Research papers

The Welwitschia genome reveals a unique biology underpinning extreme longevity in deserts

Tao Wan, Zhiming Liu, Ilia J. Leitch, H. P. Xin, Gillian Maggs‐Kölling, Yanbing Gong, Zhen Li, Eugène Marais, Yiying Liao, C…

The gymnosperm Welwitschia mirabilis belongs to the ancient, enigmatic gnetophyte lineage. It is a unique desert plant with extreme longevity and two ever-elongating leaves. We present a chromosome-level assembly of its genome (6.8 Gb/1 C) together with methylome and transcriptome data to explore its astonishing biology. We also present a refined, high-quality assembly of Gnetum montanum to enhance our understanding of gnetophyte genome evolution. The Welwitschia genome has been shaped by a lineage-specific ancient, whole genome duplication (~86 million years ago) and more recently (1-2 million years) by bursts of retrotransposon activity. High levels of cytosine methylation (particularly at CHH motifs) are associated with retrotransposons, whilst long-term deamination has resulted in an exceptionally GC-poor genome. Changes in copy number and/or expression of gene families and transcription factors (e.g. R2R3MYB, SAUR) controlling cell growth, differentiation and metabolism underpin the plant's longevity and tolerance to temperature, nutrient and water stress.

Meroterpenoids: A Comprehensive Update Insight on Structural Diversity and Biology

Mamona Nazir, Muhammad Saleem, Muhammad Imran Tousif, Muhammad Aijaz Anwar, Frank Surup, Iftikhar Ali, Daijie Wang, Nilufar …

Meroterpenoids are secondary metabolites formed due to mixed biosynthetic pathways which are produced in part from a terpenoid co-substrate. These mixed biosynthetically hybrid compounds are widely produced by bacteria, algae, plants, and animals. Notably amazing chemical diversity is generated among meroterpenoids via a combination of terpenoid scaffolds with polyketides, alkaloids, phenols, and amino acids. This review deals with the isolation, chemical diversity, and biological effects of 452 new meroterpenoids reported from natural sources from January 2016 to December 2020. Most of the meroterpenoids possess antimicrobial, cytotoxic, antioxidant, anti-inflammatory, antiviral, enzyme inhibitory, and immunosupressive effects.

Biology, Diversity, Detection and Management of Fusarium oxysporum f. sp. niveum Causing Vascular Wilt Disease of Watermelon (Citrullus lanatus): A Review

Muhammad Ziaur Rahman, Khairulmazmi Ahmad, Abdulaziz Bashir Kutawa, Yasmeen Siddiqui, Norsazilawati Saad, Tan Geok Hun, Erne…

Fusarium oxysporum f. sp. niveum (Fon) is the causative agent of Fusarium wilt disease of watermelon; it is the most serious soil-borne pathogen around the globe. The yield loss is around 30–80% or even more, and is presently a major hindrance to watermelon cultivation worldwide. Initially, the infected watermelon plant shows symptoms like loss of turgor pressure of the leaves and vines that can be recovered at night. The progress of the disease in contaminated transplants turns into dull green to yellow and finally necrotic. When the fungus continues to colonize the xylem vessel, it usually forms more tyloses, finally limiting water movement and causing wilt. The correct identification of the pathogen is necessary for proper disease control. As such, the selection of a molecular marker could serve as an effective means of screening the pathogen. Additionally, different methods have also been reported for the identification of Fon. Therefore, this review focused on the comprehensive description of the biology, diversity, detection, aggressiveness, mycotoxin production, and eco-friendly management strategies of the Fusarium wilt disease of watermelon.

