bluuebunny/crossref_metadata_2025 huggingface dataset:
The selective α1adrenoceptor antagonist HEAT reduces L‐DOPA‐induced dyskinesia in a rat model of Parkinson's disease
Authors: Buck Kerstin , Ferger Boris
Published: October 2009

In Parkinson's disease (PD), the long term use of L‐DOPA results in major adverse effects including dyskinesia or abnormal involuntary movements. The present study focuses on the effect of the selective α1adrenoceptor antagonist HEAT (2‐[[β‐(‐4‐hydroxyphenyl)ethyl]aminomethyl]‐1‐tetralone) in the 6‐hydroxydopamine rat model of L‐DOPA‐induced dyskinesia. We demonstrate that the selective α1adrenoceptor antagonist HEAT (1 and 2 mg kg−1), the α2adrenoceptor antagonist idazoxan (9 mg kg−1), and the nonselective β1/β2adrenoceptor antagonist propranolol (20 mg kg−1) alleviate dyskinetic movements induced by L‐DOPA. Furthermore, the adrenoceptor antagonists at the doses used did not influence exploratory behavior in the open field system indicating that the antidyskinetic effect is not due to a reduction in general motor activity. Intrastriatal administration of the selective α1adrenoceptor agonist cirazoline via reverse in vivo microdialysis did not induce dyskinesia. Additionally, we measured plasma, brain, and CSF levels of HEAT. HEAT is a CNS active compound with a brain/plasma and CSF/plasma ratio of 4.29 and 0.15, respectively, which is appropriate for the investigation of α1‐mediated mechanisms in CNS disorders. In conclusion, these results demonstrated for the first time that a α1adrenoceptor antagonist reduced L‐DOPA‐induced dyskinesia in a rat model. Further studies assessing the risk benefit in comparison to existing therapies are needed before considering α1adrenoceptor antagonists as a target for the development of new antidyskinetic compounds. Synapse 64:117–126, 2010. © 2009 Wiley‐Liss, Inc.
Postnatal binge‐like alcohol exposure decreases dendritic complexity while increasing the density of mature spines in mPFC Layer II/III pyramidal neurons
Authors: Hamilton Gillian F. , Whitcher Lee T. , Klintsova Anna Y.
Published: October 2009

Prenatal exposure to alcohol in humans can result in a wide range of deficits collectively referred to as fetal alcohol spectrum disorders. Of these deficits, cognitive impairments are among the most debilitating and long‐lasting. Specifically, cognitive impairments in executive functioning suggest damage to the prefrontal cortex (PFC). Several external stimuli, such as morphine, chronic stress, and maternal stress have been found to alter the dendritic structure of cells within the PFC. In this study, three groups of rat pups were used: intubated with alcohol (5.25 g/kg/day; AE), sham intubated (SI), or suckle controls (SC) on PD 4–9. On PD 26–30 rats were anesthetized, perfused with saline and brains were processed for Golgi‐Cox staining. Basilar dendritic complexity, spine density, and spine phenotypes were evaluated for Layer II/III neurons in the medial PFC. Results indicate that AE rats have an altered basilar dendritic complexity due to a significant decrease in both length and number of intersections in proximity to the neuronal soma. Furthermore, spine density patterns of basilar dendrites remain unchanged while the density of mature vs. immature spines significantly changes. These effects were not seen in the apical dendrites, indicating alcohol's influence on different neuronal parts in a single cell. In addition, these results suggest that the innervations of the soma and basilar dendrites by thalamic projections may play a role. Thus, our data demonstrates that postnatal exposure to alcohol produces changes in the neuronal organization of rat adolescent PFC that may affect the performance on prefrontal‐dependant behavioral tasks. Synapse 64:127–135, 2010. © 2009 Wiley‐Liss, Inc.
“Paraduodenal” Pancreatitis: Results of Surgery on 58 Consecutives Patients from a Single Institution
Authors: Casetti L. , Bassi C. , Salvia R. , Butturini G. , Graziani R. , Falconi M. , Frulloni L. , Crippa S. , Zamboni G. , Pederzoli P.
Published: October 2009

Background

Cystic dystrophy of heterotopic pancreas, groove pancreatitis, pancreatic hamartoma of the duodenum, paraduodenal wall cyst, and myoadenomatosis are all terms grouped together, from a pathological viewpoint, as definitions of paraduodenal pancreatitis (PP). The objective of the present study was to investigate the clinical characteristics, therapeutic strategies, and results in 58 patients undergoing pancreatic resection for PP.

Methods

From January 1990 to December 2006 data were prospectively collected on 58 patients who were diagnosed with PP who then underwent pancreaticoduodenectomy.

Results

In this patient cohort the median age was 44.7 years; only 4 patients were women, and only 3 had non‐drinker and/or non smoker habits. The overall morbidity was 18.9%, and the median hospitalization was 11 days. There were no postoperative deaths. In a median follow‐up of 96.3 months, all patients noted a decrease in the pain associated with PP; 35 patients (76%) had complete disappearance of pain, whereas occasional relapsing pain occurred in the remaining 11 (24%).

