Evaluation of the Combined Effect of Heterodera glycines and Macrophomina phaseolina on Soybean Yield in Naturally Infested Fields with Spatial Regression Analysis and in Greenhouse Studies.

Heterodera glycines, the soybean cyst nematode, and Macrophomina phaseolina, causal agent of charcoal rot, are economically important soybean pathogens. The impact and effect of these pathogens on soybean yield in coinfested fields in the Midwest production region is not known. Both pathogens are soilborne, with spatially aggregated distribution and effects. Spatial regression analysis, therefore, is an appropriate method to account for the spatial dependency in either the dependent variable or regression error term from data produced in fields naturally infested with H. glycines and M. phaseolina. The objectives of this study were twofold: to evaluate the combined effect of H. glycines and M. phaseolina on soybean yield in naturally infested commercial fields with ordinary least squares and spatial regression models; and to evaluate, under environmentally controlled conditions, the combined effect of H. glycines and M. phaseolina through nematode reproduction and plant tissue fungal colonization. Six trials were conducted in fields naturally infested with H. glycines and M. phaseolina in Ohio. Systematic-grid sampling was used to determine the population densities of H. glycines and M. phaseolina, and soybean yield estimates. Though not used in any statistical analysis, M. phaseolina colony forming units from plant tissue, charcoal rot severity, and H. glycines type were also recorded and summarized. In two greenhouse experiments, treatments consisted of H. glycines alone, M. phaseolina alone, and coinfestation of soybean with both pathogens. Moran's I test indicated that the yield from five fields was spatially correlated (P < 0.05) and aggregated. In these fields, to account for spatial dependence, spatial regression models were fitted to the data. Spatial regression analyses revealed a significant interaction effect between H. glycines and M. phaseolina on soybean yield for fields with high initial population densities of both pathogens. In the greenhouse experiments, H. glycines reproduction was significantly (P < 0.05) reduced in the presence of M. phaseolina; however, soybean tissue fungal colonization was not affected by the presence of H. glycines. The direct mechanisms by which H. glycines and M. phaseolina interact were not demonstrated in this study. Future studies must be conducted in the field and greenhouse to better understand this interaction effect.

Using photo-elicitation to explore perceptions of physical activity among young people with cystic fibrosis.

BACKGROUND: Physical activity is recommended in the management of cystic fibrosis (CF). The aim of this study was to explore motives, barriers and enablers to physical activity among this population. METHODS: Twelve participants (12-18 years) were recruited via convenience sampling. Photo-elicitation alongside semi-structured interviews were used to explore participants' views and experiences of physical activity. RESULTS: Our findings revealed motives for physical activity including health, enjoyment and autonomy. Those with families who valued physical activity tended to have positive attitudes towards physical activity, and valued and integrated it into their lives. Moreover, they were likely to be intrinsically motivated to be active. Several factors enable and act as barriers to physical activity. Whilst CF influenced physical activity, the majority of enablers and barriers raised where congruent with the general populations. CONCLUSION: This study provides support that healthcare providers should encourage both young people with CF and their families to be active, and subsequently informs the development of clinical interventions to support physical activity among young people with CF and their families.

Exercise intensity and the protection from postprandial vascular dysfunction in adolescents.

