Information Science Research Articles

A consensus on the definition of positive animal welfare.

The concept of animal welfare is evolving due to progress in our scientific understanding of animal biology and changing societal expectations. Animal welfare science has been primarily concerned with minimizing suffering, but there is growing interest in also promoting positive experiences, grouped under the term positive animal welfare (PAW). However, there are discrepancies in the use of the term PAW. An interdisciplinary group arrived at a consensus that 'PAW can be defined as the animal flourishing through the experience of predominantly positive mental states and the development of competence and resilience. PAW goes beyond ensuring good physical health and the prevention and alleviation of suffering. It encompasses animals experiencing positive mental states resulting from rewarding experiences, including having choices and opportunities to actively pursue goals and achieve desired outcomes'. The definition also considers individual and species-specific differences. It provides a framework for researchers to investigate PAW and thereby generate innovative, informative and reproducible science. Studies of PAW can contribute to a richer picture of an animal's life and may elucidate the biological foundations of happiness. The definition creates opportunities to inspire scientific progress in animal biology and to align animal care practices, legislation and markets with societal expectations.

The impact of high-speed rail network on high-end service industry development: Evidence from the Yangtze River Delta, China

Amidst the rapid evolution of transportation infrastructure, high-speed rail emerges as a transformative force reshaping regional economies. This study addresses a critical research gap by exploring the influence of HSR on high-end service industries within China's dynamic Yangtze River Delta region. Recognizing the strategic importance of HSR in contemporary economic landscapes, the research delves into its role as a catalyst for industrial growth, particularly in sectors pivotal for knowledge-intensive high-end service industry. Using Social Network Analysis and fixed effect models, the study assesses the multifaceted impacts of HSR network accessibility and connectivity on key sectors like scientific research, financial services, business services, and information transmission. Findings indicate a significant positive influence on most sectors, although nuances emerge in financial services, highlighting the complex interplay between HSR and sector-specific dynamics. The study further reveals distinct effects across various urban sizes and locations, pointing to an urban-centric advantage in HSR's economic impacts. By identifying market demand, technology spillover, and labor pooling as principal channels of HSR's influence, this research contributes to the understanding of how modern transportation infrastructures can be leveraged for regional economic integration and sectoral development. While focusing on the YRD, the study's insights offer a broader reflection on the strategic planning of HSR in similar global contexts.

The legal foundations of the Francoist regime

The object of the study is the legal aspect of the Francoist political regime as an element of the form of the state (public relations in the field of governance of Francoist Spain), the subject is regulatory legal acts expressing the existing political system in the state. The authors of the article studied the regime of Francisco Franco and revealed its legislative framework, revealing the legal nature of authoritarianism in a single country, Spain, pointing to the concealment of the authoritarian nature of the dictatorship by democratic laws, as well as the abuse of the right to impose martial law or other emergency forms legalizing the usurpation of power. The relevance of the research topic lies in the possibility of using methods of legislative consolidation of a political structure, as well as substantiating the authoritarian legal nature of specific political regimes, forecasting prospects and modeling the development of dictatorships. The research is relevant for legal theorists and practitioners who substantiate the foundations of the constitutional order of states. The authors considered not the political, but the legal side of the rule of the Spanish speaker, introduced into scientific circulation new information about the norms of Spanish law of the Francoist period of the history of the relevant state. The methodological basis of the research is made of general scientific (comparison, analysis, synthesis, analogy, deduction, induction, and others) and special (formal logical, interpretation of law, and others), historical-legal, systemic, and other methods of cognition. The scientific novelty of the work is due to the analysis of the "Fundamental Laws of the Kingdom." The authors note that the law on succession to the throne provided for the possibility of the usurpation of supreme power in Spain by the Regency Council after the death of Francisco Franco. The purpose of the study is to identify legal methods of consolidating the authoritarian regime. The objectives of the research include the study of the normative legal acts that established the regime of Francisco Franco in Spain, as well as the relevant Russian and foreign doctrine on the topic of the scientific article. The fundamental laws of the Kingdom established the regime of Francisco Franco: a personalistic autocracy, making it stable for the duration of the dictator's life, while at the same time determining its gradual design and transformation in the future. The Francoist regime finally took shape by 1967 with the adoption of the Organic Law of the State, the last of the Fundamental Laws of the Kingdom, which came into force during the lifetime of the authoritarian leader.