Conclusions

Patients with PP have clinical characteristics similar to those of chronic pancreatitis. The diagnostic imaging modalities of choice are ultrasonographic endoscopy and magnetic resonance cholangiopancreaticography. Based on our surgical experience, pancreaticoduodenectomy seems to be a reasonable choice of treatment in patients with PP.
Magnetic resonance imaging of hepatocellular carcinoma: a pictorial review of novel insights into pathophysiological features revealed by magnetic resonance imaging
Authors: Shimofusa Ryota , Ueda Takuya , Kishimoto Takashi , Nakajima Masayuki , Yoshikawa Masaharu , Kondo Fukuo , Ito Hisao
Published: October 2009

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Magnetic resonance (MR) imaging is one of the most powerful modalities for the assessment of HCC with sufficient sensitivity and specificity. In addition to its capacity for lesion detection, MR imaging delineates some unique in vivo pathophysiological features of tumors, which cannot be assessed by other modalities. Chemical shift imaging may depict steatosis of the tumor. Dynamic contrast‐enhanced MR imaging is the most powerful tool to assess the vascularity of the tumor, which is closely related to malignant transformation in hepatocarcinogenesis. Diffusion‐weighted imaging illustrates the cellularity of the tumor. Super‐paramagnetic iron oxide, a liver‐specific MR contrast agent accumulating in Kupffer cells, enables detection of the hepatocellular architecture in the lesion. Recently, a new liver‐specific MR contrast agent, gadoxetic acid [gadolinium‐ethoxybenzyl (Gd‐EOB)‐diethylenetriaminopentoacetic acid (DTPA)], has been introduced for clinical imaging. Gd‐EOB‐DTPA has a significant impact on the imaging of HCC, with potential capacity for the concurrent assessment of vascularity of the tumor and hepatocellular‐specific properties within the tumor. Understanding the characteristics of MR imaging methods and contrast agents is essential for the optimal diagnosis and characterization of HCCs.
Combined effect of ENSO and SAM on the population dynamics of the invasive yellowjacket wasp in central Chile
Authors: Estay Sergio A. , Lima Mauricio
Published: October 2009

The population dynamics of the yellowjacket wasp (Vespula germanica Fabricus) in central Chile were analyzed for the first time. Using a simple Ricker logistic model and adding the effects of local weather variables (temperature and precipitation) and large‐scale climate phenomena as El Niño Southern Oscillation (ENSO) and the Southern Annular Mode (SAM), we modeled the interannual fluctuations in nest density. The best model according to the Bayesian information criterion (BIC) included 1‐year‐lag negative feedback combined with the positive additive effects of ENSO and SAM. According to this model, yellowjacket nest density was favored by warm and dry winters, which probably influenced the survival of overwintering queens. Large‐scale climatic variables [Southern Oscillation Index (SOI) and SAM] described the effect of exogenous factors in wasp fluctuations better than local weather variables did. Our results emphasize the usefulness of climate indices and simple theoretical‐based models in insect ecological research.
A Prospective Audit of Postoperative Pain Control in Pediatric Patients
Authors: Trudeau Jacqueline D. , Lamb Elizabeth , Gowans Margot , Lauder Gillian
Published: October 2009

Pain is a subjective experience that is affected by physical, emotional, and psychological factors, and reliable assessment of pain can be a challenge in the pediatric population.

A quality improvement project was conducted at one Canadian health care facility to examine the effectiveness of the postoperative pain management strategy for children admitted to the postanesthesia care unit (PACU).

Effective control of postoperative pain involves several preventive strategies that include preoperative analgesia, appropriate use of intraoperative analgesic techniques, and identification of children at risk for significant postoperative pain. Successful implementation of these techniques requires a multidisciplinary team approach involving the patient, the PACU nurses, the anesthesia care provider, and other surgical team members. AORN J 90 (October 2009) 531–542. © AORN, Inc, 2009.
Using a Collaborative Child Life Approach for Continuous Surgical Preparation
Authors: Sorensen Hayley L. , Card Carrie A. , Malley Mary T. , Strzelecki Jessica M.
Published: October 2009

Child life specialists in surgical and perioperative programs use a systematic approach to provide continuous preparation for pediatric surgical patients.

Within the context of family‐centered care, all staff members share in the ongoing responsibility of minimizing stress and maximizing effective coping for children and their parents or caregivers. Multidisciplinary collaboration increases positive outcomes for pediatric patients and their families.

Detailed descriptions of the procedures used at Children's Hospital Boston and a case study are discussed to exemplify the coping benefits of using a collaborative child life approach to provide continuous preparation for surgical patients. AORN J 90 (October 2009) 557–566. © AORN, Inc, 2009.
Effect of supplementing a fibre basal diet with different nitrogen forms on ruminal fermentation and microbial growth in an in vitro semi-continuous culture system (RUSITEC)
Authors: Carro M. D. , Miller E. L.
Published: October 2009

