921 resultados para MUCOSAL DAMAGE
Resumo:
The Red-billed Quelea (Quelga quelaa), because of its widespread destruction of grain crops throughout its range in Africa, is one of the most studied and written about granivorous bird species. Less publicized are more local bird pests in Africa which may be equally Important. The Village Weaver, (Ploceus cucullatus), for example, is a pest in many countries, while some other Ploecids with limited destructive habits create local problems. Significant crop losses also occur where there are large populations of Golden Sparrows (Passer luteus), House Sparrows (Passer domesticus), Red Bishops (Euplectes oryx), Doves (Streptopelia spp.), Glossy Starlings (Lamprotornis chalybaeus), Parakeets (Psittacula spp.), and some waterfowl (Mackworth-Praed and Grant, 1952; Pans Manual No. 3, 1974; Park, 1974). Crop losses from local bird pests were reported in early February 1975 to the Sudan Plant Protection Bird Control Unit of the Ministry of Agriculture. A mechanized farm scheme in Khartoum North had large concentrations of Red Bishops roosting in maize and feeding on an early-maturing wheat variety (Mexicana). Small flocks of Golden Sparrows and House Sparrows also were present. Bird damage was clearly visible, especially at the corners and along the edges of the ripening wheatfields. Ground spraying with Queletox (60% a.1. Fenthion) on roosts of the Golden and House Sparrows was conducted along hedge rows of acacia (Acacia mellifera) located at the north end of the farm. Although the spray killed large numbers of roosting birds, damage con- tinued as the wheat matured. Pilot field trials were thus organized to test the effectiveness of other crop protection techniques. Because birds fed throughout many blocks of wheat which matured at different periods, it was felt that several different experiments could be conducted without Interfering with each other. The control techniques Included an acoustical repellent, a chemical repellent, a chemical frightening agent, and a trap. The experiments, conducted from February 7 through February 23, 1975, were not designed as an integrated control operation.
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To many people, California is synonomous with Disneyland, freeways, Los Angeles smog, Yosemite, the California missions, or for you bird aficionados, the California Condor. But do you think about California when you eat strawberry shortcake? You should -- California leads the nation in strawberry production. How about artichokes? California produces over 98% of the artichokes raised in the United States. Dates? California produces over 99% of the dates in the United States. Yes, California is all of these, and it is much more. California may well be the most diverse state in the United States. Within its 100.2 million acres, California has the lowest place in the U.S. in Death Valley and one of the highest mountains with Mt. Whitney. Because California is such a diverse state and has a wide variety of micro- climates, it supports a uniquely diverse agriculture. Agriculture uses only about 36 million acres of its total 100.2 million acres, and most of the cash return from crops is produced on 8,6 million acres that are irrigated. California produces about 250 crops and livestock commodities (excluding nursery crops) and provides the U.S. with about 25% of its table foods. California leads the nation in the production of 46 commercial crops and livestock commodities; its farmers and ranchers marketed $8.6 billion of crop and livestock products in 1975, and the state’s harvested farm production in 1975 set a new record at 51.1 million tons. HISTORY OF BIRD PROBLEMS Records such as this are not achieved without some risk. Crops growing in Cali- fornia have always had competition from many types of vertebrate pests. The wide variety of crops grown in California and the varied climates and situations in which they are grown has resulted in many different species of birds damaging crops. Birds have compet- ed with man for his crops since the dawn of agriculture. McAtee (1932) cited examples of bird damage that occurred in a wide variety of crops in California during the early 1900s. During the 1920s, many requests for Information and relief from damage caused by a wide variety of birds, culminated in the assignment, in May 1929, of two biologists, S. E. Piper and Johnson Neff, of the former U.S. Bio- logical Survey, to initiate field studies in California. In cooperation with the Cali- fornia Department of Food and Agriculture and County Agricultural Commissioners, the study was to determine the problems and devise control procedures relative to bird depredations. Piper and Neff found such damage as Horned Larks pulling sprouting crops, House Finches disbudding deciduous fruit trees and devouring mature fruit. Blackbirds were a problem in the rice crop. Early controls were varied and, for the most part, lacked effectiveness. Flagging of fields was common to deter Horned Larks. Windmill devices were tried to frighten birds. Shooting to kill birds was common; scarecrows were.used. The six-year study brought forth the basis of most of the depredating bird control techniques still in use in California. At the end of the study, these two biologists compiled a book called “Procedure and Methods in Controlling Birds Injurious to Crops in California.” This was and still is the “Bible” for bird damage control techniques used in California. The thorough investigations conducted by these biologists resulted in techniques that have remained valid in California for over 40 years.
