bluuebunny/crossref_metadata_2025 huggingface dataset:
Gender, Work, and the Sexual Division of Labor
Authors: Ferguson Lucy
Published: January 2014

This article shows how work is gendered, both in how it plays out in labor markets and the ways it is constructed. It first looks at how the gender dynamics of paid work have been radically restructured worldwide over the last five decades and then shows the impact of the sexual division of labor on gender and work. The next sections study the restructuring of global production, two modern trends in gendered employment—labor migration and informalization—gender segregation in employment, and the influence of women’s unpaid labor in the labor market. The article also develops the argument that gender is not always the most prominent inequality.
Sex, Gender, and Civil Society
Authors: Strolovitch Dara Z. , Townsend-Bell Erica
Published: January 2014

This article discusses the way that gender forms civil society, particularly in the context of Latin America and the United States. It begins with a study of the history and development of the definition of civil society and its implications for women and gender. The next section discusses women’s historical and modern presence in civil society and considers whether civil society operates practically and conceptually as an autonomous sphere. The article also explores civil society’s ability to empower women and reproduce gendered norms of equality.
Local—Global—Local: Women’s Global Organizing
Authors: Joachim Jutta
Published: January 2014

This article provides a closer look at the interdependencies and relations present between the local and global. It uses social-movement literature and the concept of the rooted cosmopolitan to describe historically how the local and personal experiences of women have led to global campaigns and served as sources of conflict. This is followed by a discussion of modern debates and the ways global ideas and norms related to gender inform local debates and are organized to fit certain circumstances.
Political Representation
Authors: Childs Sarah , Lovenduski Joni
Published: January 2014

This article considers the centrality of political representation to feminist politics. It discusses the traditional theories of representation and then explains how scholars of gender and politics have used the term. The next section outlines the state of scholarship on the political representation and substantive representation of women. The last part of the article discusses eight questions that are deemed central to the modern research agenda on substantive representation.
Electoral Institutions
Authors: Krook Mona Lena , Schwindt-Bayer Leslie
Published: January 2014

This article serves as a review on electoral institutions, specifically on how they shape the election outcomes, the dynamics of democratic politics, and the emergence of candidates. It addresses the need to consider how electoral institutions are gendered and sheds some light on the political advantages men have long received from electoral institutions designed by men. The article also identifies the ways women contribute to—and benefit from—the basic frameworks of electoral politics.
Judicial Politics and the Courts
Authors: Cichowski Rachel
Published: January 2014

This article views law, courts, and constitutionalism using a gendered perspective. It examines several key debates and improvements in this field of study and presents a detailed conceptual framework of law and courts. In the next section, the article discusses three major areas that define the scholarship in this field (and are of special interest to scholars of gender and politics), namely, gender and the courts, gender, constitutionalism and human rights, and feminist jurisprudence. It also includes a template that can help in studying the global challenges faced by law and courts scholars today.
The State and Governance
Authors: Chappell Louise
Published: January 2014

This article takes a look at the changes in feminist thinking. It outlines the competing feminist theories, and studies the transition from a monolithic and patriarchal conception of the state to a differentiated and gendered conception of the state. The article then explains how gender functions within the state and how the state represents gender relations within society. Finally, it also considers feminist engagement with the state, which includes the venues, strategies, orientation, and results of the interaction.
Gender, Institutions, and Multilevel Governance
Authors: Bedford Kate
Published: January 2014

This article serves as an introduction to the debates about multilevel governance trends and how they relate to gender and politics, first discussing multilevel governance and the debates gender scholars and activists are having on the topic. It then considers the argument that multilevel governance is an important and gendered topic for concern, along with five specific themes that help in determining some significant questions being raised by feminist researchers. The article also attempts to broaden the disciplinary ground on which the conversations about multilevel governance rest.
Multiculturalism and Identity
Authors: Prins Baukje , Saharso Sawitri
Published: January 2014

This article is concerned with critical and liberal multiculturalism as well as the gender dilemmas between relativism and universalism. It identifies four liberal answers to the question of how to deal with the issue of universalism–relativism and discusses in detail the “multiculturalism versus feminism” debate. The article ends with a section on the important contributions of feminists to multiculturalism.
Advances in Cost Frontier Analysis of the Firm
Authors: Lovell C.A. Knox , Grifell-Tatjé Emili
Published: January 2014

We study various analytical frameworks relating productivity change to change in the cost structure and cost efficiency of the firm. We begin by motivating a focus on the cost side, and not the revenue side, of the profit objective of the firm. We continue by relating the cost accounting tool of standard cost variance analysis to the economics tool of cost efficiency analysis. We focus on managerially controllable drivers of cost efficiency, including productivity change and its components. We conclude by noting some significant empirical applications of the analysis, by recommending cost efficiency analysis as a valuable tool for benchmarking against the best, and by suggesting some new directions for research.
Supply Chain Design for Managing Disruptive Risks
Authors: Chopra Sunil , Sodhi ManMohan S.
Published: January 2014

