959 resultados para Weed occurrence


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OBJECTIVE The aim of this study was to elucidate the relationship between the echogenicity of carotid artery plaques and the following risk factors: circulating oxLDL, hsCRP, the metabolic syndrome (MetS), and several of the traditional cardiovascular (CV) risk factors. MATERIAL AND METHODS A cross-sectional population-based study of 513 sixty-one-year-old men. The levels of circulating oxLDL were determined in plasma samples by sandwich ELISA utilizing a specific murine monoclonal antibody (mAb-4E6). High-sensitivity CRP was measured in plasma by ELISA. Plaque occurrence, size and echogenicity were evaluated from B-mode ultrasound registrations in the carotid arteries. Plaque echogenicity was assessed based on a four-graded classification scale. RESULTS A higher frequency of echolucent carotid plaques was observed with increasing levels of oxLDL and systolic blood pressure (p = 0.008 and p = 0.041, respectively). Subjects with the MetS had a significantly higher frequency of echogenic plaques than subjects without the MetS (p = 0.009). In a multiple logistic regression analysis, oxLDL turned out to be independently associated with echolucent carotid plaques. CONCLUSIONS The occurrence of echolucent carotid plaques was associated with oxLDL and systolic blood pressure, and oxLDL was associated with echolucent carotid plaques independently of systolic blood pressure.

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OBJECTIVE: This research was aimed to determine the occurrence of Brachyspira (B.) hyodysenteriae in Swiss multiplier pig herds. MATERIALS AND METHODS: In a pilot study a direct real-time polymerase chain reaction (PCR) method for B. hyodysenteriae was compared to culture followed by PCR on 106 samples from three herds. Subsequently 40 multiplier herds were epidemiologically characterized and analysed for the presence of B. hyodysenteriae using direct PCR on 1412 rectal swabs. For external validation 20 swabs obtained from two positive conventional herds were analysed. RESULTS: The comparison of direct PCR with culture followed by PCR resulted in a moderate agreement (kappa index: 0.58). In the two conventional herds, 35% of the samples (7/20) tested positive. Samples from 39 multipliers tested negative. In one multiplier herd, 25% (9/36) of the samples tested PCR positive. Risk factors in the multiplier herd may have been rodents or birds, but not pig purchase. CONCLUSION AND CLINICAL RELEVANCE: B. hyodysenteriae have been detected in a Swiss multiplier herd, which underlines the threat of potential spread by replacement pigs. Consequently, a Brachyspira monitoring programme was established for Swiss multiplier herds.

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The bulk magnetic mineral record from Lake Ohrid, spanning the past 637 kyr, reflects large-scale shifts in hydrological conditions, and, superimposed, a strong signal of environmental conditions on glacial–interglacial and millennial timescales. A shift in the formation of early diagenetic ferrimagnetic iron sulfides to siderites is observed around 320 ka. This change is probably associated with variable availability of sulfide in the pore water. We propose that sulfate concentrations were significantly higher before  ∼  320 ka, due to either a higher sulfate flux or lower dilution of lake sulfate due to a smaller water volume. Diagenetic iron minerals appear more abundant during glacials, which are generally characterized by higher Fe / Ca ratios in the sediments. While in the lower part of the core the ferrimagnetic sulfide signal overprints the primary detrital magnetic signal, the upper part of the core is dominated by variable proportions of high- to low-coercivity iron oxides. Glacial sediments are characterized by high concentration of high-coercivity magnetic minerals (hematite, goethite), which relate to enhanced erosion of soils that had formed during preceding interglacials. Superimposed on the glacial–interglacial behavior are millennial-scale oscillations in the magnetic mineral composition that parallel variations in summer insolation. Like the processes on glacial–interglacial timescales, low summer insolation and a retreat in vegetation resulted in enhanced erosion of soil material. Our study highlights that rock-magnetic studies, in concert with geochemical and sedimentological investigations, provide a multi-level contribution to environmental reconstructions, since the magnetic properties can mirror both environmental conditions on land and intra-lake processes.

