bluuebunny/crossref_metadata_2025 huggingface dataset:
Ovarian ultrastructure and vitellogenesis in ten species of shallow-water and bathyal sea cucumbers (Echinodermata: Holothuroidea)
Authors: Eckelbarger Kevin J. , Young Craig M.
Published: May 2009

Comparative ultrastructural features of the ovary and vitellogenesis have been described for six shallow water and four bathyal species of sea cucumbers representing four major holothuroid orders. Ovarian structure is similar in all ten species except for features of the peritoneal cells of the outer layer and the follicular inner epithelial cells surrounding the developing oocytes. The peritoneal cells vary from monociliated squamous or cuboidal cells to large columnar cells. Ultrastructural evidence suggests that these cells might be capable of incorporating materials from the perivisceral coelom. The follicular inner epithelial cells of two deep-sea species resemble podocytes, a feature previously unre-ported in holothuroid ovaries. It is suggested that these cells function to increase nutrient exchange between the genital haemal sinus and the oocyte during vitellogenesis. In all ten species, the oocytes appear to participate in yolk synthesis through the interaction of the Golgi complex and rough endoplasmic reticulum. The similarity in the ultrastructural features of vitellogenesis suggests that the process of yolk synthesis has been highly conserved in holothuroids. Endocytotic activity was detected in seven of ten species but it is uncertain if this is directly related to vitellogenesis. Cilia and intracellular structures resembling striated ciliary rootlets were observed in the oocytes of four of the ten species studied. The significance of this finding is unclear but could indicate that germ cells have a somatic cell origin.
Causes of the Observed Distribution of Fish in the North Sea
Authors: Cunningham J. T.
Published: May 2009

As my paper in the previous number indicates, my interest in these investigations was chiefly excited by the fact that no satisfactory explanation appeared to have been discovered for the remarkable abundance of small plaice in the German Bight of the North Sea. The explanation suggested, and held by many to be sufficient, was that there was a current from west to east which carried floating or buoyant objects towards the German shores, and that, therefore, the buoyant eggs and larvæ of the plaice were carried thither in great numbers. Dr. Fulton has recently made direct experiments on the course of the drift, by putting floating bottles into the sea in the neighbourhood of the Firth of Forth. In certain cases, out of groups of bottles put overboard at the same spot, some were afterwards found on the English Coast to the south, and others on the coast of Schleswig and the Island of Heligoland. The course thus determined for the general circulation would probably cause more of the plaice spawn, shed in the North Sea, to be conveyed to the German and Danish Coasts than to English. But the difficulty that perplexed me was that the peculiarity of the German grounds seemed to consist not in the greater numbers of plaice generally, but in the exclusive occurrence of small plaice at distances from land at which, on the opposite English Coast, large mature plaice seemed also to occur with the small.
A List of the Parasitic Copepoda of Fish obtained at Plymouth
Authors: Bassett-Smith P. W. , Surgeon R.N.
Published: May 2009

The material from which the present list of Parasitic Copepoda has been compiled was obtained in part by the examination of fish at the Marine Biological Association's Laboratory, but to a still greater extent by daily and diligent search at certain fishmongers' in the town. The following are the most important works consulted:—
The Protection of Crabs and Lobsters
Authors: Allen E. J.
Published: May 2009

“Every legislative restriction means the creation of a new offence. In the case of fishery it means that a simple man of the people, earning a scanty livelihood by hard toil, shall be liable to fine or imprisonment for doing that which he and his fathers before him have, up to that time, been free to do.

“If the general interest clearly requires that this burden should be put upon the fisherman—well and good. But if it does not—if, indeed, there is any doubt about the matter—I think that the man who has made the unnecessary law deserves a heavier punishment than the man who breaks it.”—Huxley, Inaugural Address, Fisheries Exhibition, 1883.
Some Characteristics of the Non-Protein Moiety of Vitellogenic Substances in the Starfish, Asterias Rubens (L.)
Authors: Broertjes J. J. S. , de Waard P. , Kamerling J. P. , Voogt P. A.
Published: May 2009

In previous papers (Broertjes, de Waard & Voogt, 1984a, b) we reported on the presence of vitellogenic substances in the starfish Asterias rubens and described their separation into three fractions, called 2, 3 and 4, which were isolated and purified. The interrelationship between these fractions was discussed and evidence was given that fractions 3 and 4 may be derived from fraction 2.
Life History Patterns of Polychaete Species of the Family Spionidae
Authors: Gudmundsson H.
Published: May 2009

The reproductive morphology and larval development in Spionidae has been dealt with extensively by Soderström (1920), Hannerz (1956), Orrhage (1964). Simon (1967), Blake (1969) and Rice (1980). The family shows a considerable variation in gamete morphology, modes of sperm transfer and types of larval development. One might also expect variability in features of the life history patterns, such as the life span, reproductive age, reproductive cycles and fecundity, both between and within species.

Previous population studies on spionids include the work on populations of Polydora ciliata (Johnston) (Dorsett, 1961); (Daro & Polk, 1973), on populations of Scolelepis squamata (Müller) (Joyner, 1962); (Richards, 1970), on a population of Scolecolepides viridis (Verrill) (George, 1966) and on a laboratory reared population of Malacoceros cf. fuliginosus (Guérin, 1973). The present paper is an attempt to analyse the patterns of life history as they appear in littoral populations of Spio martinensis Mesnil, Polydora ciliata (Johnston), Pygospio elegans Claparede and Malacoceros fuliginosus (Claparède) at localities in N. E. England. The main features considered here are the changes in the size (age) distributions, the annual cycles of reproduction, the output of offspring and population density changes.

