Mathematical modelling and numerical simulations of actin dynamics in the eukaryotic cell

The aim of this article is to study cell deformation and cell movement by considering both the mechanical and biochemical properties of the cortical network of actin filaments and its concentration. Actin is a polymer that can exist either in fil- amentous form (F-actin) or in monometric form (G-actin) (Chen et al. 2000) and the filamentous form is arranged in a paired helix of two protofilaments (Ananthakrish- nan et al. 2006). By assuming that cell deformations are a result of the cortical actin dynamics in the cell cytoskeleton, we consider a continuum mathematical model that couples the mechanics of the network of actin filaments with its bio-chemical dy- namics. Numerical treatment of the model is carried out using the moving grid finite element method (Madzvamuse et al. 2003). Furthermore, by assuming slow deforma- tions of the cell, we use linear stability theory to validate the numerical simulation results close to bifurcation points. Far from bifurcation points, we show that the math- ematical model is able to describe the complex cell deformations typically observed in experimental results. Our numerical results illustrate cell expansion, cell contrac- tion, cell translation and cell relocation as well as cell protrusions. In all these results, the contractile tonicity formed by the association of actin filaments to the myosin II motor proteins is identified as a key bifurcation parameter

Using Artificial Intelligence for the Automation of Knitting Patterns

Knitting patterns are a crucial component in the creation and design of knitted materials. Traditionally, these patterns were taught informally, but thanks to advancements in technology, anyone interested in knitting can use the patterns as a guide to start knitting. Perhaps because knitting is mostly a hobby, with the exception of industrial manufacturing utilising specialised knitting machines, the use of Al in knitting is less widespread than its application in other fields. However, it is important to determine whether knitted pattern classification using an automated system is viable. In order to recognise and classify knitting patterns. Using data augmentation and a transfer learning technique, this study proposes a deep learning model. The Inception ResNet-V2 is the main feature extraction and classification algorithm used in the model. Metrics like accuracy, logarithmic loss, F1-score, precision, and recall score were used to evaluate the model. The model evaluation's findings demonstrate high model accuracy, precision, recall, and F1 score. In addition, the AUC score for majority of the classes was in the range (0.7-0.9). A comparative analysis was done using other pretrained models and a ResNet-50 model with transfer learning and the proposed model evaluation results surpassed all others. The major limitation for this project is time, as with more time, there might have been better accuracy over a larger number of epochs

Groundwater Quality Assessment for Drinking Water using Water Quality Index (WQI): A Case Study of Eastern Obolo, Southeastern Nigeria

Groundwater, an important source of drinking water for coastal communities of the world including Eastern Obolo, South eastern Nigeria has been adversely affected by both natural and anthropogenic activities. Understanding the quality of this resource for proper management is pertinent. Consequently, this project aims at assessing the groundwater quality of the study area using Water Quality Index (WQI). Eleven (11) groundwater samples from different locations were collected in 120ml plastic bottles and transported to the laboratory for analyses.  Physiochemical and chemical analysis including EC, TDS, temperature, pH, Ca2+, Mg2+, K+, Na+, Mn2+, Fe2+, NH4+, PO4-, NO3-, NO2-, Cl-, F-, SO42-, HCO32- were analysed for in the water samples. The result of the physicochemical analysis reveals that the groundwater in the area is slightly acidic to alkaline. The chemical analysis result showed concentration of major cations and anions in order of Fe2+> Mg2+> Na+> Ca2+> Mn2+> K and Cl-> HCO3-> NO3-> NO2-> F-> SO42-> PO42- respectively. The dominant hydrochemical facies in the study area are; Ca-Mg-Cl-HCO3-, and Na+K-Cl-HCO3- with Na+K-Cl as minor water type. The Water Quality Index (WQI) for the different samples in the study area range from 191.2171 to 1309.489. The Index reveals that the groundwater in this area has poor water quality and are unsuitable for drinking purposes. Hence, treatment before consumption due to high concentration of chloride, bicarbonates, magnesium, iron and manganese is recommended. Keywords: Water Quality Index, Eastern Obolo, Coastal Regio

Adsorptive Removal of Phosphorus from Aqueous Solution using Recycled Bricks and Modified Clay Pellets and the Potential for a Slow Release Fertilizer