Physics-informed machine learning

George Em Karniadakis, Ioannis G. Kevrekidis, Lu Lu, Paris Perdikaris, Sifan Wang, Liu Yang

Genome-wide association study of more than 40,000 bipolar disorder cases provides new insights into the underlying biology

Niamh Mullins, Andreas J. Forstner, Kevin S. O’Connell, Brandon J. Coombes, Jonathan R. I. Coleman, Zhen Qiao, Thomas D. Als…

Bipolar disorder is a heritable mental illness with complex etiology. We performed a genome-wide association study of 41,917 bipolar disorder cases and 371,549 controls of European ancestry, which identified 64 associated genomic loci. Bipolar disorder risk alleles were enriched in genes in synaptic signaling pathways and brain-expressed genes, particularly those with high specificity of expression in neurons of the prefrontal cortex and hippocampus. Significant signal enrichment was found in genes encoding targets of antipsychotics, calcium channel blockers, antiepileptics and anesthetics. Integrating expression quantitative trait locus data implicated 15 genes robustly linked to bipolar disorder via gene expression, encoding druggable targets such as HTR6, MCHR1, DCLK3 and FURIN. Analyses of bipolar disorder subtypes indicated high but imperfect genetic correlation between bipolar disorder type I and II and identified additional associated loci. Together, these results advance our understanding of the biological etiology of bipolar disorder, identify novel therapeutic leads and prioritize genes for functional follow-up studies. Genome-wide association analyses of 41,917 bipolar disorder cases and 371,549 controls of European ancestry provide new insights into the etiology of this disorder and identify novel therapeutic leads and potential opportunities for drug repurposing.

Professional image of nursing and midwifery in East Africa: an exploratory analysis

Eunice Ndirangu‐Mugo, Ahmed M. Sarki, Columba Mbekenga, Grace Edwards

BACKGROUND: Evidence suggests that there is a negative image of nursing and midwifery that does not promote these professions as attractive career options. Furthermore, there is a paucity of studies documenting how nursing and midwifery is perceived in East Africa and where such studies exist they are country-specific. The aim of this study was to explore views regarding the image of nursing and midwifery among nurses and midwives in three East African countries, Kenya, Tanzania and Uganda. METHODS: An exploratory descriptive cross-sectional study administered online using Survey Monkey Questionnaires assessed the views and perceptions of nurses and midwives regarding the image of nursing and midwifery professions. Descriptive statistics and Pearson's Chi square tests were used to analyse the data. The semi-structured questions were analysed using content analysis. RESULTS: A total of 551 participants took part in the study. The majority were females (61.8%), registered nurses/midwives (45.8%), and aged 30-39 years (34.2%). Most of the respondents were from Kenya (39.7%) and Uganda (32.9%). About two-thirds of the nurses and midwives in this study perceived nursing/midwifery as both trusted and respected professions and expressed having a level of control over how their image was portrayed. Conversely, the nurses and midwives were conscious that the public had mixed responses about the nursing/midwifery professions specifically, some members of the public described nurses/midwives as professionals, knowledgeable and caring, others perceived nurses/midwives to be rude, cruel, unkind, lazy, unkempt, and maids. CONCLUSION: This study offers an interesting insight about the image of nursing/midwifery in East Africa. Findings from this study will inform policy makers and educators about key concepts that affect the image of nursing and midwifery in East Africa. The findings will be used to design marketing materials to help improve the image of nursing and midwifery in the region and other African countries.

A Call to the CMS: Mandate Adequate Professional Nurse Staffing in Nursing Homes

Ann Kolanowski, Tara Cortes, Christine Mueller, Barbara J. Bowers, Marie Boltz, Debra Bakerjian, Charlene Harrington, Lori P…

Editor's note: This article is by 22 nursing gerontology experts who are all advocates of nursing home reform. They are listed at the end of this article.

Anticancer Potential of <i>Moringa oleifera</i> on BRCA-1 Gene: Systems Biology

Toheeb A. Balogun, Kaosarat D. Buliaminu, Onyeka S. Chukwudozie, Zainab Tiamiyu, Taiwo J Idowu

