 2009

Two species belonging to the Nematode genus Physaloptera have up to the present been reported from Man; P. caucasica v. Linstow, 1902, which has been obtained on one occasion only from the Caucasus, and P. mordens Leiper, 1908, which has been reported on several occasions from Man and Monkeys from Central Africa. Until quite recently the only account of the former species was that of v. Linstow, and from this it was quite plain that the two species were distinct. Schulz (1926), however, has had the opportunity of re-examining the types of P. caucasica and on the basis of his excellent descriptions and figures it is possible to make a closer comparison between it and P. mordens. Schulz was able to rectify several inaccuracies in v. Linstow's description, and he came to the conclusion that the two species were very closely related, the only difference between the two being that in P. caucasica there is in addition to the three large teeth on each lip also a series of small teeth between and exterior to them on the inner face of the lip, which teeth are absent in P. mordens; also that the former species was smaller than the latter, 14–24 mm. to 29–34 mm. for the male and 24 mm. to 41–100 mm. for the female respectively, and that the eggs of the former were larger.
On the occurrence of Hepaticola hepatica as a natural infection of the Wild Rabbit in England
Authors: Morgan D. O.
Published: November 2009

In the experiments carried out by Nishigori (1925) and Saito (1925) on the life-history of Hepaticola hepatica it was shewn that this parasite does not reach maturity when a rabbit is artificially infected with embryonated eggs. It is true that the worms shewed some development, but after a time they disappeared leaving only nodules of connective tissue. In view of these results it may be of interest to record a case, observed by the writer where a rabbit carried a natural infection.
Further Observations on Occurrence and Incidence of Helminths in British Partridges
Authors: Clapham Phyllis A.
Published: November 2009

1. Raillietina cesticillus, Amoebotaenia cuneata and Harmostomum commutatum are recorded from Perdix perdix for the first time.

2. Some remarks are made on the factors influencing infestation with T. tennis, Choanotaenia infundibulum and Hymenolepis phasianina in the partridge and Hymenolepis microps and Davainea urogalli in the grouse.
On the Incidence of the Abomasal Parasites in the Lambs of South-West Britain
Authors: Davey D. G.
Published: November 2009

An account is given of the incidence of the abomasal parasites in the lambs of South-West Britain. Some 600 lambs were examined, and counts of the parasites were conducted in 100 cases.

It is suggested that to explain the constancy of infection with Ostertagia, and the great difference between these “healthy figures” and the pathogenic figures (10,000) of other authors, it is necessary to assume a resistance to the accumulation of the parasite present within the sheep.
On Schwartziella, a new nematode Genus for Cooperia nodulosa Schwartz, 1928.
Authors: Leroux P. L.
Published: November 2009

During the study of the telamon of various species of Cooperias collected from domesticated and wild ruminants in South Africa and from domesticated ruminants in Great Britain, it was observed that Cooperia serrata Mönnig, 1931 had no telamon and that it also differed from the other members of the genus in other respects.
The Effect on the Cyst Contents of Heterodera schachtii of the Cultivation of Maize on Potato Sick Land
Authors: Franklin Mary T.
Published: November 2009

Field observations made in 1935 on a potato crop growing on what was thought to be potato sick land in Bedfordshire seemed to indicate that eelworm damage due to Heterodera schachtii was less pronounced where maize had been the previous crop than in other cases. As particulars of the history of this piece of ground were not available, detailed observations were not made, but it was decided that it might be valuable to carry out experiments with maize to determine whether this plant had any effect on eelworm cysts. Other members of the natural order Gramineae have been shown by Triffitt to stimulate the larvae of H. schachtii to hatch from the cysts, and it was thought that maize might have a similar effect.
The Bone Marrow in Trichinosis of the Rat
Authors: van Someren Vernon D.
Published: November 2009

Trichinosis is a disease which is characterised by profound absolute and relative variations in the leucocyte ratios of the circulating blood, more particularly a marked eosinophilia, and in moderate cases, concurrent neutrophilia (van Someren, 1938). It is obvious that these changes in the peripheral blood are the outcome of disturbances in the development of the precursor cells of the haemopoietic system, especially in the bone marrow; the lymphocytogenic tissue in the spleen and lymph glands does not appear to be so markedly activated, except in very severe cases or late in the course of the disease.
Experiments on the Use of Isothiocyanates in the Control of the Potato Strain of Heterodera schachtii (Schmidt)
Authors: Smedley Enid M.
Published: November 2009

It has been established that a concentration of ·001% of phenyl isothiocyanate is sufficient to kill the cysts of the potato strain of Heterodera schachtii when they are kept submersed in it for a period of three days or longer.
On Flies as Intermediate Hosts of Syngamus trachea
Authors: Clapham Phyllis A.
Published: November 2009

