Repositório RCAAP
An endemic‐rich island through the eyes of children: Wildlife identification and conservation preferences in São Tomé (Gulf of Guinea)
Species that the public knows and is willing to protect often do not align with international conservation priorities. Assessing perceptions on wildlife is thus essential to guide conservation initiatives, especially in island developing states where native and introduced species often have contrasting values for biodiversity. We used a game to assess the ability of third class students in São Tomé Island (São Tomé and Príncipe, central Africa) to identify wildlife and their conservation preferences. Students correctly identified 28% of the animals shown. Children who were poorer, male or from rural schools were more likely to correctly identify species. Urban children were less successful identifying species endemic to São Tomé and Príncipe than rural children. Conservation preferences were not associated with species identification and instead were justified by subjective species-specific traits, such as attractiveness or profitability. Despite the low identification rates for endemic (10% correct identifications) and threatened birds (2%), children were keen on preserving endemic species, indicating that these might become effective flagships for the unique biodiversity of the island. These results illustrate the need to consider separately the attributes that affect knowledge and willingness to protect, and how both can be used to guide conservation strategies.
2022
Panisi, Martina Pissarra, Vasco Oquiongo, Gabriel M. Palmeirim, Jorge F. De Lima, Ricardo Nuno, Ana
Climate action: is coronavirus what we have been waiting for? (and now what?)
In the beginning of 2020, it looked like serious climate action was finally going to take place after decades of procrastination, but we are now inevitably leaving the transformation path. Abruptly (and remarkably), the coronavirus outbreak silenced ongoing efforts to protect climate, while also partly bringing carbon emissions to a halt. A global tragedy is still unfolding with vast social impacts and we are reaching a roundabout with several distinct exits. While embracing the uncertainty of current times, we try to envision likely transition pathways using the multi-level perspective. Climate activists, social innovators, dreamers, and networkers are expected to gain momentum and play critical roles in a sequence of co-evolutionary waves leading to a just, conscious, and regenerative recovery.
2021
Macedo, Pedro Santos, F.D. Pedersen, Jiesper Strandsbjerg Tristan Penha-Lopes, Gil
On the Synonymization of Acaulon longifolium Herrnst. & Heyn with Acaulon fontiquerianum Casas & Sérgio (Pottiaceae)
During bryological work conducted in the Sharon plane region (Israel), a colony of Acaulon Müll. Hal. was discovered. The plants showed morphological affinities both to A. longifolium Herrnst. & Heyn and A. fontiquerianum Casas & Sérgio depending on the floras used for their identification which challenged their recognition as separate species. In order to solve this taxonomic dilemma, we conducted a detailed morphological characterization of the two species based on representative samples. The micromorphological study of vegetative, sporophytic and spore traits revealed the large overlap of range values between both species. Both species showed the characteristic combination of morphological characters, including the broadly incurved leaves with smooth cells and the 4-6 rows of inflated cells on the adaxial surface of nerve. Spore micromorphology revealed the same ornamentation pattern and the presence of 1-2 lamellar glomeruli on spore surface. Multivariate and ordination analyses based on quantitative traits did not reveal a significant separation among samples of the two species, thus opposing their recognition as separate species. As A. fontiquerianum has priority over A. longifolium, the latter is thus subsumed in the synonymy of A. fontiquerianum. The addition of new chorological data and amended taxonomy reveals that A. fontiquerianum has a distribution area extending from the Canary Islands to the eastern Mediterranean basin. However, the scattered pattern suggests its known distribution is largely incomplete because of the tiny size of the plants and their ephemeral nature.
