Immediate effects of microclimate modification enhance native shrub encroachment

Shrubs have become more dense and expanded beyond their range all over the world for a variety of reasons including increased temperatures, overgrazing, and alteration of historical fire regime. Native shrubs have been encroaching on Virginia barrier island grasslands for over half a century for unknown reasons. Species composition, soil nutrients, leaf area index (LAI), and ground and air temperature were recorded across the shrub to grass transition and at free-standing shrubs in a coastal grassland in order to determine the effect of shrub encroachment on plant community and microclimate. Species richness was significantly lower inside shrub thickets. Soil water content, organic matter, nitrogen (N), carbon (C), and LAI were higher in shrub thickets and free-standing shrubs compared to grasslands. Summer and fall maximum temperatures were lower and more moderate where shrubs were present. Fall and winter minimum temperatures were highest inside shrub thickets. Native shrubs impact microclimate and species composition immediately upon encroachment. These shrubs lower overall species composition, increase soil nutrients and moisture, moderate summer temperature, and increase winter temperature, which has consequences on a larger scale. As barrier islands are critical for protecting marsh and mainland habitats, understanding this mechanism for shrub expansion is important to predict future encroachment of shrubs and displacement of grassland habitat

Long-term Effect of Intraocular Lens vs Contact Lens Correction on Visual Acuity after Cataract Surgery during Infancy: A Randomized Clinical Trial

© 2020 American Medical Association. All rights reserved. Importance: Although intraocular lenses (IOLs) are often implanted in children, little is known whether primary IOL implantation or aphakia and contact lens correction results in better long-term visual outcomes after unilateral cataract surgery during infancy. Objective: To compare long-term visual outcomes with contact lens vs IOL correction following unilateral cataract surgery during infancy. Design, Setting, and Participants: This multicenter randomized clinical trial enrolled 114 infants with a unilateral congenital cataract who underwent cataract surgery with or without primary IOL implantation between 1 and 6 months of age. Data on long-term visual outcomes were collected when the children were age 10.5 years (July 14, 2015, to July 12, 2019) and analyzed from March 30 through August 6, 2019. Interventions: Intraocular lens implantation at the time of cataract surgery. Main Outcomes and Measures: Best-corrected visual acuity using the electronic Early Treatment Diabetic Retinopathy Study (E-ETDRS) testing protocol. Analysis was performed on an intention-to-treat basis. Results: Best-corrected visual acuity was measured at age 10.5 years for 110 of the 114 patients (96%) enrolled as infants. The participants included 58 girls (53%) and 52 boys (47%). Overall, 27 of the children (25%) had good (logMAR 0.30 [Snellen equivalent, 20/40] or better) visual acuity in the treated eye (12 [22%] in the IOL group and 15 [27%] in the aphakia group), but 50 children (44%) had a visual acuity of logMAR 1.00 (Snellen equivalent, 20/200) or worse (25 [44%] in the IOL group and 25 [44%] in the aphakia group). The median logMAR acuity in the treated eye was similar in children randomized to receive an IOL at the time of cataract extraction (0.89; interquartile range [IQR], 0.33-1.43 [Snellen equivalent, 20/159]) and those who remained aphakic (0.86; IQR, 0.30-1.46 [Snellen equivalent, 20/145]) (IQR, 0.30-1.46; P =.82). Although the overall difference in median visual acuity between the 2 groups was small, the estimate was imprecise (99% CI for the difference in medians was-0.54 to 0.47). Conclusions and Relevance: As in previous phases of the study, visual acuity outcomes were highly variable with only 27 children (25%) achieving excellent visual acuity in their treated eye and 50 children (44%) having poor vision in the treated eye. Implanting an IOL at the time of cataract extraction was neither beneficial nor detrimental to the visual outcome

Maximal and submaximal intended velocity squat sets: Do they selectively impact mechanical performance in paired multijoint upper‐body exercise sets?

