1,989 research outputs found
Finite temperature QED3 with light fermions
Non-compact QED3 is simulated both in the quenched and unquenched cases. In
particular, we investigate the restoration of chiral symmetry at finite
temperature. We also compute the zero temperature spectrum of the theory,
including (in the quenched case) the dynamical fermion mass. From these two set
of data, one can obtain estimates for the ratio of the mass gap to the critical
temperature, of particular interest for applications to high-Tc
superconductivity.Comment: talk given at lattice'92, 3 LaTeX pages (using espcrc.sty), figures
available upon reques
Protection from the elements: a comparative study of hair density, shelter use and heat loss in donkeys, horses and mules
It is widely believed that donkeys are less adapted to wet, temperate climates than horses, often requiring shelter in addition to natural protection and rugs. However, to date there has been no scientific study assessing the shelter needs of donkeys and current guidelines often consider all horses and donkeys as a homogenous group. Our project provides a comprehensive assessment of the requirements of donkeys for protection from the elements across the four seasons in the British Isles and directly compares these findings to those from horses and mules. Some preliminary results are presented below
Archeological Survey Of The Proposed Capitol Parks Little League Ball Fields, San Antonio, Bexar County, Texas
On April 10 and June 6, 2018, personnel with Prewitt and Associates, Inc., conducted an intensive archeological survey on 23.7 acres of undeveloped land to be utilized for the creation new Little League baseball fields just east of the intersection of Wurzbach Parkway and Wetmore Road in northeast San Antonio, Texas. This survey was conducted under the direction of Adams Environmental, Inc., for Cude Engineers, partially under Texas Antiquities Permit No. 8379. The proposed development will be done as a private-public partnership. Most of the project area (23.0 acres) is privately owned land (Capitol Aggregates, Inc.). The public component of the project will involve use of City of San Antonio bond money to construct a road and bridge to access the property on its southeast side. This will be done on 0.7 acres of publicly owned land, and only this part of the project is governed by the terms of the antiquities permit.
No prehistoric or historic artifacts or archeological sites were identified during the survey. The access bridge and road section has seen extensive disturbance from development along the eastern creek bank, and the main western section of the proposed park has seen disturbance associated with land clearing and the construction of embankments along Wurzbach Parkway. Shovel testing and examination of cut banks in this western section found no evidence of archeological sites. The proposed project will not impact any archeological resources that meet eligibility criteria for listing in the National Register of Historic Places or designation as a State Antiquities Landmark. Prewitt and Associates, Inc., recommends that the proposed project be allowed to proceed without additional archeological investigations
The analytic structure of heavy quark propagators
The renormalised quark Dyson-Schwinger equation is studied in the limit of
the renormalised current heavy quark mass m_R --> infinity. We are particularly
interested in the analytic pole structure of the heavy quark propagator in the
complex momentum plane. Approximations in which the quark-gluon vertex is
modelled by either the bare vertex or the Ball-Chiu Ansatz, and the Landau
gauge gluon propagator takes either a gaussian form or a gaussian form with an
ultraviolet asymptotic tail are used.Comment: 21 pages Latex and 5 postscript figures. The original version of this
paper has been considerably extended to include a formalism dealing with the
renormalised heavy quark Dyson-Schwinger equation and uses a more realistic
Ansatz for the gluon propagator
Nonperturbative Vertices in Supersymmetric Quantum Electrodynamics
We derive the complete set of supersymmetric Ward identities involving only
two- and three- point proper vertices in supersymmetric QED. We also present
the most general form of the proper vertices consistent with both the
supersymmetric and U(1) gauge Ward identities. These vertices are the
supersymmetric equivalent of the non supersymmetric Ball-Chiu vertices.Comment: seventeen pages late
Book Reviews
Reviews of the following books: The Early Potters and Potteries of Maine by Lelyn Branin; The Promise of Power: The Emergency of the Legal Profession in Massachusetts 1760-1840 by Gerard W. Gawal
QED in external fields, a functional point of view
A functional partial differential equation is set for the proper graphs
generating functional of QED in external electromagnetic fields. This equation
leads to the evolution of the proper graphs with the external field amplitude
and the external field gauge dependence of the complete fermion propagator and
vertex is derived non-perturbativally.Comment: 8 pages, published versio
Researching Bradford: A review of social research on Bradford District
A synthesis of findings from social research on the District of Bradford. This report synthesises the findings from a wide range of social research undertaken on the District of Bradford, primarily between 1995 and 2005. The researchers reviewed almost 200 pieces of work. The key results are summarised under thematic headings: - The social, economic and institutional context - Community cohesion - Housing, neighbourhoods and regeneration - Business and enterprise - Health, disability and social care - Children and young people - Education, skills and the labour market - Crime and community safety It also identifies a future research agenda. The main purpose of the review was to provide the Joseph Rowntree Foundation and local organisations in Bradford with a firm basis upon which to build future work in the District
Shelter seeking behaviour of donkeys and horses in a temperate climate
Domestic donkeys descended from wild asses, adapted to the semi-arid climates of Africa, whereas domestic horses originate from more temperate areas of Eurasia. Despite this difference in evolutionary history, modern domestic equids can be found throughout the world, in a wide range of conditions, many of which are very different from their natural environments.
