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Erratum: Dallago et al. Keeping dairy cows for longer: A critical literature review on dairy cow longevity in high milk-producing countries. Animals 2021, 11, 808
No full textAsymptotic iteration method for solving Hahn difference equations
No full textHahn’s difference operator Dq;wf(x)=(f(qx + w) – f(x))/((q – 1)x + w), q ∈ (0, 1), w > 0,
x = w/(1 – q) is used to unify the recently established difference and q-asymptotic
iteration methods (DAIM, qAIM). The technique is applied to solve the second-order
linear Hahn difference equations. The necessary and sufficient conditions for
polynomial solutions are derived and examined for the (q;w)-hypergeometric
equation.Natural Sciences and Engineering Research Council of CanadaCanadian Network for Research and Innovation in Machining Technolog
Effect of environmental stress on reactive oxygen species metabolism and oxidative stress response in rainbow trout (Oncorhynchus mykiss)
No full textAquatic organisms are exposed to different environmental stressors including temperature variations, low dissolved oxygen and metals pollution that may cause physiological perturbation attributed to altered mitochondrial function and dysregulation of reactive oxygen species (ROS) metabolism. Therefore, it is important to understand how these stressors act and interact to disrupt ROS homeostasis leading to oxidative stress. The study investigated the effects of temperature, anoxia-reoxygenation and cadmium (Cd) on rainbow trout (O. mykiss) liver mitochondrial ROS (as hydrogen peroxide, H2O2) production and consumption under different bioenergetic states. The overall hypothesis was that temperature, anoxia-reoxygenation and Cd will stimulate ROS emission and that the combined effect of Cd and temperature or anoxia-reoxygenation will heighten the individual stressor effects. The first study investigated the effect of temperature and Cd on H2O2 emission and consumption in liver mitochondria and showed that temperature and Cd acted cooperatively to increase the rate of H2O2 emission. In addition, Cd imposed different H2O2 emission response patterns depending on the concentration and substrate. Cd evoked a graded H2O2 emission response that plateaued at 5 μM for mitochondria oxidizing glutamate-malate but a biphasic concentration-response with a spike in H2O2 emission at 1 μM Cd followed by a gradual diminution at higher Cd concentration during succinate oxidation. The biphasic H2O2 emission response observed in mitochondria oxidizing succinate was due primarily to site IIF while the saturable graded H2O2 emission in mitochondria oxidizing glutamate-malate was consistent with the effect of Cd on site IF. However, Cd and temperature did not affect the kinetics of mitochondrial H2O2 consumption irrespective of the bioenergetic state. The second study investigated the biotic and abiotic factors that affect mitochondrial H2O2 emission and showed that optimization of assay conditions is critical for quantitation of maximal H2O2 emission. Moreover, the study showed that NADPH oxidase 4 is a major source of H2O2 emission in unenergized mitochondria. The third study showed that anoxia-reoxygenation attenuated H2O2 emission while Cd evoked monotonic responses for glutamate-malate and palmitoylcarnitine-malate, but evoked a biphasic response for succinate oxidizing mitochondria. Anoxia-reoxygenation more severely inhibited mitochondrial respiration with palmitoylcarnitine-malate compared with succinate or glutamate-malate. The effect of anoxia-reoxygenation and Cd on site-specific H2O2 emission depended on substrate and site. Contrary to the expectation, anoxia-reoxygenation blunted the effect of Cd on mitochondria site-specific H2O2 emission. The fourth study investigated the effect of Cd and anoxia-reoxygenation on mitochondria H2O2 emission during glycerol 3-phosphate (G3P) oxidation and showed that Cd evoked a low concentration stimulatory-high concentration inhibitory pattern of H2O2 emission that was blunted by anoxia-reoxygenation. The study showed that mitochondrial glycerol phosphate dehydrogenase activity was very low and that state 2 and state 3 respiration during oxidation of G3P was also low. Overall, the research unveiled the mechanisms by which temperature, anoxia-reoxygenation and Cd disrupt mitochondrial ROS metabolism, and increased the understanding of how these stressors cause oxidative stress
Occurrence of extended-spectrum β-lactamase and AmpC-producing Escherichia coli in retail meat products from the Maritime Provinces, Canada