This study aimed to investigate how squat protocols performed at maximal and submaximal intended velocities during interset periods of paired upper‐body exercises that impact the mechanical performance of these multijoint upper‐body exercises. Twenty‐one young and healthy adults (seven women) completed three experimental sessions, each comprising four sets of five repetitions at 75% of their 1‐repetition maximum, with a 4‐min break between sets using the bench press and bench pull exercises. The experimental sessions differed in the protocol utilized during the interset periods: (i) Passive—no physical exercise was performed; (ii) SQfast—5 repetitions of the squat exercise at maximal intended velocity against the load associated with a mean velocity (MV) of 0.75 m s−1; and (iii) SQslow—5 repetitions of the squat exercise at submaximal velocity (intended MV of 0.50 m s−1) against the load associated with an MV of 0.75 m s−1. Level of significance was p ≤ 0.05. The main findings revealed negligible differences (effect size [ES] < 0.20) among the exercise protocols (passive vs. SQfast vs. SQslow) for all mechanical variables during the bench pull, whereas during the bench press, small differences (ES from 0.23 to 0.31) emerged favoring the passive protocol over SQfast and SQslow in terms of mean set velocity and fastest MV of the set. The absence of significant differences between the SQfast and SQslow protocols, irrespective of the particular upper‐body exercise, implies that the intended lifting velocity does not influence the potential interference effect during paired set training procedures

Some Aspects of Cost/ Benefit Analysis for In-Service Inspection of PWR Steam Generators

This report discusses a number of aspects of cost/benefit (C/B) analysis for in-service inspection (lSI} of pressurized water reactor (PWR) steam generators (SGs) and identifies several problem areas that must be addressed prior to a full C/B analysis capability. Following a brief review of the impact of SG problems on the productivity of PWR units and of the scope and variability of SG problems among U.S. PWRs, various occupational implications of SG lSI are considered, namely manpower, time, and rad exposure. The opportunities provided by refueling outages in respect to lSI frequency and work time windows are reviewed. Indices for characterizing the nondestructive testing {NDT) information, rad exposure, $impact, and manpower and time attributes of single ISIs and a series of ISIs over an arbitrary evaluation period are presented and calculated for a number of lSI cases using SG parameters for three typical PWR units. A comparison of the$ impact of unscheduled outages attributable to SG problems with the $cost of ambitious lSI strategies indicates that the$ cost is virtually negligible for well-planned ISis. Considering the ALARA constraint on occupational rad exposure, the skilled manpower pool for NDT work appears to be the principal factor limiting lSI scope and frequency. Analysis of the manpower and time requirements for inspection of a 40-unit PWR population indicates, however, that an lSI strategy embodying two campaigns per year and a total population inspection within a 2-year interval is not far beyond current capabilities

Atmospheric particulate matter characterization by Fourier transform infrared spectroscopy: a review of statistical calibration strategies for carbonaceous aerosol quantification in US measurement networks

Atmospheric particulate matter (PM) is a complex mixture of many different substances and requires a suite of instruments for chemical characterization. Fourier transform infrared (FT-IR) spectroscopy is a technique that can provide quantification of multiple species provided that accurate calibration models can be constructed to interpret the acquired spectra. In this capacity, FT-IR spectroscopy has enjoyed a long history in monitoring gas-phase constituents in the atmosphere and in stack emissions. However, application to PM poses a different set of challenges as the condensed-phase spectrum has broad, overlapping absorption peaks and contributions of scattering to the mid-infrared spectrum. Past approaches have used laboratory standards to build calibration models for prediction of inorganic substances or organic functional groups and predict their concentration in atmospheric PM mixtures by extrapolation. In this work, we review recent studies pursuing an alternate strategy, which is to build statistical calibration models for mid-IR spectra of PM using collocated ambient measurements. Focusing on calibrations with organic carbon (OC) and elemental carbon (EC) reported from thermal–optical reflectance (TOR), this synthesis serves to consolidate our knowledge for extending FT-IR spectroscopy to provide TOR-equivalent OC and EC measurements to new PM samples when TOR measurements are not available. We summarize methods for model specification, calibration sample selection, and model evaluation for these substances at several sites in two US national monitoring networks: seven sites in the Interagency Monitoring of Protected Visual Environments (IMPROVE) network for the year 2011 and 10 sites in the Chemical Speciation Network (CSN) for the year 2013. We then describe application of the model in an operational context for the IMPROVE network for samples collected in 2013 at six of the same sites as in 2011 and 11 additional sites. In addition to extending the evaluation to samples from a different year and different sites, we describe strategies for error anticipation due to precision and biases from the calibration model to assess model applicability for new spectra a priori. We conclude with a discussion regarding past work and future strategies for recalibration. In addition to targeting numerical accuracy, we encourage model interpretation to facilitate understanding of the underlying structural composition related to operationally defined quantities of TOR OC and EC from the vibrational modes in mid-IR deemed most informative for calibration. The paper is structured such that the life cycle of a statistical calibration model for FT-IR spectroscopy can be envisioned for any substance with IR-active vibrational modes, and more generally for instruments requiring ambient calibrations.</p

