Modeling growth and yield of loblolly pinestands under intensive management

Abstract:The objective of this work was to develop and validate a prognosis system for volume yield and basal area of intensively managed loblolly pine (Pinus taeda) stands, using stand and diameter class models compatible in basal area estimates. The data used in the study were obtained from plantations located in northern Uruguay. For model validation without data loss, a three-phase validation scheme was applied: first, the equations were fitted without the validation database; then, model validation was carried out; and, finally, the database was regrouped to recalibrate the parameter values. After the validation and final parameterization of the models, a simulation of the first commercial thinning was carried out. The developed prognosis system was precise and accurate in estimating basal area production per hectare or per diameter classes. There was compatibility in basal area estimates between diameter class and whole stand models, with a mean difference of -0.01 m2ha-1. The validation scheme applied is logic and consistent, since information on the accuracy and precision of the models is obtained without the loss of any information in the estimation of the models' parameters.

An active strain electromechanical model for cardiac tissue

We propose a finite element approximation of a system of partial differential equations describing the coupling between the propagation of electrical potential and large deformations of the cardiac tissue. The underlying mathematical model is based on the active strain assumption, in which it is assumed that a multiplicative decomposition of the deformation tensor into a passive and active part holds, the latter carrying the information of the electrical potential propagation and anisotropy of the cardiac tissue into the equations of either incompressible or compressible nonlinear elasticity, governing the mechanical response of the biological material. In addition, by changing from an Eulerian to a Lagrangian configuration, the bidomain or monodomain equations modeling the evolution of the electrical propagation exhibit a nonlinear diffusion term. Piecewise quadratic finite elements are employed to approximate the displacements field, whereas for pressure, electrical potentials and ionic variables are approximated by piecewise linear elements. Various numerical tests performed with a parallel finite element code illustrate that the proposed model can capture some important features of the electromechanical coupling, and show that our numerical scheme is efficient and accurate.

From pathogen defence to food allergy; The multiple facets of the mucosal immune system