Acute exercise transiently improves endothelial function and protects the vasculature from the deleterious effects of a high-fat meal (HFM). We sought to identify whether this response is dependent on exercise intensity in adolescents. Twenty adolescents (10 male, 14.3 ± 0.3 yr) completed three 1-day trials: 1) rest (CON); 2) 8 × 1 min cycling at 90% peak power with 75 s recovery [high-intensity interval exercise (HIIE)]; and 3) cycling at 90% of the gas exchange threshold [moderate-intensity exercise (MIE)] 1 h before consuming a HFM (1.50 g/kg fat). Macrovascular and microvascular endothelial function was assessed before and immediately after exercise and 3 h after the HFM by flow-mediated dilation (FMD) and laser Doppler imaging [peak reactive hyperemia (PRH)]. FMD and PRH increased 1 h after HIIE [P < 0.001, effect size (ES) = 1.20 and P = 0.048, ES = 0.56] but were unchanged after MIE. FMD and PRH were attenuated 3 h after the HFM in CON (P < 0.001, ES = 1.78 and P = 0.02, ES = 0.59). FMD remained greater 3 h after the HFM in HIIE compared with MIE (P < 0.001, ES = 1.47) and CON (P < 0.001, ES = 2.54), and in MIE compared with CON (P < 0.001, ES = 1.40). Compared with CON, PRH was greater 3 h after the HFM in HIIE (P = 0.02, ES = 0.71) and MIE (P = 0.02, ES = 0.84), with no differences between HIIE and MIE (P = 0.72, ES = 0.16). Plasma triacylglycerol concentration and total antioxidant status concentration were not different between trials. We conclude that exercise intensity plays an important role in protecting the vasculature from the deleterious effects of a HFM. Performing HIIE may provide superior vascular benefits than MIE in adolescent groups.

Benign neurofibromas in type 1 neurofibromatosis (NF1) show somatic deletions of the NF1 gene.

Neurofibromatosis type 1 (NF1) is one of the most common human autosomal dominant diseases. NF1 is characterized by café-au-lait spots (CLS), axillary freckles and Lisch nodules of the iris. Another hallmark of NF1 is the development of neurofibromas, benign tumours that arise from peripheral nerve sheaths. NF1 patients also have an increased incidence of certain malignant tumours. Malignancies in NF1 are believed to follow the 'two-hit' hypothesis, in which one allele is constitutionally inactivated while the other allele is subsequently inactivated ('second hit') at the somatic level. This hypothesis has not, however, been fully tested in the aetiology of benign neurofibromas. This is a crucial issue since it addresses not only the basic mechanism behind the genesis of neurofibromas, but may also indicate a mechanism common to many or all NF1 features. Using both NF1 intragenic polymorphisms as well as markers from flanking and more distal regions of chromosome 17, we have investigated loss of heterozygosity (LOH) in 22 neurofibromas from five unrelated NF1 patients. Eight of these tumours revealed somatic deletions involving NF1, indicating that inactivation of NF1 is associated with at least some neurofibromas.

External exercise information provides no immediate additional performance benefit to untrained individuals in time trial cycling.

OBJECTIVE: To determine the importance of the provision of external exercise information to the setting of the pacing strategy, in subjects unfamiliar with a cycling task. DESIGN: Twenty-two healthy, untrained cyclists (VO(2max), 50 ± 9 mL-(1)·kg-(1)·min-(1)) were randomly assigned to a control (CON) group or an experimental (EXP) group and two successive 4 km time trials (TT) were performed, separated by a 17 min recovery. The CON group received distance knowledge and distance feedback; the EXP group received neither, but knew that each TT was to be of the same distance. RESULTS: No significant difference in completion time (p>0.05) was observed between the groups for either time to complete TT one (TT1) (CON=443 ± 33 s versus EXP=471 ± 63 s) or time to complete TT two (time trial 2) (CON=461 ± 37 s versus EXP=501 ± 94 s). No significant difference in the final RPE was observed between groups. However, a significant interaction for RPE (rating of perceived exertion)×TT in the CON was observed (F7,70=5.32, p<0.05), with significantly higher RPE values in the final kilometre of TT2 (p<0.05). CONCLUSION: The lack of any performance improvement in either group, despite the differences in exercise information received, indicates both a reliance on the afferent feedback for setting a pacing strategy and slow learning effect from practice in subjects unfamiliar with the task. The modification in RPE profile observed in the CON, despite no performance improvement, suggests exercise perception based changes may pre-empt work rate based changes and thus not immediately translate to improved performance.

Diagnosing low-mode (ℓ < 6) and mid-mode (6 ≤ ℓ ≤ 60) asymmetries in the post-stagnation phase of laser-direct-drive deuterium-tritium cryogenic implosions on OMEGA.

