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Evaluation of environmental and comfort improvements on affective welfare in heifer calves on smallholder dairy farms
No full textA controlled trial on zero-grazed smallholder dairy farms was conducted to determine the effect of environmental and comfort improvements on sucking and lying behaviours in heifer calves on Kenyan smallholder dairy farms.
The study involved 187 heifer calves from 150 farms in two Kenyan counties, 75 farms per county. Farms in one county received animal welfare training and improvements in the calf pen that included: 1) placement of rubber mats on the lying area; 2) fixing gaps/holes in the flooring and roofing; and 3) attaching a rubber nipple on the wall of the calf pen. During the 16-month data collection period, bimonthly farm visits were used to collect data on lying time (using accelerometers) and other animal- and farm-level factors. Multilevel mixed-effects linear regression was used to model daily lying times and frequency of lying bouts, with the animal as a random effect.
Over the visits, daily lying times and lying bout durations averaged 12.6–86.7 min/bout, respectively, while the median for the frequency of lying bouts was between 30–46/day. Provision of rubber nipples for non-nutritive sucking lowered proportions of cross-sucking, self-sucking and object-sucking behaviours slightly but not significantly. In a final daily lying time model, superficial lymph node enlargement, body condition score and use of wood shaving/ sawdust/ crop waste as beddings had positive associations. In contrast, group housing and rubber mat use had negative associations with daily lying time. In an interaction term, lying time was significantly higher for calves on clean versus dirty floors if the age was <190 days but this difference diminished significantly in older animals. In a second interaction term, lying time was lower for calves with leaking versus non-leaking roofs, regardless of the pen floor level, but lying time was higher on elevated than non-elevated floors if the roof was intact. In the final model of the frequency of lying bouts, the use of a rubber mat, the years of experience in dairy farming, and calf body weight had negative associations. In contrast, body condition score had a positive association. In an interaction, the frequency of daily lying bouts was lower on clean floors than dirty floors, irrespective of tethering status, but when the floor was dirty, the lying bouts were higher for animals not tethered than the ones sometimes tethered. We conclude that the comfort improvements enhanced the welfare and lying experience of heifer calves on smallholder dairy farms
Piecewise convex deterministic dynamical systems and weakly convex random dynamical systems and their invariant measures
No full textAbsolutely continuous invariant measures of deterministic dynamical systems and random dynamical systems respectively are studied via a general spline maximum entropy optimization method. In the first part of this paper, we consider piecewise convex deterministic dynamical systems (maps) τ : [0, 1] → [0, 1] and we study their absolutely continuous invariant measures. We assume that the deterministic piecewise convex transformation τ has a unique absolutely continuous invariant measure (acim) μ∗ with density f ∗ . We present a general spline maximum entropy optimization method for the approximation of f ∗ . The proof of convergence of our general spline maximum entropy optimization method is presented. A numerical example is presented for the general spline (linear, quadratic and cubic respectively) maximum entropy numerical scheme for the approximation of f ∗ . In the second part of this paper, we generalize above results for weakly convex position dependent random map T = {τ1 (x), τ2 (x), . . . , τ K (x); p1 (x), p2 (x), . . . , p K (x)} on I = [0, 1], where τk : [0, 1] → [0, 1]), k = 1, 2, . . . , K is a piecewise convex map and { p1 (x), p2 (x), . . . , p K (x)} is a set of position dependent probabilities on [0, 1]. We assume that T has a unique acim ν ∗ with density h ∗ . We present a general spline maximum entropy optimization method for the approximation of h ∗ . The proof of convergence of our numerical schemes is presented. Also, we present a numerical example of the general spline maximum entropy method for the approximation of h ∗
Critical illness and rurality: Interfacility transfers to urban centres and the impact on rural families
No full textA relative’s critical illness is an intensely stressful time for family members. In the past, it was generally assumed that family members were relatively unaffected by a relative’s admission to an intensive care unit. However, there has been increasing understanding and concern in the healthcare community that family members experience negative, long-term psychological, emotional, physical and financial consequences from this experience. In addition to these noted negative consequences, it has been suggested that the unique context of rural family members of critically ill patients may result in additional burdens. In rural areas, a critically ill patient’s healthcare needs at times exceed the service capacity of the local hospital, thereby necessitating an interfacility transfer of the patient to a distant urban centre for advanced critical care services. To date, the rural family member’s experience of this phenomenon is poorly understood, specifically within the context of North America. The purpose of this study was to gain an increased understanding of the meaning of the lived experiences for rural family members whose relative undergoes an interfacility transfer to an urban tertiary centre for advanced critical care services. Munhall’s method of interpretive phenomenology was used to guide this study. Purposive sampling strategies resulted in the recruitment of 11 participants who experienced this phenomenon. Data analysis revealed the common themes of a longing for home, a sacrifice of self, and a persistent need to be close to the critically ill patient. Unique, context-specific meanings