847 resultados para Grain -- Disease and pest resistance


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Background: This pilot study aimed to investigate systemic and retinal vascular function and their relationship to circulatory markers of cardiovascular risk in early age-related macular degeneration (AMD) patients without any already diagnosed systemic vascular pathologies. Methods: Fourteen patients diagnosed with early AMD and 14 age- and gender-matched healthy controls underwent blood pressure, carotid intima-media thickness (C-IMT) and peripheral arterial stiffness measurements. Retinal vascular reactivity was assessed by means of dynamic retinal vessel analysis (DVA) using a modified protocol. Blood analyses were conducted for glutathione levels and plasma levels of total cholesterol (CHOL), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG). Results: The AMD patients showed significantly greater C-IMT (p = 0.029) and augmentation index (AIx) (p = 0.042) than the age-matched controls. In addition, they demonstrated a shallower retinal arterial dilation slope (Slope AD) (p = 0.005) and a longer retinal venous reaction time (RT) to flickering light (p = 0.026). Blood analyses also revealed that AMD patients exhibited higher oxidized glutathione (GSSG) (p = 0.024), lower redox index (p = 0.043) and higher LDL-C (p = 0.033) levels than the controls. Venous RT parameter correlated positively with blood GSSG levels (r = 0.58, p = 0.038) in AMD subjects, but not in the controls (p > 0.05). Conclusions: Patients diagnosed with early AMD exhibit signs of systemic and retinal vascular alterations that correlated with known risk markers for future cardiovascular morbidity. © 2013 Springer-Verlag Berlin Heidelberg.

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Despite improvements in interventional and pharmacological therapy of atherosclerotic disease, it is still the leading cause of death in the developed world. Hence, there is a need for further development of effective therapeutic approaches. This requires better understanding of the molecular mechanisms and pathophysiology of the disease. Atherosclerosis has long been identified as having an inflammatory component contributing to its pathogenesis, whereas the available therapy primarily targets hyperlipidemia and prevention of thrombosis. Notwithstanding a pleotropic anti-inflammatory effect to some therapies, such as acetyl salicylic acid and the statins, none of the currently approved medicines for management of either stable or complicated atherosclerosis has inflammation as a primary target. Monocytes, as representatives of the innate immune system, play a major role in the initiation, propagation, and progression of atherosclerosis from a stable to an unstable state. Experimental data support a role of monocytes in acute coronary syndromes and in outcome post-infarction; however, limited research has been done in humans. Analysis of expression of various cell surface receptors allows characterization of the different monocyte subsets phenotypically, whereas downstream assessment of inflammatory pathways provides an insight into their activity. In this review we discuss the functional role of monocytes and their different subpopulations in atherosclerosis, acute coronary syndromes, cardiac healing, and recovery with an aim of critical evaluation of potential future therapeutic targets in atherosclerosis and its complications. We will also discuss technical difficulties of delineating different monocyte subpopulations, understanding their differentiation potential and function.

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Objective - To evaluate behavioural components and strategies associated with increased uptake and effectiveness of screening for coronary heart disease and diabetes with an implementation science focus. Design - Realist review. Data sources - PubMed, Web of Knowledge, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register and reference chaining. Searches limited to English language studies published since 1990. Eligibility criteria - Eligible studies evaluated interventions designed to increase the uptake of cardiovascular disease (CVD) and diabetes screening and examined behavioural and/or strategic designs. Studies were excluded if they evaluated changes in risk factors or cost-effectiveness only. Results - In 12 eligible studies, several different intervention designs and evidence-based strategies were evaluated. Salient themes were effects of feedback on behaviour change or benefits of health dialogues over simple feedback. Studies provide mixed evidence about the benefits of these intervention constituents, which are suggested to be situation and design specific, broadly supporting their use, but highlighting concerns about the fidelity of intervention delivery, raising implementation science issues. Three studies examined the effects of informed choice or loss versus gain frame invitations, finding no effect on screening uptake but highlighting opportunistic screening as being more successful for recruiting higher CVD and diabetes risk patients than an invitation letter, with no differences in outcomes once recruited. Two studies examined differences between attenders and non-attenders, finding higher risk factors among non-attenders and higher diagnosed CVD and diabetes among those who later dropped out of longitudinal studies. Conclusions - If the risk and prevalence of these diseases are to be reduced, interventions must take into account what we know about effective health behaviour change mechanisms, monitor delivery by trained professionals and examine the possibility of tailoring programmes according to contexts such as risk level to reach those most in need. Further research is needed to determine the best strategies for lifelong approaches to screening.

