RESUMEN
The aim of this systematic review was to determine whether antibiotics, compared to placebo, can prevent infection or dry socket after third molar surgery. A systematic review and network meta-analysis (NMA) was performed following registration of the protocol (CRD42021276266). Four databases and the grey literature were searched, and papers were selected based on the PICOS question. RoB 2 and GRADE were used to evaluate the risk of bias and certainty of the evidence, respectively. The NMA was performed using Stata. Of 58 randomized clinical trials identified, 34 were included in the NMA. Patients treated with amoxicillin (relative risk (RR) 0.56, 95% confidence interval (CI) 0.38-0.84; low quality of evidence) and those treated with metronidazole (RR 0.51, 95% CI 0.31-0.84; low quality of evidence) showed a lower risk of infection and dry socket when compared to patients given a placebo. Postoperative amoxicillin (750 mg) and amoxicillin plus clavulanate (500 mg + 125 mg, or 2000 mg + 125 mg), and preoperative metronidazole (800 mg) are useful to prevent infection or dry socket when compared to placebo. The low rate of infection after third molar surgery, the correct concept of antibiotic prophylaxis, and antibiotic resistance must be taken into account when choosing to treat healthy patients undergoing third molar surgery with antibiotics.
Asunto(s)
Alveolo Seco , Tercer Molar , Amoxicilina/uso terapéutico , Combinación Amoxicilina-Clavulanato de Potasio/uso terapéutico , Antibacterianos/uso terapéutico , Profilaxis Antibiótica , Humanos , Metronidazol/uso terapéutico , Tercer Molar/cirugía , Metaanálisis en RedRESUMEN
We discuss how different accelerator-based techniques can be employed synergistically as a powerful analytical tool for forensic studies of foodstuff. Brazilian and Jamaican coffees were chosen as a showcase due to its popularity and potential risk of adulteration and/or falsification. Comprehensive characterization of major and trace elements, age since production and compound contents were achieved using different techniques, including PIXE (Particle-Induced X-ray Emission), FTIR (Fourier Transform Infrared), and AMS-14C (Accelerator Mass Spectrometry - Radiocarbon Analysis). While PIXE provides information on the elements present in the samples, FTIR probes the types of compounds through their vibrational spectra. Finally, AMS-14C is capable of dating organic samples regarding their harvesting time. Five different laboratories from research institutions around the world took part in the experiments. The integration of the results obtained with different techniques provided multifaceted perspectives on the coffee under study, thus allowing a direct assessment of the material for forensic purposes such as authentication, determination of provenance, and combat counterfeiting.
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Café , Oligoelementos , Brasil , Contaminación de Medicamentos , Espectrometría de Masas/métodosRESUMEN
Bovine anaplasmosis causes considerable economic losses in dairy cattle production systems worldwide, ranging from $300 million to $900 million annually. It is commonly detected through rectal temperature, blood smear microscopy, and packed cell volume (PCV). Such methodologies are laborious, costly, and difficult to systematically implement in large-scale operations. The objectives of this study were to evaluate (1) rumination and activity data collected by Hr-Tag sensors (SCR Engineers Ltd.) in heifer calves exposed to anaplasmosis; and (2) the predictive ability of recurrent neural networks in early identification of anaplasmosis. Additionally, we aimed to investigate the effect of time series length before disease diagnosis (5, 7, 10, or 12 consecutive days) on the predictive performance of recurrent neural networks, and how early anaplasmosis disease can be detected in dairy calves (5, 3, and 1 d in advance). Twenty-three heifer calves aged 119 ± 15 (mean ± SD) d and weighing 148 ± 20 kg of body weight were challenged with 2 × 107 erythrocytes infected with UFMG1 strain (GenBank no. EU676176) isolated from Anaplasma marginale. After inoculation, animals were monitored daily by assessing PCV. The lowest PCV value (14 ± 1.8%) and the finding of rickettsia on blood smears were used as a criterion to classify an animal as sick (d 0). Rumination and activity data were collected continuously and automatically at 2-h intervals, using SCR Heatime Hr-Tag collars. Two time series were built including last sequence of -5, -7, -10, or -12 d preceding d 0 or a sequence of 5, 7, 10, or 12 d randomly selected in a window from -50 to -15 d before d 0 to ensure a sequence of days in which PCV was considered normal (32 ± 2.4%). Long short-term memory was used as a predictive approach, and a leave-one-animal-out cross-validation (LOAOCV) was used to assess prediction quality. Anaplasmosis disease reduced 34 and 11% of rumination and activity, respectively. The accuracy, sensitivity, and specificity of long short-term memory in detecting anaplasmosis ranged from 87 to 98%, 83 to 100%, and 83 to 100%, respectively, using rumination data. For activity data, the accuracy, sensitivity, and specificity varied from 70 to 98%, 61 to 100%, and 74 to 100%, respectively. Predictive performance did not improve when combining rumination and activity. The use of longer time-series did not improve the performance of models to predict anaplasmosis. The accuracy and sensitivity in predicting anaplasmosis up to 3 d before clinical diagnosis (d 0) were greater than 80%, confirming the possibility for early identification of anaplasmosis disease. These findings indicate the great potential of wearable sensors in early identification of anaplasmosis diseases. This could positively affect the profitability of dairy farmers and animal welfare.
