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Search Results: 1 - 10 of 588990 matches for " A.N.; PEREZ "
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Prevalencia de anticuerpos séricos contra Neospora caninum en dos reba?os lecheros de la IX Región de Chile
PATITUCCI,A.N.; PEREZ,M.J.; ISRAEL,K.F.; ROZAS,M.A.;
Archivos de medicina veterinaria , 2000, DOI: 10.4067/S0301-732X2000000200008
Abstract: neosporosis is an important cause of economic loss in the cattle industry throughout the world. in chile, it has been recently detected and,. since then, veterinarians and producers have required information about different aspects of the disease. in this paper we present data of the prevalence of the disease in two dairy herds of the ix region of chile. a commercial indirect fluorescent antibody test (ifa) was performed at 1:200 dilution for bovine and at 1:50 for canine sera. results indicate a 30.2% (52/173, ic=6.8%) infection in bovines from farm "a" and a 15.7% (31/198, ic=5%) in bovines from farm "b" (c2 = 10.42, p = 0.0012). in addition, 57% (4/7) of the dogs from farm "a" had antibodies. differences were observed in each farm as well as amongst age groups: in farm "a" 39.6% (42/106) of heifers and 15.2% (10/66) of cows (c2=10.42, p=0.0012) had antibodies against n. caninum; in farm "b": 22.7% (15/66) of calves, 17.8% (8/45) of heifers and 9.2% (8/87) of cows were positive. there were differences amongst cows, calves and heifers groups (c2=4,07, p=0.043). although it was not the aim of the study it is discussed if the source of infection could be the cause of the difference in prevalence. in contrast with farm "b"," the higher prevalence in farm "a was related to the group fed also with supplements. how the disease spreads in our environment is unknown, different mechanisms could be involved since in most of the farms the animals spend half of the year under confinement and the other half on pasture. the present article gives values of neospora prevalence and preliminary data for further studies on this progressively important disease
Prevalencia de anticuerpos séricos contra Neospora caninum en dos reba os lecheros de la IX Región de Chile Prevalence of Neospora caninum in two dairy herds of the IX Region of Chile
A.N. PATITUCCI,M.J. PEREZ,K.F. ISRAEL,M.A. ROZAS
Archivos de medicina veterinaria , 2000,
Abstract: La neosporosis ha sido reconocida y descrita como causa de aborto en la mayoría de las áreas ganaderas del mundo. En Chile se demostró la presencia de la enfermedad, sin embargo, muchos aspectos son desconocidos, razón por la cual se estudió la prevalencia de infección medida a través de anticuerpos séricos mediante la técnica de IFA en dos predios lecheros con antecedentes de abortos causados por este parásito. Se consideró a un bovino positivo cuando se evidenció fluorescencia a una dilución de 1:200. El 30,2% (52/173, IC=6,8%) de los animales estudiados en el predio A y el 15,7% (31/198, IC=5%) del predio B presentaron anticuerpos séricos contra el parásito. Los resultados por edades fueron para el predio A de 39,6% (42/106) para las vaquillas y de 15,2% (10/66) para las vacas (ji2=10,42, P=0,0012) y para el predio B de 22,7% (15/66) para las terneras, de 17,8% (8/45) para las vaquillas y de 9,2% (8/87) para las vacas. Las terneras y vaquillas positivas del predio B difirieron de las vacas adultas (ji2=4,07, P=0,043). Cuatro de los siete caninos existentes en el predio A presentaron anticuerpos contra N. caninum en dilución 1:50. Se discuten los resultados en relación a las posibles vías de difusión de infección en nuestro medio Neosporosis is an important cause of economic loss in the cattle industry throughout the world. In Chile, it has been recently detected and,. since then, veterinarians and producers have required information about different aspects of the disease. In this paper we present data of the prevalence of the disease in two dairy herds of the IX Region of Chile. A commercial indirect fluorescent antibody test (IFA) was performed at 1:200 dilution for bovine and at 1:50 for canine sera. Results indicate a 30.2% (52/173, IC=6.8%) infection in bovines from farm "A" and a 15.7% (31/198, IC=5%) in bovines from farm "B" (chi2 = 10.42, P = 0.0012). In addition, 57% (4/7) of the dogs from farm "A" had antibodies. Differences were observed in each farm as well as amongst age groups: in farm "A" 39.6% (42/106) of heifers and 15.2% (10/66) of cows (chi2=10.42, P=0.0012) had antibodies against N. caninum; in farm "B": 22.7% (15/66) of calves, 17.8% (8/45) of heifers and 9.2% (8/87) of cows were positive. There were differences amongst cows, calves and heifers groups (chi2=4,07, P=0.043). Although it was not the aim of the study it is discussed if the source of infection could be the cause of the difference in prevalence. In contrast with farm "B"," the higher prevalence in farm "A was related to the group fed also with supplements. How the disea
Attainment of Self-Reliance through Senior Secondary School Science and Technical Curriculum: An Appraisal
A.N Igboabuchi
African Research Review , 2010,
Abstract: All over the world, the importance of science is never in doubt since the 17th century AD. The countries of Europe were the first to acknowledge and develop it for man’s use. The developing countries of the third world like Nigeria, depend for their total development today on the already developed countries of Western Europe and America. The attainment of good degree of self-reliance had been, since this age of science and technology, the major focus of developing countries. To this effect, Nigeria changed her education structure since 1976 and reorganized her secondary school curricular with emphasis on science and technical subjects with the intention of cultivating scientific culture in Nigeria and equipping secondary school graduates with skills that would make them self-reliant. This work x-rayed the many –sided advantages of science and its application and analyzed the effects of the journey so far as regards the extent the science and technical schools are impacting on the school graduates and the society. The appraisal revealed a near zero impact leading the author to provide possible solutions as a way out of the woods.