2021
Melamed, Dror Segarra-Moragues, José Gabriel Puche, Felisa Garcia, César Sergio, Cecilia
Valuable Secondary Habitats or Hazardous Ecological Traps? Environmental Risk Assessment of Minor and Trace Elements in Fly Ash Deposits across the Czech Republic
Deposits of coal combustion wastes, especially fly ash, are sources of environmental and health risks in industrial regions. Recently, fly ash deposits have been reported as habitat surrogates for some threatened arthropods in Central Europe. However, the potential environmental risks of fly ash have not yet been assessed in the region. We analysed concentrations of 19 minor and trace elements in 19 lignite combustion waste deposits in the Czech Republic. We assessed their environmental risks by comparison with the national and EU legislation limits, and with several commonly used indices. Over 50% of the samples exceeded the Czech national limits for As, Cu, V, or Zn, whilst only V exceeded the EU limits. For some studied elements, the high-risk indices were detected in several localities. Nevertheless, the measured water characteristics, the long-term presence of fly ash, previous leaching by acid rains, and the low amount of organic matter altogether can infer low biological availability of these elements. We presume the revealed high concentrations of some heavy metals at some studied sites can be harmful for some colonising species. Nevertheless, more ecotoxicological research on particular species is needed for final decision on their conservation potential for terrestrial and freshwater biota.
2021
Chmelová, Eliška Kolar, Vojtech Jan, Jiří Carreira, Bruno M. Landeira-Dabarca, Andrea Otáhalová, Šárka Poláková, Martina Vebrová, Lucie Borovec, Jakub Boukal, David S. Tropek, Robert
Raccoon (Procyon lotor) in Iberia: Status update and suitable habitats for an invasive carnivore
Raccoons are American carnivores, considered invasive across several countries worldwide, especially in Europe. In the Iberian Peninsula, previous studies on raccoons documented several breeding populations in Spain a decade ago and only two confirmed records from isolated individuals in Portugal. Given the need for updating its Iberian distribution and identifying suitable areas with higher invasion risk, we compiled presence records from established breeding populations and isolated individuals. By using a Maxent approach based on breeding records, we forecasted the suitable habitats in Iberia with higher invasion risk for raccoons and identified the related environmental drivers. Overall, we collected 1039 records of raccoon presence throughout the Iberian Peninsula, including 980 records from established breeding populations. Their origin is probably linked to escapes from captivity. Climatic conditions, linked to both drier and wetter environments, and proximity to water bodies were the main predictors of suitable areas for raccoon’s expansion from the currently established breeding nuclei in Iberia. The forecasted high probability areas showed a wide, but fragmented distribution concentrated on four main areas: central, central-north, central-east, and north-west Iberia. NW Portugal seems to be the area with higher invasion risk in the country, although field surveys showed no evidence of raccoon presence yet. However, there are several records in Spain near the Portuguese border, comprising isolated individuals and breeding populations. Therefore, it is crucial to ensure regular monitoring of areas with high invasion risk, particularly those near facilities with captive raccoons that often act as a source of feral individuals, to assure early detection and effective control for the expansion of this invasive carnivore.
2022
Valdez, Vasco Álvares, Francisco Layna, Jorge F. González, José Luis Herrera, Javier Lucas, Jesús de Louppe, Vivien Rosalino, L. M.
Framing the application of Adaptation Pathways for agroforestry in Mediterranean drylands
Adaptation Pathways is a decision support tool designed to create adaptation policies under different climate change scenarios. This tool has been used successfully in several sectors and contexts such as coastal and river adaptation, urban heat waves, floods and rural livelihoods but its use in natural resource management, has faced several challenges and limitations. In the sector of agroforestry its use has seldom been done or documented and one of the reasons for this may due to some of its specific challenges. In this study, these challenges were addressed when using the Adaptation Pathways for the adaptation planning of three case studies in the semi-arid Alentejo region, a Mediterranean dryland of southern Portugal. This tool was integrated in a participatory approach combined with the Scenario Workshop method, to plan the adaptation of the agriculture and forestry sector of one municipality (Mértola) and two agroforestry farms (221 ha and 1000 ha). The methodology included, for each case study, 20 interviews, two workshops, literature review, expert analysis and the use of indicators of efficacy of adaptation measures, to define tipping points. The adaptation process and the resulting adaptation plans were evaluated by questionnaire and expert review. This combination of methods has supported the choice of effective adaptation measures for the case studies and when combined with several adaptation pathways and a landscape approach it supported the creation of integrated climate change adaptation plans that are now in implementation. We discuss how this combination of methods deals with limitation to Adaptation Pathways identified in the literature, conclude that the method was able to create adaptation plans that are now under implementation and present avenues for future research.
