Influence of removal of a non-native tree species Mimosa caesalpiniifolia Benth. on the regenerating plant communities in a tropical semideciduous forest under restoration in Brazil

Exotic species are used to trigger facilitation in restoration plantings, but this positive effect may not be permanent and these species may have negative effects later on. Since such species can provide a marketable product (firewood), their harvest may represent an advantageous strategy to achieve both ecological and economic benefits. In this study, we looked at the effect of removal of a non-native tree species (Mimosa caesalpiniifolia) on the understory of a semideciduous forest undergoing restoration. We assessed two 14-year-old plantation systems (modified taungya agroforestry system; and mixed plantation using commercial timber and firewood tree species) established at two sites with contrasting soil properties in São Paulo state, Brazil. The experimental design included randomized blocks with split plots. The natural regeneration of woody species (height ≥0.2 m) was compared between managed (all M. caesalpiniifolia trees removed) and unmanaged plots during the first year after the intervention. The removal of M. caesalpiniifolia increased species diversity but decreased stand basal area. Nevertheless, the basal area loss was recovered after 1 year. The management treatment affected tree species regeneration differently between species groups. The results of this study suggest that removal of M. caesalpiniifolia benefited the understory and possibly accelerated the succession process. Further monitoring studies are needed to evaluate the longer term effects on stand structure and composition. The lack of negative effects of tree removal on the natural regeneration indicates that such interventions can be recommended, especially considering the expectations of economic revenues from tree harvesting in restoration plantings.

Effect of avocado/soybean unsaponifiables on ligature-induced bone loss and bone repair after ligature removal in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sulfamethoxazole and ciprofloxacin removal using a horizontal-flow anaerobic immobilized biomass reactor

The antibiotics sulfamethoxazole (SMTX) and ciprofloxacin (CIP) are commonly used in human and veterinary medicine, which explains their occurrence in wastewater. Anaerobic reactors are low-cost, simple and suitable technology to wastewater treatment, but there is a lack of studies related to the removal efficiency of antibiotics. To overcome this knowledge gap, the objective of this study was to evaluate the removal kinetics of SMTX and CIP using a horizontal-flow anaerobic immobilized biomass reactor. Two different concentrations were evaluated, for SMTX 20 and 40 μg L(-1); for CIP 2.0 and 5.0 μg L(-1). The affluent and effluent analysis was carried out in liquid chromatography/tandem mass spectrometry (LC-MS/MS) with the sample preparation procedure using an off-line solid-phase extraction. This method was developed, validated and successfully applied for monitoring the affluent and effluent samples. The removal efficiency found for both antibiotics at the two concentrations studied was 97%. Chemical oxygen demand (COD) exhibited kinetic constants that were different from that observed for the antibiotics, indicating the absence of co-metabolism. Also, though the antibiotic concentration was increased, there was no inhibitory effect in the removal of COD and antibiotics.

Effects of seminal plasma removal on bacterial growth in stallion semen

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Surface-Potential-Based Drain Current Analytical Model for Triple-Gate Junctionless Nanowire Transistors

This paper proposes a drain current model for triple-gate n-type junctionless nanowire transistors. The model is based on the solution of the Poisson equation. First, the 2-D Poisson equation is used to obtain the effective surface potential for long-channel devices, which is used to calculate the charge density along the channel and the drain current. The solution of the 3-D Laplace equation is added to the 2-D model in order to account for the short-channel effects. The proposed model is validated using 3-D TCAD simulations where the drain current and its derivatives, the potential, and the charge density have been compared, showing a good agreement for all parameters. Experimental data of short- channel devices down to 30 nm at different temperatures have been also used to validate the model.