Incubation trials were carried out with the rumen simulation technique (RUSITEC) to study the effects of four forms of N on the growth of ruminal micro-organisms and the fermentation variables when an all-fibre basal diet was incubated. The basal diet consisted of 10 g neutral-detergent fibre (NDF) from grass hay plus 2 g NDF from sugarbeet pulp. N forms were isolated soyabean protein, soyabean peptides, amino acids blended to profile soyabean protein and NH3 as NH4Cl. Half of the daily N supply was infused as NH4Cl and the other half was infused as each of the four treatments described. Non-NH3 N (NAN) forms increased NDF (P = 0·006), acid-detergent fibre (P = 0·003) and cellulose (P = 0·015) disappearance after 48 h incubation, CO2 (P < 0·001), CH4 (P = 0·002) and total volatile fatty acids production (P < 0·001), as well as the molar percentages of isobutyrate, isovalerate and valerate, which reflected the fermentation of amino acid C skeletons. NAN treatments also increased microbial N flow (P < 0·001) compared with NH3, with peptides and protein supporting more (P = 0·036) than amino acids. The proportion of microbial N derived from NH3 decreased successively (P < 0·05) with NH3 > amino acids > peptides > protein treatments, indicating preferential uptake of peptides without passage through the NH3 pool. Microbial efficiency (g microbial N/kg organic matter apparent disappearance) was greater (P = 0·002) for the NAN forms than for the NH3 treatment, with peptides and protein treatments supporting higher (P = 0·009) values than amino acid treatment. These results indicate that N forms other than NH3 are required for optimal fibre digestion and microbial growth.
Tentacular ultrastructure and feeding behaviour ofNeopentadactyla mixta(Holothuroidea: Dendrochirota)
Authors: Smith Timothy B.
Published: October 2009

Suspension-feeding in the holothurianNeopentadactyla mixta(Östergren), 1898 is accomplished by an adhesive secretion synthesized in modified retractable discs of epithelial cells located on the terminal tentacular nodes. Besides secretory cells, each disc epithelium is composed of three other cell types: ciliated, granular and nerve cells. The fine structure and possible functions of the epithelium are described with reference to the behaviour of tentacles during feeding and the observations are compared with existing information on holothuroid feeding mechanisms.
The genus Listriella (Crustacea: Amphipoda) in British and Irish waters, with the description of a new species
Authors: Myers A. A. , McGrath D.
Published: October 2009

A new species of Listriella is described and figured from maerl deposits in Kilkieran Bay, Co. Galway. The holotype of the only other British species is figured for comparison. The amphipod fauna of Kilkieran Bay (Co. Galway) maerl is compared with that of Eddystone shell gravels.
The chromatic and motor effects of neurotransmitter injection in intact and brain-lesionedOctopus
Authors: Andrews P. L. R. , Messenger J. B. , Tansey E. M.
Published: October 2009

Various neurotransmitters were injected into the blood supplying the brain ofOctopus vulgarisand the effects, particularly on the chromatophores, were observed.l-glutamate, GABA, dopamine, noradrenaline and octopamine caused expansion of the chromatophores and darkening of the skin; ACh caused retraction of the chromatophores and paling; 5HT caused differential expansion and retraction: mottling. These responses, which are neurally mediated, were particularly well defined for ACh and 5HT and the effects of these drugs were studied in more detail. The paling effect of ACh was mimicked by nicotine but not muscarine and was partially antagonized by tubocurarine. The mottling induced by 5HT was transiently antagonized by methysergide maleate, as was ink-ejection and defaecation. Brain lesions to localize the sites of action of ACh and 5HT suggest that they act at the level of the sub-oesophageal lobes to control the chromatophores, but that 5 HT may act at the level of the optic lobe to control inking and defaecation. These results are related to the pharmacology and histochemistry of the cephalopod brain and to the organization of the chromatophore control system.
Establishment of the symbiosis inConvoluta roscoffensis
Authors: Douglas A. E.
Published: October 2009

Of a wide range of algae tested, juvenileConvoluta roscoffensisingested onlyPlatymonas convolutae, the natural symbiont; related species of the generaPlatymonas, PrasinocladusandTetraselmis; andChlamydomonas coccoides. Platymonas convolutaewas not ingested to a greater extent thanPrasinocladus marinus, Tetraselmis tetratheleandTetraselmis verrucosa, or taken up in preference toT. verrucosawhen animals were exposed to a choice between the two species. Convoluta ingested fewer cells ofC. coccoidesthanP. convolutaeand related species. Uptake ofP. convolutaewas not affected by pretreatment of the cells with lectins or proteases, incubation in media of pH 5·0–9·0 or inhibition of algal photosynthesis, but was substantially reduced if the algae were killed.

Cells ofP. convolutae, Pr. marinus, T. tetratheleandT. verrucosapersisted and divided in juvenile Convoluta. The algal population in the worms started to increase 2–3 d after ingestion and within 15–20 d the animals were uniformly green. These algae formed a viable symbiosis with Convoluta and promoted the growth of the animals. In contrast,C. coccoidescells did not persist in Convoluta for more than 12–24 h a nd were probably disrupted.

P. convolutaecells lost their thecae within a few days of ingestion and before migration from the central to sub-epidermal region of the animal. Animal vacuoles surrounded recently ingested thecate algae. Structural studies of the adult symbiosis suggest that the algae were also intracellular and enclosed in vacuoles.

