Phenology and temperature tolerance of the red algae Chondria baileyana, Lomentaria baileyana, Griffithsia globifera, and Dasya baillouviana in Nova Scotia

1987 ◽  
Vol 65 (1) ◽  
pp. 57-62 ◽  
Author(s):  
I. Novaczek ◽  
C. J. Bird ◽  
J. McLachlan
Keyword(s):  
Nova Scotia ◽  
Population Size ◽  
Red Algae ◽  
Temperature Tolerance ◽  
Reproductive Period ◽  
The Other ◽  
Maximum Temperature ◽  
Cape Cod ◽  
Northern Limit ◽  
Warm Temperate

The warm-temperate species Chondria baileyana, Lomentaria baileyana, Griffithsia globifera, and Dasya baillouviana are restricted, north of Cape Cod on the eastern American coast, to embayments and estuaries. The northern limit of distribution is the southern Gulf of St. Lawrence. In culture, isolates of these species from Nova Scotia survived 28 to 34 °C. In the field all reproduced during the period of maximum temperature, and in G. globifera and C. baileyana the progeny also reproduced. Some of the progeny of D. baillouviana developed as cold- and heat-resistant pads that survived the winter, whereas the other three species died back to perennating holdfast structures. Lomentaria baileyana was the least successful of the group, being unable to form resistant holdfast pads in midsummer temperatures and having the most limited reproductive period and smallest population size.

Canada, Nova Scotia, New Brunswick, and the Other British Provinces in North America

2009 ◽  
Author(s):  
James Silk Buckingham
Keyword(s):  
Nova Scotia ◽  
North America ◽  
New Brunswick ◽  
The Other

Predictions of Current Attachment at Thermionic Cathode for TIG Arcs

2008 ◽  
Vol 580-582 ◽  
pp. 319-322 ◽  
Author(s):  
Manabu Tanaka ◽  
Kentaro Yamamoto ◽  
Tashiro Shinichi ◽  
John J. Lowke
Keyword(s):  
Melting Point ◽  
Work Function ◽  
Atmospheric Pressure ◽  
The Other ◽  
Numerical Calculations ◽  
Maximum Temperature ◽  
Arc Plasma ◽  
Melting Points ◽  
Thermionic Cathode ◽  
Uniform Current

Study of current attachment at thermionic cathode for TIG arc at atmospheric pressure is attempted from numerical calculations of arc-electrodes unified model. The calculations show that the maximum temperature of arc plasma close to the cathode tip for W-2% ThO2 reaches 19,000 K and it is the highest value in comparison with the other temperatures for W-2% La2O3 and W-2% CeO2, because the current attachment at the cathode tip is constricted by a centralized limitation of liquid area of ThO2 due to its higher melting point. The calculations also show that, in cases of W- 2% La2O3 and W-2% CeO2, the liquid areas of La2O3 and Ce2O3 are widely expanded at the cathode tip due to their lower melting points and then produce uniform current attachments at the cathode. It is concluded that the current attachment at thermionic cathode is strongly dependent on work function, melting point and Richardson constant of emitter materials.

A semi-hybrid model for malaria with limited superinfection

1998 ◽  
Vol 30 (04) ◽  
pp. 1027-1057 ◽  
Author(s):  
Philippe Picard
Keyword(s):  
Stochastic Model ◽  
Population Size ◽  
Hybrid Model ◽  
Human Population ◽  
Threshold Level ◽  
The Other ◽  
The Difference ◽  
The One

Modelling malaria with consistency necessitates the introduction of at least two families of interconnected processes. Even in a Markovian context the simplest fully stochastic model is intractable and is usually transformed into a hybrid model, by supposing that these two families are stochastically independent and linked only through two deterministic connections. A model closer to the fully stochastic model is presented here, where one of the two families is subordinated to the other and just a unique deterministic connection is required. For this model a threshold theorem can be proved but the threshold level is not the one obtained in a hybrid model. The difference disappears only when the human population size approaches infinity.

Spatial and Temporal Overlap of the American Lobster (Homarus americanus) and Sea Scallop (Placopecten magellanicus) as Related to the impact of Inshore Scallop Dragging

1992 ◽  
Vol 49 (7) ◽  
pp. 1486-1492 ◽  
Author(s):  
D. L. Roddick ◽  
R. J. Miller
Keyword(s):  
Nova Scotia ◽  
Homarus Americanus ◽  
Fishing Effort ◽  
The Other ◽  
American Lobster ◽  
Placopecten Magellanicus ◽  
Time And Space ◽  
Sea Scallop ◽  
The Impact ◽  
Temporal Overlap

Assessment of the damage of one fishery by another requires knowledge of the overlap, in time and space, of the damaging fishing effort and the abundance of the damaged species, as well as a measure of the rate of damage. This approach was used to measure the impact of inshore scallop dragging on lobsters in Nova Scotia. Areas of reported co-occurrence of lobster and scallop grounds were surveyed by divers to determine the extent of overlap. Only 2 of 52 sites surveyed had lobsters on scallop grounds that could be dragged. Divers surveyed one site six times during 1987 and 1988 and found lobsters most abundant during August and September. Only 2% of the lobsters in the path of scallop drags were either captured or injured. The estimated value of lobsters destroyed by dragging for scallops during periods of peak lobster abundance was minor: $757 at one site and $176 at the other. Restricting dragging to periods of low lobster abundance significantly reduces this cost.