Until 1934 the life history of Syngamus trachea was usually considered to be direct though Walker in 1886 and Waite in 1920 had both tentatively suggested that earthworms play a part in the dissemination of the parasite. In that year, however, I was able to show conclusively in this laboratory that the rôle they play in transmitting the nematode is a very important one, for by means of this annelid it was possible to effect with certainty heavy infections in various birds of domestic importance. The following year it was shown also that Syngamus from starlings can easily be transmitted to chickens by earthworms: this method apparently overcomes the resistance due to a different “host strain” such as Taylor had previously encountered when he tried to infect chickens directly with material obtained from starlings. In 1938 using earthworms as vectors chickens, pheasants and partridges were easily given definite infections with various other “strains” of Syngamus. Consideration of these results made it no longer possible to ignore the importance of earthworms in the life cycle of “Gapes.”
Haematological Studies on the Gut Contents of Certain Nematode and Trematode Parasites
Authors: Rogers W. P.
Published: November 2009

The examination ofStrongylus edentatusandS. vulgarisrevealed that these parasites ingest the hosts' blood and that haematin is the result of the digestion of haemoglobin. The amounts of blood necessary to form the quantities recorded as being present in the parasites' intestines have been calculated.
Digestion in Parasitic Nematodes. III. The Digestion of Proteins
Authors: Rogers W. P.
Published: November 2009

Tryptic-like enzymes have been extracted from the intestines and intestinal contents of Ascarts lumbricoides and Strongylus edentatus. The action of these enzymes, in relation to hydrogen ion concentration, has been examined.

The parasite trypsins resembled pancreatic trypsin in that the relative production of “free acid” and “formaldehyde acid” was similar, but though acting only on the alkaline side of the isoelectric points of the substrate proteins, optimum action on gelatin, blood-albumin and casein was obtained at pH 6·2.

The amount of protease extracted from a given weight of S. edentatus tissue was far greater than that from a similar amount of A. lumbricoides. Thus Strongylus digested 4·9 to 8·3 times as much gelatin, 12·5 to 40·9 times as much casein and 2·5 to 5·2 times as much blood-albumin as Ascaris.

Spectroscopic examination of the process of digestion of oxyhaemoglobin showed, first, the formation of reduced haemoglobin and then the formation of haematin. These changes took place most rapidly at higher hydrogen ion concentrations.
Dilution Egg-Counts and the Poisson Series
Authors: Peters B. G.
Published: November 2009

Researches involving dilution egg-counts, recently carried out by members of the staff of this Institute, have shown that the error variance, i.e. that between parallel counts, approximates more or less closely to the mean count. The following examples illustrate this point:—

The counts were all made by the same technique, and it is fair to total them in order to observe the average effect. This agreement between variance (or mean square) and mean is a feature of the Poisson distribution, and it has been assumed that dilution counts are in fact distributed according to the terms of that series, in all cases where the technique is adequate. Reasonable agreement between mean and error variance becomes, indeed, a criterion of the accuracy of the sampling technique. The purpose of the present note is to enquire a little further into the theoretical basis of this assumption, doubts having arisen as to whether high counts (say, up to 100) can be expected to conform to the Poisson series.

The essence of the McMaster (Gordon & Whitlock) technique is that one counts the eggs lying under a centimetre square engraved on a coverglass which is supported 0·15 cm. above a slide, i.e. the eggs contained in 0·15 cc. of faecal suspension. Since the suspending liquid is a half-saturated solution of salt, the eggs float up into one optical plane immediately below the coverglass, this making for ease in counting.
Identification of Heterodera Species by Larval Length. Technique for Estimating the Constants determining the Length Variations Within a given Species
Authors: Fenwick D. W. , Franklin M. T.
Published: November 2009

A complete investigation of the variations likely to occur in the lengths of larvae of Heterodera rostochiensis (for example) under all conditions would involve measuring larvae from a great number of varieties of potato grown in a great number of different localities, and also of larvae from tomatoes of different varieties grown under various conditions. The results obtained so far for this species of Heterodera make but a small contribution towards the mass of information which might be accumulated. Until such further data become available, certain conclusions have been drawn as to the best method of taking samples of larvae for measurement, but it must be remembered that these conclusions may need revision at a later date in the light of new information. According to our present knowledge it appears that the variety of potato on which a cyst has developed does not significantly affect the mean length of the larvae within, but that the mean length of the larvae from a single plant, irrespective of the variety, may differ significantly from that of larvae from another plant. It is also deduced that the variations in the mean lengths of the larvae from different cysts are greater than the variations within the individual cysts. From these facts it follows that if one wishes to estimate parameters for larval lengths of a population of H. rostochiensis larvae, a better estimate will be obtained if one takes a small number of larvae from each of a large number of cysts rather than the same total number of larvae from a small number of cysts. Similarly the cysts should have come from a large rather than a small number of plants, but apparently it is not necessary that the plants should be of as many varieties as possible, though this last assumption is based on information derived from only seven varieties of potato, all of them maincrop varieties, and it may need modification when larvae from other varieties have been examined.
OnRhabditis curvicaudata(Schneider) andR. paraciliatan. sp.
Authors: Goodey T.
Published: November 2009

