VARIATIONS IN FALL EMBRYOLOGICAL DEVELOPMENT IN THREE GRASSHOPPER SPECIES

1948 ◽  
Vol 80 (1-12) ◽  
pp. 83-88 ◽  
Author(s):  
H. W. Moore
Keyword(s):  
Seasonal Development ◽  
Embryological Development ◽  
General Study ◽  
Grasshopper Species ◽  
Stage Of Development

A study of embryological development in grasshopper eggs was made as a part of a general study of the effect of weather on the seasonal development of grasshoppers. The variation in the stage of development in which eggs of Melanoplus bivittatus (Say), Melanoplus mexicanus mexicanus (Sauss.), and Camnula pellucida (Scud.) entered the winters of 1941 to 1947 in different areas of the Prairie Region of Canada is presented in the following paper.

scholarly journals The Epidemiology of Powdery Mildew on Concord Grapes

2001 ◽  
Vol 91 (10) ◽  
pp. 948-955 ◽  
Author(s):  
David M. Gadoury ◽  
Robert C. Seem ◽  
Andrea Ficke ◽  
Wayne F. Wilcox
Keyword(s):  
Powdery Mildew ◽  
Fruit Set ◽  
Disease Incidence ◽  
The United States ◽  
Seasonal Development ◽  
Peak Period ◽  
Late Season ◽  
Stage Of Development ◽  
Concord Grapes ◽  
Moderately Resistant

Vitis labruscana ‘Concord’ is a grape cultivar widely grown in the United States for processing into juice and other grape products. Concord grapes are sporadically but sometimes severely damaged by the grape powdery mildew pathogen, Uncinula necator. Although the foliage is often reported to be moderately resistant to powdery mildew, severe fruit infection occurs in some years. We observed the seasonal development of powdery mildew on leaves, rachises, and berries of unsprayed Concord grapevines. Inoculations of flower and fruit clusters revealed a brief period of berry susceptibility and a protracted period of rachis susceptibility. The rachis remained highly susceptible to infection, and the severity of rachis infection increased throughout the growing season until the rachis formed a periderm shortly before harvest. In contrast, berries were nearly immune to infection within 2 weeks after fruit set. Rachis and berry infections were detected before the disease was observed on foliage, and the incidence of rachis and berry infection often exceeded disease incidence observed on foliage until after fruit acquired substantial ontogenic resistance. Excellent control of fruit infection, and adequate control of leaf infection, was achieved by two fungicide applications targeted at the peak period of fruit susceptibility. Although Concord is thought to be moderately resistant to powdery mildew, the rachis is highly susceptible, and may be the avenue by which prebloom infections make their way onto the developing fruit. Late-season infection of the rachis neither spread to the fruit, nor did it cause fruit to drop prematurely, and may be of little economic consequence on fruit destined for processing. Although fruit of V. vinifera cultivars have been reported to remain susceptible to infection until berry sugar levels reach 8 to 15%, Concord fruit become nearly immune to infection nearly 6 weeks before this stage of development. Because powdery mildew does not become conspicuous on foliage until late summer, it is generally regarded as a late-season problem on Concord grapes, and previous management programs have reflected this belief. However, the greatest contribution to control of fruit infection is due to fungicides applied during the peak period of fruit susceptibility, from bloom until shortly after fruit set, long before the disease is observed on foliage.

SOME OBSERVATIONS ON THE BIOLOGY AND BEHAVIOUR OF CAMNULA PELLUCIDA (ORTHOPTERA: ACRIDIDAE)

1967 ◽  
Vol 99 (9) ◽  
pp. 952-971 ◽  
Author(s):  
P. W. Riegert
Keyword(s):  
Meteorological Factors ◽  
Historical Review ◽  
Pest Species ◽  
The Sun ◽  
Life Stages ◽  
Embryological Development ◽  
Recent Information ◽  
Stage Of Development ◽  
Sandhill Cranes ◽  
Incubation Temperatures