Pandemic or "Plandemic"?: The Mediating Role of Epistemic Justification Strategies in the Relationship Between COVID-19 Conspiracy Beliefs and COVID-19 Vaccine Conspiracy Beliefs.

In today's post-truth times, where personal feelings and beliefs have become increasingly important, determining what is accurate knowledge has become an important skill. This is especially important during uncertainty crises (e.g., epidemics and pandemics) because alternative explanations other than scientific knowledge may be disseminated vigorously. Epistemic justification concerns how and in what way the truth of knowledge claims is justified and the criteria for knowledge to be true and/or a fact. Given this backdrop, the present study examined how individuals reacted to conspiracies in an uncertainty crisis (using the COVID-19 pandemic as an example). The mediating role of epistemic justification was investigated regarding its relationship between COVID-19 conspiracy beliefs and COVID-19 vaccine conspiracy beliefs. A cross-sectional study was conducted incorporating a multifactorial correlational design. Using convenience sampling, 690 participants (55.7% females, Mage=32.24years, SD=9.75) from different regions of Türkiye completed an online survey via Google Forms. The results demonstrated a strong and statistically significant correlation between beliefs in COVID-19 conspiracy theories and beliefs in COVID-19 vaccination conspiracy theories. The mediating effects of justification by authority and personal justification were statistically significant between COVID-19 conspiracy beliefs and COVID-19 vaccine conspiracy theories. Using the COVID-19 pandemic as an example, the present results indicated the complex relationships between conspiracy beliefs and epistemic justification. The present results indicate the importance of authorities intaking early action to provide scientific evidence and information to the public to avoid individuals believing false information.

Conflict of interests in modern ukrainian science

The Ukrainian Institute of Scientific and Technical Expertise and Information conducted an in-depth study of the conflict of interests in scientific activity, in particular, regarding the conduct of scientific and technical expertise (UkrISTEI). Based on the analysis of Ukrainian and foreign experience, it was determined that any interests or relationships, financial or otherwise, that can be perceived as influencing the objectivity of the author, are considered a potential source of conflict of interests. Accordingly, the conflict of interest can be financial or non-financial, professional or personal. The issue of conflict of interests in the scientific activity of Ukraine remains insufficiently regulated at the level of regulatory and legislative acts. Therefore, UkrISTEI was asked to make changes to the Methodological recommendations for the performers of scientific research and development and reviewers regarding the open review of scientific research. In particular, it is proposed to add the term conflict of interest and define it as anything that interferes or can be perceived as interfering with the full and objective presentation, review, editorial decision-making or publication of materials of scientific works and development of research or non-research articles. It is important to take into account the presence of a conflict of interests during the examination of scientific projects and/or works that are carried out with the funds of the state budget or other sources of funding. After all, it affects various aspects of the life of society, in particular, related to environmental and national security, the sphere of health care, energy independence and many others. In the draft of the Law of Ukraine “On Amendments to the Law of Ukraine “On Scientific and Scientific-Technical Expertise”, it is proposed to define a conflict of interests as anything that interferes or can be perceived as something that interferes with a full and objective examination. It is also proposed to add provisions on avoiding conflicts of interest, as well as the procedure for the participants of the expert process, in the event of a conflict of interests.

Diet diversity score might be associated with reproductive health in women and infant outcomes: a systematic review.

Lifestyle and diet may affect the reproductive cycle. A dietary index called Diet Diversity Score (DDS) may be related to various reproductive outcomes. The present review aims to look over and conclude the prior studies on the relationship between the diversity of food ingredients and issues related to reproductive health and pregnancy. In the case of this relationship, our findings can increase clinical knowledge and help recommend a well-balanced diet for the target group. A comprehensive search was performed in major databases such as PubMed, Google Scholar, Web of Science, Scopus, and Scientific Information Database until March 2024. This research was combined with a search of Elsevier and SpringerLink databases, which led to the inclusion of relevant articles in this review. Our study was conducted based on 27 articles from 2012 to 2023, all containing a possible link between dietary diversity and reproductive complications. The Newcastle-Ottawa Scale quality assessment was used to evaluate the quality of included studies. Due to our results, a higher score in DDS, which led to an increased intake of major nutrients and a greater variety of foods, was correlated with a lower risk of reproductive health disorders such as polycystic ovary syndrome, maternal anaemia, and maternal bone status, as well as a reduced likelihood of certain birth outcomes, including low-birth weight infants, Apgar score and congenital heart defect. These findings highlight the importance of improving the DDS for maternal and infant health.

