916 resultados para Direct effects


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While much of the study of molecular biology inevitably focuses on the parts of the genome that contain active genes, there are also non-coding regions that nonetheless play an essential role in maintaining genome integrity. One such region are telomeres, which cap the ends of all eukaryotic chromosomes and play an important role in chromosome protection. Telomere loss occurs at each cell division as a result of the ‘end replication problem’ and a relatively short telomere length is indicative of poor biological state. Thus far, the majority of studies on the dynamics and role of telomeres have been biased towards certain taxa. Research to date has mostly focussed on humans, other mammals and birds. There has been far less research on the telomere dynamics of ectotherms. It is important that we do so, especially since ectothermic vertebrates do not seem to down-regulate telomerase expression in the same way as endotherms, suggesting that their telomere dynamics may be less predictable in the later life stages. The main objective of this thesis was therefore to investigate how life history and environmental effects may influence telomere dynamics in Atlantic salmon Salmo salar. I carried out carefully designed experiments, both in the laboratory and in the wild, using a longitudinal approach where possible, in order to address a number of specific questions that are connected to this central theme. In chapter 2, I demonstrate that there can be significant links between parental life history and offspring telomere dynamics. Maternal life history traits, in particular egg size, were most strongly related to offspring telomere length at the embryonic stages. Paternal life history traits, such as early life growth rate, had a greater association with offspring telomere dynamics in the later stages of development. In chapter 3, using a wild Atlantic salmon population, I found that most individuals experienced a reduction in telomere length during the migratory phase of their life cycle; however the relative rate of telomere loss was dependent on sex, with males experiencing a relatively greater loss. Unexpectedly, I also found that juvenile salmon that had the shortest telomeres at the time of outward migration, had the greatest probability of surviving through to the return migration. In chapter 4, again using a wild system involving experimental manipulations of juvenile Atlantic salmon in Scottish streams, I found that telomere length in juvenile fish was influenced by parental traits and by direct environmental effects. Faster-growing fish had shorter telomeres and there was a greater cost (in terms of reduced telomere length) if the growth occurred in a harsher environment. I also found a positive association between offspring telomere length and the growth history of their fathers (but not mothers), represented by the number of years that fathers had spent at sea. Chapter 5 explored the hypotheses that oxidative DNA damage, catalase (CAT) antioxidant activity and cell proliferation rate are underlying mechanisms linking incubation temperature and telomere dynamics in salmon embryos. No evidence was found for any such effects, but telomere lengths in salmon embryos were found to be significantly affected by the temperature of the water in which they were living. There is also evidence that telomere length significantly increases during embryonic development. In summary, this thesis has shown that a complex mix of environmental and parental effects appear to influence telomere dynamics in Atlantic salmon, with parental effects especially evident during early life stages. It also demonstrated that telomeres lengthen through the embryo stages of development before reducing once the fry begin feeding, indicating that the patterns of telomere loss commonly found in endotherms may differ in ectotherms. Reasons for this variation in telomere dynamics are presented in the final Discussion chapter of the thesis.

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Este proyecto se origina en el interés de analizar las estrategias actuales de promoción de productos farmacéuticos, en el marco del debate sobre el efecto persuasivo o informativo que la publicidad directa tiene sobre los consumidores. El objetivo es determinar el efecto de las estrategias de promoción directa para consumidores (Direct to Consumer Advertising [DTCA]) sobre el comportamiento de compra de pacientes y las prescripciones que formulan los médicos en el mercado de productos bajo receta en Estados Unidos. Para tal fin se propuso realizar una monografía que incluyera una revisión de literatura de carácter argumentativo, consultando información de nivel secundario en bases de datos científicas cuyos contenidos obedecieran a criterios metodológicos determinados por la naturaleza argumentativa del estudio. Adicionalmente, se analizó el debate sobre estos anuncios a la luz de dos estudios realizados a pacientes con cáncer de seno, próstata y colon, liderados por el Pennsylvania Cancer Registry con los productos biofarmacéuticos Avodart® y Flomax®. Finalmente, la investigación se fundamentó en la relación del mercado farmacéutico en Estados Unidos con cada uno de los agentes que interactúan en él; consumidores, médicos prescriptores y empresas farmacéuticas, así como el valor que estos comparten través de dichas interacciones. Se concluye que el comportamiento de compra de los consumidores está determinado por la naturaleza de la patología que padecen y el comportamiento de los profesionales que prescriben a sus pacientes se ve influenciado por los anuncios DTCA.