No full textThis study was conducted to determine the occurrence of antimicrobial resistance to the extended-spectrum cephalosporins (ESC) in Escherichia coli isolates. The isolates were collected from retail meat products collected in the Maritime Provinces of Canada. Our analyses involved the use of both selective and traditional culture methods; we also conducted genotype analyses using multiplex polymerase chain reactions. ESC-resistant (ESC-R) E. coli were detected in 33 of 559 samples (5.9%) using the traditional culture method, compared with 151 of 557 samples (27.1%) using the selective culture method. We recovered more isolates of ESC-R E. coli from poultry compared with beef and pork (P < 0.001). Multidrug resistance, extended-spectrum β-lactamase (ESBL), and AmpC phenotypes were more common in chicken-derived isolates than other retail meat products (P < 0.001). From the 98 isolates examined, 76 isolates (77.6%) were positive for either ESBL and AmpC β-lactamases or both. Among the 76 isolates, blaCMY-2 (78.9%), blaCTXM (46.1%), blaTEM (21.1%), and blaSHV (1.3%) genes were detected. Among the blaCTXM-producing isolates, blaCTXM-1, blaCTXM-2, and blaCTXM-9 phylogenetic groups were detected. β-lactamase genes were more commonly detected in chicken-derived isolates compared with other meat types (P < 0.01). This study demonstrates the occurrence of ESBL- and AmpC-resistance genes in retail meat products in the Maritime Provinces of Canada. We found that selective culture significantly improved the recovery of ESC-R E. coli isolates from retail meat samples
Exposure of American lobster (Homarus americanus) to the pesticide chlorpyrifos results in changes in gene expression
No full textChlorpyrifos is an organophosphate that is currently used to reduce arthropod pests for the protection of agricultural crops. Coastal marine ecosystems may be exposed to agricultural pesticides via runoff and pesticide exposure can impact the health and survival of non-target species such as the American lobster (Homarus americanus). In the current study, the gene expression changes of H. americanus stage IV larvae were evaluated to understand the physiological mechanisms affected by exposure to sublethal concentrations of chlorpyrifos. After 48 h chlorpyrifos exposure, surviving lobsters were processed for Illumina RNA sequencing (RNA-seq). Genes of interest that showed significant changes using RNA-seq were verified using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). Analysis of RNA-seq and the confirmation of gene expression patterns via RT-qPCR found altered expression in genes related to stress response (glutathione peroxidase 3 and heat shock protein 60), hypoxia response (hairy, astakine 2, hemocyanin), moulting (cytochrome P450 307a1 and chitinase), and immunity (astakine 2) pathways. Changes to gene expression were most notable in lobsters exposed to 0.57 μg/L chlorpyrifos
Analysis of the white sturgeon (Acipenser transmontanus) immune response during immunostimulation and Veronaea botryosa infection
No full textSystemic phaeohyphomycosis caused by Veronaea botryosa is regarded as an important emerging mycotic disease of sturgeon aquaculture. However, no vaccines or treatments are currently available. The effects of dietary β-glucan supplementation on resistance to V. botryosa infection was examined in controlled challenges by exposing immunostimulated and control fish to ~7.25 × 105 fungal spores/fish via intra-muscular injection. Six weeks post-challenge, cumulative mortality was determined and antibodies to acute phase-proteins (APP) were used to quantify the conserved APP peptides in the serum of challenged and control fish using Western blot. Transcript levels for all tested pro-inflammatory cytokines, APP, and regulatory cytokines in the spleen were similar amongst treatments at the end of the three-week feeding period. However, significantly higher survival occurred in fingerlings fed 0.3% β-glucans compared to non-immunostimulated fish groups (p < 0.05) six weeks post-challenge. A strong proinflammatory response was detected in exposed treatment groups, and greater survival at after 6 weeks was associated with higher transcript abundance of Il-17 in fish fed β-glucans. Findings support the important role of this cytokine in response to fungal infection.National Institute of Food and Agriculture (U.S.)Ocean Frontier Institut
The long-term impact of multisystemic therapy: An experiential study of the adolescent-young adult life transition