Schneider (1866), under the nameLeptodera curvicaudata, described and figured certain nematodes obtained from moist soil and decaying matter. The species was removed to the genusRhabditisby Oerley (1886) and the name becameR. curvicaudata(Schneider, 1866) Oerley, 1886. Apart from the original description there appears to be no further record of the species in the literature dealing with this genus of free-living nematodes. The discovery of adult worms which agree well with Schneider's account provides an opportunity for redescribing the species and for giving some account of its very interesting association with flies belonging to the genusPsychoda. The writer is indebted for the material to Mr. G. H. Satchell who is investigating sewage purification problems at the University of Leeds (under a grant made by the Department of Scientific and Industrial Research) and discovered the association between the larvae of the worms andPsychodaflies concerning which further particulars are given later on.
Anguillulina dipsaci in the inflorescence of onions and in samples of onion seed
Authors: Goodey T.
Published: November 2009

Disease in onions due to the stem eelworm, Anguillulina dipsaci, causing a soft rot of the bulb and a general stunting of the plant, commonly called “bloat,” has been known for many years. Its symptoms and pathology were fairly fully described and figured by Bos (1888–92). More recently a considerable amount of investigation on the disease has been carried out in U.S.A., particularly by Newhall and Chitwood [see Newhall & Chitwood (1940), Chitwood, Newhall & Clement (1940), Newhall (1941) and (1943)]. It is not intended to discuss this work here but merely to indicate that our knowledge of the disease set up both in the seedling plant and in the grown bulb is now fairly full and detailed.

Certain gaps in out knowledge of the bionomics of the disease have, however, remained, particularly those relating to its sporadic incidence in areas where onions have' not previously been grown or have not been grown for many years. One possibility which needed exploration was whether the parasite could be seed-borne. Bos (1889, ṕ. 346) provided a note on this matter. He said that in seed harvested from a diseased crop of onions and sent to him in the spring of 1886, he was able on close examination to see that some of the seed contained eelworms but only in small quantity.
Symptoms of disease in tulips caused by Anguillulina dipsaci
Authors: Goodey T.
Published: November 2009

A brief description has been given in an earlier paper (Goodey, 1943) of damage to tulip bulbs caused by the stem and bulb eelworm, Anguillulina dipsaci. In April, 1944, an opportunity arose, through the good offices of Mr. J. Oldnall Page, of Spalding, Lincs., of visiting a field in his district, in which eelworm-affected tulips were growing. Two of the varieties inspected were in flower and the other two were in an advanced bud condition. All four varieties exhibited marked symptoms of attack, and in the case of two of them in which there were a considerable number of plants, the damage caused to the blooms would entail a distinct financial loss to the grower. The largest planting consisted of the variety “ Rijnland,” the next largest was the variety “Wonderful.” In addition to these there were smaller plantings of “ William Copland ” and “ Mrs. Farncombe Sanders.” In all four varieties evidences of attack were apparent on leaves, stems and flowers and, in general, the writer can confirm the findings of Chitwood and Machmer (1942) on the symptoms manifested by the growing plant. They mention longitudinal splitting of leaf, flower-stem and corolla. It may be well, however, to attempt a more detailed description of the chief symptoms and types of lesion shown by affected plants: see also the two photographs accompanying this paper.
The Eggs of Schistosoma bovis, S. mattheei and S. haematobium
Authors: Alves William
Published: November 2009

Measurements of 500 eggs respectively of S. bovis, S. mattheei and S. haematobium were made. These measurements included length, maximum breadth, and breadth at a point 50 microns from the non-spiked end of the egg. Statistical analysis of the results shows that it is possible, to differentiate between the three groups of eggs.

Reasons are adduced for suggesting that the statement that S. mattheei cannot infect man is not well founded; the question is under active investigation by the author.
Investigations on the Emergence of Larvae from Cysts of the Potato-root Eelworm Heterodera rostochiensis. I. Technique and Variability
Authors: Fenwick D. W.
Published: November 2009

Fifteen lots of fifty individual cysts from three separate batches were exposed to the action of potato root diffusate, the hatching allowed to continue to completion and the total larvae liberated from each cyst were counted. The data obtained were analysed both as they stood and after three different transformations for variability, as well as for independence between mean and variance. Very high variability corresponding to a coefficient of variation of 1.00 was detected, and there was, moreover, a very significant correlation between mean and variance. The most suitable transformations appeared to be either logarithmic or angular—the latter being probably the more useful. The latter, moreover, tended to increase the sensitivity of analysis. The importance of residual counts when hatching is complete is emphasized even in the absence of an angular transformation of the data.
Nutritional Factors affecting the Rate of Development of Fasciola hepatica in Limnaea truncatula
Authors: Kendall S. Brian
Published: November 2009

This paper describes some hitherto unrecorded aspects of trematode development in a molluscan host.

It is shown that the rate of development of Fasciola hepatica in its host Limnaea truncatula is influenced not only by temperature but by the amount of food assimilated by the snail and by the number of rediae which are in competition within a single host.

The most rapid development of the parasite will occur in hosts which have access to ample supplies of food and in which moderate numbers of rediae become established. At laboratory temperatures, infection with a single miracidium rarely leads to the establishment of more than 40 rediae, a number which is apparently adjusted to the economy of the host, since it allows development at a maximum rate.
On a New Anoplocephalid Cestode, Pulluterina nestoris gen. et sp. nov., from the Kea (Nestor notabilis)
Authors: Smithers S. R.
Published: November 2009

The following description is based upon a specimen which was evacuated from a Kea, Nestor notabilis, kept in captivity in the London Zoological Gardens. The Kea, a member of the Psittacciformes, has a very limited distribution, occurring only in South Island, New Zealand. This particular bird had arrived from New Zealand and had been living in the Zoo six months before the cestode was evacuated.