Twin birth order, birthweight and birthweight discordance: any relationship
Onyiriuka A.N.
Saratov Journal of Medical Scientific Research , 2010,
Abstract: Background: It is widely believed that in twin pairs, at birth, the first-born weigh more than the second-born but this concept has been challenged. Objective: To assess the truthfulness of this common concept that first-born twins are usually heavier than their second-born siblings at birth. Methods: In a series of 104 sets of live-born twins, the birth weights of first-born twins were compared with those of their second-born siblings, after controlling for gender. Their intra-pair birthweight differences were determined and twin pairs whose birthweight difference was 15% or more were designated as discordant. Results: Twin I was heavier than Twin II in 61.5% of cases while Twin II was heavier than Twin I in 28.9% of cases. Twins I and II had equal birthweights in 9.6% of cases. Comparing the mean birthweight of the first-born-male twin with that of second-born- male twin, it was 2515+427g (95% Confidence Interval, CI=2402-2628) versus 2432 +435g (95% CI=2321-2543) p>0.05. The mean birthweight of first-born-female twin was 2326+445g (95% CI=2214-2439) while that of the second-born-female twin was 2325+501g (95% CI=2197-2453) p>0.05. When the birthweight difference exceeded 750g, the probability that Twin I will be heavier than Twin II was 83.3% (5 of 6). Conclusion: Although the first-born twin was more often heavier than their second-born siblings, either could weigh more or less at birth. The larger the birthweight difference between growth-discordant twin pair, the greater the probability that the heavier twin would be delivered first
Impact of interspousal violence and maternal deprivation on a child's mental health: a case report
Onyriuka A.N.
Saratov Journal of Medical Scientific Research , 2011,
Abstract: This paper presents a case of an emotionally deprived child with some evidence of child neglect resulting from husband-wife violence and subsequent separation of parents. It also further confirms the long recognized fact that the most successful treatment of growth failure and weight loss due to psychosocial deprivation is restoration of a normal social environment. In particular, it highlights the need for a high index of suspicion and awareness on the part of medical personnel with regard to emotional disorders in children
"THE EFFECT OF CHLOROQUINE ON THE INFECTIVITY OF RODENT MALARIA PARASITES TO ANOPHELES STEPHENSI "
A.N.,Hamidi
Iranian Journal of Public Health , 1977,
Abstract: There was a statistically significant difference in the number of oocysts, developed in Anopheles stephensi which had fed on mice infected with chloroquine resistant strains (NY 151./2B and. P.y. nigeriensis) and treated with 1 or 10 mg/kg chloroquine phosphate, when compared with the mosquitoes fed on saline injected control animals infected with the same lines. There was no significant difference between the oocyst counts in anophelines that fed on mice which were treated with chloroquine sensitive strains. In the first experiments on rats, with P.y. nigeriensis, greater increase has been shown in oocyst number in mosquitoes fed on dosed rats than in control. In duplicated experiments however, enhancement was approximately double. In chloroquine sensitive strain (ANKA), there was no statistically difference between the numbers, of oocyst developed in chloroquine treated and control rats.
Speleogenesis in carbonate rocks
Palmer,A.N.
