Trajectories and tipping points of piñon-juniper woodlands after fire and thinning.

Piñon-juniper (PJ) woodlands are a dominant community type across the Intermountain West, comprising over a million acres and experiencing critical effects from increasing wildfire. Large PJ mortality and regeneration failure after catastrophic wildfire have elevated concerns about the long-term viability of PJ woodlands. Thinning is increasingly used to safeguard forests from fire and in an attempt to increase climate resilience. We have only a limited understanding of how fire and thinning will affect the structure and function of PJ ecosystems. Here, we examined vegetation structure, microclimate conditions, and PJ regeneration dynamics following ~20 years post-fire and thinning treatments. We found that burned areas had undergone a state shift that did not show signs of returning to their previous state. This shift was characterized by (1) distinct plant community composition dominated by grasses; (2) a lack of PJ recruitment; (3) a decrease in the sizes of interspaces in between plants; (4) lower abundance of late successional biological soil crusts; (5) lower mean and minimum daily soil moisture values; (6) lower minimum daily vapor pressure deficit; and (7) higher photosynthetically active radiation. Thinning created distinct plant communities and served as an intermediate between intact and burned communities. More intensive thinning decreased PJ recruitment and late successional biocrust cover. Our results indicate that fire has the potential to create drier and more stressful microsite conditions, and that, in the absence of active management following fire, there may be shifts to persistent ecological states dominated by grasses. Additionally, more intensive thinning had a larger impact on community structure and recruitment than less intensive thinning, suggesting that careful consideration of goals could help avoid unintended consequences. While our results indicate the vulnerability of PJ ecosystems to fire, they also highlight management actions that could be adapted to create conditions that promote PJ re-establishment.

Nutrient identity modifies the destabilising effects of eutrophication in grasslands.

Nutrient enrichment can simultaneously increase and destabilise plant biomass production, with co-limitation by multiple nutrients potentially intensifying these effects. Here, we test how factorial additions of nitrogen (N), phosphorus (P) and potassium with essential nutrients (K+) affect the stability (mean/standard deviation) of aboveground biomass in 34 grasslands over 7 years. Destabilisation with fertilisation was prevalent but was driven by single nutrients, not synergistic nutrient interactions. On average, N-based treatments increased mean biomass production by 21-51% but increased its standard deviation by 40-68% and so consistently reduced stability. Adding P increased interannual variability and reduced stability without altering mean biomass, while K+ had no general effects. Declines in stability were largest in the most nutrient-limited grasslands, or where nutrients reduced species richness or intensified species synchrony. We show that nutrients can differentially impact the stability of biomass production, with N and P in particular disproportionately increasing its interannual variability.

The consequences of climate change for dryland biogeochemistry.

Drylands, which cover > 40% of Earth's terrestrial surface, are dominant drivers of global biogeochemical cycling and home to more than one third of the global human population. Climate projections predict warming, drought frequency and severity, and evaporative demand will increase in drylands at faster rates than global means. As a consequence of extreme temperatures and high biological dependency on limited water availability, drylands are predicted to be exceptionally sensitive to climate change and, indeed, significant climate impacts are already being observed. However, our understanding and ability to forecast climate change effects on dryland biogeochemistry and ecosystem functions lag behind many mesic systems. To improve our capacity to forecast ecosystem change, we propose focusing on the controls and consequences of two key characteristics affecting dryland biogeochemistry: (1) high spatial and temporal heterogeneity in environmental conditions and (2) generalized resource scarcity. In addition to climate change, drylands are experiencing accelerating land-use change. Building our understanding of dryland biogeochemistry in both intact and disturbed systems will better equip us to address the interacting effects of climate change and landscape degradation. Responding to these challenges will require a diverse, globally distributed and interdisciplinary community of dryland experts united towards better understanding these vast and important ecosystems.

Development of a professional competency framework for Australian sonographers-perspectives for developing competencies using a Delphi methodology.

