The planetary boundaries framework defines a safe operating space for humanity based on the intrinsic biophysical processes that regulate the stability of the Earth system. Here, we revise and update the planetary boundary framework, with a focus on the underpinning biophysical science, based on targeted input from expert research communities and on more general scientific advances over the past 5 years. Several of the boundaries now have a two-tier approach, reflecting the importance of cross-scale interactions and the regional-level heterogeneity of the processes that underpin the boundaries. Two core boundaries—climate change and biosphere integrity—have been identified, each of which has the potential on its own to drive the Earth system into a new state should they be substantially and persistently transgressed.

/pdf/planetary-boundaries-guiding-human-development-on-a-changing-5gmf909etg.pdf

Planetary boundaries: Guiding human development on a changing planet

TiO2 photocatalysis and related surface phenomena

Anthropogenic pressures on the Earth System have reached a scale where abrupt global environmental change can no longer be excluded. We propose a new approach to global sustainability in which we define planetary boundaries within which we expect that humanity can operate safely. Transgressing one or more planetary boundaries may be deleterious or even catastrophic due to the risk of crossing thresholds that will trigger non-linear, abrupt environmental change within continental- to planetary-scale systems. We have identified nine planetary boundaries and, drawing upon current scientific understanding, we propose quantifications for seven of them. These seven are climate change (CO2 concentration in the atmosphere <350 ppm and/or a maximum change of +1 W m-2 in radiative forcing); ocean acidification (mean surface seawater saturation state with respect to aragonite ≥ 80% of pre-industrial levels); stratospheric ozone (<5% reduction in O3 concentration from pre-industrial level of 290 Dobson Units); biogeochemical nitrogen (N) cycle (limit industrial and agricultural fixation of N2 to 35 Tg N yr-1) and phosphorus (P) cycle (annual P inflow to oceans not to exceed 10 times the natural background weathering of P); global freshwater use (<4000 km3 yr-1 of consumptive use of runoff resources); land system change (<15% of the ice-free land surface under cropland); and the rate at which biological diversity is lost (annual rate of <10 extinctions per million species). The two additional planetary boundaries for which we have not yet been able to determine a boundary level are chemical pollution and atmospheric aerosol loading. We estimate that humanity has already transgressed three planetary boundaries: for climate change, rate of biodiversity loss, and changes to the global nitrogen cycle. Planetary boundaries are interdependent, because transgressing one may both shift the position of other boundaries or cause them to be transgressed. The social impacts of transgressing boundaries will be a function of the social-ecological resilience of the affected societies. Our proposed boundaries are rough, first estimates only, surrounded by large uncertainties and knowledge gaps. Filling these gaps will require major advancements in Earth System and resilience science. The proposed concept of "planetary boundaries" lays the groundwork for shifting our approach to governance and management, away from the essentially sectoral analyses of limits to growth aimed at minimizing negative externalities, toward the estimation of the safe space for human development. Planetary boundaries define, as it were, the boundaries of the "planetary playing field" for humanity if we want to be sure of avoiding major human-induced environmental change on a global scale.

/pdf/planetary-boundaries-exploring-the-safe-operating-space-for-ir5ysgjg96.pdf

Planetary boundaries: Exploring the safe operating space for humanity

Photoinduced reactivity of titanium dioxide

The global decline in estuarine and coastal ecosystems (ECEs) is affecting a number of critical benefits, or ecosystem services. We review the main ecological services across a variety of ECEs, including marshes, mangroves, nearshore coral reefs, seagrass beds, and sand beaches and dunes. Where possible, we indicate estimates of the key economic values arising from these services, and discuss how the natural variability of ECEs impacts their benefits, the synergistic relationships of ECEs across seascapes, and management implications. Although reliable valuation estimates are beginning to emerge for the key services of some ECEs, such as coral reefs, salt marshes, and mangroves, many of the important benefits of seagrass beds and sand dunes and beaches have not been assessed properly. Even for coral reefs, marshes, and mangroves, important ecological services have yet to be valued reliably, such as cross-ecosystem nutrient transfer (coral reefs), erosion control (marshes), and pollution control (mangroves). An important issue for valuing certain ECE services, such as coastal protection and habitat-fishery linkages, is that the ecological functions underlying these services vary spatially and temporally. Allowing for the connectivity between ECE habitats also may have important implications for assessing the ecological functions underlying key ecosystems services, such coastal protection, control of erosion, and habitat-fishery linkages. Finally, we conclude by suggesting an action plan for protecting and/or enhancing the immediate and longer-term values of ECE services. Because the connectivity of ECEs across land-sea gradients also influences the provision of certain ecosystem services, management of the entire seascape will be necessary to preserve such synergistic effects. Other key elements of an action plan include further ecological and economic collaborative research on valuing ECE services, improving institutional and legal frameworks for management, controlling and regulating destructive economic activities, and developing ecological restoration options.