It is believed that this cestode represents a genus new to science, and the name Pulluterina is proposed, with the specific name P. nestoris after the host.
A Modification of the Baermann Funnel Technique for the Collection of Nematodes from Plant Material
Authors: Staniland L. N.
Published: November 2009

The Baermann funnel technique is now well known to nematologists, but the modification here described was devised to facilitate the collection of large numbers of nematodes in a small volume of water with the minimum of plant debris present. The method has proved very satisfactory in obtaining nematodes for toxicity tests, for example, from “tulip-rooted” oats infested with stem eelworm. It is often a lengthy procedure to remove nematodes from a relatively large bulk of water such as is contained in a full watch-glass, particularly if much fine plant debris is also present. By means of the modification described an almost “pure culture” of nematodes is obtained, the amount of water being very little greater in volume than the nematodes.

The apparatus is shown diagrammatically in Fig. 1:—

The funnel, f, has resting in it a small metal sieve, s, which may easily be made by cutting off a section about ¾-in. deep from a piece of copper pipe of from 2½–8-in. diameter. Fine copper wire mesh, wm, is then soldered on to the bottom rim. This wire mesh need not be fine enough to retain all fragments of plant material, since a circle of fine bolting silk, bs, is laid within the sieve on top of the wire mesh, so that it fits exactly within the inside of the sieve. No bolting silk has yet been found which will retain living nematodes. The bolting silk, however, retains all plant material and is easily removed and cleaned.
A New Method for: Estimating the Cyst Contents of the Potato-root EelwormHeterodera rostochiensisWollenweber
Authors: Bijloo J. D.
Published: November 2009

Research on cysts of the potato-root eelworm is handicapped by the fact that the cyst contents vary considerably in quantity. So it is impossible to characterize the infectivity of a soil sample by determining only the number of cysts present. Though not all larvae are hatched from the cysts in one season, a better impression of the infectivity is got when we know how many living eggs and larvae are present in the cysts.

Oostenbrink (1950) estimates the number of living eggs and larvae by crushing each cyst separately under the microscope. Especially when a large number of cysts is present, this technique takes much time. During our research this estimation appeared to be very subjective; it was almost impossible to get a clear impression of the viability of the cysts, especially when many mouldy or empty eggs were found.

Fenwick (1952) developed the bleaching powder technique in which the presoaked cysts are dissected by means of a Hagedorn-needle (Reid, 1952) and for 80 minutes are exposed to a nominal 1 per cent, solution of bleaching powder. This solution helps to break up the egg masses within the cut cysts and to free the larvae from their egg shells. Thus the larvae and eggs may be counted. Using this method some difficulties have been met with. Working with three samples of filtered bleaching powder solution, several cysts were found containing a large number of unseparated eggs, thus giving counts which were too low.
On the Occurrence of Ostertagia pinnata Daubney, 1933, in Association with Ostertagia trifurcata Ransom, 1907 in India and Great Britain
Authors: Sarwar M. M.
Published: November 2009

Ostertagia trifurcata was first described by Ransom (1907) from sheep and goats in United States. It has since been reported from various other countries and appears to have a world wide distribution. This species is recorded from India for the first time, in the present paper.

In Great Britain, O. trifurcata was first recorded by Boulenger (1914) but his record seems to have been overlooked by Travassos (1987). It has also been reported from sheep and goats in different parts of Great Britain by Morgan (1925), Jones (1926) and Oldham and Morgan (1984). All these workers report the occurrence of this species in association with Ostertagia circumcincta. Elsewhere, the association of O. circumcincta and O. trifurcata has been reported by Tetley (1984) from New Zealand, Ransom (1911) from United States, Gebauer (1982) from Germany and Saquenet (1946) from Algeria. In my collection from India (Kangra District), O. trifurcata,is present in small numbers together with O. circumcincta which is always the predominant species. In a collection of helminths from Cyprus in the London School of Hygiene and Tropical Medicine a few O. trifurcata were found in association with a large number of O. circumcincta.
On Some Helminths from British Small Mammals, with a Re-description ofEchinorhynchus rosaiPorta, 1910
Authors: James Phyllis M.
Published: November 2009

The geographical and host distribution of 32 specíes of helmínths found in a survey of 254 carcases of 13 species of British small mammals is given.

A description ofEchinorhynchus rosaiPorta, 1910 from three specimens found encysted in the liver and mesentery of a hedgehog,Erinaceus europaeus, corresponds in most respects with that originally given by Porta. Comments are made on the unusual location of the parasites and on other species from the same host.
Observations on Races of Ditylenchus dipsaci Infesting Bulbs
Authors: Southey J. F.
Published: November 2009

The results obtained in the tests described above are summarized in the following table :—

Matricaria matricarioides (Less.) Porter, self-sown in one of the inoculated pots, is an addition to the known weed hosts of narcissus races of D. dipsaci and a new host record for the species.