Breast cancer has consistently been a global challenge that is prevalent among women. There is a continuous increase in the high number of women mortality rates because of breast cancer and affecting nations at all modernization levels. Women with high-risk factors, including hereditary, obesity, and menopause, have the possibility of developing breast cancer growth. With the advent of radiotherapy, chemotherapy, hormone therapy, and surgery in breast cancer treatment, breast cancer survivors have increased. Also, the design and development of drugs targeting therapeutic enzymes effectively treat the tumour cells early. However, long-term use of anticancer drugs has been linked to severe side effects. This research aims to develop potential drug candidates from Moringa oleifera, which could serve as anticancer agents. In silico analysis using Schrödinger Molecular Drug Discovery Suite and SWISS ADME was employed to determine the therapeutic potential of phytochemicals from M oleifera against breast cancer via molecular docking, pharmacokinetic parameters, and drug-like properties. The result shows that rutin, vicenin-2, and quercetin-3-O-glucoside have the highest binding energy of −7.522, −6.808, and −6.635 kcal/mol, respectively, in the active site of BRCA-1. The essential amino acids involved in the protein-ligand interaction following active site analysis are ASN 1678, ASN 1774, GLY 1656, LEU 1657, GLN 1779, LYS 1702, SER 1655, PHE 1662, ARG 1699, GLU 1698, and VAL 1654. Thus, we propose that bioactive compounds from M oleifera may be potential novel drug candidates in the treatment of breast cancer.

University students’ knowledge and readiness to practice genomic nursing in Nigeria

Prisca Olabisi Adejumo, Ifeoluwapo Oluwafunke Kolawole, Iyanuoluwa Oreofe Ojo, Rose Ekama Ilesanmi, Olaolorunpo Olorunfemi, …

Genetic nursing education provides knowledge of traits and inherited diseases. This has not been well integrated into nursing practice in Nigeria. This study evaluated university nursing students’ knowledge of genomic concepts and readiness to practice genomic nursing in Nigeria. A cross-sectional study was conducted. Three universities were purposively selected in Nigeria. A total of 136 participants were recruited using convenient sampling technique. A modified Genetic Nursing Concept Inventory questionnaire was distributed to participants in their classrooms. Data were analyzed with SPSS (23); descriptive data were presented in tables and figures with their mean and standard deviations. Chi-square test and multivariate analysis were used to ascertain association between variables at p < 0.05 level of significance. Findings indicated that participants have poor knowledge (89%) and lack readiness (66%) to practice genomic nursing in Nigeria. Their knowledge influenced their readiness (χ2 = 21.033, df = 1, p = 0.001). Institution type was the most consistent predictor of knowledge (χ2 = 48.586, df = 2, p = 0.001) and readiness (OR = 14.817, p = 0.326, C.I. = 3.190, 319.57) as those in federal institution were more knowledgeable and prepared to practice genetic nursing. Participants perceived that poor funding, lack of trained personnel, and social/environmental factors could affect their readiness to practice genetic nursing. The study has brought to the fore that nursing students have low knowledge and were not ready to practice genetic nursing, efforts should be made to look into the adequacy of nursing training on genetic nursing and strategies needed for its integration in education and practice.

Education for Critical Consciousness

Paulo Freiré

Famous for his advocacy of 'critical pedagogy', Paulo Freire was Latin America's foremost educationalist, a thinker and writer whose work and ideas continue to exert enormous influence in education throughout the world today. Education for Critical Consciousness is the main statement of Freire's revolutionary method of education. It takes the life situation of the learner as its starting point and the raising of consciousness and the overcoming of obstacles as its goals. For Freire, man's striving for his own humanity requires the changing of structures which dehumanize both the oppressor and the oppressed. This edition includes a substantial new introduction by Carlos Alberto Torres, Distinguished Professor and Founding Director of the Paulo Freire Institute, UCLA, USA.

