Exchange Interface Research Articles

Boundary conditions at the interface of finite thickness between ferromagnetic and antiferromagnetic materials

Systematic approach has been applied to obtain the boundary conditions for magnetization at an interface between ferromagnetic (FM) and antiferromagnetic (AFM) materials in the continuous medium approximation. Three order parameters are considered inside an interface of finite thickness magnetization M of FM, magnetizations of both sublattices M1 and M2 of AFM. The boundary conditions are defined in terms of some average properties of the FM/AFM interface. The interface has a finite thickness which is much less than spin wave length. This approach allowed to take into account the interface anisotropy, interface symmetric exchange coupling and interface coupling resulting from inversion symmetry breaking in the vicinity of the interface.

Heaviness, space and journey – innovation opportunities and restrictions

PurposeThe purpose of this paper is to argue that if the authors want to understand the role of heaviness, space and journey in innovation, the authors have to start with the interaction itself, that is the exchange process taking place between economic actors. Three major aspects will be considered: the first is that heaviness, space and journey imply restrictions, the second is that these aspects can be positively utilised in innovation processes, and the third is their joint importance to contemporary policy. All innovation processes must bypass and build on existing investments in social and material resources, related across time and space.Design/methodology/approachThe theoretical foundation is a basic IMP observation: exchange has a content. Exchange is captured as an interaction process that creates specific imprints on material and social resources involved – across firm boundaries, and across time and space. The methodology is a consequence of the research question and the theoretical point of departure and is based on three earlier IMP studies, where heaviness has been measured in different ways. The authors utilize two earlier presented case studies to focus on the heaviness, space and journey dimensions.FindingsThree main aspects are discussed: the first aspect concerns the need for utilisation of others heaviness in order for the innovation to gain heaviness in itself. The second aspect concerns the consequences that the search for heaviness has for the creation of an innovation space. The third aspect concerns the innovation journey; the specific interaction patterns between significant actors as well as places hosting heavy using, producing and developing activities created through interactions over time.Research limitations/implicationsIn order to change or to establish a new economic exchange interface, there is an urgent need to be aware of and utilise heaviness, to find out in what way existing investments made in related interfaces can be taken advantage of. In order to do that, there is a need for a better understanding of the function of heaviness, spatial and journey aspects included.Practical implicationsIn contemporary policy, certain heaviness is recognised, however, only in a non-business developing setting. The first conclusion is that heaviness of established producing and using settings is a policy blind spot. This implies that analytical policy approaches are not equipped for recognitions or of estimations of heaviness, nor as a hindrance or as a possibility in producing and using settings. The second conclusion is that the policy definition of the role of place implies neglecting the innovation space. The third conclusion is that there is a need for policy to recognise the innovation journey and its consequences.Social implicationsIf the policy is expected to have regional effects, policy analysis has to start out from the established heaviness of the region and consider how it can be taken advantage of.Originality/valueThe paper draws attention to an aspect neglected in policy attempts to boost innovation, that the mobilising support has to come from actors representing heavy producing and using networks – and that these already have space and journey characteristics. A peripheral actor can come up with a suggestion for change – but it cannot alone mobilise the resources necessary for an innovation to get a space and journey in relation to established resource constellations.

Stability Analysis of a Multi Area System with Renewable Energy and Multi-Terminal DC Tie Lines

Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits of multi terminal DC (MTDC) tie lines as compared to the traditional HVAC forms the main objective of this paper. Probabilistic load flow (PLF) is applied to determine the system parameters while the uncertainties are modelled using Scenario Based Method (SBM). The simulation results reveal that with the use of MTDC tie lines, the frequency and voltage stability in the MAMODED with renewable energy sources (RES) are enhanced while keeping the MTDC power exchange interface nodes at secure levels.

MODELING OF HEAT TRANSFER IN A POROUS TURBINE BEARING COOLING SYSTEM

A new porous cooling system in which the coolant supply is produced by the combined action of capillary and gravitational forces is proposed and studied for various technical devices and systems developed by the authors. The cooling surface is made of stainless steel, brass, copper, bronze, nickel, glass and alundum. The wall thickness is (0.05–2.00) ∙ 10⁻³m. Visual observations were carried out by using high-speed camera filming with the use of SCS-1M. Experiments were carried out with water at pressures ranging between 0.01–10.00 MPa, under-heating to 0–20 K, excess liquid of 1–14 of steam flow, thermal load of (1–60) ∙ 104 W/m², temperature pressure of 1–60 K and the system orientation of ±(0–90) degrees. Studies carried out on a model plant has identified two areas of the process of vaporization of the liquid and an influence of operating and design characteristics. The optimal coolant flow and the most effective form of reticulated porous structure are identified. Visual observations have made it possible to describe the physical picture of the processes and to generalize experimental data on the removed heat flows with an accuracy of ±20 % depending on the thermophysical properties of the fluid, wall, temperature difference, excess fluid, porous structures and heat exchange interface.

