Soil N²O emissions from long-term agroecosystems: interactive effects of rainfall seasonality and crop rotation in the Brazilian cerrado.

2016

Efeitos da ingestão de cafeína Em exercício aeróbio de alta intensidade em hipóxia : parâmetros fisiológicos e perceptuais = Effects of caffeine ingestion on high-intensity aerobic exercise in hypoxia : physiological and perceptual parameters

Universidade Estadual de Campinas . Faculdade de Educação Física

Effects of nitrate and phosphate availabilities on growth, photosynthesis and pigment and protein contents in colour strains of Hypnea musciformis (Wulfen in Jacqu.) J.V. Lamour. (Gigartinales, Rhodophyta)

In Brazil, Hypnea musciformis is the main raw material for carrageenan production and the knowledge of nitrogen and phosphorus metabolism in algae is critical for the success of cultivation because these elements can limit seaweed productivity. Thus, the objective of this study was to evaluate the effects of nitrate (zero to 100 μM) and nitrate plus phosphate (zero to 25 μM) availabilities on the growth, the contents of photosynthetic pigments (phycobiliproteins and chlorophyll a) and proteins, and the photosynthesis and respiration of the brown (BR) and light green (LG) strains of H. musciformis. The results revealed metabolic differences between the colour strains of H. musciformis for nitrogen metabolism: upon nitrate addition, the LG strain stored nitrogen mainly as proteins, while the BR strain stored it as proteins and pigments. Moreover, the respiration of the LG strain and the photosynthesis of the BR strain increased with nitrate concentrations, indicating that the BR strain fixed more photosynthetic carbon than the LG strain.

Non-additive genetic effects on weights and performance of a Brazilian Bos taurus x Bos indicus beef composite

The aim of the present study was to evaluate the heterosis effects on weaning weight at 205 days (WW, N = 146,464), yearling weight at 390 days (YW, N = 69,315) and weight gain from weaning to yearling (WG, N = 59,307) in composite beef cattle. The fixed models were: RM, which included contemporary groups, class of age of dam, outcrossing percentages for direct and maternal effects, and additive direct and maternal ( AM) breed effects; R, RM model, minus AM breed effects, and H, RM model, minus additive breed effects. The estimates for W205 were in general positive (P < 0.01). The R and H models resulted in similar estimates, but they were very different from the ones estimated by the RM model. For W390, the R and H models resulted in general positive estimates (P < 0.05). For WG, the RM model resulted in general significant heterosis effects (P < 0.05). It can be concluded that the RM model seems to supply estimates of better quality (P < 0.01).

A Comparison of Bimatoprost 0.03% Versus the Fixed-Combination of Latanotoprost 0.005% and Timolol 0.5% in Adult Patients With Elevated Intraocular Pressure: An Eight-Week, Randomized, Open-Label Trial

Introduction and Purpose: Bimatoprost and the fixed combination of latanoprost with timolol maleate are 2 medications widely used to treat glaucoma and ocular hypertension (OHT). The aim of the study is to compare the efficacy of these 2 drugs in reducing intraocular pressure (IOP) after 8 weeks of treatment in patients with primary open angle glaucoma (POAG) or OHT. Methods: In this randomized, open-label trial, 44 patients with POAG or OHT were allocated to receive either bimatoprost (1 drop QD) or latanoprost/timolol (1 drop QD). Primary outcome was the mean diurnal IOP measurement at the 8th week, calculated as the mean IOP measurements taken at 8:00 AM, 10: 00 AM, and 12: 00 PM Secondary outcomes included the baseline change in IOP measured 3 times a day, after the water-drinking test (performed after the last IOP measurement), and the assessment of side effects of each therapy. Results: The mean IOP levels of latanoprost/timolol (13.83, SD = 2.54) was significantly lower than of bimatoprost (16.16, SD = 3.28; P < 0.0001) at week 8. Also, the change in mean IOP values was significantly higher in the latanoprost/timolol group at 10:00 AM (P = 0.013) and 12:00 PM (P = 0.01), but not at 8: 00 AM (P = ns). During the water-drinking test, there was no signifi cant difference in IOP increase (absolute and percentage) between groups; however, there was a signifi cant decrease in mean heart rate in the latanoprost/timolol group. Finally, no signifi cant changes in blood pressure and lung spirometry were observed in either groups. Conclusions: The fixed combination of latanoprost/timolol was significantly superior to bimatoprost alone in reducing IOP in patients with POAG or OHT. Further studies with large sample sizes should be taken to support the superior efficacy of latanoprost/timolol, as well as to better assess its profile of side effects.

