Changes in bird assemblages because of vegetation homogenisation in communal livestock systems

Protected areas are intended to promote biodiversity representation and persistence; yet, whether they are effective in degraded landscapes where much of the original vegetation structure remains intact has received relatively little attention. We test whether avian assemblages in communal rangelands in savannas differ from savannas supporting a full complement of native herbivores and predators. Birds were surveyed in 36 transect counts conducted over 18 days. We also compare the vegetation structure between the two land-use types to assess whether differences in bird assemblages could be attributed to changes in vegetation structure. Bird assemblages were richer, had greater abundances and different compositions inside protected areas than rangelands. The median body mass of birds was larger inside than outside protected areas, and rangelands supported fewer grassland specialists, but more closed-canopy specialists. However, no differences in feeding guild composition were found between protected areas and communal rangelands. Additionally, vegetation structure, but not richness, differed between protected areas and communal rangelands: communal rangelands had higher densities of woody vegetation and shorter grass height than the protected areas. Our findings suggest that the altered vegetation structure in communal grazing camps has led to changes in the species richness and composition of bird communities and has been selected by closed-canopy specialists at the cost of open grassy specialists. Hunting in communal rangelands is likely to have resulted in the loss of large birds and in reductions in bird abundance in the rangelands. Therefore, land-use management that does not lead to irreversible landscape transformation can nevertheless result in changes in the diversity, composition and functioning of native assemblages. Conservation implications: Savanna landscapes that are degraded, but not transformed, support fewer bird species, fewer open habitat specialists and smaller birds because of vegetation homogenisation.South African National Research Foundationhttps://koedoe.co.zapm2020Plant Production and Soil Scienc

The role of browsers in maintaining the openness of savanna grazing lawns

In savannas, ruminant herbivores can have divergent impacts on tree recruitment and subsequent woody cover. Whereas heavy grazing by cattle results in woody thickening, intensive grazing by wildlife instead tends to be associated with lower woody cover. To disentangle why woody cover is low in areas heavily grazed by wildlife, we investigated (a) whether grazing lawns attract indigenous mammalian browsers, and if a preference for short-grass habitat decreases with browser body mass as predator susceptibility decreases; and (b) whether browser attraction to grazing lawns translates into the suppression of woody plants, including seedlings and saplings, thus maintaining the openness of heavily grazed short-grass areas. In Kruger National Park, South Africa, we contrasted browser abundance (using dung counts) on grazing lawns and on low-herbivory sites characterised by tall grass. Additionally, a herbivore exclosure experiment was set up to investigate the combined impact of browser removal and grass height habitat type on seedling survival and sapling growth of a dominant woody plant species. Finally, in Hluhluwe-iMfolozi Park (HiP), we examined the long-term (10 years) impact of browser removal on the growth rates of a range of woody species, monitored across ten sites along a gradient of herbivory ranging from grazing lawn to tall grass. Steenbok and impala selected short- over tall grass as preferred browsing sites, while elephant preferred tall grass. Browser abundance on short grass decreased with browser body mass, indicating that predator avoidance might be a key factor driving mesoherbivores to utilise grazing lawns. Seedling survival was lowest on grazing lawns when browsers were present, with mortality occurring in two out of every three seedlings. Similarly, sapling growth was lowest on grazing lawns, although browser removal had no significant effect. Evidence for increased browser impact on grazing lawns was clearest from our long-term herbivore exclosure experiment in HiP, which demonstrated that browsers strongly modify the growth rates of woody plants in short-grass habitats. Synthesis. These results provide support for the hypothesis that browsers, particularly browsing mesoherbivores and mixed feeders, are attracted to short-grass habitats, and that they help maintain grazing lawn openness by suppressing seedling survival and woody plant growth where grass is kept short by grazers.SUPPORTING INFORMATION: Table S1. Proportion short grass calculated as the mean proportion of grass height below 10 cm, recorded at ten sites in HiP (Hluhluwe and iMfolozi Game Reserves). The mean number of grazer dung piles per year (species: buffalo, blue wildebeest, impala, warthog, white rhino and zebra) are shown for each site. Values in brackets represent standard errors.Figure S1. The effect of grass height and exclosure status (fenced vs. unfenced) on tree height gain (mean ± SE). Browsing impact on tree height gain was higher in areas with short grass i.e. browsers utilised trees in short-grass ecosystems more than in tall-grass ecosystems. Results of linear regression analyses are displayed for the unfenced treatment of two dominant woody plant species: a) D. cinerea (R2 = 0.38, p = 0.05) and b) A. nilotica (R2 = 0.44, p = 0.11), and for two woody plant functional types: c) fine-leaved (R2 = 0.33, p = 0.09) and d) broad-leaved (R2 = 0.60, p = 0.02), across 10 sites in Hluhluwe-iMfolozi Park for the period 2000-2009.DATA AVAILABILITY STATEMENT: Data are available from the Dryad Digital Repository https://doi-org.uplib.idm.oclc.org/10.5061/dryad.76hdr7st3 (Voysey et al., 2020).The USAID/NAS program ‘Partnerships for Enhanced Engagement in Research' (sub-grant 2000004946, Cycle 3) and the South African National Research Foundation, Department of Science and Technology, Innovation and Priority Research Masters Scholarship.http://www.wileyonlinelibrary.com/journal/jechj2022Plant Production and Soil Scienc

