RESUMO

BACKGROUND: Fever of unknown origin (FUO) is a diagnostic challenge with highly heterogeneous causes. Its etiology can change according to the studied regions, and the chance of reaching a diagnosis depends on available resources. The aim of this study is to describe the clinical characteristics, etiology and the usefulness of diagnostic aids in cases of FUO managed over 12 years in a Colombian reference center. METHODOLOGY: Single-institution retrospective case series. All cases of FUO between 2006 and 2017 were identified with the help of an electronic medical record search software. Cases of adults with fever for more than three weeks who remained undiagnosed after three days of hospitalization are described. RESULTS: Of 1,009 cases evaluated, 112 cases met the inclusion criteria (median age 43 years, 66% men). The etiologies identified were infectious (31.2%), inflammatory (20.5%), neoplastic (14.3%), and miscellaneous (2.7%) diseases. 31.2% remained without etiological diagnosis. The most frequent conditions were tuberculosis (17%), Hodgkin's lymphoma (7.1%), systemic lupus erythematosus (6.3%), disseminated histoplasmosis, and adult Still's disease. Contrast tomography and biopsies were the studies that most frequently supported or confirmed the final diagnosis. CONCLUSIONS: This series of contemporary Latin American cases suggests that the categories of FUO etiologies are similar to those reported in studies from developed countries, with tuberculosis being the most frequent cause in our setting. Our results highlight the importance of tomography-guided invasive studies in the diagnostic approach to FUO.

Assuntos

RESUMO

Road traffic is the primary source of environmental noise pollution in cities. This problem is also spreading due to inadequate urban expansion planning. Hence, integrating road traffic noise analysis into urban planning is necessary for reducing city noise in an effective, adaptable, and sustainable way. This study aims to develop a methodology that applies to any city for the stratification of urban roads by their functionality through only their urban features. It is intended to be a tool to cluster similar streets and, consequently, traffic noise to enable urban and transportation planners to support the reduction of people's noise exposure. Three multivariate ordered logistic regression statistical models (Model 1, 2, and 3) are presented that significantly stratify urban roads into five, four, and three categories, respectively. The developed models exhibit a McFadden pseudo-R2 between 0.5 and 0.6 (equivalent to R2 >0.8). The choice between Model 1 or 2 depends on the scale of the city. Model 1 is recommended for developed cities with an extensive road network, while Model 2 is most suitable in intermediate and growing cities. On the other hand, Model 3 could be applied at any city scale but focused on local management of transit routes and for designing acoustic sensor installations, urban soundwalks, and identification of quiet areas. Urban features related to road width and length, presence of transport infrastructure, and public transport routes are associated with increased traffic noise in all three models. These models prove useful for future action plans aimed at reducing noise through strategic urban planning.

RESUMO

The ecotoxic effect of Zn species arising from the weathering of the marmatite-like sphalerite ((Fe, Zn)S) in Allium cepa systems was herein evaluated in calcareous soils and connected with its sulfide oxidation mechanism to determine the chemical speciation responsible of this outcome. Mineralogical analyses (X-ray diffraction patterns, Raman spectroscopy, scanning electron microscopy and atomic force microscopy), chemical study of leachates (total Fe, Zn, Cd, oxidation-reduction potential, pH, sulfates and total alkalinity) and electrochemical assessments (chronoamperometry, chronopotentiometry, cyclic voltammetry, and electrochemical impedance spectroscopy) were carried out using (Fe, Zn)S samples to elucidate interfacial mechanisms simulating calcareous soil conditions. Results indicate the formation of polysulfides (Sn2-), elemental sulfur (S0), siderite (FeCO3)-like, hematite (Fe2O3)-like with sorbed CO32- species, gunningite (ZnSO4·H2O)-like phase and smithsonite (ZnCO3)-like compounds in altered surface under calcareous conditions. However, the generation of gunningite (ZnSO4·H2O)-like phase was predominant bulk-solution system. Quantification of damage rates ranges from 75 to 90% of bulb cells under non-carbonated conditions after 15-30 days, while 50-75% of damage level is determined under neutral-alkaline carbonated conditions. Damage ratios are 70.08 and 30.26 at the highest level, respectively. These findings revealed lower ecotoxic damage due to ZnCO3-like precipitation, indicating the effect of carbonates on Zn compounds during vegetable up-taking (exposure). Other environmental suggestions of the (Fe, Zn)S weathering and ecotoxic effects under calcareous soil conditions are discussed.

