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Development of management zones for site-specific fertilization in potato fields
No full textSoil variability and the resultant lower potato tuber yield can be mitigated through precision agricultural practices. This study has quantified variability of soil and crop properties, identified significant factors responsible for fluctuations in tuber yield, and delineated management zones (MZs) for site-specific soil fertility characterization of potato fields through proximal sensing of fields. The field experiments were conducted during potato growing seasons of 2017 and 2018 in the region of Souris alongside the La Pierre Lane in Prince Edward Island (PEI), Canada. Grids of 25 m x 25 m were established, and soil was sampled from each grid and analyzed for soil chemical properties. Time Domain Reflectometry (TDR), DualEM-2 sensor, and GreenSeekerTM were used to collect each grid’s moisture content (θ), horizontal coplanar geometry (HCP) of the apparent ground electrical conductivity, and normalized difference vegetation index (NDVI), respectively, at various plant growth stages during the cropping seasons. The soil samples were collected from the same grids to determine soil organic matter content (SOM), pH, Lime Index (LI), phosphorous (P), potassium (K), calcium (Ca), iron (Fe), cation exchange capacity (CEC) and %P/Al (P aluminum ratio) using standard methods. Potato tuber yield was collected manually from 0.91 x 3 m strips at the same grids. Results suggested that most of the parameters had moderate to high variability in both fields. Tuber yield was high in both fields due to high HCP, θ and SOM. Results from semivariograms revealed that the selected soil and crop properties showed a low, moderate, and high spatial dependence within the fields. Tuber yield had highly significant (p < 0.001) correlations with HCP, θ, SOM, and P during first sampling in the beginning of the growing season. However, during the second sampling, the tuber yield was significantly correlated with HCP, θ, NDVI, SOM, P, and K. Stepwise regression (through backward elimination at α = 0.01) excluded the low important variables, namely P and K, leaving HCP, θ, SOM, and NDVI as the most influential variables for tuber yield. Stepwise regression shortlisted the major properties of soil and crop that explained 71 to 86% of within-field variability. The cluster analysis grouped the soil and crop data into three zones, termed as excellent, medium, and poor, at a 40% similarity level. The coefficient of variation and the interpolated maps characterized least to moderate variability of soil fertility parameters except for HCP and K, which were highly variable. The results of multiple means comparison indicated that the tuber yield and HCP were significantly different in all MZs. The significant relationship of HCP and yield suggested that the ground conductivity data can be used to develop MZs for site‐specific fertilization in potato fields like those used in this study. The soil and crop variability data helped establishing MZs that can facilitate site-specific precision nutrient management for improving soil fertility and optimizing potato tuber yield. Moreover, this study suggested that managing the crop inputs based on HCP, θ and NDVI has significant potential to enhance tuber yield. The delineation of MZs has been suggested as a solution to mitigate adverse impacts of soil variability on potato tuber yield
Relationships among factors related to childbirth and breastfeeding outcomes in primiparous women
No full textObjectives
To explore the relationships among potentially modifiable factors related to childbirth and effective breastfeeding initiation at approximately 36 hours after birth and duration and exclusivity at hospital discharge, 2 weeks, 2 months, and 6 months after birth in primiparous women and to explore whether modifiable and nonmodifiable secondary factors and covariates influenced the relationships among factors related to childbirth and these breastfeeding outcomes.
Design
A prospective, longitudinal, cohort study.
Setting
The postpartum units of two general hospitals in eastern Canada.
Participants
Ninety-seven mother–infant dyads.
Methods
We recorded demographic, childbirth, obstetric history, and breastfeeding data through chart review. A breastfeeding observation was completed at approximately 36 hours after birth by unit nurses. Participants maintained breastfeeding logs in hospital and for 6 months after birth and completed three self-report questionnaires before discharge. We analyzed outcomes using backward stepwise linear and logistic regression.
