Stable Consensus Research Articles

‘Autism’ or ‘Autism Spectrum Disorder’: Does either represent a natural kind of psychological disorder?

In DSM-5, ‘autism spectrum disorder’ (ASD) is a new diagnostic category effectively replacing the previous category of ‘autism’. In this paper I question whether either effectively represents a psychological natural kind with significant scientific and explanatory value. Despite the new categorisation, ‘ASD’ and ‘autism’ are effectively synonymous, and current understandings of ASD are based largely on previous research focused specifically on autism. However, there has been no stable consensus over the past 40 years about what autism actually is. No biological explanation has been discovered, and no single psychological theory can account for the heterogeneity of autistic symptoms. A recent large-scale population-based study failed to identify a unifying cognitive account of the variety of symptoms of autism. In the philosophy of science literature, there are widely accepted accounts of natural kinds which emphasise their role in scientific explanations and induction. These claim that natural kinds can typically be identified by clusters of properties which are held together by causal processes and which reflect the causal structure of the world in terms of their explanatory and predictive value. However, the concept of ASD fails to indicate any causal explanation and has very limited discriminant and predictive validity. Consequently ASD, as a diagnosis, cannot plausibly be seen as a psychological natural kind, since it does not appear to function as a powerful explanatory concept in science. Psychologists involved in autism diagnostic services should try to explain more clearly what it is that they believe they are diagnosing.

Fusion to a highly stable consensus albumin binding domain allows for tunable pharmacokinetics.

A number of classes of proteins have been engineered for high stability using consensus sequence design methods. Here we describe the engineering of a novel albumin binding domain (ABD) three-helix bundle protein. The resulting engineered ABD molecule, called ABDCon, is expressed at high levels in the soluble fraction of Escherichia coli and is highly stable, with a melting temperature of 81.5°C. ABDCon binds human, monkey and mouse serum albumins with affinity as high as 61 pM. The solution structure of ABDCon is consistent with the three-helix bundle design and epitope mapping studies enabled a precise definition of the albumin binding interface. Fusion of a 10 kDa scaffold protein to ABDCon results in a long terminal half-life of 60 h in mice and 182 h in cynomolgus monkeys. To explore the link between albumin affinity and in vivo exposure, mutations were designed at the albumin binding interface of ABDCon yielding variants that span an 11 000-fold range in affinity. The PK properties of five such variants were determined in mice in order to demonstrate the tunable nature of serum half-life, exposure and clearance with variations in albumin binding affinity.

Distributed Consensus of Multi-Agent Systems With Input Constraints: A Model Predictive Control Approach

The discrete-time double-integrator consensus problem is addressed for multi-agent systems with directed switching proximity topologies and input constraints. Some model predictive control protocols are developed to achieve stable consensus under the condition that the proximity graph has a directed spanning tree and the sampling period is sufficiently small. Moreover, the control horizon is extended to larger than one, which endows sufficient degrees of freedom to accelerate the convergence to consensus. Numerical simulations are conducted to show the effectiveness of the control algorithm.

Evolutionary Origin of Asymptotically Stable Consensus

Consensus is widely observed in nature as well as in society. Up to now, many works have focused on what kind of (and how) isolated single structures lead to consensus, while the dynamics of consensus in interdependent populations remains unclear, although interactive structures are everywhere. For such consensus in interdependent populations, we refer that the fraction of population adopting a specified strategy is the same across different interactive structures. A two-strategy game as a conflict is adopted to explore how natural selection affects the consensus in such interdependent populations. It is shown that when selection is absent, all the consensus states are stable, but none are evolutionarily stable. In other words, the final consensus state can go back and forth from one to another. When selection is present, there is only a small number of stable consensus state which are evolutionarily stable. Our study highlights the importance of evolution on stabilizing consensus in interdependent populations.

Consensus based Approach to the Signal Control of Urban Traffic Networks

The paper presents a signal control strategy of urban traffic networks (UTNs), under which states of UTNs can realize asymptotic stable consensus. We first propose a simulation model of UTNs, where the topology of road network is represented by a directed dynamic graph, and the transfer of underlying traffic flows is modeled by the cell transmission model (CTM). Furthermore, under some assumptions, we can obtain a signal control model of UTNs, which is a discrete-time linear time-invariant control system, and then design a state-feedback control law, under which the proposed control system can realize asymptotic stable consensus. At last, we illustrate basic ideas of our methods by an example.

