Alternative Basis Research Articles

Logical Reduction of Biological Networks to Their Most Determinative Components.

Boolean networks have been widely used as models for gene regulatory networks, signal transduction networks, or neural networks, among many others. One of the main difficulties in analyzing the dynamics of a Boolean network and its sensitivity to perturbations or mutations is the fact that it grows exponentially with the number of nodes. Therefore, various approaches for simplifying the computations and reducing the network to a subset of relevant nodes have been proposed in the past few years. We consider a recently introduced method for reducing a Boolean network to its most determinative nodes that yield the highest information gain. The determinative power of a node is obtained by a summation of all mutual information quantities over all nodes having the chosen node as a common input, thus representing a measure of information gain obtained by the knowledge of the node under consideration. The determinative power of nodes has been considered in the literature under the assumption that the inputs are independent in which case one can use the Bahadur orthonormal basis. In this article, we relax that assumption and use a standard orthonormal basis instead. We use techniques of Hilbert space operators and harmonic analysis to generate formulas for the sensitivity to perturbations of nodes, quantified by the notions of influence, average sensitivity, and strength. Since we work on finite-dimensional spaces, our formulas and estimates can be and are formulated in plain matrix algebra terminology. We analyze the determinative power of nodes for a Boolean model of a signal transduction network of a generic fibroblast cell. We also show the similarities and differences induced by the alternative complete orthonormal basis used. Among the similarities, we mention the fact that the knowledge of the states of the most determinative nodes reduces the entropy or uncertainty of the overall network significantly. In a special case, we obtain a stronger result than in previous works, showing that a large information gain from a set of input nodes generates increased sensitivity to perturbations of those inputs.Electronic supplementary materialThe online version of this article (doi:10.1007/s11538-016-0193-x) contains supplementary material, which is available to authorized users.

From biodiversity-based conservation to an ethic of bio-proportionality

Nature conservation has in recent decades become largely synonymous with biodiversity conservation. Biodiversity is a term with scientific meaning but in policy contexts it also carries a normative loading. Under this normative aspect, the notion of biodiversity has received little scrutiny. Upon examination it may be shown to set the bar of conservation too low. The goal of biodiversity conservation, as framed in the terms of the Convention on Biological Diversity, is to assure viability rather than abundance for species populations. This results in a tendency towards an “ecology of the minimal” which is compatible with large-scale human exploitation of natural environments. To equate conservation with biodiversity conservation is thus to tailor conservation to the requirements of “development”. In its implicit concession to human hegemony, biodiversity-based conservation reveals its underlying anthropocentrism. In this paper it is argued that, as an anthropocentric project, biodiversity-based conservation cannot assure the future of earth-life and that a bio-inclusive value base, which exceeds the requirement of biodiversity conservation, is therefore needed: over-reliance on the concept of biodiversity has skewed conservation policy towards a possibly self-defeating minimalism. As an alternative basis for conservation policy, an ethic of bio-proportionality is proposed. The goal of such an ethic would be not mere viability but optimization: it would seek not merely viable but optimal populations of all species. This has specific policy implications for human population and strengthens the case for increasing the extent of protected areas.

Retracted: The Value‐relevance of Equity Accounted Carrying Amounts and Disclosed Fair Values of Listed Associates

Equity accounting is a controversial accounting treatment. Although fair value measurement represents a potential alternative measurement base, information content may be lost under a pure fair value measurement approach. This study investigates the value‐relevance of equity accounted carrying amounts and disclosed fair values of listed associates, using a sample of the largest firms listed in South Africa, Australia and the UK. The main finding is that the alternative measurement bases are incrementally value‐relevant during the sample period of 31 December 2005 to 31 December 2011, implying that equity investors do not blindly accept either measurement base. Rather, investors include their own assessment of the intrinsic value of an entity's listed associates in their valuations.