were also revealed by analyzing data through the lenses of the four life-worlds: corporeality, relationality, spatiality, and temporality. These meanings included a sense of vulnerability in the urban centre, a reluctance to communicate with urban healthcare providers, a loss of connection to both the critically ill relative and other family members, and a need to maintain responsibilities at home while in the urban centre. Through this study, nurses may better understand the multiple possible, context-specific meanings of this experience for rural family members thereby enhancing the individualized nursing care of these family members. Specifically, rural nurses may advocate for family members to be provided telephone contact details of the transport team or be permitted to accompany their relative during transfer to maintain a sense of closeness during transport. Urban nurses may appreciate the uniqueness of both rurality as culture and the loss of supports experienced by family members during this event and, thus, offer additional supports to rural family members. This improved understanding is specifically important for urban and rural critical care nurses who are in a key position to implement interventions to mitigate additive burdens experienced by rural family members
TSNet: Predicting transition state structures with tensor field networks and transfer learning
No full textTransition states are among the most important molecular structures in chemistry, critical to a variety of fields such as reaction kinetics, catalyst design, and the study of protein function. However, transition states are very unstable, typically only existing on the order of femtoseconds. The transient nature of these structures makes them incredibly difficult to study, thus chemists often turn to simulation. Unfortunately, computer simulation of transition states is also challenging, as they are first-order saddle points on highly dimensional mathematical surfaces. Locating these points is resource intensive and unreliable, resulting in methods which can take very long to converge. Machine learning, a relatively novel class of algorithm, has led to radical changes in several fields of computation, including computer vision and natural language processing due to its aptitude for highly accurate function approximation. While machine learning has been widely adopted throughout computational chemistry as a lightweight alternative to costly quantum mechanical calculations, little research has been pursued which utilizes machine learning for transition state structure optimization. In this paper TSNet is presented, a new end-to-end Siamese message-passing neural network based on tensor field networks shown to be capable of predicting transition state geometries. Also presented is a small dataset of SN2 reactions which includes transition state structures – the first of its kind built specifically for machine learning. Finally, transfer learning, a low data remedial technique, is explored to understand the viability of pretraining TSNet on widely available chemical data may provide better starting points during training, faster convergence, and lower loss values. Aspects of the new dataset and model shall be discussed in detail, along with motivations and general outlook on the future of machine learning-based transition state prediction.Natural Sciences and Engineering Research Council of CanadaCompute CanadaCanada Foundation for Innovatio
Asymptotic iteration method for the inverse power potentials
No full textThe asymptotic iteration method (AIM) is used to accurately calculate the eigenvalues of the Schrödinger equation with the potential ()=−−, ∈(0,1), in arbitrary dimensions. The recently studied case, =1/2, is discussed in detail where we give a reason for non-polynomial solutions. Using AIM sequences, we develop a method to compute the coefficients of the series solution in this case. AIM applications for =1/3,=1/4 and =2/3 are also discussed
A cannabis pricing mistake from California to Canada: Government can’t tax cannabis optimally
No full textWe apply a simple three good general equilibrium model to examine the optimality of a Pigouvian tax on a legal cannabis market which faces competition from a well-established illicit market. Despite the widespread support for Pigouvian taxes on cannabis, the availability of untaxed illicit cannabis with comparable costs and higher externalities renders taxation of legal cannabis suboptimal. Our results, derived from a relatively simple model, show that the welfare improving properties of a Pigouvian tax can be undermined by illicit market competition. Based on this simple analysis, we conclude that it is impossible for the pricing policies implemented in multiple jurisdictions (including California and Canada) to achieve the optimal, welfare maximizing outcome
Insights into creating and implementing Project SCORE!: Lessons learned and future pathways
No full textThis article offers insight about the creation and implementation of a self-directed online tool called Project SCORE (www.projectscore.ca) which aims to help coaches and parents foster positive youth development through sport. More specifically, in this paper we describe (a) how Project SCORE was created, (b) its evolution to enable better developmental outcomes across diverse socio-cultural contexts, (c) the lessons learned throughout the delivery of Project SCORE, and (d) future pathways for researchers, coaches, parents and other stakeholders interested in implementing Project SCORE
Infectivity of gastropod-shed third-stage larvae of Angiostrongylus vasorum and Crenosoma vulpis to dogs
No full textBackground
Metastrongyloid parasites Angiostrongylus vasorum and Crenosoma vulpis infect wild and domestic canids and are important pathogens in dogs. Recent studies indicate that gastropod intermediate hosts infected with various metastrongyloids spontaneously shed infective third-stage larvae (L3) into the environment via feces and mucus under laboratory conditions. Shed L3 retain motility up to 120 days, but whether they retain infectivity was unknown.