Low- and mid-mode perturbations are possible candidates for performance limitations in cryogenic direct-drive implosions on the OMEGA laser at the Laboratory of Laser Energetics. Simulations with a 3D hydrocode demonstrated that hotspot imagers do not show evidence of the shell breakup in the dense fuel. However, these same simulations revealed that the low- and mid-mode perturbations in the dense fuel could be diagnosed more easily in the post-stagnation phase of the implosion by analyzing the peak in the x-ray emission limb at the coronal-fuel interface than before or at the stagnation phase. In experiments, the asymmetries are inferred from gated images of the x-ray emission of the implosion by using a 16-pinhole array imager filtered to record x-ray energies >800 eV and an x-ray framing camera with 40-ps time integration and 20-µm spatial resolution. A modal analysis is applied to the spatial distribution of the x-ray emission from deuterium and tritium cryogenic implosions on OMEGA recorded after the bang time to diagnose the low- and mid-mode asymmetries, and to study the effect that the beam-to-target ratio (Rb/Rt) has on the shell integrity.

A knock-on deuteron imager for measurements of fuel and hotspot asymmetry in direct-drive inertial confinement fusion implosions (invited).

A knock-on deuteron imager (KoDI) has been implemented to measure the fuel and hotspot asymmetry of cryogenic inertial confinement fusion implosions on OMEGA. Energetic neutrons produced by D-T fusion elastically scatter ("knock on") deuterons from the fuel layer with a probability that depends on ρR. Deuterons above 10 MeV are produced by near-forward scattering, and imaging them is equivalent to time-integrated neutron imaging of the hotspot. Deuterons below 6 MeV are produced by a combination of side scattering and ranging in the fuel, and encode information about the spatial distribution of the dense fuel. The KoDI instrument consists of a multi-penumbral aperture positioned 10-20 cm from the implosion using a ten-inch manipulator and a detector pack at 350 cm from the implosion to record penumbral images with magnification of up to 35×. Range filters and the intrinsic properties of CR-39 are used to distinguish different charged-particle images by energy along the same line of sight. Image plates fielded behind the CR-39 record a 10 keV x-ray image using the same aperture. A maximum-likelihood reconstruction algorithm has been implemented to infer the source from the projected penumbral images. The effects of scattering and aperture charging on the instrument point-spread function are assessed. Synthetic data are used to validate the reconstruction algorithm and assess an appropriate termination criterion. Significant aperture charging has been observed in the initial experimental dataset, and increases with aperture distance from the implosion, consistent with a simple model of charging by laser-driven EMP.

The effect of non-contingent and accurate performance feedback on pacing and time trial performance in 4-km track cycling.

OBJECTIVE: To determine whether the provision of comparative performance feedback during 4 km track cycling affects completion time. DESIGN: Five highly trained male cyclists first performed a baseline (BL) 4-km time trial (TT) on a velodrome track, followed by two further randomised 4-km TT, during which riders received either correct (COR) or non-contingent (FAL) feedback based on their BL performance. RESULTS: Participants completed the COR TT in a significantly faster time (t(4)=-3.10, p<0.05) than the FAL TT (341 (8) s vs 350 (12) s). Over the TT, a significant difference in mean speed was apparent between the two conditions (F(15,60)=1.95, p<0.05) on the second (t(4)=4.71, p<0.05), 15th (t(4)=3.45, p<0.05) and final lap (t(4)=3.30, p<0.05). CONCLUSION: The significant difference in completion time and pacing strategy between the two conditions suggests that accurate, comparative performance feedback is beneficial to performance, especially during the start and end of an exercise bout. The results support the previously unfounded assumption that performance feedback is advantageous during exercise and highlights the importance of an athlete's support team during an event.

Establishing maximal oxygen uptake in young people during a ramp cycle test to exhaustion.

