Search Results - (Author, Cooperation:D. Innes)

2014-10-18

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

1600-0714

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The ultrastructural and enzyme cytochemical features of two follicular ameloblastomas were investigated. The peripherial cells of the follicular areas in both lesions had several types of tall columnar cells which were highly polarized and showed varying degrees of cellular differentiation. These polarized cells had their nuclei situated away from the basal lamina, and often contained dilated strands of endoplasmic reticulum in the subnuclear cytoplasm. Some of these cells also contained dense-cored secretory granules, condensing granules and coated vesicles in the cytoplasm adjacent to the basal plasma membrane. These cells bore a striking resemblance to pre-ameloblasts and early secretory ameloblasts. Alkaline phosphatase and ATPase cytochemistry supported these morphologic observations. Interestingly, the central cells of the follicular areas were consistently negative for alkaline phosphatase activity as were the peripheral cells, while both cell types had ATPase activity demonstrable at their cell surface.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] The solar network is the pattern of supergranulation cells seen over the entire surface of the Sun. The cell boundaries, along which the magnetic flux concentrates, is in a state of continuous variability and violent activity. Sudden small-scale plasma jets, microflares9'13 and explosive ...

Electronic Resource

0022-460X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Electronic Resource

0196-9781

F8Fa ; FMRFamide ; Neuropeptide FF ; Opioid analgesia ; Sex differences ; Stress-induced analgesia

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract Genetic differentiation within the intertidal zone was examined in six populations of the asexually reproducing alga Enteromorpha linza growing in the Long Island Sound, USA. Four of the five populations sampled in 1981 showed significant differentiation between high and low intertidal positions with respect to the GOT-2 locus. The pattern of differentiation was consistent for samples collected at several times during the year with some seasonal modifications. Four additional polymorphic loci, resolved in 1982, identified a total of 13 five-locus genotypes or clones. Four of the six populations sampled in 1982 showed significant differences in clone frequency between high and low intertidal positions. Laboratory experiments revealed differences in response to temperature among the clones. At 24°C a high intertidal associated clone showed an increase in growth, while low intertidal associated clones showed decreased growth compared to growth at 15°C. These results suggest that the microgeographic differentiation observed for E. linza in the intertidal zone may in part be due to the differential adaptation of clones to different intertidal environments. Additional demographic information is needed for individual clones in order to determine the role longevity, reproductive output, recruitment and interclonal competition play in maintaining the observed differentiation.

Electronic Resource

1432-1351

spatial learning ; sex differences ; opioids ; 60 Hz magnetic fields

Springer Online Journal Archives 1860-2000

Biology

Medicine

Abstract We examined the effects of brief exposure to weak 60 Hz extremely low frequency (ELF) magnetic fields and opioid systems on spatial behavior and learning in reproductive adult male and female deer mice, Peromyscus maniculatus. Sex differences were evident in spatial performance, with male deer mice displaying significantly better performance than female mice in the Morris water maze, whereby animals had to acquire and retain the location of a submerged hidden platform. Brief (maximum 5 min) exposure to weak (100 μT) 60 Hz magnetic fields during task acquisition significantly improved female performance, eliminating the sex differences in acquisition. The opiate antagonist, naltrexone, also improved female acquisition, though significantly less than the magnetic fields. These facilitatory effects involved alterations of “non-spatial” (task familiarization and reduction of related anxiety/aversive related behaviors) and possibly “spatial” aspects of the task. Enhancement of enkephalin activity with the enkephalinase inhibitor, SCH 34826, significantly reduced task performance by male deer mice. Both naltrexone and the 60 Hz magnetic fields attenuated the enkephalin mediated reductions of spatial performance. These findings indicate that brief exposure to 60 Hz magnetic fields can enhance water maze task acquisition by deer mice and suggest that these facilitatory effects on spatial performance involve alterations in opioid activity.

Electronic Resource

1573-093X

Springer Online Journal Archives 1860-2000

Physics

Abstract The Solar Ultraviolet Measurements of Emitted Radiation instrument (SUMER) observations show high Doppler shifts and temporal variations in profiles of ultraviolet lines from low temperature gas in the corona above the active region NOAA 7974. The profiles indicate ≈ 100 km s-1 flows coming from an almost stationary source that appears bright in the lines of N III and Si III. The variations in line-of-sight velocities and intensities suggest small knots of cooling plasma emanating from a small region high in the corona. A few arc sec sunward of the region where the cool flows are seen is an elongated region of enhanced higher temperature, low velocity Ne VI and Mg VI line emission.

