Population Dynamics and Regulation

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This page intentionally left blank An Introduction to Law and RegulationText and MaterialsIn recent years, regulation has emerged as one of the most distinct and importantfields of study in the social sciences, both for policy-makers and for scholarswho require a theoretical framework that can be applied to any social sector.This timely textbook provides a conceptual map of the field and an accessible andcritical introduction to the subject. Morgan and Yeung set out a diverse andstimulating selection of materials and give them context with a compre-hensive and critical commentary. By adopting an interdisciplinary approachand emphasising the role of law in its broader social and political context, itwill be an invaluable tool for the student coming to regulation for the firsttime. This clearly structured, academically rigorous title, with a contextualizedperspective is essential reading for all students of the subject.BRONWENMORGANis Professor of Socio-legal Studies at the University ofBristol. Her research focuses on the political economy of regulatory reformand global governance. She is the author of Social Citizenship in the Shadow ofCompetition (2003).KARENYEUNGis Professor of Law at Kings’ College London. She was auniversity lecturer at Oxford University and a Tutorial Fellow in Law atSt Anne’s College from 1996 until 2006. Her research lies in the intersectionof public law and socio-economic regulation. The Law in Context SeriesEditors: William Twining (University College London) and Christopher McCrudden(Lincoln College, Oxford)Since 1970 the Law in Context series has been in the forefront of the movement tobroaden the study of law. It has been a vehicle for the publication of innovative scholarlybooks that treat law and legal phenomena critically in their social, political and eco-nomic contexts from a variety of perspectives. The series particularly aims to publishscholarly legal writing that brings fresh perspectives to bear on new and existing areas oflaw taught in universities. A contextual approach involves treating legal subjects broadly,using materials from other social sciences, and from any other discipline that helpsto explain the operation in practice of the subject under discussion. It is hoped thatthis orientation is at once more stimulating and more realistic than the bare expositionof legal rules. The series includes original books that have a different emphasis fromtraditional legal textbooks, while maintaining the same high standards of scholarship.They are written primarily for undergraduate and graduate students of law and of otherdisciplines, but most also appeal to wider readership. In the past, most books in theseries have focused on English law, but recent publications include books on Europe law,globalisation, transnational legal processes and comparative law.Books in the SeriesAnderson, Schum & Twining: Analysis of EvidenceAshworth: Sentencing and Criminal JusticeBarton & Douglas: Law and ParenthoodBeecher-Monas: Evaluating Scientific Evidence: An InterdisciplinaryFramework for Intellectual Due ProcessBell: French Legal CulturesBercusson: European Labour LawBirkinshaw: European Public lawBirkinshaw: Freedom of Information: The Law, the Practice and the IdealCane: Atiyah’s Accidents, Compensation and the LawClarke & Kohler: Property Law: Commentary and MaterialsCollins: The Law of ContractDavies: Perspectives on Labour LawDembour: Who Believes in Human Rights?: The European Convention in Questionde Sousa Santos: Toward a New Legal Common SenseDiduck: Law’s FamiliesElworthy & Holder: Environmental Protection: Text and MaterialsFortin: Children’s Rights and the Developing LawGlover-Thomas: Reconstructing Mental Health Law and PolicyGobert & Punch: Rethinking Corporate CrimeHarlow & Rawlings: Law and Population Dynamics and Regulation Population Dynamics and Regulation Bởi: OpenStaxCollege The logistic model of population growth, while valid in many natural populations and a useful model, is a simplification of real-world population dynamics Implicit in the model is that the carrying capacity of the environment does not change, which is not the case The carrying capacity varies annually: for example, some summers are hot and dry whereas others are cold and wet In many areas, the carrying capacity during the winter is much lower than it is during the summer Also, natural events such as earthquakes, volcanoes, and fires can alter an environment and hence its carrying capacity Additionally, populations not usually exist in isolation They engage in interspecific competition: that is, they share the environment with other species, competing with them for the same resources These factors are also important to understanding how a specific population will grow Nature regulates population growth in a variety of ways These are grouped into densitydependent