In the Short Term We Divide, in the Long Term We Unite: Demographic Crisscrossing and the Effects of Faultlines on Subgroup Polarization

Do strong demographic faultlines breed opinion polarization in work teams? We integrate two theories that have been used to explain faultline effects. The first, the approach of Lau and Murnighan [Lau DC, Murnighan JK (1998) Demographic diversity and faultlines: The compositional dynamics of organizational groups. Acad. Management Rev. 23(2):325–340], suggests that in teams with strong faultlines the mechanisms of homophilous selection of interaction partners and persuasive influence cause subgroup polarization, defined as the split of the team into subgroups holding opposing opinions. The second, from sociological and anthropological traditions, emphasizes that crisscrossing actors bridge faultlines because they share demographic attributes with several subgroups. Demographically crisscrossing actors help to prevent polarization in social groups. We argue that Lau and Murnighan’s theory implicitly factors in the effects of crisscrossing actors. However, we show that the authors overlooked crucial implications of their theory because they did not consider crisscrossing actors explicitly. Most importantly, we demonstrate that demographic crisscrossing implies that even teams with strong faultlines will overcome polarization in the long run, although they might suffer from it in the short term. We develop and analyze a formal computational model of the opinion and network dynamics in work teams to show the consistency of our reasoning with Lau and Murnighans’ theory. The model also revealed another counterintuitive effect: strong faultlines lead to structures of interaction that make teams with strong faultlines faster in arriving at a stable consensus than teams with weak faultlines.

Generation of anti-c-met single domain antibody fragment based on human stable frameworks

The size reduction is an important issue in the biomedical application of antibody and single domain antibody fragment is recognized as very attractive tool. However, it is very time-consuming and laborious to generate the fragment antibody with targeted binding function. Here, we investigated the possibility to prepare single domain antibody (sdAb) by a simple grafting method based on stable human consensus framework sequences. The complementarity determining region sequences in VH domain of anti-c-Met scFv from rabbit were grafted with the human VH3 consensus framework sequences, which generated the anti-c-Met single domain antibody showing almost same binding activity to its scFv form. The generated single domain antibody could be produced as functional form in oxidizing cytoplasm of E. coli, but produced as inactive form in reducing cytoplasm. The structural analysis of the homology models gave us the insight on the stability of the single domain antibody. In this report, we have demonstrated that the very stable human consensus framework sequence can be used for the generation of active anti-c-Met sdAb via complementarity determining regions grafting. We expect that this kind of grafting method for the generation of sdAb may provide us with the opportunities to prepare sdAbs based on the known antibody sequences.

Primates

Primates

Application of Rank Correlation, Clustering and Classification in Information Security

This article is devoted to experimental investigation of a novel application of a clustering technique introduced by the authors recently in order to use robust and stable consensus functions in information security, where it is often necessary to process large data sets and monitor outcomes in real time, as it is required, for example, for intrusion detection. Here we concentrate on a particular case of application to profiling of phishing websites. First, we apply several independent clustering algorithms to a randomized sample of data to obtain independent initial clusterings. Silhouette index is used to determine the number of clusters. Second, rank correlation is used to select a subset of features for dimensionality reduction. We investigate the effectiveness of the Pearson Linear Correlation Coefficient, the Spearman Rank Correlation Coefficient and the Goodman--Kruskal Correlation Coefficient in this application. Third, we use a consensus function to combine independent initial clusterings into one consensus clustering. Fourth, we train fast supervised classification algorithms on the resulting consensus clustering in order to enable them to process the whole large data set as well as new data. The precision and recall of classifiers at the final stage of this scheme are critical for the effectiveness of the whole procedure. We investigated various combinations of several correlation coefficients, consensus functions, and a variety of supervised classification algorithms.

Acertando o passo! Falar de deficiência mental é um erro: deve falar-se de dificuldade intelectual e desenvolvimental (DID). Por quê?

A nova concepção e terminologia adotada pela língua inglesa no contexto da ainda designada "deficiência mental" parece ter alcançado um consenso estável e satisfatório face às expectativas que a sociedade deve esperar das populações com esse diagnóstico, enfatizando agora o impacto que as exigências do envolvimento detém no desenvolvimento individual, reforçando-se, assim, a necessidade emergente da alteração de mentalidades e atitudes para com estas populações. Para este efeito, o presente artigo introduz uma nova proposta de alteração da terminologia em português de deficiência mental/intelectual para "dificuldade intelectual e desenvolvimental", explicitando e fundamentando as razões para a mesma.