Assuntos

RESUMO

This paper presents the Synthetic Polyphonic Ambient Sound Source (SPASS) dataset, a publicly available synthetic polyphonic audio dataset. SPASS was designed to train deep neural networks effectively for polyphonic sound event detection (PSED) in urban soundscapes. SPASS contains synthetic recordings from five virtual environments: park, square, street, market, and waterfront. The data collection process consisted of the curation of different monophonic sound sources following a hierarchical class taxonomy, the configuration of the virtual environments with the RAVEN software library, the generation of all stimuli, and the processing of this data to create synthetic recordings of polyphonic sound events with their associated metadata. The dataset contains 5000 audio clips per environment, i.e., 25,000 stimuli of 10 s each, virtually recorded at a sampling rate of 44.1 kHz. This effort is part of the project ``Integrated System for the Analysis of Environmental Sound Sources: FuSA System'' in the city of Valdivia, Chile, which aims to develop a system for detecting and classifying environmental sound sources through deep Artificial Neural Network (ANN) models.

RESUMO

This study aims the development of photoelectrodes to be incorporated in a photoelectrocatalytic ozonation (PECO) process for tertiary treatment of urban wastewaters, targeting the removal of contaminants of emerging concern (CEC). PECO tests were performed using urban wastewater after secondary treatment fortified with Cefadroxil (CFX, C16H17N3O5S), as target model CEC. Three Nitrogen and Carbon doped TiO2 (CN-TiO2) electrodes were synthesized by anodizing at 50, 70, and 90 V, and calcined. These materials were characterized by X-Ray diffraction and Rietveld refinement, Scanning Electron Microscopy, Diffuse Reflectance Spectroscopy, X-ray photoelectron spectroscopy, chronoamperometry, and electrochemical impedance spectroscopy, to correlate defects with photoactivity. All photoanodes considerably reduced their main bandgaps by the incorporation of C and N species, to enable absorption capacities in the UV region using a Xe lamp. The lowest oxygen vacancy content and largest crystallite size were found for CN-TiO2-70, favoring the reduction of bulk defects that could act as recombination of charge carriers. Therefore, oxygen vacancies affect more the TiO2 photoactivity compared to the crystallite size or the light absorption capacity, confirming that a lower content of vacancies in the material bulk and surface doping significantly influence the activity as detected by Rietveld refinement, DRS, and XPS. The electrochemical techniques confirm that the highest photocurrent was obtained for CN-TiO2-70, whence this photoanode was chosen to carry out the CFX degradation. A point defect model simulating Nyquist plot reveals that the photoactivity depends on the speed to diffuse oxygen vacancies through the TiO2 coating. All abatement processes were followed by high-performance liquid chromatography, and Total Organic Carbon (TOC). At neutral and alkaline conditions, CFX is eliminated to levels below the analytical detection limit after 90 min of treatment (TOC removals of 87 and 91%, respectively), indicating that the coupling between the CN-TiO2-70 photocatalyst and ozone is effective in eliminating the contaminant due to parallel routes forming •OH species. Lower CFX degradation observed at acidic pH (TOC removal of 70%) is assigned to the difficulty of oxidizing protonated CFX species.

