bluuebunny/crossref_metadata_2025 huggingface dataset:
The Vertical Distribution of Marine Macroplankton. V. The Distribution of Animals Caught in the Ring-trawl in the Daytime in the Plymouth Area
Authors: Russell F. S.
Published: May 2009

1. The vertical distribution of many species in daylight in the Plymouth area is shown, as a result of the examination of a number of serial hauls taken with the stramin ring-trawl between the dates April 2nd and August 6th, 1926.

2. It is shown that probably the errors introduced by the employment of a non-closing net are for the present purpose negligible.

3. The indications are that most species have an optimum level at which they live, in the daytime, the actual depth varying from day to day according to weather and other conditions.

4. A few species appear to show no preference, being present equally abundantly at all depths or showing marked changes in the region of greatest abundance from day to day.

5. A provisional list is given on page 567, showing the order in which many of the different species appear in greatest abundance from the surface downwards.

6. The vertical distribution appears to differ for the two sexes of Calanus finmarchicus, the males tending to avoid the surface layers more than the females.

7. The presence of the medusa Cosmetira pilosella in fair numbers in a catch in the daytime in the Plymouth region would seem to be a reliable indication that the net has been fishing below 20 metres.

8. A catch of Calanus finmarchicus made by the stramin ring-trawl consists nearly always of over 80 per cent adults.

9. No attempt has been made definitely to correlate behaviour with external factors: more observations are to be desired.

10. Brief notes are given on the seasonal distribution of various species. The danger of drawing conclusions about seasonal abundance from daylight hauls only is shown by the results for Tomopteris helgolandica (p. 575).
The Phosphorus and Arsenic Compounds of Sea-Water
Authors: Atkins W. R. G. , Wilson Edith G.
Published: May 2009

1. Much of what was formerly considered to be phosphorus in organic combination, in sea-water, is in reality arsenic.

2. Certain analyses giving high values for phosphate in sea-water and a June minimum very far from complete exhaustion of phosphate are vitiated by the inclusion of arsenate, as arsenomolybdate, in the phosphomolybdate precipitate.

3. Arsenic in sea-water exists mainly in the form of arsenite. The arsenate present, if any, has hitherto been included in the results obtained for phosphate.

4. Since arsenic is found in algæ and has been recorded as increasing in quantity with increase of depth it seems that the arsenic present in sea-water must undergo seasonal changes.
Notes on Nucula
Authors: Hirasaka Kyosuke
Published: May 2009

These notes record the result of work done at the Plymouth Laboratory during the summer of 1926. They deal chiefly with the feeding habits of Nucula, a Protobranch possessing the type of feeding mechanism characteristic of that order, and not found in any other Lamellibranch. During the course of my work I found Vlès' interesting paper on the sense organ of Nucula. After studying the organ, I arrived at a different interpretation of its function from that reached by Vlès.
The Medusa Mitrocomella polydiademata and its hydroid
Authors: Edwards C.
Published: May 2009

The hydroid, hitherto unknown, of the leptomedusa Mitrocomella polydiademata has been reared from medusae collected in the Firth of Clyde. The growth and structure of the hydroid and the stages of development of the medusa are described and figured.
Monitoring the Vertical Movements and Light Responses of Herring and Plaice Larvae
Authors: Blaxter J. H. S.
Published: May 2009

The movements of herring and plaice larvae of different age, from hatching to about 8 weeks old, were monitored at different levels in a vertical tube by means of matched pairs of thermistors controlled and ‘balanced’ by bridge circuits. Movement of larvae past the thermistors upset the balance and the resulting change in the circuit could be followed on a pen-recorder. Having established, by visual comparisons, the interpretation of the pen record, experiments could be performed over extended periods or at low light intensities when visual observations would have been tedious or impossible. The numbers of larvae present were shown by the number of spikes on the pen record per unit time, while a measure of their size or activity was given by the height of the spikes.

The light intensity could be altered by interposing neutral-density filters between an artificial light source and the surface of the tube. Alternatively, natural daylight could be beamed in by a mirror above the tube when placed by a window. Using artificial light, changes of very large intensity had little effect on the larvae until a critical level was reached (equivalent to the intensity at late dusk or early dawn) when a vertical migration took place. A similar vertical migration took place when the natural light at dusk was beamed in; many larvae then moved to the surface and remained there, apparently very active throughout the night untill the light increased at dawn. Vertical migration could be simulated in the laboratory at any time by imposing an artificial light-cycle of appropriate amplitude on the larvae.
Seasonal Changes in the Organic Forms of Carbon, Nitrogen and Phosphorus in Sea Water at E1 in the English Channel During 1968
Authors: Banoub M. W. , Williams P. J. leB.
Published: May 2009

A seasonal survey of particulate and dissolved organic material was made at E1 in the English Channel during 1968. The average integral mean values were: dissolved organic carbon 65 μg-at C/l (780 μg C/l); dissolved organic nitrogen 4·6 μg-at N/l (64 μg N/l); dissolved organic phosphorus 0·12 μg-at P/l (3·8 μg P/l); particulate organic carbon 190 μg C/l and particulate organic nitrogen 21 μg N/l. Dissolved organic carbon and the particulate organic carbon and nitrogen showed increases subsequent to the spring bloom; such increases were less evident in the dissolved organic nitrogen results and not apparent in those of dissolved organic phosphorus.