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DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY AND INFORMATION SERVICES WITH PRIOR ARRANGEMENT

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Threshold stress intensity values, ranging from ∼6 to 16 MN m −3/2 can be obtained in powder-formed Nimonic AP1 by changing the microstructure. The threshold and low crack growth rate behaviour at room temperature of a number of widely differing API microstructures, with both ‘necklace’ and fully recrystallized grain structures of various sizes and uniform and bimodal γ′-distributions, have been investigated. The results indicate that grain size is an important microstructural parameter which can control threshold behaviour, with the value of threshold stress intensity increasing with increasing grain size, but that the γ′-distribution is also important. In this Ni-base alloy, as in many others, near threshold fatigue crack growth occurs in a crystallographic manner along {111} planes. This is due to the development of a dislocation structure involving persistent slip bands on {111} planes in the plastic zone, caused by the presence of ordered shearable precipitates in the microstructure. However, as the stress intensity range is increased, a striated growth mode takes over. The results presented show that this transition from faceted to striated growth is associated with a sudden increase in crack propagation rate and occurs when the size of the reverse plastic zone at the crack tip becomes equal to the grain size, independent of any other microstructural variables.

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Epidemiological studies have suggested that hormone replacement therapy (HRT) offers protection from atherosclerosis, a precursor of cardiovascular disease (CVD), in postmenopausal women. There is good evidence that oxidation of low-density lipoprotein (LDL) by leucocyte-derived reactive oxygen species plays a key role in development of an atherosclerotic plaque. Therefore we have investigated whether the possible protection against CVD by HRT could be due to immunomodulation, specifically of free radical production. The study involves 2 approaches: I) analysing the production of free radicals by leucocytes from women on HRT, 2) investigating the effect of I7p-oestradiol and progesterone on cultured myeloid cells (HL60 and U937). Free radical production by leucocytes was determined using a recently developed bioluminescent assay. In the assay, Pholasin® emits light in the presence of free radicals produced by the NADPH oxidase system of leucocytes stimulated with PMA or fMLP. Cell viability was also investigated using a bioluminescent assay (Cell Titer-Glo®) in which cytosolic ATP levels were measured by the production of luminescence in the presence of Luciferin/Luciferase reagent. Studies of leucocytes from HRT patients showed considerable variation in free radical production, which appeared to be dependent on HRT regime. Studies on the cultured cells showed that there was no cell proliferation at low hormone concentrations, while high concentrations caused cytotoxicity. The effect of hormones on free radical production in this in vitro model system is currently being investigated. The results show that the effects of the hormones on cells of the immune system are very dose dependent, and that both beneficial and adverse effects may occur. In conclusion, luminescent techniques offer a valuable and sensitive approach to studying inflammatory and oxidative processes both in vivo and in vitro.

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The mechanisms by which bacteria resist killing by antibiotics and biocides are still poorly defined, although repeated exposure to sublethal concentrations of antibacterial agents undoubtedly contributes to their development. This study aimed both to investigate the potential of Salmonella enterica and Escherichia coli O157 for adaptive resistance to commonly used biocides and to determine any cross-resistance to antibiotics. Strains were repeatedly passaged in media containing increasing concentrations of a biocide or antibiotic until adaptive resistance was obtained. A wide panel of antimicrobial agents was then screened by using the adapted strain to determine cross-resistance, if any. Adaptive resistance was readily achieved for both S. enterica and E. coli O157. Cross-resistance in adaptively resistant S. enterica varied with the serotype; Salmonella enterica serovar Enteritidis expressed cross-resistance to chloramphenicol, whereas Salmonella enterica serovar Typhimurium expressed cross-resistance to chlorhexidine. Benzalkonium chloride-resistant Salmonella enterica serovar Virchow showed elevated resistance to chlorhexidine; however, chlorhexidine-resistant Salmonella serovar Virchow did not demonstrate reciprocal cross-resistance to benzalkonium chloride, suggesting specific rather than generic resistance mechanisms. E. coli O157 strains acquired high levels of resistance to triclosan after only two sublethal exposures and, when adapted, repeatedly demonstrated decreased susceptibilities to various antimicrobial agents, including chloramphenicol, erythromycin, imipenem, tetracycline, and trimethoprim, as well as to a number of biocides. These observations raise concern over the indiscriminate and often inappropriate use of biocides, especially triclosan, in situations where they are unnecessary, whereby they may contribute to the development of microbial resistance mechanisms.

