Armillaria species in Newfoundland

2000 ◽  
Vol 30 (3) ◽  
pp. 507-512 ◽  
Author(s):  
Jean A Bérubé
Keyword(s):  
Natural Habitats ◽  
Phosphogluconate Dehydrogenase ◽  
Positive Identification ◽  
Armillaria Ostoyae ◽  
Exotic Tree ◽  
Mountain Ash ◽  
Isoenzyme Patterns ◽  
Armillaria Species ◽  
City Park ◽  
Made In

Crosses with standard testers were used to identify 96 haploid Armillaria isolates from 34 collections made in Newfoundland. Isoenzyme patterns were also used to identify 36 diploid and 3 haploid Armillaria isolates from 39 other collections. Diagnostic electromorphs at Rf 0.70 for esterases, Rf 0.32 for succinate dehydrogenase, and Rf 0.31 for 6-phosphogluconate dehydrogenase permitted positive identification of Armillaria ostoyae (Romagn.) Herink for all isolates tested by electrophoresis, and the method worked with haploid and diploid isolates. Crosses of the 96 haploid isolates collected on hardwoods and conifers were all positive for A. ostoyae, except for eight isolates. These eight isolates from three collections made on or near an American mountain-ash (Sorbus americana Marsh.) in a St. John's city park, where numerous exotic tree species are present, were found to be Armillaria sinapina Bérubé & Dessureault. These isolated collections in an area of limited natural hardwood presence may be the result of an introduction from the mainland; thus, A. ostoyae appears to be the only Armillaria species found in natural habitats in Newfoundland.

scholarly journals Coarse-scale population structure of pathogenic Armillaria species in a mixed-conifer forest in the Blue Mountains of northeast Oregon

2003 ◽  
Vol 33 (4) ◽  
pp. 612-623 ◽  
Author(s):  
B A Ferguson ◽  
T A Dreisbach ◽  
C G Parks ◽  
G M Filip ◽  
C L Schmitt
Keyword(s):  
Population Structure ◽  
Biological Species ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
Coarse Scale ◽  
Blue Mountains ◽  
Armillaria Ostoyae ◽  
Mixed Conifer Forest ◽  
Scale Population ◽  
Armillaria Species

The coarse-scale population structure of pathogenic Armillaria (Fr.) Staude species was determined on approximately 16 100 ha of relatively dry, mixed-conifer forest in the Blue Mountains of northeast Oregon. Sampling of recently dead or live, symptomatic conifers produced 112 isolates of Armillaria from six tree species. Armillaria species identifications done by using a polymerase chain reaction based diagnostic and diploid–diploid pairings produced identical results: 108 of the isolates were Armillaria ostoyae (Romagn.) Herink and four were North American Biological Species X (NABS X). Five genets of A. ostoyae and one of NABS X were identified through the use of somatic incompatibility pairings among the putatively diploid isolates. Armillaria ostoyae genet sizes were approximately 20, 95, 195, 260, and 965 ha; cumulative colonization of the study area was at least 9.5%. The maximum distance between isolates from the 965-ha A. ostoyae genet was approximately 3810 m, and use of three estimates of A. ostoyae spread rate in conifer forests resulted in age estimates for the genet ranging from 1900 to 8650 years. Results are discussed in relation to possible mechanisms that influenced the establishment, expansion, and expression of these genets; the genetic structure and stability of Armillaria; and the implications for disease management in this and similar forests.

COSMIC RAY PHENOMENA AT MINIMUM IONIZATION IN A NEW NUCLEAR EMULSION HAVING A FINE GRAIN, MADE IN THE LABORATORY

1954 ◽  
Vol 32 (8) ◽  
pp. 538-554 ◽  
Author(s):  
Pierre Demers
Keyword(s):  
Grain Size ◽  
Nuclear Emulsion ◽  
Electron Pair ◽  
Cosmic Ray ◽  
Silver Bromide ◽  
Positive Identification ◽  
Fine Grain ◽  
Scattering Measurements ◽  
Made In ◽  
Grain Diameter

The preparation of a silver bromide emulsion in the form of baseless sheets and their use in thick homogeneous stacks are described. In these sheets, a suitable development brings out minimum ionization tracks with a grain diameter 0.1 to 0.2 μ, and a linear grain density of 15 per 100 μ. The sequence of observations which led to the positive identification of minimum tracks is discussed. Short recoils and delta rays are visible, and excellent discrimination is available at all ionizing powers. The influence of grain size on fog is analyzed.Several cosmic ray phenomena containing minimum tracks are presented: single tracks, hard showers, πμe events, and an electron pair. Distortion is very small, and it is shown that the small grain size renders feasible better scattering measurements on higher energy particles. With this emulsion, nearly every possible measurement should become feasible with greater accuracy.

