RESUMO
The compendium of RNA-binding proteins (RBPs) has been greatly expanded by the development of RNA-interactome capture (RIC). However, it remained unknown if the complement of RBPs changes in response to environmental perturbations and whether these rearrangements are important. To answer these questions, we developed "comparative RIC" and applied it to cells challenged with an RNA virus called sindbis (SINV). Over 200 RBPs display differential interaction with RNA upon SINV infection. These alterations are mainly driven by the loss of cellular mRNAs and the emergence of viral RNA. RBPs stimulated by the infection redistribute to viral replication factories and regulate the capacity of the virus to infect. For example, ablation of XRN1 causes cells to be refractory to SINV, while GEMIN5 moonlights as a regulator of SINV gene expression. In summary, RNA availability controls RBP localization and function in SINV-infected cells.
Assuntos
Células Epiteliais/virologia , Perfilação da Expressão Gênica/métodos , RNA Viral/genética , Proteínas de Ligação a RNA/genética , Sindbis virus/genética , Transcriptoma , Neoplasias do Colo do Útero/virologia , Regiões 5' não Traduzidas , Sítios de Ligação , Células Epiteliais/metabolismo , Exorribonucleases/genética , Exorribonucleases/metabolismo , Feminino , Regulação Viral da Expressão Gênica , Células HEK293 , Células HeLa , Interações Hospedeiro-Patógeno , Humanos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Ligação Proteica , RNA Viral/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteínas Nucleares Pequenas/genética , Ribonucleoproteínas Nucleares Pequenas/metabolismo , Proteínas do Complexo SMN , Sindbis virus/crescimento & desenvolvimento , Sindbis virus/metabolismo , Sindbis virus/patogenicidade , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo , Replicação ViralRESUMO
Oil palm is a major driver of tropical deforestation. A key intervention proposed to reduce the footprint of oil palm is intensifying production to free up spare land for nature, yet the indirect land-use implications of intensification through market forces are poorly understood. We used a spatially explicit land-rent modeling framework to characterize the supply and demand of oil palm in Indonesia under multiple yield improvement and demand elasticity scenarios and explored how shifts in market equilibria alter projections of crop expansion. Oil palm supply was sensitive to crop prices and yield improvements. Across all our scenarios, intensification raised agricultural rents and lowered the effectiveness of reductions in crop expansion. Increased yields lowered oil palm prices, but these price-drops were not sufficient to prevent further cropland expansion from increased agricultural rents under a range of price elasticities of demand. Crucially, we found that agricultural intensification might only result in land being spared when the demand relationship was highly inelastic and crop prices were very low (i.e., a 70% price reduction). Under this scenario, the extent of land spared (â¼0.32 million ha) was countered by the continued establishment of new plantations (â¼1.04 million ha). Oil palm intensification in Indonesia could exacerbate current pressures on its imperiled biodiversity and should be deployed with stronger spatial planning and enforcement to prevent further cropland expansion.
Cambios en el uso de suelo causados por la reacción del mercado a la intensificación de la palma aceitera en Indonesia Resumen La palma aceitera es una de las principales causas de la deforestación. Una intervención importante propuesta para reducir la huella de esta palma es la intensificación de la producción para que el suelo sobrante sea usado por la naturaleza, pero se sabe muy poco sobre las implicaciones del uso indirecto de suelo de la intensificación a través de las fuerzas del mercado. Usamos un marco de modelos de renta de suelo espacialmente explícito para caracterizar la oferta y demanda de la palma aceitera en Indonesia bajo varios escenarios de mejoras en la producción y elasticidad de demandas y exploramos cómo los cambios en el equilibrio del mercado alteran las proyecciones de la expansión agrícola. La oferta de palma aceitera fue susceptible a los precios de los cultivos y a las mejoras en la producción. La intensificación elevó la renta agrícola y redujo la efectividad de la reducción de la expansión agrícola en todos nuestros escenarios. El aumento en la producción bajó los precios de la palma, pero estas caídas no fueron suficientes para evitar la expansión agrícola a partir de las rentas agrícolas elevadas bajo un rango de elasticidad de precios de demanda. Más importante, descubrimos que la intensificación agrícola puede sólo resultar en que sobre el suelo cuando la relación de demanda casi no sea elástica y los precios de las cosechas sean muy bajos (una reducción del 70% en los precios). Bajo este escenario, la extensión de suelo sobrante (â¼0.32 millones de ha) fue contrarrestado por el establecimiento continuo de nuevos sembradíos (â¼1.04 millones de ha). La intensificación de la palma aceitera en Indonesia podría agravar las presiones existentes sobre su biodiversidad en peligro y debería implementarse con una mayor planeación espacial y aplicación para prevenir una expansión agrícola superior.