Results
One childbirth factor, labor induced with oxytocin, was negatively associated with effective initiation of breastfeeding, and none was related to breastfeeding duration and exclusivity at any time point. Maternal weight; professional support; and newborn’s gestational age at birth, 5-minute Apgar score, weight loss, LATCH score, and active feeds (newborn actively suckled at the breast) were significantly associated with breastfeeding outcomes.
Conclusion
Induction of labor with oxytocin should be used judiciously; when used, nurses must be hypervigilant to assess the mother–infant dyad for breastfeeding issues and to intervene to prevent or remediate them
Parent experiences caring for a child with bronchiolitis: A qualitative study
No full textBackground:
Bronchiolitis is an acute lower respiratory infection, with significant impacts on children and families and strains on the health care system. Understanding parents’ experiences and information needs caring for a child with bronchiolitis is crucial to highlight misconceptions or issues contributing to the high burden. The objective of this qualitative study was to describe parents’ experiences caring for a child with bronchiolitis.
Methods:
Qualitative description guided this study. Participants were recruited from the Stollery Children’s Hospital emergency department (ED), a specialized pediatric ED in a major Canadian urban center. Semi-structured interviews were conducted with 15 parents.
Results:
Five major themes were identified: (a) their children’s symptoms and behaviors, (b) bronchiolitis affects the entire family, (c) factors influencing parent’s decision to go to ED, (d) ED experience for parents and their children, and (e) bronchiolitis treatment and management. Interviews revealed bronchiolitis has significant effects on both children and families and parents are generally unaware of bronchiolitis symptoms, treatment, and management.
Conclusions:
Our study highlights that parents have knowledge deficits when it comes to recognizing the presence and severity of bronchiolitis symptoms. Parents would benefit from having more evidence-based resources to enhance their knowledge about the nature of bronchiolitis.Knowledge Translation in Child HealthStollery Children’s Hospital FoundationKnowledge Synthesis and TranslationNetworks of Centres of Excellence (Knowledge Mobilization Initiative)Women and Children’s Health Research Institut
Highly biocompatible porous NiTi alloys
No full textNickel Titanium alloys have proved to be a perfect choice for materials used for medical devices like catheters, pacemakers and stone removal mesh. However, there are some challenges related to the shape and size modifications required to suffice the applications. The alloy needs improvements particularly in the areas of porosity for bone replacement, radiopacity, super elasticity and fatigue strength. There is a wide range of applications of biocompatible Porous NiTi alloys in the areas of inter body fusion devices, synthetic bone grafting, etc. Although it cannot be denied of the possibility of high corrosion factor of Porous NiTi alloys as compared to solid NiTinol due to greater surface area in contact with the body fluids. Such cases include definite surface preparation to cater to the need for increased biocompatibility. This paper includes the synthesis of porous NiTi alloys through the sintering process along with a check of the surface treatments and its effects on the properties related to corrosion of Porous NiTinol. The Alloys were subjected to different treatments like dry heating, boiling in water and passivation. The corrosion resistance, after and before the treatments were evaluated
PAFit : An R Package for the Non-Parametric Estimation of Preferential Attachment and Node Fitness in Temporal Complex Networks
No full textMany real-world systems are profitably described as complex networks that grow over time. Preferential attachment and node fitness are two simple growth mechanisms that not only explain certain structural properties commonly observed in real-world systems, but are also tied to a number of applications in modeling and inference. While there are statistical packages for estimating various parametric forms of the preferential attachment function, there is no such package implementing non-parametric estimation procedures. The non-parametric approach to the estimation of the preferential attachment function allows for comparatively finer-grained investigations of the "rich-get-richer" phenomenon that could lead to novel insights in the search to explain certain nonstandard structural properties observed in real-world networks. This paper introduces the R package PAFit, which implements non-parametric procedures for estimating the preferential attachment function and node fitnesses in a growing network, as well as a number of functions for generating complex networks from these two mechanisms. The main computational part of the package is implemented