Limnetic Zooplankton Assemblages in Atlantic Canada with Special Reference to Acidification

1986 ◽  
Vol 43 (2) ◽  
pp. 444-456 ◽  
Author(s):  
J. C. H. Carter ◽  
W. D. Taylor ◽  
R. Chengalath ◽  
D. A. Scruton
Keyword(s):  
Nova Scotia ◽  
New Brunswick ◽  
Fish Predation ◽  
Low Ph ◽  
Buffering Capacity ◽  
The Other ◽  
Bay Of Fundy ◽  
Factor Scores ◽  
Multiple Discriminant Analysis ◽  
Biological Factors

Crustacean and rotifer plankton assemblages of 93 lakes in Labrador, 107 in Newfoundland, and 142 in New Brunswick – Nova Scotia were investigated for evidence of correlations with lake morphometric, chemical, or biological factors. Labrador assemblages were almost completely lacking in identifiable structure. Newfoundland species clustered into two groups of different body size, suggesting the influence of fish predation. Only one species in Labrador and Newfoundland was significantly correlated with a derived factor related to lake water buffering capacity. New Brunswick – Nova Scotia species clustered into two groups, one featuring significant positive and the other significant negative correlations with the buffering factor. From this we conclude that acidification is having an impact on the limnetic zooplankton of these two provinces. Multiple discriminant analysis was used to demonstrate that New Brunswick – Nova Scotia lakes differing in their buffering capacity were also distinct in zooplankton composition. Lakes with low factor scores (low pH, alkalinity, and calcium) were mainly located in the Bay of Fundy region; this area has above average fog and precipitation, and lies within the summer air flow carrying pollutants from the south.

Brachioteuthis beanii Verrill, 1881 (Cephalopoda: Brachioteuthidae) in the northwest Atlantic

2020 ◽  
Vol 96 (2) ◽  
pp. 309-322
Author(s):  
Elizabeth K Shea ◽  
Judy Stadler ◽  
Annie Lindgren
Keyword(s):  
Nova Scotia ◽  
Food Web ◽  
Population Size ◽  
Size Distribution ◽  
Protected Area ◽  
Marine Protected Area ◽  
Measurement Data ◽  
Spawning Aggregation ◽  
Males And Females ◽  
External Ornamentation

Four research cruises to the Gully Marine Protected Area (known as "the Gully") off Nova Scotia, Canada (2007–2010) collected 1454 specimens of the oegopsid squid family Brachioteuthidae. All specimens were identified as Brachioteuthis beanii, and the 842 individuals collected in 2007 were used to describe the morphology and ecology of the species. A subset of 565 specimens were measured for population size distribution, and over 200 of these individuals (21–117 mm ML) were fixed, vouchered, measured, dissected, and sexed to examine the internal and external characters of juveniles, males, and females. Specimens <40 mm ML were almost entirely juveniles. Specimens 40–49 mm ML were a mix of juveniles, males, and females. The smallest specimens, where the spermatophoric complex and nidamental glands could be identified, were approximately 39 mm ML in both males and females, suggesting that maturation begins at roughly the same size in both sexes. Specimens >50 mm ML could be sexed based solely on the color and texture of the mantle. Male mantles were fusiform in shape with few small, widely spaced chromatophores and a reticulated net on the mantle that developed concurrent with the internal spermatophoric complex. Females had a flaccid mantle with larger and denser chromatophores on the mantle and head and no external ornamentation (i.e., ridges or nodules). Measurement data showed that males had slightly larger arms and wider fins than females. The high abundance of B. beanii at the Gully in August/September may be a spawning aggregation and suggests that this small squid is an important component of the canyon food web.