Rab11 family expression in the human placenta: Localization at the maternal-fetal interface.

Rab proteins are a family of small GTPases involved in a variety of cellular processes. The Rab11 subfamily in particular directs key steps of intracellular functions involving vesicle trafficking of the endosomal recycling pathway. This Rab subfamily works through a series of effector proteins including the Rab11-FIPs (Rab11 Family-Interacting Proteins). While the Rab11 subfamily has been well characterized at the cellular level, its function within human organ systems is still being explored. In an effort to further study these proteins, we conducted a preliminary investigation of a subgroup of endosomal Rab proteins in a range of human cell lines by Western blotting. The results from this analysis indicated that Rab11a, Rab11c(Rab25) and Rab14 were expressed in a wide range of cell lines, including the human placental trophoblastic BeWo cell line. These findings encouraged us to further analyse the localization of these Rabs and their common effector protein, the Rab Coupling Protein (RCP), by immunofluorescence microscopy and to extend this work to normal human placental tissue. The placenta is a highly active exchange interface, facilitating transfer between mother and fetus during pregnancy. As Rab11 proteins are closely involved in transcytosis we hypothesized that the placenta would be an interesting human tissue model system for Rab investigation. By immunofluorescence microscopy, Rab11a, Rab11c(Rab25), Rab14 as well as their common FIP effector RCP showed prominent expression in the placental cell lines. We also identified the expression of these proteins in human placental lysates by Western blot analysis. Further, via fluorescent immunohistochemistry, we noted abundant localization of these proteins within key functional areas of primary human placental tissues, namely the outer syncytial layer of placental villous tissue and the endothelia of fetal blood vessels. Overall these findings highlight the expression of the Rab11 family within the human placenta, with novel localization at the maternal-fetal interface.

Identification of the Dimer Exchange Interface of the Bacterial DNA Damage Response Protein UmuD.

The Escherichia coli SOS response, an induced DNA damage response pathway, confers survival on bacterial cells by providing accurate repair mechanisms as well as the potentially mutagenic pathway translesion synthesis (TLS). The umuD gene products are upregulated after DNA damage and play roles in both nonmutagenic and mutagenic aspects of the SOS response. Full-length UmuD is expressed as a homodimer of 139-amino-acid subunits, which eventually cleaves its N-terminal 24 amino acids to form UmuD'. The cleavage product UmuD' and UmuC form the Y-family polymerase DNA Pol V (UmuD'2C) capable of performing TLS. UmuD and UmuD' exist as homodimers, but their subunits can readily exchange to form UmuDD' heterodimers preferentially. Heterodimer formation is an essential step in the degradation pathway of UmuD'. The recognition sequence for ClpXP protease is located within the first 24 amino acids of full-length UmuD, and the partner of full-length UmuD, whether UmuD or UmuD', is degraded by ClpXP. To better understand the mechanism by which UmuD subunits exchange, we measured the kinetics of exchange of a number of fluorescently labeled single-cysteine UmuD variants as detected by Förster resonance energy transfer. Labeling sites near the dimer interface correlate with increased rates of exchange, indicating that weakening the dimer interface facilitates exchange, whereas labeling sites on the exterior decrease the rate of exchange. In most but not all cases, homodimer and heterodimer exchange exhibit similar rates, indicating that somewhat different molecular surfaces mediate homodimer exchange and heterodimer formation.