No full textThis qualitative study examines the possible long-term impact of multisystemic therapy (MST) as young people experience the transition from adolescence to young adulthood. MST is an intensive intervention aimed at reducing antisocial behavior among young people. Interviews were conducted with 32 young people aged 16 to 22 years at their 48-month follow-up as part of the Systemic Therapy for At-Risk Teens (START) evaluation trial in the United Kingdom. Sixteen participants had received MST while 16 received management as usual (MAU). Interviews addressed participants’ current life experiences and were analyzed with interpretative phenomenological analysis (IPA). The inductive qualitative analysis data were transformed into numerical data. Interview extracts were coded as either forward-looking and hopeful (“mature”) or static and frustrated (“stuck”). Among males, significantly more mature outcomes were found among participants who had received MST compared with MAU. No differences were seen between the female groups. A detailed qualitative commentary shows how the constructs, mature and stuck, are manifest across the four domains. The findings suggest that working with an MST therapist during adolescence helped young men cultivate more mature, forward-looking viewpoints and life activities 4 years later when transitioning into adulthood. Findings are discussed in relation to relevant theory and practical applications
A novel application of a data mining technique to study intersections in the social determinants of mental health among young Canadians
No full textObjectives
Adolescent mental health is an emergent clinical and public health priority in Canada. Gender-based differences in mental health are well established. The objective of this study was to evaluate a new data mining technique to identify social locations of young Canadians where differences in mental health between adolescent males and females were most pronounced.
Methods
We examined reports from 21,221 young Canadians aged 11–15 years (10,349 males, 10,872 females) who had responded to a 2018 national health and health behaviours survey. Using recursive partitioning for subgroup identification (SIDES), we identified social locations that were associated with the strongest differences between males and females for three reported mental health outcomes: positive psychosomatic health, symptoms of depression, and having a diagnosed mental illness.
Results
The SIDES algorithm identified both established and new intersections of social factors that were associated with gender-based differences in mental health experiences, most favouring males.
Discussion
This analysis represents a novel proof-of-concept to demonstrate the utility of a subgroup identification algorithm to reveal important differences in mental health experiences between adolescent males and females. The algorithm detected new social locations (i.e., where gender intersected with other characteristics) associated with poor mental health outcomes. These findings set the stage for further intersectional research, involving both quantitative and qualitative analyses, to explore how axes of discrimination may intersect to shape potential gender-based health inequalities that emerge during childhood
Metastatic myxoid nerve sheath tumor of the dorsal fin in a rainbow trout, Oncorhynchus mykiss (Walbaum)
No full textSynergistic effects of metallic Fe and other homogeneous/heterogeneous catalysts in hydrothermal liquefaction of woody biomass
No full textIn order to determine the synergistic effects of the mixed additives of Fe and other catalysts on the yields and characteristics of bio-oil products, hydrothermal liquefaction (HTL) of pinewood sawdust (PW) was performed at 300 °C for 30 min (biomass/water mass ratio = 1:10) in the presence of metallic iron (Fe), other homogeneous/heterogeneous catalysts (Na2CO3, NaOH, FeSO4, MgO, Ru/C, FeS), as well as mixed additives. The results indicated that the metallic Fe could increase the yield and promote the degree of hydrodeoxygenation of bio-oil products. Noticeable synergistic effects on improving the bio-oil yields were found in the presence of mixed additives of Fe and an alkali catalyst (Na2CO3/NaOH) or FeS. The maximum bio-oil yield and the most energy recovery from bio-oil (81%) were obtained with Fe + Na2CO3. In addition, the combination of Fe + Ru/C produced bio-oil with the highest carbon and hydrogen contents, the highest HHV (30.93 MJ/kg), as well as the lowest contents of oxygenated compounds and the largest amount of hydrocarbons. In summary, this work demonstrates the synergistic effects of the mixed additives of Fe and several catalysts (Na2CO3, FeS and Ru/C) in HTL of woody biomass, promoting both yields and quality of bio-oil products.National Natural Science Foundation of ChinaNatural Sciences and Engineering Research Council of Canada (NSERC