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Identité dans l'interstice: Une enquête narrative auprès d'élèves anglo-dominants d'héritage francophone qui fréquentent l'école de langue française à l'Île-du-Prince-Édouard
No full textSymposium review: Considerations for the future of dairy cattle housing: An animal welfare perspective
No full textMany contemporary dairy cattle housing practices are at odds with societal perceptions of positive animal welfare. The public (i.e., those external to the dairy industry) typically emphasizes the importance of naturalness for dairy cattle, such as through provision of pasture, freedom of movement, and the ability to interact socially with conspecifics. Yet, in the United States, the majority of lactating dairy cattle are reportedly housed without any access to pasture, and almost 39% of dairy farms use tiestalls, which restrict movement and social interactions. In addition to being in conflict with public expectations, a lack of pasture access and restrictive housing systems are also in conflict with the animals' own motivations, which can adversely affect their welfare. For example, dairy cattle are highly motivated to access pasture and show a reduction in oral stereotypies when allowed on pasture after periods of tethering. Calves housed without social contact have cognitive deficits and exhibit increased fear responses to novelty. We argue that the long-term sustainability of the dairy industry will depend on the extent to which housing systems reflect public concerns and the animals' priorities. The adoption of technologies, such as automated feeders and remote monitoring systems, may represent a means to practically promote the animals' natural behavior while simultaneously improving individualized care. Although older generations of the public may consider technological solutions to be a further deviation from naturalness and a departure from dairy farming's agrarian roots, the definition of “naturalness” for younger generations may well have expanded to include technology. As the buying power shifts to these younger generations, the adoption of technologies that promote natural cattle behaviors may be one means toward reconciling the disconnect between public perceptions of animal welfare and contemporary dairy farming practices
Modeling neuronal consequences of autism-associated gene regulatory variants with human induced pluripotent stem cells
No full textGenetic factors contribute to the development of autism spectrum disorder (ASD), and although non-protein-coding regions of the genome are being increasingly implicated in ASD, the functional consequences of these variants remain largely uncharacterized. Induced pluripotent stem cells (iPSCs) enable the production of personalized neurons that are genetically matched to people with ASD and can therefore be used to directly test the effects of genomic variation on neuronal gene expression, synapse function, and connectivity. The combined use of human pluripotent stem cells with genome editing to introduce or correct specific variants has proved to be a powerful approach for exploring the functional consequences of ASD-associated variants in protein-coding genes and, more recently, long non-coding RNAs (lncRNAs). Here, we review recent studies that implicate lncRNAs, other non-coding mutations, and regulatory variants in ASD susceptibility. We also discuss experimental design considerations for using iPSCs and genome editing to study the role of the non-protein-coding genome in ASD
Recruitment of international students in Canadian higher education: factors influencing students’ perceptions and experiences
No full textWorking with education agents is common for many Canadian higher education institutions (HEIs) to recruit international students due to the key role education agents play in bridging the international students with foreign HEIs. The purpose of this study was to explore international students' perceptions and experiences with education agents, thus collecting feedback from international students, revealing potential issues, and suggesting improvements in HEIs’ recruitment strategy. An online survey combined with a paper format survey was distributed to current or recent international students across Canada. Two scales were used to measure participants' perceptions and experiences with education agents. A total of 385 participants completed the survey. Findings revealed that nearly half of the participants used education agent services during their application to Canadian HEIs. However, their perceptions and experiences with education agents were not positive. Participants described practices of double-dipping by agents and the more participants paid agents, the less satisfied they tended to be. The outcome of this study highlights issues in the recruitment of international students, identifies strategies to regulate agents’ practices, and strategies to better support international students. These findings can be used by Canadian HEIs to improve their recruitment strategy and create a better working relationship with education agents to support the transition of international students to Canadian HEIs
Rearing and handling injuries in broiler chickens and risk factors for wing injuries during loading