It is proposed that Convoluta discriminates against algae unrelated toP. convolutaeon initial contact and in the central region of the host. The nature of the recognition mechanism(s) has not been established.
Uric acid utilization inPlatymonas convolutaeand symbioticConvoluta roscoffensis
Authors: Douglas A. E.
Published: October 2009

Uric acid is an excellent nitrogen source for the growth of cultures ofPlatymonas convolutae, the symbiotic alga fromConvoluta roscoffensis, and relatedPlatymonasandTetraselmisspecies. Nitrate-grown cells ofP. convolutaeandT. tetrathelehave two uptake systems for uric acid, which conform to Michaelis–Menten kinetics; a high-affinity system operating in the concentration range 0·2–4·5 μM a nd a low-affinity system operating at higher concentrations of uric acid. Uric acid uptake byP. convolutaeis abolished by uncouplers of phosphorylation. In darkness, intact cells ofP. convolutaemetabolize [2-14C]uric acid to [14C]carbon dioxide. These results are consistent with the proposal that the algal symbionts ofC. roscoffensisutilize uric acid, received from the host, as a nitrogen source.

Aposymbiotic juvenile and symbiotic adultC. roscoffensisunder standard culture conditions contain uric acid. The solid uric acid content of juveniles declines on establishment of symbiosis withP. convolutaeand the endogenous uric acid is utilized in the adult symbiosis under conditions of nitrogen demand. However, adultC. roscoffensisdo not utilize exogenous uric acid. The growth of adult but not juvenileC. roscoffensisis dependent on nitrogen enrichment of the medium, and it is proposed that uric acid utilization is of significance to the growth of the developing symbiosis in a nitrogen-poor environment.
The endogenous locomotor activity rhythm of four supralittoral peracarid crustace
Authors: Williams John A.
Published: October 2009

The ‘strength’ of the endogenous locomotor activity rhythm of four peracarid crustacean species, denned by the precision and persistence of the rhythm, was examined with particular reference to a ‘burrowing’ versus epifaunal supralittoral life-style. The ‘strength’ of the endogenous component of the activity rhythm was also illustrated using a modified periodogram analysis. In all species, the talitrid amphipodsTalitrus saltator, Talorchestia deshayesi, Orchestra gammarellaand the oniscoid isopodLigia oceanica, the laboratory-monitored rhythm and the field emergence pattern displayed a nocturnal, circadian pattern with no clear evidence of any circa-tidal influence. The precision and particularly the persistence of the rhythm of the sand-shore burrowing speciesT. saltatorandT. deshayesiare especially well developed, although a ‘strong’ endogenous component is present in the rhythm of all four species. The significance of the endogenous locomotor rhythms is considered with respect to the supralittoral ecology of the species.
Phenotypic and genotypic spacing within an aggregation of the anemone, Actinia equina
Authors: Quicke D. L. J. , Brace R. C.
Published: October 2009

Enzyme and colour phenotypes were determined within a single mid-shore aggregation (n = 106) of the anemone, Actinia equina L. on the east coast of Britain. On the basis of allelic variation at four enzyme loci, a large number (n ≃ 30) of genotypes were distinguished of which only three consisted often or more anemones. Little evidence was found of obvious genotypic clustering, a result which was unexpected since this species broods young which are genetically identical with their parents, and which are potentially available for local (within site) colonization. We propose that the unexpectedly high level of genetic variability encountered at this site, can be explained by the following factors: (1) site and anemone longevities are probably measurable in tens of years, (2) distances travelled by anemones during their lifetime may be considerable, thus resulting in extensive inter-digitation of clones over time, and (3) the reproductive strategy of A. equina incorporates sexual reproduction with a planktonic dispersal phase.

Nearest-neighbour analyses applied to the distribution of phenotypes within this aggregation revealed several examples of auto-phenotypic under-dispersion. These results, together with (1) departure from Hardy–Weinberg equilibrium at a hexokinase locus, (2) evidence of linkage disequilibrium between hexokinase and malate dehydrogenase alleles, and (3) linkage between alleles at both these loci with a colour phenotype (grey pedal disc), all indicate that the genetic composition of this group of anemones had been strongly influenced by founder effects followed by clonal reproduction.

A comparative analysis of the size distributions of the various phenotypes and genotypes yielded few conclusions relating either to colonization history or to differential selection; reasons are given to account for this failure.
The reproductive biology and ecology of Gammarus duebeni (Crustacea: Amphipoda) in southern England
Authors: Sheader Martin
Published: October 2009

A study was made of the life cycle and reproductive ecology of Gammarus duebeni in the Test Estuary on the south coast of England. The species is towards the southern limit of its distributional range in the north-east Atlantic, which results in breeding continuing throughout much of the year. The breeding strategy employed was found to vary with season. The size of eggs produced and the rate of egg production were both temperature dependent, whereas the proportion of production expended on eggs and the number of eggs per brood, although probably influenced by temperature appeared to be controlled by food availability and female size. Factors affecting the mortality of eggs within the marsupium and breeding synchrony were considered in relation to season. The life cycle consisted of two major overlapping generations.
Diet-induced changes in fatty acid composition of herring larvae reared in enclosed ecosystems
Authors: Gatten R. R. , Sargent J. R. , Gamble J. C.
Published: October 2009

Fertilized herring eggs were hatched in large sea water enclosures containing natural populations of phytoplankton and Zooplankton and the developing fish sampled at intervals for a period of 90 days to determine the levels and composition of their depot triacylglycerols. The percentage of triacylglycerols in total lipid declined from hatching to about 40 days post-hatch and then increased markedly during the remaining 50 days. During the first 30 days from hatching the acyl groups of the triacylglycerols were dominated by polyunsaturated fatty acids, especially 18:4 (n−3), 20:5 (n−3) and 22:6 (n−3), characteristic of a predominantly phytoplanktonic diet. For the remainder of the 90-day experiment the percentages of polyunsaturated fatty acids decreased, to be replaced by increasing percentages of 20:1 (n−9) and 22:1 (n−11 ) fatty acids characteristic of a predominantly zooplanktonic diet.
Bathyal benthic polychaetes from the N.E. Atlantic Ocean, S.W. of the British Isles
Authors: Kirkegaard Jørgen B.
Published: October 2009

