Digital Commons Network^™

Mursamacin: A Novel Class Of Antibiotics From Soil-Dwelling Roundworms Of Central Kenya That Inhibits Methicillin-Resistant Staphylococcus Aureus, Ryan Musumba Awori, Peter Njenga Ng'ang'a, Lorine Nanjala Nyongesa, Nelson Onzere Amugune, Daniel Masiga

All Peer-Reviewed Publications

Antibiotic-resistant bacteria, also called " superbugs", can at worst retrogress modern medicine to an era where even sore throats resulted in death. A solution is the development of novel types of antibiotics from untapped natural sources. Yet, no new class of antibiotic has been developed in clinical medicine in the last 30 years. Here, bacteria from insect-killing Steinernema roundworms found in the soils of Central Kenya were isolated and subjected to specific molecular identification. These were then assayed for production of antibiotic compounds with potential to treat methicillin-resistant Staphylococcus aureus infections. The bacteria were identified as Xenorhabdus griffiniae and produced …

Cotesia Icipe Sp. N., A New Microgastrinae Wasp (Hymenoptera, Braconidae) Of Importance In The Biological Control Of Lepidopteran Pests In Africa, Komi K.M. Fiaboe, Jose Fernández-Triana, Faith W. Nyamu, Komi M. Agbodzavu

All Peer-Reviewed Publications

A new species of Microgastrinae, Cotesia icipe Fernández-Triana & Fiaboe, sp. n., is described from eastern Africa. It was reared in Kenya as a solitary parasitoid from two major amaranth pests, Spodoptera littoralis (Boisduval, 1833) and S. exigua (Hübner, 1808); study of specimens in collections also revealed its presence in four other countries in the Afrotropical region (Madagascar, Saudi Arabia, South Africa, and Yemen). Morphological, molecular and biological characters are used to describe the new species and to distinguish it from all 12 previously described species of Afrotropical Cotesia. Cotesia icipe shows potential in the biological control of key Lepidopteran …

Impact Of Push-Pull Technology On The Nutritional Status Of Farmers' Children In Western Kenya, Nicholas O. Ogot, J. O. Pittchar, C. A.O. Midega, Z. R. Khan

All Peer-Reviewed Publications

This study examined the impact of push-pull technology (PPT) on the nutritional status of children aged 1-12 years. Non-push-pull (NPPT) farmers were used as a control group to establish a comparative model for this study. It determined household production, consumption, and surpluses, comparing the PPT adopters to the nonadopters; found out the incomes and food expenditures from farm products; found out the household dietary diversity scores; and finally found the nutritional status of the two household groups. A six faceted household-level metrics was employed. A sample of 216 households that registered 326 children was derived. This study was conducted in …

Plant–Insect Interactions In A Changing World, S. Pincebourde, J. Van Baaren, S. Rasmann, P. Rasmont, G. Rodet, B. Martinet, P. A. Calatayud

All Peer-Reviewed Publications

Global change is resetting the spatial and ecological equilibrium of complex co-evolutionary relationships between plants and their insect herbivores. We review the mechanisms at play in the responses of plant–insect interactions to global changes, including increased temperature and atmospheric CO2 concentrations, modification of land use and pollution. We distinguish between the direct effects of global changes on each partner from the indirect impacts on insects via the responses of plants. The indirect effects include a change in the nutritional quality of the plant tissues for herbivore insects, as well as a change in the microclimatic conditions at the leaf surface. …

Impact Of Cross-Level Measurement Noninvariance On Hospital Rankings Based On Patient Experiences With Care In 7 European Countries, Benedict O. Orindi, Emmanuel Lesaffre, Walter Sermeus, Luk Bruyneel

All Peer-Reviewed Publications

Background: Hospital-level findings on patient experiences with care are increasingly reported publicly. A critical aspect left unexamined is the commonality of composite measures of patient experiences across different groups of patients, nursing units, hospitals, and countries. Absence of commonality is termed measurement noninvariance and is hypothesized to have a strong impact on performance assessment. Aim: The aim of this study is to examine measurement invariance across groups and levels under study (patients, nursing units, hospitals, and countries) and illustrate the degree to which this method of analysis impacts hospital rankings. Research Design: Data were collected from 11,289 patients in 7 …

Response To Climate Risks Among Smallholder Farmers In Malawi: A Multivariate Probit Assessment Of The Role Of Information, Household Demographics, And Farm Characteristics, Chalmers Mulwa, Paswel Marenya, Dil Bahadur Rahut, Menale Kassie

