scholarly journals The periodical cicada four-year acceleration hypothesis revisited and the polyphyletic nature of Brood V, including an updated crowd-source enhanced map (Hemiptera: Cicadidae: Magicicada)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5282 ◽  
Author(s):  
John R. Cooley ◽  
Nidia Arguedas ◽  
Elias Bonaros ◽  
Gerry Bunker ◽  
Stephen M. Chiswell ◽  
...  

The periodical cicadas of North America (Magicicada spp.) are well-known for their long life cycles of 13 and 17 years and their mass synchronized emergences. Although periodical cicada life cycles are relatively strict, the biogeographic patterns of periodical cicada broods, or year-classes, indicate that they must undergo some degree of life cycle switching. We present a new map of periodical cicada Brood V, which emerged in 2016, and demonstrate that it consists of at least four distinct parts that span an area in the United States stretching from Ohio to Long Island. We discuss mtDNA haplotype variation in this brood in relation to other periodical cicada broods, noting that different parts of this brood appear to have different origins. We use this information to refine a hypothesis for the formation of periodical cicada broods by 1- and 4-year life cycle jumps.

2018 ◽  
pp. 1-34
Author(s):  
Jørgen Olesen

Crustacea (or Pancrustacea) have explored virtually all possible milieus in different parts of their life cycle, including freshwater, marine, and terrestrial habitats, and even the air (pterygote insects). Many crustacean taxa display complex life cycles that involve prominent shifts in environment, lifestyle, or both. In this chapter, the overwhelming diversity of crustacean life cycles will be explored by focusing on changes in the life cycles, and on how different phases in a life cycle are adapted to their environment. Shifts in crustacean life cycles may be dramatic such as those seen in numerous decapods and barnacles where the development involves a change from a pelagic larval phase to an adult benthic phase. Also, taxa remaining in the same environment during development, such as holoplanktonic Copepoda, Euphausiacea, and Dendrobranchiata, undergo many profound changes in feeding and swimming strategies. Numerous taxa shift from an early larval naupliar (anterior limbs) feeding/swimming system using only cephalic appendages to a juvenile/adult system relying almost exclusively on more posterior appendages. The chapter focuses mainly on nondecapods and is structured around a number of developmental concepts such as anamorphosis, metamorphosis, and epimorphosis. It is argued that few crustacean taxa can be characterized as entirely anamorphic and none as entirely metamorphic. Many taxa show a combination of the two, even sometimes with two distinct metamorphoses (e.g., in barnacles), or being essentially anamorphic but with several distinct jumps in morphology during development (e.g., Euphausiacea and Dendrobranchiata). Within the Metazoa the Crustacea are practically unrivalled in diversity of lifestyles involving, in many taxa, significant changes in milieu (pelagic versus benthic, marine versus terrestrial) or in feeding mode. Probably such complex life cycles are among the key factors in the evolutionary success of Crustacea.


2021 ◽  
Vol 111 ◽  
pp. 587-592
Author(s):  
Elizabeth Weber Handwerker ◽  
Sara Moreira ◽  
David Piccone

We document new stylized facts on the occupational mix of businesses in the United States and how their internal organization evolves over their life cycles. Our main empirical finding is that younger businesses have fewer hierarchical layers and lower span of control than comparable older businesses do. Our results suggest that businesses become simultaneously more hierarchical and increase their managerial span of control over their life cycles. We show that this pattern is not entirely driven by selection or differences in size and is pervasive across cohorts and sectors.


2020 ◽  
Vol 1 (10) ◽  
pp. 26-35
Author(s):  
E. A. SHUBINA ◽  
◽  
Yu. A. KOMAROVSKY ◽  
A. V. MERKUSHEV ◽  
◽  
...  

The article is devoted to the study of the largest mergers and acquisitions (M&A, “Mergers & Acquisitions”) in Russia for 2017–2019. (the acquired block of shares is not less than 99%). The concept of life cycles of organizations and theoretical aspects of mergers and acquisitions are described. The stages of the life cycle of the merged and reorganized companies, the goals of mergers and acquisitions, depending on the stages of the life cycle are analyzed.


