RESUMO

Scavenging is a key process for the cycling of nutrients in ecosystems, yet it is still neglected in the ecological literature. Apart from the importance of specific groups of animals in scavenging, there have been few ecological studies that compare them. Furthermore, the ecological studies on scavenging have mainly focused on vertebrates despite the crucial importance of invertebrates in this process. Here, we performed a large-scale ant suppression and vertebrate exclusion experiment to quantify the relative contribution of ants, non-ant invertebrates and vertebrates in scavenging nitrogen-rich (insect carcasses) and carbon-rich (seeds) baits in two contrasting mountainous habitats in Brazil (grasslands and forests). Overall, bait removal was 23.2% higher in forests than in grasslands. Ants were the primary scavengers in grasslands, responsible for more than 57% of dead insect larvae and seed removal, while, in forests, non-ant invertebrates dominated, removing nearly 65% of all baits. Vertebrates had a minor role in scavenging dead insect larvae and seeds in both habitats, with <4% of removals. Furthermore, our results show that animal-based baits were more consumed in forests than seeds, and both resources were equally consumed in grasslands. Therefore, we demonstrate the superiority of invertebrates in this process, with a particular emphasis on the irreplaceable role of ants, especially in this grassland ecosystem. As such, we further advance our knowledge of a key ecosystem process, showing the relative importance of three major groups in scavenging and the differences in ecosystems functioning between two contrasting tropical habitats.

Assuntos

RESUMO

Myrmecochory-seed dispersal by ants-is a mutualistic interaction in which ants attracted by seed appendices take them away from the parental plant location, where seeds usually have better development odds. Not all ant species benefit plants, and the mechanisms of those divergent outcomes are still unclear, especially from the perspective of microbial third parties. Here, we explore the effects of seed manipulation on fungi communities promoted by two ant species with contrasting effects on seed germination and antimicrobial cleaning strategies. We hypothesize that: i) fungi richness is higher in seeds manipulated by Acromyrmex subterraneus (species that negatively affect seed germination), followed by unmanipulated seeds and seeds manipulated by Atta sexdens (ant species that increase seed germination) and ii) seeds manipulated by A. sexdens, Ac. subterraneus and unmanipulated seeds present dissimilar fungi compositions. We identified fungal morphotypes in three groups of seeds: i) manipulated by A. sexdens; ii) manipulated by Ac. subterraneus; iii) unmanipulated. Seeds manipulated by Ac. subterraneus exhibited higher fungal richness than those manipulated by A. sexdens and unmanipulated seeds, indicating that the ant species known to impair germination increases the fungal load on seeds. Additionally, we found that A. sexdens ants were unable to reduce fungal richness compared to unmanipulated seeds. Furthermore, fungal composition differed among all three treatments. Our results underscore the significance of ant species identity in shaping the fungal communities associated with myrmecochorous seeds. Given the potential influence of microbial infection on seed fate, we suggest considering manipulation strategies when evaluating the overall quality of an ant as a seed disperser.

Assuntos

RESUMO

BACKGROUND: SARS-CoV2 induces flu-like symptoms that can rapidly progress to severe acute lung injury and even death. The virus also invades the central nervous system (CNS), causing neuroinflammation and death from central failure. Intravenous (IV) or oral dexamethasone (DXM) reduced 28 d mortality in patients who required supplemental oxygen compared to those who received conventional care alone. Through these routes, DMX fails to reach therapeutic levels in the CNS. In contrast, the intranasal (IN) route produces therapeutic levels of DXM in the CNS, even at low doses, with similar systemic bioavailability. AIMS: To compare IN vs. IV DXM treatment in hospitalized patients with COVID-19. METHODS: A controlled, multicenter, open-label trial. Patients with COVID-19 (69) were randomly assigned to receive IN-DXM (0.12 mg/kg for three days, followed by 0.6 mg/kg for up to seven days) or IV-DXM (6 mg/d for 10 d). The primary outcome was clinical improvement, as defined by the National Early Warning Score (NEWS) ordinal scale. The secondary outcome was death at 28 d between IV and IN patients. Effects of both treatments on biochemical and immunoinflammatory profiles were also recorded. RESULTS: Initially, no significant differences in clinical severity, biometrics, and immunoinflammatory parameters were found between both groups. The NEWS-2 score was reduced, in 23 IN-DXM treated patients, with no significant variations in the 46 IV-DXM treated ones. Ten IV-DXM-treated patients and only one IN-DXM patient died. CONCLUSIONS: IN-DMX reduced NEWS-2 and mortality more efficiently than IV-DXM, suggesting that IN is a more efficient route of DXM administration.