The Connection of Information Science and Psychology in the Case of the Wisdom Paradox - Part Two

The Connection of Information Science and Psychology in the Case of the Wisdom Paradox - Part Two

Motivation of nursing undergraduate program entrants: A scoping review protocol.

Motivation is of great importance in the teaching-learning process, because motivated students seek out opportunities and show interest and enthusiasm in carrying out their tasks. The objective of this review is to identify and present the information available in the literature on the status quo of motivation among nursing program entrants. This is a qualitative scoping review study, a type of literature review designed to map out and find evidence to address a specific research objective, following the Joanna Briggs Institute methodology. The objective was outlined using the PCC (Population, Concept, Context) acronym. The protocol was developed and registered on the Open Science Framework (OSF) platform under DOI 10.17605/OSF.IO/EJNGY. The search strategy and database selection were defined by a library and information science professional together with the authors. The search will be carried out in the following databases: Cumulative Index to Nursing and Allied Health Literature, Literatura Latino Americana e do Caribe em Ciências da Saúde, Lilacs Esp, National Library of Medicine (PubMed), ScienceDirect, Scopus, and the Web of Science platform. The researchers will meet to discuss discrepancies and make decisions using a consensus model, and a third researcher will be tasked with independently resolving any conflicts. Data extraction will involve two independent researchers reviewing each article. Documents such as original articles; theoretical studies; experience reports; clinical study articles; case studies; normative, integrative, and systematic reviews; meta-analyses; meta-syntheses; monographs; theses; and dissertations in English, Portuguese, and Spanish from 2017 to 2023 were included. The results will be presented in tabular and/or diagrammatic format, along with a narrative summary.

Sustainable Leadership and Employee Performance: The Role of Organizational Culture in Malaysia’s Information Science Sector

Sustainable Leadership and Employee Performance: The Role of Organizational Culture in Malaysia’s Information Science Sector

Correlated excitonic signatures of individual van der Waals NiPS3 antiferromagnet nanoflakes.

Composite quasi-particles with emergent functionalities in spintronic and quantum information science can be realized in correlated materials due to entangled charge, spin, orbital, and lattice degrees of freedom. Here we show that by reducing the lateral dimension of correlated antiferromagnet NiPS3 flakes to tens of nanometers and thickness to less than ten nanometers, we can switch-off the bulk spin-orbit entangled exciton in the near-infrared (1.47 eV) and activate visible-range (1.8-2.2 eV) transitions. These ultra-sharp lines (<120 μeV at 4.2 K) share the spin-correlated nature of the bulk exciton by displaying a strong linear polarization below Néel temperature. Furthermore, exciton photoluminescence lineshape analysis indicates a polaronic character VIA coupling with at-least 3 phonon modes and a comb-like Stark effect through discretization of charges in each layer. These findings augment the knowledge on the many-body nature of excitonic quasi-particles in correlated antiferromagnets and also establish the nanoscale correlated antiferromagnets as a promising platform for integrated magneto-optic devices.

Nanomaterials for spin-based quantum information.

Quantum information science has garnered significant attention due to its potential in solving problems that are beyond the capabilities of classical computations based on integrated circuits. At the heart of quantum information science is the quantum bit or qubit, which is used to carry information. Achieving large-scale and high-fidelity quantum bits requires the optimization of materials with trap-free characteristics and long coherence times. Nanomaterials have emerged as promising candidates for building qubits due to their inherent quantum confinement effect, enabling the manipulation and addressing of individual spins within nanostructures. In this comprehensive review, we focus on quantum bits based on nanomaterials, including 0D quantum dots, 1D nanotubes and nanowires, and 2D nanoplatelets and nanolayers. Our review aims to bridge the gap between nanotechnology and quantum information science, with a particular emphasis on material science aspects such as material selection, properties, and synthesis. By providing insights into these areas, we contribute to the understanding and advancement of nanomaterial-based quantum information science.

