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1.
Sci Total Environ ; 869: 161670, 2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-36657679

RESUMEN

There is an increasing need for long-term monitoring of ecosystems and their services to inform on-ground management. The supply of many ecosystem services relies on connections that span multiple ecosystems. Monitoring the underlying condition of interconnected ecosystems is therefore required to track effectiveness of past interventions and identify impending change. Here we test the performance of indicators of ecosystem services with the aim of identifying the time-scales over which indicators of ecosystem services responded to change. We chose a case-study of a catchment in Northern Australia, where water resource development is a threat to the river flows that support vegetation growth and the life-cycle of coastal fishery species. We developed a novel approach to performance testing that drew on state-space modelling to capture ecological dynamics, and structural equation modelling to capture covariation in indicator time series. We first quantified covariation among three ecological indicators that had time-series data: pasture biomass, vegetation greenness and barramundi catch per unit effort. Higher values of all indicators occurred in years with greater river flow. We then predicted the emergence times for each indicator, as the time taken for a trend in an indicator to emerge from the background of natural variation. Emergence times were > 10 years in all cases, quantified at 80 % and higher confidence levels. Past trends and current status of ecosystem service flows are often used by decision makers to directly inform near-term actions, particularly for provisioning services (such as barramundi catch) due to their important contribution to regional economies. We found that ecological indicators could be used to assess historical performance over decadal timespans, but not as short-term indicators of recent change. More generally, we offer an approach to performance testing of indicators. This approach could be useful for quantifying timescales of ecosystem response in systems where cross-ecosystem connections are important.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Ríos , Recursos Hídricos , Biomasa , Monitoreo del Ambiente
2.
Environ Manage ; 71(2): 304-320, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36269373

RESUMEN

Freshwater ecosystems, such as wetlands, are among the most impacted by agricultural expansion and intensification through extensive drainage and pollution. There is a pressing need to identify ways of managing agricultural landscapes to ensure food and water security without jeopardising biodiversity and other environmental benefits. Here we examine the potential fish biodiversity and landholder financial benefits arising from the integration of constructed lagoons to improve drainage, flow regulation and habitat connectivity within a sugarcane dominated catchment in north Queensland, Australia. A hybrid approach was used, combining the findings of both fish ecological surveys and a financial cost-benefit analysis. We found that the constructed lagoons supported at least 36 native freshwater fishes (over half of all native freshwater fishes in the region), owing to their depth, vegetated margins, moderate water quality and high connectivity to the Tully River. In addition to biodiversity benefits, we estimated that surrounding sugarcane farms would have financially benefited from reduced flooding of cropland and the elevation of low-lying cropland with deposited spoil excavated from lagoon construction. Improved drainage and flow regulation allowed for improvement in sugarcane yield and elevated land increased gross margins from extending the length of the cane production cycle or enabling a switch from cattle grazing to cane production. Restoring or creating wetlands to reduce flooding in flood-prone catchments is a globally applicable model that could improve both agricultural productivity and aquatic biodiversity, while potentially increasing farm income by attracting payments for provision of ecosystem services.


Asunto(s)
Ecosistema , Saccharum , Animales , Bovinos , Humedales , Conservación de los Recursos Naturales , Biodiversidad , Agua Dulce , Peces
3.
Sci Rep ; 12(1): 14298, 2022 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-35995915

RESUMEN

Light-induced oxidation of the reaction center dimer and periplasmic cytochromes was detected by fast kinetic difference absorption changes in intact cells of wild type and cytochrome mutants (cycA, cytC4 and pufC) of Rubrivivax gelatinosus and Rhodobacter sphaeroides. Constant illumination from a laser diode or trains of saturating flashes enabled the kinetic separation of acceptor and donor redox processes, and the electron contribution from the cyt bc1 complex via periplasmic cytochromes. Under continuous excitation, concentrations of oxidized cytochromes increased in three phases where light intensity, electron transfer rate and the number of reduced cytochromes were the rate liming steps, respectively. By choosing suitable flash timing, gradual steps of cytochrome oxidation in whole cells were observed; each successive flash resulted in a smaller, damped oxidation. We attribute this damping to lowered availability of reduced cytochromes resulting from both exchange (unbinding/binding) of the cytochromes and electron transfer at the reaction center interface since a similar effect is observed upon deletion of genes encoding periplasmic cytochromes. In addition, we present a simple model to calculate the damping effect; application of this method may contribute to understanding the function of the diverse range of c-type cytochromes in the electron transport chains of anaerobic phototrophic bacteria.


