scholarly journals Population studies of tree-defoliating insects in Canada: a century in review

2016 ◽  
Vol 148 (S1) ◽  
pp. S58-S81 ◽  
Author(s):  
R.C. Johns ◽  
L. Flaherty ◽  
D. Carleton ◽  
S. Edwards ◽  
A. Morrison ◽  
...  
Keyword(s):  
Life History Traits ◽  
Population Studies ◽  
Future Research ◽  
Past Century ◽  
Larval Feeding ◽  
The Past ◽  
Major Species ◽  
Time Series Studies ◽  
The Impact ◽  
Egg Clustering

AbstractOur review highlights research during the past century focussed on the population ecology of outbreak-prone insect defoliators in Canadian forests. Based on reports from national and provincial surveys that began in the 1930s, there have been at least 106 insect defoliators reported to outbreak, most of which are native Lepidoptera, Hymenoptera (sawflies), or Coleoptera (in order of frequency from most to least). Studies comparing life-history traits of outbreak versus non-outbreak species to better understand why certain species are more outbreak-prone indicate several traits especially common among outbreak species, including egg clustering and aggregative larval feeding. There have been at least 50 time-series studies examining the spatiotemporal population behaviour of 12 major defoliator species. These studies provide evidence for both regular periodicity and spatial synchrony of outbreaks for most major species. Life-table studies seeking to understand the agents causing populations to fluctuate have been carried out for at least seven outbreak species, with the majority identifying natural enemies (usually parasitoids) as the major driver of outbreak collapse. Our review concludes with several case studies highlighting the impact and historical underpinnings of population studies for major defoliator species and a discussion of potential avenues for future research.

Fire, people and ecosystem change in Pleistocene Australia

2016 ◽  
Vol 64 (8) ◽  
pp. 643 ◽  
Author(s):  
Christopher N. Johnson
Keyword(s):  
Fire Regimes ◽  
Ecosystem Change ◽  
Future Research ◽  
Cascading Effects ◽  
Continental Scale ◽  
The Past ◽  
The 1960S ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

Since the 1960s, Australian scientists have speculated on the impact of human arrival on fire regimes in Australia, and on the relationship of landscape fire to extinction of the Pleistocene megafauna of Australia. These speculations have produced a series of contrasting hypotheses that can now be tested using evidence collected over the past two decades. In the present paper, I summarise those hypotheses and review that evidence. The main conclusions of this are that (1) the effects of people on fire regimes in the Pleistocene were modest at the continental scale, and difficult to distinguish from climatic controls on fire, (2) the arrival of people triggered extinction of Australia’s megafauna, but fire had little or no role in the extinction of those animals, which was probably due primarily to hunting and (3) megafaunal extinction is likely to have caused a cascade of changes that included increased fire, but only in some environments. We do not yet understand what environmental factors controlled the strength and nature of cascading effects of megafaunal extinction. This is an important topic for future research.

Quality of life following surgery for congenital cardiac malformations in neonates and infants

2005 ◽  
Vol 15 (S1) ◽  
pp. 174-178 ◽  
Author(s):  
Kathleen Mussatto ◽  
James Tweddell
Keyword(s):  
Quality Of Life ◽  
Future Research ◽  
Cardiac Malformations ◽  
The Past ◽  
Congenital Cardiac Disease ◽  
Major Shift ◽  
Neonates And Infants ◽  
The Impact

The past two decades have witnessed a major shift towards repair of most congenital cardiac malformations during the neonatal or infant periods of life.1 Early anatomic correction or palliation, dramatic improvements in survival, and reduced morbidity due to improvements in perioperative and long-term medical management, have resulted in new populations of children that have reaped the benefits of the best care currently available for treatment of congenital cardiac disease. The impact of the congenital cardiac malformations, however, extends far beyond the walls of the hospital or clinic where we diagnose, treat, and follow our patients. The breakthrough of achieving predictable results with repair or palliation of most lesions during the neonatal and infant periods mandates us to look beyond survival, and to examine the lives our patients lead when they are outside of our care. Our purpose in this review is to discuss the measures of psychosocial outcome that are appropriate for exploration in those neonates and infants who survive cardiac surgery, to explore what is known about the psychosocial outcomes and quality of life for these patients, and what needs exist for future research.