All Peer-Reviewed Publications

Why do many smallholder farmers fail to adopt what appear to be relatively simple agronomic or management practices which can help them cope with climate-induced stressors? Using household and plot level data collected in 2011, we implement a multivariate probit model to assess the determinants of farmer adaptation behavior to climatic risks and the relative contribution of information, credit and education on the probability of adopting specific practices in response to adverse changes in weather patterns. We find that plot characteristics, credit constraints and availability of climate-related information explain the adoption of several of these practices. In relative terms, we …

Randomised Controlled Trial Of Two Sequential Artemisinin-Based Combination Therapy Regimens To Treat Uncomplicated Falciparum Malaria In African Children: A Protocol To Investigate Safety, Efficacy And Adherence, Henk D.F.H. Schallig, Halidou Tinto, Patrick Sawa, Harparkash Kaur, Stephan Duparc, Deus S. Ishengoma, Pascal Magnussen, Michael Alifrangis, Colin J. Sutherland

All Peer-Reviewed Publications

Background Management of uncomplicated Plasmodium falciparum malaria relies on artemisininbased combination therapies (ACTs). These highly effective regimens have contributed to reductions in malaria morbidity and mortality. However, artemisinin resistance in Asia and changing parasite susceptibility to ACT in Africa have now been well documented. Strategies that retain current ACT as efficacious treatments are urgently needed. Methods We present an open-label, randomised three-arm clinical trial protocol in three African settings representative of varying malaria epidemiology to investigate whether prolonged ACTbased regimens using currently available formulations can eliminate potentially resistant parasites. The protocol investigates whether a sequential course of two licensed ACT …

Is Feedback To Medical Learners Associated With Characteristics Of Improved Patient Care?, Victoria Hayes, Robert Bing-You, Kalli Varaklis, Robert Trowbridge, Heather Kemp, Dina Mckelvy

MaineHealth Maine Medical Center

Our Research Question: "What is the association of medical learner feedback with characteristics of improved patient care?"

Structurofunctional Resting-State Networks Correlate With Motor Function In Chronic Stroke, Benjamin Kalinosky, Reivian B. Barillas, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Purpose

Motor function and recovery after stroke likely rely directly on the residual anatomical connections in the brain and its resting-state functional connectivity. Both structural and functional properties of cortical networks after stroke are revealed using multimodal magnetic resonance imaging(MRI). Specifically, functional connectivity MRI (fcMRI) can extract functional networks of the brain at rest, while structural connectivity can be estimated from white matter fiber orientations measured with high angular-resolutiondiffusion imaging (HARDI). A model that marries these two techniques may be the key to understanding functional recovery after stroke. In this study, a novel set of voxel-level measures …

Smartphone Based Optical Spectrometer For Diffusive Reflectance Spectroscopic Measurement Of Hemoglobin, Perry Edwards, Chenji Zhang, Baigang Zhang, Xiangqian Hong, Vivek K. Nagarajan, Bing Yu, Zhiwen Liu

Biomedical Engineering Faculty Research and Publications

We report a miniature, visible to near infrared G-Fresnel spectrometer that contains a complete spectrograph system, including the detection hardware and connects with a smartphone through a microUSB port for operational control. The smartphone spectrometer is able to achieve a resolution of ~5 nm in a wavelength range from 400 nm to 1000 nm. We further developed a diffuse reflectance spectroscopy system using the smartphone spectrometer and demonstrated the capability of hemoglobin measurement. Proof of concept studies of tissue phantoms yielded a mean error of 9.2% on hemoglobin concentration measurement, comparable to that obtained with a commercial benchtop spectrometer. The …

Virtual Faculty Learning Community Implementation Framework, Angela Atwell, Cristina Cottom, Lisa Martino, Sara Ombres

Publications

This framework is meant to be a useful guide for those interested in creating a V-FLC. You may skip around to the various sections or read the framework from start to finish. The framework consists of twelve questions to ask as you begin developing a V-FLC, answers to these questions based on our experience, as well as a visual representation of the framework.