Asunto(s)
Proteínas del Complejo del Centro de Reacción Fotosintética , Rhodobacter sphaeroides , Grupo Citocromo c/genética , Citocromos/metabolismo , Transporte de Electrón , Cinética , Oxidación-Reducción , Proteínas del Complejo del Centro de Reacción Fotosintética/genética , Proteínas del Complejo del Centro de Reacción Fotosintética/metabolismo , Rhodobacter sphaeroides/metabolismo
4.
Hypertension ; 79(11): 2493-2504, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36043416

RESUMEN

BACKGROUND: Natural killer (NK) cell impairment is a feature of pulmonary arterial hypertension (PAH) and contributes to vascular remodeling in animal models of disease. Although mutations in BMPR2, the gene encoding the BMP (bone morphogenetic protein) type-II receptor, are strongly associated with PAH, the contribution of BMPR2 loss to NK cell impairment remains unknown. We explored the impairment of IL (interleukin)-15 signaling, a central mediator of NK cell homeostasis, as both a downstream target of BMPR2 loss and a contributor to the pathogenesis of PAH. METHODS: The expression, trafficking, and secretion of IL-15 and IL-15Rα (interleukin 15 α-type receptor) were assessed in human pulmonary artery endothelial cells, with or without BMPR2 silencing. NK cell development and IL-15/IL-15Rα levels were quantified in mice bearing a heterozygous knock-in of the R899X-BMPR2 mutation (bmpr2+/R899X). NK-deficient Il15-/- rats were exposed to the Sugen/hypoxia and monocrotaline models of PAH to assess the impact of impaired IL-15 signaling on disease severity. RESULTS: BMPR2 loss reduced IL-15Rα surface presentation and secretion in human pulmonary artery endothelial cells via impaired trafficking through the trans-Golgi network. bmpr2+/R899X mice exhibited a decrease in NK cells, which was not attributable to impaired hematopoietic development but was instead associated with reduced IL-15/IL-15Rα levels in these animals. Il15-/- rats of both sexes exhibited enhanced disease severity in the Sugen/hypoxia model, with only male Il15-/- rats developing more severe PAH in response to monocrotaline. CONCLUSIONS: This work identifies the loss of IL-15 signaling as a novel BMPR2-dependent contributor to NK cell impairment and pulmonary vascular disease.


Asunto(s)
Deficiencia GATA2 , Hipertensión Pulmonar , Hipertensión Arterial Pulmonar , Humanos , Femenino , Masculino , Ratas , Ratones , Animales , Hipertensión Pulmonar/etiología , Interleucina-15/genética , Interleucina-15/metabolismo , Monocrotalina , Células Endoteliales/metabolismo , Deficiencia GATA2/complicaciones , Deficiencia GATA2/metabolismo , Deficiencia GATA2/patología , Receptores de Proteínas Morfogenéticas Óseas de Tipo II/genética , Receptores de Proteínas Morfogenéticas Óseas de Tipo II/metabolismo , Arteria Pulmonar/metabolismo , Hipoxia/metabolismo
5.
J Environ Manage ; 314: 115102, 2022 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-35462256

