LEAFHOPPERS OF THE SUBFAMILY TYPHLOCYBINAE FROM BIRCHES

1967 ◽  
Vol 99 (2) ◽  
pp. 170-180 ◽  
Author(s):  
I. W. Varty
Keyword(s):  
Life Histories ◽  
Main Species ◽  
Ecological Requirements ◽  
Birch Trees

AbstractMany of the small leafhoppers that feed and reproduce upon the foliage of birch trees belong to the subfamily Typhlocybinae. The main species are Typhlocyba hockingensis Knull, T. pomaria McAtee, Ribautiana foliosa (Knull), Edwardsiana bergmani (Tullgren), Empoa latifasciata Christian, Dikrella cruentata (Gillette), Alebra albostriella (Fallen) and several Erythroneura species. Their ecological requirements and life histories are described. Notes on morphology and illustrations of each species except the Erythroneura are included.

ERYTHRONEURA LEAFHOPPERS FROM BIRCHES IN NEW BRUNSWICK: II. SUBGENUS ERATONEURA (HOMOPTERA: CICADELLIDAE)

1967 ◽  
Vol 99 (6) ◽  
pp. 570-573 ◽  
Author(s):  
I. W. Varty
Keyword(s):  
New Brunswick ◽  
Ecological Requirements ◽  
Birch Trees

AbstractIn New Brunswick at least nine species of Erythroneura leafhoppers feed and oviposit on birch trees. The appearance and ecological requirements of two species in the subgenus Eratoneura are described.

Comparative ecology of the native and alien floras of the British Isles

1996 ◽  
Vol 351 (1345) ◽  
pp. 1251-1259 ◽  
Keyword(s):  
Life History ◽  
Plant Species ◽  
Life Histories ◽  
Leaf Shape ◽  
Vascular Plant ◽  
Alien Plants ◽  
Tall Stature ◽  
Comparative Ecology ◽  
Dispersal Syndrome ◽  
Ecological Requirements

Why do different plant species thrive where they do? This is a difficult question to answer because plants have invaded new niches and subsequently evolved to become better adapted within those niches. Distinguishing the traits that allow successful invasion and those that are evolved adaptations to current environments is not usually possible. We attempt to identify life history components that allow successful invasion by analysing the life history variables and ecological requirements of plant species that have successfully invaded the U.K. in recent years. The British flora is uniquely suited for this analysis because we have precise information on the dates of arrival, rates of spread and final spatial distribution of all our alien vascular plant species. Data on alien plants controls for evolution after invasion because there has been relatively little time for evolution to occur. We use modern phylogenetically-based comparative methods in an attempt to tease apart those components of life histories that have allowed successful invasion (large seeds, tall stature, protracted seed dormancy) from those that are irrelevant (dispersal syndrome, mating system, leaf shape).

scholarly journals The Biology of The Small Planktonic Copepods of Plymouth

1950 ◽  
Vol 29 (2) ◽  
pp. 393-438 ◽  
Author(s):  
P. S. B. Digby
Keyword(s):  
Life Histories ◽  
Absolute Abundance ◽  
Main Species ◽  
Oithona Similis ◽  
Acartia Clausi ◽  
Temora Longicornis ◽  
Planktonic Copepods ◽  
Paracalanus Parvus

The life histories of the small planktonic copepods of Plymouth were studied during 1947. The samples were taken at Station L4 with Harvey measuring nets, and are thus truly quantitative.The main species concerned were Pseudocalanus elongatus, Paracalanus parvus, Centropages typtcus, Temora longicornis, Acartia clausi, Oithona similis, O. nana, Oncaea venusta and Corycaeus anglicus.The species common in summer—all but the last three of the above—behaved in a very similar way, producing probably five generations in the course of the year, but differing from each other in the relative and absolute abundance of the different stages at different times of the year.