Asunto(s)
Anaplasma marginale , Anaplasmosis , Enfermedades de los Bovinos , Anaplasmosis/diagnóstico , Anaplasmosis/microbiología , Animales , Bovinos , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/microbiología , Eritrocitos , Femenino , Vacunación/veterinariaRESUMEN
Objetivos: Identificar estratégias para melhorar conhecimentos, atitudes e práticas (CAP) sobre medidas de prevenção e controle da COVID-19 no mundo.Métodos: Foi realizada uma revisão sistemática de evidência quantitativa e qualitativa com busca nas bases de dados PubMed, LILACS e Scopus. A qualidade do relato e da metodologia dos estudos incluídos foi avaliada por meio da ferramenta do Joanna Briggs Institute.Resultados: De 2.196 registros identificados na busca, 12 estudos foram incluídos. A maioria avaliou estratégias educacionais (n=10), principalmente treinamentos baseados em simulação (n=6) para profissionais de saúde (n=9). Independente da estratégia ou público, todos os estudos identificaram melhorias em conhecimento (n=7), prática (n=7) e atitude (n=4). Entretanto, todos os estudos apresentaram pelo menos uma limitação de qualidade.Conclusões: Estratégias efetivas foram identificadas para melhorar CAP na prevenção e controle da COVID-19, especialmente para profissionais de saúde com treinamento baseado em simulação (baixa qualidade). (AU)
Objectives: To identify strategies to improve knowledge, attitude, and practice (KAP) about prevention and control measures of COVID-19 in the world.Method: A systematic review of quantitative and qualitative evidence was conducted, searching PubMed, LILACS and Scopus databases. Reporting and methodological quality of the included studies was assessed using the Joanna Briggs Institute tool.Results: Of 2,196 records identified in the search, 12 studies were included. Most studies evaluated educational strategies (n=10), mainly training based on simulation (n=6) for health professionals (n=9). Regardless of strategy or audience, all studies identified improvements in knowledge (n=7), practice (n=7), and attitude (n=4). However, all studies presented at least one quality limitation.Conclusions: Effective strategies have been identified to improve CAP in the prevention and control of COVID-19, especially aimed at healthcare professionals with simulation-based training (low quality). (AU)
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Humanos , Salud Pública , Educación en Salud , Coronavirus , Infecciones , TerapéuticaRESUMEN
The aim of this review was to compare mandibular angle fracture fixation methods that were evaluated through randomized clinical trials considering postoperative complications. Additionally, different treatment methods were ranked based on their performance. A systematic review was performed based on the Cochrane and PRISMA guidelines. The quality of evidence and network meta-analysis were conducted using the GRADE tool and R software, respectively. Four databases were searched, and the papers were selected based on the PICOS strategy. A total of 3584 papers were found. After screening 15 papers were included. One plate placed on lateral border (tension zone) presented lower risk than one plate placed on superior border (tension zone) for infection [risk ratio (RR): 0.48, 95% confidence interval (CI): 0.33 to 0.71] and plate removal necessity (RR: 0.44, 95% CI: 0.28 to 0.69), with moderate quality of evidence. There were no significant differences among the mandibular angle fracture treatments for malocclusion and paraesthesia outcomes. In conclusion, one plate placed on the lateral border in the tension zone is the best choice regarding postoperative infection and plate removal necessity when fixing mandibular angle fractures. None of the tested fixation methods were associated with a significant risk of malocclusion and paraesthesia events.