Résumé destiné à un large public Le système immunitaire associé aux muqueuses gastro-intestinales doit être capable de protéger notre organisme contre l'invasion de pathogènes. Parallèlement, il doit identifier en Cant que tels, des composés inoffensifs comme la nourriture ou les milliards de bactéries qui résident dans notre intestin. Le travail présenté ici aborde ces deux aspects essentiels au bon fonctionnement de notre muqueuse intestinale. Dans une première partie, la protéine nommée pièce sécrétoire a été étudiée pour ses propriétés protectrices contre le pathogène viral rotavirus. Le rôle de la pièce sécrétoire est de transporter les anticorps que nous produisons vers la surface des muqueuses. En dehors de cette fonction bien connue, il se peut que cette protéine soit également capable de protéger notre organisme contre certains virus. L'hypothèse de travail était donc que la pièce sécrétoire se lie directement au virus, l'empêchant ainsi d'infecter des cellules épithéliales de l'intestin. En utilisant différentes techniques biochimiques, cette hypothèse s'est révélée fausse car aucune interaction entre la pièce sécrétoire et le virus n'a pu être observée, et logiquement, aucune protection n'a pu prendre place. En revanche, la pièce sécrétoire se lie à d'autres structures pathogéniques et permet ainsi de neutraliser leurs effets néfastes. La pièce sécrétoire participe donc activement à la protection de nos muqueuses, en plus de son rôle de transporteur. La deuxième partie de ce travail avait pour sujet les réactions inappropriées que le système immunitaire induit parfois contre un aliment, ou, autrement dit, les allergies alimentaires. Un modèle d'allergie alimentaire à donc été développé chez la souris et a permis de mesurer plusieurs symptômes et facteurs liés à l'allergie. Puis, ce modèle a été utilisé afin de tester les effets bénéfiques d'une bactérie lactique, dite probiotique, sur le développement de l'allergie. Il a été observé que, sous certaines circonstances, l'administration de la bactérie lactique protégeait entièrement les souris contre les réactions allergiques. L'effet bénéfique dépend donc du probiotique mais également d'autres facteurs encore inconnus â ce jour. Cette étude ouvre la voie sur la compréhension des mécanismes liés aux allergies alimentaires et sur l'impact que peuvent avoir les bactéries probiotiques sur cette maladie. Résumé Le système immunitaire associé aux muqueuses intestinales doit être capable de différencier les antigènes inoffensifs tels que 1a nourriture ou les bactéries commensales des microorganismes potentiellement dangereux. Cet aspect est essentiel pour le maintien de l'homéostase intestinale et fait l'objet du travail présenté ici. Dans un premier projet, les propriétés protectrices de la protéine appelée pièce sécrétoire (SC) ont été étudiées. SC est une protéine connue pour le transport des immunoglobulines à la surface des muqueuses. Cette protéine est fortement glycosylée paz des sucres complexes, ce qui nous a mené à postuler que SC puisse interagir avec le pathogène rotavirus. Cette hypothèse était soutenue par le fait que ce virus adhère aux cellules épithéliales par des résidus glycosylés. Des analyses biochimiques et biologiques ont démontré qu'aucune interaction entre SC et le virus ne prenait place, et que par conséquent SC n'offrait aucune protection contre ce pathogène. En revanche, SC interagit avec d'autres structures pathogéniques, comme la toxine A de Clostridium difficile, et la molécule d'adhésion intimine de la bactérie entéropathogène Escherichia coli. La liaison se fait par l'intermédiaire des sucres et confère ainsi une protection contre ces pathogènes. Ainsi, SC a été identifié comme agent neutralisant au niveau de l'intestin. La deuxième partie de ce travail abordait le sujet des allergies alimentaires, et avait pour but de tester les effets bénéfiques potentiels d'une bactérie probiotique, Lactobacillus paracasei NCC2461, contre les réactions allergiques. Un modèle marin d'allergie alimentaire a été mis au point, permettant de mesurer des immunoglobulines E, des symptômes allergiques, et la dégranulation de mastocytes. Lorsque le probiotique a été administré aux souris, celles-ci ont été complètement protégées des réactions allergiques dans une première expérience. Cependant, cette protection n'a pas été reproduite et suggère que des facteurs environnementaux encore inconnus sont critiques pour que le probiotique agisse positivement. Ce travail a permis de mettre en évidence la complexité de l'approche des traitements liés aux probiotiques et ouvre la voie sur la compréhension des mécanismes liés à l'allergie. Abstract The mucosal immune system associated to the gastrointestinal mucosa must efficiently distinguish between innocuous antigens, such as food proteins and commensal bacteria and potentially infectious agents. The work presented here deals with these two essential aspects guaranteeing intestinal homeostasis. In the first part of this work, the protective properties of secretory component (SC) toward the pathogen rotavirus were investigated. SC, which allows the transport of polymeric immunoglobulins (Ig) to mucosal surfaces, is highly glycosylated with complex glycan structures. The abundance and the nature of these carbohydrates led us to speculate that SC might interact with rotavirus, which is known to bind target cells with glycan receptors. Using various biological and biochemical techniques, we demonstrated that SC did not interact with rotaviruses, nor protected epithelial cells from infection. However, SC was shown to bind to Clostridium difficile toxin A and to the enteropathogenic Echerischia coli adhesion molecule intimin in a glycan-dependent fashion. These interactions allow in vitro protection of epithelial cells using physiological concentrations of SC. These data identify SC as a microbial scavenger at mucosal surfaces, and in the context of secretory IgA, further enhance the neutralising properties of the complex. The second project was inscribed in the domain of food allergy and aimed to test the modulatory functions of a probiotic strain of Lactobacillus paracasei toward allergic reactions. A model of food-mediated allergy was developed in the mouse using mucosal sensitisation. Several parameters associated to allergy were quantified after allergen challenge, and included allergen-specific IgE, allergic signs like diarrhea and temperature drop, and degranulation of mast cells. Administration of the probiotic strain was shown to completely protect mice from allergic reactions. However, these data were not reproduced, suggesting that unknown environmental factors are required so that protection mediated by the probiotic strain occurs. This study paves the way to the understanding of the mechanisms associated to allergy, and highlights the tremendous complexity that probiotic treatments will have to face.

