2,232 research outputs found
The economic contribution of protected natural areas: benefits from human use
This paper presents two examples from Australia where economic contributions from human use of protected natural areas have been quantified and a clear argument for increased investment in management resources generated
Assessment of the economic value of cultural heritage tourism in the City of Perth, Western Australia
This study measured the direct annual overnight visitor expenditure attributable to cultural heritage in the City of Perth local government area. Appendix 1 provides the project terms of reference.A visitor expenditure survey was used to estimate the average expenditure per visitor per day in the City of Perth. The annual expenditure of all visitors was then calculated by multiplying this figure by the average number of annual overnight visitors (domestic and international) and then multiplying by the average length of stay. In order to determine the proportion of the total visitor expenditure directly attributable to cultural heritage, an attribution factor was generated using a number of variables derived from the visitor survey. The attribution factor was multiplied by the total annual visitor expenditure to create a best estimate of the economic value of heritage tourism
Non-native Coccinellid beetles and land use abundance patterns in the Quad Cities region
Harmonia axyridis was introduced in 1916. This species of coccinellid beetle is considered a desirable species for agriculture practices because of its ability to control pests. There is increasing evidence that H. axyridis may be outcompeting native species which could be contributing to the decline of some species that are disappearing from the landscape. Harmonia axyridis has a large migration range of 2 Km enabling the species to affect a large area of land. Invasive species often increase in abundance in urban landscapes which may be the case with H. axyridis. During the summer of 2021 we investigated H. axyridis in relation to land use surrounding the Quad City region (Scott county Iowa and Rock Island county Illinois). Surveys were conducted by sweep net, visual search, and yellow sticky traps at thirty-five different sites in seven land use categories: agriculture, industrial/commercial, forest, gardens, mowed grass areas, native prairie, and unmowed grass areas. Two especially-invasive on-native species (Harmonia axyridis & C. septempunctata) comprised 59% of all lady beetles collected. C. septempunctata was most abundant at the agriculture and unmowed grass sites. In contrast, H. axyridis was most abundant at the industrial/commercial sites. Although the amount of impervious surface within 500m and 1000m of the sites showed no relationship with the abundance of either species (regression, p-values of 0.14 & 0.24 for H. axyridis & 0.25 & 0.31 for C. septempunctata respectively), forest cover showed a strong negative association with the abundance of both species (regression, p-values of 0.04 & 0.02 for H. axyridis & 0.05 & 0.03 for C. septempunctata respectively). Most of the agriculture and prairie sites were highly urbanized. This pattern may help explain why we did not observe the positive relationship between impervious surfaces and invasive abundance found in other studies
A Statistical Treatment of Bioassay Pour Fractions
The binomial probability distribution is used to treat the statistics of a microbiological sample that is split into two parts, with only one part evaluated for spore count. One wishes to estimate the total number of spores in the sample based on the counts obtained from the part that is evaluated (pour fraction). Formally, the binomial distribution is recharacterized as a function of the observed counts (successes), with the total number (trials) an unknown. The pour fraction is the probability of success per spore (trial). This distribution must be renormalized in terms of the total number. Finally, the new renormalized distribution is integrated and mathematically inverted to yield the maximum estimate of the total number as a function of a desired level of confidence ( P(<n)=LOC ). Selected results of the indicated numerical calculations are presented. For LOC=0.5, or the likely value, the estimates differ little from the usual calculation: the number of spores counted divided by the pour fraction. The extension to recovery efficiency corrections is also presented. Now the product of recovery efficiency and pour fraction may be small enough that the likely value may be much larger than the usual calculation: the number of spores divided by that product. The use of this analysis would not be limited to microbiological data
Where the Skies Are Blue
With Ukulele arrangement. Contains advertisements and/or short musical examples of pieces being sold by publisher.https://digitalcommons.library.umaine.edu/mmb-vp/6900/thumbnail.jp
Concentric versus eccentric training: Effect on muscle strength, regional morphology, and architecture
