944 resultados para Retained Trees


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Silvo-pastoral are mixed systems of trees and grass, which have been proposed as a means to extend the benefits of forest to farmed land. Agro-forestry systems under semi-arid Mediterranean conditions, called montados in Portugal and dehesas in Spain, cover substantial areas in the world. These silvo-pastoral systems are the most extensive European agro-forestry system, as they cover 3.5–4.0 Mha in Spain and Portugal. Long-term studies are essential to assess the magnitude of the temporal nutrient flow dynamics in terrestrial ecosystems and to understand the response of these systems to fertilizer management. In order to implement the conservation task and recovery of resources through silvo-pastoral systems it is necessary to know and correct potential limiting factors, especially the soil factor, and this requires agronomic knowledge as well as the implmentation of the available new technologies. In this context, this task aims at a better understanding of the contribution of the two components of montado ecosystem (trees and herbaceous vegetation) on the soil nutrient and water dynamics, that allow for the interpretation of the variability of pasture dry matter yield and help the farmer in the management of tree density. Collaterally the task will evaluate and calibrate new technologies that simplify the monitoring of soil, grassland, trees and grazing animals.

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In this study, we investigated the different responses of Spondias tuberosa (umbu) trees, which grow in two different ecological life zones in northeast Brazil: tropical wet and tropical arid ecosystems. We evaluated the responses of plants grown under humid and dry conditions by measuring the photosynthesis, water status, fluorescence parameters, carbon isotopes and antioxidant system activity. The higher net photosynthesis values were recorded contemporaneously with the lower VPD values. The highest internal-to-ambient CO2 concentration and the absence of typical changes in the fluorescence parameters suggested an onset of a nonstomatal limitation in the photosynthesis. Our results showed that umbu plants can adjust their antioxidant activity during the dry season as a defensive strategy against the deleterious effects of water stress. This evidence is supported by the observed modifications in the pigment concentrations, increased accumulation of hydrogen peroxide and malondialdehyde, high levels of electrolyte leakage, increased antioxidant activity, and decreased carbon isotope discrimination in the umbu trees during the dry season. Supported by multivariate analysis of variance, significantly effect of interaction between categorical months of collect and location predicts a strong ?dry season effect? on our dataset. Taken together, our data show that umbu trees grown in a wet tropical environment are more susceptible to drought, as compared with their tropical arid counterparts.

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The competitive influence of the root system of the exotic grass Urochloa brizantha and the widespread forb Leonotis nepetifolia on the emergence, survival and early growth of the seedlings of eight tropical heliophilous herbaceous species, six early-successional woody species and five late-successional woody species from Brazil, grown in 3500-cm3 pots and in greenhouse without light restriction were assessed. The density of fine-root systems produced by the forb and the grass in pots were 6.8 cm cm-3 soil and 48.1 cm cm-3 soil, respectively. Seedlings survival of the heliophilous herbaceous, early- and late-successional woody species were 86%, 70% and 100% in presence of the forb root system and 12%, 14% and 100% in competition with grass root system, respectively. The competitive pressure applied by the grass root system on seedling growth of the heliophilous herbaceous, early- and late-successional woody species were 2.4, 1.9 and 1.4 times greater than the forb root system. Total root length of the heliophilous herbaceous, early- and late-successional woody species grown without competitors were 13, 33 and 5 times greater than in competition with forb, and were 66, 54 and 6 times greater than in competition with grass root system, respectively. The averages of fine-root diameter of plants grown without competitors were 209 microm for the heliophilous herbaceous, 281 microm for early-successional trees and 382 microm for late-successional trees. The root system of the forb did not avoid seedling establishment of most plant species, but the grass root system hampered more the establishment of heliophilous herbaceous and early-successional woody species than the seedling establishment of late-successional woody species. The different density of root systems produced in soil by the forb and the grass, and the distinct root traits (e.g. root diameter and root tissue density) of the early- and late-successional plant species can explain the differences in the establishment of seedlings of plant species belonging to different groups of tropical succession when exposed to below-ground competition.