Analyses were also made in March and June in 1969 at two other stations in the English Channel, in addition to E1. The results from the three stations were basically similar.
An overview of the amphipod genus Haploops (Ampeliscidae)
Authors: Dauvin Jean-Claude , Bellan-Santini Denise
Published: May 2009

Available data concerning the taxonomy, biology, ecology and biogeography of the genus Haploops is presented. The genus, represented by 15 valid species, is typically associated with deep and cold waters. Haploops is confined to the Arctic, north Atlantic and north Pacific Oceans with the exception of two Tasmanian species. Phyletic relationships show four principal groups of species, but there is no clear correlation between these groups and their biogeographical distribution. The biology of Haploops is typical of the biology of a cold-water amphipod. The distribution and the biology of Haploops is contrasted with that of Ampelisca, another genus of the family Ampeliscidae.
Loss of meal antigenicity during digestion in Sepia officinalis (Cephalopoda: Sepioidea)
Authors: Kear Amanda J. , Boyle Peter R.
Published: May 2009

Some of the limits to the use of serology to identify prey species in the digestive tracts of cephalopods have been evaluated. Cuttlefish, Sepia officinalis, were given meals of krill slurry (Euphausia superba). Protein extracts of contents from four regions of the digestive tract, stomach, caecum, digestive gland and intestine, were tested for prey antigenicity. Digestion times (loss of antigenicity) ranged from 1 to 8 h depending on sampling site. Stomach and caecum emptied rapidly, but meal antigenicity persisted longer in the digestive gland. The Sepia experiments provide a basis for interpretation of results from natural predation by cephalopods).
The response of decapod and mysid crustaceans to artificially lighted trawls
Authors: Hargreaves P. M. , Herring P. J.
Published: May 2009

A sampling series was undertaken with an opening/closing mid water trawl to assess the responses of midwater crustaceans to illumination and to compare these with previous reports resulting from the use of an open net. An electric light fitted on an RMT8 midwater trawl was switched on for alternate hauls of a series of 31 tows at a depth of 800 ± 25 m at 20°30'N 19°40'W. Turning the light on had no significant effect on the numbers or sizes of the numerically dominant species in the catches.
Fenestrulina Asturiasensis sp. nov. (Bryozoa: Cheilostomida) from the Northern Coast of the Iberian Peninsula
Authors: Alvarez Juan A.
Published: May 2009

A new species of Fenestrulina Jullien, 1888, F. asturiasensis sp. nov., is described from the northern coast of the Iberian Peninsula. The main diagnostic features of this species are: four to five oral spines, a completely porous frontal wall and non-stellate frontal pores. These features have allowed the author to differentiate it from F. malusii (Audouin), another species of the genus Fenestrulina Jullien recorded in the same region.
Food availability for sprat larvae in the Irish Sea
Authors: Coombs S. H. , Nichols J. H. , Conway D. V. P. , Milligan S. , Halliday N. C.
Published: May 2009

The distribution of larvae of sprat (Sprattus sprattus) is described in relation to feeding conditions in the Irish Sea. Larvae were most abundant towards the coastal margins. Relatively few were taken in the mixed water of the central Irish Sea. Preferred food organisms were also more abundant in coastal regions. Both sprat eggs and larvae, and microplankton, were more dispersed down the water column when it was fully mixed than when stratified. Characterization of food availability for larvae, as peak (modal) abundance down the water-column, is shown to be related to the degree of stratification.
Preliminary Note on Trawling Experiments in certain Bays on the South Coast of Devon
Authors: Stead F. B.
Published: May 2009

The following pages are intended to be preliminary to a fuller report which I shall hope to publish later on. For the present I shall confine myself to an account of the objects in view of which these investigations were begun, and of the method by which they have so far been carried out. I further propose to append a brief summary of some of the facts ascertained, reserving a more detailed statement for a future occasion.
Notes on Plymouth Hydroids
Authors: Nutting C. C.
Published: May 2009

The following notes are based upon observations made during April and the first half of May, 1895. Although the Plumularidœ were the special objects of study, a number of facts concerning other forms were noticed, which, together with the discussion of certain matters brought out in the special study of the Plumularidœ, were considered by the Director to be of sufficient interest for publication in this Journal. It will be understood that no general discussion of the hydroids at Plymouth is attempted, nor is it my purpose to give a list of the hydroid forms of that exceedingly rich field, no species being mentioned unless some new fact has been observed concerning it.
The Scottish, Newfoundland, and United States Reports
Authors: Cunningham J. T.
Published: May 2009

ArtificialHatching ofFishEggs.—The Scottish Report, whose title is given above, is stated to refer to the year 1894; but as a matter of fact, a great deal of the work recorded in it was carried out during the earlier portion of 1895. This is the case with the operations of the Dunbar Hatchery, described by Mr. Harald Dannevig, the Manager of that establishment. We find that 44,085,000 eggs of plaice were collected last spring, and from these 38,615,000 fry were obtained, and liberated in the sea. This shows a loss of only 12 per cent, in the process of hatching. But large as the numbers appear, it should not be forgotten that the above number of eggs represents the produce of only 220 female fish, reckoning 200,000 eggs to each, which is a low estimate, for it has been proved by Dr. Fulton that the larger female plaice produce each from 300,000 to 500,000 eggs in one season.
Free-Running, Endogenous Semilunar Rhythmicity in a Marine Isopod Crustacean
Authors: Reid D. G. , Naylor E.
Published: May 2009

