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1.
Conserv Biol ; 38(1): e14149, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37424370

RESUMO

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 (∼0.32 million ha) was countered by the continued establishment of new plantations (∼1.04 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 (∼0.32 millones de ha) fue contrarrestado por el establecimiento continuo de nuevos sembradíos (∼1.04 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/fisiologia
2.
Ecol Lett ; 21(6): 804-813, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29601670

RESUMO

To estimate species loss from habitat destruction, ecologists typically use species-area relationships, but this approach neglects the spatial pattern of habitat fragmentation. Here, we provide new, easily applied, analytical methods that place upper and lower bounds on immediate species loss at any spatial scale and for any spatial pattern of habitat loss. Our formulas are expressed in terms of what we name the 'Preston function', which describes triphasic species-area relationships for contiguous regions. We apply our method to case studies of deforestation and tropical tree species loss at three different scales: a 50 ha forest plot in Panama, the tropical city-state of Singapore and the Brazilian Amazon. Our results show that immediate species loss is somewhat insensitive to fragmentation pattern at small scales but highly sensitive at larger scales: predicted species loss in the Amazon varies by a factor of 16 across different spatial structures of habitat loss.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Florestas , Brasil , Ecossistema , Panamá , Árvores
3.
Biol Lett ; 13(4)2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28381631

RESUMO

Restricting future global temperature increase to 2°C or less requires the adoption of negative emissions technologies for carbon capture and storage. We review the potential for deployment of enhanced weathering (EW), via the application of crushed reactive silicate rocks (such as basalt), on over 680 million hectares of tropical agricultural and tree plantations to offset fossil fuel CO2 emissions. Warm tropical climates and productive crops will substantially enhance weathering rates, with potential co-benefits including decreased soil acidification and increased phosphorus supply promoting higher crop yields sparing forest for conservation, and reduced cultural eutrophication. Potential pitfalls include the impacts of mining operations on deforestation, producing the energy to crush and transport silicates and the erosion of silicates into rivers and coral reefs that increases inorganic turbidity, sedimentation and pH, with unknown impacts for biodiversity. We identify nine priority research areas for untapping the potential of EW in the tropics, including effectiveness of tropical agriculture at EW for major crops in relation to particle sizes and soil types, impacts on human health, and effects on farmland, adjacent forest and stream-water biodiversity.


Assuntos
Mudança Climática , Agricultura , Conservação dos Recursos Naturais , Florestas , Humanos , Clima Tropical , Tempo (Meteorologia)
4.
Int J Med Educ ; 14: 108-116, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37651983

RESUMO

Objectives: The current study sought to explain how different professional experiences led Singaporean psychiatrists to alter their clinical reasoning processes as their careers evolved from psychiatry residents to senior consultant psychiatrists. Methods: The current qualitative study interviewed 26 clinicians at various stages of their psychiatric career, spanning residents to senior psychiatrists.  The authors used a constructivist grounded theory approach to structure the collection and analysis of data. Analyses produced a dense theoretical explanation rooted in the experiences of participants. Results: Several differences emerged between the way psychiatry residents and senior psychiatrists explained their reasoning process and the experiences on which they based their preference. Residents preferred using deductive logic-driven frameworks that were diagnosis-centric, because of the pressures they experienced during their training and assessments. Senior psychiatrists emphasized a more holistic and problem-centric approach. Participants attributed the changes that occurred over time to practical experiences, such as their greater clinical responsibility and independence, and individual experiences, such as growing sensitivity to the clinical reasoning process or their growing propensity for professional reflectiveness. These changes manifest as an increase in repertoire and flexibility in deployment of different clinical reasoning strategies. Conclusions: It is important for trainees to be aware of the deductive and inductive modes of clinical reasoning during supervision and to be comfortable with shifting clinical focus from diagnoses to specific individual problems. Training programs should provide and plan adequate longitudinal clinical exposure to develop clinical reasoning abilities in a way that allows consequences of decisions to be explored. Continued faculty development to ease the diversification of clinical reasoning skills should be encouraged, as should reflectivity in the learners during clinical supervision.


Assuntos
Competência Clínica , Raciocínio Clínico , Humanos , Singapura , Consultores , Resolução de Problemas
5.
Ambio ; 45(4): 387-97, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26961010

RESUMO

Despite the large implications of the use of tropical land for exports ("land absorption") on ecosystem services (ES) and global biodiversity conservation, the magnitude of these externalities is not known. We quantify the net value of ES lost in tropical countries as a result of cropland, forestland and pastureland absorption for exports after deducting ES gains through imports ("land displacement"). We find that net ES gains occur only in 7 out of the 41 countries and regions considered. We estimate global annual net losses of over 1.7 x 10(12) international dollars (I$) (I$1.1 x 10(12) if carbon-related services are not considered). After deducting the benefits from agricultural, forest and livestock rents in land replacing tropical forests, the net annual losses are I$1.3 and I$0.7 x 10(12), respectively. The results highlight the large magnitude of tropical ES losses through international trade that are not compensated by the rents of land uses in absorbed land.