Removal of Pb2+ from aqueous solutions using two Brazilian rocks containing zeolites

The removal of Pb2+ from aqueous solution by two Brazilian rocks that contain zeolites-amygdaloidal dacite (ZD) and sandstone (ZS)-was examined by batch experiments. ZD contains mordenite and ZS, stilbite. The effects of contact time, concentration of metal in solution and capacity of Na+ to recover the adsorbed metals were evaluated at room temperature (20A degrees C). The sorption equilibrium was reached in the 30 min of agitation time. Both materials removed 100% of Pb2+ from solutions at concentrations up to 50 mg/L, and at concentrations larger than 100 mg/L of Pb2+, the adsorption capacity of sandstone was more efficient than that of amygdaloidal dacite due to the larger quantities and the type of zeolites (stilbite) in the cement of this rock. All adsorbed Pb2+ was easily replaced by Na+ in both samples. The analysis of the adsorption models using nonlinear regression revealed that the Sips and the Freundlich isotherms provided the best fit for the ZS and ZD experimental data, respectively, indicating the heterogeneous adsorption surfaces of these zeolites.

Torque removal evaluation of prosthetic screws after tightening and loosening cycles: an in vitro study

Objectives: The aim of this study was to evaluate the variation in removal torque of implant prosthetic abutment screws after successive tightening and loosening cycles, in addition to evaluating the influence of the hexagon at the abutment base on screw removal torque. Material and methods: Twenty hexagonal abutments were tightened to 20 regular external hex implants with a titanium alloy screw, with an insertion torque of 32 N cm, measured with a digital torque gauge. The implant/abutment/screw assemblies were divided into two groups: ( 1) abutments without hexagon at the base and ( 2) abutments with a hexagon at the base. Each assembly received a provisional restoration and was submitted to mechanical loading cycles. After this, the screws were removed and the removal torque was measured. This sequence was repeated 10 times, then the screw was replaced by a new one, and another cycle was performed. Linear regression analysis was performed. Results: Removal torque values tended to decrease as the number of insertion/removal cycles increased, for both groups. Comparisons of the slopes and the intercepts between groups showed no statistical difference. There was no significant difference between the mean values of last five cycles and the 11th cycle. Within the limitations of this in vitro study, it was concluded that ( 1) repeated insertion/removal cycles promoted gradual reduction in removal torque of screws, ( 2) replacing the screw with a new one after 10 cycles did not increase resistance to loosening, and ( 3) removal of the hexagon from the abutment base had no effect on the removal torque of the screws.

Performance of rest myocardial perfusion imaging in the management of acute chest pain in the emergency room in developing nations (PREMIER trial)

Background. Rest myocardial perfusion imaging (MPI) is effective in managing patients with acute chest pain in developed countries. We aimed to define the role and feasibility of rest MPI in low-to-middle income countries. Methods and Results. Low-to-intermediate risk patients (n = 356) presenting with chest pain to ten centers in eight developing countries were injected with a Tc-99m-based tracer, and standard imaging was performed. The primary outcome was a composite of death, non-fatal myocardial infarction (MI), recurrent angina, and coronary revascularization at 30 days. Sixty-nine patients had a positive MPI (19.4%), and 52 patients (14.6%) had a primary outcome event. An abnormal rest-MPI result was the only variable which independently predicted the primary outcome [adjusted odds ratio (OR) 8.19, 95% confidence interval 4.10-16.40, P = .0001]. The association of MPI result and the primary outcome was stronger (adjusted OR 17.35) when only the patients injected during pain were considered. Rest-MPI had a negative predictive value of 92.7% for the primary outcome, improving to 99.3% for the hard event composite of death or MI. Conclusions. Our study demonstrates that rest-MPI is a reliable test for ruling out MI when applied to patients in developing countries. (J Nucl Cardiol 2012;19:1146-53.)

Debris and smear removal in flattened root canals after use of different irrigant agitation protocols

