An analysis of climatic environments for plant-breeding purposes

1976 ◽  
Vol 27 (1) ◽  
pp. 19 ◽  
Author(s):  
WJR Boyd ◽  
NA Goodchild ◽  
WK Waterhouse ◽  
BB Singh

Variations in the regional means of a number of growing-season climatic variables, and combinations of them, are not highly correlated with the long-term regional distribution of mean wheat yields in Western Australia or with their variation between years. The data suggest that the growing season is characterized by a cyclical alternation of favourable and unfavourable conditions for crop growth. This oscillating pattern varies in amplitude and wavelength as a result of unpredictable 'between'- and 'within'-season variation in the regional distribution of rainfall. In the central zone of the study area, wheat production is subject mainly to between-season variation whilst in more marginal areas yield variation is confounded by opposing and reciprocating within-season effects. The consequences for plant breeding are that specific regional environments expected on the basis of climate do not occur predictably in the short term. It is argued that breeding objectives, selection strategies and regional testing should initially avoid complications associated with specific marginal environments by concentrating on general adaptability within the central zone, which monitors between-season variation only. Subsequent evaluation for additional adaptive features specific to marginal areas should be undertaken.

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Chien-Wei Huang ◽  
Tsung-Han Yang ◽  
Guan-Bo Lin

Potholes, one of the major types of distress on pavement surfaces, damage vehicles and are a safety hazard for the travelling public. In order to mitigate the effect of potholes, cold-mix asphalt (CMA) patching materials are commonly used for urgent repair of pavement surfaces before resurfacing can be undertaken. Therefore, the short-term (initial stability) and long-term (in-service durability) performance evaluation of CMA patching materials is necessary. This study conducted several curing conditions in the laboratory to investigate short-term, long-term, and moisture effects on pavement surfaces. Moreover, this study compared the Marshall stability of samples prepared under various compaction conditions. Marshall stability, Cantabro abrasion, and UK wheel tracking tests were conducted to evaluate the performance of CMA patching materials. The results indicated that the Marshall stability of dense-gradation (DG) CMA patching materials was higher than that of open-graded (OG) CMA patching materials and the Marshall stability of OG CMA patching materials was highly influenced by the coarse aggregate proportion. The DG and OG CMA patching materials exhibited comparable abrasion resistance, and the Cantabro abrasion ratio was highly correlated to the estimated asphalt film thickness for the OG CMA patching materials. A moisture indicator (MI) was proposed, and the effect of moisture damage on Marshall stability and Cantabro abrasion ratio was related to the proposed MI. The rutting resistance of the DG CMA patching materials was higher than that of the OG CMA patching materials, which is consistent with the Marshall stability result.


2012 ◽  
Vol 140 (1) ◽  
pp. 28-43 ◽  
Author(s):  
Michael J. Pook ◽  
James S. Risbey ◽  
Peter C. McIntosh

Abstract Synoptic weather systems form an important part of the physical link between remote large-scale climate drivers and regional rainfall. A synoptic climatology of daily rainfall events is developed for the Central Wheatbelt of southwestern Australia over the April–October growing season for the years 1965–2009. The climatology reveals that frontal systems contribute approximately one-half of the rainfall in the growing season while cutoff lows contribute about a third. The ratio of frontal rainfall to cutoff rainfall varies throughout the growing season. Cutoff lows contribute over 40% of rainfall in the austral autumn and spring, but this falls to about 20% in August when frontal rainfall climbs to more than 60%. The number of cutoff lows varies markedly from one growing season to another, but does not exhibit a significant long-term trend. The mean rainfall per cutoff system is also highly variable, but has gradually declined over the analysis period, particularly in the past decade. The decline in rainfall per frontal system is less significant. Cutoff low rainfall has contributed more strongly in percentage terms to the recent decline in rainfall in the Central Wheatbelt than the frontal component and accounts for more than half of the overall trend. Atmospheric blocking is highly correlated with rainfall in the region where cutoff low rainfall makes its highest proportional contribution. Hence, the decline in rain from cutoff low systems is likely to have been associated with changes in blocking and the factors controlling blocking in the region.


1987 ◽  
Vol 35 (1) ◽  
pp. 87-92 ◽  
Author(s):  
W E Stumpf ◽  
J K Morin ◽  
B W Ennis ◽  
J E Zielinski ◽  
R B Hochberg

We demonstrate the utility of [16 alpha-125I]iodoestradiol for thaw-mount autoradiography with 2 micron and 4 micron thick sections of rat and mouse uterus, pituitary, and brain after in vivo administration. Under the conditions of the experiments, short-term autoradiography with exposure times between 3 and 14 days provides optimal cellular resolution, whereas long-term autoradiography with 1-2 months of exposure may be used to obtain topographic-regional surveys of distribution.


Author(s):  
Fabio Costa ◽  
Francesco Saverio Ambesi-Impiombato ◽  
Tommaso Beccari ◽  
Carmela Conte ◽  
Samuela Cataldi ◽  
...  

Space travel is an extreme experience even for the astronaut who has received extensive basic training in various fields, from aeronautics to engineering, from medicine to physics and biology. Microgravity puts a strain on members of space crews, both physically and mentally: short-term or long-term travel in orbit the International Space Station may have serious repercussions on the human body, which may undergo physiological changes affecting almost all organs and systems, particularly at the muscular, cardiovascular and bone compartments. This review aims to highlight recent studies describing damages of human body induced by the space environment for microgravity, and radiation. All novel conditions, to ally unknown to the Darwinian selection strategies on Earth, to which we should add the psychological stress that astronauts suffer due to the inevitable forced cohabitation in claustrophobic environments, the deprivation from their affections and the need to adapt to a new lifestyle with molecular changes due to the confinement. In this context, significant nutritional deficiencies with consequent molecular mechanism changes in the cells that induce to the onset of physiological and cognitive impairment have been considered.