Electronic Resource

1573-093X

Springer Online Journal Archives 1860-2000

Physics

Abstract Two-dimensional (2D) compressible magnetohydrodynamic simulations are performed to explore the idea that the asymmetric reconnection between newly emerging intranetwork magnetic field flux and pre-existing network flux causes the explosive events in the solar atmosphere. The dependence of the reconnection rate as a function of time on the density and temperature of the emerging flux are investigated. For a Lundquist number of L u= 5000 we find that the tearing mode instability can lead to the formation and growth of small magnetic islands. Depending on the temperature and density ratio of the emerging plasma, the magnetic island can be lifted upward and convected out of the top boundary, or is suppressed downward and convected out of the top boundary, or is suppressed downward nad submerged below the bottom boundary. The motions of the magnetic islands with different direction are accompanied respectively with upward or downward high velocity flow which might be associated with the red- and blue-shifted components detected in the explosive events.

Electronic Resource

1420-9071

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary Lesions of portions of the basal and cortical amygdaloid nuclei and the stria terminalis reversed or abolished arterial pressor responses to ipsilateral centripetal vagal stimulation (CVS). Destruction of these particular limbic structures in the rat did not affect cardiopulmonary responses to CVS.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract Limited sampling of Mytilus spp. in eastern Newfoundland has suggested that M. trossulus Gould and M. edulis L. are distributed as pure populations or mixtures of both species. In 1989 and 1990 we collected a wider series of samples of Mytilus spp. from 16 sites in eastern Newfoundland in order to determine the genetic structure based on four polymorphic enzyme loci (Est, Pgm, Lap, Ap). Associations among loci (particularly Pgm and Est), and a bimodal distribution of individual principal-component scores (based on fourlocus genotypes) provided evidence for the presence of both M. trossulus and M. edulis. Most of the sites consisted of a mixture of the two species. The relative frequency of each species in the samples varied on both a macro- and microgeographic scale. Two wave-exposed sites had the highest frequency (〉90%) of M. trossulus. The distribution of hybrid index scores, based on three partially diagnostic loci (Est, Pgm, Lap), provided no evidence for hybridization.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract Allopatric populations of Mytilus species show distinct shell morphology which may be due to genetic and/or environmental effects. Sympatric populations of Mytilus species show similar shell morphology which may be due to hybridization eroding morphological differences and/or the influence of common environmental conditions. The present study examined shell morphology and shell shape from 16 sites in eastern Newfoundland where M. edulis L. and M. trossulus Gould coexist in common environments with limited hybridization. Shell morphology was based on measurements of eight characters, and shell shape was quantified by elliptic Fourier analysis of shell outlines. Significant differences were observed between species for both shell morphology and shell shape across 16 sites sampled. The relatively small differences in morphology and shape between the species were probably due to exposure to common environments rather than hybridization. Shell shape for M. edulis was more eccentric compared to M. trossulus which was more elongated. Shell shape analysis of a range of size classes at one site showed a change from an eccentric to an elongated shape going from the smaller to the larger size classes. Both species showed a similar trend, with the larger M. edulis more eccentric and the larger M. trossulus more elongated.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract Mytilus trossulus Gould and M. edulis L. coexist in mixed populations in Atlantic Canadian waters. Although there is evidence that the two species hybridize in natural populations and that hybrids produce progeny through backcrosses, no study of the microgeographic distribution of the two forms and their hybrids has been made. Here we examine subtidal samples of mussels taken in July 1997 from two locations in eastern Newfoundland (Canada) and from wave-exposed and protected environments within each location. Shell lengths ranged from 15 to about 90 mm. Mussels were classified as pure forms or hybrids (F1, F2 and from backcrosses) based on four diagnostic markers, two allozyme loci (Mpi and Est-D) and two nuclear PCR-based DNA markers (ITS and Glu-5). In addition, a PCR-based mtDNA marker (COIII) was used to characterize the distribution of mtDNA mitotypes among pure and hybrid individuals. There were differences in the proportions of pure M. edulis and M. trossulus between sites and between environments at one location. M. trossulus was the predominant species at one of the two exposed sites. In all four samples, M. trossulus was also the predominant form among small individuals. The frequency of hybrids was 26% overall and did not differ among samples. Hybrids consisted mostly of backcrosses that were M. trossulus-biased among small mussels and M. edulis-biased among large ones. We conclude that both intrinsic genetic factors and extrinsic environmental factors influence the relative frequency of M. edulis, M. trossulus and their hybrids.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract We estimated the broad-sense heritability of larval size in 20 full-sib families of the giant scallop, Placopecten magellanicus (Gmelin, 1791) grown in laboratory culture in August and September 1991. The goal was to compare scallops with other bivalves which have been shown to have significant heritabilities for larval growth. Secondly, we estimated the lipid content of occytes from female parents, since this is hypothesized to affect larval growth and survival. Finally, we estimated the among-family variation in mortality from 4 to 21 d as a test of possible genetic variation for viability among larval scallops. Significant genetic variation (h2=1.10 to 1.24) was estimated for larval shell length at 4, 14, and 21 d. There was a significant correlation (r=0.66) between larval size at 4 d and lipid content of oocytes, but only when two females with high levels of lipid oocyte−1 were excluded as outliers. There was no correlation between larval size at 14 and 21 d and lipid content of oocytes. Mortality among families from 4 to 21 d was high (69 to 97%), and was significantly different among families. These results indicate that there is significant heritability for larval growth which is largely independent of the lipid content of the oocytes. A high heritability for larval growth may indicate that this trait is only weakly correlated with fitness.