https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1890/10-1510.1

The value of estuarine and coastal ecosystem services

Research and development (R&D) management is increasingly about managing knowledge rather than simply managing its generation. Better management of knowledge is a key success factor for industry competitiveness through continuous innovation. R&D management processes developed in the past, which can be described as the first, second, or third generation models, deal with concepts, techniques and tools for managing research as an investment portfolio of the firm. These models focus on the creation and diffusion of knowledge internal to the firm. Management of R&D is also about managing knowledge external to the firm and it involves the management of complementary skills, technological dependencies, and knowledge transfers across research links. This paper addresses the concept of research management as the generation of intellectual capital, which drives future businesses and new products. It examines, as a case study, research management practices employed by biotechnology and pharmaceutical research groups in industries and universities and outlines a fourth generation approach to managing research.

Towards a fourth generation R&D management model-research networks in knowledge management

A mathematical model has been developed that predicts the cell population dynamics and production of recombinant protein and infective extracellular virus progeny by insect cells after infection with baculovirus in batch suspension culture. Infection in the model is based on the rate of virus attachment to suspended insect cells under culture conditions. The model links the events following infection with the sequence of gene expression in the baculovirus replicative cycle. Substrate depletion is used to account for the decrease in product yield observed when infecting at high cell densities. Model parameters were determined in shaker flasks for two media: serum-supplemented IPL-41 medium and serum free Sf900II medium. There was good agreement between model predictions and the results from an independent series of experiments performed to validate the mode. The model predicted: (1) the optimal time of infection at high multiplicity of infection: (2) the timing and magnitude of recombinant protein production in a 2-L bioreactor; and (3) the timing and magnitude of recombinant protein production at multiplicities of infection from 0.01 to 100 plaque-forming units per cell. Through its ability to predict optimal infection strategies in batch suspension culture, the model has use in the design and optimization of large-scale systems for the production of recombinant products using the baculovirus expression vector system.

Modeling and optimization of the baculovirus expression vector system in batch suspension culture.

The variance of observed cell counts using a hemacytometer was analyzed The variance was found to be greater than expected under the normally assumed Poisson distribution because of variations in the volume of the counting area Furthermore, counts from the two sides of the hemacytometer were found to be correlated Total cell count on a hemacytometer was better described using a normal distribution with quadratic variance, N(lambda, lambda + sigma-lambda-2), with sigma = 0012 Because hemacytometer cell counts are not Poisson distributed, modified counting protocols are recommended

Hemacytometer Cell Count Distributions: Implications of Non‐Poisson Behavior

Energy metabolism and the production of ammonia in hybridoma cell culture and its inhibitory effects on cell growth are reviewed. The interactive roles of glucose and glutamine metabolism affect the rate of production of ammonia, and these interactions are described. It is shown that growth inhibition usually occurs between 2-4 mM ammonia although some cell lines have been shown to adapt to much higher concentrations, particularly in continuous culture. In batch cultures cell growth appears to be particularly susceptible to increased ammonia concentrations during the early stages of growth; ammonia increased the rate of cell death in the late stage of batch growth. The specific productivity of monoclonal antibodies is much less sensitive to the released ammonia than is growth; lower volumetric productivities relate to the lower viable cell concentrations which are achieved at the high ammonia levels. Techniques to prevent ammonia accumulation or remove ammonia selectively have been relatively unsuccessful to date.

Paul F. Greenfield

Papers

Towards a fourth generation R&D management model-research networks in knowledge management

Modeling and optimization of the baculovirus expression vector system in batch suspension culture.

Hemacytometer Cell Count Distributions: Implications of Non‐Poisson Behavior

Hybridoma growth limitations: the roles of energy metabolism and ammonia production.

Computational fluid dynamic modelling of wastewater ponds to improve design