Assuntos

RESUMO

Background: Congenital heart disease (CHD) survival rate has improved dramatically due to advances in diagnostic and therapeutic techniques. However, concerning the unrepaired CHD population of moderate and severe complexity, the data regarding risk predictors and surgical outcomes are scarce. Our aim was to describe the surgical results and predictors of in-hospital outcomes in adult patients with moderate-to-severe complexity CHD that were not repaired in childhood. Methods: We conducted a retrospective cohort study that included 49 adult patients with moderate-to-complex CHD who were treated in a single medical centre. Clinical and echocardiographic variables were obtained on admission, after surgical procedures and during follow-up. Results: Most of the patients were female (66%). Left ventricular ejection fraction and right ventricular outflow tract fractional shortening were within the normal range. The median pulmonary artery systolic pressure was 37 (27-55) mm Hg. The median time was 118 (80-181) minutes for extracorporeal circulation and 76 (49-121) minutes for aortic cross-clamping. The most frequent complication was postoperative complete atrioventricular block (12.2%). In-hospital survival rate was 87.7%. The development of low cardiac output syndrome with predominant right ventricle failure in the postoperative period was the most important predictor of in-hospital death (P = 0.03). Conclusions: Deciding to treat adults with CHD is challenging in moderate and severe unrepaired cases. Adequate clinical, functional, and imaging evaluation is essential to determine each patient's suitability for surgical management and to achieve the best clinical outcome for this population.

Contexte: Grâce aux avancées réalisées en matière de techniques diagnostiques et thérapeutiques, la survie des patients atteints d'une cardiopathie congénitale s'est considérablement améliorée. Cependant, en ce qui concerne les personnes atteintes d'une cardiopathie congénitale non corrigée présentant une complexité modérée ou extrême, les données portant sur les facteurs de risque prédictifs ainsi que sur les résultats chirurgicaux sont rares. Notre objectif était de décrire les résultats chirurgicaux ainsi que les facteurs prédictifs des résultats obtenus en milieu hospitalier chez les patients adultes atteints d'une cardiopathie congénitale présentant une complexité modérée ou extrême qui n'a pas été corrigée pendant l'enfance. Méthodologie: Nous avons mené une étude de cohorte rétrospective comprenant 49 patients adultes atteints d'une cardiopathie congénitale modérée ou complexe qui ont reçu leurs traitements dans un seul centre médical. Les variables cliniques et échocardiographiques ont été obtenues au moment de l'admission, après les interventions chirurgicales et pendant la période de suivi. Résultats: Les patients étaient en majorité des femmes (66 %). La fraction d'éjection du ventricule gauche ainsi que la fraction de raccourcissement de la voie d'éjection ventriculaire droite sont demeurées dans les limites de la normale. La pression systolique médiane de l'artère pulmonaire a été de 37 mmHg (27-55 mmHg). Le temps médian écoulé pour la circulation extracorporelle a été de 118 minutes (80-181 minutes) et pour le clampage de la crosse aortique, de 76 minutes (49-121 minutes). Le bloc auriculo-ventriculaire postopératoire complet a été la complication la plus fréquente (12,2 %). Le taux de survie en milieu hospitalier a été de 87,7 %. Le développement du syndrome du faible débit cardiaque accompagné d'une insuffisance prédominante du ventricule droit durant la période postopératoire a constitué le principal facteur prédictif de décès à l'hôpital (p = 0,03). Conclusion: Il est difficile de traiter les adultes qui présentent une cardiopathie congénitale modérée ou sévère non corrigée. Il est essentiel que les évaluations cliniques, fonctionnelles et par imagerie soient réalisées de façon adéquate pour déterminer si une prise en charge chirurgicale convient aux patients et pour garantir les meilleurs résultats cliniques chez ces derniers.