RESUMEN

A systems analysis perspective related to soil science is necessary to achieve many of the sustainability targets articulated by the United Nations Sustainable Development Goals (SDGs). The System of Environmental-Economic Accounting - Ecosystem Accounting (SEEA-EA) framework is the international statistical standard for quantifying both the contributions that ecosystems make to the economy, and the impacts of economic activity on ecosystems. However, due to the difficulty of obtaining empirical data on ecosystem service flows, in many cases such quantification is informed by ecosystem service models. Previous research on the Mitchell catchment, Queensland Australia provided a novel opportunity to quantify the implications of using a model of hillslope erosion and sediment delivery in isolation (as represented in one of the most frequently used ecosystem service models - InVEST), by comparing such estimates against multiple lines of local empirical data, and a more comprehensive representation of locally important erosion and deposition processes through a sediment budget model. Estimates of the magnitude of hillslope erosion modelled using an approach similar to InVEST and the calibrated sediment budget differed by an order of magnitude. If an uncalibrated InVEST-type model was used to inform the relative distribution of erosion magnitude, findings suggest the incorrect erosion process would be identified as the dominant contributor to suspended sediment loads. However, the sediment budget model could only be calibrated using data on sediment sources and sinks that had been collected through sustained research effort in the catchment. A comparable level of research investment may not be available to inform ecosystem service assessments elsewhere. Findings for the Mitchell catchment demonstrate that practitioners should exercise caution when using model-derived estimates of the sediment retention ecosystem service, which have not been calibrated and validated against locally collected empirical data, to inform an ecosystem account and progress towards achieving the SDGs.


Asunto(s)
Ecosistema , Ríos , Australia , Monitoreo del Ambiente , Sedimentos Geológicos/análisis
6.
Sci Total Environ ; 790: 147824, 2021 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-34380262

RESUMEN

In this paper, we investigate the potential gains in cost-effectiveness from changing the spatial scale at which nutrient reduction targets are set for the Baltic Sea, with particular focus on nutrient loadings from agriculture. The costs of achieving loading reductions are compared across five levels of spatial scale, namely the entire Baltic Sea; the marine basin level; the country level; the watershed level; and the grid square level. A novel highly-disaggregated model, which represents decreases in agricultural profits, changes in root zone N concentrations and transport to the Baltic Sea is used. The model includes 14 Baltic Sea marine basins, 14 countries, 117 watersheds and 19,023 10-by-10 km grid squares. The main result which emerges is that there is a large variation in the total cost of the program depending on the spatial scale of targeting: for example, for a 40% reduction in loads, the costs of a Baltic Sea-wide target is nearly three times lower than targets set at the smallest level of spatial scale (grid square). These results have important implications for both domestic and international policy design for achieving water quality improvements where non-point pollution is a key stressor of water quality.


Asunto(s)
Eutrofización , Contaminación del Agua , Agricultura , Países Bálticos , Análisis Costo-Beneficio , Nitrógeno/análisis , Nutrientes , Fósforo/análisis
7.
Mar Pollut Bull ; 170: 112628, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34218029

RESUMEN

To protect and improve water quality in the Great Barrier Reef, the Queensland Government's Reef 2050 Water Quality Improvement Plan targets that 90% of sugarcane, horticulture, cropping and grazing lands in priority areas be managed using best management practices for sediment, nutrient and pesticides by 2025. Progress towards this target is insufficient and variable across catchments and industries. The motivation to adopt improvements in management practices is heavily influenced by social, economic, cultural and institutional dimensions. In this paper we synthesise the literature on how these human dimensions influence decision making for land management practice and highlight where future investment could be focussed. We highlight that focussing on -1) investigating systems to support landholder decision making under climate uncertainty (risk); 2) generating a better understanding of the extent and drivers of landholder transaction cost; 3) understanding if there are competing 'right' ways to farm; and 4) improving understanding of the social processes, trust and power dynamics within GBR industries and what these means for practice change- could improve practice change uptake in the future.