Scanning electron microscopy (SEM) can be used to analyze the presence of debris and smear layer on the internal walls of root canal. This study evaluated the debris and smear removal in flattened root canals using SEM after use of different irrigant agitation protocols. Fifty mandibular incisors were distributed into five groups (n = 10) according to the irrigant agitation protocol used during chemomechanical preparation: conventional syringe irrigation with NaviTip needle (no activation), active scrubbing of irrigant with brush-covered NaviTip FX needle, manual dynamic irrigation, continuous passive ultrasonic irrigation, and apical negative pressure irrigation (EndoVac system). Canals were irrigated with 5 mL of 2.5% NaOCl at each change of instrument and received a final flush with 17% EDTA for 1 min. After instrumentation, the roots were split longitudinally and SEM micrographs at x 100 and x 1,000 were taken to evaluate the amount of debris and smear layer, respectively, in each third. Data were analyzed by KruskalWallis and Dunn's post-hoc tests (a = 5%). Manual dynamic activation left significantly (p < 0.05) more debris inside the canals than the other protocols, while ultrasonic irrigation and EndoVac were the most effective (p < 0.05) for debris removal. Regarding the removal of smear layer, there was no statistically significant difference (p > 0.05) either among the irrigant agitation protocols or between the protocolcanal third interactions. Although none of the irrigant agitation protocols completely removed debris and smear layer from flattened root canals, the machine-assisted agitation systems (ultrasound and EndoVac) removed more debris than the manual techniques. Microsc. Res. Tech. 75:781790, 2012. (C) 2011 Wiley Periodicals, Inc.

EDGE-PRESERVING SPECKLE TEXTURE REMOVAL BY INTERFERENCE-BASED SPECKLE FILTERING FOLLOWED BY ANISOTROPIC DIFFUSION

Ultrasonography has an inherent noise pattern, called speckle, which is known to hamper object recognition for both humans and computers. Speckle noise is produced by the mutual interference of a set of scattered wavefronts. Depending on the phase of the wavefronts, the interference may be constructive or destructive, which results in brighter or darker pixels, respectively. We propose a filter that minimizes noise fluctuation while simultaneously preserving local gray level information. It is based on steps to attenuate the destructive and constructive interference present in ultrasound images. This filter, called interference-based speckle filter followed by anisotropic diffusion (ISFAD), was developed to remove speckle texture from B-mode ultrasound images, while preserving the edges and the gray level of the region. The ISFAD performance was compared with 10 other filters. The evaluation was based on their application to images simulated by Field II (developed by Jensen et al.) and the proposed filter presented the greatest structural similarity, 0.95. Functional improvement of the segmentation task was also measured, comparing rates of true positive, false positive and accuracy. Using three different segmentation techniques, ISFAD also presented the best accuracy rate (greater than 90% for structures with well-defined borders). (E-mail: fernando.okara@gmail.com) (C) 2012 World Federation for Ultrasound in Medicine & Biology.

Totally implantable venous catheters: insertion via internal jugular vein with pocket implantation in the arm is an alternative for diseased thoracic walls

Purpose: Insertion of totally implantable catheters via deep vessels that drain into the superior vena cava results in a lower incidence of venous thrombosis and infection as compared to catheters inserted into femoral and arm veins. Superior vena cava obstruction and inadequacy of the thoracic wall are conditions that prevent reservoir implantation in the chest wall. In this article, we describe a technical innovation that enables the pocket to be fixed in the arm while still allowing access to be achieved via the internal jugular vein. Method: The procedure reported maintains the use of the internal jugular vein for access even when the patient's chest is not suited for reservoir implantation, which is localized in the arm. Results: The procedure was successful and no complications occurred. The position of the catheter tip did not alter with arm movement. Conclusion: The implantation of a port reservoir in the arm following venous access via the internal jugular vein is both safe and convenient.

Assessment of myocardial infarction by CT angiography and cardiovascular MRI in patients with cocaine-associated chest pain: a pilot study

