92,536 research outputs found
Virginia Tech Duck Pond Retrofit for Improved Water Quality in Stroubles Creek
No full textStroubles Creek is registered on Virginiaâ s 303(d) list of impaired waters for both benthic and fecal coliform impairments. The upper reach of the creekâ s watershed drains into two ponds on the Virginia Tech campus. The area draining to the ponds, approximately 715 acres, encompasses most of the Town of Blacksburg and the Virginia Tech campus. Below the ponds, the creekâ s watershed is primarily forested and agricultural, with some areas of residential development.
In order to improve water quality downstream, the two ponds will be converted to a water quality facility by redirecting all flow from the northern branch of Stroubles Creek into the upper, smaller pond, which then flows into the larger pond below. With flow into the upper pond increasing dramatically, the dam between the two ponds and associated overflow structures were evaluated and redesigned to protect the dam from overtopping and possible washout. In addition, concrete weirs were designed and will be constructed on both branches of Stroubles Creek above the ponds for future installation of flow and water quality monitoring equipment. Above the ponds, the banks along both branches of the creek have become severely eroded. Interlocking concrete block armoring was designed for the stream banks to reduce erosion and protect the trees growing along the creek.
This project was jointly funded by Virginia Tech and a grant from the Virginia Department of Conservation and Recreation Water Quality Improvement Fund. Construction will be performed by the Capital Design department of Virginia Tech.Master of Scienc
Biological traits of European pond macroinvertebrates
No full textWhilst biological traits of river macroinvertebrates show unimodal responses to geographic changes in habitat conditions in Europe, we still do not know whether spatial turnover of species result in distinct combinations of biological traits for pond macroinvertebrates. Here, we used data on the occurrence of 204 macroinvertebrate taxa in 120 ponds from four biogeographic regions of Europe, to compare their biological traits. The Mediterranean, Atlantic, Alpine, and Continental regions have specific climate, vegetation and geology. Only two taxa were exclusively found in the Alpine and Continental regions, while 28 and 34 taxa were exclusively recorded in the Atlantic and Mediterranean regions, respectively. Invertebrates in the Mediterranean region allocated much energy to reproduction and resistance forms. Most Mediterranean invertebrate species had narrow thermal ranges. In Continental areas, invertebrates allocated lesser energy to reproduction and dispersal, and organisms were short lived with high diversity of feeding groups. These characteristics suggest higher resilience. The main difference between ponds in the Alpine and Atlantic regions was their elevation. Alpine conditions necessitate specific adaptations related to rapid temperature fluctuations, and low nutrient concentrations. Even if our samples did not cover the full range of pond conditions across Europe, our analyses suggest that changes in community composition have important impacts on pond ecosystem functions. Consistent information on a larger set of ponds across Europe would be much needed, but their low accessibility (unpublished data and/or not disclosed by authors) remains problematic. There is still, therefore, a pressing need for the incorporation of high quality data sets into a standardized database so that they can be further analyzed in an integrated European-wide manner
Pond research and management in Europe: "Small is Beautiful"
No full textThe phrase "Small is Beautiful" was first used by the talented scholar Leopold Kohr (1909 131994), but it becames more popular thanks to the essays of one of his students, the British economist E. F. Schumacher, and it was coined as a response to the socially established idea that "Big is Powerful". It could be argued that this desire for "bigness" explains why current legal frameworks and the conservation planning and management related to standing waters often overlook ponds, despite their well-known value in terms of biodiversity and socio-economic benefits (Oertli et al., 2004; Cereghino et al., 2008). Of course, this is only one of several possible explanations, but it is important to understand that such long-established ideas can have a lasting effect upon the efficiency of our conservation actions. Beyond this social perspective, the history of science can also provide some explanation as to why ponds have been undervalued for so long
Vegetation and discharge effects on the hydraulic residence time distribution within a natural pond
No full textResults are presented from sets of field and laboratory experiments conducted to
measure and quantify the Hydraulic Residence Time Distribution in treatment
ponds containing vegetation. The field measurements were taken in the Lyby field
pond (Sweden) with complementary experiments on a distorted, laboratory scale
model pond designed and built in the University of Warwick’s engineering
laboratory. Rhodamine WT Dye tracer experiments were used in both the Lyby
field pond and the distorted physical scale model to investigate vegetation and
discharge affects on HRTD characteristics and the technique of PIV (Particle
Image Velocimetry) was used in the distorted physical scale model to investigate
how surface flow profiles were affected by different vegetation and discharge
configurations.
The results show that the distorted physical scale pond did not reflect the HRTD
characteristics of the field site, with the actual residence time, (tm), for the distorted
physical scale pond ranging from 85 % to 125% of its nominal residence time. For
the distorted scale model, pond vegetation and discharge did not affect the relative
HRTD centroid, em, or the actual residence time, tm. This finding is attributed to
the unique pond geography and associated aspect ratios However, flow rates did
have a significant effect on the HRTD e0 (time of first dye arrival at the outlet) and
ep (time of peak dye concentration). Changes in vegetation were found to have
little effect on e0 and ep. For the laboratory pond, vegetation had a significant
control on the surface flow field whereas, flow rates did not – the latter suggests
that surface flow fields are not representative of the internal flow field in different
layers of the pond.