2021
Vizinho, André Avelar, David Fonseca, Ana Lúcia Carvalho, Silvia Sucena-Paiva, Leonor Pinho, Pedro Nunes, Alice Branquinho, Cristina Vasconcelos, Ana Cátia Santos, Filipe Roxo, Maria José Penha-Lopes, Gil
Decisão médica partilhada em obstetrícia
Atualmente, o modelo de Medicina Centrada no Paciente (MCP) é defendido por diversas organizações vocacionadas para a saúde (incluindo a Organização Mundial de Saúde, ou OMS), em detrimento do modelo de Medicina Centrada na Doença. Na MCP, as decisões clínicas devem resultar de uma Decisão Médica Partilhada (DMP) entre este o doente e o médico. A DMP em Obstetrícia é um processo dinâmico que tem em consideração os valores, interesses e necessidades individuais da mulher/casal, e as circunstâncias particulares da sua gravidez, parto e/ou puerpério. Este processo deve ser caracterizado por uma comunicação otimizada, pela disponibilidade para explorar opções e pelo respeito mútuo entre a utente e o profissional de saúde. Esta revisão atualizada da literatura acerca da tomada de DMP inclui cerca de duas centenas de artigos científicos, encontrados através do recurso à PubMed® e recorrendo a palavras-chave, tais como “tomada de decisão partilhada”, “obstetrícia”, “autonomia” e “plano de parto”. Foram redigidos nas línguas portuguesa e inglesa e as suas datas de publicação vão desde 1995 até 2021.
Alterações estruturais na esquizofrenia
A esquizofrenia é uma doença psiquiátrica crónica caracterizada por sintomas positivos, negativos e cognitivos cujo diagnóstico assenta exclusivamente numa base clínica. Com o advento da ressonância magnética, tem sido possível uma maior compreensão da fisiopatologia subjacente à perturbação. Paralelamente, observou-se que doentes com primeiro episódio psicótico já apresentavam alterações neuro-imagiológicas. Neste trabalho pretendeu-se comparar as alterações apresentadas por doentes crónico e por doentes com primeiro episódio psicótico, e, ainda, compará-las com as apresentadas por doentes com perturbação afetiva bipolar. Para a realização desta revisão narrativa procedeu-se a uma pesquisa bibliográfica através da Pubmed. A evidência revelou uma extensa heterogeneidade de dados. Contudo, verificaram-se, no doente crónico, com maior frequência as seguintes alterações: aumento volumétrico dos ventrículos laterais e III ventrículo acompanhado por uma diminuição do volume cerebral total; diminuição volumétrica do lobo temporal, quer das suas estruturas neocorticais, quer dos elementos do sistema límbico, incluindo o complexo amígdala-hipocampo, circunvoluções para-hipocâmpica, temporal superior e circunvolução do corpo caloso; do córtex pré-frontal e circunvoluções frontais média e inferior; do lobo parietal, incluindo a circunvolução parietal ascendente e o lóbulo parietal inferior com as circunvoluções supramarginal e angular. Foi constatado um envolvimento das estruturas subcorticais tendo sido identificado um aumento volumétrico dos gânglios da base e uma redução do volume talâmico. De maneira global, estes mesmos achados são identificados nos doentes com primeiro episódio psicótico, à exceção do volume intracraniano e do volume da amígdala que frequentemente se encontram preservados. A comparação com as alterações presentes na perturbação afetiva bipolar exibiu uma extensa sobreposição. Porém, nesta o que mais contrasta com a esquizofrenia é a aparente manutenção do volume da amígdala e hipocampo e ausência de diminuição do volume talâmico. Conclui-se que as alterações neuro-imagiológicas são visíveis desde fases precoces da esquizofrenia e há uma extensa sobreposição com a doença bipolar.