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Fracturas Mandibulares , Placas Óseas , Fijación de Fractura , Fijación Interna de Fracturas , Humanos , Fracturas Mandibulares/cirugía , Metaanálisis en Red , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
This work aimed to verify the existence of patterns on the electrophysiological systemic responses of tomato plants inoculated with a pathogenic fungus in an environment with controlled light and temperature. Electrical signalling was measured before and after inoculation in the same plants, and data were analysed with time series techniques and approximate multi-scale entropy (ApEn). Machine learning algorithms were utilised in order to classify data before and after infection throughout the five days of experiments. The obtained results have shown that it is possible to distinguish differences in the plant's electrome activity before and after the fungus inoculation. In some cases, we have found scale invariance quantified by the power law decay in the distribution histogram. We also found a higher degree of internal organisation quantified by ApEn. The results of the classification algorithms achieved higher accuracy of infection detection at the initial stage of pathogen recognition by the plant. Besides, this study showed evidence that long-distance electrical signalling is likely involved in the plant-pathogen interaction, since signals were obtained in the stem and the inoculum applied on the plant leaves. This might be useful for the early detection of plant infections.
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Ascomicetos/fisiología , Enfermedades de las Plantas/microbiología , Hojas de la Planta/microbiología , Solanum lycopersicum/microbiología , Técnicas Electroquímicas , Interacciones Huésped-Patógeno , Solanum lycopersicum/fisiología , Hojas de la Planta/fisiologíaRESUMEN
The aim of this systematic review was to verify whether the presence of a lower third molar in the mandibular angle fracture line is associated with postoperative complications. An electronic survey was conducted in five databases. Eligibility criteria included observational and experimental studies that evaluated the association between the presence of the lower third molar in the fracture line of mandibular angle fractures and possible postoperative complications, including infection, paresthesia, necessity of plate removal, temporomandibular joint disorders, malocclusion, dehiscence, and non-union. Thirty-four papers were included in the qualitative analysis and 26 of those in the meta-analysis. The risk of bias of observational studies was assessed by Newcastle-Ottawa scale and of the clinical trials by Cochrane Collaboration risk-of-bias tool. Absence of the third molar was associated with a lower chance of postoperative infection in angle fractures compared to presence of the tooth (odds ratio 0.55, 95% confidence interval 0.34-0.88). No statistically significant difference between the groups was found for the other outcomes evaluated. The findings of this systematic review suggest that the absence of the third molar in the mandibular angle fracture line is associated with a lower postoperative infection rate when compared to angle fractures with a third molar present.
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Fracturas Mandibulares , Diente Impactado , Manejo de Datos , Humanos , Mandíbula , Tercer Molar , Complicaciones Posoperatorias , Estudios RetrospectivosRESUMEN
The scientific publication landscape is changing quickly, with an enormous increase in options and models. Articles can be published in a complex variety of journals that differ in their presentation format (online-only or in-print), editorial organizations that maintain them (commercial and/or society-based), editorial handling (academic or professional editors), editorial board composition (academic or professional), payment options to cover editorial costs (open access or pay-to-read), indexation, visibility, branding, and other aspects. Additionally, online submissions of non-revised versions of manuscripts prior to seeking publication in a peer-reviewed journal (a practice known as pre-printing) are a growing trend in biological sciences. In this changing landscape, researchers in biochemistry and molecular biology must re-think their priorities in terms of scientific output dissemination. The evaluation processes and institutional funding for scientific publications should also be revised accordingly. This article presents the results of discussions within the Department of Biochemistry, University of São Paulo, on this subject.