The experiments demonstrate that the specific shape of the distorted physical
scale pond in this study enables optimal actual resident times to be achieved over
a wide range of vegetation and flow rate configurations. If full scale field ponds
based upon this design give the same stable centroid results, then this would be a
substantial breakthrough in pond design, which would aid the design and
management of pond treatment and allow more robust optimisation of treatment
efficiency
Boat electrofishing survey of the Waimapu and Kopurererua streams, Bay of Plenty, Waitara River, and a pond at Mokoia, Taranaki
No full textWe conducted boat electrofishing surveys at four sites to establish the presence of, and to remove, koi carp (Cyprinus carpio). We fished the lower Waimapu Stream, Bay of Plenty, on 15 April and 14 June 2005, and the adjacent Kopurererua Stream on 15 June 2005. We caught and removed two large koi carp ( a 7.9 kg male and a 6.9 kg female) from the Waimapu Stream in 15 April, but saw no other koi carp in 3.2-km reaches of both streams on 14-15 June. We did, however, catch a wide diversity of native fish species, including common smelt, shortfin and longfin eels, yelloweye mullet, brown and rainbow trout, giant bullies, and black flounder. We also caught a lamprey macrophthalmia in the Waimapu Stream.
No koi carp were found in a 2.4-km tidal reach of the Waitara River, northern Taranaki, on 8 June 2005, but we did catch a sparse native fish assemblage of adult inanga, shortfin eels, a few common smelt, black flounder, yelloweye mullet, and a 200-mm giant bully.
We caught and killed 16 large koi carp (total weight 58.5 kg) from a pond on private farmland near Mokoia, southern Taranaki, on 9 June 2005. This pond had a perimeter of 215 m, a surface area of 951 m², and maximum depth of 2.0 m. These fish were removed by depletion fishing in 7 circuits of the pond. We caught 9, 3, 1, 1, 1, 1, and 0 carp in successive circuits. The Zippin method of population estimation (±95% confidence interval) suggests that there were 16±1 koi carp in the pond, so it is possible that we eradicated all of the koi. All the carp were the same age and no juveniles were found, so it appears that the carp had not breed successfully in this pond
Estimating selection pressures on HIV-1 using phylogenetic likelihood models
No full textHuman immunodeficiency virus (HIV-1) can rapidly evolve due to selection pressures exerted by HIV-specific immune responses, antiviral agents, and to allow the virus to establish infection in different compartments in the body. Statistical models applied to HIV-1 sequence data can help to elucidate the nature of these selection pressures through comparisons of non-synonymous (or amino acid changing) and synonymous (or amino acid preserving) substitution rates. These models also need to take into account the non-independence of sequences due to their shared evolutionary history. We review how we have developed these methods and have applied them to characterize the evolution of HIV-1 in vivo. To illustrate our methods, we present an analysis of compartment-specific evolution of HIV-1 em) in blood and cerebrospinal fluid and of site-to-site variation in the gag gene of subtype C HIV-1. Copyright (C) 2008 John Wiley & Sons, Ltd
Pond, S A F, VX44770
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/411184Surname: POND. Given Name(s) or Initials: S A F. Military Service Number or Last Known Location: VX44770. Missing, Wounded and Prisoner of War Enquiry Card Index Number: 20876.226897
Item: [2016.0049.43450] "Pond, S A F, VX44770
A Remedial Arithmetic Program in Computational Skills for Culturally Disadvantaged Fifth Grade Pupils
No full textA Plan B Paper Submitted to the Faculty of the Graduate School of the University of Minnesota, A Requirement for the Degree Master of Arts (Plan B), by Thomas F. Pond Jr., August 1968.Pond, Thomas F., Jr.. (1968). A Remedial Arithmetic Program in Computational Skills for Culturally Disadvantaged Fifth Grade Pupils. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/229754
Letter from the office of Bremer Whidden Pond to Edward Y. Blewett, June 25, 1936
No full textA one page typed letter from the office of landscape architect Bremer Whidden Pond, signed by Gladys [F. Churchill], to executive secretary Edward Y. Blewett dated June 25, 1936
Columbia rules the sea
No full textAn emblem of an eagle supported by two American flags, illustrates the sheet music cover for a song by Josiah D. Canning. The eagle's wings are spread and its mouth holds a streamer with the composer's sobriquet "The Peasant Bard of Mass." The Library's copy was deposited for copyright on August 9, 1858.Entered . . . 1858 by Firth, Pond & Co.New York. Published by Firth, Pond & Co 547 Broadway.Signed: Wakelam & Bros.Title appears as it is written on the item.Published in: American political prints, 1766-1876 / Bernard F. Reilly. Boston : G.K. Hall, 1991, entry 1858-2
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