Wet Oxidation of Concentrated Wastewaters: Process Combination and Reaction Kinetic Modeling

The accumulation of aqueous pollutants is becoming a global problem. The search for suitable methods and/or combinations of water treatment processes is a task that can slow down and stop the process of water pollution. In this work, the method of wet oxidation was considered as an appropriate technique for the elimination of the impurities present in paper mill process waters. It has been shown that, when combined with traditional wastewater treatment processes, wet oxidation offers many advantages. The combination of coagulation and wet oxidation offers a new opportunity for the improvement of the quality of wastewater designated for discharge or recycling. First of all, the utilization of coagulated sludge via wet oxidation provides a conditioning process for the sludge, i.e. dewatering, which is rather difficult to carry out with untreated waste. Secondly, Fe2(SO4)3, which is employed earlier as a coagulant, transforms the conventional wet oxidation process into a catalytic one. The use of coagulation as the post-treatment for wet oxidation can offer the possibility of the brown hue that usually accompanies the partial oxidation to be reduced. As a result, the supernatant is less colored and also contains a rather low amount of Fe ions to beconsidered for recycling inside mills. The thickened part that consists of metal ions is then recycled back to the wet oxidation system. It was also observed that wet oxidation is favorable for the degradation of pitch substances (LWEs) and lignin that are present in the process waters of paper mills. Rather low operating temperatures are needed for wet oxidation in order to destruct LWEs. The oxidation in the alkaline media provides not only the faster elimination of pitch and lignin but also significantly improves the biodegradable characteristics of wastewater that contains lignin and pitch substances. During the course of the kinetic studies, a model, which can predict the enhancements of the biodegradability of wastewater, was elaborated. The model includes lumped concentrations suchas the chemical oxygen demand and biochemical oxygen demand and reflects a generalized reaction network of oxidative transformations. Later developments incorporated a new lump, the immediately available biochemical oxygen demand, which increased the fidelity of the predictions made by the model. Since changes in biodegradability occur simultaneously with the destruction of LWEs, an attempt was made to combine these two facts for modeling purposes.

Applying the principles of life cycle assessment and costing in process modeling to examine profit-making capability

Static process simulation has traditionally been used to model complex processes for various purposes. However, the use of static processsimulators for the preparation of holistic examinations aiming at improving profit-making capability requires a lot of work because the production of results requires the assessment of the applicability of detailed data which may be irrelevant to the objective. The relevant data for the total assessment gets buried byirrelevant data. Furthermore, the models do not include an examination of the maintenance or risk management, and economic examination is often an extra property added to them which can be performed with a spreadsheet program. A process model applicable to holistic economic examinations has been developed in this work. The model is based on the life cycle profit philosophy developed by Hagberg and Henriksson in 1996. The construction of the model has utilized life cycle assessment and life cycle costing methodologies with a view to developing, above all, a model which would be applicable to the economic examinations of complete wholes and which would require the need for information focusing on aspects essential to the objectives. Life cycle assessment and costing differ from each other in terms of the modeling principles, but the features of bothmethodologies can be used in the development of economic process modeling. Methods applicable to the modeling of complex processes can be examined from the viewpoint of life cycle methodologies, because they involve the collection and management of large corpuses of information and the production of information for the needs of decision-makers as well. The results of the study shows that on the basis of the principles of life cycle modeling, a process model can be created which may be used to produce holistic efficiency examinations on the profit-making capability of the production line, with fewer resources thanwith traditional methods. The calculations of the model are based to the maximum extent on the information system of the factory, which means that the accuracyof the results can be improved by developing information systems so that they can provide the best information for this kind of examinations.

