943 resultados para 415 Other agricultural sciences
Resumo:
The levels of As and various other trace elements found in the irrigated agricultural soil (Tsoil) of southern Libya were compared with non-irrigated soil (Csoil) from the same sampling campaign collected between April and May 2008. The soil samples represented agronomic practice in the southern Libyan regions of Maknwessa (MAK), Aril (ARL) and Taswaa (TAS), and were analyzed by Inductively coupled plasma mass spectrometry (ICP-MS) for Co, Ni, Cu, Se, Mo, Zn, As, Pb, Cd and P. Concentrations of P and As in TAS and MAK were found to be higher in Tsoil compared to Csoil, while the opposite was true for ARL. In general, As concentrations in these areas were 2-3 times lower than the global average. In ARL, the average P concentrations of the Csoil samples were significantly higher than those of Tsoil samples: this site is composed mainly of pasture for animal production, where phosphate fertilizers are used regularly. Distance from the source of irrigation was found to be of an important influence on the heavy metal concentration of the soil, with greater concentrations found closer to the irrigation source. It can be concluded from the results that irrigation water contains elevated levels of As, which finds its way into the soil profile and can lead to accumulation of As in the soil over time.
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It is well documented that the majority of Tuberculosis (TB) cases diagnosed in Canada are related to foreign-bom persons from TB high-burden countries. The Canadian seasonal agricultural workers program (SAWP) operating with Mexico allows migrant workers to enter the country with a temporary work permit for up to 8 months. Preiimnigration screening of these workers by both clinical examination and chest X-ray (CXR) reduces the risk of introducing cases of active pulmonary TB to Canada, but screening for latent TB (LTBI) is not routinely done. Studies carried out in industrialized nations with high immigration from TBendemic countries provide data of lifetime LTBI reactivation of around 10% but little is known about reactivation rates within TB-endemic countries where new infections (or reinfections) may be impossible to distinguish from reactivation. Migrant populations like the SAWP workers who spend considerable amounts of time in both Canada and TBendemic rural areas in Mexico are a unique population in terms of TB epidemiology. However, to our knowledge no studies have been undertaken to explore either the existence of LTBI among Mexican workers, the probability of reactivation or the workers' exposure to TB cases while back in their communities before returning the following season. Being aware of their LTBI status may help workers to exercise healthy behaviours to avoid TB reactivation and therefore continue to access the SAWP. In order to assess the prevalence of LTBI and associated risk factors among Mexican migrant workers a preliminary cross sectional study was designed to involve a convenience sample of the Niagara Region's Mexican workers in 2007. Research ethics clearance was granted by Brock University. Individual questionnaires were administered to collect socio-demographic and TB-related epidemiological data as well as TB knowledge and awareness levels. Cellular immunity to M tuberculosis was assessed by both an Interferon-y release assay (lGRA), QuantiFERON -TB Gold In-Tube (QFf™) and by the tuberculin skin test (TSn using Mantoux. A total of 82 Mexican workers (out of 125 invited) completed the study. Most participants were male (80%) and their age ranged from 22 to 65 years (mean 38.5). The prevalence of LTBI was 34% using TST and 18% using QFTTM. As previously reported, TST (using ~lOmm cut-off) showed a sensitivity of 93.3% and a specificity of 79.1 %. These findings at the moment cannot predict the probability of progression to active TB; only longitudinal cohort studies of this population can ascertain this outcome. However, based on recent publications, lORA positive individuals may have up to 14% probability of reactivation within the next two years. Although according to the SA WP guidelines, all workers undergo TB screening before entering or re-entering Canada, CXR examination requirements showed to be inconsistent for this population: whereas 100% of the workers coming to Canada for the first time reported having the procedure done, only 31 % of returning participants reported having had a CXR in the past year. None of the participants reported ever having a CXR compatible with TB which was consistent with the fact that none had ever been diagnosed with active pulmonary TB and with only 3.6% reporting close contact with a person with active TB in their lifetime. Although Mexico reports that 99% of popUlation is fully immunized against TB within the first year of age, only 85.3% of participants reported receiving BOC vaccine in childhood. Conversely, even when TST is not part of the routine TB screening in endemic countries, a suqDrisingly high 25.6% reported receiving a TST in the past. In regards to TB knowledge and awareness, 74% of the studied population had previous knowledge about (active) TB, 42% correctly identified active TB symptomatology, 4.8% identified the correct route of transmission, 4.8% knew about the existence of LTBI, 3.6% knew that latent TB could reactivate and 48% recognized TB as treatable and curable. Of all variables explored as potential risk factors for LTBI, age was the only one which showed statistical significance. Significant associations could not be proven for other known variables (such as sex, TB contact, history of TB) probably because of the small sample size and the homogeneity of the sample. Screening for LTBI by TST (high sensitivity) followed by confirmation with QFT''"'^ (high specificity) suggests to be a good strategy especially for immigrants from TB high-burden countries. After educational sessions, workers positive for LTBI gained greater knowledge about the signs and symptoms of TB reactivation as well as the risk factors commonly associated with reactivation. Additionally, they were more likely to attend their annual health check up and request a CXR exam to monitor for TB reactivation.