Experimental and Numerical Studies of Controlling Thermal Cracks in Mass Concrete Foundation by Circulating Water

This paper summarizes an engineering experience of solving the problem of thermal cracking in mass concrete by using a large project, Zhongguancun No.1 (Beijing, China), as an example. A new method is presented for controlling temperature cracks in the mass concrete of a foundation. The method involves controlled cycles of water circulating between the surface of mass concrete foundation and the atmospheric environment. The temperature gradient between the surface and the core of the mass concrete is controlled at a relatively stable state. Water collected from the well-points used for dewatering and from rainfall is used as the source for circulating water. Mass concrete of a foundation slab is experimentally investigated through field temperature monitoring. Numerical analyses are performed by developing a finite element model of the foundation with and without water circulation. The calculation parameters are proposed based on the experiment, and finite element analysis software MIDAS/CIVIL is used to calculate the 3D temperature field of the mass concrete during the entire process of heat of hydration. The numerical results are in good agreement with the measured results. The proposed method provides an alternative practical basis for preventing thermal cracks in mass concrete.

Bohr complementarity in memory retrieval

We comment on the use of the mathematical formalism of Quantum Mechanics in the analysis of the documented subadditivity phenomenon in human episodic memory. This approach was first proposed by Brainerd et al. in Brainerd et al. (2013). The subadditivity of probability in focus arises as a violation of the disjunction rule of Boolean algebra. This phenomenon is viewed as a consequence of the co-existence of two types of memory traces: verbatim and gist. Instead of assuming that verbatim and gist trace can combine into a coherent memory state of superposition as is done in the QEM model, we propose to model gist and verbatim traces as Bohr complementary properties of memory. In mathematical terms, we represent the two types of memory as alternative bases of one and the same Hilbert Space. We argue that, in contrast with the QEM model, our model appeals to the one essential distinction between classical and quantum models of reality namely the existence of incompatible but complementary properties of a system. This feature is also at the heart of the quantum cognition approach to mental phenomena. We sketch an experiment that could separate the two models. We next test our model with data from the same word list experiment as the one used by Brainerd et al. While our model entails significantly less degrees of freedom it yields a good fit to the experimental data.

Exposure versus Susceptibility as Alternative Bases for New Approaches to Surveillance for Schistosoma japonicum in Low Transmission Environments.

Currently, schistosomiasis in China provides an excellent example of many of the challenges of moving from low transmission to the elimination of transmission for infectious diseases generally. In response to the surveillance dimension of these challenges, we here explore two strategic approaches to inform priorities for the development of improved methods addressed specifically to schistosomiasis in the low transmission environment. We utilize an individually-based model and the exposure data used earlier to explore surveillance strategies, one focused on exposure assessment and the second on our estimates of variability in individual susceptibility in the practical context of the current situation in China and the theoretical context of the behavior of transmission dynamics near the zero state. Our findings suggest that individual susceptibility is the major single determinant of infection intensity in both the low and medium risk environments. We conclude that there is considerable motivation to search for a biomarker of susceptibility to infection in humans, but that there would also be value in a method for monitoring surface waters for the free-swimming forms of the parasite in endemic or formerly endemic environments as an early warning of infection risk.

Результаты экспериментальных исследований маломодовых режимов волоконных брэгговских решеток на многомодовых световодах

Nowadays fiber Bragg gratings (FBGs) are widely used in various devices and applications of fiber optics. They become a basic component for fiber optic sensor networks. The most of those both commercial and prototype fiber optic sensor systems are based on well-researched either singlemode or multimode regime of signal transmission over optical fibers. However some works are concerned with researches of FBGs written on silica multimode optical fibers (MMF) for various photonics and fiber optics applications. Thus, FBGs written on graded-index MMFs are used in optical filters of fiber optic data transmission systems 10G designed for local area networks and radio-over-fiber systems covering micro- and pico-cells. Some works are focused on FBGs written on step-index MMFs. Slanted or tilted multimode FBGs are also widely used in vibration, temperature, deformation etc. fiber optic sensors. Another group of publications is devoted to conventional FBGs on silica telecommunication graded-index MMFs 50/125 as well as 62.5/125 and experimental approbation of various fiber optic sensors based on them. However, the most part of mentioned papers are focused on just analysis of FBG spectral response during laser-excited optical signal propagation that corresponds to a few-mode regime. Few-mode regime adds a new another one dimension to parameter space that is associated with guided modes of particular order which limited number (from two to a few dozens) transfer the most part of optical signal power over tested optical fiber. Optical fiber operating in a few-mode regime of data transmission is interferometer that in combination with FBG can be considered as an alternative basis for design of elements with new unique properties. This work is concerned with experimental researches of few-mode regimes of FBG operating during transferring of laser based optical signals. We tested FBGs written on silica graded-index multimode fibers 50/125 Cat. OM2+/OM3 with Bragg wavelength 1550 nm by using them in a set of developed experimental schemes based on excitation of multimode fibers by corresponding laser sources. The researches were also focused on analysis of both spectral and pulse responses under changing of selected mode mixing and power diffusion processes due to tension and/or stress local and distributed action to FBG or sensor fiber. Results of spectral and pulse response measurements at the output of schemes with installed described FBGs are represented.