Modeling and measuring organizational renewal capability

Globalization and new information technologies mean that organizations have to face world-wide competition in rapidly transforming, unpredictable environments, and thus the ability to constantly generate novel and improved products, services and processes has become quintessential for organizational success. Performance in turbulent environments is, above all, influenced by the organization's capability for renewal. Renewal capability consists of the ability of the organization to replicate, adapt, develop and change its assets, capabilities and strategies. An organization with a high renewal capability can sustain its current success factors while at the same time building new strengths for the future. This capability does not only mean that the organization is able to respond to today's challenges and to keep up with the changes in its environment, but also that it can actas a forerunner by creating innovations, both at the tactical and strategic levels of operation and thereby change the rules of the market. However, even though it is widely agreed that the dynamic capability for continuous learning, development and renewal is a major source of competitive advantage, there is no widely shared view on how organizational renewal capability should be defined, and the field is characterized by a plethora of concepts and definitions. Furthermore,there is a lack of methods for systematically assessing organizational renewal capability. The dissertation aims to bridge these gaps in the existing research by constructing an integrative theoretical framework for organizational renewal capability and by presenting a method for modeling and measuring this capability. The viability of the measurement tool is demonstrated in several contexts, andthe framework is also applied to assess renewal in inter-organizational networks. In this dissertation, organizational renewal capability is examined by drawing on three complimentary theoretical perspectives: knowledge management, strategic management and intellectual capital. The knowledge management perspective considers knowledge as inherently social and activity-based, and focuses on the organizational processes associated with its application and development. Within this framework, organizational renewal capability is understood as the capacity for flexible knowledge integration and creation. The strategic management perspective, on the other hand, approaches knowledge in organizations from the standpoint of its implications for the creation of competitive advantage. In this approach, organizational renewal is framed as the dynamic capability of firms. The intellectual capital perspective is focused on exploring how intangible assets can be measured, reported and communicated. From this vantage point, renewal capability is comprehended as the dynamic dimension of intellectual capital, which consists of the capability to maintain, modify and create knowledge assets. Each of the perspectives significantly contributes to the understanding of organizationalrenewal capability, and the integrative approach presented in this dissertationcontributes to the individual perspectives as well as to the understanding of organizational renewal capability as a whole.

Dynamic drag modeling of submerged aquatic vegetation canopy flows

Vegetation has a profound effect on flow and sediment transport processes in natural rivers, by increasing both skin friction and form drag. The increase in drag introduces a drag discontinuity between the in-canopy flow and the flow above, which leads to the development of an inflection point in the velocity profile, resembling a free shear layer. Therefore, drag acts as the primary driver for the entire canopy system. Most current numerical hydraulic models which incorporate vegetation rely either on simple, static plant forms, or canopy-scaled drag terms. However, it is suggested that these are insufficient as vegetation canopies represent complex, dynamic, porous blockages within the flow, which are subject to spatially and temporally dynamic drag forces. Here we present a dynamic drag methodology within a CFD framework. Preliminary results for a benchmark cylinder case highlight the accuracy of the method, and suggest its applicability to more complex cases.

Functional error modeling for uncertainty quantification in hydrogeology

Approximate models (proxies) can be employed to reduce the computational costs of estimating uncertainty. The price to pay is that the approximations introduced by the proxy model can lead to a biased estimation. To avoid this problem and ensure a reliable uncertainty quantification, we propose to combine functional data analysis and machine learning to build error models that allow us to obtain an accurate prediction of the exact response without solving the exact model for all realizations. We build the relationship between proxy and exact model on a learning set of geostatistical realizations for which both exact and approximate solvers are run. Functional principal components analysis (FPCA) is used to investigate the variability in the two sets of curves and reduce the dimensionality of the problem while maximizing the retained information. Once obtained, the error model can be used to predict the exact response of any realization on the basis of the sole proxy response. This methodology is purpose-oriented as the error model is constructed directly for the quantity of interest, rather than for the state of the system. Also, the dimensionality reduction performed by FPCA allows a diagnostic of the quality of the error model to assess the informativeness of the learning set and the fidelity of the proxy to the exact model. The possibility of obtaining a prediction of the exact response for any newly generated realization suggests that the methodology can be effectively used beyond the context of uncertainty quantification, in particular for Bayesian inference and optimization.

Morphological, hydrological, biogeochemical and ecological changes and challenges in river restoration - the Thur River case study

River restoration can enhance river dynamics, environmental heterogeneity and biodiversity, but the underlying processes governing the dynamic changes need to be understood to ensure that restoration projects meet their goals, and adverse effects are prevented. In particular, we need to comprehend how hydromorphological variability quantitatively relates to ecosystem functioning and services, biodiversity as well as ground-and surface water quality in restored river corridors. This involves (i) physical processes and structural properties, determining erosion and sedimentation, as well as solute and heat transport behavior in surface water and within the subsurface; (ii) biogeochemical processes and characteristics, including the turnover of nutrients and natural water constituents; and (iii) ecological processes and indicators related to biodiversity and ecological functioning. All these aspects are interlinked, requiring an interdisciplinary investigation approach. Here, we present an overview of the recently completed RECORD (REstored CORridor Dynamics) project in which we combined physical, chemical, and biological observations with modeling at a restored river corridor of the perialpine Thur River in Switzerland. Our results show that river restoration, beyond inducing morphologic changes that reshape the river bed and banks, triggered complex spatial patterns of bank infiltration, and affected habitat type, biotic communities and biogeochemical processes. We adopted an interdisciplinary approach of monitoring the continuing changes due to restoration measures to address the following questions: How stable is the morphological variability established by restoration? Does morphological variability guarantee an improvement in biodiversity? How does morphological variability affect biogeochemical transformations in the river corridor? What are some potential adverse effects of river restoration? How is river restoration influenced by catchment-scale hydraulics [GRAPHICS] and which feedbacks exist on the large scale? Beyond summarizing the major results of individual studies within the project, we show that these overarching questions could only be addressed in an interdisciplinary framework.