Assuntos

RESUMO

Nanofibers, which are formed by the electrospinning process, are used in a variety of applications. For this purpose, a specific diameter suited for each application is required, which is achieved by varying a set of parameters. This parameter adjustment process is empirical and works by trial and error, causing high input costs and wasting time and financial resources. In this work, an artificial neural network model is presented to predict the diameter of polyethylene nanofibers, based on the adjustment of 15 parameters. The model was trained from 105 records from data obtained from the literature and was then validated with nine nanofibers that were obtained and measured in the laboratory. The average error between the actual results was 2.29%. This result differs from those taken in an evaluation of the dataset. Therefore, the importance of increasing the dataset and the validation using independent data is highlighted.

RESUMO

OBJECTIVE: We evaluated the discriminatory ability of variations in lymphocyte, D-dimer, C-reactive protein (CRP), and lactate dehydrogenase (LDH) serum levels at 48 to 72 hours of hospitalization compared with baseline measurements to predict unfavorable clinical outcomes in patients with COVID-19. METHODS: We analyzed diagnostic test results based on a retrospective cohort to determine the ability of variations (gradients or ratios) in patients' lymphocyte, D-dimer, CRP, and LDH serum levels taken 48 to 72 hours after hospital admission to predict adverse outcomes such as death, mechanical ventilation, or intensive care unit (ICU) admission developing. RESULTS: Among 810 patients (56.1% men, age 61.6 ± 16.2 years), 37.5% had at least one adverse outcome; 28.2% required ICU admission, 26.5% required mechanical ventilation, and 19.4% died during hospitalization. In comparing baseline measurements with measurements at 48 to 72 hours, D-dimer, lymphocyte delta, LDH, and CRP had similar discriminatory ability (area under the receiver operating characteristic curve [AUC] 0.57 vs. 0.56, 0.53 vs. 0.57, 0.64 vs. 0.66, and 0.62 vs. 0.65, respectively). CONCLUSIONS: Measuring serum risk markers upon hospital admission can be used to evaluate risk of adverse outcomes in hospitalized patients with COVID-19. Repeating these measurements at 48 to 72 hours does not improve discriminatory ability.

Assuntos

RESUMO

In this study, the thermoluminescence (TL) properties of natural NaCl from Lluta, Arequipa-Peru was investigated. The number of peaks and the kinetic parameters associated with the TL glow peaks of NaCl sample after gamma-irradiation were analyzed by initial rise and deconvolution method. Defect centers induced in pure salt by gamma irradiation have been studied by electron spin resonance (ESR) with a view to identify the centers associated with the TL process in the salt. Thermal annealing experiments indicate the presence of three defect centers. Center I characterized by the g-value 2.011 is identified as an O- ion and relates with the dominant TL peak at 220 °C. Center II with a g-value of 2.0058 is attributed to a F center and is found to correlate with the 128 °C TL peak. Center III has of g-value 2.014 and is also assigned to an O- ion.

RESUMO

The aim of this study is to propose a continuous physicochemical model accounting for the active chlorine production used to degrade recalcitrant sulfamethoxazole (SMX) in an electrochemical flow reactor. The computational model describes the fluid mechanics and mass transfer occurring in the re/actor, along with the electrode kinetics of hydrogen evolution reaction arising on a stainless steel cathode, and the chloride oxidation on a DSA. Specifically, the anodic contributions assume the heterogeneous nature of the adsorbed chlorine species formed on this surface, which are a model requirement to correctly define the experimental reactor performance and degradation efficiency of the contaminant. The experimental validation conducted at different applied current densities, volumetric flows, and chloride concentrations is adequately explained by the model, thus evidencing some of the phenomena controlling the electrocatalytic chlorine production for environmental applications. The best conditions to eliminate the SMX are proposed based on the theoretical analysis of the current efficiency calculated with the model, and experimentally confirmed. The use of the Ti/RuO2-ZrO2-Sb2O3 anode at the bench scale improves the SMX removal by using electro-generated chlorine species adsorbed on its surface, which remarkably increases the oxidation potential of the system along with chlorine desorbed from the electrode. This is a technological innovation concerning other mediated oxidation methods entirely using oxidants in solution.

