Second-harmonic generation-based Mueller matrix polarization analysis of collagen-rich tissues

Quantitative assessment of the properties of fibrillar collagen in tissue can yield deeper insight into structure-function correlations of the cell and its surrounding matrix. Second-harmonic generation (SHG) microscopy is especially well-suited as an image acquisition technique, due to its specificity to the non-centrosymmetric structure of collagen, and inherent confocality which enables three-dimensional sectioning. SHG imaging can be undertaken in a quantifiable manner, or combined with other techniques that highlight desired properties. A powerful property for characterizing collagenous tissue microstructure is the Mueller matrix polarization response. Two polarimetric imaging approaches are demonstrated for robust Mueller matrix characterization of collagenous tissue. One approach, called the two-photon Mueller matrix second-harmonic generation (MMSHG) microscopy, involves the generalization of Mueller matrix to the case of two-photon excitation. This 4-by-9 two-photon Mueller matrix is extracted using second-harmonic generation microscopy and analyzed for quantitative collagen assessment. The matrix and associated degree-of-polarization parameter from different sample types and thicknesses are also investigated. It was observed that the polarization-dependent degree-of-polarization distribution shape changes and a model-based bimodal mean difference metric increases with sample thickness. The second polarization technique which we developed, called second-harmonic patterned polarization-analyzed reflection confocal (SPPARC) microscopy, uses the conventional linear polarimetry of confocal images, delineated with a second-harmonic mask. This latter approach, combining the metric richness of linear polarimetry with the specificity of SHG imaging, is used for assessing collagen, as well as non-collagenous regions, in porcine tendon and ligament. We observed differences in depolarization and circular degree-of-polarization parameters, that have potential for dfferentiating tissues in varying states. Next, we present the results of SPPARC microscopy and analysis of collagen on varying pathologies of breast tissues. Experiments were conducted on a breast tissue microarray having benign tissues (BT), malignant invasive lobular carcinoma (ILC), and benign stroma adjacent to the malignant tissues (called the benign adjacent tissue, or BAT). We observed that stroma in BAT and ILC exhibits the largest parameter differences, with collagen readings in ILC showing lower depolarization, lower diattenuation and higher linear degree-of-polarization values than stromal collagen in BAT. This result suggests that the optical properties of collagen change most in the vicinity of tumors. A similar trend is also exhibited in the non-collagenous extrafibrillar matrix plus cells (EFMC) region. We finally discuss additional work involving polarization modeling, setup optimization, and implementation of other decomposition techniques

Mueller-matrix-based analysis for second-harmonic generation imaging

Second-harmonic generation microscopy takes advantage of second-order nonlinear property for imaging of biological structures. Invoking quantitative image analysis techniques facilitates the assessment of tissues in varying states. This thesis presents a quantitative description of the relative structural difference in collagen-based tissues by second harmonic generation (SHG) imaging techniques involving polarization investigation. The Mueller matrix formalism demonstrates a polarization-based analysis approach for assessment of varying samples. The associated second-order Mueller matrices are generated by applying image processing algorithms to sub-grids of image sets obtained from a forward imaging microscope. By defining scalar metrics such as the degree of polarization and the depolarization, a quantitative evaluation of the samples under investigation is provided. A discussion of the capabilities for tissue assessment and techniques for improvements in the data acquisition speed and analysis will also be proffere

Demonstration of an optical-coherence converter

Studying the coherence of an optical field is typically compartmentalized with respect to its different optical degrees of freedom (DoFs) -- spatial, temporal, and polarization. Although this traditional approach succeeds when the DoFs are uncoupled, it fails at capturing key features of the field's coherence if the DOFs are indeed correlated -- a situation that arises often. By viewing coherence as a `resource' that can be shared among the DoFs, it becomes possible to convert the entropy associated with the fluctuations in one DoF to another DoF that is initially fluctuation-free. Here, we verify experimentally that coherence can indeed be reversibly exchanged -- without loss of energy -- between polarization and the spatial DoF of a partially coherent field. Starting from a linearly polarized spatially incoherent field -- one that produces no spatial interference fringes -- we obtain a spatially coherent field that is unpolarized. By reallocating the entropy to polarization, the field becomes invariant with regards to the action of a polarization scrambler, thus suggesting a strategy for avoiding the deleterious effects of a randomizing system on a DoF of the optical field.Comment: 7 pages; 6 figure