BACKGROUND: Professional competencies are important for enhancing alignment between the needs of education, industry and health consumers, whilst describing public expectations around health professionals. The development of competency standards for the sonography profession defines the behaviours, skills and knowledge sonographers should demonstrate for each learning and experience level. OBJECTIVE: The objective of this project was to develop a set of professional competency standards for the sonography profession which described in depth the behaviours, skills and knowledge sonographers should demonstrate across multiple learning and experience levels. METHODS: Representatives of three Australian ultrasound professional associations and seven tertiary institutions involved in entry-level sonographer education in Australia formed a research team (RT). The RT recruited an expert panel that responded to six survey rounds. Using a Delphi methodology, the results and free-text comments from each previous round were fed back to participants in the subsequent survey rounds to achieve a consensus. RESULTS: The project developed a professional competency framework for sonographers, which included four major domains: detailed competency standards, sonographer knowledge, sonographer attitudes and a holistic competency matrix [https://doi.org/10.6084/m9.figshare.17148035.v2.]. CONCLUSION: The Delphi methodology is an effective way to develop professional competency standards. This paper describes the methods and challenges in developing such standards for sonographers which could be translated to other health professionals.

Muted responses to chronic experimental nitrogen deposition on the Colorado Plateau.

Anthropogenic nitrogen (N) deposition is significantly altering both community structure and ecosystem processes in terrestrial ecosystems across the globe. However, our understanding of the consequences of N deposition in dryland systems remains relatively poor, despite evidence that drylands may be particularly vulnerable to increasing N inputs. In this study, we investigated the influence of 7 years of multiple levels of simulated N deposition (0, 2, 5, and 8 kg N ha-1 year-1) on plant community structure and biological soil crust (biocrust) cover at three semi-arid grassland sites spanning a soil texture gradient. Biocrusts are a surface community of mosses, lichens, cyanobacteria, and/or algae, and have been shown to be sensitive to N inputs. We hypothesized that N additions would decrease plant diversity, increase abundance of the invasive annual grass Bromus tectorum, and decrease biocrust cover. Contrary to our expectations, we found that N additions did not affect plant diversity or B. tectorum abundance. In partial support of our hypotheses, N additions negatively affected biocrust cover in some years, perhaps driven in part by inter-annual differences in precipitation. Soil inorganic N concentrations showed rapid but ephemeral responses to N additions and plant foliar N concentrations showed no response, indicating that the magnitude of plant and biocrust responses to N fertilization may be buffered by endogenous N cycling. More work is needed to determine N critical load thresholds for plant community and biocrust dynamics in semi-arid systems and the factors that determine the fate of N inputs.

Current Status of Transvaginal Ultrasound Accuracy in the Diagnosis of Deep Infiltrating Endometriosis Before Surgery: A Systematic Review of the Literature.

Endometriosis is a common gynecologic condition affecting as many as 1 per 10 women. Transvaginal ultrasound (TVUS) has become a frontline tool in the diagnosis of deep infiltrating endometriosis (DIE) before surgery. The primary aim of this review was to determine the accuracy of TVUS for DIE. The secondary aim was to determine accuracy specifically when a sonographer performed the TVUS examination. A systematic review was performed, searching literature by following a population, intervention, comparator, and outcome outline. MEDLINE, Embase, Emcare, and Google Scholar were searched in July 2018 and in November 2019. Including "sonographer" in the search terms yielded no results, so our terms were expanded. Two hundred and four articles were returned from the searches, and 35 were ultimately included in the final review. Analysis of the returned articles revealed the TVUS is a valuable diagnostic tool for DIE before surgery. Sensitivities ranged from 78.5% to 85.3%, specificities from 46.1% to 92.5%, and accuracies from 75.7% to 97%. Most authors reported site-specific sensitivities and specificities, which varied greatly between locations. Site-specific sensitivities ranged from 10% to 88.9% (uterosacral ligaments), 20% to 100% (bladder), 33.3% to 98.1% (rectosigmoid colon), and 31% to 98.7% (pouch of Douglas). Site-specific specificities ranged from 75% to 99.6% (uterosacral ligaments), 96.4% to 100% (bladder), 86% to 100% (rectosigmoid colon), and 90% to 100% (pouch of Douglas). Transvaginal ultrasound is an accurate tool in the diagnosis of DIE; however, limited data exist as to whether this technique is accurate when performed by sonographers. More evidence surrounding the reliability between operators is also needed.