From bathyal depths in the Bay of Biscay, southwest of the British Isles, 89 species of polychaetes are described, among which are two new species, one new genus, and one new Combination, i.e. Pholoe fauveli sp. nov., Paracapitella southwardi n.gen., n. sp., and Galathowenia oculata, new combination. Of the species taken, 52 % are also known from abyssal depths. The bathyal polychaete fauna of the North Atlantic seems to be common with that of the Arctic and the North Pacific.
Sargassum muticum: a taxonomic history including world-wide and western Pacific distributions
Authors: Critchley Alan T.
Published: October 2009

Sargassum muticum(Yendo) Fensholt was first described from Japan as the formamuticus(sic.) ofS. kjellmanianumYendo. Subsequently,s. kjellmanianumandS. miyabeiYendo have been recognised as conspecific with dioecious reproductive structures.S. muticumis monoecious. The taxonomic history ofS. muticumand confusions arising are presented.

The spread ofSargassum muticum to regionsof the world outside of Japan is illustrated. A distribution map ofS. kjellmanianum, S. miyabeiandS. muticumin the western Pacific is also presented with a discussion of this selected species group. Further work is required to determine the exact extent ofS. muticumin the western Pacific region.
Oxygen and the developing eggs and larvae of the lumpfish, Cyclopterus lumpus
Authors: Davenport John
Published: October 2009

Unfertilized eggs in the oviducts of female lumpsuckers are exposed to low oxygen tension (ca. 40% air saturation). After spawning and fertilization water agitation aids percolation of water through Cyclopterus egg masses, but early in development oxygen tensions within non-ventilated egg masses fall slowly because of the eggs’ low metabolic rate (consistent with their slow development – 40 days to hatching at 5 °C). There is a considerable increase in oxygen uptake at hatching; in this respect the lumpsucker resembles the herring, Clupea harengus.

Early stage eggs are tolerant of hypoxic conditions and can even survive brief exposure to anoxic sea water. Later eggs and larvae are much more susceptible to oxygen lack. However, fanning behaviour by the brooding male parent (usually assumed to be designed to promote oxygen uptake by egg masses) is almost continuous at the beginning of development but becomes less frequent later. It is suggested that the initial intensive fanning helps to drive off ammonia which is released as the eggs stick together.
The effect of sediment type upon the position and depth at which byssal attachment occurs in Mytilus edulis
Authors: Young G. A.
Published: October 2009

The effect of changes in particle size and sediment depth on byssal attachment was assessed in laboratory experiments. Mytilus edulis did not attach byssus pads to mud or silt less than 0·85 mm in diameter, but did attach pads to gravel. On gravel more pads were attached to the substrate (mean = 19·44 threads/mussel/week) than to other mussels in the group (mean = 7·34 threads/mussel/week). Because no byssal attachment to the finer substrates occurred and preference for other mussels in the groups rather than the plastic of the holding tank was shown, clumps, characteristic of mussel beds in the field, were formed. The clumps became increasingly well defined as the depth of the substrate increased. Few clumps were formed on the coarsest substrate as a result of preferential byssal attachment to gravel particles.
Autoradiographic studies on the uptake of dissolved amino acids from sea water by bivalve larvae
Authors: Manahan Donal T. , Crisp Dennis J.
Published: October 2009

Uptake and incorporation of [3H]glycine from 1 μM solutions was observed in the tissues of larval oysters, Crassostrea gigas, Ostrea edulis, and mussels, Mytilus edulis. In all cases, radiolabel first appears in the larva's velum. Following increasing exposure time, label begins to appear in other organs. In newly settled larvae of the oyster, C. gigas, and the scallop, Pecten maximus, uptake occurs via the developing gill buds. All experiments provide evidence of direct epidermal uptake of soluble nutrients without any participation of the digestive tract. Scanning electron micrographs show that there is no bacterial population visible on the surface of the velum that might act as an intermediate step in nutrient transport. These studies on veligers, pediveligers and settled larvae link the phenomenon of larval uptake with the extensive literature on the direct uptake of soluble nutrients by adult bivalves.
Benthic regions within the North Sea
Authors: Dyer M. F. , Fry W. G. , Fry P. D. , Cranmer G. J.
Published: October 2009

During five annual ground fish surveys of the North Sea, all the benthic invertebrates trawled at 48 primary stations were recorded. The data were subjected to classification analysis, which showed a basic division between northern and southern North Sea benthos. The southern North Sea was further divided into three benthic regions, and the northern North Sea into four benthic regions (including one to the west of Shetland). The factors influencing the faunal assemblages in the various regions were discussed.
Responses of a hydroid to surface water samples from the River Tamar and Plymouth Sound in relation to metal concentrations
Authors: Stebbing A. R. D. , Cleary J. J. , Brinsley M. , Goodchild C. , Santiago-Fandino V.
Published: October 2009