The Spio species in the population at Black Middens, North Shields, which is referred to S. martinensis Mesnil (1896) in this paper, was previously referred to S. filicornis (Müller, 1776) by Brady (1943). This species is identical to Mesnil's species, both in morphology and with regard to known biological features, while S. filicornis differs from it morphologically and its distribution pattern (Hannerz, 1956; Rasmussen, 1973; Wolff, 1973, Gudmundsson, in preparation).
On the Spawning and Nursery Grounds of Bass, Dicentrarchus Labrax, in the Plymouth Area
Authors: Dando P. R. , Demir Necla
Published: May 2009

Despite concern over declining catches of bass, Dicentrarchus labrax (L.), and disagreement over the cause, overfishing or erratic year classes (Kennedy & Fitzmaurice, 1972; Holden & Williams, 1974; Kelley, 1979), little is known of the early life history of this fish in the wild. Only occasional post-larvae have been recorded previously in young fish collections off Plymouth (Russell, 1935). These were caught between March and June, 2–24 km offshore and commonly below 20 m. The marine spawning grounds in the Plymouth area are unknown. Although Kennedy & Fitzmaurice (1968) found bass eggs at Splaugh Rock and Youghal Harbour on the south coast of Ireland and Barnabé (1978) observed spawning near the breakwater at Sète in the Gulf of Lions, bass eggs have not previously been found near Plymouth. Hartley (1940) recorded the growth and diet of bass in the Tamar Estuary. He noted that adults were very rare in the estuary which was used only as a nursery ground for this species.
The Distribution of Hyas Araneus (L.) and Hyas Coarctatus Leach (Crustacea: Decapoda: Brachyura) in the North Sea and the Svalbard Region
Authors: Dyer M. F.
Published: May 2009

The distribution patterns of many marine benthic invertebrates are not well known, and when records exist they are usually in the form of presence and absence data with little or no information on the relative density of populations from area to area.
New Synaptidae (Holothuroidea: Apoda) from the Rockall Trough
Authors: Gage J. D.
Published: May 2009

Apart from isolated records of species of the genus Protankyra and a brief reference to a ‘Leptosynapta sp.’ from 1985 to 2360 m depth from the northern Bay of Biscay (Sibuet, 1977), the holothurian family Synaptidae is unknown in the deep sea. Yet this family of small, deposit-feeding forms are often numerous in soft sediments of shallow water. The present paper describes two previously unknown species of synaptid discovered from recent benthic sampling in the Rockall Trough (N.E. Atlantic). These species belong to the genus Labidoplax, four other species of which have been described from coastal areas in the north eastern Atlantic.
Laboratory Studies of the Ecological Significance of Host-Algal Nutritional Associations in Solitary and Colonial Radiolaria
Authors: Anderson O. R. , Swanberg N. R. , Bennett P.
Published: May 2009

Symbiont-bearing solitary and colonial radiolaria occur abundantly in diverse water masses throughout the major oceans of the world, including oligotrophic surface water (e.g. Strelkov & Reshetnyak, 1971; Casey, 1971, 1977; Anderson, 1983; Swanberg, 1979, 1983). Studies of their nutrition (Anderson, 1978, 1983; Swanberg, 1983) suggest that the algal symbionts may serve a substantial role in sustaining host nutrition. Our studies on the role of symbiotic algae in radiolaria have shown that Amphidinium-type, dinoflagellate symbionts (Anderson, 1983, p. 118) associated with the solitary species, Thalassicolla nucleata, and a colonial form Collosphaera sp. contribute photosynthetically-derived carbon to the host. The amount assimilated by T. nucleata is proportional to the primary productivity of the symbionts (Anderson, Swanberg & Bennett, 1983 b). Little is known, however, about the effects of environmental variables such as light intensity and quality on the primary productivity of the symbionts and the kinds of photosynthetic products accumulated within the host cytoplasm.
Larval and Early Post-Larval Development of Arctica Islandica
Authors: Lutz R. A. , Mann R. , Goodsell J. G. , Castagna M.
Published: May 2009

Mature eggs were stripped from ripe adult specimens of Arctica islandica and exposed to a dilute solution of ammonium hydroxide for various lengths of time before addition of stripped sperm. Larval and early post-larval stages were cultured under experimental laboratory conditions using standard bivalve rearing techniques. Larval cultures were maintained at various controlled temperatures ranging from 8·5 to 14·5 °C. Minimum time to settlement was 32 days at a temperature of approximately 13 °C; at temperatures between 8·5 and 10·0 °C, settlement was not observed until approximately 55 days after fertilization. Larval growth rates were significantly faster at temperatures between 11·0 and 145 °C than at temperatures between 8°C. Morphometry of the larval shell and morphology of the larval hinge apparatus were independent of larval growth rates and experimental culture conditions.
Biological Studies of the Exploited Stock ofLoligo Forbesi (Mollusca: Cephalopoda) in the Azores
Authors: Martins Helen Rost
Published: May 2009

Five hundred and twenty-eight specimens of Loligo forbesi Steenstrup, from landings in Horta, Faial, Azores, during the year 1 March 1980 to 28 February 1981, were tudied; 59·3 % were males, 40·7 % females. Of the males 80·2 % were sexually mature, of the females 91·6 %, both sexes showing the highest degree of maturity in spring and he lowest in autumn. The mean dorsal mantle length of the mature males was 56·5 cm, or females 33·5 cm. A weight-length relationship was calculated. he stomachs of 622 specimens were sampled, of which 306 contained food.