This article discusses disruptive supply chain risks that can have large negative impacts on the supply chain’s performance. Using stylized network models and examples, the article first looks at how to incorporate probability in supply chain design given the difficulty of estimating the probability of a disruption. Next, the article deals with two fundamental strategies a supply chain designer can use to mitigate the effects of disruptive risks: (a) containment, i.e., containing the risk, and (b) tailoring reserves like capacity and inventory. Finally, the article discusses how a company can respond to disruptions. These response considerations need to be taken into the supply chain configuration as well.
Behavioral Economics and Strategic Decision Making
Authors: Garbuio Massimo , Lovallo Dan , Ketenciouglu Elif
Published: January 2014

Modern strategic decision theory focuses on those actions taken by senior executives (on behalf of the owners) that commit substantial resources, set precedents, and create waves of less important decisions. This chapter explores key behavioral assumptions that dispute the notion that strategic decisions are wholly rational in a neoclassical economics sense. It classifies deviations from rationality as non-standard preferences, non-standard beliefs, and non-standard decisions. Insights are provided on how behavioral economics can be applied to strategic decisions in organizational settings, and moreover on how behavioral economics can be enriched by asking questions that are unique to the role of executives making strategic decisions within firms.
Product Distribution and Promotion
Authors: Ingene Charles , Zhang Xubing
Published: January 2014

We model multiple brands in a product category so as to determine how channel members’ profits and consumers’ surplus are affected by distribution channel structure, manufacturer and retailer pricing policies, brand differentiation, and brand promotion. We employ a game-theoretic analysis with linear demand to prove that, in a decentralized channel, there are parametric values for which (1) jointly setting prices to maximize total category profits leads to more brands than does individually setting each brand’s price to maximize that brand’s profit; (2) unless brands are little differentiated, all channel members would be better off pricing to maximize brand profit rather than category profit. Neither of these points hold for a vertically-integrated channel. (3) We also prove that a decentralized channel that maximizes brand profit generates more consumers’ surplus than does a vertically-integrated channel.
Organizational Design and Firm Performance
Authors: Colombo Massimo G. , Delmastro Marco , Rabbiosi Larissa
Published: January 2014

This chapter provides a critical survey of the stream of studies that have examined the effect of organizational design decisions on firm performance. The focus is on selected organizational design dimensions that can be measured using quantitative indicators, notably i) organizationalconfiguration, ii) allocation of decision-making authority, and iii) adoption offormal organizational practices. The aim is to highlight ‘stylized facts’ supported by robust quantitative empirical findings, and to link them to insights provided by theoretical work. Moreover, we consider firm-, industry-, and country-specific factors that moderate the organizational design-firm performance relation. In reviewing this emergent and still quite fragmented empirical literature, we also take the opportunity to present open issues, and to indicate avenues for future research.
Italy and the First Age of Globalization, 1861–1940
Authors: James Harold , O’Rourke Kevin H.
Published: January 2014

The paper presents trade policy as in line with that of other continental European powers, with a move to moderate levels of tariff protection for politically sensitive sectors, such as steel and textiles and clothing, but also in agriculture, with levels of protection falling slightly before the First World War. Monetary policy was similarly driven by the constraints of capital scarcity and by the political priority attached to reducing the cost of funding government debt. The most innovative area was probably in industrial policy, where after the 1880s and again in the 1930s, in response to severe shocks, quite creative institutional policies were adopted. In particular, financial restructuring was used as an opportunity to reshape the structure of industry.
National Accounts, 1861–2011
Authors: Baffigi Alberto
Published: January 2014

A great deal of new quantitative research has been produced over the last three decades which has radically changed the received interpretation of Italian economic development. Against this backdrop, the Bank of Italy, Istat and the University of Rome "Tor Vergata", together with academics from other institutions, developed a project to estimate a new historical national accounts time series. The reconstruction covers the 150 years following the political unification of Italy and is based on the most up-to-date results in the literature. It provides estimates of supply and uses at constant and at current prices. In this chapter a general picture of the new time series is drawn. Historically significant periods are taken into consideration, using them as case studies in order to illustrate some features of the new data, both technical and substantial. A detailed methodological account is given in the appendices.
Standards of Living
Authors: Brandolini Andrea , Vecchi Giovanni
Published: January 2014

The chapter describes the evolution of the Italians' well-being during the 150 years since the country's unification. The progress in material standard of living has been substantial, with GDP per capita growing thirteen times between 1861 and 2011 and hours of work (and hence effort) falling considerably, but roughly in line with that experienced by most other European countries. By relying on a novel database on household budgets, it is shown that economic growth has been accompanied by a long-run reduction of inequality that however appears to have been reversed in the last two decades. Progress has not been limited to the economic domain: educational attainment has improved considerably, although less than in other countries, and life expectancy has grown at a spectacular pace, allowing Italians to lead current international rankings.
Migrations
Authors: Gomellini Matteo , Ó Gráda Cormac
Published: January 2014

