EXTREMAL F-INDICES FOR BICYCLIC GRAPHS WITH k PENDANT VERTICES

RUHUL AMIN,SK. MD. ABU NAYEEM 한국수학교육학회 2020 純粹 및 應用數學 Vol.27 No.4

Long back in 1972, it was shown that the sum of the squares of vertex degrees and the sum of cubes of vertex degrees of a molecular graph both have large correlations with total π-electron energy of the molecule. Later on, the sum of squares of vertex degrees was named as first Zagreb index and became one of the most studied molecular graph parameter in the field of chemical graph theory. Whereas, the other sum remained almost unnoticed until recently except for a few occasions. Thus it got the name “forgotten” index or F-index. This paper inves- tigates extremal graphs with respect to F-index among the class of bicyclic graphs with n vertices and k pendant vertices, 0≤k≤n − 4. As consequences, we obtain the bicyclic graphs with largest and smallest F-indices.

Comparing the effects of GM and non‐GM soybean varieties on non‐target arthropods

Amin Md Ruhul,Oh Sung‐Dug,Suh Sang Jae 한국곤충학회 2020 Entomological Research Vol.50 No.9

In order to guarantee the safety of genetically modified (GM) soybean crops, it is important to assess the potential toxicity of their expressed insecticidal proteins to non‐target organisms. In the present study, the effects of the GM soybean Insulin‐like Growth Factor (IGF), which is tolerant to the herbicide glufosinate, on plant‐dwelling non‐target insects and arachnids were evaluated in soybean agroecosystems. For comparison, the non‐GM parental cultivar of soybean Gwangan‐kong was used as a control. Data were collected in 2016 and 2017 via surveying at Ochang and Jeonju, Korea. In total, 13,031 individual insects and arachnids, representing 64 families in 11 orders, were captured during the study. Firstly, the results indicate that the GM soybean IGF did not negatively affect plant‐dwelling non‐target insects and arachnids. However, the numbers of captured individuals on both IGF and Gwangan‐kong were higher at Ochang in 2017. The occurrence of insect pests, natural enemies, and other insects differed significantly according to region, region and survey year, and survey year, respectively. In addition, the dominance, diversity, evenness, and richness indices for the collected insects varied significantly among the regions and survey years regardless of soybean variety. The score from PROXSCAL multidimensional scaling using combined data showed that insects and arachnids in different natural environments were separated by their cultivation regions and years irrespective of soybean cultivars.

Impact of insect‐resistant transgenic rice on above‐ground non‐target arthropods in Korea

Amin Md Ruhul,Oh Sung‐Dug,Bae Eunji,Park Soo‐Yun,Suh Sang Jae 한국곤충학회 2020 Entomological Research Vol.50 No.11

Transgenic rice (Bt‐T event) shows resistance against rice leaf roller (Cnaphalocrocis medinalis) by expressing a toxic protein (mCry1Ac1) mediated from the soil bacterium Bacillus thuringiensis. Environmental risk assessment of Bt‐T event, in addition to the parent variety Dongjin‐byeo and cultivar Ilmi‐byeo, was performed during the rice cultivation seasons of 2016 and 2017 at LMO quarantine fields in Gunwi and Jeonju, Korea. Non‐target arthropods (insects and spiders) were captured using an aspirator from the three rice ecosystems of both locations, and in total 39,734 individuals of 57 families and 11 orders were collected. The numbers of individuals collected from the Bt‐T, Dongjin‐byeo and Ilmi‐byeo rice ecosystems were 12,899, 12,730, and 14,105, respectively, which did not differ significantly among rice ecosystems. The dominance, diversity, evenness, and richness indices of the collected insects were not statistically different among the rice ecosystems, but significant variations between the two locations and survey years were detected. Principal component analysis showed that insects and spiders in the Bt‐T, Dongjin‐ byeo, and Ilmi‐byeo rice ecosystems were separated by the study locations and years irrespective of rice variety. In conclusion, results obtained in two consecutive years from two non‐genetically modified rice ecosystems and a Bt‐T rice ecosystem showed that the Bt‐T rice had no significant negative impacts on the above‐ground insect and spider communities.