The River Tamar and its tributaries drain a highly metalliferous area; and increased metal levels in river water might be expected to affect biological water quality in the estuary. In order to detect possible effects we have used sensitive responses to stress of the hydroid Campanularia flexuosa as an index of quality of water samples from the River Tamar, Plymouth Sound and Cattewater. No water samples caused inhibition of colonial growth rate, but in each experiment there were significant variations in other more sensitive responses. It is these variations that we have related to metal distributions, although of the metals measured, only copper and cadmium occasionally occur in concentrations that could be biologically significant, and at the same time show any correlation with the hydroid responses. The limitation of the survey to water of relatively high salinity does not permit a firm conclusion about the origin of these metals, but there are some indications that local inputs may be important.
Ammonia output by eggs and larvae of the lumpsucker,Cyclopterus lumpus, the cod,Gadus morhuaand the plaice,Pleuronectes platessa
Authors: Davenport John , Lønning Sunniva , Kjørsvik Elin
Published: October 2009

Cod and plaice eggs show a gradually increasing rate of ammonia excretion during development and in neither species was there a great change in individual output at hatching. The rates of ammonia excretion recorded for cod and plaice larvae were similar to those recorded for planktonic Crustacea of comparable size by Conover & Corner (1968).

Lumpsucker eggs and larvae have a basically low rate of ammonia excretion (consistent with their slow rate of development and low oxygen consumption), but much ammonia was released from the eggs in the first day or two after spawning. This ammonia was of non-metabolic origin, but was not accumulated from the ovarian fluid prior to spawning. Lumpfish eggs become very sticky when they are first exposed to sea water, but this stickiness is lost within 24 h. Stickiness stems from a viscous elastic slime; it is suggested that the non-metabolic output of ammonia is caused by changes in the composition of the slime as the eggs are bound together in a lattice.
Mortalities of Salmo gairdneri exposed to cultures of Gyrodinium aureolum
Authors: Roberts R. J. , Bullock A. M. , Turners M. , Jones K. , Tett P.
Published: October 2009

Rainbow trout were exposed to five different concentrations of a unialgal culture of Gyrodinium aureolum in laboratory tanks. All the concentrations used proved lethal within 24 h. The gills of the dead fish showed no mechanical occlusion by the algae but all displayed marked histological changes characterized by necrotic degeneration and disintegration of the lamellar epithelium.
Changes in fish and benthos catches off the Danish coast in September 1981
Authors: Dyer M. F. , Pope J. G. , Fry P. D. , Law R. J. , Portmann J. E.
Published: October 2009

During a routine North Sea demersal fish survey, very low fish catches were recorded at two primary stations off the Danish coast in September 1981. The catch of benthos at thesestations was much greater than the previous year, and underwater photographs from a headline camera revealed that this was a result of most infaunal species having emerged from beneath the sand. The phenomenon was assumed to be caused by low oxygen concentrations in bottom water following the collapse of a bloom of the dinoflagellate Ceratium furca.
A geometric analysis of growth in gastropod shells, with particular reference to turbinate forms
Authors: Ekaratne S. U. K. , Crisp D. J.
Published: October 2009

Nucella lapillusandLittorina littoreaafford examples of turbinately coiled shells with no space between the columella and the inner face of the whorls. Three constants are sufficient to determine the form of such shells: λ, the ratio between diameters of successive whorls; β, the semi-apical angle and ρ, the ratio of aperture length and breadth in the apertural plane passing through the axis. The variation of these three constants with size was examined and shown to be relatively small and insignificant inNucella, but inLittorinait was significant.

ForNucellaandLittorinathese shell characteristics were used to relate for thenth whorl, the length along the shell spiral (ln) to the shell height (Hn), the latter being the measure usually employed in growth studies. This relation was derived mathematically and confirmed empirically as

where α is the angle of the logarithmic spiral given by α = tan−12π sin β/logeλ. The increased resolution of the micro-growth band increments, which are measured along the shell spiral was directly related to theln:Hnratios.

Since the formula for theln/Hnratio (= shell conversion factor) includes λ, β and ρ, the three constants necessary to determine shell form in turbinately coiled shells of the type described, the shell conversion factor may be a better index of shell shape than indices based on a single constant. In species where the shell grows isometrically this ratio will remain constant, whereas changes in shell shape with size will influence this ratio. Such changes in shell shape during growth can be quantified in terms of the shell constants and when included in calculating the shell conversion factor, will show the relative magnitude of shell shape changes brought about by growth. The shell conversion factor may also be used to study the effects of ecological variations on the geometry of the shell.

The conical shell of the limpet,Patella vulgata, is geometrically a much simpler system in which direct shell measurements were used to relate length along the direction of maximum growth to the antero-posterior diameter of aperture.
A chronology of new European sites of attachment for the invasive brown alga,Sargassum muticum, 1973–1981
Authors: Critchley Alan T. , Farnham W. F. , Morrell S. L.
Published: October 2009

The spread of the immigrant brown algaSargassum muticum( Yendo) Fensholt, within European waters is chronicled from 1973–1981. New populations of the attached alga are listed together with maps indicating the annual addition of sites. No populations of the alga were known beyond the bounds of the Solent region, southern Britain, until after 1975.

The age of the originalSargassumpopulation found at Bembridge in 1973, and the discovery of driftingS. muticumin 1971, seems to date the initial introduction of the alga in the Channel as possibly the late 1960s.

