scholarly journals Mitochondrial diversity inGonionemus(Trachylina:Hydrozoa) and its implications for understanding the origins of clinging jellyfish in the Northwest Atlantic Ocean

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3205 ◽  
Author(s):  
Annette F. Govindarajan ◽  
Mary R. Carman ◽  
Marat R. Khaidarov ◽  
Alexander Semenchenko ◽  
John P. Wares
Keyword(s):  
Pacific Northwest ◽  
Life Cycles ◽  
Future Research ◽  
Northwest Pacific ◽  
Complex Life Cycles ◽  
Northwest Atlantic ◽  
Resting Stages ◽  
Worldwide Distribution ◽  
Lineage Admixture ◽  
Multiple Scenarios

Determining whether a population is introduced or native to a region can be challenging due to inadequate taxonomy, the presence of cryptic lineages, and poor historical documentation. For taxa with resting stages that bloom episodically, determining origin can be especially challenging as an environmentally-triggered abrupt appearance of the taxa may be confused with an anthropogenic introduction. Here, we assess diversity in mitochondrial cytochrome oxidase I sequences obtained from multiple Atlantic and Pacific locations, and discuss the implications of our findings for understanding the origin of clinging jellyfishGonionemusin the Northwest Atlantic. Clinging jellyfish are known for clinging to seagrasses and seaweeds, and have complex life cycles that include resting stages. They are especially notorious as some, although not all, populations are associated with severe sting reactions. The worldwide distribution ofGonionemushas been aptly called a “zoogeographic puzzle” and our results refine rather than resolve the puzzle. We find a relatively deep divergence that may indicate cryptic speciation betweenGonionemusfrom the Northeast Pacific and Northwest Pacific/Northwest Atlantic. Within the Northwest Pacific/Northwest Atlantic clade, we find haplotypes unique to each region. We also find one haplotype that is shared between highly toxic Vladivostok-area populations and some Northwest Atlantic populations. Our results are consistent with multiple scenarios that involve both native and anthropogenic processes. We evaluate each scenario and discuss critical directions for future research, including improving the resolution of population genetic structure, identifying possible lineage admixture, and better characterizing and quantifying the toxicity phenotype.

scholarly journals Reverse development in Cnidaria

2004 ◽  
Vol 82 (11) ◽  
pp. 1748-1754 ◽  
Author(s):  
S Piraino ◽  
D De Vito ◽  
J Schmich ◽  
J Bouillon ◽  
F Boero
Keyword(s):  
Cell Death ◽  
Life Cycles ◽  
General Strategy ◽  
Complex Life Cycles ◽  
Developmental Patterns ◽  
Resting Stages ◽  
Cellular Processes ◽  
Temporal Persistence ◽  
Variable Combination ◽  
Reverse Development

Cnidarians have long been considered simple animals in spite of the variety of their complex life cycles and developmental patterns. Several cases of developmental conversion are known, leading to the formation of resting stages or to offspring proliferation. Besides their high regenerative and asexual-reproduction potential, a number of cnidarians can undergo ontogeny reversal, or reverse development: one or more stages in the life cycle can reactivate genetic programs specific to earlier stages, leading to back-transformation and morph rejuvenation. The switch is achieved by a variable combination of cellular processes, such as transdifferentiation, programmed cell death, and proliferation of interstitial cells. The potential for ontogeny reversal has limited ecological meaning and is probably just an extreme example of a more general strategy for withstanding unfavourable periods and allowing temporal persistence of species in the environment.

scholarly journals Advances of 2nd Life Applications for Lithium Ion Batteries from Electric Vehicles Based on Energy Demand

2021 ◽  
Vol 13 (10) ◽  
pp. 5726
Author(s):  
Aleksandra Wewer ◽  
Pinar Bilge ◽  
Franz Dietrich
Keyword(s):  
Life Cycle ◽  
Lithium Ion Batteries ◽  
Electric Vehicles ◽  
Energy Demand ◽  
Lithium Ion ◽  
Life Cycles ◽  
Future Research ◽  
Research Areas ◽  
Study Results ◽  
The Impact