Asunto(s)
Calidad del Agua , Agua , Agricultura , Conservación de los Recursos Naturales , Humanos , Mejoramiento de la Calidad
8.
Mar Pollut Bull ; 167: 112373, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33895596

RESUMEN

Eutrophication of coastal and nearshore receiving environments downstream of intensive agricultural production areas is a global issue. The Reef 2050 Water Quality Improvement Plan (2017-2022) sets ambitious targets for reducing pollutant loads entering the Great Barrier Reef from contributing agricultural catchments. At a regional scale, the Wet Tropics end-of-catchment target load reduction for dissolved inorganic nitrogen (DIN) is 60% from the 2012-2013 anthropogenic load level. However, not even with the combined efforts of the Reef Regulations (December 2019) mandate and adoption of best practice nutrient management on farm, is it likely that these DIN targets will be reached. Thus, there is a need for innovative and cost-effective approaches to deliver further water quality improvement. Transitioning low-lying, marginal sugarcane land to alternative land uses that require lower or no nitrogen inputs, but still provide farmers with income streams, is a potentially attractive solution. In this study, a multi-criteria analysis was conducted to identify sites suitable for such alternative land uses. The cost-effectiveness of DIN reductions from these land use changes were calculated, accounting for reductions in annuity gross margins and land conversion cost. In certain locations (where conversion costs are low and DIN reductions are high) treatment wetlands and no-input cattle grazing offer cost-effective DIN reduction in the range of 20-26$/kg DIN. This compares favourably with existing agricultural extension-based approaches (c. $50/kg DIN reduction). Ecosystem service wetlands (i.e., wetland restoration for fish production) - again when appropriately situated - offer the prospect of even more cost-effective performance (11-14 $/kg DIN reduction). These results, in conjunction with best management practices, support the premise that alternative land uses are cost-effective options for improving water quality in certain areas of low-lying, low productivity sugarcane land. On-going investments by government in addition to private market funding mechanisms could be appropriate for supporting such land use transitions. These approaches need to be tested and refined via targeted pilot projects, as part of a whole-of-landscape approach to achieve broader reef water quality targets.


Asunto(s)
Saccharum , Calidad del Agua , Agricultura , Animales , Bovinos , Ecosistema , Eutrofización , Nitrógeno/análisis
9.
Sci Rep ; 10(1): 14012, 2020 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-32814810

RESUMEN

Antenna systems serve to absorb light and to transmit excitation energy to the reaction center (RC) in photosynthetic organisms. As the emitted (bacterio)chlorophyll fluorescence competes with the photochemical utilization of the excitation, the measured fluorescence yield is informed by the migration of the excitation in the antenna. In this work, the fluorescence yield concomitant with the oxidized dimer (P+) of the RC were measured during light excitation (induction) and relaxation (in the dark) for whole cells of photosynthetic bacterium Rhodobacter sphaeroides lacking cytochrome c2 as natural electron donor to P+ (mutant cycA). The relationship between the fluorescence yield and P+ (fraction of closed RC) showed deviations from the standard Joliot-Lavergne-Trissl model: (1) the hyperbola is not symmetric and (2) exhibits hysteresis. These phenomena originate from the difference between the delays of fluorescence relative to P+ kinetics during induction and relaxation, and in structural terms from the non-random distribution of the closed RCs during induction. The experimental findings are supported by Monte Carlo simulations and by results from statistical physics based on random walk approximations of the excitation in the antenna. The applied mathematical treatment demonstrates the generalization of the standard theory and sets the stage for a more adequate description of the long-debated kinetics of fluorescence and of the delicate control and balance between efficient light harvest and photoprotection in photosynthetic organisms.


Asunto(s)
Fluorescencia , Luz , Fotosíntesis , Proteínas del Complejo del Centro de Reacción Fotosintética/química , Proteínas del Complejo del Centro de Reacción Fotosintética/metabolismo , Rhodobacter sphaeroides/metabolismo , Transporte de Electrón , Cinética , Procesos Fotoquímicos , Termodinámica
10.
Sci Total Environ ; 707: 135904, 2020 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-31865069

