934 resultados para Emergence percentage
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This study aimed to verify the effect of vibration of plants in the production of fruits and seeds and in the physiological quality of the seeds of the “Malagueta” pepper in a protected cultivated area with open and closed sides. The experiment was conducted at the Experimental Farm of the School of Agronomic Sciences of Universidade Estadual Paulista (FCA/UNESP), located in the city of São Manuel (SP). Two treatments were carried out, which consisted of plants that did and did not undergo vibration. Plants were vibrated manually by swinging the wire attached to the supporting bamboo for about 5 seconds, twice a day for 11 weeks. The design was a randomized block with six repetitions. The same experiment was conducted in two protected environments, with and without anti-aphids screens on the sides, cultivated in the same season. For the comparison of environments, a combined analysis was performed considering each environment as a separate experiment. The characteristics evaluated were: weight and number of fruits per plant; weight, diameter and length of fruit; weight and amount of seeds per fruit; and plant height. For the analysis of seed quality, the characteristics evaluated were: germination percentage; first count of germination; dry matter of seedlings; seedling emergence in substrate; and seedling emergence speed index. Regardless of the environment, vibration affects the physiological quality of seeds. The presence of pollinator insects benefited the production and quality of “Malagueta” pepper seeds and increases the fruit weight.
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Interest in the epidemiology of emerging diseases of humans and livestock as they relate to wildlife has increased greatly over the past several decades. Many factors, most anthropogenic, have facilitated the emergence of diseases from wildlife. Some livestock diseases have ‘‘spilled over’’ to wildlife and then ‘‘spilled back’’ to livestock. When a population is exposed to an infectious agent, depending on an interaction of factors involving the host, agent, and environment, the population may be resistant to infection or may become a dead-end host, a spillover host, or a maintenance host. Each exposure is unique; the same species of host and agent may respond differently in different situations. Management actions that affect the environment and behavior of a potential host animal may allow the emergence of a new or as yet undetected disease. There are many barriers in preventing, detecting, monitoring and managing wildlife diseases. These may include political and legal hurdles, lack of knowledge about many diseases of wildlife, the absence of basic data on wildlife populations, difficulties with surveillance, and logistical constraints. Increasing interaction between wildlife and humans or domestic animals may lead to disease emergence and require innovative methods and strategies for disease surveillance and management in wildlife.
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This extension circular is a slide rule used to help a producer calculate the row spacing, seed population, and estimated percentage of emergence of sugarbeet. A producer can also use this slide rule to find the plant population from plants/100 feet of row at 22" and 30" row spacings.
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Background and objectives: Extracorporeal circulation (ECC) may change drug pharmacokinetics as well as brain function. The objectives of this study are to compare emergence time and postoperative sedation intensity assessed by the bispectral index (BIS) and the Ramsay sedation scale in patients undergoing myocardial revascularization (MR) with or without ECC. Method: Ten patients undergoing MR with ECC (ECC group) and 10 with no ECC (no-ECC group) were administered with sufentanyl, propofol 2.0 mu g.mL(-1) and pancuronium target controlled infusion. After surgery, propofol infusion was reduced to 1 mu g.mL(-1) and suspended when extubation was indicated. Patients BIS, Ramsay scale and time to wake up were assessed. Results: The ECC group showed lower BIS values beginning at 60 minutes after surgery (no-ECC = 66 +/- 13 and ECC = 53 +/- 14, p = 0.01) until 120 minutes after infusion (no-ECC = 85 +/- 8 and ECC = 73 +/- 12, p = 0.02). Sedation level measured by the Ramsay scale was higher in the ECC group at 30 minutes after the end of the surgery (no-ECC = 5 +/- 1 and ECC = 6 +/- 0, p = 0.021), at the end of infusion (no-ECC = 5 +/- 1 and ECC = 6 +/- 1, p = 0.012) and 5 minutes after the end of infusion (no-ECC = 4 +/- 1 and ECC = 5 +/- 0.42, p = 0.039). Emergence from anesthesia time was higher in the ECC group (no-ECC = 217 +/- 81 and ECC = 319 +/- 118, p = 0.038). Conclusions: There was a higher intensity of sedation after the end of surgery and a longer wake up time in ECC group, suggesting changes in the pharmacokinetics of propofol or effects of ECC on central nervous system.
