6,370 research outputs found
The aquatic fauna of King Island's streams and wetlands
King Island has a wide range of freshwater aquatic environments including rivers and
streams and ephemeral and permanent wetlands (ponds, swamps, lagoons). The fauna
of these environments is not well known, and the writing of this chapter required
some new sampling to be done. As a result we now know that the island has many
species (more than 140) of aquatic macroinvertebrates, including burrowing crayfish,
aquatic insects, freshwater crabs and snails, as well as eight species of freshwater fish.
The island is highly seasonal in its rainfall, and, as a consequence most of the streams
and rivers have very low or no flow during the summer and autumn months. Some
sections have permanent water, especially near the coast or those associated with
springs or escarpments.
The landscape of the island has changed substantially since European settlement, and
significant changes have occurred to its freshwater habitats. Most of the catchments
no longer have their original vegetation cover, and that, coupled with intensive
agriculture, has undoubtedly led to changes in stream flows and water quality.
Changes to the bankside or riparian vegetation have been significant, with many
stream sections and wetlands now having no or limited areas of natural riparian
vegetation (1), and with many of these areas being accessed by stock, with effects on
bank erosion and water quality. There is evidence of higher levels of turbidity,
nutrients and salinity in several streams, as well as in some wetlands (2, K Brown
unpub data).
Before European settlement, most of the streams on the island were swamp-channel
complexes with shallow channels containing large amounts of woody and other
organic matter, often overlying sands. They were heavily shaded, slow flowing
(except for in the south east) and many sections probably experienced seasonal
(summer) drops in dissolved oxygen levels due to decomposition of organic material,
during periods of slow flow and higher temperatures. In some cases, surface waters in
swamps and lagoons and some stream sections were probably devoid of oxygen and
contained hydrogen sulphide (rotten egg gas). This can be seen today in places like
Collier's Swamp. Overall though, water quality was probably better than today, and
stream habitats were more uniform across the island.
Despite these changes and the highly seasonal rainfall, the majority of streams and
wetlands on the island still manage to maintain a reasonably diverse fauna, which in
many cases is highly abundant
Resource use data by patient report or hospital records: Do they agree?
Background: Economic evaluations alongside clinical trials are becoming increasingly common.
Cost data are often collected through the use of postal questionnaires; however, the accuracy of
this method is uncertain. We compared postal questionnaires with hospital records for collecting
data on physiotherapy service use.
Methods: As part of a randomised trial of orthopaedic medicine compared with orthopaedic
surgery we collected physiotherapy use data on a group of patients from retrospective postal
questionnaires and from hospital records.
Results: 315 patients were referred for physiotherapy. Hospital data on attendances was available
for 30% (n = 96), compared with 48% (n = 150) of patients completing questionnaire data (95% Cl
for difference = 10% to 24%); 19% (n = 59) had data available from both sources. The two methods
produced an intraclass correlation coefficient of 0.54 (95% Cl 0.31 to 0.70). However, the two
methods produced significantly different estimates of resource use with patient self report recalling
a mean of 1.3 extra visits (95% Cl 0.4 to 2.2) compared with hospital records.
Conclusions: Using questionnaires in this study produced data on a greater number of patients
compared with examination of hospital records. However, the two data sources did differ in the
quantity of physiotherapy used and this should be taken into account in any analysi
City of Klamath Falls, Oregon Geothermal Power Plant Feasibility Study
The purpose of the Klamath Falls project is to demonstrate the effectiveness of a combined thermal distribution system and power generation facility. The city of Klamath Falls operates a geothermal district heating system which would appear to be an attractive opportunity to install a power generation system. Since the two wells have operated reliably and consistently over many years, no new sources or resource exploration would be necessary. It appears that it will cost more to construct, operate, maintain and amortize a proposed geothermal facility than the long?term value of the power it would produce. The success of a future project will be determined by whether utility power production costs will remain low and whether costs of construction, operations, or financing may be reduced. There are areas that it would be possible to reduce construction cost. More detailed design could enable the city to obtain more precise quotes for components and construction, resulting in reduction in contingency projections. The current level of the contingency for uncertainty of costs is between 300,000. Another key issue with this project appears to be operation cost. While it is expected that only minimal routine monitoring and operating expenses will occur, the cost of water supply and waste water disposal represents nearly one quarter of the value of the power. If the cost of water alone could be reduced, the project could become viable. In addition, the projected cost of insurance may be lower than estimated under a city?wide policy. No provisions have been made for utilization of federal tax incentives. If a transaction with a third-party owner/taxpayer were to be negotiated, perhaps the net cost of ownership could be reduced. It is recommended that these options be investigated to determine if the costs and benefits could be brought together. The project has good potential, but like many alternative energy projects today, they only work economically if the federal tax incentives come into play
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Plant-Wide Assessment Report for Shaw Industries, Plant #78; Aiken, SC
