857 research outputs found
A classification of New Zealand’s terrestrial ecosystems
This study produces a comprehensive terrestrial ecosystem classification by subjectively constructing a heirarchy of perceived key environmental drivers.
Introduction: The ecosystem concept is at the centre of international agreements, New Zealand legislation, and modern policy and planning systems that aim to sustainably manage natural resources. All definitions of ecosystems include the concept of the physical environment being integrated with its biotic components. Functionally, the concept embodies disturbance cycles, and flows of energy, nutrients and non-living materials, with these processes underpinning the concept of ecosystem health or integrity. Since these processes operate at variable spatio-temporal scales, and species and communities intergrade variably along environmental gradients, there is no single optimal scale at which to apply the ecosystem concept. Rather, the openness and hierarchical nature of ecosystem processes lead to any one classification scale being viewed as nested within coarser and finer scale components.
One of the goals of the New Zealand Biodiversity Strategy is to ‘maintain and restore a full range of remaining habitats and ecosystems …’. However, although many environmental agencies and individuals can contribute to this goal, any investment decisions are currently being made in the absence of a comprehensive list of ecosystems or a systematic threat ranking. Therefore, classification of the full range of ecosystem types for New Zealand is overdue.
 
Flowering curves and the summer-gap mystery
Results from year-round weekly monitoring of 93 taxa (179 accessions) at the Royal Botanic Garden Edinburgh (RBGE) are presented in the form of flowering curves. These are provisionally grouped into classes, and hypotheses are suggested to explain the different patterns. Attention is drawn to a prominent ‘summer gap’ in flowering in some species, and possible explanations for the gap are discussed
Energy Conservation and Gravity Waves in Sound-proof Treatments of Stellar Interiors: Part I Anelastic Approximations
Typical flows in stellar interiors are much slower than the speed of sound.
To follow the slow evolution of subsonic motions, various sound-proof equations
are in wide use, particularly in stellar astrophysical fluid dynamics. These
low-Mach number equations include the anelastic equations. Generally, these
equations are valid in nearly adiabatically stratified regions like stellar
convection zones, but may not be valid in the sub-adiabatic, stably stratified
stellar radiative interiors. Understanding the coupling between the convection
zone and the radiative interior is a problem of crucial interest and may have
strong implications for solar and stellar dynamo theories as the interface
between the two, called the tachocline in the Sun, plays a crucial role in many
solar dynamo theories. Here we study the properties of gravity waves in
stably-stratified atmospheres. In particular, we explore how gravity waves are
handled in various sound-proof equations. We find that some anelastic
treatments fail to conserve energy in stably-stratified atmospheres, instead
conserving pseudo-energies that depend on the stratification, and we
demonstrate this numerically. One anelastic equation set does conserve energy
in all atmospheres and we provide recommendations for converting low-Mach
number anelastic codes to this set of equations.Comment: Accepted for publication in ApJ. 20 pages emulateapj format, 7
figure
Estimation of body fat in normal and obese mice
There is at present an enormous interest in the mechanisms which serve to regulate food
intake and lipid deposition and thus the causes and effects of obesity. There are a number of
animal models of obesity which are the subject of intensive study; in rodents obesity may be
induced by chemical agents such as gold thioglucose (GTG; Brecher & Waxler, 1949)
and bipiperidyl mustard (BPM; Rutman et al. 1966), by providing pleasant-tasting food or
sugar solutions (Kanarek & Hirsch, 1977) or by genetic inheritance as in the ob/ob mouse
and Zucker fatty rat (Bray & York, 1971). However, obesity as defined by an excessive
accumulation of fat (Davidson et al. 1975) is not always associated with a high bodyweight
(Larsson, 1967; Rogers et al. 1979) and therefore an objective measure of adiposity
should always be used as the criterion for obesity. Direct measurement of body fat in the
mouse involves drying and extraction procedures which are not only time-consuming but
also destructive, precluding for example histological examination of organs. We now report
experiments in which a number of methods of indicating obesity are assessed to determine
whether they are reliable indices of obesity and also whether they are sensitive enough to
give an accurate estimate of the body fat content of normal mice which have a comparatively
narrow range of body fat contents. Preliminary results on a normal population have
previously been communicated (Webb & Rogers, I 979)
Drawing diagrams in TEX documents
The typesetting language TEX [Knuth (1984)] is now available on a range of computers from mainframes to micros. It has an unequalled ability to typeset mathematical text, with its many formatting features and fonts. TEX has facilities for drawing diagrams using the packages tpic and PiCTEX. This paper describes a TEX preprocessor written in Pascal which allows a programmer to embed diagrams in TEX documents. These diagrams may involve straight or curved lines and labelling text. The package is provided for people who either do not have access to tpic or PiCTEX or who prefer to program in Pascal
Absence of a metallicity effect for ultra-short-period planets
Ultra-short-period (USP) planets are a newly recognized class of planets with
periods shorter than one day and radii smaller than about 2 Earth radii. It has
been proposed that USP planets are the solid cores of hot Jupiters that lost
their gaseous envelopes due to photo-evaporation or Roche lobe overflow. We
test this hypothesis by asking whether USP planets are associated with
metal-rich stars, as has long been observed for hot Jupiters. We find the
metallicity distributions of USP-planet and hot-Jupiter hosts to be
significantly different (), based on Keck spectroscopy of
Kepler stars. Evidently, the sample of USP planets is not dominated by the
evaporated cores of hot Jupiters. The metallicity distribution of stars with
USP planets is indistinguishable from that of stars with short-period planets
with sizes between 2--4~. Thus it remains possible that the USP
planets are the solid cores of formerly gaseous planets smaller than Neptune.Comment: AJ, in pres
The individual as the key-stakeholder of Next Generation Infrastructure: Defining the social value of transport infrastructure in the United Kingdom
The idea of social value has arisen from the psychological approach, and more specifically it is based on the principle of “independence of irrelevant alternatives” from the game theory introduced by Luce and Raiffa1. According to this, each alternative situation has an utility/value for the individual, which is a function of the features of the alternative situation and of the features of the individual who makes the choice. Beyond that, it assumed that the individual, who makes the choice, has a clear and measurable knowledge of the value, which each choice provides. Although even after the evaluation of each choice, it is a tentative situation regarding the choice of the individual. In other words, there is an element of possibility. Under the same principle of Luce and Raiffa, the possibility of a choice is in direct ratio to its value. The above mentioned assumptions constitute the “strict utility choice mode”. The exponential form of the value function is achieved by simple transformations of the “strict utility choice mode”,where X and S have a linear correlation. The exponential functions of the total value have a sigmoid form relative to the linear function of the value of the possible choice. This means that the exponential function may have a sigmoid form relative to the X-axis or Y-axis, based on the defined axes and values. The key challenge addressed is a quantitative sense of value, when the perceptions of value are qualitative. To measure social value quantitatively is challenging, since it is observed that pricing systems are “not based primarily on the users’ identity or activity”, but on the ability and willingness of the final user to pay. The social value gained by the individual is difficult to calculate, since it is defined by human behaviour and human needs. According to Maslow's Hierarchy of Needs, these needs belong to specific groups with specific hierarchy.