Leaf-cutter ants engineer large nitrous oxide hot spots in tropical forests.

Though tropical forest ecosystems are among the largest natural sources of the potent greenhouse gas nitrous oxide (N2O), the spatial distribution of emissions across landscapes is often poorly resolved. Leaf cutter ants (LCA; Atta and Acromyrmex, Myrmicinae) are dominant herbivores throughout Central and South America, and influence multiple aspects of forest structure and function. In particular, their foraging creates spatial heterogeneity by concentrating large quantities of organic matter (including nitrogen, N) from the surrounding canopy into their colonies, and ultimately into colony refuse dumps. Here, we demonstrate that refuse piles created by LCA species Atta colombica in tropical rainforests of Costa Rica provide ideal conditions for extremely high rates of N2O production (high microbial biomass, potential denitrification enzyme activity, N content and anoxia) and may represent an unappreciated source of heterogeneity in tropical forest N2O emissions. Average instantaneous refuse pile N2O fluxes surpassed background emissions by more than three orders of magnitude (in some cases exceeding 80 000 µg N2O-N m-2 h-1) and generating fluxes comparable to or greater than those produced by engineered systems such as wastewater treatment tanks. Refuse-concentrating Atta species are ubiquitous in tropical forests, pastures and production ecosystems, and increase density strongly in response to disturbance. As such, LCA colonies may represent an unrecognized greenhouse gas point source throughout the Neotropics.

Remotely sensed canopy nitrogen correlates with nitrous oxide emissions in a lowland tropical rainforest.

Tropical forests exhibit significant heterogeneity in plant functional and chemical traits that may contribute to spatial patterns of key soil biogeochemical processes, such as carbon storage and greenhouse gas emissions. Although tropical forests are the largest ecosystem source of nitrous oxide (N2 O), drivers of spatial patterns within forests are poorly resolved. Here, we show that local variation in canopy foliar N, mapped by remote-sensing image spectroscopy, correlates with patterns of soil N2 O emission from a lowland tropical rainforest. We identified ten 0.25 ha plots (assemblages of 40-70 individual trees) in which average remotely-sensed canopy N fell above or below the regional mean. The plots were located on a single minimally-dissected terrace (<1 km2 ) where soil type, vegetation structure and climatic conditions were relatively constant. We measured N2 O fluxes monthly for 1 yr and found that high canopy N species assemblages had on average three-fold higher total mean N2 O fluxes than nearby lower canopy N areas. These differences are consistent with strong differences in litter stoichiometry, nitrification rates and soil nitrate concentrations. Canopy N status was also associated with microbial community characteristics: lower canopy N plots had two-fold greater soil fungal to bacterial ratios and a significantly lower abundance of ammonia-oxidizing archaea, although genes associated with denitrification (nirS, nirK, nosZ) showed no relationship with N2 O flux. Overall, landscape emissions from this ecosystem are at the lowest end of the spectrum reported for tropical forests, consist with multiple metrics indicating that these highly productive forests retain N tightly and have low plant-available losses. These data point to connections between canopy and soil processes that have largely been overlooked as a driver of denitrification. Defining relationships between remotely-sensed plant traits and soil processes offers the chance to map these processes at large scales, potentially increasing our ability to predict N2 O emissions in heterogeneous landscapes.

Nutrient acquisition, soil phosphorus partitioning and competition among trees in a lowland tropical rain forest.