in C++ with OpenMP to ensure scalability to large-scale networks. In this paper, we first introduce the main functionalities of PAFit through simulated examples, and then use the package to analyze a collaboration network between scientists in the field of complex networks. The results indicate the joint presence of "richget-richer" and "fit-get-richer" phenomena in the collaboration network. The estimated attachment function is observed to be near-linear, which we interpret as meaning that the chance an author gets a new collaborator is proportional to their current number of collaborators. Furthermore, the estimated author fitnesses reveal a host of familiar faces from the complex networks community among the field's topmost fittest network scientists
An overview of photocatalyst immobilization methods for air pollution remediation
No full textAs the global population increases, the environmental burden from industrial and transportation related pollution will continue to rise. Photocatalysis has been presented as a promising method of removing several environmental pollutants from the atmosphere. Within the literature, there are a wide variety of approaches that have been adopted to immobilize or secure the photocatalyst onto support material. A critical review of each of the major methods of photocatalyst immobilization, as well as their application to air pollution remediation, is presented. Immobilization methods can include sol-gel, solvent deposition, electrophoresis, thermal spraying, and chemical and physical vapour deposition. Literature presented on these methods provides a wide range of photocatalytic efficiencies for the removal of NOx and VOCs in the gas phase. This is due, in part, to the wide range of methodologies that have been employed to evaluate the performance of the developed materials and coatings. Of the literature included herein only six studies followed the ISO 22197 procedure and all evaluated the removal of NOx in air. Through this review it was determined that the sol-gel technique was relatively well researched compared to other immobilization techniques and that it had the highest normalized removal rate for NOx at 16.7 mg m−2 min. Thermal spraying (TS), on average, was found to have the highest VOC removal at 107 mg m−2 min. Most of the studies that evaluated the removal of VOCs used a batch style reactor which may not reflect real world conditions
Corncob-derived activated carbon for roxarsone removal from aqueous solution: isotherms, kinetics, and mechanism
No full textIn this study, the adsorption of roxarsone (ROX) onto corncob-derived activated carbon (AC) was optimized using response surface methodology (RSM). Following this, the AC was comprehensively characterized by FT-IR, SEM, and EDS analysis. The results showed that the highest ROX adsorption efficiency of 304.34 mg/g was obtained at the contact time of 262 min, initial pH of 2.5, adsorbent dosage of 0.4 g/L, and initial concentration of 240 mg/L. Besides, it was found that the adsorption equilibrium data was fitted well to the Langmuir and Sips isotherm models. The thermodynamic parameters (e.g., ΔG, ΔH, and ΔS) revealed the spontaneous and exothermic nature of ROX adsorption. As indicated by pseudo second-order kinetics model, the adsorption of ROX onto AC could be achieved through the hydrogen bond, π-π adsorbate–adsorbent interaction, and electrostatic interaction between AC surface functional group and molecular species variations of ROX at different pH values. Overall, it can be concluded that corncob-derived AC is an alternative option for removing ROX from aqueous solution.Science and Technology Department of Henan ProvinceProcessing and Efficient Utilization of Biomass Resources of Henan Center for Outstanding Overseas Scientist
Hydrothermal liquefaction of biomass to fuels and value-added chemicals: Products applications and challenges to develop large-scale operations
No full textLignocellulosic biomass is a promising alternative to petroleum oil for producing energy and chemicals, owing to its abundance and sustainability. In the past decades, extensive research has applied a wide range of thermo-chemical technologies for converting biomass into value-added products. Among them, hydrothermal liquefaction (HTL) is regarded to be one of the most effective techniques to produce bio-fuels and bio-based chemicals. However, there are still several technical barriers that must be addressed before the industrialization of HTL technology. Although many previous reviews have summarized the reaction mechanism, properties of liquefaction products, and various operating parameters, few articles have discussed the potential applications of HTL products and the techno-economic problems facing by the industrialization of HTL. Therefore, in this review, the possible applications of HTL products (bio-crude, aqueous phase, solid residue, and gas) were thoroughly discussed. In addition, the current challenges of HTL treatment, especially for the continuous operation, to produce bio-based fuel and chemicals is reviewed. Finally, the possible future directions and the main conclusions are covered.Natural Sciences and Engineering Research Council of CanadaAgriculture and Agri-Food Canada through BioMass Canada (BMC)-BioFuelNet cluster programAgri-Science ClusterNational Key Research and Development Program of ChinaNatural Scientific Foundation of Chin
