Restoring riparian ecosystems: The challenge of accommodating variability and designing restoration trajectories

Flood disturbance processes play a key role in the functioning of riparian ecosystems and in the maintenance of biodiversity along river corridors. As a result, riparian ecosystems can be described as mobile habitat mosaics characterized by variability and unpredictability. Any river restoration initiative should aim to mimic these attributes. This paper suggests that there needs to be an increased institutional capacity to accept some levels of both variability and unpredictability in the ecological outcomes of river restoration projects. Restoration projects have frequently used some form of historical or contemporary reference system to define objectives and to help in the evaluation process. Using these reference systems can give a false sense of the predictability of ecological outcomes. We suggest that reference systems need to be used with caution for six reasons: (1) there are often no appropriate reference systems to use, (2) many catchment parameters have changed since the times of chosen historic reference systems, (3) climate change has been continuous throughout the Holocene, (4) projected climate change is of uncertain magnitude, (5) alien species cannot be avoided, and (6) landscape context changes through time. As well as defining short-term objectives, we suggest that river restoration projects should also formulate longer-term (decadel) restoration trajectories that are less predictable but more representative of real system attributes. Restoration trajectories could be defined using a range of ecological outcomes to accommodate interannual variability. The challenges of defining what levels of variability are important for restoring European floodplain forests are used to demonstrate the difficulties of broadening approaches and creating trajectories. In particular, the changing significance of variability at different spatial and temporal scales is discussed. An account is given of a restoration project at Wicken Fen in the United Kingdom in which nondeterministic approaches to goal setting have been initiated

Regional variation in the mechanical properties of cortical bone from the porcine femur

Despite the widespread use of porcine bone as a substitute for human bone in the development of surgical technique and the use of fixation devices, relatively few studies have reported on the mechanical behaviour of porcine long bones. Regional variation in the mechanical properties of cortical bone from porcine femora was investigated using three-point bending and cutting tests. Results were related to measurements of bone architecture and composition and Rutherford backscattering spectrometry (RBS) was used to calculate the calcium to phosphorus ratio. There was significant, but limited, regional variation in the strength of the femur with bone from the distal, posterior quadrant (241.4 10.43 MPa) being significantly stronger than that of the lateral quadrant (162.3 17.96 MPa). Cortical bone was also anisotropic; samples cut transverse to the bone’s axis were around six times tougher than those cut parallel to the axis (p < 0.05). This corresponded with a significant negative correlation between the Young’s modulus and toughness when cut along the longitudinal axis. RBS analysis of cortical bone samples gave a Ca : P ratio of 1.37 ± 0.035, somewhat lower than that reported for cortical bone of adult human femora. These results indicate that the mechanical properties of cortical bone show significant, but limited, variation around the porcine femur and that this should be taken into consideration when sampling and choosing an appropriate animal model for orthopaedic biomechanics research

Evaluating the use of agricultural moisture probes in the historic built environment

Much of the deterioration affecting historic buildings is a direct result of moisture penetration in porous building materials. This damage can be wide-ranging and severe – from “puddle staining” and mould, to decay fungi and deterioration due to the crystallisation of soluble salts. The relationship between masonry moisture content and the extent of the decay is complex, and monitoring moisture movement, particularly within mass masonry structures is problematic. If, however, effective conservation strategies are to be developed and adopted, it is imperative that a full understanding of the causes and mechanisms behind moisture-driven deterioration is achieved, and the development of an effective method for monitoring masonry moisture movement key. Current research has been evaluating the potential of utilising technology, normally used in agriculture, for the historic built environment. Methodologies for establishing calibration protocols for the Delta-T PR2 capacitance-type soil moisture probe (Delta-T Devices Ltd) is discussed for a range of historic masonry materials, and an assessment given of its suitability for use in historic masonry structures. A three-year case-study at North Foreland Lighthouse (a grade II listed building in Kent, England), carried out in parallel with the probe evaluation and calibration, provided invaluable ‘real’ data for validating the use of the probe in historic contexts. The impact of moisture ingress into the thick masonry walls of North Foreland’s tower, and its subsequent impact on the internal environment and observed salt-induced material decay, was evaluated, and has been used to inform an effective conservation strategy for the lighthouse

