A Comparison of the Genetic Factors Influencing Host Response to Infection with One of Two Isolates of Porcine Reproductive and Respiratory Syndrome Virus

Host genetic differences in viral load (VL) and weight gain (WG) during porcine reproductive and respiratory syndrome virus (PRRSV) challenge were assessed for thirteen trials of ~200 commercial crossbred piglets each, from several different commercial suppliers. Piglets were experimentally infected with PRRSV isolates NVSL-97-7895 (NVSL) or KS-2006-72109 (KS06). VL and WG were moderately heritable and were antagonistically related for both virus isolates. The genetic correlation of host response to NVSL with host response to KS06 was high for both VL and WG. Consistent with previous findings, animals that were heterozygous (AB) for the WUR10000125 (WUR) marker on Chromosome 4 (SSC4) had significantly lower VL than their AA counterparts when infected with either virus isolate; however, a significant increase in WG was only observed when piglets were infected with the NVSL isolate. These results suggest that selecting for increased resistance or reduced susceptibility to PRRSV may be effective across virus isolates. Selecting for the AB genotype for WUR is expected to reduce VL across PRRSV isolates but its effect on WG during infection may differ between virus isolates

Factors Associated with N-specific IgG Response in Piglets Experimentally Infected with Porcine Reproductive and Respiratory Syndrome Virus

This study examined serum porcine reproductive and respiratory syndrome virus (PRRSV) N protein-specific IgG levels from sera collected from 464 Large White-Landrace commercial crossbred piglets from three separate experimental infection trials with PRRSV isolate NVSL-97- 7895. IgG levels at 42 days post infection (dpi) were measured by fluorescent microsphere immunoassay, herein referred to as total antibody (tAb) response. tAb levels were assessed for an association with different disease-related traits, the presence of a heritable genetic component, and for genomic regions associated with tAb response. tAb response was negatively associated with viral load (VL) and weight gain from 28-42 dpi (WG) and positively associated with virus rebound (REB) and neutralizing antibody (nAb) levels. Furthermore, tAb response had a heritable genetic component, with a major QTL located on chromosome 7 in the major histocompatibility complex (MHC), whereby heterozygous individuals had a lower tAb response and increased weight gain from 28-42 dpi. These results suggest that genetic selection for tAb response may be useful for selecting for pigs that have increased resistance or reduced susceptibility to PRRSV

Validation of the Effects of a SNP on SSC4 Associated with Viral Load and Weight Gain in Piglets Experimentally Infected with a 2006 PRRS Virus Isolate

Host genetic differences in viral load (VL) and weight gain (WG) during challenge were assessed for five trials of ~200 commercial crossbred piglets each, all from different commercial suppliers. Piglets were experimentally infected with porcine reproductive and respiratory syndrome virus (PRRSV) isolate KS-2006-72109 in order to validate the effects of a SNP previously identified on SSC4 (WUR10000125), whereby AB individuals had increased WG and reduced VL when experimentally infected with PRRSV isolate NVSL-97-7895. VL was defined as the area under the curve of logged viremia from 0-21 dpi. WG was defined as the weight gained from 0-42 dpi. The SNP effects on VL and WG were assessed. AB individuals had higher WG and lower VL than AA individuals, suggesting this marker may be useful for genetic selection of pigs for increased resistance or reduced susceptibility to PRRSV isolates that differ genetically and possibly pathogenically

Factors Associated with Neutralizing Antibody Response in Piglets Experimentally Infected with Porcine Reproductive and Respiratory Virus

Host genetic differences and other factors associated with neutralizing antibody (NAb) response were examined in 464 Large White-Landrace piglets that were experimentally challenged with porcine reproductive and respiratory virus (PRRSv) isolate NVSL-97-7895. Serum samples and viremia data were collected on piglets periodically for 42 days post infection (dpi). NAb response was defined as the inverse of the highest 1:2 serial dilution of serum without cytopathic effects. Heritability and other factors associated with NAb response were estimated using an animal model in ASReml. These analyses identified two aspects of viremia that were associated with NAb response: viral load (area under the curve from 0-21 dpi) and virus rebound (a two Log increase in viremia after the virus had started to clear). These results also suggested that NAb response may be lowly heritable and provided the groundwork for further characterization of NAb response

Maternal dental history, child's birth outcome and early cognitive development: Childhood outcomes