In recent years several workers have postulated the occurrence in a number of coastal animals of endogenous behaviour and physiological rhythms of semilunar periodicity (see Naylor, 1982). However, only a few of these long term rhythms have been demonstrated as free-running cyclical behaviour over long periods of time in constant conditions. For example, the supra-littoral amphipod Talitrus saltator (Montagu) has been shown to express semilunar variations in daily locomotor activity over three cycles of neap/spring tides during 46 days in constant conditions in the laboratory (Williams, 1979). In contrast, in the mid-shore sand-beach isopod E. pulchra (Leach) semilunar variations in swimming behaviour (Fish & Fish, 1972; Alheit & Naylor, 1976) and of respiration (Hastings, 1981a) have so far been demonstrated only in isopods collected at various stages of the neaps/springs cycle of tides and recorded for a few days in the laboratory. It, therefore, still remains to confirm unequivocally in Eurydice, and in many other forms, which appear to show semilunar periodicity, that such rhythmicity is expressed as a free-running rhythm over long periods of time in constant conditions.
A Red Tide of Gyrod Inium Aurelum in Sea Lochs of the Firth of Clyde and Associated Mortality of Pond-Reared Salmon
Authors: Jones K. J. , Ayres P. , Bullock A. M. , Roberts R. J. , Tett P.
Published: May 2009

Red tides of the naked dinoflagellate Gyrodinium aureolum Hulburt occurred in sealochs in the north of the Firth of Clyde, Scotland, during late September 1980. Greatestconcentrations of the organism were found in the top 1 m layer of the water column, which was stabilized, and probably also enriched with nutrients, by freshwater input fromland drainage. In addition vertical and horizontal concentration must be postulated toexplain Gyrodinium cell densities of 2 x to7 cells I"1 and chlorophyll concentrations of 2228 mg m“”3 near the shore at Otter Ferry, Loch Fyne.

On 28 September 1980, water containing the red tide at Otter Ferry was unintentionally pumped into fish ponds at a shore-based salmon farm and resulted in the death, in one pond, of 3000 salmon each weighing about 1 kg and of 200–300 smolts in another when water was transferred to it from the affected pond. Pathological investigation of affected salmon showed that death was likely to have resulted from asphyxiation and osmotic shock as a result of extensive cellular damage to gills and guts. Results of mouse bioassays, using acidic and ether extracts of flesh and guts from affected salmon, suggest that necrotizing toxin(s) was associated with the cells of Gyrodinium aureolum during the bloom. The clinical signs exhibited by mice injected with toxin extracts were, however, unlike those caused by paralytic shellfish poison or toxins of the Gymnodinium breve type.
Horizontal And Vertical Dencity Distribution of Platfarm and Cirripede Larvae Over an Inshore Rock Platform Off Northumberland
Authors: Wilson Stephen R.
Published: May 2009

A fixed bottom net was used to study the relationship between the horizontal and vertical density distribution of polychaete and cirripede larvae over an inshore rock platform.

Strong horizontal density distributions were obtained close to the bottom in many species from both groups, while the vertical samples showed larvae to be distributed towards the bottom both during the day and at night. It is suggested that the concentration of larvae within the slow-moving bottom water was responsible for the observed limited lateral larval dispersal.

The results are discussed in relation to their bearing upon a number of problems within the field of meroplanktonic ecology.
Presidential Address: The Peoples of Britain and Ireland, 1100–1400: IV Language and Historical Mythology
Authors: Davies R. R.
Published: May 2009

Sincethe beginning of the nineteenth century language has come to occupy a prominent place, often a provocative and intolerant one, in the ideology and rhetoric of nations. ‘Every people (Volk)’, so Herder asserted, ‘has its own language as it has its own culture (Bildung).’ Bishop Stubbs spoke with equal certainty, if only to vindicate the Germanic character of the English people and to clear it of the charge of being infected with Roman or Celtic traits. Language, he pronounced roundly, is ‘the nearest approach to a perfect test of national extraction’. It is a sentiment whose certainty and content would command almost no historical support today. We are much more likely to agree with Eric Hobsbawm's opinion that ‘language was merely one, and not necessarily the primary, way of distinguishing between cultural communities’.
Presidential Address
Authors: Firth C. H.
Published: May 2009

When I remembered that I had to address the Society to-day I thought at first of choosing some subject remote from the troubles of the moment, something analogous to my former addresses on the development of historical studies in England. But it was not possible to do so. The events which are in progress now have too absorbing an interest to permit us to abstract ourselves from them, for which of us is not in some way or other intimately affected by them? Besides that, these events have for any historian not merely the interest which all of us share, but an interest of a very special kind. The historian sees in action before his eyes the abstractions he has been reading about in books all his life: the struggle of races, the conflict of opposing ideas, the operation of economic laws, the development of historical tendencies, and perceives what these phrases really mean when they are translated into facts. There has been no such open conflict of ideals since the wars of the French Revolution. There has been no such huge conflict of races since the time when the Teutonic peoples moved westward to overthrow Roman civilisation and plant their own in its place. One of Milton's similes for the Satanic host pictures their coming:

