scholarly journals Evolution of long-term coloration trends with biochemically unstable ingredients

2016 ◽  
Vol 283 (1831) ◽  
pp. 20160403 ◽  
Author(s):  
Dawn M. Higginson ◽  
Virginia Belloni ◽  
Sarah N. Davis ◽  
Erin S. Morrison ◽  
John E. Andrews ◽  
...  
Keyword(s):  
Breeding Season ◽  
Ecological Factors ◽  
Carotenoid Pigments ◽  
Animal Coloration ◽  
Selective Expression ◽  
Carotenoid Composition ◽  
And Migration ◽  
Short Time ◽  
Repeated Samples

The evolutionarily persistent and widespread use of carotenoid pigments in animal coloration contrasts with their biochemical instability. Consequently, evolution of carotenoid-based displays should include mechanisms to accommodate or limit pigment degradation. In birds, this could involve two strategies: (i) evolution of a moult immediately prior to the mating season, enabling the use of particularly fast-degrading carotenoids and (ii) evolution of the ability to stabilize dietary carotenoids through metabolic modification or association with feather keratins. Here, we examine evolutionary lability and transitions between the two strategies across 126 species of birds. We report that species that express mostly unmodified, fast-degrading, carotenoids have pre-breeding moults, and a particularly short time between carotenoid deposition and the subsequent breeding season. Species that expressed mostly slow-degrading carotenoids in their plumage accomplished this through increased metabolic modification of dietary carotenoids, and the selective expression of these slow-degrading compounds. In these species, the timing of moult was not associated with carotenoid composition of plumage displays. Using repeated samples from individuals of one species, we found that metabolic modification of dietary carotenoids significantly slowed their degradation between moult and breeding season. Thus, the most complex and colourful ornamentation is likely the most biochemically stable in birds, and depends less on ecological factors, such as moult timing and migration tendency. We suggest that coevolution of metabolic modification, selective expression and biochemical stability of plumage carotenoids enables the use of unstable pigments in long-term evolutionary trends in plumage coloration.

Turning Oranges into Apples

2017 ◽  
Author(s):  
Morgan W. Tingley
Keyword(s):  
Empirical Studies ◽  
Repeated Measurements ◽  
Historical Research ◽  
Careful Planning ◽  
Long Term Changes ◽  
Methodological Bias ◽  
Short Time ◽  
Time Frames ◽  
Repeated Samples

Documenting long-term changes in biological systems requires empirical studies that span time frames from decades to centuries. Such time spans generally preclude planned experiments, but revisiting historical research programs or sites and repeating past methods or resurveying sites are being used to infer long-term changes. However, the unplanned nature of such resurveys, along with the uncontrolled environment, in which time becomes one of the treatments, results in imperfectly repeated samples. This chapter reviews inherent problems of resurveys and summarizes methods that help account for imprecision and biases in methods for the design of resurveys and analysis of the resulting data. These methods can also be used to compare repeated measurements taken over short time spans (e.g., days, months, years), although such replicates often minimize bias by having been designed when the first sample was collected. Without such careful planning, however, methodological bias increases with the time elapsed between samples.

Markets, Technological Change and Economic Growth (The Quaid-i-Azam Lecture)

1994 ◽  
Vol 33 (4I) ◽  
pp. 327-356 ◽  
Author(s):  
Richard G. Lipsey
Keyword(s):  
United States ◽  
Economic Growth ◽  
Developing Countries ◽  
Common Ground ◽  
The United States ◽  
Industrial Countries ◽  
Canadian Institute ◽  
Primary Focus ◽  
Short Time

I am honoured to be invited to give this lecture before so distinguished an audience of development economists. For the last 21/2 years I have been director of a project financed by the Canadian Institute for Advanced Research and composed of a group of scholars from Canada, the United States, and Israel.I Our brief is to study the determinants of long term economic growth. Although our primary focus is on advanced industrial countries such as my own, some of us have come to the conclusion that there is more common ground between developed and developing countries than we might have first thought. I am, however, no expert on development economics so I must let you decide how much of what I say is applicable to economies such as your own. Today, I will discuss some of the grand themes that have arisen in my studies with our group. In the short time available, I can only allude to how these themes are rooted in our more detailed studies. In doing this, I must hasten to add that I speak for myself alone; our group has no corporate view other than the sum of our individual, and very individualistic, views.