Author(s):  
Valeriy S. Gerasimov ◽  
Vladimir I. Ignatov ◽  
Konstantin G. Sovin

According to forecasts for 2022, the number of self-propelled agricultural machinery that will fail will be about 100 thousand units. This will have a significant impact on the overall productivity in the field of agricultural production and will require additional financial costs for effective resource-saving environmental-oriented utilization of agricultural machinery with the maximum recovery of secondary resources in the processing of its components. (Research purpose) The research purpose is considering the main life cycles of machinery, including agricultural, and determining the possibility of obtaining secondary resources in the recycling of components of machinery and equipment. (Materials and methods) The authors found that the establishment of an industry-wide recycling system would allow the reuse of usable and recovered parts obtained from decommissioned equipment, as well as receive additional funding from the sale of secondary resources. The authors have found that for the functioning of the whole system, it is necessary to work with a large amount of data related to the ongoing recycling processes, as well as constantly monitor changes in the state and properties of materials. They also found that the maximum use of digital technology is the only way to combine all these requirements and make the system work. (Results and discussion) The article reviews the key points of the use of life cycle method for equipment, including agricultural, reviews the state of machine and tractor park of agro-industrial complex, shows the possibility of using resource-saving ecologically oriented branch system of recycling of agricultural machinery, as well as the movement of waste and material flows in the processing components of utilized machines. (Conclusion) The article presents recommendations on the possibility of efficient disposal of equipment, including agricultural, with the maximum recovery of secondary resources from recycled waste.


Author(s):  
Adrián Félix

In the context of research on the “thickening” of borders, Specters of Belonging raises the related question: How does transnational citizenship thicken across the political life cycle of Mexican migrants? In addressing this question, this book resembles what any good migration corrido (ballad) does—narrate the thickening of transnational citizenship from beginning, middle, to end. Specifically, Specters of Belonging traces Mexican migrant transnationalism across the migrant political life cycle, beginning with the “political baptism” (i.e., naturalization in the United States) and ending with repatriation to México after death. In doing so, the book illustrates how Mexican migrants enunciate, enact, and embody transnational citizenship in constant dialectical contestation with the state and institutions of citizenship on both sides of the U.S.-México border. Drawing on political ethnographies of citizenship classrooms, the first chapter examines how Mexican migrants enunciate transnational citizenship as they navigate the naturalization process in the United States and grapple with the contradictions of U.S. citizenship and its script of singular political loyalty. The middle chapter deploys transnational ethnography to analyze how Mexican migrants enact transnational citizenship within the clientelistic orbit of the Mexican state, focusing on a group of returned migrant politicians and transnational activists. Last, the final chapter turns to how Mexican migrants embody transnational citizenship by tracing the cross-border practice of repatriating the bodies of deceased Mexican migrants from the United States to their communities of origin in rural México.


2020 ◽  
Vol 40 (6) ◽  
pp. 825-832 ◽  
Author(s):  
Miku Yabuta ◽  
Jens T Høeg ◽  
Shigeyuki Yamato ◽  
Yoichi Yusa

Abstract Although parasitic castration is widespread among rhizocephalan barnacles, Boschmaella japonica Deichmann & Høeg, 1990 does not completely sterilise the host barnacle Chthamalus challengeri Hoek, 1883. As little information is available on the relationships with the host in “barnacle-infesting parasitic barnacles” (family Chthamalophilidae), we studied the life cycles of both B. japonica and C. challengeri and the effects of the parasite on the host reproduction. Specimens of C. challengeri were collected from an upper intertidal shore at Shirahama, Wakayama, western Japan from April 2017 to September 2018 at 1–3 mo intervals. We recorded the body size, number of eggs, egg volume, and the presence of the parasite for each host. Moreover, settlement and growth of C. challengeri were followed in two fixed quadrats. Chthamalus challengeri brooded from February to June. The prevalence of B. japonica was high (often exceeded 10%) from April to July, and was rarely observed from September to next spring. The life cycle of the parasite matched well with that of the host. The parasite reduced the host’s brooding rate and brood size, to the extent that no hosts brooded in 2018.


2021 ◽  
Vol 13 (10) ◽  
pp. 5726
Author(s):  
Aleksandra Wewer ◽  
Pinar Bilge ◽  
Franz Dietrich

Electromobility is a new approach to the reduction of CO2 emissions and the deceleration of global warming. Its environmental impacts are often compared to traditional mobility solutions based on gasoline or diesel engines. The comparison pertains mostly to the single life cycle of a battery. The impact of multiple life cycles remains an important, and yet unanswered, question. The aim of this paper is to demonstrate advances of 2nd life applications for lithium ion batteries from electric vehicles based on their energy demand. Therefore, it highlights the limitations of a conventional life cycle analysis (LCA) and presents a supplementary method of analysis by providing the design and results of a meta study on the environmental impact of lithium ion batteries. The study focuses on energy demand, and investigates its total impact for different cases considering 2nd life applications such as (C1) material recycling, (C2) repurposing and (C3) reuse. Required reprocessing methods such as remanufacturing of batteries lie at the basis of these 2nd life applications. Batteries are used in their 2nd lives for stationary energy storage (C2, repurpose) and electric vehicles (C3, reuse). The study results confirm that both of these 2nd life applications require less energy than the recycling of batteries at the end of their first life and the production of new batteries. The paper concludes by identifying future research areas in order to generate precise forecasts for 2nd life applications and their industrial dissemination.