This chapter is an analytic account of Italian emigration and immigration between 1861 and the present. After describing the economic and demographic characteristics of emigrants, it analyzes the causes and effects of their migrations. It explores the consequences of the two main waves of Italian emigration (before 1914 and after 1945) for those left behind, and reckons that in the long run, emigration accounted for 4-5% of the growth in GDP per capita, with the South benefiting considerably more than the North. The chapter also describes the impact of recent immigration on those in residence in Italy, with a particular focus on the links with the economic activity, the labor market, the balance of payments, crime and public opinion, on the other.
A Long-Run Perspective on Comparative Advantage
Authors: Federico Giovanni , Wolf Nikolaus
Published: January 2014

The history of Italy since its unification in 1861 was accompanied by a dramatic increase in the country's integration with European and global commodity markets: foreign trade in the long run grew on average faster than the overall economy. Italy's comparative advantage changed fundamentally, from a high concentration of a few trading partners and a handful of rather simple commodities, into a wide diversification of trading partners and more sophisticated commodities. The chapter uses a new long-term database on Italian foreign trade at a high level of disaggregation to document and analyze these changes. The chapter concludes with an assessment of Italy's prospects from a historical perspective.
Measurement of Blend Concentrations of Conventional and Waxy Hard Wheats Using NIR Spectroscopy
Authors: Delwiche Stephen R. , Graybosch Robert A.
Published: January 2014

Breeding development of waxy (amylose‐free) hard wheat lines adapted to the North American climate has been underway for more than a decade, with releases of competitive varieties imminent. Because of required identity preservation and a possible premium value placed on waxy lots, a rapid and accurate method is desired to identify and quantify the mixing of conventional wheat with waxy wheat, a condition that might occur at harvest or any point downstream. Our previous work demonstrated that lines pure with waxy starch can be identified from nonwaxy lines by use of near‐infrared (NIR) spectroscopy applied either on a whole kernel or ground meal basis. However, mixture quantification by NIR techniques has not been examined until now. Using hard winter wheat grown in two seasons (2011 and 2012) and at two locations (Nebraska and Arizona), a series of mixtures ranging in proportion (conventional/waxy) percentage by weight, from 0:100 to 100:0, were formed from nine pairs of waxy and nonwaxy varieties or lines, with year and location being consistent within a pair. Twenty‐nine mixtures (0, 1, 2, 3, 4, 5, 10, 15, …, 85, 90, 95, 96, 97, 98, 99, and 100%) were formed for each pair. Partial least squares regression models were developed by using eight of the nine pairs, with model validation accomplished by using the pair excluded. This procedure was repeated for each pair. The results indicate that, regardless of sample format or spectral pretreatment, the optimal models typically produce coefficients of determination in excess of 0.98, with standard errors of 4–7%, thus demonstrating the feasibility of the use of the NIR technique to predict the mixture level to within 10% by weight.
Bran Characteristics and Bread‐Baking Quality of Whole Grain Wheat Flour
Authors: Cai Liming , Choi Induck , Lee Choon‐Ki , Park Kwang‐Keun , Baik Byung‐Kee
Published: January 2014

Variations in physical and compositional bran characteristics among different sources and classes of wheat and their association with bread‐baking quality of whole grain wheat flour (WWF) were investigated with bran obtained from Quadrumat milling of 12 U.S. wheat varieties and Bühler milling of six Korean wheat varieties. Bran was characterized for composition including protein, fat, ash, dietary fiber, phenolics, and phytate. U.S. soft and club wheat brans were lower in insoluble dietary fiber (IDF) and phytate content (40.7–44.7% and 10.3–17.1 mg of phytate/g of bran, respectively) compared with U.S. hard wheat bran (46.0–51.3% and 16.5–22.2 mg of phytate/g of bran, respectively). Bran of various wheat varieties was blended with a hard red spring wheat flour at a ratio of 1:4 to prepare WWFs for determination of dough properties and bread‐baking quality. WWFs with U.S. hard wheat bran generally exhibited higher dough water absorption and longer dough mixing time, and they produced smaller loaf volume of bread than WWFs of U.S. soft and club wheat bran. WWFs of two U.S. hard wheat varieties (ID3735 and Scarlet) produced much smaller loaves of bread (<573 mL) than those of other U.S. hard wheat varieties (>625 mL). IDF content, phytate content, and water retention capacity of bran exhibited significant relationships with loaf volume of WWF bread, whereas no relationship was observed between protein content of bran and loaf volume of bread. It appears that U.S. soft and club wheat bran, probably owing to relatively low IDF and phytate contents, has smaller negative effects on mixing properties of WWF dough and loaf volume of bread than U.S. hard wheat bran.
Fungicide Resistance Profiles in Botrytis cinerea from Strawberry Fields of Seven Southern U.S. States
Authors: Fernández-Ortuño Dolores , Grabke Anja , Bryson Patricia Karen , Amiri Achour , Peres Natália A. , Schnabel Guido
Published: January 2014