scholarly journals Orchid conservation: the next ten years

Lankesteriana ◽  
2013 ◽  
Author(s):  
Philip Seaton ◽  
Jonathan P. Kendon ◽  
Hugh W. Pritchard ◽  
Dwi Murti Puspitaningtyas ◽  
Tim R. Marks
Keyword(s):  
Endangered Species ◽  
Action Plan ◽  
Sustainable Use ◽  
Rapid Decline ◽  
Conservation Action ◽  
Natural Habitats ◽  
Orchid Species ◽  
Orchid Conservation ◽  
Orchid Seed ◽  
Made In

In 1996 the IUCN/SSC Orchid Specialist Group published a Status Survey and Conservation Action Plan that included a number of recommendations designed to address the problem of a projected imminent and rapid decline of species. Orchids remain subject to a multiplicity of threats in their natural habitats and, in addition to the usual suspects of habitat loss and land conversion, climate change has exerted a measurable effect on some orchid populations. Collection of orchids for traditional medicine is having a significant effect both within China and surrounding countries. Some progress has been made in achieving the targets set for Red Listing of endangered species in some countries, but other countries are lagging behind. In addition to successful initiatives in preserving natural habitats, a number of projects around the world have demonstrated that it is possible both to bring endangered species into cultivation and successfully reintroduce them into the wild. Orchid Seed Stores for Sustainable Use, with its goal of storing seeds representing a minimum of 1000 orchid species in institutes in at least 30 countries over the next five years, provides an example of what can be achieved by a small, dedicated group determined to share their technical expertise and develop a deeper understanding of the underlying science. There is, however, also an urgent need to promote awareness in the wider community about the importance of all sorts of biodiversity (not only orchids) through educational programs and involve people from as wide a range of backgrounds as possible.

scholarly journals Studies upon morhological and biological traits of Festuca rubra, subsp.fallax (Poaceae)

2013 ◽  
Vol 52 (1-2) ◽  
pp. 43-48 ◽  
Author(s):  
Bogusław Sawicki
Keyword(s):  
Biological Traits ◽  
Festuca Rubra ◽  
Natural Habitats ◽  
Experimental Station ◽  
Good Material ◽  
New Varieties ◽  
Made In

Observation and measurements of some traits of <em>Festuca rubra</em> L., subsp. <em>fallax </em>(Thuill.) Hack. ecotypes were made in 1995-1997 using samples selected from natural habitats and collected in Grassland Experimental Station in Sosnowica. High differentiation of traits under study and their correlations were found. Valorized ecotypes are good material for new varieties breeding.

ESTABLISHMENT OF OLESICAMPE GENICULATAE QUEDNAU AND LIM (HYMENOPTERA: ICHNEUMONIDAE) TO CONTROL THE MOUNTAIN ASH SAWFLY, PRISTIPHORA GENICULATA (HARTIG) (HYMENOPTERA: TENTHREDINIDAE), IN NEWFOUNDLAND

1994 ◽  
Vol 126 (1) ◽  
pp. 7-11 ◽  
Author(s):  
R.J. West ◽  
P.L. Dixon ◽  
F.W. Quednau ◽  
K.P. Lim ◽  
K. Hiscock
Keyword(s):  
Biological Control ◽  
Field Cage ◽  
The West ◽  
Open Release ◽  
Mountain Ash ◽  
Made In ◽  
Mated Female

AbstractMated female Olesicampe geniculatae Quednau and Lim were released in St. John’s, Newfoundland, to establish a biological control against the mountain ash sawfly, Pristiphora geniculata (Hartig). Two hundred and fifty-nine females were released during 1981–1984 in a field cage constructed over a mountain ash tree and provided with thousands of host larvae; 171 females were released outside the cage in 1984. A second open release of 368 P. geniculata cocoons, obtained as larvae from the field cage and presumably parasitized by O. geniculatae, was made in 1986 at Pasadena in western Newfoundland. Olesicampe geniculatae rapidly established in the St. John’s area where host populations dropped to insignificant levels by 1990. Island-wide monitoring during 1989 and 1990 indicated that O. geniculatae had spread to the west and south coasts, at rates as high as 50 km per year. Effective and persistent suppression of P. geniculata by O. geniculatae is anticipated.