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BACKGROUND: Drosophila suzukii is a primary insect pest that causes direct damage to fruits with a thin epidermis such as strawberries, cherries and blueberries. In strawberry fields, the co-occurrence of D. suzukii and Zaprionus indianus has increased production losses. This study evaluated the toxicities and effects of insecticidal baits to control adults and larvae of both D. suzukii and Z. indianus . RESULTS: Organophosphate (dimethoate and malathion), spinosyn (spinosad and spinetoram), pyrethroid (lambda-cyhalothrin) and diamide (cyantraniliprole) insecticides exhibited high toxicity to both adults and larvae of D. suzukii and Z. indianus (mortality > 80%) in topical and dip bioassays. However, when the insecticides were mixed with a feeding attractant, a positive effect was observed only for adults of D. suzukii . Insecticides containing neonicotinoids (acetamiprid and thiamethoxam) and pyrolle (chlorfenapyr) caused intermediate mortality to adults of D. suzukii (40?60%) and low mortality for Z. indianus (mortality < 23%); however, these compounds reduced the larval infestation of the two species by 55?86%. Botanical (azadirachtin) and sulphur insecticides exhibited low toxicity (mortality < 40%) on adults and larvae of both species. CONCLUSION: Dimethoate, malathion, spinosad, spinetoram, lambda-cyhalothrin and cyantraniliprole are highly toxic to both larvaeandadultsof D. suzukii and Z.indianus .Theuseoftoxicbaitsforadultsof D. suzukii couldbeanalternativeinmanagement of this species. © 2016 Society of Chemical Industry Keywords: spotted-wing drosophila; fig fly; chemical control; strawberry; toxic bait; pest control.

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The reproductive efficiency is directly related to the nutritional management. The diet lipid inclusion, especially with enhanced sources of omega 6 and omega 3 fatty acids, is positively associated to the ovarian follicular development of ruminants. The objective of this study was to evaluate the effects of toasted soybean grain addition on restricted or ad libitum feeding on ovarian follicular development of Santa Inês ewe lambs In conclusion, the diameter of the largest follicle and the number of >5 mm follicles were not influenced by the restricted intake diet nor the lipid inclusion; however, they increased in a direct relationship with the age of the animals.

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Based upon qualitative parameters experiments, this study aims to investigate how the elements of the environment, where the coffee is produced, contribute to the final quality of the product. For the analyses, it was used approximately one kilogram of coffee cherry samples collected in 14municipalities previously chosen on the East side of the Minas Gerais State, Brazil. The coffee cherry samples were collected and analyzed for each of the two varieties in four levels of altitude for each exposure side of the mountain in relation to the Sun. The quality of the coffee was evaluated through the analysis of its physical characteristics and sensory analysis, popularly known as "Test of drink or Cupping" carried out by three tasters that belonging to the group of Q -Graders, according to the rules of national and international competitions of the Brazilian Association of Special Coffees (BSCA). Were performed analysis by means descriptive statistics, analysis of variance and multivariate analysis, all of them aiming to study the individual sensor y characteristics of quality of the coffee beverage from the ?Matas de Minas? region. Path coefficient analysis also was carried out for the partition of the phenotypic correlation coefficients into measures of direct and indirect effects, in order to determine the individual sensory characteristics that playeda major role in the beverage final score. The results demonstrat e that it is not possible to concl usively establish the differences among coffees evaluated with basis on varieties and environmental factors previously cited. It can be concluded that it is not recommended to associate the quality of coffee only to a specific factor whether from the environment or being it a specific of the culture of coffee. However, the cafes that were evaluated had intrinsic quality, which were derived from the specific characteristics of the ?Matas de Minas? region where they were grown.

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BACKGROUND: Drosophila suzukii is a primary insect pest that causes direct damage to fruits with a thin epidermis such as strawberries, cherries and blueberries. In strawberry fields, the co-occurrence of D. suzukii and Zaprionus indianus has increased production losses. This study evaluated the toxicities and effects of insecticidal baits to control adults and larvae of both D. suzukii and Z. indianus . RESULTS: Organophosphate (dimethoate and malathion), spinosyn (spinosad and spinetoram), pyrethroid (lambda-cyhalothrin) and diamide (cyantraniliprole) insecticides exhibited high toxicity to both adults and larvae of D. suzukii and Z. indianus (mortality > 80%) in topical and dip bioassays. However, when the insecticides were mixed with a feeding attractant, a positive effect was observed only for adults of D. suzukii . Insecticides containing neonicotinoids (acetamiprid and thiamethoxam) and pyrolle (chlorfenapyr) caused intermediate mortality to adults of D. suzukii (40?60%) and low mortality for Z. indianus (mortality < 23%); however, these compounds reduced the larval infestation of the two species by 55?86%. Botanical (azadirachtin) and sulphur insecticides exhibited low toxicity (mortality < 40%) on adults and larvae of both species. CONCLUSION: Dimethoate, malathion, spinosad, spinetoram, lambda-cyhalothrin and cyantraniliprole are highly toxic to both larvaeandadultsof D. suzukii and Z.indianus .Theuseoftoxicbaitsforadultsof D. suzukii couldbeanalternativeinmanagement of this species. © 2016 Society of Chemical Industry Keywords: spotted-wing drosophila; fig fly; chemical control; strawberry; toxic bait; pest control.