Autarky Or Interdependence? U.S. Vs. European Security And Defense Industries In A Globalized Market, Diane Maye Zorri

Publications

Globalization theorists show how downward pressure to compete and/or

save costs in global markets will lead producers and consumers to source

goods and services in the cheapest and most efficient manner. However, in

certain sectors, such as the defense industry, security concerns and politics

can overshadow economic logic when it comes to making procurement

decisions. These political and security concerns keep the U.S. defense

industry from using the most cost-effective supply chains and

manufacturing centers, whereas in Europe, post-Cold War socioeconomic

and political realities allowed for more transnational cooperation on

defense procurement. Three cases serve to illustrate the spectrum between …

Volume 41, No. 3

The Weldon Times

A student-run newspaper published at the Schulich School of Law at Dalhousie University.

Editor in Chief: Marina Bruggeman

Digital Editor: Jessica Patrick

Editors: Theron Davis, Lisandra Naranjo Hernandez, Melissa Pike

Information Technology Approaches To Forest Management, Mary Snow, Richard Snow

Publications

The majority of the world’s forests occur where there is a dry season long enough to affect a seasonal change in the forest community. The seasonal forest may include evergreen, semi-deciduous, deciduous trees, or some combination of these. Local differences in soil or other site characteristics often determine which community persists. Since the seasonal forests exist where there is seasonal precipitation, the character of the forest is closely associated with the length of the rainy season. As the length of the rainy season decreases, the density of the canopy decreases. If the global climate system warms and prolonged drought gives …

Hubble Parameter Measurement Constraints On The Redshift Of The Deceleration-Acceleration Transition, Dynamical Dark Energy, And Space Curvature, Omer Farooq, Foram Ranjeet Madiyar, Sara Crandall, Bharat Ratra

Publications

We compile an updated list of 38 measurements of the Hubble parameter H(z) between redshifts 0.07 ≤ z ≤ 2.36 and use them to place constraints on model parameters of constant and time-varying dark energy cosmological models, both spatially flat and curved. We use five models to measure the redshift of the cosmological deceleration-acceleration transition, zda, from these H(z) data. Within the error bars, the measured zda are insensitive to the model used, depending only on the value assumed for the Hubble constant H0. The weighted mean of our measurements is zda = 0.72±0.05 (0.84±0.03) for H0 = 68 ± …

Multi-Scale Cardiovascular Flow Analysis By An Integrated Meshless-Lumped Parameter Model, Leonardo A. Bueno, Eduardo A. Divo, Alain J. Kassab

Publications

A computational tool that integrates a Radial basis function (RBF)-based Meshless solver with a Lumped Parameter model (LPM) is developed to analyze the multi-scale and multi-physics interaction between the cardiovascular flow hemodynamics, the cardiac function, and the peripheral circulation. The Meshless solver is based on localized RBF collocations at scattered data points which allows for automation of the model generation via CAD integration. The time-accurate incompressible flow hemodynamics are addressed via a pressure-velocity correction scheme where the ensuing Poisson equations are accurately and efficiently solved at each time step by a Dual-Reciprocity Boundary Element method (DRBEM) formulation that takes advantage …

Takecare, A Video To Promote Bystander Behavior On College Campuses: Replication And Extension, Ernest N. Jouriles, Kelli Sargent, Katie Lee Salis, Christina Caiozzo, David Rosenfield, Michele Cascardi, John H. Grych, K. Daniel O'Leary, Renee Mcdonald

Psychology Faculty Research and Publications

Previous research has demonstrated that college students who view TakeCARE, a video bystander program designed to encourage students to take action to prevent sexual and relationship violence (i.e., bystander behavior), display more bystander behavior relative to students who view a control video. The current study aimed to replicate and extend these findings by testing two different methods of administering TakeCARE and examining moderators of TakeCARE’s effects on bystander behavior. Students at four universities (n = 557) were randomly assigned to one of three conditions: (a) view TakeCARE in a monitored computer lab, (b) view TakeCARE at their own convenience …

The Role Of Internalized Homonegativity In The Faith And Psychological Health Of Lesbians, Dane R. Whicker, Ed De St. Aubin, Kimberly R. Skerven

Psychology Faculty Research and Publications

Among lesbians, faith-based beliefs and behaviors may be associated with negative psychological health due to the interplay between religious and sexual identities. The present study examined health outcomes, faith-based beliefs (views of God as loving and controlling), faith-based behaviors (personal spiritual practices, religious activities), and internalized homonegativity in a sample of 225 self-identified lesbians. We hypothesized that internalized homonegativity would moderate the relationship between health outcomes and faith-based beliefs and behaviors among lesbians. Generally, results indicated that some faith-based beliefs and behaviors were related to negative health outcomes among lesbians with higher levels of internalized homonegativity, but among those with …