RESUMO

BACKGROUND: The impact of cirrhosis and portal hypertension on perioperative outcomes of minimally invasive left lateral sectionectomies remains unclear. We aimed to compare the perioperative outcomes between patients with preserved and compromised liver function (noncirrhotics versus Child-Pugh A) when undergoing minimally invasive left lateral sectionectomies. In addition, we aimed to determine if the extent of cirrhosis (Child-Pugh A versus B) and the presence of portal hypertension had a significant impact on perioperative outcomes. METHODS: This was an international multicenter retrospective analysis of 1,526 patients who underwent minimally invasive left lateral sectionectomies for primary liver malignancies at 60 centers worldwide between 2004 and 2021. In the study, 1,370 patients met the inclusion criteria and formed the final study group. Baseline clinicopathological characteristics and perioperative outcomes of these patients were compared. To minimize confounding factors, 1:1 propensity score matching and coarsened exact matching were performed. RESULTS: The study group comprised 559, 753, and 58 patients who did not have cirrhosis, Child-Pugh A, and Child-Pugh B cirrhosis, respectively. Six-hundred and thirty patients with cirrhosis had portal hypertension, and 170 did not. After propensity score matching and coarsened exact matching, Child-Pugh A patients with cirrhosis undergoing minimally invasive left lateral sectionectomies had longer operative time, higher intraoperative blood loss, higher transfusion rate, and longer hospital stay than patients without cirrhosis. The extent of cirrhosis did not significantly impact perioperative outcomes except for a longer duration of hospital stay. CONCLUSION: Liver cirrhosis adversely affected the intraoperative technical difficulty and perioperative outcomes of minimally invasive left lateral sectionectomies.

Assuntos

RESUMO

Condyloma acuminatum is a common clinical outcome of human papillomavirus (HPV) in men. A prospective investigation was performed of the clinical and molecular profile of 122 patients with condyloma acuminatum treated by the Brazilian public healthcare system. The patients were evaluated clinically. The fragments were submitted to molecular analysis for the identification of HPV genotypes. A total of 104 (85.2%) patients presented multiple warts and 18 (14.8%) presented a single wart. The predominant location was the body of the penis (48.4% of cases of multiple warts and 7.4% of cases of single warts), and 49 (40.2%) cases were recurrences and 73 (59.8%) were initial occurrences. Regarding sexual activity, 56 patients (45.9%) had multiple partners and 65 (53.3%) had a single partner. The most frequent genotype was HPV6 (70%). In conclusion, the most frequent anatomic location of condyloma acuminatum was the body of the penis in the present sample. The present findings suggest that the natural history of infection by HPV is not yet completely known and that greater care is needed to ensure clinical safety in the follow-up of these patients due to the oncogenic potential.

RESUMO

BACKGROUND: By end December of 2021, COVID-19 has infected around 276 million individuals and caused over 5 million deaths worldwide. Infection results in dysregulated systemic inflammation, multi-organ dysfunction, and critical illness. Cells of the central nervous system are also affected, triggering an uncontrolled neuroinflammatory response. Low doses of glucocorticoids, administered orally or intravenously, reduce mortality among moderate and severe COVID-19 patients. However, low doses administered by these routes do not reach therapeutic levels in the CNS. In contrast, intranasally administered dexamethasone can result in therapeutic doses in the CNS even at low doses. METHODS: This is an approved open-label, multicenter, randomized controlled trial to compare the effectiveness of intranasal versus intravenous dexamethasone administered in low doses to moderate and severe COVID-19 adult patients. The protocol is conducted in five health institutions in Mexico City. A total of 120 patients will be randomized into two groups (intravenous vs. intranasal) at a 1:1 ratio. Both groups will be treated with the corresponding dexamethasone scheme for 10 days. The primary outcome of the study will be clinical improvement, defined as a statistically significant reduction in the NEWS-2 score of patients with intranasal versus intravenous dexamethasone administration. The secondary outcome will be the reduction in mortality during hospitalization. CONCLUSIONS: This protocol is currently in progress to improve the efficacy of the standard therapeutic dexamethasone regimen for moderate and severe COVID-19 patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT04513184 . Registered November 12, 2020. Approved by La Comisión Federal para la Protección contra Riesgos Sanitarios (COFEPRIS) with identification number DI/20/407/04/36. People are currently being recruited.