Using telemetry data to develop conceptual models of movement to support the management of riverine fishes

2017 ◽  
Vol 68 (8) ◽  
pp. 1567 ◽  
Author(s):  
W. M. Koster ◽  
D. A. Crook
Keyword(s):  
Fish Species ◽  
Life Histories ◽  
Environmental Changes ◽  
Conservation Management ◽  
Management Strategies ◽  
Fish Populations ◽  
Limited Information ◽  
Ecological Requirements ◽  
Management Actions ◽  
Species Specific

As human demands for freshwater resources increase, there is growing concern for the long-term viability of native fish populations globally. Understanding the movements of fish, and how these are influenced by or respond to environmental changes, is a critical knowledge requirement for effective management; however, limited information on the ecological requirements of many fish species currently hinders our ability to sustainably manage fish populations. In this paper, we use four native Australian fish species with contrasting life histories as case studies to demonstrate how data derived from acoustic and radiotelemetry studies can be synthesised into conceptual diagrams to help scientists and managers develop targeted and effective conservation management strategies. Commonalities in the observed movement patterns were observed among the species despite their contrasting life histories, but there were also important differences that need to be recognised in the development of species-specific conservation management strategies. We conclude by discussing how such information has been or could be incorporated into conservation management actions, including the implementation of environmental flow releases and the identification of critical habitats.

Life Histories of Patients With Chronic Ulcerative Colitis: A Review of 2,000 Cases

1950 ◽  
Vol 16 (1) ◽  
pp. 25-38 ◽  
Author(s):  
Wyman P. Sloan ◽  
F. Arnold Bargen ◽  
Robert P. Gage
Keyword(s):  
Ulcerative Colitis ◽  
Chronic Ulcerative Colitis ◽  
Life Histories

Review of methods of slag removal from melt surface in hot metal and steel ladles

2020 ◽  
Vol 76 (12) ◽  
pp. 1243-1252
Author(s):  
B. A. Sivak ◽  
A. V. Protasov ◽  
L. A. Smirnov
Keyword(s):  
Settling Tank ◽  
Necessary Condition ◽  
Hot Metal ◽  
Slag Removal ◽  
Production Scale ◽  
Technical Parameters ◽  
Ecological Requirements ◽  
The Usa ◽  
Work Done ◽  
Technological Methods

The removal of slag from melt surface of hot metal and steel ladles is a necessary condition to provide a deep desulphurization and dephosphorization of hot metal and steel in the process of their processing. A review of methods of slag skimming presented, mainly based on slag mechanical shoveling and its removal out of ladles by vacuum sucking. It was shown, that manipulators design for the slag skimming working instrument moving depends on the production scale, mass of the processed heats, amount and properties of the slag to be removed, production process intensity and ecological requirements. Peculiarities of designs and technical parameters of machines for slag skimming presented, designed by Irkutsk plant of heavy machinery, Scientific and Production Enterprise n.a. M.I. Platov, VNIIMETMASH, Kuznetsk and Novolipetsk steel plants. Technological methods of control of slag composition and physical properties considered, first of all of viscosity and fluidity, which have significant effect on selection of a method of slag skimming. Advantages and drawbacks of actions, aimed at more complete slag removal from metal surface by a scraper noted including bath blowing off by an inert gas, liquid slag tapping into am intermediate settling tank following its removal into a slag bowl. In case of satisfactory fluidity it is possible to slag removal by vacuum sucking, which at the same time promoted the melt degassing. Work done in this area abroad noted. Methods of vacuum slag removal developed in the USA and Japan described.

Power and politics in migration narrative methodology: Research with young Congolese migrants in Uganda

2009 ◽  
Vol 6 (2) ◽  
pp. 131-141 ◽  
Author(s):  
Christina Clark-Kazak
Keyword(s):  
Qualitative Research ◽  
Young People ◽  
Life Histories ◽  
Narrative Research ◽  
Power Dynamics ◽  
Methodological Issues ◽  
Personal Boundaries ◽  
Migration Narratives ◽  
Narrative Methodology

This paper explores the power dynamics inherent in qualitative research involving migration narratives. Drawing on the author’s experiences collecting life histories and constructing narratives of Congolese young people in Uganda, this article addresses the ethical and methodological issues of representivity, ownership, anonymity and confidentiality. It also explores the importance of investment in relationships in migration narrative research, but also the difficulties that arise when professional and personal boundaries become blurred.

Sign in / Sign up

Export Citation Format

Share Document