Assuntos
Arecaceae , Conservação dos Recursos Naturais , Indonésia , Agricultura , Biodiversidade , Arecaceae/fisiologiaRESUMO
Consensus statements have proposed the use of the National Early Warning Score 2 (NEWS2) to identify stable patients with acute pulmonary embolism (PE) and an intermediate-high risk of adverse outcomes. We aimed to externally validate NEWS2 and compare it to another predictive score (Bova). Using NEWS2 (cutoff ≥5 and ≥7) and the Bova score (cutoff >4), we classified patients as intermediate-high risk (vs. non-intermediate-high risk), and we compared the test characteristics of these risk classification tools for a complicated course within 30 days after PE diagnosis. We also assessed the validity of NEWS2 for predicting a complicated course by adding the results of echocardiography and troponin testing to the model. Of the 848 enrolled patients, the NEWS2 score ≥5 classified 471 (55.5%) and the Bova score classified 37 (4.4%) as intermediate-high risk. NEWS2 had a significantly lower specificity for a 30-day complicated course than Bova (45.4 vs. 96.3%, respectively; p < 0.001). Using the higher score threshold (≥7), the NEWS2 classified 99 (11.7%) as intermediate-high risk, and the specificity was 88.9% (difference with Bova, 7.4%; p < 0.001). The proportion of patients with intermediate-high risk PE was 2.4% for the combination of a positive troponin testing and echocardiographic right ventricle dysfunction and a positive NEWS2 (score ≥7), while the specificity was 97.8% (difference with Bova, 1.5%; p = 0.07). Bova outperforms NEWS2 for predicting a complicated course among stable patients with PE. Addition of troponin testing and echocardiography improved the specificity of NEWS2, although it was not superior to Bova. CLINICALTRIALS.GOV NUMBER: : NCT02238639.
Assuntos
Escore de Alerta Precoce , Embolia Pulmonar , Humanos , Estudos Retrospectivos , Medição de Risco/métodos , Embolia Pulmonar/diagnóstico , Embolia Pulmonar/complicações , TroponinaRESUMO
Understanding the spatial scales at which environmental factors drive species richness patterns is a major challenge in ecology. Due to the trade-off between spatial grain and extent, studies tend to focus on a single spatial scale, and the effects of multiple environmental variables operating across spatial scales on the pattern of local species richness have rarely been investigated. Here, we related variation in local species richness of ground beetles, landbirds and small mammals to variation in vegetation structure and topography, regional climate, biome diversity and glaciation history for 27 sites across the USA at two different spatial grains. We studied the relative influence of broad-scale (landscape) environmental conditions using variables estimated at the site level (climate, productivity, biome diversity and glacial era ice cover) and fine-scale (local) environmental conditions using variables estimated at the plot level (topography and vegetation structure) to explain local species richness. We also examined whether plot-level factors scale up to drive continental scale richness patterns. We used Bayesian hierarchical models and quantified the amount of variance in observed richness that was explained by environmental factors at different spatial scales. For all three animal groups, our models explained much of the variation in local species richness (85%-89%), but site-level variables explained a greater proportion of richness variance than plot-level variables. Temperature was the most important site-level predictor for explaining variance in landbirds and ground beetles richness. Some aspects of vegetation structure were the main plot-level predictors of landbird richness. Environmental predictors generally had poor explanatory power for small mammal richness, while glacial era ice cover was the most important site-level predictor. Relationships between plot-level factors and richness varied greatly among geographical regions and spatial grains, and most relationships did not hold when predictors were scaled up to the continental scale. Our results suggest that the factors that determine richness may be highly dependent on spatial grain, geography, and animal group. We demonstrate that instead of artificially manipulating the resolution to study multiscale effects, a hierarchical approach that uses fine grain data at broad extents could help solve the issue of scale selection in environment-richness studies.
Assuntos
Biodiversidade , Besouros , Animais , Teorema de Bayes , Clima , Ecossistema , MamíferosRESUMO
A recent review suggests that forest cover needs to be restored or maintained on at least 40% of land area. In the absence of empirical evidence to support this threshold, we discuss how this suggestion is unhelpful and potentially dangerous. We advocate for regionally defined thresholds to inform conservation and restoration.
Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Ecossistema , FlorestasRESUMO
Noncanonical translation, and particularly initiation on non-AUG codons, are frequently used by viral and cellular mRNAs during virus infection and disease. The Sindbis virus (SINV) subgenomic mRNA (sgRNA) constitutes a unique model system to analyze the translation of a capped viral mRNA without the participation of several initiation factors. Moreover, sgRNA can initiate translation even when the AUG initiation codon is replaced by other codons. Using SINV replicons, we examined the efficacy of different codons in place of AUG to direct the synthesis of the SINV capsid protein. The substitution of AUG by CUG was particularly efficient in promoting the incorporation of leucine or methionine in similar percentages at the amino terminus of the capsid protein. Additionally, valine could initiate translation when the AUG is replaced by GUG. The ability of sgRNA to initiate translation on non-AUG codons was dependent on the integrity of a downstream stable hairpin (DSH) structure located in the coding region. The structural requirements of this hairpin to signal the initiation site on the sgRNA were examined in detail. Of interest, a virus bearing CUG in place of AUG in the sgRNA was able to infect cells and synthesize significant amounts of capsid protein. This virus infects the human haploid cell line HAP1 and the double knockout variant that lacks eIF2A and eIF2D. Collectively, these findings indicate that leucine-tRNA or valine-tRNA can participate in the initiation of translation of sgRNA by a mechanism dependent on the DSH. This mechanism does not involve the action of eIF2, eIF2A, or eIF2D.
Assuntos
Códon de Iniciação/genética , Biossíntese de Proteínas , RNA Mensageiro/genética , RNA Viral/genética , Transdução de Sinais/genética , Sindbis virus/genética , Proteínas do Capsídeo/biossíntese , Proteínas do Capsídeo/genética , Linhagem Celular Tumoral , Códon de Iniciação/metabolismo , Fator de Iniciação 2 em Eucariotos/deficiência , Fator de Iniciação 2 em Eucariotos/genética , Fibroblastos/metabolismo , Fibroblastos/virologia , Regulação da Expressão Gênica , Haploidia , Interações Hospedeiro-Patógeno/genética , Humanos , Sequências Repetidas Invertidas , Leucina/genética , Leucina/metabolismo , Metionina/genética , Metionina/metabolismo , Conformação de Ácido Nucleico , RNA Mensageiro/metabolismo , RNA de Transferência de Leucina/genética , RNA de Transferência de Leucina/metabolismo , RNA de Transferência de Valina/genética , RNA de Transferência de Valina/metabolismo , RNA Viral/metabolismo , Replicon , Sindbis virus/metabolismo , Valina/genética , Valina/metabolismoRESUMO
Climate adaptation strategies are being developed and implemented to protect biodiversity from the impacts of climate change. A well-established strategy involves the identification and addition of new areas for conservation, and most countries agreed in 2010 to expand the global protected area (PA) network to 17% by 2020 (Aichi Biodiversity Target 11). Although great efforts to expand the global PA network have been made, the potential of newly established PAs to conserve biodiversity under future climate change remains unclear at the global scale. Here, we conducted the first global-extent, country-level assessment of the contribution of PA network expansion toward three key land prioritization approaches for biodiversity persistence under climate change: protecting climate refugia, protecting abiotic diversity, and increasing connectivity. These approaches avoid uncertainties of biodiversity predictions under climate change as well as the issue of undescribed species. We found that 51% of the countries created new PAs in locations with lower mean climate velocity (representing better climate refugia) and 58% added PAs in areas with higher mean abiotic diversity compared to the available, non-human-dominated lands not chosen for protection. However, connectivity among PAs declined in 53% of the countries, indicating that many new PAs were located far from existing PAs. Lastly, we identified potential improvements for climate adaptation, showing that 94% of the countries have the opportunity to improve in executing one or more approaches to conserve biodiversity. Most countries (60%) were associated with multiple opportunities, highlighting the need for integrative strategies that target multiple land protection approaches. Our results demonstrate that a global improvement in the protection of climate refugia, abiotic diversity, and connectivity of reserves is needed to complement land protection informed by existing and projected species distributions. Our study also provides a framework for countries to prioritize land protection for climate adaptation using publicly available data.
Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Aclimatação , Mudança Climática , Ecossistema , Refúgio de Vida SelvagemRESUMO
About 70% of the world's main crops depend on insect pollination. Climate change is already affecting the abundance and distribution of insects, which could cause geographical mismatches between crops and their pollinators. Crops that rely primarily on wild pollinators (e.g., crops that cannot be effectively pollinated by commercial colonies of honey bees) could be particularly in jeopardy. However, limited information on plant-pollinator associations and pollinator distributions complicate the assessment of climate change impacts on specific crops. To study the potential impacts of climate change on pollination of a specific crop in North America, we use the case of open-field tomato crops, which rely on buzz pollinators (species that use vibration to release pollen, such as bumble bees) to increase their production. We aimed to (1) assess potential changes in buzz pollinator distribution and richness, and (2) evaluate the overlap between areas with high densities of tomato crops and high potential decrease in richness. We used baseline (1961-1990) climate and future (2050s and 2080s) climatic projections in ecological niche models fitted with occurrences of wild bees, documented in the literature as pollinators of tomatoes, to estimate the baseline and future potential distribution of suitable climatic conditions of targeted species and to create maps of richness change across North America. We obtained reliable models for 15 species and found important potential decreases in the distribution of some pollinators (e.g., Lasioglossum pectorale and Augochlorella aurata). We observed geographical discrepancies in the projected change in species richness across North America, detecting important declines in the eastern United States (up to 11 species decrease for 2050s). After overlapping the maps of species richness change with a tomato crop map for the United States, we found spatial correspondence between richness declines and areas with high concentration of tomato crops. Disparities in the effects of climate change on the potential future distribution of different wild pollinators and geographical variation in richness highlight the importance of crop-specific studies. Our study also emphasizes the challenges of compiling and modeling crop-specific pollinator data and the need to improve our understanding of current distribution of pollinators and their community dynamics under climate change.
Assuntos
Mudança Climática , Solanum lycopersicum , Animais , Abelhas , Produtos Agrícolas , América do Norte , PolinizaçãoRESUMO
Global demands for agricultural and forestry products provide economic incentives for deforestation across the tropics. Much of this deforestation occurs with a lack of information on the spatial distribution of benefits and costs of deforestation. To inform global sustainable land-use policies, we combine geographic information systems (GIS) with a meta-analysis of ecosystem services (ES) studies to perform a spatially explicit analysis of the trade-offs between agricultural benefits, carbon emissions, and losses of multiple ecosystem services because of tropical deforestation from 2000 to 2012. Even though the value of ecosystem services presents large inherent uncertainties, we find a pattern supporting the argument that the externalities of destroying tropical forests are greater than the current direct economic benefits derived from agriculture in all cases bar one: when yield and rent potentials of high-value crops could be realized in the future. Our analysis identifies the Atlantic Forest, areas around the Gulf of Guinea, and Thailand as areas where agricultural conversion appears economically efficient, indicating a major impediment to the long-term financial sustainability of Reducing Emissions from Deforestation and forest Degradation (REDD+) schemes in those countries. By contrast, Latin America, insular Southeast Asia, and Madagascar present areas with low agricultural rents (ARs) and high values in carbon stocks and ES, suggesting that they are economically viable conservation targets. Our study helps identify optimal areas for conservation and agriculture together with their associated uncertainties, which could enhance the efficiency and sustainability of pantropical land-use policies and help direct future research efforts.
Assuntos
Agricultura/economia , Conservação dos Recursos Naturais/economia , Agricultura Florestal/métodos , Florestas , Internacionalidade , Modelos Econômicos , Meio Selvagem , Agricultura/tendências , Poluição do Ar/efeitos adversos , Poluição do Ar/economia , Poluição do Ar/prevenção & controle , Animais , Ciclo do Carbono , Dióxido de Carbono/análise , Dióxido de Carbono/toxicidade , Conservação dos Recursos Naturais/tendências , Produtos Agrícolas/economia , Produtos Agrícolas/crescimento & desenvolvimento , Ecossistema , Agricultura Florestal/economia , Agricultura Florestal/tendências , Humanos , Clima TropicalRESUMO
Multiple sclerosis (MS) is the prototypical inflammatory disease of the central nervous system (CNS), leading to multifocal demyelination and neurodegeneration. The etiology of this incurable disease is unknown and remains a matter of intensive research. The possibility that microbial infections, such as viruses or bacteria, can trigger an autoimmune reaction in CNS tissue has been suggested. However, the recent demonstration that bacteria are present in CNS tissue points to a direct involvement of microbial infections in the etiology of MS. In the present study, we provide the first evidence of fungal infection in CNS tissue of MS patients, and demonstrate that fungal DNA from different species can be detected in the CNS. We used, nested PCR assays together with next-generation sequencing to identify the fungal species in the nervous tissue of 10 patients with MS. Strikingly, Trichosporon mucoides was found in the majority of MS patients, and particularly high levels of this fungus were found in two patients. Importantly, T. mucoides was not detected in the CNS of control subjects. We were also able to visualize fungal structures in CNS tissue sections by immunohistochemistry using specific antifungal antibodies, which also revealed the accumulation of a number of microbial cells in microfoci. Again, microbial structures were not observed in CNS sections from controls. In addition to fungi, neural tissue from MS patients was also positive for bacteria. In conclusion, our present observations point to the novel concept that MS could be caused by polymicrobial infections. Thus, mycosis of the CNS may be accompanied by opportunistic bacterial infection, promoting neuroinflammation and directly causing focal lesions, followed by demyelination and axonal injury.
