Deciphering salt stress responses in Solanum pimpinellifolium through high-throughput phenotyping.

Soil salinity is a major environmental stressor affecting agricultural productivity worldwide. Understanding plant responses to salt stress is crucial for developing resilient crop varieties. Wild relatives of cultivated crops, such as wild tomato, Solanum pimpinellifolium, can serve as a useful resource to further expand the resilience potential of the cultivated germplasm, S. lycopersicum. In this study, we employed high-throughput phenotyping in the greenhouse and field conditions to explore salt stress responses of a S. pimpinellifolium diversity panel. Our study revealed extensive phenotypic variations in response to salt stress, with traits such as transpiration rate, shoot mass, and ion accumulation showing significant correlations with plant performance. We found that while transpiration was a key determinant of plant performance in the greenhouse, shoot mass strongly correlated with yield under field conditions. Conversely, ion accumulation was the least influential factor under greenhouse conditions. Through a Genome Wide Association Study, we identified candidate genes not previously associated with salt stress, highlighting the power of high-throughput phenotyping in uncovering novel aspects of plant stress responses. This study contributes to our understanding of salt stress tolerance in S. pimpinellifolium and lays the groundwork for further investigations into the genetic basis of these traits, ultimately informing breeding efforts for salinity tolerance in tomato and other crops.

Improved Salinity Tolerance-Associated Variables Observed in EMS Mutagenized Wheat Lines.

Salinity tolerance-associated phenotypes of 35 EMS mutagenized wheat lines originating from BARI Gom-25 were compared. Vegetative growth was measured using non-destructive image-based phenotyping. Five different NaCl concentrations (0 to 160 mM) were applied to plants 19 days after planting (DAP 19), and plants were imaged daily until DAP 38. Plant growth, water use, leaf Na+, K+ and Cl- content, and thousand kernel weight (TKW) were measured, and six lines were selected for further analysis. In saline conditions, leaf Na+, K+, and Cl- content variation on a dry weight basis within these six lines were ~9.3, 1.4, and 2.4-fold, respectively. Relative to BARI Gom-25, two (OA6, OA62) lines had greater K+ accumulation, three (OA6, OA10, OA62) had 50-75% lower Na+:K+ ratios, and OA62 had ~30% greater water-use index (WUI). OA23 had ~2.2-fold greater leaf Na+ and maintained TKW relative to BARI Gom-25. Two lines (OA25, OA52) had greater TKW than BARI Gom-25 when grown in 120 mM NaCl but similar Na+:K+, WUI, and biomass accumulation. OA6 had relatively high TKW, high leaf K+, and WUI, and low leaf Na+ and Cl-. Phenotypic variation revealed differing associations between the parameters measured in the lines. Future identification of the genetic basis of these differences, and crossing of lines with phenotypes of interest, is expected to enable the assessment of which combinations of parameters deliver the greatest improvement in salinity tolerance.

The wheat Seven in absentia gene is associated with increases in biomass and yield in hot climates.

Wheat (Triticum aestivum L.) productivity is severely reduced by high temperatures. Breeding of heat-tolerant cultivars can be achieved by identifying genes controlling physiological and agronomical traits when high temperatures occur and using these to select superior genotypes, but no gene underlying genetic variation for heat tolerance has previously been described. We advanced the positional cloning of qYDH.3BL, a quantitative trait locus (QTL) on bread wheat chromosome 3B associated with increased yield in hot and dry climates. The delimited genomic region contained 12 putative genes and a sequence variant in the promoter region of one gene, Seven in absentia, TaSINA. This was associated with the QTL's effects on early vigour, root growth, plant biomass, and yield components in two distinct wheat populations grown under various growth conditions. Near isogenic lines carrying the positive allele at qYDH.3BL underexpressed TaSINA and had increased vigour and water use efficiency early in development, as well as increased biomass, grain number, and grain weight following heat stress. A survey of worldwide distribution indicated that the positive allele became widespread from the 1950s through the CIMMYT wheat breeding programme but, to date, has been selected only in breeding programmes in Mexico and Australia.

High-throughput 3D modelling to dissect the genetic control of leaf elongation in barley (Hordeum vulgare).