The sensitivity to seven chemical classes of fungicides was investigated in 1,810 Botrytis cinerea isolates collected from strawberry blossoms and fruit in 181 strawberry fields from seven southern states in the United States across 2 years. Ten isolates were examined from each field. Fungicide sensitivity assays were carried out based on visual assessment of diametrical mycelial growth after 4 days of incubation on media amended with discriminatory doses of fungicides in microtiter plates. Results of visual assessments were verified with selected isolates using a previously published germination assay and by inoculating representative isolates with resistant phenotypes on fungicide-sprayed fruit. The overall resistance frequencies of 750 isolates collected in 2012 for thiophanate-methyl, pyraclostrobin, boscalid, cyprodinil, fenhexamid, iprodione, and fludioxonil were 76, 42, 29, 27, 25, 3, and 1%, respectively. Frequencies of 1,060 isolates collected in 2013 were 85, 59, 5, 17, 26, 2, and 1%, respectively. Resistance to thiophanate-methyl and pyraclostrobin was found in virtually every location in both years, whereas resistance to iprodione and fludioxonil was rarely found. Resistant isolates were resistant to either one (23%), two (18%), three (19%), four (14%), five (3%), or six (0.1%) chemical classes of fungicides in 2012. In 2013, this distribution was 24, 29, 26, 8, 2, and 0.3%, respectively. Multifungicide-resistant isolates of B. cinerea were widespread in southern states and evidence suggests that the frequency of isolates with multifungicide resistance increased from 2012 to 2013. The data also show that fungicide resistance in B. cinerea was already present in blossoms, indicating that resistance management needs to be implemented early in the season.
Parasites that change predator or prey behaviour can have keystone effects on community composition
Authors: Hatcher Melanie J. , Dick Jaimie T. A. , Dunn Alison M.
Published: January 2014

Parasites play pivotal roles in structuring communities, often via indirect interactions with non-host species. These effects can be density-mediated (through mortality) or trait-mediated (behavioural, physiological and developmental), and may be crucial to population interactions, including biological invasions. For instance, parasitism can alter intraguild predation (IGP) between native and invasive crustaceans, reversing invasion outcomes. Here, we use mathematical models to examine how parasite-induced trait changes influence the population dynamics of hosts that interact via IGP. We show that trait-mediated indirect interactions impart keystone effects, promoting or inhibiting host coexistence. Parasites can thus have strong ecological impacts, even if they have negligible virulence, underscoring the need to consider trait-mediated effects when predicting effects of parasites on community structure in general and biological invasions in particular.
Natural selection can favour ‘irrational’ behaviour
Authors: McNamara J. M. , Trimmer P. C. , Houston A. I.
Published: January 2014

Understanding decisions is the fundamental aim of the behavioural sciences. The theory of rational choice is based on axiomatic principles such as transitivity and independence of irrelevant alternatives (IIA). Empirical studies have demonstrated that the behaviour of humans and other animals often seems irrational; there can be a lack of transitivity in choice and seemingly irrelevant alternatives can alter decisions. These violations of transitivity and IIA undermine rational choice theory. However, we show that an individual that is maximizing its rate of food gain can exhibit failure of transitivity and IIA. We show that such violations can be caused because a current option may disappear in the near future or a better option may reappear soon. Current food options can be indicative of food availability in the near future, and this key feature can result in apparently irrational behaviour.
Singing in the moonlight: dawn song performance of a diurnal bird varies with lunar phase
Authors: York Jennifer E. , Young Andrew J. , Radford Andrew N.
Published: January 2014

It is well established that the lunar cycle can affect the behaviour of nocturnal animals, but its potential to have a similar influence on diurnal species has received less research attention. Here, we demonstrate that the dawn song of a cooperative songbird, the white-browed sparrow weaver (
Plocepasser mahali
), varies with moon phase. When the moon was above the horizon at dawn, males began singing on average 10 min earlier, if there was a full moon compared with a new moon, resulting in a 67% mean increase in performance period and greater total song output. The lack of a difference between full and new moon dawns when the moon was below the horizon suggests that the observed effects were driven by light intensity, rather than driven by other factors associated with moon phase. Effects of the lunar cycle on twilight signalling behaviour have implications for both pure and applied animal communication research.
Sideways walking: preferred is slow, slow is optimal, and optimal is expensive
Authors: Handford Matthew L. , Srinivasan Manoj
Published: January 2014

When humans wish to move sideways, they almost never walk sideways, except for a step or two; they usually turn and walk facing forward. Here, we show that the experimental metabolic cost of walking sideways, per unit distance, is over three times that of forward walking. We explain this high metabolic cost with a simple mathematical model; sideways walking is expensive because it involves repeated starting and stopping. When walking sideways, our subjects preferred a low natural speed, averaging 0.575 m s−1(0.123 s.d.). Even with no prior practice, this preferred sideways walking speed is close to the metabolically optimal speed, averaging 0.610 m s−1(0.064 s.d.). Subjects were within 2.4% of their optimal metabolic cost per distance. Thus, we argue that sideways walking is avoided because it is expensive and slow, and it is slow because the optimal speed is low, not because humans cannot move sideways fast.
Ejaculate economics: an experimental test in a moth
Authors: Xu Jin , Wang Qiao
Published: January 2014