No full textSome injuries to broilers occur during rearing, but most injuries occur during handling before slaughter. Records provided by a processing plant for loads transported over a 19-month period during 2009 and 2010 were examined. The median percentage of wing injuries per load was 5.7%; while injuries to the legs, breast or shoulders were all less than 1% per load. Risk factors for wing injuries were examined by considering the data from each load by handling event (i.e. loads originating from the same producer on the same date). A multilevel model with three levels: producer (n=86), handling event (n=1694) and load (n=4219) was fitted. The final model included: weight, sex, season, catching team, time of day at which loading began, speed of loading, and an interaction between speed of loading and time of day. Factors that reduced the risk of wing injuries were loading lighter birds, loads containing only cockerels and loading in the fall. The predicted percentage of wing injuries was relatively constant for slower loading speeds but was increased significantly when faster loading speeds were adopted during daytime (0700 to 1700 h). Identification of these risk factors can be used to adjust loading practices
Management factors associated with time-to-onset and fecal egg/oocyst counts of gastrointestinal parasites in heifer calves on Kenyan smallholder farms
No full textA prospective cohort study on zero-grazed smallholder dairy farms was conducted to determine factors associated with onset and counts of gastrointestinal parasitism in heifer calves. The researchers recruited 187 newborn heifer calves from 150 farms in Kenya. Over 16 months, farm visits every two months were used to collect rectal fecal samples and animal- and farm-level measures. Fecal samples underwent centrifugal fecal flotation with Sheather’s sugar to determine counts of strongyle-type eggs and coccidia oocysts. Cox proportional hazard (Cox PH) analysis and mixed-effects negative binomial (MeNB) regression determined factors associated with time-to-onset and counts of strongyle-type eggs and coccidia oocysts, respectively (P < 0.05). The incidence rate of strongyles was 0.0011 cases/animal-day while coccidia was 0.0073 cases /animal-day. Incidence risks of strongyles and coccidia over the study period were 28.3 % (53/187) and 87.7 % (164/187), respectively. For infected calves, median time-to-onset for strongyles and coccidia was 78 (interquartile-range: IQR 38–117) and 43 (IQR 29–92) days, respectively. In the final Cox PH model for strongyles, breed (Ayrshires and Jerseys) and weaned calves had a greater hazard of infection than Friesians and preweaned calves, respectively. Calf tethering outside the pen was associated with a higher hazard of strongyle infection. In the final Cox PH model for coccidia, calves with watery and/or hemorrhagic diarrhea had a higher hazard compared with those with hard or soft feces. Weaning status and birth weight (kg) were time-varying covariates, leading to increased hazard over time. In the final MeNB model for strongyles, weaned animals had higher counts than those still on milk. In an interaction variable, the predicted strongyle-type egg counts increased with longer duration of farm operation when herd size was less than five cattle, but decreased when herd size was more than five. In the final MeNB model for coccidia, calves sometimes tethered outside their pens had higher counts than those continuously enclosed in the pen. Calf pen floors with either scant manure or moderate slurry had higher predicted counts than those on a clean pen floor. Calves with watery or hemorrhagic diarrhea and fed fresh Napier grass (Pennisetum purpureum) had higher counts compared with soft or hard feces and those not given fresh Napier, respectively. In an interaction variable, calves experiencing diarrhea and raised on elevated slatted floors had lower oocyst counts compared with those having diarrhea but not on elevated floors. The identified management practices associated with onset and counts of gastrointestinal parasitism should be considered in control efforts
Synaptic dysfunction in human neurons with autism-associated deletions in PTCHD1-AS
No full textBackground
The Xp22.11 locus that encompasses PTCHD1, DDX53, and the long noncoding RNA PTCHD1-AS is frequently disrupted in male subjects with autism spectrum disorder (ASD), but the functional consequences of these genetic risk factors for ASD are unknown.
Methods
To evaluate the functional consequences of PTCHD1 locus deletions, we generated induced pluripotent stem cells (iPSCs) from unaffected control subjects and 3 subjects with ASD with microdeletions affecting PTCHD1-AS/PTCHD1, PTCHD1-AS/DDX53, or PTCHD1-AS alone. Function of iPSC-derived cortical neurons was assessed using molecular approaches and electrophysiology. We also compiled novel and known genetic variants of the PTCHD1 locus to explore the roles of PTCHD1 and PTCHD1-AS in genetic risk for ASD and other neurodevelopmental disorders. Finally, genome editing was used to explore the functional consequences of deleting a single conserved exon of PTCHD1-AS.
Results
iPSC-derived neurons from subjects with ASD exhibited reduced miniature excitatory postsynaptic current frequency and N-methyl-D-aspartate receptor hypofunction. We found that 35 ASD-associated deletions mapping to the PTCHD1 locus disrupted exons of PTCHD1-AS. We also found a novel ASD-associated deletion of PTCHD1-AS exon 3 and showed that exon 3 loss altered PTCHD1-AS splicing without affecting expression of the neighboring PTCHD1 coding gene. Finally, targeted disruption of PTCHD1-AS exon 3 recapitulated diminished miniature excitatory postsynaptic current frequency, supporting a role for the long noncoding RNA in the etiology of ASD.
