An Architecture for an Infrastructure as a Service for the Internet of Things

Internet of things (IoT) refers to things such as sensors and actuators interacting with each other to reach common goals. It enables multiple applications in sectors ranging from agriculture to health. Nowadays, applications and IoT infrastructure are tightly coupled and this may lead to the deployment of redundant IoT infrastructures, thus, cost inefficiency. Cloud computing can help in tackling the problem. It is a paradigm to quickly provision configured resources (computing, network, memory) on demand for cost efficiency. It has three layers, the infrastructure as a service (IaaS), the platform as a service (PaaS) and the software as a service (SaaS). Through the IaaS, configured hardware resources (CPU, storage, etc.) are provisioned on demand. However, designing and implementing an IoT IaaS architecture for the provisioning of IoT resource on demand remains very challenging. An example of a challenge is using the appropriate publishing and discovery mechanism suitable for IoT devices. Orchestrating a virtualized IoT device over several physical IoT devices is another challenge that needs to be addressed. The main contribution of this thesis is twofold. First, a novel IoT IaaS architecture is proposed where IoT devices can be provisioned as a configured infrastructure resource on demand via node virtualization. Second, the architecture is prototyped and evaluated using real-life sensors that support node virtualization. Node level virtualization achieves resource efficiency in contrast to middleware solutions. The essential architectural features, such as publication, discovery, and orchestration are identified and proposed. Two sets of a high-level interface are also introduced. A low-level uniform interface is suggested to decouple the IoT devices from the applications by allowing the applications to access the heterogeneous devices in a uniform way. In addition, a cloud management interface is proposed to expose the IoT IaaS to the cloud consumers (for example - the PaaS, the application, etc.) and allow them to provision the IoT resources. By allowing the capability sharing of the IoT devices using the node virtualization, the cost efficiency and energy efficiency are achieved in the proposed architecture. Addressing other challenges allowed the proposed architecture to expose the IoT devices to the IaaS in a more abstract manner. Thus allowing the application to provision the IoT resources on demand as well as handling the IoT device heterogeneity in the IaaS

Framework for transfer learning: Maximization of quadratic mutual information to create discriminative subspaces

In the area of pattern recognition and computer vision, Transfer learning has become an emerging topic in recent years. It is motivated by the mechanism of human vision system that is capable of accumulating previous knowledge or experience to unveil a novel domain. Learning an effective model to solve a classification or recognition task in a new domain (dataset) requires sufficient data with ground truth information. Visual data are being generated in an enormous amount every moment with the advance of photo capturing devices. Most of these data remain unannotated. Manually collecting and annotating training data by human intervention is expensive and hence the learned model may suffer from performance bottleneck because of poor generalization and label scarcity. Also an existing trained model may become outdated if the distribution of training data differs from the distribution where the model is tested. Traditional machine learning methods generally assume that training and test data are sampled from the same distribution. This assumption is often challenged in real life scenario. Therefore, adapting an existing model or utilizing the knowledge of a label-rich domain becomes inevitable to overcome the issue of continuous evolving data distribution and the lack of label information in a novel domain. In other words, a knowledge transfer process is developed with a goal to minimize the distribution divergence between domains such that a classifier trained using source dataset can also generalize over target domain. In this thesis, we propose a novel framework for transfer learning by creating a common subspace based on maximization of non-parametric quadratic mutual information (QMI) between data and corresponding class labels. We extend the prior work of QMI in the context of knowledge transfer by introducing soft class assignment and instance weighting for data across domains. The proposed approach learns a class discriminative subspace by leveraging soft-labeling. Also by employing a suitable weighting scheme, the method identifies samples with underlying shared similarity across domains in order to maximize their impact on subspace learning. Variants of the proposed framework, parameter sensitivity, extensive experiments using benchmark datasets and also performance comparison with recent competitive methods are provided to prove the efficacy of our novel framework

Prevalence and determinants of adolescent childbearing: comparative analysis of 2017–18 and 2014 Bangladesh Demographic Health Survey

