Economic Sustainability and Multiple Risk Management Strategies: Examining Interlinked Decisions of Small American Farms

Economic viability of small farms and farming businesses depends on multiple factors. These farms have limited production and financial resources to maintain their operation. Therefore, to sustain farming, adopting appropriate risk management strategies is a pivotal decision for small farmers. We surveyed Tennessee’s small farms and utilized multivariate probit models to study factors influencing the adoption of various risk management strategies. Our findings suggest that the decisions related to the adoption of risk management strategies are significantly interlinked. Along with factors representing the operator’s age, education, and farm operator’s income and land holdings, we also found that the government incentives (payments), smartphones, and farmers’ continuation plan significantly influence the strategic decisions of adopting risk management strategies

Structural Performance Evaluation of Interlocking Concrete Pavement Crosswalk Designs

Interlocking Concrete Pavements (ICP) have been successfully used in many pavement applications all across the world. ICP design and analysis methods, construction practices and materials specifications have been developed. However, there is very limited field data to quantify structural performance with respect to traffic and environmental loadings. The interaction between traffic loadings and environmental factors needs to be explored in order to improve relationships between pavement performance and response. Pavement performance prediction in terms of fatigue cracking and surface rutting are essential for any mechanistically-based pavement design method. The estimation of the expected fatigue performance in the field is based on the quantification of the maximum tensile strain in bound base layers and the expected rutting performance is based on maximum vertical stress/strain in granular layers. This thesis presents an innovative research project involving the design, construction, instrumentation, performance modeling and distress evaluation of seven ICP crosswalks with four different design assemblies. The research projects were constructed at the Centre for Pavement and Transportation Technology (CPATT) test track and at the University of Waterloo ring road. Each of the test sections is instrumented with structural and environmental sensors of sensors to monitor the pavement performance under heavy truck traffic, typical municipal loadings and to quantify environmental effects. A database is generated and the measured stress, strain, temperature and moisture measurements are analysed to evaluate the expected long-term performance of the structural components of ICP crosswalk designs

Effect of different levels of nitrogen on growth and yield of hybrid maize (Zea mays L.) varieties

Nitrogen (N) fertilizer is considered as one of the most important factors affecting growth and grain yield of hybrid maize. This study was conducted to determine the effects of different rates of nitrogen and varieties on growth and yield of hybrid maize in Lamahi Municipality, Dang, Nepal from June to October, 2019. Three levels of hybrid maize varieties (10V10, Rajkumar F1 and NMH-731) and four levels of nitrogen (160, 180, 200 and 220 kg N ha-1) were evaluated using two factorial randomized complete block design with three replications. The results showed that grain yield and yield attributing traits of hybrid maize varieties increased with the increasing level of nitrogen from 160 to 220 kg ha-1. The application of nitrogen @ 220 kg N ha-1 produced the highest grain yield (10.07 t ha-1), cob length (16.33 cm), no of rows per cob (14.97), no of grains per row (33.37), cob diameter (4.54), thousand grain weight (276.77 g), stover yield (12.91 t ha-1), biological yield (23.00 t ha-1), harvest index (43.80), gross return (NRs. 208940 ha-1), net return (NRs.104488 ha-1) and B:C ratio (2.001). The hybrid maize variety 10V10 produced the highest grain yield (9.35 t ha-1), net returns (NRs. 91740.66 ha-1) and B:C ratio (1.91) accompanied by the highest cob length (16.25 cm), and as number of grains per row (32.35) as compared to other varieties. This study suggested that maize production can be maximized by cultivating hybrid maize variety 10V10 with the use of 220 kg N ha-1 in inner Terai region of Nepal

From impact to control: inertially amplified friction bearings

The conventional friction bearings have limitations in controlling the structures’ vibration. To overcome their limitations and upgrade their seismic performances, the inertial amplifiers and inerters are applied to the core material of the conventional friction bearings. Accordingly, this paper introduces two kinds of upgraded friction bearings: inertial amplifier friction bearings and inerter-based friction bearings. These upgraded friction bearings are installed at the base of the single and multi-story buildings with an adjacent retaining wall. The impact between the building and the retaining wall is considered. Following Newton’s second law, the governing equations of motion for the isolated structures, including the impact, are derived. The impact is formulated by the signum function to derive analytical optimal closed-form solutions for the design parameters of these upgraded base isolators. H2 and H∞ optimization methods are applied to derive the exact closed-form expression for the optimal design parameters. To employ the H2 optimization method, the statistical linearization method is applied to linearize each nonlinear element of the governing equations of motion. Parametric studies show that optimum frequency and damping ratios decrease with increasing isolator mass ratio, increase with increasing inertial angle, and decrease with increasing isolator mass ratio. Transfer function development is the first step in obtaining dynamic reactions of isolated structures. Furthermore, Newmark-beta method is employed to validate the results of the frequency domain analysis and obtained dynamic response histories for the isolated single-degree-of-freedom systems. According to the results, the dynamic response reduction capacities of the inerter-based friction bearing and inertial amplifier friction bearing are significantly 97.16% and 96.62% superior to the conventional base isolators. All results are mathematically derived and accurate; hence, applicable to practical implementations