We hypothesized that dinitrogen (N2 )- and non-N2 -fixing tropical trees would have distinct phosphorus (P) acquisition strategies allowing them to exploit different P sources, reducing competition. We measured root phosphatase activity and arbuscular mycorrhizal (AM) colonization among two N2 - and two non-N2 -fixing seedlings, and grew them alone and in competition with different inorganic and organic P forms to assess potential P partitioning. We found an inverse relationship between root phosphatase activity and AM colonization in field-collected seedlings, indicative of a trade-off in P acquisition strategies. This correlated with the predominantly exploited P sources in the seedling experiment: the N2 fixer with high N2 fixation and root phosphatase activity grew best on organic P, whereas the poor N2 fixer and the two non-N2 fixers with high AM colonization grew best on inorganic P. When grown in competition, however, AM colonization, root phosphatase activity and N2 fixation increased in the N2 fixers, allowing them to outcompete the non-N2 fixers regardless of P source. Our results indicate that some tropical trees have the capacity to partition soil P, but this does not eliminate interspecific competition. Rather, enhanced P and N acquisition strategies may increase the competitive ability of N2 fixers relative to non-N2 fixers.

Grassland management impacts on soil carbon stocks: a new synthesis.

Grassland ecosystems cover a large portion of Earths' surface and contain substantial amounts of soil organic carbon. Previous work has established that these soil carbon stocks are sensitive to management and land use changes: grazing, species composition, and mineral nutrient availability can lead to losses or gains of soil carbon. Because of the large annual carbon fluxes into and out of grassland systems, there has been growing interest in how changes in management might shift the net balance of these flows, stemming losses from degrading grasslands or managing systems to increase soil carbon stocks (i.e., carbon sequestration). A synthesis published in 2001 assembled data from hundreds of studies to document soil carbon responses to changes in management. Here we present a new synthesis that has integrated data from the hundreds of studies published after our previous work. These new data largely confirm our earlier conclusions: improved grazing management, fertilization, sowing legumes and improved grass species, irrigation, and conversion from cultivation all tend to lead to increased soil C, at rates ranging from 0.105 to more than 1 Mg C·ha-1 ·yr-1 . The new data include assessment of three new management practices: fire, silvopastoralism, and reclamation, although these studies are limited in number. The main area in which the new data are contrary to our previous synthesis is in conversion from native vegetation to grassland, where we find that across the studies the average rate of soil carbon stock change is low and not significant. The data in this synthesis confirm that improving grassland management practices and conversion from cropland to grassland improve soil carbon stocks.

Environmental controls on canopy foliar nitrogen distributions in a Neotropical lowland forest.

Distributions of foliar nutrients across forest canopies can give insight into their plant functional diversity and improve our understanding of biogeochemical cycling. We used airborne remote sensing and partial least squares regression to quantify canopy foliar nitrogen (foliar N) across ~164 km2 of wet lowland tropical forest in the Osa Peninsula, Costa Rica. We determined the relative influence of climate and topography on the observed patterns of foliar N using a gradient boosting model technique. At a local scale, where climate and substrate were constant, we explored the influence of slope position on foliar N by quantifying foliar N on remnant terraces, their adjacent slopes, and knife-edged ridges. In addition, we climbed and sampled 540 trees and analyzed foliar N in order to quantify the role of species identity (phylogeny) and environmental factors in predicting foliar N. Observed foliar N heterogeneity reflected environmental factors working at multiple spatial scales. Across the larger landscape, elevation and precipitation had the highest relative influence on predicting foliar N (30% and 24%), followed by soils (15%), site exposure (9%), compound topographic index (8%), substrate (6%), and landscape dissection (6%). Phylogeny explained ~75% of the variation in the field collected foliar N data, suggesting that phylogeny largely underpins the response to the environmental factors. Taken together, these data suggest that a large fraction of the variance in foliar N across the landscape is proximately driven by species composition, though ultimately this is likely a response to abiotic factors such as climate and topography. Future work should focus on the mechanisms and feedbacks involved, and how shifts in climate may translate to changes in forest function.

What is the accuracy of transvaginal ultrasound for endometriosis mapping prior to surgery when performed by a sonographer within an outpatient women's imaging centre?