Thermal Modelling and Analysis of A 10HP Induction Machine Using the Lumped Parameter Approach

The essence of this research work is to develop a thermal model for an induction machine that will enable the prediction of temperature in different parts of the machine. This is very important first to the manufacturer or designer of an induction machine because with these predictions one can decide on the insulation class limits the machine belongs to. Also modern trends in the construction of machines is moving in the direction of making machines with reduced weights, costs and increased efficiency. In order to achieve this, the thermal analysis becomes very crucial in deciding on what types of insulators and other materials that would be used to make these machines. In industries, the knowledge of the thermal limits of machines if well utilized increases the life span of the machines and reduces downtime; thereby increasing production and profit. Specifically, this paper (i) predicted the temperature limits of the induction machine and its components, (ii) developed an accurate thermal model for an induction machine, (iii) predicted the temperature in different parts of the induction machine using the thermal model and software program and lastly (iv) investigated how the machine symmetry is affected by the nodal configuration

Impact of Capital Expenditure on the Manufacturing Sector of the Nigerian Economy

The importance of capital expenditure in an economy cannot be overemphasized. In Nigeria, capital expenditure has been given meager allocation, and the manufacturing sector has been experiencing poor growth. To this end, this study examines whether the low manufacturing sector’s growth in Nigeria is as a result of the poor allocation to capital expenditure, also whether there is any causal relationship between capital expenditure and manufacturing sector’s growth. In executing this study, the Error Correction Mechanism (ECM) is employed after Augmented Dickey Fuller (ADF) unit root test as well as Johansen Co-integration analysis have been applied to the variables in our model- Manufacturing Output in Nigeria; Capital Expenditure; Foreign Direct Investment; Interest Rate; and Exchange Rate. Granger causality test is employed to determine whether there is any causal relationship between capital expenditure and manufacturing sector’s growth. The study finds that capital expenditure has significant impact on manufacturing sector’s growth. It also finds that capital expenditure Granger causes manufacturing sector’s growth in Nigeria. The study recommended imperative policy options which we believe that if implemented; there will be tremendous improvements in the manufacturing sector’s growth in Nigeria

Exponentiated Rama Distribution: Properties and Application

In this study, a new distribution known as the Exponentiated Rama distribution has been proposed. The aim was to generalize the one parameter Rama distribution using the exponentiation technique. Some properties of proposed distribution are derived. The maximum likelihood method was used for the estimation of model parameters. The proposed distribution was subjected to real life application using a set of lifetime data and compared to Rama distribution, Exponentiated Akash distribution and Exponentiated Exponential distribution and it was found to provide the best fit than other competing distributions. Keywords: Rama distribution, Exponentiated distributions, Order statistics, Moment

Pattern and correlates of psychoactive substance use among new prison inmates in Nigeria

Psychoactive substance disorders among prison inmates are challenges to the prison authority, and this may interfere with the processes of reformation and rehabilitation therein. The study assessed the prevalence, pattern, and correlates of psychoactive substance use in a cross-sectional study involving 552 new inmates in a custodial center in Enugu, Nigeria. Diagnoses were made using the MINI-Plus (version 6) in line with the ICD 10. Lifetime and 12-month prevalence of psychoactive substance disorder were 57.4% and 50.7%, respectively. The commonest substance disorders were tobacco (48.2% lifetime and 41.1% 12-month), cannabis (36.8% lifetime, and 32.4% 12-month), and alcohol (7.2% lifetime, and 6.9% 12-month). Descriptive statistics, Mann-Whitney U test, Chi-squared test, and regression analyses were performed to assess the extent to which socio-demographic characteristics, type of offence, and family dysfunction predicted psychoactive substance use or disorder. Four hundred and seventy eight (86.6%) of participants had used psychoactive substance in their lifetime, while it was 405 (73.4%) in the last 12 months prior to imprisonment. Lifetime and 12-month rates of psychoactive substance disorder were 57.4% (n=317) and 50.7% (n=280), respectively. Male gender, unemployment, parental divorce, and parental drug use respectively, significantly predicted 12-month psychoactive substance disorder [β = 0.12, 95% (CI: 0.04, 0.39)], [β = 1.79, 95% (CI: 1.24, 2.60)], [β = 0.29, 95% (CI: 0.14, 0.59)], and [β = 0.56, 95% (CI: 0.39, 0.81)]. Lifetime disorder was significantly predicted by male gender [β = 0.12, 95% (CI: 0.04, 0.35)], unemployment [β = 1.60, 95% (CI: 1.10, 2.32)], parental divorce [β = 0.23, 95% (CI: 0.10, 0.52)], and parental drug use [β = 0.49, 95% (CI: 0.34, 0.72)]. Similarly, lifetime psychoactive substance disorder was associated with older age (U = 33355, Z = -2.104, p = 0.035), while the prevalence of 12-month use of psychoactive substance was significantly associated with charges of violent offences (χ2=13.55, p˂0.01). Conclusively, there is a high prevalence of psychoactive substance use and disorders among new prison inmates with  tobacco, cannabis and alcohol as the commonest. Given that male gender, unemployment, parental divorce and parental drug use  increase the likelihood of these disorders, it will be worthwhile for any drug intervention program to address these factors. Keywords: Psychoactive substances; drug; inmates; crime; Nigeria