Maslow developed value (utility) curves of each category of need relative to the age of the individual. The
sum of the curves gives an almost sigmoid curve. Winters et al. created a Transportation Hierarchy of
Needs and they found the following transport hierarchy of needs: [1] safety and security, [2] time, [3]
societal acceptance, [4] cost and [5] comfort and convenience. This research studied value as something
holistically affected by all the above factors (time, cost, comfort and convenience, safety and security),
without considering their ranking, by asking individuals representative of the UK’s demography to
evaluate the social value of eight transport modes (walking, cycling, rail, bus, car, taxi, water and air) and
each factor for each mode with a questionnaire survey. The hypothesis tested is that the value to the
individual, collectively, from the aforementioned factors should have an almost sigmoid curve, which was
verified
Next Generation Infrastructure Interdependencies: An economic deterministic model of transport interdependencies in the United Kingdom
The role of infrastructure interdependencies is challenging due to the complexity and dynamic environment of all infrastructures and vital for critical infrastructure systems. There is an ongoing debate about the value of the benefits of the five national infrastructure sectors (energy, water, transport, waste and communication) in the UK and how they interact in terms of social, economic and environmental wellbeing , . This study focuses only on one of the three aforementioned values, the economic value. The hypothesis tested is whether the transport sector is economically complemented by the energy, water and waste sectors and economically substituted by the communication sector1. The authors use the process analysis “networks and cohorts”, an analysis that uses tables, diagrams, models and networks of interactions along with organizational linkages . Of interest for this study in particular is the grand total of all revenues (capital value) which create incomes into other sectors and creates dependencies. This, by definition, is the Gross Value Added. The last five symmetric (product by product) Input-Output tables of gross value added are used: 2010, 2005, 1995, 1990 and 1984 . The theory underpinning the hypothesis was verified and one mathematical equation was developed based on the historical data of the gross value added by the value created in millions of pounds (£m) from the other critical sectors to transport
Transport Infrastructure Interdependencies with Energy, Water, Waste and Communication Infrastructure in the United Kingdom
The role of infrastructure interdependencies is challenging due to the complexity and dynamic
environment of all infrastructures and vital for critical infrastructure systems. There is an ongoing
debate about the value of the benefits of the five national infrastructure sectors (energy, water,
transport, waste and communication) in the UK and how they interact in terms of social, economic
and environmental wellbeing (Hall et al., 2016, p.10; iBUILD, 2015; Liveable Cities, 2015; National
Infrastructure Plan, 2013). This study focuses only on one of the three aforementioned values, the
economic value. The hypothesis tested is whether the transport sector is economically
complemented by the energy, water and waste sectors and economically substituted by the
communication sector. The authors use the process analysis “networks and cohorts”, an analysis
that uses tables, diagrams, models and networks of interactions along with organizational linkages
(Hill, 1993). Of interest for this study in particular is the grand total of all revenues (capital value)
which create incomes into other sectors and creates dependencies. This, by definition, is the Gross
Value Added. The last five symmetric (product by product) Input-Output tables of gross value added
are used: 2010, 2005, 1995, 1990 and 1984 (Office for National Statistics, 2015). The theory
underpinning the hypothesis was verified and one mathematical equation was developed based on
the historical data of the gross value added by the value created in millions of pounds (£m) from the
other critical sectors to transport
Rapid-Survey Methods for Flowering Phenology
The Weekly Phenology Project at the Royal Botanic Garden Edinburgh has been running for three and a half years at the time of writing. Insufficient data have been collected so far for scientific analysis, but we present provisional conclusions concerning several methods of monitoring flowering behaviour. These range from objective methods, such as presence/absence of open flowers and counts of flowers or inflorescences, to non-objective methods involving assessment of the degree to which full flowering has been achieved. One monitoring method, relying on the relative numbers of flowers in the three states ‘bud’, ‘open’, and ‘gone-over’, is illustrated by the flowering behaviour of ‘simultaneously’ and ‘sequentially’ flowering species. We conclude with a discussion of the relative values of the different methods
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