Mapeando mundos no mundo de futebol : abordagem semiótico-cognitiva dos media alemães
A presente dissertação visa o estudo semiótico dos mapeamentos conducentes a imagens metafóricas vigentes na imprensa alemã (Bild, Sportbild, Kicker, Spiegel, Focus), com especial incidência nas suas versões on-line, durante os Campeonatos Europeus e Munidas de Futebol de 2006 a 2010 a luz do modelo dos espaços mentais de Brandt (2004a) Brandt/Brandt (2005a). Na senda de outros trabalhos de estudo das construções metafóricas e mescladas na imprensa desportiva portuguesa (Almeida (2003, 2004, 2005, 2006a, 2006b, 2010a, 2010b, 2011); Almeida, Órfão, Teixeira (2010); Almeida, Sousa (2010)), a presente dissertação debruça-se sobre as ocorrências metafóricas elaboradas a partir dos mapeamentos dos diversos domínios-fonte da experiência para o domínio-alvo dos eventos futebolísticos, tendo por objetivo elencar o conjunto de imagens presentes nos textos jornalísticos alemães. Tomando como ponto de partida a metáfora conceptual e convencional de DESPORTO E GUERRA” (Lakoff/Johnson, 1980a), analisaremos a panóplia de entrecruzamentos dos diversos mundos no mundo do futebol, numa dupla abordagem qualitativa e quantitativa, por forma a aquilatar a relevância das diversas imagens mescladas na representação dos eventos futebolísticos e dos seus protagonistas, os jogadores de futebol, na imprensa alemã.
NIHSS underestimates right hemisphere stroke injury : raising an old issue with a new cognitive approach
Introdução: A escala de acidente vascular cerebral (AVC) do National Institute of Health (NIHSS) é uma ferramenta de quantificação da gravidade de um AVC. Apesar de amplamente utilizada, estudos sugerem que não avalia igualmente os 2 hemisférios cerebrais. Pensa-‐se que o NIHSS subestima o volume das lesões do hemisfério direito possivelmente devido ao facto de 2 pontos serem atribuídos ao neglect e 7 às alterações de linguagem. Embora o NIHSS de doentes com neglect possa sugerir melhor outcome funcional comparativamente com doentes com afasia, estudos demonstram que o neglect está associado a piores outcomes. Objetivos: Comparar as correlações entre o volume da lesão e o NIHSS de doentes com neglect e sem neglect e estudar se uma modificação das regras de pontuação de neglect no NIHSS aumentaria a sua capacidade de predição do volume de lesão. Métodos: A amostra de doentes com AVC na artéria cerebral média direita foi dividida 2 grupos: doentes com neglect e sem neglect. Comparámos as correlações entre o volume de lesão e o NIHSS dos grupos e calculámos a correlação parcial entre o volume da lesão, NIHSS e a variável ter ou não neglect. Estudamos ainda diferentes modificações das regras de pontuação de neglect e repetimos a análise. Resultados: A correlação entre volume de lesão e NIHSS foi menor em doentes com neglect e a correlação parcial entre volume de lesão e a variável grupo, controlando o NIHSS, foi estatisticamente significativa. Com a pontuação de neglect triplicada e com a soma de todas as modalidades de neglect duplicada e triplicada, a correlação entre o volume da lesão e o NIHSS foi significativamente maior do que com o NIHSS original e a correlação parcial deixou de ser estatisticamente significativa.
ISBE & Cochrane Portugal Newsletter nº 176: Glossário - termos utilizados nas revisões sistemáticas e meta-análises
Esta Newsletter (NL) resulta de uma parceria entre o Instituto de Saúde Baseada na Evidência e a Cochrane Portugal, e tem como objectivo disponibilizar informação sobre áreas interessantes para a prática clínica, com base na melhor evidência científica. São incluídos estudos relevantes, criticamente avaliados pela sua validade, importância dos resultados e aplicabilidade prática, resumidos numa óptica de suporte à decisão. É dada prioridade a estudos de causalidade incluindo-se ainda, quando justificado, estudos qualitativos e metodológicos, assim como revisões científicas. O conteúdo da NL é da exclusiva responsabilidade do(s) seu(s) autor(es).
