Electronic Structures and Photoredox Chemistry of Tungsten(0) Arylisocyanides.

ConspectusThe high energy barriers associated with the reaction chemistry of inert substrates can be overcome by employing redox-active photocatalysts. Research in this area has grown exponentially over the past decade, as transition metal photosensitizers have been shown to mediate challenging organic transformations. Critical for the advancement of photoredox catalysis is the discovery, development, and study of complexes based on earth-abundant metals that can replace and/or complement established noble-metal-based photosensitizers.Recent work has focused on redox-active complexes of 3d metals, as photosensitizers containing these metals most likely would be scalable. Although low lying spin doublet ("spin flip") excited states of chromium(III) and metal-to-ligand charge transfer (MLCT) excited states of copper(I) have relatively long lifetimes, the electronic excited states of many other 3d metal complexes fall on dissociative potential energy surfaces, owing to the population of highly energetic σ-antibonding orbitals. Indeed, we and other investigators have shown that low lying spin singlet and triplet excited states of robust closed-shell metal complexes are too short-lived at room temperature to engage in bimolecular reactions in solutions. In principle, this problem could be overcome by designing and constructing 3d metal complexes containing strong field π-acceptor ligands, where thermally equilibrated MLCT or intraligand charge transfer excited states might fall well below the upper surfaces of dissociative 3d-3d states. Notably, such design elements have been exploited by investigators in very recent work on redox-active iron(II) systems. Another approach, one we have actively pursued, is to design and construct closed-shell complexes of earth-abundant 5d metals containing very strong π-acceptor ligands, where vertical excitation of 5d-5d excited states at the ground state geometry would require energies far above minima in the potential surfaces of MLCT excited states. As this requirement is met by tungsten(0) arylisocyanides, these complexes have been the focus of our work aimed at the development of robust redox-active photosensitizers.In the following Account, we review recent work on homoleptic tungsten(0) arylisocyanides. Originally reported by our group 45 years ago, W(CNAr)6 complexes have exceptionally large one- and two-photon absorption cross-sections. One- or two-photon excitation produces relatively long-lived (hundreds of nanoseconds to microsecond) MLCT excited states in high yields. These MLCT excited states, which are very strong reductants with E°(W+/*W0) = -2.2 to -3.0 V vs Fc[+/0], mediate photocatalysis of organic reactions with both visible and near-infrared (NIR) light. Here, we highlight design principles that led to the development of three generations of W(CNAr)6 photosensitizers; and we discuss likely steps in the mechanism of a prototypal W(CNAr)6-catalyzed base-promoted homolytic aromatic substitution reaction. Among the many potential applications of these very bright luminophores, two-photon imaging and two-photon-initiated polymerization are ones we plan to pursue.

Influence of further decompensation on survival across clinical stages of decompensated cirrhosis: The role of portal hypertension and HVPG changes.

BACKGROUND AND AIMS: Decompensated-cirrhosis encompasses several stages with different prognosis, such as bleeding, ascites and bleeding-plus-ascites. Development of further-decompensation worsens survival, while non-selective ß-blockers (NSBBs) can modify the risk. However, how this applies to each stage is uncertain. We aimed to investigate, in each stage of decompensated-cirrhosis, the influence of further-decompensation on mortality and whether changes in portal-pressure (HVPG) under NSBBs influence these outcomes. METHODS: Patients with variceal bleeding were consecutively included differentiating those with bleeding-alone from those who also had ascites. Patients with ascites and high-risk varices referred for primary-prophylaxis were also investigated. A baseline haemodynamic study was performed and was repeated after 1-3-months under NSBBs. Outcomes were investigated by competing-risk. RESULTS: Totally 103 patients had bleeding-alone, 186 bleeding-plus-ascites and 187 ascites-alone. Mean follow-up was 32-months (IQR, 12-60). Patients with bleeding-plus-ascites had higher HVPG and were more hyperdynamic than patients with ascites-alone and these than those with bleeding-alone. At each stage, the mortality risk was more than twice in patients developing further-decompensation vs. those without (p < .001). In each stage, HVPG-decrease under NSBBs showed better discrimination to predict further-decompensation than the baseline MELD, Child-Pugh or HVPG, by time-dependent ROC-curves (c-statistic >70%). At each stage, patients without HVPG-decreases, either ≥10% or ≥20% from the baseline, had higher risk of further-decompensation (sHR from 2.43 to 6.73, p < .01) and worse survival. CONCLUSIONS: In each stage of decompensated cirrhosis, mortality risk significantly and very markedly increase with further-decompensation. HVPG-non-response to NSBBs may adequately stratify the risk of further decompensation and death, in each stage. This suggests potential benefit with pre-emptive therapies in HVPG-non-responders at each-stage.

