Simple Competition Research Articles

Allelochemicals determine competition and grazing control in Alexandrium catenella

The production of allelochemicals by the toxigenic dinoflagellate Alexandrium catenella is one of the suggested mechanisms to facilitate its bloom formation and persistence by outcompeting other phototrophic protists and reducing grazing pressure. In Southern California, toxic events caused by A. catenella and paralytic shellfish toxins (PSTs) regularly impact coastal ecosystems; however, the trophic interactions and mechanisms promoting this species in a food web context are still not fully understood. In the present study, we combined a dynamical mathematical model with laboratory experiments to investigate potential toxic and allelochemical effects of an A. catenella strain isolated off the coast of Los Angeles, Southern California, on competitors and a common zooplankton consumer. Experiments were conducted using three toxigenic strains of A. catenella, comparing the new Californian isolate (Alex Cal) to two strains previously described from the North Sea, a lytic (Alex2) and non-lytic (Alex5) strain, testing for donor density-dependent effects on two phytoplankton species (Rhodomonas salina, Tetraselmis sp.) and on the rotifer Brachionus plicatilis. Bioassays revealed a steep decline in competitor and consumer populations with increasing Alex Cal concentrations, indicating an intermediate lytic activity compared to the North Sea strains (lytic Alex2 and non-lytic Alex5). The rotifer fed and grew well on the PST- toxic, but non-lytic Alex5 strain, while its survival significantly decreased with increasing concentrations of the two lytic strains Alex Cal and Alex 2, indicating that negative effects on the rotifer were mediated by allelochemicals rather than PST-toxins. Mixed culture experiments including both competitors and consumers demonstrated that the intensity of allelochemical effects not only depended on the A. catenella density but also on the target density. Negative effects on grazers were alleviated by co-occurring competitors with a lower sensitivity to allelochemicals, thus reducing harmful compounds and allowing grazing control on the dinoflagellate to come into effect again. Results from mixed culture experiments were supported by the mathematical approach used in this study which was calibrated with data from simple monoculture growth, pairwise competition and predator-prey experiments, demonstrating the applicability of this model approach to predict the outcome of more complex food web dynamics at the community level.

Emergence of biconnected clusters in explosive percolation.

By introducing a simple competition mechanism for bond insertion in random graphs, explosive percolation exhibits a sharp phase transition with rich critical phenomena. We investigate high-order connectivity in explosive percolation using an event-based ensemble, focusing on biconnected clusters, where any two sites are connected by at least two independent paths. Our numerical analysis confirms that explosive percolation with different intracluster bond competition rules shares the same percolation threshold and universality, with biconnected clusters percolating simultaneously with simply connected clusters. However, the volume fractal dimension d_{f}^{'} of biconnected clusters varies depending on the competition rules of intracluster bonds. The size distribution of biconnected clusters exhibits double-scaling behavior: large clusters follow the standard Fisher exponent derived from the hyperscaling relation τ^{'}=1+1/d_{f}^{'}, while small clusters display a modified Fisher exponent τ_{0}<τ^{'}. These findings provide insights into the intricate nature of connectivity in explosive percolation.

Keterlibatan High Involvement Management untuk Menjamin Kualitas Manajemen Sumber Daya Manusia

Studies on human resource management (HRM) have been supported by previous research that there are best practices, high-involvement management (HIM) that can guarantee superior organizational performance. However, there are still concerns that contingency theory still applies, namely that the fit between the human resource system and its context, and in particular the organization's business strategy, is important, and thus, High-Involvement Management (HIM) will only outperform other systems in certain circumstances. In the 1990s, there was a spate of research that attempted to test whether High-Involvement Management (HIM) was indeed universally relevant. This journal reviews these studies. This journal first introduces the conceptual dimensions of HRM and performance. This suggests that the issues are more than a simple competition between universalism and contingency theory. There are more complex hypotheses linking human resource practices beneath the surface of the current literature. This journal reviews research based on these hypotheses, and shows that the studies provide an uneven picture. First, there are conceptual differences underlying the studies and, second, the results vary across studies, and the effects of High-Involvement Management (HIM) vary across performance measures, even within particular studies. Although quite a number of studies claim to support universalism, their claims are not always unequivocally supported by their research evidence, and it is premature to conclude that they support universalism. There is more support for the 'lean production' argument which emphasizes the interaction effect between DIA and total quality management on performance.