Self-Sustained Irregular Activity in an Ensemble of Neural Oscillators

An ensemble of pulse-coupled phase-oscillators is thoroughly analysed in the presence of a mean-field coupling and a dispersion of their natural frequencies. In spite of the analogies with the Kuramoto setup, a much richer scenario is observed. The "synchronised phase", which emerges upon increasing the coupling strength, is characterized by highly-irregular fluctuations: a time-series analysis reveals that the dynamics of the order parameter is indeed high-dimensional. The complex dynamics appears to be the result of the non-perturbative action of a suitably shaped phase-response curve. Such mechanism differs from the often invoked balance between excitation and inhibition and might provide an alternative basis to account for the self-sustained brain activity in the resting state. The potential interest of this dynamical regime is further strengthened by its (microscopic) linear stability, which makes it quite suited for computational tasks. The overall study has been performed by combining analytical and numerical studies, starting from the linear stability analysis of the asynchronous regime, to include the Fourier analysis of the Kuramoto order parameter, the computation of various types of Lyapunov exponents, and a microscopic study of the inter-spike intervals.

Directional decomposition of the acoustic wave equation for fluids and metafluids in spherical geometries, with application to transformational acoustics

A new directional decomposition of the acoustic 3D wave equation is derived for spherically symmetric geometries, where the wave fields do not need to possess such a symmetry. This provides an alternative basis for various applications of techniques like invariant embedding and time domain Green functions in spherically symmetric geometries. Contrary to previous results on spherical wave splittings, the new decomposition is given in a very explicit form. The wave equation considered incorporates effects from radially varying compressibility and density, but also from anisotropic density, a property of certain so called metafluids. By applying the new spherical wave splitting, we show that all spherically symmetric acoustic metafluid cloaks are diffeomorphic images of a homogeneous and isotropic spherical ball of perfect fluid.

Level 16 analogue of Ramanujan's theories of elliptic functions to alternative bases

The analogous theory for level 16 of Ramanujan's theories of elliptic functions to alternative bases is developed by studying the level 16 modular functionh(q)=q∏j=1∞(1−q16j)2(1−q2j)(1−qj)2(1−q8j).

Merit matters: Student perceptions of faculty quality and reward

This empirical research explores a role that the quality of teaching and students’ competence play in shaping students’ views about the upward mobility opportunities in their higher education institutions. It is often understood that the principal role of higher education is to promote merit-based mobility amongst students, as well as espouse the merit-based upward mobility amongst its faculty. How exactly students in higher education form their views about the presence of meritorious upward mobility is the question that remains largely unanswered, especially in developing societies. To help answer this question, the study relies on the binary logistic regression of data collected via 762 surveys from 6 public higher education institutions in Bosnia and Herzegovina and determines what factors help predict students’ views on whether faculty promotions are merited or not. Findings in this article are sub-selected from a broader empirical work, and they point to a novel link: the quality of teaching and students’ views on whether the most competent students are first to graduate in their faculties are the key predictors of whether students believe the faculty members within their higher education institutions are promoted based on merit. In the absence of meritocracy, students are, as this research finds, likely to categorize the educational system as corrupt. When the merit-based competition does not determine who moves up within higher education, one's belonging to the political, social, and economic elites tends to become the alternative basis for the upward mobility. Moving away from the merit-based mobility can have broad social consequences particularly in developing countries that are poorly equipped to react to such digressions, underlining the relevance of this work cross-nationally.