Evaluating the use of agricultural moisture probes in the historic built environment

Much of the deterioration affecting historic buildings is a direct result of moisture penetration in porous building materials. This damage can be wide-ranging and severe – from “puddle staining†and mould, to decay fungi and deterioration due to the crystallisation of soluble salts. The relationship between masonry moisture content and the extent of the decay is complex, and monitoring moisture movement, particularly within mass masonry structures is problematic. If, however, effective conservation strategies are to be developed and adopted, it is imperative that a full understanding of the causes and mechanisms behind moisture-driven deterioration is achieved, and the development of an effective method for monitoring masonry moisture movement key. Current research has been evaluating the potential of utilising technology, normally used in agriculture, for the historic built environment. Methodologies for establishing calibration protocols for the Delta-T PR2 capacitance-type soil moisture probe (Delta-T Devices Ltd) is discussed for a range of historic masonry materials, and an assessment given of its suitability for use in historic masonry structures. A three-year case-study at North Foreland Lighthouse (a grade II listed building in Kent, England), carried out in parallel with the probe evaluation and calibration, provided invaluable ‘real’ data for validating the use of the probe in historic contexts. The impact of moisture ingress into the thick masonry walls of North Foreland’s tower, and its subsequent impact on the internal environment and observed salt-induced material decay, was evaluated, and has been used to inform an effective conservation strategy for the lighthouse.</p

Global Incidence and Risk Factors Associated With Postoperative Urinary Retention Following Elective Inguinal Hernia Repair

Importance Postoperative urinary retention (POUR) is a well-recognized complication of inguinal hernia repair (IHR). A variable incidence of POUR has previously been reported in this context, and contradictory evidence surrounds potential risk factors.Objective To ascertain the incidence of, explore risk factors for, and determine the health service outcomes of POUR following elective IHR.Design, Setting, and Participants The Retention of Urine After Inguinal Hernia Elective Repair (RETAINER I) study, an international, prospective cohort study, recruited participants between March 1 and October 31, 2021. This study was conducted across 209 centers in 32 countries in a consecutive sample of adult patients undergoing elective IHR.Exposure Open or minimally invasive IHR by any surgical technique, under local, neuraxial regional, or general anesthesia.Main Outcomes and Measures The primary outcome was the incidence of POUR following elective IHR. Secondary outcomes were perioperative risk factors, management, clinical consequences, and health service outcomes of POUR. A preoperative International Prostate Symptom Score was measured in male patients.Results In total, 4151 patients (3882 male and 269 female; median [IQR] age, 56 [43-68] years) were studied. Inguinal hernia repair was commenced via an open surgical approach in 82.2% of patients (n = 3414) and minimally invasive surgery in 17.8% (n = 737). The primary form of anesthesia was general in 40.9% of patients (n = 1696), neuraxial regional in 45.8% (n = 1902), and local in 10.7% (n = 446). Postoperative urinary retention occurred in 5.8% of male patients (n = 224), 2.97% of female patients (n = 8), and 9.5% (119 of 1252) of male patients aged 65 years or older. Risk factors for POUR after adjusted analyses included increasing age, anticholinergic medication, history of urinary retention, constipation, out-of-hours surgery, involvement of urinary bladder within the hernia, temporary intraoperative urethral catheterization, and increasing operative duration. Postoperative urinary retention was the primary reason for 27.8% of unplanned day-case surgery admissions (n = 74) and 51.8% of 30-day readmissions (n = 72).Conclusions The findings of this cohort study suggest that 1 in 17 male patients, 1 in 11 male patients aged 65 years or older, and 1 in 34 female patients may develop POUR following IHR. These findings could inform preoperative patient counseling. In addition, awareness of modifiable risk factors may help to identify patients at increased risk of POUR who may benefit from perioperative risk mitigation strategies