IslandScholar
Not a member yet
16367 research outputs found
Sort by
Dairy producer satisfaction and knowledge transfer with the veterinary-administered risk assessment and management plan in a voluntary Johne's disease control program
No full textThe Atlantic Johne's Disease Initiative (AJDI) aims to control Mycobacterium avium ssp. paratuberculosis infection by using veterinary-administered risk assessments to identify high-risk management practices and prompt changes in management behavior. Objectives for this study were to measure producer satisfaction with the veterinary-administered risk assessment and management plan (RAMP) process in a voluntary Johne's disease (JD) control program, compare RAMP-specific satisfaction results based on herd JD status, and measure knowledge transfer from certified veterinarians to producers during the RAMP. A satisfaction questionnaire was adapted to the RAMP process in the AJDI to measure producer satisfaction. The questionnaire included 9 RAMP-specific producer satisfaction items, 1 global RAMP satisfaction item, and 16 questions to assess producer knowledge and knowledge translation about JD, bovine viral diarrhea (BVD), and bovine leukosis virus (BLV) during the RAMP (BVD and BLV used for comparison purposes). A total of 133 dairy producers in the AJDI (79.6% response rate) completed the questionnaire by telephone. The RAMP-specific satisfaction was high among the AJDI producers surveyed, and these results were not found to differ based on herd JD status. The lowest satisfaction scores and the highest number of “unable to assess” responses were for the item relating to cost. Factors that contributed to RAMP-specific producer satisfaction were not identified from the demographic and herd information available in this study. The knowledge scores indicated moderate knowledge about JD and fair knowledge about BVD and BLV. Evidence of knowledge translation from the RAMP was mixed in this study. Bovine viral diarrhea knowledge scores were not found to differ based on whether or not the certified veterinarian discussed BVD during the preceding RAMP, but BLV knowledge scores were higher among dairy producers that discussed BLV during the preceding RAMP. Strengths and gaps in producer knowledge about these 3 infectious diseases were identified. By using this producer questionnaire, interventions aimed at improving the content, delivery, and satisfaction of RAMP in JD control programs, such as the AJDI, can be developed.Dairy Farmers of Prince Edward Island, Nova Scotia, New Brunswick, and Newfoundland and LabradorAgriculture and Agri-Foo
Factors affecting liver mitochondrial hydrogen peroxide emission
No full textMitochondria are key cellular sources of reactive oxygen species (ROS) and contain at least 12 known sites on multiple enzymes that convert molecular oxygen to superoxide and hydrogen peroxide (H2O2). Quantitation of site-specific ROS emission is critical to understand the relative contribution of different sites and the pathophysiologic importance of mitochondrial ROS. However, factors that affect mitochondrial ROS emission are not well understood. We characterized and optimized conditions for maximal total and site-specific H2O2 emission during oxidation of standard substrates and probed the source of the high H2O2 emission in unenergized rainbow trout liver mitochondria. We found that mitochondrial H2O2 emission capacity depended on the substrate being oxidized, mitochondrial protein concentration, and composition of the ROS detection system. Contrary to our expectation, addition of exogenous superoxide dismutase reduced H2O2 emission. Titration of conventional mitochondrial electron transfer system (ETS) inhibitors over a range of conditions revealed that one size does not fit all; inhibitor concentrations evoking maximal responses varied with substrate and were moderated by the presence of other inhibitors. Moreover, the efficacy of suppressors of electron leak (S1QEL1.1 and S3QEL2) was low and depended on the substrate being oxidized. We found that H2O2 emission in unenergized rainbow trout liver mitochondria was suppressed by GKT136901 suggesting that it is associated with NADPH oxidase activity. We conclude that optimization of assay conditions is critical for quantitation of maximal H2O2 emission and would facilitate more valid comparisons of mitochondrial total and site-specific H2O2 emission capacities between studies, tissues, and species
Longitudinal assessment of behaviour and associated bio-markers following chronic consumption of β-Sitosterol β-D-Glucoside in rats: A putative model of Parkinson’s disease
No full textThe consumption of cycad (Cycas circinalis) seeds has been linked to the development of Amyotrophic Lateral Sclerosis-Parkinsonism Dementia Complex (ALS-PDC) in humans. ALS-PDC is a clinically variable disease presenting as a combination of symptoms typical of PD and/or ALS. Chronic consumption of β-sitosterol β-D-glucoside (BSSG), a component of the cycad seed, by rats (Rattus norvegicus) has been previously reported to initiate a progressive pathology that develops over several months and manifests as behavioural and histopathological changes that resemble characteristic features of Parkinson’s disease. As part of an independent multi-site validation study, we have tried to replicate and further characterize the BSSG model with a focus on motor function, and associated immunohistochemical markers. Beginning at 3 months of age, male CD® (Sprague Dawley) rats (N = 80) were dosed orally with either a flour pellet or a flour pellet containing BSSG (3 mg) daily (5×/week) for 16 weeks