Changes in temporomandibular joint disc position and form following Herbst and fixed orthodontic treatment

Objective: To determine the changes in the position and form of the temporomandibular joint articular disc in adolescents with Class II division 1 malocclusion and mandibular retrognathism treated with the Herbst appliance (phase I) and fixed orthodontic appliance (phase II). Materials and Methods: Thirty-two consecutive adolescents went through phase I of treatment and 23 completed phase II. The temporomandibular joints were evaluated qualitatively by means of magnetic resonance images at the beginning of treatment (T1), during phase I (T2), at the end of phase I (T3), and at the end of phase II (T4). Results: Significant changes in disc position were not observed with the mouth closed between T1 X T3 (P = .317), T3 X T4 (P = .287), or T1 X T4 (P = .261). At T2, on average, the disc was positioned regressively. With the mouth open, no difference was observed between T1 X T3 (P = .223) or T1 X T4 (P = .082). We did observe a significant difference between T3 X T4 (P < .05). Significant changes in the disc form were found with the mouth closed between T1 X T2 (P < .001) and T2 X T3 (P < .001). Conclusions: At the end of the two-phase treatment, in general terms, the position and form of the initial articular discs were maintained; however, in some temporomandibular joints some seemingly adverse effects were observed at T4. (Angle Orthod. 2010;80:843-852.)

An experimental study of the effects of work stress, work control, and task information on adjustment

The present study was designed to examine the main and interactive effects of task demands, work control, and task information on levels of adjustment. Task demands, work control, and task information were manipulated in an experimental setting where participants completed a letter-sorting activity (N = 128). Indicators of adjustment included measures of positive mood, participants' perceptions of task performance, and task satisfaction. Results of the present study provided some support for the main effects of objective task demands, work control, and task information on levels of adjustment. At the subjective level of analysis, there was some evidence to suggest that work control and task information interacted in their effects on levels of adjustment. There was minimal support for the proposal that work control and task information would buffer the negative effects of task demands on adjustment. There was, however, some evidence to suggest that the stress-buffering role of subjective work control was more marked at high, rather than low, levels of subjective task information.

Effects of promoters on catalytic activity and carbon deposition of Ni/gamma-Al2O3 catalysts in CO2 reforming of CH4

Catalytic reforming of methane with carbon dioxide was studied in a fixed-bed reactor using unpromoted and promoted Ni/gamma-Al2O3 catalysts. The effects of promoters, such as alkali metal oxide (Na2O), alkaline-earth metal oxides (MgO, CaO) and rare-earth metal oxides (La2O3, CeO2), on the catalytic activity and stability in terms of coking resistance and coke reactivity were systematically examined. CaO-, La2O3- and CeO2-promoted Ni/gamma-Al2O3 catalysts exhibited higher stability whereas MgO- and Na2O-promoted catalysts demonstrated lower activity and significant deactivation. Metal-oxide promoters (Na2O, MgO, La2O3, and CeO2) suppressed the carbon deposition, primarily due to the enhanced basicities of the supports and highly reactive carbon species formed during the reaction. In contrast, CaO increased the carbon deposition; however, it promoted the carbon reactivity. (C) 2000 Society of Chemical Industry.