Increasing evidence shows that spermatogenesis is costly. As a consequence, males should optimize the use of their sperm to maximize their reproductive outputs in their lifetime. However, experimental evidence on this prediction is largely lacking. Here, we examine how a male mothEphestia kuehniellaZeller (Lepidoptera: Pyralidae) responds to the presence of rivals or additional mates and how such response influences his lifetime reproductive fitness. We show that when rival males are present around a copulating pair, the male ejaculates more sperm to win a sperm competition battle but in such an environment he inseminates fewer females, sires fewer offspring and lives shorter. The opposite is the case when additional females are present during copulation. These findings reveal that elevated reproductive expenditure owing to sperm competition intensity is made at the expense of longevity and future reproduction.
How sticky should a virus be? The impact of virus binding and release on transmission fitness using influenza as an example
Authors: Handel Andreas , Akin Victoria , Pilyugin Sergei S. , Zarnitsyna Veronika , Antia Rustom
Published: January 2014

Budding viruses face a trade-off: virions need to efficiently attach to and enter uninfected cells while newly generated virions need to efficiently detach from infected cells. The right balance between attachment and detachment—the right amount of stickiness—is needed for maximum fitness. Here, we design and analyse a mathematical model to study in detail the impact of attachment and detachment rates on virus fitness. We apply our model to influenza, where stickiness is determined by a balance of the haemagglutinin (HA) and neuraminidase (NA) proteins. We investigate how drugs, the adaptive immune response and vaccines impact influenza stickiness and fitness. Our model suggests that the location in the ‘stickiness landscape’ of the virus determines how well interventions such as drugs or vaccines are expected to work. We discuss why hypothetical NA enhancer drugs might occasionally perform better than the currently available NA inhibitors in reducing virus fitness. We show that an increased antibody or T-cell-mediated immune response leads to maximum fitness at higher stickiness. We further show that antibody-based vaccines targeting mainly HA or NA, which leads to a shift in stickiness, might reduce virus fitness above what can be achieved by the direct immunological action of the vaccine. Overall, our findings provide potentially useful conceptual insights for future vaccine and drug development and can be applied to other budding viruses beyond influenza.
Mechanistic analysis of the search behaviour ofCaenorhabditis elegans
Authors: Salvador Liliana C. M. , Bartumeus Frederic , Levin Simon A. , Ryu William S.
Published: January 2014

A central question in movement research is how animals use information and movement to promote encounter success. Current random search theory identifies reorientation patterns as key to the compromise between optimizing encounters for both nearby and faraway targets, but how the balance between intrinsic motor programmes and previous environmental experience determines the occurrence of these reorientation behaviours remains unknown. We used high-resolution tracking and imaging data to describe the complete motor behaviour ofCaenorhabditis eleganswhen placed in a novel environment (one in which food is absent).Movement inC. elegansis structured around different reorientation behaviours, and we measured how these contributed to changing search strategies as worms became familiar with their new environment. This behavioural transition shows that different reorientation behaviours are governed by two processes: (i) an environmentally informed ‘extrinsic’ strategy that is influenced by recent experience and that controls for area-restricted search behaviour, and (ii) a time-independent, ‘intrinsic’ strategy that reduces spatial oversampling and improves random encounter success. Our results show how movement strategies arise from a balance between intrinsic and extrinsic mechanisms, that search behaviour inC. elegansis initially determined by expectations developed from previous environmental experiences, and which reorientation behaviours are modified as information is acquired from new environments.
The evolutionary origins of diadromy inferred from a time-calibrated phylogeny for Clupeiformes (herring and allies)
Authors: Bloom Devin D. , Lovejoy Nathan R.
Published: January 2014

One of the most remarkable types of migration found in animals is diadromy, a life-history behaviour in which individuals move between oceans and freshwater habitats for feeding and reproduction. Diadromous fishes include iconic species such as salmon, eels and shad, and have long fascinated biologists because they undergo extraordinary physiological and behavioural modifications to survive in very different habitats. However, the evolutionary origins of diadromy remain poorly understood. Here, we examine the widely accepted productivity hypothesis, which states that differences in productivity between marine and freshwater biomes determine the origins of the different modes of diadromy. Specifically, the productivity hypothesis predicts that anadromous lineages should evolve in temperate areas from freshwater ancestors and catadromous lineages should evolve in tropical areas from marine ancestors. To test this, we generated a time-calibrated phylogeny for Clupeiformes (herrings, anchovies, sardines and allies), an ecologically and economically important group that includes high diversity of diadromous species. Our results do not support the productivity hypothesis. Instead we find that the different modes of diadromy do not have predictable ancestry based on latitude, and that predation, competition and geological history may be at least as important as productivity in determining the origins of diadromy.
A carbohydrate-rich diet increases social immunity in ants
Authors: Kay Adam D. , Bruning Abbie J. , van Alst Andy , Abrahamson Tyler T. , Hughes W. O. H. , Kaspari Michael
Published: January 2014