factors, in which the density of the population at a given time affects growth rate and mortality, and density-independent factors, which influence mortality in a population regardless of population density Note that in the former, the effect of the factor on the population depends on the density of the population at onset Conservation biologists want to understand both types because this helps them manage populations and prevent extinction or overpopulation Density-dependent Regulation Most density-dependent factors are biological in nature (biotic), and include predation, inter- and intraspecific competition, accumulation of waste, and diseases such as those caused by parasites Usually, the denser a population is, the greater its mortality rate For example, during intra- and interspecific competition, the reproductive rates of the individuals will usually be lower, reducing their population’s rate of growth In addition, low prey density increases the mortality of its predator because it has more difficulty locating its food source 1/8 Population Dynamics and Regulation An example of density-dependent regulation is shown in [link] with results from a study focusing on the giant intestinal roundworm (Ascaris lumbricoides), a parasite of humans and other mammals N.A Croll et al., “The Population Biology and Control of Ascaris lumbricoides in a Rural Community in Iran.” Transactions of the Royal Society of Tropical Medicine and Hygiene 76, no (1982): 187-197, doi:10.1016/0035-9203(82)90272-3 Denser populations of the parasite exhibited lower fecundity: they contained fewer eggs One possible explanation for this is that females would be smaller in more dense populations (due to limited resources) and that smaller females would have fewer eggs This hypothesis was tested and disproved in a 2009 study which showed that female weight had no influence Martin Walker et al., “Density-Dependent Effects on the Weight of Female Ascaris lumbricoides Infections of Humans and its Impact on Patterns of Egg Production.” Parasites & Vectors 2, no 11 (February 2009), doi:10.1186/1756-3305-2-11 The actual cause of the density-dependence of fecundity in this organism is still unclear and awaiting further investigation In this population of roundworms, fecundity (number of eggs) decreases with population density N.A Croll et al., “The Population Biology and Control of Ascaris lumbricoides in a Rural Community in Iran.” Transactions of the Royal Society of Tropical Medicine and Hygiene 76, no (1982): 187-197, doi:10.1016/ 0035-9203(82)90272-3 Density-independent Regulation and Interaction with Density-dependent Factors Many factors, typically physical or chemical in nature (abiotic), influence the mortality of a population regardless of its density, including weather, natural disasters, and pollution An individual deer may be killed in a forest fire regardless of how many deer happen to be in that area Its chances of survival are the same whether the population density is high or low The same holds true for cold winter weather 2/8 Population Dynamics and Regulation In real-life situations, population regulation is very complicated and density-dependent and independent factors can interact A dense population that is reduced in a densityindependent manner by some environmental factor(s) will be able to recover differently than a sparse population For example, a population of deer affected by a harsh winter will recover faster if there are more deer remaining to reproduce Evolution Connection Why Did the Woolly Mammoth Go Extinct? The three photos include: (a) 1916 mural of a mammoth herd from the American Museum of Natural History, (b) the only stuffed mammoth in the world, from the Museum of Zoology located in St Petersburg, Russia, and (c) a one-month-old baby mammoth, named Lyuba, discovered in Siberia in 2007 (credit a: modification of work by Charles R Knight; credit b: ...Original article Patterns in individual growth, branch population dynamics, and growth and mortality of first-order branches of Betula platyphylla in northern Japan Kiyoshi Umeki a,* and Kihachiro Kikuzawa a Hokkaido Forestry Research Institute, Koshunai, Bibai, Hokkaido 079-0198, Japan b Laboratory of Forest Biology, Graduate School of Agriculture, Kyoto University, Japan (Received 1 February 1999; accepted 27 March 1999) Abstract – Growth of individual trees, population dynamics of first-order branches within individuals, and growth and mortality of first-order branches were followed for two years in an plantation of Betula platyphylla in central Hokkaido, northern Japan. The data were analyzed by stepwise regressions. The relative growth rate in terms of above-ground biomass of individuals was negatively correlated with a log-transformed competition index (ln(CI)), which was calculated for each individual from the size and distance of its neighbours. The change in branch number within an individual was also correlated