Assuntos

RESUMO

Urban greenspace soundscapes can contribute to the restorative effects that nature provides for the psychological and emotional health of people when certain conditions are met. The main objective of this paper is to propose practical criteria to help planners and managers in the design, development and preservation of urban greenspaces whose soundscapes may contribute to the renewal of health. Systematic literature review informed a conceptual potential Health Restoration Soundscapes (HeReS) model, based on five conditions: (1) Naturalness, (2) Sound Levels, (3) Perceived Sound Sources, (4) Soundscape Assessment, and (5) Sensescape Coherence and proposed Health Restoration Soundscapes Criteria (HeReS-C), for HeReS evaluation in urban green areas. The HeReS-C were applied in 21 sites in Argentina, Sweden, and Chile. General results are provided for all 21 sites, along with three in-depth profiles of HeReS-C applications that provide case studies across a range of resulting HeReS-C scenarios, including sites that meet the HeReS-C criteria, those that do not, and sites that could qualify in the future, if appropriate management measures are taken. HeReS-C showed to be a promising tool for the recognition of potential health-restoring soundscapes in urban greenspaces; informing their design and management to favor the well-being and health of the population.

Assuntos

RESUMO

The carbamazepine (CBZ) abatement is herein evaluated using catalytic ozonation at different NiO concentrations as catalyst: 100, 300, and 500 mg L-1, revealing its total destruction after 5 min of reaction either by conventional or catalytic ozonation. The NiO incorporation in the reactor does not increase the destruction rate, but the catalyst presence enhances the partial mineralization of the contaminant by conversion into oxalic and formic acids and the removal of total organic carbon (TOC) associated with the formation of oxidant species such as hydroxyl radical. Evidence for this behavior is the accumulation rate of the above acids which rise proportionally to the NiO concentration. The highest NiO concentration (500 mg L-1) reached a maximum TOC removal of 79.2%, which exceeds by 50% the outcome of the conventional treatment. The accumulation-decomposition profiles of oxalic and formic acids suggest the occurrence of simultaneous reaction mechanisms (hydroxyl radicals and complex formations) on the catalyst during CBZ ozonation. According to XPS analysis, the presence of nitrogen species in the NiO-ozonated was attributable to byproducts of CBZ decomposition. The toxicity bioassay based on Lactuca sativa seeds demonstrate that ozonated samples attained similar plant germination than the reference substance (water) after 120 min of treatment. This result is comparable with or without the catalyst presence, indicating the formation of non-toxic accumulated byproducts at the end of the ozonation reaction.

Assuntos

RESUMO

Pottery fragments from the Yumina archaeological site, Arequipa, Peru, were dated by means of thermoluminescence (TL) and optically stimulated luminescence (OSL). Electron paramagnetic resonance (EPR) technique was used to study the firing temperature using the iron signal (Fe3+) as a firing temperature reference. The ages of the samples were found to be between 1190 ±â€¯30 and 1240 ±â€¯80 years (777 ±â€¯80 and 827 ±â€¯30 A.D.) determined by both techniques. The firing temperature of ceramics was found to be around 550  ± 50 °C. Our study, based on the combination of TL and OSL techniques to study Yumina archaeological site pottery, will be helpful for archaeologists in Peru. With the results of this investigation, we can understand the chronology and determine the areas of dispersion and density of the archaeological occupation in the Arequipa Valley. In addition, the calculated ages are consistent with the occupation period of the Yumina archaeological site estimated by stratigraphic analysis of the potteries.

RESUMO

In the present work, carbonate samples covering wall painting of four points in the same site found at Peruaçu National Park in the extreme northwest of the state of Minas Gerais, Brazil, has been investigated and dated by thermoluminescence (TL) and electron paramagnetic resonance (EPR) techniques. The EPR spectrum of the carbonate samples presented the typical six signals due to Mn2+ ion and signals around g~2.0 due to SO2- and CO2-. The thermal stability and dose response of the EPR signals were found to be suitable for an age determination using the center due to CO2-. The carbonate sample exhibits TL peaks at approximately 350 °C. TL and EPR dating of the carbonate samples that covered the cave paintings gave an age of 33.13 to 48.40 ka. This series of dating data indicate that in the region about 220-250 km from the coast and extending from the State of Piaui, Bahia to Minas Gerais people lived around 50000 years ago.