Methods
To assess the infectivity of shed L3, the heart/lungs of six red foxes (Vulpes vulpes) were obtained from trappers in Newfoundland, Canada. Lungs were examined for first-stage larvae (L1) by the Baermann technique. A high number of viable A. vasorum L1 and a low number of C. vulpis L1 were recovered from one fox; these were used to infect naïve laboratory-raised Limax maximus. L3 recovered from slugs by artificial digestion were fed to two naïve purpose-bred research beagles (100 L3/dog). L1 shed by these two dogs was used to infect 546 L. maximus (2000–10,000 L1/slug). L3 shedding was induced by anesthetizing slugs in soda water and transferring them into warm (45 °C) tap water for at least 8 h. Shed L3 recovered from slugs were aliquoted on romaine lettuce in six-well tissue culture plates (80–500 L3/well) and stored at 16 °C/75% relative humidity. Four naïve research beagles were then exposed to 100 L3/dog from larvae stored for 0, 2, 4, or 8 weeks, respectively, after shedding.
Results
All four dogs began shedding C. vulpis L1 by 26–36 days post-infection (PI). All four dogs began shedding A. vasorum L1 by 50 days PI.
Conclusions
L3 infectivity for the definitive host was retained in both metastrongyloids, indicating the potential for natural infection in dogs through exposure from environmental contamination. As an additional exposure route, eating or licking plant or other material(s) contaminated with metastrongyloid L3 could dramatically increase the number of dogs at risk of infection from these parasites.University of Prince Edward IslandElanco (United States
Knowledge, attitudes and influencers of pet-owners surrounding antimicrobials and antimicrobial stewardship in North America
No full textThe primary aim of this research project was to establish the current knowledge, attitudes and influencers (KAI) of North American pet-owners with respect to antimicrobial stewardship (AMS) and resistance (AMR). A secondary aim was to utilise a novel survey technique to identify what aspects of antimicrobial drug prescriptions petowners view as important for their animal. The project was divided into two parts, which are described in the two chapters below.
Chapter 2 explores the KAIs of North American dog-owners. Three populations were surveyed via an online questionnaire: dog-owners in the United States, dog-owners in Canada, and dog-owners recruited via educational social media (ESM). A novel study methodology (conjoint analysis) determined to what extent specific features (cost, method of administration, and importance in human medicine) influenced dog-owner decision-making when selecting between two antimicrobials. We determined that cost had the largest influence on a dog-owner’s choice between two (otherwise similar) antimicrobials, accounting for 47% of the decision-making preference. Method of administration accounted for 31%, and drug importance in human medicine had the smallest influence (22%). All groups preferred low-cost medications that were administered once by injection. Canadian and US participants were more likely to prefer drugs that were “very important” in human medicine whereas ESM participants preferred drugs that were “not important.”
In the descriptive (KAI) analyses, dog-owners were asked a series of closed-ended Likert questions. The majority (86%) of participants considered AMR to be important. In contrast, only 29% of dog-owners reported that antimicrobial use (AMU) in pets posed a risk to humans. This study determined that the dog-owners surveyed prioritise cost over all other features when their pets are prescribed an antimicrobial, despite considering AMR important.
Chapter 3 describes cat-owner understanding and priorities when their pet is prescribed an antimicrobial drug. Cat-owners were recruited and surveyed in the same manner as dog owners in chapter 2. Conjoint analysis was used to calculate what proportion each of the three features (cost, dosing frequency, and importance in human medicine) of a prescription influenced cat-owner preferences when choosing between antimicrobials for their cat. Method of administration (38%) and cost (37%) had a similar weight in owner decision-making. Drug importance in human medicine had the smallest impact on the decision-making process (25%). The most desirable drugs were low-cost, single injection medications that were “very important” in human medicine for the US and Canadian groups. Conjoint analysis for the ESM group was not available. Analysis of cat-owners’ KAIs revealed that 86% reported AMR to be important in human medicine. However, only 28% stated that AMU in pets may be a risk to humans. This study demonstrates that North American cat-owners are equally concerned by cost and ease of drug administration. Cat-owners appear to have low levels of understanding of AMR in pets and view it as lower priority when their animal is prescribed an antimicrobial medication.
Our work indicates knowledge of AMR in human and veterinary medicine is limited. Education and inclusion of pet-owners is likely to be an important component of future AMS efforts
Closed‐form approximated pricing of multivariate derivatives under switching regime models
No full textMarkov switching regime models have played an increasingly important role in finance and economics, especially for business cycles and long swings in currencies. Regime-switching models provide a simple way to capture stochastic volatility and thus overcomes the drawback of the classical lognormality assumption characterized by constant volatility. This paper considers multivariate Black and Scholes type models with a Markov regime-switching mechanism. We show that the pricing of some multivariate derivatives under models where the Markov chain has two or three states, can be approximated accurately in closed-form, based on linear and quadratic Taylor polynomials. Closed form approximation methods are computationally advantageous as they perform in constant time, compared with alternative methods such as Monte-Carlo, where the accuracy of the estimation is directly linked to the number of executed simulations