To explore the protection from the elements that different equid species may require in the temperate climate of the UK, the shelter seeking behaviour of 135 donkeys and 73 horses was assessed across a period of 16 months, providing a total of 13513 observations. The location of each animal (inside a constructed shelter, outside unprotected or using natural shelter) was recorded alongside measures of environmental conditions including temperature, wind speed, lux, precipitation and level of insect challenge. Statistical models revealed clear differences in the constructed-shelter-seeking behaviour of donkeys and horses. Donkeys sought shelter significantly more often at lower temperatures whereas horses tended to move inside when the temperature rose above 20°C. Donkeys were more affected by precipitation, with the majority of them moving indoors when it rained. Donkeys also showed a higher rate of shelter use when wind speed increased to moderate, while horses remained outside. Horses appeared to be more affected by insect challenge, moving inside as insect harassment outside increased. There were also significant differences in the use of natural shelter by the two species, with donkeys using natural shelter relatively more often to shelter from rain and wind and horses seeking natural shelter relatively more frequently when sunny.
These results reflect donkeys’ and horses’ adaptation to different climates and suggest that the shelter requirements of these two equid species differ, with donkeys seeking additional protection from the elements in temperate climates
Weathering the weather: effects of the environment on donkey, mule and horse welfare
It is widely believed that donkeys are less adapted to wet, temperate climates than horses. To date there has been no scientific study assessing the shelter needs of donkeys.
Our research addressed this important welfare area through three studies conducted in Devon, UK: (1) a comparison of hair coat properties between horses, mules and donkeys over the four seasons, (2) a behavioural study of shelter use (man-made and natural), and (3) a study of heat loss using infrared thermography.
In study 1 hair samples were taken from 42 animals, 18 donkeys, 16 horses and eight mules, in March, June, September and December. The weight, length and width of hair were measured as indicators of the hair coat insulation properties. The donkeys’ coats properties did not differ much across the seasons, unlike the horses’, indicating that donkeys do not grow a winter coat. The donkeys’ coats were significantly lighter, shorter and thinner than that of horses and mules in winter.
In study 2 the shelter seeking behaviour of 75 donkeys and 65 horses was observed over a period of 18 months. Results showed that donkeys’ and horses’ behaviour was differentially affected by environmental factors. When it rained there was a 54% increase in the number of donkeys in shelters and only a 14% increase in horses seeking shelter. Most donkeys stayed inside when the temperature was below 10°C and they came outside as temperatures increased. Horses preferred to be outside in temperatures up to 20°C, above which they started to seek shelter.
In study 3 we used a thermoimaging camera to take photos of donkeys and horses at different temperatures. In addition to the rate of overall heat loss, the amount of heat lost from specific body areas was assessed (ears, neck, torso, rear and legs). In concordance with the findings of study 1 we found that in cold temperatures donkeys lose more heat than mules and horses, and also that their heat loss is higher through their ears and their rear.
These findings provide valuable scientific evidence that can inform future guidelines on the welfare and shelter needs of equines and support the idea that donkeys are less well adapted to temperate climates and may require additional protection from the elements (in the form of man-made shelters) when compared to many horses
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