RESUMO

Resumen El Síndrome de apnea - hipopnea obstructiva del sueño es una enfermedad con compromiso multisistémico, con especial repercusión en el sistema cardiovascular y por tanto con alto impacto en la morbimortalidad general. Se han demostrado múltiples mecanismos fisiopatológicos que explican y sugieren una asociación directa y proporcional al daño generado por esta entidad, en especial para las taquiarritmias, específicamente para fibrilación auricular y también para las bradiarrimias, con mejoría demostrada tras el tratamiento con presión positiva continua de la vía aérea. La asociación con aleteo auricular y arritmias ventriculares ha mostrado resultados contradictorios en algunos estudios, por lo que aún no es tan clara.

Abstract Obstructive sleep apnoea / hypopnoea syndrome is a disease of multisystemic involvement, with particular repercussions on the cardiovascular system, and thus a high impact on morbidity and mortality. Several pathophysiological mechanisms have been demonstrated that explain and suggest a direct and proportional relationship to the damaged caused by the condition, especially for tachyarrhythmias, specifically for atrial fibrillation, and also for bradyarrhythmias, with a demonstrated improvement with continuous positive airway pressure. As the association with atrial flutter and ventricular arrhythmias has shown contradictory results in some studies, the relationship is still not clear.

Assuntos

RESUMO

The elimination of cephalexin (CPX) using electro-generated Cl2-active on Ti/RuO2-IrO2 anode was assessed in different effluents: deionized water (DW), municipal wastewater (MWW) and urine. Single Ti/RuO2 and Ti/IrO2 catalysts were prepared to compare their morphologies and electrochemical behavior against the binary DSA. XRD and profile refinement suggest that Ti/RuO2-IrO2 forms a solid solution, where RuO2 and IrO2 growths are oriented by the TiO2 substrate through substitution of Ir by Ru atoms within its rutile-type structure. SEM reveals mud-cracked structures with flat areas for all catalysts, while EDS analysis indicates atomic ratios in the range of the oxide stoichiometries in the nominal concentrations used during synthesis. A considerably higher CPX degradation is achieved in the presence of NaCl than in Na2SO4 or Na3PO4 media due to the active chlorine generation. A faster CPX degradation is reached when the current density is increased or the pH value is lowered. This last behavior may be ascribed to an acid-catalyzed reaction between HClO and CPX. Degradation rates of 22.5, 3.96, and 0.576 µmol L-1 min-1 were observed for DW, MWW and urine, respectively. The lower efficiency measured in these last two effluents was related to the presence of organic matter and urea in the matrix. A degradation pathway is proposed based on HPLC-DAD and HPLC-MS analysis, indicating the fast formation (5 min) of CPX-(S)-sulfoxide and CPX-(R)-sulfoxide, generated due the Cl2-active attack at the CPX thioether. Furthermore, antimicrobial activity elimination of the treated solution is reached once CPX, and the initial by-products are considerably eliminated. Finally, even if only 16% of initial TOC is removed, BOD5 tests prove the ability of electro-generated Cl2-active to transform the antibiotic into biodegradable compounds. A similar strategy can be used for the abatement of other recalcitrant compounds contained in real water matrices such as urine and municipal wastewaters.