Seinhorst (1952) has emphasized the need for caution in interpreting the results of host tests with D. dipsaci. Exposure to heavy infestations will often result in invasion and local necrosis of the tissues of plants which are not true hosts of the race concerned. Seedlings may easily be killed outright in this way. The present tests lead to similar conclusions as shown, for example, by the results obtained with red clover and oat seedlings. Even deposition of eggs in the tissues cannot be taken as evidence that the eelworms have established themselves. It is considered, however, that a plant may be regarded as a true host when it is clear that the eelworms are breeding freely in the tissues, i.e. when eelworms in all stages of development are present with numerous eggs, and when infestation is able to persist during the normal life of the plant. With bulbous plants, the establishment of an infestation in the new bulbs after the leaves and flowers had died down was taken as evidence that the plant was a true host. The typical effects of D. dipsaci on the tissues of its hosts, e.g. hypertrophy of parenchyma tissues, enlargement and loosening of the cells and dry, mealy rotting, are also useful criteria, but some of these effects may be produced occasionally after invasion of non-hosts, as was found in a few of the inoculated clover seedlings.
Capsulata edenensis gen. et sp. nov. a New Cestode with an Unusual Type of Growth, from Limosa lapponica (L.); with Systematic Notes on the Genera Southwellia Moghe, 1925 and Malika Woodland, 1929
Authors: Sandeman Ian M.
Published: November 2009

Description: The specimens were collected from three Bartailed Godwits shot in the winters of 1956 and 1957. The description below applies mainly to the first infestation found. There are certain differences between the infestations which are noted later. There were up to 150 individuals in each infestation, varying from immature worms consisting of a scolex and a few proglottides to mature strobilas containing some 300 segments and reaching a length of 75 mm. The maximum breadth of the strobila is 1·8 mm. The onset of maturity is accompanied by a marked increase in the breadth of the strobila and the mature proglottides are broader than long.
Observations on Coconut Palms Artificially Infected by the Nematode Rhadinaphelenchus cocophilus (Cobb, 1919) Goodey, 1960
Authors: Goberdhan Lincoln
Published: November 2009

Studies on the symptomatology of red-ring disease were carried out by the author (Goberdhan; 1961) on thirty-two trees at La Forest Estate. It was hoped that from this study, methods for detecting the disease at an early stage would have been developed. If this were possible, then therapeutic treatment might be administered to combat the disease and so save a tree from destruction. From these field observations, it appeared unlikely that very early infection could be detected visually, since infection in the stem was found to be well advanced even when only one or more leaves showed signs of rich, gold, yellowing, typical of the disease. The initial time of infection could not be determined nor could the length of time elapsing between infection and the onset of symptons. It was therefore decided to artificially infect young, and apparently healthy palms, to estimate rate of spread of infection, the length of time from infection to appearance of symptoms, and the possible detection of very early infection.
A Contribution to the Light Sensitivity of the “Chromatrope” of Mermis subnigrescens
Authors: Croll N. A.
Published: November 2009

In the limited period available Mermis was found to be influenced by light, in activity, orientation and oviposition. The peak would appear to be in green light, with a peak at 540µ, corresponding closely to the β absorption band of Mermis oxyhaemoglobin.
Filaricidal properties of a wild herb, Andrographis paniculata
Authors: Dutta Anita , Sukul Nirmal C.
Published: November 2009

Water decoction of the leaves of Andrographis paniculata killed in vitro the microfilaria of Dipetalonema reconditum in 40 min. Three subcutaneous injections of the extract into infected dogs at 0·06 ml per kg bodyweight reduced the number of microfilariae in blood by more than 85%. The larvae were not totally eliminated with more infections but the reduced microfilarial level persisted. No toxiceffect of the extract was observed in rabbits. The treated dogs became lethargic initially for a week, probably due to the mass killing of microfilariae.
The effect of controlled release copper sulphate and tributyltin fluoride on the mortality and infectivity ofSchistosoma mansonicercariae
Authors: Viyanant Vithoon , Thirachantra Sanam , Sornmani Santasiri
Published: November 2009

Mortality and infectivity orSchistosoma mansonicercariae were tested against various concentrations of controlled release copper sulphate (EC-8) and tributyltin fluoride (CBL-9B). The results indicate that survival of cercariae varied with concentrations of molluscicide and times of exposures. Statistical analysis reveals that LC50and LC90for EC-8 were 1·8mg/1/hour and 1·82 mg/1/hour while LC50and LC90for CBL-9B were 16·8 μg/1/hour and 21·7 μg/1/hour respectively. Sublethal concentration of both molluscicides reduced cercarial infectivity considerably. The doses of 0·25 to 0·5 mg/1/hour for EC-8 and 2·0 to 6·0 μg/1/hour for CBL-9B were found to be sufficient to inhabit cercarial penetration of the host skin.
Pathology associated with vaccination against Schistosoma mansoni in mice using cryopreserved radiation-attenuated schistosomula
Authors: James E. R. , Lucas S. B. , Dobinson A. R.
Published: November 2009