Assuntos

RESUMO

INTRODUCTION: Lung ultrasound (LUS) implementation in patients with COVID-19 can help to establish the degree of pulmonary involvement, evaluate treatment response and estimate in-hospital outcome. OBJECTIVE: To evaluate the application of a LUS protocol in patients with COVID-19 infection to predict in-hospital mortality. METHODS: The study was carried out from April 1 to August 1, 2020 in patients with COVID-19 infection admitted to the Intensive Care Unit. Lung evaluation was carried out by physicians trained in critical care ultrasonography. RESULTS: Most patients were males, median age was 56 years, and 59 % required mechanical ventilation. In-hospital mortality was 39.4 %, and in those with a LUS score ≥ 19, mortality was higher (50 %). The multiple logistic regression model showed that a LUS score ≥ 19 was significantly associated with mortality (hazard ratio = 2.55, p = 0.01). CONCLUSIONS: LUS is a safe and fast clinical tool that can be applied at bedside in patients with COVID-19 infection to establish the degree of parenchymal involvement and predict mortality.

INTRODUCCIÓN: La implementación del ultrasonido pulmonar (LUS) en los pacientes con COVID-19 puede ayudar a establecer el grado de afectación pulmonar, evaluar la respuesta al tratamiento y estimar el desenlace intrahospitalario. OBJETIVO: Evaluar la aplicación de un protocolo LUS en pacientes con infección por COVID-19 para predecir mortalidad intrahospitalaria. MÉTODOS: El estudio se realizó del 1 de abril al 1 de agosto de 2020 en pacientes con infección por COVID-19, ingresados en la Unidad de Terapia Intensiva. Se realizó evaluación pulmonar por médicos entrenados en ultrasonografía crítica. RESULTADOS: La mayoría de los pacientes fue del sexo masculino, la edad mediana fue de 56 años y 59 % requirió ventilación mecánica. La mortalidad intrahospitalaria fue de 39.4 % y en aquellos con puntuación de LUS ≥ 19, de 50 %. El modelo de regresión logística múltiple mostró que la puntuación de LUS ≥ 19 se asoció significativamente a mortalidad (cociente de riesgo = 2.55, p = 0.01). CONCLUSIONES: El LUS es una herramienta clínica segura y rápida que puede realizarse al lado de la cama de los pacientes con infección por COVID-19, para establecer el grado de afectación parenquimatosa y predecir la mortalidad.

Assuntos

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) frequently involves cardiovascular manifestations such as right ventricular (RV) dysfunction and alterations in pulmonary hemodynamics. We evaluated the application of the critical care ultrasonography ORACLE protocol to identify the most frequent alterations and their influence on adverse outcomes, especially those involving the RV (dilatation and dysfunction). METHODS: This cross-sectional study included 204 adult patients with confirmed COVID-19 admitted at three centers. Echocardiography and lung ultrasound images were acquired on admission using the ORACLE ultrasonography algorithm. RESULTS: Two-hundred and four consecutive patients were evaluated: 22 (11.9%) demonstrated a fractional shortening of < 35%; 33 (17.1%) a tricuspid annular plane systolic excursion (TAPSE) of < 17 mm; 26 (13.5%) a tricuspid peak systolic S wave tissue Doppler velocity of < 9.5 cm/sec; 69 (37.5%) a RV basal diameter of > 41 mm; 119 (58.3%) a pulmonary artery systolic pressure (PASP) of > 35 mm Hg; and 14 (11%) a TAPSE/PASP ratio of < .31. The in-hospital mortality rate was 37.6% (n = 71). Multiple logistic regression modeling showed that PASP > 35 mm Hg, RV FS of < 35%, TAPSE < 17 mm, RV S wave < 9.5, and TAPSE/PASP ratio < .31 mm/mm Hg were associated with this outcome. PASP and the TAPSE/PASP ratio had the lowest feasibility of being obtained among the investigators (62.2%). CONCLUSION: The presence of RV dysfunction, pulmonary hypertension, and alteration of the RV-arterial coupling conveys an increased risk of in-hospital mortality in patients presenting with COVID-19 upon admission; therefore, searching for these alterations should be routine. These parameters can be obtained quickly and safely with the ORACLE protocol.