Resumo:
Bird damage to commercial fruits has long been a problem in many coun- tries, but the true magnitude of the damage incurred is difficult to determine objectively. Often the opinions of fruit growers provide the only measure of importance. In 1972, the U.S. Fish and Wildlife Service, the Michigan Department of Agriculture, and the Statistical Reporting Service of the U.S. Department of Agriculture obtained quantitative information on bird damage to tart cherries (Prunus mahalob) in Michigan. The results of the survey are presented in this paper.
Resumo:
The history of wildlife damage management in the United States, beginning with the roots of the federal Biological Survey, is examined. Selected lessons are drawn from history and applied to today's situation, in the hope that they will be useful to those who guide this profession in the 21st Century.
Resumo:
As a nation we have gained world recognition for our ability to utilize our resources. In forestry our greatest accomplishments have been in the mechanization of harvest methods and in improvements in forest products. The renewal of this resource has been our greatest neglect. Though the end of the 19th Century marked the beginning of the conservation movement, it was not until a half century later that the force of economics through the demands of a growing population made forest re-establishment more than just a desire. Conservation in itself is a Utopian concept which requires other motivating forces to make it a reality. In the post-war years, and as late as the early 195O's, stocked land in the Pacific Northwest could be purchased for less than the cost of planting; the economic incentive was lacking. Only with sustained yield management and increased land values was there a balance in favor of true values. With greater effort placed on forest regeneration there was an increased need for methods of reducing losses to wildlife. The history of forest wildlife damage research, therefore, parallels that of forest land management; after rather austere beginnings, development became predominantly a response to economics. It was not until 1950 that the full time of one scientist was assigned to this important activity. The development of control methods for forest animal damage is a relatively new area of research. All animal life is dependent upon plants for its existence; forest wildlife is no exception. The removal of seed and foliage of undesirable plants often benefits the land managers; only when the losses or injuries are in conflict with man's interest is there damage involved. Unfortunately, the feeding activities of wildlife and the interests of the land managers are often in conflict. Few realize the breadth, scope, and subtilities associated with forest wildlife damage problems. There are not only numerous species of animals involved, but also a myriad of conditions, each combination possessing unique facets. It is a foregone conclusion that an understanding of the conditions is essential to facilitate a solution to any given problem. Though there are numerous methods of reducing animal damage, all of which have application under some situations, in this discussion emphasis will be placed on the role of chemicals and on western problems. Because of the broadness and complexity of the problem, generalizing is necessary and only brief coverage will be possible. However, an attempt will be made to discuss the use and limitations of various control methods.