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This work aimed to evaluate the influence of different concentrations of Zantedeschia aethiopica Spreng. extract on the physiological performance of the seed and on the response of the antioxidant metabolism of lettuce seedlings. The treatments consisted of leaves extracts from Z. aethiopica at concentrations of 0, 6, 12, 25 and 50%. Germination, first germination count, germination speed and index, length of shoot and radicle, seedling total dry mass, chlorophyll content, activity of superoxide dismutase, catalase and ascorbarte peroxidase enzymes, lipid peroxidation, hydrogen peroxide quantification and seedling emergence, length of organs, and total dry mass of seedlings were evaluated. The percentage of germination, the length of the shoot and radicle of seedlings and the total dry mass of seedlings grown in the greenhouse were reduced as the concentration of the extract increased. There were increases of electrical conductivity, of superoxide dismutase, catalase and ascorbate peroxidadase enzymes and the amount of hydrogen peroxide and lipid peroxidation in seedlings with increasing extract concentration. The extract reduced the physiological quality of lettuce seeds and induced an increased production of hydrogen peroxide in seedlings, which increased the activity of antioxidant enzymes that were not effective in tissue detoxification, resulting in cellular damage and increased numbers of abnormal seedlings.
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Eggplant seeds germination can be slow and uneven, justifying the use of pre-germinative treatments to improve the performance of seed lots. One option of treatment is the controlled hydration of seeds by priming. In this way, this study aimed to evaluate the performance of eggplant seeds cv. Embu submitted to different methodologies of priming. The seeds used in the experiment were stored in cold chamber (15 degrees C and 55% RH) in paper bags. The research was carried out at Central Laboratory of Seeds/UFLA. The seeds were submitted to the priming in aerated solutions varying the following factors: temperature (15 degrees C and 25 degrees C), time (24, 48 and 72 hours) and solution (water, PEG, KNO3 and PEG+KNO3). Seeds were washed in running water and dried at 30 degrees C, until the return to the initial moisture content, around 10%. The variables analyzed were percentage of germination, percentage of emergence, speed index of emergence and electrical conductivity. The treatments were arranged in a completely randomized design, according to a factorial arrangement 2x3x4+1 (control - seeds without priming). The results showed that priming improves the vigour of eggplant seeds with no effect on viability; the priming in water or KNO3 is efficient to improve the seed vigour and priming in water or KNO3 may use temperature of 15 degrees C or 25 degrees C for 24, 48 or 72 hours.
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Study Objective: To estimate the concentration of natural killer (NK) cells in the peripheral blood in patients with and without endometriosis. Design: Case-control study (Canadian Task Force classification II-2). Setting: Tertiary referral hospital. Patients: One hundred fifty-five patients who had undergone videolaparoscopy were divided into 2 groups: those with endometriosis (n = 100) and those without endometriosis (n = 55). Interventions: The percentage of NK cells relative to peripheral lymphocytes was quantified at flow cytometry in 155 patients who had undergone laparoscopy. In addition to verifying the presence of endometriosis, stage of disease and the sites affected were also evaluated. Measurements and Main Results: The mean (SD) percentage of NK cells was higher (15.3% [9.8%]) in patients with endometriosis than in the group without the disease (10.6% [5.8%]) (p < .001). The percentage of NK cells was highest (19.8 [10.3%]) in patients with advanced stages of endometriosis and in those in whom the rectosigmoid colon was affected. In a statistical model of probability, the association of this marker (NK cells >= 11%) with the presence of symptoms such as pain and intestinal bleeding during menstruation and the absence of previous pregnancy yielded a 78% likelihood of the rectosigmoid colon being affected. Conclusion: Compared with patients without endometriosis, those with endometriosis demonstrate a higher concentration of peripheral NK cells. The percentage of NK cells is greater, primarily in patients with advanced stages of endometriosis involving the rectosigmoid colon. Therefore, it may serve as a diagnostic marker for this type of severe endometriosis, in particular if considered in conjunction with the symptoms. Journal of Minimally Invasive Gynecology (2012) 19, 317-324 (C) 2012 AAGL. All rights reserved.
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The emergence of new infectious bronchitis virus (IBV) genotypes or serotypes along with the poor cross-protection observed among IBV serotypes have complicated the avian infectious bronchitis (IB) control programs in different geographic regions. In Cuba, the lack of genetic information regarding IBV and the increasing epidemiological importance of this virus in Cuban chicken flocks demand further characterization of IBV isolates. In the present work, studies of genetic diversity and phylogenetic relationships among recent IBV isolates from Cuban chicken flocks showing respiratory disorders were performed. Two putative genotypes genetically different to the Massachusetts genotype H120 strain used in the Cuban vaccination program were found in the flocks assessed. In addition, a potential nephropathogenic IBV isolate was found by first time in Cuba. (C) 2012 Elsevier Ltd. All rights reserved.
