1,870 research outputs found
Incontinence-specific quality of life measures used in trials of treatments for female urinary incontinence: a systematic review.
This systematic review examined the use of incontinence-specific QOL measures in clinical trials of female incontinence treatments, and systematically evaluated their quality using a standard checklist.
Of 61 trials included in the review, 58 (95.1%) used an incontinence-specific QOL measure. The most commonly used were IIQ (19 papers), I-QoL (12 papers) and UDI (9 papers). Eleven papers (18.0%) used measures which were not referenced or were developed specifically for the study. The eight QOL measures identified had good clinical face validity and measurement properties.
We advise researchers to evaluate carefully the needs of their specific study, and select the QOL measure that is most appropriate in terms of validity, utility and relevance, and discourage the development of new measures. Until better evidence is available on the validity and comparability of measures, we recommend that researchers consider using IIQ or I-QOL with or without UDI in trials of incontinence treatments
Carbon, nitrogen, and phosphorus stoichiometric response to hydrologic extremes in a tributary to Lake Erie, USA
Anthropogenic activities are a major cause of water quality impairment. We evaluated how hydrologic extremes (5th and 95th percentile of flow) affect carbon (C), nitrogen (N), and phosphorus (P) stoichiometry in a tile-drained agricultural tributary to Lake Erie. Water samples collected (2003ā2009) from three sites along one agricultural drainage ditch and its receiving third-order stream were analyzed for C, N, and P. The C/N/P concentrations were transformed to compare against the Redfield ratio (106:16:1 C/N/P), ideal for algal proliferation. Nitrogen was depleted relative to C and P at two sites on the agricultural ditch during extreme low-flow conditions, whereas P was depleted to C and N at the third. Tile drainage N and P losses during high flows shifted stoichiometry toward the Redfield ratio. Stoichiometry in the third-order stream was near the Redfield ratio at both hydrologic extremes, likely from wastewater treatment plant effluent
Carbon, nitrogen, and phosphorus stoichiometry and eutrophication in River Thames tributaries, UK
Primary productivity in aquatic systems relies on carbon (C), nitrogen (N), and phosphorus (P) availability, with a reference stoichiometric ratio of 106 C/16 N/1 P, known as the Redfield ratio. This paper presents a methodology to visualize river water C/N/P stoichiometry and examine phytoplankton response. Redfield total dissolved C/N/P concentration ratios (TDC/TDNR/TDPR) from five River Thames tributaries were plotted in a ternary diagram, allowing relationships between nutrient stoichiometry, total P concentrations, and chlorophyll a, as a surrogate for phytoplankton biomass, to be explored. Chlorophyll a concentrations above 100 Ī¼g Lā1 were not observed below 14% TDPR, and concentrations above 30 Ī¼g Lā1 were not observed below 13% TDPR. This indicates a potentially lower TDPR limit for highly eutrophic waters. These rivers are C and N rich, and this methodology should be applied to a wider range of rivers to explore C, N and P thresholds across different river typologies
Variational Approach to the Modulational Instability
We study the modulational stability of the nonlinear Schr\"odinger equation
(NLS) using a time-dependent variational approach. Within this framework, we
derive ordinary differential equations (ODEs) for the time evolution of the
amplitude and phase of modulational perturbations. Analyzing the ensuing ODEs,
we re-derive the classical modulational instability criterion. The case
(relevant to applications in optics and Bose-Einstein condensation) where the
coefficients of the equation are time-dependent, is also examined
Prosocial exchange systems: Nonreciprocal giving, lending, and skill-sharing
Prosocial exchange systems support cooperation and exchange in support of more sustainable forms of consumption. While often assumed that exchanges within such systems are reciprocal, it remains unproven as to what extent reciprocity occurs. This study uses data from a live service-Streetbank.com-to present an analysis of direct and indirect reciprocal relationships (for interactions of giving, lending, and skillsharing) over 4 and half years. The dataset contains behavioural data relating to 5053 acts of offline non-monetary exchange. The analysis categorised different forms of exchange that took place-giving, lending, and skill sharing. These exchanges were then analysed for direct (one-to-one) and indirect reciprocity (chains of three or more users). The results show that instances of reciprocity are rare, and when present often span more than one type of exchange. The conclusion is that reciprocity cannot be assumed to be the norm in prosocial exchange systems. Practically, design and deployment should not be predicated on reciprocity. Furthermore, any means to encourage reciprocity should make patterns of exchange visible, and do so across hybrid forms of exchange
The latitudes, attitudes, and platitudes of watershed phosphorus management in North America
Phosphorus (P) plays a crucial role in agriculture as a primary fertilizer nutrientāand as a cause of the eutrophication of surface waters. Despite decades of efforts to keep P on agricultural fields and reduce losses to waterways, frequent algal blooms persist, triggering not only ecological disruption but also economic, social, and political consequences. We investigate historical and persistent factors affecting agricultural P mitigation in a transect of major watersheds across North America: Lake Winnipeg, Lake Erie, the Chesapeake Bay, and Lake Okeechobee/Everglades. These water bodies span 26 degrees of latitude, from the cold climate of central Canada to the subtropics of the southeastern United States. These water bodies and their associated watersheds have tracked trajectories of P mitigation that manifest remarkable similarities, and all have faced challenges in the application of science to agricultural management that continue to this day. An evolution of knowledge and experience in watershed P mitigation calls into question uniform solutions as well as efforts to transfer strategies from other arenas. As a result, there is a need to admit to shortcomings of past approaches, plotting a future for watershed P mitigation that accepts the sometimes two-sided nature of Hennig Brandtās āDevilās Element.