Resumo:
"How large a sample is needed to survey the bird damage to corn in a county in Ohio or New Jersey or South Dakota?" Like those in the Bureau of Sport Fisheries and Wildlife and the U.S.D.A. who have been faced with a question of this sort we found only meager information on which to base an answer, whether the problem related to a county in Ohio or to one in New Jersey, or elsewhere. Many sampling methods and rates of sampling did yield reliable estimates but the judgment was often intuitive or based on the reasonableness of the resulting data. Later, when planning the next study or survey, little additional information was available on whether 40 samples of 5 ears each or 5 samples of 200 ears should be examined, i.e., examination of a large number of small samples or a small number of large samples. What information is needed to make a reliable decision? Those of us involved with the Agricultural Experiment Station regional project concerned with the problems of bird damage to crops, known as NE-49, thought we might supply an ans¬wer if we had a corn field in which all the damage was measured. If all the damage were known, we could then sample this field in various ways and see how the estimates from these samplings compared to the actual damage and pin-point the best and most accurate sampling procedure. Eventually the investigators in four states became involved in this work1 and instead of one field we were able to broaden the geographical base by examining all the corn ears in 2 half-acre sections of fields in each state, 8 sections in all. When the corn had matured well past the dough stage, damage on each corn ear was assessed, without removing the ear from the stalk, by visually estimating the percent of the kernel surface which had been destroyed and rating it in one of 5 damage categories. Measurements (by row-centimeters) of the rows of kernels pecked by birds also were made on selected ears representing all categories and all parts of each field section. These measurements provided conversion factors that, when fed into a computer, were applied to the more than 72,000 visually assessed ears. The machine now had in its memory and could supply on demand a map showing each ear, its location and the intensity of the damage.
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The object is to hash over a few problems as we see them on this red-winged blackbird situation. I'm Mel Dyer, University of Guelph, Guelph, Ontario. Around the table are Tom Stockdale, Extension Wildlife Specialist, Ohio Cooperative Extension Service, Columbus; Maurice Giltz, Ohio Agriculture Research and Development Center, Wooster, Ohio; Joe Halusky, U.S. Fish and Wildlife Service, Columbus, Ohio; Daniel Stiles, U.S. Fish and Wildlife Service, Washington, D.C.; Paul Rodeheffer, U.S. Fish and Wildlife Service, Columbus, Ohio; Brian Hall, Blackbird Research Project, University of Guelph, Guelph, Ontario; George Cornwell, Virginia Polytechnic Insti¬tute, Blacksburg, Va.; Dick Warren, Peavey Grain Company, Minneapolis, Minn.; Bob Fringer, N.J. Department of Agriculture, Trenton, N.J.; Charles Stone, U.S. Fish and Wildlife Service, Columbus, Ohio; Larry Holcomb, Ohio Agricultural Research and Development Center, Wooster, Ohio; Doug Slack, Ohio Agricultural Research and Development Center, Wooster, Ohio; Charles Wagg, N.J. Department of Agriculture, Trenton, N.J.; Dick Smith, U.S. Fish and Wildlife Service, Columbus, Ohio; and Jim Caslick, U.S. Fish and Wildlife Service, Gainesville, Fla. As I see the situation, as a director of a red-winged blackbird research project, we have a problem which has been defined in human terms concerning a natural animal population.
Resumo:
In this paper is presented a multilayer perceptron neural network combined with the Nelder-Mead Simplex method to detect damage in multiple support beams. The input parameters are based on natural frequencies and modal flexibility. It was considered that only a number of modes were available and that only vertical degrees of freedom were measured. The reliability of the proposed methodology is assessed from the generation of random damages scenarios and the definition of three types of errors, which can be found during the damage identification process. Results show that the methodology can reliably determine the damage scenarios. However, its application to large beams may be limited by the high computational cost of training the neural network.
Resumo:
Toluene is an organic solvent used in numerous processes and products, including industrial paints. Toluene neurotoxicity and reproductive toxicity are well recognized: however, its genotoxicity is still under discussion, and toluene is not classified as a carcinogenic solvent. Using the comet assay and the micronucleus test for detection of possible genotoxic effects of toluene, we monitored industrial painters from Rio Grande do Sul, Brazil. The putative involvement of oxidative stress in genetic damage and the influences of age, smoking, alcohol consumption, and exposure time were also assessed. Although all biomarkers of toluene exposure were below the biological exposure limits, painters presented significantly higher DNA damage (comet assay) than the control group; however, in the micronucleus assay, no significant difference was observed. Painters also showed alterations in hepatic enzymes and albumin levels, as well as oxidative damage, suggesting the involvement of oxidative stress. According to multiple linear regression analysis, blood toluene levels may account for the increased DNA damage in painters. In summary, this study showed that low levels of toluene exposure can cause genetic damage, and this is related to oxidative stress, age, and time of exposure. (C) 2012 Elsevier B.V. All rights reserved.