The Urban Waste Water Treatment Directive increases government regulatory pressure required to ensure phosphate discharged by Waste Water Treatment Works (WWTWs) meet consent. Bricks from construction waste have been viewed as an alternative treatment medium for phosphate. This thesis examines the use of recycled bricks and novel brick-like materials to afford an opportunity for the provision of a green solution to issues associated with phosphate removal and recovery. This thesis builds on existing studies on the use of recycled bricks, firstly eliminating the problem associated with use of powdered form of clay material by pelletising these materials. The pellets developed performed better than conventional brick dust. The composition of pelletised material was modified to ascertain the extent of phosphate adsorption. Optimization of pelletised material was carried out in batch studies, and phosphate removal was found to vary with elemental composition and increase with treatment time among other factors. The maximum adsorption capacity was 42.37 mg/g, 70.42 mg/g and 52.91 mg/g for AlMFCP, CaMFCP and FeMFCP respectively. The modified pellets show a faster kinetic that was up to five times faster than FCP signifying that the modified pellets will require a reactor that was five times smaller in size than FCP. Physisorption was the dominant adsorption mechanism supported by some pore diffusion for AlMFCP and FeMFCP but the dominant mechanism for adsorption using CaMFCP was chemisorption supported by some physical diffusion processes. Acidic pH favoured adsorption using FeMFCP, and slightly acidic pH for AlMFCP while adsorption using CaMFCP was favoured at acidic and neutral pH. Phosphate adsorption achieved using materials of this study was compared to materials of other studies through the comparison of adsorption isotherms. Pellets modified with calcium carbonate showed the best performance and was consequently used in further studies. Phosphate adsorption involved different mechanisms at different stages but tending to physisorption as the dominant mechanism. Fixed bed column study performed on the pellets showed the practicability of a full-scale application in a wastewater treatment plant. Increase in bed height and column diameter improved adsorption capacity due to longer empty bed contact time (EBCT) between the adsorbent and phosphate in solution. Higher flow rate hindered adsorption as a result of shorter contact between adsorbent and phosphate in solution. The column with column diameter of 2 cm, bed height of 10 cm and influent phosphate concentration of 20 mg/L showed the shortest retention time of 1.75 minutes, followed by the column with a bed height of 10 cm, column diameter of 5 cm and influent phosphate concentration of 20 mg/L. Phosphate sorbed to materials in this study was recycled as a slow release fertilizer for agricultural production. The spent adsorbent compared favourably with yield obtained from KH2PO4 fertilizer. The yield increased with increase in application rate of phosphate with 382.17 kgP/ha producing the highest yield. The performance of pots with P added in the form of phosphate sorbed to CaMFCP was similar to pots with P added in the form of KH2PO4 when germination rate, plant height and WM yield were considered while pots with added KH2PO4 showed a better DM yield than pots with P added in the form of phosphate sorbed to CaMFCP. Relative effectiveness of fertilizer showed improvement as growth progressed. At the latter stages, yield using phosphate from spent filter materials surpassed KH2PO4 fertilizer. This demonstrated that spent fired clay pellets could be used as a slow release fertilizer for agricultural purpose thereby offering a green and cost effective option for phosphate removal in wastewater and the management of the resultant waste pellets

A numerical approach to studying cell dynamics

The focus of this thesis is to propose and implement a highly efficient numerical method to study cell dynamics. Three key phases are covered: mathematical modelling, linear stability analytical theory and numerical simulations using the moving grid finite element method. This aim is to study cell deformation and cell movement by considering both the mechanical and biochemical properties of the cortical network of actin filaments and its concentration. These deformations are assumed to be a result of the cortical actin dynamics through its interaction with a protein known as myosin II in the cell cytoskeleton. The mathematical model that we consider is a continuum model that couples the mechanics of the network of actin filaments with its bio-chemical dynamics. Numerical treatment of the model is carried out using the moving grid finite element method. By assuming slow deformations of the cell boundary, we verify the numerical simulation results using linear stability theory close to bifurcation points. Far from bifurcation points, we show that the model is able to describe the deformation of cells as a function of the contractile tonicity of the complex formed by the association of actin filaments with the myosin II motor proteins. Our results show complex cell deformations and cell movements such as cell expansion, contraction, translation and protrusions in accordance with experimental observations. The migratory behaviour of cells plays a crucial role in many biological events such as immune response, wound healing, development of tissues, embryogenesis, inflammation and the formation of tumours

Promoting family-centred care through primary nursing practice in Nigeria : an action research project

The context of the family in developing countries, especially in Nigeria, is very wide and embraces the immediate as well as the extended family members. The involvement of the family in health care can not be over-emphasised in the Nigerian society where every family member assumes the role of his/her brother's keeper. The expectations of and the role of the Nigerian extended family system in the health care of its members, the problem of incompatibility of the nursing process with the Nigerian nursing organisational pattern, which is predominantly functional nursing, and the increased call for the improvement of the quality of nursing care in Nigeria informed this study.The 'outsider' model of action research project using an 'insider' was undertaken to promote family-centred care through the introduction of primary nursing in Nigeria. The project involved introduction and evaluation of change in a model ward in a Nigerian hospital. The change was implemented in phases. A 37-bed medical-surgical ward in a 400-bed tertiary health institution formed the nucleus site for the change. Twenty-eight nursing staff (25 trained and 3 untrained), all patients and their families in the model ward and others took part in the change. In the pre-change evaluation study, 10 patients and 8 family members were assessed, while 8 patients and 6 family members were involved in the post-change evaluation. Data collection was carried out before and after the introduction of the change through observation, review of records, interview and self-report questionnaire. Measures used in the study included: QUALPACS, nurse-patient and nurse-family interaction sheets, modified Riser satisfaction questionnaire for patient and family satisfaction, questionnaire to determine the focus of nursing care and questionnaire to assess the practice of primary nursing in the model ward.Families and patients were supportive of the change, nurses were receptive of the change, hospital administration was helpful and other health care practitioners were neutral about the change. Other wards in the hospital and other hospitals expressed willingness to join in the change. After the introduction of primary nursing into the model ward, there appeared to be (1) marked improvement in the quality of nursing care received by the patients, (2) higher levels of family and patient satisfaction with nursing care, (3) an increase in the frequency of nurse-patient and nurse-family interactions, (4) improvement in the level of patient and family involvement in interactions and (5) an increase in the number of nurse-patient and nurse-family interactions in which supportive nursing activities were involved.Despite the study limitations, further research and replication studies are suggested to enable the spread of family-centred nursing care into other hospitals. Possibilities for continuity measures, outcomes for nursing staff and other health care practitioners have been raised as necessary variables for future evaluative studies. The need for more long term studies on primary nursing, and an in-depth study to ascertain the association between presence of family at patient's beside while the patient is under care and the level of patient satisfaction with nursing care have been implicated from this study