To optimize shoot growth and structure of cereals, we need to understand the genetic components controlling initiation and elongation. While measuring total shoot growth at high throughput using 2D imaging has progressed, recovering the 3D shoot structure of small grain cereals at a large scale is still challenging. Here, we present a method for measuring defined individual leaves of cereals, such as wheat and barley, using few images. Plant shoot modelling over time was used to measure the initiation and elongation of leaves in a bi-parental barley mapping population under low and high soil salinity. We detected quantitative trait loci (QTL) related to shoot growth per se, using both simple 2D total shoot measurements and our approach of measuring individual leaves. In addition, we detected QTL specific to leaf elongation and not to total shoot size. Of particular importance was the detection of a QTL on chromosome 3H specific to the early responses of leaf elongation to salt stress, a locus that could not be detected without the computer vision tools developed in this study.

Ustekinumab Pharmacokinetics and Exposure Response in a Phase 3 Randomized Trial of Patients With Ulcerative Colitis.

BACKGROUND & AIMS: The efficacy of antibody-based therapeutics depends on their pharmacokinetics. The pharmacokinetic and exposure response profiles of ustekinumab, a monoclonal antibody against interleukin 12/interleukin 23, are known in patients with Crohn's disease, yet there are few data from patients with ulcerative colitis. We characterized ustekinumab's pharmacokinetics, exposure response, and optimal serum concentrations in patients with ulcerative colitis. METHODS: We collected data from 2 phase 3 trials (1 induction and 1 maintenance), in which patients with moderate to severe ulcerative colitis received an intravenous induction dose of ustekinumab (130 mg, n = 320; or approximately 6 mg/kg, n = 322). Responders were assigned randomly to groups that received subcutaneous maintenance ustekinumab (90 mg) every 8 weeks (n = 176) or 12 weeks (n = 172), or placebo (n = 175). We evaluated the association between ustekinumab concentration and efficacy, serum based on clinical effects (Mayo score), histologic features, and inflammation (measurement of C-reactive protein, fecal calprotectin, and fecal lactoferrin), as well as safety (infections, serious infections, and serious adverse events), during induction and maintenance therapy. Optimal serum concentrations of ustekinumab were identified using receiver operating characteristic curve analyses. RESULTS: In patients with ulcerative colitis, dose-proportional serum concentrations of ustekinumab, unaffected by prior biologic or concomitant immunomodulator therapy, reached steady state by the second maintenance dose; the median trough concentration for dosing every 8 weeks was approximately 3-fold that of dosing every 12 weeks. Serum concentrations were associated with clinical and histologic features of efficacy and normalization of inflammation markers. The week-8 concentration threshold for induction of response was 3.7 µg/mL. A steady-state trough serum concentration of 1.3 µg/mL or higher was associated with a higher rate of clinical remission compared with patients who had lower serum concentrations. Serum concentrations of ustekinumab were not associated with infections, serious infections, or serious adverse events. CONCLUSIONS: In an analysis of data from 2 phase 3 trials of patients with ulcerative colitis, we found that serum concentrations of ustekinumab were proportional to dose, unaffected by prior biologic or concomitant immunomodulator therapies, associated with clinical and histologic efficacy and markers of inflammation, and were not associated with safety events at doses evaluated. Ustekinumab pharmacokinetics are consistent between patients with Crohn's disease vs ulcerative colitis.

A single nucleotide substitution in TaHKT1;5-D controls shoot Na+ accumulation in bread wheat.

Improving salinity tolerance in the most widely cultivated cereal, bread wheat (Triticum aestivum L.), is essential to increase grain yields on saline agricultural lands. A Portuguese landrace, Mocho de Espiga Branca accumulates up to sixfold greater leaf and sheath sodium (Na+ ) than two Australian cultivars, Gladius and Scout, under salt stress in hydroponics. Despite high leaf and sheath Na+ concentrations, Mocho de Espiga Branca maintained similar salinity tolerance compared to Gladius and Scout. A naturally occurring single nucleotide substitution was identified in the gene encoding a major Na+ transporter TaHKT1;5-D in Mocho de Espiga Branca, which resulted in a L190P amino acid residue variation. This variant prevents Mocho de Espiga Branca from retrieving Na+ from the root xylem leading to a high shoot Na+ concentration. The identification of the tissue-tolerant Mocho de Espiga Branca will accelerate the development of more elite salt-tolerant bread wheat cultivars.

Resource allocation to growth or luxury consumption drives mycorrhizal responses.