Increased potential for disease transmission among nest-mates means living in groups has inherent costs. This increased potential is predicted to select for disease resistance mechanisms that are enhanced by cooperative exchanges among group members, a phenomenon known as social immunity. One potential mediator of social immunity is diet nutritional balance because traits underlying immunity can require different nutritional mixtures. Here, we show how dietary protein–carbohydrate balance affects social immunity in ants. When challenged with a parasitic fungusMetarhizium anisopliae, workers reared on a high-carbohydrate diet survived approximately 2.8× longer in worker groups than in solitary conditions, whereas workers reared on an isocaloric, high-protein diet survived only approximately 1.3× longer in worker groups versus solitary conditions. Nutrition had little effect on social grooming, a potential mechanism for social immunity. However, experimentally blocking metapleural glands, which secrete antibiotics, completely eliminated effects of social grouping and nutrition on immunity, suggesting a causal role for secretion exchange. A carbohydrate-rich diet also reduced worker mortality rates when whole colonies were challenged withMetarhizium. These results provide a novel mechanism by which carbohydrate exploitation could contribute to the ecological dominance of ants and other social groups.
Evolutionary stasis and lability in thermal physiology in a group of tropical lizards
Authors: Muñoz Martha M. , Stimola Maureen A. , Algar Adam C. , Conover Asa , Rodriguez Anthony J. , Landestoy Miguel A. , Bakken George S. , Losos Jonathan B.
Published: January 2014

Understanding how quickly physiological traits evolve is a topic of great interest, particularly in the context of how organisms can adapt in response to climate warming. Adjustment to novel thermal habitats may occur either through behavioural adjustments, physiological adaptation or both. Here, we test whether rates of evolution differ among physiological traits in the cybotoids, a clade of tropical
Anolis
lizards distributed in markedly different thermal environments on the Caribbean island of Hispaniola. We find that cold tolerance evolves considerably faster than heat tolerance, a difference that results because behavioural thermoregulation more effectively shields these organisms from selection on upper than lower temperature tolerances. Specifically, because lizards in very different environments behaviourally thermoregulate during the day to similar body temperatures, divergent selection on body temperature and heat tolerance is precluded, whereas night-time temperatures can only be partially buffered by behaviour, thereby exposing organisms to selection on cold tolerance. We discuss how exposure to selection on physiology influences divergence among tropical organisms and its implications for adaptive evolutionary response to climate warming.
Ocean acidification increases the vulnerability of native oysters to predation by invasive snails
Authors: Sanford Eric , Gaylord Brian , Hettinger Annaliese , Lenz Elizabeth A. , Meyer Kirstin , Hill Tessa M.
Published: January 2014

There is growing concern that global environmental change might exacerbate the ecological impacts of invasive species by increasing theirper capitaeffects on native species. However, the mechanisms underlying such shifts in interaction strength are poorly understood. Here, we test whether ocean acidification, driven by elevated seawaterpCO2, increases the susceptibility of native Olympia oysters to predation by invasive snails. Oysters raised under elevatedpCO2experienced a 20% increase in drilling predation. When presented alongside control oysters in a choice experiment, 48% more high-CO2oysters were consumed. The invasive snails were tolerant of elevated CO2with no change in feeding behaviour. Oysters raised under acidified conditions did not have thinner shells, but were 29–40% smaller than control oysters, and these smaller individuals were consumed at disproportionately greater rates. Reduction in prey size is a common response to environmental stress that may drive increasingper capitaeffects of stress-tolerant invasive predators.
Migratory connectivity and population-specific migration routes in a long-distance migratory bird
Authors: Trierweiler Christiane , Klaassen Raymond H. G. , Drent Rudi H. , Exo Klaus-Michael , Komdeur Jan , Bairlein Franz , Koks Ben J.
Published: January 2014

Knowledge about migratory connectivity, the degree to which individuals from the same breeding site migrate to the same wintering site, is essential to understand processes affecting populations of migrants throughout the annual cycle. Here, we study the migration system of a long-distance migratory bird, the Montagu's harrier
Circus pygargus
, by tracking individuals from different breeding populations throughout northern Europe. We identified three main migration routes towards wintering areas in sub-Saharan Africa. Wintering areas and migration routes of different breeding populations overlapped, a pattern best described by ‘weak (diffuse) connectivity’. Migratory performance, i.e. timing, duration, distance and speed of migration, was surprisingly similar for the three routes despite differences in habitat characteristics. This study provides, to our knowledge, a first comprehensive overview of the migration system of a Palaearctic-African long-distance migrant. We emphasize the importance of spatial scale (e.g. distances between breeding populations) in defining patterns of connectivity and suggest that knowledge about fundamental aspects determining distribution patterns, such as the among-individual variation in mean migration directions, is required to ultimately understand migratory connectivity. Furthermore, we stress that for conservation purposes it is pivotal to consider wintering areas as well as migration routes and in particular stopover sites.
Long-term survival of tuberculosis complex mycobacteria in soil
Authors: Ghodbane Ramzi , Medie Felix Mba , Lepidi Hubert , Nappez Claude , Drancourt Michel
Published: January 2014

