OALib Journal期刊

ISSN: 2333-9721

費用:99美元

投稿

時間不限

2020 ( 6 )

2019 ( 13 )

2018 ( 15 )

2017 ( 10 )

自定義范圍…

匹配條件: “Fiona Kenyon” ,找到相關結果約1438條。
列表顯示的所有文章,均可免費獲取
第1頁/共1438條
每頁顯示
The Prevalence of Sexual Partner Concurrency Is Not Correlated with Markers of Poverty or Gender Inequality: An Ecological Analysis  [PDF]
Chris Kenyon
World Journal of AIDS (WJA) , 2015, DOI: 10.4236/wja.2015.54035
Abstract: High rates of overlapping sexual relationships (concurrency) are believed to be important in the generation of generalized HIV epidemics in sub-Saharan Africa. Different authors favor socioeconomic, gender-equity or cultural explanations for the high concurrency rates in this region. We performed linear regression to analyze the association between the point-prevalence of concurrency in 15 - 49 years old males and various indicators of socioeconomic status and gender-equity using data from 11 countries surveyed in 1989/1990. We found no meaningful association between concurrency and the various markers of socioeconomic status and gender-equity. This analysis supports the findings of other studies that high concurrency rates in sub-Saharan Africa could be reduced without having to address socioeconomic and gender-equity factors.
Generation, analysis and functional annotation of expressed sequence tags from the ectoparasitic mite Psoroptes ovis
Stewart TG Burgess, Alasdair J Nisbet, Fiona Kenyon, John F Huntley
Parasites & Vectors , 2011, DOI: 10.1186/1756-3305-4-145
Abstract: In order to further expand upon the transcriptomic coverage of P. ovis thus facilitating novel insights into the mite biology we undertook a larger scale EST approach, incorporating newly generated and previously described P. ovis transcript data and representing the largest collection of P. ovis ESTs to date. We sequenced 1,574 ESTs and assembled these along with 484 previously generated P. ovis ESTs, which resulted in the identification of 1,545 unique P. ovis sequences. BLASTX searches identified 961 ESTs with significant hits (E-value < 1E-04) and 584 novel P. ovis ESTs. Gene Ontology (GO) analysis allowed the functional annotation of 880 ESTs and included predictions of signal peptide and transmembrane domains; allowing the identification of potential P. ovis excreted/secreted factors, and mapping of metabolic pathways.This dataset currently represents the largest collection of P. ovis ESTs, all of which are publicly available in the GenBank EST database (dbEST) (accession numbers FR748230 - FR749648). Functional analysis of this dataset identified important homologues, including house dust mite allergens and tick salivary factors. These findings offer new insights into the underlying biology of P. ovis, facilitating further investigations into mite biology and the identification of novel methods of intervention.Sheep scab, caused by the mite Psoroptes ovis is, arguably, the most important ectoparasitic disease of sheep in the UK in terms of both animal welfare and financial impact. In continental Europe and in the USA, psoroptic mange is also a welfare problem in cattle and is becoming increasingly common in cattle in the UK [1]. Psoroptic mange is highly contagious, causing considerable pruritis and irritation [2]. Current disease control strategies are heavily reliant upon chemotherapy; however concerns over residues, eco-toxicity and the development of parasite resistance threaten the sustainability of current control strategies and have highlighted interes
Reduction in Greenhouse Gas Emissions Associated with Worm Control in Lambs
Fiona Kenyon,Jan M. Dick,Ron I. Smith,Drew G. Coulter,David McBean,Philip J. Skuce
Agriculture , 2013, DOI: 10.3390/agriculture3020271
Abstract: There are currently little or no data on the role of endemic disease control in reducing greenhouse gas (GHG) emissions from livestock. In the present study, we have used an Intergovernmental Panel on Climate Change (IPCC)-compliant model to calculate GHG emissions from naturally grazing lambs under four different anthelmintic drug treatment regimes over a 5-year study period. Treatments were either “monthly” (NST), “strategic” (SPT), “targeted” (TST) or based on “clinical signs” (MT). Commercial sheep farming practices were simulated, with lambs reaching a pre-selected target market weight (38 kg) removed from the analysis as they would no longer contribute to the GHG budget of the flock. Results showed there was a significant treatment effect over all years, with lambs in the MT group consistently taking longer to reach market weight, and an extra 10% emission of CO 2e per kg of weight gain over the other treatments. There were no significant differences between the other three treatment strategies (NST, SPT and TST) in terms of production efficiency or cumulated GHG emissions over the experimental period. This study has shown that endemic disease control can contribute to a reduction in GHG emissions from animal agriculture and help reduce the carbon footprint of livestock farming.
The use of a Psoroptes ovis serodiagnostic test for the analysis of a natural outbreak of sheep scab
Stewart TG Burgess, Giles Innocent, Francesca Nunn, David Frew, Fiona Kenyon, Alasdair J Nisbet, John F Huntley
Parasites & Vectors , 2012, DOI: 10.1186/1756-3305-5-7
