Interactive Tree and N Supply Effect on Root Mass of Two Annual Pasture Grasses

A major aim of integrated crop livestock system (ICLS) with trees is to increase the overall land productivity and/or its sustainability by making best use of the environmental resources (water, light and nutrients) used by plant for growth (Jose et al. 2008). Consequently, research efforts have been done in order to investigate the complex animal-plant-soils interactions operating upon the biological production of these systems, and their environmental impacts. For instance, since roots return to soil as a stock of C in the soil is in general larger than shoot return, interest in describing plant root system has increased due the current debate over sequestration of C by vegetation. Therefore, an important issue of ICLS is the degree of competition or, conversely, the complementary level that exists between root development and root system activities (Gregory 2006). However, our knowledge about the mechanisms by which biomass allocation (aerial parts of the plant vs. root system) is regulated is poor (Poorter et al. 2011), mainly when considering simultaneous stresses (e.g. light and nutrients). In the present study we report the shoot:root ratio and root mass variation responses to N fertilization levels of two forage grass species growing in field situation under a tree canopy while grazed by beef heifers versus an open, treeless ICLS

Nut production in Bertholletia excelsa across a logged forest mosaic: implications for multiple forest use

Although many examples of multiple-use forest management may be found in tropical smallholder systems, few studies provide empirical support for the integration of selective timber harvesting with non-timber forest product (NTFP) extraction. Brazil nut (Bertholletia excelsa, Lecythidaceae) is one of the world’s most economically-important NTFP species extracted almost entirely from natural forests across the Amazon Basin. An obligate out-crosser, Brazil nut flowers are pollinated by large-bodied bees, a process resulting in a hard round fruit that takes up to 14 months to mature. As many smallholders turn to the financial security provided by timber, Brazil nut fruits are increasingly being harvested in logged forests. We tested the influence of tree and stand-level covariates (distance to nearest cut stump and local logging intensity) on total nut production at the individual tree level in five recently logged Brazil nut concessions covering about 4000 ha of forest in Madre de Dios, Peru. Our field team accompanied Brazil nut harvesters during the traditional harvest period (January-April 2012 and January-April 2013) in order to collect data on fruit production. Three hundred and ninety-nine (approximately 80%) of the 499 trees included in this study were at least 100 m from the nearest cut stump, suggesting that concessionaires avoid logging near adult Brazil nut trees. Yet even for those trees on the edge of logging gaps, distance to nearest cut stump and local logging intensity did not have a statistically significant influence on Brazil nut production at the applied logging intensities (typically 1–2 timber trees removed per ha). In one concession where at least 4 trees ha-1 were removed, however, the logging intensity covariate resulted in a marginally significant (0.09) P value, highlighting a potential risk for a drop in nut production at higher intensities. While we do not suggest that logging activities should be completely avoided in Brazil nut rich forests, when a buffer zone cannot be observed, low logging intensities should be implemented. The sustainability of this integrated management system will ultimately depend on a complex series of socioeconomic and ecological interactions. Yet we submit that our study provides an important initial step in understanding the compatibility of timber harvesting with a high value NTFP, potentially allowing for diversification of forest use strategies in Amazonian Perù