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Les facteurs climatiques ainsi bien que les facteurs non-climatiques doivent être pris en considération dans le processus d'adaptation de l'agriculture aux changements et à la variabilité climatiques (CVC). Ce changement de paradigme met l'agent humain au centre du processus d'adaptation, ce qui peut conduire à une maladaptation. Suite aux débats sur les changements climatiques qui ont attiré l'attention scientifique et publique dans les années 1980 et 1990, l'agriculture canadienne est devenue un des points focaux de plusieurs études pionnières sur les CVC, un phénomène principalement dû à l’effet anthropique. Pour faire face aux CVC, ce n’est pas seulement la mitigation qui est importante mais aussi l’adaptation. Quand il s'agit de l'adaptation, c'est plutôt la variabilité climatique qui nous intéresse que simplement les augmentations moyennes des températures. L'objectif général de ce mémoire de maîtrise est d'améliorer la compréhension des processus d'adaptation et de construction de la capacité d'adaptation ai niveau de la ferme et de la communauté agricole à travers un processus ascendant, c’est-à-dire en utilisant l'approche de co-construction (qui peut également être considéré comme une stratégie d'adaptation en soi), pour développer une gestion et des outils de planification appropriés aux parties prenantes pour accroître ainsi la capacité d'adaptation de la communauté agricole. Pour y arriver, l'approche grounded theory est utilisée. Les résultats consistent de cinq catégories interdépendantes de codes élargis, conceptuellement distinctes et avec un plus grand niveau d'abstraction. La MRC du Haut-Richelieu a été choisie comme étude de cas en raison de plusieurs de ses dimensions agricoles, à part de ses conditions biophysiques favorables. 15 entrevues ont été menées avec les agriculteurs. Les résultats montrent que si certains agriculteurs ont reconnu les côtés positifs et négatifs des CVC, d’autres sont très optimistes à ce sujet comme se ils ne voient que le côté positif; d'où la nécessité de voir les deux côtés des CVC. Aussi, il y a encore une certaine incertitude liée aux CVC, qui vient de la désinformation et la désensibilisation des agriculteurs principalement en ce qui concerne les causes des CVC ainsi que la nature des événements climatiques. En outre, et compte tenu du fait que l'adaptation a plusieurs caractéristiques et types, il existe de nombreux types d'adaptation qui impliquent à la fois l'acteur privé et le gouvernement. De plus, les stratégies d'adaptation doivent être élaborées conjointement par les agriculteurs en concert avec d'autres acteurs, à commencer par les agronomes, car ils servent en tant que relais important entre les agriculteurs et d'autres parties prenantes telles que les institutions publiques et les entreprises privées.
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La butirilcolinesterasa humana (BChE; EC 3.1.1.8) es una enzima polimórfica sintetizada en el hígado y en el tejido adiposo, ampliamente distribuida en el organismo y encargada de hidrolizar algunos ésteres de colina como la procaína, ésteres alifáticos como el ácido acetilsalicílico, fármacos como la metilprednisolona, el mivacurium y la succinilcolina y drogas de uso y/o abuso como la heroína y la cocaína. Es codificada por el gen BCHE (OMIM 177400), habiéndose identificado más de 100 variantes, algunas no estudiadas plenamente, además de la forma más frecuente, llamada usual o silvestre. Diferentes polimorfismos del gen BCHE se han relacionado con la síntesis de enzimas con niveles variados de actividad catalítica. Las bases moleculares de algunas de esas variantes genéticas han sido reportadas, entre las que se encuentra las variantes Atípica (A), fluoruro-resistente del tipo 1 y 2 (F-1 y F-2), silente (S), Kalow (K), James (J) y Hammersmith (H). En este estudio, en un grupo de pacientes se aplicó el instrumento validado Lifetime Severity Index for Cocaine Use Disorder (LSI-C) para evaluar la gravedad del consumo de “cocaína” a lo largo de la vida. Además, se determinaron Polimorfismos de Nucleótido Simple (SNPs) en el gen BCHE conocidos como responsables de reacciones adversas en pacientes consumidores de “cocaína” mediante secuenciación del gen y se predijo el efecto delos SNPs sobre la función y la estructura de la proteína, mediante el uso de herramientas bio-informáticas. El instrumento LSI-C ofreció resultados en cuatro dimensiones: consumo a lo largo de la vida, consumo reciente, dependencia psicológica e intento de abandono del consumo. Los estudios de análisis molecular permitieron observar dos SNPs codificantes (cSNPs) no sinónimos en el 27.3% de la muestra, c.293A>G (p.Asp98Gly) y c.1699G>A (p.Ala567Thr), localizados en los exones 2 y 4, que corresponden, desde el punto de vista funcional, a la variante Atípica (A) [dbSNP: rs1799807] y a la variante Kalow (K) [dbSNP: rs1803274] de la enzima BChE, respectivamente. Los estudios de predicción In silico establecieron para el SNP p.Asp98Gly un carácter patogénico, mientras que para el SNP p.Ala567Thr, mostraron un comportamiento neutro. El análisis de los resultados permite proponer la existencia de una relación entre polimorfismos o variantes genéticas responsables de una baja actividad catalítica y/o baja concentración plasmática de la enzima BChE y algunas de las reacciones adversas ocurridas en pacientes consumidores de cocaína.