A cell competition system with one gene expression from a single-copy gene in one cell.

Even with advanced plasmid and viral vectors, attaining copy numbers of multiple genes among different transfected cells is challenging. We achieved one gene expression from a single-copy gene in one cell using a transgene competition system, a combination of the Kazusa cDNA clones and our dual recombinase-mediated cassette exchange system. All 48 nuclear receptors were simultaneously expressed in one dish at the same expression level in HEK293 using this system, and the cell proliferation rate was compared. Significant differences were observed between cells transfected with CMV- or EF1 promoter-driven expression of the 48 nuclear receptors after 8 weeks. The EF1-NR1I2 cell line, which exhibited the highest increase from 2 to 8 weeks, showed 1.13-fold higher proliferation than the EF1-DsRed line. On the other hand, the EF1-NR4A1 cell line, which showed the maximum decrease at 8 weeks, showed 0.88-fold lower proliferation than the EF1-DsRed line. The results were confirmed in both our transgene competition system and long-term growth experiments. Our transgene competition system offers a wide-range, simple, and accurate cell competition method.

Eco-evolutionary feedbacks in the human gut microbiome

Gut microbiota can evolve within their hosts on human-relevant timescales, but little is known about how these changes influence (or are influenced by) the composition of their local community. Here, by combining ecological and evolutionary analyses of a large cohort of human gut metagenomes, we show that the short-term evolution of the microbiota is linked with shifts in its ecological structure. These correlations are not simply explained by expansions of the evolving species, and often involve additional fluctuations in distantly related taxa. We show that similar feedbacks naturally emerge in simple resource competition models, even in the absence of cross-feeding or predation. These results suggest that the structure and function of host microbiota may be shaped by their local evolutionary history, which could have important implications for personalized medicine and microbiome engineering.

Monetary Policy, Market Power, and SMEs

Monetary policy aims to affect corporate borrowing by influencing the marginal costs of firms, but its potency can be conditioned by the degree of market competition. We first identify conditions under which changes in marginal costs have different effects on credit constraints and output under different competitive environments, in a simple Cournot competition setting. We then exploit a monetary policy easing shock in the euro area to examine whether policy pass-through is conditioned by market structure. We show that small firms within less concentrated sectors experienced a larger reduction in credit constraints than similar firms in more concentrated sectors.

Program Baca Tulis Al-Qur'an; Penerapan Habituasi Pendidikan Karakter pada Anak di Desa Pesisir Kecamatan Sumberasih Kabupaten Probolinggo

Character education has an important role in creating quality next generations. One of the efforts made in instilling character values for future generations is through reading and writing Al-Qur'an activities. The purpose of writing this article is to describe how character education is habituated through reading and writing Al-Qur'an programs in Pesisir Village, Kec. Sumberasih Kab. Probolinggo. Based on the preparation and results of trials from the community that was carried out. The author uses a literature review that comes from various sources and scientific journals in the results analysis section. The results of the discussion explained that reading and writing Al-Qur'an activities make children who have habituation so that they can practice Islamic religious teachings and form a religious character. Al-Qur'an reading and writing activities are implemented through a fun approach for children, namely by holding simple games and competitions. Therefore, reading and writing the Qur'an is a reflection by bridging the child's religious character which can be applied from childhood to the end of his life.

Dynamics of ternary complex formation of an IDP and two binding partners and their allosteric effects studied by three-color single-molecule FRET.