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Bioquímica , Biología Molecular , Publicaciones Periódicas como Asunto/estadística & datos numéricos , Edición/tendencias , Investigación , Brasil , Humanos , Publicaciones Periódicas como Asunto/normas , Publicaciones Periódicas como Asunto/tendenciasRESUMEN
This systematic review aimed to answer the following PICO question: Does the intramuscular injection of dexamethasone result in less pain, swelling, and trismus after mandibular third molar removal when compared to other routes of administration or a control group (saline solution injection or no treatment)? An electronic search was conducted in Virtual Health Library, PubMed, and Web of Science, through March 2018. Eligibility criteria included clinical trials. The search strategy resulted in 331 studies. Following the selection process, 15 articles were included in the systematic review; eight of these were included in the meta-analysis. Most of the studies had an unclear risk of bias (Cochrane Handbook assessment). Pain (mean difference (MD) -1.58, 95% confidence interval (CI) -1.99 to -1.16) and oedema (MD -1.76, 95% CI -2.38 to -1.14) were lower in the intramuscular dexamethasone group when compared to the control group. When compared to the submucosal route, the intramuscular route was more effective only for pain on the third postoperative day (MD -0.79, 95% CI -1.38 to -0.20). The results suggest that the intramuscular injection of dexamethasone may be an alternative route of administration, since it is effective at reducing pain and oedema when compared to non-steroidal treatment and has similar results to the submucosal route.
Asunto(s)
Tercer Molar , Trismo , Dexametasona , Edema , Humanos , Dolor PostoperatorioRESUMEN
The scientific publication landscape is changing quickly, with an enormous increase in options and models. Articles can be published in a complex variety of journals that differ in their presentation format (online-only or in-print), editorial organizations that maintain them (commercial and/or society-based), editorial handling (academic or professional editors), editorial board composition (academic or professional), payment options to cover editorial costs (open access or pay-to-read), indexation, visibility, branding, and other aspects. Additionally, online submissions of non-revised versions of manuscripts prior to seeking publication in a peer-reviewed journal (a practice known as pre-printing) are a growing trend in biological sciences. In this changing landscape, researchers in biochemistry and molecular biology must re-think their priorities in terms of scientific output dissemination. The evaluation processes and institutional funding for scientific publications should also be revised accordingly. This article presents the results of discussions within the Department of Biochemistry, University of São Paulo, on this subject.
Asunto(s)
Humanos , Publicaciones Periódicas como Asunto/estadística & datos numéricos , Edición/tendencias , Investigación , Bioquímica , Biología Molecular , Publicaciones Periódicas como Asunto/normas , Publicaciones Periódicas como Asunto/tendencias , BrasilRESUMEN
Although the cross-talk between auxin and ethylene has been described during plant development, the role played by auxin upon gene expression during aerenchyma formation is poorly understood. Root aerenchyma formation results from the opening of gas spaces in the cortex. It is part of a developmental program (constitutive) or due to ethylene treatment or abiotic stress (induced) such as flooding and nutrient starvation. This process relies on programmed cell death and cell wall modifications. Here we followed development of aerenchyma formation in sugarcane along 5 cm from the root apex. As a constitutive process, the aerenchyma formation was observed in the cortex from the 3rd cm onwards. This occurred despite 1-methylcyclepropene (1-MCP) treatment, an inhibitor of ethylene perception. However, this process occurred while ethylene (and auxin) levels decreased. Within the aerenchyma formation zone, the concentration of ethylene is lower in comparison to the concentration in maize. Besides, the ratio between both hormones (ethylene and auxin) was around 1:1. These pieces of evidence suggest that ethylene sensitivity and ethylene-auxin balance may play a role in the formation of aerenchyma. Furthermore, the transcriptional analysis showed that genes related to cell expansion are up-regulated due to 1-MCP treatment. Our results help explaining the regulation of the formation constitutive aerenchyma in sugarcane.
Asunto(s)
Ciclopropanos/farmacología , Etilenos/metabolismo , Ácidos Indolacéticos/metabolismo , Raíces de Plantas/anatomía & histología , Saccharum/anatomía & histología , Raíces de Plantas/efectos de los fármacos , Saccharum/efectos de los fármacosRESUMEN
Studies on plant electrophysiology are mostly focused on specific traits of single cells. Inspired by the complexity of the signalling network in plants, and by analogy with neurons in human brains, we sought evidence of high complexity in the electrical dynamics of plant signalling and a likely relationship with environmental cues. An EEG-like standard protocol was adopted for high-resolution measurements of the electrical signal in Glycine max seedlings. The signals were continuously recorded in the same plants before and after osmotic stimuli with a -2 MPa mannitol solution. Non-linear time series analyses methods were used as follows: auto-correlation and cross-correlation function, power spectra density function, and complexity of the time series estimated as Approximate Entropy (ApEn). Using Approximate Entropy analysis we found that the level of temporal complexity of the electrical signals was affected by the environmental conditions, decreasing when the plant was subjected to a low osmotic potential. Electrical spikes observed only after stimuli followed a power law distribution, which is indicative of scale invariance. Our results suggest that changes in complexity of the electrical signals could be associated with water stress conditions in plants. We hypothesised that the power law distribution of the spikes could be explained by a self-organised critical state (SOC) after osmotic stress.