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The use of antiretroviral therapy has proven to be remarkably effective in controlling the progression of human immunodeficiency virus (HIV) infection and prolonging patient's survival. Therapy however may fail and therefore these benefits can be compromised by the emergence of HIV strains that are resistant to the therapy. In view of these facts, the question of finding the reason for which drug-resistant strains emerge during therapy has become a worldwide problem of great interest. This paper presents a deterministic HIV-1 model to examine the mechanisms underlying the emergence of drug-resistance during therapy. The aim of this study is to determine whether, and how fast, antiretroviral therapy may determine the emergence of drug resistance by calculating the basic reproductive numbers. The existence, feasibility and local stability of the equilibriums are also analyzed. By performing numerical simulations we show that Hopf bifurcation may occur. The model suggests that the individuals with drug-resistant infection may play an important role in the epidemic of HIV. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
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Objective: Describe the total energy value and percentage contribution of calories from macronutrients in the diet of elderly individuals living in Fortaleza/CE. Methods: This is a population-based, cross-sectional domiciliary study, which included 458 elderly individuals (66.6% women). The variables evaluated were total energy value (TEV) and the percentage contribution of calories from proteins, carbohydrates, and lipids. The results are shown as mean, standard deviation, and percentile distribution (P5, P10, P25, P50, P75, P90, P95). The Student's t-test and analysis of variance (one-way ANOVA) with LSD post-hoc tests were used to determine the statistical significance of means between two groups and among three or more groups, respectively. Results: When comparing the mean values of TEV among categories of socioeconomic and demographic variables, statistically significant differences were found between women for ethnicity, years of schooling and socioeconomic level. Among men, differences were found for years of schooling and socioeconomic level. The mean energy value of men's diet was significantly higher than that of women (1475.8 kcal and 1236.4 kcal, respectively). The mean values of calorie percentage contribution from proteins, carbohydrates, and lipids were similar between men and women. Conclusion: The elderly of this study showed significant differences in mean values of TEV between sexes and between the categories years of schooling and socioeconomic level. Women also showed significant differences between the ethnic categories. The mean relative contribution of macronutrients in TEV was similar between genders and age groups.
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Circadian rhythms in pacemaker cells persist for weeks in constant darkness, while in other types of cells the molecular oscillations that underlie circadian rhythms damp rapidly under the same conditions. Although much progress has been made in understanding the biochemical and cellular basis of circadian rhythms, the mechanisms leading to damped or self-sustained oscillations remain largely unknown. There exist many mathematical models that reproduce the circadian rhythms in the case of a single cell of the Drosophila fly. However, not much is known about the mechanisms leading to coherent circadian oscillation in clock neuron networks. In this work we have implemented a model for a network of interacting clock neurons to describe the emergence (or damping) of circadian rhythms in Drosophila fly, in the absence of zeitgebers. Our model consists of an array of pacemakers that interact through the modulation of some parameters by a network feedback. The individual pacemakers are described by a well-known biochemical model for circadian oscillation, to which we have added degradation of PER protein by light and multiplicative noise. The network feedback is the PER protein level averaged over the whole network. In particular, we have investigated the effect of modulation of the parameters associated with (i) the control of net entrance of PER into the nucleus and (ii) the non-photic degradation of PER. Our results indicate that the modulation of PER entrance into the nucleus allows the synchronization of clock neurons, leading to coherent circadian oscillations under constant dark condition. On the other hand, the modulation of non-photic degradation cannot reset the phases of individual clocks subjected to intrinsic biochemical noise.
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Background Statistical methods for estimating usual intake require at least two short-term dietary measurements in a subsample of the target population. However, the percentage of individuals with a second dietary measurement (replication rate) may influence the precision of estimates, such as percentiles and proportions of individuals below cut-offs of intake. Objective To investigate the precision of the usual food intake estimates using different replication rates and different sample sizes. Participants/setting Adolescents participating in the continuous National Health and Nutrition Examination Survey 2007-2008 (n=1,304) who completed two 24-hour recalls. Statistical analyses performed The National Cancer Institute method was used to estimate the usual intake of dark green vegetables in the original sample comprising 1,304 adolescents with a replication rate of 100%. A bootstrap with 100 replications was performed to estimate CIs for percentiles and proportions of individuals below cut-offs of intake. Using the same bootstrap replications, four sets of data sets were sampled with different replication rates (80%, 60%, 40%, and 20%). For each data set created, the National Cancer Institute method was performed and percentiles, Cl, and proportions of individuals below cut-offs were calculated. Precision estimates were checked by comparing each Cl obtained from data sets with different replication rates with the Cl obtained from original data set. Further, we sampled 1,000, 750, 500, and 250 individuals from the original data set, and performed the same analytical procedures. Results Percentiles of intake and percentage of individuals below the cut-off points were similar throughout the replication rates and sample sizes, but the Cl increased as the replication rate decreased. Wider CIs were observed at 40% and 20% of replication rate. Conclusions The precision of the usual intake estimates decreased when low replication rates were used. However, even with different sample sizes, replication rates >40% may not lead to an important loss of precision. J Acad Nutr Diet. 2012;112:1015-1020.