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Background - This review provides a worked example of ‘best fit’ framework synthesis using the Theoretical Domains Framework (TDF) of health psychology theories as an a priori framework in the synthesis of qualitative evidence. Framework synthesis works best with ‘policy urgent’ questions. Objective - The review question selected was: what are patients’ experiences of prevention programmes for cardiovascular disease (CVD) and diabetes? The significance of these conditions is clear: CVD claims more deaths worldwide than any other; diabetes is a risk factor for CVD and leading cause of death. Method - A systematic review and framework synthesis were conducted. This novel method for synthesizing qualitative evidence aims to make health psychology theory accessible to implementation science and advance the application of qualitative research findings in evidence-based healthcare. Results - Findings from 14 original studies were coded deductively into the TDF and subsequently an inductive thematic analysis was conducted. Synthesized findings produced six themes relating to: knowledge, beliefs, cues to (in)action, social influences, role and identity, and context. A conceptual model was generated illustrating combinations of factors that produce cues to (in)action. This model demonstrated interrelationships between individual (beliefs and knowledge) and societal (social influences, role and identity, context) factors. Conclusion - Several intervention points were highlighted where factors could be manipulated to produce favourable cues to action. However, a lack of transparency of behavioural components of published interventions needs to be corrected and further evaluations of acceptability in relation to patient experience are required. Further work is needed to test the comprehensiveness of the TDF as an a priori framework for ‘policy urgent’ questions using ‘best fit’ framework synthesis.

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Cuban Americans, a minority Hispanic subgroup, have a high prevalence of type 2 diabetes. Persons with diabetes experience a higher rate of coronary heart disease (CHD) compared to those without diabetes. The objectives of the National Institute of Diabetes and Digestive and Kidney Disease (NIDDK) are to investigate the risk factors of CHD and the etiology of diabetes among diabetics of minority ethnic populations. No information is available on the etiology of CHD risks for Cuban Americans. ^ This cross-sectional study compared Cuban Americans with (N = 79) and without (N = 80) type 2 diabetes residing in South Florida. Data on risk factors of CHD and type 2 diabetes were collected using sociodemographics, smoking habit, Rose Angina, Modifiable Activity, and Willet's food frequency questionnaires. Anthropometrics and blood pressure (BP) were recorded. Glucose, glycated hemoglobin, lipid profile, homocysteine, and C-reactive protein were assessed in fasting blood. ^ Diabetics reported a significantly higher rate of angina symptoms than non-diabetics (P = 0.008). After adjusting for age and gender, diabetics had significantly (P < 0.001) larger waist circumference and higher systolic BP than non-diabetics. There was no significant difference in major nutrient intakes between the groups. One quarter of subjects, both diabetics and non-diabetics, exceeded the intake of percent calories from total fat and almost 60% had cholesterol intake >200 mg/d and more than 60% had fiber intake <20 gm/d. The pattern of physical activity did not differ between groups though, it was much below the recommended level. After adjusting for age and gender, diabetics had significantly (P < 0.001) higher levels of blood glucose, glycated hemoglobin, triglycerides, and homocysteine than non-diabetics. In contrast, diabetics had significantly (P < 0.01) lower levels of high-density lipoprotein cholesterol (HDL-C). ^ Multivariate logistic regression analyses showed that increasing age, male gender, large waist circumference, lack of acculturation, and high levels of triglycerides were independent risk factors of type 2 diabetes. In contrast, moderate alcohol consumption conferred protection against diabetes. ^ The study identified several risk factors of CHD and diabetes among Cuban Americans. Health care providers are encouraged to practice ethno-specific preventive measures to lower the burden of CHD and diabetes in Cuban Americans. ^