INTRODUCTION: This study aimed to assess the accuracy of transvaginal ultrasound (TVUS) for the mapping of endometriosis before surgery when performed by sonographers in an outpatient women's imaging centre. METHODS: A prospective longitudinal cohort study was performed. The study group comprised of 201 women who underwent a comprehensive TVUS assessment, performed by a sonographer. Laparoscopy was performed as the reference standard. Complete TVUS and surgical data were available for 53 women who were included in the final analysis. RESULTS: Endometriosis was confirmed at a surgery in 50/53 (94.3%) participants, with 25/53 (47.2%) having deep endometriosis (DE) nodules and/or endometriomas present. TVUS for mapping of DE had an overall sensitivity of 84.0%, specificity of 89.3%, PPV of 87.5%, NPV of 86.2%, LR+ of 7.85, LR- of 0.18, and accuracy of 86.8% (P < 0.001). Ovarian immobility had poor sensitivity for detecting localised superficial endometriosis, DE, adhesions, and/or endometriomas (Left = 61.9% and right = 13.3%) but high specificities (left = 87.5% and right = 94.7%). Site-specific tenderness had low sensitivities and moderate specificities for the same. All soft markers of endometriosis failed to reach statistical significance except for left ovarian immobility (P = <0.001). CONCLUSION: Sonographers well experienced in obstetric and gynaecological imaging, working in an outpatient women's imaging setting can accurately map DE; however, the performance of soft markers for detection of SE was poor.

How long does a transvaginal ultrasound examination for endometriosis take in comparison to a routine transvaginal ultrasound examination?

INTRODUCTION: This study aimed to determine the additional time needed to perform an endometriosis transvaginal ultrasound (eTVUS) compared to routine transvaginal ultrasound (rTVUS). METHODS: A retrospective case-control study was performed. The study group included 199 eTVUS performed between September 2019 and September 2020. The control group comprised 105 consecutive rTVUS studies performed in the same time period. The time stamps on the ultrasound images of all cases in both groups were reviewed to determine the time taken to perform each study. Mean, median, minimum and maximum scan times for both groups were calculated as was percentage difference between scan times. A two-tailed, unpaired t-test of the normalised data and a Mann-Whitney U test assessing time difference of scans between two groups were performed with P value <0.05 considered statistically significant. RESULTS: Performing eTVUS took significantly longer than rTVUS with increases in the mean (8.4 vs 13.8 min, 64%), median (7 vs 12 min, 71%), minimum (4 vs 7 min, 75%) and maximum (19 vs 42 min, 121%) scan times. The Mann-Whitney U test indicated a statistically significant difference in the median scan times (5.0, CI 4.0-6.0), P < 0.001. An independent t-test of the normalised data revealed a significantly larger mean scan time for eTVUS than rTVUS, Mean = 9.05 95%CI [13.17-4.94], t(302) = 4.327, P < 0.001. R 2 = 0.583. CONCLUSION: Endometriosis transvaginal ultrasound added an average 5.4 min to rTVUS, which is statistically significant. For ultrasound departments wanting to offer this technique, doubling the scan time allocated to perform a transvaginal ultrasound (TVUS) is suggested.

Toll-like receptors in the mechanism of tributyltin-induced production of pro-inflammatory cytokines, IL-1ß and IL-6.

Tributyltin (TBT) is an environmental contaminant due to its use in a variety of applications as a biocide, including in marine anti-fouling paints. It has been detected in a number of human tissues including blood. Previous studies have shown that exposure to TBT increases the cellular production (secretion plus intracellular levels) of the pro-inflammatory cytokines IL-1ß and IL-6 by peripheral blood mononuclear cells (PMBCs) and this increase requires MAPK activation. Toll-like receptors (TLR) activate immune cells to produce pro-inflammatory cytokines in response to pathogen associated molecular patterns (PAMPs) and damage associated molecular patterns (DAMPs) leading to activation of MAPKs as well as other intracellular components that regulate cytokine production. The current study shows that selective inhibition of TLRs 4,1/2, and 8 diminishes the ability of TBT to stimulate IL-1ß and IL-6 production. However, selective inhibition of TLR3 enhanced the TBT-induced production of IL-1ß. This indicates that TBT may be either directly or indirectly interacting with certain TLR receptors as part of its mechanism of stimulating pro-inflammatory cytokine production. These results provide an important advance in understanding TBT stimulation of IL-1ß and IL-6, which has the potential to cause chronic inflammation and its attendant pathologies.

