On Extension of the CurrentBiomolecular EmpiricalForce Field for the Description of Halogen Bonds

Kolá,ř,, Michal,Hobza, Pavel American Chemical Society 2012 Journal of chemical theory and computation Vol.8 No.4

<P>Until recently, the description of halogen bonding by standard molecular mechanics has been poor, owing to the lack of the so-called sigma hole localized at the halogen. This region of positive electrostatic potential located on top of a halogen atom explains the counterintuitive attraction of halogenated compounds interacting with Lewis bases. In molecular mechanics, the sigma hole is modeled by a massless point charge attached to the halogen atom and referred to as an explicit sigma hole (ESH). Here, we introduce and compare three methods of ESH construction, which differ in the complexity of the input needed. The molecular mechanical dissociation curves of three model complexes containing bromine are compared with accurate CCSD(T)/CBS data. Furthermore, the performance of the Amber force field enhanced by the ESH on geometry characteristics is tested on the casein kinase 2 protein complex with seven brominated inhibitors. It is shown how various schemes depend on the selection of the ESH parameters and to what extent the energies and geometries are reliable. The charge of 0.2e placed 1.5 angstrom from the bromine atomic center is suggested as a universal model for the ESH.</P>

Ligand Conformational and Solvation/Desolvation Free Energy in Protein−Ligand Complex Formation

Kolá,ř,, Michal,Fanfrlí,k, Jindř,ich,Hobza, Pavel American Chemical Society 2011 The journal of physical chemistry. B, Condensed ma Vol.115 No.16

<P>In this study, an extensive sampling of the conformational space of nine HIV-1 protease inhibitors was performed to estimate the uncertainty with which a single-conformation scoring scheme approximates the ligand−protein binding free energy. The SMD implicit solvation/desolvation energy and gas-phase PM6-DH2 energy were calculated for a set of 1600 conformations of each ligand. The probability density functions of the energies were compared with the values obtained from the single-conformation approach and from a short <I>ab initio</I> molecular dynamics simulation. The relative uncertainty in the score within the set of nine inhibitors was calculated to be 3.5 kcal·mol<SUP>−1</SUP> and 2.7 kcal·mol<SUP>−1</SUP> for the single-conformation and short dynamics, respectively. These results, though limited to the consideration of flexible ligands, provide a valuable insight into the precision of rigid models in the current computer-aided drug design.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpcbfk/2011/jpcbfk.2011.115.issue-16/jp2010265/production/images/medium/jp-2011-010265_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp2010265'>ACS Electronic Supporting Info</A></P>

Near λ-lattices

CHAJDA, IVAN,KOLAŘÍK 대한수학회 2007 Kyungpook mathematical journal Vol.47 No.2

By a near λ-lattice is meant an upper λ-semilattice where is defined a partial binary operation x ∧ y with respect to the induced order whenever x, y has a common lower bound. Alternatively, a near λ-lattice can be described as an algebra with one ternary operation satisfying nine simple conditions. Hence, the class of near λ-lattices is a quasi-variety. A λ-semilattice A = (A; ∨) is said to have sectional (antitone) involutions if for each a ∈ A there exists an (antitone) involution on [a, 1], where 1 is the greatest element of A. If this antitone involution is a complementation, A is called an ortho λ-semilattice. We characterize these near λ-lattices by certain identities.

Role of Probiotics in the Treatment and Prevention of Common Gastrointestinal Conditions in Children

Iva Hojsak,Sanja Kolaček 대한소아소화기영양학회 2024 Pediatric gastroenterology, hepatology & nutrition Vol.27 No.1

Probiotics are live microorganisms that confer health benefits to the host when administered in adequate amounts. Although recommendations for probiotic use should be strain-specific, many systematic reviews, including recommendations from different societies, recommend probiotic use in general, providing no relevant information for healthcare professionals regarding which probiotic to recommend for which clinical indication, at what dose, and for how long. This narrative review aimed to present the available evidence on the use of probiotics in the prevention and treatment of common gastrointestinal diseases in children, considering the strain and dose used. Furthermore, this study summarizes the evidence on the possible side effects and quality of products containing probiotics.

Effect of microwave sintering on the structural studies of Sr2+-substituted BCZT ceramics synthesized through the solid-state reaction method

Kola Srimannarayana,Kocharlakota Venkata Ramesh,Gurrala Veereswara Swamy 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.83 No.7

Sr2+-Substituted lead-free Ba0.85Ca0.15−xSrxZr0.9Ti0.1O3 for x=0.000, 0.005, 0.010, 0.015, and 0.020 was prepared by a conventional solid-state reaction method. These samples were sintered through microwave heating rather than conventional sintering. The structural properties were studied with XRD, SEM and FTIR. The crystallinity was calculated using Scherrer’s formula, particle density was calculated with Smith and Vijn formula, and micro strain and dislocation densities were calculated from Williamson–Hall plots. Nelson–Riley plot was used for fnding the exact lattice parameters. FTIR was used to study the chemical bonding of the crystalline samples. The average size of the particle was increased, whereas the lattice parameters, densities and porosity were decreased with an increasing concentration of Sr2+ ions. XRD studies indicated that the samples were of cubic structure for all the compositions. The analysis of FTIR showed broad peaks for all concentrations of Sr2+. SEM analysis showed that the particles were of irregular shapes and the porosity was calculated from SEM images and coincided with XRD studies.

