Rapid microwave-assisted seeding and secondary growth synthesis of ZIF-8 membrane for propylene/propane separation

Owing to their permanent porosity, diverse topology structures, and coordination factors combined with chemical tunability, the zeolitic imidazolate framework (ZIF) has shown great potential for the effective separation of hydrocarbon mixtures. In this work, the authors presented a simple microwave-assisted seeding strategy to rapidly prepare a seed layer for the synthesis of high-quality ZIF-8 membranes for propylene/propane separation. The resulted membranes grown on planar alumina support displayed excellent separation performances for a wide range of propylene/propane mixtures. The membrane displayed a propylene/propane separation factor of 70 and propylene permeance of 105×10-10 mol.m-2s-1Pa-1. Long-term stability test also showed stable gas permeance and separation performance of the ZIF-8 membranes in both atmospheric conditions and propylene/propane mixture stream.

Meta-analysis using a Lehmann classifier of obligate seeding species germination in fire-prone Mediterranean Type environments

The generalization that specific seed traits such as dormancy, longevity, or heat-triggered germination of plant species expanding in pyrogenic environments where stochastically but recurrently fire disturbance occurs is a fitness increasing adaptation of obligate seeders dates from the early 20th century. During the last few decades, this hypothesis, qualified as a pyrophytic strategy, is re-evaluated under the lenses of conservation biology and climate change research. The validity of pyrophytism as an equilibrium response to fire vs. the interpretation that the obligate seeding strategy is instead an opportunistic or generalist response to the multitude of abiotic and biotic factors determining the variability and heterogeneity of fire-prone environments such as the Mediterranean Type Ecosystems is indirectly examined and narratively promoted in the renewed fire ecology literature. In this paper, I suggest a need for a typified meta-analysis of the abundant but disparate wealth of research protocols and data to achieve a quantitatively strict understanding of the limits of the contrasting hypotheses. I develop a meta-analytic classifier and test its feasibility and applicability across taxonomic, biologic, and ecological levels of organization, i.e., from the intra-population or inter-individual local level progressively to inter-genus and intra-family levels, across the Mediterranean Basin. Cistaceae species, emblems of the Mediterranean shrublands, are the model for this research. The results of this exercise support the feasibility and flexibility of the Lehmann-type classifier developed. Although Cistus species do respond positively to heat-shocks at the local level, significant variability is uncovered among higher taxa levels and furthermost as the environmental variability increases. The germination variability complicates generalizations when climatic variability and change come into play, questioning long-standing ‘certitudes’ and Mediterranean forest managers and conservation planners' practices.

MegaPath: sensitive and rapid pathogen detection using metagenomic NGS data

Background Next-generation sequencing (NGS) enables unbiased detection of pathogens by mapping the sequencing reads of a patient sample to the known reference sequence of bacteria and viruses. However, for a new pathogen without a reference sequence of a close relative, or with a high load of mutations compared to its predecessors, read mapping fails due to a low similarity between the pathogen and reference sequence, which in turn leads to insensitive and inaccurate pathogen detection outcomes. Results We developed MegaPath, which runs fast and provides high sensitivity in detecting new pathogens. In MegaPath, we have implemented and tested a combination of polishing techniques to remove non-informative human reads and spurious alignments. MegaPath applies a global optimization to the read alignments and reassigns the reads incorrectly aligned to multiple species to a unique species. The reassignment not only significantly increased the number of reads aligned to distant pathogens, but also significantly reduced incorrect alignments. MegaPath implements an enhanced maximum-exact-match prefix seeding strategy and a SIMD-accelerated Smith-Waterman algorithm to run fast. Conclusions In our benchmarks, MegaPath demonstrated superior sensitivity by detecting eight times more reads from a low-similarity pathogen than other tools. Meanwhile, MegaPath ran much faster than the other state-of-the-art alignment-based pathogen detection tools (and compariable with the less sensitivity profile-based pathogen detection tools). The running time of MegaPath is about 20 min on a typical 1 Gb dataset.