The initial impact of COVID-19 on Australasian Sonographers Part 1: Changes in scan numbers and sonographer work hours.

Introduction: COVID-19 has seen a series of lockdowns and suspension on non-urgent elective surgeries. Subsequently, there was a drop in the number of diagnostic imaging services billed in April, May, 2020. A survey was undertaken from March to June 2020 to determine the initial impact of COVID-19 on Australasian Sonographers. This article, the first in a 3-part series presents and discusses the results of this survey pertaining to changes in the number of scans performed, and changes in the working hours of sonographers. The remaining two articles in this series address other initial COVID-19 impacts on Australasian Sonographers. Methods: An online survey was conducted containing questions regarding changes to work hours and examination numbers. Results: 444 participants answered the survey. Seventy eight percent of sonographers reported a decrease in the number of examinations being performed in their department A decrease in work hours was reported by 68% of sonographers with almost a quarter of these reporting that they had lost all their hours. A higher percentage of work hours changes were seenin private practices. Many reductions in work hours were reported to be voluntary. Conclusion: Scan numbers in ultrasound departments were affected by COVID-19, as were sonographers' work hours.

The initial impact of COVID-19 on Australasian sonographers part 2: Changes to sonographic examination protocols and access to personal protective equipment.

INTRODUCTION: COVID-19 brought with it the requirement for healthcare workers to limit community transmission of the virus as much as possible by limiting patient contact and wearing Personal Protective Equipment (PPE). This study aimed to capture the initial adaptations to sonographic examination protocols within ultrasound departments and sonographer access to PPE. METHODS: An online survey was used to gather data on sonographer reflections of sonographic examination protocol changes seen in their departments and access to PPE between the 11th of March 2020 and the 14th of June 2020. RESULTS: To reduce the time sonographers spent with the patients and hence reduce the risk of exposure to COVID-19, sonographers reported adjustments to sonographic examination protocols including their duration and scheduling. Access to PPE was reported as poor. CONCLUSION: Numerous sonographic examination protocol changes were observed within ultrasound departments in Australasia in the initial response to COVID-19. Access to PPE was varied along with sonographer feelings around the impact of these changes.

The initial impact of COVID-19 on Australasian sonographers part 3: Sonographer professional, personal, and social wellbeing.

INTRODUCTION: The wellbeing of front-line healthcare workers can be impacted during a pandemic. This paper reports the initial impact on the wellbeing of COVID-19 on Australasian sonographers. METHODS: An online qualitative and quantitative survey was conducted between March and June 2020 to explore the wellbeing of Australasian sonographers in the early stages of the COVID-19 pandemic. RESULTS: Whilst most sonographers felt supported at work (300/379), those working in public hospitals felt more so than those in private practice. Sonographers in private practice felt more as though their job was at risk and were more likely to consider an alternate source of income. Sonographers felt they were working on the front line and many felt anxious about themselves (74%) or family (78%) contracting COVID-19 due to their employment. Forty-one percent of sonographers felt more isolated than normal, with younger age groups (18-34 years) feeling less like they had enough hobbies or selfcare activities to get them through. Twelve percent of sonographers reported never, or rarely, coping with the juggle of work and home life. CONCLUSION: The initial impact of the COVID-19 pandemic on the wellbeing of sonographers is evident. Longitudinal data will enable wellbeing to be tracked over time.

The value of the erect abdominal radiograph for the diagnosis of mechanical bowel obstruction and paralytic ileus in adults presenting with acute abdominal pain.