Intrinsically disordered proteins (IDPs) are highly flexible and can bind multiple binding partners by folding into different structures. This promiscuity of IDPs is especially important for their function as hub proteins in the formation protein-protein interaction networks, which is a key regulatory mechanism of complex biological processes such as gene transcription and signal transduction. IDPs often have more than one binding domain, suggesting they can interact with multiple binding partners simultaneously. Ternary complexes formed by an IDP and two binding partners have been observed by NMR, but it is difficult to obtain more detailed kinetic information from ensemble measurements. In this work, we used three-color single-molecule FRET to directly visualize the formation and dissociation of a ternary complex. We studied binding of an IDP (p53 transactivation domain (TAD)) and two competitive binding partners (TAZ2 of CBP and MDM2). By labeling TAD with Alexa 488 (donor) and Alexa 647 (acceptor 1) and TAZ2 with CF680R (acceptor 2), it is possible to detect the formation of not only two binary complexes (TAD-TAZ2 and TAD-MDM2) but also the ternary complex (TAD-MDM2-TAZ2), which can be distinguished by the fraction of acceptor 2 intensity. From the kinetic analysis, we found that the TAD-TAZ2 binary complex is the most stable and the ternary complex is formed only transiently. Interestingly, the presence of MDM2 induces more rapid dissociation of TAZ2 in the ternary complex whereas the dissociation rate of MDM2 is not affected by TAZ2. This asymmetric allosteric effect results in the more effective replacement of CBP on p53 with MDM2, which is a novel regulatory mechanism beyond the simple competition between multiple binding partners.

Trade credit financing for supply chain coordination under financial challenges: a multi-leader–follower game approach

This study is designed to solve supply chain inefficiencies caused by some members' financial problems, such as capital shortages and financing restrictions in a stochastic environment. To this end, we have established a supply chain finance framework by designing two novel coordinating contracts based on trade credit financing for different problem settings. These contracts are modeled in the form of multi-leader Stackelberg games that address horizontal and vertical competition in a supply chain consisting of multiple suppliers and a financially constrained manufacturer. However, previous studies in the trade credit literature have addressed only simple vertical competition, that is, seller-buyer competition. To solve the proposed models, two algorithms were developed by combining population-based metaheuristics, the Nash-domination concept, and the Nikaido-Isoda function. The results demonstrate that the proposed supply chain finance framework can eliminate supply chain inefficiencies and make a large profit for suppliers, as well as the financially constrained manufacturer. Furthermore, the results of the contracts’ analysis showed that if the manufacturer is required to settle its payments to suppliers before the end of the period, the trade credit contract cannot coordinate the supply chain because of a lack of incentive for suppliers. However, if the manufacturer is allowed to extend its payments to the end of the period, the proposed trade credit financing contract can coordinate the supply chain. Finally, the sensitivity analysis results indicate that the worse the financial status of the manufacturer, the more bargaining power suppliers have in determining the contract parameters for more profit.

Endogenous timing in tax competition: The effect of asymmetric information

AbstractThis study explores the effects of asymmetric information on endogenous leadership in a simple tax competition environment. The study models a two‐country economy where one country is informed about its own and opponent's productivity of private goods, while the other country only knows its productivity. The results show that each type of informed country has an incentive to pretend to be the other type, which leads to a Stackelberg outcome endogenously, while the simultaneous move is the unique outcome under complete information. Under the Stackelberg outcome, the uninformed country moves first and the informed country moves second. Moreover, ex‐post social welfare under asymmetric information can become larger than that under complete information, because the uninformed country chooses a less aggressive tax rate under asymmetric information. These results depend on the type of uncertainty, and capital ownership and share.

An integrated methodology for selecting the building material suppliers with interval-valued intuitionistic fuzzy information

At present, with the continuous changes in the market situation and the continuous improvement of the supply chain network structure, the competition in all walks of life has become more and more intense, which has risen from simple enterprise competition to competition in the entire supply chain. In the construction industry, the structure of the construction supply chain is more complex and diverse, and it is more necessary to select high-quality suppliers for sincere cooperation. This requires construction companies to establish a complete supply chain management system, select high-quality suppliers to achieve win-win cooperation and improve their competitiveness. Therefore, construction enterprises need to comprehensively consider various factors, build a reasonable and feasible evaluation index system according to their own demand for materials, and use appropriate evaluation methods to select material suppliers with specific advantages, so as to ensure the entire construction supply chain of the project. of smooth operation. In this paper, we introduced some calculating laws on interval-valued intuitionistic fuzzy sets (IVIFSs), Hamacher sum and Hamacher product and further propose the induced interval-valued intuitionistic fuzzy Hamacher ordered weighted average (I-IVIFHOWA) operator. Meanwhile, we also study some ideal properties of built operator. Then, we apply the I-IVIFHOWA operator to deal with the multiple attribute decision making (MADM) problems under IVIFSs. Finally, an example for selecting the building material suppliers is used to test this new approach.