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Synthetic lethality represents an anticancer strategy that targets tumor specific gene defects. One of the most studied application is the use of PARP inhibitors (e.g. olaparib) in BRCA1/2-less cancer cells. In BRCA2-defective tumors, olaparib (OLA) inhibits DNA single-strand break repair, while BRCA2 mutations hamper homologous recombination (HR) repair. The simultaneous impairment of those pathways leads BRCA-less cells to death by synthetic lethality. The projects described in this thesis were aimed at extending the use of OLA in cancer cells that do not carry a mutation in BRCA2 by combining this drug with compounds that could mimic a BRCA-less environment via HR inhibition. We demonstrated the effectiveness of our “fully small-molecule induced synthetic lethality” by using two different approaches. In the direct approach (Project A), we identified a series of neo-synthesized compounds (named RAD51-BRCA2 disruptors) that mimic BRCA2 mutations by disrupting the RAD51-BRCA2 interaction and thus the HR pathway. Compound ARN 24089 inhibited HR in human pancreatic adenocarcinoma cell line and triggered synthetic lethality by synergizing with OLA. Interestingly, the observed synthetic lethality was triggered by tackling two biochemically different mechanisms: enzyme inhibition (PARP) and protein-protein disruption (RAD51-BRCA2). In the indirect approach (Project B), we inhibited HR by interfering with the cellular metabolism through inhibition of LDH activity. The obtained data suggest an LDH-mediated control on HR that can be exerted by regulating either the energy supply needed to this repair mechanism or the expression level of genes involved in DNA repair. LDH inhibition also succeeded in increasing the efficiency of OLA in BRCA-proficient cell lines. Although preliminary, these results highlight a complex relationship between metabolic reactions and the control of DNA integrity. Both the described projects proved that our “fully small-molecule-induced synthetic lethality” approach could be an innovative approach to unmet oncological needs.

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T2Well-ECO2M is a coupled wellbore reservoir simulator still under development at Lawrence Berkeley National Laboratory (USA) with the ability to deal with a mixture of H2O-CO2-NaCl and includes the simulation of CO2 phase transition and multiphase flow. The code was originally developed for the simulation of CO2 injection into deep saline aquifers and the modelling of enhanced geothermal systems; however, the focus of this research was to modify and test T2Well-ECO2M to simulate CO2 injection into depleted gas reservoirs. To this end, the original code was properly changed in a few parts and a dedicated injection case was developed to study CO2 phase transition inside of a wellbore and the corresponding thermal effects. In the first scenario, the injection case was run applying the fully numerical approach of wellbore to formation heat exchange calculation. Results were analysed in terms of wellbore pressure and temperature vertical profiles, wellhead and bottomhole conditions, and characteristic reservoir displacement fronts. Special attention was given to the thorough analysis of bottomhole temperature as the critical parameter for hydrate formation. Besides the expected direct effect of wellbore temperature changes on reservoir conditions, the simulation results indicated also the effect of CO2 phase change in the near wellbore zone on BH pressure distribution. To test the implemented software changes, in a second scenario, the same injection case was reproduced using the improved semi-analytical time-convolution approach for wellbore to formation heat exchange calculation. The comparison of the two scenarios showed that the simulation of wellbore and reservoir parameters after one year of continuous CO2 injection are in good agreement with the computation time to solve the time-convolution semi-analytical reduced. The new updated T2Well-ECO2M version has shown to be a robust and performing wellbore-reservoir simulator that can be also used to simulate the CO2 injection into depleted gas reservoirs.