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.

scholarly journals Effect of Barley Sowing Density on the Integrated Weed Management of Lolium rigidum (Annual Ryegrass) in Mediterranean Dryland: A Modeling Approach

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1565
Author(s):  
María Belén D’Amico ◽  
Guillermo R. Chantre ◽  
Guillermo L. Calandrini ◽  
José L. González-Andújar
Keyword(s):  
Weed Management ◽  
Life Cycles ◽  
Integrated Weed Management ◽  
Future Research ◽  
Seed Removal ◽  
Weed Infestation ◽  
High Control ◽  
Weed Dynamics ◽  
The Impact

Population models are particularly helpful for understanding long-term changes in the weed dynamics associated with integrated weed management (IWM) strategies. IWM practices for controlling L. rigidum are of high importance, mainly due to its widespread resistance that precludes chemical control as a single management method. The objective of this contribution is to simulate different IWM scenarios with special emphasis on the impact of different levels of barley sowing densities on L. rigidum control. To this effect, a weed–crop population model for both L. rigidum and barley life cycles was developed. Our results point out: (i) the necessity of achieving high control efficiencies (>99%), (ii) that the increase of twice the standard sowing density of barley resulted in a reduction of 23.7% of the weed density, (iii) non-herbicide-based individual methods, such as delayed sowing and weed seed removal at harvest, proved to be inefficient for reducing drastically weed population, (iv) the implementation of at least three control tactics (seed removal, delay sowing and herbicides) is required for weed infestation eradication independently of the sowing rate, and (v) the effect of an increase in the sowing density is diluted as a more demanding weed control is reached. Future research should aim to disentangle the effect of different weed resistance levels on L. rigidum population dynamics and the required efficiencies for more sustainable IWM programs.

scholarly journals Molecular Identification of New Cases of Human Dirofilariosis (Dirofilaria repens) in Italy

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 251
Author(s):  
Simona Gabrielli ◽  
Valentina Mangano ◽  
Federica Furzi ◽  
Alessandra Oliva ◽  
Serena Vita ◽  
...  
Keyword(s):  
Molecular Diagnosis ◽  
Central Italy ◽  
Research Work ◽  
Pulmonary Nodules ◽  
Elisa Test ◽  
Future Research ◽  
Worldwide Distribution ◽  
Human Dirofilariosis ◽  
Vector Borne ◽  
Etiological Agents

(1) Dirofilariosis is a vector-borne parasitic disease mainly in domestic and wild carnivores caused by Dirofilaria (Noctiella) repens, which is endemic in many countries of the Old World, and D. immitis, which has a worldwide distribution. In recent years, an increase in the number of human cases has been reported, suggesting that dirofilariosis is an emergent zoonosis. Here, we describe further cases (N = 8), observed in Central Italy during the years 2018–2019. (2) Molecular diagnosis was performed on: (i) live worms extracted from ocular conjunctiva, cheek, and calf muscle; (ii) histological sections of surgically removed nodules from parenchymal lung, coccyx, and breast. (3) Sequence analysis (650-bp) of the mitochondrial cytochrome oxidase subunit I gene (mtDNA cox1) showed a match of 100% with the sequences of D. repens previously deposited in GenBank. ELISA test to detect IgG against filarial antigens was performed on four patients’ sera and resulted positive in two patients who showed ocular and subcutaneous dirofilariosis, respectively. Microfilariae have been never detected in the peripheral blood of the patients. (4) The occurrence of N = 8 new cases of human D. repens-infections observed in a two-year period suggests an increased circulation of the parasite in Italy. Therefore, dirofilariosis should be included in differential diagnosis in patients presenting subcutaneous and/or pulmonary nodules. Molecular diagnosis of the etiological agents is fundamental. Specific serological diagnosis needs to be improved in future research work.

scholarly journals Impacts of climate change on the complex life cycles of fish

2012 ◽  
Vol 22 (2) ◽  
pp. 121-139 ◽  
Author(s):  
Pierre Petitgas ◽  
Adriaan D. Rijnsdorp ◽  
Mark Dickey-Collas ◽  
Georg H. Engelhard ◽  
Myron A. Peck ◽  
...  
Keyword(s):  
Climate Change ◽  
Life Cycles ◽  
Complex Life Cycles ◽  
Impacts Of Climate Change

Complex Life Cycles: Why Refrain from Growth before Reproduction in the Adult Niche?