Assuntos

RESUMO

Resumen: La embolia pulmonar es una enfermedad de alta incidencia a pesar del subdiagnóstico y acarrea alto riesgo de morbilidad y mortalidad. Las herramientas preprueba actuales (clínica, escalas de probabilidad y dímero D) han permitido optimizar la precisión diagnóstica con miras a seleccionar al subgrupo de pacientes que obtendrán el mayor beneficio de la práctica de una angiotomografía para establecer el diagnóstico de embolia pulmonar. Este artículo revisa críticamente la evidencia publicada de la escala de predicción clínica PERC y el ajuste del dímero D por edad para el diagnóstico de embolia pulmonar aguda. Se hizo una revisión estructurada de la bibliografía médica en las bases de datos PubMed, TripDatabase y Epistemonikos. La búsqueda se limitó a metanálisis, estudios aleatorios, estudios de cohorte y guías de manejo, sin límites en idioma o fecha de publicación, utilizando los términos MESH d-dimer, pulmonary embolism, diagnosis y Pulmonary Embolism Rule-Out Criteria. Se hizo la lectura del título y el resumen de 1512 referencias de las que se seleccionaron 50 que fueron representativas para el tema de esta revisión; después de una clasificación y extracción de los datos se procedió a la redacción del texto. La escala PERC y el dímero D ajustado por edad son estrategias recomendadas en el abordaje diagnóstico del paciente con embolia pulmonar.

Abstract: Pulmonary embolism is a high incidence disease despite underdiagnosis and carries a high risk of morbidity and mortality. The current pre-test tools (clinical, probability scales and D-dimer) have allowed to optimize the diagnostic accuracy, since it is problematic to select the subgroup of patients who will obtain a greater benefit from the practice of an angiotomography to establish the diagnosis of pulmonary embolism. This paper reviews critically the published evidence on the PERC scale and the adjusting of the D-dimer with age for the diagnosis of acute pulmonary embolism. As structured review of the medical literature on PubMed, Tripdatabase and Epistemonikos databases was made. Search was limited to meta-analysis, randomized studies, cohort studies, review articles and treatment guidelines without limits on language or date of publication, using MESH terms: d-dimer, pulmonary embolism, diagnosis. It was performed the reading of the title and abstract of 1512 references of which 50 were selected as representative for the subject of this review. We wrote the manuscript after classification and data extraction. The use of the PERC scale and age-adjusted D-dimer are recommended in the diagnostic approach of the patient with pulmonary embolism.

RESUMO

A geochemical-environmental mapping was carried for a low polluted forest in North-western Mexico (Santiago Papasquiaro mining area), as part of the North American forests accounting for environmental behavior of arsenic (As), lead (Pb), zinc (Zn) and copper (Cu) in soil and tree components (stem wood and aciculums). Spectroscopic and microscopic techniques along with standard protocols were used to determine the mineralogical phases containing these elements, and their corresponding spatial distributions in soil and forests and mobility. In soil, total As, Pb, Zn and Cu ranged from 4.9 to 98.3, 19.6 to 768.6, 19.6 to 407.1, and 1.6 to 63.8 mg kg-1, respectively. Ultrafine particles (<5-10 µm) of arsenopyrite and sphalerite (and complex Zn-Fe phase) were the main As and Zn-bearing phases determined by SEM-EDS, respectively. Complex Pb-Cu-Fe and Cu-O oxide-like phases were the only ones containing Pb and Cu, respectively. Mobility was low for Pb, Zn and Cu, whereas a significant mobility was assessed for As. Concentrations vs. depth profiles suggested progressive accumulations of As, Pb, Zn and Cu in top soil. Total As, Pb, Zn and Cu in pine stem wood varied from 11.5 to 184.5, 98.9 to 7359.8, 3242.7 to 22197.3, 689.2 to 7179.6 µg kg-1, respectively. The respective concentrations in the pine needles ranged from 50 to 624.2, 100 to 16353.1, 120 to 46440.9 and 720 to 7200 µg kg-1, indicating an active bioaccumulation of As, Pb, Zn and Cu. A prospective environmental behavior was discussed for As, Pb, Zn and Cu in the low-polluted forest.