Program Baca Tulis Al-Qur’an; Sebuah Habituasi Pendidikan Karakter Pada Anak Di Kecamatan Anjir Muara, Barito Kuala

Character education has an important role in forming a quality generation. One effort that can be made to instill character values in future generations is through reading and writing Al-Qur'an activities. This article aims to describe the habituation of character education through reading and writing Al-Quran program in Sei Ulak Canoco Village, Anjir Muara District, Barito Kuala Regency. This article was compiled from the results of community service carried out on October 13 and 25, 2020. In the results of the analysis part, researchers used literature studies from various sources and scientific journals. The results of the discussion described that reading and writing Al-Qur'an can be an activity to habituate children with applying religious teachings and forming religious characters. The Al-Qur'an reading and writing activities are carried out using a fun approach for children such as simple games and competitions. Therefore, reading and writing Al-Qur’an is a reflection that instilling a religious character can be done from childhood, until the end of his life.

Non-microRNA binding competitively inhibits LIN28 regulation.

SUMMARYRNA binding protein (RBP) expression is finite. For RBPs that are vastly outnumbered by their potential target sites, a simple competition for binding can set the magnitude of post-transcriptional control. Here, we show that LIN28, best known for its direct regulation of let-7 miRNA biogenesis, is also indirectly regulated by its widespread binding of non-miRNA transcripts. Approximately 99% of LIN28 binding sites are found on non-miRNA transcripts, like protein coding and ribosomal RNAs. These sites are bound specifically and strongly, but they do not appear to mediate direct post-transcriptional regulation. Instead, non-miRNA sites act to sequester LIN28 protein and effectively change its functional availability, thus impeding the regulation of let-7 in cells. Together, these data show that the binding properties of the transcriptome broadly influence the ability of an RBP to mediate changes in RNA metabolism and gene expression.

Physical Interactions between Heme Oxygenase‐1 and the Cytochromes P450 Lead to Complex Changes in Enzyme Activity

The cytochromes P450 (P450s) catalyze the oxygenation of endogenous and exogenous organic substrates, including most prescribed drugs. Heme oxygenase-1 (HO-1) is an inducible enzyme responsible for the rate-limiting step of heme catabolism. HO-1 and the P450s are membrane-bound proteins expressed on the cytosolic face of the endoplasmic reticulum where they must interact with NADPH-cytochrome P450 reductase (POR) for activity. Because POR levels are often limiting, HO-1 and the P450s must compete for POR binding in order to function. However, simple competition for POR is often complicated by homomeric and heteromeric P450•P450 interactions. We hypothesized that HO-1 might participate with the P450s in their competition for POR and that this competition might lead to changes in P450 and/or HO-1 activity. We were also interested in determining whether HO-1 could physically interact with P450s and measuring what functional effects any P450•HO-1 complex might have. Using bioluminescence resonance energy transfer (BRET), we were able to establish that HO-1 formed physical complexes with CYP1A1, CYP1A2, and CYP2D6 in transiently transfected HEK293T cells. The stability of these complexes was determined by measuring the BRET signal generated by GFP- and Renilla luciferase-tagged P450 and HO-1 in the presence and absence of untagged POR. The presence of POR did not have a significant effect on the interactions of HO-1 with CYP1A2 and CYP2D6 but caused an increase in the BRET signal generated by the HO-1/CYP1A1 pair. Further BRET studies of these three P450s showed that the presence of HO-1 inhibited the formation of POR•P450 complexes, while, conversely, the presence of untagged P450 caused marginal disruption of POR•HO-1 complex formation. The differences in the response of the HO-1•CYP1A1 complex and the HO-1•CYP1A2 complex to POR indicated the possibility of different functional consequences of these P450/HO-1 interactions. Activity measurements of purified enzymes in lipid reconstituted systems confirmed that this was the case. CYP1A1 and HO-1 had large inhibitory effects on each other over a large range of POR concentrations. HO-1 activity in the presence of CYP1A1 approached that of HO-1 alone only in the presence of a large excess of POR. The parallel experiments with HO-1 and CYP1A2 yielded results that differed both qualitatively and quantitatively from those seen with CYP1A1. Like CYP1A1, CYP1A2 caused inhibition of HO-1 activity, though the effect of CYP1A2 was much milder. The effect of HO-1 on CYP1A2 was also smaller in magnitude than was observed with CYP1A1, but CYP1A2 activity increased in the presence of HO-1 and subsaturating POR. In the presence of HO-1 and excess POR, CYP1A2 activity was slightly inhibited. Kinetic analysis of these results showed that they were inconsistent with a simple model of competition between HO-1 and P450 for POR.