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Electrofisiología/métodos , Glycine max/metabolismo , Presión Osmótica/fisiología , Glycine max/fisiologíaRESUMEN
Because of the complexity of plant responses to water deficit, researchers have attempted to identify simplified models to understand critical aspects of the problem by searching for single indicators that would enable evaluations of the effects of environmental changes on the entire plant. However, this reductionist approach, which is often used in plant sciences, makes it difficult to distinguish systemic emergent behaviours. Currently, a new class of models and epistemology have called attention to the fundamental properties of complex systems. These properties, termed 'emergent', are observed at a large scale of the system (top hierarchical level) but cannot be observed or inferred from smaller scales of observation in the same system. We propose that multivariate statistical analysis can provide a suitable tool to quantify global responses to water deficit, allowing a specific and partially quantitative assessment of emergent properties. Based on an experimental study, our results showed that the classical approach of the individual analysis of different data sets might provide different interpretations for the observed effects of water deficit. These results support the hypothesis that a cross-scale multivariate analysis is an appropriate method to establish models for systemic understanding of the interactions between plants and their changing environment.
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Brachiaria/fisiología , Glycine max/fisiología , Biomasa , Deshidratación , Membranas , Análisis Multivariante , Ósmosis , Fenoles/metabolismo , Fotosíntesis , Hojas de la Planta/fisiología , Raíces de Plantas/crecimiento & desarrollo , Tallos de la Planta/crecimiento & desarrollo , Análisis de Componente Principal , Prolina/metabolismo , Teoría Cuántica , Solubilidad , Sacarosa/metabolismo , AguaRESUMEN
The present study estimated the prevalence of metabolic syndrome (MS) according to the criteria established by the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATPIII) and the International Diabetes Federation (IDF) and analyzed the contribution of social factors in an adult urban population in the Southeastern region of Brazil. The sample plan was based on multistage probability sampling according to family head income and educational level. A random sample of 1116 subjects aged 30 to 79 years was studied. Participants answered a questionnaire about socio-demographic variables and medical history. Fasting capillary glucose (FCG), total cholesterol, high-density lipoprotein cholesterol (HDL-C), and triglycerides were determined and all non-diabetic subjects were submitted to the 75-g oral glucose tolerance test. Body mass index (BMI, kg/m(2)), waist circumference and blood pressure (BP) were determined. Age- and gender-adjusted prevalence of MS was 35.9 and 43.2% according to NCEP-ATPIII and IDF criteria, respectively. Substantial agreement was found between NCEP-ATPIII and IDF definitions. Low HDL-C levels and high BP were the most prevalent MS components according to NCEP-ATPIII criteria (76.3 and 59.2%, respectively). Considering the diagnostic criteria adopted, 13.5% of the subjects had diabetes and 9.7% had FCG ≥100 mg/dL. MS prevalence was significantly associated with age, skin color, BMI, and educational level. This cross-sectional population-based study in the Southeastern region of Brazil indicates that MS is highly prevalent and associated with an important social indicator, i.e., educational level. This result suggests that in developing countries health policy planning to reduce the risk of MS, in particular, should consider improvement in education.
