Access Management in Lightweight IoT: A Comprehensive review of ACE-OAuth framework

With the expansion of Internet of Things (IoT), the need for secure and scalable authentication and authorization mechanism for resource-constrained devices is becoming increasingly important. This thesis reviews the authentication and authorization mechanisms in resource-constrained Internet of Things (IoT) environments. The thesis focuses on the ACE-OAuth framework, which is a lightweight and scalable solution for access management in IoT. Traditional access management protocols are not well-suited for the resource-constrained environment of IoT devices. This makes the lightweight devices vulnerable to cyber-attacks and unauthorized access. This thesis explores the security mechanisms and standards, the protocol flow and comparison of ACE-OAuth profiles. It underlines their potential risks involved with the implementation. The thesis delves into the existing and emerging trends technologies of resource-constrained IoT and identifies limitations and potential threats in existing authentication and authorization methods. Furthermore, comparative analysis of ACE profiles demonstrated that the DTLS profile enables constrained servers to effectively handle client authentication and authorization. The OSCORE provides enhanced security and non-repudiation due to the Proof-of-Possession (PoP) mechanism, requiring client to prove the possession of cryptographic key to generate the access token. The key findings in this thesis, including security implications, strengths, and weaknesses for ACE OAuth profiles are covered in-depth. It shows that the ACE-OAuth framework’s strengths lie in its customization capabilities and scalability. This thesis demonstrates the practical applications and benefits of ACE-OAuth framework in diverse IoT deployments through implementation in smart home and factory use cases. Through these discussions, the research advances the application of authentication and authorization mechanisms and provides practical insights into overcoming the challenges in constrained IoT settings

Effects of 5��-Dihydrotestosterone (DHT) on Mouse Gut Microbiome– A Study of Sex Differences and Hormonal Effects on Gut Microbiome Composition

Type 1 Diabetes (T1D) is a polygenic and multifactorial disease, traditionally attributed to genetic susceptibility and diet. Over the past decade, novel studies have placed a higher significance on the role of gut microbiome in T1D pathogenesis. Furthermore, diabetic mouse models have shown higher incidence of T1D in females compared to males, attributed to the differences in gut microbial community structure. Interestingly, female mouse models elicit male-like protection from T1D when transplanted with the male gut microbiome. In a previous study, we observed that female Non-obese diabetic (NOD) mice implanted with slow release 5��-Dihydrotestosterone(DHT) for 90 days showed improved glucose tolerance when compared to untreated females. We hypothesized that DHT treatment alters female gut microbial profile to resemble a male-like gut microbiome that induces improved glucose tolerance, a determinant of T1D protection. We compared the gut microbiome composition of DHT-treated female mice with placebo-treated females and age-matched males to identify and characterize changes in the gut microbiome. Extracted bacterial DNA from intestinal samples were subjected to 16S rRNA sequencing. Sequence reads were analyzed using MicrobiomeAnalyst and Piphillin, two web-based programs for phylogenetic and functional analysis. We identified a significant increase in Bacteroides acidifaciens in DHT-treated females, which can potentially improve glucose tolerance and attenuate T1D. Additionally, we noticed strong similarity trends in the proportional composition of the most abundant taxa between DHT-treated females and age-matched males. Our study shows that DHT-treatment alters the female gut microbial profile to resemble a male-like microbiome and possibly induce improved glucose tolerance, a determinant of T1D protection

Digital soil mapping in the Bara district of Nepal using kriging tool in ArcGIS

Digital soil mapping has been widely used to develop statistical models of the relationships between environmental variables and soil attributes. This study aimed at determining and mapping the spatial distribution of the variability in soil chemical properties of the agricultural floodplain lands of the Bara district in Nepal. The study was carried out in 23 Village Development Committees with 12,516 ha total area, in the southern part of the Bara district. A total of 109 surface soil samples (0 to 15 cm depth) were collected and analyzed for pH, organic matter (OM), nitrogen (N), phosphorus (P, expressed as P2O5), potassium (K, expressed as K2O), zinc (Zn), and boron (B) status. Descriptive statistics showed that most of the measured soil chemical variables (other than pH and P2O5) were skewed and nonnormally distributed and logarithmic transformation was then applied. A geostatistical tool, kriging, was used in ArcGIS to interpolate measured values for those variables and several digital map layers were developed based on each soil chemical property. Geostatistical interpolation identified a moderate spatial variability for pH, OM, N, P2O5, and a weak spatial variability for K2O, Zn, and B, depending upon the use of amendments, fertilizing methods, and tillage, along with the inherent characteristics of each variable. Exponential (pH, OM, N, and Zn), Spherical (K2O and B), and Gaussian (P2O5) models were fitted to the semivariograms of the soil variables. These maps allow farmers to assess existing farm soils, thus allowing them to make easier and more efficient management decisions and maintain the sustainability of productivity

Sediment management for catchments with hydropower dams under uncertainty in future projections.