A plant-wide energy assessment sponsored by the U.S. Department of Energy was conducted at Shaw Industries Group, plant #78 in Aiken, SC. The assessment team consisted of Georgia Tech faculty from the Energy & Environmental Management Center and Shaw personnel from plant #78 and the corporate energy group. The purpose of this assessment was to uncover as many opportunities for saving energy usage and costs using techniques that have been established as best practices in the energy engineering field. In addition, these findings are to be shared with similar plants in Shaw Industries Group to multiply the lessons learned. The findings from this assessment are included in this report
Two-Week versus Six-Month Sampling Interval in a Short-Term Natural History Study of Oral HPV Infection in an HIV-Positive Cohort
BACKGROUND: Oral HPV infections detected six-months apart were compared to those detected bi-weekly, in an HIV-positive cohort, during the intervening months to elucidate systematic biases introduced into natural history studies by sampling interval. METHODS: Fourteen consecutive oral rinse samples were collected every two weeks for six months from an HIV-positive cohort (n = 112) and evaluated for the presence of 37 HPV types. The cumulative probability of type-specific HPV detection at visits 1 through 14 was determined as a function of infection categorized at visits 1 and 14 as persistent, newly detected, cleared or absent. Transition models were used to evaluate the effect of HPV viral load (measured by RT-PCR for HPV 16, 18, 31, 33, 35) on infection persistence. RESULTS: The average point prevalence of oral HPV infection was similar at two-week and six-month sampling intervals (45% vs. 47%, p = 0.52), but cumulative prevalence was higher with the former (82% vs. 53%, p<0.001) as was the cumulative prevalence of type-specific infections (9.3% vs 3.8%, p<0.0001). Type-specific infections persistent under a six-month sampling interval had a high probability (0.93, 95%CI 0.83-0.98) of detection at 50% or more of the intervening visits and infections that were absent had a high probability (0.94, 95% CI 0.93-0.95) of no interval detection. The odds of detection at any visit significantly increased for each unit increase in HPV viral load at the previous visit. CONCLUSIONS: Six-month sampling is appropriate to model factors associated with type-specific oral HPV infection persistence but may misclassify HPV-exposed individuals as unexposed
Nutritional status and the gonadotrophic response to a polar expedition.
Polar expeditions have been associated with changes in the hypothalamic-pituitary-testicular axis consistent with central hypogonadism (i.e., decreased testosterone, luteinising hormone (LH), and follicle stimulating hormone (FSH)). These changes are typically associated with body mass loss. Our aim was to evaluate whether maintenance of body mass during a polar expedition could mitigate against the development of central hypogonadism. Male participants (n = 22) from a 42-day expedition (British Services Antarctic Expedition 2012) volunteered to take part in the study. Body mass, body composition, and strength data were recorded pre- and postexpedition in addition to assessment of serum testosterone, LH, FSH, thyroid hormones, insulin-like growth factor 1 (IGF-1), and trace elements. Energy provision and energy expenditure were assessed at mid- and end-expedition. Daily energy provision was 6335 Ā± 149 kcalĀ·day(-1). Estimated energy expenditure midexpedition was 5783 Ā± 1690 kcalĀ·day(-1). Body mass and percentage body fat did not change between pre- and postexpedition. Total testosterone (nmolĀ·L(-1)) (14.0 Ā± 4.9 vs. 17.3 Ā± 4.0, p = 0.006), calculated free testosterone (pmolĀ·L(-1)) (288 Ā± 82 vs. 350 Ā± 70, p = 0.003), and sex hormone binding globulin (nmolĀ·L(-1)) (33 Ā± 12 vs. 36 Ā± 11, p = 0.023) concentrations increased. LH and FSH remained unchanged. Thyroid stimulating hormone (TSH; IUĀ·L(-1)) (2.1 Ā± 0.8 vs. 4.1 Ā± 2.1, p < 0.001) and free triiodothyronine (FT3; IUĀ·L(-1)) (5.4 Ā± 0.4 vs. 6.1 Ā± 0.8, p < 0.001) increased while free thyroxine, IGF-1, and trace elements remained unchanged. Hand-grip strength was reduced postexpedition but static lift strength was maintained. Maintenance of body mass and nutritional status appeared to negate the central hypogonadism previously reported from polar expeditions. The elevated TSH and free FT3 were consistent with a previously reported "polar T3 syndrome"
An assessment of road-verge grass as a feedstock for farm-fed anaerobic digestion plants
Cuttings from road-verge grass could provide biomass for energy generation, but currently this potential is not exploited. This research assessed the technical, practical and financial feasibility of using grass harvested from road verges as a feedstock in farm-fed anaerobic digestion (AD) plants. The methane potential (191 mL CH4 gDMā1) and digestion characteristics of verge grass were similar to those of current farm feedstocks; indicating suitability for AD. Ensiling had no significant impact on the biomethane generated. Testing co-digestions of verge grass with current farm feedstocks showed enhanced methane yields, suggesting that verge grass could be a valuable addition to AD feedstock mixes. In a case study of the UK county of Lincolnshire, potential volumes and locations of verge grass biomass were estimated, with capacities and locations of existing AD plants, to assess the potential to supply practical grass volumes. Grass harvesting costs were modelled and compared with other feedstock costs. Finally, the attitudes of AD operators to using verge grass were investigated to understand whether a market for verge grass exists. In a small survey all operators were willing to use it as a feedstock and most were prepared to pay over the estimated harvesting cost. If verge grass was legally recognised as a waste product it could be attractive to AD operators especially where financial incentives to use waste feedstocks are in place. In rural areas, verge grass could be harvested and co-digested by existing farm-fed AD plants, potentially reducing the cost of road verge maintenance and increasing biodiversity
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