Management of sows and their piglets around the periparturient period: observing the effects on survival and performance of the litter

The periparturient period, defined as the period immediately before and after birth, is a challenging event for both sow and piglets. With piglet preweaning mortality being a significant issue in the pork industry, the aim of this thesis was to see whether a particular management strategy could be implemented to improve the survival or performance of the litter. The overarching hypothesis for this body of work was that manipulations during the key period would result in more robust piglets better able to survive to weaning. Chapter 1 identified that the periparturient phase is a period where sow and litter performance are intrinsically linked, so assistance to sow farrowing and/or lactation performances would be beneficial to piglets. This led to studies conducted with dexamethasone, and whether this potent anti-inflammatory steroid could relieve sows of discomfort and assist in farrowing and early lactation performance. Administering dexamethasone to sows on the day before farrowing reduced piglet birthweights (P 0.05), and improvements were seen to the daily weight gain of piglets to weaning (P = 0.01; Chapter 2). When investigated further, the administration of dexamethasone on the day of farrowing did not influence the number of pain related behaviours, posture changes or time spent in lateral recumbency for primiparous and parity one sows (P > 0.05). Considering dexamethasone is a glucocorticoid, we also investigated whether this maternal treatment was influencing fetal maturity, specifically gut macromolecule permeability in low birthweight piglets (Chapter 4). The maternal treatment with dexamethasone did not affect the rate of gut permeation pre-closure (P > 0.05), opening up further queries as to how dexamethasone was able to improve daily weight gain of piglets in Chapter 2. A theme running through the conducted studies was that having control over the farrowing process may be critical to effectiveness of a tested management technique or treatment. Maternal dexamethasone may improve piglet performance, but the chances of unfavorable side effects with improper timing makes these advantages difficult to realise To have greater control over the timing of farrowing onset, a drug delivery system was formulated to trigger induction of parturition in sows (Chapter 5). The deposition of the novel drug delivery system into the vagina successfully resulted in farrowing onset with similar efficacy as sows induced via localized injection (current practice). The non-injection formulation of this novel inducing agent for sows has the potential to provide farmers with better control of the farrowing process, test management strategies for improving performance and ensure piglets at-risk are properly managed, in addition to moving away from injectable medications.Thesis (Ph.D.) -- University of Adelaide, School of Animal and Veterinary Sciences, 202

Ability of fabric face mask materials to filter ultrafine particles at coughing velocity.

OBJECTIVE:We examined the ability of fabrics which might be used to create home-made face masks to filter out ultrafine (0.02-0.1 µm) particles at the velocity of adult human coughing. METHODS:Twenty commonly available fabrics and materials were evaluated for their ability to reduce air concentrations of ultrafine particles at coughing face velocities. Further assessment was made on the filtration ability of selected fabrics while damp and of fabric combinations which might be used to construct home-made masks. RESULTS:Single fabric layers blocked a range of ultrafine particles. When fabrics were layered, a higher percentage of ultrafine particles were filtered. The average filtration efficiency of single layer fabrics and of layered combination was found to be 35% and 45%, respectively. Non-woven fusible interfacing, when combined with other fabrics, could add up to 11% additional filtration efficiency. However, fabric and fabric combinations were more difficult to breathe through than N95 masks. CONCLUSIONS:The current coronavirus pandemic has left many communities without access to N95 face masks. Our findings suggest that face masks made from layered common fabric can help filter ultrafine particles and provide some protection for the wearer when commercial face masks are unavailable

Comparing the fit of N95, KN95, surgical, and cloth face masks and assessing the accuracy of fit checking.

INTRODUCTION: The COVID-19 pandemic has made well-fitting face masks a critical piece of protective equipment for healthcare workers and civilians. While the importance of wearing face masks has been acknowledged, there remains a lack of understanding about the role of good fit in rendering protective equipment useful. In addition, supply chain constraints have caused some organizations to abandon traditional quantitative or/and qualitative fit testing, and instead, have implemented subjective fit checking. Our study seeks to quantitatively evaluate the level of fit offered by various types of masks, and most importantly, assess the accuracy of implementing fit checks by comparing fit check results to quantitative fit testing results. METHODS: Seven participants first evaluated N95 and KN95 respirators by performing a fit check. Participants then underwent quantitative fit testing wearing five N95 respirators, a KN95 respirator, a surgical mask, and fabric masks. RESULTS: N95 respirators offered higher degrees of protection than the other categories of masks tested; however, it should be noted that most N95 respirators failed to fit the participants adequately. Fit check responses had poor correlation with quantitative fit factor scores. KN95, surgical, and fabric masks achieved low fit factor scores, with little protective difference recorded between respiratory protection options. In addition, small facial differences were observed to have a significant impact on quantitative fit. CONCLUSION: Fit is critical to the level of protection offered by respirators. For an N95 respirator to provide the promised protection, it must fit the participant. Performing a fit check via NHS self-assessment guidelines was an unreliable way of determining fit

Comparing the fit of N95, KN95, surgical, and cloth face masks and assessing the accuracy of fit checking.