Business Process Modeling in Software Requirements Engineering for Small and Medium Software Projects

Vaatimusmäärittelyn tavoitteena on luoda halutun järjestelmän kokonaisen, yhtenäisen vaatimusluettelon vaatimusten määrittämiseksi käsitteellisellä tasolla. Liiketoimintaprosessien mallintaminen on varsin hyödyllinen vaatimusmäärittelyn varhaisissa vaiheissa. Tämä työ tutkii liiketoimintaprosessien mallintamista tietojärjestelmien kehittämistä varten. Nykyään on olemassa erilaisia liiketoimintaprosessien mallintamiseen tarkoitettuja tekniikoita. Tämä työ tarkastaa liiketoimintaprosessien mallintamisen periaatteet ja näkökohdat sekä eri mallinnustekniikoita. Uusi menetelmä, joka on suunniteltu erityisesti pienille ja keskisuurille ohjelmistoprojekteille, on kehitetty prosessinäkökohtien ja UML-kaavioiden perusteella.

Metal dealing at the origin of the Chordata phylum: The metallothionein system and metal overload response in Amphioxus.

Non-vertebrate chordates, specifically amphioxus, are considered of the utmost interest for gaining insight into the evolutionary trends, i.e. differentiation and specialization, of gene/protein systems. In this work, MTs (metallothioneins), the most important metal binding proteins, are characterized for the first time in the cephalochordate subphylum at both gene and protein level, together with the main features defining the amphioxus response to cadmium and copper overload. Two MT genes (BfMT1 and BfMT2) have been identified in a contiguous region of the genome, as well as several ARE (antioxidant response element) and MRE (metal response element) located upstream the transcribed region. Their corresponding cDNAs exhibit identical sequence in the two lancelet species (B. floridae and B. lanceolatum), BfMT2 cDNA resulting from an alternative splicing event. BfMT1 is a polyvalent metal binding peptide that coordinates any of the studied metal ions (Zn, Cd or Cu) rendering complexes stable enough to last in physiological environments, which is fully concordant with the constitutive expression of its gene, and therefore, with a metal homeostasis housekeeping role. On the contrary, BfMT2 exhibits a clear ability to coordinate Cd(II) ions, while it is absolutely unable to fold into stable Cu (I) complexes, even as mixed species. This identifies it as an essential detoxification agent, which is consequently only induced in emergency situations. The cephalochordate MTs are not directly related to vertebrate MTs, neither by gene structure, protein similarity nor metal-binding behavior of the encoded peptides. The closest relative is the echinoderm MT, which confirm proposed phylogenetic relationships between these two groups. The current findings support the existence in most organisms of two types of MTs as for their metal binding preferences, devoted to different biological functions: multivalent MTs for housekeeping roles, and specialized MTs that evolve either as Cd-thioneins or Cu-thioneins, according to the ecophysiological needs of each kind of organisms.

Spectral Color Appearance Modeling

Kuvien laatu on tutkituimpia ja käytetyimpiä aiheita. Tässä työssä tarkastellaan värin laatu ja spektrikuvia. Työssä annetaan yleiskuva olemassa olevista pakattujen ja erillisten kuvien laadunarviointimenetelmistä painottaen näiden menetelmien soveltaminen spektrikuviin. Tässä työssä esitellään spektriväriulkomuotomalli värikuvien laadunarvioinnille. Malli sovelletaan spektrikuvista jäljennettyihin värikuviin. Malli pohjautuu sekä tilastolliseen spektrikuvamalliin, joka muodostaa yhteyden spektrikuvien ja valokuvien parametrien välille, että kuvan yleiseen ulkomuotoon. Värikuvien tilastollisten spektriparametrien ja fyysisten parametrien välinen yhteys on varmennettu tietokone-pohjaisella kuvamallinnuksella. Mallin ominaisuuksien pohjalta on kehitetty koekäyttöön tarkoitettu menetelmä värikuvien laadunarvioinnille. On kehitetty asiantuntija-pohjainen kyselymenetelmä ja sumea päättelyjärjestelmä värikuvien laadunarvioinnille. Tutkimus osoittaa, että spektri-väri –yhteys ja sumea päättelyjärjestelmä soveltuvat tehokkaasti värikuvien laadunarviointiin.