‘A multitude like which the populous North Poured never from her frozen loins to pass Rhene or the Danaw, when her barbarous sons Came like a deluge on the South, and spread Beneath Gibraltar to the Libyan sands.’
Cryptosporidiosis from a community swimming pool: outbreak investigation and follow-up study
Authors: BOEHMER T. K. , ALDEN N. B. , GHOSH T. S. , VOGT R. L.
Published: May 2009

Tri-County Health Department investigated an outbreak of cryptosporidiosis linked to a community swimming pool. A cohort study was conducted in 37 persons who were invited to the pool party; 12 (57%) of 21 attendees had primary cryptosporidiosis infection. Risk factors for illness included swimming, getting water in mouth, and swallowing water. The pool met chlorination guidelines and used UV light irradiation, a supplemental disinfection technology that inactivatesCryptosporidium. A follow-up survey of the cohort was completed 7–8 weeks after the pool party; four (25%) of 16 non-attendees had secondary cryptosporidiosis infection. The median duration of illness, including patients with recurring symptoms, was 26 days. Clinical response rate to nitazoxanide, a therapeutic agent, was 67%. This study is unique because it describes a cryptosporidiosis outbreak from a well-maintained community swimming pool using supplemental disinfection. It also reports information on disease burden and treatment response.
n-3 Fatty acid intake from marine food products among Quebecers: comparison to worldwide recommendations
Authors: Lucas Michel , Asselin Geneviève , Plourde Mélanie , Cunnane Stephen C , Dewailly Éric , Dodin Sylvie
Published: May 2009

Objective

To quantify marine food product consumption and EPA + DHA intake among Quebecers, and to compare the results with the most recent recommendations.

Design

Data were obtained from a representative cross-sectional telephone survey (June 2006). Intakes of marine food product species and EPA + DHA were estimated from a validated FFQ on the consumption of marine food products during the previous month. Prevalence of fish oil consumption in the last 6 months was also assessed.

Setting

Province of Quebec (Canada).

Subjects

A representative sample (n 1001) of adults in the province of Quebec. Of these, eight were excluded from the present analysis (n 993).

Results

Mean and median EPA + DHA intakes for all participants were estimated to be 291 mg/d (sem 11) and 207 mg/d, respectively. 85·0 % (95 % CI 82·7, 87·3) of Quebecers had an EPA + DHA intake lower than 500 mg/d, which is the amount internationally recommended for the prevention of CVD. Mean and median DHA intakes among women of childbearing age (n 128, 18–34 years) were estimated to be 169 mg/d (sem 17) and 126 mg/d, respectively. Of these women, 27·7 % had a daily intake >200 mg DHA and 15·9 % had an intake >300 mg DHA. We noted that 13 % of Quebecers take ≥1 capsule of fish oil/d.

Conclusions

Consumption of marine food products and EPA + DHA among Quebecers clearly appears to be lower than international recommendations. Since EPA + DHA confer health benefits and may reduce health costs, strategies to increase their consumption should be implemented to improve public health in Quebec.
Workforce gender, company size and corporate financial support are predictors of availability of healthy meals in Danish worksite canteens
Authors: Thorsen Anne Vibeke , Lassen Anne Dahl , Andersen Jens Strodl , Mikkelsen Bent Egberg
Published: May 2009

Objective

Environmental strategies at worksites may help consumers change dietary behaviour towards a more healthy diet. The present study aimed to evaluate the availability of healthy meal options at Danish worksite canteens and to identify predictors of worksite canteens providing healthy meals.

Design

A self-administered questionnaire was randomly mailed to 1967 worksite canteen managers. Besides information and characteristics about the canteen and the worksite, the canteen managers specified the menus available. Two different health groups (Healthy and Less Healthy) were defined in three different meal categories (Sandwiches, Hot meals and Salads) as well as a combined category (Combined) combining all the three meal categories. The characteristics of the worksites were compared with regard to the different health groups.

Setting

Randomly selected Danish worksite canteens.

Subjects

553 Danish worksite canteen managers replied, resulting in a response rate of 29 %.

Results

Only 12 % of the canteens applied to the Healthy group combining all the three meal categories. In particular, worksites with more than 75 % female employees served healthy menus on a frequent basis. The size of the worksite was positively correlated with more healthy meal options. Furthermore, the present study suggests a positive relationship between corporate financial support and the availability of healthy meal options.

Conclusions

Among the selected variables studied, workforce gender, company size and corporate financial support were significant predictors of the availability of healthy meal options in worksite canteens. More research is needed on the role that variance in organisation environment plays for the potential of worksite intervention, to make a difference in terms of healthy eating.
Behavioral modeling and linearization of a millimeter-wave power amplifier
Authors: Melczarsky Ilan , Gilabert Pere L. , Di Giacomo Valeria , Bertran Eduard , Filicori Fabio
Published: May 2009

The use of digital predistortion for linearizing a millimeter-wave power amplifier (PA) is investigated. A PA operating at 38 GHz is designed using an accurate non-quasi-static transistor model, taking into account both short- and long-term memory effects. A realistic test signal is then used for the identification of a nonlinear auto-regressive moving average (NARMA) behavioral model of the PA. The NARMA-based digital predistorter is then derived and formulated in terms of basic predistortion cells, especially suitable for efficient implementation in an FPGA. The performance of the predistortion solution is preliminarily assessed by means of computer simulations.
GaN devices for power amplifier design
Authors: Martín-Guerrero Teresa M. , Ducatteau Damien , Camacho-Peñalosa Carlos , Gaquière Christophe
Published: May 2009