Highly variable phenotypic responses in mycorrhizal plants challenge our functional understanding of plant-fungal mutualisms. Using non-invasive high-throughput phenotyping, we observed that arbuscular mycorrhizal (AM) fungi relieved phosphorus (P) limitation and enhanced growth of Brachypodium distachyon under P-limited conditions, while photosynthetic limitation under low nitrogen (N) was exacerbated by the fungus. However, these responses were strongly dependent on host genotype: only the faster growing genotype (Bd3-1) utilised P transferred from the fungus to achieve improved growth under P-limited conditions. Under low N, the slower growing genotype (Bd21) had a carbon and N surplus that was linked to a less negative growth response compared with the faster growing genotype. These responses were linked to the regulation of N : P stoichiometry, couples resource allocation to growth or luxury consumption in diverse plant lineages. Our results attest strongly to a mechanism in plants by which plant genotype-specific resource economics drive phenotypic outcomes during AM symbioses.

Genome-wide association of barley plant growth under drought stress using a nested association mapping population.

BACKGROUND: Barley (Hordeum vulgare L.) is the fourth most important cereal crop worldwide. Barley production is compromised by many abiotic stresses including drought. Wild barley is a valuable source of alleles that can improve adaptation of cultivated barley to drought stress. RESULTS: In the present study, a nested association mapping population named HEB-25, consisting of 1420 BC1S3 lines that were developed by crossing 25 different wild barley accessions to the elite barley cultivar 'Barke', was evaluated under both control and drought-stressed conditions in the Australian Plant Phenomics Facility, University of Adelaide. Overall, 14 traits reflecting the performance of individual plants in each treatment were calculated from non-destructive imaging over time and destructive end-of-experiment measurements. For each trait, best linear unbiased estimators (BLUEs) were calculated and used for genome-wide association study (GWAS) analysis. Among the quantitative trait loci (QTL) identified for the 14 traits, many co-localise with known inflorescence and developmental genes. We identified a QTL on chromosome 4H where, under drought and control conditions, wild barley alleles increased biomass by 10 and 17% respectively compared to the Barke allele. CONCLUSIONS: Across all traits, QTL which increased phenotypic values were identified, providing a wider range of genetic diversity for the improvement of drought tolerance in barley.

A field and laboratory investigation of kerb side inlet pits using four media types.

Kerb side inlets with adjacent leaky wells are an emerging tool to harvest stormwater and to reduce runoff volumes and peak flow rates. This is achieved by collecting the first flush runoff into kerb side storages and infiltrating this water into the surrounding soil, thereby also reducing stormwater pollutant loadings. The hydraulic performance of the kerb side inlet, filter media and surrounding soil are key factors in the performance of these systems. However, no field or laboratory data are currently available for the hydraulic performance of a kerb side tree inlet pit. In this study, 12 tree inlet pits were constructed and filled with various media types including gravel, water treatment solids (a recycled waste product), sandy loam and clay to examine (1) leaky well infiltration rates (2) emptying times of the wells and (3) the well capacity (runoff storage volume) before and after runoff filtering through the wells. Using a laboratory model, the water harvesting performance of the kerb side inlet plate was also examined for various road longitudinal slopes. Using the field and laboratory data, simulation of the well performance was undertaken using the Model for Urban Stormwater Improvement Conceptualisation (MUSIC) to assess the capacity of these systems to reduce runoff volumes at the residential street scale. It was hypothesised that the type of filter media used in leaky well systems has a significant impact on the infiltration rate, regardless of the native soil type through which the stormwater eventually infiltrates. The results showed that the infiltration rates of systems filled with gravel were significantly higher than for the other media types, and this was followed by water treatment solids, sandy loam and clay. The results of the MUSIC modelling indicated that 2.8% of the mean annual runoff volume in the catchment could be harvested by the systems at the case study site. It was found that selection of high infiltration rate media and regular maintenance are the key factors for maintaining long-term performance of these systems.

Mapping of novel salt tolerance QTL in an Excalibur × Kukri doubled haploid wheat population.