RESUMEN

It is a substantial challenge to quantify the benefits which ecosystems provide to water supply at scales large enough to support policy making. This study tested the hypothesis that vegetation could reduce riverbank erosion, and therefore contribute to reducing turbidity and the cost of water supply, during a large magnitude flood along a 62 km riparian corridor where land cover differed substantially from natural conditions. Several lines of evidence were used to establish the benefits that vegetation provided to reducing eleven riverbank erosion processes over 1688 observations. The data and analyses confirmed that vegetation significantly reduced the magnitude of the riverbank erosion process which was the largest contributor to total erosion volume. For this process, a 1% increase in canopy cover of trees higher than five metres reduced erosion magnitude by between 2 and 3%. Results also indicate that riverbank erosion was likely to be affected by direct changes to the riparian corridor which influenced longitudinal coarse sediment connectivity. When comparing the impact of these direct changes on a relative basis, sand and gravel extraction was likely to be the dominant contributor to changed erosion rates. The locations where erosion rates had substantially increased were of limited spatial extent and in general substantial change in river form had not occurred. This suggests that the trajectory of river condition and increasing turbidity are potentially reversible if the drivers of river degradation are addressed through an ecosystem restoration policy.


Asunto(s)
Ecosistema , Agua Potable , Inundaciones , Ríos , Árboles
12.
Conserv Biol ; 31(4): 818-827, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-27696549

RESUMEN

Conservation of biodiversity, including birds, continues to challenge natural-area managers. Stated-preference methods (e.g., choice experiment [CE]) are increasingly used to provide data for valuation of natural ecosystems. We used a CE to calculate birders' willingness to pay for different levels of bioecological attributes (threatened species, endemic species, and diversity) of birding sites with hypothetical entry fees. The CE was delivered at popular birding and avitourism sites in Australia and the United Kingdom. Latent-class modeling results revealed heterogeneous preferences among birders and correspondingly variable willingness to pay. Four clear groups were apparent: quantity-driven birders, special-birds seekers, confused respondents, and price-is-no-object birders. Quantity-driven birders were attracted to sites that deliver high levels of diversity and endemic species for which they were willing to pay $135 and $66 to visit, respectively, above what they were willing to pay to visit a site with low levels of diversity and few endemic and threatened species . Special-bird seekers valued threatened species and high levels of endemic species most (willingness to pay $45 and $46, respectively). Confused respondents' preferences were difficult to determine, but they were the most sensitive to the hypothetical entry fees, unlike the price-is-no-object birders, who were not at all sensitive to cost. Our findings demonstrate that birders are amenable to paying for their preferred birding experience. These payments could provide an alternative source of funding in some avitourism sites on both public and private land. Such alternative revenue streams should be explored and given full consideration in increasingly competitive conservation-financing environments.


Asunto(s)
Aves , Financiación del Capital , Conservación de los Recursos Naturales/economía , Animales , Australia , Conducta de Elección , Especies en Peligro de Extinción , Motivación , Reino Unido
13.
Histochem Cell Biol ; 145(5): 561-72, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26708151

RESUMEN

Ras homolog enriched in brain (RHEB1) is a member within the superfamily of GTP-binding proteins encoded by the RAS oncogenes. RHEB1 is located at the crossroad of several important pathways including the insulin-signaling pathways and thus plays an important role in different physiological processes. To understand better the physiological relevance of RHEB1 protein, the expression pattern of RHEB1 was analyzed in both embryonic (at E3.5-E16.5) and adult (1-month old) mice. RHEB1 immunostaining and X-gal staining were used for wild-type and Rheb1 gene trap mutant mice, respectively. These independent methods revealed similar RHEB1 expression patterns during both embryonic and postnatal developments. Ubiquitous uniform RHEB1/ß-gal and/or RHEB1 expression was seen in preimplantation embryos at E3.5 and postimplantation embryos up to E12.5. Between stages E13.5 and E16.5, RHEB1 expression levels became complex: In particular, strong expression was identified in neural tissues, including the neuroepithelial layer of the mesencephalon, telencephalon, and neural tube of CNS and dorsal root ganglia. In addition, strong expression was seen in certain peripheral tissues including heart, intestine, muscle, and urinary bladder. Postnatal mice have broad spatial RHEB1 expression in different regions of the cerebral cortex, subcortical regions (including hippocampus), olfactory bulb, medulla oblongata, and cerebellum (particularly in Purkinje cells). Significant RHEB1 expression was also viewed in internal organs including the heart, intestine, urinary bladder, and muscle. Moreover, adult animals have complex tissue- and organ-specific RHEB1 expression patterns with different intensities observed throughout postnatal development. Its expression level is in general comparable in CNS and other organs of mouse. Thus, the expression pattern of RHEB1 suggests that it likely plays a ubiquitous role in the development of the early embryo with more tissue-specific roles in later development.