Comparative study of conventional incision and drainage versus percutaneous placement of suction drain: changing trend of breast abscess management

Background: We present a comparative study of conventional incision and drainage vs minimally invasive percutaneously placed suction catheter in patients of puerperal breast abscess. The aim was to develop an effective technique for management of breast abscess giving less morbidity and its efficacy over conventional method. Methods: Sample size was 100 patients of age ranged from 18 to 34 years and duration July 2013 to July 2015, which was divided in two groups of 50 patients each. First group was treated by incision and drainage and second by percutaneous suction drainage, selection of patients was on alternate basis. Informed consent was taken from each patient before procedure. In suction drain placement procedure under local, 0.5% lignocaine with adrenaline, infiltration anesthesia16F suction catheter was placed percutaneously in abscess cavity for 3-5 days. Results: There was complete resolution of symptoms in all patients however healing time was significantly less in aspiration group (5 to 10 days) as compared with surgical drainage (9-19 days). There was 1 (2%) patient in drain group who required conversion to open surgical drainage. There were 2 cases presented with fistula out of 50 Incision and drainage patients. Breast feeding/ emptying was not interrupted in any patient of this minimally invasive method. Conclusions: This technique is technically safer, effective, very less painful, cosmetically more promising and healing is quicker in this technique compare to conventional incision and drainage.

The EU's Competence Gap in Public Health and Non-Communicable Disease Policy

The European Union (EU) has had a Treaty competence in the field of public health since 1993, however the slow development of this competence has not kept up with the rate at which the EU's policy ambitions in public health have developed, especially in the field of non-communicable disease (NCD) prevention. This has led the EU to rely on alternative legal bases in order to realise these ambitions, leading to a ‘competence gap’ between the legal bases that authorise EU action on NCD prevention and the policies the EU would like to pursue. This paper will explore, in three stages, how this competence gap might be addressed. First, it will examine the arguments for and against giving the EU public health competences. Second, it will analyse the EU's specific public health competence in Article 168 of the Treaty on the Functioning of the European Union (TFEU) and the general internal market harmonisation competence in Article 114 TFEU, in order to explore the precise boundaries of each competence as legal bases for EU public health action. Third, it will explore the legal relationship between Articles 168 and 114 and explain why, despite a more powerful specific public health competence being a theoretically neat solution to the competence gap, the likelihood of the EU being given increased public health powers is low.

Sustainable development goals, universal health coverage and equity in health systems: the Orang Asli commons approach.

Universal health coverage is a key health target in the Sustainable Development Goals (SDGs) that has the means to link equitable social and economic development. As a concept firmly based on equity, it is widely accepted at international and national levels as important for populations to attain 'health for all' especially for marginalised groups. However, implementing universal coverage has been fraught with challenges and the increasing privatisation of health care provision adds to the challenge because it is being implemented in a health system that rests on a property regime that promotes inequality. This paper asks the question, 'What does an equitable health system look like?' rather than the usual 'How do you make the existing health system more equitable?' Using an ethnographic approach, the authors explored via interviews, focus group discussions and participant observation a health system that uses the commons approach such as which exists with indigenous peoples and found features that helped make the system intrinsically equitable. Based on these features, the paper proposes an alternative basis to organise universal health coverage that will better ensure equity in health systems and ultimately contribute to meeting the SDGs.

State-sponsored “Feminism” and women empowerment in Nigeria: The case of the better life programme, 1987 – 1993

This paper argues that although the issues of first ladyism and the role of women in the transition politics of the Babangida regime are important in the examination of the state-sponsored Better Life Programme (BLP), the significance of the programme can, however, be better understood if it is situated within the context of the massive opposition to the neo-liberal Structural Adjustment Programme (SAP), and attempts at delegitimising the opposition while creating an alternative basis of support for the Babangida regime from among rural dwellers. Since it was believed that the opposition was mainly urban-based, the regime decided to woo the rural dwellers by sponsoring various supposedly rural transformation and grassroots empowerment projects, with the BLP being one of such projects. However, given the antecedents of the BLP, the programme soon became a reflection of the undemocratic, corrupt and decadent neocolonial Nigerian state and so, did not succeed in either empowering the rural women or in creating a new basis of popular support for the Babangida regime.

