8,516 research outputs found
WaND Briefing Note 28 Revised Options for UK Domestic Water Reduction - A Review
Demand pressure on UK water supplies is expected to increase in the next 20 years driven by increasing population, new housing development and reducing household size. Regionally and at town level migration will also affect demand particularly in the South-East which is forecast to have a larger than average growth in population and house building.
The water demand moderating trends that are considered to have the greatest effect on UK consumption, in approximate order, are:
1. Metering
2. Low flush toilets
3. Normal showers
4. Efficient washing machines
5. Dishwashers
6. Cistern displacement devices (in existing homes with large cisterns)
7. Water efficient gardening measures can play an important role in reducing demand during critical drought period
The Options for UK Domestic Water Reduction: A Review
Demand pressure on UK water supplies is expected to increase in the next 20 years driven by increasing population, new housing development and reducing household size. Regionally and locally migration will also afect demand particularly in the South-East.
The water reduction trends that will have the greatest reduction effect on UK consumption are:
1. For new homes; metering and new efficiencies in design and construction (e.g. low flush toilets, heating and plumbing efficiences)
2. For established housing; metering and modern washing machines
MACROWater: a Top-down, Policy-driven Model for Forecasting Domestic Water Demand
MACROWater is a top-down domestic water demand model developed for the WaND project (Water Cycle Management for New Developments). Forecasts have been produced for all local authorities in England and Wales. They can be aggregrated for different reporting areas (such as Government Office Regions, Sustainable Communities and water companies). Sustainable community is the official term for key strategic areas, earmarked for rapid expansion of housing supply (such as the M11 corridor, Ashford, Milton Keynes). This model description uses the UK's biggest Sustainable Community, Thames Gateway, as the example case study.
Utilising Domestic Consumption Monitors from the water companies supplying this area, combined with housing, household and population projections, the authors have modelled domestic demand in detail. Alternative futures are considered using a set of urban water management scenarios, which represent different levels of adoption of water-saving technologies and different consumption patterns. For example, under the greener scenarios, new homes are fitted out with water-efficient equipment, allied with incentives to replace/refurbish as much old housing stock as possible. The modelling work demonstrates that increased demand from new developments can be accommodated but only through strict demand management and some new water supply measures
Great cities look small
Great cities connect people; failed cities isolate people. Despite the
fundamental importance of physical, face-to-face social-ties in the functioning
of cities, these connectivity networks are not explicitly observed in their
entirety. Attempts at estimating them often rely on unrealistic
over-simplifications such as the assumption of spatial homogeneity. Here we
propose a mathematical model of human interactions in terms of a local strategy
of maximising the number of beneficial connections attainable under the
constraint of limited individual travelling-time budgets. By incorporating
census and openly-available online multi-modal transport data, we are able to
characterise the connectivity of geometrically and topologically complex
cities. Beyond providing a candidate measure of greatness, this model allows
one to quantify and assess the impact of transport developments, population
growth, and other infrastructure and demographic changes on a city. Supported
by validations of GDP and HIV infection rates across United States metropolitan
areas, we illustrate the effect of changes in local and city-wide
connectivities by considering the economic impact of two contemporary inter-
and intra-city transport developments in the United Kingdom: High Speed Rail 2
and London Crossrail. This derivation of the model suggests that the scaling of
different urban indicators with population size has an explicitly mechanistic
origin.Comment: 19 pages, 8 figure
On the gamma-ray emission of Type Ia Supernovae
A multi-dimension, time-dependent Monte Carlo code is used to compute sample
gamma-ray spectra to explore whether unambiguous constraints could be obtained
from gamma-ray observations of Type Ia supernovae. Both spherical and
aspherical geometries are considered and it is shown that moderate departures
from sphericity can produce viewing-angle effects that are at least as
significant as those caused by the variation of key parameters in
one-dimensional models. Thus gamma-ray data could in principle carry some
geometrical information, and caution should be applied when discussing the
value of gamma-ray data based only on one-dimensional explosion models. In
light of the limited sensitivity of current gamma-ray observatories, the
computed theoretical spectra are studied to revisit the issue of whether useful
constraints could be obtained for moderately nearby objects. The most useful
gamma-ray measurements are likely to be of the light curve and time-dependent
hardness ratios, but sensitivity higher than currently available, particularly
at relatively hard energies (~2-3 MeV), is desirable.Comment: 10 pages, 8 figures. Accepted by MNRAS. Minor changes to clarify
discussion in Section
Late-onset bloodstream infection and perturbed maturation of the gastrointestinal microbiota in premature infants
Late-onset bloodstream infection (LO-BSI) is a common complication of prematurity, and lack of timely diagnosis and treatment can have life-threatening consequences. We sought to identify clinical characteristics and microbial signatures in the gastrointestinal microbiota preceding diagnosis of LO-BSI in premature infants.Daily faecal samples and clinical data were collected over two years from 369 premature neonates (<32 weeks gestation). We analysed samples from 22 neonates who developed LO-BSI and 44 matched control infants. Next-generation sequencing of 16S rRNA gene regions amplified by PCR from total faecal DNA was used to characterise the microbiota of faecal samples preceding diagnosis from infants with LO-BSI and controls. Culture of selected samples was undertaken, and bacterial isolates identified using MALDI-TOF. Antibiograms from bloodstream and faecal isolates were compared to explore strain similarity.From the week prior to diagnosis, infants with LO-BSI had higher proportions of faecal aerobes/facultative anaerobes compared to controls. Risk factors for LO-BSI were identified by multivariate analysis. Enterobacteriaceal sepsis was associated with antecedent multiple lines, low birth weight and a faecal microbiota with prominent Enterobacteriaceae. Staphylococcal sepsis was associated with Staphylococcus OTU faecal over-abundance, and the number of days prior to diagnosis of mechanical ventilation and of the presence of centrally-placed lines. In 12 cases, the antibiogram of the bloodstream isolate matched that of a component of the faecal microbiota in the sample collected closest to diagnosis.The gastrointestinal tract is an important reservoir for LO-BSI organisms, pathogens translocating across the epithelial barrier. LO-BSI is associated with an aberrant microbiota, with abundant staphylococci and Enterobacteriaceae and a failure to mature towards predominance of obligate anaerobes
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