Modelling the impacts of wildfire on the viability of metapopulations of the endangered Australian species of arboreal marsupial, Leadbeater's Possum
Catastrophic events such as intensive wildfires have a major effect on the dynamics of some wildlife populations. In this investigation, the computer package ALEX (Analysis of the Likelihood of EXtinction), was used to simulate the impacts of wildfires on the persistence of metapopulations of the endangered species Leadbeater's possum (Gymnobelideus leadbeateri) which is restricted to the montane ash forests of the Central Highlands of Victoria. A range of scenarios was examined. First, the response of G. leadbeateri to tires in hypothetical patches of old growth forest of varying size was modelled. Metapopulation dynamics were then modelled in four existing forest management areas: the O'Shannassy Water Catchment and the Steavenson, Ada and Murrindindi Forest Blocks using GIS-derived forest inventory data on complex spatial arrangements of potentially suitable old growth habitat patches. The impacts of different fire frequencies and the proportion of forest area that was burnt in the Steavenson Forest Block and the O'Shannassy Water Catchment were examined. Finally, the combined impacts of both wildfires and post-fire salvage logging operations on the persistence of populations of G. leadbeateri were assessed. Our analyses indicated that, even in the absence of wildfires, populations of G. leadbeateri are very susceptible to extinction within single isolated habitat patches of 20 ha or less. The probability of persistence approached 100% in patches of 250 ha. The incorporation of the effects of wildfire was predicted to have a major negative impact on isolated populations of G. leadbeateri. In these cases, the probability of population extinction remained above 60%, even when a single patch of 1200 ha of old growth forest was modelled. In the absence of wildfires, there was a low probability of extinction of G. leadbeateri in the O'Shannassy Water Catchment where very large patches of old growth forest presently exist. The risk of extinction of the species was significantly higher in the Murrindindi and Ada Forest Blocks where there are lower total areas of, and significantly smaller, suitable habitat patches. Wildfires resulted in an increase in the predicted probability of metapopulation extinction in the four areas that were targeted for study. An investigation of the Steavenson Forest Block and the O'Shannassy Water Catchment revealed that the predicted values for the probability of extinction were sensitive to inter-relationships between the frequency of fires and the proportion of habitat patches that were burnt during a given fire event. The probability of extinction of G. leadbeateri was predicted to be lowest when there were frequent fires that burnt only relatively small areas of a given forest block. Conversely, the results of our analyses suggested that populations of the species are vulnerable to infrequent but intensive conflagrations that burnt a large proportion of the forest. The results of the suite of analyses completed in this study suggest hat four management strategies will be important for the long-term conservation of G. leadbeateri. (1) Attempts to suppress wildfires should be maintained as even the largest remaining areas of old growth forest may be susceptible to being burnt by repeated widespread wildfires that could result in localised and/or global extinction of the species. (2) Because the probability of population persistence is greatest in those areas that support more extensive stands of old growth forest, it will be important to grow relatively large patches of existing regrowth forest (over 50 ha) through to ecological maturity. This will be particularly important in some wood production forest blocks where there are only limited areas of old growth forest. (3) Patches that are set aside for the conservation of G. leadbeateri should be spatially separated to minimise the risk that all of the reserved areas in a region are destroyed in a single major fire event. (4) Salvage logging operations should be excluded from stands of old growth forest and reserved areas that are burnt in a wildfire. This is because such activities can have a major negative impact of the development of suitable habitat for G. leadbeateri
- ā¦