with ln(CI). The growth and mortality of branches was correlated with the size of branches, size of individuals, growth of individuals, relative height of branches, and ln(CI). Generally, the patterns revealed by the regressions were consistent with what was expected and can be used as references against which the behavior of more detailed process-based models can be checked. Betula platyphylla / branch population dynamics / competition / branch growth / branch mortality Résumé – Modèles de croissance individuelle, dynamique de développement des branches et croissance et mortalité des branches du Betula Platyphylla. La croissance des arbres individuels, la dynamique de développement des branches de premier ordre sur les arbres individuels ainsi que la croissance et la mortalité des branches de premier ordre ont été étudiées pendant deux ans dans une pépinière de Betula Platyphylla de la région centrale du Hokkaido dans le nord du Japon. Les modèles de croissance indivi- duelle, la dynamique de développement des branches et la croissance et la mortalité des branches ont été analysées selon leur régres- sion progressive. Le taux de croissance relatif en termes de biomasse aérienne des arbres individuels s’est avéré en rapport inverse à l’index de concurrence des grumes (ln(CI)), après calcul pour chaque individu d’après la taille et l’éloignement de ses voisins. Le changement du nombre de branches sur un même individu est également en rapport avec ln(CI). La croissance et la mortalité des branches s’est avérée en rapport avec la taille des branches, la taille des individus, la croissance des individus, la hauteur relative des branches et ln(CI). En général, les modèles mis en évidence par les régressions sont conformes aux hypothèses avancées et peuvent servir de référence pour le contrôle d’autres modèles plus détaillés. Betula platyphylla / dynamique de développement des branches / compétition / croissance des branches / mortalité des branches Ann. For. Sci. 57 (2000) 587–598 587 © INRA, EDP Sciences * Correspondence and reprints Tel. +81-1266-3-4164; Fax. +81-1266-3-4166; e-mail: umeki@hfri.bibai.hokkaido.jp K. Umeki and K. Kikuzawa 588 1. INTRODUCTION An individual tree is constructed from structural units growing and iterating within an individual [12, 45], and can be thought of as a population of structural units [45]. Thus far, various components of an individual plant such as branches, shoots, and metamers [34] have been used as the structural unit, or module, of a tree. In this paper, the term “module” is defined, following Harper [13], as “a repeated unit of multicellular structure, normally arranged in a branch system.” The spatial and static aspects of a module population within a tree can be expressed by the spatial distribution of modules within a tree. The distribution of modules is important because it determines the crown form and the amount of light captured by the crown; future growth is RESEARC H Open Access Evolution of Dengue Virus Type 3 Genotype III in Venezuela: Diversification, Rates and Population Dynamics Alvaro Ramírez 1† , Alvaro Fajardo 2† , Zoila Moros 1 , Marlene Gerder 1 , Gerson Caraballo 1 , Daria Camacho 3 , Guillermo Comach 3 , Victor Alarcón 4 , Julio Zambrano 4 , Rosa Hernández 4 , Gonzalo Moratorio 2 , Juan Cristina 2* , Ferdinando Liprandi 1 Abstract Background: Dengue virus (DENV) is a member of the gen us Flavivirus of the family Flaviviridae. DENV are comprised of four distinct serotypes (DENV-1 through DENV-4) and each serotype can be divided in different genotypes. Currently, there is a dramatic emergence of DENV-3 genotype III in Latin America. Nevertheless, we still have an incomplete understanding of the evolutionary forces underlying the evolution of this genotype in this region of the world. In order to gain insight into the degree of genetic variability, rates and patterns of evolution of this genotype in Venezuela and the South American region, phylogenetic analysis, based on a large number (n = 119) of envelope gene sequences from DENV-3 genotype III strains isolated in Venezuela from 2001 to 2008, were performed. Results: Phylogenetic analysis revealed an in situ evolution of DENV-3 genotype III following its introduction in the Latin American region, where three different genetic clusters (A to C) can be observed among the DENV-3 genotype III strains circulating in this region. Bayesian coalescent inference analyses revealed an evolutionary rate of 8.48 × 10 -4 substitutions/site/year (s/s/y) for strains of cluster A, composed entirely of strains isolated in Venezuela. Amino acid substitution at position 329 of domain III of the E protein (A®V) was found in almost all E proteins from Cluster A strains. Conclusions: A significant evolutionary change between DENV-3 genotype III strains that circulated in the initial years of the introduction in the continent and strains isolated in the Latin American region in recent