Speleogenesis and Evolution of Karst Aquifers , 2003,
Abstract: This paper outlines the current views on cave origin in carbonate rocks, combining ideas from a variety of sources. A typical dissolution cave develops in several stages that grade smoothly from one to the next: (1) Initial openings are slowly enlarged by water that is nearly at solutional equilibrium with the local bedrock. (2) As the early routes enlarge, those with the greatest amount of flow grow fastest. (3) These favoured routes eventually become wide enough that groundwater is able to retain most of its solutional aggressiveness throughout the entire distance to the spring outlets. This breakthrough time usually requires times on the order of 104 to 105 years and ends the inception phase of speleogenesis. (4) Discharge along these selected routes increases rapidly, allowing them to enlarge into cave passages rather uniformly over their entire length. Maximum enlargement rates are roughly 0.001-0.1 cm/yr, depending on the local water chemistry and lithology. (5) The cave acquires a distinct passage pattern that depends on the nature of groundwater recharge, the geologic setting, and the erosional history of the region. Branchwork patterns dominate in most carbonate aquifers. Maze caves are produced by any of the following: steep hydraulic gradients (e.g. during floods), short flow paths, uniform recharge to many openings, and mixing of waters that contrast in chemistry. (6) Enlargement rate usually decreases as passages become air-filled, owing to loss of aggressiveness as carbon dioxide escapes through openings to the surface. (7) The cave typically evolves by diversion of water to new and lower routes as the fluvial base level drops. (8) The cave is eventually destroyed by roof collapse and by intersection of passages by surface erosion. At any given time, different parts of the same cave may be experiencing different stages in this sequence.
Patterns of dissolutional porosity in carbonate rocks
Palmer,A.N.
Speleogenesis and Evolution of Karst Aquifers , 2003,
Abstract: This paper reviews the hydrochemical processes that determine the patterns of caves and other solutional features within carbonate rocks. The model presented relies on the functional relationships expressed by chemical mass balances, flow equations, and kinetic expressions for dissolution rate. Although it shares many aspects of purely conceptual models and is backed by field evidence, its quantitative basis places it into the realm of analytical models. The conclusions merely summarize earlier work (mainly Palmer, 1981, 1991). Solutional enlargement of caves and other karst features is highly selective in water that is close to equilibrium with dissolved carbonate minerals, enlarging only the most favorable openings – i.e. those that transmit the greatest discharge. This is characteristic of long flow paths within a typical karst aquifer. In contrast, solutional enlargement will be rather uniform along many competing flow paths where there is (1) high discharge, (2) sustained steep hydraulic gradients, (3) short flow paths, or (4) local renewal of aggressiveness by mixing, oxidation of sulfides, etc. These conditions produce maze caves and epikarstic networks. In general, this condition prevails if Q/rL > 0.001 cm/sec (tubes), or /bL > 0.001 cm/sec (fissures), where Q = discharge, r = tube radius, b = long dimension of fissure cross section, and L = distance of flow from where the initial aggressive solution comes in contact with the carbonate rock.
Dynamics of cave development by allogenic water
Palmer,A.N.
Speleogenesis and Evolution of Karst Aquifers , 2003,
Abstract: Streams that drain from non karstic surfaces tend to have great discharge fluctuations and low concentrations of dissolved solids. Where these streams encounter karstic rocks they can form caves with hydraulic and chemical dynamics quite different from those fed by autogenic recharge (e.g. through dolines). In either case, caves form only along those paths in which the discharge can increase with time. Only a few favorable paths achieve this goal, while the others stagnate with small and diminishing enlargement rates. Caves in carbonate rocks that are fed by allogenic streams have a relatively short inception period, after which the mean annual rate of dissolutional wall retreat is typically about 0.01 cm/yr. Most of the annual growth takes place during a few major floods that occupy only a small fraction of the year. Local growth rates can be enhanced by abrasion from sediment. During floods, highly aggressive water is delivered rapidly to points deep within the karst aquifer. As flood discharge increases, cave streams become ponded by constrictions caused by detrital sediment, insoluble beds, or collapse material. The head loss across a constriction varies with the fifth power of the diameter ratio under pipe full conditions. Head loss also increases with the square of the discharge. Because the discharge during a flood rises by several orders of magnitude, the head loss across constrictions can increase enormously, causing water to fill parts of the cave under considerable pressure. This highly aggressive water is injected into all available openings in the surrounding bedrock, enlarging them at a rapid and nearly uniform rate. Depending on the structural nature of the bedrock, a dense array of blind fissures, pockets, anastomoses, or spongework is formed. Many such caves develop traversable mazes that serve either as bypass routes around constrictions, or as "karst annexes", which store and later release floodwaters. Many features that are sometimes attributed to slow phreatic flow or mixing corrosion are actually generated by ponded floodwaters. In caves that experience severe flooding, adjacent fissures or bypass routes with initial widths at least 0.01 cm can grow to traversable size within 10,000 years.
Processing of a coal waste as a measure for savings of resources and power savings on Cherepovets Metallurgical Industrial complex of Open Society "Severstal"
Vinogradov A.N.
Sovremennaa Ekonomika : Problemy, Tendencii, Perspektivy , 2011,
Abstract: In article the problem existing on thermal power station on Cherepovets Metallurgical Industrial complex of Open Society "Severstal" connected with efficiency and expediency of use of the energy carrier in the form of power coal and a way of its decision is underlined. In the form of a way of a solution of a problem realization of the investment project on processing coal waste is offered. The offered investment project solves a number, both commercial problems, and problems of socially-ecological character.
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