This paper presents the establishment ofSargassum muticumas a permanent addition to the European marine flora. It is hoped that its future spread will continue to be documented, providing useful information upon the invasion strategy of an ‘aggressive’ introduced marine species.
Sargassum muticum: a morphological description of European material
Authors: Critchley Alan T.
Published: October 2009

The shape of such morphological characters as leaves and air vesicles of the introduced brown algaSargassum muticum(Yendo) Fensholt were found to vary seasonally. A range of observations is presented together with a general description of European material.
Experimental observations on variability of leaf and air vesicle shape of Sargassum muticum
Authors: Critchley Alan T.
Published: October 2009

Seasonal variations in the range of air vesicle and leaf shape upon the brown alga Sargassum muticum (Yendo) Fensholt provide some discrepancies with descriptions of material from the alga's indigenous Japanese and introduced British Columbian habitats.

Experimental observations indicate that mucronate air vesicles are most common at low (i.e. 10 °C) and high (i.e. 25 °C) temperatures, with those of 30 °C being injurious to plant growth. Air vesicles with spiked proliferations are also seen to increase in occurrence with an increasing light intensity at 20 °C. Excised ‘winter’ form leaves collected in February were able to regenerate ‘summer’ form leaves from their damaged bases, under culture conditions.

Field and laboratory investigations show that leaf and air vesicle shape tend to vary seasonally and may be experimentally changed by both temperature and light intensity. Such plasticity observed in the morphology of these characters in S. muticum raises doubts as to the taxonomic status of many species ascribed to the large genus Sargassum.
The Mauthner system of deep sea teleosts
Authors: Bone Q. , Marshall N. B.
Published: October 2009

Spinal cords in deep sea fishes of 37 families have been examined for the presence and relative size of Mauthner axons. No correlation has been found between fish size, and the relative diameter of the Mauthner axon in different species. However, counts of primary motoneuron number and myotomal muscle fibre number in each segment suggest that Mauthner axon diameter is related to the numbers of these in each segment. The behavioural role of the Mauthner system is discussed, and it is concluded that in certain elongate-bodied fishes such as halosaurs and macrourids, a C-type startle response is unlikely.
Vertical distribution and feeding of Thalia democratica on the Agulhas Bank during march 1994
Authors: Gibbons M.J.
Published: October 2009

Diel vertical migration (DVM) and in situ feeding of Thalia democratica (Tunicata: Thaliacea) was studied in the field (Agulhas Bank, South Africa) over a 48 h period in March 1994. Thalia democratica did not display DVM, and both aggregates and solitaires were mostly confined to the upper layers of the water column throughout the study period. Thalia democratica did not display any discernible diel feeding rhythm, and pigment content increased with salp size. Individuals with greatest pigment content were found at the chlorophyll maximum. Estimates of grazing impact varied with salp abundance and gut passage time, ranging from less than 1% to greater than 100% of phytoplankton productivity.
Efficient acceleration of a small dense plasma pellet by consecutive action of multiple short intense laser pulses
Authors: Wang X. , Yu W. , Yu M.Y. , Senecha V.K. , Xu H. , Wang J.W. , Yuan X. , Sheng Z.M.
Published: October 2009

The acceleration of a micrometer-sized plasma pellet at 100 critical densities (1023 cm−3) by consecutive application of ultra-short ultra-intense laser pulses is studied using two-dimensional particle-in-cell simulation. It is shown that due to the repeated actions of the laser ponderomotive force, a small dense plasma pellet can be efficiently accelerated, with a considerable fraction of the plasma ions accelerated to high speeds. The proposed scheme can provide a high-density flux of energetic ions, which should be valuable in many practical applications.
Electron energy enhancement by a circularly polarized laser pulse in vacuum
Authors: Singh K.P. , Gupta D.N. , Sajal V.
Published: October 2009

Energy enhancement by a circularly polarized laser pulse during acceleration of the electrons by a Gaussian laser pulse has been investigated. The electrons close to the temporal peak of the laser pulse show strong initial phase dependence for a linearly polarized laser pulse. The energy gained by the electrons close to the rising edge of the pulse does not show initial phase dependence for either linearly- or circularly-polarized laser pulse. The maximum energy of the electrons gets enhanced for a circularly polarized in comparison to a linearly polarized laser pulse due to axial symmetry of the circularly polarized pulse. The variation of electron energy with laser spot size, laser intensity, initial electron energy, and initial phase has been studied.
Assessment of oil content and fatty acid composition variability in different peanut subspecies and botanical varieties
Authors: Wang M. L. , Chen C. Y. , Davis J. , Guo B. , Stalker H. T. , Pittman R. N.
Published: October 2009