years was observed. The presence of DENV-3 genotype III strains belonging to different clusters was observed in Venezuela, revealing several introduction events into this country. The evolutionary rate found for Cluster A strains circulating in Venezuela is similar to the others previously established for this genotype in other regions of the world. This suggests a lack of correlation among DENV genotype III substitution rate and ecological pattern of virus spread. Background Dengue virus (DENV) is a member of the genus Flavi- virus of the family Flaviviridae. DENV are mosquito-borne flaviviruses with a single- stranded, nonsegmented, positive-sense RNA genome of approximately 11 kb in le ngth [1]. Dengue viruses are comprised of four distinct sero types (DENV-1 through DENV-4), which are transmitted to humans through the bites of two mosquito species: Aedes aegypti and Aedes albopictus [2]. DENV causes a wide range of diseases in humans, from the acute febrile illness dengue fever (DF) to life- threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). Dengue has spread throughout tropical and subtropical r egions worldwide over the past several decades, with an estimated 100 million infections and tens of millions of cases occurring annually [3]. Currently, there is a dramatic re-emergence of DENV in * Correspondence: cristina@cin.edu.uy † Contributed equally 2 Laboratorio de Virología Molecular. Centro de Investigaciones Nucleares. Facultad de Ciencias, Igua 4225, 11400 Montevideo, Uruguay Full list of author information is available at the end of the article Ramírez et al. Virology Journal 2010, 7:329 http://www.virologyj.com/content/7/1/329 © 2010 Ramírez et al; licensee BioMed Central Ltd. This is an Open Ac cess article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is Institut für Nutzpflanzenwissenschaften und Ressourcenschutz der Rheinischen Friedrich-Wilhelms-Universität Bonn Characterisation of fitness parameters and population dynamics of Botrytis cinerea for the development of fungicide resistance management strategies in grapevine Inaugural-Dissertation zur Erlangung des Grades Doktor der Agrarwissenschaften (Dr agr.) der Landwirtschaftlichen Fakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn vorgelegt am 08.08.2013 von Jürgen Derpmann aus Kalkar ABSTRACT Referent: Prof Dr H.-W Dehne Korreferent: Prof Dr H E Goldbach Tag der mündlichen Prüfung: 21.02.2014 Erscheinungsjahr: 2014 ABSTRACT Dedicated To My Parents ABSTRACT Jürgen Derpmann Characterization of Fitness Parameters and Population Dynamics of Botrytis cinerea for the Development of Fungicide Resistance Management Strategies in Grapevine Gray mold caused by the fungus Botrytis cinerea is an economically important disease in grapevine The pathogen has a high tendency to become resistant to frequently applied systemic fungicides Only a few years after introduction of the fungicide class of benzimidazoles (MBC), resistant strains appeared frequently in European vineyards Since the discontinuation of the use of benzimidazoles to control B cinerea in 1975, the frequency of MBC-resistant strains decreased significantly In the present study, the influence of fungicide resistance management strategies on the population dynamics of B cinerea isolates resistant to fungicides was investigated in a three year field trial at three sites near Bordeaux The tested strategies were mixture, alternation and annual alternation of thiophanate-methyl (TM) and mepanipyrim (MP) Strategies were compared to the solo application of TM and conventional fungicide treatments, where no TM was applied Frequencies of fungicide-resistant isolates were determined in monitoring procedures conducted prior and subsequent to fungicide applications In all three years, spray programs including TM resulted in significantly higher frequencies of TM-resistant isolates (BenR1 phenotype) compared to those detected in conventionally treated plots In the first year, all strategies tested led to similar BenR1 isolate frequencies compared to the solo application of TM (23%) In the second year, solo application of MP as part of the annual alternation resulted in significantly lower BenR1 isolate frequencies (16%) compared to spray programs including TM (39%) However, at the end of the study no significant differences in BenR1 isolate frequencies were detected between the strategies tested and the solo application of TM (47%) Different single nucleotide polymorphisms (SNP) in the β-tubulin gene confer resistance to MBC fungicides Allele-specific polymerase chain reactions (as-PCR) as well as EvaGreen® real-time as-qPCR showed a high correlation between the BenR1 isolate and E198A allele frequency Over the winter period 2009/10, a decrease of BenR1 isolate frequency was detected (-12%), which points to difference in fitness of MBC-sensitive (BenS) and BenR1 isolates Therefore, various fitness parameters were tested comparing ten BenS