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HDL-Colesterol/sangre , LDL-Colesterol/sangre , Síndrome Metabólico/epidemiología , Factores Socioeconómicos , Adulto , Anciano , Biomarcadores/sangre , Índice de Masa Corporal , Brasil/epidemiología , Enfermedades Cardiovasculares/etiología , Estudios Transversales , Escolaridad , Femenino , Prueba de Tolerancia a la Glucosa , Humanos , Lipoproteínas HDL , Masculino , Persona de Mediana Edad , Prevalencia , Distribución por Sexo , Población Urbana , Circunferencia de la CinturaRESUMEN
The present study estimated the prevalence of metabolic syndrome (MS) according to the criteria established by the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATPIII) and the International Diabetes Federation (IDF) and analyzed the contribution of social factors in an adult urban population in the Southeastern region of Brazil. The sample plan was based on multistage probability sampling according to family head income and educational level. A random sample of 1116 subjects aged 30 to 79 years was studied. Participants answered a questionnaire about socio-demographic variables and medical history. Fasting capillary glucose (FCG), total cholesterol, high-density lipoprotein cholesterol (HDL-C), and triglycerides were determined and all non-diabetic subjects were submitted to the 75-g oral glucose tolerance test. Body mass index (BMI, kg/m²), waist circumference and blood pressure (BP) were determined. Age- and gender-adjusted prevalence of MS was 35.9 and 43.2 percent according to NCEP-ATPIII and IDF criteria, respectively. Substantial agreement was found between NCEP-ATPIII and IDF definitions. Low HDL-C levels and high BP were the most prevalent MS components according to NCEP-ATPIII criteria (76.3 and 59.2 percent, respectively). Considering the diagnostic criteria adopted, 13.5 percent of the subjects had diabetes and 9.7 percent had FCG ≥100 mg/dL. MS prevalence was significantly associated with age, skin color, BMI, and educational level. This cross-sectional population-based study in the Southeastern region of Brazil indicates that MS is highly prevalent and associated with an important social indicator, i.e., educational level. This result suggests that in developing countries health policy planning to reduce the risk of MS, in particular, should consider improvement in education.
Asunto(s)
Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Síndrome Metabólico/epidemiología , Factores Socioeconómicos , Índice de Masa Corporal , Biomarcadores/sangre , Brasil/epidemiología , Estudios Transversales , Enfermedades Cardiovasculares/etiología , Escolaridad , Prueba de Tolerancia a la Glucosa , Lipoproteínas HDL , Prevalencia , Distribución por Sexo , Población Urbana , Circunferencia de la CinturaRESUMEN
The present study investigated changes in photosynthetic characteristics of Guazuma ulmifolia Lam. (early successional species) and Hymenaea courbaril L. (late successional species) grown in contrasting light conditions as a way of assessing photosynthetic plasticity. Early successional species typically inhabit gap environments being exposed to variability in multiple resources, hence it is expected that these species would show higher photosynthetic plasticity than late successional ones. In order to test this hypothesis, light and CO2 response curves and chlorophyll content (Chl) were measured in plants grown in high and low light environments. G. ulmifolia presented the highest amounts of both Chl a and b, especially in the low light, and both species presented higher Chl a than b in both light conditions. The Chl a/b ratio was higher in high light leaves of both species and greater in G. ulmifolia. Taken together, these results evidence the acclimation potential of both species, reflecting the capacity to modulate light harvesting complexes according to the light environment. However, G. ulmifolia showed evidence of higher photosynthetic plasticity, as indicated by the greater amplitude of variation on photosynthetic characteristics between environments shown by more significant shade adjusted parameters (SAC) and principal component analysis (PCA). Thus, the results obtained were coherent with the hypothesis that the early successional species G. ulmifolia exhibits higher photosynthetic plasticity than the late successional species H. courbaril.
Asunto(s)
Adaptación Fisiológica/fisiología , Hymenaea/fisiología , Malvaceae/fisiología , Fotosíntesis/fisiología , Luz Solar , Dióxido de Carbono/análisis , Clorofila/análisis , Hymenaea/química , Malvaceae/químicaRESUMEN
This study addressed some questions about how a suitable leaf carbon balance can be attained for different functional groups of tropical tree species under contrasting forest light environments. The study was carried out in a fragment of semi-deciduous seasonal forest in Narandiba county, São Paulo Estate, Brazil. 10-month-old seedlings of four tropical tree species, Bauhinia forficata Link (Caesalpinioideae) and Guazuma ulmifolia Lam. (Sterculiaceae) as light-demanding pioneer species, and Hymenaea courbaril L. (Caesalpinioideae) and Esenbeckia leiocarpa Engl. (Rutaceae) as late successional species, were grown under gap and understorey conditions. Diurnal courses of net photosynthesis (Pn) and transpiration were recorded with an open system portable infrared gas analyzer in two different seasons. Dark respiration and photorespiration were also evaluated in the same leaves used for Pn measurements after dark adaptation. Our results showed that diurnal-integrated dark respiration (Rdi) of late successional species were similar to pioneer species. On the other hand, photorespiration rates were often higher in pioneer than in late successional species in the gap. However, the relative contribution of these parameters to leaf carbon balance was similar in all species in both environmental conditions. Considering diurnal-integrated values, gross photosynthesis (Pgi) was dramatically higher in gap than in understorey, regardless of species. In both evaluated months, there were no differences among species of different functional groups under shade conditions. The same was observed in May (dry season) under gap conditions. In such light environment, pioneers were distinguished from late successional species in November (wet season), showing that ecophysiological performance can have a straightforward relation to seasonality.