Engineering precision nanoparticles for drug delivery

Michael J. Mitchell, Margaret M. Billingsley, Rebecca M. Haley, Marissa E. Wechsler, Nicholas A. Peppas, Róbert Langer

Global Burden of Cardiovascular Diseases and Risk Factors, 1990–2019

Gregory A. Roth, George A. Mensah, Catherine O. Johnson, Giovanni Addolorato, Enrico Ammirati, Larry M. Baddour, Noël C. Bar…

Cardiovascular diseases (CVDs), principally ischemic heart disease (IHD) and stroke, are the leading cause of global mortality and a major contributor to disability. This paper reviews the magnitude of total CVD burden, including 13 underlying causes of cardiovascular death and 9 related risk factors, using estimates from the Global Burden of Disease (GBD) Study 2019. GBD, an ongoing multinational collaboration to provide comparable and consistent estimates of population health over time, used all available population-level data sources on incidence, prevalence, case fatality, mortality, and health risks to produce estimates for 204 countries and territories from 1990 to 2019. Prevalent cases of total CVD nearly doubled from 271 million (95% uncertainty interval [UI]: 257 to 285 million) in 1990 to 523 million (95% UI: 497 to 550 million) in 2019, and the number of CVD deaths steadily increased from 12.1 million (95% UI:11.4 to 12.6 million) in 1990, reaching 18.6 million (95% UI: 17.1 to 19.7 million) in 2019. The global trends for disability-adjusted life years (DALYs) and years of life lost also increased significantly, and years lived with disability doubled from 17.7 million (95% UI: 12.9 to 22.5 million) to 34.4 million (95% UI:24.9 to 43.6 million) over that period. The total number of DALYs due to IHD has risen steadily since 1990, reaching 182 million (95% UI: 170 to 194 million) DALYs, 9.14 million (95% UI: 8.40 to 9.74 million) deaths in the year 2019, and 197 million (95% UI: 178 to 220 million) prevalent cases of IHD in 2019. The total number of DALYs due to stroke has risen steadily since 1990, reaching 143 million (95% UI: 133 to 153 million) DALYs, 6.55 million (95% UI: 6.00 to 7.02 million) deaths in the year 2019, and 101 million (95% UI: 93.2 to 111 million) prevalent cases of stroke in 2019. Cardiovascular diseases remain the leading cause of disease burden in the world. CVD burden continues its decades-long rise for almost all countries outside high-income countries, and alarmingly, the age-standardized rate of CVD has begun to rise in some locations where it was previously declining in high-income countries. There is an urgent need to focus on implementing existing cost-effective policies and interventions if the world is to meet the targets for Sustainable Development Goal 3 and achieve a 30% reduction in premature mortality due to noncommunicable diseases.

Floral Biology and Pollination Efficiency in Yam (Dioscorea spp.)

Jean M. Mondo, Paterne A. Agre, Alex Edemodu, Patrick Adebola, Robert Asiedu, M. O. Akoroda, Asrat Asfaw

Yam (Dioscorea spp.) is a monocotyledonous herbaceous vine cultivated for its starchy underground or aerial tubers in the tropics and subtropics. It is an allogamous and polyploid species that reproduces by both sexual and asexual mechanisms. However, many of the landrace cultivars, including most of the popular varieties, reproduce exclusively by vegetative propagation (planting the tubers). These varieties are either sterile or produce sparse and irregular flowering with high flower abortion rate, low fruit and seed set. Production of crossbreed seeds for genetic improvement and for maintaining genetic diversity in yams is, therefore, mainly achieved through natural or managed pollination. Flowering in yam is mostly dioecious and, in some instances, monoecious. Flowering asynchrony, sticky nature of the pollen grains, and cross incompatibility are among the challenges in making genetic progress in yam breeding. There are many limitations in basic and applied knowledge of yam flower biology and pollination. This paper, therefore, reviews the flowering biology, pollination, and methods of improving pollination efficiency in yam breeding programs.

Cognitive-behavioural reflective training for improving critical thinking disposition of nursing students

Godwin C. Abiogu, Moses Onyemaechi Ede, John J. Agah, Felix Okechukwu Ugwuozor, Maduka L. Nweke, Nneka Nwosu, Ogechi Nnamani…