Military Children’S Difficulty With Reintegration After Deployment: A Relational Turbulence Model Perspective, Leanne K. Knobloch, Lynne M. Knobloch-Fedders, Jeremy B. Yorgason, Aaron T. Ebata, Patricia C. Mcglaughlin

Psychology Faculty Research and Publications

This study drew on the relational turbulence model to investigate how the interpersonal dynamics of military couples predict parents’ reports of the reintegration difficulty of military children upon homecoming after deployment. Longitudinal data were collected from 118 military couples once per month for 3 consecutive months after reunion. Military couples reported on their depressive symptoms, characteristics of their romantic relationship, and the reintegration difficulty of their oldest child. Results of dyadic growth curve models indicated that the mean levels of parents’ depressive symptoms (H1), relationship uncertainty (H2), and interference from a partner (H3) were positively associated with parents’ reports of …

Incremental Clinical Utility Of Adhd Assessment Measures With Latino Families, Margaret Grace, Theresa Lauer Kapke, Al Castro, Alyson C. Gerdes

Psychology Faculty Research and Publications

Objective: This study examined the incremental clinical utility of parent and teacher reports of ADHD symptomatology and functional impairment in Latino youth, as well as parent and teacher agreement with the final clinical judgment on a diagnostic structured interview. Method: Participants included 70 Latino youth (47 males, 23 females; M age = 8.13 years, SD = 2.51 years) and their parents and teachers; 60 participants were diagnosed with ADHD. Correlations, percent agreement, kappas, and regressions were utilized. Results: Results demonstrated that teachers agreed with the final clinical judgment more often than did parents. Results additionally demonstrated that functional impairment did …

Stochastic Modelling For Levy Distributed Systems, Jonathan Blackledge, T Raja Rani

Articles

The purpose of this paper is to examine a range of results that can be derived from Einstein’s evolution equation focusing on (but not in an exclusive sense) the effect of introducing a L´evy distribution. In this context, we examine the derivation (as derived from the Einstein’s evolution equation) of the classical and fractional diffusion equations, the classical and generalised Kolmogorov-Feller equations, the evolution of self-affine stochastic fields through the fractional diffusion equation and the fractional Schr¨odinger equation, the fractional Poisson equation (for the time independent case), and, a derivation of the Lyapunov exponent. In this way, we provide a …

Information Hiding With Data Diffusion Using Convolutional Encoding For Super-Encryption, Jonathan Blackledge, Paul Tobin, J. Myeza, C.M. Adolfo

Articles

The unification of data encryption with information hiding methods continues to receive significant attention because of the importance of protecting encrypted information by making it covert. This is because one of the principal limitations in any cryptographic system is that encrypted data flags the potential importance of the data (i.e. the plaintext information that has been encrypted) possibly leading to the launch of an attack which may or may not be successful. Information hiding overcomes this limitation by making the data (which may be the plaintext or the encrypted plaintext) imperceptible, the security of the hidden information being compromised if …

Aphonic: Adaptive Thresholding For Noise Cancellation In Smart Mobile Environments, Ruairí De Fréin

Articles

We propose a signal-channel, adaptive threshold selection technique for binary mask construction, namely APHONIC, (AdaPtive tHreshOlding for NoIse Cancellation) for smart mobile environments. Using this mask, we introduce two noise cancellation techniques that perform robustly in the presence of real-world interfering signals that are typically encountered by mobile users: a violin busker, a subway and busy city square sounds. We demonstrate that when the power of the time-frequency components of the voice of a mobile user does not significantly overlap with the components of the interference signal, the threshold learning and noise cancellation techniques significantly improve the Signal-to-Interference Ratio (SIR) …

Probabilistics Risk Assessment Of Power Quality Variations And Events Under Temporal And Spatial Characteristic Of Increased Pv Integration In Low Voltage Distribution Networks, Shivananda Pukhrem, Malabika Basu, Michael Conlon

Articles

Integration of PVDG reduces the voltage unbalance as compared with no or low PVDG penetration. There is a higher probability of observing deep sag at the site as PVDG integration increases. This probabilistic approach can be used as a tool to assess the likely impacts due to PVDG integration against the worst-case scenarios.