Differential Effects of Alcohol Policies Across Race/Ethnicity and Socioeconomic Status.

Sociocultural characteristics, including race/ethnicity and socioeconomic status (SES), may affect individuals' attitudes and norms regarding alcohol use and treatment as well as their access to emerging health knowledge, innovative technologies, and general resources for improving health. As a result of these differences, as well as social determinants of health such as stigma and uneven enforcement, alcohol policies may not benefit all population subgroups equally. This review addresses research conducted within the last decade that examined differential effects of alcohol policies on alcohol consumption, alcohol harm, and alcohol treatment admissions across racial/ethnic and socioeconomic groups. The authors used the following Boolean phrase search terms to assess the association between race/ethnicity and outcomes: ("alcohol policy" OR "alcohol policies") AND ("race" OR "ethnicity" OR "first nations" OR "African American" OR "Hispanic American" OR "Latino American" OR "Asian American" OR "Native American"). Association with SES was assessed using these terms: ("alcohol policy" OR "alcohol policies") AND ("socioeconomic" OR "class") AND ("effect" OR "impact" OR "outcome"). Both searches were conducted on August 28, 2023, using advanced search in seven EBSCOhost research databases: (1) EBSCO Biomedical Reference Collection: Corporate; (2) EBSCOhost E-Journals; (3) EBSCO MEDLINE Complete; (4) SocINDEX with Full Text; (5) APA PsycInfo; (6) LISTA (Library Information Sciences and Technology Abstracts); and (7) GreenFILE. Inclusion criteria for both searches were: (1) publication dates between 2014 and 2023; (2) peer-reviewed research articles; (3) data disaggregated by racial/ethnic and/or SES subgroups; and (4) English language only. The racial/ethnic search produced 64 articles, of which 14 were reviewed as relevant to this study and 50 were excluded. The SES search generated 100 articles, of which 18 were reviewed as relevant to this study and 82 were excluded. Eight of the studies identified by these two searches overlapped (i.e., included both racial/ethnic and SES outcomes), resulting in a total of 24 articles included in this review. Relying upon data from both U.S. and international research, the identified studies focused on differential effects of financially focused alcohol control policies (e.g., taxation and minimum unit pricing policies) as well as access/availability reduction policies (e.g., those governing outlet density, on-/off-premise sales, and establishment licensing). Several studies concluded that price increases via taxes or minimum unit pricing might be particularly effective in reducing the risk of alcohol-related harms in low-income/low-SES populations. Limitations of the present review include lack of standardization in the ways that SES was measured and the difficulty of measuring policy enforceability. Studies focused on differential effects of alcohol control policies across racial/ethnic groups demonstrated complex associations and the need to conduct further research that identifies better ways to reduce policy-induced health disparities across diverse populations.

Molecularly-anchored single PbS quantum dots as resonant tunnelling transistors.

The growing need for high-performance computing continues to drive improvement in circuit and device technologies, particularly with respect to speed and power efficiency. Device scaling remains the most effective strategy for meeting circuit performance requirements while reducing power consumption. Thanks to their solution processability, colloidal semiconductor quantum dots (QDs) are highly suitable for device miniaturisation as quantum information science platforms. Quantum mechanical effects must be carefully considered when designing nanometre-scale electronic devices (i.e., transistors) that incorporate a single QD. Here, we demonstrate a resonant tunnelling transistor (RTT) based on a single lead sulfide (PbS) QD anchored by a bidentate ligand molecule attached to heteroepitaxial spherical Au/Pt nanogap electrodes. Five negative differential resistances (NDRs) were observed at both positive and negative drain voltages in output characteristics, which could be attributed to the formation of a double-barrier "quantum well" structure with the strong Fermi level pinning of the discrete energy level of the QD to one electrode. Furthermore, these NDRs could be tuned by applying a gate electric field, which will become one of the keys for enabling quantum and neuromorphic electronics. This demonstration of single PbS-QD-based RTTs paves the way for sub-10 nm solution-processable quantum electronic devices.

Feedback literacy and peer review experiences within library and information science journals

Feedback literacy and peer review experiences within library and information science journals

Tetracycline Resistance among Escherichia coli Isolates from Broilers in Iran: A Systematic Review and Meta-Analysis.