BACKGROUND/OBJECTIVE: The importance of critical thinking in improving treatment practices in, for instance, the nursing profession, cannot be overemphasized. Despite this importance, empirical studies have shown that helping strategies to train learners on critical thinking disposition are needed. Given this knowledge gap, this study investigated the impacts of cognitive-behavioral reflective training for improving the critical thinking disposition of nursing students. METHOD: Of all the students screened, a total of 167 participants were assigned to the treatment group and waitlisted control group. A researchers-developed training program aimed at improving critical thinking disposition was delivered in English language by therapists. RESULTS: Repeated-measures ANOVA showed that there was no significant difference between the critical thinking disposition of nursing students in the treatment and control groups as measured by CTDI-M at the posttest. At the posttreatment and follow-up measures, there were consistently improved impacts of CBRT on the critical thinking disposition of nursing students in Nigeria as measured by CTDI-M. CONCLUSION: Following the results, we concluded that cognitive-behavioral reflective training was beneficial and had sustained improvement in enhancing the critical thinking disposition of nursing students.

Monkeypox Virus in Nigeria: Infection Biology, Epidemiology, and Evolution

Emmanuel Alakunle, Ugo Moens, Godwin Nchinda, Malachy Ifeanyi Okeke

Monkeypox is a zoonotic disease caused by monkeypox virus (MPXV), which is a member of orthopoxvirus genus. The reemergence of MPXV in 2017 (at Bayelsa state) after 39 years of no reported case in Nigeria, and the export of travelers' monkeypox (MPX) from Nigeria to other parts of the world, in 2018 and 2019, respectively, have raised concern that MPXV may have emerged to occupy the ecological and immunological niche vacated by smallpox virus. This review X-rays the current state of knowledge pertaining the infection biology, epidemiology, and evolution of MPXV in Nigeria and worldwide, especially with regard to the human, cellular, and viral factors that modulate the virus transmission dynamics, infection, and its maintenance in nature. This paper also elucidates the role of recombination, gene loss and gene gain in MPXV evolution, chronicles the role of signaling in MPXV infection, and reviews the current therapeutic options available for the treatment and prevention of MPX. Additionally, genome-wide phylogenetic analysis was undertaken, and we show that MPXV isolates from recent 2017 outbreak in Nigeria were monophyletic with the isolate exported to Israel from Nigeria but do not share the most recent common ancestor with isolates obtained from earlier outbreaks, in 1971 and 1978, respectively. Finally, the review highlighted gaps in knowledge particularly the non-identification of a definitive reservoir host animal for MPXV and proposed future research endeavors to address the unresolved questions.

Array programming with NumPy

Charles R. Harris, K. Jarrod Millman, Stéfan J. van der Walt, Ralf Gommers, Pauli Virtanen, David Cournapeau, Eric Wieser, J…

Abstract Array programming provides a powerful, compact and expressive syntax for accessing, manipulating and operating on data in vectors, matrices and higher-dimensional arrays. NumPy is the primary array programming library for the Python language. It has an essential role in research analysis pipelines in fields as diverse as physics, chemistry, astronomy, geoscience, biology, psychology, materials science, engineering, finance and economics. For example, in astronomy, NumPy was an important part of the software stack used in the discovery of gravitational waves 1 and in the first imaging of a black hole 2 . Here we review how a few fundamental array concepts lead to a simple and powerful programming paradigm for organizing, exploring and analysing scientific data. NumPy is the foundation upon which the scientific Python ecosystem is constructed. It is so pervasive that several projects, targeting audiences with specialized needs, have developed their own NumPy-like interfaces and array objects. Owing to its central position in the ecosystem, NumPy increasingly acts as an interoperability layer between such array computation libraries and, together with its application programming interface (API), provides a flexible framework to support the next decade of scientific and industrial analysis.