consistent with previous reports of the model. Following BSSG intoxication, separate cohorts of animals (n = 10/treatment) were exposed to a behavioural test battery at 16, 24, 32, or 40 weeks post-initial BSSG feeding. The test battery consisted of the open field test, cylinder test, and ultrasonic vocalization (USV) assessment. No changes in behaviour were observed at any time point. Following behavioural testing, animals were processed for immunohistochemical markers of substantia nigra integrity. Immunohistochemistry of brain tissue revealed no differences in the microglial marker, Iba1, or the dopaminergic integrity marker, tyrosine hydroxylase (TH), in the substantia nigra at any assessment point. The absence of any group differences in behaviour and immunhistochemistry indicates an inability to replicate previous reports. Further investigation into the sources of variability in the model is necessary prior to further utilization of the BSSG model in preclinical studies
The impact of insurance institutional investors on corporate value from selection and creation perspective
No full textThe majority of insurance investment funds are derived from policy liability debt funds. It differs from other institutional investors in a number of ways, including investment size, horizon, duration, risk, and so on. However, only a small portion of the extant literature focuses on in-depth and extensive analysis of Insurance Institutional Investors’ holdings (IIIs). This study analyses the impact of shareholding by insurance institutions on the value of Shanghai and Shenzhen A-share listed companies in China’s capital market. The paper offers three major contributions. First, we discovered that long-term equity-holding IIIs have both value selection and value creation functions. Second, the value creation function becomes more significant among long-term stock-holding IIIs with an increase in the period during which they retain the company’s shares; Third, fast-in and fast-out (FIFO) IIIs have a value-inhibiting effect on the held company and serve a value selection role, rather than a value creation function. This study provides more insight on the lack of academic interest in insurance institutions and serves as a foundation and reference for the design of regulatory policies for insurance institutions’ involvement in stock markets. It also gives empirical evidence for corporations to accurately analyze shareholding by insurance institutions. Furthermore, since this study concentrates on China’s capital market, it can serve as a benchmark for other nations, particularly, those designated as developing market economies
Fisheries dataset on moulting patterns and shell quality of American lobsters H. americanus in Atlantic Canada
No full textMonitoring the moulting phenology of American lobsters (Homarus americanus) is important for maintaining sustainable lobster stocks. Changes in lobster landings can affect reproduction and disease susceptibility. Data on lobster moult indicators and on life-history traits (sex, size) were collated from a twelve-year monitoring program (2004–2015) in six lobster fishing areas in Atlantic Canada. A total of 141,659 lobsters were sampled over 1,195 sampling events using a standardized protocol and commercial lobster fishing traps. The dataset contains pleopod stages, estimated hemolymph protein levels (°Brix values) and shell hardness as well as lobster sex and size. Evaluation of sex ratio dynamics is also possible but existing biases in sampling males and females needs to be noted. This dataset is valuable in terms of inferring spatio-temporal trends in the life history of lobsters, as well as in the analysis of their moult cycle, and hence more generally for fisheries science and marine ecology.Fisheries and Oceans CanadaProvince of Nova ScotiaFirst NationsFishermen & Scientists Research SocietyAtlantic Canada Opportunities Agenc
Design and engineering: A classification and commentary
No full textThere are myriad understandings of design that have evolved over time and vary by the industries and disciplines that practice it. In the engineering context, design is often described as a process or problem-solving ability. Through interviews with 12 experienced engineers, it was found that there are diverse understandings of the relationship between design and engineering. This qualitative study presented a classification of their perspectives through three emergent categories: the relationship between design and engineering, the proportion of design tasks within a job, and the level or stage of development where design occurs. A synthesis of the data revealed that engineers demonstrate an ownership of design within engineering and there are diverse understandings of how design occurs within engineering. The implications of these findings were discussed and recommendations were offered for engineering educators, researchers, and industry. Engineering educators can help prepare designers as catalysts to produce a more inclusive, holistic, and sustainably minded profession.National Science and Engineering Research Council of
Canad
Antioxidant responses induced by PFAS exposure in freshwater fish in the Veneto region