This paper describes some aspects of the fabrication and modeling of a GaN device to be employed in a power amplifier covering one WiMAX frequency band. The work has been carried out in the frame of the TARGET's NoE work package WiSELPAS. Details concerning the AlGaN/GaN device technology and the performed linear and nonlinear measurements are provided. Since these new devices require specific nonlinear models, a procedure for selecting an appropriate simplified nonlinear model and for extracting its parameters is discussed and evaluated. The developed nonlinear model has been experimentally tested under linear and nonlinear conditions. The agreement between experimental and model-predicted performance suggests that the described model could be useful in a preliminary power amplifier design.
Clay fabric intensity in natural and artificial fault gouges: Implications for brittle fault zone processes and sedimentary basin clay fabric evolution
Authors: Haines Samuel H. , van der Pluijm Ben A. , Ikari Matt J. , Saffer Demian M. , Marone Chris
Published: May 2009

The role of phyllosilicate fabrics in fault gouge is a poorly understood component of the mechanical and hydrologic behavior of brittle fault zones. We present 90 fabric intensity measurements using X‐ray texture goniometry on 22 natural clay‐rich fault gouges from low‐angle detachment faults (Death Valley area detachments, California; Ruby Mountains, Nevada; West Salton Detachment Fault, California) and the Peramola thrust in NE Spain. Natural fault gouges have uniformly weak clay fabrics (multiples of a random distribution (MRD) = 1.7–4.5, average MRD = 2.6) when compared to phyllosilicate‐rich rocks found in other geologic settings. Clay fabric intensities in natural gouges do not vary significantly either as a function of tectonic environment or of dominant clay mineralogy in the gouge. We compare these natural samples with 69 phyllosilicate fabric intensities measured in laboratory experiments on synthetic clay‐quartz mixtures. Clay fabric intensities from laboratory samples are similar to those in natural gouges (MRD = 1.7–4.6), but increase systematically with increasing shear strain and normal stress. Total phyllosilicate content does not significantly affect clay fabric intensity. Shear strain is important for developing stronger fabrics; samples subjected solely to compression exhibit uniformly weak fabrics (MRD = 1.6–1.8) even when compressed at high normal stresses (150 MPa). The weak fabrics found in natural fault gouge indicate that if anisotropic and overall low fault zone permeability allow elevated pore fluid pressures and fault weakening, this anisotropy must be a transient feature that is not preserved. Our data also reinforce the idea that clay fabric development in sedimentary rocks is primarily a function of authigenic mineral growth and not of compaction‐induced particle rotation.
Numerical convergence of viscous‐plastic sea ice models
Authors: Lemieux Jean‐François , Tremblay Bruno
Published: May 2009

We investigate the convergence properties of the nonlinear solver used in viscous‐plastic (VP) sea ice models. More specifically, we study the nonlinear solver that is based on an implicit solution of the linearized system of equations and an outer loop (OL) iteration (or pseudo time steps). When the time step is comparable to the forcing time scale, a small number of OL iterations leads to errors in the simulated velocity field that are of the same order of magnitude as the mean drift. The slow convergence is an issue at all spatial resolution but is more severe as the grid is refined. The metrics used by the sea ice modeling community to assess convergence are misleading. Indeed, when performing 10 OL iterations with a 6 h time step, the average kinetic energy of the pack is always within 2% of the fully converged value. However, the errors on the drift are of the same order of magnitude as the mean drift. Also, while 40 OL iterations provide a VP solution (with stress states inside or on the yield curve), large parts of the domain are characterized by errors of 0.5–1.0 cm s−1. The largest errors are localized in regions of large sea ice deformations where strong ice interactions are present. To resolve those deformations accurately, we find that more than 100 OL iterations are required. To obtain a continuously differentiable momentum equation, we replace the formulation of the viscous coefficients with capping with a tangent hyperbolic function. This reduces the number of OL iterations required to reach a certain residual norm by a factor of ∼2.
Tension infiltrometer enhancements with automated pneumatic control and more durable base plate
Authors: Selker J. S. , Suter J. D. , Cuenca R. H. , Flugstad B. A. , Kelly S. F.
Published: May 2009

Measurement of soil hydraulic retention and conduction parameters using tension infiltrometers has been found to be useful but has suffered from unreliable instrument membranes at the soil interface and the need for manual control, which limits the range of boundary conditions that can feasibly be established. An automated design is presented that is capable of maintaining time‐varying pressure and flux using high‐speed computer‐regulated pneumatic valves. Further, a durable stainless steel supply membrane designed to withstand multiple uses under harsh field conditions with bubbling pressure head <−0.60 m H2O is demonstrated.
Remote sensing lower thermosphere wind profiles using non‐specular meteor echoes
Authors: Oppenheim Meers M. , Sugar Glenn , Slowey Nicholas O. , Bass Elizabeth , Chau Jorge L. , Close Sigrid
Published: May 2009

This article describes a new method of measuring wind velocity profiles between 93 km and 110 km altitude by tracking non‐specular meteor echoes as neutral winds transport the plasma trails. This requires a large VHF radar with interferometric capability able to point nearly perpendicular to the geomagnetic field. A small data sample from the Jicamarca Radio Observatory allows the measurement of horizontal wind speeds and directions with a range resolution of a few hundred meters. These observations show speeds reaching 150 m/s and sometimes changing by as much as 100 m/s over a 6 km altitude range. At the best times, these measurements can be made with only a few minutes of data. With some refinement of the data collection and analysis techniques, this technique should produce high resolution images of lower thermospheric winds as they change in both altitude and time.
Examination of cathode emission area variation with applied electric field
Authors: He Xin , Scharer John , Booske John , Sule Nishant , Sengele Sean
Published: May 2009