The different architectural adaptations and the regional changes that occur with eccentric (ECC) vs. concentric (CON) muscle actions are not fully understood. The purpose was to investigate regional changes in vastus lateralis muscle (VL) after ECC and CON training. Sixteen males (23 ± 3 y) performed ECC or CON twice weekly over 5 weeks, using a single-leg design. Both training modalities caused similar increases in knee extensor strength (measured with dynamometry) (10-13%) and muscle volume (8%) (measured with 3D ultrasound) after 5-weeks of training. Anatomical cross-sectional area at the mid-point of the muscle was greater after CON training (9%), but greater at the distal end after ECC training (8%). CON training increased fascicle angle at the mid-point (8%), with little change at the distal end (2%). There was a small increase in fascicle length at the mid-point after CON training (3%). Conversely, ECC training caused a greater variation in regional and architectural adaptations. Fascicle length increased at both the mid-point (6%) and distal ends (8%) after ECC training, and similar changes in fascicle angle were also observed in both regions (3-4%). Different region-specific changes are evident after CON and ECC training, with implications for performance and injury risk
An Empirical Study of Link Quality Assessment in Wireless Sensor Networks applicable to Transmission Power Control Protocols
Transmission Power Control (TPC) protocols are poised for wide spread adoption in Wireless Sensor Networks (WSNs) to address energy constraints. Identifying the optimum transmission power is a significant challenge due to the complex and dynamic nature of the wireless transmission medium and this has resulted in several previous TPC protocols reporting poor reliability and energy efficiency in certain scenarios. In line with current studies, this study presents an empirical characterisation of the transmission medium in typical WSN environments. Through this, the sources of link quality degradation are identified and extensive empirical evidence of their effects are presented. The results highlight that low power wireless links are significantly affected by spatio-temporal factors with the severity of these factors being heavily dependent on environment
Twin Grid-array as 3.6 GHz Epidermal Antenna for Potential Backscattering 5G Communication
Emerging 5G infrastructures can boost innovative paradigms for future wearable and epidermal devices exploiting low-power (even passive) wireless backscattering-based communication. To compensate high body- and path-losses, and to extend the read range, array configurations are required. This work proposes a flexible monolithic epidermal layout, based on Krauss array concept, that operates at 3.6 GHz and it is suitable to be directly attached to the human body. The antenna involves a dual grid configuration with a main radiating grid backed by a grid reflector placed in touch with the skin. Overall, the amount of conductor an dielectric substrate are minimized with benefit to breathability. The antenna is suitable to surface feeding and produces a broadside radiation. Parametric analysis are performed and an optimal configuration of four-cells grid is derived and experimentally demonstrated to provide a maximum
gain of more than 6 dBi
Why should we investigate the morphological disparity of plant clades?
Background Disparity refers to the morphological variation in a sample of taxa, and is distinct from diversity or taxonomic richness. Diversity and disparity are fundamentally decoupled; many groups attain high levels of disparity early in their evolution, while diversity is still comparatively low. Diversity may subsequently increase even in the face of static or declining disparity by increasingly fine sub-division of morphological ‘design’ space (morphospace). Many animal clades reached high levels of disparity early in their evolution, but there have been few comparable studies of plant clades, despite their profound ecological and evolutionary importance. This study offers a prospective and some preliminary macroevolutionary analyses. Methods Classical morphometric methods are most suitable when there is reasonable conservation of form, but lose traction where morphological differences become greater (e.g. in comparisons across higher taxa). Discrete character matrices offer one means to compare a greater diversity of forms. This study explores morphospaces derived from eight discrete data sets for major plant clades, and discusses their macroevolutionary implications. Key Results Most of the plant clades in this study show initial, high levels of disparity that approach or attain the maximum levels reached subsequently. These plant clades are characterized by an initial phase of evolution during which most regions of their empirical morphospaces are colonized. Angiosperms, palms, pines and ferns show remarkably little variation in disparity through time. Conifers furnish the most marked exception, appearing at relatively low disparity in the latest Carboniferous, before expanding incrementally with the radiation of successive, tightly clustered constituent sub-clades. Conclusions Many cladistic data sets can be repurposed for investigating the morphological disparity of plant clades through time, and offer insights that are complementary to more focused morphometric studies. The unique structural and ecological features of plants make them ideally suited to investigating intrinsic and extrinsic constraints on disparity
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