No full textIn recent decades, the interest in PFAS has grown exponentially around the world, due to the toxic effects induced by these chemical compounds in humans, as well as in other animals and plants. However, current knowledge related to the antistress responses that organisms can express when exposed to these substances is still insufficient and, therefore, requires further investigation. The present study focuses on antioxidant responses in Squalius cephalus and Padogobius bonelli, exposed to significant levels of PFAS in an area of the Veneto Region subjected to a recent relevant pollution case. These two ubiquitous freshwater species were sampled in three rivers characterised by different concentrations of PFAS. Several biomarkers of oxidative stress were evaluated, and the results suggest that PFAS chronic exposure induces some physiological responses in the target species, at both cellular and tissue scales. The risk of oxidative stress seems to be kept under control by the antioxidant system by means of gene activation at the mitochondrial level. Moreover, the histological analysis suggests an interesting protective mechanism against damage to the protein component based on lipid vacuolisation.European Union Horizon 2020 Research and Innovation Programm
Auxeticity in biosystems: an exemplification of its effects on the mechanobiology of heterogeneous living cells
No full textAuxeticity (negative Poisson’s ratio) is the unique mechanical property found in an extensive variety of materials, such as metals, graphene, composites, polymers, foams, fibers, ceramics, zeolites, silicates and biological tissues. The enhanced mechanical features of the auxetic materials have motivated scientists to design, engineer and manufacture man-made auxetic materials to fully leverage their capabilities in different fields of research applications, including aeronautics, medical, protective equipments, smart sensors, filter cleaning, and so on. Atomic force microscopy (AFM) indentation is one of the most widely used methods for characterizing the mechanical properties and response of the living cells. In this contribution, we highlight main consequences of auxeticity for biosystems and provide a representative example to quantify the effect of nucleus auxeticity on the force response of the embryonic stem cells. A parametric study has been conducted on a heterogeneous stem cell to evaluate the effect of nucleus diameter, nucleus elasticity, indenter’s shape and location on the force-indentation curve. The developed model has also been validated with the recently reported experimental studies available in the literature. Our results suggest that the nucleus auxeticity plays a profound role in cell mechanics especially for large size nucleus. We also report the mechanical stresses induced within the hyperelastic cell model under different loading conditions that would be quite useful in decoding the interrelations between mechanical stimuli and cellular behavior of auxetic biosystems. Finally, current and potential areas of applications of our findings for regenerative therapies, tissue engineering, 3 D/4D bioprinting, and the development of meta-biomaterials are discussed
Investigating the function of the Schwann cells in impaired diabetic wound healing
No full textType-2 Diabetes Mellitus (T2DM) is a multifactorial disorder that occurs due to insulin resistance at early stages and a lack of insulin at late stages, resulting in hyperglycemia. In this work, we related the two major chronic+ complications of T2DM: wound healing defects and diabetic peripheral neuropathy in the skin. Cutaneous nerves extend throughout the dermis and epidermis and control both the functional and reparative capacity of the skin. Nerve axons are reduced in the skin of a diabetic and further decrease in wounds. From previous work, our lab demonstrated as in proximity to the nerve axons, the associated Schwann cells located around the wound are important to undergo an extensive reprogramming process and migrate towards the wound bed releasing bioactive molecules, which contribute to wound closure. However, their role is still unknown in diabetic wound healing. The PURPOSE of this study was to evaluate the presence and contribution of Schwann cells in cutaneous wounds following an injury and observe the effectiveness of Oncostatin M to rescue diabetic wounds. METHODS: To investigate this, we have used the diabetic rodent model— genetically modified Db/Db diabetic mice (n=5) lacking leptin receptors. A 6mm punch biopsy wound is induced in the back skin and healing is tracked for 5, 10, 15 and 21 days. As days 10 and 15 showed the most significant changes, we performed the immunofluorescent analysis of S100B & P75NTR and neurofilaments will determine the numbers of Schwann cells and axons to examine the interventions. Immunohistochemistry was performed to understand the mechanism of Oncostatin-M, a pleiotropic, IL-6 family member that is released from Schwann cells (SCs) to rescue the diabetic wound as an experimental therapy. RESULTS: Following analysis 85.2±10% reduction in S100β positive and 80.1±10% reduction in p75NTR positive Schwann cell markers on day 10 as well as 72.3±11% S100β positive cells and 65.2±24% p75NTR positive cells still reduced at day 15 indicating a significant (p≤0.05) percentage reduction of Schwann cells number in the dermis
of diabetic skin wounds and healing is delayed while the control wounds returned to baseline by day 15 post-injury. The rescue treatment with Oncostatin-M contributed to the healing progression of the diabetic wound compared to vehicle treatment increased proliferation of epidermal cells to 61±35% and angiogenesis to 38.8±18.8% than vehicle-treated wound. CONCLUSION: The outcome of this study could pave the path for novel therapeutic intervention for diabetic wound healing and could be a potential clinical trial to explore the possibility of accelerating wound healing to rescue peripheral vascular disease and other chronic wound-induced limb amputation