Conclusions
Our genetic findings provide strong evidence that PTCHD1-AS deletions are risk factors for ASD, and human iPSC-derived neurons implicate these deletions in the neurophysiology of excitatory synapses and in ASD-associated synaptic impairment
Strategies for culturally responsive assessment adopted by educators in Inuit Nunangat
No full textThe education systems of Inuit Nunangat (the four regions of the Canadian Arctic that are the traditional homes of Inuit) have undergone significant change and continue to experience transitions in terms of purpose, curriculum, administration, and control. A key part of this transition is ensuring that the assessment of student learning is culturally responsive. Hence, the purpose of this study was to explore Inuit educators’ culturally responsive assessment practices. Five case studies were conducted in four regions of Inuit Nunangat (Nunatsiavut, Nunavik, Nunavut, and Inuvialuit) which resulted in a sample of 180 participants. In-depth interviews and focus groups were held with teachers, students, administrators, and Elders. Data were synthesized and resulted in themes related to the challenges and achievements in developing assessment practices that were grounded in Inuit culture, values, and worldview. We conclude recommending that more support and attention are needed to focus on developing culturally responsive assessment tools and understanding the impact of such tools on student success and engagement
Identification, tissue characterization, and innate immune role of Angiogenin-4 expression in young broiler chickens
No full textIntestinal epithelial cells are major producers of antimicrobial proteins, which play an important role in innate immunity. In addition to defensins, the Ribonuclease A superfamily includes important antimicrobial proteins involved in host-defense mechanisms in vertebrates. Angiogenin-4 (Ang4), a member of this RNase superfamily, has been demonstrated to be secreted by Paneth cells in mice. We have successfully cloned and characterized a new chicken gene (chAng4), found for the first time in a nonmammalian species, from intestinal epithelial and lymphoid cells. Characterization of chAng4 revealed 99% nucleotide and 97% amino acid sequence homology to mouse Ang4. Similar functional regions were identified, suggesting a role in innate immunity and regulation of gut microbiota. Furthermore, the mRNA expression pattern of chAng4 was studied in broilers in the presence or absence of beneficial bacteria (probiotics) and organic acids. The results showed that one-day-old chickens expressed low levels of Ang4 in almost all the evaluated tissues (crop, proventriculus, duodenum, jejunum, ileum, and cecal tonsils), except in the bursa of Fabricius that presented the highest expression level. The addition of probiotics and organic acids for either 7 or 14 consecutive days demonstrated a direct effect of probiotics and organic acids on chAng4 expression; moreover, broilers receiving probiotics and organic acids for only 7 D showed higher levels of chAng4 expression compared with those treated for 14 D. Broilers without treatment had a constant high level of expression in cecal tonsils and bursa. In conclusion, we were able to identify and characterize a new antimicrobial gene in chickens (chAng4) throughout the gastrointestinal tract. chAng4 mRNA gene expression was associated with the presence of naturally occurring and supplemented (probiotic) bacteria. The encoded protein might have a potential bactericidal effect against intestinal nonpathogenic and pathogenic microbes, modulating the intestinal microbiota and the innate immunity, and thereby may help minimize the use of antibiotics in poultry feed.AlltechCanadian Poultry Research CouncilNatural Sciences and Engineering Research Council of Canad
Real-time valuation of large variable annuity portfolios: A geen mesh approach
No full textThe valuation of large variable annuity (VA) portfolios is an important problem of interest, not only because of its practical relevance but also because of its theoretical significance. This is prompted by the phenomenon that many existing sophisticated algorithms are typically efficient at valuing a single VA policy but they are not scalable to valuing large VA portfolios consisting of hundreds of thousands of policies. As a result, this sparks a new research direction exploiting machine learning methods (such as data clustering, nearest neighbor kriging, neural network) on providing more efficient algorithms to estimate the market values and sensitivities of large VA portfolios. The idea underlying these approximation methods is to first determine a set of VA policies that is “representative” of the entire large VA portfolio. Then the values from these representative VA policies are used to estimate the respective values of the entire large VA portfolio. A substantial reduction in computation time is possible because we only need to value the representative set of VA policies, which typically is a much smaller subset of the entire large VA portfolio. Ideally the large VA portfolio valuation method should adequately address issues such as (1) the complexity of the proposed algorithm; (2) the cost of finding representative VA policies; (3) the cost of the initial training set, if any; (4) the cost of estimating the entire large VA portfolio from the representative VA policies; (5) the computer memory constraint; and (6) the portability to other large VA portfolio valuation. Most of the existing large VA portfolio valuation methods do not necessary reflect all of these issues, particularly the property of portability, which ensures that we only need to incur the start-up time once and the same representative VA policies can be recycled to valuing other large portfolios of VA policies. Motivated by their limitations and by exploiting the greater uniformity of the randomized low discrepancy sequence and the Taylor expansion, we show that our proposed method, a green mesh method, addresses all of the above issues. The numerical experiment further highlights its simplicity, efficiency, portability, and, more important, its real-time valuation application