ObjectivesBangladesh has one of the highest adolescent childbearing rates in South Asia, which prevent women from realizing their full potential in life. This study aimed to compare the prevalence and determinants of adolescent childbearing in Bangladesh using data from the 2014 and 2017–18 Bangladesh Demographic and Health Survey (BDHS).MethodsNationally representative surveys of respondents were selected using a two-stage sampling process. The study recruited 2,023 and 1,951 ever-married women aged 15–19 from 2014 and 2017–18 BDHS surveys, respectively, from rural and urban settings from all eight geographic divisions of Bangladesh. Univariate and multivariate logistic regression models were fit to determine the factors associated with adolescent childbearing.ResultThe adolescent childbearing prevalence rate was 30.8% in 2014 BDHS and 27.6% in 2017–18 BDHS. Marriage at age 13 years or less also reduced significantly in 2017–18 compared to 2014 (12.7% vs. 17.4%, respectively). Significantly higher odds of adolescent childbearing were found in 2014 among women in the Sylhet Division (adjusted odds ratio (AOR) = 3.0; 95% confidence interval (CI): 1.6–6.1) and the Chittagong Division (AOR = 1.8; 95% CI: 1.8–2.7) compared to the Barisal Region; however, in 2017, there were no significant differences was found across the geographic Divisions. Compared to women in the lowest wealth quintile, women in all other quintiles had lower odds of adolescent childbearing, with the lowest odds found among women in the wealthiest quintile (AOR = 0.3; 95% CI: 0.2–0.6). Women who married at age 14–17 had 60% lower odds of adolescent childbearing compared to the women who married at age 10–13.ConclusionNearly one-third of married adolescents in Bangladesh were pregnant or had at least one child in 2014, and it was reduced only marginally in 2017–18. Marriage at an early age and income inequalities among families were significant predictors of adolescent childbearing in Bangladesh. This study highlighted change in the magnitude and determinants of adolescent childbearing in Bangladesh taken data from two nationally representative surveys conducted 4 years apart

IN-VITRO COMPARATIVE STUDY OF ANTI-INFLAMMATORY AND ANTI-ARTHRITIC EFFECTS OF FLEMINGIA STRICTA ROXB AND NYMPHAEA NOUCHALI LEAF

Objective: To evaluate the comparative study of anti-inflammatory, anti-arthritic activity of methanol extract of Flemingia stricta and Nymphaea nouchali leaf.Methods: Human Red Blood Cell (HRBC) membrane stabilization method was evaluated for anti-inflammatory activity. Anti-denaturation method was performed by using Bovine Serum Albumin (BSA) to evaluate the anti-arthritic potential.Results: The in vitro anti-inflammatory activity of the methanol extracts of Flemingia stricta and Nymphaea nouchali showed 81.85±0.67% (P<0.01) and 85.59±0.58% (P<0.01) of membrane stabilization at 1000µg/ml conc. and 51.85±0.49% (P<0.01) and 70.63±0.50% (P<0.01) at 31.25µg/ml respectively. All the results were compared with standard Diclofenac which showed 93.15±1.03% protection at 1000µg/ml conc. The in vitro study on both leaves also showed the presence of significant anti-arthritic activity. Here the extracts showed 70.43±1.42% (P<0.01) and 83.33±0.54% of protein denaturation at the highest conc. (1000 µg/ml) and 39.25±1.08% (P<0.01) and 38.71±0.93% (P<0.01) at the lowest conc. (31.25µg/ml), in where the standard drug displayed the 86.56±2.15% at 1000ug/ml and 51.08±1.42% at 31.25 µg/ml.Conclusion: These results suggest that both the methanol extract of Flemingia stricta and Nymphaea nouchali possess significant anti-inflammatory and anti-arthritic activity.Â

Resistance Pattern of Levofloxacin against Uropathogens Causing Urinary Tract Infection in Selected Areas of Dhaka city, Bangladesh

A crucial public health problem in developing country like Bangladesh is resistance of antibiotics to different types of bacteria and the rates of these bacterial resistances are changing for various antibiotic therapy. Our aim was to assess the susceptible pattern of Levofloxacin a 3rd generation Quinolone antibiotic against uropathogens. A total of 12943 urine samples were collected in 2016 (Jan-Dec) and out of which 1236 (9.55%) were bacteriologically positive. Among the isolated uropathogens, 95.1% were gram negative and 4.9% gram positive organism. Male were found more prone to get UTI under 10 years and between 51-90 years of age and female were more affected in 10 to 50 years and over 90 years of age group. E. coli was the most prevalent (83.9%) isolate followed by Klebsiella spp. (6.7%), Staphylococcus aureus (2.6%), Pseudomonas spp. (2.2%), Enterococcus spp. (2.0%) and Proteus spp. (1.1%). The most predominant Levofloxacin sensitive organisms were found in male Enterobacter spp. (100%) and in female patients Serretia spp. (100%), Citrobacter spp. (100%) and Streptococcus Group B (100%). On the other hand the most predominant Levofloxacin resistant organisms were found in male and female both Acinetobacter spp. (100%). Around (61.7%) male and (46.9%) female were found resistant to E. coli. Keywords: Levofloxacin, Quinolone, UTI, Resistance, Uropathogen