Este estudo considerou algumas questões sobre como um adequado balanço de carbono foliar pode ser obtido por diferentes grupos funcionais de espécies tropicais arbóreas sob contrastantes ambientes luminosos em uma floresta. O estudo foi realizado em um fragmento de floresta estacional semidecidual localizada no município de Narandiba, Estado de São Paulo. Plântulas com dez meses de idade de quatro espécies, Bauhinia forficata Link (Caesalpinioideae) e Guazuma ulmifolia Lam. (Sterculiaceae) como espécies pioneiras, e Hymenaea courbaril L. (Caesalpinioideae) e Esenbeckia leiocarpa Engl. (Rutaceae) como espécies secundárias, cresceram em um ambiente de clareira e um de sub-bosque durante nove meses. Cursos diários da fotossíntese líquida (Pn) e transpiração foram medidos com um medidor portátil de trocas gasosas por infravermelho nas estações seca e chuvosa. A respiração no escuro (Rd) e a fotorrespiração (Pr) foram também avaliadas nas mesmas folhas utilizadas para as medidas de Pn após um período de adaptação ao escuro. Nossos resultados mostraram que a respiração integrada ao longo do dia foi similar entre as espécies dos dois grupos sucessionais. Por outro lado, a fotorrespiração das espécies pioneiras foi freqüentemente maior do que nas espécies secundárias em condições de clareira. Todavia, a contribuição relativa de Pr no balanço de carbono nas folhas foi similar em todas as espécies em ambos os ambientes. Independentemente da espécie, a fotossíntese bruta, considerando os valores integrados ao longo do dia, foi significativamente maior na clareira que no sub-bosque. Nas duas épocas avaliadas, não foram observadas diferenças significativas em nenhum dos parâmetros avaliados entre as espécies crescidas no ambiente de sub-bosque. O mesmo foi observado no mês de maio sob condições de clareira. No mês de novembro, as espécies pioneiras apresentaram uma performance ecofisiológica significativamente distinta das espécies secundárias no ...
Asunto(s)
Carbono/metabolismo , Fabaceae/fisiología , Fotosíntesis/fisiología , Rutaceae/fisiología , Malvaceae/fisiología , Fabaceae/metabolismo , Rutaceae/metabolismo , Estaciones del Año , Malvaceae/metabolismo , Clima Tropical , Árboles/metabolismo , Árboles/fisiologíaRESUMEN
Sugarcane is a highly productive crop used for centuries as the main source of sugar and recently to produce ethanol, a renewable bio-fuel energy source. There is increased interest in this crop due to the impending need to decrease fossil fuel usage. Sugarcane has a highly polyploid genome. Expressed sequence tag (EST) sequencing has significantly contributed to gene discovery and expression studies used to associate function with sugarcane genes. A significant amount of data exists on regulatory events controlling responses to herbivory, drought, and phosphate deficiency, which cause important constraints on yield and on endophytic bacteria, which are highly beneficial. The means to reduce drought, phosphate deficiency, and herbivory by the sugarcane borer have a negative impact on the environment. Improved tolerance for these constraints is being sought. Sugarcane's ability to accumulate sucrose up to 16% of its culm dry weight is a challenge for genetic manipulation. Genome-based technology such as cDNA microarray data indicates genes associated with sugar content that may be used to develop new varieties improved for sucrose content or for traits that restrict the expansion of the cultivated land. The genes can also be used as molecular markers of agronomic traits in traditional breeding programs.