Photoredox Catalysis Mediated by Tungsten(0) Arylisocyanides.

W(CNAr)6 (CNAr = arylisocyanide) photoreductants catalyze base-promoted homolytic aromatic substitution (BHAS) of 1-(2-iodobenzyl)-pyrrole in deuterated benzene. Moderate to high efficiencies correlate with W(CNAr)6 excited-state reduction potentials upon one-photon 445 nm excitation, with 10 mol % loading of the most powerful photoreductants W(CNDipp)6 (CNDipp = 2,6-diisopropylphenylisocyanide) and W(CNDippPhOMe3)6 (CNDippPhOMe3 = 4-(3,4,5-trimethoxyphenyl)-2,6-diisopropylphenylisocyanide) affording nearly complete conversion. Stern-Volmer quenching experiments indicated that catalysis is triggered by substrate reductive dehalogenation. Taking advantage of the large two-photon absorption (TPA) cross sections of W(CNAr)6 complexes, we found that photocatalysis can be driven with femtosecond-pulsed 810 nm excitation. For both one- and two-photon excitation, photocatalysis was terminated by the formation of seven-coordinate WII-diiodo [WI2(CNAr)5] complexes. Notably, we discovered that W(CNDipp)6 can be regenerated by chemical reduction of WI2(CNDipp)5 with excess ligand present in solution.

Tripodal P3XFe-N2 Complexes (X = B, Al, Ga): Effect of the Apical Atom on Bonding, Electronic Structure, and Catalytic N2-to-NH3 Conversion.

Terminal dinitrogen complexes of iron ligated by tripodal, tetradentate P3X ligands (X = B, C, Si) have previously been shown to mediate catalytic N2-to-NH3 conversion (N2RR) with external proton and electron sources. From this set of compounds, the tris(phosphino)borane (P3B) system is most active under all conditions canvassed thus far. To further probe the effects of the apical Lewis acidic atom on structure, bonding, and N2RR activity, Fe-N2 complexes supported by analogous group 13 tris(phosphino)alane (P3Al) and tris(phosphino)gallane (P3Ga) ligands are synthesized. The series of P3XFe-N2[0/1-] compounds (X = B, Al, Ga) possess similar electronic structures, degrees of N2 activation, and geometric flexibility as determined from spectroscopic, structural, electrochemical, and computational (DFT) studies. However, treatment of [Na(12-crown-4)2][P3XFe-N2] (X = Al, Ga) with excess acid/reductant in the form of HBArF4/KC8 generates only 2.5 ± 0.1 and 2.7 ± 0.2 equiv of NH3 per Fe, respectively. Similarly, the use of [H2NPh2][OTf]/Cp*2Co leads to the production of 4.1 ± 0.9 (X = Al) and 3.6 ± 0.3 (X = Ga) equiv of NH3. Preliminary reactivity studies confirming P3XFe framework stability under pseudocatalytic conditions suggest that a greater selectivity for hydrogen evolution versus N2RR may be responsible for the attenuated yields of NH3 observed for P3AlFe and P3GaFe relative to P3BFe.

Third-Generation W(CNAr)6 Photoreductants (CNAr = Fused-Ring and Alkynyl-Bridged Arylisocyanides).