A recently published field emission cathode parameter extraction method [X. He et al., J. Appl. Phys. 102, 056107 (2007)] provides unambiguous and reliable cathode parameters. The method utilizes a transfer matrix method (TMM) to solve a one-dimensional model that includes both thermionic and field electron emission. However, there are modest differences between our TMM simulation results and experimental data near the transition point between thermal-dominated and field-dominated electron emission. We hypothesize that this discrepancy is due a dependence of effective emitting area with applied electric field. Incorporating surface field enhancement factors and emission area variations that are physically intuitive as the applied field is varied within our TMM simulation, we obtain much better agreement with the experimental data. This result supports the hypothesis that the effective emission area varies as a function of the applied electric field between the A-K (anode-cathode) gap.
Rapid thermal annealing effect on amorphous hydrocarbon film deposited by CH4/Ar dielectric barrier discharge plasma on Si wafer: Surface morphology and chemical evaluation
Authors: Majumdar Abhijit , Bhattacharayya S. R. , Hippler Rainer
Published: May 2009

The effects of rapid thermal annealing (RTA) on amorphous hydrogenated carbon-coated film on Si wafer, deposited by CH4/Ar dielectric barrier discharge plasma (at half of the atmospheric pressure), was examined. Bubbles-like structures were formed on the surface of the deposited carbon-coated film. The surface morphology studied by scanning electron microscopy (SEM), which showed that the effect of RTA on the film changing the morphological property drastically at 600 °C and most of the bubbles started evaporating above 200 °C. The inbuilt energy dispersive x-ray in SEM gives the quantitative analysis of the annealed surface. X-ray photoelectron spectroscopy results of the as-deposited films agree with the IR results in that the percent of Si–CH3, Si–O–Si and C–O(H) stretching vibrational band in the film. Most of these bands disappeared as the sample was annealed at 600 °C in Ar medium.
Effects of anisotropic elasticity on stress concentration in micro mechanical structures fabricated on (001) single-crystal silicon films
Authors: Ikehara Tsuyoshi , Tsuchiya Toshiyuki
Published: May 2009

Anisotropy in the elastic properties of single-crystal materials is often neglected when designing microelectromechanical systems (MEMS) made of single-crystal silicon. In this report, the effects of anisotropic elasticity in single-crystal silicon on the stress concentration were analyzed and compared to isotropic simulation results. Semicircular notched beams, quarter-circle curved beams, and notched curved beams were analyzed using two-dimensional finite element method structural simulation. Two different material configurations on the (001) plane and isotropic material constants were compared for each model to clarify the anisotropy effects. The stress concentration factor of a circular notch was modified from the isotropic estimation by 7%–9% with the introduction of the anisotropic effect and became crystal-orientation dependent. Both the peak stress and stress distribution were dependent on the model configuration against the crystal axis. The results for other models were explicitly explained also by the rotation of the principal stress axis around the curved surface. A simple estimation method to select crystal orientation was proposed to minimize or maximize the stress concentration factor using elastic anisotropy. These findings will be useful for reducing the peak stress in MEMS structures and improving their reliability.
Phase transitions in Josephson junction arrays in a weak magnetic field
Authors: Chen Qing-Hu , Liu Huan , Lv Jian-Ping
Published: May 2009

Based on the resistively shunted junction dynamics, we numerically investigate the superconducting phase transitions of two-dimensional Josephson junction arrays exposed to a dilute external field with the magnetic flux density f=1/25. Dynamic scaling analysis of current-voltage characteristics shows that a Kosterlitz–Thouless–Berezinskii (KTB) phase transition occurs at a finite temperature in the absence of disorder. When the disorder is introduced into the bond, the phase transition would be driven into a non-KTB type, where a possible glass transition is suggested. The effects of the bond disorder on the critical temperature and critical exponents are also discussed. The further experimental works to realize well known KTB and glass transitions in Josephson junction arrays are clearly called for.
Converse piezoelectric effect on the electron tunneling across a multiferroic junction
Authors: Wang Jian , Ju Sheng , Li Z. Y.
Published: May 2009

Converse piezoelectric effect on the electron tunneling across a tunnel junction with a multiferroic barrier is investigated theoretically. It is found that the spin filtering, tunnel magnetoresistance (TMR), and tunnel electroresistance (TER) are enhanced (reduced) due to the presence of the strain in the barrier when the electrical polarization is oriented antiparallel (parallel) to the applied field. The TMR and TER can even increase with the increasing applied voltage when the converse piezoelectric effect is very strong in the barrier, which is totally different from the voltage dependence in the junction with the barrier without piezoelectric effect.
Ishimori-I equation with self-consistent sources
Authors: Hu Juan , Hu Xing-Biao , Tam Hon-Wah
Published: May 2009