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Signatur des Originals: S 36/F10234

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Signatur des Originals: S 36/F10412

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In the United States, approximately 4,000 pregnancies each year are affected by the two most common birth defects, spina bifida and anencephaly. Studies have shown that exposure to environmental chemicals before and after conception may adversely affect reproduction by inducing cell death or dysfunction, which leads to infertility, fetal loss, lowered weight at birth, or birth anomalies in the offspring. The objective of the study was to evaluate the relationship between Neural Tube Defect births and residence at conception in proximity to hazardous waste sites in the Texas-Mexico border region between 1993 and 2000. ^ The study design was a nested matched case-control and utilized secondary data from a project, “The role of chemical and biological factors in the etiology of neural tube birth defects births along the Texas-Mexico Border” (Irina Cech, Principal Investigator). Geographic Information Systems (GIS) database methods were used to compare Neural Tube Defects cases to controls on status of conception residence occurring within a one-mile radius from hazardous waste sites, as compared to conception residence further away. Information on the exposures was obtained from the OnTarget Database and Environment Protection Agency website. Conditional logistic regression was used for the matched case-control study to investigate the relationship between an outcome of being a case or a control and proximity to hazardous waste sites. ^ The result of the study showed a 36 percent non-significant increased risk of having an NTD birth associated with maternal proximity to abandoned hazardous waste sites (95% CI = 0.62–3.02). In addition, there was a 24% non-significant elevated risk of having an NTD birth when living in proximity to air pollutant sites than when living further away (95% CI = 0.67–2.32). Although this study did not find statistically significant associations, it will expand on the existing knowledge of the relationship between NTD and proximity to hazardous waste sites. ^

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It is still unclear if an association exists between the smoking of marijuana and the occurrence of lung cancer although one clearly exists between cigarette smoking and lung cancer. The objective of this study was to systematically review the literature in order to assess the impact of marijuana smoking, which is increasingly becoming a significant public health issue, on the occurrence of the number one killing cancer, lung cancer. ^ Method. Selected studies in the English language conducted on humans that assess the impact of marijuana smoking on lung cancer were identified from EBSCO MEDLINE, PUBMED, and GOOGLE databases. The search keywords were marijuana, cannabis, hashish, kif, and lung cancer with selection criteria including studies in the English language identified from 1950 to April 2008. Excluded were non-research studies such as editorials, letters, and reviews. Also excluded were studies that did not involve humans with direct intentional marijuana smoking or in vivo studies with mice. Case report studies or case series studies involving less than 10 patients were also excluded as well as studies that did not examine lung conditions related to premalignant or cancerous changes. ^ Results. Ten studies met the selection criteria and were analyzed. The ten studies in this review overall offer biological evidence of the potential association between marijuana smoking and premalignant lung findings but no overwhelming conclusive evidence for the association between marijuana smoking and the occurrence of lung cancer. Two of the observational studies [1, 2] failed to demonstrate an association between marijuana and lung cancer, but the remaining studies supported an association between marijuana smoking and premalignant or malignant lung findings. ^ Conclusion. It must, therefore, be concluded that no convincing evidence exists, based on the existing data, for an association between marijuana smoking and the occurrence of lung cancer even though the few observational studies failing to report such an association may be due to certain limitations particularly the relative young age of the participants precluding sufficient lag time for the identification of lung cancer outcome as explained in other sections of this paper. ^ Further research is, therefore, necessary to better evaluate this critical issue, while recommendations against smoking marijuana because of its potential harmful effects, including the potential for premalignant lung changes as noted in this review, should continue to be made. ^ In the future, large prospective studies with study participants representing a much wider spectrum of ages, and longer follow-up periods, with detailed assessment of marijuana exposure and definitive pathologic diagnosis of lung cancer are necessary^

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The occurrence of waste pharmaceuticals has been identified and well documented in water sources throughout North America and Europe. Many studies have been conducted which identify the occurrence of various pharmaceutical compounds in these waters. This project is an extensive review of the documented evidence of this occurrence published in the scientific literature. This review was performed to determine if this occurrence has a significant impact on the environment and public health. This project and review found that pharmaceuticals such as sex hormone drugs, antibiotic drugs and antineoplastic/cytostatic agents as well as their metabolites have been found to occur in water sources throughout the United States at levels high enough to have noticeable impacts on human health and the environment. It was determined that the primary sources of this occurrence of pharmaceuticals were waste water effluent and solid wastes from sewage treatment plants, pharmaceutical manufacturing plants, healthcare and biomedical research facilities, as well as runoff from veterinary medicine applications (including aquaculture). ^ In addition, current public policies of US governmental agencies such as the Environmental Protection Agency (EPA), Food and Drug Administration (FDA), and Drug Enforcement Agency (DEA) have been evaluated to see if they are doing a sufficient job at controlling this issue. Specific recommendations for developing these EPA, FDA, and DEA policies have been made to mitigate, prevent, or eliminate this issue.^ Other possible interventions such as implementing engineering controls were also evaluated in order to mitigate, prevent and eliminate this issue. These engineering controls include implementing improved current treatment technologies such as the advancement and improvement of waste water treatment processes utilized by conventional sewage treatment and pharmaceutical manufacturing plants. In addition, administrative controls such as the use of “green chemistry” in drug synthesis and design were also explored and evaluated as possible alternatives to mitigate, prevent, or eliminate this issue. Specific recommendations for incorporating these engineering and administrative controls into the applicable EPA, FDA, and DEA policies have also been made.^