Recent advances in hydroliquefaction of biomass for bio-oil production using in Situ hydrogen donors
No full textWith the rapid growth of energy demand and environmental concerns associated with traditional fossil fuels, renewable and sustainable energy sources have attracted intensive research attention in recent years. Biomass is considered as one of the most promising alternative energy resources due to its many advantages including abundance, renewability, carbon neutrality, and worldwide distribution. Liquefaction is an efficient thermochemical conversion route for the production of bioderived fuels and chemicals under mild reaction conditions. In addition, this process does not require energy-intensive drying as a preprocessing step of the wet biomass feedstocks. Nevertheless, subsequent hydrogenation and upgrading treatment of the bio-oil with high oxygen content are imperative for practical applications mainly for improving the calorific value of the bio-oil. The cost and safety issues of external hydrogen are main obstacles for the liquefaction-upgrading route, which can be somewhat offset by the use of in situ hydrogen. The research on in situ hydrogen generation and use for biomass liquefaction is nascent. Therefore, the latest research developments on hydroliquefaction of biomass feedstocks in the presence of various in situ hydrogen donors are reviewed in this article. Several commonly applied in situ hydrogen donors including formic acid, alcohols (isopropyl alcohol, methanol and ethanol), and zerovalent metals (zinc, aluminum, iron, etc.) are discussed in detail focusing mainly on their influence on the distribution of liquefied products and the mechanisms of hydrogen-donation/hydrogenation reactions. Moreover, future research directions toward the commercial applications of biomass liquefaction technology with in situ hydrogenation strategies are presented
The dynamics of molecular evolution of emerging avian reoviruses through accumulation of point mutations and genetic re-assortment
No full textIn the last decade, the emergence of variant strains of avian reovirus (ARV) has caused enormous economic impact in the poultry industry across Canada and USA. ARVs are non-enveloped viruses with ten segments of double-stranded RNA genome. So far, only six genotyping cluster groups are identified worldwide based on sequence analysis of the σC protein encoded by the S1 segment. In this study, we performed deep next generation whole-genome sequencing and analysis of twelve purified ARVs isolated from Saskatchewan, Canada. The viruses represent different genotyping cluster. A genome-wide sequence divergence of up to 25 per cent was observed between the virus isolates with a comparable and contrasting evolutionary history. The proportion of synonymous single-nucleotide variations (sSNVs) was higher than the non-synonymous (ns) SNVs across all the genomic segments. Genomic segment S1 was the most variable as compared with the other genes followed by segment M2. Evidence of positive episodic/diversifying selection was observed at different codon positions in the σC protein sequence, which is the genetic marker for the classification of ARV genotypes. In addition, the N-terminus of σC protein had a persuasive diversifying selection, which was not detected in other genomic segments. We identified only four ARV genotypes based on the most variable σC gene sequence. However, a different pattern of phylogenetic clustering was observed with concatenated whole-genome sequences. Together with the accumulation of point mutations, multiple re-assortment events appeared as mechanisms of ARV evolution. For the first time, we determined the mean rate of molecular evolution of ARVs, which was computed as 2.3 × 10−3 substitution/site/year. In addition, widespread geographic intermixing of ARVs was observed between Canada and USA, and between different countries of the world. In conclusion, the study provides a comprehensive analysis of the complete genome of different genotyping clusters of ARVs including their molecular rate of evolution and spatial distribution. The new findings in this study can be utilized for the development of effective vaccines and other control strategies against ARV-induced arthritis/tenosynovitis in the poultry industry worldwide.Natural Sciences and Engineering Research Council of Canada (NSERC)Saskatchewan Agriculture Development FundChicken Farmers of Saskatchewan/Saskatchewan Chicken Industry Development FundAgriculture and Agri-Food Canada (AAFC) Growing Forward 2 Agri-Innovation Progra