2022
Carneiro, António Vaz Henriques, Susana Oliveira
Populism and nationalism revisited: A comparative study of the Spanish and Portuguese New Left
Current definitions of populism are insufficiently determinate. They fail to distinguish between populism and nationalism. We propose to remedy this problem by advancing a new definition of populism as the logic of democratic resentment. We apply this new definition to a comparison between Spain's Podemos and Portugal's Left Bloc (BE), which we classify as social carriers of populism. We make two contributions to the literature. First, our findings dispute existing characterisations of the Portuguese case, which fail to distinguish between populist and nationalist claim-making. Second, our analysis undermines depictions of Podemos as the consummate populist party in Iberia: In 2015, the little studied BE was a stronger populist carrier than Podemos. The analytical framework underpinning this conclusion offers a more refined approach to populism than the alternatives and sets a higher standard for empirical replication.
2022
Silva, Filipe Carreira da Manucci, Luca Veloso Larraz, David
Murid Gammaherpesvirus latency-associated protein M2 promotes the formation of conjugates between transformed B lymphoma cells and T helper cells
Establishment of persistent infection in memory B cells by murid herpesvirus-4 (MuHV-4) depends on the proliferation of latently infected germinal center B cells, for which T cell help is essential. Whether the virus is capable of modulating B-T helper cell interaction for its own benefit is still unknown. Here, we investigate if the MuHV-4 latency associated M2 protein, which assembles multiprotein complexes with B cell signaling proteins, plays a role. We observed that M2 led to the upregulation of adhesion and co-stimulatory molecules in transduced B cell lines. In an MHC-II restricted OVA peptide-specific system, M2 polarized to the B-T helper contact zone. Furthermore, it promoted B cell polarization, as demonstrated by the increased proximity of the B cell microtubule organizing center to the interface. Consistent with these data, M2 promoted the formation of B-T helper cell conjugates. In an in vitro competition assay, this translated into a competitive advantage, as T cells preferentially conjugated with M2-expressing B cells. However, expression of M2 alone in B cells was not sufficient to lead to T cell activation, as it only occurred in the presence of specific peptide. Taken together, these findings support that M2 promotes the formation of B-T helper cell conjugates. In an in vivo context this may confer a competitive advantage to the infected B cell in acquisition of T cell help and initiation of a germinal center reaction, hence host colonization.
2015
Fontinha, Diana Lopes, Filipa B. Marques, Sofia Simas, J Pedro
BDNF, via truncated TrkB receptor, modulates GlyT1 and GlyT2 in astrocytes
Glycine transporters (GlyT), GlyT1 and GlyT2, are responsible for the termination of glycine-mediated synaptic activity through removal of neurotransmitter from synaptic cleft. Brain-derived neurotrophic factor (BDNF) activates its high affinity tropomyosin-related kinase (Trk) receptors, namely TrkB, which includes full length (TrkB-FL) and truncated (TrkB-T) isoforms. In this article we evaluated the influence of BDNF upon the activity of glycine transporters in astrocytes. We report that BDNF decreases GlyT1- and GlyT2- mediated [(3) H]glycine transport in primary cultures of astrocytes from rat cerebral cortex. BDNF decreased Vmax but not Km values of transport, which suggests that BDNF induces transporter internalization. Accordingly, dynasore, an inhibitor of dynamin/clathrin-dependent endocytosis, prevented the influence of BDNF upon GlyT-mediated transport. While quantifying mRNA and protein levels, we detected a predominance of truncated isoforms over the TrkB-FL receptor. The effect of BDNF was not abolished by specific inhibitors of PLCγ, PI3K and MAPK, indicating that it did not occur through TrkB-FL canonical pathways. However, BDNF action was lost in the presence of a Rho family-specific blocker (toxin B), a signaling pathway that has been associated to TrkB-T1. Furthermore, the effect of BDNF was abolished upon TrkB-T knockdown in astrocytes by RNA interference. Immunofluorescence assays confirmed an increased GlyT expression in endosomes upon BDNF incubation, which was prevented in the presence of either dynasore or toxin B. We conclude that BDNF, acting on TrkB-T1 receptors, inhibits glycine uptake in astrocytes by promoting GlyT internalization through a Rho-GTPase activity dependent mechanism.