AbstractA brief historical review of the occurrence of the clear-winged grasshopper, Camnula pellucida (Scudd.), is presented as well as recent information pertaining to the biology of its various life stages. In the egg stage, diapause is more successfully terminated by chilling at 5 °C for 70 days than at either 0 or −7 °C. Embryological development proceeded very favourably at incubation temperatures of 30 °C while 35 °C produced excessive mortality especially to pre-blastokinesis embryos. Most embryos in eggs of this species reach the same pre-blastokinesis stage of development more consistently every year than do those of other pest species of grasshopper in Saskatchewan. Thirty days of chilling at −12, −18, and −23 °C reduced the viability of the eggs by about 10, 20, and 50% respectively. Exposure to −29 °C killed all eggs in 3.5 to 5 hours.The phototactic and thermokinetic reactions of nymphs and adults, leading to aggregation, basking, and dispersal, are discussed and compared with those of other species. Details of nymphal migrations are described and related to such meteorological factors as wind, temperature, and position of the sun. Some further details of mating and oviposition are described, especially aggregation on egg beds and oviposition in stubble fields. Observations of predation by sandhill cranes and skunks are also recorded.

INFLUENCE OF DATE OF OVIPOSITION ON EGG HATCHING AND EMBRYO SURVIVAL IN THE RED TURNIP BEETLE, ENTOMOSCELIS AMERICANA (COLEOPTERA: CHRYSOMELIDAE)

1984 ◽  
Vol 116 (4) ◽  
pp. 645-652 ◽  
Author(s):  
G. H. Gerber
Keyword(s):  
Embryological Development ◽  
Egg Hatching ◽  
Embryo Survival ◽  
Band Formation ◽  
Stage Of Development ◽  
Stage Embryo ◽  
Embryo Stage ◽  
Time Required ◽  
Late Stage Embryo ◽  
Late Embryo

AbstractEmbryological development and hatching for the red turnip beetle, Entomoscelis americana Brown, were studied at 20 °C. In eggs kept at this temperature for > 12 days, embryological development proceeded until a late stage embryo was formed, at which time the embryo entered diapause for the winter. The time required for 50% of the eggs to reach the late embryo stage was estimated to be 11 days. The late embryo stage was not reached before winter in eggs kept at 20 °C for < 11 days, but most of them survived and hatched. Embryogenesis proceeded normally after winter without any apparent adverse effects, and hatching was delayed by the amount of time required to complete embryogenesis. Although it was not essential for the eggs to reach the late embryo stage to overwinter successfully and hatch, a critical minimum stage of development had to be reached during embryogenesis for the eggs to survive. The critical minimum stage of development occurred in the germ band formation stage and was reached during the first 1.5 days of embryogenesis. Most of the eggs laid from 1 to 15 September 1980 and kept outdoors reached the late embryo stage before winter and hatched the next spring; those laid from 15 September to 15 October reached the critical minimum stage of development before winter and also hatched successfully; and those laid after 15 October did not hatch, because they apparently had not reached the critical minimum stage. An evaluation of the data for the eggs kept outdoors and of atmospheric air temperature data suggested that embryo death due to eggs not reaching the critical minimum stage of development before winter normally should not be an important factor in the population dynamics of E. americana in the rapeseed- and canola-growing areas of western Canada. The ecological significance of the data is discussed.

Surveys of Adult Grasshoppers in Saskatchewan in Relation to Seasonal Development

1963 ◽  
Vol 95 (9) ◽  
pp. 936-941 ◽  
Author(s):  
P. W. Riegert ◽  
R. Pickford
Keyword(s):  
Sexual Maturity ◽  
Dominant Species ◽  
Adult Stage ◽  
The Other ◽  
Seasonal Development ◽  
Grasshopper Species ◽  
Total Period ◽  
Nymphal Development ◽  
The Past