Within the cultivated peanut species (Arachis hypogaeaL.), there are two subspecies comprising six botanical varieties, and the effect of botanical taxon on oil content and fatty acid composition variability is unclear. To gauge the variability, 83 peanut accessions were analyzed for oil content (expressed at 0% moisture) and fatty acid composition. We found that within the subsp.hypogaea, var.hypogaeacontained a much higher amount of oil in seeds than did the var.hirsutaKöhler (520 vs. 473 g/kg,P < 0.05); within the subsp.fastigiataWaldron, the vars.aequatorianaKrapov. & W.C. Gregory andvulgarisHarz contained a similar amount of oil in seeds (491 g/kg), not significantly different from other botanical varieties, but var.fastigiatacontained a higher amount of oil (500 g/kg) than the var.peruvianaKrapov. & W.C. Gregory (483 g/kg). In terms of the fatty acid composition, oil from seeds of var.hypogaeacontained much more oleic acid than did var.hirsuta(491 vs. 377 g/kg,P < 0.05), but much less palmitic acid (97 vs. 138 g/kg,P < 0.05%) and linoleic acid (308 vs. 402 g/kg,P < 0.05). Oil from seeds of var.vulgariscontained much more oleic acid than did var.aequatoriana(437 vs. 402 g/kg,P < 0.05), but much less linoleic acid (346 vs. 380 g/kg,P < 0.05). Significant negative correlations of oleic with palmitic and linoleic acids were detected. The information on the oil content and fatty acid composition variability among botanical varieties would be useful for peanut breeders seeking germplasm containing both high oil content and proper fatty acid composition.
Modeling transport and fate of riverine dissolved organic carbon in the Arctic Ocean
Authors: Manizza M. , Follows M. J. , Dutkiewicz S. , McClelland J. W. , Menemenlis D. , Hill C. N. , Townsend‐Small A. , Peterson B. J.
Published: October 2009

The spatial distribution and fate of riverine dissolved organic carbon (DOC) in the Arctic may be significant for the regional carbon cycle but are difficult to fully characterize using the sparse observations alone. Numerical models of the circulation and biogeochemical cycles of the region can help to interpret and extrapolate the data and may ultimately be applied in global change sensitivity studies. Here we develop and explore a regional, three‐dimensional model of the Arctic Ocean in which, for the first time, we explicitly represent the sources of riverine DOC with seasonal discharge based on climatological field estimates. Through a suite of numerical experiments, we explore the distribution of DOC‐like tracers with realistic riverine sources and a simple linear decay to represent remineralization through microbial degradation. The model reproduces the slope of the DOC‐salinity relationship observed in the eastern and western Arctic basins when the DOC tracer lifetime is about 10 years, consistent with published inferences from field data. The new empirical parameterization of riverine DOC and the regional circulation and biogeochemical model provide new tools for application in both regional and global change studies.
Distributed topographic indicators for predicting nitrogen export from headwater catchments
Authors: Creed I. F. , Beall F. D.
Published: October 2009

The possibility of using topographic indicators to predict spatial variation in dissolved nitrogen (N) export from headwater catchments was explored within a sugar maple forest in the Algoma Highlands of central Ontario, Canada, where the average annual export of total dissolved N export ranged from 3.58 to 6.96 kg N ha−1 a−1. Topographic indicators representing both “nondistributed” and “distributed” properties of the catchments were derived. Distributed topographic indicators that were designed to represent hydrologic flushing mechanism for N export were superior in predicting nitrate‐N export, explaining up to 85% in average annual nitrate‐N export and 90% in the slope of discharge versus peak nitrate‐N export which occurred during spring melt. However, the distributed topographic indicators were comparable to nondistributed ones for dissolved organic nitrogen export, explaining up to 68% of the variance compared to 65%. This study shows that spatial variation in N export from catchments within a relatively small region can be substantial, but that distributed topographic indicators can be used to predict a majority of this N export and thereby provide a basis for extrapolating N export from a few intensively monitored catchments to many other catchments within the sugar maple forest of the Algoma Highlands.
Prediction of unsaturated soil hydraulic conductivity with electrical conductivity
Authors: Doussan Claude , Ruy Stéphane
Published: October 2009

Soil hydraulic conductivity (K) varies greatly with matric potential (h) and exhibits a high variability at the field scale. However, this key property for estimating water flux in soils is difficult to measure. In contrast, soil electrical conductivity (σ) is easier to measure and is influenced by the same parameters affecting K. We derive a simple relationship between σ and K(h) and test it against laboratory and literature data. Importantly, we show that parameters of this σ‐K(h) relationship can be completely determined with accessible measurements of saturated hydraulic conductivity, electrical conductivity of the soil solution, and clay content. This results in K(h) estimation with a RMSE ranging between 0.4 and 0.5 for log K, i.e., of the order of most experimental determinations of K. A further test of the σ‐K(h) relationship on the large UNSODA hydraulic database shows good agreement and the robustness of the relationship. Such a relation could be useful in the spatial monitoring of water fluxes at the field scale using electrical resistivity tomography if the σ(h) relationship can be obtained.
IMF clock angle control of multifractality in ionospheric velocity fluctuations
Authors: Abel G. A. , Freeman M. P. , Chisham G.
Published: October 2009

We present an analysis of 8 years of meridional line‐of‐sight ionospheric plasma velocity measurements from the Halley SuperDARN radar which investigates the effect of the interplanetary magnetic field (IMF) clock angle on the scaling exponents of the first three order velocity structure functions. We only use velocity measurements made poleward of the open/closed magnetic field line boundary in the nightside ionosphere. The measured scaling exponents are consistent with multifractal Kraichnan‐Iroshnikov turbulence for all clock angles but with varying intermittency that decreases to zero during purely northward IMF conditions. We thus propose that intermittency is inherited from the solar wind but also discuss other possible reasons for this relationship.