Asunto(s)
Embrión de Mamíferos/metabolismo , Proteínas de Unión al GTP Monoméricas/análisis , Proteínas de Unión al GTP Monoméricas/metabolismo , Neuronas/metabolismo , Animales , Animales Recién Nacidos , Ratones , Ratones Endogámicos C57BL , Proteínas de Unión al GTP Monoméricas/genética , Especificidad de Órganos
14.
Oncoimmunology ; 4(10): e1040218, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26451305

RESUMEN

Ipilimumab is a standard therapy for advanced melanoma. Severe immune related adverse events occur in up to 30% of patients and require treatment with immunosuppressants such as steroids or the anti-TNFα antibody, infliximab. We describe two patients with advanced melanoma treated with ipilimumab. Both suffered from severe immune related side effects and required prolonged immunosuppression with steroids and/or infliximab. Both patients recovered and in spite of the immune suppression, demonstrate clinical evidence of tumor control. This argues that distinct immunological effector functions control nosocomial infection and tumor, respectively. To our knowledge, these are also the first two case reports of pneumocystis pneumonia in this setting.

15.
J Surg Oncol ; 112(5): 486-91, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26337393

RESUMEN

BACKGROUND: Phaeochromocytomas and paragangliomas arise from the same chromaffin cell, but evidence suggests they do not represent a single clinical entity. The aim of this study was to compare clinical presentations, outcomes of surgical and oncological treatments and survival in patients with phaeochromocytomas and paragangliomas. METHODS: A retrospective review was undertaken of all patients treated for these conditions at our centre between 1983 and 2012. RESULTS: One hundred and six patients (88 adults, 18 children) with phaeochromocytoma (n = 83) or paraganglioma (n = 23) were studied. Catecholamine symptoms and incidentalomas were the main presentations in phaeochromocytoma patients (67% and 17%) respectively, but in those with paragangliomas pain (39%) was more common (P < 0.001). More paragangliomas were malignant (14/23 vs 9/83, P < 0.0001), larger (9.17 ± 4.95 cm vs. 5.8 ± 3.44 cm, P = 0.001) and had a higher rate of conversion to open surgery (P = <0.01), more R2 resections, more postoperative complications and a longer hospital stay (P = 0.014). MIBG uptake in malignant paragangliomas was lower than in malignant phaeochromocytomas (36% vs. 100%, P = 0.002) and disease stabilisation was achieved in 29% and 86% of patients respectively. (90) Y-DOTA-octreotate had a 78% response rate in malignant paragangliomas. CONCLUSION: The clinical differences between paragangliomas and phaeochromocytomas support the view that they should be considered as separate clinical entities.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/mortalidad , Neoplasias de las Glándulas Suprarrenales/patología , Paraganglioma/mortalidad , Paraganglioma/patología , Feocromocitoma/mortalidad , Feocromocitoma/patología , 3-Yodobencilguanidina/farmacocinética , Adolescente , Neoplasias de las Glándulas Suprarrenales/diagnóstico por imagen , Neoplasias de las Glándulas Suprarrenales/terapia , Adulto , Anciano , Niño , Terapia Combinada , Femenino , Estudios de Seguimiento , Compuestos Heterocíclicos/farmacocinética , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Compuestos Organometálicos/farmacocinética , Paraganglioma/diagnóstico por imagen , Paraganglioma/terapia , Feocromocitoma/diagnóstico por imagen , Feocromocitoma/terapia , Pronóstico , Cintigrafía , Radiofármacos/farmacocinética , Estudios Retrospectivos , Tasa de Supervivencia , Distribución Tisular , Tomografía Computarizada por Rayos X , Adulto Joven
16.
Neural Dev ; 9: 5, 2014 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-24594058