Association Between Serum Vitamin D Status and Uterine Leiomyomas: A Case-Control Study

OBJECTIVE: Uterine leiomyoma is a common gynecological condition that negatively affects women\u27s quality of life. Vitamin D plays an important role in tumor development and progression. However, clinical studies comparing serum vitamin D levels between women with and without uterine leiomyomas are limited and inconclusive. This study aimed to compare serum vitamin D levels in women with and without uterine leiomyomas. METHODS: This hospital-based case-control study included 150 women who visited a gynecological clinic. The cases included 75 women with uterine leiomyoma, whereas the controls included 75 age-and parity-matched participants without uterine leiomyoma. Serum vitamin D levels were measured in each participant and volumes of the uterine leiomyomas were determined using the water displacement method following myomectomy. The statistical significance was inferred at P\u3c0.05. RESULTS: The mean serum vitamin D level was 15.26±4.96 ng/mL and 22.45±6.93 ng/mL for the case and control groups, respectively. The difference was statistically significant (t-value -7.302 and P CONCLUSION: Women with uterine leiomyoma had lower vitamin D levels than women in the control group. Lower vitamin D levels were associated with larger fibroid masses. Therefore, vitamin D supplementation may reduce fibroid growth and development

Association between serum vitamin D status and uterine leiomyomas: a case-control study

Objective Uterine leiomyoma is a common gynecological condition that negatively affects women’s quality of life. Vitamin D plays an important role in tumor development and progression. However, clinical studies comparing serum vitamin D levels between women with and without uterine leiomyomas are limited and inconclusive. This study aimed to compare serum vitamin D levels in women with and without uterine leiomyomas. Methods This hospital-based case-control study included 150 women who visited a gynecological clinic. The cases included 75 women with uterine leiomyoma, whereas the controls included 75 age-and parity-matched participants without uterine leiomyoma. Serum vitamin D levels were measured in each participant and volumes of the uterine leiomyomas were determined using the water displacement method following myomectomy. The statistical significance was inferred at P<0.05. Results The mean serum vitamin D level was 15.26±4.96 ng/mL and 22.45±6.93 ng/mL for the case and control groups, respectively. The difference was statistically significant (t-value −7.302 and P<0.001). Within the fibroid group, nine (12.0%), 49 (65.33%), and 17 (22.67%) participants had vitamin D deficiency, insufficiency, and sufficiency, respectively; and in the control group, two (2.67%), 24 (45.33%), and 39 (52.0%) participants had vitamin D deficiency, insufficiency, and sufficiency, respectively. There was significant negative correlation between the fibroid volume and the serum vitamin D level (r=−0.591, P<0.001). Conclusion Women with uterine leiomyoma had lower vitamin D levels than women in the control group. Lower vitamin D levels were associated with larger fibroid masses. Therefore, vitamin D supplementation may reduce fibroid growth and development

Cast report: Intrauterine Retention of Fetal Bones: An Unusual Cause of Infertility

Couples presenting with infertility face peculiar sociocultural problems, these are especially evident in African countries where a very high premium is placed on children and childbearing.We report a case of a 30-year-old nullipara with a 3-year history of secondary infertility who on investigation was found to have fetal bones from an earlier incomplete abortion. She achieved pregnancy within three months of endoscopic removal of the fetal bones. Keywords: Intrauterine bone fragments, Secondary infertility, Foreign body, Termination of pregnanc