Industrial Internet of things over tactile Internet in the context of intelligent manufacturing

With the rapid advance of wireless technologies and its related domains, numerous emerging solutions and applications of industrial wireless systems have been developed, such as industrial Internet of things (2IoT), industrial wireless sensor networks, big data, cloud computing and augmented reality. The present development of communication in industrial environments drives the need for ubiquitous access to distributed resources and services that are connected to things, devices, and systems. However, given the fact that most industrial wireless sensor devices are resource constrained and operate on batteries, the communication overhead is therefore important issues for 2IoT’s design. In the context of intelligent manufacture, all kinds of intelligent equipment (e.g., industrial robots, industrial control system, industrial machine tools and test equipment) supported by wired or wireless networks are widely adopted, and both real-time, delayed signals and system security coexist. In order to efficiently manage these wireless devices in a unified manner, the intelligent manufacture authorities should be able to provide a network infrastructure supporting various 2IoT applications and services. This paper presents an overview of 2IoT’s network infrastructure and describe the information interaction among different devices. Then, a tactile Internet 2IoT architecture is proposed to manage physical devices and provide an interface for information exchange. Finally, the paper is discussed the prominent problems and possible solutions for tactile Internet 2IoT. This work will open a new research direction of 2IoT, and accelerate the implementation of intelligent manufacturing technical architecture.

Identification of the Dimer Exchange Interface of the Bacterial DNA Damage Response Protein UmuD

The SOS response, an induced DNA damage response pathway in Escherichia coli, is temporally separated into two stages. The initial stage affords an opportunity for the cell to utilize accurate repair mechanisms such as homologous recombination and nucleotide excision repair. During the later stage, cells employ a potentially mutagenic pathway termed translesion synthesis (TLS) to tolerate damage and promote survival. The umuD gene products are upregulated during the SOS response and play a role in both early and late stages. Full‐length UmuD is expressed as a homodimer of 139‐amino‐acid subunits which eventually cleave their N‐terminal 24 amino acids to form UmuD′. The cleavage product, UmuD′, together with UmuC, form the Y‐family polymerase DNA Pol V (UmuD′2C) capable of performing TLS. UmuD and UmuD′ exist as homodimers, but their subunits can readily exchange to form UmuDD′ heterodimers preferentially. Heterodimer formation is an essential step in the degradation pathway for the pro‐mutagenic UmuD′. Full‐length UmuD is targeted for degradation by the ClpXP protease due to a recognition sequence located on the N‐terminal arm of UmuD. Formation of UmuD′ via cleavage removes this recognition sequence, making UmuD′ invisible to ClpX. Thus, UmuD in the context of heterodimer acts as a delivery factor for UmuD′. To better understand the mechanism by which UmuD subunits exchange, we measured the kinetics of exchange for a number of single‐cysteine UmuD variants. By conjugating fluorescent molecules at different positions on the protein we were able to observe their effect on exchange kinetics. Interestingly, the most dramatic differential effects on exchange were observed at two adjacent positions in the peptide backbone. These findings provide insight into the molecular surfaces responsible for mediating exchange.Support or Funding InformationSupported by NSF CAREER MCB‐0845033 and American Cancer Society RSG‐12‐161‐01‐DMC.

Investigating strategy tools from an interactive perspective

PurposeThe purpose of this paper is to investigate how the strategic management concept of “strategy tools” (STs) can be reinterpreted from an industrial network perspective. It considers how STs are used to influence the substance of relationships and how firms engage in strategic action by using such tools.Design/methodology/approachUsing case study research involving three focal firms, the paper scrutinizes use of selected STs to examine how they are used to systematically relate to others and create benefits and affect development paths in business relationships.FindingsSTs can be viewed as an integrated part of a networking pattern of mobilizing resources, linking activities and relating actors. Seen in this manner, use of STs can be interaction-facilitating or interaction-creating.Research limitations/implicationsIn an interactive approach, STs must be seen in relation to others as they are used in strategic (co-)action to engage and involve others. In this view, tools are strategic when used to affect the long-term development of important business relationships.Practical implicationsPractitioners should acknowledge that the use of a ST to handle counterparts is emerging, and valuable only in relation to specific others. Because the value of STs is unknowable until it is revealed how they can affect the substance of a specific relationship, there is no best-practice or one-size-fits-all approach.Originality/valueThis paper illuminates the phenomenon of “strategy tools” by considering it from both sides of the business exchange interface.

Exceptional Anti-Icing Performance of Self-Impregnating Slippery Surfaces.