Homoleptic tungsten(0) arylisocyanides possess photophysical and photochemical properties that rival those of archetypal ruthenium(II) and iridium(III) polypyridine complexes. Previous studies established that extending the π-system of 2,6-diisopropylphenylisocyanide (CNDipp) by coupling aryl substituents para to the isocyanide functionality results in W(CNDippAr)6 oligoarylisocyanide complexes with greatly enhanced metal-to-ligand charge transfer (MLCT) excited-state properties relative to those of W(CNDipp)6. Extending electronic modifications to delineate additional design principles for this class of photosensitizers, herein we report a series of W(CNAr)6 compounds with naphthalene-based fused-ring (CN-1-(2-iPr)-Naph) and CNDipp-based alkynyl-bridged (CNDippCCAr) arylisocyanide ligands. Systematic variation of the secondary aromatic system in the CNDippCCAr platform provides a straightforward method to modulate the photophysical properties of W(CNDippCCAr)6 complexes, allowing access to an extended range of absorption/luminescence profiles and highly reducing excited states, while maintaining the high molar absorptivity MLCT absorption bands, high photoluminescence quantum yields, and long excited-state lifetimes of previous W(CNAr)6 complexes. Notably, W(CN-1-(2-iPr)-Naph)6 exhibits the longest excited-state lifetime of all W(CNAr)6 complexes explored thus far, highlighting the potential benefits of utilizing fused-ring arylisocyanide ligands in the construction of tungsten(0) photoreductants.

Catalytic Nitrogen-to-Ammonia Conversion by Osmium and Ruthenium Complexes.

Despite the critical role Ru and Os complexes have played in the development of transition metal dinitrogen chemistry, they have not been shown to mediate catalytic N2-to-NH3 conversion (N2RR), nor have M-NxHy complexes been derived from protonation of their M-N2 precursors. To help delineate factors for N2RR catalysis, we report on isostructural tris(phosphino)silyl Ru and Os complexes that mediate catalytic N2RR, and compare their activities with an isostructural Fe complex. The Os system is most active, and liberates more than 120 equiv NH3 per Os center in a single batch experiment using Cp*2Co and [H2NPh2][OTf] as reductant and acid source. Isostructural Ru and Fe complexes generate little NH3 under the same conditions. Protonation of Os-N2- affords a structurally characterized Os=NNH2+ hydrazido species that mediates NH3 generation, suggesting it is a plausible intermediate of the catalysis. Inactive Os hydrides are characterized that form during catalysis.

Observation of room temperature B-Cl activation of the HCB11Cl11(-) anion and isolation of a stable anionic carboranyl phosphazide.

The perchlorinated carba-closo-dodecaborate anion is typically inert toward B-Cl functionalization. We present here the observation of two competing reactions that occur with this anion at ambient temperature. When this molecule is treated with n-BuLi and subsequently reacted with tosyl azide, a cycloaddition occurs and results in chloride substitution at a B-Cl vertex. The competing and dominant pathway is a substitution reaction to form the azide N3CB11Cl11(-). This rare anionic carboranyl azide reacts with PPh3 in FC6H5 to afford a stable anionic phosphazide. When dissolved in tetrahydrofuran, the phosphazide is in equilibrium with free PPh3 and N3CB11Cl11(-). Both the triazole and phosphazide are characterized by single-crystal X-ray diffraction, NMR and IR spectroscopy, and high-resolution mass spectrometry.

Duration of membership at sports centers and reasons for quitting.

Reasons for quitting membership at a sports center and their relation with socio-demographic characteristics and duration of membership were investigated. 642 individuals (55.4% men, 44.6% women), who had recently quit membership at a Spanish sports center, completed a questionnaire. There were significant differences in reasons for quitting on age, occupation, type of activities, and time spent on membership activities. The main reason was financial, regardless of the duration of membership.

Quantum chain amplification in nanocrystalline Dewar benzenes by intramolecular sensitization.