Assuntos

RESUMO

Chemical and surface analyses are carried out using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM-EDS), atomic force microscopy (AFM), confocal laser scanning microscopy (CLSM), glow discharge spectroscopy (GDS) and extracellular surface protein quantification to thoroughly investigate the effect of supplementary As(V) during biooxidation of arsenopyrite by Acidithiobacillus thiooxidans. It is revealed that arsenic can enhance bacterial reactions during bioleaching, which can strongly influence its mobility. Biofilms occur as compact-flattened microcolonies, being progressively covered by a significant amount of secondary compounds (S n2- , S0, pyrite-like). Biooxidation mechanism is modified in the presence of supplementary As(V), as indicated by spectroscopic and microscopic studies. GDS confirms significant variations between abiotic control and biooxidized arsenopyrite in terms of surface reactivity and amount of secondary compounds with and without As(V) (i.e. 6 µm depth). CLSM and protein analyses indicate a rapid modification in biofilm from hydrophilic to hydrophobic character (i.e. 1-12 h), in spite of the decrease in extracellular surface proteins in the presence of supplementary As(V) (i.e. stressed biofilms).

Assuntos

RESUMO

Urban soundscapes are dynamic and complex multivariable environmental systems. Soundscapes can be organized into three main entities containing the multiple variables: Experienced Environment (EE), Acoustic Environment (AE), and Extra-Acoustic Environment (XE). This work applies a multidimensional and synchronic data-collecting methodology at eight urban environments in the city of Córdoba, Argentina. The EE was assessed by means of surveys, the AE by acoustic measurements and audio recordings, and the XE by photos, video, and complementary sources. In total, 39 measurement locations were considered, where data corresponding to 61 AE and 203 EE were collected. Multivariate analysis and GIS techniques were used for data processing. The types of sound sources perceived, and their extents make up part of the collected variables that belong to the EE, i.e. traffic, people, natural sounds, and others. Sources explaining most of the variance were traffic noise and natural sounds. Thus, a Green Soundscape Index (GSI) is defined here as the ratio of the perceived extents of natural sounds to traffic noise. Collected data were divided into three ranges according to GSI value: 1) perceptual predominance of traffic noise, 2) balanced perception, and 3) perceptual predominance of natural sounds. For each group, three additional variables from the EE and three from the AE were applied, which reported significant differences, especially between ranges 1 and 2 with 3. These results confirm the key role of perceiving natural sounds in a town environment and also support the proposal of a GSI as a valuable indicator to classify urban soundscapes. In addition, the collected GSI-related data significantly helps to assess the overall soundscape. It is noted that this proposed simple perceptual index not only allows one to assess and classify urban soundscapes but also contributes greatly toward a technique for separating environmental sound sources.

Assuntos

RESUMO

Water extraction from the underground aquifers of the Pampa del Tamarugal (Atacama Desert, Chile) reduced the growing area of Prosopis tamarugo, a strict phreatic species endemic to northern Chile. The objective of this work was to evaluate the effect of various architectural and morpho-physiological traits adjustment of P. tamarugo subjected to three groundwater depletion intervals (GWDr): <1 m (control), 1-4 m and 6-9 m. The traits were evaluated at three levels, plant [height, trunk cross-section area, leaf fraction (fGCC), and crown size], organ [length of internodes, leaf mass per unit area (LMA), leaflet mass and area], and tissue level [wood density (WD), leaf 13C, 18O isotope composition (δ), and intrinsic water use efficiency (iWUE)]. In addition, soil water content (VWC) to 1.3 m soil depth, pre-dawn and midday water potential difference (ΔΨ), and stomatal conductance (gs) were evaluated. At the deeper GWDr, P. tamarugo experienced significant growth restriction and reduced fGCC, the remaining canopy had a significantly higher LMA associated with smaller leaflets. No differences in internode length and WD were observed. Values for δ13C and δ18O indicated that as GWDr increased, iWUE increased as a result of partial stomata closure with no significant effect on net assimilation over time. The morpho-physiological changes experienced by P. tamarugo allowed it to acclimate and survive in a condition of groundwater depletion, keeping a functional but diminished canopy. These adjustments allowed maintenance of a relatively high gs; ΔΨ was not different among GWDrs despite smaller VWC at greater GWDr. Although current conservation initiatives of this species are promising, forest deterioration is expected continue as groundwater depth increases.