Endemic Corruption in Supply Chain and Procurement in the Local Sphere of Government in South Africa

Kola O. Odeku 한국유통과학회 2018 유통과학연구 Vol.16 No.9

Purpose - This article accentuates that there is pervasive corruption in the supply chain and procurement of goods and services in the South African public sector, particularly in the local sphere of government. Consequently, the poor and the indigents who are supposed to receive quality services are affected. Therefore, the article emphasizes the need to strengthen compliance in the supply chain and procurement processes in order to combat corruption. Research design, data, and methodology - This article extensively utilized qualitative literature review approach to address and solve the problem of endemic corruption in the supply chain and procurement being perpetrated by local government officials. Results - The synthesis shows that by strengthening compliance of supply chain and procurement strategies, measures and frameworks, the likelihood of corruption will be drastically reduced if not totally eradicated. It demonstrates that the poor and the indigents who are supposed to receive quality services are being denied due to corruption. It also shows that failure to comply should result to enforcement of punitive sanctions against perpetrators. Conclusions - This study indicates that effective and efficient implementation of supply chain and procurement strategies, measures and frameworks are panacea for curbing corruption in South Africa public sector especially at the local sphere of government.

LSTM Prediction of Streamflow during Peak Rainfall of Piney River

Kola Yusuff Kareem,성연정,정영훈 한국방재안전학회 2021 한국방재안전학회 논문집 Vol.14 No.4

Streamflow prediction is a very vital disaster mitigation approach for effective flood management and water resources planning. Lately, torrential rainfall caused by climate change has been reported to have increased globally, thereby causing enormous infrastructural loss, properties and lives. This study evaluates the contribution of rainfall to streamflow prediction in normal and peak rainfall scenarios, typical of the recent flood at Piney Resort in Vernon, Hickman County, Tennessee, United States. Daily streamflow, water level, and rainfall data for 20 years (2000-2019) from two USGS gage stations (03602500 upstream and 03599500 downstream) of the Piney River watershed were obtained, preprocesssed and fitted with Long short term memory (LSTM) model. Tensorflow and Keras machine learning frameworks were used with Python to predict streamflow values with a sequence size of 14 days, to determine whether the model could have predicted the flooding event in August 21, 2021. Model skill analysis showed that LSTM model with full data (water level, streamflow and rainfall) performed better than the Naive Model except some rainfall models, indicating that only rainfall is insufficient for streamflow prediction. The final LSTM model recorded optimal NSE and RMSE values of 0.68 and 13.84 m3 /s and predicted peak flow with the lowest prediction error of 11.6%, indicating that the final model could have predicted the flood on August 24, 2021 given a peak rainfall scenario. Adequate knowledge of rainfall patterns will guide hydrologists and disaster prevention managers in designing efficient early warning systems and policies aimed at mitigating flood risks

Removal of Limonin Bitterness by Treatment of Ion Exchange and Adsorbent Resins

Osman Kola,Cemal Kaya,Ali Altan,Hüseyin Duran 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.2

This study, the selective removal of limonin bitterness from Washington navel orange juice by batch adsorption to the Amberlite XAD-16HP and Dowex Optipore L285 was investigated and the determination of some compositional changes that occurred with orange juices debittering using adsorption resins were the primary focus. Amberlite XAD-16HP and Dowex Optipore L285have been successfully used to reduce bitterness to acceptable levels in Washington navel orange juices. Amberlite XAD-16HP does not have any important negative effects on the quality characteristics of orange juices. However, Dowex Optipore L285 reduces the titratable acidity (TA) in the orange juices and so increases the content of soluble solids contents (SSC), pH value, and ratio accordingly.

Post-Flood Damage Assessment using Satellite Imagery and Deep Learning Techniques

Kareem Kola Yusuff(카림 콜라 유수프),Park, Ki-doo(박기두),Nam, Gyu-Hyeon(남규현),Jung, Young-Hun(정영훈) 한국지반환경공학회 2022 한국지반환경공학회 학술발표회논문집 Vol.2022 No.9

Nation Branding and Public Diplomacy: Examining Japan’s 2019 Rugby World Cup and 2020(21) Olympic Games in the Midst of a Global Economic Downturn and the COVID-19 Pandemic

Joel Rookwood,Kola Adeosun 글로벌지식마케팅경영학회 2023 Journal of Global Sport Management Vol.8 No.3

For many superpowers sport mega events have become central to their political and financial ambitions within the global society. Over the last century Japan has established itself as a superpower both politically and economically. Even in the midst of a global economic downturn Japan has been successful in acquiring several globally significant sporting events, most notably the 2002 FIFA World Cup, and more recently the 2019 Rugby World Cup and 2020(21) summer Olympic Games. This paper examines how the latter two SMEs are perceived to present economic and political challenges in the midst of a global economic downturn and the COVID-19 pandemic through the context of public diplomacy and nation branding. The paper explores the perspectives of several relevant stakeholder demographics, including those working for various bodies relating to the staging and analysis of the events. Data were obtained through semi-structured interviews in order to frame the potential significance of sports mega events in Japan as a platform to showcase nation branding, public diplomacy, economic development and sport tourism.