Quantum chain reactions are characterized by the formation of several photoproducts per photon absorbed (ΦQC > 1) and constitute a promising signal amplification mechanism. The triplet-sensitized isomerization of Dewar benzene is known to undergo quantum chain reactions characterized by an adiabatic valence-bond isomerization to the excited state of Hückel benzene, which is able to transfer its triplet energy to a new ground state Dewar benzene that reacts to continue the chain. Given that diffusion-mediated energy transfer is the chain-limiting event in solution, we demonstrate here that reactions in crystals are significantly more efficient by taking advantage of energy transfer by a presumed exciton delocalization mechanism. Using Dewar benzenes with covalently attached, high energy triplet sensitizers we have demonstrated the efficiency of the solid state by the amplification of a quantum yield of ca. ΦQC ≈ 76 in acetonitrile solution to as much as ca. ΦQC ≈ 100-120 in submicron size specimens prepared by the re-precipitation method, and up to ca. ΦQC ≈ 300 with microcrystalline powders suspended in water.

The performance of protected-area expansions in representing tropical Andean species: past trends and climate change prospects.

Protected area (PA) extent has increased significantly over the last 150 years globally, but it is yet unclear whether progress in expanding coverage has been accompanied by improved performance in ecological representation. Here, we explore temporal trends in the performance of PA networks in representing > 16,000 vertebrate and plant species in tropical Andean countries based on species bioclimatic niche modelling. We use a randomization analysis to assess whether representation gains over time (1937-2015) are the expected consequence of increasing the overall area of the network or the result of better designed networks. We also explore the impact of climate change on protected-area representation based on projected species distributions in 2070. We found that PAs added in the last three to four decades were better at representing species diversity than random additions overall. Threatened species, amphibians and reptiles are the exception. Species representation is projected to decrease across PAs under climate change, although PA expansions over the last decade (2006-2015) better represented species' future bioclimatic niches than did sites selected at random for most evaluated groups. These findings indicate an unbalanced representation across taxa, and raises concern over under-represented groups, including threatened species, and species' representation under climate change scenarios. However, they also suggest that decisions related to locating protected areas have become more strategic in recent decades and illustrate that indicators tracking representativeness of networks are crucial in PA monitoring frameworks.

School-age involvement in sport and perceived quality of sport services.

Creating an active and healthy lifestyle starts in infancy and adolescence. A number of individual and collective factors affect whether or not sport is taken up and continued, which is an essential element in achieving a healthy lifestyle in adolescence and extending this into adult life. This study sets out to determine the perceived quality of the sport service provided by schools with organised physical activities, and whether the most positively assessed public organisations have a higher percentage of participation than those with a more negative assessment. The study population was 1109 adolescents from 28 towns comprising part of a sport provision system. A self-devised questionnaire with all the necessary properties, validity and reliability was conducted. The results showed that 42% of the adolescents take part in organised physical sport, and give the service provided a positive assessment. It was found that in organisations with a more positive assessment, the town has a higher rate of involvement in sporting activities.

Protected area networks do not represent unseen biodiversity.

Most existing protected area networks are biased to protect charismatic species or landscapes. We hypothesized that conservation networks designed to include unseen biodiversity-species rich groups that consist of inconspicuous taxa, or groups affected by knowledge gaps-are more efficient than networks that ignore these groups. To test this hypothesis, we generated species distribution models for 3006 arthropod species to determine which were represented in three networks of different sizes and biogeographic origin. We assessed the efficiency of each network using spatial prioritization to measure its completeness, the increment needed to achieve conservation targets, and its specificity, the extent to which proposed priority areas to maximize unseen biodiversity overlap with existing networks. We found that the representativeness of unseen biodiversity in the studied protected areas, or extrinsic representativeness, is low, with ~ 40% of the analyzed unseen biodiversity species being unprotected. We also found that existing networks should be expanded ~ 26% to 46% of their current area to complete targets, and that existing networks do not efficiently conserve the unseen biodiversity given their low specificity (as low as 8.8%) unseen biodiversity. We conclude that information on unseen biodiversity must be included in systematic conservation planning approaches to design more efficient and ecologically representative protected areas.