A heat exchange interface at subzero temperature in a water vapor environment exhibits high probability of frost formation due to freezing condensation, a factor that markedly decreases the heat transfer efficacy due to the considerable thermal resistance of ice. Here we report a novel strategy to delay ice nucleation on these types of solid-water vapor interfaces. With a process-driven mechanism, a self-generated liquid intervening layer immiscible to water is deposited on a textured superhydrophobic surface and acts as a barrier between the water vapor and the solid substrate. This liquid layer imparts remarkable slippery conditions resulting in high mobility of condensing water droplets. A large increase of the ensuing ice coverage time is shown compared to the cases of standard smooth hydrophilic or textured superhydrophobic surfaces. During deicing of these self-impregnating surfaces we show an impressive tendency of ice fragments to skate expediting defrosting. Robustness of such surfaces is also demonstrated by operating them under subcooling for at least 490 h without a marked degradation. This is attributed to the presence of the liquid intervening layer, which protects the substrate from hydrolyzation, enhancing longevity and sustaining heat transfer efficiency.

Development of the protocol of the interface of data exchange with the GBTX chip

The structure of the interface of data exchange with the GBTX chip for the CBM experiment is considered. The interface generates a data package, consisting of the digital codes of signal amplitude, signal superposition in peak detector, signal arrival time and channel number, wherein the event has occurred, all these codes being generated by the readout blocks of IC. The created data package is coded according to the 8b/10b format for transferring to the GBTX chip. The packages register of controlling data (warnings on error and desynchronization) are generated for a correct exchange (correspondence) under the GBTX protocol. The adjustment of the quantity of channels, generating data packages and being connected to the GBTX chip, is possible. The interface has been designed according to the 180 nm CMOS technology of UMC.

Complex function block of processing and transferring asynchronous data for the IC of reading out the signals of multichannel detectors

The structure of a 32-channel system of asynchronous data processing is considered. The data come from the detectors of nuclear physics experiments. Processing is provided for signals with a mean frequency of up to 10 MHz in each channel. The system provides generation of data packages, consisting of digital codes of signal amplitude, of signal superposition in peak detectors, of signal arrival time and number of channel wherein the event has occurred with a subsequent 8b10b coding. The considered system allows us to regulate dynamically the number of active channels. Two interface of data exchange – the slow I2C and high-speed (320 MHz), providing communication IC with the GBTX chip, have been built in the system. The results of developing the structural diagram and circuital-layout solutions of separate units are presented. System prototyping is implemented by the 180nm CMOS technology of UMC. The results of testing both separate blocks and the whole system are presented.

Placental labyrinth formation in mice requires endothelial FLRT2/UNC5B signaling.

The placental labyrinth is the interface for gas and nutrient exchange between the embryo and the mother; hence its proper development is essential for embryogenesis. However, the molecular mechanism underlying development of the placental labyrinth, particularly in terms of its endothelial organization, is not well understood. Here, we determined that fibronectin leucine-rich transmembrane protein 2 (FLRT2), a repulsive ligand of the UNC5 receptor family for neurons, is unexpectedly expressed in endothelial cells specifically in the placental labyrinth. Mice lacking FLRT2 in endothelial cells exhibited embryonic lethality at mid-gestation, with systemic congestion and hypoxia. Although they lacked apparent deformities in the embryonic vasculature and heart, the placental labyrinths of these embryos exhibited aberrant alignment of endothelial cells, which disturbed the feto-maternal circulation. Interestingly, this vascular deformity was related to endothelial repulsion through binding to the UNC5B receptor. Our results suggest that the proper organization of the placental labyrinth depends on coordinated inter-endothelial repulsion, which prevents uncontrolled layering of the endothelium.

Geological fluid flow in sedimentary basins

For over 50 years, sedimentary basins have been considered as the lithosphere's surface film, belonging to the subsurface domain and containing the vast majority of accessible mineral and energy resources. Beyond their human use, sedimentary basins are more importantly the ultimate exchange interface between the earth's main reservoirs. Firstly, between the upper lithosphere and the atmosphere-hydrosphere reservoirs, exchanges are mainly vertical. Next, between the onshore reservoirs, i.e., on the continental part, and the offshore reservoirs, i.e., in the submerged part of the margins, exchanges are lateral and may take place over great distances. Unexpected low accumulations and/or dry...