The prey omponents were studied qualitatively. The main prey was fish (82·0%), of which 0·5 % were horse mackerel, Trachurus picturatus, this being the most important food rganism. Preliminary results of statolith readings are given.
Enlarged Stem Glands in the Foot of the Post-Larval Mussel, Mytilus Edulis: Adaptation for Bysso-Pelagic Migration
Authors: Lane D. J. W. , Nott J. A. , Crisp D. J.
Published: May 2009

Following primary settlement and metamorphosis in Myiilus edulu (L.), the original larval stem glands (S1 and S2) increase enormously in size in the plantigrade. These glands, packed with mature secretion, discharge into a multi-partitioned posterior ducted system which is transitional in form between that of the larva and the adult. The gross enlargement of the stem glands appears to be an adaptation for frequent and copious production of byssus material during the bysso-pelagic and attachment phases of early post-larval life. This interpretation is supported by the fact that the volume ratio of the stem glands to the foot declines during subsequent growth of the young mussel and that other glands take over the function of byssus stem formation in mature mussels. Enhanced dispersal of post-larvae by bysso-pelagic drifting would account for the widespread and heavy fouling of offshore platforms by the almost exclusively intertidal mussel, particularly where these structures are far distant from coastal stocks.
The Segregation and Elimination of Radioand Fluorescent-Belled Marine Bacteria from the Haemolymph of the Shore Crab, Carcinus Maenas
Authors: White K. N. , Ratcliffe N. A.
Published: May 2009

The dynamics of clearance, segregation and elimination of a marine bacterium, Moraxella sp., by the shore crab, Carcinus maenas (L.) has been studied utilizing fluorescent and radiolabelling techniques. In addition to the gills, the hepatopancreas was a major site of bacterial accumulation with sequestration occurring within haemocyte clumps and groups of stationary cells in this organ. The heart, excretory organ and subcuticular tissues also incorporated bacteria, but to a lesser extent. By the first day post-injection, many of the segregated micro-organisms had been removed from the organs. This latter process was not due to the exodus of laden haemocytes or of intact cell clumps from the host but seemed to result from lytic action by the host blood cells. Little material arising from such bacterial/haemocytic interaction was, however, immediately excreted, and much was relocated in the general body tissues as well as the gill nephrocytes.
Small Scale Laboratory Culture of the Ormer, Haliotis Tuberculata
Authors: Hayashi Ikuo
Published: May 2009

A simple aquarium system was used to keep large ormers collected from the wild and to rear juveniles from fertilization up to age one year. Spawning was induced by exposure to u.v. irradiated sea water and counts made of gamete production. Repeated spawning was observed in males and from egg counts it was inferred that females also undergo repeat spawning in the wild.

Juvenile ormers were reared on simple collectors up to 4 mm shell length and later in open mesh cages. There was large variation in growth rate between individuals among the juvenile ormers. After one year shell lengths varied in the range 6·2–21·o mm.

Twenty-three adult ormers (shell length 40·4–93·6 mm) were reared for eight months in a tank with a concrete shelter. The smaller ormers remained under the shelter much more than the larger ones, some of which adopted a permanent position outside the shelter. In the study period growth was greater in the smaller specimens (less than 70 mm shell length) than in the larger ones.
A Description of Spawning and Post-Gastrula Development of the Cool Temperate Coral, Caryophyllia Smithi
Authors: Tranter P. R. G. , Nicholson D. N. , Kinchington D.
Published: May 2009

Spawning and post-gastrula development of planula larvae of the ahermatype Caryophyllia smithi are described. Gametes develop within the mesenteries of the adults usually between January and March, are discharged through the mouth of the polyp and fertilized externally in the sea water. Ova are either brown or cream in colour, spherical or slightly oval in shape and are 130–150 µm in diameter. Planulae are fully formed after 48 h, when feeding commences. A large apical tuft (30–60 µm in length) is present but only during the first six weeks of pelagic life. After 8–10 weeks of feeding in culture larvae reach a length of 800–1000 µm: they are then fully developed and ready to settle. Attention is paid to the effects of sea water temperatures on reproduction; locomotion and feeding behaviour of planulae are also discussed.
The Influence of Barnacle Cover on the Numbers, Growth and Behaviour of Patella Vulgata on a Vertical Pier
Authors: Hawkins S. J. , Hartnoll R. G.
Published: May 2009

The effects of experimentally manipulated barnacle cover on the population size, mortality and growth of Patela vulgata L. were investigated on a vertical, barnaclecovered pier at Port Erin in the Isle of Man. One area was left untouched as a control, half of the barnacles on a second were scraped off in a chequered pattern, and on the third the barnacle cover was reduced to less than 2 °0. Subsequent growth rates were inversely proportional to barnacle cover. Mortality was highest on the control. Recruitment of limpets was markedly enhanced by the mosaic of 50 % barnacle cover.