RESUMEN

BACKGROUND: Neuronal polarization is an essential step of morphogenesis and connectivity in the developing brain. The serine/threonine kinase LKB1 is a key regulator of cell polarity, metabolism, tumorigenesis, and is required for axon formation. It is allosterically regulated by two related and evolutionarily conserved pseudokinases, STe20-Related ADapters (STRADs) α and ß. The roles of STRADα and STRADß in the developing nervous system are not fully defined, nor is it known whether they serve distinct functions. RESULTS: We find that STRADα is highly spliced and appears to be the primal STRAD paralog. We report that each STRAD is sufficient for axogenesis and promoting cell survival in the developing cortex. We also reveal a reciprocal protein-stabilizing relationship in vivo between LKB1 and STRADα, whereby STRADα specifically maintains LKB1 protein levels via cytoplasmic compartmentalization. CONCLUSIONS: We demonstrate a novel role for STRADß in axogenesis and also show for the first time in vivo that STRADα, but not STRADß, is responsible for LKB1 protein stability.


Asunto(s)
Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Axones/fisiología , Corteza Cerebral/metabolismo , Neuronas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Quinasas Activadas por AMP , Animales , Axones/metabolismo , Axones/ultraestructura , Corteza Cerebral/citología , Ratones , Neuronas/citología
17.
Ambio ; 43(1): 11-25, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24414801

RESUMEN

The Baltic Sea Action Plan (BSAP) requires tools to simulate effects and costs of various nutrient abatement strategies. Hierarchically connected databases and models of the entire catchment have been created to allow decision makers to view scenarios via the decision support system NEST. Increased intensity in agriculture in transient countries would result in increased nutrient loads to the Baltic Sea, particularly from Poland, the Baltic States, and Russia. Nutrient retentions are high, which means that the nutrient reduction goals of 135 000 tons N and 15 000 tons P, as formulated in the BSAP from 2007, correspond to a reduction in nutrient loadings to watersheds by 675 000 tons N and 158 000 tons P. A cost-minimization model was used to allocate nutrient reductions to measures and countries where the costs for reducing loads are low. The minimum annual cost to meet BSAP basin targets is estimated to 4.7 billion Euro.


Asunto(s)
Eutrofización , Países Bálticos , Asignación de Costos , Modelos Económicos , Océanos y Mares
18.
Mar Pollut Bull ; 62(12): 2642-8, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22018881

RESUMEN

We analysed the extent to which European politicians have adhered to scientific recommendations on annual total allowable catches (TACs) from 1987 to 2011, covering most of the period of the Common Fisheries Policy (CFP). For the 11 stocks examined, TACs were set higher than scientific recommendations in 68% of decisions. Politically-adjusted TACs averaged 33% above scientifically recommended levels. There was no evidence that the 2002 reform of the CFP improved decision-making, as was claimed at the time. We modelled the effects of such politically-driven decision-making on stock sustainability. Our results suggest that political adjustment of scientific recommendations dramatically increases the probability of a stock collapsing within 40 years. In 2012 European fisheries policy will undergo a once-a-decade reform. Ten years ago radical reforms were promised but the changes failed to improve sustainability. It is likely that the 2012 reform will be similarly ineffective unless decision-making is changed so that catch allocations are based on science rather than politics.


Asunto(s)
Conservación de los Recursos Naturales , Unión Europea , Explotaciones Pesqueras/legislación & jurisprudencia , Regulación Gubernamental , Animales , Toma de Decisiones , Política Ambiental , Peces , Modelos Biológicos , Océanos y Mares , Dinámica Poblacional , Especificidad de la Especie
19.
Endocrinology ; 152(5): 1901-10, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21343252