Dye-Sensitised Solar Cell Antenna, Oisin O'Conchubhair, Patrick Mcevoy, Max Ammann

Articles

Dye-sensitised solar cells are proposed as a solarantenna in the form of a proof-of-concept dipole operating at 1.1 GHz. Comprised of glass plates in basic rectangular shapes, various material properties are considered for impact on antenna performance at three phases of assembly. Simulated and empirical analyses indicate how such low-cost solar cells can also realise viable concurrent antenna designs.

An Analysis Of Harmonic Heating In Smart Buildings And Distribution Network Implications With Increasing Non-Linear (Domestic) Load And Embedded Generation, Chittesh Veni Chandran, Keith Sunderland, Malabika Basu

Articles

Harmonic distortion is generally not taken into account within domestic installations and the associated wiring systems, as its potential is considered sufficiently small to be neglected. Standards to limit harmonic manifestations in the low voltage (LV) network are available, but these can be breached as a consequence of advancements in power electronics in some modern household devices contributing higher levels of harmonic distortion than permitted. While these devices individually might not be considered serious in terms of system level harmonic distortion manifestations, electrical equipment failures and insulation failures - increasingly being derived from harmonic cable heating - suggest a different …

Magnetic Field Sensing Using Whispering Gallery Modes In A Cylindrical Microresonator Infilitrated With Ferronematic Liquid Crystal, Aseel Mahmood, Vishnu Kavungal, Sudad S. Ahmed, Peter Kopcansky, Vlasta Zavisova, Gerald Farrell, Yuliya Semenova

Articles

An all-fiber magnetic field sensor based on whispering-gallery modes (WGM) in a fiber micro-resonator infiltrated with ferronematic liquid crystal is proposed and experimentally demonstrated. The cylindrical microresonator is formed by a 1 cm-long section of a photonic crystal fiber infiltrated with ferronematic materials. Both ferronematics suspensions are prepared based on the nematic liquid crystal 1-(trans-4-Hexylcyclohexyl)-4-isothiocyanatobenzene (6CHBT) doped with rod-like magnetic particles in the first case and with spherical magnetic particles in the second case. WGMs are excited in the fiber microresonator by evanescent light coupling using a tapered fiber with a micron-size diameter. The Q-factor of the microresonator determined from …

Adaptive Linear Prediction For Optimal Control Of Wind Turbines, Mahinsasa Narayana, Keith Sunderland, Ghanim Putrus, Michael Conlon

Articles

In order to obtain maximum power output of a Wind Energy Conversion System (WECS), the rotor speed needs to be optimised for a particular wind speed. However, due to inherent inertia, the rotor of a WECS cannot react instantaneously according to wind speed variations. As a consequence, the performance of the system and consequently the wind energy conversion capability of the rotor are negatively affected. This study considers the use of a time series Adaptive Linear Prediction (ALP) technique as a means to improve the performance and conversion efficiency of wind turbines. The ALP technique is introduced as a real …

Enhanced Network Voltage Management (Nvm) Techniques Under The Proliferation Of Rooftop Solar Pv Installation In Low Voltage Distribution Network (Lvdn), Shivananda Pukhrem, Malabika Basu, Michael Conlon, Keith Sunderland

Articles

Proliferation of rooftop solar PV distributed generator (PVDG) installation in low voltage distribution network (LVDN) imposes voltage fluctuation challenges that are a threat to distribution system operators. Reactive power control (RPC) methods are insufficient in isolation to combat the overvoltage fluctuations manifested in LVDN with significant grid-tied PVDG installations. Whereas active power curtailment (APC) control can alleviate the voltage fluctuation in such situations and it is achieved at the cost of reduced active power injection. This paper explores how deficiencies in both RPC and APC as separate approaches can be mitigated by suitably combining RPC and APC algorithms. Strategies combining …

Development Of Ferroelectricity In The Smectic Phases Of 4-Cyanoresorcinol Derived Achiral Bent-Core Liquid Crystals With Long Terminal Alkyl Chains, Sithara Pavithran Sreenilayam, J. K. Vij, Yuri Panarin, Anne Lehman

Articles

Bent-core molecules can form numerous polar and symmetry broken liquid crystalline phases with fascinating properties. Here we report the characteristics of a previously unknown polar synclinic smectic phase, Sm C S P X , found in the phase sequence of an achiral bent-core material with a 4-cyanoresorcinol bisbenzoate core, terminated by long linear alkyl chains ( n = 18 ) on both ends. This phase exists over a narrow range of temperatures and is sandwiched in between the random polar synclinic smectic phase ( Sm C S P R ) and polar synclinic ferroelectric ( Sm C S P F …