Behaviour on this vertical face differed from that on nearby more gently sloping shores, with foraging during emersion being more prevalent: however, barnacle removal reduced this foraging when the tide was out. The foraging of Patella vulgata whilst emersed was similarly shown to be more prevalent on vertical than horizontal surfaces at other localities in Britain. Emersed foraging on the pier was dependent on high humidity. It is suggested that on vertical surfaces, particularly if barnacle-covered, P. vulgata are more dependent on foraging whilst emersed because of the greater risk of dislodgement by waves when feeding whilst the tide is in.
The reproductive biology ofPlutonaster Bifrons, Dytaster InsignsandPsilaster Andromeda(Asteroidea: Astropectinidae) from the Rockall Trough
Authors: Tyler P. A. , Pain S. L.
Published: May 2009

Examination of the reproductive biology of three closely related sympatric astropectinid asteroidshas revealed two distinct reproductive strategies. In Plutonaster bifrons and Dytaster insignis the gonads are serially arranged and open at gonopores located at the tip of genital papillae found on the dorsal arm surface between the bases of the paxillae. The ovaries of these species produce numerous small (ca. 120/«n diameter) eggs which in Plutonaster bifrons appear to show a distinct synchrony of production. Initiation of gametogenesis occurs in June to August of each year with oocyte growthcontinuing until March with a spawn-out in the period March to early June. In specimens where spawningdoesnot occur, there would appear to be internal oocyte degeneration, or after spawning relict oocytesundergo phagocytosis. In males initiation of spermatogenesis may occur in August/September of eachyear but after this synchrony of sperm development is not evident. In Psilaster andromeda gonads are located at the base of the arms and each gonad opens at a single gonopore. A number of small (<300 /«n) oocytes are produced by each gonad. Some of these are phagocytosed and some undergo vitellogenesis and grow to a maximum size of 950 fim before being spawned. Unspent oocytes undergo internal degeneration. In neither females nor males is there any evidence of reproductive synchrony. From these egg sizes, fecundities and gametogenic strategies, we infer indirect planktotrophic development for Plutonaster bifrons, the transfer of a seasonal surface production to deep water providing a food source for developing larvae. The egg size and or close to the sea-bed, as there is no evidence of brooding in this species.
Bacterial Symbionts in Pogonophora
Authors: Southward Eve C.
Published: May 2009

Prokaryote organisms, with characteristics of Gram-negative bacteria, occur intracellularly in Pogonophora, as described here for seven small species. The tissue containing the bacteria lies between the two longitudinal blood vessels in the posterior part of the trunk and has a special blood supply. This tissue is probably homologous with the so-called trophosome tissue of the much larger vestimentiferan pogonophores, which also contains bacteria, and the term can be applied to all pogonophores. The presence of such bacteria-containing trophosome tissue may be a characteristic of the phylum. In both large and small species examined the bacteria appear to be chemoautotrophs and probably assist the nutrition and/or metabolism of their hosts. It is not yet certain if the bacterium-containing cells do originate from mesoderm or endoderm, but, if the latter, then the trophosome represents the remains of the missing gut. The trophosome tissue situated internally, and transfer of bacteria must take place early in the life history, in the egg or embryo.
Caste Away? Subaltern Engagement with the Modern Indian State
Authors: DORON ASSA
Published: May 2009

Mayawati's recent victory, in May 2007, in the Uttar Pradesh elections has been hailed as a ‘spectacular display of subaltern power’. The questions remain: who are these subalterns? To what extent do they form a coherent block, with similar fears, hopes and aspirations, and how are subalterns’ visions of the state, social justice and equality articulated? This paper explores some of these questions, by examining the example of the boatman community in Banaras, belonging to the Mallah (Nishad) caste, and the strategies they use to be heard as legitimate citizens of the state. Such strategies and techniques reveal a sophisticated and organized apparatus of caste and community associations that call into question some recent theoretical formulations of the Indian state as one dominated and manipulated by powerful elites, while subalterns remain passive or, at best, compliant.
‘A Question of Principle with Political Implications’ – Investigating Collaboration in the Chinese Maritime Customs Service, 1945–1946
Authors: WHITE BENJAMIN GEOFFREY
Published: May 2009

In the winter of 1945, the multinational Chinese Maritime Customs Service opened an inquiry into the cooperation of hundreds of its own employees with Japanese occupation forces in China. This was, as far as the historical record allows us to say, the most thorough investigation undertaken in China into collaboration during World War Two. This paper represents the first historical analysis of the Customs ‘Staff Investigation Committee.’ It argues that the investigation represented a new direction for the Customs Service in China. The investigation's underpinning rationale was that Customs staff, Chinese and foreign, served the Kuomintang government before any other notion of Chinese or Service interests—a dramatic change in direction for an organisation that had been emblematic of treaty-port China. The investigation thus offers historians an insight into the understudied final years of the Customs Service, into the late Republican government's efforts to deal with the legacy of imperialism, and into the extent and rationale of collaboration in Nationalist China.
Eating behaviour and eating disorders in students of nutrition sciences
Authors: Korinth Anne , Schiess Sonja , Westenhoefer Joachim
Published: May 2009

Objective

Sometimes the suspicion is put forward that nutrition students show more disordered eating patterns, which may be among the motivating factors to study nutrition. At the same time, it is not clear whether the students’ increasing knowledge about diet and nutrition is associated with a more healthy eating behaviour or with an unhealthy obsession with food choices.