The physical characteristics of specific phases of play during rugby union match-play

Purpose: This study quantified the frequencies and timings of rugby union match-play phases (i.e., attacking, defending, ball in play (BIP) and ball out of play (BOP)) and then compared the physical characteristics of attacking, defending and BOP between forwards and backs. Methods: Data were analysed from 59 male rugby union academy players (259 observations). Each player wore a micro-technology device (Optimeye S5, Catapult) with video footage analysed for phase timings and frequencies. Dependent variables were analysed using a linear mixed-effects model and assessed with magnitude-based inferences and Cohen’s d effect sizes (ES). Results: Attack, defence, BIP and BOP times were 12.7 ± 3.1, 14.7 ± 2.5, 27.4 ± 2.9 and 47.4 ± 4.1 min, respectively. Mean attack (26 ± 17 s), defence (26 ± 18 s) and BIP (33 ± 24 s) phases were shorter than BOP phases (59 ± 33 s). The relative distance in attacking phases was similar (112.2 ± 48.4 vs. 114.6 ± 52.3 m·min-1, ES = 0.00 ±0.23) between forwards and backs, while greater in forwards (114.5 ± 52.7 vs. 109.0 ± 54.8 m·min-1, ES = 0.32 ±0.23) during defence and greater in backs during BOP (ES = -0.66 ±0.23). Conclusion: Total time in attack, defence and therefore BIP was less than BOP. Relative distance was greater in forwards during defence, while greater in backs during BOP and similar between positions during attack. Players should be exposed to training intensities from in play phases (i.e., attack and defence) rather than whole-match data and practice technical skills during these intensities

Phylogeny and Biogeography of the Carnivorous Plant Family Sarraceniaceae

The carnivorous plant family Sarraceniaceae comprises three genera of wetland-inhabiting pitcher plants: Darlingtonia in the northwestern United States, Sarracenia in eastern North America, and Heliamphora in northern South America. Hypotheses concerning the biogeographic history leading to this unusual disjunct distribution are controversial, in part because genus- and species-level phylogenies have not been clearly resolved. Here, we present a robust, species-rich phylogeny of Sarraceniaceae based on seven mitochondrial, nuclear, and plastid loci, which we use to illuminate this family's phylogenetic and biogeographic history. The family and genera are monophyletic: Darlingtonia is sister to a clade consisting of Heliamphora+Sarracenia. Within Sarracenia, two clades were strongly supported: one consisting of S. purpurea, its subspecies, and S. rosea; the other consisting of nine species endemic to the southeastern United States. Divergence time estimates revealed that stem group Sarraceniaceae likely originated in South America 44–53 million years ago (Mya) (highest posterior density [HPD] estimate = 47 Mya). By 25–44 (HPD = 35) Mya, crown-group Sarraceniaceae appears to have been widespread across North and South America, and Darlingtonia (western North America) had diverged from Heliamphora+Sarracenia (eastern North America+South America). This disjunction and apparent range contraction is consistent with late Eocene cooling and aridification, which may have severed the continuity of Sarraceniaceae across much of North America. Sarracenia and Heliamphora subsequently diverged in the late Oligocene, 14–32 (HPD = 23) Mya, perhaps when direct overland continuity between North and South America became reduced. Initial diversification of South American Heliamphora began at least 8 Mya, but diversification of Sarracenia was more recent (2–7, HPD = 4 Mya); the bulk of southeastern United States Sarracenia originated co-incident with Pleistocene glaciation, <3 Mya. Overall, these results suggest climatic change at different temporal and spatial scales in part shaped the distribution and diversity of this carnivorous plant clade