OBJECTIVES: This study tested the hypotheses that (1) secondary criteria (respiratory exchange ratio (RER), heart rate, blood [lactate]) traditionally used to verify the determination of maximum oxygen uptake (VO2(max)) in children can result in the acceptance of a 'submaximal' VO2(max) or falsely reject a 'true' VO(2max) and (2) the VO2(peak) recorded during a ramp test in children is comparable to the VO2(peak) achieved during supramaximal testing. METHODS: Thirteen children (9-10 years) completed a ramp cycle test to exhaustion to determine their VO2(peak). After 15 min of recovery, the participants performed a supramaximal cycle test to exhaustion at 105% of their ramp test peak power. RESULTS: Compared with the VO2(peak) during the ramp test, a significantly lower VO2 was recorded at a RER of 1.00 (1.293 litre/min (SD 0.265) vs 1.681 litre/min (SD 0.295), p < 0.001, n = 12), at a heart rate of 195 beats/min (1.556 litre/min (SD 0.265) vs 1.721 litre/min (SD 0.318), p < 0.001, n = 10) and at 85% of age-predicted maximum (1.345 litre/min (SD 0.228) vs 1.690 litre/min (SD 0.284), p < 0.001, n = 13). Supramaximal testing yielded a VO2(peak) that was not significantly different from the ramp test (1.615 litre/min (SD 0.307) vs 1.690 litre/min (SD 0.284), p = 0.090, respectively). CONCLUSIONS: The use of secondary criteria to verify a maximal effort in young people during ramp cycling exercise may result in the acceptance of a submaximal VO2(max). As supramaximal testing elicits a VO2(peak) similar to the ramp protocol, thus satisfying the plateau criterion, the use of such tests is recommended as the appropriate method of confirming a 'true' VO2(max) with children.

Specificity of test selection for the appropriate assessment of different measures of stretch-shortening cycle function in children.

AIM: The purpose of this study was to determine from a range of vertical jump and rebound tests, which were the most suitable to measure different forms of stretch-shortening cycle function, and whether such tests could be used interchangeably. METHODS: Two hundred and fifty male youths (age, 12.26 ± 2.94 years; body mass, 47.11 ± 16.91 kg; standing height, 152.98 ± 17.40 cm; and sitting height, 76.89 ± 9.32 cm) were tested for squat and countermovement jump height, reactive strength index (during a maximal hopping test), and leg stiffness (during a sub-maximal hopping test). Stepwise multiple regressions were used to examine the relationships between different measures of SSC function in youths. RESULTS: Absolute leg stiffness was best predicted by body mass (r2=62%), however the explained variance was significantly reduced when normalized to leg length and body mass (r2=15.3%). Squat jump height best explained the total variance for reactive strength index (r2=53.9%), whilst countermovement and squat jump height were the best predictors of each other (r2=86%). CONCLUSION: Results would suggest that the test protocols used in this study were representative of different forms of SSC performance. Coaches and athletes should take these findings into account when attempting to select the appropriate testing protocols to measure the correct SSC action.

Atmospheric Carbon and Transport - America (ACT-America) Data Sets: Description, Management, and Delivery.

The ACT-America project is a NASA Earth Venture Suborbital-2 mission designed to study the transport and fluxes of greenhouse gases. The open and freely available ACT-America data sets provide airborne in situ measurements of atmospheric carbon dioxide, methane, trace gases, aerosols, clouds, and meteorological properties, airborne remote sensing measurements of aerosol backscatter, atmospheric boundary layer height and columnar content of atmospheric carbon dioxide, tower-based measurements, and modeled atmospheric mole fractions and regional carbon fluxes of greenhouse gases over the Central and Eastern United States. We conducted 121 research flights during five campaigns in four seasons during 2016-2019 over three regions of the US (Mid-Atlantic, Midwest and South) using two NASA research aircraft (B-200 and C-130). We performed three flight patterns (fair weather, frontal crossings, and OCO-2 underflights) and collected more than 1,140 h of airborne measurements via level-leg flights in the atmospheric boundary layer, lower, and upper free troposphere and vertical profiles spanning these altitudes. We also merged various airborne in situ measurements onto a common standard sampling interval, which brings coherence to the data, creates geolocated data products, and makes it much easier for the users to perform holistic analysis of the ACT-America data products. Here, we report on detailed information of data sets collected, the workflow for data sets including storage and processing of the quality controlled and quality assured harmonized observations, and their archival and formatting for users. Finally, we provide some important information on the dissemination of data products including metadata and highlights of applications of ACT-America data sets.