The Economics of Early Interventions Aimed at Child Development

2019 ◽  
Author(s):  
Samuel Berlinski ◽  
Marcos Vera-Hernández
Keyword(s):  
Child Development ◽  
Early Childhood Development ◽  
Parental Leave ◽  
Decision Makers ◽  
Childhood Development ◽  
Parenting Programs ◽  
Future Research ◽  
Early Interventions ◽  
The Past ◽  
The Impact

A set of policies is at the center of the agenda on early childhood development: parenting programs, childcare regulation and subsidies, cash and in-kind transfers, and parental leave policies. Incentives are embedded in these policies, and households react to them differently. They also have varying effects on child development, both in developed and developing countries. We have learned much about the impact of these policies in the past 20 years. We know that parenting programs can enhance child development, that centre based care might increase female labor force participation and child development, that parental leave policies beyond three months don’t cause improvement in children outcomes, and that the effects of transfers depend much on their design. In this review, we focus on the incentives embedded in these policies, and how they interact with the context and decision makers to understand the heterogeneity of effects and the mechanisms through which these policies work. We conclude by identifying areas of future research.

scholarly journals Impact of Recent Climate Change on Water-Use Efficiency Strategies of Larix sibirica in the Altai-Sayan Mountain Range

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1103
Author(s):  
Olga V. Churakova (Sidorova) ◽  
Marina V. Fonti ◽  
Rolf T. W. Siegwolf ◽  
Matthias Saurer ◽  
Vladimir S. Myglan
Keyword(s):  
Water Use ◽  
Air Temperature ◽  
Siberian Larch ◽  
Larix Sibirica ◽  
Strong Increase ◽  
Past Century ◽  
Mountain Range ◽  
The Past ◽  
Recent Climate ◽  
The Impact

A strong increase in the mean annual air temperature during the past 50 years by up to 0.54 °C was recorded in the Altai region (45°–52° N; 84°–99° E) compared to the global value of 0.07 °C over the period 1901–2008. The impact of the climatic changes on the hydrology are complex in these mountainous forest ecosystems and not fully understood. We aim to reveal differences in the intrinsic water-use efficiencies (iWUE) strategy by larch (Larix sibirica Ledeb.) derived from stable carbon isotopes at contrasting sites, ranging from the steppe (Ersin, Chadan) to high-elevation (Mongun, Koksu) sites of the Altai over the past century. The iWUE trends increased rapidly for all study sites except Chadan, where a decreasing trend after 2010 has been observed. This decline can be related to increased amount of precipitation compared to increased drought at the other sites. In general, the iWUE is increased up to 14% (1985–2019 compared to 1919–1984), which is lower compared to other studies across the globe likely due to harsh climatic conditions. Vapor pressure deficit and maximal air temperature are impacting Siberian larch significantly and affecting their iWUE differently at the high-elevated and steppe sites of the Altai over the past century.

The Impact of Anarchy on English Monasticism, 1135-1154

1974 ◽  
Vol 6 (3) ◽  
pp. 218-232 ◽  
Author(s):  
Thomas Callahan
Keyword(s):  
Civil Wars ◽  
Twelfth Century ◽  
Traditional View ◽  
Past Century ◽  
The Past ◽  
The Impact

King Stephen's reign has long been recognized as a crucial period for monasticism in England. Many authors have written about alleged anarchical conditions during those nineteen years, and scholars have done a great deal of work on twelfth century English monasticism; nevertheless, comparatively little attention has been paid to the impact of this supposed anarchy on the monastic establishment. This impact is the concern of this essay. Due to the limitation of space, I will confine myself to the material damages suffered by monastic houses during Stephen's reign and will offer an extended summary of my findings.The traditional picture of anarchy in England during Stephen's reign is that the civil wars wreaked havoc with nearly all aspects of life and inflicted massive and long lasting material damages. Medieval writers—most memorably the Peterborough chronicler— emotionally depicted scenes of terror and devastation, and the majority of later scholars—most notably H. W. C. Davis—upheld the basic validity of this picture. During the past century, however, historians have somewhat modified the traditional view. Whereas most medieval writers described an England embroiled in internal warfare for nearly all of Stephen's nineteen year reign, modern scholars have realized that the area of active fighting was more limited and that actual warfare lasted less than half of the reign. Also, modern scholars have shown that many of the occurrences in Stephen's reign were not characterized by aimless chaos and confusion, but rather by purposeful actions directed towards specific ends.