Assuntos
Infecções Bacterianas/patologia , Sistema Nervoso Central/microbiologia , Sistema Nervoso Central/patologia , Coinfecção/patologia , Esclerose Múltipla/microbiologia , Esclerose Múltipla/patologia , Micoses/patologia , Bactérias/isolamento & purificação , Infecções Bacterianas/epidemiologia , Encéfalo/microbiologia , Encéfalo/patologia , Coinfecção/epidemiologia , Feminino , Fungos/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Micoses/epidemiologia , Análise de Sequência de DNA/métodos , Medula Espinal/microbiologia , Medula Espinal/patologiaRESUMO
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease and the main cause of motor neuron pathology. The etiology of the disease remains unknown, and no effective therapy exists to halt the disease or improve the quality of life. Here, we provide compelling evidence for the existence of fungal infection in ALS. Immunohistochemistry analysis using a battery of antifungal antibodies revealed fungal structures such as yeast and hyphae in the motor cortex, the medulla and the spinal cord, in eleven patients with ALS. Some fungal structures were localized intracellularly and even intranuclearly, indicating that this infection is not the result of post-mortem colonization. By contrast, this burden of fungal infection cannot be observed in several CNS areas of control subjects. PCR analysis and next generation sequencing of DNA extracted from frozen neural tissue identified a variety of fungal genera including Candida, Malassezia, Fusarium, Botrytis, Trichoderma and Cryptococcus. Overall, our present observations provide strong evidence for mixed fungal infections in ALS patients. The exact mixed infection varies from patient to patient consistent with the different evolution and severity of symptoms in each ALS patient. These novel findings provide a logical explanation for the neuropathological observations of this disease, such as neuroinflammation and elevated chitinase levels, and could help to implement appropriate therapies.
Assuntos
Esclerose Lateral Amiotrófica/complicações , Esclerose Lateral Amiotrófica/patologia , Infecções Fúngicas do Sistema Nervoso Central/complicações , Infecções Fúngicas do Sistema Nervoso Central/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Esclerose Lateral Amiotrófica/microbiologia , Feminino , Genômica , Humanos , Imuno-Histoquímica , Masculino , Bulbo/microbiologia , Bulbo/patologia , Metagenoma , Pessoa de Meia-Idade , Córtex Motor/microbiologia , Córtex Motor/patologia , Neurônios/microbiologia , Neurônios/patologia , Reação em Cadeia da Polimerase , Análise de Sequência , Medula Espinal/microbiologia , Medula Espinal/patologiaRESUMO
Translation initiation of alphavirus subgenomic mRNA (sgmRNA) can occur in the absence of several initiation factors (eIFs) in infected cells; however, the precise translation mechanism is still poorly understood. In this study, we have examined the mechanism of initiation and AUG selection in Sindbis virus (SINV) sgmRNA. Our present findings suggest that sgmRNA is translated via a scanning mechanism, since the presence of a hairpin structure before the initiation codon hampers protein synthesis directed by this mRNA. In addition, translation is partially recovered when an in-frame AUG codon is placed upstream of this hairpin. This scanning process takes place without the participation of eIF4A and active eIF2. These results, combined with our findings through modifying the SINV sgmRNA leader sequence, do not support the possibility of a direct initiation from the start codon without previous scanning, or a shunting mechanism. Moreover, studies carried out with sgmRNAs containing two alternative AUG codons within a good context for translation reveal differences in AUG selection which are dependent on the cellular context and the phosphorylation state of eIF2α. Thus, initiation at the additional AUG is strictly dependent on active eIF2, whereas the genuine AUG codon can start translation following eIF2α inactivation. Collectively, our results suggest that SINV sgmRNA is translated by a scanning mechanism without the potential participation of crucial eIFs. A model is presented that explains the mechanism of initiation of mRNAs bearing two alternative initiation codons.