Design

Cross-sectional comparison of nutrition students from German universities during the first year of their studies (n123) and during higher semesters (n96), with a control group from other study programmes (n68 andn46, respectively). Dietary restraint, disinhibition, the tendency towards orthorexia nervosa and healthy food choices were assessed using a questionnaire.

Results

Nutrition students showed higher levels of dietary restraint than the control group. Disinhibition and orthorexia nervosa did not differ between nutrition students and controls. Orthorexic tendencies were lower in the more advanced nutrition students. Healthy food choices did not differ among students in the first year. More advanced nutrition students showed healthier food choices, whereas the corresponding controls showed slightly more unhealthy food choices.

Conclusions

Nutrition students, more than other students, tend to restrict their food intake in order to control their weight, but they do not have more disturbed or disordered eating patterns than other students. Moreover, during the course of their studies, they adopt slightly more healthy food choices and decrease their tendency to be obsessive in their eating behaviour.
Eating out of home and obesity: a Brazilian nationwide survey
Authors: Bezerra Ilana Nogueira , Sichieri Rosely
Published: May 2009

Objective

The aim of the present study was to investigate the relationship between out-of-home (OH) eating and overweight and obesity among adults in Brazil.

Design

Data were based on the 2002–2003 Household Budget Survey (48 470 households) conducted by The Brazilian Census Bureau. Foods and drinks purchased for OH eating during a one-week period were recorded by each participant. We considered OH eating as the purchase of at least one food or drink item for OH consumption during this period. We classified items as: soft drinks, deep-fried snacks, fast foods, sweets and sit-down meals.

Setting

Urban areas in Brazil.

Subjects

56 178 participants (26 225 men and 29 953 women), aged 25–65 years.

Results

The weighted prevalence of OH eating was 40·3 %. Overall, OH eating was positively associated with overweight (OR = 1·21; 95 % CI 1·10, 1·33) and obesity (OR = 1·35; 95 % CI 1·16, 1·57) among men, but not among women. Sit-down meals and soft drinks were the most frequently reported food groups. Both were positively associated with overweight (OR = 1·34 for meals; OR = 1·17 for soft drinks, P < 0·05) and obesity (OR = 1·51 for meals; OR = 1·39 for soft drinks, P < 0·05) among men, but negatively associated with overweight and obesity among women.

Conclusions

OH eating was associated with overweight and obesity only among men, whereas, among women, eating sit-down meals out of home was protective for obesity, suggesting that women make healthier food choices when they eat out of home.
Application and comparison of Kalman filters for coastal ocean problems: An experiment with FVCOM
Authors: Chen Changsheng , Malanotte‐Rizzoli Paola , Wei Jun , Beardsley Robert C. , Lai Zhigang , Xue Pengfei , Lyu Sangjun , Xu Qichun , Qi Jianhua , Cowles Geoffrey W.
Published: May 2009

Twin experiments were made to compare the reduced rank Kalman filter (RRKF), ensemble Kalman filter (EnKF), and ensemble square‐root Kalman filter (EnSKF) for coastal ocean problems in three idealized regimes: a flat bottom circular shelf driven by tidal forcing at the open boundary; an linear slope continental shelf with river discharge; and a rectangular estuary with tidal flushing intertidal zones and freshwater discharge. The hydrodynamics model used in this study is the unstructured grid Finite‐Volume Coastal Ocean Model (FVCOM). Comparison results show that the success of the data assimilation method depends on sampling location, assimilation methods (univariate or multivariate covariance approaches), and the nature of the dynamical system. In general, for these applications, EnKF and EnSKF work better than RRKF, especially for time‐dependent cases with large perturbations. In EnKF and EnSKF, multivariate covariance approaches should be used in assimilation to avoid the appearance of unrealistic numerical oscillations. Because the coastal ocean features multiscale dynamics in time and space, a case‐by‐case approach should be used to determine the most effective and most reliable data assimilation method for different dynamical systems.
Subparallel thrust and normal faulting in Albania and the roles of gravitational potential energy and rheology contrasts in mountain belts
Authors: Copley Alex , Boait Fran , Hollingsworth James , Jackson James , McKenzie Dan
Published: May 2009

The active tectonics of Albania and surrounding regions, on the eastern margin of the Adriatic Sea, is characterized by subparallel thrust and normal faulting which, we suggest, is likely to be related to gravitational potential energy contrasts between the low‐lying Adriatic Sea and the elevated mountainous areas inland. We calculate the magnitude of the force which the mountains and lowlands exert upon each other as a result of this potential energy contrast. It is likely that this force is largely supported by shear stresses on faults, and if so, the average stresses are less than ∼20 MPa. Alternatively, if the mountains are supported by stresses in the ductile part of the lithosphere, the stresses are likely to be ∼80–240 MPa in magnitude. The mountains of Albania are significantly lower than other ranges, such as the Peruvian Andes, which are thought to be extending in response to potential energy differences, and we discuss the relation between Albania and these other, higher, mountain belts from the perspective of differences in lithosphere rheology. We suggest that the lowlands of western Albania and the Adriatic Sea may have been weakened through time as a result of the deposition of large thicknesses of sediment, which lead to heating of the crystalline basement, a reduction in the potential energy contrast that could be supported by the lowlands, and so normal faulting in the mountains of eastern Albania.
Application of a Monte Carlo integration method to collision and coagulation growth processes of hydrometeors in a bin‐type model
Authors: Sato Yousuke , Nakajima Teruyuki , Suzuki Kentaroh , Iguchi Takamichi
Published: May 2009