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

O discurso dos profissionais sobre a demanda e a humanização

A humanização dos serviços da atenção primária à saúde depende, em grande parte, da resolução das necessidades em saúde e da conseqüente organização da demanda. OBJETIVO: O artigo objetiva conhecer as implicações da demanda sobre a humanização das práticas de atenção primária. METODOLOGIA: Trata-se de uma pesquisa exploratória com abordagem qualitativa. O universo empírico da pesquisa foi composto por 10 trabalhadores de uma Unidade Básica de Saúde: 1 gestora, 1 médica, 1 dentista, 2 enfermeiros, 3 técnicos em enfermagem, 1 atendente da portaria e 1 encarregado do almoxarifado. A coleta de dados aconteceu em 8 reuniões de discussão focal sobre temas como política de humanização, direito à saúde, integralidade, acolhimento, subjetividade em saúde, processos de trabalho. As discussões foram gravadas e transcritas. Os dados foram trabalhados pela análise do discurso. RESULTADOS: Como resultados, apareceram três repertórios lingüísticos ligados à demanda: compreensão das necessidades em saúde; entendimento do acolhimento como triagem e aplicação de protocolo; influência do modelo biomédico na organização dos serviços. A excessiva demanda e a falta de resolubilidade estão ligadas a uma compreensão das necessidades de saúde como o simples acesso à tecnologia, e do acolhimento apenas como triagem de sintomas. Os profissionais da enfermagem reportam como uma causa da excessiva demanda o fato de que os usuários sempre querem ser atendidos pelo médico, o que pode ser explicado pela cultura da atenção criada pelo modelo biomédico no qual eles próprios se encontram quando entendem as necessidades e o acolhimento na perspectiva biomédica.Humanization of Primary Health Care Services depends mostly on the resolution of the health needs and on the consequen organization of demand. OBJECTIVE: The article searches to know the implications of demand to the humanization of Primary Health Care practices. METHODOLOGY: It is an exploratory research with qualitative approach. The empirical universe was formed by 10 professionals: 1 manager; 1 physician; 1 dentist; 2 nurses, 3 nursing technicians; 1 reception attendant; 1 stockroom commissioner. Data were collected through 8 meetings in which discussion focused on themes such as humanization policy, right to health, integrality, users' reception, subjectivity in health, work processes. The discussions have been recorded and a transcription was made. Analysis of data was done through discourse analysis. RESULTS: As results, three linguistic repertories were found linked with the demand: the understanding of health needs; the understanding of users' reception as screening and application of protocols; the influence of the biomedical model in the organization of the services. The excessive demand and the lack of resolution are linked to the understanding of heath needs simply as access to technology, and of users' reception simply as screening of symptoms. Nurses claim that excessive demand is due to users always wanting to be seen by a physician, which can be explained by the health care culture created by the biomedical model which is also adopted by professionals when they understand health needs and the users' reception in the biomedical perspective

Comparative serology techniques for the diagnosis of Trypanosoma cruzi infection in a rural population from the state of Querétaro, Mexico

Immunological diagnostic methods for Trypanosoma cruzi depend specifically on the presence of antibodies and parasitological methods lack sensitivity during the chronic and “indeterminate” stages of the disease. This study performed a serological survey of 1,033 subjects from 52 rural communities in 12 of the 18 municipalities in the state of Querétaro, Mexico. We detected anti-T. cruzi antibodies using the following tests: indirect haemagglutination assay (IHA), indirect immunofluorescence assay (IFA), ELISA and recombinant ELISA (rELISA). We also performed Western blot (WB) analysis using iron superoxide dismutase (FeSOD), a detoxifying enzyme excreted by the parasite, as the antigen. Positive test results were distributed as follows: ELISA 8%, rELISA 6.2%, IFA and IHA 5.4% in both cases and FeSOD 8%. A comparative study of the five tests was undertaken. Sensitivity levels, specificity, positive and negative predictive values, concordance percentage and kappa index were considered. Living with animals, trips to other communities, gender, age, type of housing and symptomatology at the time of the survey were statistically analysed using SPSS software v.11.5. Detection of the FeSOD enzyme that was secreted by the parasite and used as an antigenic fraction in WBs showed a 100% correlation with traditional ELISA tests

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Contrasting nitrogen fertilization treatments impact xylem gene expression and secondary cell wall lignification in Eucalyptus

BackgroundNitrogen (N) is a main nutrient required for tree growth and biomass accumulation. In this study, we analyzed the effects of contrasting nitrogen fertilization treatments on the phenotypes of fast growing Eucalyptus hybrids (E. urophylla x E. grandis) with a special focus on xylem secondary cell walls and global gene expression patterns.ResultsHistological observations of the xylem secondary cell walls further confirmed by chemical analyses showed that lignin was reduced by luxuriant fertilization, whereas a consistent lignin deposition was observed in trees grown in N-limiting conditions. Also, the syringyl/guaiacyl (S/G) ratio was significantly lower in luxuriant nitrogen samples. Deep sequencing RNAseq analyses allowed us to identify a high number of differentially expressed genes (1,469) between contrasting N treatments. This number is dramatically higher than those obtained in similar studies performed in poplar but using microarrays. Remarkably, all the genes involved the general phenylpropanoid metabolism and lignin pathway were found to be down-regulated in response to high N availability. These findings further confirmed by RT-qPCR are in agreement with the reduced amount of lignin in xylem secondary cell walls of these plants.ConclusionsThis work enabled us to identify, at the whole genome level, xylem genes differentially regulated by N availability, some of which are involved in the environmental control of xylogenesis. It further illustrates that N fertilization can be used to alter the quantity and quality of lignocellulosic biomass in Eucalyptus, offering exciting prospects for the pulp and paper industry and for the use of short coppices plantations to produce second generation biofuels.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-014-0256-9) contains supplementary material, which is available to authorized users