Inhaled Nitric Oxide in preterm infants: a systematic review and individual patient data meta-analysis

BACKGROUND: Preterm infants requiring assisted ventilation are at significant risk of both pulmonary and cerebral injury. Inhaled Nitric Oxide, an effective therapy for pulmonary hypertension and hypoxic respiratory failure in the full term infant, has also been studied in preterm infants. The most recent Cochrane review of preterm infants includes 11 studies and 3,370 participants. The results show a statistically significant reduction in the combined outcome of death or chronic lung disease (CLD) in two studies with routine use of iNO in intubated preterm infants. However, uncertainty remains as a larger study (Kinsella 2006) showed no significant benefit for iNO for this combined outcome. Also, trials that included very ill infants do not demonstrate significant benefit. One trial of iNO treatment at a later postnatal age reported a decrease in the incidence of CLD. The aim of this individual patient meta-analysis is to confirm or refute these potentially conflicting results and to determine the extent to which patient or treatment characteristics may explain the results and/or may predict benefit from inhaled Nitric Oxide in preterm infants. METHODS/DESIGN: The Meta-Analysis of Preterm Patients on inhaled Nitric Oxide (MAPPiNO) Collaboration will perform an individual patient data meta-analysis to answer these important clinical questions. Studies will be included if preterm infants receiving assisted ventilation are randomized to receive inhaled Nitric Oxide or to a control group. The individual patient data provided by the Collaborators will be analyzed on an intention-to-treat basis where possible. Binary outcomes will be analyzed using log-binomial regression models and continuous outcomes will be analyzed using linear fixed effects models. Adjustments for trial differences will be made by including the trial variable in the model specification. DISCUSSION: Thirteen (13) trials, with a total of 3567 infants are eligible for inclusion in the MAPPiNO systematic review. To date 11 trials (n = 3298, 92% of available patients) have agreed to participate. Funding was successfully granted from Ikaria Inc as an unrestricted grant. A collaborative group was formed in 2006 with data collection commencing in 2007. It is anticipated that data analysis will commence in late 2009 with results being publicly available in 2010

Effect of oral Dexamethasone without immediate antibiotics vs placebo on acute sore throat in adults:a randomized clinical trial

Importance: acute sore throat poses a significant burden on primary care and is a source of inappropriate antibiotic prescribing. Corticosteroids could be an alternative symptomatic treatment.Objective: to assess the clinical effectiveness of oral corticosteroids for acute sore throat in the absence of antibiotics.Design, Setting, and Participants: double-blind, placebo-controlled randomized trial (April 2013-February 2015; 28-day follow-up completed April 2015) conducted in 42 family practices in South and West England, enrolled 576 adults recruited on the day of presentation to primary care with acute sore throat not requiring immediate antibiotic therapy.Interventions: single oral dose of 10 mg of dexamethasone (n = 293) or identical placebo (n = 283).Main Outcomes and Measures: Primary: proportion of participants experiencing complete resolution of symptoms at 24 hours. Secondary: complete resolution at 48 hours, duration of moderately bad symptoms (based on a Likert scale, 0, normal; 6, as bad as it could be), visual analog symptom scales (0-100 mm; 0, no symptom to 100, worst imaginable), health care attendance, days missed from work or education, consumption of delayed antibiotics or other medications, adverse events.Results: among 565 eligible participants who were randomized (median age, 34 years [interquartile range, 26.0-45.5 year]; 75.2% women; 100% completed the intervention), 288 received dexamethasone; 277, placebo. At 24 hours, 65 participants (22.6%) in the dexamethasone group and 49 (17.7%) in the placebo group achieved complete resolution of symptoms, for a risk difference of 4.7% (95% CI, -1.8% to 11.2%) and a relative risk of 1.28 (95% CI; 0.92 to 1.78; P = .14). At 24 hours, participants receiving dexamethasone were not more likely than those receiving placebo to have complete symptom resolution. At 48 hours, 102 participants (35.4%) in the dexamethasone group vs 75 (27.1%) in the placebo group achieved complete resolution of symptoms, for a risk difference of 8.7% (95% CI, 1.2% to 16.2%) and a relative risk of 1.31 (95% CI, 1.02 to 1.68; P = .03). This difference also was observed in participants not offered delayed antibiotic prescription, for a risk difference of 10.3% (95% CI, 0.6% to 20.1%) and a relative risk of 1.37 (95% CI, 1.01 to 1.87; P = .046). There were no significant differences in any other secondary outcomes.Conclusions and Relevance: among adults presenting to primary care with acute sore throat, a single dose of oral dexamethasone compared with placebo did not increase the proportion of patients with resolution of symptoms at 24 hours. However, there was a significant difference at 48 hours.<br/