An equivalent algorithm for simulating thermal effects of magma intrusion problems in porous rocks

An equivalent algorithm is proposed to simulate thermal effects of the magma intrusion in geological systems, which are composed of porous rocks. Based on the physical and mathematical equivalence, the original magma solidification problem with a moving boundary between the rock and intruded magma is transformed into a new problem without the moving boundary but with a physically equivalent heat source. From the analysis of an ideal solidification model, the physically equivalent heat source has been determined in this paper. The major advantage in using the proposed equivalent algorithm is that the fixed finite element mesh with a variable integration time step can be employed to simulate the thermal effect of the intruded magma solidification using the conventional finite element method. The related numerical results have demonstrated the correctness and usefulness of the proposed equivalent algorithm for simulating the thermal effect of the intruded magma solidification in geological systems. (C) 2003 Elsevier B.V. All rights reserved.

Modelling the Distribution of Ischaemic Stroke-Specific Survival Time Using an EM-based Mixture Approach with Random Effects Adjustment

A two-component survival mixture model is proposed to analyse a set of ischaemic stroke-specific mortality data. The survival experience of stroke patients after index stroke may be described by a subpopulation of patients in the acute condition and another subpopulation of patients in the chronic phase. To adjust for the inherent correlation of observations due to random hospital effects, a mixture model of two survival functions with random effects is formulated. Assuming a Weibull hazard in both components, an EM algorithm is developed for the estimation of fixed effect parameters and variance components. A simulation study is conducted to assess the performance of the two-component survival mixture model estimators. Simulation results confirm the applicability of the proposed model in a small sample setting. Copyright (C) 2004 John Wiley Sons, Ltd.

Influence of the reinforcement magnitude on omission effects

Reinforcement Omission Effects (ROEs), indicated by higher rate of responses after nonreinforced trials in a partial reinforcement schedule, have been interpreted as behavioral transient facilitation after nonreinforcement induced by primary frustration, and/or behavioral transient inhibition after reinforcement induced by demotivation or temporal control. The size of the ROEs should depend directly on the reinforcement magnitude. The present experiment aimed to clarify the relationship between reinforcement magnitude and the omission effects manipulating the magnitude linked to discriminative stimuli in a partial reinforcement FI schedule. The results showed that response rates were higher after omission than after reinforcement delivery. Besides, response rates were highest immediately after the reinforcement omission of a larger magnitude than of a smaller magnitude. These data are interpreted in terms of ROEs multiple process behavioral facilitation after nonreinforcement, and behavioral transient inhibition after reinforcement. (C) 2011 Elsevier B.V. All rights reserved.

Numerical modelling of chemical effects of magma solidification problems in porous rocks

The solidification of intruded magma in porous rocks can result in the following two consequences: (1) the heat release due to the solidification of the interface between the rock and intruded magma and (2) the mass release of the volatile fluids in the region where the intruded magma is solidified into the rock. Traditionally, the intruded magma solidification problem is treated as a moving interface (i.e. the solidification interface between the rock and intruded magma) problem to consider these consequences in conventional numerical methods. This paper presents an alternative new approach to simulate thermal and chemical consequences/effects of magma intrusion in geological systems, which are composed of porous rocks. In the proposed new approach and algorithm, the original magma solidification problem with a moving boundary between the rock and intruded magma is transformed into a new problem without the moving boundary but with the proposed mass source and physically equivalent heat source. The major advantage in using the proposed equivalent algorithm is that a fixed mesh of finite elements with a variable integration time-step can be employed to simulate the consequences and effects of the intruded magma solidification using the conventional finite element method. The correctness and usefulness of the proposed equivalent algorithm have been demonstrated by a benchmark magma solidification problem. Copyright (c) 2005 John Wiley & Sons, Ltd.