Assuntos
Fatores de Iniciação de Peptídeos/fisiologia , RNA Mensageiro/genética , Sindbis virus/genética , Aedes , Animais , Sequência de Bases , Linhagem Celular , Códon de Iniciação , Cricetinae , Fator de Iniciação 2 em Eucariotos/fisiologia , Genoma Viral , Sequências Repetidas Invertidas , Camundongos , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Biossíntese de Proteínas , RNA Mensageiro/metabolismo , RNA Viral/genética , RNA Viral/metabolismo , Proteínas Virais/biossíntese , Proteínas Virais/genéticaRESUMO
Infection of mammalian cells by Sindbis virus (SINV) profoundly blocks cellular mRNA translation. Experimental evidence points to viral non-structural proteins (nsPs), in particular nsP2, as the mediator of this inhibition. However, individual expression of nsP1, nsP2, nsP3 or nsP1-4 does not block cellular protein synthesis in BHK cells. Trans-complementation of a defective SINV replicon lacking most of the coding region for nsPs by the co-expression of nsP1-4 propitiates viral RNA replication at low levels, and inhibition of cellular translation is not observed. Exit of nuclear proteins including T-cell intracellular antigen and polypyrimidine tract-binding protein is clearly detected in SINV-infected cells, but not upon the expression of nsPs, even when the defective replicon was complemented. Analysis of a SINV variant with a point mutation in nsP2, exhibiting defects in the shut-off of host protein synthesis, indicates that both viral RNA replication and the release of nuclear proteins to the cytoplasm are greatly inhibited. Furthermore, nucleoside analogues that inhibit cellular and viral RNA synthesis impede the blockade of host mRNA translation, in addition to the release of nuclear proteins. Prevention of the shut-off of host mRNA translation by nucleoside analogues is not due to the inhibition of eIF2α phosphorylation, as this prevention is also observed in PKR(-/-) mouse embryonic fibroblasts that do not phosphorylate eIF2α after SINV infection. Collectively, our observations are consistent with the concept that for the inhibition of cellular protein synthesis to occur, viral RNA replication must take place at control levels, leading to the release of nuclear proteins to the cytoplasm.
Assuntos
Interações Hospedeiro-Patógeno , Proteínas Nucleares/metabolismo , Biossíntese de Proteínas , RNA Viral/metabolismo , Sindbis virus/fisiologia , Proteínas não Estruturais Virais/metabolismo , Replicação Viral , Animais , Linhagem Celular , Cricetinae , Citoplasma/metabolismo , Camundongos , Camundongos KnockoutRESUMO
The supposition that agricultural intensification results in land sparing for conservation has become central to policy formulations across the tropics. However, underlying assumptions remain uncertain and have been little explored in the context of conservation incentive schemes such as policies for Reducing Emissions from Deforestation and forest Degradation, conservation, sustainable management, and enhancement of carbon stocks (REDD+). Incipient REDD+ forest carbon policies in a number of countries propose agricultural intensification measures to replace extensive "slash-and-burn" farming systems. These may result in conservation in some contexts, but will also increase future agricultural land rents as productivity increases, creating new incentives for agricultural expansion and deforestation. While robust governance can help to ensure land sparing, we propose that conservation incentives will also have to increase over time, tracking future agricultural land rents, which might lead to runaway conservation costs. We present a conceptual framework that depicts these relationships, supported by an illustrative model of the intensification of key crops in the Democratic Republic of Congo, a leading REDD+ country. A von Thünen land rent model is combined with geographic information systems mapping to demonstrate how agricultural intensification could influence future conservation costs. Once postintensification agricultural land rents are considered, the cost of reducing forest sector emissions could significantly exceed current and projected carbon credit prices. Our analysis highlights the importance of considering escalating conservation costs from agricultural intensification when designing conservation initiatives.