KEY MESSAGE: Novel QTL for salinity tolerance traits have been detected using non-destructive and destructive phenotyping in bread wheat and were shown to be linked to improvements in yield in saline fields. Soil salinity is a major limitation to cereal production. Breeding new salt-tolerant cultivars has the potential to improve cereal crop yields. In this study, a doubled haploid bread wheat mapping population, derived from the bi-parental cross of Excalibur × Kukri, was grown in a glasshouse under control and salinity treatments and evaluated using high-throughput non-destructive imaging technology. Quantitative trait locus (QTL) analysis of this population detected multiple QTL under salt and control treatments. Of these, six QTL were detected in the salt treatment including one for maintenance of shoot growth under salinity (QG(1-5).asl-7A), one for leaf Na+ exclusion (QNa.asl-7A) and four for leaf K+ accumulation (QK.asl-2B.1, QK.asl-2B.2, QK.asl-5A and QK:Na.asl-6A). The beneficial allele for QG(1-5).asl-7A (the maintenance of shoot growth under salinity) was present in six out of 44 mainly Australian bread and durum wheat cultivars. The effect of each QTL allele on grain yield was tested in a range of salinity concentrations at three field sites across 2 years. In six out of nine field trials with different levels of salinity stress, lines with alleles for Na+ exclusion and/or K+ maintenance at three QTL (QNa.asl-7A, QK.asl-2B.2 and QK:Na.asl-6A) excluded more Na+ or accumulated more K+ compared to lines without these alleles. Importantly, the QK.asl-2B.2 allele for higher K+ accumulation was found to be associated with higher grain yield at all field sites. Several alleles at other QTL were associated with higher grain yields at selected field sites.

Drought-inducible expression of Hv-miR827 enhances drought tolerance in transgenic barley.

Drought is one of the major abiotic stresses reducing crop yield. Since the discovery of plant microRNAs (miRNAs), considerable progress has been made in clarifying their role in plant responses to abiotic stresses, including drought. miR827 was previously reported to confer drought tolerance in transgenic Arabidopsis. We examined barley (Hordeum vulgare L. 'Golden Promise') plants over-expressing miR827 for plant performance under drought. Transgenic plants constitutively expressing CaMV-35S::Ath-miR827 and drought-inducible Zm-Rab17::Hv-miR827 were phenotyped by non-destructive imaging for growth and whole plant water use efficiency (WUEwp). We observed that the growth, WUEwp, time to anthesis and grain weight of transgenic barley plants expressing CaMV-35S::Ath-miR827 were negatively affected in both well-watered and drought-treated growing conditions compared with the wild-type plants. In contrast, transgenic plants over-expressing Zm-Rab17::Hv-miR827 showed improved WUEwp with no growth or reproductive timing change compared with the wild-type plants. The recovery of Zm-Rab17::Hv-miR827 over-expressing plants also improved following severe drought stress. Our results suggest that Hv-miR827 has the potential to improve the performance of barley under drought and that the choice of promoter to control the timing and specificity of miRNA expression is critical.

Differential expression of microRNAs and potential targets under drought stress in barley.

Drought is a crucial environmental constraint limiting crop production in many parts of the world. microRNA (miRNA) based gene regulation has been shown to act in several pathways, including crop response to drought stress. Sequence based profiling and computational analysis have revealed hundreds of miRNAs and their potential targets in different plant species under various stress conditions, but few have been biologically verified. In this study, 11 candidate miRNAs were tested for their expression profiles in barley. Differences in accumulation of only four miRNAs (Ath-miR169b, Osa-miR1432, Hv-miRx5 and Hv-miR166b/c) were observed between drought-treated and well-watered barley in four genotypes. miRNA targets were predicted using degradome analysis of two, different genotypes, and genotype-specific target cleavage was observed. Inverse correlation of mature miRNA accumulation with miRNA target transcripts was also genotype dependent under drought treatment. Drought-responsive miRNAs accumulated predominantly in mesophyll tissues. Our results demonstrate genotype-specific miRNA regulation under drought stress and evidence for their role in mediating expression of target genes for abiotic stress response in barley.

A QTL on the short arm of wheat (Triticum aestivum L.) chromosome 3B affects the stability of grain weight in plants exposed to a brief heat shock early in grain filling.