INTRODUCTION: There is discord on the value of the erect abdominal radiograph for diagnosing acute abdominal pathologies. The erect radiograph can be uncomfortable for patients in pain and increases patient radiation dose. AIM: To determine if including the erect abdominal radiograph in plain abdominal radiography (PAR) improved diagnostic accuracy for identifying mechanical bowel obstruction and/or paralytic ileus in adults presenting with acute abdominal pain. METHODS: PAR of 40 consecutive adults presenting with suspected bowel obstruction or paralytic ileus was retrospectively sampled and independently reviewed by two emergency department (ED) consultants and two radiology consultants for bowel obstruction and paralytic ileus across two sessions. In session 1, the assessors assessed the supine abdominal radiographs (PAR 1) and clinical details in a randomised order, and session 2, at least 6 weeks later, they assessed the supine and erect radiographs (PAR 2) and clinical details of the randomly re-ordered cases. Computed tomography was the reference standard. Pair-wise comparisons of receiver operating characteristic curves were calculated to assess for significant differences in participants' diagnostic accuracy using MedCalc 16.4.3. RESULTS: Average sensitivity, specificity and area under the receiver operating characteristic curves (AUROC) were 69.7%, 61.0% and 0.642 for PAR 1, respectively, and 80.0%, 53.4% and 0.632 for PAR 2 respectively. For AUROC there were no significant differences (P > 0.05) between PAR 1 and PAR 2. Intra-rater and inter-rater agreement improved in PAR 2. CONCLUSION: There was no statistically significant improvement in diagnostic accuracy when including the erect radiograph in PAR for the acute abdomen.

The acute effects of exercise on tendon dimensions and vascularity. An exploratory study using diagnostic ultrasound of the male Achilles tendon.

OBJECTIVES: This study examines the acute morphological changes (up to three days) in the normal, asymptomatic Achilles tendon (AT) in response to a single bout of exercise in relation to tendon dimensions and vascularity. DESIGN: Within-subject pre-post design. METHODS: Participants conducted a 7.7km pack march on a sealed road in a time of 1h 16min (approximately 6kmh-1). The longitudinal image of the sagittal diameter, transverse image of the area and vascularity at 20mm proximal to the superior aspect of the calcaneus and longitudinal image of the sagittal diameter at the insertion was measured the day before the pack march, immediately afterwards and then three days later. RESULTS: The tendon showed no significant change in sagittal diameter and cross-sectional area at 20mm proximal to the calcaneus and at the insertion immediately post-exercise. Tendon vascularity increased significantly in 91% of the left ATs and 87% of the right ATs in response to the pack march. Three days after the pack march an increase in sagittal diameter at the insertion and 20mm proximal to the calcaneus was observed and increased vascularity was still present in 22% of the ATs. CONCLUSIONS: This study highlighted the tendon's response to exercise and has shown that at three days post-exercise that the tendon had not recovered to pre-exercise levels with respect to tendon dimensions and vascularity.

Understanding how microbiomes influence the systems they inhabit.

Translating the ever-increasing wealth of information on microbiomes (environment, host or built environment) to advance our understanding of system-level processes is proving to be an exceptional research challenge. One reason for this challenge is that relationships between characteristics of microbiomes and the system-level processes that they influence are often evaluated in the absence of a robust conceptual framework and reported without elucidating the underlying causal mechanisms. The reliance on correlative approaches limits the potential to expand the inference of a single relationship to additional systems and advance the field. We propose that research focused on how microbiomes influence the systems they inhabit should work within a common framework and target known microbial processes that contribute to the system-level processes of interest. Here, we identify three distinct categories of microbiome characteristics (microbial processes, microbial community properties and microbial membership) and propose a framework to empirically link each of these categories to each other and the broader system-level processes that they affect. We posit that it is particularly important to distinguish microbial community properties that can be predicted using constituent taxa (community-aggregated traits) from those properties that cannot currently be predicted using constituent taxa (emergent properties). Existing methods in microbial ecology can be applied to more explicitly elucidate properties within each of these three categories of microbial characteristics and connect them with each other. We view this proposed framework, gleaned from a breadth of research on environmental microbiomes and ecosystem processes, as a promising pathway with the potential to advance discovery and understanding across a broad range of microbiome science.