2013 ◽  
Vol 181 (1) ◽  
pp. 39-51 ◽  
Author(s):  
Daniel P. Benesh ◽  
James C. Chubb ◽  
Geoff A. Parker
Keyword(s):  
Life Cycles ◽  
Complex Life Cycles

scholarly journals Perceptions of Shared Leadership within Academic Libraries Suggest Room for Improvement

2011 ◽  
Vol 6 (3) ◽  
pp. 82
Author(s):  
Genevieve C. Gore
Keyword(s):  
Pacific Northwest ◽  
Academic Libraries ◽  
Shared Leadership ◽  
Middle Managers ◽  
The United States ◽  
Future Research ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
The Third ◽  
Level Of Agreement

Objective – To survey middle managers’ beliefs regarding their participation in shared leadership and their libraries’ practices of shared leadership. Design – Cross-sectional survey. Setting – Twenty-two academic libraries within four-year public master’s level institutions in the Pacific Northwest of the United States. Subjects – A total of 115 middle managers were invited to participate; 77 completed the survey for a response rate of 66.9%. Methods – Selected middle managers were contacted by email a total of five times and were invited to complete a Web-based survey composed of three sections. The first section contained 10 statements for rating shared leadership within their own institutions, which they were asked to rate on an eight-point Likert scale from 1 (strongly agree) to 7 (strongly disagree), with 8 as an option for no opinion. The second section used the same scale to rate their levels of agreement with conceptual definitions of shared leadership from Jackson’s Framework. Jackson’s Framework consists of four components for ascertaining levels of shared leadership from both managerial and staff perspectives: accountability, equity, partnership and ownership. The third section invited subjects to provide their own definition of shared leadership. A three-part pretest served to validate the survey instrument. Mean scores were calculated for each statement. Main Results – In the first section, there was the highest overall level of agreement (1.52) with the statement “I am accountable for the decisions within the scope of my responsibility” followed by “I share information with the senior library administration” (1.71). There was the lowest overall level of agreement (3.65) with the statement that “Ideas presented at all levels of staff in the library are equally considered.” In the second section, respondents’ mean scores for Jackson’s definitions of four concepts of shared leadership were 2.62 for ownership, 2.68 for both partnership and equity, and 2.77 for accountability. In the third section, respondents most often linked their definitions of shared leadership with communication, learning and collaboration. Conclusion – Examining middle managers’ perceptions of shared leadership may help us understand organizational trends and capacity for leadership within libraries. Future research could examine shared leadership at levels below middle management as well as the relationship between accountability and shared leadership throughout the organization.

scholarly journals Tropical cyclone-related socio-economic losses in the western North Pacific region

2013 ◽  
Vol 13 (1) ◽  
pp. 115-124 ◽  
Author(s):  
C. Welker ◽  
E. Faust
Keyword(s):  
Purchasing Power Parity ◽  
North Pacific ◽  
Western North Pacific ◽  
Economic Losses ◽  
Future Research ◽  
Northwest Pacific ◽  
Pacific Region ◽  
Power Parity ◽  
Decadal Scale ◽  
Loss Data

