Green Infrastructure (GI) practices have been identified as a sustainable method of managing stormwater over the years. Due to the increasing popularity of GI as an integrated urban water management ...strategy, most of the current catchment modeling tools incorporate these practices, as built-in modules. GI practices are also viewed as economically viable methods of stormwater management when compared to conventional approaches. Therefore, cost-benefit analysis or economics of GI are also emerging as obligatory components of modeling tools. Since these tools are regularly upgraded with latest advancements in the field, an assessment of tools for modeling stormwater management and economic aspects of GI practices is vital to developing them into more sophisticated tools. This review has undergone a three-phase process starting with 20 identified modeling tools available in the literature followed by a detailed review of a selection of ten most recent and popular modeling tools, based on their accessibility. The last phase of the review process is a comparison of the ten modeling tools along with their different attributes. The major aim of this review is to provide readers with the fundamental knowledge of different modeling tools currently available in the field, which will assist them with screening for a model, according to their requirements from the number of tools available. A secondary aim is to provide future research directions on developing more comprehensive tools for GI modeling, and recommendations have been presented.
Exercise prevents falls in older adults. Regular updates of estimated effects of exercise on falls are warranted given the number of new trials, the increasing number of older people globally and the ...major consequences of falls and fall-related injuries.
This update of a 2019 Cochrane Review was undertaken to inform the World Health Organization guidelines on physical activity and sedentary behaviour. Searches were conducted in six databases. We included randomised controlled trials evaluating effects of any form of physical activity as a single intervention on falls in people aged 60+ years living in the community. Analyses explored dose-response relationships. The certainty of the evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).
This review included 116 studies, involving 25,160 participants; nine new studies since the 2019 Cochrane Review. Exercise reduces the rate of falls by 23% (pooled rate ratio (RaR) 0.77, 95% confidence interval (CI) 0.71 to 0.83, 64 studies, high certainty evidence). Subgroup analysis showed variation in effects of different types of exercise (p < 0.01). Rate of falls compared with control is reduced by 24% from balance and functional exercises (RaR 0.76, 95% CI 0.70 to 0.82, 39 studies, high certainty evidence), 28% from programs involving multiple types of exercise (commonly balance and functional exercises plus resistance exercises, RaR 0.72, 95% CI 0.56 to 0.93, 15 studies, moderate certainty evidence) and 23% from Tai Chi (RaR 0.77, 95% CI 0.61 to 0.97, 9 studies, moderate certainty evidence). The effects of programs that primarily involve resistance training, dance or walking remain uncertain. Interventions with a total weekly dose of 3+ h that included balance and functional exercises were particularly effective with a 42% reduction in rate of falls compared to control (Incidence Rate Ratio (IRR) 0.58, 95% CI 0.45 to 0.76). Subgroup analyses showed no evidence of a difference in the effect on falls on the basis of participant age over 75 years, risk of falls as a trial inclusion criterion, individual versus group exercise, or whether a health professional delivered the intervention.
Given the strength of this evidence, effective exercise programs should now be implemented at scale.
A recent OECD report estimated that more than 4000 per- and polyfluorinated alkyl substances (PFASs) have been produced and used in a broad range of industrial and consumer applications. However, ...little is known about the potential hazards (e.g., bioactivity, bioaccumulation, and toxicity) of most PFASs. Here, we built machine-learning-based quantitative structure–activity relationship (QSAR) models to predict the bioactivity of those PFASs. By examining a number of available molecular data sets, we constructed the first PFAS-specific database that contains the bioactivity information on 1012 PFASs for 26 bioassays. On the basis of the collected PFAS data set, we trained 5 different machine learning models that cover a variety of conventional models (e.g., random forest and multitask neural network (MNN)) and advanced graph-based models (e.g., graph convolutional network). Those models were evaluated based on the validation data set. Both MNN and graph-based models demonstrated the best performance. The average of the best area-under-the-curve score for each bioassay is 0.916. For predictions on the OECD list, most of the biologically active PFASs have perfluoroalkyl chain lengths less than 12 and are categorized into fluorotelomer-related compounds and perfluoroalkyl acids and their precursors.