Electronic Resource

1572-946X

radiative shocks ; spectroscopy

Springer Online Journal Archives 1860-2000

Physics

Abstract This paper presents models of optical emission line features that characterise catastrophic cooling in radiative shocks. The computations are based on a 1-D magnetohydrodynamic model. Runaway cooling results in the formation of secondary shocks which travel through the previously shocked cooling layer. Several filaments of emission with specific properties and spectral signatures are produced.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract There is significant differentiation at five polymorphic loci ofMytilus edulis among certain geographical areas of the Atlantic coast of North America. Non-metric multidimensional numerical methods distinguished three population groups: (I) populations south of Cape Cod, (II) populations throughout the Gulf of Maine, Gulf of St. Lawrence, areas of both southern and northern Newfoundland, and southern Hudson Bay, and (III) populations in southeastern Nova Scotia, northern Newfoundland and Hudson Strait, Quebec. Each subset consists of populations that exhibit characteristic multilocus, multiple allele genotypes. Populations in Groups II and III are spatially interdigitated among each other. At least one geographical area of mixing between genetically distinct populations occurs in northeastern Newfoundland. There is no evidence for interbreeding among genetically distinct individuals in mixed populations, suggesting the possibility that populations in the Atlantic Canadian Provinces and areas of northern Canada may consist of two distinct species.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract Thirteen asexually reproducing clones of Enteromorpha linza were found in samples collected from March to September 1982 in Long Island Sound, USA, based on variation at five enzyme loci. Significant differences in the relative frequency of each clone were observed among samples from 16 localities. There was a tendency for localities at the eastern end of the Sound to form a group genetically differentiated from localities at the western end, but in general there was no strong relationship between geographic distance and genetic distance. Areas separated by only a few hundred meters were genetically differentiated, despite the presence of a dispersing spore stage in this species. Samples from areas of low salinity were genetically similar but distinct from adjacent high salinity areas. One clone restricted to high salinity localities and one associated with low salinity localities were tested for growth under high and low salinity conditions in the laboratory. The clone from the high salinity habitat grew more slowly under low salinity conditions. However, there was no evidence for a detrimental effect of high salinity on the low salinity associated clone. Additional environmental factors, as well as biological factors such as limited recruitment and competitive interactions among clones, may also be important determinants of genetic differentiation among populations of E. linza. Temporal shifts in clone frequency were observed within some localities and may be due to seasonal-dependent regeneration from microscopic holdfasts for different clones or a seasonal recruitment of new clones from other areas. The pattern of differentiation among populations of E. linza in Long Island Sound appears to be maintained by factors operating on a microgeographic scale.

Electronic Resource

1618-2650

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Electronic Resource

1618-2650

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Electronic Resource

1618-2650

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Electronic Resource