Prognostic value of chromosomal imbalancies and the colon gene expression signatures in rectal cancer.

465 Background: Some studies have suggested colon and rectal cancer as two different entities when considering DNA mutations or chromosomal imbalances. We therefore wondered if two colon gene expression signatures could predict specific survival. We also tested the influence of chromosomal imbalancies on prognosis in rectal cancer. Methods: Between 1998-2001 a series of 94 patients (pts) with rectal adenocarcinoma (T1-2-3 M0) were treated with preoperative radiotherapy (RT) with or without concurrent chemotherapy (CT) (78 pts) or with curative RT alone using contact X Ray therapy (CXRT) (18 pts). High-throughput analysis of genomic imbalancies and DNA expression were performed within the frame of the Carte d’Identité des Tumeurs (CIT) programme of Ligue du Cancer- France. Biostatistical analysis were performed and correlated with metastasis-free survival (MFS) and specific survival (SS). Coloprint and Oncotype DX colon signatures were tested on this cohort. Results: The median survival of the 96 patients was 105 months. The overall specific survival rate at 8 years was 75% for the preoperative group and 65 % for the RT alone group. Overall the rate of distant metastases was 30 % at 8 years (26 pts). A validated biopsy specimen was analysed in 67 pts for DNA expression and for genomic imbalances. Deletion of 8p and 1p36-35 correlated with MFS (p=0.001 and p=0.02 respectively) and SS (p=0.0002 and p=0.008 respectively). Multivariate analysis identified -8p as an independent prognostic factor of MFS (p=0.004) and SS (p=0.003). Validation of this deletion on an independent cohort is on-going. Regarding mRNA profile analysis, no stable consensus could identify clusters that accurately separate patients of bad and good SS or MFS, whatever the method used (28 methods of clustering). Coloprint signature could discriminate patients with the worst prognosis (SS: p<0.05) whereas Oncotype DX colon signature did not (SS: p=0.4). Conclusions: By analysing this series of patients from a single center we have been able for the first time in rectal cancer to identify -8p as an independent prognostic factor of MFS and SS. mRNA analysis suggest that colon and rectal cancer may not always share the same DNA expression profile.

Analysis of career competency of food and beverage managers in international tourist hotels in Taiwan

The purpose of this study is to establish indicators of career competencies of food and beverage managers in international tourist hotels in Taiwan. Panel discussions and the Delphi technique were adopted. Two panel discussions were conducted with a total of 11 industry experts and seven academic experts. The framework of career competencies was established based on these experts’ opinions. Delphi questionnaires were sent to 23 experts 13 in the hospitality industry and ten academic experts to collect data. By using such questionnaire twice, the 23 panelists reached a stable consensus. The results indicate career competencies include two categories: (1) career planning and development, and (2) core employability. The data demonstrated that the core employability competency was slightly more important for an individual's career development than the career development and planning competency.

SRNA-Xcc1, an integron-encoded transposon- and plasmid-transferred trans-acting sRNA, is under the positive control of the key virulence regulators HrpG and HrpX of Xanthomonas campestris pathovar campestris

sRNA-Xcc1 is a trans-acting sRNA recently identified from the plant pathogenic bacterium Xanthomonas campestris pathovar campestris (Xcc). Here, the phylogenetic distribution, predicted secondary structure and regulation of expression of sRNA-Xcc1 were analyzed. The analysis showed (1) a total 81 sRNA-Xcc1 homologs that are found in some bacterial strains that are taxonomically unrelated, belonging to the a-, b-, g-, and d-proteobacteria (2) that some sRNA-Xcc1 homologs are located in a plasmid-borne transposon or near a transposase coding gene, (3) that sRNA-Xcc1 is encoded by a integron gene cassette in Xcc and sRNA-Xcc1 homologs occur in integron gene cassettes of some uncultured bacteria and (4) that sRNA-Xcc1 homologs have a highly conserved sequence motif and a stable consensus secondary structure. These findings strongly support the idea that sRNA-Xcc1 represents a novel family of sRNAs which may be originally captured by integrons from natural environments and then spread among different bacterial species via horizontal gene transfer, possibly by means of transposons and plasmids. The expression analysis results demonstrated that the transcription of sRNA-Xcc1 is under the positive control of the key virulence regulators HrpG and HrpX, indicating that sRNA-Xcc1 may be involved in the virulence regulation of Xcc.