MECHANICAL PROPERTIES OF HOLLOW AND SOLID WHEAT STEMS

Harvesting wheat is carried out by cutting the stem and threshed. When the stem (straw) bends due to pest and weather, losses are incurred especially during harvesting. Solid stem wheat varieties have been bred to resist pest like wheat stem sawfly and lodging. Solid stem varieties may lead to higher straw strength and energy which consequently impacts harvesting and collection. Also, farmers are faced with the challenge of increased cost of transporting the straw outside the farm due to their high volume. Previous research investigations have been done on increasing the straw bulk density and have led to producing more dense straws (double-compressed bales, pellets, cube, and briquette) but the cost of processing them and their physical quality is still a challenge. There has been a report that it takes low capital producing bale than other dense products. This means that if the bulk density of bales can be further increased through compression, it will be more economical using the wheat straw in a dense bale form. The research project investigated the mechanical properties of stems of twelve varieties of wheat (solid and hollow stem) at different moisture levels and internode positions. Aside from the compression test that was carried out on single moisture (14% w.b), samples were conditioned to three moisture content levels (14, 18, and 22% w.b) before testing was carried out. Shearing, cutting, tensile, and compression tests were done using different tools mounted on the InstronTM universal tester while the texture analyzer and a three point tool were used for bending test. The shear box apparatus was employed in determining the coefficient of internal friction. The stem diameters were determined by individually imaging the stems to be tested. Compression and relaxation models were fitted to the compression test data to determine their applicability to wheat straw compression and relaxation experimental data, respectively. Different orientations of fibers were obtained across varieties for studies on stem imaging with varying stem areas. Data analysis revealed that moisture had significant effect on coefficient of internal friction while moisture and internode position had positive correlation on shearing, cutting, and tensile strength as well as shearing and cutting energy but a negative effect on bending strength and modulus of elasticity for all varieties (P< 0.05). The coefficient of internal friction ranged from 0.095-0.669. Average shearing, tensile, and cutting strength varied between 4.9-23.0 MPa, 14.3- 114.7 MPa, and 1.4- 10.2 MPa, respectively, while the average shearing and cutting energy ranged from 62.4-270.0 mJ and 27.0-133.3 mJ, respectively. Mean bending strength and modulus of elasticity varied between 43.9-4.2 MPa and 3.5-0.1 GPa, respectively. Different trends were found across varieties when the mechanical properties were compared with respect to the internode position. Solid stem varieties had much lower shearing, cutting, and tensile strength than hollow stem wheat varieties while there was no difference between both stem types in relation to coefficient of internal friction, shearing, and cutting energy as well as bending strength and modulus of elasticity. The compression and relaxation models fitted accurately to the compression and relaxation test data, respectively, for all wheat varieties. The k4 values obtained from fitting the Peleg and Moreyra model to the relaxation data were greater than one (k4 > 1). Average percentage relaxation and asymptotic modulus range from 38.6 to 42.4% and 10.57 to 11.49 MPa, respectively, with no difference between the average percentage relaxation and asymptotic modulus of solid and hollow stem varieties. Models developed relating moisture content to shearing strength and energy, cutting strength and energy, bending strength, modulus of elasticity, and coefficient of internal friction, respectively, had varying R2 values

The Use of International Standard Bibliographic Description (ISBD) and the Quality of Books Published in Nigeria

This study sought to determine the extent to which Nigerian publishers use the International Standard Bibliographic Descriptions (ISBD) in Nigerian published books. Publishers and documentary evidence were used for the study. Two hundred and fifty publishers and one thousand books were used as sample for the study. The instruments used for the study were a standardized checklist of the book and a questionnaire. One null hypothesis was formulated and tested. The data collected were analysed using percentages and Pearson Product Moment Correlation (PPMC). The study found out that use of ISBD significantly influences quality book publishing and affects the process of retrieving information easily. The study concluded that lack of essential ISBD elements by Nigerian publishers creates problems for cataloguers, documentalists, and library users, and has a significant relationship to the quality of book publishing