Assuntos

RESUMO

Resumen Introducción: La implementación del ultrasonido pulmonar (LUS) en los pacientes con COVID-19 puede ayudar a establecer el grado de afectación pulmonar, evaluar la respuesta al tratamiento y estimar el desenlace intrahospitalario. Objetivo: Evaluar la aplicación de un protocolo LUS en pacientes con infección por COVID-19 para predecir mortalidad intrahospitalaria. Métodos: El estudio se realizó del 1 de abril al 1 de agosto de 2020 en pacientes con infección por COVID-19, ingresados en la Unidad de Terapia Intensiva. Se realizó evaluación pulmonar por médicos entrenados en ultrasonografía crítica. Resultados: La mayoría de los pacientes fue del sexo masculino, la edad mediana fue de 56 años y 59 % requirió ventilación mecánica. La mortalidad intrahospitalaria fue de 39.4 % y en aquellos con puntuación de LUS ≥ 19, de 50 %. El modelo de regresión logística múltiple mostró que la puntuación de LUS ≥ 19 se asoció significativamente a mortalidad (cociente de riesgo = 2.55, p = 0.01). Conclusiones: El LUS es una herramienta clínica segura y rápida que puede realizarse al lado de la cama de los pacientes con infección por COVID-19, para establecer el grado de afectación parenquimatosa y predecir la mortalidad.

Abstract Introduction: Lung ultrasound (LUS) implementation in patients with COVID-19 can help to establish the degree of pulmonary involvement, evaluate treatment response and estimate in-hospital outcome. Objective: To evaluate the application of LUS in patients with COVID-19 infection to predict in-hospital mortality. Methods: The study was carried out from April 1 to August 1, 2020 in patients with COVID-19 infection admitted to the Intensive Care Unit. Lung evaluation was carried out by physicians trained in critical care ultrasonography. Results: Most patients were males, median age was 56 years, and 59 % required mechanical ventilation. In-hospital mortality was 39.4 %, and in those with a LUS score ≥ 19, mortality was higher (50 %). The multiple logistic regression model showed that a LUS score ≥ 19 was significantly associated with mortality (hazard ratio = 2.55, p = 0.01). Conclusions: LUS is a safe and fast clinical tool that can be applied at bedside in patients with COVID-19 infection to establish the degree of parenchymal involvement and predict mortality.

Assuntos

RESUMO

Territoriality is costly, and the accurate identification of intruders and the decision to perform aggressive responses are key behavioral traits in social animals. We studied aggression among individuals belonging to close and distant nests of the plant-ant Azteca muelleri, which lives in stems of the pioneer tree Cecropia glaziovii. More specifically, we aim to investigate if the DE (dear-enemy effect-less aggression towards neighbors than strangers) or NN (nasty-neighbor effect-less aggression to strangers than neighbors) effects or even none of them apply for this iconic Azteca-Cecropia system. We further checked if ant aggression towards conspecifics is related to cuticular hydrocarbon profiles (CHCs), which provide chemical cues for nestmate recognition. Therefore, we sampled 46 nests of A. muelleri in three Brazilian Atlantic forest fragments and performed behavioral trials within and between sites. Consistently with the DE effect, we found higher aggression levels in 'between sites' versus 'within sites' treatments as well as a positive effect of spatial distance on ant aggressiveness. We found no effect of the overall dissimilarities on CHC blend on ant aggressiveness, but of one CHC class, the methylated alkanes. Overall, we provide key insights on nest-mate recognition in obligatory ant-plant mutualisms.