Distributed Higher Order Consensus Protocols in Multiagent Dynamical Systems

This paper studies general higher order distributed consensus protocols in multiagent dynamical systems. First, network synchronization is investigated, with some necessary and sufficient conditions derived for higher order consensus. It is found that consensus can be reached if and only if all subsystems are asymptotically stable. Based on this result, consensus regions are characterized. It is proved that for the m th-order consensus, there are at most ⌊(m+1)/2⌋ disconnected stable and unstable consensus regions. It is shown that consensus can be achieved if and only if all the nonzero eigenvalues of the Laplacian matrix lie in the stable consensus regions. Moreover, the ratio of the largest to the smallest nonzero eigenvalues of the Laplacian matrix plays a key role in reaching consensus and a scheme for choosing the coupling strength is derived. Furthermore, a leader-follower control problem in multiagent dynamical systems is considered, which reveals that to reach consensus the agents with very small degrees must be informed. Finally, simulation examples are given to illustrate the theoretical analysis.

Second-order consensus in multi-agent dynamical systems with sampled position data

This paper studies second-order consensus in multi-agent dynamical systems with sampled position data. A distributed linear consensus protocol with second-order dynamics is designed, where both the current and some sampled past position data are utilized. It is found that second-order consensus in such a multi-agent system cannot be reached without any sampled position data under the given protocol while it can be achieved by appropriately choosing the sampling period. A necessary and sufficient condition for reaching consensus of the system in this setting is established, based on which consensus regions are then characterized. It is shown that if all the eigenvalues of the Laplacian matrix are real, then second-order consensus in the multi-agent system can be reached for any sampling period except at some critical points depending on the spectrum of the Laplacian matrix. However, if there exists at least one eigenvalue of the Laplacian matrix with a nonzero imaginary part, second-order consensus cannot be reached for sufficiently small or sufficiently large sampling periods. In such cases, one nevertheless may be able to find some disconnected stable consensus regions determined by choosing appropriate sampling periods. Finally, simulation examples are given to verify and illustrate the theoretical analysis.

Phylogenetic history of Simosuchus clarki (Crocodyliformes: Notosuchia) from the Late Cretaceous of Madagascar

ABSTRACT The bizarre crocodyliform Simosuchus clarki shares several derived cranial characteristics with basal notosuchian taxa. In the original phylogenetic analysis assessing placement of Simosuchus among other crocodyliforms, it was recovered as a basal notosuchian. Additional preparation of the holotype skull and postcranium, and discovery of additional specimens, provides new information on the suite of morphologies in this notosuchian. Morphological analysis of all available material of S. clarki yields 60 autapomorphies distributed across the skeleton. To provide an updated test of the phylogeny of Notosuchia and placement of Simosuchus within the clade, we added seven new characters and expanded taxon sampling to include recently described notosuchians. A phylogenetic analysis of 301 characters and 84 crocodyliforms supports the position of Simosuchus as sister to Libycosuchus, more derived than Araripesuchus and Uruguaysuchus, and basal to other ziphosuchian notosuchians. We did not recover an Anatosuchus + Simosuchus clade, nor a monophyletic Araripesuchus, but did recover a peirosaurid clade including Peirosaurus, Lomasuchus, Uberabasuchus, and Hamadasuchus (but not Stolokrosaurus). We also found weak support for inclusion of Anatosuchus, Araripesuchus, Peirosauridae, and Mahajangasuchidae within Notosuchia and therefore for the conclusion that all basal mesoeucrocodylians from Gondwana, with the exception of Stolokrosuchus, are notosuchians. The results of this analysis demonstrate that basal mesoeucrocodylian relationships are currently in a state of flux and the need for caution in naming higher-level taxa until a more stable consensus topology is achieved. Similarly, large gaps in the notosuchian record render inconclusive the biogeographic origins of Simosuchus and the clade it represents on Madagascar.