BACKGROUND: Molecular markers and knowledge of traits associated with heat tolerance are likely to provide breeders with a more efficient means of selecting wheat varieties able to maintain grain size after heat waves during early grain filling. RESULTS: A population of 144 doubled haploids derived from a cross between the Australian wheat varieties Drysdale and Waagan was mapped using the wheat Illumina iSelect 9,000 feature single nucleotide polymorphism marker array and used to detect quantitative trait loci for heat tolerance of final single grain weight and related traits. Plants were subjected to a 3 d heat treatment (37 °C/27 °C day/night) in a growth chamber at 10 d after anthesis and trait responses calculated by comparison to untreated control plants. A locus for single grain weight stability was detected on the short arm of chromosome 3B in both winter- and autumn-sown experiments, determining up to 2.5 mg difference in heat-induced single grain weight loss. In one of the experiments, a locus with a weaker effect on grain weight stability was detected on chromosome 6B. Among the traits measured, the rate of flag leaf chlorophyll loss over the course of the heat treatment and reduction in shoot weight due to heat were indicators of loci with significant grain weight tolerance effects, with alleles for grain weight stability also conferring stability of chlorophyll ('stay-green') and shoot weight. Chlorophyll loss during the treatment, requiring only two non-destructive readings to be taken, directly before and after a heat event, may prove convenient for identifying heat tolerant germplasm. These results were consistent with grain filling being limited by assimilate supply from the heat-damaged photosynthetic apparatus, or alternatively, accelerated maturation in the grains that was correlated with leaf senescence responses merely due to common genetic control of senescence responses in the two organs. There was no evidence for a role of mobilized stem reserves (water soluble carbohydrates) in determining grain weight responses. CONCLUSIONS: Molecular markers for the 3B or 6B loci, or the facile measurement of chlorophyll loss over the heat treatment, could be used to assist identification of heat tolerant genotypes for breeding.

Integrating Image-Based Phenomics and Association Analysis to Dissect the Genetic Architecture of Temporal Salinity Responses in Rice.

Salinity affects a significant portion of arable land and is particularly detrimental for irrigated agriculture, which provides one-third of the global food supply. Rice (Oryza sativa), the most important food crop, is salt sensitive. The genetic resources for salt tolerance in rice germplasm exist but are underutilized due to the difficulty in capturing the dynamic nature of physiological responses to salt stress. The genetic basis of these physiological responses is predicted to be polygenic. In an effort to address this challenge, we generated temporal imaging data from 378 diverse rice genotypes across 14 d of 90 mm NaCl stress and developed a statistical model to assess the genetic architecture of dynamic salinity-induced growth responses in rice germplasm. A genomic region on chromosome 3 was strongly associated with the early growth response and was captured using visible range imaging. Fluorescence imaging identified four genomic regions linked to salinity-induced fluorescence responses. A region on chromosome 1 regulates both the fluorescence shift indicative of the longer term ionic stress and the early growth rate decline during salinity stress. We present, to our knowledge, a new approach to capture the dynamic plant responses to its environment and elucidate the genetic basis of these responses using a longitudinal genome-wide association model.

A sexual health quality improvement program (SHIMMER) triples chlamydia and gonorrhoea testing rates among young people attending Aboriginal primary health care services in Australia.

BACKGROUND: In Australia, chlamydia is the most commonly notifiable infection and over the past ten years chlamydia and gonorrhoea notification rates have increased. Aboriginal compared with non-Aboriginal Australians have the highest notifications rates of chlamydia and gonorrhoea. Regular testing of young people for chlamydia and gonorrhoea is a key prevention strategy to identify asymptomatic infections early, provide treatment and safe sex education. This study evaluated if a sexual health quality improvement program (QIP) known as SHIMMER could increase chlamydia and gonorrhoea testing among young people attending four Aboriginal primary health care services in regional areas of New South Wales, Australia. METHODS: We calculated the proportion of 15-29 year olds tested and tested positivity for chlamydia and gonorrhoea in a 12-month before period (March 2010-February 2011) compared with a 12-month QIP period (March 2012-February 2013). Logistic regression was used to assess the difference in the proportion tested for chlamydia and gonorrhoea between study periods by gender, age group, Aboriginal status and Aboriginal primary health service. Odds ratios (OR) and their 95 % confidence intervals (CIs) were calculated with significance at p < 0.05. RESULTS: In the before period, 9 % of the 1881 individuals were tested for chlamydia, compared to 22 % of the 2259 individuals in the QIP period (OR): 1.43, 95 % CI: 1.22-1.67). From the before period to the QIP period, increases were observed in females (13 % to 25 %, OR: 1.32, 95 % CI: 1.10-1.59) and males (3 % to 17 %, OR: 1.85, 95 % CI: 1.36-2.52). The highest testing rate in the QIP period was in 15-19 year old females (16 % to 29 %, OR: 1.02, 95 % CI: 0.75-1.37), yet the greatest increase was in 20-24 year olds males (3 % to 19 %, OR: 1.65, 95 % CI: 1.01-2.69). Similar increases were seen in gonorrhoea testing. Overall, there were 70 (11 %) chlamydia diagnoses, increasing from 24 in the before to 46 in the QIP period. Overall, 4 (0.7 %) gonorrhoea tests were positive. CONCLUSIONS: The QIP used in SHIMMER almost tripled chlamydia and gonorrhoea testing in young people and found more than twice as many chlamydia infections. The QIP could be used by other primary health care centres to increase testing among young people.