New algorithms for calculating the collision‐coagulation growth process of hydrometeors were developed and implemented into a bin cloud microphysics model in order to improve its computational efficiency. Computation of collision‐coagulation growth is a bottleneck in the bin‐type cloud microphysics calculation that takes a large amount of computing time. Improvement in the efficiency of the process can significantly reduce computing time. In this study, a new stochastic algorithm was developed and implemented into the collision‐coagulation growth process of a nonhydrostatic cloud model. Simulations showed that the computing time was reduced by about 90%. We verified that the error range of the simulation results from the new scheme is much smaller than the internal variability involved the traditional bin‐type model and also in the real atmosphere. The newly developed scheme was implemented into the mesoscale operational model of the Japan Meteorological Agency. The precipitation field was accurately simulated in a numerical weather prediction simulation.
Characteristics of light nonaqueous phase liquid recovery in the presence of fine‐scale soil layering
Authors: Johnston C. D. , Trefry M. G.
Published: May 2009

The effects of fine‐scale layering of soil properties on light nonaqueous phase liquid (LNAPL) recovery using pumped groundwater drawdown were investigated using a Monte Carlo approach. Three‐dimensional simulations were performed to study the characteristics of a variety of measures describing LNAPL recovery in heterogeneous sandy aquifers. Heterogeneity models included both uncorrelated and correlated vertical permeability distributions, with both permeability‐scaled and unscaled retention characteristics. Lognormal permeability variances of 0.594 and 1.188 were considered. The Monte Carlo ensemble mean LNAPL recovery rates and cumulative recovery volumes differ significantly from homogeneous soil models. The ensemble variances are large, and confidence intervals on recovery measures are wide. Generally, lognormality is not preserved; recovery rates and volumes display asymmetric densities with standard deviations of the order of the means. Overall recovery efficiency depends critically on the layer permeability at specific elevations. Practical outcomes for field practitioners are discussed including the degree to which substantially increased times may be required for LNAPL recovery and the increased occurrence of situations where larger than expected volumes will remain unrecovered. Guidance is also given for the key measurements of layer permeabilities and their expected influence on recovery performance. It is concluded that moderate vertical layering of soil properties is sufficient to render homogeneous recovery models inappropriate.
Practical implications of uncertainty in observed SSTs
Authors: Goddard Lisa , DeWitt David G. , Reynolds Richard W.
Published: May 2009

Uncertainties in the accuracy of observed sea surface temperature (SST) estimates limit a number of efforts relevant to seasonal‐to‐interannual climate variability and its prediction. Some of the efforts that may be hampered by uncertain SSTs include estimates of skill in predicted SSTs, attribution studies of seasonal climate anomalies, and calibration of probabilistic seasonal climate forecast systems. This study examines the explicit impact of SST uncertainties on the climate response from an atmospheric general circulation model. Uncertainties in Western Pacific SSTs play a substantial role in the sensitivity of the seasonal climate.
TCD8 response in diverse outcomes of recurrent exposure to hepatitis C virus
Authors: Bharadwaj Mandvi , Thammanichanond Duangtawan , Aitken Campbell Kynoch , Moneer Sarah , Drummer Heidi E , Tracy Samantha , Holdsworth Rhonda , Bowden Scott , Jackson David , Hellard Margaret , Torresi Joseph , McCluskey James
Published: May 2009

To analyse the immune correlates in a setting of recurrent exposure to hepatitis C virus (HCV), we studied TCD8 responses in injecting drug users (IDUs) with different disease outcomes. Ex vivo HCV‐specific TCD8 responses assessed by interferon‐γ (IFNγ) enzyme‐linked immunospot (ELISPOT) were comparable in human lymphocyte antigen (HLA)‐matched IDUs with spontaneous HCV clearance or persistent infection. A detailed characterization of these TCD8 cells in age and HLA‐matched IDUs demonstrated that HCV clearance and protection from reinfection correlated with HCV‐specific TCD8 cells that could proliferate in vitro, possessed cytotoxic potential and produced IFNγ and tumour‐necrosis factor‐α, rather than with the circulating frequency of responding TCD8 cells determined ex vivo. While validating the importance of multifunctional TCD8 in mediating protection in IDUs with recurrent exposure to HCV our findings highlight that the magnitude and/or breadth of HCV‐specific TCD8 determined in ex vivo ELISPOT may not be the sole determinant of protection especially in a setting of recurrent exposure.
Signature of fast H atoms from cathode glow region of a dc discharge
Authors: Bharathi P. , Suraj K. S. , Prahlad V. , Mukherjee S. , Vasu P.
Published: May 2009

Asymmetric broadening of Hα line from cathode glow region has been studied. In the cathode glow, mean energy and fractional population of very fast hydrogen atoms were found to be ∼130 eV and ∼55%, respectively. These values reduced to ∼90 eV and ∼20% when measured at negative glow region. The observed asymmetry was attributed to the presence of the fast hydrogen atoms near the cathode surface. The mean energy and number density of excited fast hydrogen atoms were estimated from the velocity distribution of H+, H2+, and H3+ considering collisions inside the cathode sheath. The reduction in the mean energy and number density of the excited fast hydrogen atoms, at the other locations of the discharge, was explained by energy relaxation and thermalization of the neutrals with the background gas.
Entropy determinations and magnetocaloric parameters in systems with first-order transitions: Study of MnAs
Authors: Tocado Leticia , Palacios Elías , Burriel Ramón
Published: May 2009