2015
Aroeira, Rita I. Sebastião, Ana M Valente, Cláudia A.
Is the time in therapeutic range using the ratio of tests equivalent to the Rosendaal method?
The percentage of time in therapeutic range (TTR) is a measure of anticoagulation quality with vitamin K antagonists (VKAs). The method most commonly used in clinical trials is the Rosendaal TTR. However, the application of this method in daily practice for clinical decision lacks appropriate instruments. We aimed to evaluate the percentage of tests within the target international normalized ratio (INR) (tests ratio) as a surrogate of Rosendaal TTR. We performed an observational and retrospective study to evaluate the TTR according to the Rosendaal method and tests ratio. We included all outpatients who attended the cardiology anticoagulation clinic of a Portuguese hospital (2011-2013), whose target INR was 2.0-3.0. Three hundred and seventy-seven VKA-treated patients followed for a mean 1.3 years were evaluated. Rosendaal methold and tests ratio significantly correlated (Rho Spearman 0.88, P < 0.001), but the Bland-Altman plot evaluation showed a clinically relevant data dispersion [95% confidence interval (95% CI) -12.9 to 23.1] around a mean difference in TTR -5.1% using the tests ratio method. The linear regression Passing-Bablok confirmed the existence of significant data dispersion and systematic differences. The tests ratio less than 60% had a sensitivity of 91.6%, specificity of 72.3%, positive predictive value (PPV) of 72.2% and negative predictive value (NPV) of 91.6%, for the diagnosis of patients inadequately anticoagulated (Rosendaal TTR <60%). Tests ratio had a c-statistics of 0.94 (95% CI 0.91-0.96). Number of tests in 6 months had a c-statistics of 0.70 (95% CI 0.65-0.75). Tests ratio underestimated TTR in 5% and was not considered equivalent to Rosendaal TTR due to the high variability between methods. Nevertheless, the use of tests ratio less than 60% may be a reasonable option to detect inadequate anticoagulation, as it is a sensitive method and excluded most of the patients with adequate control.
2015
Caldeira, Daniel Cruz, Inês Morgado, Gonçalo Stuart, Bruno Gomes, Ana Catarina Martins, Cristina João, Isabel Pereira, Helder
Persistence of a single clone of Streptococcus agalactiae causing disease in tilapia (Oreochromis sp.) cultured in Colombia over 8 years
Streptococcosis is a disease with major health and economic impacts on the tilapia industry worldwide (Mian et al. 2009). In 1997, more than US$150 million of annual losses representing treatment, morbidity and mortality were recorded and this value increased to US$250 million by 2008 (Klesius, Shoemaker & Evans 2008). In Colombia, Streptococcus agalactiae (Lancefield group B streptococci; GBS) is the main bacterial pathogen of tilapia (Jiménez et al. 2007), causing heavy but not yet quantified losses.
2015
Barato, P. Martins, Elisabete R. Melo Cristino, José Iregui, C. A. Ramirez, Mário
Malaria prevalence and incidence in an isolated, meso-endemic area of Mozambique
Isolated areas, such as the 2 × 7 km peninsula of Linga Linga in Mozambique, are the places where malaria might be most easily eliminated. Currently available control strategies include long-lasting insecticidal bednets impregnated with pyrethroid insecticides (LLINs), rapid diagnostic tests (RDTs) for diagnosis and artemisinin based combination therapy (ACT) for treatment and these were applied on the peninsula. In 2007, following a census of the population and mapping of 500 households, five annual all-age prevalence surveys were conducted. Information on LLIN use, house construction, and animal ownership was obtained. A spatially structured generalized additive model indicated that malaria risk was greatest towards the northern end of the peninsula and that people living in houses with grass or thatch roofs had a greater risk of malaria than those living in houses with corrugated iron roofs. Incidence peaked nine weeks after rainfall (r (2) = 0.34, p = 0.0002). From 2009 incidence was measured at a centrally based project clinic. The proportion of under nine-year-old resident attendees diagnosed with malaria decreased significantly from 48% in 2009, to 35% in 2010 and 25% in 2011. At the same time, there was a shift in the peak age of cases from 1-4 year olds to 5-9 year olds. Nevertheless, in order to further reduce malaria transmission in an area such as Linga Linga, additional vector control measures need to be considered.