Aphid population abundance and pestiferous effect on various bean plant species

Amin Md Ruhul,Sharmin Mohsen Ara,Miah Md Ramiz Uddin,Akanda Abdul Mannan,Suh Sang Jae,Kwon Yong Jung,Kwon Ohseok 한국곤충학회 2020 Entomological Research Vol.50 No.6

The population abundance, infestation, and harmful effects of the aphid Aphis craccivora Koch (Hemiptera: Aphididae) were studied on four bean plant species, namely the country bean (Lablab purpureus var. BARI Seem 1), the yard-long bean (Vigna sesquipedalis var. BARI Borboti 1), the hyacinth bean (Dolichos lablab var. BARI Seem 6), and the bush bean (Phaseolus vulgaris var. BARI Jar Seem 3). Aphid abundance and infestation on the leaves, inflorescences, flowers, and pods differed significantly among the bean plant species, with P. vulgaris and V. sesquipedalis having the lowest and highest results, respectively. Aphid severity grade and the number of trichomes of the bean plant species were negatively correlated. The duration of the growth stages among the bean plant species were significantly different, with V. sesquipedalis having the shortest durations. Aphid abundance and infestation significantly affected the physical and phytochemical characteristics of the bean plant species. The highest reduction of number of leaves, flower inflorescences, and pod inflorescences per plant, and moisture and chlorophyll content in the leaves was found in L. purpureus. The results for V. sesquipedalis revealed the highest reduction in plant height, seed weight, and pH, while those of D. lablab showed the highest reduction in leaf area.

The effect of thioredoxin-gene-expressed transgenic soybean on associated non-target insects and arachnids

Amin Md Ruhul,Oh Sung‐Dug,Park Soo-Yun,Ha Kihun,Kang Sera,Park Jung-Ho,Kim Minwook,Eun Chang Uk,김영군,서상재 한국식물생명공학회 2022 Plant biotechnology reports Vol.16 No.1

The evaluation of genetically modified (GM) crops regarding their effect on non-target organisms is necessary to safeguard ecosystem components. In this study, we assessed the effects of transgenic soybean events TRX (expressing the human thioredoxin gene under the control of the β-conglycinin promoter with tolerance to the herbicide glufosinate, PPT) on plant‐ dwelling non-target insects and arachnids compared with those of a non‐GM parental cultivar, Gwangan soybean. Field surveys of soybean fields were carried out at Ochang and Jeonju, Korea, in 2016 and 2017. We found that the number of captured individuals was higher at Ochang in 2017 on both TRX and Gwangan soybean plants. From 2016 to 2017, the aver- age population density of the insect pests and natural enemies decreased; however, in the case of other insects, the population density remained unchanged. The dominance index of the captured non-target insects and arachnids decreased, whereas the diversity and richness indices increased over time on the genotypes at both regions. The evenness index of non-target insects and arachnids decreased at Jeonju but showed no change at Ochang, regardless of the genotype. Hemiptera, Hymenoptera, and Diptera were the most dominant orders of the insect pests, natural enemies, and other insects, respectively. The score from PROXSCAL multidimensional scaling using combined data showed that insects and arachnids in different natural environments differed due to their cultivation regions and years, irrespective of soybean cultivars. Overall, the results indi- cated that the GM soybean TRX did not negatively affect the community of plant‐dwelling non-target insects and arachnids.

Conservation and Utilization of Insect Pollinators for Promotion of Agricultural Production in Bangladesh

Amin, Md. Ruhul,Hossain, Md. Shamim,Suh, Sang Jae,Kwon, Yong Jung Institute of Agricultural Science and Technology 2014 慶北大農學誌 Vol.32 No.4

Agriculture in Bangladesh is slowly transforming to the production of high-value fruit and vegetable crops to satisfy the nutrient requirements of their large size population, and this transformation is creating new challenges as regards improving and maintaining the productivity and crop quality. The country has a declining trend of insect pollinators due to habitat loss, land use changes, monoculture-dominated agriculture, and the excessive and indiscriminate use of pesticides. Such pollinator deficiencies can cause reduced yields, thereby threatening the subsistence of marginal farmers. In Bangladesh, growers enjoy free pollination services from the naturally occurring insect populations. While honeybees pollinate mustard, onions, and melons, many other hymenopterans, coleopterans, hemipterans, dipterans, and thysanopterans also visit the crop fields, making these insects significant for the food security, environment, and economy of the nation. Therefore, attention should be given to public policy, research, and human resource development that promotes knowledge and appreciation of the conservation and utilization of insect pollinators.