Impact response of functionally graded conical shells

This paper presents low velocity impact response of functionally graded pretwisted conical shells. The modified Hertzian contact law which accounts for permanent indentation is utilized to compute the contact force and other impact parameter. The time dependent equations are solved by Newmark's time integration scheme. An eight noded isoparametric quadratic element is employed in the present finite element formulation. A parametric study is carried out to investigate the effects of triggering parameters like initial velocity of impactor, twist angle, oblique impact angle, location of impact for Stainless Steel-Nickel functionally graded conical shell subjected to low velocity impact

Rifamycin Resistance in Clostridium difficile Is Generally Associated with a Low Fitness Burden

We characterized clinically occurring and novel mutations in the β subunit of RNA polymerase in Clostridium difficile (CdRpoB), conferring rifamycin (including rifaximin) resistance. The Arg(505)Lys substitution did not impose an in vitro fitness cost, which may be one reason for its dominance among rifamycin-resistant clinical isolates. These observations were supported through the structural modeling of CdRpoB. In general, most mutations lacked in vitro fitness costs, suggesting that rifamycin resistance may in some cases persist in the clinic

Evaluation of Phytochemical, Antioxidant and Antibacterial Activities of Selected Medicinal Plants

Medicinal plants are important reservoirs of bioactive compounds that need to be explored systematically. Because of their chemical diversity, natural products provide limitless possibilities for new drug discovery. This study aimed to investigate the biochemical properties of crude extracts from fifteen Nepalese medicinal plants. The total phenolic contents (TPC), total flavonoid contents (TFC), and antioxidant activity were evaluated through a colorimetric approach while the antibacterial activities were studied through the measurement of the zone of inhibition (ZoI) by agar well diffusion method along with minimum inhibitory concentrations (MIC) by broth dilution method. The methanolic extracts of Acacia catechu and Eupoterium adenophorum showed the highest TPC (55.21 ± 11.09 mg GAE/gm) and TFC (10.23 ± 1.07 mg QE/gm) among the studied plant extracts. Acacia catechu showed effective antioxidant properties with an IC50 value of 1.3 μg/mL, followed by extracts of Myrica esculenta, Syzygium cumini, and Mangifera indica. Morus australis exhibited antibacterial activity against Klebsiella pneumoniae (ZoI: 25mm, MIC: 0.012 mg/mL), Staphylococcus aureus ATCC 25923 (ZoI: 22 mm, MIC: 0.012 mg/mL), Pseudomonas aeruginosa (ZoI; 20 mm, MIC: 0.05 mg/mL), and methicillin-resistant Staphylococcus aureus (MRSA) (ZoI: 19 mm, MIC: 0.19 mg/mL). Morus australis extract showed a broad-spectrum antibacterial activity, followed by Eclipta prostrata, and Hypericum cordifolium. Future study is recommended to explore secondary metabolites of those medicinal plants to uncover further clinical efficacy

A Global Collaboration to Develop and Pilot Test a Mobile Application to Improve Cancer Pain Management in Nepal

INTRODUCTION: Quality palliative care, which prioritizes comfort and symptom control, can reduce global suffering from non-communicable diseases, such as cancer. To address this need, the Nepalese Association of Palliative Care (NAPCare) created pain management guidelines (PMG) to support healthcare providers in assessing and treating serious pain. The NAPCare PMG are grounded in World Health Organization best practices but adapted for the cultural and resource context of Nepal. Wider adoption of the NAPCare PMG has been limited due to distribution of the guidelines as paper booklets. METHODS: Building on a long-standing partnership between clinicians and researchers in the US and Nepal, the NAPCare PMG mobile application (“app”) was collaboratively designed. Healthcare providers in Nepal were recruited to pilot test the app using patient case studies. Then, participants completed a Qualtrics survey to evaluate the app which included the System Usability Scale (SUS) and selected items from the Mobile App Rating Scale (MARS). Descriptive and summary statistics were calculated and compared across institutions and roles. Regression analyses to explore relationships (α = 0.05) between selected demographic variables and SUS and MARS scores were also conducted. RESULTS: Ninety eight healthcare providers (n = 98) pilot tested the NAPCare PMG app. Overall, across institutions and roles, the app received an SUS score of 76.0 (a score > 68 is considered above average) and a MARS score of 4.10 (on a scale of 1 = poor, 5 = excellent). 89.8% (n = 88) “agreed” or “strongly agreed” that the app will help them better manage cancer pain. Age, years of experience, and training in palliative care were significant in predicting SUS scores (p-values, 0.0124, 0.0371, and 0.0189, respectively); institution was significant in predicting MARS scores (p = 0.0030). CONCLUSION: The NAPCare PMG mobile app was well-received, and participants rated it highly on both the SUS and MARS. Regression analyses suggest end-user variables important to consider in designing and evaluating mobile apps in lower resourced settings. Our app design and pilot testing process illustrate the benefits of cross global collaborations to build research capacity and generate knowledge within the local context