AbstractIn the past twenty years in Saskatchewan the rate of nymphal development of three species of grasshoppers has varied considerably from year to year and region to region. Camnula pellucida appeared as early as, or earlier than, the other two species. The average date of attainment of the adult stage was July 21 compared to August 4th for Melanoplus bilituratus and M. bivittatus. Adult surveys in Saskatchewan have generally coincided with the time when the dominant species of grasshoppers, in any region, have attained full morphological and sexual maturity and have had an opportunity to disperse and stabilize density. Duration of the surveys, in any one of seven regions, in the years 1958-1961, varied from 4-31 days and averaged 19 days per year. The total period of survey for the province varied from 25-42 days and averaged 30 days per year.Variations in seasonal histories of the several grasshopper species demand an elastic schedule for surveys. The concept of maintaining a standard and rigid “best time” for surveys is untenable in the light of the present investigations.

Ontogenesis of Tissue Plasminogen Activator in the Human

1971 ◽  
Vol 25 (03) ◽  
pp. 469-480 ◽  
Author(s):  
B Åstedt ◽  
M Pandolfi
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Vena Cava ◽  
Vasa Vasorum ◽  
Moderate Activity ◽  
Foetal Development ◽  
Plasminogen Activator Activity ◽  
Stage Of Development ◽  
Tissue Plasminogen ◽  
Enzyme Pattern

SummaryThe ontogenesis of tissue plasminogen activator in various tissues was studied in 10 embryos and 58 foetuses with a histochemical method.The first appearance of activator activity was seen in a 4-weeks old embryo. At 8-9 weeks it was seen in the eye, meninges, heart, lungs, kidney and vena cava. In the foetal heart high activity was found in the coronary vessels, which can be regarded as the vasa vasorum of the heart. In the lungs a moderate activity increased at 24 weeks of age, when vascularisation increases more rapidly. Intense activity was seen in the highly vascularized corneoscleral junction of the eye later involved in the drainage of aqueous humor.In the kidney the activity could be related to the vessels, while no activity was seen in the glomeruli, the collecting system or the pelvis. In the vessels the activator activity was fairly high. No activity was seen in any stage of development of the liver.The plasminogen activator activity may be of importance for maintaining the foetomaternal circulation and micro-circulation in rapidly growing foetal organs. In the embryo the enzyme pattern is dominated by protein synthetizing enzymes. During foetal development the enzyme pattern changes owing to supervention of enzymes necessary for the function of the various organs. Plasminogen activator belongs to this latter group. The appearance of plasminogen activator activity may therefore be regarded mainly as a sign of functional maturity of the foetal organs.

Russian Federalism at the Critical Stage of Development

2008 ◽  
pp. 70-83 ◽  
Author(s):  
E. Bukhvald
Keyword(s):  
Economic Development ◽  
Social Processes ◽  
Self Management ◽  
Intergovernmental Fiscal Relations ◽  
Critical Stage ◽  
Municipal Reform ◽  
Stage Of Development ◽  
Social And Economic Development ◽  
Basic Course

Transformations in the sphere of federal relations concern the most important directions of the reforming processes in the country. However, not all proposed and actually developing components of the federal reform seem well-argued and corresponding to long-term, strategic interests of the Russian statehood. The basic course of reform should meet the objective requirements of further decentralization of governing economic and social processes and the need to ensure strengthening the responsibility of RF subjects’ executive bodies and local self-management for steady social and economic development of their territories. The solution of these problems calls for a new model of federal policy of regional development, specification of some important components of the municipal reform as well as inserting certain amendments into the system of intergovernmental fiscal relations in order to stir up their stimulating function.