Death at the End of the 20th Century: Individual Processes and Developmental Tasks in Old Age

2002 ◽  
Vol 54 (4) ◽  
pp. 315-333 ◽  
Author(s):  
Christina Röcke ◽  
Katie E. Cherry
Keyword(s):  
Life Expectancy ◽  
Old Age ◽  
Personal Experience ◽  
Public Awareness ◽  
Developmental Tasks ◽  
Past Century ◽  
Research Practice ◽  
The Past ◽  
And Coping ◽  
The Impact

In this article, we address the topic of death from historic and contemporary perspectives. In the first section, we describe the changes in life expectancy, personal experience, and public awareness of death that have occurred over the past century. In the next section, we examine the impact these changes have had on the mastery of the two developmental tasks in adulthood, acceptance of one's own mortality and coping with the death of a spouse. We describe select findings from the literature on attitudes, fear or acceptance of death, and grief processes. Implications for research, practice, and social change are considered.

Civilization and Rapid Climatic Change

1988 ◽  
Vol 15 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Reid A. Bryson
Keyword(s):  
Climatic Change ◽  
Volcanic Activity ◽  
Plate Tectonics ◽  
Field Experiments ◽  
Climatic Changes ◽  
Climatic Variation ◽  
Past Century ◽  
Ice Ages ◽  
The Past ◽  
The Impact

Research over the past century has shown that the rates and magnitudes of climatic change constitute a continuum. Changes have now been identified in the climatic record that range in duration from interannual through decades and centuries to the multi-millennial time-scale. Examples range from the drought years of the 1930 and 1970 decades to the ponderous comings and goings of the ice-ages. More recently it has become clear that some changes can be quite rapid. In recent decades great progress has been made in identifying the causes of climatic variation.The present understanding of the causes of climatic change emphasizes continental drift (or ‘plate tectonics’) at the million-years' scale, with pulses of plate movement producing significant bursts of volcanic activity that may act on the millennial or century scale. At the multi-millennial scale there is growing agreement that the variations in irradiance of the Earth, resulting from slow changes in the Sun-Earth geometry (the so-called Milankovitch variations), exercise the operative control on the timing of ice-ages and interglacials. At the decadal and interannual scales there is less agreement; but there is at least a body of research which suggests that significant volcanic activity is a contributing factor. There is considerable agreement—but little direct evidence—that anthropogenic causes such as increased carbon dioxide and other Man-made or-enhanced trace gases in the atmosphere, will be important in the coming decades.Cultural responses might be expected to differ across this continuum. To assess the expected response to a climatic variation, one must know at least the shape of the response surface.There is probably a critical threshold combination of climatic change magnitude and duration. Human cultures seem to be adapted to frequently-occurring short ‘aberrations’ from the expected climate. Some evidence indicates, on the other hand, that relatively small changes of climates (of the order of a century in duration) have been associated over the past 8,000 years with cultural changes that proved large enough to lead to different names being assigned in perhaps half of the cultural termini identified. A climate model which includes the effect of volcanic aerosols, suggests that most of the climatic changes associated with these globally synchronous cultural termini are related to peaks of volcanic activity. Some apparently catastrophic events have been recognized in this connection.There remains the problem of assessing, in realistic terms, the impact of large-magnitude climatic variations on modern human societies. Of particular concern is the effect of climatic events associated with very large-scale short-term insertions of aerosols into the atmosphere. It is likely that non-equilibrium models of the atmosphere, with specified sea-surface temperatures, would give realistic results if refined to the degree that they could replicate events of lesser magnitude which have occurred in the past century. At present there appear to be no models in which the formulation of the radiative effect of aerosols or gases gives a good match with observed radiative effects. It seems that much more research, including field experiments, will be needed if science is to supply reliable advice to society on the nature of coming climatic changes.

scholarly journals ABOUT THE POSSIBILITY OF COOLANT FLOWING THROUGH THE PIPES OF THE SOLAR COLLECTOR SYSTEM FOR HEATING

2020 ◽  
pp. 131-137
Author(s):  
А.N. Odintsov ◽  
L.A. Nichkova ◽  
I.I. Zaruk
Keyword(s):  
Past Century ◽  
Anthropogenic Pressure ◽  
Solar Collectors ◽  
Additional Energy ◽  
The Past ◽  
Collector System ◽  
Average Global Temperature ◽  
Instrumental Observations ◽  
Gaseous Coolant ◽  
The Impact