1993 ◽  
Vol 20 (3) ◽  
pp. 315 ◽  
Author(s):  
B Hariono ◽  
J Ng ◽  
RH Sutton

Lead concentrations were measured in tissues from 37 fruit bats from the Brisbane area and 5 bats from non-urban areas. On the basis of toxicity levels of 25 ug per g of kidney and 10 ug per g of liver, 11 of the Brisbane bats had concentrations consistent with toxicity. Other Brisbane bats had very high lead concentrations in bone and teeth. The lead concentrations in the non-urban bats were very low. Lead concentrations in the fur were variable but were highly correlated with concentrations in bones and teeth, reflecting long-term exposure to lead. High concentrations of lead were recovered from fur washings, which correlated very highly with the concentrations in kidney and liver, reflecting more recent and continuing exposure to lead. The source of the lead was not verified but the atmosphere was the probable source. Measurement of lead concentrations in the fur and its washings would appear to provide a means of monitoring lead accumulation in the tissues of fruit bats over both the long and short term. Such measurements could be valuable in monitoring environmental exposure to lead.


2020 ◽  
Vol 42 (1) ◽  
pp. 1
Author(s):  
Magalí D. Valenta ◽  
Rodolfo A. Golluscio ◽  
Ana L. Frey ◽  
Lucas A. Garibaldi ◽  
Pablo A. Cipriotti

Grazing modifies ecosystem function through direct effects on plants, but also through indirect effects mediated by floristic changes induced by grazing. Although both types of effects occur in the long term, only the direct effects are evident in the short term. We evaluated the short-term direct effects of sheep (Ovis aries) grazing on a Patagonian steppe during one growing season. We measured plant aerial cover in permanent transects located at increasing distances from a watering point in three paddocks with different stocking rates through the growing season. We also measured frequency of defoliation for vegetative and reproductive phases of different plant species located along these transects. Sheep grazing directly (a) reduced aerial cover and/or increased frequency of defoliation of certain preferred grasses and perennial forbs, (b) did not increase the aerial cover of any life form, but only the proportion of bare soil, (c) did not change the litter aerial cover, and (d) defoliated the flowers of even the least preferred shrub. Result a) was coincident with previous plant aerial cover long-term studies; but results (b) and (c) were contrary to long-term studies, probably because they resulted from indirect rather than direct grazing effects. Result (d) was not detected by long-term studies, probably because flower defoliation through grazing is undetectable when measuring shrub plant aerial cover. Our study showed that grazing has short-term direct effects mainly on the most preferred species. This could be useful for rangeland management and conservation of Patagonian steppes because short-term effects may be more easily reversible than long-term ones, and may provide early warning of rangeland condition deterioration.


2016 ◽  
Author(s):  
Matthew Sag

This Article undertakes a broad-based empirical review of intellectualproperty (“IP”) litigation in U.S. federal district courts from 1994 to2014. Unlike the prior literature, this study analyzes federal copyright,patent, and trademark litigation trends as a unified whole. It undertakes asystematic analysis of the records of more than 190,000 cases filed infederal courts and examines the subject matter, geographical, and temporalvariation within federal IP litigation over the last two decades.This Article analyzes changes in the distribution of IP litigation overtime and their regional distribution. The key findings of this Article stemfrom an attempt to understand long-term patterns in the filing data as wellas short-term deviations from various trends. This data-driven approach hasyielded insights in relation to such diverse topics as Internet filesharinglitigation, the true impact of patent trolls on the level of patentlitigation, and the extent of forum shopping and forum selling patentlitigation. Just as importantly, this Article lays the foundation forplanning and evaluating future empirical studies of IP litigation with anarrower focus. Many of the results and conclusions herein demonstrate thedangers of basing empirical conclusions on narrow slices of data fromselected regions or selected time periods.


Behaviour ◽  
2014 ◽  
Vol 151 (9) ◽  
pp. 1281-1311 ◽  
Author(s):  
Jacquelyn K. Grace ◽  
David J. Anderson

Despite a rapid increase in animal personality research, critical gaps remain. We have little knowledge of the long-term (as opposed to short-term) consistency of personality and the relationships between personality and behavioural flexibility in wild, free-living animals. This study investigates personality (i.e., consistent inter-individual differences in behaviour) and contextual plasticity (i.e., plasticity in behaviour between contexts) of these traits in the Nazca booby (Sula granti), a long-lived, free-living seabird. We tested birds for personality in the field, during incubation, using a human intruder test, two novel object tests, and a social stimulus test (mirror), and determined repeatability of behavioural traits both within-season (short-term) and between several years (long-term). We found high short- and long-term repeatability of aggressive and anxiety-related behaviours when confronted with a nest intruder and novel objects, but lower repeatability during social stimulation. Contextual plasticity was highly repeatable across years for aggressive behaviours, and low for anxiety-related behaviours. Plasticity did not correlate across behaviours into a ‘meta-personality’ trait. Contextual plasticity in behavioural traits was highly correlated with the expression of those traits, suggesting that individuals are able to both react strongly and modify their behaviour depending on context, perhaps due to consistent differences in individual quality. Model selection exercises using structural equation models evaluated the relationships between personality factors, indicating a behavioural syndrome in which anxiety- or agitation-related behaviours covary strongly and positively, and both covary weakly and negatively with aggression.


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