Twenty-one mice were injected intramusclarly with 2000 Schistosoma mansoni schistosomula irradiated at 20 Krad and cryopreserved; three mice were killed on each of days 0, 2, 5, 9, 19, 28 and 44 days after infection and muscle from the site of injection in the left hind leg, the lungs and livers removed for histological examination. Schistosomula were seen in sections from the leg muscle from days 0 to 19 inclusive, in the lungs from day 2 to day 28 inclusive and in the livers from days 9 to 28 inclusive. Most schistosomula were seen in sections of the leg muscle with considerably fewer parasites occurring in the lungs and especially the livers. Granulomatous reactions comprising cosinophils, polymorphs, plasma cells and macrophages were first seen in the leg muscle on day 2, in the lungs on day 5 and in the liver on day 19. The peak infiammatory reactions appeared to occur between days 5 and 9, 9 and 19 and 28 and 44 respectively in the three tissues. The pathology is discussed in relation to the dose of irradiation required to attenuate the schistosomula for optimal immunogenicity.
Cluster observations of energetic electron flux variations within the plasma sheet
Authors: Burin des Roziers E. , Li X. , Baker D. N. , Fritz T. A. , McPherron R. L. , Dandouras I.
Published: November 2009

The variability of energetic electron fluxes (>40 keV) within the plasma sheet is explored using measurements from the Cluster spacecraft from 2001 through 2005. Only cases where the spacecraft remains inside the plasma sheet throughout the event are considered. Interesting cases were found using a combination of automated methods and visual inspection. Events are classified into 4 main types: (1) plasma sheet empty of energetic electrons; (2) decreasing plasma sheet energetic electron fluxes; (3) increasing plasma sheet energetic electron fluxes; and (4) sharp (rising and falling) variations in plasma sheet energetic electron fluxes during a single plasma sheet crossing. Case studies are presented for each type of event. The time it takes to fill/empty the plasma sheet of energetic electrons is quantified based on these events. Extreme events, most of which are associated with enhanced geomagnetic activity, showed that energetic electrons in the plasma sheet can vary up to several orders of magnitude. Interestingly, the energetic electron fluxes inside the plasma sheet can still undergo rapid variations when the solar wind is calm and geomagnetic activity is low.
On the origins of Earth rotation anomalies: New insights on the basis of both “paleogeodetic” data and Gravity Recovery and Climate Experiment (GRACE) data
Authors: Peltier W. R. , Luthcke Scott B.
Published: November 2009

The theory previously developed to predict the impact on Earth's rotational state of the late Pleistocene glaciation cycle is extended. In particular, we examine the extent to which a departure of the infinite time asymptote of the viscoelastic tidal Love number of degree 2, “k2T,” from the observed “fluid” Love number, “kf,” impacts the theory. A number of tests of the influence of the difference in these Love numbers on theoretical predictions of the model of the glacial isostatic adjustment (GIA) process are explored. Relative sea level history predictions are shown not to be sensitive to the difference even though they are highly sensitive to the influence of the changing rotational state itself. We also explore in detail the accuracy with which the Gravity Recovery and Climate Experiment (GRACE) satellite system is able to observe the global GIA process including the time‐dependent amplitude of the degree 2 and order 1 spherical harmonic components of the gravitational field, the only components that are significantly influenced by rotational effects. It is explicitly shown that the GRACE observation of these properties of the time‐varying gravitational field is sufficiently accurate to rule out the values predicted by the ICE‐5G (VM2) model of Peltier (2004). However, we also note that this model is constrained only by data from an epoch during which modern greenhouse gas induced melting of both the great polar ice‐sheets and small ice sheets and glaciers was not occurring. Such modern loss of grounded continental ice strongly influences the evolving rotational state of the planet and thus the values of the degree 2 and order 1 Stokes coefficients as they are currently being measured by the GRACE satellite system. A series of sensitivity tests are employed to demonstrate this fact. We suggest that the accuracy of scenarios for modern land ice melting may be tested by ensuring that such scenarios conform to the GRACE observations of these crucial time‐dependent Stokes coefficients.
Retrieval of vertical columns of sulfur dioxide from SCIAMACHY and OMI: Air mass factor algorithm development, validation, and error analysis
Authors: Lee Chulkyu , Martin Randall V. , van Donkelaar Aaron , O'Byrne Gray , Krotkov Nickolay , Richter Andreas , Huey L. Gregory , Holloway John S.
Published: November 2009