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This study was conducted by either literature review or actual field survey. Results are summarized as follows: (1) Long-term occupational exposure of workers to benzene vapor at levels of 3-7 ppm, 2-3 ppm and 1.6 ppm may result in a decreased level of leucocyte alkaline phosphates, an increased incidence of chromosome aberrations and an increased level of ALA in erythrocytes, respectively; (2) Benzene is capable of causing fetotoxic effects in animals at levels as low as 10 ppm by volume; (3) Exposure of animals to or less than 1 ppm benzene vapor may result in leucopenia, an inverse ratio of muscle antagonist chronaxy and a decreased level of ascorbic acid in fetus's and mother's liver as well as whole embryo; (4) Benzene is causally associated with the increased incidence of pancytopenia, including unicytopenia, bicytopenia and aplastic anemia, and chromosome aberrations in occupational exposure population, and at best benzene must also be considered as a leukemogen; (5) Since it can be emitted into the atmosphere from both man-made and natural sources, benzene in some concentrations is present everywhere in the various compartments of the environment; (6) The findings of the emission of benzene from certain natural sources indicate that reducing benzene to a zero-level of exposure is theoretically impossible; (7) The annual average of benzene concentration detected in the Houston ambient air is 2.50 ppb, which is about 2.4 times higher than the nation-wide annual average exposure level and may have been some health implications to the general public; (8) In the Houston area, stationary sources are more important than mobile sources in contributing to benzene in the ambient air. ^

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The occurrence of group G streptococci in cats and evaluation of the recovered organisms as potential human pathogens was investigated. Throat swabs were obtained from 89 cats (47 males and 42 females) and vaginal swabs from 39 female cats. Eighty-three of the examined cats were housed in individual cages at a University Animal Care Facility. Six cats, 2 mature males, 2 mature females and 2 young females were family pets in a rural area. Beta-hemolytic streptococci were recovered from 33 (37%) of the 89 cat throats cultured, and 27 (30.3%) were identified as group G. More males (34%) than females (24%) had throat cultures positive for group G. From the 39 vaginal cultures examined, 24 (61.5%) contained beta-hemolytic streptococci and 23 (58.9%) were identified as group G streptococci. Streptococci were not recovered from the vaginal cultures of the 5 females under 6 months of age.^ Thirty one group G streptococci isolated from cats were compared with 37 isolates of group G obtained from humans (health status or site of origin unknown). More group G cat isolates (81%) produced deoxyribonuclease (DNase) than did the human isolates (36%). The proportion of cat throat and vaginal isolates producing DNase was the same. Production of nicotinamide adenine dinucleotide glycohydrolase (NADase) by group G isolates of human origin was 70%, cat throat isolates 53% and cat vaginal isolates 37%. The Serum Opacity Factor was present in 73% of the cat throat isolates of group G, 43.7% of the cat vaginal isolates and 58.6% of the human isolates. Possession of an anti-phagocytic factor (M protein like substance) demonstrated by the ability to multiply in fresh human blood was greater in the group G from cat throats (46.7%) than from cat vagina (37.5%) or from the human isolates (13.5%). Many of the biochemical characteristics of the group G streptococci of cat origin were more similar to the biochemical characteristics of group A streptococci, than to the characteristics of group G of human origin. The group G streptococci, found in a large number of cats, could be potential human pathogens, as their physiological and biological characteristics are very similar to those of group A, a known human pathogen. ^

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The purpose of this study was to evaluate various herbicides for corn injury and weed control when applied preemergence and postemergence.

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The purpose of this study was to evaluate various herbicides for corn injury and weed control when applied preemergence and postemergence.