The Spread of Pollutants from Harbour Sludge Depots

1984 ◽  
Vol 16 (3-4) ◽  
pp. 623-633
Author(s):  
M Loxham ◽  
F Weststrate
Keyword(s):  
Time Scales ◽  
Molecular Diffusion ◽  
Near Field ◽  
Parameter Analysis ◽  
Migration Patterns ◽  
Long Time ◽  
Dilution Effects ◽  
Short Time ◽  
Harbour Sludge

It is generally agreed that both the landfill option, or the civil techniques option for the final disposal of contaminated harbour sludge involves the isolation of the sludge from the environment. For short time scales, engineered barriers such as a bentonite screen, plastic sheets, pumping strategies etc. can be used. However for long time scales the effectiveness of such measures cannot be counted upon. It is thus necessary to be able to predict the long term environmenttal spread of contaminants from a mature landfill. A model is presented that considers diffusion and adsorption in the landfill site and convection and adsorption in the underlaying aquifer. From a parameter analysis starting form practical values it is shown that the adsorption behaviour and the molecular diffusion coefficient of the sludge, are the key parameters involved in the near field. The dilution effects of the far field migration patterns are also illustrated.

scholarly journals Climate Mobility and Development Cooperation

2021 ◽  
Author(s):  
Robert Stojanov ◽  
Sarah Rosengaertner ◽  
Alex de Sherbinin ◽  
Raphael Nawrotzki
Keyword(s):  
Climate Adaptation ◽  
Human Mobility ◽  
Climate Impacts ◽  
Development Cooperation ◽  
Climate Variability And Change ◽  
Policy Frameworks ◽  
And Migration ◽  
And Function ◽  
Role And Function

AbstractDevelopment cooperation actors have been addressing climate change as a cross-cutting issue and investing in climate adaptation projects since the early 2000s. More recently, as concern has risen about the potential impacts of climate variability and change on human mobility, development cooperation actors have begun to design projects that intentionally address the drivers of migration, including climate impacts on livelihoods. However, to date, we know little about the development cooperation’s role and function in responding to climate related mobility and migration. As such, the main aim of this paper is to outline the policy frameworks and approaches shaping development cooperation actors’ engagement and to identify areas for further exploration and investment. First, we frame the concept of climate mobility and migration and discuss some applicable policy frameworks that govern the issue from various perspectives; secondly, we review the toolbox of approaches that development cooperation actors bring to climate mobility; and third, we discuss the implications of the current Covid-19 pandemic and identify avenues for the way forward. We conclude that ensuring safe and orderly mobility and the decent reception and long-term inclusion of migrants and displaced persons under conditions of more severe climate hazards, and in the context of rising nationalism and xenophobia, poses significant challenges. Integrated approaches across multiple policy sectors and levels of governance are needed. In addition to resources, development cooperation actors can bring data to help empower the most affected communities and regions and leverage their convening power to foster more coordinated approaches within and across countries.

scholarly journals A 20-Year Follow-Up Study of Objectively Measured Physical Activity

2021 ◽  
Vol 18 (6) ◽  
pp. 3076
Author(s):  
Anders Raustorp ◽  
Andreas Fröberg
Keyword(s):  
Physical Activity ◽  
Early Adolescence ◽  
Total Sample ◽  
Short Time Span ◽  
Steps Per Day ◽  
Objectively Measured ◽  
Short Time ◽  
Objectively Measured Physical Activity

Background: The objectives of this study were to explore the effect of time, long-term tracking, and the proportion of objectively measured physical activity (PA) from early adolescence to the mid-thirties. Methods: PA was measured as mean steps per day (SPD) with pedometers during 2000 (T1), 2003 (T2), 2005 (T3), 2010 (T4), 2016 (T5) and 2020 (T6). Data from 64 participants (n = 32 males) were analysed from their early adolescence (T1) to their mid-thirties (T6). Results: SPD decreased in the total sample and among males and females (all, p < 0.001). Males took more mean SPD than females during T1 (p = 0.002), whereas females took more mean SPD during T2 (p = 0.009) and T6 (p = 0.008). Males’ mean SPD tracked between T1 and T2 (p = 0.021), T2 and T3 (p = 0.030), T3 and T4 (p = 0.015) and T4 and T5 (p = 0.003). Females’ mean SPD tracked between T3 and T4 (p = 0.024) and T5 and T6 (p < 0.001). In the total sample, more mean SPD were found on weekdays compared to weekend days at T3 (p = 0.017) and T5 (p < 0.001). Conclusions: SPD decreased between T1 and T6. Mean SPD tracked low-to-moderate in the short time span. From late adolescence to the mid-thirties, more mean SPD was observed during weekdays compared to weekend days.