While there is evidence for the persistence of Mycobacterium bovis in soil, there are no reports for the other Mycobacterium tuberculosis complex (MTC) mycobacteria. Here, soil was inoculated with 108 c.f.u. g−1
M. tuberculosis, M. bovis and M. canettii and subcultured monthly for 12 months. The pathogenicity of mycobacterial colonies, identified by using matrix-assisted laser desorption/ionization time of flight mass spectrometry, was assessed in a mouse model. Moreover, mice were fed with food that contained 16.7 % M. tuberculosis-contaminated soil. The three tested MTC species survived in soil for 12 months with a final inoculum of 2×103 c.f.u. g−1 for M. tuberculosis, 150 c.f.u. g−1 for M. bovis and 2×104 c.f.u. g−1 for M. canettii. In an experiment that included negative controls, all (5/5) mice inoculated with such M. tuberculosis and M. canettii developed 0.03–0.3 granulomas mm−2 in their lungs and spleen and grew mycobacteria; five mice that were inoculated with M. bovis from soil did not develop granulomas but grew mycobacteria. Furthermore, 0.2–0.4 granulomas mm−2 were observed in the lungs and spleen of 3/5 mice fed with M. tuberculosis-contaminated soil in the presence of two negative control mice. M. tuberculosis grew in the stomach, intestine, spleen and lung in 5/5 challenged mice, whereas the negative controls remained M. tuberculosis-free (P = 0.008, Fisher exact test). This study provides clear evidence that MTC mycobacteria survive in soil, and that M. tuberculosis remains virulent while in the soil, outside its hosts, for extended periods of time.
Recombination strategies and evolutionary dynamics of the Human enterovirus A global gene pool
Authors: Lukashev Alexander N. , Shumilina Elena Yu. , Belalov Ilya S. , Ivanova Olga E. , Eremeeva Tatiana P. , Reznik Vadim I. , Trotsenko O. E. , Drexler Jan Felix , Drosten Christian
Published: January 2014

We analysed natural recombination in 79 Human enterovirus A strains representing 13 serotypes by sequencing of VP1, 2C and 3D genome regions. The half-life of a non-recombinant tree node in coxsackieviruses 2, 4 and 10 was only 3.5 years, and never more than 9 years. All coxsackieviruses that differed by more than 7 % of the nucleotide sequence in any genome region were recombinants relative to each other. Enterovirus 71 (EV71), on the contrary, displayed remarkable genetic stability. Three major EV71 clades were stable for 19–29 years, with a half-life of non-recombinant viruses between 13 and 18.5 years in different clades. Only five EV71 strains out of over 150 recently acquired non-structural genome regions from coxsackieviruses, while none of 80 contemporary coxsackieviruses had non-structural genes transferred from the three EV71 clades. In contrast to earlier observations, recombination between VP1 and 2C genome regions was not more frequent than between 2C and 3D regions.
Emergence of structural and dynamical properties of ecological mutualistic networks
Authors: Suweis Samir , Simini Filippo , Banavar Jayanth R. , Maritan Amos
Published: January 2014

Mutualistic networks are formed when the interactions between two classes of species are mutually beneficial. They are important examples of cooperation shaped by evolution. Mutualism between animals and plants plays a key role in the organization of ecological communities1-3. Such networks in ecology have generically evolved a nested architecture4,5independent of species composition and latitude6,7- specialists interact with proper subsets of the nodes with whom generalists interact1. Despite sustained efforts5,8,9,10to explain observed network structure on the basis of community-level stability or persistence, such correlative studies have reached minimal consensus11,12,13. Here we demonstrate that nested interaction networks could emerge as a consequence of an optimization principle aimed at maximizing the species abundance in mutualistic communities. Using analytical and numerical approaches, we show that because of the mutualistic interactions, an increase in abundance of a given species results in a corresponding increase in the total number of individuals in the community, as also the nestedness of the interaction matrix. Indeed, the species abundances and the nestedness of the interaction matrix are correlated by an amount that depends on the strength of the mutualistic interactions. Nestedness and the observed spontaneous emergence of generalist and specialist species occur for several dynamical implementations of the variational principle under stationary conditions. Optimized networks, while remaining stable, tend to be less resilient than their counterparts with randomly assigned interactions. In particular, we analytically show that the abundance of the rarest species is directly linked to the resilience of the community. Our work provides a unifying framework for studying the emergent structural and dynamical properties of ecological mutualistic networks2,5,10,14.
A Novel Protective Function for Cytokinin in the Light Stress Response Is Mediated by the ARABIDOPSIS HISTIDINE KINASE2 and ARABIDOPSIS HISTIDINE KINASE3 Receptors
Authors: Cortleven Anne , Nitschke Silvia , Klaumünzer Marion , AbdElgawad Hamada , Asard Han , Grimm Bernhard , Riefler Michael , Schmülling Thomas
Published: January 2014