Assuntos
Agricultura , Ciclo do Carbono , Comércio , Conservação dos Recursos Naturais/economia , Ecossistema , Biodiversidade , Clima Tropical
6.
PLoS One ; 11(3): e0152802, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27028399

RESUMO

With the continuous growth of internet usage, Google Trends has emerged as a source of information to investigate how social trends evolve over time. Knowing how the level of interest in conservation topics--approximated using Google search volume--varies over time can help support targeted conservation science communication. However, the evolution of search volume over time and the mechanisms that drive peaks in searches are poorly understood. We conducted time series analyses on Google search data from 2004 to 2013 to investigate: (i) whether interests in selected conservation topics have declined and (ii) the effect of news reporting and academic publishing on search volume. Although trends were sensitive to the term used as benchmark, we did not find that public interest towards conservation topics such as climate change, ecosystem services, deforestation, orangutan, invasive species and habitat loss was declining. We found, however, a robust downward trend for endangered species and an upward trend for ecosystem services. The quantity of news articles was related to patterns in Google search volume, whereas the number of research articles was not a good predictor but lagged behind Google search volume, indicating the role of news in the transfer of conservation science to the public.


Assuntos
Mudança Climática , Ecossistema , Disseminação de Informação , Mídias Sociais , Navegador , Animais , Bases de Dados Factuais , Humanos
7.
J Clin Oncol ; 20(21): 4313-8, 2002 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-12409329

RESUMO

PURPOSE: To determine whether granulocyte-macrophage colony-stimulating factor (GM-CSF) would improve response to influenza vaccination in cancer patients. PATIENTS AND METHODS: In a randomized, patient-blinded, placebo-controlled trial carried out in 1997 to 2000, 133 patients were stratified into five groups of treatment and disease. Single doses of standard split trivalent influenza vaccine and either placebo or 250 micro g of GM-CSF were administered at the same time. Hemagglutination inhibition assay titers were measured before and 4 weeks after vaccination. RESULTS: Standard analyses, which define response as at least a four-fold increase in titers, detect no effect of GM-CSF for any of the three influenza subtypes in the trivalent vaccines (P >or=.12). Analysis that includes the magnitude of the change in titers and combines responses of the subtypes suggests that the placebo group had the greater response (P =.051), thus indicating that GM-CSF does not improve response. Ancillary analyses show that response declines both with increasing age and with higher initial titers. The fraction of patients with at least a four-fold increase in titers was 0.36 (95% confidence interval, 0.29 to 0.42) CONCLUSION: A single 250- micro g dose of GM-CSF administered with the influenza vaccine does not improve response to vaccination. Response in cancer patients is low and declines as age and initial titer increase.


Assuntos
Fator Estimulador de Colônias de Granulócitos e Macrófagos/administração & dosagem , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Neoplasias/complicações , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Formação de Anticorpos , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Humanos , Vacinas contra Influenza/administração & dosagem , Influenza Humana/imunologia , Masculino , Pessoa de Meia-Idade , Método Simples-Cego
8.
PLoS One ; 10(7): e0133781, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26222280

RESUMO

Previous studies have shown that contact with urban green spaces can produce positive effects on people's stress, health and well-being levels. However, much of this research has been conducted in the temperate regions of Europe or North America. Additionally, most studies have only compared the effects of urban and natural areas on health and well-being, but not made a finer distinction between different types of urban green spaces. We tested the relationship between well-being and the access or use of different types of green spaces among young adults in Singapore, a tropical city-state. The results showed that extraversion and emotional stability increased subjective well-being, positive affect and life satisfaction and decreased stress and negative affect. In addition, we found that level of physical activity increased positive affect and health problems increased negative affect. Neither access to green spaces nor the use of green spaces in Singapore significantly affected the well-being metrics considered, contradicting findings in the temperate regions of the world. We hypothesize that the differences in temperature and humidity and the higher greenery and biodiversity levels outside parks in Singapore could explain this phenomenon. Our results thus question the universality of the relationship between well-being and park usage and highlight the need for more research into the multifaceted effects of green spaces on well-being in the tropics.


Assuntos
Felicidade , Parques Recreativos/estatística & dados numéricos , Clima Tropical , Adolescente , Adulto , Feminino , Humanos , Masculino , Singapura , Inquéritos e Questionários , Adulto Jovem
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