Incidence and predictors of annual chlamydia testing among 15-29 year olds attending Aboriginal primary health care services in New South Wales, Australia.

BACKGROUND: For the past two decades, chlamydia has been the most commonly notified infectious disease among young people (15-29 year olds) in Australia, the United States of America and the United Kingdom and rates have increased annually in these three countries. In Australia, rates of chlamydia are three times higher in Aboriginal compared with non-Aboriginal people. Australian sexually transmissible infection guidelines recommend annual chlamydia testing for 15-29 year old females and males. This analysis will examine the incidence and predictors of annual chlamydia testing in 15-29 year olds attending four Aboriginal Community Controlled Health Services (ACCHS) in Australia. METHODS: From 2009-2011, attendance and chlamydia testing data were extracted from the patient system to calculate the number and proportion of 15-29 year olds that were tested for chlamydia and that tested positive for chlamydia by gender (male, female), age-group (15-19, 20-24, 25-29 years), Aboriginal status (Aboriginal, non-Aboriginal people) and by the four ACCHSs sites (1, 2, 3 and 4). A cohort was created to calculate the incidence rate per 100 person-years (PY) and predictors of an annual chlamydia test (a test within 12-months of a previous test/visit) by the above factors using Cox regression. Unadjusted and adjusted hazard ratios (AHR) and their 95 % confidence intervals (CIs) and p-values were calculated with significance at p < 0.05. RESULTS: From 2009-2011, there were 2896 individuals who attended the four ACCHSs. Overall , 17 % (22 % of females and 10 % of males) were tested for chlamydia and 9 % tested positive (8 % of females and 14 % of males). The median time to an annual chlamydia test was 10.7 months. The cohort included 2318 individuals. Overall the incidence rate of an annual chlamydia test was 9.1 per 100 PY (11.6 in females and 5.8 in males). Predictors of an annual chlamydia test were being female (AHR: 1.7, 95 % CI: 1.2-2.2, p < 0.01), being 15-19 years old (AHR: 1.6, 95 % CI: 1.1-2.3, p < 0.01) and attending ACCHS site 2 (AHR: 3.8, 95 % CI: 1.8-8.0, p < 0.01). CONCLUSIONS: This analysis highlights that opportunistic STI testing strategies are needed to increase annual chlamydia testing in young people; especially males.

Experimental power considerations--justifying replication for animal care and use committees.

A common practice in poultry science is to compare new treatments with a control or between treatments tested in planned experiments. The overall F-test from an ANOVA of the data allows the researcher to reject or not reject the null hypothesis. However, the correct conclusion from such analysis depends on sufficient replicates being included in the experiment. On the other hand, restrictions are imposed to reduce the number of birds used in experiments for welfare reasons and to save scarce resources. We review the basic concepts needed to determine the number of replicates before conducting an experiment. We use these concepts to assess the results of several real experiments and to show what might be done in future experiments. We describe how to do the computations in R software.

Diaphragm electrical activity during weaning of nasal high-flow therapy in preterm infants.