We present a study of the giant magnetocaloric effect in MnAs produced by a magnetostructural first-order phase transition. Results deduced from magnetization, M, and heat capacity, Cp,B(T), are compared and discussed. Some spurious effects are explained, and especially a spike in the isothermal entropy change, ΔST, occurring at TC when obtained via the Maxwell relation (∂S/∂B)T=(∂M/∂T)B. Alternative determination methods are given to circumvent this problem. The spike is explained as an artifact due to the incorrect application of the Maxwell relation to path dependent thermodynamic functions that are not state functions. The added wrong contribution to ΔST has been calculated using calorimetric data, giving a good agreement with the result from the magnetization measurements.
Third-generation infrared photodetector arrays
Authors: Rogalski A. , Antoszewski J. , Faraone L.
Published: May 2009

Hitherto, two distinct families of multielement detector arrays have been used for infrared (IR) imaging system applications: linear arrays for scanning systems (first generation) and two-dimensional arrays for staring systems (second generation). Nowadays, third-generation IR systems are being developed which, in the common understanding, provide enhanced capabilities such as larger numbers of pixels, higher frame rates, better thermal resolution, multicolor functionality, and/or other on-chip signal-processing functions. In this paper, fundamental and technological issues associated with the development and exploitation of third-generation IR photon detectors are discussed. In this class of detectors the two main competitors, HgCdTe photodiodes and quantum-well photoconductors, are considered. This is followed by discussions focused on the most recently developed focal plane arrays based on type-II strained-layer superlattices and quantum dot IR photodetectors. The main challenges facing multicolor devices are concerned with complicated device structures, thicker and multilayer material growth, and more difficult device fabrication, especially for large array sizes and/or small pixel dimensions. This paper also presents and discusses the ongoing detector technology challenges that are being addressed in order to develop third-generation infrared photodetector arrays.
Magnetic confinement in a ring-cusp ion thruster discharge plasma
Authors: Sengupta Anita
Published: May 2009

An experimental investigation, in conjunction with a volume averaged analytical model, has been developed to improve the confinement and production of the discharge plasma for plasma thrusters and ion sources. The research conducted explores the discharge performance of a ring-cusp ion source based on the magnetic field configuration, geometry, and power level. Analytical formulations for electron and ion confinement are developed to predict the ionization efficiency for a given discharge chamber design. Explicit determination of discharge loss and volume averaged plasma parameters are obtained via a series of experimental measurements on a ring-cusp NASA Solar Technology Application Readiness (NSTAR) ion thruster to assess the validity of the analytical model. Measurements of the discharge loss with multiple magnetic field configurations compare well with plasma parameter predictions for propellant utilizations between 80% and 95%. The results indicate that increasing the magnetic strength of the first closed magnetic contour line reduces Maxwellian electron diffusion and electrostatically confines the ion population and subsequent loss to the anode wall. The results also indicate that increasing the strength and minimizing the area of the magnetic cusps improves primary electron confinement, increasing the probability of an ionization collision prior to loss at the cusp.
Energy spectra of tailored particle beams from trapped single-component plasmas
Authors: Weber T. R. , Danielson J. R. , Surko C. M.
Published: May 2009

A nondestructive technique was developed recently to create beams of electrons (or positrons) with small transverse spatial extent and high brightness from single-component plasmas confined in a Penning–Malmberg trap [T. R. Weber et al., Phys. Plasmas 90, 123502 (2008)]. A model for beam extraction was developed that successfully predicts the resulting beam profiles. This model is used here to predict the beam amplitudes and the energy distribution of the beams as a function of the exit-gate voltage. The resulting expressions, suitably scaled by the plasma parameters, depend only on the exit-gate voltage and the electrode radius. Predictions of the theory are confirmed using electron plasmas. This technique permits the formation of beams with both small transverse spatial extent and small energy spread. Applications involving antimatter beams (e.g., positrons) are discussed, including bright beams for improved spatial resolution, short pulses for time-resolved studies, and cold beams for improved energy resolution.
Localized exfoliation versus delamination in H and He coimplanted (001) Si
Authors: Reboh S. , de Mattos A. A. , Barbot J. F. , Declemy A. , Beaufort M. F. , Papaléo R. M. , Bergmann C. P. , Fichtner P. F. P.
Published: May 2009

X-ray diffraction measurements as well as electron (scanning and transmission), optical, and atomic force microscopies are used to study the thermally induced stress relief mechanisms in coimplanted H+ and He+ ions into (001) Si substrates at moderate energies, resulting in damage layers located at ≈1.5 μm underneath the surface. By changing the implantation fluence rate from 0.25 to 1.5 μA cm−2, two distinct phenomena take place: localized blistering/exfoliations or complete surface delamination, resulting into freestanding 1.5 μm thick single crystalline Si films. The results are discussed on the basis of linear fracture mechanics arguments. Localized exfoliation is explained by means of distinct coarsening processes linking the initially formed gas filled nanosized platelets to crack structures of several micrometers in diameter. The delamination behavior is explained in terms of unstable crack propagation process triggered at a single nucleation site.
Cathodoluminescence characterization of a nitrogen-doped homoepitaxial diamond thin film
Authors: Watanabe H. , Kitamura T. , Nakashima S. , Shikata S.
Published: May 2009