Trichinella nativa in sylvatic wild boars

1999 ◽  
Vol 73 (1) ◽  
pp. 87-89 ◽  
Author(s):  
E. Pozio ◽  
C.M.O. Kapel
Keyword(s):  
Sus Scrofa ◽  
Trichinella Spiralis ◽  
Temperature Tolerance ◽  
Biological Characteristics ◽  
The Other ◽  
Wild Boars ◽  
Domestic Pigs ◽  
Trichinella Nativa

Of 17 Trichinella isolates from domestic pigs and wild boars (Sus scrofa) in regions where Trichinella nativa is widespread among sylvatic animals, two wild boars from Estonia were found to be naturally infected with this Trichinella species. The other 15 animals were infected with Trichinella spiralis. Trichinella nativa is tolerant to freezing when in the muscles of carnivores. The biological characteristics and temperature tolerance of this species in swine need to be further investigated if pork is certified for consumption following freezing.

scholarly journals Fidelity and the Speed of the Treadmill: The Combined Impact of Population Size, Transmission Fidelity, and Selection on the Accumulation of Cultural Complexity

2016 ◽  
Vol 81 (3) ◽  
pp. 576-590 ◽  
Author(s):  
Claes Andersson ◽  
Petter Törnberg
Keyword(s):  
Population Size ◽  
The Other ◽  
Cambrian Explosion ◽  
Cultural Complexity ◽  
Causal Factors ◽  
Human Culture ◽  
Domain Of Existence ◽  
General Scientific ◽  
Combined Action ◽  
Combined Impact

Human culture signifies the emergence of an entirely new domain of existence: an event in natural history that is paralleled only by the Cambrian Explosion in terms of creativity and scope. The question of how human culture—as opposed to its animal counterparts—came to become open-endedly creative and cumulative is therefore one of wide and general scientific importance. Several causal factors have been proposed to date to explain this unique quality, including population size, transmission fidelity, pedagogy, and creativity. Inquiries, however, tend to focus exclusively on one factor at a time, leaving us blind to important issues regarding their relative roles and combined action. We here combine two models, one focusing on population size and the other on imitation fidelity, as constraints and enablers of evolutionary cumulativity. We explore how these factors interact to promote and inhibit evolutionary cumulativity and how the synthetic model compares to the original models individually and to empirical and experimental data. We report several findings that do not emerge in the models that we combine individually. For example, group size is found to be important for small but not for larger groups, an observation that moreover substantially improves agreement with data.

scholarly journals Phenological study of congeneric Myrcia species and Clethra scabra in wetland and drained habitats in a Montane Forest

2020 ◽  
Author(s):  
Vinícius Londe ◽  
Jaqueline Alves Pereira ◽  
Hildeberto Caldas de Sousa
Keyword(s):  
Relative Humidity ◽  
Abiotic Factors ◽  
Montane Forest ◽  
The Other ◽  
Maximum Temperature ◽  
Wetland Soil ◽  
Congeneric Species ◽  
Abiotic Conditions ◽  
Local Factors ◽  
The Tropics

Abstract Although important, phenological studies comparing congeneric species or the same species growing in different habitats are still scarce for the tropics. Herein, we integrate phylogeny, ecology and biometeorology to verify whether the phenophases of congeneric species Myrcia laruotteana and Myrcia amazonica or Clethra scabra differ when their populations inhabit wetland and drained habitats and to determine what abiotic factors affect the vegetative and reproductive phenophases of these species in distinct habitat patches. We collected data on phenological events of 80 trees for 1 year in Itacolomi State Park, Brazil, and related them to abiotic local factors. Contrary to our expectation, the phenophases of the congeneric species did not differ between habitats, but the reproductive phenophases of C. scabra did and was greater in drained soil. Phenophases of C. scabra were affected by the depth of the water table and maximum temperature in the wetland soil. Insolation, precipitation, maximum temperature and relative humidity influenced Myrcia and Clethra in the drained soil. The differences between C. scabra populations suggest that this species is phenotypically plastic and can present distinct phenophases depending on the habitat it inhabits. On the other hand, the congeneric Myrcia species may have similar phenophases in distinct habitats because of their shared similarities during their evolution. This study provides a better understanding of the ecology of these species and their adaptations to different abiotic conditions. Data of this nature are important in a changing world and can inform strategies for adaptive management.

Rheotaxis of Elvers of the American Eel (Anguilla rostrata) in the Laboratory to Water from Different Streams in Nova Scotia

1968 ◽  
Vol 25 (8) ◽  
pp. 1591-1602 ◽  
Author(s):  
S. G. Miles
Keyword(s):  
Organic Matter ◽  
Nova Scotia ◽  
Fresh Water ◽  
Stream Water ◽  
Salt Water ◽  
The Other ◽  
Anguilla Rostrata ◽  
American Eel ◽  
Heat Stable ◽  
Experimental Apparatus

In an experimental apparatus, elvers of the American eel (Anguilla rostrata) showed a stronger positive rheotaxis to fresh water than to salt water. The attractiveness of the fresh water was due to dissolved and particulate organic matter; these components were bio-degradable, heat stable, and nonvolatile. Four streams near Halifax, Nova Scotia, were tested, and were found to differ greatly in their attraction of elvers. Elvers were collected from each of three of these streams, and were not found to be attracted to their own stream water; elvers from one stream gave a greater rheotactic response than elvers from the other streams. The presence of adult eels in the water rendered it more attractive, whereas the presence of elvers made it less so.

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