Advancing HL7 v2 to New Heights: A Platform for Developing Specifications, Test Plans, and Testing Tools

Development of HL7 v2 data exchange interface specifications has long been problematic, plagued with ambiguous and inconsistent requirement specifications. This situation leads to potential misinterpretation by implementers, thus limiting the effectiveness of the specification and creating artificial and unnecessary barriers to interoperability. Likewise, the ability to test implementations effectively for conformance to the specifications is hindered. The current approach of specification development and test plan creation relies on word processing tools, meaning implementers and testers must read and interpret the information in these documents and then translate it into machine-computable requirements and test assertions. This approach is error prone—a better methodology is needed. We present a set of productivity tools in an integrated platform that allow users to define and constrain HL7 v2 specifications and to develop test plans that result in machine-computable artifacts. A testing infrastructure and framework subsequently uses these artifacts to create conformance testing tools automatically. We present and demonstrate the utility of a platform for developing specifications, writing test plans, and creating testing tools. The value proposition of this end-to-end methodology is explained for authors writing HL7 v2 specifications, for developers implementing interfaces, and for testers creating validation tools.

Assessment of heat mining and hydrogeochemical reactions with data from a former geothermal injection well in the Malm Aquifer, Bavarian Molasse Basin, Germany

With high temperatures, high transmissivities, and low salinities the Malm aquifer in the Bavarian Molasse Basin, Germany, offers ideal conditions for the exploration of geothermal energy in Germany. In 2011, the Pullach geothermal doublet system was extended with a third geothermal well (Th3) to account for increasing heat demand. The third well was then used as injection well and the former injection well (Th2) was converted to a production well. Hence, for the first time in the history of geothermal exploration of the Malm aquifer, data became accessible from the formation surrounding an injection well which had been in operation for more than 5 years. This data provides access to the processes at the injection well and sets the baseline for an assessment of the long term behaviour of geothermal heat and power plants in the Molasse Basin.The increase of the production temperatures at the former injection well after conversion from injection to production went faster than expected; after 3 years of production the initial temperatures have almost been reached. This can be explained with a vertically heterogeneous distribution of the aquifer transmissivity with one thin, highly permeable layer. In this setting, the cold water forms a thin disc which extends much further from the injection well compared to a vertically homogeneous setting, with a cylindrical propagation of the injected water. Hence, in a heterogeneous setting the effective interface for conductive heat exchange between injected cool water and hot aquifer matrix with low permeability is larger.The hydrochemical data of the water from the former injection well showed a significant increase of the concentrations of calcium, magnesium, and bicarbonate, indicating dissolution of dolomite with about 0.6mmol/L of produced water. Together with thermoelastic effects and hydrostatic stress, the dissolution significantly contributes to an increasing injectivity. The effects are overcompensating the effects of the increased viscosity of the injected cold water. Results from the hydrogeochemical model show that lower temperatures and different lithostratigraphic origin of the injected water are responsible for the dissolution. The kinetic model suggests that the dissolution takes place close to the bore hole.The data collected from the Pullach site provides experimental proof for the processes in the surrounding of injection wells, i.e., the assumed aquifer heterogeneity, the connection to overlying strata, and for the hydrogeochemical model of the Malm aquifer. The data serves as a benchmark and reference for future exploration.

The chick embryo chorioallantoic membrane (CAM) assay

During avian development the mesodermal layers of the allantois and chorion fuse to form the chorioallantoic membrane (CAM). This structure rapidly expands generating a rich vascular network that provides an interface for gas and waste exchange. The CAM allows to study tissue grafts, tumor growth and metastasis, drugs delivery and toxicologic analysis, and angiogenic and anti-angiogenic molecules. The CAM is relatively simple, quick, and low-cost model that allows screening of a large number of pharmacological samples in a short time; does not require administrative procedures for obtaining ethics committee approval for animal experimentation. Moreover, being naturally immunodeficient, the chick embryo may receive transplantations from different tissues and species, without immune responses.

Emergence of a Wave of Wnt Signaling that Regulates Lung Alveologenesis by Controlling Epithelial Self-Renewal and Differentiation

Alveologenesis is the culmination of lung development and involves the correct temporal and spatial signals to generate the delicate gas exchange interface required for respiration. Using a Wnt-signaling reporter system, we demonstrate the emergence of a Wnt-responsive alveolar epithelial cell sublineage, which arises during alveologenesis, called the axin2+ alveolar type 2 cell, or AT2Axin2. The number of AT2Axin2 cells increases substantially during late lung development, correlating with a wave of Wnt signaling during alveologenesis. Transcriptome analysis, invivo clonal analysis, and exvivo lung organoid assays reveal that AT2sAxin2 promote enhanced AT2 cell growth during generation of the alveolus. Activating Wnt signaling results in the expansion of AT2s, whereas inhibition of Wnt signaling inhibits AT2 cell development and shunts alveolar epithelial development toward the alveolar type 1 cell lineage. These findings reveal a wave of Wnt-dependent AT2 expansion required for lung alveologenesis and maturation.