We develop an improved retrieval of sulfur dioxide (SO2) vertical columns from two satellite instruments (SCIAMACHY and OMI) that measure ultraviolet solar backscatter. For each SCIAMACHY and OMI observation, a local air mass factor (AMF) algorithm converts line‐of‐sight “slant” columns to vertical columns using altitude‐dependent scattering weights computed with a radiative transfer model (LIDORT), weighted by relative vertical SO2 profile (shape factor) determined locally with a global atmospheric chemistry model (GEOS‐Chem). The scattering weights account for viewing geometry, surface albedo, cloud scattering, absorption by ozone, and scattering and absorption by aerosols. Absorption of radiation by mineral dust can reduce seasonal mean instrument sensitivity by 50%. Mean SO2 shape factors simulated with GEOS‐Chem and used in the AMF calculation are highly consistent with airborne in situ measurements (INTEX‐A and INTEX‐B); differences would affect the retrieved SO2 columns by 10%. The retrieved vertical columns are validated with coincident airborne in situ measurements (INTEX‐A, INTEX‐B, and a campaign over east China). The annual mean AMF errors are estimated to be 35–70% in polluted regions (e.g., East Asia and the eastern United States) and less than 10% over clear ocean regions. The overall SO2 error assessment is 45–80% for yearly averages over polluted regions. Seasonal mean SO2 columns retrieved from SCIAMACHY and OMI for 2006 are significantly spatially correlated with those from GEOS‐Chem, in particular over the United States (r = 0.85 for SCIAMACHY and 0.82 for OMI). A sensitivity study confirms the sensitivity of SCIAMACHY and OMI to anthropogenic SO2 emissions.
Mitochondrial targeting of the electrophilic lipid 15-deoxy-Δ12,14prostaglandin J2 increases apoptotic efficacy via redox cell signalling mechanisms
Authors: Diers Anne R. , Higdon Ashlee N. , Ricart Karina C. , Johnson Michelle S. , Agarwal Anupam , Kalyanaraman Balaraman , Landar Aimee , Darley-Usmar Victor M.
Published: November 2009

Prototypical electrophiles such as the lipid 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) are well recognized for their therapeutic potential. Electrophiles modify signalling proteins in both the cytosol and mitochondrion, which results in diverse cellular responses, including cytoprotective effects and, at high doses, cell death. These findings led us to the hypothesis that targeting electrophiles to specific compartments in the cell could fine-tune their biological effects. To examine this, we synthesized a novel mitochondrially targeted analogue of 15d-PGJ2 (mito-15d-PGJ2) and tested its effects on redox cell signalling. Mito-15d-PGJ2 caused profound defects in mitochondrial bioenergetics and mitochondrial membrane depolarization when compared with 15d-PGJ2. We also found that mito-15d-PGJ2 modified different members of the electrophile-responsive proteome, was more potent at initiating intrinsic apoptotic cell death and was less effective than 15d-PGJ2 at up-regulating the expression of HO-1 (haem oxygenase-1) and glutathione. These results demonstrate the feasibility of modulating the biological effects of electrophiles by targeting the pharmacophore to mitochondria.
Fractal growth in organic thin films: Experiments and modeling
Authors: Zhang Gengxin , Weeks Brandon , Gee Richard , Maiti Amitesh
Published: November 2009

Optical microscopy and atomic force microscopy were used to investigate the solidification process of the organic energetic material pentaerythritol tetranitrate thermally deposited on a silicon surface. The metastable films spontaneously undergo dendrite formation where the measured fractal dimensions indicate a diffusion-limited-aggregation mechanism. The branch growth rate was investigated as a function of temperature and fitted by a theoretical model that takes into account competing thermally activated processes of surface diffusion and molecular desorption. Consideration of the internal molecular degrees of freedom is shown to be essential for quantitative consistency between theory and experiment.
Stacking of polycyclic aromatic hydrocarbons as prototype for graphene multilayers, studied using density functional theory augmented with a dispersion term
Authors: Feng C. , Lin C. S. , Fan W. , Zhang R. Q. , Van Hove M. A.
Published: November 2009

The interlayer π-π interaction between finite-size models of graphene sheets was investigated by using a density functional theory method, augmented with an empirical R−6 term for the description of long-range dispersive interaction; these were calibrated by studying the π-π interaction between various benzene dimer configurations and comparing the results with previous calculations. For stacked bilayers (dimers) and multilayers of polyaromatic hydrocarbons, which serve as molecular models of graphene sheets, we found that binding energies and energy gaps are strongly dependent on their sizes, while the stacking order and the number of stacked layers have a minor influence. The remarkably broad variation of the energy gap, ranging from 1.0 to 2.5 eV, due mainly to variation of the model size, suggests the potential of broadband luminescence in the visible range for carbon-based nanomaterials that have π-π interacting.
Nonuniversal percolation exponents and broadband dielectric relaxation in carbon black loaded epoxy composites
Authors: El Bouazzaoui S. , Droussi A. , Achour M. E. , Brosseau C.
Published: November 2009

In this study we present measurements and data analysis of the dielectric relaxation in carbon black (CB) loaded epoxy composites over a wide range of CB concentration (below and above the percolation threshold) and a broad range of frequency (180–1.5×107 Hz). We show that our data are in conflict with the expectation that the fit parameters of the much-discussed two exponent phenomenological percolation equation (TEPPE) represent the critical exponents of the standard percolation theory. This result therefore gives new insight to the problem of why the TEPPE has a limited applicability in representing the effective permittivity versus CB volume fraction functional relationship. We believe that the reason for this discrepancy is that the true dependence of the internal length scales of the mesostructure and the elasticity network is too complicated to fulfill a simple unified functional equation.
Enhanced response of current-driven coupled quantum wells
Authors: Balassis Antonios , Gumbs Godfrey
Published: November 2009