Avian colibacillosis are infections caused by Avian Pathogenic Escherichia coli which causes high morbidity, high mortality, and significant economic losses. Antibiotics such as tetracycline are an important treatment choice for colibacillosis in Iran. However, the irrational use of antibiotics has caused high antibiotic resistance. The aim of this study was to estimate the tetracycline resistance rate among E. coli isolates from broilers in Iran. PubMed, Scopus, Web of Science, Google Scholar, Islamic World Science Citation, Scientific Information Database, and MagIran databases were searched from 2013 and 2023. Risk of bias assessment was assessed with Appraisal tool for Cross-Sectional Studies. For meta-analysis, a random effects model with Freeman-Tukey double arcsine transformation was used. Subgroup analysis for the year of publication and sensitivity analysis to assess the influence of individual studies were conducted and a province-level map of point estimates was drawn. Among 13 included studies, the pooled tetracycline resistance was 85% (95% CI: 76-92%) and I-squared was 94.29%. In subgroup analysis, resistance rate was higher for articles published in 2018-2023 (91%) compared to articles published in 2013-2017 (76%), but heterogeneity between groups was not statistically-significant (P=0.12). sensitivity analysis showed that the omission of individual studies caused no apparent change. The province-level map showed that most of the studies belonged to northern parts of Iran with Ardabil (99.65%) having the highest value. Resistance against tetracycline in E. coli isolates from broilers in Iran is alarming. The sensible use of tetracycline is advised.

Service Quality in Iranian Hospitals From Patients' Perspectives Based on the SERVQUAL Model: A Systematic Review and Meta-Analysis.

This study aimed to evaluate the service quality in Iranian hospitals from patients' perspectives based on the SERVQUAL model. A thorough exploration of online electronic databases, including Scopus, PubMed, Web of Science, IranMedex, and the Scientific Information Database (SID), was undertaken using keywords extracted from Medical Subject Headings such as "Quality of Health Care," "Hospital," and "Patients" spanning from the earliest available records up to August 11, 2023. In the context of 25 cross-sectional studies encompassing a collective participant pool of 8021 hospitalized patients in Iranian medical facilities, an assessment of patients' perspectives on the quality of hospital services revealed a mean perception score of 3.54 (SE = 0.08). Concurrently, the mean expectation score for the quality of services was determined to be 4.43 (SE = 0.06). Using the SERVQUAL model, the overall disparity between patients' perceptions and expectations was calculated as -0.89. Subsequent examination of specific dimensions within the SERVQUAL framework revealed gaps between patients' perceptions and expectations in the tangibility dimension (-0.84), reliability dimension (-0.94), responsiveness dimension (-0.91), assurance dimension (-0.89), and empathy dimension (-0.82). Therefore, healthcare administrators consider the study's findings as a motivating force to initiate measures aimed at improving service quality in Iranian hospitals. Tackling the recognized shortcomings and areas requiring enhancement holds the promise of raising patient satisfaction levels and, consequently, improving overall healthcare outcomes.

Technical examination of Wat Sisowath Ratanaram panel painting

The technical examination on the early 20th century panel painting of Wat Sisowath Ratanaram was performed using optical microscopy (OM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), Micro-Raman spectroscopy (μ-RAMAN), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and pyrolysis gas chromatography-mass spectrometry (Py-GC/MS). The investigation shows the mixture of minium, cinnabar and baryte in red preparation layer, quartz from the natural earth pigment in the underpaint layer and the pigments mixed with the additives in the paint layer. There are various pigments found in the paint layer ranging from emerald green, chalk, baryte, chrome yellow, ultramarine blue, carbon black and zinc white. Zinc white was widely utilized as the additive of green, yellow and blue paint layer. In addition, minium and carbon black were used to draw fine lines for image details. The degradation products of gypsum in the paint layer were evidenced by SEM-EDS and XRD. While the darkening of red lead in the red preparation layer was observed by OM. The trace of natural plant resin as a binding meium was found in S_Wood and S_Black samples evidencing by ATR-FTIR and Py-GC/MS. The 7 steps of painting technique were proposed by implementing all detailed scientific information.