Evidence Linking the Role of Placental Expressions of Peroxisome Proliferator-Activated Receptor-γ and Nuclear Factor-Kappa B in the Pathogenesis of Preeclampsia Associated With Periodontitis.

Peroxisome proliferator-activated receptor (PPAR)-γ activation leads to suppression of production of a broad range of proinflammatory molecules. It plays a role in differentiation of trophoblasts and helps in normal placentation and formation of vascular exchange interface. Activation of nuclear factor-kappa (NF-κ) B triggers proinflammatory molecules inducing abnormal placentation and premature labor. This study aims to explore expression of PPAR-γ and NF-κB in placentas of women with periodontitis-associated preeclampsia compared with that in normotensive pregnant women. Fifty pregnant women were included. Twenty-five were controls (normotensive pregnant women) and 25 were pregnant women with preeclampsia, including those with gestational hypertension. Demographic data, pregnancy characteristics, and periodontal parameters were recorded, including: 1) plaque index; 2) gingival index; 3) bleeding on probing (BOP); 4) probing depth; and 5) attachment loss (AL). Placental tissue samples were collected from both groups and analyzed to quantify expression of PPAR-γ and NF-κB using real-time polymerase chain reaction. BOP and AL were significantly higher in pregnant women with preeclampsia compared with normotensive pregnant women (P <0.05). Expression of PPAR-γ was downregulated in patients with preeclampsia compared with that of healthy normotensive patients, which was statistically significant (P <0.05), whereas NF-κB was significantly activated (P <0.05) in pregnant women with preeclampsia compared with normotensive pregnant women. Higher periodontal disease prevalence is found among pregnant women with preeclampsia, with increased percentage of sites with BOP and greater AL. This study provides novel information on host response to systemic inflammation induced by periodontal pathogens through mechanisms involving downregulation of PPAR-γ and increased activation of NF-κB.

A model inter-comparison study to examine limiting factors in modelling Australian tropical savannas

Abstract. The savanna ecosystem is one of the most dominant and complex terrestrial biomes, deriving from a distinct vegetative surface comprised of co-dominant tree and grass populations. While these two vegetation types co-exist functionally, demographically they are not static but are dynamically changing in response to environmental forces such as annual fire events and rainfall variability. Modelling savanna environments with the current generation of terrestrial biosphere models (TBMs) has presented many problems, particularly describing fire frequency and intensity, phenology, leaf biochemistry of C3 and C4 photosynthesis vegetation, and root-water uptake. In order to better understand why TBMs perform so poorly in savannas, we conducted a model inter-comparison of six TBMs and assessed their performance at simulating latent energy (LE) and gross primary productivity (GPP) for five savanna sites along a rainfall gradient in northern Australia. Performance in predicting LE and GPP was measured using an empirical benchmarking system, which ranks models by their ability to utilise meteorological driving information to predict the fluxes. On average, the TBMs performed as well as a multi-linear regression of the fluxes against solar radiation, temperature and vapour pressure deficit but were outperformed by a more complicated nonlinear response model that also included the leaf area index (LAI). This identified that the TBMs are not fully utilising their input information effectively in determining savanna LE and GPP and highlights that savanna dynamics cannot be calibrated into models and that there are problems in underlying model processes. We identified key weaknesses in a model's ability to simulate savanna fluxes and their seasonal variation, related to the representation of vegetation by the models and root-water uptake. We underline these weaknesses in terms of three critical areas for development. First, prescribed tree-rooting depths must be deep enough, enabling the extraction of deep soil-water stores to maintain photosynthesis and transpiration during the dry season. Second, models must treat grasses as a co-dominant interface for water and carbon exchange rather than a secondary one to trees. Third, models need a dynamic representation of LAI that encompasses the dynamic phenology of savanna vegetation and its response to rainfall interannual variability. We believe that this study is the first to assess how well TBMs simulate savanna ecosystems and that these results will be used to improve the representation of savannas ecosystems in future global climate model studies.