Amorphizing metal-organic framework towards multifunctional polysulfide barrier for high-performance lithium-sulfur batteries

Rational design of separator is especially critical in lithium-sulfur (Li–S) battery electrochemistry in view of the highly mobile intermediates and their detrimental chemical/electrochemical side reactions, which give rise to the notorious “shuttle effect”. Herein, we develop a novel strategy of amorphizing metal organic framework (MOF) exemplified by MIL-88B to construct advanced separator for Li–S batteries. The amorphization is achieved via a simple ligand competition method, and the product is endowed with higher adsorbability and catalytic activity to sulfur species attributed to the undercoordination effect. Therefore, Li–S batteries with the as-developed amorphous MOF (aMIL-88B)-modified separator realize efficient and reversible sulfur electrochemistry, exhibiting superb cyclability with high capacity retention of 740 mAh g−1 after 500 cycles at 1 C, rate performance up to 5 C, and also decent areal capacity under a high sulfur loading of 4.3 mg cm−2. This work provides a facile pathway towards multifunctional separators in Li–S batteries, and is also instructive to defect engineering of advanced materials in other related energy storage fields.

Influence of Single and Combined Mixtures of Metal Oxide Nanoparticles on Eggplant Growth, Yield, and Verticillium Wilt Severity.

Verticillium wilt, caused by Verticillium dahliae, is one of the major diseases of eggplants. Nanoparticles (NPs) of CuO, Mn2O3, and ZnO were sprayed alone onto leaves of young eggplants and in different combinations and rates, and then seedlings were transplanted into soil infested with V. dahliae in the greenhouse and field between 2015 and 2018. All combinations of NPs were consistently less effective than CuO NPs applied alone at 500 µg/ml at increasing disease suppression, biomass, and fruit yield. CuO NPs were associated with an increase in fruit yield (17 and 33% increase) and disease suppression (28 and 22% reduction) in 2016 and 2017, respectively, when compared with untreated controls. However, this effect was negated in the greenhouse and field experiments when CuO NPs were combined with Mn2O3. Combining NPs of CuO with ZnO resulted in variable effects; amendments increased growth and suppressed disease in greenhouse experiments, but results were mixed in the field. Leaf tissue analyses from the greenhouse experiments showed that Cu concentration in leaves was reduced when CuO NPs were combined with other NPs, even when application rates were the same amount. A simple competition for entry sites may explain why combinations of CuO NPs and Mn2O3 NPs reduced efficacy but does not explain the lack of inhibition between Cu and Zn. NPs of CuO performed better than their larger bulk equivalent, and studies on application rate found 500 µg/ml was optimal. No phytotoxicity, as determined, by leaf burning, necrotic spots, or dead apical buds was noted even at the highest combined rates of 1,500 µg/ml.