The Mission and Philosophy of National Bioethics Commissions: Contributing to a Stable Societal Consensus

The Mission and Philosophy of National Bioethics Commissions: Contributing to a Stable Societal Consensus

Optimal Consensus Seeking in a Network of Multiagent Systems: An LMI Approach

In this paper, an optimal control design strategy for guaranteeing consensus achievement in a network of multiagent systems is developed. Minimization of a global cost function for the entire network guarantees a stable consensus with an optimal control effort. In solving the optimization problem, it is shown that the solution of the Riccati equation cannot guarantee consensus achievement. Therefore, a linearmatrix-inequality (LMI) formulation of the problem is used to address the optimization problem and to simultaneously resolve the consensus achievement constraint. Moreover, by invoking an LMI formulation, a semidecentralized controller structure that is based on the neighboring sets, i.e., the network underlying graph, can be imposed as an additional constraint. Consequently, the only information that each controller requires is the one that it receives from agents in its neighboring set. The global cost function formulation provides a deeper understanding and insight into the optimal system performance that would result from the global solution of the entire network of multiagent systems. Simulation results are presented to illustrate the capabilities and characteristics of our proposed multiagent team in achieving consensus.

Between Usurpation and Abdication? The Right to Health in the Courts of Brazil and South Africa

In this paper I argue that the dilemma between usurpation and abdication that courts inevitably face when they are called upon to adjudicate constitutionalised social and economic rights is indeed a real and intractable one. I try to substantiate my conclusion with a comparative analysis of the social rights jurisprudence of the South African and Brazilian courts (particularly in the field of the right to health) which currently stand on opposite sides of the 'justiciability spectrum'. Whereas the South African reasonableness approach is seen as too deferential and abdicative of the judiciary’s role in protecting rights, the Brazilian individually enforceable rights approach is deemed too intrusive and usurpative of the prerogative of elected representatives to define how the limited resources of the state should be allocated among unlimited social needs. I argue, also, that the emerging cooperative constitutionalism theories, which try to apply the institutional dialogue theories of judicial review to social rights adjudication, do not solve the dilemma. They are currently largely procedural, and therefore liable to the same charges of abdication levelled at the reasonableness approach of the South African Constitutional Court. But if they try to become more substantive, they will certainly attract the accusations of usurpation currently levelled at more assertive courts such as the Brazilian STF. I conclude, then, that the dilemma might be unsolvable until either a more stable consensus on what social and economic rights entail emerges or the expectation that rights necessarily imply strong judicial remedies gradually wanes.

Asparaginyl β-Hydroxylation of Proteins Containing Ankyrin Repeat Domains Influences Their Stability and Function

Recent reports have provided evidence that the β-hydroxylation of conserved asparaginyl residues in ankyrin repeat domain (ARD) proteins is a common posttranslational modification in animal cells. Here, nuclear magnetic resonance (NMR) and other biophysical techniques are used to study the effect of asparaginyl β-hydroxylation on the structure and stability of ‘consensus’ ARD proteins. The NMR analyses support previous work suggesting that a single β-hydroxylation of asparagine can stabilize the stereotypical ARD fold. A second asparaginyl β-hydroxylation causes further stabilization. In combination with mutation studies, the biophysical analyses reveal that the stabilizing effect of β-hydroxylation is, in part, mediated by a hydrogen bond between the asparaginyl β-hydroxyl group and the side chain of a conserved aspartyl residue, two residues to the N-terminal side of the target asparagine. Removal of this hydrogen bond resulted in reduced stabilization by hydroxylation. Formation of the same hydrogen bond is also shown to be a factor in inhibiting binding of hydroxylated ARDs to factor-inhibiting hypoxia-inducible factor (FIH). The effects of hydroxylation appear to be predominantly localized to the target asparagine and proximal residues, at least in the consensus ARD protein. The results reveal that thermodynamic stability is a factor in determining whether a particular ARD protein is an FIH substrate; a consensus ARD protein with three ankyrin repeats is an FIH substrate, while more stable consensus ARD proteins, with four or five ankyrin repeats, are not. However, NMR studies reveal that the consensus protein with four ankyrin repeats is still able to bind to FIH, suggesting that FIH may interact in cells with natural ankyrin repeats without resulting hydroxylation. Overall, the work provides novel biophysical insights into the mechanism by which asparaginyl β-hydroxylation stabilizes the ARD proteins and reduces their binding to FIH.