A Review of the Biology and Control of Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), with Special Reference to Biological Control Using Entomopathogenic Fungi

Ibrahim Sani, Siti Izera Ismail, Sumaiyah Abdullah, Johari Jalinas, Syari Jamian, Norsazilawati Saad

Whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), consists of genetically diverse species known to cause significant destruction in several crops around the world. Nymphs and adults of B. tabaci cause damage to plants during feeding, and they can act as a virus vector, thus causing significant yield loss to crops in the tropical and subtropical regions. Chemical pesticides are widely used to control B. tabaci due to their immediate action, but this approach has several drawbacks including food safety issues, insecticide resistance, environmental pollution, and the effect on non-target organisms. A biological control agent using entomopathogenic fungi (EPF) has therefore been developed as an alternative against the conventional use of chemical pesticides in an integrated pest management (IPM) system to effectively control B. tabaci. It is apparent from this review that species of hyphomycetes fungi are the most common EPF used to effectively control B. tabaci, with the second instar being the most susceptible stage of infection. Therefore, this review article focuses specifically on the control of B. tabaci with special emphasis on the use of EPF as biological control agents and their integration in IPM.

The Effectiveness of Multimedia Instructional Learning Packages in Enhancing Secondary School Students’ Attitudes toward Biology

Bukola Omowumi Akinbadewa, Olaniyi Alaba Sofowora

The study investigated the effectiveness of multimedia learning packages in improving the attitudes of students toward learning Biology in secondary schools. The study employed a quantitative and qualitative research approach. The population for the study consisted of all students offering Biology as a subject in the senior secondary schools in Ibadan North Local Government Area of Nigeria, from where a sample of 80 students was randomly selected from three secondary schools and assigned to three groups (one control and two experimental groups). Two multimedia instructional learning packages (MILP) were designed for the study. The topic treated was Cell Division, and the study lasted for six weeks. The packages and all instruments used were validated for content and construct validity, and reliability test was also done. The results showed that multimedia instructional packages used in teaching and learning Biology in secondary schools enhanced better students’ engagements and positive attitudes toward learning. It was concluded that students developed positive attitudes toward learning Biology after using the packages and that multimedia instructional packages are an interesting and creative method of teaching, learning, and enhancing positive attitudes towards learning among secondary school students.

Molecular Biology and Epidemiology of Neurotropic Viruses

Abba Musa Abdullahi, Shah T Sarmast, Romil Singh

Neurotropic viruses are those viruses that can cause central nervous system (CNS) diseases with both neuroinvasive and neurovirulence properties. It comprises a wide range of viruses, including herpes simplex virus, poliovirus, enteroviruses, parechovirus, West Nile virus, Japanese encephalitis virus, measles, and mumps viruses among others. Some of these viruses are highly neuroinvasive and neurovirulent, while others are weakly neuroinvasive and neurovirulent. Moreover, some of them, like herpes simplex viruses, are highly neuroinvasive but weakly neurovirulent for the peripheral nervous system and highly neurovirulent but weakly neuroinvasive for the central nervous system. All these disparities are a result of differences in their genomic constitution, associated vectors, geographical region, and environmental factors. Therefore, a successful intervention will be almost impossible without a clear understanding of the molecular biology and epidemiology of these viruses. Thus, we conducted a review of the published studies on the molecular biology and epidemiology of the common neurotropic viruses to make the viral genetic makeup more understandable for targeted intervention and provide the morbidity and mortality data of the different neurotropic viruses for more serious action.

Dementia prevention, intervention, and care: 2020 report of the Lancet Commission

Gill Livingston, Jonathan Huntley, Andrew Sommerlad, David Ames, Clive Ballard, Sube Banerjee, Carol Brayne, Alistair Burns,…

ENHANCING STUDENTS' ATTITUDE AND ACHIEVEMENT IN BIOLOGY THROUGH INNOVATIVE STRATEGIES

Martha Ijok Adibe Njoku, Chinwe Nwagbo

In this research, the impact of peer tutoring and group tutoring led to team learning approaches on the attitude of the students towards and achievement in biology. The thesis had been motivated by four research questions and six null hypotheses. The research had used a quasi-experimental method. In particular, the design of the un-equivalent control group. The sample size was 182 SS 1 students from the four sampled government senior high schools in Port-Harcourt metropolis, River State, Nigeria in four intact classrooms. Two of the classes were exposed to peer tutoring while the remaining two were exposed to peer-led team learning strategies. Biology Attitudinal Scale (BAS), and Biology Achievement Test (BAT) were data collection instruments. BAS construct validity was developed using factor analysis, while BAT material validity was calculated using the specification table. Reliability for BAS and BAT was obtained using formula 20 (K-R 20) from Cronbach Alpha and Kudar-Richardson. Mean and the standard deviation was used to answer the study questions while Covariance analysis (ANCOVA) was used to evaluate the hypotheses at 0.05 significance point. The findings showed that peer-led team learning approach is better than peer tutoring in enhancing the attitude and achievement of the students in biology. The implications of the findings were highlighted and recommendations made.