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Wastewater reuse has become an important alternative to agricultural irrigation; on the other hand, it poses concern with regard to public health. Total coliform and Escherichia coli concentration, presence of helminth eggs and Salmonella, and physical-chemical parameters were evaluated in raw and treated wastewater. Chemical and biochemical oxygen demand removal efficiency was 74.6 and 77.9%, respectively. As for organic nitrogen, total phosphorus, and total suspended solids, total efficiency removal was 17.4, 12.5, and 32.9%, respectively. The average density of total coliforms and E. coli was 3.5 x 10(9) and 1.8 x 10(8) MPN/100 mL and 1.1 x 10(7) MPN/100 mL and 3.9 x 10(5) MPN/100 mL for raw and treated wastewater, respectively. Ascaris eggs were observed in 80.8% of the samples collected, and viable eggs in 42.3% of the samples. Salmonella was detected in 36.4% of the samples. The values observed in treated wastewater did not show the adequate bacteriological quality, as recommended by World Health Organization (Geneva, Switzerland). Therefore, additional measures should be taken to achieve an improved microbiological and parasitological quality.
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Blastocystis hominis é um protozoário, causador de infecção intestinal denominada blastocistose humana, cujo diagnóstico é realizado pelo exame coproparasitológico e por meio de técnicas de coloração permanente. Este estudo foi desenvolvido para avaliar a freqüência da infecção por Blastocystis hominis em habitantes da região de Araraquara/SP, bem como comparar diferentes métodos para a pesquisa desse protozoário em amostras de fezes. Foram estudadas 503 amostras de fezes submetidas ao exame direto a fresco, às técnicas de Faust e cols, Lutz e de Rugai e cols, além das colorações pela hematoxilina férrica, tricrômio e de Kinyoun modificada. Entre as 503 amostras examinadas, 174 (34,6%) apresentaram-se positivas para a presença de parasitas intestinais. O protozoário e o helminto mais freqüentes foram Entamoeba coli (14,6%) e Strongyloides stercoralis (6,7%), respectivamente. Blastocystis hominis foi observado em 23 (4,6%) amostras fecais com consistência predominantemente pastosa, não caracterizando quadro diarréico. Apesar da baixa freqüência de Blastocystis hominis encontrada na região de Araraquara, comparativamente a outras regiões brasileiras, é importante a realização do diagnóstico laboratorial desse protozoário. O encontro de Blastocystis hominis em material fecal é indicativo de contaminação de alimentos e água de consumo, desde que se admita a rota de transmissão oral-fecal desse parasita, o que implica na orientação da população sobre as medidas de saneamento básico e higiene como meio para se controlar problemas de saúde ocasionados pelos enteroparasitas.