Complementing the Self-Determination Theory With the Need for Novelty: Motivation and Intention to Be Physically Active in Physical Education Students.

The theoretical framework of the self-determination theory establishes that the satisfaction of basic psychological needs and more self-determined motivational forms are related to positive behavioral consequences and, therefore, may increase the intention to be physically active in Physical Education students. In this sense, the need for novelty has been proposed as a psychological need by recent scientific evidence, so it is necessary to prove its possible contribution to the prediction of young people's behavior. Therefore, the main objective of the study was to test a model that analyzed the power of prediction of the satisfaction of the needs for autonomy, competence, relatedness, and novelty as well as the motivation experienced in Physical Education on the intention to be physically active. A questionnaire was administered to 1665 Physical Education students with an average age of 12.43 years (SD = 1.87), of which 835 were boys and 830 were girls. An adaptation of the Spanish educational context of the Basic Psychological Needs in Exercise Scale (BPNES) that includes the need for novelty, the Perceived Locus of Causality Scale (PLOC), and the Intention to be Physically Active Scale (IPAS) was used. Path analysis results showed that the satisfaction of the psychological needs for autonomy, competence, relatedness, and novelty predicted autonomous motivation. On the other hand, the need for autonomy positively predicted controlled motivation, while the satisfaction of relatedness did so negatively. The need for competence and autonomous motivation positively predicted the intention to be physically active in Physical Education students, obtaining an explained variance of 33%. However, controlled motivation was not related in a statistically significant way to the intention to be physically active. In conclusion, the results of the hypothesized model highlight the importance of satisfying all the basic psychological needs (including novelty) and give special emphasis to the need for competence, since it predicts autonomous motivation and the intention to be physically active outside of the educational context.

High-Speed Swimsuits and Their Historical Development in Competitive Swimming.

The goal of this research was to review the experimental studies that have analyzed the influence of "high-speed swimsuits" on sports performance up to the appearance of the model "Jammer" in competitive swimmers. The design was a review following PRISMA Methodology, in which 43 studies were reviewed of a total of 512. Several searches were conducted in electronic databases of the existing research in this field (Google Scholar, Dialnet, Web of Sciences, and Scopus). The only studies excluded were those that reviewed the effects with neoprene and tests with triathletes. The studies that were included were published and peer-reviewed from 1999 to 2018 in which the effect of high-speed swimsuits was analyzed. The results showed the possible effects that high-speed swimwear can have in relation or not to competitive performance, biomechanical, physiological and psychological factors, flotation, drag, the material and the design until the introduction of the model "Jammer." As conclusions, the lack of consensus due to the variety of fields of study means that improvements in competitions are still not clarified. In addition, the change in the rules may have effects on swimmers even though they have beaten records with other swimwear. Finally, the debate concerning whether medals were won unfairly or not is proposed.

[Evacuation of critical care areas due to an initial outbreak of fire in a second level hospital]. / Evacuación de áreas críticas por conato de incendio en un hospital de segundo nivel.

In this letter to the editor, it is exposed an initial outbreak of fire that affected a secondary care center in Córdova, Veracruz, Mexico, and, most of all, the lack of a hospital fire evacuation plan in the presence of a fire event.

En la presente carta al editor, se expone un conato de incendio ocurrido en un hospital de segundo nivel de atención en Córdova, Veracruz, México, y, sobre todo, la carencia de un plan hospitalario de evacuación ante un evento de este tipo.

Kawasaki disease with coronary artery sequelae.

BACKGROUND: Kawasaki disease is an acute febrile illness characterized by mucosal inflammation, skin rash, and cervical lymphadenopathy, with potential for cardiac sequelae, including coronary aneurysms with subsequent thrombosis, infarction, and death. Pregnancy in affected women presents multiple maternal risks. CASE: A woman with Kawasaki disease complicated by coronary aneurysms underwent two consecutive pregnancies without further difficulty. She was maintained on therapeutic enoxaparin, alpha-methyldopa, and labetalol, with labor induction, passive second stage, and continued anticoagulation for 6 weeks postpartum. During gestations she was assessed with echocardiography, electrocardiography, and cardiac event monitor and managed by a maternal-fetal medicine and cardiology team. CONCLUSION: Kawasaki disease with coronary aneurysms presents challenges for obstetric management; obstetricians should be familiar with the disease, implications, and management in pregnancy.