New concepts on R₁ fuzzy soft topological spaces

Ruhul Amin,Raihanul Islam 원광대학교 기초자연과학연구소 2021 ANNALS OF FUZZY MATHEMATICS AND INFORMATICS Vol.22 No.2

In this paper, we have introduced and studied some new notions of $R_{1}$ separation axiom in fuzzy soft topological spaces by using quasi-coincident relation for fuzzy soft points. We have observed that all these notions satisfy good extension property. We have shown that these notions are preserved under the one-one, onto and FSP continuous mapping. Moreover, we have obtained some other properties of this new concept.

UAVs-assisted passive source localization using robust TDOA ranging for search and rescue

Ruhul Amin Khalil,Nasir Saeed,Muhannad Almutiry 한국통신학회 2023 ICT Express Vol.9 No.4

Mobile connections and applications are growing unprecedentedly with the advent and increasing popularity of wireless services worldwide, which greatly increases the demands on data traffic. This led to considering millimeter-wave bands and ultra-dense deployment as part of the key enabler solutions in 5G networks. However, these solutions radically increase the number of handovers (HOs), thus increasing the rate of unnecessary HO and dropping call probabilities. In this regard, optimizing HO control parameters appropriately is the main factor that can efficiently address HO issues during user mobility. This paper proposes a fuzzy-coordinated self-optimizing HO scheme to achieve a seamless HO while users move in multi-radio access networks. The proposed scheme resolves the conflict between mobility robustness and load balancing functions by utilizing a fuzzy system considering three input parameters: signal-to-interference-plus-noise ratio, cell load and UE speed. Simulation results show that the proposed scheme manages to control the mobility optimization in terms of ping-pong HO, radio link failure and HO latency over different mobile speed scenarios. Moreover, the proposed scheme reduces the outage probability compared to other schemes from literature.

Foraging Behavior of Helicoverpa armigera $H{\ddot{u}}bner$ (Lepidoptera: Noctuidae) First Instar Larvae on Selected Cotton Varieties

Amin, Md. Ruhul,Azad, H.M. Saifullah,Hossain, Md. Shamim,Suh, Sang Jae,Kwon, Yong Jung Institute of Agricultural Science and Technology 2014 慶北大農學誌 Vol.32 No.4

The movement, survival, and weight gain of Helicoverpa armigera $H{\ddot{u}}bner$ (Lepidoptera: Noctuidae) first instar larvae were studied on CB9, CB10 and SR05 cotton varieties under field conditions. The neonate H. armigera were released on the cotton varieties at the squaring stage of the plants and, after a period of 72 hours, the survival, weight gain, and final location of the larvae were observed. While the different cotton varieties had no effect on the survival and weight gain of the larvae, the release locations on the cotton varieties had a significant influence on the larval survival and weight gain. The larvae fed small squares of the cotton varieties were significantly heavier and showed a higher mortality than the larvae fed leaflets and mature leaves. For the cotton varieties in this study, the larvae released on leaflets showed a significantly higher rate of recovery compared to the larvae released on mature leaves and squares. This study also found that that the larvae on leaflets did not move up or downward unlike the larvae on mature leaves and squares. This information on the foraging behavior of larvae on cotton varieties will assist researchers to interpret field data and thereby help with the development of pest management decisions.

Relationship between abiotic factors and the incidence of sucking pests on rose plants

Amin Md Ruhul,Islam Md Ariful,Suh Sang Jae,Kwon Ohseok,Lee Keyong‐Yeoll 한국곤충학회 2020 Entomological Research Vol.50 No.10

This study was conducted from November 2017 to May 2018 in the experimental field of the Department of Entomology, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh, to investigate the effects of temperature, relative humidity, and rainfall on the incidence of sucking pests (thrips, aphids, and red spider mites) on roses. The results showed that the thrips population started to increase in the first week of January, gradually increasing and reaching its maximum (2.6 ± 0.2 individuals/flower) in the first week of February, and then declining. The aphid population started to increase in the second week of November, reached its peak (8.4 ± 0.6 individuals/shoot) in the last week of December, and then declining. The mite population started increasing in the second week of December, increased continuously until its peak (8.4 ± 0.4 individuals/shoot) in the first week of March, and then declining. The populations of thrips, aphids, and mites persisted until the third week of April, the third week of May, and the first week of April, respectively. Daily mean temperature and rainfall were negatively correlated with the increase in the thrips and aphid populations, while relative humidity was positively correlated with it; however, these correlations were not significant. The mite population had a significant positive correlation with temperature and a non‐significant negative correlation with relative humidity and rainfall. Multiple linear regression analysis showed that weather variables together predicted 34%, 53.1%, and 41.7% of thrips, aphid, and mite abundance on rose plants.