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The degree to which pruning helps reestablish balance in agroforestry was assessed in a system established in São Carlos, São Paulo, Brazil, in 2008. Seven native tree species were planted at a density of 600 trees/ha in five strips of three rows each, and annual crops were cultivated in the 17-m crop strips between the tree strips. Competition was established after 35 months, decreasing the aboveground biomass production of corn planted close to the trees. An assessment of black oats in the dry season following tree pruning showed that the proximity of trees caused reductions in plant and panicle density, aboveground biomass production, number of grains per panicle and grain weight. Because pruning was not sufficient to maintain crop yields, tree thinning is recommended in order to minimize competition and restore conditions for adequate crop production.

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This study was perfonned in PSPs located at the CPAr-ACRE EMORAPA expcrirnental area and at the PC Peixoto management areas. AI CPA F-ACR E the managed area was meehanically exploited in 1992 and at PC Peixoto animal traction was used to extract the planks.

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Agroforestry systems with eucalyptus prevail in Central and Southeast Brazil, and little information is available about systems using native trees. The aim of the present study was to evaluate the development of seven native tree species grown under two agroforestry systems. The experiment was conducted starting in 2007 in 12-hectare area in the municipality of São Carlos, São Paulo state, Brazil. The tree species planted in the two systems (a silvopastoral system and an agrisilvicultural system) were: 'capixingui' (Croton floribundus) and 'mutambo' (Guazuma ulmifolia) (tutors), 'jequitibá-branco' (Cariniana estrellensis), 'canafistula' (Peltophorum dubium) and 'ipê felpudo' (Zeyheria tuberculosa) (timber trees), and 'angico-branco' (Anadenanthera colubrina) and 'pau-jacaré' (Piptadenia gonoacantha) (N-fixing trees). Data were collected for 48 months. The results show differences among tree development, which was evaluated as growth in height and diameter, as well as sensitivity to insect and disease damage. The overall results show that the agrisilvicultural system allowed better tree development. The species with best performance in the two systems were capixingui, mutambo and canafístula. Ipê-felpudo and jequitibá-branco showed the worst results. The high variability among individuals of the same species indicates the possibility of high production advances with selective breeding of these species.

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Grapholita molesta (Busck) is one of the main pests of apple trees, and lives on their shoots and fruits. In southern Brazil, the insect is also found on old branches and structures similar to aerial roots, so-called burrknots. This study evaluated the development and population growth potential of G. molesta fed on burrknots, compared with apple fruit cultivar. Fuji and a corn-based artiÞcial diet. The study was carried out in the laboratory under controlled temperature (25 1C), relative humidity (7010%), and photophase (16 h). The biological parameters of the immature and adult stages were determined, and a fertility life table was constructed. Insects fed on burrknots showed a longer duration and a lower survival for the egg-to-adult period (29.3 d and 22.5%) compared with those that fed on apples (25.1 d and 30.0%) and artiÞcial diet (23.9 d and 54.8%). Insects reared on aerial roots had a lower pupal weight (10.0 mg) compared with those reared on either artiÞcial diet (13.7 mg) or apple cultivar. Fuji (12.4 mg). The fecundity and longevity of males and females did not signiÞcantly differ for the three foods. Based on the fertility life table, insects reared on burrknots had the lowest net reproductive rate (Ro), intrinsic rate of population growth (rm) and finite rate of increase, compared with insects reared on artiÞcial diet and apple fruit. Burrknots support the development of the complete cycle of G. molesta, which allows populations of this pest to increase in orchards.

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Today’s data are increasingly complex and classical statistical techniques need growingly more refined mathematical tools to be able to model and investigate them. Paradigmatic situations are represented by data which need to be considered up to some kind of trans- formation and all those circumstances in which the analyst finds himself in the need of defining a general concept of shape. Topological Data Analysis (TDA) is a field which is fundamentally contributing to such challenges by extracting topological information from data with a plethora of interpretable and computationally accessible pipelines. We con- tribute to this field by developing a series of novel tools, techniques and applications to work with a particular topological summary called merge tree. To analyze sets of merge trees we introduce a novel metric structure along with an algorithm to compute it, define a framework to compare different functions defined on merge trees and investigate the metric space obtained with the aforementioned metric. Different geometric and topolog- ical properties of the space of merge trees are established, with the aim of obtaining a deeper understanding of such trees. To showcase the effectiveness of the proposed metric, we develop an application in the field of Functional Data Analysis, working with functions up to homeomorphic reparametrization, and in the field of radiomics, where each patient is represented via a clustering dendrogram.