Large expansion of oil industry in the Ecuadorian Amazon: biodiversity vulnerability and conservation alternatives.

Ecuador will experience a significant expansion of the oil industry in its Amazonian region, one of the most biodiverse areas of the world. In view of the changes that are about to come, we explore the conflicts between oil extraction interests and biodiversity protection and apply systematic conservation planning to identify priority areas that should be protected in different oil exploitation scenarios. First, we quantified the current extent of oil blocks and protected zones and their overlap with two biodiversity indicators: 25 ecosystems and 745 species (whose distributions were estimated via species distribution models). With the new scheme of oil exploitation, oil blocks cover 68% (68,196 km(2)) of the Ecuadorian Amazon; half of it occupied by new blocks open for bids in the southern Amazon. This region is especially vulnerable to biodiversity losses, because peaks of species diversity, 19 ecosystems, and a third of its protected zones coincide spatially with oil blocks. Under these circumstances, we used Marxan software to identify priority areas for conservation outside oil blocks, but their coverage was insufficient to completely represent biodiversity. Instead, priority areas that include southern oil blocks provide a higher representation of biodiversity indicators. Therefore, preserving the southern Amazon becomes essential to improve the protection of Amazonian biodiversity in Ecuador, and avoiding oil exploitation in these areas (33% of the extent of southern oil blocks) should be considered a conservation alternative. Also, it is highly recommended to improve current oil exploitation technology to reduce environmental impacts in the region, especially within five oil blocks that we identified as most valuable for the conservation of biodiversity. The application of these and other recommendations depends heavily on the Ecuadorian government, which needs to find a better balance between the use of the Amazon resources and biodiversity conservation.

Glomus tumor in teen and repetition pneumonia: Case report.

Glomus tumors are uncommon tumors that are originated from smooth muscle cells of the neuromioarterials glomus bodies located in the arteriovenous anastomoses subcutaneous tissue or deep dermis of the extremities, mainly in the palms of the hands, wrists and subungual areas of the fingers. Carcinoid tumor, as the glomus tumor, can show an organoid pattern, increased vascularity, and uniform, round cells with eosinophilic cytoplasm, but usually are positive for cytokeratin and always stained with chromogranin and synaptophysin showing negative for smooth muscle markers which is presented in our case. Glomus tumors have a good prognosis and surgical resection is the treatment of choice. In our case, the patient underwent pulmonary bilobectomy because of the location of the tumor in the transition between the middle lobe and the basal bronchial trunk right lower lobe divisions. It is presented thus a glomus tumor with exceptional localization (pulmonary and bronchial) of benign histological features, according to most of the cases reported in the literature emphasizing their particular rare location, histological, and immunohistochemical profile, which helps the differential diagnosis with other most common tumors of bronchial location.

Scenario-modelling for the sustainable management of non-timber forest products in tropical ecosystems / Modelagem de cenários para o manejo sustentável de produtos florestais não-madeireiros em ecossistemas tropicais