Promotion of physical activity for adolescents with cystic fibrosis: a qualitative study of UK multi disciplinary cystic fibrosis teams.

BACKGROUND: The Cystic Fibrosis Trust recently published a standards of care document which stated that patients should be given a physical activity (PA) programme based on their motivations, fitness, and willingness to be active. However, there remains much debate regarding the roles and responsibilities for PA promotion, as well as "optimal" recommendations and advice. This study aimed to qualitatively explore cystic fibrosis (CF) multidisciplinary teams (MDTs) advice, recommendations and practices relating to PA promotion for adolescents with CF. METHOD: Semi-structured interviews were conducted with fifteen members of CF MDTs (11 physiotherapists, two dieticians and two paediatricians). Thematic analysis was used to analyse the data. RESULTS: Major themes identified were: (1) structure of MDTs, (2) recommendations relating to intensities, durations and types of PA, and (3) use of exercise testing. Participants reported variation between MDTs in terms of who is responsible for promoting and supporting PA, the nature of advice given to patients, and the use of exercise testing. Participants consistently lacked confidence in their own or others' knowledge to provide standardised recommendations to patients and highlighted that PA promotion and support was often overlooked during busy periods. CONCLUSIONS: Despite its importance, PA support and promotion is not always prioritised. MDTs lack confidence in their ability to promote PA. Standardised advice and training relating to optimal intensities, durations and types of PA would provide a baseline from which to individualise advice to each patient and could increase confidence in PA promotion among MDTs.

Antigen-antibody reactions in rat brain sites induce transient changes in drinking behavior.

The septum or hypothalamus of rat brain was injected through implanted cannulas with antibody against membrane antigens in the rat brain or with antibody against exogenous soluble antigens (such as ovalbumin) followed by the specific antigen. Both immunological systems produced a moderate but highly significant decrease in drinking by thirsty rats. This phenomenon is suggested as an experimental model for behavioral disorders resulting from nondegenerative, immunological processes in the brain.

Antigenic correspondence of serum albumins among the primates.

The relative cross-reactivities as judged by tile quantitative precipitation reaction of 22 primate serum albumins were determined with pooled antiserums against human Serum albumnini. The atitgenic correspondences to human serum albumin of all but three serum albumin fell into narrow ranges, and the groups defined by these ranges are distinct taxonomic categories. The values of the cross-reactivity ranges are consistent with the presumed phylogenetic relationships to man on the assumption that the evolutionary modification of protein structure has been progressive and divergent.

Reproducibility of task activation using the Addenbrooke's cognitive examination in healthy controls: A functional Transcranial Doppler ultrasonography study.

INTRODUCTION: Cerebral blood flow velocity (CBFv) changes occurring with cognitive stimulation can be measured by Transcranial Doppler ultrasonography (TCD). The aim of this study was to assess the reproducibility of CBFv changes to the Addenbrooke's cognitive examination (ACE-III). NEW METHOD: 13 volunteers underwent bilateral TCD (middle cerebral artery), continuous heart rate (HR, 3-lead ECG, Finometer), beat-to-beat mean arterial pressure (MAP, Finometer), and end-tidal CO2 (ETCO2, capnography). After 5min baseline, all ACE-III tasks were performed in 3 domains (A/B/C). Data presented are population CBFv peak normalised changes and area under the curve (AUC). Statistical analysis was by 2-way repeated measures (ANOVA), intra-class correlation coefficient (ICC), standard error of measurement (SEM) and coefficient of variation (CV). RESULTS: 12 bilateral data sets were obtained (10 right hand dominant, 6 female). Baseline parameters (MAP, HR, ETCO2) did not differ between visits. All tasks increased CBFv. Only domain A on AUC analysis differed significantly on ANOVA, and one task on post hoc testing (p <0.05). ICC values were poor (<0.4) for most tasks, but 3 tasks produced more consistent results on AUC and peak CBFv analysis (range ICC: 0.15-0.73, peak CV: 16.2-56.1(%), AUC CV: 23.2-60.2(%), peak SEM: 2.5-6.0 (%), AUC SEM: 21.8-135.8 (%*s). COMPARISON WITH EXISTING METHODS: This is the first study to examine reproducibility of CBFv changes to a complete cognitive assessment tool. CONCLUSIONS: Reproducibility of CBFv measurements to the ACE-III was variable. AUC may provide more reliable estimates than peak CBFv responses. These data need validating in patient populations.