RESUMEN
This study addressed some questions about how a suitable leaf carbon balance can be attained for different functional groups of tropical tree species under contrasting forest light environments. The study was carried out in a fragment of semi-deciduous seasonal forest in Narandiba county, São Paulo Estate, Brazil. 10-month-old seedlings of four tropical tree species, Bauhinia forficata Link (Caesalpinioideae) and Guazuma ulmifolia Lam. (Sterculiaceae) as light-demanding pioneer species, and Hymenaea courbaril L. (Caesalpinioideae) and Esenbeckia leiocarpa Engl. (Rutaceae) as late successional species, were grown under gap and understorey conditions. Diurnal courses of net photosynthesis (Pn) and transpiration were recorded with an open system portable infrared gas analyzer in two different seasons. Dark respiration and photorespiration were also evaluated in the same leaves used for Pn measurements after dark adaptation. Our results showed that diurnal-integrated dark respiration (Rdi) of late successional species were similar to pioneer species. On the other hand, photorespiration rates were often higher in pioneer than in late successional species in the gap. However, the relative contribution of these parameters to leaf carbon balance was similar in all species in both environmental conditions. Considering diurnal-integrated values, gross photosynthesis (Pgi) was dramatically higher in gap than in understorey, regardless of species. In both evaluated months, there were no differences among species of different functional groups under shade conditions. The same was observed in May (dry season) under gap conditions. In such light environment, pioneers were distinguished from late successional species in November (wet season), showing that ecophysiological performance can have a straightforward relation to seasonality.
Asunto(s)
Carbono/metabolismo , Fabaceae/fisiología , Malvaceae/fisiología , Fotosíntesis/fisiología , Rutaceae/fisiología , Fabaceae/metabolismo , Malvaceae/metabolismo , Rutaceae/metabolismo , Estaciones del Año , Árboles/metabolismo , Árboles/fisiología , Clima TropicalRESUMEN
Avaliou-se o efeito da suplementação protéico-energética em dois níveis de ingestão diária, 0,17 e 0,37 por cento do peso vivo médio, sobre o no desempenho e consumo de matéria seca por bovinos, em pastagens de Brachiaria brizantha cv. Marandu. Para avaliação do desempenho foram utilizados 42 novilhos (Holandês x Gir - HG), com média de 211kg de peso vivo inicial (PVI) e para a avaliação do consumo de matéria seca total (CMST) e de forragem (CMSF) foram usados 15 novilhos inteiros HG, com 239kg de PVI. Os tratamentos foram: SM - controle; SUP1 - suplementação protéico-energética com ingestão média diária de 0,17 por cento do peso vivo e SUP2 - suplementação protéico-energética com ingestão média diária de 0,37 por cento do peso vivo (PV). Os valores do CMSF foram de 2,6, 2,4 e 2,3 por cento PV, e os de CMST 2,6, 2,6 e 2,6 por cento PV, para SM, SUP1 e SUP2, respectivamente. Esses valores não diferiram entre si (P>0,05). A suplementação protéico-energética proporcionou maior ganho de peso, 0,54, 0,66 e 0,75kg/cabeça/dia para SM, SUP1 e SUP2, respectivamente.
The effect of two levels of daily intake (0.17 percent and 0.37 percent of live weight) of protein and energy supplementation on weight gain and on dry matter intake of bulls grazing Brachiaria Brizantha cv. Marandu grass was evaluated. Forty two bulls (Holstein x Gir - HG), averaging 211kg initial LW, were used in the performance trial, and 15 HG steers, averaging 239kg initial LW, for evaluation of total dry matter intake (TDMI) and forage dry matter intake (FDMI). The treatments were: MS - mineral supplementation, SUP1 - protein and energy supplementation with an average daily intake of 0.17 percent of the live body weight, and SUP2 - protein and energy supplementation with an average daily intake of 0.37 percent of the live body weight. The average FDMI intakes were 2.6, 2.4, and 2.3 percent of the LW, for MS, SUP1 and SUP2, respectively. The average TDMI intakes were 2.6, 2.6, and 2.6 percent for MS, SUP1, and SUP2, respectively. Protein and energy supplementation increased weight gain from 0.54kg/day in the MS treatment to 0.66 and 0.75kg/day for SUP1 and SUP2, respectively.