Perceptions of students of pedagogical training programs in universities about ways to ensure children’s safety

Introduction. Modern reality demonstrates various threats to children’s safety. Family, society, state and education should act as a guarantor of children’s safety in an unstable world with many different threats and dangers. Therefore, identifying the ideas of students of pedagogical training programs in universities about ways to ensure children’s safety is relevant. Enrichment of scientific information on this issue will allow it to be taken into account when developing the appropriate content of professional training for future teachers. The study was aimed at identifying the ideas of students of pedagogical training programs at universities about ways to ensure the safety of children. Methodology and methods. The survey included 120 students of Yelets State University named after I.A. Bunin (Russian Federation). Closed questionnaires were processed by means of comparison, analysis, generalization, calculation of percentage ratios between answer options (response frequency was calculated); ranking (distribution of quantitative indicators of security methods according to their degree of priority). Results. The following levels of priority were identified for methods of ensuring child safety: 1st – 40%-96% of responses (cultivating respect for teachers, restricting access to dangerous objects, equal distribution of parental attention between older and younger children, etc.); 2nd – 29%-39% of responses (blocking access to “adult websites”, promptly paying attention to health problems, accustoming children to comply with the requirements of grandparents, choosing a qualified doctor, talking to parents with children about problematic situations in communication with teachers, cultivating politeness with the elderly, adult control over the safety of children, etc.); 3rd – 25%-28% of responses (parents’ control over their children’s treatment, following doctor’s orders, teaching traffic rules, life safety lessons, eliminating negative patterns of adult behavior, informing about proper nutrition, etc.). The types of coincidence of views of students under 20 and over 20 years old were identified: complete identity (60%) and incomplete identity (40%). Conclusion. The results of the study will enrich the design and implementation of the content of professional training of students of pedagogical education on issues of ensuring the safety of children.

The Importance of Sharing Current Scientific Information with Biology Teachers in Weekly Newsletters

High-school teachers and students do not usually have access to scientific research advances because original research papers contain many highly specialized words that are specific to the discipline. Scientific newsletters (SNs) summarize current scientific research advances and trends. During the 2022–2023 school year, 21 SNs teaching biology content were written by a team of science-education and biology specialists working at the National Center for High-School Biology Teachers in Israel, according to the following criteria: (a) the SNs were based on primary research papers published in international well-known scientific journals such as Nature, Cell or Science; (b) the biological content was related, albeit not necessarily directly, to the Israeli high-school biology curriculum; (c) some of the SNs were related to biological events that occurred during the week in which the SN was distributed, such as World Diabetes Day. The SNs were written in Hebrew, translated to Arabic, and sent weekly via WhatsApp to 901 high-school biology teachers. After sending 10 SNs, an anonymous questionnaire was sent to the teachers to understand their use of the SNs and identify topics to which teachers would like us to relate in the next SNs. Forty-nine teachers answered the questionnaire, revealing that according to their open-ended answers, some of the teachers valued the importance of receiving SNs teaching biology topics as a way to enrich their own biological knowledge, and to engage their students with meaningful scientific research and with the real-world work of scientists. Further research is needed to analyze the impact of the SNs on teachers’ professional development.

Phytochemical and analgesic profile of hydroalcoholic and aqueous extracts froM Aristolochia constricta Griseb

Introduction: Aristolochia constricta is widely spread in Ecuador and has traditionally been reported to have anti-inflammatory, antispasmodic, anticancer and emmenagogue activity; however, scientific information is scarce. Objective: Determine the chemical composition and analgesic activity of hydroalcoholic and aqueous extracts from A. constricta.Methods: An aqueous extract was prepared by decoction and another hydroalcoholic extract by maceration, which were chemically characterized by the quantification of phenols, flavonoids, alkaloids, carbohydrates and proteins, by the methods of Folin-Ciocalteu, aluminum trichloride, bromocresol green, phenol -sulfuric and Bradford, respectively. The analgesic activity of the extracts was evaluated at doses of 100, 200 and 300 mg/kg, using the acetic acid-induced writhing test in mice. Results: In the quantitative determinations, significant differences were perceived, with the content of each metabolite being higher in the hydroalcoholic extract. Both extracts significantly decreased the number of abdominal contortions produced by acetic acid, highlighting the hydroalcoholic extract at a dose of 300 mg/kg with an analgesic effect similar to acetylsalicylic acid used as reference drug. Conclusions: The results provide the first findings on the analgesic potential of A. constricta and make a contribution to the study of its chemical composition