Objectives: Cocaine is a commonly used illicit drug that leads to the most emergency department (ED) visits. Chest pain is the most common presentation, reported in 40% of patients. Our aim was to evaluate the incidence of previous myocardial infarction among young cocaine users (18-40 years) with cocaine-associated chest pain by the assessment of myocardial fibrosis by cardiovascular MRI. Second, we also intended to evaluate the coronary tree by CT angiography (CTA). Methods: 24 cocaine users (22 males) who frequently complained about cocaine-associated chest pain underwent CTA and cardiovascular MRI. Mean age of patients was 29.7 years and most of them (79%) had frequently used inhalatory cocaine. Results: The calcium score turned out to be positive in only one patient (Agatston=54). Among the coronary segments evaluated, only one patient had calcified plaques at the anterior descending coronary artery (proximal and medium segments). Assessment of regional ventricular function by the evaluation of 17 segments was normal in all patients. None of the patients showed myocardial delayed enhancement, indicative of myocardial fibrosis. CTA therefore confirmed the low cardiovascular risk of these patients, since most of them (96%) had no atherosclerosis detected by this examination. Only one patient (4%) had coronary atherosclerosis detected, without significant coronary stenosis. Conclusion: Cardiovascular MR did not detect the presence of delayed enhancement indicative of myocardial fibrosis among young cocaine users with low cardiovascular risk who had complained of cocaine-associated chest pain.

The Dependence of Retention Time on Gate Length in UTBOX FBRAM With Different Source/Drain Junction Engineering

The floating-body-RAM sense margin and retention-time dependence on the gate length is investigated in UTBOX devices using BJT programming combined with a positive back bias (so-called V th feedback). It is shown that the sense margin and the retention time can be kept constant versus the gate length by using a positive back bias. Nevertheless, below a critical L, there is no room for optimization, and the memory performances suddenly drop. The mechanism behind this degradation is attributed to GIDL current amplification by the lateral bipolar transistor with a narrow base. The gate length can be further scaled using underlap junctions.

Assessment of a UASB reactor for the removal of sulfate from acid mine water

A bench-scale Upflow Anaerobic Sludge Blanket (UASB) reactor was used to study the treatment of acid mine drainage through the biological reduction of sulfate. The reactor was fed with acid mine drainage collected at the Osamu Utsumi uranium mine (Caldas, MG, Brazil) and supplemented with ethanol as an external carbon source. Anaerobic granular sludge originating from a reactor treating poultry slaughterhouse wastewater was used as the inoculum. The reactor's performance was studied according to variations in the chemical oxygen demand (COD)/SO42- ratio, influent dilution and liquid-phase recirculation. The digestion of a dilution of the acid mine drainage resulted in a 46.3% removal of the sulfate and an increase in the effluent pH (COD/SO42- = 0.67). An increase in the COD/SO42- ratio to 1.0 resulted in an 85.6% sulfate reduction. The reduction of sulfate through complete oxidation of the ethanol was the predominant path in the reactor, although the removal of COD was not greater than 68% in any of the operational stages. The replenishment of the liquid phase with tap water positively affected the reactor, whereas the recirculation of treated effluent caused disequilibrium and decreased efficiency. (C) 2012 Elsevier Ltd. All rights reserved.

Hydrogen and Methane Production, Energy Recovery, and Organic Matter Removal from Effluents in a Two-Stage Fermentative Process

This study evaluates the potential for using different effluents for simultaneous H-2 and CH4 production in a two-stage batch fermentation process with mixed microflora. An appreciable amount of H-2 was produced from parboiled rice wastewater (23.9 mL g(-1) chemical oxygen demand [COD]) and vinasse (20.8 mL g(-1) COD), while other effluents supported CH4 generation. The amount of CH4 produced was minimum for sewage (46.3 mL g(-1) COD), followed by parboiled rice wastewater (115.5 mL g(-1) COD) and glycerol (180.1 mL g(-1) COD). The maximum amount of CH4 was observed for vinasse (255.4 mL g(-1) COD). The total energy recovery from vinasse (10.4 kJ g(-1) COD) corresponded to the maximum COD reduction (74.7 %), followed by glycerol (70.38 %, 7.20 kJ g(-1) COD), parboiled rice wastewater (63.91 %, 4.92 kJ g(-1) COD), and sewage (51.11 %, 1.85 kJ g(-1) COD). The relatively high performance of vinasse in such comparisons could be attributed to the elevated concentrations of macronutrients contained in raw vinasse. The observations are based on kinetic parameters of H-2 and CH4 production and global energy recovery of the process. These observations collectively suggest that organic-rich effluents can be deployed for energy recovery with sequential generation of H-2 and CH4.