2021 ◽  
Vol 13 (5) ◽  
pp. 2525
Author(s):  
Camila López-Eccher ◽  
Elizabeth Garrido-Ramírez ◽  
Iván Franchi-Arzola ◽  
Edmundo Muñoz

The aim of this study is to assess the environmental impacts of household life cycles in Santiago, Chile, by household income level. The assessment considered scenarios associated with environmental policies. The life cycle assessment was cradle-to-grave, and the functional unit considered all the materials and energy required to meet an inhabitant’s needs for one year (1 inh/year). Using SimaPro 9.1 software, the Recipe Midpoint (H) methodology was used. The impact categories selected were global warming, fine particulate matter formation, terrestrial acidification, freshwater eutrophication, freshwater ecotoxicity, mineral resource scarcity, and fossil resource scarcity. The inventory was carried out through the application of 300 household surveys and secondary information. The main environmental sources of households were determined to be food consumption, transport, and electricity. Food consumption is the main source, responsible for 33% of the environmental impacts on global warming, 69% on terrestrial acidification, and 29% on freshwater eutrophication. The second most crucial environmental hotspot is private transport, whose contribution to environmental impact increases as household income rises, while public transport impact increases in the opposite direction. In this sense, both positive and negative environmental effects can be generated by policies. Therefore, life-cycle environmental impacts, the synergy between policies, and households’ socio-economic characteristics must be considered in public policy planning and consumer decisions.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Mikas Ilgūnas ◽  
Carolina Romeiro Fernandes Chagas ◽  
Dovilė Bukauskaitė ◽  
Rasa Bernotienė ◽  
Tatjana Iezhova ◽  
...  

Abstract Background Haemoproteus parasites (Haemosporida, Haemoproteidae) are cosmopolitan in birds and recent molecular studies indicate enormous genetic diversity of these pathogens, which cause diseases in non-adapted avian hosts. However, life-cycles remain unknown for the majority of Haemoproteus species. Information on their exoerythrocytic development is particularly fragmental and controversial. This study aimed to gain new knowledge on life-cycle of the widespread blood parasite Haemoproteus majoris. Methods Turdus pilaris and Parus major naturally infected with lineages hPHYBOR04 and hPARUS1 of H. majoris, respectively, were wild-caught and the parasites were identified using microscopic examination of gametocytes and PCR-based testing. Bayesian phylogeny was used to determine relationships between H. majoris lineages. Exoerythrocytic stages (megalomeronts) were reported using histological examination and laser microdissection was applied to isolate single megalomeronts for genetic analysis. Culicoides impunctatus biting midges were experimentally exposed in order to follow sporogonic development of the lineage hPHYBOR04. Results Gametocytes of the lineage hPHYBOR04 are indistinguishable from those of the widespread lineage hPARUS1 of H. majoris, indicating that both of these lineages belong to the H. majoris group. Phylogenetic analysis supported this conclusion. Sporogony of the lineage hPHYBOR04 was completed in C. impunctatus biting midges. Morphologically similar megalomeronts were reported in internal organs of both avian hosts. These were big roundish bodies (up to 360 μm in diameter) surrounded by a thick capsule-like wall and containing irregularly shaped cytomeres, in which numerous merozoites developed. DNA sequences obtained from single isolated megalomeronts confirmed the identification of H. majoris. Conclusions Phylogenetic analysis identified a group of closely related H. majoris lineages, two of which are characterized not only by morphologically identical blood stages, but also complete sporogonic development in C. impunctatus and development of morphologically similar megalomeronts. It is probable that other lineages belonging to the same group would bear the same characters and phylogenies based on partial cytb gene could be used to predict life-cycle features in avian haemoproteids including vector identity and patterns of exoerythrocytic merogony. This study reports morphologically unique megalomeronts in naturally infected birds and calls for research on exoerythrocytic development of haemoproteids to better understand pathologies caused in avian hosts.


Author(s):  
YASUSHI UMEDA ◽  
AKIRA NONOMURA ◽  
TETSUO TOMIYAMA

Environmental issues require a new manufacturing paradigm because the current mass production and mass consumption paradigm inevitably cause them. We have already proposed a new manufacturing paradigm called the “Post Mass Production Paradigm (PMPP)” that advocates sustainable production by decoupling economic growth from material and energy consumption. To realize PMPP, appropriate planning of a product life cycle (design of life cycle) is indispensable in addition to the traditional environmental conscious design methodologies. For supporting the design of a life cycle, this paper proposes a life-cycle simulation system that consists of a life-cycle simulator, an optimizer, a model editor, and knowledge bases. The simulation system evaluates product life cycles from an integrated view of environmental consciousness and economic profitability and optimizes the life cycles. A case study with the simulation system illustrates that the environmental impacts can be reduced drastically without decreasing corporate profits by appropriately combining maintenance, reuse and recycling, and by taking into consideration that optimized modular structures differ according to life-cycle options.


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