with ten BenR1 isolates At favourable conditions, no significant differences were detected between the two sensitivity groups At unfavourable conditions, mycelium growth, lesion size and spore production of BenS isolates were significantly higher than those of BenR1 isolates In a competitive assay on leaf discs as well as on grapevine plants a decrease in BenR1 conidia frequency of % per generation was observed Fitness costs associated with resistance could have reduced the frequency of BenR1 isolates within the primary inoculum, when the fungus was confronted with unfavourable development conditions If no MBC fungicides are applied during the season, then the short-distance dispersal of BenS conidia from the infected flowers and other sources leads to a decrease of the resistant fraction in the consecutive berry-associated population, as PROGRAM ON THE GLOBAL DEMOGRAPHY OF AGING Working Paper Series Population Aging and Economic Growth in China Judith Banister, David E. Bloom, and Larry Rosenberg March 2010 PGDA Working Paper No. 53 http://www.hsph.harvard.edu/pgda/working.htm The views expressed in this paper are those of the author(s) and not necessarily those of the Harvard Initiative for Global Health. The Program on the Global Demography of Aging receives funding from the National Institute on Aging, Grant No. 1 P30 AG024409-06. Population Aging and Economic Growth in China Judith Banister, David E. Bloom, and Larry Rosenberg March 2010 Executive Summary According to current UN projections, the population of the world age 60 or older will be 2 billion by 2050. With populations aging in nearly all countries, there has been widespread concern about the possible effects on economic growth and on the ability of countries to provide support for their elderly populations. In particular, because the elderly are in general less economically productive than younger people, a preponderance of old-age individuals would seem to suggest that (a) economic growth will be slower than in the past, and (b) relatively smaller working-age cohorts of the future will be burdened by the need to care for, and pay for the support of, the elderly population. These concerns have found resonance in China, where more than 30% of the population is expected to be age 60 or older in 2050. In part as a consequence of China’s process of population aging to date, the ratio of individuals age 15-64 to those younger and older, which grew rapidly during the last few economic boom decades, has reached its peak and is slated to decline rapidly in coming decades. Because a labor force that is large in size relative to the dependent population is plausibly crucial to rapid economic growth, the decline of this ratio could conceivably herald economic difficulties. The roots of population aging in China are the same as elsewhere: a low fertility rate, rising life expectancy, and the cumulative effect of past changes in birth and death rates. In China, obviously, the decline in the fertility rate, brought about in significant measure by the one-child policy and government efforts leading up to its adoption, has been a central factor in the changing age structure of the Chinese population. Greater longevity has also obviously been a key factor in population aging. If an older population is in fact cause for concern about the future of the Chinese economy, it would be prudent to identify, as soon as possible, measures that could serve to counteract any negative economic effects of population aging. Numerous countries have identified policies that might mitigate the potential economic problems associated with population aging. These policies seek to raise the age of retirement, spur higher savings, facilitate work for those caring for children, increase the labor force participation of women, liberalize immigration, and give more incentives for education. China could indeed begin to change the legal age of retirement, for those to whom this applies. It is unlikely to seek a higher savings rate, since its savings are already Population Growth and Regulation Population Growth and Regulation Bởi: OpenStaxCollege Population ecologists make use of a variety of methods to model population dynamics An accurate model should be able to describe the changes occurring in a population and predict future changes Population Growth The two simplest models of population growth use deterministic ... the population density is high or low The same holds true for cold winter weather 2/8 Population Dynamics and Regulation In real-life situations, population regulation is very complicated and. .. survived in isolated island populations as recently as 1700 BC We know a lot about these animals from carcasses found frozen in the ice of Siberia and 3/8 Population Dynamics and Regulation other regions.. .Population Dynamics and Regulation An example of density-dependent regulation is shown in [link] with results from a study focusing