Impact of round-the-clock CSF Gram stain on empirical therapy for suspected central nervous system infections.

The impact of round-the-clock cerebrospinal fluid (CSF) Gram stain on overnight empirical therapy for suspected central nervous system (CNS) infections was investigated. All consecutive overnight CSF Gram stains between 2006 and 2011 were included. The impact of a positive or a negative test on empirical therapy was evaluated and compared to other clinical and biological indications based on institutional guidelines. Bacterial CNS infection was documented in 51/241 suspected cases. Overnight CSF Gram stain was positive in 24/51. Upon validation, there were two false-positive and one false-negative results. The sensitivity and specificity were 41 and 99 %, respectively. All patients but one had other indications for empirical therapy than Gram stain alone. Upon obtaining the Gram result, empirical therapy was modified in 7/24, including the addition of an appropriate agent (1), addition of unnecessary agents (3) and simplification of unnecessary combination therapy (3/11). Among 74 cases with a negative CSF Gram stain and without formal indication for empirical therapy, antibiotics were withheld in only 29. Round-the-clock CSF Gram stain had a low impact on overnight empirical therapy for suspected CNS infections and was associated with several misinterpretation errors. Clinicians showed little confidence in CSF direct examination for simplifying or withholding therapy before definite microbiological results.

A Feedfordward Adaptive Controller to Reduce the Imaging Time of Large-Sized Biological Samples with a SPM-Based Multiprobe Station

The time required to image large samples is an important limiting factor in SPM-based systems. In multiprobe setups, especially when working with biological samples, this drawback can make impossible to conduct certain experiments. In this work, we present a feedfordward controller based on bang-bang and adaptive controls. The controls are based in the difference between the maximum speeds that can be used for imaging depending on the flatness of the sample zone. Topographic images of Escherichia coli bacteria samples were acquired using the implemented controllers. Results show that to go faster in the flat zones, rather than using a constant scanning speed for the whole image, speeds up the imaging process of large samples by up to a 4x factor.

A System-Level Simulation Model for a Protocol Processor

As the development of integrated circuit technology continues to follow Moore’s law the complexity of circuits increases exponentially. Traditional hardware description languages such as VHDL and Verilog are no longer powerful enough to cope with this level of complexity and do not provide facilities for hardware/software codesign. Languages such as SystemC are intended to solve these problems by combining the powerful expression of high level programming languages and hardware oriented facilities of hardware description languages. To fully replace older languages in the desing flow of digital systems SystemC should also be synthesizable. The devices required by modern high speed networks often share the same tight constraints for e.g. size, power consumption and price with embedded systems but have also very demanding real time and quality of service requirements that are difficult to satisfy with general purpose processors. Dedicated hardware blocks of an application specific instruction set processor are one way to combine fast processing speed, energy efficiency, flexibility and relatively low time-to-market. Common features can be identified in the network processing domain making it possible to develop specialized but configurable processor architectures. One such architecture is the TACO which is based on transport triggered architecture. The architecture offers a high degree of parallelism and modularity and greatly simplified instruction decoding. For this M.Sc.(Tech) thesis, a simulation environment for the TACO architecture was developed with SystemC 2.2 using an old version written with SystemC 1.0 as a starting point. The environment enables rapid design space exploration by providing facilities for hw/sw codesign and simulation and an extendable library of automatically configured reusable hardware blocks. Other topics that are covered are the differences between SystemC 1.0 and 2.2 from the viewpoint of hardware modeling, and compilation of a SystemC model into synthesizable VHDL with Celoxica Agility SystemC Compiler. A simulation model for a processor for TCP/IP packet validation was designed and tested as a test case for the environment.