2015
Charlwood, Jacques Derek Tomás, Erzelia V. E. Bragança, Mauro Cuamba, Nelson Alifrangis, Michael Stanton, Michelle
Temporomandibular joint arthroscopy: inverted portal technique for more effective retrodiscal coblation
Temporomandibular joint (TMJ) retrodiscal tissue coblation is regularly performed as part of level 2 arthroscopy. It is usually performed with a coblator probe, which is introduced into the joint via an anterior working portal and visualized with an arthroscope connected to the posterior cannula. Coblation with the traditional landmarks is relatively easy in the medial, posterior, and anterior parts of the TMJ upper compartment; however, TMJ arthroscopy cannot access the entire upper compartment. Using the classical technique, it was estimated that surgeons can reach approximately 50–65% of the joint, and it is almost impossible to access the lateral and posterolateral areas. This technical note describes a simple and effective technique that improves access to the posterolateral area of the capsule for optimal retrodiscal coblation, increasing the treatment area by an estimated 10–15% without the need for any additional puncture.
Application of plant–soil feedbacks in the selection of crop rotation sequences
Plant–soil feedback (PSF) can be a major driver of plant performance in com- munities, and this concept can be used in selecting crop rotation sequences to maximize agricultural yields. Potential benefits of using PSF in this context include nutrient use optimization, pathogen reduction, and enhancement of mutualisms between crops and microbes. Yet the contributions of these com- bined mechanisms are poorly understood. Here we investigated the relative contributions of these mechanisms using five major crops commonly culti- vated in rotation (alfalfa, canola, maize, soybean, and wheat) under controlled conditions. We trained soil by growing each of the five crops in a “training phase,” and then reciprocally planted the five crops in the trained soils in a “feedback phase.” To tease out soil biota from nutrient effects, we established three treatments: “control” (trained unsterilized soil used in the feedback phases), “biota” (sterilized soil in the feedback phase inoculated with soil biota from the control treatment after the training phase), and “nutrient” (sterilized soils in both phases). Plant–soil feedback for each crop was calculated by com- paring the total biomass of each crop grown in soils trained by each of the four other crops (i.e., in rotation) against total biomass in self-trained soil (i.e., monocropping). We found that PSF values varied among crop combina- tions in all the treatments, but such variation was the greatest in the nutrient treatment. Overall, soil biota feedback tended to be lower, whereas nutrient feedback tended to be greater compared to the unsterilized control soil, suggesting that effects of antagonistic biota outweighed those of beneficial microbes in the biota treatment, and that plants optimized nutrient uptake when the soil microbiome was absent in the nutrient treatment. Furthermore, soils in the nutrient treatment trained by the legume crops (alfalfa and soy- bean) tended to provide the greatest positive feedback, emphasizing the impor- tant legacy of N2 fixers in crop rotation. Taken together, our data demonstrate how nutrients and soil biota can be integral to PSFs among crops, and that assessing PSFs under controlled conditions can serve as a basis to determine the most productive crop rotation sequences prior to field testing.
2022
Koyama, Akihiro Dias, Teresa Antunes, Pedro M.
Mousetrapping: the ordeals of interpretation
The assumption that interpretation is widespread and must be tamed is illustrated in the ambition for a touchstone capable of showing the authenticity, or veracity, of certain entities. Such touchstone would have the capacity to help us distinguish friends from enemies, of identifying the quality of particular lines, and of bringing the truth to light. This touchstone, used for the comprehension of others, may be an object, a form of test, or a person. It will, however, be seen that accurate judgments do not derive from the use of the touchstone itself, but from a technical understanding of interpretation conducted by accomplished individuals. Precise forms of judgment are, thus, the result of a combination of factors that include good intuition, or conviction, the ability to learn a specific method or technique, to show something, detect errors and ask questions.