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Foreword, 2000 John A . Schmitz. Professor and Department Head Veterinary and Biomedical Sciences Personnel Faculty Profiles Teaching program Research program Extension Program Nebraska Veterinary and Diagnostic Laboratory Systems Grants and Contracts Funded or Active in 2000 Patents by VBMS Faculty in 2000 Publications by VBMS Faculty in 2000 Presentations by VBMS Faculty in 2000 Articles Regarding the Department in 2000 Selected Committees, Editorial and Other Appointments of VBMS Faculty Departmental Budget Summaries Nebraska Agricultural Statistics 1999
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Veterinary and Biomedical Sciences Personnel VBMS Teaching Program VBMS Research Program International Activities, 2004 Veterinary Extension Program. 2004 VBMS Grants and Contracts Program. 2004 Refereed Publications by VBMS Faculty in 2004 Department of Veterinary and Biomedical Sciences. Selected Committees, Editorial and Other Appointments. 2004 Articles Regarding the Department in 2004 Departmental Budget Summaries. 2004 Nebraska Agricultural Statistics. 2003/2004
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In Arkansas, blackbirds are responsible for appreciable damage to rice, grain sorghum, oats, wheat, rye, and corn. By far, the greatest damage is to rice. As is shown in the following table, the losses to rice producers amounted to an estimated $3,049,055 in 1968, the last year that a survey was made. Nearly two-thirds (63%) of this loss was to standing rice destroyed and to the cost of bird control measure in standing rice. The remaining losses ($2,140,320 ) are to seeding or to efforts to control bird depredations to new seeding, (see Table 1). Blackbird damage to grain sorghum and corn was mostly to standing grain; that to oats, wheat and rye, to seeding, although there is occasional damage to standing grain. Additional problems are caused by blackbirds in feed lots. The total losses to Arkansas agricultural producers due to blackbirds in 1968 was about $3,500,000. Bird damage in a specific locality and on specific crops seems to vary in intensity from year to year. However, surveys during the past ten years suggest a fairly consistent level of total damage state-wide. The damage in 1968-and I believe in 1969—was somewhat lighter than we have come to expect from past exper¬ience. (See table 2.) On a per acre basis the damage in 1968 showed a considerable decline when compared to previous years. A part of this decline is probably a temporary situation. Some of the decline in losses to rice and grain sorghum, however, are due to changes in varieties, such as development of bird-resistant milo, and to changes in cultural methods. Further appreciable reductions due to changes in these factors seem unlikely, (see table 3.) Since rice producers sustain the greatest losses to birds, they have generated the greatest demand for bird control programs. Three species are responsible for most of the damage to rice. They are the red-winged blackbird, common grackle and brown-headed cowbird. These birds have created problems for rice producers since the first successful rice crop was grown near Lonoke, Arkansas, in 1904.
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Our chairman has wisely asked that we not spend all of our time here telling each other about our bird problems. In the Southeast, our difficulties with blackbirds are based upon the same bird habits that cause trouble elsewhere: they flock, they roost and they eat, generally taking advantage of the readily available handouts that today's agricul¬tural practices provide. Those of us on the receiving end of these de¬predations of course think that damage in our own particular area must be far the worst, anywhere. Because of the location of our meeting place today, perhaps it is worthwhile to point out that a report prepared by our Bureau's Washington office this year outlined the problem of blackbird damage to corn in the Middle Atlantic States, the Great Lakes Region and in Florida, and then followed with this statement--"An equally serious problem occurs in rice and grain sorghum fields of Arkansas, Mississippi, Texas and Louisiana." The report also men¬tions that the largest winter concentrations of blackbirds are found in the lower Mississippi Valley. Our 1963-64 blackbird-starling survey showed 43 principal roosts totaling approximately 100 million of these birds in Virginia, the Carolinas, Georgia, Alabama, Tennessee and Kentucky. We have our own birds during the summer plus the "tourist" birds from up here and elsewhere during the winter, and all of these birds must eat, so suffice it to say that we, too, have some bird problems in the Southeast. I'm sure you're more interested in what we're doing about them. To keep this in perspective also, please bear in mind that against the magnitude of these problems, our blackbird control research staff at Gainesville consists of 3 biologists, 1 biochemist and one technician. And unfortunately, none of us happens to be a miracle worker. I think, though, we have made great progress toward solving the bird problems in the Southeast for the man-hours that have been expended in this re¬search. My only suggestion to those who are impatient about not having more answers is that they examine the budget that has been set up for this work. Only then could we intelligently discuss what might be expected as a reasonable rate of research progress. When I think about what we have accomplished in a short span of time, with very small expenditure, I can assure you that I am very proud of our small research crew at Gainesville--and I say this quite sincerely. At the Gainesville station, we work under two general research approaches to the bird damage problem. These projects have been assigned to us. The first is research on management of birds, particularly blackbirds and starlings destructive to crops or in feedlots, and, secondly, the development and the adaptation of those chemical compounds found to be toxic to birds but relatively safe to mammals. These approaches both require laboratory and field work that is further subdivided into several specific research projects. Without describing the details of these now, I want to mention some of our recent results. From the results, I'm sure you will gather the general objectives and some of the procedures used.
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Almost two-thirds of the Brazilian territory still has prevalence of natural vegetation. Although not all pristine, much of these areas have high conservation value. 170 million hectare (Mha) of the natural vegetation is located within Federal and State protected areas. Most of the remaining 367 Mha is on private agriculture lands, where the Forest Act is the most important legal framework for conservation. In July 2010, the Brazilian parliament began the analysis of a substitutive legislation for the Forest Act. The main motivations for the revision is that, on the one hand, it has been found ineffective in protecting natural vegetation, and on the other hand, it is perceived as a barrier against development in the agriculture sector. The substitutive Forest Act, as it presently stands, does not represent a balance between existing standpoints and objectives; it may drive development towards either more private protection through market-driven compensation actions, or increased deforestation and less nature protection/restoration. This article uses outcomes from modeling analyses to discuss weaknesses of the substitutive Forest Act and to suggest possible improvements. (C) 2011 Elsevier Ltd. All rights reserved.