In this paper, Grammian solutions of the Ishimori-I (Ish-I) equation are first obtained by Hirota’s direct method. Utilizing the source generation procedure, this equation with self-consistent sources is then presented and the corresponding Grammian solutions are derived. Finally, as a simple case, the (1,1) dromion solution is examined.
Catastrophic optical mirror damage in diode lasers monitored during single-pulse operation
Authors: Ziegler Mathias , Tomm Jens W. , Reeber David , Elsaesser Thomas , Zeimer Ute , Larsen Henning E. , Petersen Paul M. , Andersen Peter E.
Published: May 2009

Catastrophic optical mirror damage (COMD) is analyzed for 808 nm emitting diode lasers in single-pulse operation in order to separate facet degradation from subsequent degradation processes. During each pulse, nearfield and thermal images are monitored. A temporal resolution better than 7 μs is achieved. The thermal runaway process is unambiguously related to the occurrence of a “thermal flash.” A one-by-one correlation between nearfield, thermal flash, thermal runaway, and structural damage is observed. The single-pulse excitation technique allows for controlling the propagation of the structural damage into the cavity. We propose this technique for the analysis of early stages of COMD.
Effect of boiling water, seed coat structure and provenance on the germination of Acacia melanoxylon seeds
Authors: Burrows Geoffrey E. , Virgona James M. , Heady Roger D.
Published: May 2009

Acacia melanoxylon (Mimosoideae or Mimosaceae) is a high quality timber tree with an extensive natural distribution in Australia and a wide genetic and phenotypic diversity. Seeds from three widely differing provenances in Tasmania were tested to determine whether they had different responses to various dormancy-breaking treatments. All provenances had limited germination (<11%) if seeds were untreated and between 85% and 91% germination after 40 days if the seeds were nicked. For all provenances short (≤60 s) exposure to boiling water gave high germination percentages. These values were generally lower, although usually not significantly so, than the germination percentages following nicking. Germination percentages decreased with increasing time of exposure to boiling water, although one provenance had a significantly greater tolerance to one of the longer (20 min) treatments. Nicked seeds germinated quickly and uniformly, whereas those subjected to the boiling-water treatments germinated after a longer period and more gradually. In untreated seeds, the lens was a low, elliptically shaped dome (~110–135 µm wide, 140–190 µm long). In more than 99% of the seeds examined, the structure of the lens was markedly altered after a 10-s exposure to boiling water. A wide diversity of altered lens structure was found, from a circular hole between the macrosclereids, to a short fissure where the macrosclereids did not separate to their bases. Nicked seeds had a 200–375 times greater area for water uptake than a fully disrupted lens and this was probably the principal reason why the nicked seeds germinated sooner and more rapidly.
Comment: Hypocotyl hairs: an historical perspective
Authors: Parsons R. F.
Published: May 2009

The presence of distinctive hypocotyl hairs on young seedlings of some species has been known for some time, although largely ignored. A recent paper (Robinson et al. 2008) suggests that they may be of great ecological significance in the Australian shrub Melaleuca ericifolia. There is a scattered and little-known literature on this topic going back at least as far as 1904. Here, I provide an overview of that literature. The 21 families and 55 genera of flowering plants in which hypocotyl hairs have been recorded are tabulated. The life forms involved range from annual herbs to shrubs and trees and the habitats from marine to freshwater wetlands to fully terrestrial habitats, including those in semiarid areas. The functions attributed to hypocotyl hairs include anchoring seedlings to the substrate, facilitating the development of geotropism and water uptake until the root hairs develop.
Short Communication. A robust method for chromosome quantification and ploidy determination in woody species
Authors: Gamage Harshi K. , Schmidt Susanne
Published: May 2009

Accurate determination of ploidy level of putative polyploid plants is essential for tree breeding and other applications. Methods for ploidy determination include quantification of chromosome numbers in root-tip cells via light microscopy and indirect assessment via anatomical and morphological traits. Flow cytometry is potentially a high-throughput method to quantify nuclear DNA content; however, it does not allow determining chromosome numbers and interfering compounds often prevent its use. Microscopy-based quantification of chromosomes in active root-tip cells remains the most unambiguous method for ploidy determination, although root tips are difficult to obtain from field-grown plants, and light microscopy can result in insufficient resolution in species with many and small chromosomes. Here, we present a robust technique that uses 2, 4-diamidino-2-phenylindole (DAPI) dye and 1000-fold magnification fluorescence microscopy for quantification of chromosomes in root and shoot tips of woody angiosperms and gymnosperms, and overcomes the reported difficulties. Rather than the conventional tip squashing, spreading tips on glass slides resulted in very good chromosome separation in diverse species, with up to 56 chromosomes and a chromosome size of 2–20 μm. Chromosome counts were performed in diploid Agathis robusta, Elaeocarpus angustifolius, Eucalyptus robusta, Paulownia tomentosa, Pongamia pinnata and Toona ciliata, and di- and tetraploid Acacia crassicarpa and Citrus species.
The activation-induced cytidine deaminase (AID) efficiently targets DNA in nucleosomes but only during transcription
Authors: Shen Hong Ming , Poirier Michael G. , Allen Michael J. , North Justin , Lal Ratnesh , Widom Jonathan , Storb Ursula
Published: May 2009