Are hippos Africa's most influential megaherbivore? A review of ecosystem engineering by the semi-aquatic common hippopotamus

Megaherbivores perform vital ecosystem engineering roles, and have their last remaining stronghold in Africa. Of Africa's remaining megaherbivores, the common hippopotamus (Hippopotamus amphibius) has received the least scientific and conservation attention, despite how influential their ecosystem engineering activities appear to be. Given the potentially crucial ecosystem engineering influence of hippos, as well as mounting conservation concerns threatening their long-term persistence, a review of the evidence for hippos being ecosystem engineers, and the effects of their engineering, is both timely and necessary. In this review, we assess, (i) aspects of hippo biology that underlie their unique ecosystem engineering potential; (ii) evaluate hippo ecological impacts in terrestrial and aquatic environments; (iii) compare the ecosystem engineering influence of hippos to other extant African megaherbivores; (iv) evaluate factors most critical to hippo conservation and ecosystem engineering; and (v) highlight future research directions and challenges that may yield new insights into the ecological role of hippos, and of megaherbivores more broadly. We find that a variety of key life-history traits determine the hippo's unique influence, including their semi-aquatic lifestyle, large body size, specialised gut anatomy, muzzle structure, small and partially webbed feet, and highly gregarious nature. On land, hippos create grazing lawns that contain distinct plant communities and alter fire spatial extent, which shapes woody plant demographics and might assist in maintaining fire-sensitive riverine vegetation. In water, hippos deposit nutrient-rich dung, stimulating aquatic food chains and altering water chemistry and quality, impacting a host of different organisms. Hippo trampling and wallowing alters geomorphological processes, widening riverbanks, creating new river channels, and forming gullies along well-utilised hippo paths. Taken together, we propose that these myriad impacts combine to make hippos Africa's most influential megaherbivore, specifically because of the high diversity and intensity of their ecological impacts compared with other megaherbivores, and because of their unique capacity to transfer nutrients across ecosystem boundaries, enriching both terrestrial and aquatic ecosystems. Nonetheless, water pollution and extraction for agriculture and industry, erratic rainfall patterns and human–hippo conflict, threaten hippo ecosystem engineering and persistence. Therefore, we encourage greater consideration of the unique role of hippos as ecosystem engineers when considering the functional importance of megafauna in African ecosystems, and increased attention to declining hippo habitat and populations, which if unchecked could change the way in which many African ecosystems function.https://onlinelibrary.wiley.com/journal/1469185x2024-04-24hj2023Mammal Research InstituteZoology and EntomologySDG-15:Life on lan

Oral corticosteroid use for clinical and cost-effective symptom relief of sore throat: study protocol for a randomized controlled trial

BackgroundManagement of acute sore throat poses a significant burden on UK general practices, with almost 10% of registered patients attending their GP with sore throat every year. Nearly half of all patients presenting with acute sore throat are treated with antibiotics, despite their limited effect. In a recent systematic review we demonstrated that a single dose of steroids reduced the severity and time to resolution of sore throat. However, all of the trials included looked at the use of steroids alongside antibiotics and only one was in a primary care setting. This trial aims to assess the efficacy and cost-effectiveness of a single oral dose of corticosteroids on symptoms of sore throat in patients receiving either a delayed antibiotic prescription or no antibiotics at all in UK primary care.Methods/DesignA double-blind, two arm, randomized, placebo controlled trial in adults (?18 years of age) presenting to primary care with acute sore throat (&lt;seven days). Participants are recruited on the day of presentation to their GP practice. GPs or nurses assess eligibility, record baseline clinical features and obtain a throat swab for bacterial culture. Participants are being randomized to treatment arms at a ratio of 1:1. Treatment arms will be stratified according to whether patients are being given a delayed antibiotic prescription or no antibiotic prescription and by recruiting centre (Oxford, Bristol or Southampton). Outcome data is being collected at 24 and 48 hours via text message or telephone call, from days 0 to 7 using a patient symptom diary and at one month via a GP notes review.DiscussionThis will be the first randomized controlled trial of oral corticosteroids in adults presenting to primary care with sore throat in the UK, and the first to examine the clinical and cost-effectiveness of oral corticosteroids for the treatment of sore throat in the absence of antibiotics.Trial registrationThis trial is registered with Current Controlled Trials on 26 March 2013, registration number: ISRCTN17435450