Abstract Ecosystems degradation, and consequently biodiversity loss, has severe impacts on people around the world. The Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) is one of the international initiatives that have emerged to inform policy makers and aid decisions to prevent further global biodiversity loss, focusing on the interdependence between natural systems and human culture. IPBES promotes the use of scenarios and modelling approaches as a fundamental tool to advance the understanding of the relationships between drivers of change, Nature's Contributions to People (NCP), and social systems. Local-scale case studies with a system approach demonstrating how current knowledge can be used to inform decision-making are still scarce. Here, we present a comprehensive conceptual model and a series of four scenarios under different policies for shea tree species management, as a case-study of applying systems thinking and the NCP concept to a local-scale socio-ecological system. We first characterized the central processes, NCP, drivers and pressures affecting the shea tree system, to investigate the impacts of the multiple uses of the shea tree species on the system as a whole. We then described potential policy options, developed four scenarios, and evaluated them by a Bayesian Belief Network (BBN). We predicted qualitative outcomes of the proposed scenarios: Business-as-usual (BAU), "Conservation and fair trade", "Agroforestry and fair trade" and "Industrial development". We found that the scenarios focussing on conservation, fair trade and agroforestry, can improve the conservation status of shea trees, and enhance wellbeing in the local communities. In this case study, we demonstrate that the development of a comprehensive conceptual model at a local scale can be a useful exercise to identify opportunities for effective policy strategies and social innovation. The shea tree case study can provide an example for modelling non-timber forest products in other regions around the world that face similar drivers and pressures. Species for which this model could be adapted include Central and South American species such as the Brazilian nut (Bertholletia excelsa), cocoa (Theobroma cacao), andiroba (Carapa guianensis), açai (Euterpe oleracea) and the wax palm (Ceroxylon quindiuense). The model and workflow applied here may thus be used to understand similar socio-ecological systems with local and international economic value across the Neotropical region.

Resumo A degradação dos ecossistemas e sua consequente perda de biodiversidade apresentam graves impactos sobre as pessoas em todo o mundo. A Plataforma Intergovernamental de Biodiversidade e Serviços Ecossistêmicos (IPBES) é uma das iniciativas internacionais que surgiram para informar tomadores de decisão e o desenvolvimento de políticas para evitar mais perdas globais de biodiversidade, com foco na interdependência entre sistemas naturais e a cultura humana. O IPBES promove o uso de cenários futuros e abordagens de modelagem como uma ferramenta fundamental para avançar no entendimento das relações entre fatores motivadores de mudança (vetores), as Contribuições da Natureza para as Pessoas (NCP) e sistemas sociais. Estudos de caso em escala local com uma abordagem de sistemas mostrando como o conhecimento atual pode ser usado para informar a tomada de decisão ainda são poucos. Neste trabalho, apresentamos um modelo conceitual abrangente e um conjunto de quatro cenários sob diferentes políticas para o manejo da árvore de karité, como estudo de caso para a aplicação de uma abordagem de sistemas e do conceito de NCP em um sistema socioecológico em escala local. Primeiro nós caracterizamos os processos centrais, os NCP, e os vetores e pressões que afetam o sistema da árvore de karité, para então, investigar os impactos dos múltiplos usos da espécie no sistema como um todo. Em seguida, descrevemos opções de políticas possíveis, a partir das quais desenvolvemos quatro cenários e os avaliamos por Redes Bayesianas baseadas em Crenças (BBN). Nós avaliamos os resultados qualitativos dos quatro cenários de manejo propostos: "business-as-usual" (BAU), "Conservação e Fair Trade", "Agrofloresta e Fair Trade", e "Desenvolvimento Agroindustrial". Verificamos que os cenários que incluíam medidas de conservação e comércio justo, assim como o que previa práticas agroflorestais indicaram potenciais melhorias no status de conservação das árvores de karité e aprimoramento do bem-estar das comunidades locais. Neste estudo de caso, demonstramos que o desenvolvimento de um modelo conceitual mais completo na escala local pode ser útil na identificação de oportunidades para a proposição de estratégias políticas efetivas e inovação social. O estudo de caso da árvore de karité pode fornecer um exemplo de modelagem de produtos florestais não-madeireiros para outras regiões do mundo que enfrentam vetores de mudança e pressões semelhantes. As espécies para as quais esse modelo pode ser adaptado incluem espécies da América Central e do Sul, como a castanha-do-brasil (Bertholletia excelsa), cacau (Theobroma cacao), andiroba (Carapa guianensis), açaí (Euterpe oleracea) e a palma da cera (Ceroxylon quindiuense). O modelo e a proposta de trabalho aplicados aqui podem, portanto, ser usados para entender sistemas socio-ecológicos semelhantes com espécies de valor econômico local e internacional em toda a região neotropical.