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In this work we present an agent-based model for the spread of tuberculosis where the individuals can be infected with either drug-susceptible or drug-resistant strains and can also receive a treatment. The dynamics of the model and the role of each one of the parameters are explained. The whole set of parameters is explored to check their importance in the numerical simulation results. The model captures the beneficial impact of the adequate treatment on the prevalence of tuberculosis. Nevertheless, depending on the treatment parameters range, it also captures the emergence of drug resistance. Drug resistance emergence is particularly likely to occur for parameter values corresponding to less efficacious treatment, as usually found in developing countries.
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Objectives: Previous evidence supports a direct relationship between the calcium burden (volume) on post-contrast CT with the percent internal carotid artery (ICA) stenosis at the carotid bifurcation. We sought to further investigate this relationship by comparing non-enhanced CT (NECT) and digital subtraction angiography (DSA). Methods: 50 patients (aged 41-82 years) were retrospectively identified who had undergone cervical NECT and DSA. A 64-multidetector array CT (MDCT) scanner was utilised and the images reviewed using preset window widths/levels (30/300) optimised to calcium, with the volumes measured via three-dimensional reconstructive software. Stenosis measurements were performed on DSA and luminal diameter stenoses >40% were considered "significant". Volume thresholds of 0.01, 0.03, 0.06, 0.09 and 0.12 cm(3) were utilised and Pearson's correlation coefficient (r) was calculated to correlate the calcium volume with percent stenosis. Results: Of 100 carotid bifurcations, 88 were available and of these 7 were significantly stenotic. The NECT calcium volume moderately correlated with percent stenosis on DSA r=0.53 (p<0.01). A moderate-strong correlation was found between the square root of calcium volume on NECT with percent stenosis on DSA (r=0.60, p<0.01). Via a receiver operating characteristic curve, 0.06 cm(3) was determined to be the best threshold (sensitivity 100%, specificity 90.1%, negative predictive value 100% and positive predictive value 46.7%) for detecting significant stenoses. Conclusion: This preliminary investigation confirms a correlation between carotid bifurcation calcium volume and percent ICA stenosis and is promising for the optimal threshold for stenosis detection. Future studies could utilise calcium volumes to create a "score" that could predict high grade stenosis.
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Background The evolutionary advantages of selective attention are unclear. Since the study of selective attention began, it has been suggested that the nervous system only processes the most relevant stimuli because of its limited capacity [1]. An alternative proposal is that action planning requires the inhibition of irrelevant stimuli, which forces the nervous system to limit its processing [2]. An evolutionary approach might provide additional clues to clarify the role of selective attention. Methods We developed Artificial Life simulations wherein animals were repeatedly presented two objects, "left" and "right", each of which could be "food" or "non-food." The animals' neural networks (multilayer perceptrons) had two input nodes, one for each object, and two output nodes to determine if the animal ate each of the objects. The neural networks also had a variable number of hidden nodes, which determined whether or not it had enough capacity to process both stimuli (Table 1). The evolutionary relevance of the left and the right food objects could also vary depending on how much the animal's fitness was increased when ingesting them (Table 1). We compared sensory processing in animals with or without limited capacity, which evolved in simulations in which the objects had the same or different relevances. Table 1. Nine sets of simulations were performed, varying the values of food objects and the number of hidden nodes in the neural networks. The values of left and right food were swapped during the second half of the simulations. Non-food objects were always worth -3. The evolution of neural networks was simulated by a simple genetic algorithm. Fitness was a function of the number of food and non-food objects each animal ate and the chromosomes determined the node biases and synaptic weights. During each simulation, 10 populations of 20 individuals each evolved in parallel for 20,000 generations, then the relevance of food objects was swapped and the simulation was run again for another 20,000 generations. The neural networks were evaluated by their ability to identify the two objects correctly. The detectability (d') for the left and the right objects was calculated using Signal Detection Theory [3]. Results and conclusion When both stimuli were equally relevant, networks with two hidden nodes only processed one stimulus and ignored the other. With four or eight hidden nodes, they could correctly identify both stimuli. When the stimuli had different relevances, the d' for the most relevant stimulus was higher than the d' for the least relevant stimulus, even when the networks had four or eight hidden nodes. We conclude that selection mechanisms arose in our simulations depending not only on the size of the neuron networks but also on the stimuli's relevance for action.