INTRODUCTION: The COVID-19 pandemic has made well-fitting face masks a critical piece of protective equipment for healthcare workers and civilians. While the importance of wearing face masks has been acknowledged, there remains a lack of understanding about the role of good fit in rendering protective equipment useful. In addition, supply chain constraints have caused some organizations to abandon traditional quantitative or/and qualitative fit testing, and instead, have implemented subjective fit checking. Our study seeks to quantitatively evaluate the level of fit offered by various types of masks, and most importantly, assess the accuracy of implementing fit checks by comparing fit check results to quantitative fit testing results. METHODS: Seven participants first evaluated N95 and KN95 respirators by performing a fit check. Participants then underwent quantitative fit testing wearing five N95 respirators, a KN95 respirator, a surgical mask, and fabric masks. RESULTS: N95 respirators offered higher degrees of protection than the other categories of masks tested; however, it should be noted that most N95 respirators failed to fit the participants adequately. Fit check responses had poor correlation with quantitative fit factor scores. KN95, surgical, and fabric masks achieved low fit factor scores, with little protective difference recorded between respiratory protection options. In addition, small facial differences were observed to have a significant impact on quantitative fit. CONCLUSION: Fit is critical to the level of protection offered by respirators. For an N95 respirator to provide the promised protection, it must fit the participant. Performing a fit check via NHS self-assessment guidelines was an unreliable way of determining fit

Face mask fit hacks: Improving the fit of KN95 masks and surgical masks with fit alteration techniques.

INTRODUCTION: During the course of the COVID-19 pandemic, there have been suggestions that various techniques could be employed to improve the fit and, therefore, the effectiveness of face masks. It is well recognized that improving fit tends to improve mask effectiveness, but whether these fit modifiers are reliable remains unexplored. In this study, we assess a range of common "fit hacks" to determine their ability to improve mask performance. METHODS: Between July and September 2020, qualitative fit testing was performed in an indoor living space. We used quantitative fit testing to assess the fit of both surgical masks and KN95 masks, with and without 'fit hacks', on four participants. Seven fit hacks were evaluated to assess impact on fit. Additionally, one participant applied each fit hack multiple times to assess how reliable hacks were when reapplied. A convenience of four participants took part in the study, three females and one male with a head circumference range of 54 to 60 centimetres. RESULTS AND DISCUSSION: The use of pantyhose, tape, and rubber bands were effective for most participants. A pantyhose overlayer was observed to be the most effective hack. High degrees of variation were noted between participants. However, little variation was noted within participants, with hacks generally showing similar benefit each time they were applied on a single participant. An inspection of the fit hacks once applied showed that individual facial features may have a significant impact on fit, especially the nose bridge. CONCLUSIONS: Fit hacks can be used to effectively improve the fit of surgical and KN95 masks, enhancing the protection provided to the wearer. However, many of the most effective hacks are very uncomfortable and unlikely to be tolerated for extended periods of time. The development of effective fit-improvement solutions remains a critical issue in need of further development

Drivers of intimate partner violence against women in three refugee camps

This qualitative study examined the drivers- of intimate partner violence (IPV) against women in displacement to identify protective factors and patterns of risk. Qualitative data were collected in three refugee camps in South Sudan, Kenya, and Iraq (N = 284). Findings revealed interrelated factors that triggered and perpetuated IPV: gendered social norms and roles, destabilization of gender norms and roles, men's substance use, women's separation from family, and rapid remarriages and forced marriages. These factors paint a picture of individual, family, community and societal processes that exacerbate women's risk of IPV in extreme conditions created by displacement. Implications for policy and practice are indicated.sch_iih24pub4838pub

Nutritional Epigenomics and Age-Related Disease

Recent advances in epigenetic research have enabled the development of epigenetic clocks, which have greatly enhanced our ability to investigate molecular processes that contribute to aging and age-related disease. These biomarkers offer the potential to measure the effect of environmental exposures linked to dynamic changes in DNA methylation, including nutrients, as factors in age-related disease. They also offer a compelling insight into how imbalances in the supply of nutrients, particularly B-vitamins, or polymorphisms in regulatory enzymes involved in 1-carbon metabolism, the key pathway that supplies methyl groups for epigenetic reactions, may influence epigenetic age and interindividual disease susceptibility. Evidence from recent studies is critically reviewed, focusing on the significant contribution of the epigenetic clock to nutritional epigenomics and its impact on health outcomes and age-related disease. Further longitudinal studies and randomized nutritional interventions are required to advance the field