Representing uncertainty in the Rescorla-Wagner model: Blocking, the redundancy effect, and outcome base rate

It is generally assumed that the Rescorla and Wagner (1972) model adequately accommodates the full results of simple cue competition experiments in humans (e.g. Dickinson et al., 1984), while the Bush and Mosteller (1951) model cannot. We present simulations that demonstrate this assumption is wrong in at least some circumstances. The Rescorla-Wagner model, as usually applied, fits the full results of a simple forward cue-competition experiment no better than the Bush-Mosteller model. Additionally, we present a novel finding, where letting the associative strength of all cues start at an intermediate value (rather than zero), allows this modified model to provide a better account of the experimental data than the (equivalently modified) Bush-Mosteller model. This modification also allows the Rescorla-Wagner model to account for a redundancy effect experiment (Uengoer et al., 2013); something that the unmodified model is not able to do. Furthermore, the modified Rescorla-Wagner model can accommodate the effect of varying the proportion of trials on which the outcome occurs (i.e. the base rate) on the redundancy effect (Jones et al., 2019). Interestingly, the initial associative strength of cues varies in line with the outcome base rate. We propose that this modification provides a simple way of mathematically representing uncertainty about the causal status of novel cues within the confines of the Rescorla-Wagner model. The theoretical implications of this modification are discussed. We also briefly introduce free and open resources to support formal modelling in associative learning. Keywords: associative learning, prediction error, uncertainty, modelling, blocking, redundancy effect, open science.

Dynamics of a fractal set of first-order magnetic phase transitions in frustrated Lu2CoMnO6

Magnetic frustration can produce exotic spin configurations and dynamics. Here, the authors explore the seemingly simple competition between ferromagnetic nearest- and antiferromagnetic next-nearest neighbor interactions along Ising spin chains, as realized in the magnetoelectric compound Lu${}_{2}$CoMnO${}_{6}$. Commonly, this situation is described by the axial next-nearest-neighbor Ising model. For the first time, the authors measure and calculate its correlated magnetic dynamics, resulting from a characteristic fractal set of first-order phase boundaries. Experiments and Monte Carlo simulations reveal a dynamics slowdown while approaching the phase transition regime.

Passive Versus Active Regulation in the Actin Cytoskeleton

The actin cytoskeleton is a fundamental system in cells powering a diverse array of functions including adhesion, division, and motility. To perform these functions, cells must be able to control the architecture and mechanical properties of this system in both time and space. This control is achieved using a wide range of actin binding proteins that regulate these properties by controlling nucleation, severing, and crosslinking. In this talk, I will discuss our past and ongoing work using theory, modeling, and molecular simulation to describe how the regulation of these properties can be performed in a passive way, i.e. with only simple physical principles and competition between binding proteins. I will then discuss how actin binding protein affinity and activity can be altered by non-equilibrium processes such as myosin motor activity and actin filament polymerization. The interplay between these passive and active processes presents new mechanisms that must be considered when designing new experiments to probe regulation of cytoskeletal structure and dynamics.

Coupled nuclear-electronic decay dynamics of O2 inner valence excited states revealed by attosecond XUV wave-mixing spectroscopy.

Multiple Rydberg series converging to the O2+c4Σ-u state, accessed by 20-25 eV extreme ultraviolet (XUV) light, serve as important model systems for the competition between nuclear dissociation and electronic autoionization. The dynamics of the lowest member of these series, the 3sσg state around 21 eV, has been challenging to study owing to its ultra-short lifetime (<10 fs). Here, we apply transient wave-mixing spectroscopy with an attosecond XUV pulse to investigate the decay dynamics of this electronic state. Lifetimes of 5.8 ± 0.5 fs and 4.5 ± 0.7 fs at 95% confidence intervals are obtained for v = 0 and v = 1 vibrational levels of the 3s Rydberg state, respectively. A theoretical treatment of predissociation and electronic autoionization finds that these lifetimes are dominated by electronic autoionization. The strong dependence of the electronic autoionization rate on the internuclear distance because of two ionic decay channels that cross the 3s Rydberg state results in the different lifetimes of the two vibrational levels. The calculated lifetimes are highly sensitive to the location of the 3s potential with respect to the decay channels; by slight adjustment of the location, values of 6.2 and 5.0 fs are obtained computationally for the v = 0 and v = 1 levels, respectively, in good agreement with experiment. Overall, an intriguing picture of the coupled nuclear-electronic dynamics is revealed by attosecond XUV wave-mixing spectroscopy, indicating that the decay dynamics are not a simple competition between isolated autoionization and predissociation processes.