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Tsunamis are rare events. However, their impact can be devastating and it may extend to large geographical areas. For low-probability high-impact events like tsunamis, it is crucial to implement all possible actions to mitigate the risk. The tsunami hazard assessment is the result of a scientific process that integrates traditional geological methods, numerical modelling and the analysis of tsunami sources and historical records. For this reason, analysing past events and understanding how they interacted with the land is the only way to inform tsunami source and propagation models, and quantitatively test forecast models like hazard analyses. The primary objective of this thesis is to establish an explicit relationship between the macroscopic intensity, derived from historical descriptions, and the quantitative physical parameters measuring tsunami waves. This is done first by defining an approximate estimation method based on a simplified 1D physical onshore propagation model to convert the available observations into one reference physical metric. Wave height at the coast was chosen as the reference due to its stability and independence of inland effects. This method was then implemented for a set of well-known past events to build a homogeneous dataset with both macroseismic intensity and wave height. By performing an orthogonal regression, a direct and invertible empirical relationship could be established between the two parameters, accounting for their relevant uncertainties. The target relationship is extensively tested and finally applied to the Italian Tsunami Effect Database (ITED), providing a homogeneous estimation of the wave height for all existing tsunami observations in Italy. This provides the opportunity for meaningful comparison for models and simulations, as well as quantitatively testing tsunami hazard models for the Italian coasts and informing tsunami risk management initiatives.

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Amphibians have been declining worldwide and the comprehension of the threats that they face could be improved by using mark-recapture models to estimate vital rates of natural populations. Recently, the consequences of marking amphibians have been under discussion and the effects of toe clipping on survival are debatable, although it is still the most common technique for individually identifying amphibians. The passive integrated transponder (PIT tag) is an alternative technique, but comparisons among marking techniques in free-ranging populations are still lacking. We compared these two marking techniques using mark-recapture models to estimate apparent survival and recapture probability of a neotropical population of the blacksmith tree frog, Hypsiboas faber. We tested the effects of marking technique and number of toe pads removed while controlling for sex. Survival was similar among groups, although slightly decreased from individuals with one toe pad removed, to individuals with two and three toe pads removed, and finally to PIT-tagged individuals. No sex differences were detected. Recapture probability slightly increased with the number of toe pads removed and was the lowest for PIT-tagged individuals. Sex was an important predictor for recapture probability, with males being nearly five times more likely to be recaptured. Potential negative effects of both techniques may include reduced locomotion and high stress levels. We recommend the use of covariates in models to better understand the effects of marking techniques on frogs. Accounting for the effect of the technique on the results should be considered, because most techniques may reduce survival. Based on our results, but also on logistical and cost issues associated with PIT tagging, we suggest the use of toe clipping with anurans like the blacksmith tree frog.

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Background. Benign prostatic hyperplasia (BPH) pharmacological treatment may promote a decrease in prostate vascularization and bladder neck relaxation with theoretical improvement in prostate biopsy morbidity, though never explored in the literature. Methods. Among 242 consecutive unselected patients who underwent prostate biopsy, after excluding those with history of prostate biopsy/surgery or using medications not for BPH, we studied 190 patients. On the 15th day after procedure patients were questioned about symptoms lasting over a week and classified according to pharmacological BPH treatment. Results. Thirty-three patients (17%) were using alpha-blocker exclusively, five (3%) 5-alpha-reductase inhibitor exclusively, twelve (6%) patients used both medications, and 140 (74%) patients used none. There was no difference in regard to age among groups (P = 0.5). Postbiopsy adverse effects occurred as follows: hematuria 96 (50%), hematospermia 53 (28%), hematochezia 22 (12%), urethrorrhagia 19 (10%), fever 5 (3%), and pain 20 (10%). There was a significant negative correlation between postbiopsy hematuria and BPH pharmacological treatment with stronger correlation for combined use of 5-alpha-reductase inhibitor and alpha-blocker over 6 months (P = 0.0027). Conclusion. BPH pharmacological treatment, mainly combined for at least 6 months seems to protect against prostate biopsy adverse effects. Future studies are necessary to confirm our novel results.