RESUMO

Herbivory is ubiquitous. Despite being a potential driver of plant distribution and performance, herbivory remains largely undocumented. Some early attempts have been made to review, globally, how much leaf area is removed through insect feeding. Kozlov et al., in one of the most comprehensive reviews regarding global patterns of herbivory, have compiled published studies regarding foliar removal and sampled data on global herbivory levels using a standardized protocol. However, in the review by Kozlov et al., only 15 sampling sites, comprising 33 plant species, were evaluated in tropical areas around the globe. In Brazil, which ranks first in terms of plant biodiversity, with a total of 46,097 species, almost half (43%) being endemic, a single data point was sampled, covering only two plant species. In an attempt to increase knowledge regarding herbivory in tropical plant species and to provide the raw data needed to test general hypotheses related to plant-herbivore interactions across large spatial scales, we proposed a joint, collaborative network to evaluate tropical herbivory. This network allowed us to update and expand the data on insect herbivory in tropical and temperate plant species. Our data set, collected with a standardized protocol, covers 45 sampling sites from nine countries and includes leaf herbivory measurements of 57,239 leaves from 209 species of vascular plants belonging to 65 families from tropical and temperate regions. They expand previous data sets by including a total of 32 sampling sites from tropical areas around the globe, comprising 152 species, 146 of them being sampled in Brazil. For temperate areas, it includes 13 sampling sites, comprising 59 species. Thus, when compared to the most recent comprehensive review of insect herbivory (Kozlov et al.), our data set has increased the base of available data for the tropical plants more than 460% (from 33 to 152 species) and the Brazilian sampling was increased 7,300% (from 2 to 146 species). Data on precise levels of herbivory are presented for more than 57,000 leaves worldwide. There are no copyright restrictions. Please cite this paper when using the current data in publications; the authors request to be informed how the data is used in the publications.

RESUMO

Abstract The planning of a new thermal power plant is linked to the various decision elements and evaluation criteria. Factors such as the plant's geographic positioning, primary energy supply points, paths, and means of delivery of this primary energy should be analyzed. Similar studies are imposed when studying the change of a thermoelectric plant's primary energy source occurs. In Brazil, several plants are currently investigating the exchange of their primary fuel from oil to gas due to the decrees issued by ANEEL. This paper presents software, which uses virtual reality to assist in the various stages of the planning process and in the analyses that must be performed. This software was developed for the Hidrotermica Group and had as the primary target the Borborema Thermoelectric Power Plant.

RESUMO

Abstract The multicriteria decision-making process is still an open problem, especially when the decision criteria are not numerical or fully outlined. Several numerical, intelligent, or hybrid techniques have been developed, creating contributions to this problem's solution. This paper is another step in this direction. Based on the Modified Analytic Hierarchy Process (MAHP), a methodology for diagnosis and performance analysis is presented for the dispatch ranking of generating units in a thermoelectric plant. The problem is complex because it covers a power plant, where 99 generating units may be dispatched, according to 10 possible evaluation criteria, which should be used together. This article also presents details of the implementation of the sensors necessary to add to the supervisory system existing in the Palmeiras de Goias Thermal Power Plant.

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) is characterized by severe lung involvement and hemodynamic alterations. Critical care ultrasonography is vital because it provides real time information for diagnosis and treatment. Suggested protocols for image acquisition and measurements have not yet been evaluated. METHODS: This cross-sectional study was conducted at two centers from 1 April 2020 to 30 May 2020 in adult patients with confirmed COVID-19 infection admitted to the critical care unit. Cardiac and pulmonary evaluations were performed using the ORACLE protocol, specifically designed for this study, to ensure a structured process of image acquisition and limit staff exposure to the infection. RESULTS: Eighty-two consecutively admitted patients were evaluated. Most of the patients were males, with a median age of 56 years, and the most frequent comorbidities were hypertension and type 2 diabetes, and 25% of the patients had severe acute respiratory distress syndrome. The most frequent ultrasonographic findings were elevated pulmonary artery systolic pressure (69.5%), E/e' ratio > 14 (29.3%), and right ventricular dilatation (28%) and dysfunction (26.8%). A high rate of fluid responsiveness (82.9%) was observed. The median score (19 points) on pulmonary ultrasound did not reveal any variation between the groups. Elevated pulmonary artery systolic pressure was associated with higher in-hospital mortality. CONCLUSION: The ORACLE protocol was a feasible, rapid, and safe bedside tool for hemodynamic and respiratory evaluation of patients with COVID-19. Further studies should be performed on the alteration in pulmonary hemodynamics and right ventricular function and its relationship with outcomes.