Abstract. The western North Pacific (WNP) is the area of the world most frequently affected by tropical cyclones (TCs). However, little is known about the socio-economic impacts of TCs in this region, probably because of the limited relevant loss data. Here, loss data from Munich RE's NatCatSERVICE database is used, a high-quality and widely consulted database of natural disasters. In the country-level loss normalisation technique we apply, the original loss data are normalised to present-day exposure levels by using the respective country's nominal gross domestic product at purchasing power parity as a proxy for wealth. The main focus of our study is on the question of whether the decadal-scale TC variability observed in the Northwest Pacific region in recent decades can be shown to manifest itself economically in an associated variability in losses. It is shown that since 1980 the frequency of TC-related loss events in the WNP exhibited, apart from seasonal and interannual variations, interdecadal variability with a period of about 22 yr – driven primarily by corresponding variations of Northwest Pacific TCs. Compared to the long-term mean, the number of loss events was found to be higher (lower) by 14% (9%) in the positive (negative) phase of the decadal-scale WNP TC frequency variability. This was identified for the period 1980–2008 by applying a wavelet analysis technique. It was also possible to demonstrate the same low-frequency variability in normalised direct economic losses from TCs in the WNP region. The identification of possible physical mechanisms responsible for the observed decadal-scale Northwest Pacific TC variability will be the subject of future research, even if suggestions have already been made in earlier studies.

Autonomy and integration in complex parasite life cycles

Parasitology ◽  
2016 ◽  
Vol 143 (14) ◽  
pp. 1824-1846 ◽  
Author(s):  
DANIEL P. BENESH
Keyword(s):  
Life Cycle ◽  
Holistic Approach ◽  
Life Cycles ◽  
Complex Life Cycle ◽  
Functional Specialization ◽  
Life Stages ◽  
Free Living ◽  
New Host ◽  
Complex Life Cycles ◽  
Life Cycle Stages

SUMMARYComplex life cycles are common in free-living and parasitic organisms alike. The adaptive decoupling hypothesis postulates that separate life cycle stages have a degree of developmental and genetic autonomy, allowing them to be independently optimized for dissimilar, competing tasks. That is, complex life cycles evolved to facilitate functional specialization. Here, I review the connections between the different stages in parasite life cycles. I first examine evolutionary connections between life stages, such as the genetic coupling of parasite performance in consecutive hosts, the interspecific correlations between traits expressed in different hosts, and the developmental and functional obstacles to stage loss. Then, I evaluate how environmental factors link life stages through carryover effects, where stressful larval conditions impact parasites even after transmission to a new host. There is evidence for both autonomy and integration across stages, so the relevant question becomes how integrated are parasite life cycles and through what mechanisms? By highlighting how genetics, development, selection and the environment can lead to interdependencies among successive life stages, I wish to promote a holistic approach to studying complex life cycle parasites and emphasize that what happens in one stage is potentially highly relevant for later stages.

Abiotic versus biotic hierarchies in the assembly of parasite populations

Parasitology ◽  
2009 ◽  
Vol 137 (4) ◽  
pp. 743-754 ◽  
Author(s):  
T. K. ANDERSON ◽  
M. V. K. SUKHDEO
Keyword(s):  
Fundulus Heteroclitus ◽  
Classification Tree ◽  
Benthic Invertebrate ◽  
Life Cycles ◽  
Complex Life Cycles ◽  
Parasite Communities ◽  
Parametric Classification ◽  
The Common ◽  
Correct Category ◽  
Parasite Populations

SUMMARYThe presence or absence of parasites within host populations is the result of a complex of factors, both biotic and abiotic. This study uses a non-parametric classification tree approach to evaluate the relative importance of key abiotic and biotic drivers controlling the presence/absence of parasites with complex life cycles in a sentinel, the common killifish Fundulus heteroclitus. Parasite communities were classified from 480 individuals representing 15 fish from 4 distinct marsh sites in each of 4 consecutive seasons between 2006 and 2007. Abiotic parameters were recorded at continuous water monitoring stations located at each of the 4 sites. Classification trees identified the presence of benthic invertebrate species (Gammarus sp. and Littorina sp.) as the most important variables in determining parasite presence: secondary splitters were dominated by abiotic variables including conductance, pH and temperature. Seventy percent of hosts were successfully classified into the correct category (infected/uninfected) based on only these criteria. The presence of competent definitive hosts was not considered to be an important explanatory variable. These data suggest that the most important determinant of the presence of these parasite populations in the common killifish is the availability of diverse communities of benthic invertebrates.

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