In this review, we consider the two prevailing hypotheses for the mechanisms that control the bioaccumulation of perfluorinated alkyl acids (PFAAs). The first assumes that partitioning to membrane ...phospholipids, which have a higher affinity for charged species than neutral storage lipids, can explain the high bioaccumulation potential of these compounds. The second assumes that interactions with proteinsincluding serum albumin, liver fatty acid binding proteins (L-FABP), and organic anion transportersdetermine the distribution, accumulation and half-lives of PFAAs. We consider three unique phenomena to evaluate the two models: (1) observed patterns of tissue distribution in the laboratory and field, (2) the relationship between perfluorinated chain length and bioaccumulation, and (3) species- and gender-specific variation in elimination half-lives. Through investigation of these three characteristics of PFAA bioaccumulation, we show the strengths and weaknesses of the two modeling approaches. We conclude that the models need not be mutually exclusive, but that protein interactions are needed to explain some important features of PFAA bioaccumulation. Although open questions remain, further research should include perfluorinated alkyl substances (PFASs) beyond the long-chain PFAAs, as these substances are being phased out and replaced by a wide variety of PFASs with largely unknown properties and bioaccumulation behavior.
Per- and polyfluoroalkyl substances (PFAS) are of concern because of their high persistence (or that of their degradation products) and their impacts on human and environmental health that are known ...or can be deduced from some well-studied PFAS. Currently, many different PFAS (on the order of several thousands) are used in a wide range of applications, and there is no comprehensive source of information on the many individual substances and their functions in different applications. Here we provide a broad overview of many use categories where PFAS have been employed and for which function; we also specify which PFAS have been used and discuss the magnitude of the uses. Despite being non-exhaustive, our study clearly demonstrates that PFAS are used in almost all industry branches and many consumer products. In total, more than 200 use categories and subcategories are identified for more than 1400 individual PFAS. In addition to well-known categories such as textile impregnation, fire-fighting foam, and electroplating, the identified use categories also include many categories not described in the scientific literature, including PFAS in ammunition, climbing ropes, guitar strings, artificial turf, and soil remediation. We further discuss several use categories that may be prioritised for finding PFAS-free alternatives. Besides the detailed description of use categories, the present study also provides a list of the identified PFAS per use category, including their exact masses for future analytical studies aiming to identify additional PFAS.
This study evaluates the effectiveness of green and cool roofs as potential Urban Heat Island (UHI) mitigation strategies, and the impacts of these strategies on human thermal comfort during one of ...the most extreme heatwave events (27th - 30th January 2009) in the city of Melbourne in southeast Australia. The Weather Research and Forecasting model coupled with the Single Layer Urban Canopy Model including different physical parameterization for various types of roofs (conventional, green and cool roofs) is used to investigate the impacts of green and cool roofs. Results show that the maximum roof surface UHI is reduced during the day by 1 °C–3.8 °C by increasing green roof fractions from 30% to 90%, and by 2.2 °C–5.2 °C by increasing the albedo of cool roofs from 0.50 to 0.85. Cool roofs are more efficient than the green roofs in reducing the UHI with maximum differences of up to 1.4 °C. The reductions of the UHI vary linearly with the increasing green roof fractions, but slightly non-linearly with the increasing albedo of cool roofs. The maximum reductions in wind speed are 1.25 m s−1 and 1.75 m s−1 with 90% green and cool roofs (albedo 0.85) respectively. While previous studies report that the advection of moist air from rural areas is a key mechanism, this study shows that this is not the case for the extreme heatwave event due to the very dry and warm conditions, and instead, convective rolls play a more important role. This study also shows that initial soil moisture for green roofs does not have a substantial impact on the UHI. Finally, green roofs improve human thermal comfort by reducing the Universal Thermal Comfort Index by up to 1.5 °C and 5.7 °C for pedestrian and roof surface levels respectively, and by 2.4 °C and 8 °C for cool roofs for the same levels.
Perfluorinated alkyl acids (PFAAs) are important global pollutants with unique pharmacokinetics. Evidence is accumulating that their behavior within organisms is affected by interaction with a number ...of proteins. In mammals, serum albumin, fatty acid binding proteins (FABPs) and organic anion transporters (OATs) have been identified as important to the tissue distribution, species-specific accumulation, and species- and gender-specific elimination rates of perfluoroalkyl carboxylates and perfluoroalkane sulfonates. Similar pharmacokinetics has been identified in fish. Yet, no mechanistic model exists for the bioaccumulation of PFAAs in fish that explicitly considers protein interactions. In this work, we present the first mechanistic protein-binding bioconcentration model for PFAAs in fish. Our model considers PFAA uptake via passive diffusion at the gills, association with serum albumin in the circulatory and extracellular spaces, association with FABP in the liver, and renal elimination and reabsorption facilitated by OAT proteins. The model is evaluated using measured bioconcentration and tissue distribution data collected in two previous studies of rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio). Comparing our model with previous attempts to describe PFAA bioconcentration using a nonspecific (partitioning-type) approach shows that inclusion of protein interactions is key to accurately predicting tissue-specific PFAA distribution and bioconcentration.