The sustainability of hydropower reservoirs in catchments undergoing rapid development in the Mekong River Basin depends on the projected level of sedimentation. Excess sedimentation of reservoirs can be mitigated by using appropriate sediment management, but uncertainties in sediment predictions need to be addressed to better inform the selection of sediment management options. It is necessary to understand the magnitude of uncertainty in future sediment in response to land use/ land cover (LULC) change, climate change and sediment model parameterization. It is also necessary to evaluate the implication of catchment and reservoir-level sediment management options and costs under uncertainty in sediment projections. Hence, this study aims to evaluate the uncertainty in sediment projections due to LULC, climate and model parameterization, and the implication of sediment management options and costs for catchments with hydropower dams. The following specific questions were investigated: a. How do future climate scenarios and model parameterization affect the uncertainty in flow and sediment projections? b. How do LULC change scenarios affect the uncertainty in flow and sediment projections? c. How do combined future climate scenarios, model parameterization and LULC change scenarios affect the uncertainty in flow and sediment projections? What is the major source of uncertainty in flow and sediment projections? d. What is the implication of sediment management options and associated cost under the greatest source of uncertainty in sediment projections? The Sekong, Sesan and Srepok (3S) sub-basin of the greater Mekong River Basin was used as a case study. The Soil and Water Assessment Tool (SWAT) was used to simulate flow and sediment. Uncertainty in future climate scenarios was addressed using three Global Climate Models (GCMs) and three Representative Concentration Pathways (RCPs). Model parameter uncertainty was analyzed by calibrating SWAT model using three different optimal objective functions. For evaluation of LULC change uncertainty, twelve LULC change scenarios were generated applying Land Change Modeler (LCM), and combining three LULC demands, two transition potential models and retaining or not protected areas. The catchment-level sediment management options of terracing, vegetative filter strips and no tillage were evaluated using SWAT. The reservoir-level sediment management option of flushing was assessed using the Sediment Simulation Screening Python Model (PySedSim). Costs of sediment management options were assessed via the economic value of loss in hydropower production and the avoided cost of dredging. The evaluation of uncertainty in flow and sediment projections associated with future climate scenarios and model parameterization suggests that the dominating source of uncertainty in flow and sediment can vary spatially and temporally for large basins. In short-term period projections (2030s), model parameterization dominates the uncertainty in flow and sediment, while in long-term projections (2060s) selection of climate scenarios dominate. Model parametrization uncertainty needs to be incorporate in climate change impact studies and efforts should be made to reduce the uncertainty due to model parametrization through a careful calibration and validation. The assessment of uncertainty in flow and sediment in response to LULC change alone suggest uncertainty is primarily driven by LULC demand, resulting in large variability of flow and sediment projections. The evaluation of uncertainty in flow and sediment in response to future climate scenarios, model parametrization and LULC change suggest that for a basin undergoing rapid LULC change uncertainty in future flow and sediment is dominated by the choice of LULC change scenarios. Hence, LULC change uncertainty should not be neglected in evaluation of climate change impact on basin hydrology. Uncertainty in future sediment loads in response to LULC change can result in high variability in loss of reservoir capacity and cost of sediment management. Terracing performed best among the catchment-level management options in reducing the magnitude and variability in loss of reservoir capacity, but it is the most expensive option to implement. Flushing, although effective in increasing the life span of reservoir, was found less cost effective compared to catchment-level management options. The research outcome suggests that the best catchment- management option for reservoir sustainability may not be the best in terms of cost. Further, catchment-level management options do not address the issue to sediment starvation downstream, hence integrated sediment management approaches (i.e, combining both catchment-level and reservoir-level) may be required to reduce the adverse effect on reservoir storage and permit sediment flux downstream of the reservoir

Effects of Dihydrotestosterone on Mouse Gut Microbiome – A Study of Sex Differences and Hormonal Effects on Gut Microbiome