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The year 14,226 BP marks an important border in the actual radiocarbon (14C) calibration curve: the high resolution and precision characterising the first part (0 – 14,226 BP) of the curve are due to the potential represented by tree-ring datasets, which directly provide the atmospheric 14C content at the time of tree-rings formation with high resolution. They systematically decrease going back in time, where only a few floating tree-ring chronologies alternate to other low-resolution records. The lack of resolution in the dating procedure before 14,226 years BP leads to significant issues in the interpretation and untangling of tricky facts of our past, in the field of Human Evolution. Research on sub-fossil trees and the construction of new Glacial tree-ring chronologies can significantly improve the radiocarbon dating in terms of temporal resolution and precision until 55,000 years BP to clear puzzles in the Human Evolution history. In this thesis, the dendrochronological study, the radiocarbon dating and the extrapolation of environmental and climate information from sub-fossil trees found on the Portugal foreshore, remnants of a Glacial lagoonal forest, are presented. The careful sampling, the dendrochronological measurements and cross-dating, the application of the most suitable cellulose extraction protocol and the most advanced technologies of the MICADAS system at ETH-Zurich, led to the construction of a new 220-years long tree-ring site chronology and to high resolution, highly reliable and with a tight error range radiocarbon ages. At the moment, it results impossible to absolutely date this radiocarbon sequence by the comparison of Δ14C of the trees and 10 Be fluctuations from the ice-cores. For this reason, tree growth analysis, comparisons with a living pine stand and forest-fires history reconstruction have made it possible to hypothesize site and climate characteristics useful to constrain the positioning in time of the obtained radiocarbon sequence.

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The diagnosis of intraductal carcinoma (IDC) of the prostate remains subjective because 3 sets of diagnostic criteria are in use. An internet survey was compiled from 38 photomicrographs showing duct proliferations: 14 signed out as high-grade prostatic intraepithelial neoplasia (HGPIN), 17 IDC, and 7 invasive cribriform/ductal carcinoma. Each image was assessed for the presence of 9 histologic criteria ascribed to IDC. Thirty-nine respondents were asked to rate images as (1) benign/reactive, (2) HGPIN, (3) borderline between HGPIN and IDC, (4) IDC, or (5) invasive cribriform/ductal carcinoma. Intraclass correlation coefficient was 0.68. There was 70% overall agreement with HGPIN, 43% with IDC, and 73% with invasive carcinoma (P < .001, χ(2)). Respondents considered 19 (50%) of 38 cases as IDC candidates, of which 5 (26%) had a two-thirds consensus for IDC; two-thirds consensus for either borderline or IDC was reached in 9 (47%). Two-thirds consensus other than IDC was reached in the remaining 19 of 38 cases, with 15 supporting HGPIN and 4 supporting invasive carcinoma. Findings that differed across diagnostic categories were lumen-spanning neoplastic cells (P < .001), 2× benign duct diameters (P < .001), duct space contours (round, irregular, and branched) (P < .001), papillary growth (P = .048), dense cribriform or solid growth (both P = .023), and comedonecrosis (P = .015). When the 19 of 38 images that attained consensus for HGPIN or invasive carcinoma were removed from consideration, lack of IDC consensus was most often attributable to only loose cribriform growth (5/19), central nuclear maturation (5/19), or comedonecrosis (3/19). Of the 9 histologic criteria, only 1 retained significant correlation with a consensus diagnosis of IDC: the presence of solid areas (P = .038). One case that attained IDC consensus had less than 2× duct enlargement yet still had severe nuclear atypia and nucleomegaly. Six fold nuclear enlargement was not significant (P = .083), although no image had both 6× nuclei and papillary or loose cribriform growth: a combination postulated as sufficient criteria for IDC. Finally, 20.5% of respondents agreed that an isolated diagnosis of IDC on needle biopsy warrants definitive therapy, 20.5% disagreed, and 59.0% considered the decision to depend upon clinicopathologic variables. Although IDC diagnosis remains challenging, we propose these criteria: a lumen-spanning proliferation of neoplastic cells in preexisting ducts with a dense cribriform or partial solid growth pattern. Solid growth, in any part of the duct space, emerges as the most reproducible finding to rule in a diagnosis of IDC. Comedonecrosis is a rarer finding, but in most cases, it should rule in IDC. Duct space enlargement to greater than 2× the diameter of the largest, adjacent benign spaces is usually present in IDC, although there may be rare exceptions.