Competition for Attention in Online Social Networks: Implications for Seeding Strategies

Many firms try to leverage consumers’ interactions on social platforms as part of their communication strategies. However, information on online social networks only propagates if it receives consumers’ attention. This paper proposes a seeding strategy to maximize information propagation while accounting for competition for attention. The theory of exchange networks serves as the framework for identifying the optimal seeding strategy and recommends seeding people that have many friends, who, in turn, have only a few friends. There is little competition for the attention of those seeds’ friends, and these friends are therefore responsive to the messages they receive. Using a game-theoretic model, we show that it is optimal to seed people with the highest Bonacich centrality. Importantly, in contrast to previous seeding literature that assumed a fixed and nonnegative connectivity parameter of the Bonacich measure, we demonstrate that this connectivity parameter is negative and needs to be estimated. Two independent empirical validations using a total of 34 social media campaigns on two different large online social networks show that the proposed seeding strategy can substantially increase a campaign’s reach. The second study uses the activity network of messages exchanged to confirm that the effects are driven by competition for attention. This paper was accepted by Anandhi Bharadwaj, information systems.

Thallus sectioning as an efficient monospore release method in Pyropia yezoensis (Bangiales, Rhodophyta)

The red seaweed Pyropia yezoensis is a marine crop of important economic value and is widely cultivated in the coastal areas of northern China. The current seedling-raising system relies on the germination of conchospores, a process not fast enough to meet the increasing demand from farmers. In this study, we developed a monospore-dependent seedling method based on the asexual reproduction of the Pyropia thallus. The Pyropia thallus was physically sectioned into small pieces (microthalli) that were cultivated at 15 °C. The algal cells in the microthalli became morphologically condensed, underwent cell division, and then developed into monospores on the 5th day. The monospores were able to attach to the seeding rope in 24 h and germinated into healthy thalli. To optimize the efficiency of monospore release, we tested the effect of temperature and the size and original positions of the microthalli as well as the age of the mother thallus. Microthalli with a size of 30–50 cells from the middle and apex of 21-day-old thalli cultivated at 15 °C yielded the optimum production of monospores. Theoretically, in this thallus-to-thallus seeding strategy, 0.1 g of thallus could produce at least 107 monospores, with the same number of offspring thallus seedlings. Taking all of these advantages together, including the high efficiency, short time, low cost and easy operation, this physical sectioning method could serve as a promising seed source especially for new cultivars with superior traits in Pyropia farming and rapid replenishment of seedlings when thalli undergo disastrous diseases.

Seeded word-of-mouth marketing strategy: mapping and analysis of a network of political supporters

Objective: To analyze how a structure-based seeding strategy can improve word-of-mouth marketing efficiency in proportional elections.Methodology: This study is quantitative and qualitative. In the quantitative phase, an egocentric social network analysis (SNA) of a candidate was conducted. Using Bonacich's degree, intermediation and power centralities, the study identified, then interviewed nine seed actors, which through the snowball technique, led to the identification of 31 other interviewees and the formation of a total network of 232 actors. In the qualitative phase, the reasons for supporting ego and alters as well as their preceding characteristics were analyzed using report content analysis.Originality / Relevance: This is a study of the characteristics of the actors along with their centrality in the strategy of seeding, spreading and maintaining the reputation of the political actor, especially candidates for proportional elections.Results: The characteristics of the most central supporters within the network reflect the bonds of trust built and deposited in the candidate, with ideology and friendship being the most prone to a more effective word-of-mouth marketing. The precedents for commitment and perceived value of word-of-mouth propensity were also verified.Theoretical / Methodological Contributions: This study includes the discussion of proportional elections in electoral marketing, highlighting the power of supporters through analysis of social network marketing. It also contributes to the analysis of the characteristics of actors in the effectiveness of seeding strategy in word-of-mouth marketing.Contributions to Management: The candidate may adopt a seeding strategy in his campaign, thereby promoting effectiveness in resource allocation, while allowing the supporter to understand the difference of his role as a supporter.