Methods used to control insect pests have been mainly chemical. Given the irritations associated with the use of pesticides, a search for alternatives is required, particularly through the use of plant extracts. The present study focused on comparing the insecticidal power of the aqueous extracts of the whole plant Dittrichia viscosa (commonly known as false yellowhead), the aqueous extract ratio of D. viscosa, and the bio-adjuvant Silene fuscata (1:1), as well as the synthetic pesticides Thiamethoxam/Lambda-cyhalothrin. Abundance, fecundity, demographic parameters, and biochemical parameters (lipid-glucidic biomarkers) of the winter phenotype of the black poplar leaf aphid Chaitophorus leucomelas were considered variables to assess the effectiveness of different approaches. The results show a strong effect of the aqueous extracts of D. viscosa (A.E. Plant) on abundance, with pronounced insecticidal activity from the aqueous extract ratio (A.E. Ratio) (P < 0.05). The lipid and carbohydrate energy of sexuparae undergo significant changes depending on the products used, with a disturbing effect of the synthetic product compared to aqueous extracts (P < 0.05). Fecundity shows a remarkable disturbance under the action of the active ingredient compared to the extracts. The results confirm that the products applied cause a disturbance in the growth rate (rm) and net reproductive rate (R0) of sexuparae, with the chemical treatment having the strongest effect (P < 0.05). The full dose of the active ingredient causes remarkable disturbances in the multiplication rate (lambda) and the mean generation time (T) of the sexuparae compared to the other applied molecules. Some stability is reported for the doubling time (DT) of treated females compared to the control ones.
Let G = (V, E) be a graph and f a function defined from V(G) to {0, 1, 2, 3}. A vertex v of V is said to be doubly unprotected with respect to f if f(N[v]) < 1, where N[v] is a set consisting of vertex v and all vertices adjacent to v. The function f is said to be a weak double Roman dominating function (WDRD-function) if for every vertex v with f(v) < 1 there is a neighbor u of v with f(u) > 2 such that the function g defined by g(v) = f(v) + 1, g(u) = f(u)-1 and g(x) = f(x) for all x E V(G)-{u, v} has no doubly unprotected vertex. The weight of a WDRD-function f is the sum & sum;vEV f(v), and the weak double Roman domination number gamma wdR(G) equals the minimum weight of a WDRD-function on G. First, we show that the associate decision problem for weak double Roman domination in NP-complete for a subclass of bipartite graphs, namely star convex bipartite graphs. Then we provide two equivalent conditions for trees T with gamma wdR(T) = 2 gamma(T), answering an open problem, where gamma(T) stands for the domination number of T. Finally, we determine the exact value of the weak double Roman domination number for perfect binary trees. (c) 2025 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
A set S subset of V of vertices in a graph G = (V, E) is a dominating set if every vertex in V - S is adjacent to at least one vertex in S. Intuitively, we can think of the vertices in S as providing a service to the vertices in V - S, ensuring that every vertex outside of S has access to at least one service provider in S. Now, suppose that the set S is partitioned into two subsets R and B, where each subset offers a different type of service. If every vertex in V - S is adjacent to at least one vertex in R and at least one vertex in B, then we say that S is a dual-server dominating set. In this scenario, each vertex outside the set S is guaranteed simultaneous access to both types of services. While this model can be extended to k-server dominating sets, where S is partitioned into k service types, the focus of this introductory work is specifically on the case of dual-server domination. (c) 2026 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Understanding users’ continued usage beyond initial adoption is fundamental to the long-term success of any technology. Notwithstanding the growth of cryptocurrency usage, studies have primarily examined factors explaining use intention (pre-adoption), whereas understanding continued use remains limited (post-adoption). Consequently, this study aims to examine continuance intentions to use cryptocurrency among Malaysians by employing the Unified Theory of Acceptance and Use of Technology (UTAUT), integrating attitudes, trust, and technology readiness. Using a quantitative approach based on self-reported data collected via snowball sampling, structural equation modeling (SEM) analysis reveals that the determinants of UTAUT are positively associated with attitudes toward and trust in cryptocurrency, except for the association between effort expectancy and attitudes. Additionally, trust, attitudes, and technology readiness significantly influence continuance intention, accounting for 61% of its variance. This study makes modest theoretical contributions to the technology adoption literature by shifting the focus to cryptocurrency post-adoption (i.e., why people continue to use cryptocurrency), theorizing mechanisms linking attitude and trust within the UTAUT, and examining the role of technology readiness in predicting cryptocurrency adoption. This study provides actionable recommendations for cryptocurrency providers and policymakers to nurture sustained use of decentralized digital currencies.
Nanofertilizers represent an emerging technology with significant potential to enhance agricultural sustainability by improving nutrient use efficiency and minimizing environmental impacts. This study examines the commercialization landscape of nanofertilizers, focusing on their market benefits, availability, regulatory frameworks, and key challenges. Through a review of current research, market trends, and policy developments, we highlight benefits such as increased crop yields and reduced input costs. However, widespread adoption remains limited due to high production expenses, insufficient farmer awareness, and the need for specialized application techniques. Moreover, regulatory systems for nanofertilizers are still evolving, requiring standardized safety protocols and comprehensive risk assessments. Addressing these barriers is essential to enable the successful commercialization and large-scale integration of nanofertilizers into sustainable agricultural practices.