Study of the Subclonal Mutations in Primary Diffuse Large B-Cell Lymphoma

Tumors arise and evolve by iterative steps of mutation, subclonal selection, and clonal expansion due to growth advantage of the fittest subclones and external mutation induction and selection pressure from radiation and drug therapies. Various studies have shown that greater clonal complexities in primary tumors are correlated with poor clinical outcome of tumor progression and/or drug resistance. Recently, we have reported that very few of the driver mutations, all of which were clonal, detected in primary diffuse large B-cell lymphoma (DLBCL) were associated with DLBCL outcome as measured by 24-month event-free survival (EFS24). In the current project, we identified and studied subclonal mutations in primary DLBCL tumors and assessed their associations with EFS24, as well as the role of activation-induced cytidine deaminase (AID) in genomic mutations occurred in DLBCL tumors.The detection of subclonal mutations is still a significant bioinformatics challenge. In addition, identification of clonal mutations in samples with lower tumor purities faces similar challenges due to the low concentration of reads supporting the mutant alleles. The current methods of somatic mutation calling are not sufficiently sensitive to identify the low concentration mutations in tumor DNA sequencing data. We implemented a bioinformatics workflow for low-concentration and subclonal mutation detection which is based on the positional read pile-up data and a back-fill approach (PUB). The pile-up files were first generated using the re-aligned and re-calibrated BAM files after read alignment using Burrows-Wheeler Aligner (BWA). The variant positions with alternative bases were annotated by attributes defined in the Variant Quality Score Recalibration (VQSR). PUB then used a boosting method and a generalized linear model (GLM) to train a model of 'good quality' variants using common variants from HapMap, and prioritized and called clonal and subclonal variants based on the trained model. The VQSR attributes related to alternative allele depth were less-weighed in order to call subclonal mutations. The somatic mutations were then identified by Fisher's Exact Test using sequencing depths of the reference and alternative alleles from paired tumor and germline sequencing data.The exome sequencing data of paired tumor and peripheral blood from 48 newly diagnosed DLBCL patients were analyzed using PUB. Thirty-six of the 48 patients achieved EFS24 with the other 12 patients experienced primary treatment failure. Most of the tumors studied had tumor purities between 40-70%. PUB identified substantially higher number of somatic mutations, both clonal and subclonal, compared to those detected using existing somatic callers. We observed that the prevalence of mutations in previously reported driver genes were higher using thresholds of mutation concentration ≥ 5% and Fisher's Exact Test p ≤ 0.05, including EZH2 (mutated in 26% of DLBCL tumors analyzed by PUB, compared to 12.7% as previously reported), MLL2 (72% vs. 31%), CD79B (22% vs. 14%), TNFRSF14 (36% vs. 20%), MEF2B (22% vs. 16.4%), CARD11 (46% vs. 21.8%), and MYD88 (18% vs. 11%). In addition, other genes involved tumorigenesis that have not been previously linked to DLBCL also harbored both clonal and subclonal mutations with substantial prevalence, including FGFR3 (12%), KIT (24%), and ATM (28%). Furthermore, association of genes displaying clonal and subclonal mutations with EFS24 identified potential biomarkers for DLBCL outcome. Among these, two genes EPGN and ASTE are involved in epithelial growth factor receptor signaling and had association p values of 0.0001 and 0.0016, respectively. The oncogene MAFB was also associated with EFS24 (P = 0.0016).We searched for AID induced mutations among all identified variant positions and concluded that there was no evidence of AID site enrichments compared to a simulated data set.In summary, we developed and applied a sensitive bioinformatics pipeline for the identification of both clonal and low concentration somatic mutations in primary DLBCL exome sequencing data which further revealed the clonal complexity of the primary DLBCL tumors. Several of the genes were identified as potential biomarkers for DLBCL outcome. DisclosuresMaurer:Kite Pharma: Research Funding. Ansell:Bristol-Myers Squibb: Research Funding; Celldex: Research Funding. Link:Genentech: Consultancy, Research Funding; Kite Pharma: Research Funding. Cerhan:Kite Pharma: Research Funding.

The Immortals in Our Midst: Why Democracies in Africa Need Them

Africa lacks the particular history of liberal institutions and values that has served as the foundation for democratic institutions in the West. Without such a foundation, prospects for well-functioning democracy in African are not good. I argue that a possible alternative basis for African democracy may be found in “civic immortals,” extraordinary individuals capable of introducing dramatic shifts in political values. Civic immortals occupy the highest rung of a hierarchy of personhood in many indigenous African cultures, each of which is considered to share in a different degree of life after physical death, and each of which corresponds to a different class of citizen. I examine three examples of African civic immortals: Nelson Mandela, Sunjata Keita (founder of the Malian empire and author of the Oath of the Hunters), and Ngonnso (the founder of the Nso dynasty). These extraordinary individuals shared an ambition to achieve lasting political change, and succeeded in transforming their political systems. Understanding the critical role that these civic immortals play in creating political change—both by directly changing political institutions and by inspiring ordinary citizens—offers us another tool for establishing stable and effective democratic institutions. It also highlights the ironically impersonal nature of contemporary liberal theory, and suggests a way that individual personalities and diversity among citizens may have a role in understanding political theory and practice.