scholarly journals A normative account of choice history effects in mice and humans

2020 ◽  
Author(s):  
Junior Samuel Lopez-Yepez ◽  
Juliane Martin ◽  
Oliver Hulme ◽  
Duda Kvitsiani
Keyword(s):  
Behavioral Ecology ◽  
Variable Interval ◽  
Choice Data ◽  
Natural Habitats ◽  
The Past ◽  
History Effects ◽  
New Variant ◽  
Reward Availability ◽  
Normative Account ◽  
Made In

AbstractChoice history effects describe how future choices depend on the history of past choices. Choice history effects are typically framed as a bias rather than an adaptive phenomenon because the phenomenon generally degrades reward rates in experimental tasks. How-ever, in natural habitats, choices made in the past constrain choices that can be made in the future. For foraging animals, the probability of obtaining a reward in a given patch depends on the degree to which the animals have exploited the patch in the past. One problem with many experimental tasks that show choice history effects is that such tasks artificially decouple choice history from its consequences in regard to reward availability over time. To circumvent this, we used a variable interval (VI) reward schedule that reinstates a more natural contingency between past choices and future reward availability. By manipulating first- and second-order statistics of the environment, we dissociated choice history, reward history, and reaction times. We found that choice history effects reflect the growth rate of the reward probability of the unchosen option, reward history effects reflect environmental volatility, and reaction time reflects overall reward rate. By testing in mice and humans, we show that the same choice history effects can be generalized across species and that these effects are similar to those observed in optimal agents. Furthermore, we develop a new reinforcement learning model that explicitly incorporates choice history over multiple timescales into the decision process, and we examine its predictive adequacy in accounting for the associated behavioral data. We show that this new variant, known as the double trace model, has a higher predictive adequacy of choice data, in addition to better reward harvesting efficiency in simulated environments. Finally, we show that the choice history effects emerge in optimal models of foraging in habitats with diminishing returns, thus linking this phenomenon to a wider class of optimality models in behavioral ecology. These results suggests that choice history effects may be adaptive for natural contingencies between consumption and reward availability. This concept lends credence to a normative account of choice history effects that extends beyond its description as a bias.

scholarly journals Adaptation of the Minitek system for the rapid identification of Neisseria gonorrhoeae

1976 ◽  
Vol 3 (1) ◽  
pp. 8-13
Author(s):  
S A Morse ◽  
L Bartenstein
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Sodium Bicarbonate ◽  
Rapid Identification ◽  
Inoculum Size ◽  
Positive Identification ◽  
Agar Media ◽  
Made In

A suspending medium was developed for use with the Minitek system for the confirmatory identification of Neisseria gonorrhoeae, N. meningitidis, and N. lactamica based upon the production of acid from various carbohydrates. The addition of sodium bicarbonate to the medium made negative reactions easier to read. More isolates of N. gonorrhoeae were identified with the suspending medium in the Minitek system than with cystine-Trypticase agar media. With a suitable inoculum size, a positive identification could be made in less than 1 h; most isolates (90,8%) could be identified within 4 h of inoculation. The Minitek system is reliable and easy to use.

scholarly journals Status, Distribution, and Diversity of Birds in Mining Environment of Kachchh, Gujarat

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Nikunj B. Gajera ◽  
Arun Kumar Roy Mahato ◽  
V. Vijay Kumar
Keyword(s):  
Mineral Resources ◽  
Recent Time ◽  
Opencast Mining ◽  
Natural Habitats ◽  
Mining Environment ◽  
The Rich ◽  
The Impact ◽  
Impact Of Mining ◽  
Made In

Opencast mining is one of the major reasons for the destruction of natural habitats for many wildlife including birds. The Kachchh region belongs to the arid part of India and is one of the rich areas of mineral resources in the country. In the recent time and after the 2001 earthquake, mining and other developmental activities are increased, and as a result, the natural habitats of birds are disturbed and fragmented. So, this study was conducted to assess the impact of mining and associated activities on the diversity and distribution of birds. Birds were studied by surveying 180 transects along 9 zones around three selected major mines, and each zone is made in every 2 km radius from the mine. Based on the record, it was found that the density and diversity of birds are highest in zone 5 and lowest in zone 1 and zone 2, respectively. The result indicates that the diversity and abundance of birds were less in zones which are located close to the mines in comparison to the zones far from the mines. In conclusion, mining and its associated activities have some impacts on the diversity and distribution of birds in Kachchh region in India.

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