scholarly journals Inferring Long-Term Demand of Newly Established Stations for Expansion Areas in Bike Sharing System

2021 ◽  
Vol 11 (15) ◽  
pp. 6748
Author(s):  
Hsun-Ping Hsieh ◽  
Fandel Lin ◽  
Jiawei Jiang ◽  
Tzu-Ying Kuo ◽  
Yu-En Chang
Keyword(s):  
New York ◽  
Feature Extraction ◽  
Real World ◽  
Extraction Methods ◽  
Real World Data ◽  
Urban Dynamics ◽  
Bike Sharing ◽  
The Government ◽  
Short Time

Research on flourishing public bike-sharing systems has been widely discussed in recent years. In these studies, many existing works focus on accurately predicting individual stations in a short time. This work, therefore, aims to predict long-term bike rental/drop-off demands at given bike station locations in the expansion areas. The real-world bike stations are mainly built-in batches for expansion areas. To address the problem, we propose LDA (Long-Term Demand Advisor), a framework to estimate the long-term characteristics of newly established stations. In LDA, several engineering strategies are proposed to extract discriminative and representative features for long-term demands. Moreover, for original and newly established stations, we propose several feature extraction methods and an algorithm to model the correlations between urban dynamics and long-term demands. Our work is the first to address the long-term demand of new stations, providing the government with a tool to pre-evaluate the bike flow of new stations before deployment; this can avoid wasting resources such as personnel expense or budget. We evaluate real-world data from New York City’s bike-sharing system, and show that our LDA framework outperforms baseline approaches.

EFFECT OF CORTICOSTEROIDS ON URINARY 5β AND 5α C19 STEROIDS IN MAN

1964 ◽  
Vol 46 (2) ◽  
pp. 197-206 ◽  
Author(s):  
Hildegard Wilson ◽  
Steven Schenker
Keyword(s):  
Testosterone Propionate ◽  
Periodic Fever ◽  
Term Treatment ◽  
Long Term Treatment ◽  
Dexamethasone Therapy ◽  
Normal Women ◽  
Normal Men ◽  
Short Time

ABSTRACT A high proportion of urinary C19 5β to 5α steroid metabolites has been found on administration of glucocorticoids in a number of instances. During long term treatment with prednisone or dexamethasone, 100 mg testosterone propionate was administered to 3 patients. The ratios of the resulting metabolites etiocholanolone (E, 5β) to androsterone (A, 5α) were 2.7, 3.3 and 2.1, compared to 1.3 and 0.9 after withdrawal of corticoids from the first 2 patients. In 3 normal men, ratios of endogenously derived E and A while receiving corticoids, compared to control ratios were 2.3 to 1.0, 2.2 to 0.6 and 1.2 to 0.9. Ratios in normal women rose from 1.1 to 2.2 and 2.4 to 4.3 on receiving dexamethasone. Not all subjects gave the expected response. In 3 of these the dosage of corticoid was either low or given for a short time. The ratio of C19O3 metabolites of administered 11β-hydroxy-androst-4-ene-3,17-dione was also changed in favour of the 5β products during corticoid treatment. In a man with periodic fever the high E/A ratios observed were probably related to dexamethasone therapy rather than to the disease.

scholarly journals The Long-Term Consequences of Civil War for Migration: The Case of Tajikistan

2019 ◽  
Author(s):  
Michelle O'Brien
Keyword(s):  
Civil War ◽  
Armed Conflict ◽  
District Level ◽  
Policy Makers ◽  
Peace Accord ◽  
Logistic Regression Models ◽  
Individual Household ◽  
Level I ◽  
And Migration

Armed conflict is socially transformative. Although migration research has established the proximate relationship between armed conflict and increases in migration, much less attention has been paid to the long-term, or distal relationship. This research leverages the case of the 1992-1997 Tajikistani Civil War to examine the distal relationship between armed conflict and migration decisions nearly a decade after the war had ended. Using a series of logistic regression models and a selection-based endogeneity correction, I estimate the likelihood of migrating in 2006, given the intensity of conflict experience at the district level. I find that, controlling for individual, household, and district-level indicators, the legacy of conflict continues to influence migration – for men and for ‘stayers’ – nearly a decade after the peace accord was signed. Some evidence suggests that certain kinds of development projects can moderate this relationship. In conflict-affected countries, incorporating the legacy of conflict into empirical research can help scholars and policy-makers better understand migration in the aftermath of war.

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