Prenatal exposure to high levels of mercury, radiation, and inflammation have been associated with adverse reproductive outcomes such as increases in preterm delivery, low birthweight, and delayed neurodevelopment. Few data are available to evaluate the potential effects of prenatal low-level exposure to these factors as might occur during dental care. We evaluated maternal dental history prior to and during pregnancy in relation to birth outcomes and early communicative development among offspring in a large cohort (n=7375) of British children born in 1991–1992. Dental history was assessed by questionnaire. The child’s communicative development was assessed using the MacArthur Communicative Development Inventory at 15 months of age. Total mercury was measured in umbilical cord tissue for a subset of the children. Overall, dental care, including amalgam fillings, was not associated with birth outcomes or language development. Having x-rays taken during pregnancy was not associated with birthweight measured continuously (β=14.7, p=0.4), but was associated with slightly increased odds of having a term, low birthweight baby (OR 1.9, 95%CI 1.0–3.4). More detailed evaluation of the potential adverse effects of elective dental treatment during pregnancy, particularly dental x-rays, may be warranted

2020-04-06 DAILY UNM GLOBAL HEALTH COVID-19 BRIEFING

Executive Summary: NM case updates. Several NM policy and legislative actions. Federal vs. state conflict over medical supply lines. Healthcare workers sleep in cars to prevent family exposure. Same-day in-house testing at Cedars-Sinai. Debate over hydroxychloroquine Tx. Death rate differences: Germany and Italy. African innovations. Testing recommended with mild symptoms. CDC guidelines for law enforcement PPE. New WHO first responder training and CDC sign language resources. COVID-19 droplets can travel up to 27 feet. Transmission from the asymptomatic. Humidifiers help. Drug and vaccine progress

Parents' points of view: an evaluation of the M'Lop Tapang special needs programme, Cambodia

M’Lop Tapang is a registered non-governmental organisation working in South West Cambodia and providing services to 5000 vulnerable children and 2500 families.This evaluation was commissioned to review M’Lop Tapang’s special needs programme.Interviews were conducted with 35 parents / carers of children who receive services from M’Lop Tapang’s special needs programme . Nearly all of these parents / carers reported that they had noticed improvements in their children’s behaviour or functional ability since attending the programme. Significantly, almost all also reported a dramatic reduction in stress as a result of their child attending the programmes.While the study revealed many positive aspects of M'Lop Tapang’s special needs programme it also highlighted areas for improvement, particularly in areas of parental learning and education

Does the understanding of complex dynamic events at 10 months predict vocabulary development?

By the end of their first year, infants can interpret many different types of complex dynamic visual events, such as caused-motion, chasing, and goal-directed action. Infants of this age are also in the early stages of vocabulary development, producing their first words at around 12 months. The present work examined whether there are meaningful individual differences in infants’ ability to represent dynamic causal events in visual scenes, and whether these differences influence vocabulary development. As part of the longitudinal Language 0–5 Project, 78 10-month-old infants were tested on their ability to interpret three dynamic motion events, involving (a) caused-motion, (b) chasing behaviour, and (c) goal-directed movement. Planned analyses found that infants showed evidence of understanding the first two event types, but not the third. Looking behaviour in each task was not meaningfully related to vocabulary development, nor were there any correlations between the tasks. The results of additional exploratory analyses and simulations suggested that the infants’ understanding of each event may not be predictive of their vocabulary development, and that looking times in these tasks may not be reliably capturing any meaningful individual differences in their knowledge. This raises questions about how to convert experimental group designs to individual differences measures, and how to interpret infant looking time behaviour

Modelling tropical forest responses to drought and El Niño with a stomatal optimization model based on xylem hydraulics.

The current generation of dynamic global vegetation models (DGVMs) lacks a mechanistic representation of vegetation responses to soil drought, impairing their ability to accurately predict Earth system responses to future climate scenarios and climatic anomalies, such as El Niño events. We propose a simple numerical approach to model plant responses to drought coupling stomatal optimality theory and plant hydraulics that can be used in dynamic global vegetation models (DGVMs). The model is validated against stand-scale forest transpiration (E) observations from a long-term soil drought experiment and used to predict the response of three Amazonian forest sites to climatic anomalies during the twentieth century. We show that our stomatal optimization model produces realistic stomatal responses to environmental conditions and can accurately simulate how tropical forest E responds to seasonal, and even long-term soil drought. Our model predicts a stronger cumulative effect of climatic anomalies in Amazon forest sites exposed to soil drought during El Niño years than can be captured by alternative empirical drought representation schemes. The contrasting responses between our model and empirical drought factors highlight the utility of hydraulically-based stomatal optimization models to represent vegetation responses to drought and climatic anomalies in DGVMs.This article is part of a discussion meeting issue 'The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'