This article discusses the impact of anthropogenic pressure on the environment, in particular, the tendency for the average global temperature to change on the earth’s surface. As one of the factors that have a significant effect on the increase in temperature should certainly include an increase in the concentration of carbon dioxide in the atmosphere. Although over the past century of instrumental observations, its concentration has increased from 0.02% to 0.03%, the effect of this change is felt in all corners of the planet. One of the ways to reduce the anthropogenic load is the search for ways to further, more efficiently use the energy of solar radiation to heat various buildings and structures. The article considers the possibility and feasibility of changing the framework of traditional coaxial vacuum tubular solar collectors. The proposed changes in the framework of traditional coaxial vacuum tubular solar collectors will allow the movement of a liquid or gaseous coolant, without changing its phase state, due to the action of gravitational forces. The proposed framework can function completely autonomously and does not require additional energy sources for ability of circulation of the coolant.

scholarly journals Ecological-evolutionary analysis of lithium content in soils

2018 ◽  
Vol 17 (1-2) ◽  
pp. 31-39
Author(s):  
Y. M. Dmytruk
Keyword(s):  
Chemical Elements ◽  
Parent Rock ◽  
Analytical Determination ◽  
Future Research ◽  
Lithium Content ◽  
Evolutionary Analysis ◽  
Buried Soils ◽  
The Past ◽  
Mobile Forms ◽  
The Impact

The point is that investigation of geochemistry and behavior of Lithium in Ukraine’s soils is been rather exceptional. We have analyzed the content of Lithium in soils: modern and buried under the ramparts of various ages. The research territory includes Prut-Dniester and Prut-Siret interfluvial. Most often there are Phaeozems (Luvic Phaeozem, or Mollic Gleysol or Eutric Gleysol) and Chernozems (Luvic Chernozem or Chernic Chernozem). Buried soils are located directly near the modern background soils, so the differences between them are the result of evolution of the background soils during burial (the screening) after the construction of ramparts. On the Podvirna site current landscapes are wood and meadow-steppe; in the past, subboreal stage, were probably closer to the steppe; buried soil – Chernozem typical with a little profile, in the modern of soil structure prevails Luvic Phaeozem. The sites Ridkivtsi and Grushivka are characterized forest landscapes and in the past on those areas dominated wood-meadow landscapes. At present prevailing types of soils are Phaeozems or Gleysol. Soil samples have taken for the genetic horizons. After drying and preparing of soils in them had performed analytical determination of total content (Nitrate extract, followed by evaporation of hydrogen peroxide) of Lithium and its mobile forms (ammonium acetate-extract with pH = 4,8). The results of analyzes had processed by using statistical and mathematical testing based on the program «Statistica 6.0». Our obtained results are indicating background of total Lithium content, which ranges from 8,70 to 33,5 mg∙kg-1 and its average amount was 22,3±6,01 mg∙kg-1; amplitude quantity of Lithium mobile forms is between 0,20 to 2,60 mg∙kg-1, with an average content of 0,60±0,57 mg∙kg-1. The mean of total Lithium content of all soils with buried soils in particular are decreased from Podvirna site (27,4 mg∙kg-1) to the site Ridkivtsi (22,8 and 26,3 mg∙kg-1, accordingly) and site Grushivka (20,0 and 19,1 mg∙kg-1, accordingly), while the number of mobile forms changed significantly from substantial Podvirne hospital (1,43 mg∙kg-1) to the hospital Grushivka (0,83 and 0,91 mg∙kg-1, respectively) and hospital Ridkivtsi (0,44 and 0,79 mg∙kg-1, appropriately). In the majority of background soils we had discovered humus-eluvial-illuvial redistribution, sometimes - eluvial-illuvial redistribution. It is important to know that we had not observed high Lithium content in the parent rock of soils (except for two sections of the site Ridkivtsi with discussion rather recognition of the parent rock of the profile). This is demonstrating the determining influence of pedogenesis on the redistribution of chemical elements in the of soils. Actually, Lithium has often accumulated in the upper humus horizons (as a result of the impact of organic matter and of soil biota as a whole) or in the horizons of clay accumulation. To crown it all pedogenesis fundamentally has changing features of the vertical distribution of Lithium content. Concerning future research is necessity of application of isotopic analysis to identify the characteristics of different ages soils.

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