Assuntos
Agricultura/economia , Conservação dos Recursos Naturais/economia , Agricultura/métodos , Biodiversidade , Carbono/química , Conservação dos Recursos Naturais/métodos , Produtos Agrícolas , República Democrática do Congo , Ecossistema , Modelos Estatísticos , Árvores , Zea maysRESUMO
The aim of the current study was to analyse the effect of 10-week eccentric overload training on kinetic parameters during change of direction (COD) in U-19 football players. The outcome measured included relative peak braking (rPB) and propulsive force (rPF), contact time (CT), time spent during braking (BT) and propulsive phase (PT), relative total (rTOT_IMP), braking (rB_IMP) and propulsive (rP_IMP) impulses. Between-group results showed a substantial better improvement (likely) in CT (ES: 0.72) and BT (ES: 0.74) during side-step cutting, and in rPB (ES: 0.84) and rB_IMP (ES: 0.72) during crossover cutting, in the experimental group (EXP) in comparison to control group (CON). Within-group analysis showed a substantially better performance (likely to almost certain) in CT (ES: 1.19), BT (ES: 1.24), PT (ES: 0.70), rPB (ES: 0.75), rPF (ES: 0.68), rTOT_IMP (ES: 0.48) and rB_IMP (ES: 0.50) in EXP during side-step cutting. Regarding crossover cutting, within-group analysis showed a substantial better performance (likely to almost certain) in CT (ES: 0.75), rPB (ES: 0.75), rPF (ES: 1.34), rTOT_IMP (ES: 0.61), rB_IMP (ES: 0.76) and rP_IMP (ES: 0.46) in EXP. In conclusion, the eccentric overload-based programme led to an improvement in kinetic parameters during COD football tasks.
Assuntos
Destreza Motora/fisiologia , Treinamento Resistido/métodos , Futebol/fisiologia , Adolescente , Desempenho Atlético/fisiologia , Humanos , Masculino , Exercício PliométricoRESUMO
We analysed the time course of recovery of creatine kinase (CK) and countermovement jump (CMJ) parameters after a football match, and correlations between changes in these variables and match time-motion parameters (GPS-accelerometry) in 15 U-19 elite male players. Plasma CK and CMJ height (CMJH), average concentric force (CMJCON) and average eccentric force (CMJECC) were assessed 2 h before and 30 min, 24 h and 48 h post-match. There were substantially higher CK levels 30 min, 24 h and 48 h (ES: 0.43, 0.62, 0.40, respectively), post-match. CMJECC (ES: -0.38), CMJH (ES: -0.35) decreased 30 min post, CMJCON (ES: -0.35), CMJECC (ES: -0.35) and CMJH (ES: -1.35) decreased 24 h post, and CMJCON (ES: -0.41) and CMJH (ES: -0.53) decreased 48 h post. We found correlations between distance covered at velocities ≤21 km · h(-1) and changes in CK at 24 h (r = 0.56) and at 48 h (r = 0.54) and correlations between CK and distance covered >14 km · h(-1) (r = 0.50), accelerations (r = 0.48), and decelerations (r = 0.58) at 48 h. Changes in CMJCON 30 min and 24 h post (both r = -0.68) correlated with impacts >7.1·G. Decelerations >2 m · s(-)(2) correlated with changes CMJCON (r = -0.49) at 48 h and CMJECC (r = -0.47) at 30 min. Our results suggest that match GPS-accelerometry parameters may predict muscle damage and changes in components of neuromuscular performance immediately and 24-48 h post-match.
Assuntos
Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Músculo Esquelético/lesões , Futebol/lesões , Futebol/fisiologia , Adolescente , Creatina Quinase/sangue , Humanos , Masculino , Músculo Esquelético/enzimologia , Exercício Pliométrico , Fatores de Tempo , Estudos de Tempo e MovimentoRESUMO
Sañudo, B, Rueda, D, del Pozo-Cruz, B, de Hoyo, M, and Carrasco, L. Validation of a video analysis software package for quantifying movement velocity in resistance exercises. J Strength Cond Res 30(10): 2934-2941, 2016-The aim of this study was to establish the validity of a video analysis software package in measuring mean propulsive velocity (MPV) and the maximal velocity during bench press. Twenty-one healthy males (21 ± 1 year) with weight training experience were recruited, and the MPV and the maximal velocity of the concentric phase (Vmax) were compared with a linear position transducer system during a standard bench press exercise. Participants performed a 1 repetition maximum test using the supine bench press exercise. The testing procedures involved the simultaneous assessment of bench press propulsive velocity using 2 kinematic (linear position transducer and semi-automated tracking software) systems. High Pearson's correlation coefficients for MPV and Vmax between both devices (r = 0.473 to 0.993) were observed. The intraclass correlation coefficients for barbell velocity data and the kinematic data obtained from video analysis were high (>0.79). In addition, the low coefficients of variation indicate that measurements had low variability. Finally, Bland-Altman plots with the limits of agreement of the MPV and Vmax with different loads showed a negative trend, which indicated that the video analysis had higher values than the linear transducer. In conclusion, this study has demonstrated that the software used for the video analysis was an easy to use and cost-effective tool with a very high degree of concurrent validity. This software can be used to evaluate changes in velocity of training load in resistance training, which may be important for the prescription and monitoring of training programmes.