This study investigated the impacts of climate change on the urban heat island (UHI) and the number of very hot (maximum temperature >35°C) and very cold days (minimum temperature <5°C) in the ...central business district (CBD) of Melbourne city in Australia. A station located in Laverton (less urbanised area), which is 17 km southwest of Melbourne CBD, was selected as the reference station for the computation of UHI intensity in Melbourne CBD. Using daily minimum/maximum temperatures at the two stations, nocturnal/diurnal UHI intensities in Melbourne CBD were computed for the period 1952–2010. It was found that in Melbourne CBD, nocturnal UHI intensities show a clear rising trend over the period 1952–2010 unlike the diurnal UHI intensities. For the analysis of nocturnal UHI intensities in Melbourne CBD, under changing climate, for each calendar month statistical models based on the gene expression programming (GEP) technique were developed for downscaling general‐circulation model (GCM) outputs to monthly average minimum temperature at Melbourne CBD and Laverton. Using the outputs of HadCM3, GFDL2.0 and ECHAM5 pertaining to the A2 greenhouse gas emission scenario on the downscaling models, projections of monthly average minimum temperature were produced for the two stations over the period 2000–2099. In each season, at both stations, the ensemble average of monthly minimum temperature gradually increased over the period 2000–2099. The ensemble‐average UHI intensity in Melbourne CBD projected into the future was higher for all seasons in comparison to that of period 1952–1971. Downscaling models based on the GEP technique were developed for each calendar month for projecting the number of very hot days in November–March and very cold days in May–September in Melbourne CBD. It was found that, in the future, summer weather will spread to early autumn, and winter weather will move to early spring, in Melbourne CBD.
Summary
Associations of current and previous physical activity (PA) with bone health are unclear. In postmenopausal women with low bone mineral density (BMD), current PA was positively associated ...with femoral neck BMD and microarchitecture. Past PA was positively associated with tibial microarchitecture. PA appears beneficial for bone health throughout the lifespan.
Introduction
To compare associations of current and past self-reported bone-specific physical activity, and current accelerometer-determined physical activity (PA), with bone structure (bone mineral density BMD and microarchitecture) in postmenopausal women with osteopenia or osteoporosis.
Methods
Fifty community-dwelling postmenopausal women (mean age 64.4 ± 7.7) with hip or spine BMD T-score < − 1.0 SD were recruited for an exercise intervention. At baseline, current, past and total Bone-specific Physical Questionnaire (BPAQ) scores were self-reported, and percentages of sedentary, light and moderate to vigorous PA (MVPA) were objectively determined by accelerometer measurements. Bone structure was assessed by lumbar spine and hip dual-energy X-ray absorptiometry (DXA), 3D modelling algorithms (3D-SHAPER) of hip DXA scans and distal tibial high-resolution peripheral quantitative computed tomography (HR-pQCT) scans.
Results
Current BPAQ scores and MVPA were significantly positively associated with femoral neck areal BMD (
β
= 0.315,
p
= 0.031 and
β
= 0.311,
p
= 0.042, respectively) following multivariable adjustments. MVPA was also positively associated with femoral cortical surface BMD (
β
= 0.333,
p
= 0.028) and mean cortical thickness (
β
= 0.374,
p
= 0.013). Past and total BPAQ scores demonstrated positive associations with tibial trabecular number (
β
= 0.391,
p
= 0.008 and
β
= 0.381,
p
= 0.010, respectively), and negative associations with trabecular separation (
β
= − 0.396,
p
= 0.006 and
β
= − 0.380,
p
= 0.009, respectively) and distribution (
β
= − 0.411,
p
= 0.004 and
β
= − 0.396,
p
= 0.006, respectively). Current BPAQ score was positively associated with tibial cortical periosteal perimeter (
β
= 0.278,
p
= 0.014).
Conclusion
BPAQ scores were most consistently associated with tibial bone parameters in older women, with past PA having lasting benefits for trabecular microarchitecture, and current PA positively associated with cortical bone.
PDF