Transcranial Doppler ultrasonography in the assessment of neurovascular coupling responses to cognitive examination in healthy controls: A feasibility study.

BACKGROUND: We tested the hypothesis that paradigms from the Addenbrooke's Cognitive Examination (ACE-III), including those that had not been studied using TCD previously (novel) versus those which had been (established), would elicit changes in CBF velocity (CBFv). NEW METHOD: Healthy subjects were studied with bilateral transcranial Doppler (TCD), beat-to-beat blood pressure (Finapres), continuous electrocardiogram (ECG), and end-tidal CO2 (nasal capnography). After a 5-min baseline recording, cognitive tests of the ACE-III were presented to subjects, covering attention (SUB7, subtracting 7 from 100 sequentially), language (REP, repeating words and phrases), fluency (N-P, naming words), visuospatial (DRAW, clock-drawing), and memory (MEM, recalling name and address). An event marker noted question timing. RESULTS: Forty bilateral data sets were obtained (13 males, 37 right-hand dominant) with a median age of 31 years (IQR 22-52). Population normalized mean peak CBFv% in the dominant and non-dominant hemispheres, respectively, were: SUB7 (11.3±9.6%, 11.2±10.5%), N-P (12.7±11.7%, 11.5±12.0%), REP (12.9±11.7%, 11.6±11.6%), DRAW (13.3±11.7%, 13.2±15.4%) and MEM (13.2±10.3%, 12.0±10.1%). There was a significant difference between the dominant and non-dominant CBFv responses (p<0.008), but no difference between the amplitude of responses. COMPARISON WITH EXISTING METHODS: For established paradigms, our results are in excellent agreement to what has been found previously in the middle cerebral artery. CONCLUSIONS: Cognitive paradigms derived from the ACE-III led to significant lateralised changes in CBFv that were not distinct for novel paradigms. Further work is needed to assess the potential of paradigms to improve the interpretation of cognitive assessments in patients at risk of mild cognitive impairment.

Racial/Ethnic Differences in Correlates of Spontaneous and Medically-Indicated Late Preterm Births among Adolescents.

STUDY OBJECTIVE: To investigate the racial/ethnic differences in the correlates of spontaneous and medically-indicated late preterm birth (LPTB), defined as deliveries between 34 0/7 and 36 6/7 weeks gestation, among US adolescents. DESIGN: Population-based, retrospective cohort study. SETTING: Births in the United States to adolescents in 2012. PARTICIPANTS: Adolescents (younger than 20 years; n = 171,573) who delivered nonanomalous singleton first births between 34 and 44 weeks of gestation. INTERVENTIONS AND MAIN OUTCOME MEASURES: Bivariate and multivariable logistic regression were used to evaluate the associations between maternal risk factors and spontaneous and medically-indicated LPTB, stratified according to maternal race/ethnicity. RESULTS: Risk factors for spontaneous LPTB included single marital status among Asian adolescents; no insurance coverage among whites, Asian, and Hispanic adolescents; inadequate prenatal care among all racial/ethnic groups except American Indian, and adequate plus prenatal care among all races/ethnicities; prenatal smoking among whites and black adolescents; insufficient gestational weight gain among all racial/ethnic groups except American Indian; and prepregnancy underweight among white, black, and Hispanic adolescents. Risk factors for medically-indicated LPTB included inadequate prenatal care among white, black, and Hispanic adolescents, and adequate plus prenatal care among all racial/ethnic groups except Asian; insufficient gestational weight gain among white, black, and Hispanic adolescents; and prepregnancy overweight and obesity among white, black, and Hispanic adolescents. CONCLUSION: Our results show racial/ethnic differences in the correlates of spontaneous and medically-indicated LPTB among US adolescents and support the need for risk-specific interventions among different racial/ethnic groups.