Spherical and Rod-shaped Gold Nanoparticles for Surface Enhanced Raman Spectroscopy

Raman Spectroscopy offers an in-situ, rapid, and non-destructive characterization tool for chemical analysis of diverse samples with no or minimal preparation. However, due to the inherent weak signal of conventional Raman spectroscopy, surface plasmon resonance features of noble metal nanoparticles have been utilized to conduct Surface Enhanced Raman Spectroscopy (SERS) in detecting trace label contaminants in foods and foodstuffs. In this effort, we synthesized gold nanoparticles (AuNPs) by reduction of chloroauric acid (HAuCl4) with sodium citrate dehydrate. We prepared different sizes of AuNPs at a fixed temperature (100 oC) but with varying pHs of 4 and 8. The as-synthesized AuNPs were characterized by UV-Vis spectroscopy, dynamic light scattering (DLS), and Field Emission Scanning Electron Microscopy (FE-SEM). FE-SEM micrographs revealed spherical AuNPs with an average diameter of approx. 55 nm and rod-shaped AuNPs with an average length of approx. 170 nm for sample synthesis at pH 8 and 4, respectively. The effectiveness of the as-prepared AuNPs for SERS is tested by detecting Rhodamine 6G diluted at a trace level. This study suggests that plasmonic nanoparticles coupled with SERS have great potential for broad applications in detecting other trace amounts of hazardous chemicals in foods and foodstuffs.Comment: 4 pages, 5 figure

Anti-oxidant effect of Flemingia stricta Roxb. leaves methanolic extract

Aim of the study was to evaluate the possible anti-oxidant activity of Flemingia stricta leaf extract. In antioxidant study, plant crude methanol extract was evaluated for 1,1-diphenyl,2-picrylhydrazyl (DPPH) and reducing power capacity. Moreover, total phenolic and total flavonoid content of plant extracts were determined and expressed in mg of gallic acid equivalent per gram of dry sample (mg GAE/g dry weight). In the DPPH free radical scavenging assay, methanol extract showed concentration dependent inhibition of the free radicals. IC50 of ascorbic acid and F. stricta leaves were 4.25 µg/ml and 320.47 µg/ml respectively. In case of reducing capacity, the methanol extract at concentrations of 25, 50, 100, 200, 400 µg/ml, the absorbances were 0.56, 0.92, 1.41, 1.76, 2.23, respectively. Total phenolic content was estimated by gallic acid and expressed as milligrams of gallic acid equivalent (GAE). The methanol extracts contained a considerable amount of phenolic contents of 482±8.72 of GAE/g of extract and the total flavonoid content of the F. stricta leaf was estimated by using aluminium chloride colorimetric technique and found that the extract contained flavonoid content 340.625±4.50 of GAE/g of extract. These results suggested that the methanol extract of F. stricta Roxb. possess anti-oxidant activity. DOI: http://dx.doi.org/10.5281/zenodo.146976

Assessment of in-vivo anti-diabetic and anti-diarrheal effects of Flemingia stricta Roxb. leaf

The objective of this study was to evaluate the anti-diabetic and anti-diarrheal activity of methanol extract of Flemingia stricta Roxb. (Fabaceae) leaf. In anti-diabetic study, the extract was administered to alloxan-induce diabetic mice at two concentrations (200 mg/kg and 400 mg/kg body weight) for acute (12 hours) and prolong treatments (15 days) and blood glucose levels of diabetic mice were monitored at intervals of hours and days throughout the duration of treatment. Antidiarrheal test was conducted by castor oil induced diarrhea and enteropooling as well as intestinal motility in mice at three different concentration (100 mg/kg, 200 mg/kg and 400 mg/kg body weight). Treatment of alloxan induce diabetic mice with the extract caused a significant reduction in fasting blood glucose level of the diabetic mice both in acute (12 hours) and prolong treatment (15 days) and it was determined that the F. stricta methanol extract at both concentration (200 mg/kg and 400 mg/kg) showed the significant (P<0.05) hypoglycemic effect in comparison to the standard drug metformin. In the case of castor oil induced diarrheal test, enteropooling test and gastrointestinal motility test, the extract of F. stricta  at 100 mg/kg, 200 mg/kg and 400 mg/kg has given significant effect (P<0.05) compared to the standard drug loperamide. But 400 mg/kg demonstrated the highest activity amongst the three doses. These results suggested that the methanol extract of F. stricta Roxb. possess promising anti-diabetic effect on alloxan-induced mice and significant antidiarrheal effect on castor oil induced diarrheal mice. DOI: http://dx.doi.org/10.5281/zenodo.383974