Differences in the early biomechanical effects of hyperopic and myopic laser in situ keratomileusis

PURPOSE: To compare changes in corneal hysteresis (CH) and the corneal resistance factor (CRF) in myopic and hyperopic laser in situ keratomileusis (LASIK) and evaluate their relationship to the number of photoablative pulses delivered, a surrogate for ablation volume. SETTING: Cleveland Clinic Cole Eye Institute, Cleveland, Ohio, USA. METHODS: Preoperative and 1-week postoperative Ocular Response Analyzer measurements in eyes that had femtosecond-assisted LASIK were studied retrospectively. Changes in CH and CRF were compared and tested for correlation with the number of excimer laser pulses. RESULTS: Thirteen myopic eyes and 11 hyperopic eyes were evaluated. Preoperative corneal thickness, CH, CRF, programmed correction magnitude, flap thickness, and total number of fixed spotsize photoablative pulses were similar in the 2 groups (P>.1). Decreases in CH and CRF were greater after myopic LASIK than after hyperopic LASIK (P<.005), and changes in CRF were correlated with the number of excimer laser pulses in the myopic group only (r = -0.63, P = .02). Regardless of ablation profile, changes in CH were more strongly correlated with preoperative CH values than with attempted ablation volume. CONCLUSIONS: With comparable flap thickness and attempted ablation volumes, myopic photoablation profiles were associated with greater decreases in CRF and CH than hyperopic profiles. Results indicate that preoperative corneal biomechanical status, ablation volume, and the spatial distribution of ablation are important factors that affect corneal resistance and viscous dissipative properties differently. Preferential tissue removal in the natively thicker paracentral cornea in hyperopia may partially account for the rarity of ectasia after hyperopic LASIK.

The effects of moderate and low levels of acoustic overstimulation on stereocilia and their tip links in the guinea pig

Guinea pigs were exposed to pure tones of 10 kHz at intensities between 98 and 115 dB SPL for 5-30 min, to produce varying degrees of acoustic trauma. Changes in auditory thresholds were measured electrophysiologically, and the animals were immediately fixed for scanning electron microscopy. Correlation between morphological changes to the hair bundle and losses in threshold, showed that with the smallest degrees of trauma (98 dB SPL for 15 min, mean maximum threshold loss of 22 dB), damage was confined to a small stretch of inner hair cells (IHC), with only subtle changes to the stereocilia of the outer hair cells (OHC). At exposure intensities greater than 102 dB SPL (duration: 15 min) the IHC stereocilia in the centre of the lesion were always substantially disarrayed. Substantial damage to the OHC bundles was seen only with exposures above 110 dB SPL(duration: greater than or equal to 5 min), producing threshold losses of 50 dB or more. Tip links were lost only where the stereocilia were disarrayed. It is concluded that the tip links are not the most vulnerable components of the cochlear hair cell, but that relatively low levels of acoustic stimulation can cause significant damage to the stereociliary bundle of the IHCs.

Effects of Time on Ultrastructural Integrity of Parathyroid Tissue Before Cryopreservation

Cryopreservation of parathyroid tissue is used in the surgical treatment of secondary hyperparathyroidism. After surgical resection, the tissue is temporarily maintained in a cell culture solution until it arrives at the specialized laboratory where the cryopreservation process will take place. The present study evaluates the time that the human hyperplastic parathyroid gland tissue can wait before cryopreservation, based on parathyroid cell ultrastructural integrity. This prospective study included 11 patients who underwent total parathyroidectomy with heterotopic autotransplantation and cryopreservation of parathyroid tissue fragments. Part of the tissue was kept in cell culture solution at 4A degrees C. Five time periods between 2 and 24 h were defined, and parathyroid fragments were kept in the solution for that length of time. At the end of each period, the fragments were removed from the transport solution, fixed, and prepared for ultrathin sections. Of the 11 cases studied, 10 showed ultrastructural findings consistent with cellular viability in tissue fragments that remained in the transport solution up to 12 h. Electron microscopy revealed that cell adhesion and the integrity of plasma membranes, nuclei, and mitochondria were preserved in one case for up to 24 h. Changes in mitochondrial structure represented the most constant ultrastructural damage seen in the cases studied, in addition to the presence of edema and cell vacuoles. Analysis of the ultrastructure of hyperplastic parathyroid gland tissue showed that ultrastructural integrity was in most cases properly maintained in fragments stored up to 12 h in a cell culture solution at 4A degrees C.