Resumo:
The high consumption of fructose is linked to the increase in various characteristics of the metabolic syndrome. Fish oil is beneficial for the treatment of these comorbidities, such as insulin resistance, dyslipidemia, and hepatic steatosis. The objective of this study was to evaluate the consequences of the administration of fish oil concomitant to fructose ingestion during the experiment (45 days) and during the final 15 days in high-fructose-fed rats. Male Wistar rats were divided into 5 groups: control; those receiving 10% fish oil (FO); those receiving 60% fructose (Fr); those receiving 60% fructose and 10% fish oil for 45 days (FrFO); and those receiving fructose plus soybean oil for 30 days and fish oil for the final 15 days of the study (FrFO15). There was an increase in triacylglycerol, serum total cholesterol, and hepatic volume in the Fr group. The FO and FrFO groups experienced an increase in lipid peroxidation and a decrease in serum reduced glutathione. The FrFO group suffered greater hepatic injury, with increased alanine aminotransferase levels and DNA damage. Marked n-3 incorporation occurred in the groups receiving fish oil, favoring a better response to the oral glucose tolerance test. Fructose induced comorbidities of the metabolic syndrome, and the use of fish oil promoted a better glucose tolerance, although it was accompanied by more hepatocyte damage.
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The effect of melatonin during in vitro maturation (IVM) on DNA damage of cumulus cells (CCs) from bovine cumulus-oocyte complexes (COCs) and embryo development was evaluated. COCs from abattoir ovaries were cultured in maturation medium (MM) with 0.5 mu g/ml FSH and 5.0 mu g/ml LH (FSH-LH); 10(-9) M melatonin (MEL) or FSH-LH + MEL (FSH-LH-MEL). After 24 h of in vitro maturation, the CCs surrounding the oocyte were subjected to DNA analysis by Comet assay. After in vitro fertilization and in vitro embryo culture, the embryo development rates were evaluated on day 2 post insemination (cleavage) and days 7-8 (blastocyst). The percentage of CCs with no DNA damage was significantly superior in MEL group (37.6 +/- 2.4) than in FSH-LH-MEL (28.0 +/- 2.4) and FSH-LH (17.8 +/- 2.41) groups. Cleavage and blastocysts rates were similar among groups. Melatonin during IVM protects the CCs from DNA damage but this effect did not influence embryo development in vitro. (C) 2010 Elsevier Ltd. All rights reserved.
Carbohydrate supplementation delays DNA damage in elite runners during intensive microcycle training
Resumo:
The aim of this study was to evaluate the effect of carbohydrate supplementation on free plasma DNA and conventional markers of training and tissue damage in long-distance runners undergoing an overload training program. Twenty-four male runners were randomly assigned to two groups (CHO group and control group). The participants were submitted to an overload training program (days 1-8), followed by a high-intensity intermittent running protocol (10 x 800 m) on day 9. The runners received maltodextrin solution (CHO group) or zero energy placebo solution as the control equivalent before, during, and after this protocol. After 8 days of intensive training, baseline LDH levels remained constant in the CHO group (before: 449.1 +/- 18.2, after: 474.3 +/- 22.8 U/L) and increased in the control group (from 413.5 +/- 23.0 to 501.8 +/- 24.1 U/L, p < 0.05). On day 9, LDH concentrations were lower in the CHO group (509.2 +/- 23.1 U/L) than in the control group (643.3 +/- 32.9 U/L, p < 0.01) post-intermittent running. Carbohydrate ingestion attenuated the increase of free plasma DNA post-intermittent running (48,240.3 +/- 5,431.8 alleles/mL) when compared to the control group (73,751.8 +/- 11,546.6 alleles/mL, p < 0.01). Leukocyte counts were lower in the CHO group than in the control group post-intermittent running (9.1 +/- 0.1 vs. 12.2 +/- 0.7 cells/mu L; p < 0.01) and at 80 min of recovery (10.6 +/- 0.1 vs. 13.9 +/- 1.1 cells/mu L; p < 0.01). Cortisol levels were positively correlated with free plasma DNA, leukocytes, and LDH (all r > 0.4 and p < 0.001). The results showed that ingestion of a carbohydrate beverage resulted in less DNA damage and attenuated the acute post-exercise inflammation response, providing better recovery during intense training.