The activation-induced cytidine deaminase (AID) initiates somatic hypermutation, class-switch recombination, and gene conversion of immunoglobulin genes. In vitro, AID has been shown to target single-stranded DNA, relaxed double-stranded DNA, when transcribed, or supercoiled DNA. To simulate the in vivo situation more closely, we have introduced two copies of a nucleosome positioning sequence, MP2, into a supercoiled AID target plasmid to determine where around the positioned nucleosomes (in the vicinity of an ampicillin resistance gene) cytidine deaminations occur in the absence or presence of transcription. We found that without transcription nucleosomes prevented cytidine deamination by AID. However, with transcription AID readily accessed DNA in nucleosomes on both DNA strands. The experiments also showed that AID targeting any DNA molecule was the limiting step, and they support the conclusion that once targeted to DNA, AID acts processively in naked DNA and DNA organized within transcribed nucleosomes.
T follicular helper cells differentiate from Th2 cells in response to helminth antigens
Authors: Zaretsky Arielle Glatman , Taylor Justin J. , King Irah L. , Marshall Fraser A. , Mohrs Markus , Pearce Edward J.
Published: May 2009

The relationship of T follicular helper (TFH) cells to other T helper (Th) subsets is controversial. We find that after helminth infection, or immunization with helminth antigens, reactive lymphoid organs of 4get IL-4/GFP reporter mice contain populations of IL-4/GFP-expressing CD4+ T cells that display the TFH markers CXCR5, PD-1, and ICOS. These TFH cells express the canonical TFH markers BCL6 and IL-21, but also GATA3, the master regulator of Th2 cell differentiation. Consistent with a relationship between Th2 and TFH cells, IL-4 protein production, reported by expression of huCD2 in IL-4 dual reporter (4get/KN2) mice, was a robust marker of TFH cells in LNs responding to helminth antigens. Moreover, the majority of huCD2/IL-4–producing Th cells were found within B cell follicles, consistent with their definition as TFH cells. TFH cell development after immunization failed to occur in mice lacking B cells or CD154. The relationship of TFH cells to the Th2 lineage was confirmed when TFH cells were found to develop from CXCR5− PD-1− IL-4/GFP+ CD4+ T cells after their transfer into naive mice and antigen challenge in vivo.
IL-4–producing CD4+ T cells in reactive lymph nodes during helminth infection are T follicular helper cells
Authors: King Irah L. , Mohrs Markus
Published: May 2009

Interleukin (IL)-4 is the quintessential T helper type 2 (Th2) cytokine produced by CD4+ T cells in response to helminth infection. IL-4 not only promotes the differentiation of Th2 cells but is also critical for immunoglobulin (Ig) G1 and IgE isotype-switched antibody responses. Despite the IL-4–mediated link between Th2 cells and B lymphocytes, the location of IL-4–producing T cells in the lymph nodes is currently unclear. Using IL-4 dual reporter mice, we examined the Th2 response and IL-4 production in the draining mesenteric lymph nodes during infection with the enteric nematode Heligmosomoides polygyrus. We show that although IL-4–competent Th2 cells are found throughout the B and T cell areas, IL-4–producing Th2 cells are restricted to the B cell follicles and associate with germinal centers. Consistent with their localization, IL-4 producers express high levels of CXCR5, ICOS, PD-1, IL-21, and BCL-6, a phenotype characteristic of T follicular helper (Tfh) cells. Although IL-4 was dispensable for the generation of Th2 and Tfh cells, its deletion resulted in defective B cell expansion and maturation. Our report reveals the compartmentalization of Th2 priming and IL-4 production in the lymph nodes during infection, and identifies Tfh cells as the dominant source of IL-4 in vivo.
TNFAIP3 (A20) is a tumor suppressor gene in Hodgkin lymphoma and primary mediastinal B cell lymphoma
Authors: Schmitz Roland , Hansmann Martin-Leo , Bohle Verena , Martin-Subero Jose Ignacio , Hartmann Sylvia , Mechtersheimer Gunhild , Klapper Wolfram , Vater Inga , Giefing Maciej , Gesk Stefan , Stanelle Jens , Siebert Reiner , Küppers Ralf
Published: May 2009

Proliferation and survival of Hodgkin and Reed/Sternberg (HRS) cells, the malignant cells of classical Hodgkin lymphoma (cHL), are dependent on constitutive activation of nuclear factor κB (NF-κB). NF-κB activation through various stimuli is negatively regulated by the zinc finger protein A20. To determine whether A20 contributes to the pathogenesis of cHL, we sequenced TNFAIP3, encoding A20, in HL cell lines and laser-microdissected HRS cells from cHL biopsies. We detected somatic mutations in 16 out of 36 cHLs (44%), including missense mutations in 2 out of 16 Epstein-Barr virus–positive (EBV+) cHLs and a missense mutation, nonsense mutations, and frameshift-causing insertions or deletions in 14 out of 20 EBV− cHLs. In most mutated cases, both TNFAIP3 alleles were inactivated, including frequent chromosomal deletions of TNFAIP3. Reconstitution of wild-type TNFAIP3 in A20-deficient cHL cell lines revealed a significant decrease in transcripts of selected NF-κB target genes and caused cytotoxicity. Extending the mutation analysis to primary mediastinal B cell lymphoma (PMBL), another lymphoma with constitutive NF-κB activity, revealed destructive mutations in 5 out of 14 PMBLs (36%). This report identifies TNFAIP3 (A20), a key regulator of NF-κB activity, as a novel tumor suppressor gene in cHL and PMBL. The significantly higher frequency of TNFAIP3 mutations in EBV− than EBV+ cHL suggests complementing functions of TNFAIP3 inactivation and EBV infection in cHL pathogenesis.