Type 1 Diabetes (T1D) is a polygenic and multifactorial disease, traditionally attributed to genetic susceptibility and diet. Over the past decade, novel studies have placed a higher significance on the role of gut microbiome in T1D pathogenesis. Furthermore, diabetic mice models have shown higher incidence of T1D in females compared to males, attributed to the differences in gut microbial community structure. Interestingly, female mice models elicited male- like protection when transplanted with the male gut microbiome. In a previous study, we observed that female Non-obese diabetic (NOD) mice implanted with slow release 5-dihydrotestosterone (DHT) for 90 days showed improved glucose tolerance when compared to untreated females. We hypothesize that DHT treatment alters female gut microbial profile to resemble a male-like microbiome that induces improved glucose tolerance, a determinant of T1D protection. By comparing the gut microbiome composition of DHT treated female mice with untreated females and age matched males, we aim to identify the microbial changes and understand the relationship between gut microbiome and disease protection. Bacterial DNA was extracted from the gut microbiome and was sequenced. The sequence data will be used to identify organisms present, calculate microbial community diversity indices and identify predominant metabolic profiles in each sample. Our study will help to better understand the effects of androgens on gut microbiome composition and its protective effects against T1D

Code Injection in Web applications

Code injection is the most critical threat for the web applications. The security vulnerabilities have been growing on web applications. With the growth of the importance of web application, preventing the applications from unauthorized usage and maintaining data integrity have been challenging. Especially those applications which an interface with back-end database components like mainframes and product databases that contain sensitive data can be addressed as the attacker’s main target. The main objective of this thesis is to describe the types of code injection such as SQL injection, XML injection, XPath injection, LDAP injection and File Inclusion Injection. This thesis demonstrates the vulnerability of web applications by penetrating queries through user input. It also provides security measures to avoid such attacks. In this thesis testing was done using the WampServer and Xampp server on a localhost. A browser Adson tamper data was used. Vulnerable web applications are used to highlight the vulnerabilities. Web application were tested using different injection techniques. The result of the test proved that a successful injection can do serious damage to the database and the whole system

Prediction of saphenofemoral junction incompetence by measurement of great saphenous vein size at the level of femoral condyle

Introduction: Doppler ultrasonography (USG) is the primary modality for diagnosis of superficial venous reflux caused by incompetence of venous valves of the great saphenous vein (GSV) and usually associated with competence of saphenofemoral junction (SFJ). This study is done to know the cutoff value in size of GSV that safely predicts this junction incompetence. Methods: All varicose vein patients during the study period of January–December 2016 were included in the study. The cases underwent Doppler USG of GSV using Siemens Acuson P500 to identify GSV. The diameter of GSV was measured at the level of femoral condyle in standing position and these were compared with SFJ incompetence. Contralateral limbs which were apparently normal were taken as control limbs if there is no evidence of reflux in SFJ. Results: There were 147 patients with 16 cases (9.81%) where bilateral limb was involved making total cases as 163 limbs and controls as 131 limbs. The mean GSV diameter in disease group was 6.05 mm and in control group was 3.19 mm with P < 0.05. Receiver operating characteristic (ROC) curve of size of GSV at the level of knee and prediction of SFJ incompetence had the ideal curve depicting use of some cutoff value. The point with both best sensitivity and specificity lied on 4.95 mm with sensitivity of 82% and specificity of 83%. Conclusion: We recommend 5 mm as the cutoff value for diameter of GSV at the level of femoral condyle which successfully predicts SFJ incompetence

Vascular anomalies: Presentation and response to medical and surgical management, our experiences in the last 5 years

Aim: Vascular anomalies, lesions of abnormal vascular development pose a significant challenge in some of the cases for diagnosis and management. The International Society for the Study of Vascular Anomalies has classified this condition into two broad types as vasoproliferative or vascular neoplasms such as hemangioma and vascular malformation. We have analyzed all the cases with vascular anomalies that have presented in outpatient department (OPD) in the past 5 years. Materials and Methods: All patients presented to vascular OPD of Dhulikhel Hospital in the year 2013–2017, if patients are diagnosed with vascular anomalies, are included in the study. Details on age, sex, site of the lesion, and medical or operative management performed are analyzed. Results: Of the total 51 vascular anomalies cases, the mean age of the patient was 22.4 years (standard division. 8.4, range 6 months to 51 years). Female-to-male ratio was 2.4:1. Forty cases (70.48%) belonged to vascular malformation while 11 cases (21.56%) were of hemangioma. In case of vascular malformation, 18 cases were of venous malformation while 8 cases were of capillary malformation. There were a total of 14 arteriovenous malformations. The highest number of anomalies was noticed in the lower limb (39.22%) followed by the head (25.49%). Regarding treatment modality opted, in five cases, medical management with oral steroids and propranolol was advised. In 35 cases, surgical resection was done. Conclusion: Vascular anomalies are detected in fairly young patients with preponderance in the female. Treatment of vascular anomalies is complex and is based on stage, type, and location of each anomaly