RESUMEN

Arachidonic acid (AA) is generated in the anterior pituitary gland upon stimulation by the ACTH secretagogue, CRH. Using the patch clamp technique, we examined the action of AA on the excitability of single pituitary corticotropes obtained from a transgenic mouse strain that expresses the enhanced green fluorescent protein driven by the proopiomelanocortin promoter. CRH evoked depolarization, but AA caused hyperpolarization. Under voltage clamp condition, AA caused a rapid inhibition of the delayed rectifier K(+) current and then increased a background K(+) current. Inhibition of AA metabolism did not prevent the activation of the K(+) current by AA, suggesting a direct action of AA. The sensitivity of the AA-activated K(+) current to fluoxetine, chlorpromazine, extracellular acidification, diphenylbutylpiperidine antipsychotics, and the membrane permeable cAMP analog [8-(4-chlorophenylthio)-cAMP] suggest that the current is mediated via TWIK-related K(+) channel (TREK)-1 channels. Activation of the CRH receptors that are coupled to the adenylate cyclase pathway suppressed the activation of TREK-1 current by AA and reversed the AA-mediated hyperpolarization. Intracellular acidification (pH 7.0) increased the basal amplitude of TREK-1 current and resulted in hyperpolarizaton. CRH suppressed the basal TREK-1 current in cells with intracellular acidification and caused depolarization. Our finding indicates that TREK-1 channels are important in setting the resting potential in corticotropes. The opposing actions of CRH and AA on the excitability of corticotropes raise the possibility that AA may act as a negative feedback regulator to reduce the stimulatory action of CRH and thus prevent excessive ACTH release during chronic stress.


Asunto(s)
Ácido Araquidónico/farmacología , Corticotrofos/fisiología , Hormona Liberadora de Corticotropina/farmacología , Canales de Potasio de Dominio Poro en Tándem/fisiología , Animales , Células Cultivadas , Clorpromazina/farmacología , Corticotrofos/citología , Corticotrofos/metabolismo , AMP Cíclico/análogos & derivados , AMP Cíclico/farmacología , Fluoxetina/farmacología , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Concentración de Iones de Hidrógeno , Potenciales de la Membrana/efectos de los fármacos , Ratones , Ratones Transgénicos , Fármacos Neuroprotectores/farmacología , Técnicas de Placa-Clamp , Tionucleótidos/farmacología
20.
Proc Natl Acad Sci U S A ; 107(33): 14556-61, 2010 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-20679200

RESUMEN

Tropical forest degradation emits carbon at a rate of approximately 0.5 Pgxy(-1), reduces biodiversity, and facilitates forest clearance. Understanding degradation drivers and patterns is therefore crucial to managing forests to mitigate climate change and reduce biodiversity loss. Putative patterns of degradation affecting forest stocks, carbon, and biodiversity have variously been described previously, but these have not been quantitatively assessed together or tested systematically. Economic theory predicts a systematic allocation of land to its highest use value in response to distance from centers of demand. We tested this theory to see if forest exploitation would expand through time and space as concentric waves, with each wave targeting lower value products. We used forest data along a transect from 10 to 220 km from Dar es Salaam (DES), Tanzania, collected at two points in time (1991 and 2005). Our predictions were confirmed: high-value logging expanded 9 kmxy(-1), and an inner wave of lower value charcoal production 2 kmxy(-1). This resource utilization is shown to reduce the public goods of carbon storage and species richness, which significantly increased with each kilometer from DES [carbon, 0.2 Mgxha(-1); 0.1 species per sample area (0.4 ha)]. Our study suggests that tropical forest degradation can be modeled and predicted, with its attendant loss of some public goods. In sub-Saharan Africa, an area experiencing the highest rate of urban migration worldwide, coupled with a high dependence on forest-based resources, predicting the spatiotemporal patterns of degradation can inform policies designed to extract resources without unsustainably reducing carbon storage and biodiversity.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales/métodos , Agricultura Forestal/métodos , Árboles/crecimiento & desarrollo , Carbono/metabolismo , Conservación de los Recursos Naturales/tendencias , Agricultura Forestal/tendencias , Geografía , Modelos Biológicos , Tanzanía , Árboles/metabolismo , Clima Tropical , Madera/crecimiento & desarrollo , Madera/metabolismo
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