Resumo:
Aircraft composite structures must have high stiffness and strength with low weight, which can guarantee the increase of the pay-load for airplanes without losing airworthiness. However, the mechanical behavior of composite laminates is very complex due the inherent anisotropy and heterogeneity. Many researchers have developed different failure progressive analyses and damage models in order to predict the complex failure mechanisms. This work presents a damage model and progressive failure analysis that requires simple experimental tests and that achieves good accuracy. Firstly, the paper explains damage initiation and propagation criteria and a procedure to identify the material parameters. In the second stage, the model was implemented as a UMAT (User Material Subroutine), which is linked to finite element software, ABAQUS (TM), in order to predict the composite structures behavior. Afterwards, some case studies, mainly off-axis coupons under tensile or compression loads, with different types of stacking sequence were analyzed using the proposed material model. Finally, the computational results were compared to the experimental results, verifying the capability of the damage model in order to predict the composite structure behavior. (C) 2011 Elsevier Ltd. All rights reserved.
Resumo:
Human infections with EHEC such as O157:H7 have been a great concern for worldwide food-industry surveillance. This pathogen is commonly associated with bloody diarrhea that can evolve to the life-threatening hemolytic uremic syndrome. Animals are the natural reservoir where this pathogen remains asymptomatically, in steps of ingestion and colonization of the bowel. The bacterium is shed in the feces, contaminating the surroundings, including water and food that are directed for human consumption. A major player in this colonization process is intimin, an outer membrane adhesion molecule encoded by the E. coli attachment and effacement (eae) gene that has been shown to be essential for intimate bacterial attachment to eukaryotic host cells. In an attempt to reduce the colonization of animal reservoirs with EHEC O157:H7, we designed a vaccine model to induce an immune response against intimin gamma. The model is based on its recombinant expression in attenuated Salmonella, used as a suitable vaccine vector because of its recognized ability to deliver recombinant antigens and to elicit all forms of immunity: mucosal, systemic, and humoral responses. To test this model, mice were orally immunized with a S. enterica serovar Typhimurium strain carrying the pYA3137eaeA vector, and challenged with E. coli O157:H7. Here we show that immunization induced the production of high levels of specific IgG and IgA antibodies and promoted reduction in the fecal shedding of EHEC after challenge. The live recombinant vaccine reported herein may contribute to the efforts of reducing animal intestinal mucosa colonization.
Resumo:
The present study compared the changes in markers of muscle damage after bouts of resistance exercise employing the Multiple-sets (MS) and Half-pyramid (HP) training systems. Ten healthy men (26.1 +/- 6.3 years), who had been involved in regular resistance training, performed MS and HP bouts, 14 days apart, in a randomised, counter-balanced manner. For the MS bout, participants performed three sets of maximum repetitions at 75%-1RM (i.e. 75% of a One Repetition Maximum) for the three exercises, starting with the bench press, followed by pec deck and decline bench press. For the HP bout, the participants performed three sets of maximum repetitions with 67%-1RM, 74%-1RM and 80%-1RM for the first, second and third sets, respectively, for the same three exercise sequences as the MS bout. The total volume of load lifted was equated between both bouts. Muscle soreness, plasma creatine kinase (CK) activity, myoglobin (Mb) and C-reactive protein (CRP) concentrations were assessed before and for three days after each exercise bout, and the changes over time were compared between MS and HP using two-way repeated measures ANOVA. Muscle soreness developed significantly (P<0.01) after both bouts, but no significant difference was observed between MS and HP. Plasma CK activity and Mb concentration increased significantly (P<0.01) without significant differences between bouts, and CRP concentration did not change significantly after either bout. These results suggest that the muscle damage profile is similar for MS and HP, probably due to the similar total volume of load lifted.