OBJECTIVE: To determine whether electrical activity of the diaphragm (Edi) changes with weaning nasal high-flow (HF) therapy in preterm infants according to a standardised protocol. DESIGN: Prospective observational cohort study. SETTING: Neonatal intensive care unit. PATIENTS: Preterm infants born at <32 weeks gestation, receiving nasal HF as part of routine clinical care. INTERVENTIONS: Infants recruited to the study had their HF weaned according to set clinical criteria. Edi was measured using a modified gastric feeding tube serially from baseline (pre-wean) to 24-hours post-wean. MAIN OUTCOME MEASURES: Change in Edi from baseline was measured at four time points up to 24 hours after weaning. Minimum Edi during expiration, maximum Edi during inspiration and amplitude of the Edi signal (Edidelta) were measured. Clinical parameters (heart rate, respiratory rate and fraction of inspired oxygen) were also recorded. RESULTS: Forty preterm infants were recruited at a mean corrected gestational age of 31.6 (±2.7) weeks. Data from 156 weaning steps were analysed, 91% of which were successful. Edi did not change significantly from baseline during flow reduction steps, but a significant increase in diaphragm activity was observed when discontinuing HF (median increase in Edidelta immediately post-discontinuation 1.7 µV (95% CI: 0.6 to 3.0)) and at 24 hours 1.9 µV (95% CI: 0.7 to 3.8)). No significant difference in diaphragm activity was observed between successful and unsuccessful weaning steps. CONCLUSIONS: A protocolised approach to weaning has a high probability of success. Edi does not change with reducing HF rate, but significantly increases with discontinuation of HF from 2 L/min.

The use of mentoring for knowledge translation by allied health: a scoping review.

OBJECTIVE: To describe how allied health professionals have used mentoring as a knowledge translation strategy to inform practice. INTRODUCTION: Mentoring has been reported to be used by nursing and medicine as a knowledge translation strategy. It is not known if allied health professionals have also used mentoring to improve their use of research in practice, or what the key mentoring characteristics are that guide its application in allied health settings. Improved understanding of the barriers and facilitators to mentoring in allied health settings may be used to guide the design of future mentoring programs to assist knowledge translation. INCLUSION CRITERIA: Eligible studies must have included allied health professionals, and used the concept of mentoring to support knowledge translation in the context of healthcare. Primary empirical and synthesized studies were eligible. METHODS: An a-priori protocol was followed to complete a search of six databases (MEDLINE [OVID], EMBASE [OVID], CINAHL [EBSCO], PsycInfo [OVID], PDQ-Evidence ( www.pdq-evidence.org ), and Cochrane on the 9 March 2021. Screening for eligibility was conducted by two authors at the title and abstract stage and the full text stage. Selection criteria and the data extraction tool were established prior to the search. Findings are presented in narrative and tabular formats. RESULTS: A total of 2053 studies met the inclusion criteria for screening and nine were determined to be eligible for inclusion. Mentoring has been used by allied health professionals to improve the translation of interventional research evidence by clinicians, and to establish clinician skills and knowledge relating to knowledge translation processes. Mentoring was predominantly used as part of a multifaceted knowledge translation strategy alongside educational strategies. Mentoring characteristics such as structure, context, goals, resourcing and dosage varied depending on the context of translation. The specific barriers reported to using mentoring were varied, whereas the facilitators to mentoring were primarily related to the mentor's approach and expertise. The impact of mentoring was primarily measured through the mentee's experience of mentoring. CONCLUSIONS: Allied health professionals have used mentoring as a knowledge translation strategy to enhance the use of research evidence in their practice and to learn the process of knowledge translation. Mentoring is mostly used in conjunction with other strategies in practice, such as education. The limited number of identified barriers and facilitators to using mentoring as a knowledge translation strategy supports the need for future research to deepen our understanding about the mentoring process.

Stress reveals a specific behavioral phenotype for opioid abuse susceptibility.

Susceptibility to stress has long been considered important for the development of substance use disorders. Nonetheless, behavioral and physiological responses to stress are highly variable, making it difficult to identify the individuals who are most likely to abuse drugs. In the present study, we employed a comprehensive battery of tests for negative valence behaviors and nociception to identify individuals predisposed to opioid seeking following oral opioid self-administration. Furthermore, we examined how this profile was affected by a history of stress. We observed that mice receiving foot shock stress failed to exhibit a preference for sucrose, showed increased immobility in the forced swim task, and exhibited mechanical hypersensitivity when compared to controls. When considering these behaviors in light of future fentanyl-seeking responses, we observed that heightened mechanical sensitivity corresponded to higher opioid preference in mice with a history of stress, but not controls. Moreover, we were surprised to discover that paradoxically high sucrose preferences predicted fentanyl preference in shock mice, while signs of anhedonia predicted fentanyl preference in controls. Taken together, these results indicate that stress can act as a physiological modulator, shifting profiles of opioid abuse susceptibility depending on an individual's history.