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Trees from tropical montane cloud forest (TMCF) display very dynamic patterns of water use. They are capable of downwards water transport towards the soil during leaf-wetting events, likely a consequence of foliar water uptake (FWU), as well as high rates of night-time transpiration (Enight) during drier nights. These two processes might represent important sources of water losses and gains to the plant, but little is known about the environmental factors controlling these water fluxes. We evaluated how contrasting atmospheric and soil water conditions control diurnal, nocturnal and seasonal dynamics of sap flow in Drimys brasiliensis (Miers), a common Neotropical cloud forest species. We monitored the seasonal variation of soil water content, micrometeorological conditions and sap flow of D. brasiliensis trees in the field during wet and dry seasons. We also conducted a greenhouse experiment exposing D. brasiliensis saplings under contrasting soil water conditions to deuterium-labelled fog water. We found that during the night D. brasiliensis possesses heightened stomatal sensitivity to soil drought and vapour pressure deficit, which reduces night-time water loss. Leaf-wetting events had a strong suppressive effect on tree transpiration (E). Foliar water uptake increased in magnitude with drier soil and during longer leaf-wetting events. The difference between diurnal and nocturnal stomatal behaviour in D. brasiliensis could be attributed to an optimization of carbon gain when leaves are dry, as well as minimization of nocturnal water loss. The leaf-wetting events on the other hand seem important to D. brasiliensis water balance, especially during soil droughts, both by suppressing tree transpiration (E) and as a small additional water supply through FWU. Our results suggest that decreases in leaf-wetting events in TMCF might increase D. brasiliensis water loss and decrease its water gains, which could compromise its ecophysiological performance and survival during dry periods.

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To assess the occurrence of severe maternal complications owing to postpartum hemorrhage (PPH) and its associated factors. A secondary analysis of data from a multicenter cross-sectional prospective surveillance study included 9555 cases of severe maternal morbidity at 27 centers in Brazil between July 2009 and June 2010. Complications of PPH, conditions of severity management, and sociodemographic and obstetric characteristics were assessed. Factors independently associated with severe maternal outcome (SMO) were identified using multiple regression analysis. Overall, 1192 (12.5%) of the 9555 women experienced complications owing to PPH (981 had potentially life-threatening conditions, 181 maternal near miss, and 30 had died). The SMO ratio was 2.6 per 1000 live births among women with PPH and 8.5 per 1000 live births among women with other complications. Women with PPH had a higher risk of blood transfusion and return to the operating theater than did those with complications from other causes. Maternal age, length of pregnancy, previous uterine scar, and cesarean delivery were the main factors associated with an increased risk of SMO secondary to PPH. PPH frequently leads to severe maternal morbidity. A surveillance system can identify the main causes of morbidity and could help to improve care, especially among women identified as being at high risk of PPH.

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Dendrochemistry is based on the determination of elements retained in tree rings, which can be useful to characterize environmental occurrences. This work shows elemental mappings obtained by EDXRF of the cross section of a tree stem. The tree is originated from a polluted area in Campinas, São Paulo. Some profiles, as the sulfur one, show variations that can be attributed to external contributions, whereas the silicon one can be inferred to a protection defense natural mechanism. Besides being simultaneous and multielementar, the main advantages here are its performance through a non-destructive sample treatment and the ease of operation of XRF equipments.