Assuntos

RESUMO

Myrmecochory (seed dispersal by ants) is a unique seed dispersal syndrome among invertebrates. It comprises three main phases: seed removal, seed manipulation, and seed deposition. However, the contribution of each phase to seed and seedling fate remains unclear. Here, we experimentally quantified the effects of each phase of myrmecochory on seed germination and seedling establishment, the two most critical life history stages involved in plant recruitment. We established 30 sample points, and each included an adult Mabea fistulifera tree, an Atta sexdens nest entrance, and six seed depots. We monitored the germination of M. fistulifera seeds for 3 months and subsequently followed the growth and mortality of the resulting seedlings for 12 months. Only the dispersal distance influenced plant establishment, reducing seed germination and increasing seedling growth, but with no effect of seed manipulation and deposition site. Despite the contrasting effects of distance on seed germination and seedling growth, the positive effect of dispersal distance on seedling growth was ten times greater than the negative effect on seed germination. Moreover, A. sexdens behaved neither as granivore nor as herbivore of M. fistulifera seeds or seedlings, which suggests that seed dispersal by A. sexdens is advantageous to M. fistulifera. Thus, the joint occurrence of these two species in disturbed areas could have a positive effect on this pioneer plant population, which might promote forest regeneration.

Assuntos

RESUMO

INTRODUCTION: Different blood meal sources can affect biology of triatomines. METHODS: We studied the influence of two different blood meal sources (rabbits and hens) on five biological parameters in Meccus phyllosomus pallidipennis and collected biological parameters. RESULTS: The cohort fed on rabbits had a shorter median life-cycle and lower mortality rate than that fed on hens. Both cohorts required a similar number of blood meals to reach adulthood. Median longevity and number of blood meals for adults were similar between both cohorts. CONCLUSIONS: The studied parameters reflect the high grade of adaptation of M. p. pallidipennis feeding on different hosts.

Assuntos

RESUMO

Unfortunately, the detailed description of the ESM material went wrong in the published version of the dataset.

RESUMO

One of the major challenges in ecology is to understand the relative importance of neutral- and niche-based processes structuring species interactions within communities. The concept of neutral-based processes posits that network structure is a result of interactions between species based on their abundance. On the other hand, niche-based processes presume that network structure is shaped by constraints to interactions. Here, we evaluated the relative importance of neutral-based process, represented by species' abundance (A) and fruit production (F) models, and niche-based process, represented by spatial overlap (S), temporal overlap (T) and morphological barrier (M) models, in shaping the structure of a bird-seed dispersal network from the Brazilian Atlantic Forest. We evaluated the ability of each model, singly or in combination, to predict the general structure [represented by connectance, nestedness (NODF), weight nestedness (WNODF), interaction evenness and complementary specialization] and microstructure of the network (i.e., the frequency of pairwise interactions). Only nestedness (both NODF and WNODF) was predicted by at least one model. NODF and WNODF were predicted by a neutral-based process (A), by a combination of niche-based processes (ST and STM) and by both neutral- and niche-based processes (AM). NODF was also predicted by F and FM model. Regarding microstructure, temporal overlap (T) was the most parsimonious model able to predict it. Our findings reveal that a combination of neutral- and niche-based processes is a good predictor of the general structure (NODF and WNODF) of the bird-seed dispersal network and a niche-based process is the best predictor of the network's microstructure.

Assuntos

RESUMO

Abstract INTRODUCTION: Different blood meal sources can affect biology of triatomines. METHODS: We studied the influence of two different blood meal sources (rabbits and hens) on five biological parameters in Meccus phyllosomus pallidipennis and collected biological parameters. RESULTS: The cohort fed on rabbits had a shorter median life-cycle and lower mortality rate than that fed on hens. Both cohorts required a similar number of blood meals to reach adulthood. Median longevity and number of blood meals for adults were similar between both cohorts. CONCLUSIONS The studied parameters reflect the high grade of adaptation of M. p. pallidipennis feeding on different hosts.

Assuntos