We have investigated the conditions necessary to achieve stronger Cherenkov-like instability of plasma waves leading to emission in the terahertz regime for semiconductor quantum wells. The surface response function is calculated for a bilayer two-dimensional electron gas (2DEG) system in the presence of a periodic spatial modulation of the equilibrium electron density. The 2DEG layers are coupled to surface plasmons arising from excitations of free carriers in the bulk region between the layers. A current is passed through one of the layers and is characterized by a drift velocity vD for the driven electric charge. By means of a surface response function formalism, the plasmon dispersion equation is obtained as a function of frequency ω, in-plane wave vector q∥=(qx,qy), and reciprocal lattice vector nG, where n=0,±1,±2,… and G=2π/d, with d denoting the period of the density modulation. The dispersion equation, which yields the resonant frequencies, is solved numerically in the complex ω-plane for the real wave vector q∥. It is ascertained that the imaginary part of ω is enhanced with decreasing d and with increasing doping density of the free carriers in the bulk medium for a fixed period of the spatial modulation.
Monte Carlo simulation of charge transport in amorphous chalcogenides
Authors: Buscemi Fabrizio , Piccinini Enrico , Brunetti Rossella , Rudan Massimo , Jacoboni Carlo
Published: November 2009

The most peculiar feature exhibited by the I(V) characteristics of amorphous-chalcogenide materials is undoubtedly its S-shaped behavior. This type of characteristics is very important for the technological application, e.g., in the field of nanoscale solid-state memories. In this paper we give a microscopic particle description of the charge transport across a layer of amorphous Ge2Sb2Te5 sandwiched between two planar metallic contacts. A transport scheme based on the generalization of the variable-range hopping has been implemented in a current-driven Monte Carlo code. This approach allows one to investigate the aspects of the microscopic picture responsible for the electrical properties of the device. The results are compared with experimental data.
Spectroscopic investigation of wave driven microwave plasmas
Authors: Wijtvliet R. , Felizardo E. , Tatarova E. , Dias F. M. , Ferreira C. M. , Nijdam S. , Veldhuizen E. V. , Kroesen G.
Published: November 2009

Large H atom line broadening was found throughout the volume of surface wave generated He–H2 and H2 microwave plasmas at low pressures. The measured Doppler temperatures corresponding to the Hβ, Hγ, Hδ, Hε, and Hζ line profiles were found to be higher than the rotational temperature of the hydrogen molecular Fulcher-α band and the Doppler temperature of the 667.1 nm singlet He line. No excessive broadening has been found. The Lorentzian and Gaussian widths as determined by fitting the spectral lines with a Voigt profile increase with the principal quantum number of the upper level. In contrast, no such dependence for the Gaussian width has been observed in an Ar–H2 discharge. No population inversion has been observed from measurements of the relative intensities of transitions within the Balmer series.
Extended depth of focus in a particle field measurement using a single-shot digital hologram
Authors: Chen Wen , Quan Chenggen , Tay Cho Jui
Published: November 2009

We propose a method to extend the depth of focus in a particle field measurement using a single-shot digital hologram. A focal plane is obtained for each pixel based on an entropy method, and a depth map is subsequently extracted. A synthesized extended focused image is determined correspondingly using the extracted depth map. In addition, a wavelet modulus maxima algorithm and Canny algorithm are further employed to detect the edges of each particle, and the sizes and a three-dimensional localization of the particles are also estimated. Preliminary results are presented to show the feasibility and effectiveness of the proposed technique.
Electronic relaxation dynamics in large anionic water clusters: (H2O)n− and (D2O)n− (n=25–200)
Authors: Griffin Graham B. , Young Ryan M. , Ehrler Oli T. , Neumark Daniel M.
Published: November 2009

Electronic relaxation dynamics subsequent to s→p excitation of the excess electron in large anionic water clusters, (H2O)n− and (D2O)n− with 25≤n≤200, were investigated using time-resolved photoelectron imaging. Experimental improvements have enabled considerably larger clusters to be probed than in previous work, and the temporal resolution of the instrument has been improved. New trends are seen in the size-dependent p-state lifetimes for clusters with n≥70, suggesting a significant change in the electron-water interaction for clusters in this size range. Extrapolating the results for these larger clusters to the infinite-size limit yields internal conversion lifetimes τIC of 60 and 160 fs for electrons dissolved in H2O and D2O, respectively. In addition, the time-evolving spectra show evidence for solvent relaxation in the excited electronic state prior to internal conversion and in the ground state subsequent to internal conversion. Relaxation in the excited state appears to occur on a time scale similar to that of internal conversion, while ground state solvent dynamics occur on a ∼1 ps time scale, in reasonable agreement with previous measurements on water cluster anions and electrons solvated in liquid water.
Bipolar resistive switching in individual Au–NiO–Au segmented nanowires
Authors: Herderick Edward D. , Reddy Kongara M. , Sample Rachel N. , Draskovic Thomas I. , Padture Nitin P.
Published: November 2009

Evidence for bipolar resistive switching is reported in individual metal-oxide-metal (MOM) nanowires in the system Au–NiO–Au, and a plausible mechanism for the same is presented. The MOM nanowire architecture may be well suited for much needed fundamental studies of resistive switching because it provides (i) high-quality end-on contacts, (ii) control over the dimensions of the oxide, (iii) ability to synthesize a very large number of nearly identical nanowires in a wide variety of MOM systems, and (iv) elimination of substrate-induced strain effects.