Another nail in the coffin for non-literal software copyright infringement?

This article reviews a 2014 decision of the New Zealand Court of Appeal in Karum v Fisher & Paykel Finance, where in considering a claim for non-literal infringement of software copyright the court adopted the reasoning of UK and US authorities. As with decisions in the UK and USA, no protectable expression was found, despite homage being paid to the applicability of non-literal infringement in software copyright cases. Assuming the latter concept has validity, ‘it is necessary essentially to retrace and map each of the designer's steps—in opposite order in which they were taken in the program's creation’ (Computer Associates v Altai 982 F 2d 693, 707 (2d Cir 1992)). In this article, software engineering is employed to reveal the abstractions above program code by closely examining the design steps in software development models and in particular the Waterfall model. The objective is to ascertain if there are any areas left where protectable expression may reside within the hierarchy of abstractions which have not so far been excluded by courts. In this analysis software development work products (which may constitute ‘preparatory design material’) are comprehensively identified as a possible alternative basis for bringing claims of copyright infringement where similarities exist only at higher levels of abstraction. UK, EU and New Zealand cases reveal very clearly the influence of US law in this field of copyright whether or not it has received specific acknowledgment. Through the Software Directive and the Court of Justice of the European Union (CJEU) the continental copyright tradition (Football Dataco Ltd v Yahoo Ltd, C-604/10, EU:C:2012:115, Opinion of A-G Mengozzi, paras 36–37) has now infiltrated traditional UK copyright concepts. However, this article argues that not only are the majority of the US tests still ‘irrelevant and exotic’ (H Laddie et al, The Modern Law of Copyright and Designs (2nd edn, Butterworths, 1995) para 20.58), but the application of the doctrine of non-literal infringement to software copyright (thought to be a ‘syllogism’ by the 2nd Circuit in Computer Associates v Altai) is a logical fallacy.

Stimuli‐Responsive Reversible Fluorescence Switching in a Crystalline Donor–Acceptor Mixture Film: Mixed Stack Charge‐Transfer Emission versus Segregated Stack Monomer Emission

AbstractWe report on a molecularly tailored 1:1 donor–acceptor (D‐A) charge‐transfer (CT) cocrystal that manifests strongly red‐shifted CT luminescence characteristics, as well as noteworthy reconfigurable self‐assembling behaviors. A loosely packed molecular organization is obtained as a consequence of the noncentrosymmetric chemical structure of molecule A1, which gives rise to considerable free volume and weak intermolecular interactions. The stacking features of the CT complex result in an external stimuli‐responsive molecular stacking reorganization between the mixed and demixed phases of the D‐A pair. Accordingly, high‐contrast fluorescence switching (red↔blue) is realized on the basis of the strong alternation of the electronic properties between the mixed and demixed phases. A combination of structural, spectroscopic, and computational studies reveal the underlying mechanism of this stimuli‐responsive behavior.

Stimuli-Responsive Reversible Fluorescence Switching in a Crystalline Donor-Acceptor Mixture Film: Mixed Stack Charge-Transfer Emission versus Segregated Stack Monomer Emission.

We report on a molecularly tailored 1:1 donor-acceptor (D-A) charge-transfer (CT) cocrystal that manifests strongly red-shifted CT luminescence characteristics, as well as noteworthy reconfigurable self-assembling behaviors. A loosely packed molecular organization is obtained as a consequence of the noncentrosymmetric chemical structure of molecule A1, which gives rise to considerable free volume and weak intermolecular interactions. The stacking features of the CT complex result in an external stimuli-responsive molecular stacking reorganization between the mixed and demixed phases of the D-A pair. Accordingly, high-contrast fluorescence switching (red↔blue) is realized on the basis of the strong alternation of the electronic properties between the mixed and demixed phases. A combination of structural, spectroscopic, and computational studies reveal the underlying mechanism of this stimuli-responsive behavior.