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To evaluate the antimicrobial efficacy of Clearfil SE Protect (CP) and Clearfil SE Bond (CB) after curing and rinsed against five individual oral microorganisms as well as a mixture of bacterial culture prepared from the selected test organisms. Bacterial suspensions were prepared from single species of Streptococcus mutans, Streptococcus sobrinus, Streptococcus gordonii, Actinomyces viscosus and Lactobacillus lactis, as well as mixed bacterial suspensions from these organisms. Dentin bonding system discs (6 mm×2 mm) were prepared, cured, washed and placed on the bacterial suspension of single species or multispecies bacteria for 15, 30 and 60 min. MTT, Live/Dead bacterial viability (antibacterial effect), and XTT (metabolic activity) assays were used to test the two dentin system's antibacterial effect. All assays were done in triplicates and each experiment repeated at least three times. Data were submitted to ANOVA and Scheffe's f-test (5%). Greater than 40% bacteria killing was seen within 15 min, and the killing progressed with increasing time of incubation with CP discs. However, a longer (60 min) period of incubation was required by CP to achieve similar antimicrobial effect against mixed bacterial suspension. CB had no significant effect on the viability or metabolic activity of the test microorganisms when compared to the control bacterial culture. CP was significantly effective in reducing the viability and metabolic activity of the test organisms. The results demonstrated the antimicrobial efficacy of CP both on single and multispecies bacterial culture. CP may be beneficial in reducing bacterial infections in cavity preparations in clinical dentistry.

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The raft hypothesis proposes that microdomains enriched in sphingolipids, cholesterol, and specific proteins are transiently formed to accomplish important cellular tasks. Equivocally, detergent-resistant membranes were initially assumed to be identical to membrane rafts, because of similarities between their compositions. In fact, the impact of detergents in membrane organization is still controversial. Here, we use phase contrast and fluorescence microscopy to observe giant unilamellar vesicles (GUVs) made of erythrocyte membrane lipids (erythro-GUVs) when exposed to the detergent Triton X-100 (TX-100). We clearly show that TX-100 has a restructuring action on biomembranes. Contact with TX-100 readily induces domain formation on the previously homogeneous membrane of erythro-GUVs at physiological and room temperatures. The shape and dynamics of the formed domains point to liquid-ordered/liquid-disordered (Lo/Ld) phase separation, typically found in raft-like ternary lipid mixtures. The Ld domains are then separated from the original vesicle and completely solubilized by TX-100. The insoluble vesicle left, in the Lo phase, represents around 2/3 of the original vesicle surface at room temperature and decreases to almost 1/2 at physiological temperature. This chain of events could be entirely reproduced with biomimetic GUVs of a simple ternary lipid mixture, 2:1:2 POPC/SM/chol (phosphatidylcholine/sphyngomyelin/cholesterol), showing that this behavior will arise because of fundamental physicochemical properties of simple lipid mixtures. This work provides direct visualization of TX-100-induced domain formation followed by selective (Ld phase) solubilization in a model system with a complex biological lipid composition.

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Radiotherapy (RT) is a risk factor for accelerated carotid artery atherosclerotic disease in subjects with head and neck cancer. However, the risk factors of RT-induced carotid artery remodeling are not established. This study aimed to investigate the effects of RT on carotid and popliteal arteries in subjects with head and neck cancer and to evaluate the relationship between baseline clinical and laboratory features and the progression of RT-induced atherosclerosis. Eleven men (age = 57.9 ± 6.2years) with head and neck cancer who underwent cervical bilateral irradiation were prospectively examined by clinical and laboratory analysis and by carotid and popliteal ultrasound before and after treatment (mean interval between the end of RT and the post-RT assessment = 181 ± 47 days). No studied subject used hypocholesterolemic medications. Significant increases in carotid intima-media thickness (IMT) (0.95 ± 0.08 vs. 0.87 ± 0.05 mm; p < 0.0001) and carotid IMT/diameter ratio (0.138 ± 0.013 vs. 0.129 ± 0.014; p = 0.001) were observed after RT, while no changes in popliteal structural features were detected. In addition, baseline low-density lipoprotein cholesterol levels showed a direct correlation with RT-induced carotid IMT change (r = 0.66; p = 0.027), while no other studied variable exhibited a significant relationship with carotid IMT change. These results indicate that RT-induced atherosclerosis is limited to the irradiated area and also suggest that it may be predicted by low-density lipoprotein cholesterol levels in subjects with head and neck cancer.

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The first theoretical results of core-valence correlation effects are presented for the infrared wavenumbers and intensities of the BF3 and BCl3 molecules, using (double- and triple-zeta) Dunning core-valence basis sets at the CCSD(T) level. The results are compared with those calculated in the frozen core approximation with standard Dunning basis sets at the same correlation level and with the experimental values. The general conclusion is that the effect of core-valence correlation is, for infrared wavenumbers and intensities, smaller than the effect of adding augmented diffuse functions to the basis set, e.g., cc-pVTZ to aug-cc-pVTZ. Moreover, the trends observed in the data are mainly related to the augmented functions rather than the core-valence functions added to the basis set. The results obtained here confirm previous studies pointing out the large descrepancy between the theoretical and experimental intensities of the stretching mode for BCl3.