Strong modification of the optical spectra is apparent in nitrogen-doped chemical vapor deposited (CVD) diamonds. Nitrogen-vacancy (NV) defects in CVD diamond are effectively created by nitrogen doping with a high concentration of the gaseous phase. In particular, the 575 nm center and 637 nm centers are enhanced in intensity at a N doping level of around 1018 at./cm3, while nitrogen addition during CVD growth leads to quenching of both the exciton and H3 centers. The influence of nitrogen doping on the exciton and NV defect states in a homoepitaxial CVD diamond thin film was investigated by high-resolution cathodoluminescence experiment. In addition, Raman experiments were performed to detect the internal stress. The results show that the exciton and nitrogen-related defect emission spectra underwent a shift of the peak position to a longer wavelength by nitrogen doping. The characteristic Raman peak of diamond at 1332 cm−1 showed a shift toward lower wave numbers with increasing nitrogen incorporation.
A first-principles density functional study of chlorophenol adsorption on Cu2O(110):CuO
Authors: Altarawneh Mohammednoor , Radny Marian W. , Smith Phillip V. , Mackie John C. , Kennedy Eric M. , Dlugogorski Bogdan Z. , Soon Aloysius , Stampfl Catherine
Published: May 2009

First-principles density functional theory and a periodic-slab model have been employed to explore the adsorption of a two-chlorophenol molecule on a Cu2O(110) surface containing surface Cu–O bonds, namely, the Cu2O(110):CuO surface. The two-chlorophenol molecule is found to interact very weakly with the Cu2O(110):CuO surface, forming several vertical and flat orientations. These weakly bound states tend to result from interaction between the phenolic hydrogen and an oxygen surface atom. The formation of a two-chlorophenoxy moiety and an isolated hydrogen on the Cu2O(110):CuO surface from a vacuum two-chlorophenol molecule is determined to have an endothermicity of 8.2 kcal/mol (0.37 eV). The energy required to form a two-chlorophenoxy radical in the gas phase is also found to be much smaller when assisted by the Cu2O(110):CuO surface than direct breaking of the hydroxyl bond of a free two-chlorophenol molecule. The calculated binding energy of a two-chlorophenoxy radical adsorbed directly onto the Cu2O(110):CuO surface is −12.5 kcal/mol (0.54 eV). The Cu2O(110):CuO and Cu(100) surfaces are found to have similar energy barriers for forming a surface-bound two-chlorophenoxy moiety from the adsorption of a two-chlorophenol molecule.
Increase of the deposition rate in reactive sputtering of metal oxides using a ceramic nitride target
Authors: Severin D. , Kappertz O. , Nyberg T. , Berg S. , Pflug A. , Wuttig M.
Published: May 2009

We present a method to eliminate hysteresis effects and to increase the deposition rate for the reactive sputtering of metal oxides. This is achieved by using a ceramic nitride target in an argon-oxygen atmosphere. Although the use of a ceramic nitride target leads to pronounced changes of the processing characteristics, incorporation of nitrogen into the growing film is very small. These observations can be theoretically predicted using an extension of Berg’s model [S. Berg and T. Nyberg, Thin Solid Films 476, 215 (2005)] to two different reactive gases and a compound target.
The mechanical robustness of atomic-layer- and molecular-layer-deposited coatings on polymer substrates
Authors: Miller David C. , Foster Ross R. , Zhang Yadong , Jen Shih-Hui , Bertrand Jacob A. , Lu Zhixing , Seghete Dragos , O’Patchen Jennifer L. , Yang Ronggui , Lee Yung-Cheng , George Steven M. , Dunn Martin L.
Published: May 2009

The mechanical robustness of atomic layer deposited alumina and recently developed molecular layer deposited aluminum alkoxide (“alucone”) films, as well as laminated composite films composed of both materials, was characterized using mechanical tensile tests along with a recently developed fluorescent tag to visualize channel cracks in the transparent films. All coatings were deposited on polyethylene naphthalate substrates and demonstrated a similar evolution of damage morphology according to applied strain, including channel crack initiation, crack propagation at the critical strain, crack densification up to saturation, and transverse crack formation associated with buckling and delamination. From measurements of crack density versus applied tensile strain coupled with a fracture mechanics model, the mode I fracture toughness of alumina and alucone films was determined to be KIC=1.89±0.10 and 0.17±0.02 MPa m0.5, respectively. From measurements of the saturated crack density, the critical interfacial shear stress was estimated to be τc=39.5±8.3 and 66.6±6.1 MPa, respectively. The toughness of nanometer-scale alumina was comparable to that of alumina thin films grown using other techniques, whereas alucone was quite brittle. The use of alucone as a spacer layer between alumina films was not found to increase the critical strain at fracture for the composite films. This performance is attributed to the low toughness of alucone. The experimental results were supported by companion simulations using fracture mechanics formalism for multilayer films. To aid future development, the modeling method was used to study the increase in the toughness and elastic modulus of the spacer layer required to render improved critical strain at fracture. These results may be applied to a broad variety of multilayer material systems composed of ceramic and spacer layers to yield robust coatings for use in chemical barrier and other applications.