Assuntos
Exercício Físico/fisiologia , Treinamento Resistido/métodos , Software , Gravação de Videoteipe , Fenômenos Biomecânicos , Humanos , Masculino , Reprodutibilidade dos Testes , Adulto JovemRESUMO
OBJECTIVES: To examine the effects of a supervised aerobic exercise programme on heart rate variability (HRV) parameters and symptom severity in women with fibromyalgia (FM). METHODS: Thirty-two women with FM were randomly allocated to one of two groups: aerobic exercise (AE) or usual care control for 24 weeks. Women allocated to AE performed two aerobic exercise sessions per week of 45-60 min duration including 15-20 min of steady-state aerobic exercise at 60-65% of predicted maximum heart rate (HRmax) and 15 min of interval training at 75-80% HRmax (six repetitions of 1.5 min, with 1 min interpolated rest intervals). Cardiac autonomic modulation was assessed using power spectral analysis of HRV. Symptom severity was assessed by a 10 cm visual analogue scale (VAS) for pain, sleep disturbances, stiffness, anxiety and depression. RESULTS: After 24 weeks, the women in the exercise group showed an increase (4.8 ± 0.2 to 5.2 ± 0.2) in total power (LnTP, p<0.001), low frequency power (LnLF, p<0.01), high frequency power (LnHF, p<0.001), and the root-mean-square of successive R-R intervals (rMSSD, p<0.001). In addition, significant group-by-time interaction effects were observed for LnHF (p=0.036) and LnLF/HF (p=0.014). Improvements in anxiety and depression were also observed in AE versus control patients. CONCLUSIONS: These results show that a programme of aerobic exercise training induced changes in cardiac autonomic nervous system modulation in FM and that these changes in HRV parameters were accompanied by changes in anxiety and depression.
Assuntos
Terapia por Exercício , Fibromialgia/terapia , Frequência Cardíaca , Coração/inervação , Nervo Vago/fisiopatologia , Ansiedade/diagnóstico , Ansiedade/etiologia , Ansiedade/psicologia , Depressão/diagnóstico , Depressão/etiologia , Depressão/psicologia , Feminino , Fibromialgia/complicações , Fibromialgia/diagnóstico , Fibromialgia/fisiopatologia , Fibromialgia/psicologia , Nível de Saúde , Humanos , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Espanha , Inquéritos e Questionários , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: The utility of patient attributes associated with the spatiotemporal analysis of medical records lies not just in their values but also the strength of association between them. Estimating the extent to which a hierarchy of conditional probability exists between patient attribute associations such as patient identifying fields, patient and date of diagnosis, and patient and address at diagnosis is fundamental to estimating the strength of association between patient and geocode, and patient and enumeration area. We propose a hierarchy for the attribute associations within medical records that enable spatiotemporal relationships. We also present a set of metrics that store attribute association error probability (AAEP), to estimate error probability for all attribute associations upon which certainty in a patient geocode depends. METHODS: A series of experiments were undertaken to understand how error estimation could be operationalized within health data and what levels of AAEP in real data reveal themselves using these methods. Specifically, the goals of this evaluation were to (1) assess if the concept of our error assessment techniques could be implemented by a population-based cancer registry; (2) apply the techniques to real data from a large health data agency and characterize the observed levels of AAEP; and (3) demonstrate how detected AAEP might impact spatiotemporal health research. RESULTS: We present an evaluation of AAEP metrics generated for cancer cases in a North Carolina county. We show examples of how we estimated AAEP for selected attribute associations and circumstances. We demonstrate the distribution of AAEP in our case sample across attribute associations, and demonstrate ways in which disease registry specific operations influence the prevalence of AAEP estimates for specific attribute associations. CONCLUSIONS: The effort to detect and store estimates of AAEP is worthwhile because of the increase in confidence fostered by the attribute association level approach to the assessment of uncertainty in patient geocodes, relative to existing geocoding related uncertainty metrics.