Diagnostic accuracy of FEVER-Pain and Centor criteria for bacterial throat infection in adults with sore throat: a secondary analysis of a randomised controlled trial

Background: Sore throat is a common and self-limiting condition. There remains ambiguity in stratifying patients to immediate, delayed or no antibiotic prescriptions. NICE recommends two clinical prediction rules (CPRs), FeverPAIN and CENTOR, to guide decision-making. Aim: Describe the diagnostic accuracy of CPRs in identifying streptococcal throat infections. Design and Setting: Adults presenting to UK primary care with sore throat, who did not require immediate antibiotics. Methods: As part of the Treatment Options without Antibiotics for Sore Throat (TOAST) trial, 565 participants, aged ≥ 18, were recruited on day of presentation to general practice. Physicians could opt to give delayed prescriptions. CPR scores were not part of the trial protocol but calculated post-hoc from baseline assessments. Diagnostic accuracy was calculated by comparing scores to throat swab cultures. Results: 81/502 (16.1%) of patients had Group A, C or G streptococcus cultured on throat swab. Overall diagnostic accuracy of both CPRs was poor: area under receiver-operating-characteristics curve 0.62 for Centor; 0.59 for FeverPAIN. Post-test probability of a positive or negative test was 27.3% (95% confidence intervals: 6.0-61.0%) and 84.1% (80.6-87.2%) for FeverPAIN ≥4, versus 25.7% (16.2-37.2%) and 85.5% (81.8-88.7%) for Centor ≥3. Higher CPR scores were associated with increased delayed antibiotic prescriptions (2 = 8.42, p=0.004 for FeverPAIN ≥4; 2 = 32.0, p&lt;0.001 for Centor ≥3). Conclusions: In those that do not require immediate antibiotics in primary care, neither CPR provide a reliable way of diagnosing streptococcal throat infection. However, clinicians were more likely to give delayed prescriptions to those with higher scores

Effect of fenofibrate on amputation events in people with type 2 diabetes mellitus (FIELD study): a prespecified analysis of a randomised controlled trial

BACKGROUND: Amputations in people with type 2 diabetes mellitus substantially impair their quality of life and impose high costs on health-care systems. Our aim was to assess the effect of fenofibrate on amputation events in a large cohort of patients with type 2 diabetes. METHODS: In the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study, 9795 patients aged 50-75 years with type 2 diabetes were randomly assigned by computer-generated randomisation sequence to receive fenofibrate 200 mg per day (n=4895) or matching placebo (n=4900) for 5 years' duration. Information about non-traumatic amputation-a prespecified tertiary endpoint of the study-was routinely gathered. Clinicians who were masked to treatment allocation adjudicated amputations as minor or major (below or above the ankle, respectively). Amputations were also classified on the basis of whether or not large-vessel disease was present in the limb, to distinguish those related to large-artery atherosclerosis from those predominantly related to microvascular disease. Analysis was by intention to treat (ITT). The FIELD study is registered as an International Standard Randomised Controlled Trial, number ISRCTN64783481. FINDINGS: All 9795 patients were included in the ITT population. 115 patients had one or more non-traumatic lower-limb amputations due to diabetes. Previous cardiovascular disease, microvascular disease, previous non-traumatic amputation or skin ulcer, smoking, and longer duration of diabetes were more frequent in patients who had amputations during the trial than in those who had other cardiovascular events or in those who had neither event (all p&lt;0.001 for three-way comparison). Mean lipid concentrations differed between patients who had on-study amputations and those who had other cardiovascular events or neither event, but by no more than 0.2 mmol/L. The risks of first amputation (45 vs 70 events; hazard ratio [HR] 0.64, 95% CI 0.44-0.94; p=0.02) and minor amputation events without known large-vessel disease (18 vs 34 events; 0.53, 0.30-0.94; p=0.027) were lower for patients assigned to fenofibrate than for patients assigned to placebo, with no difference between groups in risk of major amputations (24 vs 26 events; 0.93, 0.53-1.62; p=0.79). INTERPRETATION: Classic markers of macrovascular and microvascular risk were associated with lower extremity amputations in patients with type 2 diabetes. Treatment with fenofibrate was associated with a lower risk of amputations, particularly minor amputations without known large-vessel disease, probably through non-lipid mechanisms. These findings could lead to a change in standard treatment for the prevention of diabetes-related lower-limb amputations. FUNDING: Laboratoires Fournier SA (now part of Solvay Pharmaceuticals) and National Health and Medical Research Council of Australia