A view at the Russian economic transformation

2018 ◽  
pp. 142-158 ◽  
Author(s):  
E. F. Baranov ◽  
V. A. Bessonov
Keyword(s):  
Market Economy ◽  
Growth Rates ◽  
Transition Process ◽  
Well Being ◽  
Economic Transformation ◽  
High Rate ◽  
Russian Economy ◽  
Stage Of Development ◽  
Qualitative Level ◽  
Rate Of Recovery

The transition of the Russian economy from plan to market is considered at a qualitative level. The analysis of economic dynamics in the transformation paradigm is conducted. The main stages of the transition process are discussed. Bonuses and costs due to the transition to market economy are considered. The reasons for the outstripping growth of well-being as compared to the growth of output are discussed. The signs of exhaustion of the potential of factors ensuring an abnormally high rate of recovery and accompanying welfare growth are discussed. The conclusion is made that the transformational recovery has been completed. The Russian economy has moved to the stage of development with relatively low growth rates of output and welfare, typical for stable (nontransition) economies.

Concatenation of Circumstances or Historical Regularity?

2009 ◽  
pp. 75-84
Author(s):  
V. Popov
Keyword(s):  
Transition Economies ◽  
Government Expenditure ◽  
Previous History ◽  
Shock Therapy ◽  
Economic Liberalization ◽  
Institutional Capacity ◽  
Government Failure ◽  
Stage Of Development ◽  
Optimal Policies ◽  
Cis Countries

Why have many transition economies succeeded by pursuing policies which are so different from the radical economic liberalization (shock therapy) that is normally credited for the economic success of countries of Central Europe? First, optimal policies are context dependent, they are specific for each stage of development and what worked in Slovenia cannot be expected to work in Mongolia. Second, even for the countries with the same level of development reforms that are necessary to stimulate growth are different; they depend on the previous history and on the path chosen. The reduction of government expenditure as a share of GDP did not undermine significantly the institutional capacity of the state in China, but in Russia and other CIS countries it turned out to be ruinous. The art of the policymaker is to create markets without causing government failure, as happened in many CIS countries.

The Belt and Road Initiative and Sino-Russian economic cooperation: Is there one more chance for us?

2019 ◽  
pp. 47-71
Author(s):  
Petr M. Mozias
Keyword(s):  
Regional Integration ◽  
Raw Materials ◽  
Belt And Road Initiative ◽  
Stage Of Development ◽  
Belt And Road ◽  
Flexible Framework ◽  
The One ◽  
International Transactions ◽  
The Belt And Road ◽  
Current Stage

China’s Belt and Road Initiative could be treated ambiguously. On the one hand, it is intended to transform the newly acquired economic potential of that country into its higher status in the world. China invites a lot of nations to build up gigantic transit corridors by joint efforts, and doing so it applies productively its capital and technologies. International transactions in RMB are also being expanded. But, on the other hand, the Belt and Road Initiative is also a necessity for China to cope with some evident problems of its current stage of development, such as industrial overcapacity, overdependence on imports of raw materials from a narrow circle of countries, and a subordinate status in global value chains. For Russia participation in the Belt and Road Initiative may be fruitful, since the very character of that project provides us with a space to manoeuvre. By now, Russian exports to China consist primarily of fuels and other commodities. More active industrial policy is needed to correct this situation . A flexible framework of the Belt and Road Initiative is more suitable for this objective to be achieved, rather than traditional forms of regional integration, such as a free trade zone.

The Application of UX Research in New Energy Vehicle Innovation

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Menghan TAO ◽  
Ning XIAO ◽  
Xingfu ZHAO ◽  
Wenbin LIU
Keyword(s):  
Early Stage ◽  
Rapid Expansion ◽  
The Other ◽  
Innovative Product ◽  
Stage Of Development ◽  
New Energy ◽  
New Energy Vehicle ◽  
The One ◽  
New Energy Vehicles ◽  
Degree Of Innovation

New energy vehicles(NEV) as a new thing for sustainable development, in China, on the one hand has faced the rapid expansion of the market; the other hand, for the new NEV users, the current NEVs cannot keep up with the degree of innovation. This paper demonstrates the reasons for the existence of this systematic challenge, and puts forward the method of UX research which is different from the traditional petrol vehicles research in the early stage of development, which studies from the user's essence level, to form the innovative product programs which meet the needs of users and being real attractive.

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