Abstract: Serum samples were obtained from an outbreak of sheep scab within an experimental flock (n = 480 (3 samples each from 160 sheep)) allowing the assessment, by ELISA of sheep scab specific antibody prior to infestation, mid-outbreak (combined with clinical assessment) and post-treatment.Analysis of pre-infestation samples demonstrated low levels of potential false positives (3.8%). Of the 27 animals with clinical or behavioural signs of disease 25 tested positive at the mid-outbreak sampling period, however, the remaining 2 sheep tested positive at the subsequent sampling period. Clinical assessment revealed the absence of clinical or behavioural signs of disease in 132 sheep, whilst analysis of mid-outbreak samples showed that 105 of these clinically negative animals were serologically positive, representing potential sub-clinical infestations.This study demonstrates that this ELISA test can effectively diagnose sheep scab in a natural outbreak of disease, and more importantly, highlights its ability to detect sub-clinically infested animals. This ELISA, employing a single recombinant antigen, represents a major step forward in the diagnosis of sheep scab and may prove to be critical in any future control program.Sheep scab is caused by the mite Psoroptes ovis and is, arguably, the most important ectoparasitic disease of sheep in the UK. Recent data relating to the financial impact of sheep scab suggest that the disease costs the UK sheep industry in excess of £8 million per annum, including costs associated with lost performance, preventative measures, and treatment of affected animals; with the major costs relating to disease prevention [1]. Since its deregulation as a notifiable disease in 1992, sheep scab has become endemic throughout the UK [2]. The disease is highly contagious, causing considerable pruritis and irritation and is a major welfare concern [3]. Current disease control strategies are reliant upon chemotherapy; however, concerns over residues, eco-to
North pacific cool-down: 1940s-1960s  [PDF]
Kern E. Kenyon
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.28112
Abstract: Between the 1940s and the 1960s there was a significant lowering of the surface temperatures of the central North Pacific. This cool-down is discussed on the basis of analyses of a very large surface temperature data base, covering most of the North Pacific, which began in 1947 and continued for at least 30 years afterwards. A surface area more than 20 degrees of latitude by approximately 70 degrees of longitude, centered on 40°N, cooled down within about a ten year period by typically 0.5℃ and by as much as 1.0℃. Previously a permanent surface and near surface circulation was proposed in which a shallow very broad warm surface layer flows northeastward at mid-latitudes on the eastern side of the North Pacific while colder water returns southward to the east, west and underneath the warm surface current. It is suggested that variations in this hypothesized circulation, due to natural causes not yet completely understood, potentially provide a mechanism for producing a cooling down (or warming up) of a large region of the central North Pacific at mid-latitudes in a relatively short period of time (ten years or less).
Centrifugal force: an appreciation  [PDF]
Kern E. Kenyon
Natural Science (NS) , 2011, DOI: 10.4236/ns.2011.37086
Abstract: The centrifugal force is used to increase the physical understanding of five examples taken from fluid dynamics, geophysics and the solar system, as well as four hypothetical orbital problems. Each example involves a balance of forces between the centrifugal force and one or two other forces, such as a pressure gradient and a component of the force of gravity. Among the examples chosen for examination are: the orbital motion of fluid particles in surface grav-ity waves, the boundary layer character of steady flow next to a curved rigid surface, the tornado, the rotating self-gravitating mass and the three-body problem.
Southward surface flow in the central South Pacific  [PDF]
Kern E. Kenyon
Natural Science (NS) , 2012, DOI: 10.4236/ns.2012.411109
Abstract: A large-scale surface flow with a southward component is proposed for the central South Pacific Ocean based on an interpretation of existing closely spaced and accurately measured temperatures and salinities along two latitudes in two different southern hemisphere winters: 28o S (Scorpio) and five degrees south of that (WOCE). Such a southward flow is not predicted from theory nor is it shown on current charts and globes. The observed longitudinal maximum in surface temperature along 28o S is centered around 130o W and has an amplitude of at least 5o C and an east/west range of about 60o of longitude. This striking feature is most easily explained by horizontal transport from latitudes closer to the equator. Since temperature atlases show that equatorial surface temperatures are always highest in the west, the origin of the warm water probably is toward the western side of the ocean as well. Thus the surface flow surrounding the longitudinal temperature maximum should be directed to the southeast. Where the surface temperatures are maximum the mixed layer depths are relatively large in a convex downward lens with maximum depths of 100 m; a correlation that is consistent with warm water moving south and being cooled from above. Salinities are maximum near the temperature maximum, also suggesting that the source of the surface flow is at low latitudes, where evaporation is usually expected to exceed precipitation. It is conjectured that the large-scale southeastward flow of the South Pacific is the analogue of the northeastward wide warm current off California documented over 30 years ago.
Depth decay rate for surface gravity wave pressure and velocity  [PDF]
Kern E. Kenyon
Natural Science (NS) , 2013, DOI: 10.4236/ns.2013.51007
Abstract:

Linear governing equations are formulated for the depth decay of the pressure and velocity variations associated with propagating surface gravity waves. These governing equations come from combining Bernoulli’s equation for steady frictionless flow along a streamline and the crossstream force balance involving gravity, the centrifugal force and a pressure gradient. Qualitative solutions show that the pressure decreases downward faster than the velocity does and at a rate that is probably not the normal exponential decrease, which does not agree with the classical result. The radius of curvature of the streamlines is a non-constant coefficient in these equations and it needs to be supplied, either from measurements or another theory, in order to complete the solution of the derived governing equations. There is no sensitivity of the solution to the exact path the radius of curvature takes between its minimum value at the surface of a crest and trough and infinity at great depth. In the future measurements, perhaps streak photographs, will be needed to distinguish between the new and old theories.

Seasonal sea surface temperatures of the North Pacific  [PDF]
Kern E. Kenyon
Natural Science (NS) , 2013, DOI: 10.4236/ns.2013.58105
Abstract:

Mean seasonal surface temperatures of the North Pacific are illustrated in three maps. Twenty nine years of ship-injection temperatures are used for the whole North Pacific (north of 20?N). Map number two shows geographical regions of the month of highest sea surface temperature. There are two broad bands in the central and eastern basin, trending northeast/southwest, such that the September band lies east of the August band along a given latitude line. Map three depicts regions of the lowest monthly mean temperatures. March is the most common month, but in the middle of the ocean is a band of Februarys trending northeast/southwest. These features on maps two and three are interpreted in terms of the newly proposed wide warm surface current and its seasonal variations, mainly in horizontal position, flowing northeastward off California. It has not been found possible to compare maps two and three with the results from any earlier work. Map one shows the mean seasonal range of surface temperature, which has a character similar to maps going all the way back to the late 1800s, but is based on considerably more data.

Northward Heat Flux in Midwest Summers  [PDF]
Kern E. Kenyon
International Journal of Geosciences (IJG) , 2013, DOI: 10.4236/ijg.2013.48105
Abstract:

Watching the winds in northwest Iowa during more than 30 summers has led me to two conclusions about the local atmosphere at ground level: there is a net northward transport of heat and water taking place throughout the summer; warm humid winds from the south continually alternate with cool dry winds from the north. The proposed northward heat transfer is consistent with the constraint, placed on the motions of the oceans and the atmosphere, of the earth’s heat balance due to the increased absorption of solar radiation at low latitudes compared to that at high latitudes. At mid-latitudes in the interior of continents, like North America, it is the job of the atmosphere alone to constantly help satisfy the global heat balance. Although qualitative in nature, the predicted northward heat flux is strongly based on frequent observations over lengthy time intervals.

第1頁/共1438條
每頁顯示


Home
Copyright ? 2008-2017 Open Access Library. All rights reserved.

久草在现在线中文字幕