Cytokinins are plant hormones that regulate diverse processes in plant development and responses to biotic and abiotic stresses. In this study, we show that Arabidopsis (Arabidopsis thaliana) plants with a reduced cytokinin status (i.e. cytokinin receptor mutants and transgenic cytokinin-deficient plants) are more susceptible to light stress compared with wild-type plants. This was reflected by a stronger photoinhibition after 24 h of high light (approximately 1,000 µmol m−2 s−1), as shown by the decline in maximum quantum efficiency of photosystem II photochemistry. Photosystem II, especially the D1 protein, is highly sensitive to the detrimental impact of light. Therefore, photoinhibition is always observed when the rate of photodamage exceeds the rate of D1 repair. We demonstrate that in plants with a reduced cytokinin status, the D1 protein level was strongly decreased upon light stress. Inhibition of the D1 repair cycle by lincomycin treatment indicated that these plants experience stronger photodamage. The efficiency of photoprotective mechanisms, such as nonenzymatic and enzymatic scavenging systems, was decreased in plants with a reduced cytokinin status, which could be a cause for the increased photodamage and subsequent D1 degradation. Additionally, slow and incomplete recovery in these plants after light stress indicated insufficient D1 repair. Mutant analysis revealed that the protective function of cytokinin during light stress depends on the ARABIDOPSIS HISTIDINE KINASE2 (AHK2) and AHK3 receptors and the type B ARABIDOPSIS RESPONSE REGULATOR1 (ARR1) and ARR12. We conclude that proper cytokinin signaling and regulation of specific target genes are necessary to protect leaves efficiently from light stress.
ECHIDNA Protein Impacts on Male Fertility in Arabidopsis by Mediating trans-Golgi Network Secretory Trafficking during Anther and Pollen Development
Authors: Fan Xinping , Yang Caiyun , Klisch Doris , Ferguson Alison , Bhaellero Rishi P. , Niu Xiwu , Wilson Zoe A.
Published: January 2014

The trans-Golgi network (TGN) plays a central role in cellular secretion and has been implicated in sorting cargo destined for the plasma membrane. Previously, the Arabidopsis (Arabidopsis thaliana) echidna (ech) mutant was shown to exhibit a dwarf phenotype due to impaired cell expansion. However, ech also has a previously uncharacterized phenotype of reduced male fertility. This semisterility is due to decreased anther size and reduced amounts of pollen but also to decreased pollen viability, impaired anther opening, and pollen tube growth. An ECH translational fusion (ECHPro:ECH-YELLOW FLUORESCENT PROTEIN) revealed developmentally regulated tissue-specific expression, with expression in the tapetum during early anther development and microspore release and subsequent expression in the pollen, pollen tube, and stylar tissues. Pollen viability and production, along with germination and pollen tube growth, were all impaired. The ech anther endothecium secondary wall thickening also appeared reduced and disorganized, resulting in incomplete anther opening. This did not appear to be due to anther secondary thickening regulatory genes but perhaps to altered secretion of wall materials through the TGN as a consequence of the absence of the ECH protein. ECH expression is critical for a variety of aspects of male reproduction, including the production of functional pollen grains, their effective release, germination, and tube formation. These stages of pollen development are fundamentally influenced by TGN trafficking of hormones and wall components. Overall, this suggests that the fertility defect is multifaceted, with the TGN trafficking playing a significant role in the process of both pollen formation and subsequent fertilization.
An Arabidopsis Stomatin-Like Protein Affects Mitochondrial Respiratory Supercomplex Organization
Authors: Gehl Bernadette , Lee Chun Pong , Bota Pedro , Blatt Michael R. , Sweetlove Lee J.
Published: January 2014

Stomatins belong to the band-7 protein family, a diverse group of conserved eukaryotic and prokaryotic membrane proteins involved in the formation of large protein complexes as protein-lipid scaffolds. The Arabidopsis (Arabidopsis thaliana) genome contains two paralogous genes encoding stomatin-like proteins (SLPs; AtSLP1 and AtSLP2) that are phylogenetically related to human SLP2, a protein involved in mitochondrial fusion and protein complex formation in the mitochondrial inner membrane. We used reverse genetics in combination with biochemical methods to investigate the function of AtSLPs. We demonstrate that both SLPs localize to mitochondrial membranes. SLP1 migrates as a large (approximately 3 MDa) complex in blue-native gel electrophoresis. Remarkably, slp1 knockout mutants have reduced protein and activity levels of complex I and supercomplexes, indicating that SLP affects the assembly and/or stability of these complexes. These findings point to a role for SLP1 in the organization of respiratory supercomplexes in Arabidopsis.