The effect of oxidative stress during exercise in the horse.

Oxidative stress is an imbalance of the oxidant-to-antioxidant ratio in the body. Increases in oxidative stress and changes in antioxidant status have been shown during endurance and intense exercise and eventing competition in horses. Antioxidants include vitamins, minerals, enzymes, and proteins that must be synthesized in the body or obtained from the diet. Therefore, exercise level and diet are both factors that play a role in influencing the oxidative stress and antioxidant status of the equine athlete. Along with exercise intensity and duration, diet, age, and training program can also affect oxidative stress in the horse. Several studies using exogenous supplementation of vitamin E, vitamin C, and alpha-lipoic acid have shown positive results in decreasing the effects of exercise (endurance and intense exercise)-induced oxidative stress and increasing the antioxidant status based on the markers and antioxidants measured, whereas other studies using superoxide dismutase showed little effects on the exercise horse. The "free radical theory of aging" states that long-term effects of the degenerative changes associated with aging may induce oxidative stress. However, in old horses (22 ± 2 yr), lipid peroxidation levels and blood antioxidant concentrations were similar to those found in younger but mature (12 ± 2 yr) horses both at rest and during exercise. Other studies found that yearlings (18 ± 2.4 mo) that are novel to forced exercise had less lipid peroxidation and greater antioxidant status than mature mares (13 ± 2.1 yr) prior to exercise training. Exercise training reduced oxidative stress markers and improved antioxidant status in mares, whereas few effects were seen in yearlings. This indicates that youth provided more defense against oxidative stress due to exercise than the exercise training program. Other studies during competition (endurance, jumping, eventing, and racing) have investigated the influence on oxidative stress with varying results. Despite the multitude of studies examining the levels of lipid peroxidation, antioxidant status, and other related metabolites in the horse during exercise, we still have a long way to go before we fully understand the large variation in results both with and without antioxidant supplementation.

The effect of oxygen saturation targeting on retinal blood vessel growth using retinal image data from the BOOST-II UK Trial.

PURPOSE: Retinopathy of prematurity (ROP) is a disorder of developing retinal blood vessels in preterm infants. The purpose of this nested study was to investigate the effects of higher (91-95%) and lower (85-89%) oxygen saturation (SpO2) targeting on retinal blood vessel growth in preterm infants. METHODS: Retinal blood vessel growth in the higher (91-95%) and lower (85-89%) oxygen saturation (SpO2) targeting groups was compared. Suitable RetCam (Clarity, Pleasanton, CA, USA) images collected in the BOOST-II UK trial were used. The distances between the centre of the optic disc and the ROP ridge in the temporal and nasal retina were measured in pixel units. RESULTS: Images from 38 infants were studied, 20 from the higher SpO2 target group and 18 from the lower SpO2 target group. On average, temporal blood vessels extended further from the optic disc than nasal blood vessels, mean (standard deviation (SD)) 463.39 (55.05) pixels compared with 360.13 (44.47) pixels, respectively, P<0.0001. Temporal blood vessels extended less far from the optic disc in the higher SpO2 target group than in the lower SpO2 target group: mean (SD) 449.83 (56.16) pixels compared with 480.02 (49.94), respectively, P=0.055. Nasal retinal blood vessel measurements were broadly similar in the higher and lower SpO2 target groups; mean (SD) 353.96 (41.95) compared with 370.00 (48.82) pixels, respectively, P=0.38. CONCLUSIONS: Relatively high oxygen saturation targeting (91-95%) was associated with a trend (P=0.055) towards reduced retinal blood vessel growth in this study of preterm infants.