A Mathematical Theory of Evidence

Glenn Shafer

Both in science and in practical affairs we reason by combining facts only inconclusively supported by evidence. Building on an abstract understanding of this process of combination, this book constructs a new theory of epistemic probability. The theory draws on the work of A. P. Dempster but diverges from Depster's viewpoint by identifying his as epistemic probabilities and taking his rule for combining upper and lower as fundamental. The book opens with a critique of the well-known Bayesian theory of epistemic probability. It then proceeds to develop an alternative to the additive set functions and the rule of conditioning of the Bayesian theory: set functions that need only be what Choquet called monotone of order of infinity. and Dempster's rule for combining such set functions. This rule, together with the idea of weights of evidence, leads to both an extensive new theory and a better understanding of the Bayesian theory. The book concludes with a brief treatment of statistical inference and a discussion of the limitations of epistemic probability. Appendices contain mathematical proofs, which are relatively elementary and seldom depend on mathematics more advanced that the binomial theorem.

A close look at the biology of SARS-CoV-2, and the potential influence of weather conditions and seasons on COVID-19 case spread

Kamoru A. Adedokun, Ayodeji Oluwadare Olarinmoye, Jelili Olaide Mustapha, Ramat T. Kamorudeen

BACKGROUND: There is sufficient epidemiological and biological evidence of increased human susceptibility to viral pathogens such as Middle East respiratory syndrome coronavirus, respiratory syncytial virus, human metapneumovirus and influenza virus, in cold weather. The pattern of outbreak of the coronavirus disease 2019 (COVID-19) in China during the flu season is further proof that meteorological conditions may potentially influence the susceptibility of human populations to coronaviruses, a situation that may become increasingly evident as the current global pandemic of COVID-19 unfolds. MAIN BODY: A very rapid spread and high mortality rates have characterized the COVID-19 pandemic in countries north of the equator where air temperatures have been seasonally low. It is unclear if the currently high rates of COVID-19 infections in countries of the northern hemisphere will wane during the summer months, or if fewer people overall will become infected with COVID-19 in countries south of the equator where warmer weather conditions prevail through most of the year. However, apart from the influence of seasons, evidence based on the structural biology and biochemical properties of many enveloped viruses similar to the novel severe acute respiratory syndrome coronavirus 2 or SARS-CoV-2 (aetiology of COVID-19), support the higher likelihood of the latter of the two outcomes. Other factors that may potentially impact the rate of virus spread include the effectiveness of infection control practices, individual and herd immunity, and emergency preparedness levels of countries. CONCLUSION: This report highlights the potential influence of weather conditions, seasons and non-climatological factors on the geographical spread of cases of COVID-19 across the globe.

The Biology of Lactoferrin, an Iron-Binding Protein That Can Help Defend Against Viruses and Bacteria

Douglas B. Kell, Eugene L. Heyden, Etheresia Pretorius

Lactoferrin is a nutrient classically found in mammalian milk. It binds iron and is transferred via a variety of receptors into and between cells, serum, bile, and cerebrospinal fluid. It has important immunological properties, and is both antibacterial and antiviral. In particular, there is evidence that it can bind to at least some of the receptors used by coronaviruses and thereby block their entry. Of importance are Heparan Sulfate Proteoglycans (HSPGs) and the host receptor angiotensin-converting enzyme 2 (ACE2), as based on other activities lactoferrin might prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from attaching to the host cells. Lactoferrin (and more specifically enteric-coated LF because of increased bioavailability) may consequently be of preventive and therapeutic value during the present COVID-19 pandemic.