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Coral reefs are in decline worldwide and coral disease is a significant contributing factor. However, etiologies of coral diseases are still not well understood. In contrast with the Caribbean, extremely little is known about coral diseases in the Philippines. In 2005, off Southeast Negros Island, Philippines, I investigated relationships between environmental parameters and prevalence of the two most common coral diseases, ulcerative white spot (UWS) and massive Porites growth anomalies (MPGAs). Samples were collected along a disease prevalence gradient 40.5 km long. Principal component analyses showed prevalence of MPGAs was positively correlated with water column nitrogen, organic carbon of surface sediments, and colony density. UWS was positively correlated with water column phosphorus. This is the first quantitative evidence linking anthropogenically-impacted water and sediment to a higher prevalence of these diseases. Histological and cytological alterations were investigated by comparing tissues from two distinct types of MPGA lesions (types 1 and 2) and healthy coral using light and electron microscopy. Skeletal abnormalities and sloughing, swelling, thinning, and loss of tissues in MPGAs resembled tissues exposed to bacterial or fungal toxins. Both lesion types had decreases in symbiotic zooxanthellae, which supply nutrients to corals. Notable alterations included migrations of chromophore cells (amoebocytes) (1) nocturnally to outer epithelia to perform wound-healing, including plugging gaps and secreting melanin in degraded tissues, and (2) diurnally to the interior of the tissue possibly to prevent shading zooxanthellae in order to maximize photosynthate production. Depletion of melanin (active in wound healing) in type 2 lesions suggested type 2 tissues were overtaxed and less stable. MPGAs contained an abundance of endolithic fungi and virus-like particles, which may result from higher nutrient levels and play roles in disease development. Swollen cells and mucus frequently blocked gastrovascular canals (GVCs) in MPGAs. Type 1 lesions appeared to compensate for impeded flow of wastes and nutrients through these canals with proliferation of new GVCs, which were responsible for the observed thickened tissues. In contrast, type 2 tissues were thin and more degraded. Dysplasia and putative neoplasia were also observed in MPGAs which may result from the tissue regeneration capacity being overwhelmed.

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The maturation of the public sphere in Argentina during the late nineteenth and early twentieth centuries was a critical element in the nation-building process and the overall development of the modern state. Within the context of this evolution, the discourse of disease generated intense debates that subsequently influenced policies that transformed the public spaces of Buenos Aires and facilitated state intervention within the private domains of the city’s inhabitants. Under the banner of hygiene and public health, municipal officials thus Europeanized the nation’s capital through the construction of parks and plazas and likewise utilized the press to garner support for the initiatives that would remedy the unsanitary conditions and practices of the city. Despite promises to the contrary, the improvements to the public spaces of Buenos Aires primarily benefited the porteño elite while the efforts to root out disease often targeted working-class neighborhoods. The model that reformed the public space of Buenos Aires, including its socially differentiated application of aesthetic order and public health policies, was ultimately employed throughout the Argentine Republic as the consolidated political elite rolled out its national program of material and social development.

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This flyer promotes the event "Human Rights and Civil Resistance in Cuba".

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Aim: to determine cut off points for The Homeostatic Model Assessment Index 1 and 2 (HOMA-1 and HOMA-2) for identifying insulin resistance and metabolic syndrome among a Cuban-American population. Study Design: Cross sectional. Place and Duration of Study: Florida International University, Robert Stempel School of Public Health and Social Work, Department of Dietetics and Nutrition, Miami, FL from July 2010 to December 2011. Methodology: Subjects without diabetes residing in South Florida were enrolled (N=146, aged 37 to 83 years). The HOMA1-IR and HOMA2-IR 90th percentile in the healthy group (n=75) was used as the cut-off point for insulin resistance. A ROC curve was constructed to determine the cut-off point for metabolic syndrome. Results: HOMA1-IR was associated with BMI, central obesity, and triglycerides (P3.95 and >2.20 and for metabolic syndrome were >2.98 (63.4% sensitivity and 73.3% specificity) and >1.55 (60.6% sensitivity and 66.7% specificity), respectively. Conclusion: HOMA cut-off points may be used as a screening tool to identify insulin resistance and metabolic syndrome among Cuban-Americans living in South Florida.